Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Conductor Pipe Installation Activities at Harmony Platform in Santa Barbara Channel Offshore of California, 36743-36769 [2014-15224]
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Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
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• AEWC, October 17, 2013; and
• Nanuq Commission, October 17,
2013.
BP will implement several mitigation
measures to reduce impacts on the
availability of marine mammals for
subsistence hunts in the Beaufort Sea.
Many of these measures were developed
from the 2013 CAA and previous NSB
Development Permits. In addition to the
measures listed next, BP will conclude
all airgun operations by midnight on
August 25 to allow time for the Beaufort
Sea communities to prepare for their fall
bowhead whale hunts prior to the
beginning of the fall westward migration
through the Beaufort Sea. Some of the
measures mentioned next have been
mentioned previously in this document:
• PSOs on board vessels are tasked
with looking out for whales and other
marine mammals in the vicinity of the
vessel to assist the vessel captain in
avoiding harm to whales and other
marine mammals.;
• Vessels and aircraft will avoid areas
where species that are sensitive to noise
or vessel movements are concentrated;
• Communications and conflict
resolution are detailed in the CAA. BP
will participate in the Communications
Center that is operated annually during
the bowhead subsistence hunt;
• Communications with the village of
Nuiqsut to discuss community
questions or concerns including all
subsistence hunting activities. Preproject meeting(s) with Nuiqsut
representatives will be held at agreed
times with groups in the community of
Nuiqsut. If additional meetings are
requested, they will be set up in a
similar manner;
• Contact information for BP will be
provided to community members and
distributed in a manner agreed at the
community meeting;
• BP has contracted with a liaison
from Nuiqsut who will help coordinate
meetings and serve as an additional
contact for local residents during
planning and operations; and
• Inupiat Communicators will be
employed and work on seismic source
vessels. They will also serve as PSOs.
Unmitigable Adverse Impact Analysis
and Determination
BP has adopted a spatial and temporal
strategy for its Prudhoe Bay survey that
should minimize impacts to subsistence
hunters. First, BP’s activities will not
commence until after the spring hunts
have occurred. Second, BP will
conclude all airgun operations by
midnight on August 25 prior to the start
of the bowhead whale fall westward
migration and any fall subsistence hunts
by Beaufort Sea communities. Prudhoe
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Bay is not commonly used for
subsistence hunts. Although some seal
hunting co-occurs temporally with BP’s
seismic survey, the locations do not
overlap. BP’s presence will not place
physical barriers between the sealers
and the seals. BP will work closely with
the closest affected communities and
support Communications Centers and
employ local Inupiat Communicators.
Based on the description of the
specified activity, the measures
described to minimize adverse effects
on the availability of marine mammals
for subsistence purposes, and the
required mitigation and monitoring
measures, NMFS has determined that
there will not be an unmitigable adverse
impact on subsistence uses from BP’s
activities.
Endangered Species Act (ESA)
Within the project area, the bowhead
whale is listed as endangered and the
ringed and bearded seals are listed as
threatened under the ESA. The NMFS
Office of Protected Resources Permits
and Conservation Division consulted
with the NMFS Alaska Regional Office
(AKRO) Protected Resources Division
(PRD) on the issuance of an IHA under
Section 101(a)(5)(D) of the MMPA
because the action of issuing the IHA
may affect threatened and endangered
species under NMFS’ jurisdiction. On
June 10, 2014, NMFS AKRO PRD issued
a Biological Opinion, which concluded
that the issuance of an IHA to BP for the
3D OBS seismic survey is not likely to
jeopardize the continued existence of
the endangered bowhead whale,
threatened Arctic subspecies of ringed
seal, or the threatened Beringia distinct
population segment of bearded seal.
There is no critical habitat for any of
these species in the survey area.
National Environmental Policy Act
(NEPA)
NMFS prepared an EA that includes
an analysis of potential environmental
effects associated with NMFS’ issuance
of an IHA to BP to take marine
mammals incidental to conducting a 3D
OBS seismic survey program in the
Beaufort Sea, Alaska. NMFS has
finalized the EA and prepared a FONSI
for this action. Therefore, preparation of
an Environmental Impact Statement is
not necessary.
Authorization
As a result of these determinations,
NMFS has issued an IHA to BP for
conducting a 3D OBS seismic survey in
the Prudhoe Bay area of the Beaufort
Sea, Alaska, during the 2014 open-water
season, provided the previously
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36743
mentioned mitigation, monitoring, and
reporting requirements are incorporated.
Dated: June 25, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected
Resources, National Marine Fisheries Service.
[FR Doc. 2014–15238 Filed 6–27–14; 8:45 am]
BILLING CODE 3510–22–P
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
RIN 0648–XD188
Takes of Marine Mammals Incidental to
Specified Activities; Taking Marine
Mammals Incidental to Conductor Pipe
Installation Activities at Harmony
Platform in Santa Barbara Channel
Offshore of California
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice; proposed Incidental
Harassment Authorization; request for
comments.
AGENCY:
NMFS has received an
application from ExxonMobil
Production Company (ExxonMobil), a
Division of ExxonMobil Corporation, for
an Incidental Harassment Authorization
(IHA) to take marine mammals, by
harassment, incidental to installing six
conductor pipes via hydraulic hammer
driving at the Harmony Platform, Santa
Ynez Production Unit, located in the
Santa Barbara Channel offshore of
California. Pursuant to the Marine
Mammal Protection Act (MMPA), NMFS
is requesting comments on its proposal
to issue an IHA to ExxonMobil to
incidentally harass, by Level B
harassment only, 30 species of marine
mammals during the specified activity.
DATES: Comments and information must
be received no later than July 30, 2014.
ADDRESSES: Comments on the
application should be addressed to Jolie
Harrison, Supervisor, Incidental Take
Program, Permits and Conservation
Division, Office of Protected Resources,
National Marine Fisheries Service, 1315
East-West Highway, Silver Spring, MD
20910. The mailbox address for
providing email comments is ITP.
Goldstein@noaa.gov. Comments sent via
email, including all attachments, must
not exceed a 25-megabyte file size.
NMFS is not responsible for comments
sent to addresses other than the one
provided here.
Instructions: All comments received
are a part of the public record and will
SUMMARY:
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generally be posted to https://www.nmfs.
noaa.gov/pr/permits/incidental.htm#
applications without change. All
Personal Identifying Information (for
example, name, address, etc.)
voluntarily submitted by the commenter
may be publicly accessible. Do not
submit Confidential Business
Information or otherwise sensitive or
protected information.
An electronic copy of the application
may be obtained by writing to the
address specified above, telephoning the
contact listed below (see FOR FURTHER
INFORMATION CONTACT) or visiting the
Internet at: https://www.nmfs.noaa.gov/
pr/permits/incidental.htm#applications.
Documents cited in this notice may also
be viewed, by appointment, during
regular business hours, at the
aforementioned address.
NMFS is also preparing an
Environmental Assessment (EA) in
accordance with the National
Environmental Policy Act (NEPA) and
will consider comments submitted in
response to this notice as part of that
process. The EA will be posted at the
foregoing Internet site once it is
finalized.
FOR FURTHER INFORMATION CONTACT:
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Howard Goldstein or Jolie Harrison,
Office of Protected Resources, NMFS,
301–427–8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the
MMPA (16 U.S.C. 1361 et seq.), direct
the Secretary of Commerce (Secretary)
to allow, upon request, the incidental,
but not intentional, taking of small
numbers of marine mammals, by United
States citizens who engage in a specified
activity (other than commercial fishing)
within a specified geographical region if
certain findings are made and either
regulations are issued or, if the taking is
limited to harassment, a notice of a
proposed authorization is provided to
the public for review.
An authorization for the incidental
takings shall be granted if NMFS finds
that the taking will have a negligible
impact on the species or stock(s), and
will not have an unmitigable adverse
impact on the availability of the species
or stock(s) for subsistence uses (where
relevant), and if the permissible
methods of taking requirements
pertaining to the mitigation, monitoring
and reporting of such takings are set
forth. NMFS has defined ‘‘negligible
impact’’ in 50 CFR 216.103 as ‘‘. . . an
impact resulting from the specified
activity that cannot be reasonably
expected to, and is not reasonably likely
to, adversely affect the species or stock
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through effects on annual rates of
recruitment or survival.’’
Except with respect to certain
activities not pertinent here, the MMPA
defines ‘‘harassment’’ as: Any act of
pursuit, torment, or annoyance which (i)
has the potential to injure a marine
mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has
the potential to disturb a marine
mammal or marine mammal stock in the
wild by causing disruption of behavioral
patterns, including, but not limited to,
migration, breathing, nursing, breeding,
feeding, or sheltering [Level B
harassment].
Summary of Request
On March 3, 2014, NMFS received an
application from ExxonMobil for the
taking of marine mammals incidental to
installing six conductor pipes by
hydraulic hammering at the Harmony
Platform, Santa Ynez Production Unit,
in the Santa Barbara Channel offshore of
California. Along with the IHA
application, NMFS received an
addendum titled ‘‘Assessment of
Airborne and Underwater Noise from
Pile Driving Activities at the Harmony
Platform.’’ NMFS determined that the
application was adequate and complete
on April 28, 2014.
The proposed project’s estimates
dates are from mid-August to midNovember 2014, but the proposed action
could occur anytime within a 12-month
period from the effective date of the
proposed IHA. Acoustic stimuli (i.e.,
increased underwater and airborne
sound) generated during the conductor
pipe installation activities are likely to
result in the take of marine mammals.
Take, by Level B harassment only, of 30
species is anticipated to result from the
proposed activities.
Description of the Proposed Specified
Activity
Overview
ExxonMobil proposes to install six
conductor pipes by hydraulic
hammering at the Harmony Platform,
Santa Ynez Production Unit, in the
Santa Barbara Channel offshore of
California.
Dates and Duration
ExxonMobil estimates that the
proposed conductor pipe installation
activities would occur from mid-August
to mid-November 2014, but the
proposed activities could occur anytime
within a 12-month period from the
effective date of the proposed IHA.
Precise scheduling is not presently
available due to logistical and regulatory
uncertainties. ExxonMobil has
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requested the IHA for an August start
date to allow for flexibility in
scheduling operations, equipment, and
personnel, as well as to ensure sufficient
time to arrange for monitoring field
services. The estimated duration of the
proposed project is 91 days. Under
normal working conditions, the
proposed project is expected to include
approximately 84 days of installation
activity on the Harmony Platform
bounded by 7 days of project
mobilization/demobilization activities.
It would take approximately 14 days to
install each conductor pipe (6
conductors × 14 days = 84 days). Figure
2–1 of the IHA application includes a
timeline of proposed activities over the
approximate three month duration. Of
the estimated 84 days, hammer driving
would occur over 30 intermittent
intervals of 2.5 to 3.3 hours each for a
combined total of 4.125 days, or 5% of
the entire proposed project (3.3 hours ×
5 joints × 6 conductors = 99 hours or
4.125 days).
Specified Geographic Region
Harmony Platform is located in the
Santa Barbara Channel, which is
approximately 100 km (54 nmi) long
and 40 km (21.6 nmi) wide, situated
between the Channel Islands and the
east-west trending coastline of
California. The Santa Barbara Channel is
the site of several other producing oil
fields, including Ellwood, Summerland,
Carpinteria offshore, and Dos Cuadras.
The Santa Barbara basin is the
prominent feature of the Santa Barbara
Channel, with sill depths of
approximately 250 m (820.2 ft) and 450
m (1,467.4 ft) at eastern and western
entrances, respectively, with shallow
(60 m or 196.9 ft) inter-island passages
to the south. Harmony Platform’s
geographical position is 34° 22′ 35.906″
North, 120° 10′ 04.486″ West, at a water
depth of 366 m (1,200.8 ft) on the
continental slope below a relatively
steep (7.5%) descent. The Harmony
Platform is 43.5 km (27 miles)
southwest of Santa Barbara, California
(see Figure 1 of the IHA application). It
is 4.7 km (2.5 nmi) from the shelf break,
which is typically defined at the 100 m
(328.1 ft) isobaths (USGS, 2009). It is 3.3
km (1.8 nmi) from the nearest buffered
200 m (656.2 ft) contour, which has
been noted for its association with
higher recorded densities of cetacean
species (Redfern et al., 2013). It is also
located 10 to 15 km (5.4 to 8.1 nmi)
north of a common traffic route used by
vessels to access the ports of Long Beach
and Los Angeles. Figure 1–1 of the IHA
application includes the location of the
Harmony Platform, general site
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bathymetry, and Santa Barbara area
boundaries.
Site Bathymetry and Sediment
Physical Characteristics—Harmony
Platform is located below a relatively
steep (7.5%) descent from the shelf
margin, which is defined by the 100 m
contour in this area (USGS, 2009). It sits
at a water depth of 366 m, just above the
northern rim of the Santa Barbara Basin
which is roughly confined by the 400 m
(1,312.3 ft) contour, descending to
depths exceeding 600 m (1,968.5 ft).
Depths below the Harmony Platform are
defined by a gentle slope (ca. 1%),
which extends to the 600 m contour at
the basin maximum. To the west of the
platform, the slope attenuates to about
3% grade between 100 m and 400 m
contours, near the western sill of the
basin. To the east, the slope becomes
steeper, approaching 15% grade
between 100 m and 400 m contours, at
20 km (10.8 nmi) east of the platform.
Harmony Platform is located on
unconsolidated fine-grained silty-clay
and clayey-silt sediments. Table 2–1 of
the IHA application describes the
sediment physical characteristics and
geoacoustical profile in the vicinity of
the Harmony Platform. These sediments
are typical of slope depths proceeding
into the basin where sediments may be
2,000 m (6,561.7 ft) thick. Stein (1995)
reported similar sediment grain
characteristics from core segments
penetrating 196 m (643.1 ft) below the
sediment surface at a basin depth of 565
m (1,853.7 ft). Sediments were primarily
of terrigeneous origin, dominated by
quartz and clay minerals
montmorillonite and illite. These
sediments are similar in quartz content
and clay-mineral composition to
suspended sediment introduced by the
Santa Clara River, which has an average
annual sediment load of about 600,000
m3 (2.1 x 107 ft3) (Brownlee and Taylor,
1981). These turbid sediment plumes,
arising primarily from the Santa Clara
River to the east and from Santa Maria
and Santa Inez Rivers north of Point
Conception, may extend more than 5 km
(2.7 nmi) from shore and inshore from
Harmony Platform during periods of
heavy runoff.
Sediments at Harmony Platform and
throughout the Santa Barbara Channel
slopes and basin reflect terrigeneous
origins from coastal watersheds (mainly
the Santa Clara River), with relatively
minor inclusions of marine biogenic
origin (e.g., calcareous and
diatomaceous fractions). Shell fragment
debris dislodged from the jacket
structure during peak storm wave surges
and from periodic maintenance has
been observed around the periphery of
the jacket in ROV surveys, but
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significant debris was not observed at
the conductor pipe locations designated
from this project. No known hard
substrates have been identified by the
former Minerals Management Service
and NMFS surveys within 5 km of the
Harmony Platform (Keller et al., 2005).
Extending from shore to the 100 m shelf
break, hard substrate is common,
supporting extensive kelp beds at
depths less than 20 m (65.6 ft), on
cobbles and boulders. Further offshore,
at depths of about 65 m (213.3 ft) to the
shelf break, regions of folded ridges and
pinnacles up to 3 m (9.8 ft) in relief
have been recorded (USGS, 2009).
Hydrodynamics and Water Column
Physical Properties—Hydrodynamic
and seawater properties at the Harmony
Platform are complex as a result of
shifting wind and current patterns that
occur in the Santa Barbara Channel in
response to changing coastline
orientation at Point Conception
(Beckenbach, 2004). The Santa Barbara
Channel is a cross-roads for large scale
water masses moving along the
California coast. Waters from north of
Point Conception are cooled by coastal
upwelling as they move southward.
Most of these waters pass outside the
Channel Islands but some enter the
Santa Barbara Channel at its west end.
Warmer waters from the south are
driven poleward by the Southern
California Countercurrent. Mean
nearshore circulation in the entire
Southern California Bight is dominated
by this current (Hickey, 1993), which
enters the Santa Barbara Channel from
the east. Water mass properties are
determined by relative inputs to the
Santa Barbara Channel from eastern and
western entrances.
Hydrodynamics—Aud et al. (1999)
determined that transport from the east
accounted for 60% of the water entering
the Santa Barbara Channel with 33%
originating from the southern portion of
the western entrance and the remaining
7% from southern inter-island passages.
These contrasting source waters mix in
the Santa Barbara Channel, often
forming complex patterns visible in
satellite images of sea surface
temperature. They represent the more
persistent large scale movement of water
masses, which are driven by dynamic
processes on scales much larger than the
Santa Barbara Channel. Current speed
fluctuations exhibit significant
variation, typically ranging from 10 to
40 cm s¥1 (Hickey, 1992), extending to
a depth of 200 m (656.2 ft), and tending
to follow longshore isobaths. Seasonal
mean currents over the continental
slope are 20 to 30 cm s¥1. However,
surface circulation may be driven by
winds that create rapidly developing
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36745
high energy surface flows that vary in
direction over scales of several
kilometers. In the Santa Barbara
Channel, wind stress from the northwest
creates surface flows characterized by
cyclonic, and occasionally anticyclonic, flow vortices which propagate
westward. These occur intermittently
throughout the year, and may last for
months (Beckenbach, 2004; Oey, 2001).
Vertical upwelling along the coast is
also a feature of the water mass,
occurring primarily from spring through
fall (Harms and Winant, 1998). Inlet
water mass movement in the vicinity of
Harmony Platform is from west to east,
extending to basin sill depth, with
highly variable patterns of flow at the
surface under the periodic influence of
gyre vortices lasting from days to
months, meandering from east to west,
typically from spring to fall.
Water Column Physical Properties—
Seasonal changes in water column
stability (density structure) result from
changes in temperature and salinity that
occur seasonally from air-sea surface
interactions, and from periodic
fluctuations in relative contributions of
different source waters (e.g., eastern and
western flows). The water column is
density stratified as temperatures
decline and salinity increases with
depth. Seasonal effects are evident with
the strongest density gradient occurring
during summer months, primarily
within the upper 25 m (82 ft). Water
column profiles of salinity, temperature,
and calculated sound speed are
illustrated in Figure 2–2 of the IHA
application. Temperatures range from
approximately 13 to 16.5° Celsius (C)
(55.4 to 61.7° Fahrenheit [F]) at the
surface, become nearly isothermal (9 to
9.5° C or 48.2 to 49.1° F) at 150 m (492.1
ft) depth, likely varying little to the
platform depth of 366 m (1,200.8 ft).
Seasonal salinities varied little, ranging
from about 33.3 to 33.7% at the surface
to 34 to 34.1% to 150 m depth. Figure
2–2 of the IHA application shows
salinity, temperature, and underwater
sound speed profiles in the vicinity of
the Harmony Platform derived from the
U.S. Naval Oceanographic Office’s
Generalized Digital Environmental
Model (GDEM) database. The profile for
sound speed correlates strongly with
temperature, which is the main
determinant of water density structure.
Detailed Description of the Proposed
Specified Activity
ExxonMobil propose to install six
conductor pipes by hydraulic
hammering at Harmony Platform. The
proposed conductor pipe installation
activities are estimated to occur from
mid-August to mid-November 2014, but
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the proposed action could occur
anytime within a 12-month period from
the effective date of the proposed IHA.
Harmony Platform is located 10
kilometers (km) (5.4 nautical miles
[nmi]) off the coast of California,
between Point Conception and the City
of Santa Barbara. Harmony Platform is
one of three offshore platforms in
ExxonMobil’s Santa Ynez Production
Unit, and is located in the Hondo field
(Lease OCS–P 0190) at a water depth of
336 meters (1,200.8 ft). Harmony
Platform was installed on June 21, 1989
with the sole purpose of producing
crude oil and gas condensate. It began
production of crude oil, gas and gas
condensate on December 30, 1993. A
conductor pipe is installed prior to the
commencement of drilling operations
for oil and gas wells. It provides
protection, stability/structural integrity,
and a conduit for drill cuttings and
drilling fluid to the platform. It also
prevents unconsolidated sediment from
caving into the wellbore, and provides
structural support for the well loads.
Drilling activities are currently ongoing
at Harmony Platform utilizing the
existing conductors and wells. The
platform jacket structure (see Figure 1–
2 of the IHA application) currently has
conductors installed in 51 out of 60
slots, as approved by the Bureau of
Ocean Energy Management (BOEM,
formally the Minerals Management
Service [MMS]) in the original
Development Production Plan. Addition
of eight straight conductors at the
Harmony Platform was approved by the
Bureau of Safety and Environmental
Enforcement (BSEE) on February 11,
2013 to maintain current production
levels from the existing platform.
Conductor installation with a hydraulic
hammer is consistent with approved
development plans, and is the same
method that was used to install
conductors on all three Santa Ynez
Production Unit platforms from 1981
(Hondo) through 1993 (Harmony and
Heritage). Pile-driving the conductors
are the only proven installation method
that enables management of potential
interferences with the existing platform
infrastructure that would also reach the
target depth. Non-pile-driving
conductor installation methods are not
deemed feasible at this time due to
increased risk to platform structural
integrity, offset well collision, and
shallow-hole broaching.
The total length of a single conductor
pipe is approximately 505 m (1,656.8 ft).
Each conductor consists of multiple
sections of 66.04 centimeter (cm) (26
inch [in]) diameter steel pipe that would
be sequentially welded end-to-end from
an upper deck of the platform (see
Figure 1–2 of the IHA application), and
lowered into the 366 m water column
through metal rings (conductor guides)
affixed to the jacket structure that orient
and guide the conductor. Once the
conductor reaches the sediment surface,
gravity-based penetration (i.e., the
conductor would penetrate the seabed
under its own weight) is expected to
reach approximately 30 m (98.4 ft)
below the seabed. A hydraulic hammer
(S–90 IHC) with a manufacturer’s
specified energy range of 9 to 90
kiloJoules (kJ) would be located on the
drill deck and used to drive the
conductor to a target depth of
approximately 90 to 100 m (295.3 to
328.1 ft) below the seabed; therefore,
only roughly 60 m (196.9 ft) of each 505
m (1,656.8 ft) long conductor pipe
would require hydraulic driving. The S–
90 IHC hydraulic hammer would sit on
the conductor throughout pile-driving
operations, but a ram internal to the
hammer would stroke back and forth
using hydraulic pressure to impart
energy to the conductor. No physical
dropping of a weight would be
employed to drive the conductor.
The S–90 IHC hydraulic hammer has
an estimated blow rate of about 46
blows per minute. The portion of a
complete conductor that must be
actively driven (hammered) into the
seafloor consists of 5 to 7 sections,
which are sequentially welded end-toend. Setup and welding would take 3.5
to 7.3 hours per section, mostly
depending on the type of welding
equipment used (e.g., automated
welder). Hammer pile-driving would
take an estimated 2.5 to 3.3 hours for
each section, depending primarily on
sediment physical properties, which
affect penetration rate. Complete
installation of each conductor is
estimated at approximately 14 days
based on 24-hour (continuous)
operations. Table 1–1 of the IHA
application presents a summary of
driving activities and estimated number
of joints [requiring welding] for each
conductor pipe). Figure 1–3 of the IHA
application shows the estimated time in
days for each of these activities that are
required to install a single conductor
pipe. ExxonMobil conservatively
assumes that active hammering would
be 3.3 hours, followed by 7.3 hours of
hammer downtime (i.e., ‘‘quiet time,’’ a
time at which other activities are
performed in preparation for the next
section of pile) over approximately 53
hours (2.2 days) of the approximately 14
days required to install one conductor
pipe. This schedule produces 4.125
days (99 hours) of cumulated hammer
driving for all six conductors over the
project duration. Figure 1–4 depicts the
3.3 hour pile-drive/7.3 hour downtime
cycle for an isolated 24-hour period,
showing a maximum of 9.4 hours of
hammer driving. In the event that
efficiencies produce a 2.5 hour drive/3.5
hour downtime cycle, a maximum of 10
hours of hammer pile-driving could
occur in a single 24-hour period. The
complete installation of the conductor
pipes is estimated at 14 days of
continuous operation.
TABLE 1—SUMMARY OF PROPOSED INSTALLATION ACTIVITIES AND ASSOCIATED CHARACTERISTICS OF EACH CONDUCTOR
PIPE AT HARMONY PLATFORM.
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Conductor pipe activity
Pipe length
(m)
Estimates
number of
joints
Pile-driving
required
Installation level to sea level .........................................
Sea level to seafloor .....................................................
From 0 to ∼30 m below seafloor ...................................
From ∼30 m to ∼90 m below seafloor ...........................
Hammer downtime ........................................................
Clean up and completion ..............................................
49 (160.8 ft) .....................................
366 (1,200.8 ft) ................................
30 1 (98.4 ft) .....................................
60 (196.9 ft) .....................................
NA ....................................................
NA ....................................................
4 ..................
28 ................
3 ..................
5 to 7 ...........
NA ...............
NA ...............
No .......................
No .......................
No .......................
Yes 2 ...................
No .......................
No .......................
1 Estimated
range of gravity-based penetration.
Figure 1–4 of the IHA application.
3 See Figure 1–3 of the IHA application.
2 See
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19:01 Jun 27, 2014
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30JNN1
Estimated
number of
days 3
2
5.6
0.9
0.69
1.52
3.6
Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
Platform Specifications
The Harmony Platform is owned and
operated by ExxonMobil and has a
personnel capacity of 132 people. The
Harmony Platform, located in the Santa
Barbara Channel, was installed on June
21, 1989 and first began production on
December 30, 1993. The lease location
for the Santa Ynez Production Unit is
OCS–P0190. Support vessels and
helicopters are used routinely as part of
normal platform operations and would
be utilized to provide necessary support
for proposed activities during the
project. There are no anticipated
changes in logistics from current
operations associated with the proposed
project. The contractors responsible for
protected species and noise monitoring
during the proposed project would use
existing, routine transportation vessels.
The Harmony Platform also has a
minimum of two locations as likely
observation stations from which
Protected Species Observers (PSO)
would watch for marine mammals
before and during the proposed
conductor pipe installation activities.
The station on the upper deck has an
approximately 360° view around the
Harmony Platform to monitor the Level
B harassment buffer zone. At least one
station on the lower deck would
monitor the Level A harassment
exclusion zone. More details of the
Harmony Platform can be found in the
IHA application and online at: https://
www.boem.gov/BOEM-Newsroom/
Offshore-Stats-and-Facts/PacificRegion/Pacific-PlatformOperators.aspx#Exxon.
mstockstill on DSK4VPTVN1PROD with NOTICES
Acoustic Source Specifications
Predicted Sound Levels for the PileDriving Activities
The predicted in-water sound field
during proposed impact hammer piledriving of the conductor pipes at the
Harmony Platform were modeled by
JASCO Applied Sciences, Ltd (JASCO).
See JASCO’s ‘‘Assessment of Airborne
and Underwater Noise from Pile-Driving
Activities at the Harmony Platform’’ for
a detailed description of ExxonMobil’s
modeling for this proposed action,
which is provided as an addendum to
the IHA application. NMFS refers the
reviewers to that document for
additional information. Sound levels
emitted from the conductor pipe were
estimated using underwater recordings
(Illingworth and Rodkin, 2007) for
impact pile-driving of 61 to 76.2
centimeter (cm) (24 to 30 inch [in]) steel
piles (i.e., pipes) back calculated to 1 m
from the sound source, assuming a
combination of cylindrical and
spherical spreading. Sound level at the
VerDate Mar<15>2010
19:01 Jun 27, 2014
Jkt 232001
source was then scaled to the
anticipated energy range of 9 and 90 kJ
for the impact hammer and coupled to
an acoustic model of a representative
steel pipe (Claerbout, 1976; Reinhall
and Dahl, 2011). Only modeled results
associated with the maximum hammer
energy of 90 kJ were used to estimate
potential impacts and calculate take.
Each 505 m (1,656.8 ft) long
conductor pipe is assembled from 12 m
(39.4 ft) long sections welded end-toend, and then lowered from a top deck
of the platform through 366 m (1,200.8
ft) of water until the pipe encounters the
seafloor and penetrates approximately
60 m of the seabed under its own
weight. Because of the extremely long
length of the conductor pipe compared
to those represented in the literature,
the pipe was modeled as a line array of
12 sources at 30 m (98.4 ft) intervals
(i.e., over 360 m [1,181.1 ft] pipe
length). This procedure produced a
more realistic estimates of the maximum
sound SPL (rms) from impact hammer
pile-driving of Harmony Platform’s
conductor pipes, compared with a
single sound source representation (e.g.,
mid-pipe) that is generally used for
shorter pipes (piles). At the maximum
hammer energy of 90 kJ, the
corresponding maximum sound
pressure throughout the water column is
estimated at 202 dB (rms) at 1 m from
the conductor pipe (see Figure 6–1 of
the IHA application). The predicted
sound levels were used by ExxonMobil
and NMFS to determine the buffer and
exclusion zones for the proposed
conductor pipe installation activities.
Table 2 (Table 6–4 of the IHA
application) summarizes the modeled
distances at which in-water (160, 180,
and 190 dB [rms]) and in-air (90 and 100
dB [rms]) sound levels are expected to
be received from the impact hammer
pile-driving operating at a water depth
of 366 m. For in-water noise, sound
propagation and corresponding
maximum distances were modeled
using JASCO’s model Full Waveform
Range-dependent Acoustic Model
(FWRAM), which is based on a
modified version of the U.S. Navy’s
parabolic Range-dependent Acoustic
Model (RAM) to account for an elastic
seabed. FWRAM enhances RAM by
accounting for seabed dissipation of
acoustic energy and incorporates local
bathymetry, seafloor geoacoustics, and
underwater sound speed profiles.
Physical data specific to the Harmony
Platform location were used by JASCO
to model sound propagation (see Table
2–1 and Figure 202 of the IHA
application). Representative data
include sediment grain size and density,
and water column salinity/temperature,
PO 00000
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Fmt 4703
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36747
as these properties affect seafloor
geoacoustic properties and in-water
sound speed, respectively. Routines in
FWRAM were used to model sound as
SPL (rms) over water column depth and
distance from the conductor pipe based
on maximum hammer energy (90 kJ).
Figure 6–2 of the IHA application shows
water depth versus distance from the
conductor pipe (sound source), where
the 160 dB isopleth represents the
maximum distance for in-water Level B
harassment for marine mammals. The
maximum distances are generally higher
in the top 100 m (328.1 ft) of the water
column.
To evaluate potential seasonal effects
on sound propagation in the water
column, year-round conditions using
selected monthly averages (i.e., January,
April, August, and November) of water
column salinity and temperature were
modeled along one azimuth, south of
the Harmony Platform. Results showed
no significant seasonal variations (<1 dB
[rms]) up to 1 km (0.5 nmi) from the
Harmony Platform. Potential differences
in sound propagation with direction
from the Harmony Platform also were
investigated by JASCO. There were not
significant differences in the sound field
modeled for four equally spaced
transects out to 1 km from the Harmony
Platform.
For in-air noise, JASCO used in-air
sound levels calculated from recordings
of pipe-driving tests performed by
ExxonMobil using a 90 kJ energy
hammer that is planned for use on this
proposed action. The tests used the S–
90 hammer at 90% of its maximum
energy with a steel pipe of unknown
size. The estimated sound levels
represent A-weighted received levels,
calculated at six distances between 0
and 12 m (0 to 39.4 ft), and indicated
a source level of 132.4 dB re 20 mPa
(rms) (A-weighted). Calculated distances
from the sound source to the Level B
harassment threshold for in-air noise
(SPL [rms]) using spherical spreading
loss are shown below and in Table 6–
4 of the IHA application. Using the
JASCO model, Table 2 (below) shows
the distances at which three rms
underwater sound levels and two rms
in-air sound levels are expected to be
received from the impact hammer piledriving activities. The 180 and 190 dB
re 1 mPam (rms) distances are the safety
criteria (i.e., exclusion zone) for
potential Level A harassment as
specified by NMFS (2000) and are
applicable to cetaceans and pinnipeds,
respectively. If marine mammals are
detected within or about to enter the
appropriate exclusion zone, the impact
hammer pile-driver would be shutdown immediately.
E:\FR\FM\30JNN1.SGM
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Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
TABLE 2—MODELED MAXIMUM DISTANCES TO WHICH IN-WATER SOUND LEVELS ≥190, 180 AND 160 dB re 1 μPa (rms)
AND IN-AIR SOUND LEVELS ≥90 (FOR HARBOR SEALS) AND 100 dB re 20 μPa (rms) (FOR ALL OTHER PINNIPEDS)
COULD BE RECEIVED DURING THE PROPOSED PILE-DRIVING ACTIVITIES (BASED ON MAXIMUM HAMMER ENERGY OF
90 kJ) IN THE SANTA BARBARA CHANNEL OFF THE COAST OF CALIFORNIA
Water depth
(m)
Source
Predicted RMS radii distances (m) for in-water
pile-driving
Modeled RMS radii distances
(m) for in-air pile-driving
160 dB
180 dB
190 dB
90 dB
100 dB
325
(1,066.3 ft)
10
(32.8 ft)
3.5
(11.5 ft)
123
(403.5 ft)
41
(134.5 ft)
90 kJ Impact Hammer Pile-Driver ...........
366
NMFS expects that acoustic stimuli
resulting from the proposed impact
hammer pile-driving associated with the
conductor pipe installation activities
has the potential to harass marine
mammals.
Cetaceans occur throughout the Santa
Barbara Channel proposed action area,
including nearby the Harmony Platform,
from the surf zone to open ocean
environments beyond the Channel
Islands. Distribution is influenced by a
number of factors, but primary among
these are patterns of major ocean
currents, bottom relief, and sea surface
temperature. These physical
oceanographic conditions affect prey
abundance, which may attract marine
mammals during periods of high
productivity, and vice versa. Water
movement is near continuous, varying
seasonally, and is generally greatest
from late spring to early fall in response
to varying wind stress. This
phenomenon is much greater in the
western Santa Barbara Channel. This
near continuous movement of water
from the ocean bottom to the surface
creates a nutrient-rich, highly
productive environment for marine
mammal prey (Jefferson et al., 2008).
Most of the large cetaceans are
migratory, but many small cetaceans do
not undergo extensive migrations.
Instead, they undergo local or regional
dispersal, on a seasonal basis or in
response to food availability. Population
centers may shift on spatial scales
exceeding 100 km (54 nmi) over small
time scales (days or weeks) (Dailey and
Bonnell, 1993).
Systematic surveys (1991 to 1993,
1996, 2001, 2005) in the southern
California region have been carried out
via aircraft (Carretta and Forney, 1993)
and vessel (Ferguson and Barlow, 2001;
Barlow, 2003) by NMFS. In addition, a
vessel survey in the U.S. Exclusive
Economic Zone (EEZ), and out to 556
km (300.2 nmi) offshore of California,
Oregon, and Washington, was
conducted in the summer and fall of
mstockstill on DSK4VPTVN1PROD with NOTICES
Description of the Marine Mammals in
the Area of the Proposed Specified
Activity
The marine mammals that generally
occur in the proposed action area belong
to four taxonomic groups: Mysticetes
(baleen whales), odontocetes (toothed
whales), pinnipeds (seals and sea lions),
and fissipeds (sea otters). The marine
mammal species that potentially occur
within the Pacific Ocean in proximity to
the proposed action area in the Santa
Barbara Channel off the coast of
California (ranging from Point
Conception and south, including the
entire Southern California Bight)
include 30 species of cetaceans (whales,
dolphins, and porpoises) and 6 species
of pinnipeds. The southern sea otter
(Enhydra lutris nereis) is listed as
threatened under the ESA and is
managed by the U.S. Fish and Wildlife
Service and is not considered further in
this proposed IHA notice.
Marine mammal species listed as
threatened or endangered under the U.S.
Endangered Species Act of 1973 (ESA;
16 U.S.C. 1531 et seq.), includes the
North Pacific right (Eubalaena
japonica), humpback (Megaptera
novaeangliae), sei (Balaenoptera
borealis), fin (Balaenoptera physalus),
blue (Balaenoptera musculus), and
sperm (Physeter macrocephalus) whale
as well as the Guadalupe fur seal
(Arctocephalus townsendi). Of those
threatened and endangered species, the
humpback, sei, fin, blue, and sperm
whale are likely to be encountered in
the proposed action area.
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19:01 Jun 27, 2014
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2005 by NMFS (Forney, 2007). Many
other regional surveys have also been
conducted (Carretta, 2003). Becker
(2007) analyzed data from vessel
surveys conducted since 1986, and
compiled marine mammal densities.
There are 30 cetacean and 6 pinniped
species with ranges that are known to
occur in the Eastern North Pacific Ocean
waters of the project area. These include
the North Pacific right whale, Bryde’s
whale (Balaenoptera edeni), dwarf
sperm whale (Kogia sima), harbor
porpoise (Phocoena phocoena), Steller
sea lion (Eumatopias jubatus), and
Guadalupe fur seal. However, these
species are extremely rare, found in the
Channel Islands, or are primarily found
north or south of the Santa Barbara
Channel, and are unlikely to be found
in the proposed action area. The harbor
porpoise occurs north of Point
Conception, California. Bryde’s whales
are extremely rare in the Southern
California Bight, with fewer than ten
confirmed sightings from August 2006
to September 2010 (Smultea et al.,
2012). Guadalupe fur seals are most
common at Guadalupe Island, Mexico,
which is their primary breeding ground
(Melin and Delong, 1999). Although
adult and juvenile males have been
observed at San Miguel Island,
California, since the mid-1960’s, and in
the late 1990’s a pup was born on the
islands (Melin and Delong, 1999), more
recent sightings are extremely rare.
These species are not considered further
in this document. Table 3 (below)
presents information on the occurrence,
abundance, distribution, population
status, and conservation status of the
species of marine mammals that may
occur in the proposed project area
during August to November 2014.
E:\FR\FM\30JNN1.SGM
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Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
TABLE 3—THE HABITAT, OCCURRENCE, RANGE, REGIONAL ABUNDANCE, AND CONSERVATION STATUS OF MARINE MAMMALS THAT MAY OCCUR IN OR NEAR THE PROPOSED PIPE INSTALLATION PROJECT AREA OFF THE COAST OF CALIFORNIA IN THE PACIFIC OCEAN
[See text and Tables 3–1 in ExxonMobil’s IHA application for further details]
Species
Habitat
Occurrence
Range
Coastal and pelagic.
Rare .................................
North Pacific Ocean between 20 to 60° North.
Coastal and shelf
Transient during seasonal
migrations.
North Pacific Ocean, Gulf
of California to Arctic—
Eastern North Pacific
stock.
Humpback whale
(Megaptera
novaeangliae).
Pelagic, nearshore waters,
and banks.
Seasonal, sightings near
northern Channel Islands.
Cosmopolitan ...................
Minke whale
(Balaenoptera
acutorostrata).
Pelagic and
coastal.
Tropics and sub-tropics to
ice edges.
Bryde’s whale
(Balaenoptera edeni).
Pelagic and
coastal.
Less common in summer,
small number around
northern Channel Islands.
Rare, infrequent summer
off California.
Sei whale
(Balaenoptera borealis).
Fin whale
(Balaenoptera
physalus).
Blue whale
(Balaenoptera
musculus).
Primarily offshore, pelagic.
Rare, infrequent summer
off California.
Continental
slope, pelagic.
Year-round presence .......
Pelagic, shelf,
coastal.
Seasonal, arrive April to
May, common late-summer to fall off Southern
California.
Pelagic, deep
sea.
Common year-round,
more likely in waters
>1,000 m.
Seaward of 500 to 1,000
m, Limited sightings in
Southern California
Bight.
Rare .................................
Mysticetes:
North Pacific right
whale (Eubalaena japonica).
Gray whale
(Eschrichtius
robustus).
Odontocetes:
Sperm whale (Physeter
macrocephalus).
Pelagic, slope ....
Dwarf sperm whale
(Kogia sima).
Deep waters off
the shelf.
Baird’s beaked whale
(Berardius bairdii).
Pelagic ...............
Cuvier’s beaked whale
(Ziphius cavirostris).
Pelagic ...............
Blainville’s beaked
whale (Mesoplodon
densirostris).
Pelagic ...............
Perrin’s beaked whale
(Mesoplodon perrini).
Pelagic ...............
Lesser beaked whale
(Mesoplodon
peruvianis).
mstockstill on DSK4VPTVN1PROD with NOTICES
Pygmy sperm whale
(Kogia breviceps).
Pelagic ...............
Stejneger’s beaked
whale (Mesoplodon
stejnegeri).
Pelagic ...............
Ginkgo-toothed beaked
whale (Mesoplodon
ginkgodens).
Pelagic ...............
Hubbs’ beaked
(Mesoplodon
carlhubbsi).
Pelagic ...............
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19:01 Jun 27, 2014
Jkt 232001
Primarily along continental
slope late spring to
early fall.
Possible year-round occurrence.
Rare, continental slope
region, generally seaward of 500 to 1,000 m
depth.
Rare, continental slope
region, generally seaward of 500 to 1,000 m
depth.
Rare, continental slope
region, generally seaward of 500 to 1,000 m
depth.
Rare, continental slope
region, generally seaward of 500 to 1,000 m
depth.
Rare, continental slope
region, generally seaward of 500 to 1,000 m
depth.
Rare, continental slope
region, generally seaward of 500 to 1,000 m
depth.
PO 00000
Frm 00031
Best population
estimate
(minimum) 1
NA (26)—Eastern North Pacific stock.
19,126
(18,107)—
Eastern North
Pacific stock.
155 (142)—
Western North
Pacific population.
1,918 (1,876)—
California/Oregon/Washington (CA/OR/
WA) stock.
478 (202)—CA/
OR/WA stock.
ESA 2
MMPA 3
EN ......................
D.
DL—Eastern
North Pacific
stock.
EN—Western
North Pacific
population.
NC—Eastern
North Pacific
stock.
D—Western
North Pacific
population.
EN ......................
D.
NL ......................
NC.
Tropical and sub-tropical
zones between 40°
North and 40° South.
Tropical to polar zones,
favor mid-latitude temperate areas.
Tropical, temperate, and
polar zones of all
oceans.
Tropical waters to pack
ice edges.
NA ......................
NL ......................
NC.
126 (83)—Eastern North Pacific stock.
3,051 (2,598)—
CA/OR/WA
stock.
1,647 (1,551)—
Eastern North
Pacific stock.
EN ......................
D.
EN ......................
D.
EN ......................
D.
Tropical waters to pack
ice edges.
971 (751)—CA/
OR/WA stock.
EN ......................
D.
Tropical to warm temperate zones (temperate preference).
579 (271)—CA/
OR/WA stock.
NL ......................
NC.
Tropical to warm temperate zones (warmer
preference).
North Pacific Ocean and
adjacent seas.
NA—CA/OR/WA
stock.
NL ......................
NC.
847 (466)—CA/
OR/WA stock.
NL ......................
NC.
6,950 (4,481)—
CA/OR/WA
stock.
694 (389)—
Mesoplodon
spp. CA/OR/
WA stock.
694 (389)—
Mesoplodon
spp. CA/OR/
WA stock.
694 (389)—
Mesoplodon
spp. CA/OR/
WA stock.
694 (389)—
Mesoplodon
spp. CA/OR/
WA stock.
694 (389)—
Mesoplodon
spp. CA/OR/
WA stock.
694 (389)—
Mesoplodon
spp. CA/OR/
WA stock.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
Cosmopolitan ...................
Temperate and tropical
waters worldwide.
North Pacific Ocean .........
Temperate and tropical
waters Eastern Pacific
Ocean.
North Pacific Ocean .........
Temperate and tropical
waters Indo-Pacific
Ocean.
North Pacific Ocean .........
Fmt 4703
Sfmt 4703
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36750
Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
TABLE 3—THE HABITAT, OCCURRENCE, RANGE, REGIONAL ABUNDANCE, AND CONSERVATION STATUS OF MARINE MAMMALS THAT MAY OCCUR IN OR NEAR THE PROPOSED PIPE INSTALLATION PROJECT AREA OFF THE COAST OF CALIFORNIA IN THE PACIFIC OCEAN—Continued
[See text and Tables 3–1 in ExxonMobil’s IHA application for further details]
Species
Habitat
Occurrence
Range
Killer whale (Orcinus
orca).
Pelagic, shelf,
coastal, pack
ice.
Varies on inter-annual
basis, likely in winter
(January to February).
Cosmopolitan ...................
Short-finned pilot whale
(Globicephala
macrorhynchus).
Bottlenose dolphin
(Tursiops truncatus).
Pelagic, shelf,
coastal.
Uncommon, more common before 1982.
Offshore,
inshore, coastal, estuaries.
Offshore stock—Yearround presence.
Coastal stock—Limited,
small population within
1 km of shore.
Warm temperate to tropical waters, ∼50° North
to 40° South.
Tropical and temperate
waters between 45°
North and South.
Striped dolphin
(Stenella
coeruleoalba).
Short-beaked common
dolphin (Delphinus
delphis).
Off continental
shelf.
Occasional visitor .............
Shelf, pelagic,
seamounts.
Common, more abundant
in summer.
Long-beaked common
dolphin (Delphinus
capensis).
Pacific white-sided dolphin
(Lagenorhynchus
obliquidens).
Inshore ...............
Common, more inshore
distribution, year-round
presence.
Common, year-round,
more abundant November to April.
Nearshore and tropical
waters.
Northern right whale
dolphin (Lissodelphis
borealis).
Risso’s dolphin
(Grampus griseus).
Pelagic ...............
Common, more abundant
November to April.
North Pacific Ocean, 30
to 50° North.
Deep water,
seamounts.
Dall’s porpoise
(Phocoenoides dalli).
Shelf, slope, offshore.
Common, present in summer, more abundant
November to April.
Common, more abundant
November to April.
Continental slope and
outer shelf of tropical to
temperate waters.
North Pacific Ocean, 30
to 62° North.
Coastal and inland waters.
AK to Point Conception,
CA.
Shallow temperate to subpolar waters of Northern Hemisphere.
Coastal, shelf .....
Common, Channel Island
breeding sites in summer.
Rare .................................
Eastern North Pacific
Ocean—Alaska to Mexico.
North Pacific Ocean—
Central California to
Korea.
Common, haul-outs and
rookeries in Channel Islands, bulk of stock
north of Point Conception.
Common, haul-outs and
rookeries in Channel Islands, December to
March and April to August, spend 8 to 10
months at sea.
Common, small population breeds on San
Miguel Island May to
October.
Rare, observed in Channel Islands.
Coastal temperate to
polar regions in Northern Hemisphere.
Harbor porpoise
(Phocoena
phocoena).
Pinnipeds:
California sea lion
(Zalophus
californianus).
Steller sea lion
(Eumetopias jubatus).
Offshore, slope ..
Coastal, shelf .....
Coastal ...............
Northern elephant seal
(Mirounga
angustirostris).
mstockstill on DSK4VPTVN1PROD with NOTICES
Pacific harbor seal
(Phoca vitulina
richardii).
Coastal, pelagic
when not migrating.
Northern fur seal
(Callorhinus ursinus).
Pelagic, offshore
Guadalupe fur seal
(Arctocephalus
townsendi).
Coastal, shelf .....
VerDate Mar<15>2010
19:01 Jun 27, 2014
Jkt 232001
PO 00000
Frm 00032
Best population
estimate
(minimum) 1
ESA 2
MMPA 3
240 (162)—Eastern North Pacific Offshore
stock.
346 (346)—Eastern North Pacific Transient
stock..
354 (354)—West
Coast Transient stock.
760 (465)—CA/
OR/WA stock.
NL ......................
NC.
NL ......................
NC.
1,006 (684)—CA/
OR/WA Offshore stock.
323 (290)—California Coastal
stock.
10,908 (8,231)—
CA/OR/WA
stock.
411,211
(343,990)—
CA/OR/WA
stock.
107,016
(76,224)—California stock.
26,930
(21,406)—CA/
OR/WA, Northern and Southern stock.
8,334 (6,019)—
CA/OR/WA
stock.
6,272 (4,913)—
CA/OR/WA
stock.
42,000
(32,106)—CA/
OR/WA stock.
NA ......................
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
NL ......................
NC.
296,750
(153,337)—
U.S. stock.
49,685
(45,916)—
Western stock.
58,334 to 72,223
(52,847)—
Eastern stock.
30,196
(26,667)—California stock.
NL ......................
NC.
EN—Western
stock.
DL—Eastern
stock.
D.
NL ......................
NC.
Eastern and Central North
Pacific Ocean—Alaska
to Mexico.
124,000
(74,913)—California breeding
stock.
NL ......................
NC.
North Pacific Ocean—
Mexico to Japan.
12,844 (6,722)— NL ......................
California stock.
NC.
California to Baja California, Mexico.
7,408 (3,028)—
Mexico to California stock.
D.
Tropical to temperate
waters, 50° North to 40°
South.
Tropical to temperate
waters of Atlantic and
Pacific Ocean.
Temperate waters of
North Pacific Ocean.
Fmt 4703
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TABLE 3—THE HABITAT, OCCURRENCE, RANGE, REGIONAL ABUNDANCE, AND CONSERVATION STATUS OF MARINE MAMMALS THAT MAY OCCUR IN OR NEAR THE PROPOSED PIPE INSTALLATION PROJECT AREA OFF THE COAST OF CALIFORNIA IN THE PACIFIC OCEAN—Continued
[See text and Tables 3–1 in ExxonMobil’s IHA application for further details]
Species
Fissipeds:
Southern sea otter
(Enhydra lutris
nereis).
Habitat
Occurrence
Range
Coastal ...............
Mainland coastline from
San Mateo County to
Santa Barbara County,
CA San Nicolas Island.
North Pacific Rim—Japan
to Mexico.
Best population
estimate
(minimum) 1
ESA 2
2,826 (2,723)—
T .........................
California stock.
MMPA 3
D.
NA = Not available or not assessed.
1 NMFS Marine Mammal Stock Assessment Reports.
2 U.S. Endangered Species Act: EN = Endangered, T = Threatened, DL = Delisted, and NL = Not listed.
3 U.S. Marine Mammal Protection Act: D = Depleted, S = Strategic, and NC = Not Classified.
Further detailed information
regarding the biology, distribution,
seasonality, life history, and occurrence
of these marine mammal species in the
proposed project area can be found in
sections 3 and 4 of ExxonMobil’s IHA
application. NMFS has reviewed these
data and determined them to be the best
available scientific information for the
purposes of the proposed IHA.
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Potential Effects of the Specified
Activity on Marine Mammals
This section includes a summary and
discussion of the ways that the types of
stressors associated with the specified
activity (e.g., impact hammer piledriving) have been observed to impact
marine mammals. This discussion may
also include reactions that we consider
to rise to the level of a take and those
that we do not consider to revise to the
level of take (for example, with
acoustics), we may include a discussion
of studies that showed animals not
reacting at all to sound or exhibiting
barely measureable avoidance). This
section is intended as a background of
potential effects and does not consider
either the specific manner in which this
activity will be carried out or the
mitigation that will be implemented,
and how either of those will shape the
anticipated impacts from this specific
activity. The ‘‘Estimated Take by
Incidental Harassment’’ section later in
this document will include a
quantitative analysis of the number of
individuals that are expected to be taken
by this activity. The ‘‘Negligible Impact
Analysis’’ section will include the
analysis of how this specific activity
will impact marine mammals and will
consider the content of this section, the
‘‘Estimated Take by Incidental
Harassment’’ section, the ‘‘Proposed
Mitigation’’ section, and the
‘‘Anticipated Effects on Marine Mammal
Habitat’’ section to draw conclusions
regarding the likely impacts of this
activity on the reproductive success or
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survivorship of individuals and from
that on the affected marine mammal
populations or stocks.
Acoustic Impacts
When considering the influence of
various kinds of sound on the marine
environment, it is necessary to
understand that different kinds of
marine life are sensitive to different
frequencies of sound. Based on available
behavioral data, audiograms have been
derived using auditory evoked
potentials, anatomical modeling, and
other data, Southall et al. (2007)
designate ‘‘functional hearing groups’’
for marine mammals and estimate the
lower and upper frequencies of
functional hearing of the groups. The
functional groups and the associated
frequencies are indicated below (though
animals are less sensitive to sounds at
the outer edge of their functional range
and most sensitive to sounds of
frequencies within a smaller range
somewhere in the middle of their
functional hearing range):
• Low-frequency cetaceans (13
species of mysticetes): Functional
hearing is estimated to occur between
approximately 7 Hz and 30 kHz;
• Mid-frequency cetaceans (32
species of dolphins, six species of larger
toothed whales, and 19 species of
beaked and bottlenose whales):
Functional hearing is estimated to occur
between approximately 150 Hz and 160
kHz;
• High-frequency cetaceans (eight
species of true porpoises, six species of
river dolphins, Kogia spp., the
franciscana (Pontoporia blainvillei), and
four species of cephalorhynchids):
Functional hearing is estimated to occur
between approximately 200 Hz and 180
kHz; and
• Phocid pinnipeds in water:
Functional hearing is estimated to occur
between approximately 75 Hz and 100
kHz;
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• Otariid pinnipeds in water:
Functional hearing is estimated to occur
between approximately 100 Hz and 40
kHz.
As mentioned previously in this
document, 30 marine mammal species
managed under NMFS jurisdiction (26
cetacean and 4 pinniped species) are
likely to occur in the proposed action
area. Of the 26 cetacean species likely
to occur in ExxonMobil’s proposed
action area, 6 are classified as lowfrequency cetaceans (i.e., gray,
humpback, minke, sei, fin, and blue
whale), 18 are classified as midfrequency cetaceans (i.e., sperm, Baird’s
beaked, Cuvier’s beaked, Blainville’s
beaked, Perrin’s beaked, Lesser beaked,
Stejneger’s beaked, Ginkgo-toothed
beaked, Hubb’s beaked, killer, and
short-finned pilot whale, as well as
bottlenose, striped, short-beaked
common, long-beaked common, Pacific
white-sided, northern right whale, and
Risso’s dolphin), 2 are classified as
high-frequency cetaceans (i.e., pygmy
sperm whale and Dall’s porpoise), 2 are
classified as phocids (i.e., harbor and
northern elephant seal), and 2 are
classified as otariid pinnipeds (i.e.,
California sea lion and northern fur seal)
(Southall et al., 2007). A species’
functional hearing group is a
consideration when we analyze the
effects of exposure to sound on marine
mammals.
Current NMFS practice, regarding
exposure of marine mammals to highlevel underwater sounds is that
cetaceans and pinnipeds exposed to
impulsive sounds at or above 180 and
190 dB (rms), respectively, have the
potential to be injured (i.e., Level A
harassment). NMFS considers the
potential for Level B (behavioral)
harassment to occur when marine
mammals are exposed to sounds below
injury thresholds but at or above the 160
dB (rms) threshold for impulse sounds
(e.g., impact pile-driving) and the 120
dB (rms) threshold for continuous noise
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(e.g., vibratory pile-driving). No
vibratory pile-driving is planned for
ExxonMobil’s proposed activity in the
Santa Barbara Channel. Current NMFS
practice, regarding exposure of marine
mammals to high-level in-air sounds, as
a threshold for potential Level B
harassment, is at or above 90 dB re 20
mPa for harbor seals and at or above 100
dB re 20 mPa for all other pinniped
species (Lawson et al., 2002; Southall et
al., 2007). NMFS has not established a
threshold for Level A harassment for
marine mammals exposed to in-air
noise; however, Southall et al. (2007)
recommends 149 dB re 20 mPa (peak)
(flat) as the potential threshold for
injury from in-air noise for all
pinnipeds.
Acoustic stimuli generated by the
conductor pipe installation activities,
which introduce sound into the marine
environment and in-air, may have the
potential to cause Level B harassment of
marine mammals in the proposed action
area. The effects of sounds from impact
hammer pile-driving activities might
include one or more of the following:
tolerance, masking of natural sounds,
behavioral disturbance, temporary or
permanent hearing impairment, or nonauditory physical or physiological
effects (Richardson et al., 1995; Gordon
et al., 2004; Nowacek et al., 2007;
Southall et al., 2007). Permanent
hearing impairment, in the unlikely
event that it occurred, would constitute
injury, but temporary threshold shift
(TTS) is not an injury (Southall et al.,
2007). Although the possibility cannot
be entirely excluded, it is unlikely that
the proposed project would result in
any cases of temporary or permanent
hearing impairment, or any significant
non-auditory physical or physiological
effects. Based on the available data and
studies described here, some behavioral
disturbance is expected.
The effects of pile-driving on marine
mammals depend on several factors,
including the size, type, and depth of
the animal; the depth, intensity, and
duration of the pile-driving sound; the
depth of the water column; the substrate
of the habitat; the standoff distance
between the pile and the animals; and
the sound propagation properties of the
environment. Impacts to marine
mammals from pile-driving activities
are expected to result primarily from
acoustic pathways. As such, the degree
of effect is intrinsically related to the
received level and duration of the sound
exposure, which are in turn influenced
by the distance between the animal and
the source. The further away from the
source, the less intense the exposure
should be. The substrate and depth of
the habitat affect the sound propagation
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properties of the environment. Shallow
environments are typically more
structurally complex, which leads to
rapid sound attenuation. In addition,
substrates that are soft (e.g., sand) would
absorb or attenuate the sound more
readily than hard substrates (e.g., rock),
which may reflect the acoustic wave.
Soft porous substrates would also likely
require less time to drive the pipe, and
possibly less forceful equipment, which
would ultimately decrease the intensity
of the acoustic source.
In the absence of mitigation, impacts
to marine mammal species may result
from physiological and behavioral
responses to both the type and strength
of the acoustic signature (Viada et al.,
2008). The type and severity of
behavioral impacts are difficult to
define due to limited studies addressing
the behavioral effects of impulse sounds
on marine mammals. Potential effects
from impulsive sound sources can range
in severity, ranging from effects such as
behavioral disturbance, tactile
perception, physical discomfort, slight
injury, of the internal organs and the
auditory system, to mortality (Yelverton
et al., 1973).
Tolerance
Richardson et al. (1995) defines
tolerance as the occurrence of marine
mammals in areas where they are
exposed to human activities or manmade noise. In many cases, tolerance
develops by the animal habituating to
the stimulus (i.e., the gradual waning of
responses to a repeated or ongoing
stimulus) (Richardson, et al., 1995;
Thorpe, 1963), but because of ecological
or physiological requirements, many
marine animals may need to remain in
areas where they are exposed to chronic
stimuli (Richardson, et al., 1995).
Numerous studies have shown that
pulsed underwater sounds from
industry activities are often readily
detectable in the water at distances of
many kilometers. Several studies have
shown that marine mammals at
distances more than a few kilometers
often show no apparent response (Miller
et al., 2005; Bain and Williams, 2006).
That is often true even in cases when
the pulsed sounds must be readily
audible to the animals based on
measured received levels and the
hearing sensitivity of the marine
mammal group. Although various
baleen whales and toothed whales, and
(less frequently) pinnipeds have been
shown to react behaviorally to airgun
pulses under some conditions, at other
times marine mammals of all three types
have shown no overt reactions (e.g.,
Malme et al., 1986; Richardson et al.,
1995; Madsen and Mohl, 2000; Croll et
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al., 2001; Jacobs and Terhune, 2002;
Madsen et al., 2002; Miller et al., 2005).
The relative responsiveness of baleen
and toothed whales are quite variable.
Masking
The term masking refers to the
inability of a subject to recognize the
occurrence of an acoustic stimulus as a
result of the interference of another
acoustic stimulus (Clark et al., 2009).
Introduced underwater sound may,
through masking, reduce the effective
communication distance of a marine
mammal species if the frequency of the
source is close to that used as a signal
by the marine mammal, and if the
anthropogenic sound is present for a
significant fraction of the time
(Richardson et al., 1995).
Natural and artificial sounds can
disrupt behavior by masking, or
interfering with, a marine mammal’s
ability to hear other sounds. Masking
occurs when the receipt of a sound is
interfered with by another coincident
sound at similar frequencies and at
similar or higher levels. Chronic
exposure to excessive, though not highintensity, sound could cause masking at
particular frequencies for marine
mammals that utilize sound for vital
biological functions. Masking can
interfere with detection of acoustic
signals such as communication calls,
echolocation sounds, and
environmental sounds important to
marine mammals. Therefore, under
certain circumstances, marine mammals
whose acoustic sensors or environment
are being severely masked could also be
impaired from maximizing their
performance fitness in survival and
reproduction. If the coincident
(masking) sound were man-made, it
could be potentially harassing if it
disrupted hearing-related behavior. It is
important to distinguish TTS and PTS,
which persist after the sound exposure,
from masking, which occurs during the
sound exposure. Because masking
(without resulting in threshold shift) is
not associated with abnormal
physiological function, it is not
considered a physiological effect, but
rather a potential behavioral effect.
The frequency range of the potentially
masking sound is important in
determining any potential behavioral
impacts. Because sound generated from
in-water pile-driving is mostly
concentrated at low frequency ranges, it
may have less effect on high frequency
echolocation sounds made by porpoises.
However, lower frequency man-made
sounds are more likely to affect
detection of communication calls and
other potentially important natural
sounds such as surf and prey sound. It
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may also affect communication signals
when they occur near the sound band
and thus reduce the communication
space of animals (e.g., Clark et al., 2009)
and cause increased stress levels (e.g.,
Foote et al., 2004; Holt et al., 2009).
Masking has the potential to impact
species at population, community, or
even ecosystem levels, as well as at
individual levels. Masking affects both
senders and receivers of the signals and
can potentially have long-term chronic
effects on marine mammal species and
populations. Recent research suggests
that low frequency ambient sound levels
have increased by as much as 20 dB
(more than three times in terms of SPL)
in the world’s ocean from pre-industrial
periods, and that most of these increases
are from distant shipping (Hildebrand,
2009). All anthropogenic sound sources,
such as those from vessel traffic, piledriving, and dredging activities,
contribute to the elevated ambient
sound levels, thus intensifying masking.
However, much of the sound generated
from the proposed activities is not
expected to contribute significantly to
increased ocean ambient sound.
Given that the energy distribution of
pile-driving covers a broad frequency
spectrum, sound from these sources
would likely be within the audible
range of marine mammals present in the
proposed action area. Impact piledriving activity is relatively short-term,
with rapid pulses occurring for the
duration of the driving event. The
probability that impact pile-driving
resulting from this proposed action
would mask acoustic signals important
to the behavior and survival of marine
mammal species is likely to be
discountable. Any masking event that
could possibly rise to Level B
harassment under the MMPA would
occur concurrently within the zones of
behavioral harassment already
estimated for impact pile-driving, and
which have already been taken into
account in the exposure analysis.
Behavioral Disturbance
Marine mammals may behaviorally
react to sound when exposed to
anthropogenic noise. Disturbance
includes a variety of effects, including
subtle to conspicuous changes in
behavior, movement, and displacement.
Behavioral responses to sound are
highly variable and context-specific and
reactions, if any, depend on species,
state of maturity, experience, current
activity, reproductive state, time of day,
and many other factors (Richardson et
al., 1995; Wartzok et al., 2004; Southall
et al., 2007; Weilgart, 2007).
Habituation can occur when an
animal’s response to a stimulus wanes
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with repeated exposure, usually in the
absence of unpleasant associated events
(Wartzok et al., 2003). Animals are most
likely to habituate to sounds that are
predictable and unvarying. The opposite
process is sensitization, when an
unpleasant experience leads to
subsequent responses, often in the form
of avoidance, at a lower level of
exposure. Behavioral state may affect
the type of response as well. For
example, animals that are resting may
show greater behavioral change in
response to disturbing sound levels than
animals that are highly motivated to
remain in an area for feeding
(Richardson et al., 1995; NRC, 2003;
Wartzok et al., 2003).
Controlled experiments involving
exposure to loud impulse sound sources
with captive marine mammals showed
pronounced behavioral reactions,
including avoidance of loud sound
sources (Ridgeway et al., 1997; Finneran
et al., 2003). Observed responses of wild
marine mammals to loud pulsed sound
sources (typically seismic airguns or
acoustic harassment devices, but also
including impact pile-driving) have
been varied but often consist of
avoidance behavior or other behavioral
changes suggesting discomfort (Morton
and Symonds, 2002; Thorson and Reyff,
2006; see also Gordon et al., 2004;
Wartzok et al., 2003; Nowacek et al.,
2007).
It is likely that the onset of piledriving could result in temporary, shortterm changes in an animal’s typical
behavior and/or avoidance of the
affected action area. These behavioral
reactions are often shown as: Changing
durations of surfacing and dives,
number of blows per surfacing, or
moving direction and/or speed;
reduced/increased vocal activities;
changing/cessation of certain behavioral
activities (such as socializing or
feeding); visible startle response or
aggressive behavior (such as tail/fluke
slapping or jaw clapping); avoidance of
areas where noise sources are located;
and/or flight responses (e.g., pinnipeds
flushing into the water from haul-outs
or rookeries). If a marine mammal does
react briefly to an underwater sound by
changing its behavior or moving a small
distance, the impacts of the change are
unlikely to be significant to the
individual, let alone the stock or
population. However, if a sound source
displaces marine mammals from an
important feeding or breeding area for a
prolonged period, impacts on
individuals and populations could be
significant (e.g., Lusseau and Bejder,
2007; Weilgart, 2007).
The biological significance of many of
these behavioral disturbances is difficult
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to predict, especially if the detected
disturbances appear minor. However,
the consequences of behavioral
modification could be expected to be
biologically significant if the change
affects growth, survival, and/or
reproduction. Some of these significant
behavioral modifications that could
potentially lead to effects on growth,
survival, or reproduction include:
• Change in diving/surfacing patterns
(such as those thought to be causing
beaked whale stranding due to exposure
to military mid-frequency tactical
sonar);
• Habitat abandonment due to loss of
desirable acoustic environment; and
• Cessation of feeding or social
interaction.
The onset of behavioral disturbance
from anthropogenic noise depends on
both external factors (characteristics of
noise sources and their paths) and the
specific characteristics of receiving
animals (hearing, motivation,
experience, demography) and is also
difficult to predict (Richardson et al.,
1995; Southall et al., 2007). Given the
many uncertainties in predicting the
quantity and types of impacts of noise
on marine mammals, it is common
practice to estimate how many
mammals would be present within a
particular distance of industrial
activities and/or exposed to a particular
level of sound. In most cases, this
approach likely overestimates the
numbers of marine mammals that would
be affected in some biologicallyimportant manner.
Hearing Impairment and Other Physical
Effects
Marine mammals exposed to high
intensity sound repeatedly or for
prolonged periods can experience
hearing threshold shift, which is the
loss of hearing sensitivity at certain
frequency ranges (Kastak et al., 1999;
Schlundt et al., 2000; Finneran et al.,
2002, 2005). Threshold shift can be
permanent (PTS), in which case the loss
of hearing sensitivity is not recoverable,
or temporary (TTS), in which case the
animal’s hearing threshold would
recover over time (Southall et al., 2007).
Marine mammals depend on acoustic
cues for vital biological functions (e.g.,
orientation, communication, finding
prey, avoiding predators); thus, TTS
may result in reduced fitness in survival
and reproduction. However, this
depends on the frequency and duration
of TTS, as well as the biological context
in which it occurs. TTS of limited
duration, occurring in a frequency range
that does not coincide with that used for
recognition of important acoustic cues,
would have little to no effect on an
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animal’s fitness. Repeated sound
exposures that lead to TTS could cause
PTS. PTS, in the unlikely event that it
occurred, would constitute injury, but
TTS is not considered injury (Southall
et al., 2007). It is unlikely that the
project would result in any cases of
temporary or especially permanent
hearing impairment or any significant
non-auditory physical or physiological
effects for reasons discussed later in this
document. Some behavioral disturbance
is expected, but it is likely that this
would be localized and short-term
because of the short duration of the
proposed action.
Many marine mammals are likely to
show some avoidance of the proposed
action area where received levels of
pile-driving sound high enough that
hearing impairment could potentially
occur. In those cases, the avoidance
responses of the animals themselves
would reduce or (most likely) avoid any
possibility of hearing impairment. Nonauditory physical effects may also occur
in marine mammals exposed to strong
underwater pulsed sound.
Temporary Threshold Shift—TTS is
the mildest form of hearing impairment
that can occur during exposure to a
strong sound (Kryter, 1985). While
experiencing TTS, the hearing threshold
rises and a sound must be stronger in
order to be heard. At least in terrestrial
mammals, TTS can last from minutes or
hours to (in cases of strong TTS) days.
For sound exposures at or somewhat
above the TTS threshold, hearing
sensitivity in both terrestrial and marine
mammals recovers rapidly after
exposure to the noise ends. Few data on
sound levels and durations necessary to
elicit mild TTS have been obtained for
marine mammals, and none of the
published data concern TTS elicited by
exposure to multiple pulses of sound.
Available data on TTS in marine
mammals are summarized in Southall et
al. (2007). Table 2 (above) presents the
estimated distances from the impact
hammer during pile-driving activities at
which the received energy level (per
pulse, flat-weighted) would be expected
to be greater than or equal to 180 and
190 dB re 1 mPa (rms).
To avoid the potential for injury
(Level A harassment), NMFS (1995,
2000) concluded that cetaceans and
pinnipeds should not be exposed to
pulsed underwater noise at received
levels exceeding 180 and 190 dB re 1
mPa (rms), respectively. The established
180 and 190 dB (rms) criteria are not
considered to be the levels above which
TTS might occur. Rather, they are the
received levels above which, in the view
of a panel of bioacoustics specialists
convened by NMFS before TTS
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measurements for marine mammals
started to become available, one could
not be certain that there would be no
injurious effects, auditory or otherwise,
to marine mammals. NMFS also
assumes that cetaceans and pinnipeds
exposed to levels exceeding 160 dB re
1 mPa (rms) may experience Level B
harassment.
For toothed whales, researchers have
derived TTS information for
odontocetes from studies on the
bottlenose dolphin and beluga whale
(Delphinapterus leucas). The
experiments show that exposure to a
single impulse at a received level of 207
kPa (or 30 psi, p-p), which is equivalent
to 228 dB re 1 Pa (p-p), resulted in a 7
and 6 dB TTS in the beluga whale at 0.4
and 30 kHz, respectively. Thresholds
returned to within 2 dB of the preexposure level within 4 minutes of the
exposure (Finneran et al., 2002). For the
one harbor porpoise tested, the received
level of airgun sound that elicited onset
of TTS was lower (Lucke et al., 2009).
If these results from a single animal are
representative, it is inappropriate to
assume that onset of TTS occurs at
similar received levels in all
odontocetes (cf. Southall et al., 2007).
Some cetaceans apparently can incur
TTS at considerably lower sound
exposures than are necessary to elicit
TTS in the bottlenose dolphin or beluga
whale.
For baleen whales, there are no data,
direct or indirect, on levels or properties
of sound that are required to induce
TTS. The frequencies to which baleen
whales are most sensitive are assumed
to be lower than those to which
odontocetes are most sensitive, and
natural background noise levels at those
low frequencies tend to be higher. As a
result, auditory thresholds of baleen
whales within their frequency band of
best hearing are believed to be higher
(less sensitive) than are those of
odontocetes at their best frequencies
(Clark and Ellison, 2004). From this, it
is suspected that received levels causing
TTS onset may also be higher in baleen
whales than those of odontocetes
(Southall et al., 2007).
In pinnipeds, researchers have not
measured TTS thresholds associated
with exposure to brief pulses (single or
multiple) of underwater sound. Initial
evidence from more prolonged (nonpulse) exposures suggested that some
pinnipeds (harbor seals in particular)
incur TTS at somewhat lower received
levels than do small odontocetes
exposed for similar durations (Kastak et
al., 1999, 2005; Ketten et al., 2001). The
TTS threshold for pulsed sounds has
been indirectly estimated as being an
SEL of approximately 171 dB re 1
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mPa 2·s (Southall et al., 2007) which
would be equivalent to a single pulse
with a received level of approximately
181 to 186 dB re 1 mPa (rms), or a series
of pulses for which the highest rms
values are a few dB lower.
Corresponding values for California sea
lions and northern elephant seals are
likely to be higher (Kastak et al., 2005).
Permanent Threshold Shift—When
PTS occurs, there is physical damage to
the sound receptors in the ear. In severe
cases, there can be total or partial
deafness, whereas in other cases, the
animal has an impaired ability to hear
sounds in specific frequency ranges
(Kryter, 1985). There is no specific
evidence that exposure to pulses of
airgun or pile-driving sound can cause
PTS in any marine mammal. However,
given the possibility that mammals
close to an airgun array might incur at
least mild TTS, there has been further
speculation about the possibility that
some individuals occurring very close to
airguns might incur PTS (e.g.,
Richardson et al., 1995, p. 372ff;
Gedamke et al., 2008). Single or
occasional occurrences of mild TTS are
not indicative of permanent auditory
damage, but repeated or (in some cases)
single exposures to a level well above
that causing TTS onset might elicit PTS.
Relationships between TTS and PTS
thresholds have not been studied in
marine mammals but are assumed to be
similar to those in humans and other
terrestrial mammals (Southall et al.,
2007). PTS might occur at a received
sound level at least several dBs above
that inducing mild TTS if the animal
were exposed to strong sound pulses
with rapid rise times. Based on data
from terrestrial mammals, a
precautionary assumption is that the
PTS threshold for impulse sounds (such
as an impact hammer pile-driving as
received close to the source) is at least
6 dB higher than the TTS threshold on
a peak-pressure basis, and probably
greater than 6 dB (Southall et al., 2007).
Given the higher level of sound
necessary to cause PTS as compared
with TTS, it is considerably less likely
that PTS would occur. Baleen whales
generally avoid the immediate area
around operating sound sources, as do
some other marine mammals.
Non-auditory Physiological Effects—
Non-auditory physiological effects or
injuries that theoretically might occur in
marine mammals exposed to strong
underwater sound include stress,
neurological effects, bubble formation,
resonance, and other types of organ or
tissue damage (Cox et al., 2006; Southall
et al., 2007). Studies examining such
effects are limited.
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In general, very little is known about
the potential for pile-driving sounds (or
other types of strong underwater
sounds) to cause non-auditory physical
effects in marine mammals. Such
effects, if they occur at all, would
presumably be limited to short distances
from the sound source and to activities
that extend over a prolonged period.
The available data do not allow
identification of a specific exposure
level above which non-auditory effects
can be expected (Southall et al., 2007),
or any meaningful quantitative
predictions of the numbers (if any) of
marine mammals that might be affected
in those ways. Marine mammals that
show behavioral avoidance of piledriving, including most baleen whales,
some odontocetes, and some pinnipeds,
are especially unlikely to incur auditory
impairment or non-auditory physical
effects.
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Airborne Sound Effects
Marine mammals that occur in the
proposed project area could be exposed
to airborne sounds associated with piledriving that have the potential to cause
harassment, depending on their distance
from pile-driving activities. Airborne
pile-driving sound would have less
impact on cetaceans than pinnipeds
because sound from atmospheric
sources does not transmit well
underwater (Richardson et al., 1995);
thus, airborne sound would only be an
issue for pinnipeds in the proposed
action area, whether hauled-out or in
the water with their heads in the air.
Most likely, a sound would cause
behavioral responses similar to those
discussed above in relation to
underwater sound. For instance,
anthropogenic sound could cause
hauled-out pinnipeds to exhibit changes
in their normal behavior, such as
reduction in vocalizations, or cause
them to temporarily abandon their
habitat and move further from the
source. Studies by Blackwell et al.
(2004) and Moulton et al. (2005)
indicate a tolerance or lack of response
to unweighted airborne sounds as high
as 112 dB peak and 96 dB rms.
The potential effects to marine
mammals described in this section of
the document do not take into
consideration the proposed monitoring
and mitigation measures described later
in this document (see the ‘‘Proposed
Mitigation’’ and ‘‘Proposed Monitoring
and Reporting’’ sections) which, as
noted are designed to effect the least
practicable impact on affected marine
mammal species and stocks.
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Anticipated Effects on Marine Mammal
Habitat
The proposed activities at the
Harmony Platform would not result in
permanent impacts to habitats used
directly by marine mammals, but may
have potential short-term impacts to
food sources such as forage fish and
invertebrates, and may affect acoustic
habitat. There are no rookeries or major
haul-out sites, no known foraging hotspots, or other ocean bottom structure of
significant biological importance to
marine mammals present in the marine
waters in the vicinity of the proposed
action area. Therefore, the main impact
issue associated with the proposed
activity would be temporarily elevated
sound levels and associated direct
effects on marine mammals, as
discussed previously in this document.
The most likely impact to marine
mammal habitat occurs from piledriving effects on likely marine mammal
prey near the Harmony Platform and
minor impacts to the immediate
substrate during conductor pipe
installation.
Anticipated Effects on Potential Prey
Common prey for cetaceans and
pinnipeds in the proposed action area
include a wide variety of nekton species
spanning the water column pelagic,
epipelagic, benthopelagic and demersal
zones. The most common prey groups
found in the area are hagfish, lampreys,
cartilaginous, and bony fish (including
anchovies), and large free swimming
invertebrates (e.g., squids). Pinnipeds
could also be considered prey for large
cetaceans (e.g., killer whales). Prey for
baleen whales (e.g., blue whale) include
large zooplankton (e.g., krill),
opportunistically consumed during
migration/transit through the Santa
Barbara Channel. Infaunal benthic
amphipods exist in the proposed action
area and are common prey items for
feeding gray whales, but the Santa
Barbara Channel is not known as a
feeding ground for this species.
Fish react to sounds which are
especially strong and/or intermittent
low-frequency sounds. Short duration,
sharp sounds can cause overt or subtle
changes in fish behavior and local
distribution. Hastings and Popper (2005)
and Hastings (2009) identified several
studies that suggest fish may relocate to
avoid certain areas of sound energy.
Additional studies have documented
effects of pile-driving (or other types of
sounds) on fish, although several are
based on studies in support of large
multi-year bridge construction projects
(e.g., Scholik and Yan, 2001, 2002;
Popper and Hastings, 2009). Sound
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pulses at received levels of 160 dB re 1
mPa may cause subtle changes in fish
behavior. SPLs of 180 dB may cause
noticeable changes in behavior (Pearson
et al., 1992; Skalski et al., 1992). SPLs
of sufficient strength have been known
to cause injury to fish and fish
mortality. The most likely impact to fish
from pile-driving activities in the
proposed action area would be
temporary behavioral avoidance of the
area. The duration of fish avoidance of
this area after pile-driving stops is
unknown, but a rapid return to normal
recruitment, distribution, and behavior
is anticipated. In general, impacts to
marine mammal prey species are
expected to be minor and temporary due
to the short timeframe for the proposed
activities. However, adverse impacts
may occur to a few species of fish which
may be present in the proposed action
area.
Anticipated Effects on Potential
Foraging Habitat
The Harmony Platform has been in
place for 20 years and the addition of
six conductor pipes to the existing 51
conductor pipes within the platform
structure would not produce a
quantifiable impact to marine mammals
to their existing habitat. The additional
six conductor pipes are approved
(permitted) as part of the original
Development Production Plan for
Harmony Platform.
The area likely impacted by the
project activities is relatively small
compared to the available habitat in the
Santa Barbara Channel waters. The
likelihood for avoidance by potential
prey (i.e., fish and invertebrates) of the
immediate area due to the temporary
loss of this foraging habitat is unknown,
but a rapid return to normal
recruitment, distribution, and behavior
is anticipated. Any behavioral
avoidance by fish of the disturbed area
would still leave significantly large
areas of prey and marine mammal
foraging habitat in the nearby vicinity.
Given the short hourly duration of
sound associated with individual piledriving activities and the relatively
small areas being affected, pile-driving
activities associated with the proposed
action are not likely to have a
permanent, adverse effect on any fish
habitat, or populations of fish and
invertebrate species. Therefore, piledriving is not likely to have a
permanent, adverse effect on marine
mammal foraging habitat at the
proposed action area. Furthermore, the
area around Harmony Platform in the
Santa Barbara Channel, is already
altered by various shipping activities.
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There would be no measureable loss
of existing marine mammal water
column or benthic habitat resulting from
the installation of six conductor pipes at
Harmony Platform. The impacts
associated with the proposed project are
temporary and are not expected to have
long term effects on marine mammals or
marine mammal habitat. The primary
impact of the activity on the local
environment is from sound, above and
below water surface to a depth of 366
m. The transitory nature of sound would
not impact the habitat of the marine
mammal populations. A secondary
impact from the activity would be the
temporary suspension of bottom
sediment, resulting from the installation
via hammer driving of six 26-in
diameter steel conductor pipes within
the platform jacket structure. The small
amount of suspended sediment would
quickly disperse and resettle to the
seafloor. No permanent impacts are
expected to marine mammals. The
impacts are temporary in nature and are
associated with pile-driving and
construction noise disturbance and
would not require restoration. Site
conditions are anticipated to be
unchanged from existing conditions for
marine mammals following project
implementation.
There is no potential for an oil spill
from operations/activities associated
with this project. Potential impacts from
an oil spill from existing operations are
addressed in an approved Oil Spill
Response Plan on file with BOEM for
the Santa Ynez Production Unit,
including Harmony Platform. Any
potential spill from the supply boats or
helicopters are already included in the
approved operation and plan.
Based on the preceding discussion of
potential types of impacts to marine
mammal habitat, overall, NMFS
anticipates that the proposed action is
not expected to cause significant
impacts on habitats used by the marine
mammal species in the proposed action
area or on the food sources that they
utilize.
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Proposed Mitigation
In order to issue an Incidental Take
Authorization (ITA) under section
101(a)(5)(D) of the MMPA, NMFS must
set forth the permissible methods of
taking pursuant to such activity, and
other means of effecting the least
practicable impact on such species or
stock and its habitat, paying particular
attention to rookeries, mating grounds,
and areas of similar significance, and
the availability of such species or stock
for taking for certain subsistence uses
(where relevant).
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ExxonMobil has incorporated a suite
of appropriate mitigation measures into
its project description (see Section 11 of
the IHA application).
To reduce the potential for
disturbance from acoustic stimuli
associated with the proposed activities,
ExxonMobil and/or its designees have
proposed to implement the following
mitigation measures for marine
mammals:
(1) Proposed buffer and exclusion
zones around the sound source;
(2) Hours of operation;
(3) Shut-down procedures; and
(4) Ramp-up procedures.
Proposed Exclusion Zones—
ExxonMobil uses radii to designate
exclusion and buffer zones and to
estimate take for marine mammals.
Table 2 (presented earlier in this
document) shows the distances at which
one would expect marine mammal
exposures to three received sound levels
(160, 180, and 190 dB) from the impact
hammer. The 180 and 190 dB level shutdown criteria are applicable to
cetaceans and pinnipeds, respectively,
as specified by NMFS (2000).
ExxonMobil used these levels to
establish the exclusion and buffer zones.
Based on the modeling, exclusion
zones (for triggering a shut-down) for
Level A harassment would be
established for cetaceans and pinnipeds
at 3.5 m (11.5 ft) and 10 m (32.8 ft) from
the conductor pipe sound source,
respectively. These shut-down zones
would be monitored by a dedicated
PSO. If the PSO detects a marine
mammal(s) within or about to enter the
appropriate exclusion zone, the piledriving activities would be shut-down
immediately. If marine mammals are
present within the shut-down zone
before impact pile-driving activities
begin, start of operations would be
delayed until the exclusion zones are
clear for at least 30 minutes. If marine
mammals appear in the shut-down zone
during proposed pile-driving activities,
the PSO would instruct the hammer
operator to halt all operations in a safe,
but immediate manner. Pile-driving
activities would only resume once the
exclusion zone has been cleared for at
least 30 minutes. In the unlikely event
that the marine mammal enters the
exclusion zone during pile-driving
activities, the exposure and behaviors
would be documented and reported by
the PSO and NMFS would be contacted
within 24 hours. A non-PSO safety
spotter would also be assigned to the
lower deck observation area. All
personnel operating at the lower
observation levels would be required to
wear appropriate personal protective
equipment.
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Hours of Operation—The proposed
activities would be conducted on a
continual 24-hour basis; therefore, some
of the 2.5 to 3.3 hours of active impact
pile-driving periods would be expected
to occur during non-daylight hours. To
facilitate visual monitoring during nondaylight hours, the exclusion zones
would be illuminated to permit more
effective viewing by the PSO. Lighting
would not be expected to attract marine
mammals. The areas where the
exclusion zones occur fall within the
jacket structure of the platform, and
therefore could be easily illuminated by
lights and monitored during nondaylight hours. For the buffer zone,
which would extend out to 325 m
(1,066.3 ft) from the conductor pipe,
PSOs would be stationed on an upper
deck of the Harmony Platform to
monitor for marine mammals during the
proposed pile-driving activities. During
non-daylight hours, PSOs would utilize
night-vision devices and other
appropriate equipment to monitor
marine mammals. If nighttime visual
aids are insufficient, ExxonMobil
proposes to use daytime visual counts of
marine mammals as an estimate of the
number of marine mammals present
during non-daylight hours (within a 24
hour period), noting that diurnal
activities for most marine mammals are
expected to vary somewhat.
Shut-down Procedures—ExxonMobil
would shut-down the operating hammer
if a marine mammal is detected outside
the exclusion zone, and the sound
source would be shut-down before the
animal is within the exclusion zone.
Likewise, if a marine mammal is already
within the exclusion zone when first
detected, the sound source would be
shut-down immediately.
Following a shut-down, ExxonMobil
would not resume pile-driving activities
until the marine mammal has cleared
the exclusion zone. ExxonMobil would
consider the animal to have cleared the
exclusion zone if:
• A PSO has visually observed the
animal leave the exclusion zone, or
• A PSO has not sighted the animal
within the exclusion zone for 15
minutes for species with shorter dive
durations (i.e., small odontocetes and
pinnipeds), or 30 minutes for species
with longer dive durations (i.e.,
mysticetes and large odontocetes,
including sperm, pygmy and dwarf
sperm, killer, and beaked whales).
All visual monitoring would be
conducted by qualified PSOs. Visual
monitoring would be conducted
continuously during active pile-driving
activities. PSOs would not have any
tasks other than visual monitoring and
would conduct monitoring from the best
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vantage point(s) practicable (e.g., on the
Harmony Platform or other suitable
location) that provides 360ßvisibility of
the Level A harassment exclusion zones
and Level B harassment buffer zone, as
far as possible. The PSO would be in
radio communication with the hammer
operator during pile-driving activities,
and would call for a shut-down in the
event a pinniped or cetacean appears to
be headed toward its respective
exclusion zone for cetaceans and
pinnipeds.
Ramp-Up Procedures—Ramp-up
(sometimes referred to as a ‘‘soft-start’’)
of the impact hammer provides a
gradual increase in sound levels until
the full sound level is achieved. The
purpose of a ramp-up is to ‘‘warn’’
marine mammals in the vicinity of the
impact hammer and to provide the time
for them to leave the area avoiding any
potential injury or impairment of their
hearing abilities. A ramp-up consists of
an initial set of three strikes from the
impact hammer at 40% energy, followed
by a 30 second waiting period, then two
subsequent three strike sets.
The buffer zone would be monitored
by PSOs beginning 30 minutes before
pile-driving activities, during piledriving, and for 30 minutes after piledriving stops. During ramp-up, the PSOs
would monitor the exclusion zone, and
if marine mammals are sighted, a shutdown would be implemented.
If the complete exclusion zone has not
been visible for at least 30 minutes prior
to the start of operations in either
daylight or nighttime, ExxonMobil
would not commence the ramp-up.
ExxonMobil would not initiate a rampup of the impact hammer if a marine
mammal is sighted within or near the
applicable exclusion zones during the
day or close to the Harmony Platform at
night.
Oil Spill Plan—ExxonMobil has
developed an Oil Spill Response Plan
and it is on file with BOEM.
Mitigation Conclusions
NMFS has carefully evaluated the
applicant’s proposed mitigation
measures and has considered a range of
other measures in the context of
ensuring that NMFS prescribes the
means of effecting the least practicable
impact on the affected marine mammal
species and stocks and their habitat.
NMFS’s evaluation of potential
measures included consideration of the
following factors in relation to one
another:
(1) The manner in which, and the
degree to which, the successful
implementation of the measure is
expected to minimize adverse impacts
to marine mammals;
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(2) The proven or likely efficacy of the
specific measure to minimize adverse
impacts as planned; and
(3) The practicability of the measure
for applicant implementation, including
consideration of personnel safety,
practicality of implementation, and
impact on the effectiveness of the
activity.
Any mitigation measure(s) prescribed
by NMFS should be able to accomplish,
have a reasonable likelihood of
accomplishing (based on current
science), or contribute to the
accomplishment of one or more of the
general goals listed below:
(1) Avoidance or minimization of
injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may
contribute to this goal).
(2) A reduction in the numbers of
marine mammals (total number or
number at biologically important time
or location) exposed to received levels
of hammer pile-driving, or other
activities expected to result in the take
of marine mammals (this goal may
contribute to 1, above, or to reducing
harassment takes only).
(3) A reduction in the number of
times (total number or number at
biologically important time or location)
individuals would be exposed to
received levels of hammer pile-driving,
or other activities expected to result in
the take of marine mammals (this goal
may contribute to 1, above, or to
reducing harassment takes only).
(4) A reduction in the intensity of
exposures (either total number or
number at biologically important time
or location) to received levels of
hammer pile-driving, or other activities
expected to result in the take of marine
mammals (this goal may contribute to a,
above, or to reducing the severity of
harassment takes only).
(5) Avoidance of minimization of
adverse effects to marine mammal
habitat, paying special attention to the
food base, activities that block or limit
passage to or from biologically
important areas, permanent destruction
of habitat, or temporary destruction/
disturbance of habitat during a
biologically important time.
(6) For monitoring directly related to
mitigation—an increase in the
probability of detecting marine
mammals, thus allowing for more
effective implementation of the
mitigation.
Based on NMFS’s evaluation of the
applicant’s proposed measures, as well
as other measures considered by NMFS
or recommended by the public, NMFS
has preliminarily determined that the
proposed mitigation measures provide
the means of effecting the least
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practicable impact on marine mammal
species or stocks and their habitat,
paying particular attention to rookeries,
mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an ITA for an
activity, section 101(a)(5)(D) of the
MMPA states that NMFS must set forth
‘‘requirements pertaining to the
monitoring and reporting of such
taking.’’ The MMPA implementing
regulations at 50 CFR 216.104(a)(13)
indicate that requests for ITAs must
include the suggested means of
accomplishing the necessary monitoring
and reporting that would result in
increased knowledge of the species and
of the level of taking or impacts on
populations of marine mammals that are
expected to be present in the proposed
action area. ExxonMobil submitted a
marine mammal monitoring plan as part
of the IHA application. It can be found
in Section 13 of the IHA application.
The plan may be modified or
supplemented based on comments or
new information received from the
public during the public comment
period or from the peer review panel
(see the ‘‘Monitoring Plan Peer Review’’
section later in this document).
Monitoring measures prescribed by
NMFS should accomplish one or more
of the following general goals:
(1) An increase in the probability of
detecting marine mammals, both within
the mitigation zone (thus allowing for
more effective implementation of the
mitigation) and in general to generate
more data to contribute to the analyses
mentioned below;
(2) An increase in our understanding
of how many marine mammals are
likely to be exposed to levels of sound
from impact hammer pile-driving
activities that we associate with specific
adverse effects, such as behavioral
harassment, TTS or PTS;
(3) An increase in our understanding
of how marine mammals respond to
stimuli expected to result in take and
how anticipated adverse effects on
individuals (in different ways and to
varying degrees) may impact the
population, species, or stock
(specifically through effects on annual
rates of recruitment or survival) through
any of the following methods:
• Behavioral observations in the
presence of stimuli compared to
observations in the absence of stimuli
(need to be able to accurately predict
received level, distance from source,
and other pertinent information);
• Physiological measurements in the
presence of stimuli compared to
observations in the absence of stimuli
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(need to be able to accurately predict
receive level, distance from the source,
and other pertinent information);
• Distribution and/or abundance
comparisons in times or areas with
concentrated stimuli versus times or
areas without stimuli;
(4) An increased knowledge of the
affected species; and
(5) An increase in our understanding
of the effectiveness of certain mitigation
and monitoring measures.
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Proposed Monitoring
ExxonMobil proposes to sponsor
marine mammal monitoring during the
proposed project, in order to implement
the proposed mitigation measures that
require real-time monitoring, and to
satisfy the anticipated monitoring
requirements of the IHA. ExxonMobil’s
proposed ‘‘Monitoring Plan’’ is
described below this section.
ExxonMobil understand that this
monitoring plan would be subject to
review by NMFS and that refinements
may be required. Two main types of
monitoring would be performed for this
proposed project: (1) in-situ
measurement of sound pressure levels;
and (2) visual observations of the
number and type of marine mammals
that enter sound exposure zones. In-situ
acoustic data would be used to validate
model predictions of sound pressure
levels near and with distance from the
conductor pipe sound source, including
the predicted maximum distances for
the buffer and exclusion zones. If
measured results differ from modeled
results, measured data would be used to
revise buffer and exclusion zone
boundaries to reflect actual conditions
during proposed project activities. Data
from visual monitoring would be used
to validate take estimate calculations.
Acoustic Monitoring
Acoustic monitoring using
hydrophones and microphones would
be conducted to obtain and validate
modeled in-water and in-air sound
levels during the proposed pile-driving
activities. Each hydrophone (in-water)
and microphone (in-air) would be
calibrated following the manufacturer’s
recommendations prior to the start of
the proposed project and checked for
accuracy and precision at the end of the
data collection for each conductor pipe
or as practical during conductor pipe
installation activities. Environmental
data would be collected to supplement
the acoustic monitoring and include:
wind speed and direction, air
temperature, humidity, near-surface
water temperature, weather conditions,
and other appropriate factors that could
contribute to influencing either in-air or
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in-water sound transmission levels.
Prior to deploying monitoring
equipment, the acoustics specialist
would be provided with the hammer
model and size, hammer energy settings,
and projected blows per minute for the
conductor pipe segments requiring
hammer pile-driving. Background in-air
and in-water sound levels would be
measured at Harmony Platform in the
absence of pile-driving activities to
obtain an ambient noise level, and
recorded over a frequency range of 10
Hz to 20 kHz. Ambient noise level
measurements would be conducted
before, during, and after the project. The
measured in-air and in-water sound data
would be used to recalibrate and refine
the sound propagation model used to
determine the buffer and exclusion
zones. Also, sound pressure levels
associated with ramp-up techniques
would be measured.
In-Water Monitoring—Acoustic
monitoring would be performed at a
minimum of two fixed stations located
at 10 m (32.8 ft) and approximately 325
m (1,066.3 ft) from the conductor pipe
sound source. These distances represent
the 180 dB and 160 dB (rms) modeled
sound levels. The following general
approach would be used to measure inwater sound levels:
• Acoustic monitoring would be
conducted over the entire pile-driving
period for each conductor pipe, starting
approximately 1 hour prior to piledriving through 1 hour after impact
hammering has stopped. Pre- and posthammer pile-driving data would be
used to determine ambient/background
noise levels.
• A stationary hydrophone system
with the ability to measure and record
sound pressure levels would be
deployed at a minimum of two
monitoring locations (stations). SPLs
would be recorded in voltage, converted
to microPascals (mPa), and postprocessed to decibels (dB [re 1 mPa]).
For the first conductor pipe installation,
hydrophones are placed at 10+/¥1 m
and at 325+/¥33 m from the conductor
pipe at depths ranging from 10 to 30 m
(32.8 to 98.4 ft) below the water surface
to avoid potential inferences for surface
water energy, and to target the depth
range of maximum occurrence of marine
mammals most likely in the area during
the project. The equipment would
obtain data for the most likely depth
range of marine mammal occurrence.
Horizontal displacement of +/¥10%
may be expected for instrument
movement due to the water depth and
forces from tides, currents, and storms.
Additional hydrophone mooring
systems may be deployed at additional
distances and/or depths. Following each
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successive conductor pipe installation,
the water depth and geographical
orientation of the hydrophone may be
changed to validate modeled SPLs at
varying water depths and direction.
• At a minimum, the following sound
data would be analyzed (post-processed)
from recorded sound levels: absolute
peak overpressure and under pressure
levels for each conductor pipe; average,
minimum, and maximum sound
pressure levels (rms), integrated from 3
Hz to 20 kHz; average duration of each
hammer strike (blow), and total number
of strikes per continuous hammer piledriving period for each conductor.
In the event that field measurements
indicate different sound pressure levels
(rms) values than those predicted by
modeling for either the maximum
distances of the buffer or exclusion
zones from the conductor sound source,
corresponding boundaries for the buffer
and appropriate exclusion zones would
be increased/decreased accordingly,
following NMFS notification,
concurrence, and authorization.
In-Air Monitoring—Reference
measurements would be made at
approximately 10 to 20 m (32.8 to 65.6
ft) from the initial hammer strike
position using a stationary microphone.
The microphone would be placed as far
away from other large sound sources as
practical. The in-air buffer zone
predicted for pinnipeds (non-harbor
seal, 100 dB re 20 mPa) was estimated
at 41 m (134.5 ft) from the hammer
impact point on the conductor pipe. Inair sound levels would be recorded at
several points around the base of the
Harmony Platform at sea level to
validate modeled sound levels.
Distances closer to the sound source
may be monitored for model validation
purposes, but only if safety issues are
not introduced. Recorded data would be
recorded as dB (re 20 mPa, A-weighted
and unweighted) for comparison to inair noise thresholds for Level B
harassment for pinnipeds.
Platform-Based Visual Monitoring
PSOs would be based aboard the
Harmony Platform and would watch for
marine mammals near the platform
during conductor pipe installation
activities during daytime and nighttime
pile-driving activities. Visual
monitoring for marine mammals would
be performed at a minimum during
periods of active hammer pile-driving
throughout the proposed project
following general procedures in Baker et
al. (2013). Monitoring by PSOs would
begin at least 30 minutes before the start
of impact hammer pile-driving,
continue through an estimated 2.5 to 3.3
hours of pile-driving, and conclude 30
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minutes after pile-driving stops (up to
4.3 hours of monitoring per a period of
pile-driving). Five to 7 periods of impact
hammer pile-driving would be required
for each conductor pipe. When feasible,
PSOs would conduct observations
during periods when the impact
hammer pile-driving is not operating for
comparison of sighting rates and
behavior with and without operations
and between pile-driving periods. In
addition to monitoring during piledriving activities, baseline monitoring of
marine mammals would be performed
up to one week before and one week
after conductor pipe installation, as well
as selected periods in between impact
hammer pile-driving activities.
The exclusion zone would be
monitored to prevent injury to marine
mammal species. Based on PSO
observations, the impact hammer piledriving would be shut-down when
marine mammals are observed within or
about to enter the designated exclusion
zone. The exclusion zone is a region in
which a possibility exists of adverse
effects on animal hearing or physical
effects. A comprehensive monitoring
plan would be developed to ensure
compliance with the IHA for this
proposed project.
Methods—There would be a team of
3 PSOs based aboard Harmony Platform
conducting monitoring during active
hammer pile-driving periods. Visual
observations would take place during
active hammering periods which
includes both daylight and nighttime
operations. This monitoring would
occur for approximately 4.3 hours (3.3
hour monitoring plus 0.5 hour pre- and
post-hammering) during a single
hammering phase followed by
approximately 6.3 hours of off-duty rest.
A total of 5 to 7 observation periods
corresponding to the driving of the pipe
segments would be anticipated for each
of the six conductors. It is possible that
an impact hammer pile-driving session
would take less than 3.3 hours and that
the ‘‘rest interval’’ for the visual
monitors separating driving segments
would be less than 6.3 hours. If driving
and rest intervals are reduced and
additional segments are added (e.g.,
seven instead of five), two alternating
teams of three PSOs may be required. At
the conclusion of impact hammer piledriving activities for a single conductor
pipe, PSOs may be transferred to shore
to await the next active pile-driving
phase.
PSOs would be placed at the best
practicable vantage point(s) (e.g., lower
platform level, upper platform level) to
monitor the applicable buffer and
exclusion zones for marine mammals.
The PSOs would have authority to
VerDate Mar<15>2010
19:01 Jun 27, 2014
Jkt 232001
implement shut-down/delay ramp-up
procedures, if applicable, by calling the
hammer operator for a shut-down via
radio communication. For the buffer
zone, two PSOs would be stationed on
an upper platform deck where they have
a clear view of the monitoring area.
They would be approximately 180
degrees apart and each would monitor
approximately one-half of the
corresponding buffer zone and beyond
with binoculars and other appropriate
equipment. For exclusion zone area, one
PSO would concurrently monitor the
applicable radii for pinnipeds and
cetaceans, respectively, from a lower
level observation post that provides a
clear view of the sea surface around the
actively driven conductor pipe. The
lower observation area would be
illuminated during nighttime
observations. Visual aids may be used
but would not be required, providing
the PSO has a clear view of the sea
surface with the naked eye. A non-PSO
safety spotter would also be assigned to
the lower deck observation area. The
safety spotter would be available to
deter errant California sea lions using
NMFS-recommended methods (see
below) (NMFS, 2008).
All personnel operating on the
Harmony Platform would be required to
receive required training and wear
appropriate personal protective
equipment. Personal protective
equipment is specific to the task,
location, and environmental conditions
(e.g., weather, operations risks). It
includes items such as floatation vests,
hard hats, steel-toed shoes, gloves, fireresistant clothing, gear, eye protection,
and other protective equipment. Details
on specific personal protective
equipment items required for PSO and
acoustic monitoring would be
determined via the regular work risk
assessment process, and would be
presented in the associated monitoring
plans for the project.
Equipment for monitoring would
include hearing protection from where
observations are made from high noise
areas of the platform, marine radios
with headsets, time keeping device (e.g.,
watch or cell phone), day and night
range finding binoculars (7 x 50 or
greater), notebooks with standardized
recording forms, species identification
guides, and a project-specific
monitoring plan approved by NMFS (to
be submitted separately).
PSO Qualifications—Monitoring
would be conducted by qualified PSOs
defined in Baker et al. (2013) and
approved by NMFS. PSOs dedicated to
the proposed project would have no
other activity-related tasks.
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Frm 00041
Fmt 4703
Sfmt 4703
36759
PSO Data and Documentation
PSOs would record data to estimate
the numbers of marine mammals
exposed to various received sound
levels and to document apparent
disturbance reactions or lack thereof.
Data would be used to estimate numbers
of animals potentially ‘‘taken’’ by
harassment (as defined in the MMPA).
They would also provide information
needed to order a shut-down of the
impact hammer when a marine mammal
is within or near the exclusion zone.
Visual observations would also be made
during pile-driving activities as well as
daytime periods from the Harmony
Platform when the regular operations
would be underway without piledriving activities to collect baseline
biological data.
When a sighting is made, the
following information about the sighting
would be recorded:
1. Species, group size, age/size/sex
categories (if determinable), behavior
when first sighted and after initial
sighting, heading (if consistent), bearing
and distance from platform, sighting
cue, apparent reaction to the sound
source (e.g., none, avoidance, approach,
paralleling, etc., and including
responses to ramp-up), speed of travel,
and duration of presence.
2. Date, time, location, heading,
speed, activity of the conductor pipe
installation activities, weather
conditions, Beaufort sea state and wind
force, visibility, and sun glare.
The data listed under (2) would also
be recorded at the start and end of each
observation watch, and during a watch
whenever there is a change in one or
more of the variables.
All observations, as well as
information regarding ramp-ups or shutdowns would be recorded in a
standardized format.
Results from the platform-based
visual observations would provide the
following information:
1. The basis for real-time mitigation
(impact hammer shut-down).
2. Information needed to estimate the
number of marine mammals potentially
taken by harassment, which must be
reported to NMFS.
3. Data on the occurrence,
distribution, and activities of marine
mammals in the area where the
conductor pipe installation activities are
conducted.
4. Information to compare the
distance and distribution of marine
mammals relative to the source platform
at times with and without pile-driving
activities.
5. Data on the behavior and
movement patterns of marine mammals
E:\FR\FM\30JNN1.SGM
30JNN1
36760
Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
seen at times with and without piledriving activities.
mstockstill on DSK4VPTVN1PROD with NOTICES
Proposed Reporting
ExxonMobil would submit a
comprehensive report to NMFS within
90 days after the end of the conductor
pipe installation activities and the
expiration of the IHA (if issued). The
report would describe the proposed
pile-driving activities that were
conducted and sightings of marine
mammals near the operations. The
report submitted to NMFS would
provide full documentation of methods,
results, and interpretation pertaining to
all monitoring. The 90-day report would
summarize the dates and location of
impact hammer pile-driving activities
and all marine mammal sightings (i.e.,
dates, times, locations, activities, and
associated seismic survey activities).
The report would minimally include:
• Summaries of monitoring effort—
total hours, total distances, and
distribution of marine mammals
through the activity period accounting
for Beaufort sea state and other factors
affecting visibility and detectability of
marine mammals;
• Analyses of the effects of various
factors influencing detectability of
marine mammals including Beaufort sea
state, number of PSOs, and fog/glare;
• Species composition, occurrence,
and distribution of marine mammals
sightings including date, water depth,
numbers, age/size/gender, and group
sizes; and analyses of the effects of
activities;
• Sighting rates of marine mammals
during periods with and without impact
hammer pile-driving activities (and
other variables that could affect
detectability);
• Initial sighting distances versus
operational activity state;
• Closest point of approach versus
operational activity state;
• Observed behaviors and types of
movements versus operational activity
state;
• Numbers of sightings/individuals
seen versus operational activity state;
and
• Distribution around the platform
versus operational activity state.
The report would also include estimates
of the number and nature of exposures
that could result in ‘‘takes’’ of marine
mammals by harassment or in other
ways (based on presence in the buffer
and/or exclusion zones). After the report
VerDate Mar<15>2010
19:01 Jun 27, 2014
Jkt 232001
is considered final, it would be publicly
available on the NMFS Web site at:
https://www.nmfs.noaa.gov/pr/permits/
incidental.htm#iha.
Reporting Prohibited Take—In the
unanticipated event that the specified
activity clearly causes the take of a
marine mammal in a manner prohibited
by this IHA, such as an injury (Level A
harassment), serious injury, or mortality
(e.g., ship-strike, gear interaction, and/or
entanglement), ExxonMobil would
immediately cease the specified
activities and immediately report the
incident to the Chief of the Permits and
Conservation Division, Office of
Protected Resources, NMFS at 301–427–
8401 and/or by email to Jolie.Harrison@
noaa.gov and Howard.Goldstein@
noaa.gov and the West Coast Regional
Stranding Coordinator (Justin.Greenman
@noaa.gov). The report must include the
following information:
• Time, date, and location (latitude/
longitude) of the incident;
• Type of activity involved;
• Description of the circumstances
during and leading up to the incident;
• Status of all sound source use in the
24 hours preceding the incident;
• Water depth;
• Environmental conditions (e.g.,
wind speed and direction, Beaufort sea
state, cloud cover, and visibility);
• Description of all marine mammal
observations in the 24 hours preceding
the incident;
• Species identification or
description of the animal(s) involved;
• Fate of the animal(s); and
• Photographs or video footage of the
animal(s) (if equipment is available).
Activities shall not resume until
NMFS is able to review the
circumstances of the prohibited take.
NMFS shall work with ExxonMobil to
determine what is necessary to
minimize the likelihood of further
prohibited take and ensure MMPA
compliance. ExxonMobil may not
resume their activities until notified by
NMFS via letter or email, or telephone.
Reporting an Injured or Dead Marine
Mammal with an Unknown Cause of
Death—In the event that ExxonMobil
discovers an injured or dead marine
mammal, and the lead PSO determines
that the cause of the injury or death is
unknown and the death is relatively
recent (i.e., in less than a moderate state
of decomposition as described in the
next paragraph), ExxonMobil would
immediately report the incident to the
PO 00000
Frm 00042
Fmt 4703
Sfmt 4703
Chief of the Permits and Conservation
Division, Office of Protected Resources,
NMFS, at 301–427–8401, and/or by
email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov, and the
NMFS West Coast Regional Office (1–
866–767–6114) and/or by email to the
West Coast Regional Stranding
Coordinator (Justin.Greenman@
noaa.gov). The report must include the
same information identified in the
paragraph above. Activities may
continue while NMFS reviews the
circumstances of the incident. NMFS
would work with ExxonMobil to
determine whether modifications to the
activities are appropriate.
Reporting an Injured or Dead Marine
Mammal Not Related to the Activities—
In the event that ExxonMobil discovers
an injured or dead marine mammal, and
the lead PSO determines that the injury
or death is not associated with or related
to the activities authorized in the IHA
(e.g., previously wounded animal,
carcass with moderate or advanced
decomposition, or scavenger damage),
ExxonMobil would report the incident
to the Chief of the Permits and
Conservation Division, Office of
Protected Resources, NMFS, at 301–
427–8401, and/or by email to Jolie.
Harrison@noaa.gov and Howard.
Goldstein@noaa.gov, and the NMFS
West coast Regional Office (1–866–767–
6114) and/or by email to the West Coast
Regional Stranding Coordinator (Justin.
Greenman@noaa.gov), within 24 hours
of discovery. ExxonMobil would
provide photographs or video footage (if
available) or other documentation of the
stranded animal sighting to NMFS and
the Marine Mammal Stranding Network.
Activities may continue while NMFS
reviews the circumstances of the
incident.
Estimated Take by Incidental
Harassment
Except with respect to certain
activities not pertinent here, the MMPA
defines ‘‘harassment’’ as: any act of
pursuit, torment, or annoyance which (i)
has the potential to injure a marine
mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has
the potential to disturb a marine
mammal or marine mammal stock in the
wild by causing disruption of behavioral
patterns, including, but not limited to,
migration, breathing, nursing, breeding,
feeding, or sheltering [Level B
harassment].
E:\FR\FM\30JNN1.SGM
30JNN1
Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
36761
TABLE 4—NMFS’S CURRENT UNDERWATER AND IN-AIR ACOUSTIC EXPOSURE CRITERIA
Criterion
Criterion definition
Threshold
Impulsive (Non-Explosive) Sound
Level A harassment (injury)
Permanent threshold shift (PTS) (Any level above that
which is known to cause TTS).
Level B harassment .............
Level B harassment .............
Behavioral disruption (for impulsive noise) .....................
Behavioral disruption (for continuous noise) ..................
180 dB re 1 μPa-m (root means square [rms])
(cetaceans)
190 dB re 1 μPa-m (rms) (pinnipeds).
160 dB re 1 μPa-m (rms).
120 dB re 1 μPa-m (rms).
In-Air Sound
mstockstill on DSK4VPTVN1PROD with NOTICES
Level A harassment .............
Level B harassment .............
NA ...................................................................................
Behavioral disruption .......................................................
Level B harassment is anticipated and
proposed to be authorized as a result of
the proposed conductor pipe
installation activities at the Harmony
Platform in the Santa Barbara Channel
offshore of California. Acoustic stimuli
(i.e., increased underwater and in-air
sound) generated during the pile-driving
activities are expected to result in the
behavioral disturbance of some marine
mammals. There is no evidence that the
planned activities could result in injury,
serious injury, or mortality for which
ExxonMobil seeks the IHA. The
required mitigation and monitoring
measures would minimize any potential
risk for injury, serious injury, or
mortality.
The following sections describe
ExxonMobil’s methods to estimate take
by incidental harassment and present
the applicant’s estimates of the numbers
of marine mammals that could be
affected during the proposed conductor
pipe installation activities at the
Harmony Platform in the Santa Barbara
Channel offshore of California. The
estimated takes were calculated using
information on sound source levels,
sound propagation, maximum distances
from the sound source to Level A and
Level B harassment exposure
thresholds, and estimated density of
marine mammals in the action area.
Take estimates were calculated for inwater (cetaceans and pinnipeds) and inair (pinnipeds only). The estimates are
based on the following information:
• Thresholds for marine mammals to
in-water and in-air noise;
• Sound levels at the conductor pipe
from hammer strike;
• Sound propagation (transmission/
spreading loss) through the environment
(i.e., air, water);
• Maximum distances from the sound
sources to the corresponding impact
zones (based on Level A and Level B
harassment thresholds) for marine
mammals;
VerDate Mar<15>2010
19:01 Jun 27, 2014
Jkt 232001
NA.
90 dB re 20 μPa (harbor seals).
100 dB re 20 μPa (all other pinniped species).
NA (cetaceans).
• Density estimate for each species of
marine mammals (calculated as stock
abundance divided by 12,592 km2
[3,671.2 nmi2] area [except where
noted]); and
• Number of takes for each species of
marine mammals within a group
(calculated as density multiplied by
buffer/exclusion zone multiplied by
days of activity).
Sound levels for impulsive (impact)
pile-driving by the hammer and
propagation through water and in-air at
the Harmony Platform were modeled by
JASCO Applied Sciences, Ltd. The
modeling results are presented in
JASCO’s acoustic modeling report as an
addendum to the IHA application titled
‘‘Assessment of Airborne and
Underwater Noise from Pile Driving
Activities at the Harmony Platform.’’
Methods used to estimate marine
mammal densities and takes for the
proposed action area in the Santa
Barbara Channel are presented in
Sections 6.1.5 and 6.1.6 of the IHA
application for likely exposures to
species of marine mammals.
Densities of marine mammal species
likely to occur in the proposed action
area of the Santa Barbara Channel were
taken directly from scientific literature
or calculated using corresponding
abundances in NMFS Stock Assessment
Reports. Density estimates for the blue,
fin, and humpback whale were taken
directly from Redfern et al. (2013), using
the upper limit reported for the density
contour that includes the Harmony
Platform. Redfern et al. (2013) estimated
densities for these three species using
NMFS sightings collected from
primarily August through November
over a period from 1991 to 2009
throughout the Santa Barbara Channel.
Results for blue, fin, and humpback
whales are presented in Figures 6–3, 6–
4, and 6–5 of the IHA application. These
densities are considered more accurate
than those based on reported stock
PO 00000
Frm 00043
Fmt 4703
Sfmt 4703
abundances because even though they
are for the same monthly period and
geographical location, they include a
correction factor to correct for nonobservational periods. For calculated
densities of likely affected marine
mammal species, stock abundances,
which generally range from the state of
Washington to northern Baja California,
Mexico, were assumed to be
concentrated within the 12,593 km2
(3,671.5 nmi2) proposed action area in
the Santa Barbara Channel. The
proposed action area includes the
Harmony Platform, and extends 18 km
(9.7 nmi) to the north, 60 km (32.4 nmi)
to the west, and 70 km (37.8 nmi) to the
south of Point Conception, California.
The eastern boundary is 35 km (18.9
nmi) east of Anacapa Island. Use of this
area produces a conservative density
estimate because the geographical range
of each marine mammal species
evaluated is much greater than 70 km
(nmi) of the coastline selected to
represent the proposed action area,
including season-specific ranges for
species that migrate (e.g., gray whale).
For marine mammal species potentially
exposed to in-air noise, pinniped
densities were calculated by dividing
the stock abundance for each marine
mammal species by the 1,130 m2
(12,163.2 ft2) impact area of the
Harmony Platform near sea level where
the animals could potentially haul-out
and/or have their heads out of the water.
Tables 6–7 and 6–8 of the IHA
application describe the calculated
densities and estimated take by marine
mammal species as well as associated
data for the in-water and in-air sound
thresholds, respectively. Although there
is some uncertainty about the
representativeness of the data and the
assumptions used in the calculations
below, the approach used here is
believed to be the best available
approach.
E:\FR\FM\30JNN1.SGM
30JNN1
36762
Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
TABLE 5—ESTIMATED DENSITIES AND POSSIBLE NUMBER OF MARINE MAMMAL SPECIES THAT MIGHT BE EXPOSED TO
GREATER THAN OR EQUAL TO 160 DB (PILE-DRIVING ACTIVITIES) DURING EXXONMOBIL’S PROPOSED CONDUCTOR
PIPE INSTALLATION ACTIVITIES IN THE SANTA BARBARA CHANNEL OFFSHORE OF CALIFORNIA
Density in
action area
(#/km2) 1
Calculated
take from piledriving activities in-water
(i.e., estimated
number of
individuals
exposed to
sound levels
≥160 dB re 1
μPa) 2
Calculated take
from pile-driving
activities in-air
(i.e., estimated
number of
individuals
exposed to
sound levels ≥90
dB re 20 μPa for
harbor seals and
90 dB re 20 μPa
for all other
pinnipeds) 3
Total requested
take
authorization4
NA
0
0
0
Gray whale ...............
0.5067
0.693
0
10
Humpback whale .....
0.0055
0.007
0
1
Minke whale .............
0.04
0.055
0
1
Bryde’s whale ...........
Sei whale .................
NA
0.01
0
0.014
0
0
0
1
Fin whale ..................
0.004
0.005
0
1
Blue whale ...............
0.008
0.011
0
1
Odontocetes:
Sperm whale ............
0.08
0.109
0
1
Pygmy sperm whale
0.05
0.068
0
1
Dwarf sperm whale ..
Baird’s beaked whale
NA
0.07
0
0.096
0
0
0
1
Cuvier’s beaked
whale.
Mesoplodon beaked
whale.
Killer whale ...............
0.17
0.233
0
1
0.08
0.109
0
1
0.05
0.068
0
1
Species
Mysticetes:
North Pacific right
whale.
0.06
0.082
0
1
0.11
0.151
0
10
Striped dolphin .........
mstockstill on DSK4VPTVN1PROD with NOTICES
Short-finned pilot
whale.
Bottlenose dolphin ...
0.87
1.191
0
20
Short-beaked common dolphin.
Long-beaked common dolphin.
Pacific white-sided
dolphin.
Northern right whale
dolphin.
Risso’s dolphin .........
32.65
44.691
0
45
8.5
11.635
0
120
2.14
2.929
0
30
0.66
0.903
0
1
0.5
0.684
0
10
Dall’s porpoise .........
3.34
4.572
0
50
Harbor porpoise .......
Pinnipeds:
California sea lion ....
0
0
0
0
23.6
32.249
0
33
VerDate Mar<15>2010
19:01 Jun 27, 2014
Jkt 232001
PO 00000
Frm 00044
Fmt 4703
Sfmt 4703
Approximate
percentage of
population/
stock
estimate 6
Abundance 5
NA (18 to 21)—Eastern North Pacific
stock.
19,126 (18,107)—
Eastern North Pacific stock.
155 (142)—Western
North Pacific population.
1,918 (1,876)—CA/
OR/WA stock.
478 (202)—CA/OR/
WA stock.
NA ...............................
126 (83)—Eastern
North Pacific stock.
3,051 (2,598)—CA/
OR/WA stock.
1,647 (1,551)—Eastern North Pacific
stock.
971 (751)—CA/OR/
WA stock.
579 (271)—CA/OR/
WA stock.
NA—CA/OR/WA stock
847 (466)—CA/OR/
WA stock.
6,950 (4,481)—CA/
OR/WA stock.
694 (389)—CA/OR/
WA stock.
240 (162)—Eastern
North Pacific stock.
346 (346)—Eastern
North Pacific Transient stock.
354 (354)—West
Coast Transient
stock.
760 (465)—CA/OR/
WA stock.
1,006 (684)—CA/OR/
WA stock.
NA
NA.
0.05
Increasing over past
several decades—
Eastern North Pacific stock.
0.05
Increasing.
0.2
NA.
NA
0.8
NA.
NA.
0.03
Increasing.
0.06
NA.
0.1
NA.
0.17
NA.
NA
0.12
NA.
NA.
0.01
Declining off CA/OR/
WA.
Declining off CA/OR/
WA.
NA—Eastern North
Pacific Offshore
stock; NA—Eastern
North Pacific Transient stock; Increasing—West Coast
Transient stock.
0.14
0.42/0.29/0.28
0.13
0.1
10,908 (8,231)—CA/
OR/WA stock.
411,211 (343,990)—
CA/OR/WA stock.
107,016 (76,224)—CA
stock.
26,930 (21,406)—CA/
OR/WA stock.
8,334 (6,019)—CA/
OR/WA stock.
6,272 (4,913)—CA/
OR/WA stock.
42,000 (32,106)—CA/
OR/WA stock.
NA ...............................
0.18
296,750 (153,337)—
U.S. stock.
0.01
E:\FR\FM\30JNN1.SGM
Population trend 5
30JNN1
0.01
NA.
NA—CA/OR/WA Offshore stock; NA—
CA Coastal stock.
NA.
0.11
Varies with oceanographic conditions.
Increasing over last 30
years.
NA.
0.01
NA.
0.16
NA.
0.12
NA.
NA
NA.
0.11
Increasing.
36763
Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
TABLE 5—ESTIMATED DENSITIES AND POSSIBLE NUMBER OF MARINE MAMMAL SPECIES THAT MIGHT BE EXPOSED TO
GREATER THAN OR EQUAL TO 160 DB (PILE-DRIVING ACTIVITIES) DURING EXXONMOBIL’S PROPOSED CONDUCTOR
PIPE INSTALLATION ACTIVITIES IN THE SANTA BARBARA CHANNEL OFFSHORE OF CALIFORNIA—Continued
Density in
action area
(#/km2) 1
Calculated
take from piledriving activities in-water
(i.e., estimated
number of
individuals
exposed to
sound levels
≥160 dB re 1
μPa) 2
Calculated take
from pile-driving
activities in-air
(i.e., estimated
number of
individuals
exposed to
sound levels ≥90
dB re 20 μPa for
harbor seals and
90 dB re 20 μPa
for all other
pinnipeds) 3
Total requested
take
authorization4
Steller sea lion .........
NA
0
0
0
Pacific harbor seal ...
2.4
3.285
0.011
4
Northern elephant
seal.
Northern fur seal ......
9.85
13.483
0
14
0.79
1.081
0
2
Guadalupe fur seal ..
NA
0
0
0
Species
Approximate
percentage of
population/
stock
estimate 6
Abundance 5
49,685 (42,366)—
Western stock.
58,334 (72,223)—
Eastern stock.
30,196 (26,667)—CA
stock.
124,000 (74,913)—CA
breeding stock.
12,844 (6,722)—California stock.
7,408 (3,028)—Mexico
to CA stock.
NA
0.01
0.01
0.02
NA
Population trend 5
Declining—Western
stock; Increasing—
Eastern stock; Declining in CA.
Increased 1981 to
2004.
Increasing through
2005.
Increasing.
Increasing.
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NA = Not available or not assessed.
1 Proposed action area (12,593 km2) in the Santa Barbara Channel off the coast of California.
2 Calculated take is the estimated number of animals in the in-water ensonified buffer zone multiplied by the number of days.
3 Calculated take is the estimated number of animals in the in-air ensonified buffer zone multiplied by the number of days.
4 Requested Take Authorization includes calculated takes for animals in the ensonified in-water and in-air buffer zones.
5 NMFS Marine Mammal Stock Assessment Reports.
6 Total requested (and calculated) takes expressed as percentages of the species or stock.
Numbers of marine mammals that
might be present and potentially
disturbed are estimated based on the
available data about marine mammal
distribution and densities in the
proposed Santa Barbara Channel action
area. ExxonMobil estimated the number
of different individuals of marine
mammal species that may be exposed to
in-water and in-air sounds with
received levels greater than or equal to
160 dB re 1 mPa (rms) and in-air sounds
with received levels greater than or
equal to 90 dB re 20 mPa (rms) (for
harbor seals)/100 dB re 20 mPa (rms) (for
all other pinniped species) for impact
hammer pile-driving activities on one or
more occasions by considering the total
marine area that would be within the
160 dB in-water radius and 90 dB (for
harbor seals)/100 dB (for all other
pinniped species) in-air radius around
the impact hammer pile-driving on at
least one occasion and the expected
density of marine mammals in the area
(in the absence of the conductor pipe
installation activities). The number of
possible exposures can be estimated by
considering the total marine area that
would be within the in-water 160 dB
radius and in-air 90 dB (for harbor
seals)/100 dB (for all other pinniped
species) radius around the impact
hammer pile-driving activities. The inwater 160 dB and in-air 90 dB (harbor
seal)/100 dB (for all other pinniped
species) radii are based on acoustic
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modeling data for the impact hammer
pile-driving activities that may be used
during the proposed action (see of the
addendum to the IHA application). It is
unlikely that a particular animal would
stay in the area during the entire impact
hammer pile-driving activities.
The number of different individuals
potentially exposed to received levels
greater than or equal to 160 dB re 1 mPa
(rms) for in-water noise and 90 dB re 20
mPa (rms) (for harbor seals)/100 dB re 20
mPa (rms) (for all other pinniped
species) for in-air noise from impact
hammer pile-driving activities was
calculated by multiplying:
(1) The expected species density (in
number/km2), times
(2) The anticipated area to be
ensonified to that level during
conductor pipe installation (buffer zone
= p x [maximum distance]2), times
(3) The number of days of the
conductor pipe installation activities.
Applying the approach described
above, approximately 0.3318 km2 would
be ensonified within the in-water 160
dB isopleth and approximately 0.0053
km2/0.0475 km2 would be ensonified
within the in-air 90 dB (harbor seals)/
100 dB (for all other pinniped species)
isopleths for impact hammer piledriving activities (assuming
omnidirectional spreading of sound
from the conductor pipe) during the
proposed conductor pipe installation
activities. The take calculations within
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the proposed action area account for
animals in the initial density snapshot
and account for new (i.e., turnover) or
previously exposed animals over an
approximate 4-day period that approach
and enter the area ensonified above or
equal to the 160 dB isopleth for in-water
noise and 90/100 dB isopleth for in-air
noise from the impact hammer piledriving activities; however, studies
suggest that many marine mammals
would avoid exposing themselves to
sounds at these level, which suggests
that there would not necessarily be a
large number of new animals entering
the proposed action area once the
conductor pipe installation activities
started. Also, the approach assumes that
no cetaceans or pinnipeds would move
away or toward the Harmony Platform.
The take estimates represent the number
of individuals that are expected (in
absence of a conductor pipe installation
activities) to occur over an approximate
4-day period of time in the waters that
would be exposed to greater than or
equal to 160 dB (rms) in-water and
greater than or equal to 90/100 dB (rms)
in-air for impact hammer pile-driving
activities.
ExxonMobil’s estimates of exposures
to various sound levels assume that the
proposed activities would be carried out
in full. The estimates of the numbers of
marine mammals potentially exposed to
160 dB (rms) for in-water noise and 90
dB re 20 mPa (rms) (for harbor seals)/100
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dB re 20 mPa (rms) (for all other
pinniped species) for in-air noise
received levels are precautionary and
probably overestimate the actual
numbers of marine mammals that could
be involved. These estimates include
standard contingencies for weather,
equipment, or mitigation delays in the
time planned for the proposed activities.
Table 5 shows the estimates of the
number of different individual marine
mammals anticipated to be exposed to
greater than or equal to 160 dB re 1 mPa
(rms) for the conductor pipe installation
activities if no animals moved away
from the Harmony Platform. No takes by
Level A harassment have been
requested. The total requested take
authorization is given in the fifth
column of Table 5.
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Encouraging and Coordinating
Research
ExxonMobil would coordinate the
planned marine mammal monitoring
program associated with the proposed
conductor pipe installation activities
with researchers and other parties that
express interest in this activity, area,
and anthropogenic sound effects on
marine mammals. ExxonMobil would
coordinate with applicable U.S.
agencies (e.g., NMFS), and would
comply with their requirements.
ExxonMobil supports research on
marine mammals and sound in the
environment through academic,
industry, and private sector
collaborations. ExxonMobil is a
founding member and largest
contributor to the Sound and Marine
Life Joint Industry Program (JIP) through
the International Oil and Gas Producers
(OGP), and the International Association
of Geophysical Contractors (IAGC).
Through JIP and other venues,
ExxonMobil provides annual funding
and support for fundamental and
applied scientific research to better
understand the effects of anthropogenic
sound on marine life. ExxonMobil also
conducts internal research and
monitoring programs specific to sound
effects from exploration and production
activities. These efforts have helped
produce effective mitigation strategies
and techniques to reduce potential
sound effects on marine mammals from
their operations and those from the oil
and gas industry as a whole. More
information on selected examples of
ExxonMobil’s involvement and
contributions to scientific research on
marine mammals and sound can be
found in section 14 of the IHA
application.
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Impact on Availability of Affected
Species or Stock for Taking for
Subsistence Uses
Section 101(a)(5)(D) of the MMPA
also requires NMFS to determine that
the authorization would not have an
unmitigable adverse effect on the
availability of marine mammal species
or stocks for subsistence use. There are
no relevant subsistence uses of marine
mammals implicated by this action.
Therefore, NMFS has determined that
the total taking of affected species or
stocks would not have an unmitigable
adverse impact on the availability of
such species or stocks for taking for
subsistence purposes.
Analysis and Preliminary
Determinations
Negligible Impact
Negligible impact is ‘‘an impact
resulting from the specified activity that
cannot be reasonably expected to, and is
not reasonably likely to, adversely affect
the species or stock through effects on
annual rates of recruitment or survival’’
(50 CFR 216.103). A negligible impact
finding is based on the lack of likely
adverse effects on annual rates of
recruitment or survival (i.e., populationlevel effects). An estimate of the number
of Level B harassment takes, alone, is
not enough information on which to
base an impact determination. In
addition to considering estimates of the
number of marine mammals that might
be ‘‘taken’’ through behavioral
harassment, NMFS must consider other
factors such as the likely nature of any
responses (their intensity, duration,
etc.), the context of any responses
(critical reproductive time or location,
migration, etc.), as well as the number
and nature of estimated Level A
harassment takes, the number of
estimated mortalities, and effects on
habitat.
In making a negligible impact
determination, NMFS evaluated factors
such as:
(1) The number of anticipated
injuries, serious injuries, or mortalities;
(2) The number, nature, and intensity,
and duration of Level B harassment (all
relatively limited); and
(3) The context in which the takes
occur (i.e., impacts to areas of
significance, impacts to local
populations, and cumulative impacts
when taking into account successive/
contemporaneous actions when added
to baseline data);
(4) The status of stock or species of
marine mammals (i.e., depleted, not
depleted, decreasing, increasing, stable,
impact relative to the size of the
population);
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(5) Impacts on habitat affecting rates
of recruitment/survival; and
(6) The effectiveness of monitoring
and mitigation measures.
As described above and based on the
following factors, the specified activities
associated with the conductor pipe
installation activities are not likely to
cause PTS, or other non-auditory injury,
serious injury, or death. The factors
include:
(1) The likelihood that marine
mammals are expected to move away
from a noise source that is annoying
prior to its becoming potentially
injurious;
(2) The potential for temporary or
permanent hearing impairment is
relatively low and would likely be
avoided through the implementation of
the required monitoring and mitigation
(i.e., shut-down) measures;
(3) The fact that cetaceans and
pinnipeds would have to be closer than
10 m and 3.5 m, respectively, during
impact hammer pile-driving activities to
be exposed to levels of underwater
sound believed to have a minimal
chance of causing a permanent
threshold shift (PTS; i.e., Level A
harassment); and
(4) The likelihood that marine
mammal detection ability by trained
PSOs is high at close proximity to the
platform.
No injuries, serious injuries, or
mortalities are anticipated to occur as a
result of ExxonMobil’s planned
conductor pipe installation activities,
and none are proposed to be authorized
by NMFS. Table 5 of this document
outlines the number of requested Level
B harassment takes that are anticipated
as a result of these activities. NMFS’s
practice has been to apply the 160 dB
re 1 mPa (rms) received level threshold
for underwater impulse sound levels to
determine whether take by Level B
harassment occurs. Southall et al. (2007)
provide a severity scale for ranking
observed behavioral responses of both
free-ranging marine mammals and
laboratory subjects to various types of
anthropogenic sound (see Table 4 in
Southall et al. [2007]). Current NMFS
practice, regarding exposure of marine
mammals to high-level in-air sounds, as
a threshold for potential Level B
harassment, is at or above 90 dB re 20
mPa for habor seals and at or above 100
dB re 20 mPa for all other pinniped
species (Lawson et al., 2002; Southall et
al., 2007). NMFS has not determined
Level A harassment thresholds for
marine mammals for in-air noise.
As mentioned previously, NMFS
estimates that 30 species of marine
mammals under its jurisdiction could be
potentially affected by Level B
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harassment over the course of the IHA.
The population estimates for the marine
mammal species that may be taken by
Level B harassment were provided in
Table 3 and 5 of this document. Due to
the nature, degree, and context of Level
B (behavioral) harassment anticipated
and described (see ‘‘Potential Effects on
Marine Mammals’’ section above) in this
notice, the proposed activity is not
expected to impact rates of annual
recruitment or survival for any affected
species or stock, particularly given
NMFS’s and the applicant’s proposal to
implement mitigation, monitoring, and
reporting measures to minimize impacts
to marine mammals. Additionally, the
proposed conductor pipe installation
activities would not adversely impact
marine mammal habitat.
For the marine mammal species that
may occur within the proposed action
area, there are no known designated or
important feeding and/or reproductive
areas. Many animals perform vital
functions, such as feeding, resting,
traveling, and socializing, on a diel
cycle (i.e., 24 hr cycle). Behavioral
reactions to noise exposure (such as
disruption of critical life functions,
displacement, or avoidance of important
habitat) are more likely to be significant
if they last more than one diel cycle or
recur on subsequent days (Southall et
al., 2007). Potential impacts are not
likely to be significant from the
proposed pile-driving activities as the
use of the impact hammer would occur
over 30 intermittent intervals of 2.5 to
3.3 hours each for a combined total of
about 4 days spread out over a 91-day
period. Additionally, the conductor
pipe installation activities would be
increasing sound levels in the marine
environment in a relatively small area
surrounding the Harmony Platform
(compared to the range of the animals),
and some animals may only be exposed
to and harassed by sound for less than
a day.
Of the 36 marine mammal species
under NMFS jurisdiction that may or
are known to likely to occur in the
proposed action area, seven are listed as
threatened or endangered under the
ESA: North Pacific right, humpback, sei,
fin, blue, and sperm whale and
Guadalupe fur seal. These species are
also considered depleted under the
MMPA. Of these ESA-listed species,
incidental take has been requested to be
authorized for humpback, sei, fin, blue,
and sperm whales. There is generally
insufficient data to determine
population trends for the other depleted
species in the action area. To protect
these animals (and other marine
mammals in the action area),
ExxonMobil must cease impact hammer
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pile-driving activities if any marine
mammal enters designated exclusion
zones. No injury, serious injury, or
mortality is expected to occur and due
to the nature, degree, and context of the
Level B harassment anticipated, and the
activities are not expected to impact
rates of recruitment or survival.
NMFS has preliminarily determined,
provided that the aforementioned
mitigation and monitoring measures are
implemented, the impact of conducting
pile-driving activities in the Santa
Barbara Channel off the coast of
California, may result, at worst, in a
modification in behavior and/or lowlevel physiological effects (Level B
harassment) of certain species of marine
mammals.
Changes in diving/surfacing patterns,
habitat abandonment due to loss of
desirable acoustic environment, and
cessation of feeding or social interaction
are some of the significant behavioral
modifications that could potentially
occur as a result of the proposed
conductor pipe installation activities.
While behavioral modifications,
including temporarily vacating the area
during the impact hammer pile-driving
activities, may be made by these marine
mammal species to avoid the resultant
acoustic disturbance, the availability of
alternate areas within these areas for
species and the short and sporadic
duration of the conductor pipe
installation activities, have led NMFS to
preliminary determine that the taking by
Level B harassment from the specified
activity would have a negligible impact
on the affected species in the specified
geographic region. NMFS believes that
the length of the conductor pipe
installation activities (duration of
approximately 4 days total), the
requirement to implement mitigation
measures (e.g., shut-down of impact
hammer pile-driving activities), and the
inclusion of the monitoring and
reporting measures, would reduce the
amount and severity of the potential
impacts from the activity to the degree
that it would have a negligible impact
on the species or stocks in the proposed
action area. Based on the analysis
contained herein of the likely effects of
the specified activity on marine
mammals and their habitat, and taking
into consideration the implementation
of the proposed monitoring and
mitigation measures, NMFS
preliminarily finds that the total marine
mammal take from ExxonMobil’s
proposed conductor pipe installation
activities would have a negligible
impact on the affected marine mammal
species or stocks.
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36765
Small Numbers
The estimate of the number of
individual cetaceans and pinnipeds that
could be exposed to pile-driving sounds
with received levels greater than or
equal to 160 dB re 1 mPa (rms) for all
marine mammals for in-water sound
levels and at or above 90 dB re 20 mPa
for harbor seals and at or above 100 dB
re 20 mPa for all other pinniped species
for in-air sound levels during the
proposed conductor pipe installation
activities is in Table 5 of this document.
In total, 10 gray, 1 humpback, 1
minke, 1 sei, 1 fin, 1 blue, and 1 sperm
whale could be taken by Level B
harassment during the proposed seismic
survey, which would represent 0.05,
0.05, 0.2, 0.8, 0.03, 0.06, and 0.1% of the
stock populations, respectively. Some of
the cetaceans potentially taken by Level
B harassment are delphinids and
porpoises with estimates of 1 pygmy
sperm, 1 Baird’s beaked, 1 Cuvier’s
beaked 1 Mesoplodon spp. Beaked, 1
killer, and 1 short-finned pilot whale, 10
bottlenose, 20 striped, 45 short-beaked
common, 120 long-beaked common, 20
Pacific white-sided, 1 northern right
whale, and 10 Risso’s dolphin as well as
50 Dall’s porpoise, which would
represent 0.17, 0.12, 0.01, 0.14, 0.42/
0.29/0.28, 0.13, 0.1, 0.18, 0.01, 0.11,
0.11, 0.01, 0.16, and 0.12% of the
affected stock populations, respectively.
The pinnipeds that could potentially be
taken by Level B harassment are the
California sea lion, Pacific harbor and
northern elephant seal, and northern fur
seal with estimates of 33, 4, 14, and 2
individuals, which would represent
0.01, 0.01, 0.01, and 0.02% of the
affected stock populations, respectively.
NMFS has preliminary determined
that the requested take estimates
represent small numbers relative to the
affected species or stocks sizes (i.e., all
are less than 1%). Based on the analysis
contained herein of the likely effects of
the specified activity on marine
mammals and their habitat, and taking
into consideration the implementation
of the mitigation and monitoring
measures, NMFS preliminarily finds
that small numbers of marine mammals
would be taken relative to the
populations of the affected species or
stocks. See Table 5 for the requested
authorized take numbers of marine
mammals.
Endangered Species Act
Of the species of marine mammals
that may occur in the proposed action
area, several are listed as threatened or
endangered under the ESA, including
the North Pacific right, humpback, sei,
fin, blue, and sperm whale and
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Guadalupe fur seal. ExxonMobil did not
request take of endangered North Pacific
right whales or the Guadalupe fur seals
due to the low likelihood of
encountering this species during the
proposed pile-driving activities. NMFS’s
Office of Protected Resources, Permits
and Conservation Division, has initiated
formal consultation under section 7 of
the ESA with NMFS’s West Coast
Regional Office, Protected Resources
Division, to obtain a Biological Opinion
evaluating the effects of issuing the IHA
to ExxonMobil under section
101(a)(5)(D) of the MMPA on threatened
and endangered marine mammals and,
if appropriate, authorizing incidental
take. NMFS would conclude formal
section 7 consultation prior to making a
determination on whether or not to
issue the IHA. If the IHA is issued,
ExxonMobil, in addition to the
mitigation and monitoring requirements
included in the IHA, would be required
to comply with the Terms and
Conditions of the Incidental Take
Statement corresponding to NMFS’s
Biological Opinion issued to both
ExxonMobil and NMFS’s Office of
Protected Resources.
mstockstill on DSK4VPTVN1PROD with NOTICES
National Environmental Policy Act
To meet National Environmental
Policy Act (NEPA; 42 U.S.C. 4321 et
seq.) requirements, NMFS will conduct
a NEPA analysis to evaluate the effects
of authorizing the proposed take of
marine mammals prior to making a final
determination on the issuance of the
IHA. This notice, and referenced
documents, including the IHA
application provide the environmental
issues and information relevant to the
proposed conductor pipe installation
activities as well as those specific to
NMFS’s issuance of the IHA. NMFS’s
NEPA analysis will be completed prior
to the issuance or denial of this
proposed IHA.
Proposed Authorization
As a result of these preliminary
determinations, NMFS propose to issue
an IHA to ExxonMobil for conducting
the pipe installation activities at the
Harmony Platform in the Santa Barbara
Channel offshore of California, provided
the previously mentioned mitigation,
monitoring, and reporting requirements
are incorporated. The proposed IHA
language is provided below:
ExxonMobil Production Company,
P.O. Box 4358, Houston, Texas 77210–
4358, is hereby authorized under
section 101(a)(5)(D) of the Marine
Mammal Protection Act (MMPA) (16
U.S.C. 1371(a)(5)(D)), to harass small
numbers of marine mammals incidental
to conducting conductor pipe
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installation activities at the Harmony
Platform in the Santa Barbara Channel
off the coast of California:
1. This Authorization is valid from
August 15, 2014 through August 14,
2015.
2. This Authorization is valid only for
ExxonMobil’s activities associated with
conductor pipe installation activities
that shall occur in the following
specified geographic area:
In the Santa Barbara Channel offshore
of California, the Harmony Platform is
located at 34°22′35.906″ North,
120°10′04.486″ West. The water depth at
the action area is 366 m on the
continental slope below a relatively
steep descent, and 4.7 km from the shelf
break. The conductor pipe installation
activities would be conducted 10 km off
the California coast, between Point
Conception and the city of Santa
Barbara, in the U.S. Exclusive Economic
Zone, as specified in ExxonMobil’s
Incidental Harassment Authorization
application and addendum.
3. Species Authorized and Level of
Takes
(a) The incidental taking of marine
mammals, by Level B harassment only,
is limited to the following species in the
waters of the Pacific Ocean off the coast
of California:
(i) Mysticetes—see Table 5 (above) for
authorized species and take numbers.
(ii) Odontocetes—see Table 5 (above)
for authorized species and take
numbers.
(iii) Pinnipeds—see Table 5 (above)
for authorized species and take
numbers.
(iv) If any marine mammal species is
encountered during pile-driving
activities that is not listed in Table 2
(attached) for authorized taking and is
likely to be exposed to sound pressure
levels (SPLs) greater than or equal to
160 dB re 1 mPa (rms) for impulse
underwater noise from impact hammer
pile-driving and/or at or above 100 dB
re 20 mPa (rms) for all pinnipeds species
except harbor seals (which is at or above
90 dB re 20 mPa (rms) for in-air noise,
then ExxonMobil must shut-down the
operations to avoid take.
(b) The taking by injury (Level A
harassment), serious injury, or death of
any of the species listed in Condition
3(a) above and the taking of any kind of
any other species of marine mammal is
prohibited and may result in the
modification, suspension or revocation
of this IHA.
4. The methods authorized for taking
by Level B harassment are limited to the
following acoustic sources without an
amendment to this IHA:
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(a) Pile-driving using impact hammer
(i.e., installation);
5. The taking of any marine mammal
in a manner prohibited under this
Authorization must be reported
immediately to the Office of Protected
Resources, National Marine Fisheries
Service (NMFS), at 301–427–8401.
6. Mitigation and Monitoring
Requirements
ExxonMobil is required to implement
the following mitigation and monitoring
requirements when conducting the
specified activities to achieve the least
practicable impact on affected marine
mammal species or stocks:
(a) Establish a 160 dB re 1 mPa (rms)
buffer zone for cetaceans and pinnipeds
and a 180 dB re 1 mPa (rms) exclusion
zone for cetaceans and a 190 dB re 1 mPa
(rms) exclusion zone for pinnipeds for
in-water sounds before the conductor
pipe installation activities begin so that
underwater sounds associated with
operations no longer exceed levels that
are potentially harmful to marine
mammals. See Table 2 (above) for
distances and buffer and exclusion
zones.
(b) Utilize three, NMFS-qualified,
vessel-based Protected Species Observer
(PSO) to visually watch for and monitor
marine mammals near the impact
hammer source during daytime and
nighttime pile-driving activities. The
Harmony Platform’s crew shall also
assist in detecting marine mammals,
when practicable. PSOs shall be
stationed at the best practicable vantage
point(s) (on the lower platform level,
and upper platform level) of the
Harmony Platform to monitor the
applicable buffer and exclusion zone for
marine mammals during the conductor
pipe installation activities. For the
buffer zone, two PSOs shall be stationed
on the upper platform level. For the
exclusion zone, one PSO shall be
concurrently stationed on the lower
platform level. The lower platform level
shall be illuminated during nighttime
visual observations. PSOs shall have
access to reticle binoculars (7 x 50
Fujinon) and night-vision devices. PSO
shifts shall last no longer than 5 hours
at a time. PSOs shall also make
observations during daytime periods
when the pile-driving activities are not
occurring for comparison of animal
abundance and behavior, when feasible.
In addition to monitoring during piledriving activities, baseline monitoring
for marine mammals shall be performed
up to one week before and one week
after conductor pipe installation
activities, as well as selected periods in
between impact hammer pile-driving
activities.
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(c) A PSO shall record the following
information when a marine mammal is
sighted:
(i) Species, group size, age/size/sex
categories (if determinable), behavior
when first sighted and after initial
sighting, heading (if consistent), bearing
and distance from platform, sighting
cue, apparent reaction to the conductor
pipe installation activities (e.g., none,
avoidance, approach, paralleling, etc.,
and including responses to ramp-up),
speed of travel, and duration of
presence; and
(ii) Date, time, location, activity of the
conductor pipe installation activities
(including whether in state of ramp-up
or shut-down), monitoring and
mitigation measures implemented (or
not implemented), weather conditions,
Beaufort sea state and wind force,
visibility, and sun glare; and
(iii) The data listed under Condition
6(c)(ii) shall also be recorded at the start
and end of each observation watch, and
during a watch whenever there is a
change in one or more of the variables.
(iv.) If inclement weather conditions
(i.e., fog, rain, or rough Beaufort sea
state) limits or impairs the PSO’s
visibility of the water’s surface to less
than 30.5 m (100 ft) within the action
area, then all noise-generating
conductor pipe installation activities
shall be stopped until visibility
improves.
(d) Visually observe the entire extent
of the in-water buffer zone (160 dB re
1 mPa [rms]) for cetaceans and pinnipeds
and in-water exclusion zone (180 dB re
1 mPa [rms] for cetaceans and 190 dB re
1 mPa [rms] for pinnipeds as well as the
in-air buffer zone for harbor seals (90 dB
re 20 mPa) and for all other pinnipeds
(100 dB re 20 mPa); see Table 2 [above]
for distances) using NMFS-qualified
PSOs, for at least 30 minutes prior to
starting the impact hammer (day or
night). If the PSO finds a marine
mammal within the exclusion zone,
ExxonMobil must delay the pile-driving
activities until the marine mammal(s)
has left the area. If the PSO sees a
marine mammal that surfaces, then
dives below the surface, the PSO shall
wait 30 minutes. If the PSO sees no
marine mammals during that time, they
should assume that the animal has
moved beyond the exclusion zone. If for
any reason the entire exclusion zone
radius cannot be seen for the entire 30
minutes (i.e., rough seas, fog, darkness),
or if marine mammals are near,
approaching, or in the exclusion zone,
the impact hammer may not be rampedup.
(e) Implement a ‘‘ramp-up’’ procedure
when starting up at the beginning of
pile-driving activities, which means
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starting with an initial set of three
strikes from the impact hammer at 40%
energy, followed by a 30 second waiting
period, then two subsequent three strike
sets. During ramp-up, the PSOs shall
monitor the exclusion zone, and if
marine mammals are sighted, a shutdown shall be implemented. Therefore,
initiation of ramp-up procedures from
shut-down requires that the PSOs be
able to view the full exclusion zone as
described in Condition 6(a) (above).
(f) Shut-down the pile-driving
activities if a marine mammal is
detected approaching, about to enter, or
located within the relevant exclusion
zone (as defined in Table 2, above). A
shut-down means all operating impact
hammers are shut-down (i.e., turned
off). If any marine mammal is sighted
within the relevant exclusion zone prior
to pile-driving activities, the hammer
operator (or other authorized
individual) shall delay conductor pipe
installation activities until the animal
has moved outside the exclusion zone
or the animal is not resighted within for
15 minutes for species with shorter dive
durations (small odontocetes and
pinnipeds) or 30 minutes for species
with longer dive durations (mysticetes
and large odontocetes, including sperm,
pygmy and dwarf sperm, killer, and
beaked whales).
(g) Following a shut-down, the
conductor pipe installation activities
shall not resume until the PSO has
visually observed the marine mammal(s)
exiting the exclusion zone and is not
likely to return, or has not been seen
within the exclusion zone for 15
minutes for species with shorter dive
durations (small odontocetes and
pinnipeds) or 30 minutes for species
with longer dive durations (mysticetes
and large odontocetes, including sperm,
pygmy and dwarf sperm, killer, and
beaked whales).
(h) Following a shut-down and
subsequent animal departure, conductor
pipe installation activities may resume
following ramp-up procedures
described in Condition 6(e).
(i) To facilitate visual monitoring
during non-daylight hours, the
exclusion zones shall be illuminated by
lights to allow for more effective
viewing of the area by the PSO on-duty.
(j) In-Water Monitoring—Acoustic
monitoring shall be performed at a
minimum of two fixed stations located
at 10 m and approximately 325 m from
the conductor pipe sound source. The
following general approach shall be
used to measure in-water sound levels:
(k) Acoustic monitoring shall be
conducted over the entire pile-driving
period for each conductor pipe, starting
approximately 1 hour prior to pile-
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36767
driving through 1 hour after impact
hammering has stopped. Pre- and posthammer pile-driving data shall be used
to determine ambient/background noise
levels.
(i) A stationary hydrophone system
with the ability to measure and record
sound pressure levels (SPL) shall be
deployed at a minimum of two
monitoring locations. SPLs shall be
recorded in voltage, converted to
microPascals (mPa), and post-processed
to decibels (dB [re 1 mPa]). For the first
conductor pipe installation,
hydrophones shall be placed at 10±1 m
and at 325±33 m from the conductor
pipe at depths ranging from 10 to 30 m
below the water surface to avoid
potential interferences for surface water
energy, and to target the depth range of
maximum occurrence of marine
mammal most likely in the area during
the project. If necessary, additional
hydrophone mooring systems shall be
deployed at additional distances and/or
depths. Following each successive
conductor pipe installation, the water
depth and geographical orientation of
the hydrophone may be changed to
validate modeled SPLs at varying water
depths and direction.
(ii) At a minimum, the following
sound data shall be analyzed (postprocessed) from recorded sound levels:
Absolute peak overpressure and under
pressure levels for each conductor pipe;
average, minimum, and maximum
sound pressure levels (rms), integrated
from 3 Hz to 20 kHz; average duration
of each hammer strike, and total number
of strikes per continuous hammer piledriving period for each conductor pipe.
(iii) In the event that field
measurements indicate different SPL
(rms) values than those predicted by
modeling for either the maximum
distances of the buffer or exclusion
zones from the sound source,
corresponding boundaries for the buffer
and exclusion zones shall be increased/
decreased accordingly, following NMFS
notification and concurrence.
(l) In-Air Monitoring—Reference
measurements shall be made
approximately 10 to 20 m from the
initial hammer strike position using a
stationary microphone. The microphone
shall be placed as far away from other
large sound sources as practical. In-air
sound levels shall be recorded at several
points around the base of the Harmony
Platform at sea level to validate modeled
sound levels. Recorded data shall be
recorded as dB (re 20 mPa) for
comparison to in-air noise thresholds
for Level B harassment for pinnipeds.
7. Reporting Requirements
ExxonMobil is required to:
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(a) Submit a draft report on all
activities and monitoring results to the
Office of Protected Resources, NMFS,
within 90 days of the completion of
ExxonMobil’s conductor pipe
installation activities at the Harmony
Platform in the Santa Barbara Channel
off the coast of California. This report
must contain and summarize the
following information:
(i) Dates, times, locations, weather,
sea conditions (including Beaufort sea
state and wind force), and associated
activities during all conductor pipe
installation activities and marine
mammal sightings;
(ii) Species, number, location,
distance from the platform, and
behavior of any marine mammals, as
well as associated conductor pipe
installation activities (e.g., number of
ramp-ups and shut-downs), observed
throughout all monitoring activities.
(iii) An estimate of the number (by
species) of marine mammals that: (A)
Are known to have been exposed to the
pile-driving activities (based on visual
observation) at received levels greater
than or equal to 160 dB re 1 mPa (rms),
and/or 180 dB re 1 mPa (rms) for
cetaceans and greater than or equal to
190 dB re 1 mPa (rms) for pinnipeds
with a discussion of any specific
behaviors those individuals exhibited;
and (B) may have been exposed (based
on modeled values for the impact
hammer) to the pile-driving activities at
received levels greater than or equal to
160 dB re 1 mPa (rms), and/or 180 dB
re 1 mPa (rms) for cetaceans and greater
than or equal to 190 dB re 1 mPa (rms)
for pinnipeds with a discussion of the
nature of the probable consequences of
that exposure on the individuals that
have been exposed.
(iv) A description of the
implementation and effectiveness of the:
(A) Terms and Conditions of the
Biological Opinion’s Incidental Take
Statement (ITS) (attached); and (B)
mitigation measures of the Incidental
Harassment Authorization. For the
Biological Opinion, the report shall
confirm the implementation of each
Term and Condition, as well as any
conservation recommendations, and
describe their effectiveness for
minimizing the adverse effects of the
action on Endangered Species Act-listed
marine mammals.
(l) Submit a final report to the Chief,
Permits and Conservation Division,
Office of Protected Resources, NMFS,
within 30 days after receiving comments
from NMFS on the draft report. If NMFS
decides that the draft report needs no
comments, the draft report shall be
considered to be the final report.
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8. Reporting Prohibited Take
In the unanticipated event that the
specified activity clearly causes the take
of a marine mammal in a manner
prohibited by this Authorization, such
as an injury (Level A harassment),
serious injury or mortality (e.g.,
equipment interaction, and/or
entanglement), ExxonMobil shall
immediately cease the specified
activities and immediately report the
incident to the Chief of the Permits and
Conservation Division, Office of
Protected Resources, NMFS, at 301–
427–8401 and/or by email to Jolie.
Harrison@noaa.gov and Howard.
Goldstein@noaa.gov and the West Coast
Regional Stranding Coordinator (Justin.
Greenman@noaa.gov). The report must
include the following information:
(a) Time, date, and location (latitude/
longitude) of the incident; description of
the circumstances during and leading
up to the incident; status of all sound
source use in the 24 hours preceding the
incident; water depth; environmental
conditions (e.g., wind speed and
direction, Beaufort sea state, cloud
cover, and visibility); description of
marine mammal observations in the 24
hours preceding the incident; species
identification or description of the
animal(s) involved; the fate of the
animal(s); and photographs or video
footage of the animal (if equipment is
available).
Activities shall not resume until
NMFS is able to review the
circumstances of the prohibited take.
NMFS shall work with ExxonMobil to
determine what is necessary to
minimize the likelihood of further
prohibited take and ensure MMPA
compliance. ExxonMobil may not
resume their activities until notified by
NMFS via letter, email, or telephone.
Reporting an Injured or Dead Marine
Mammal with an Unknown Cause of
Death—In the event that ExxonMobil
discovers an injured or dead marine
mammal, and the lead PSO determines
that the cause of the injury or death is
unknown and the death is relatively
recent (i.e., in less than a moderate state
of decomposition as described in the
next paragraph), ExxonMobil shall
immediately report the incident to the
Chief of the Permits and Conservation
Division, Office of Protected Resources,
NMFS, at 301–427–8401, and/or by
email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov, and the
NMFS West Coast Regional Office (1–
866–767–6114) and/or by email to the
West Coast Regional Stranding
Coordinator (Justin.Greenman@
noaa.gov). The report must include the
same information identified in
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Fmt 4703
Sfmt 4703
Condition 8(a) above. Activities may
continue while NMFS reviews the
circumstances of the incident. NMFS
shall work with ExxonMobil to
determine whether modifications in the
activities are appropriate.
Reporting an Injured or Dead Marine
mammal Not Related to the Activities—
In the event that ExxonMobil discovers
an injured or dead marine mammal, and
the lead PSO determines that the injury
or death is not associated with or related
to the activities authorized in Condition
2 of this Authorization (e.g., previously
wounded animal, carcass with moderate
to advanced decomposition, or
scavenger damage), ExxonMobil shall
report the incident to the Chief of the
Permits and Conservation Division,
Office of Protected Resources, NMFS, at
301–427–8401, and/or by email to
Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov, and the
NMFS West Coast Regional Office (1–
866–767–6114) and/or by email to the
West Coast Regional Stranding
Coordinator (Justin.Greenman@
noaa.gov), within 24 hours of the
discovery. ExxonMobil shall provide
photographs or video footage (if
available) or other documentation of the
stranded animal sighting to NMFS and
the Marine Mammal Stranding Network.
Activities may continue while NMFS
reviews the circumstances of the
incident.
9. Endangered Species Act Biological
Opinion and Incidental Take Statement
ExxonMobil is required to comply with
the Terms and Conditions of the ITS
corresponding to NMFS’s Biological
Opinion issued to both ExxonMobil and
NMFS’s Office of Protected Resources
(attached).
10. A copy of this Authorization and
the ITS must be in the possession of all
contractors and PSO(s) operating under
the authority of this Incidental
Harassment Authorization.
11. Penalties and Permit Sanctions—
Any person who violates any provision
of this IHA is subject to civil and
criminal penalties, permit sanctions,
and forfeiture as authorized under the
MMPA.
12. This IHA may be modified,
suspended or withdrawn if ExxonMobil
fails to abide by the conditions
prescribed herein or if the authorized
taking is having more than a negligible
impact on the species or stock of
affected marine mammals, or if there is
an unmitigable adverse impact on the
availability of such species or stocks for
subsistence uses.
Request for Public Comments
NMFS requests comments on our
analysis, the draft authorization, and
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Federal Register / Vol. 79, No. 125 / Monday, June 30, 2014 / Notices
any other aspect of the notice of
proposed IHA for ExxonMobil’s
proposed installation of conductor pipes
via hydraulic hammer driving at
Harmony Platform, Santa Ynez
Production Unit, located in the Santa
Barbara Channel offshore of California.
Please include with your comments any
supporting data or literature citations to
help inform our final decision on
ExxonMobil’s request for an MMPA
authorization.
Concurrent with the publication of
this notice in the Federal Register,
NMFS is forwarding copies of this
application to the Marine Mammal
Commission and its Committee of
Scientific Advisors.
Dated: June 25, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected
Resources, National Marine Fisheries Service.
[FR Doc. 2014–15224 Filed 6–27–14; 8:45 am]
BILLING CODE 3510–22–P
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
RIN 0648–XD229
Takes of Marine Mammals Incidental to
Specified Activities; Taking Marine
Mammals Incidental to a Geohazard
Survey in the Beaufort Sea, Alaska
National Marine Fisheries
Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA),
Commerce.
ACTION: Notice; issuance of an incidental
harassment authorization.
AGENCY:
In accordance with the
Marine Mammal Protection Act
(MMPA) regulations, notice is hereby
given that NMFS has issued an
Incidental Harassment Authorization
(IHA) to BP Exploration (Alaska) Inc.
(BP) to take marine mammals, by
harassment, incidental to conducting a
shallow geohazard survey in Foggy
Island Bay, Beaufort Sea, Alaska, during
the 2014 open water season.
DATES: Effective July 1, 2014, through
September 30, 2014.
ADDRESSES: Electronic copies of the
IHA, application, and associated
Environmental Assessment (EA) and
Finding of No Significant Impact
(FONSI) may be obtained by writing to
Jolie Harrison, Supervisor, Incidental
Take Program, Permits and
Conservation Division, Office of
Protected Resources, National Marine
Fisheries Service, 1315 East-West
Highway, Silver Spring, MD 20910,
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SUMMARY:
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telephoning the contact listed below
(see FOR FURTHER INFORMATION CONTACT),
or visiting the Internet at: https://www.
nmfs.noaa.gov/pr/permits/
incidental.htm. Documents cited in this
notice may also be viewed, by
appointment, during regular business
hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT:
Candace Nachman, Office of Protected
Resources, NMFS, (301) 427–8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the
MMPA (16 U.S.C. 1361 et seq.) direct
the Secretary of Commerce to allow,
upon request, the incidental, but not
intentional, taking of small numbers of
marine mammals by U.S. citizens who
engage in a specified activity (other than
commercial fishing) within a specified
geographical region if certain findings
are made and either regulations are
issued or, if the taking is limited to
harassment, a notice of a proposed
authorization is provided to the public
for review.
Authorization for incidental takings
shall be granted if NMFS finds that the
taking will have a negligible impact on
the species or stock(s), will not have an
unmitigable adverse impact on the
availability of the species or stock(s) for
subsistence uses (where relevant), and if
the permissible methods of taking, other
means of effecting the least practicable
impact on the species or stock and its
habitat, and requirements pertaining to
the mitigation, monitoring and reporting
of such takings are set forth. NMFS has
defined ‘‘negligible impact’’ in 50 CFR
216.103 as ‘‘. . . an impact resulting
from the specified activity that cannot
be reasonably expected to, and is not
reasonably likely to, adversely affect the
species or stock through effects on
annual rates of recruitment or survival.’’
Except with respect to certain
activities not pertinent here, the MMPA
defines ‘‘harassment’’ as: ‘‘any act of
pursuit, torment, or annoyance which (i)
has the potential to injure a marine
mammal or marine mammal stock in the
wild [Level A harassment]; or (ii) has
the potential to disturb a marine
mammal or marine mammal stock in the
wild by causing disruption of behavioral
patterns, including, but not limited to,
migration, breathing, nursing, breeding,
feeding, or sheltering [Level B
harassment].’’
Summary of Request
On February 4, 2014, NMFS received
an application from BP for the taking of
marine mammals incidental to
conducting a shallow geohazard survey.
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36769
NMFS determined that the application
was adequate and complete on March 6,
2014.
BP proposes to conduct a shallow
geohazard survey in Federal and state
waters of Foggy Island Bay in the
Beaufort Sea during the open-water
season of 2014. The activity would
occur between July 1 and September 30;
however, airgun and other sound source
equipment operations would cease on
August 25. The following specific
aspects of the activity are likely to result
in the take of marine mammals: Airguns
and scientific sonars/devices. Take, by
Level B harassment only, of 9 marine
mammal species is anticipated to result
from the specified activity.
Description of the Specified Activity
Overview
BP’s proposed shallow geohazard
survey would consist of two phases: A
site survey and a sonar survey. During
the first phase, the Site Survey, the
emphasis is on obtaining shallow
geohazard data using an airgun array
and a towed streamer. During the
second phase, the Sonar Survey, data
will be acquired both in the Site Survey
location and subsea pipeline corridor
area (see Figure 1 in BP’s application)
using the multibeam echosounder,
sidescan sonar, subbottom profiler, and
the magnetometer. The total discharge
volume of the airgun array will not
exceed 30 cubic inches (in3).
The purpose of the proposed shallow
geohazard survey is to evaluate
development of the Liberty field. The
Liberty reservoir is located in federal
waters in Foggy Island Bay about 8
miles (mi) east of the Endicott Satellite
Drilling Island. The project’s preferred
alternative is to build a gravel island
situated over the reservoir. In support of
the preferred alternative, a Site Survey
is planned with an emphasis on
obtaining two-dimensional highresolution shallow geohazard data using
an airgun array and a towed streamer.
Additional infrastructure required for
the preferred alternative would include
a subsea pipeline. A Sonar Survey,
using multibeam echosounder, sidescan
sonar, subbottom profiler, and
magnetometer is proposed over the Site
Survey location and subsea pipeline
corridor area. The purpose of this
proposed survey is to evaluate the
existence and location of archaeological
resources and potential geologic hazards
on the seafloor and in the shallow
subsurface.
Dates and Duration
The planned start date is
approximately July 1, 2014, with data
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]]>Agencies
[Federal Register Volume 79, Number 125 (Monday, June 30, 2014)]
[Notices]
[Pages 36743-36769]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-15224]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XD188
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Conductor Pipe Installation
Activities at Harmony Platform in Santa Barbara Channel Offshore of
California
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed Incidental Harassment Authorization; request
for comments.
-----------------------------------------------------------------------
SUMMARY: NMFS has received an application from ExxonMobil Production
Company (ExxonMobil), a Division of ExxonMobil Corporation, for an
Incidental Harassment Authorization (IHA) to take marine mammals, by
harassment, incidental to installing six conductor pipes via hydraulic
hammer driving at the Harmony Platform, Santa Ynez Production Unit,
located in the Santa Barbara Channel offshore of California. Pursuant
to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments
on its proposal to issue an IHA to ExxonMobil to incidentally harass,
by Level B harassment only, 30 species of marine mammals during the
specified activity.
DATES: Comments and information must be received no later than July 30,
2014.
ADDRESSES: Comments on the application should be addressed to Jolie
Harrison, Supervisor, Incidental Take Program, Permits and Conservation
Division, Office of Protected Resources, National Marine Fisheries
Service, 1315 East-West Highway, Silver Spring, MD 20910. The mailbox
address for providing email comments is ITP.Goldstein@noaa.gov.
Comments sent via email, including all attachments, must not exceed a
25-megabyte file size. NMFS is not responsible for comments sent to
addresses other than the one provided here.
Instructions: All comments received are a part of the public record
and will
[[Page 36744]]
generally be posted to https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications without change. All Personal Identifying
Information (for example, name, address, etc.) voluntarily submitted by
the commenter may be publicly accessible. Do not submit Confidential
Business Information or otherwise sensitive or protected information.
An electronic copy of the application may be obtained by writing to
the address specified above, telephoning the contact listed below (see
FOR FURTHER INFORMATION CONTACT) or visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Documents
cited in this notice may also be viewed, by appointment, during regular
business hours, at the aforementioned address.
NMFS is also preparing an Environmental Assessment (EA) in
accordance with the National Environmental Policy Act (NEPA) and will
consider comments submitted in response to this notice as part of that
process. The EA will be posted at the foregoing Internet site once it
is finalized.
FOR FURTHER INFORMATION CONTACT: Howard Goldstein or Jolie Harrison,
Office of Protected Resources, NMFS, 301-427-8401.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.),
direct the Secretary of Commerce (Secretary) to allow, upon request,
the incidental, but not intentional, taking of small numbers of marine
mammals, by United States citizens who engage in a specified activity
(other than commercial fishing) within a specified geographical region
if certain findings are made and either regulations are issued or, if
the taking is limited to harassment, a notice of a proposed
authorization is provided to the public for review.
An authorization for the incidental takings shall be granted if
NMFS finds that the taking will have a negligible impact on the species
or stock(s), and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103
as ``. . . an impact resulting from the specified activity that cannot
be reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.''
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: Any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment].
Summary of Request
On March 3, 2014, NMFS received an application from ExxonMobil for
the taking of marine mammals incidental to installing six conductor
pipes by hydraulic hammering at the Harmony Platform, Santa Ynez
Production Unit, in the Santa Barbara Channel offshore of California.
Along with the IHA application, NMFS received an addendum titled
``Assessment of Airborne and Underwater Noise from Pile Driving
Activities at the Harmony Platform.'' NMFS determined that the
application was adequate and complete on April 28, 2014.
The proposed project's estimates dates are from mid-August to mid-
November 2014, but the proposed action could occur anytime within a 12-
month period from the effective date of the proposed IHA. Acoustic
stimuli (i.e., increased underwater and airborne sound) generated
during the conductor pipe installation activities are likely to result
in the take of marine mammals. Take, by Level B harassment only, of 30
species is anticipated to result from the proposed activities.
Description of the Proposed Specified Activity
Overview
ExxonMobil proposes to install six conductor pipes by hydraulic
hammering at the Harmony Platform, Santa Ynez Production Unit, in the
Santa Barbara Channel offshore of California.
Dates and Duration
ExxonMobil estimates that the proposed conductor pipe installation
activities would occur from mid-August to mid-November 2014, but the
proposed activities could occur anytime within a 12-month period from
the effective date of the proposed IHA. Precise scheduling is not
presently available due to logistical and regulatory uncertainties.
ExxonMobil has requested the IHA for an August start date to allow for
flexibility in scheduling operations, equipment, and personnel, as well
as to ensure sufficient time to arrange for monitoring field services.
The estimated duration of the proposed project is 91 days. Under normal
working conditions, the proposed project is expected to include
approximately 84 days of installation activity on the Harmony Platform
bounded by 7 days of project mobilization/demobilization activities. It
would take approximately 14 days to install each conductor pipe (6
conductors x 14 days = 84 days). Figure 2-1 of the IHA application
includes a timeline of proposed activities over the approximate three
month duration. Of the estimated 84 days, hammer driving would occur
over 30 intermittent intervals of 2.5 to 3.3 hours each for a combined
total of 4.125 days, or 5% of the entire proposed project (3.3 hours x
5 joints x 6 conductors = 99 hours or 4.125 days).
Specified Geographic Region
Harmony Platform is located in the Santa Barbara Channel, which is
approximately 100 km (54 nmi) long and 40 km (21.6 nmi) wide, situated
between the Channel Islands and the east-west trending coastline of
California. The Santa Barbara Channel is the site of several other
producing oil fields, including Ellwood, Summerland, Carpinteria
offshore, and Dos Cuadras. The Santa Barbara basin is the prominent
feature of the Santa Barbara Channel, with sill depths of approximately
250 m (820.2 ft) and 450 m (1,467.4 ft) at eastern and western
entrances, respectively, with shallow (60 m or 196.9 ft) inter-island
passages to the south. Harmony Platform's geographical position is
34[deg] 22' 35.906'' North, 120[deg] 10' 04.486'' West, at a water
depth of 366 m (1,200.8 ft) on the continental slope below a relatively
steep (7.5%) descent. The Harmony Platform is 43.5 km (27 miles)
southwest of Santa Barbara, California (see Figure 1 of the IHA
application). It is 4.7 km (2.5 nmi) from the shelf break, which is
typically defined at the 100 m (328.1 ft) isobaths (USGS, 2009). It is
3.3 km (1.8 nmi) from the nearest buffered 200 m (656.2 ft) contour,
which has been noted for its association with higher recorded densities
of cetacean species (Redfern et al., 2013). It is also located 10 to 15
km (5.4 to 8.1 nmi) north of a common traffic route used by vessels to
access the ports of Long Beach and Los Angeles. Figure 1-1 of the IHA
application includes the location of the Harmony Platform, general site
[[Page 36745]]
bathymetry, and Santa Barbara area boundaries.
Site Bathymetry and Sediment Physical Characteristics--Harmony
Platform is located below a relatively steep (7.5%) descent from the
shelf margin, which is defined by the 100 m contour in this area (USGS,
2009). It sits at a water depth of 366 m, just above the northern rim
of the Santa Barbara Basin which is roughly confined by the 400 m
(1,312.3 ft) contour, descending to depths exceeding 600 m (1,968.5
ft). Depths below the Harmony Platform are defined by a gentle slope
(ca. 1%), which extends to the 600 m contour at the basin maximum. To
the west of the platform, the slope attenuates to about 3% grade
between 100 m and 400 m contours, near the western sill of the basin.
To the east, the slope becomes steeper, approaching 15% grade between
100 m and 400 m contours, at 20 km (10.8 nmi) east of the platform.
Harmony Platform is located on unconsolidated fine-grained silty-
clay and clayey-silt sediments. Table 2-1 of the IHA application
describes the sediment physical characteristics and geoacoustical
profile in the vicinity of the Harmony Platform. These sediments are
typical of slope depths proceeding into the basin where sediments may
be 2,000 m (6,561.7 ft) thick. Stein (1995) reported similar sediment
grain characteristics from core segments penetrating 196 m (643.1 ft)
below the sediment surface at a basin depth of 565 m (1,853.7 ft).
Sediments were primarily of terrigeneous origin, dominated by quartz
and clay minerals montmorillonite and illite. These sediments are
similar in quartz content and clay-mineral composition to suspended
sediment introduced by the Santa Clara River, which has an average
annual sediment load of about 600,000 m\3\ (2.1 x 10\7\ ft\3\)
(Brownlee and Taylor, 1981). These turbid sediment plumes, arising
primarily from the Santa Clara River to the east and from Santa Maria
and Santa Inez Rivers north of Point Conception, may extend more than 5
km (2.7 nmi) from shore and inshore from Harmony Platform during
periods of heavy runoff.
Sediments at Harmony Platform and throughout the Santa Barbara
Channel slopes and basin reflect terrigeneous origins from coastal
watersheds (mainly the Santa Clara River), with relatively minor
inclusions of marine biogenic origin (e.g., calcareous and diatomaceous
fractions). Shell fragment debris dislodged from the jacket structure
during peak storm wave surges and from periodic maintenance has been
observed around the periphery of the jacket in ROV surveys, but
significant debris was not observed at the conductor pipe locations
designated from this project. No known hard substrates have been
identified by the former Minerals Management Service and NMFS surveys
within 5 km of the Harmony Platform (Keller et al., 2005). Extending
from shore to the 100 m shelf break, hard substrate is common,
supporting extensive kelp beds at depths less than 20 m (65.6 ft), on
cobbles and boulders. Further offshore, at depths of about 65 m (213.3
ft) to the shelf break, regions of folded ridges and pinnacles up to 3
m (9.8 ft) in relief have been recorded (USGS, 2009).
Hydrodynamics and Water Column Physical Properties--Hydrodynamic
and seawater properties at the Harmony Platform are complex as a result
of shifting wind and current patterns that occur in the Santa Barbara
Channel in response to changing coastline orientation at Point
Conception (Beckenbach, 2004). The Santa Barbara Channel is a cross-
roads for large scale water masses moving along the California coast.
Waters from north of Point Conception are cooled by coastal upwelling
as they move southward. Most of these waters pass outside the Channel
Islands but some enter the Santa Barbara Channel at its west end.
Warmer waters from the south are driven poleward by the Southern
California Countercurrent. Mean nearshore circulation in the entire
Southern California Bight is dominated by this current (Hickey, 1993),
which enters the Santa Barbara Channel from the east. Water mass
properties are determined by relative inputs to the Santa Barbara
Channel from eastern and western entrances.
Hydrodynamics--Aud et al. (1999) determined that transport from the
east accounted for 60% of the water entering the Santa Barbara Channel
with 33% originating from the southern portion of the western entrance
and the remaining 7% from southern inter-island passages. These
contrasting source waters mix in the Santa Barbara Channel, often
forming complex patterns visible in satellite images of sea surface
temperature. They represent the more persistent large scale movement of
water masses, which are driven by dynamic processes on scales much
larger than the Santa Barbara Channel. Current speed fluctuations
exhibit significant variation, typically ranging from 10 to 40 cm
s-1 (Hickey, 1992), extending to a depth of 200 m (656.2
ft), and tending to follow longshore isobaths. Seasonal mean currents
over the continental slope are 20 to 30 cm s-1. However,
surface circulation may be driven by winds that create rapidly
developing high energy surface flows that vary in direction over scales
of several kilometers. In the Santa Barbara Channel, wind stress from
the northwest creates surface flows characterized by cyclonic, and
occasionally anti-cyclonic, flow vortices which propagate westward.
These occur intermittently throughout the year, and may last for months
(Beckenbach, 2004; Oey, 2001). Vertical upwelling along the coast is
also a feature of the water mass, occurring primarily from spring
through fall (Harms and Winant, 1998). Inlet water mass movement in the
vicinity of Harmony Platform is from west to east, extending to basin
sill depth, with highly variable patterns of flow at the surface under
the periodic influence of gyre vortices lasting from days to months,
meandering from east to west, typically from spring to fall.
Water Column Physical Properties--Seasonal changes in water column
stability (density structure) result from changes in temperature and
salinity that occur seasonally from air-sea surface interactions, and
from periodic fluctuations in relative contributions of different
source waters (e.g., eastern and western flows). The water column is
density stratified as temperatures decline and salinity increases with
depth. Seasonal effects are evident with the strongest density gradient
occurring during summer months, primarily within the upper 25 m (82
ft). Water column profiles of salinity, temperature, and calculated
sound speed are illustrated in Figure 2-2 of the IHA application.
Temperatures range from approximately 13 to 16.5[deg] Celsius (C) (55.4
to 61.7[deg] Fahrenheit [F]) at the surface, become nearly isothermal
(9 to 9.5[deg] C or 48.2 to 49.1[deg] F) at 150 m (492.1 ft) depth,
likely varying little to the platform depth of 366 m (1,200.8 ft).
Seasonal salinities varied little, ranging from about 33.3 to 33.7% at
the surface to 34 to 34.1% to 150 m depth. Figure 2-2 of the IHA
application shows salinity, temperature, and underwater sound speed
profiles in the vicinity of the Harmony Platform derived from the U.S.
Naval Oceanographic Office's Generalized Digital Environmental Model
(GDEM) database. The profile for sound speed correlates strongly with
temperature, which is the main determinant of water density structure.
Detailed Description of the Proposed Specified Activity
ExxonMobil propose to install six conductor pipes by hydraulic
hammering at Harmony Platform. The proposed conductor pipe installation
activities are estimated to occur from mid-August to mid-November 2014,
but
[[Page 36746]]
the proposed action could occur anytime within a 12-month period from
the effective date of the proposed IHA. Harmony Platform is located 10
kilometers (km) (5.4 nautical miles [nmi]) off the coast of California,
between Point Conception and the City of Santa Barbara. Harmony
Platform is one of three offshore platforms in ExxonMobil's Santa Ynez
Production Unit, and is located in the Hondo field (Lease OCS-P 0190)
at a water depth of 336 meters (1,200.8 ft). Harmony Platform was
installed on June 21, 1989 with the sole purpose of producing crude oil
and gas condensate. It began production of crude oil, gas and gas
condensate on December 30, 1993. A conductor pipe is installed prior to
the commencement of drilling operations for oil and gas wells. It
provides protection, stability/structural integrity, and a conduit for
drill cuttings and drilling fluid to the platform. It also prevents
unconsolidated sediment from caving into the wellbore, and provides
structural support for the well loads. Drilling activities are
currently ongoing at Harmony Platform utilizing the existing conductors
and wells. The platform jacket structure (see Figure 1-2 of the IHA
application) currently has conductors installed in 51 out of 60 slots,
as approved by the Bureau of Ocean Energy Management (BOEM, formally
the Minerals Management Service [MMS]) in the original Development
Production Plan. Addition of eight straight conductors at the Harmony
Platform was approved by the Bureau of Safety and Environmental
Enforcement (BSEE) on February 11, 2013 to maintain current production
levels from the existing platform. Conductor installation with a
hydraulic hammer is consistent with approved development plans, and is
the same method that was used to install conductors on all three Santa
Ynez Production Unit platforms from 1981 (Hondo) through 1993 (Harmony
and Heritage). Pile-driving the conductors are the only proven
installation method that enables management of potential interferences
with the existing platform infrastructure that would also reach the
target depth. Non-pile-driving conductor installation methods are not
deemed feasible at this time due to increased risk to platform
structural integrity, offset well collision, and shallow-hole
broaching.
The total length of a single conductor pipe is approximately 505 m
(1,656.8 ft). Each conductor consists of multiple sections of 66.04
centimeter (cm) (26 inch [in]) diameter steel pipe that would be
sequentially welded end-to-end from an upper deck of the platform (see
Figure 1-2 of the IHA application), and lowered into the 366 m water
column through metal rings (conductor guides) affixed to the jacket
structure that orient and guide the conductor. Once the conductor
reaches the sediment surface, gravity-based penetration (i.e., the
conductor would penetrate the seabed under its own weight) is expected
to reach approximately 30 m (98.4 ft) below the seabed. A hydraulic
hammer (S-90 IHC) with a manufacturer's specified energy range of 9 to
90 kiloJoules (kJ) would be located on the drill deck and used to drive
the conductor to a target depth of approximately 90 to 100 m (295.3 to
328.1 ft) below the seabed; therefore, only roughly 60 m (196.9 ft) of
each 505 m (1,656.8 ft) long conductor pipe would require hydraulic
driving. The S-90 IHC hydraulic hammer would sit on the conductor
throughout pile-driving operations, but a ram internal to the hammer
would stroke back and forth using hydraulic pressure to impart energy
to the conductor. No physical dropping of a weight would be employed to
drive the conductor.
The S-90 IHC hydraulic hammer has an estimated blow rate of about
46 blows per minute. The portion of a complete conductor that must be
actively driven (hammered) into the seafloor consists of 5 to 7
sections, which are sequentially welded end-to-end. Setup and welding
would take 3.5 to 7.3 hours per section, mostly depending on the type
of welding equipment used (e.g., automated welder). Hammer pile-driving
would take an estimated 2.5 to 3.3 hours for each section, depending
primarily on sediment physical properties, which affect penetration
rate. Complete installation of each conductor is estimated at
approximately 14 days based on 24-hour (continuous) operations. Table
1-1 of the IHA application presents a summary of driving activities and
estimated number of joints [requiring welding] for each conductor
pipe). Figure 1-3 of the IHA application shows the estimated time in
days for each of these activities that are required to install a single
conductor pipe. ExxonMobil conservatively assumes that active hammering
would be 3.3 hours, followed by 7.3 hours of hammer downtime (i.e.,
``quiet time,'' a time at which other activities are performed in
preparation for the next section of pile) over approximately 53 hours
(2.2 days) of the approximately 14 days required to install one
conductor pipe. This schedule produces 4.125 days (99 hours) of
cumulated hammer driving for all six conductors over the project
duration. Figure 1-4 depicts the 3.3 hour pile-drive/7.3 hour downtime
cycle for an isolated 24-hour period, showing a maximum of 9.4 hours of
hammer driving. In the event that efficiencies produce a 2.5 hour
drive/3.5 hour downtime cycle, a maximum of 10 hours of hammer pile-
driving could occur in a single 24-hour period. The complete
installation of the conductor pipes is estimated at 14 days of
continuous operation.
Table 1--Summary of Proposed Installation Activities and Associated Characteristics of Each Conductor Pipe at
Harmony Platform.
----------------------------------------------------------------------------------------------------------------
Estimated
Conductor pipe activity Pipe length (m) Estimates number of Pile-driving number of
joints required days \3\
----------------------------------------------------------------------------------------------------------------
Installation level to sea level.. 49 (160.8 ft)....... 4................... No................. 2
Sea level to seafloor............ 366 (1,200.8 ft).... 28.................. No................. 5.6
From 0 to ~30 m below seafloor... 30 \1\ (98.4 ft).... 3................... No................. 0.9
From ~30 m to ~90 m below 60 (196.9 ft)....... 5 to 7.............. Yes \2\............ 0.69
seafloor.
Hammer downtime.................. NA.................. NA.................. No................. 1.52
Clean up and completion.......... NA.................. NA.................. No................. 3.6
----------------------------------------------------------------------------------------------------------------
\1\ Estimated range of gravity-based penetration.
\2\ See Figure 1-4 of the IHA application.
\3\ See Figure 1-3 of the IHA application.
[[Page 36747]]
Platform Specifications
The Harmony Platform is owned and operated by ExxonMobil and has a
personnel capacity of 132 people. The Harmony Platform, located in the
Santa Barbara Channel, was installed on June 21, 1989 and first began
production on December 30, 1993. The lease location for the Santa Ynez
Production Unit is OCS-P0190. Support vessels and helicopters are used
routinely as part of normal platform operations and would be utilized
to provide necessary support for proposed activities during the
project. There are no anticipated changes in logistics from current
operations associated with the proposed project. The contractors
responsible for protected species and noise monitoring during the
proposed project would use existing, routine transportation vessels.
The Harmony Platform also has a minimum of two locations as likely
observation stations from which Protected Species Observers (PSO) would
watch for marine mammals before and during the proposed conductor pipe
installation activities. The station on the upper deck has an
approximately 360[deg] view around the Harmony Platform to monitor the
Level B harassment buffer zone. At least one station on the lower deck
would monitor the Level A harassment exclusion zone. More details of
the Harmony Platform can be found in the IHA application and online at:
https://www.boem.gov/BOEM-Newsroom/Offshore-Stats-and-Facts/Pacific-Region/Pacific-Platform-Operators.aspx#Exxon.
Acoustic Source Specifications
Predicted Sound Levels for the Pile-Driving Activities
The predicted in-water sound field during proposed impact hammer
pile-driving of the conductor pipes at the Harmony Platform were
modeled by JASCO Applied Sciences, Ltd (JASCO). See JASCO's
``Assessment of Airborne and Underwater Noise from Pile-Driving
Activities at the Harmony Platform'' for a detailed description of
ExxonMobil's modeling for this proposed action, which is provided as an
addendum to the IHA application. NMFS refers the reviewers to that
document for additional information. Sound levels emitted from the
conductor pipe were estimated using underwater recordings (Illingworth
and Rodkin, 2007) for impact pile-driving of 61 to 76.2 centimeter (cm)
(24 to 30 inch [in]) steel piles (i.e., pipes) back calculated to 1 m
from the sound source, assuming a combination of cylindrical and
spherical spreading. Sound level at the source was then scaled to the
anticipated energy range of 9 and 90 kJ for the impact hammer and
coupled to an acoustic model of a representative steel pipe (Claerbout,
1976; Reinhall and Dahl, 2011). Only modeled results associated with
the maximum hammer energy of 90 kJ were used to estimate potential
impacts and calculate take.
Each 505 m (1,656.8 ft) long conductor pipe is assembled from 12 m
(39.4 ft) long sections welded end-to-end, and then lowered from a top
deck of the platform through 366 m (1,200.8 ft) of water until the pipe
encounters the seafloor and penetrates approximately 60 m of the seabed
under its own weight. Because of the extremely long length of the
conductor pipe compared to those represented in the literature, the
pipe was modeled as a line array of 12 sources at 30 m (98.4 ft)
intervals (i.e., over 360 m [1,181.1 ft] pipe length). This procedure
produced a more realistic estimates of the maximum sound SPL (rms) from
impact hammer pile-driving of Harmony Platform's conductor pipes,
compared with a single sound source representation (e.g., mid-pipe)
that is generally used for shorter pipes (piles). At the maximum hammer
energy of 90 kJ, the corresponding maximum sound pressure throughout
the water column is estimated at 202 dB (rms) at 1 m from the conductor
pipe (see Figure 6-1 of the IHA application). The predicted sound
levels were used by ExxonMobil and NMFS to determine the buffer and
exclusion zones for the proposed conductor pipe installation
activities.
Table 2 (Table 6-4 of the IHA application) summarizes the modeled
distances at which in-water (160, 180, and 190 dB [rms]) and in-air (90
and 100 dB [rms]) sound levels are expected to be received from the
impact hammer pile-driving operating at a water depth of 366 m. For in-
water noise, sound propagation and corresponding maximum distances were
modeled using JASCO's model Full Waveform Range-dependent Acoustic
Model (FWRAM), which is based on a modified version of the U.S. Navy's
parabolic Range-dependent Acoustic Model (RAM) to account for an
elastic seabed. FWRAM enhances RAM by accounting for seabed dissipation
of acoustic energy and incorporates local bathymetry, seafloor
geoacoustics, and underwater sound speed profiles. Physical data
specific to the Harmony Platform location were used by JASCO to model
sound propagation (see Table 2-1 and Figure 202 of the IHA
application). Representative data include sediment grain size and
density, and water column salinity/temperature, as these properties
affect seafloor geoacoustic properties and in-water sound speed,
respectively. Routines in FWRAM were used to model sound as SPL (rms)
over water column depth and distance from the conductor pipe based on
maximum hammer energy (90 kJ). Figure 6-2 of the IHA application shows
water depth versus distance from the conductor pipe (sound source),
where the 160 dB isopleth represents the maximum distance for in-water
Level B harassment for marine mammals. The maximum distances are
generally higher in the top 100 m (328.1 ft) of the water column.
To evaluate potential seasonal effects on sound propagation in the
water column, year-round conditions using selected monthly averages
(i.e., January, April, August, and November) of water column salinity
and temperature were modeled along one azimuth, south of the Harmony
Platform. Results showed no significant seasonal variations (<1 dB
[rms]) up to 1 km (0.5 nmi) from the Harmony Platform. Potential
differences in sound propagation with direction from the Harmony
Platform also were investigated by JASCO. There were not significant
differences in the sound field modeled for four equally spaced
transects out to 1 km from the Harmony Platform.
For in-air noise, JASCO used in-air sound levels calculated from
recordings of pipe-driving tests performed by ExxonMobil using a 90 kJ
energy hammer that is planned for use on this proposed action. The
tests used the S-90 hammer at 90% of its maximum energy with a steel
pipe of unknown size. The estimated sound levels represent A-weighted
received levels, calculated at six distances between 0 and 12 m (0 to
39.4 ft), and indicated a source level of 132.4 dB re 20 [mu]Pa (rms)
(A-weighted). Calculated distances from the sound source to the Level B
harassment threshold for in-air noise (SPL [rms]) using spherical
spreading loss are shown below and in Table 6-4 of the IHA application.
Using the JASCO model, Table 2 (below) shows the distances at which
three rms underwater sound levels and two rms in-air sound levels are
expected to be received from the impact hammer pile-driving activities.
The 180 and 190 dB re 1 [micro]Pam (rms) distances are the safety
criteria (i.e., exclusion zone) for potential Level A harassment as
specified by NMFS (2000) and are applicable to cetaceans and pinnipeds,
respectively. If marine mammals are detected within or about to enter
the appropriate exclusion zone, the impact hammer pile-driver would be
shut-down immediately.
[[Page 36748]]
Table 2--Modeled Maximum Distances To Which In-Water Sound Levels >=190, 180 and 160 dB re 1 [mu]Pa (rms) and In-Air Sound Levels =90 (for
Harbor Seals) and 100 dB re 20 [mu]Pa (rms) (for All Other Pinnipeds) Could Be Received During the Proposed Pile-Driving Activities (Based on Maximum
Hammer Energy of 90 kJ) in the Santa Barbara Channel Off the Coast of California
--------------------------------------------------------------------------------------------------------------------------------------------------------
Predicted RMS radii distances (m) for in-water Modeled RMS radii distances (m)
Water depth pile-driving for in-air pile-driving
Source (m) ------------------------------------------------------------------------------------
160 dB 180 dB 190 dB 90 dB 100 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
90 kJ Impact Hammer Pile-Driver................... 366 325 10 3.5 123 41
(1,066.3 ft) (32.8 ft) (11.5 ft) (403.5 ft) (134.5 ft)
--------------------------------------------------------------------------------------------------------------------------------------------------------
NMFS expects that acoustic stimuli resulting from the proposed
impact hammer pile-driving associated with the conductor pipe
installation activities has the potential to harass marine mammals.
Description of the Marine Mammals in the Area of the Proposed Specified
Activity
The marine mammals that generally occur in the proposed action area
belong to four taxonomic groups: Mysticetes (baleen whales),
odontocetes (toothed whales), pinnipeds (seals and sea lions), and
fissipeds (sea otters). The marine mammal species that potentially
occur within the Pacific Ocean in proximity to the proposed action area
in the Santa Barbara Channel off the coast of California (ranging from
Point Conception and south, including the entire Southern California
Bight) include 30 species of cetaceans (whales, dolphins, and
porpoises) and 6 species of pinnipeds. The southern sea otter (Enhydra
lutris nereis) is listed as threatened under the ESA and is managed by
the U.S. Fish and Wildlife Service and is not considered further in
this proposed IHA notice.
Marine mammal species listed as threatened or endangered under the
U.S. Endangered Species Act of 1973 (ESA; 16 U.S.C. 1531 et seq.),
includes the North Pacific right (Eubalaena japonica), humpback
(Megaptera novaeangliae), sei (Balaenoptera borealis), fin
(Balaenoptera physalus), blue (Balaenoptera musculus), and sperm
(Physeter macrocephalus) whale as well as the Guadalupe fur seal
(Arctocephalus townsendi). Of those threatened and endangered species,
the humpback, sei, fin, blue, and sperm whale are likely to be
encountered in the proposed action area.
Cetaceans occur throughout the Santa Barbara Channel proposed
action area, including nearby the Harmony Platform, from the surf zone
to open ocean environments beyond the Channel Islands. Distribution is
influenced by a number of factors, but primary among these are patterns
of major ocean currents, bottom relief, and sea surface temperature.
These physical oceanographic conditions affect prey abundance, which
may attract marine mammals during periods of high productivity, and
vice versa. Water movement is near continuous, varying seasonally, and
is generally greatest from late spring to early fall in response to
varying wind stress. This phenomenon is much greater in the western
Santa Barbara Channel. This near continuous movement of water from the
ocean bottom to the surface creates a nutrient-rich, highly productive
environment for marine mammal prey (Jefferson et al., 2008). Most of
the large cetaceans are migratory, but many small cetaceans do not
undergo extensive migrations. Instead, they undergo local or regional
dispersal, on a seasonal basis or in response to food availability.
Population centers may shift on spatial scales exceeding 100 km (54
nmi) over small time scales (days or weeks) (Dailey and Bonnell, 1993).
Systematic surveys (1991 to 1993, 1996, 2001, 2005) in the southern
California region have been carried out via aircraft (Carretta and
Forney, 1993) and vessel (Ferguson and Barlow, 2001; Barlow, 2003) by
NMFS. In addition, a vessel survey in the U.S. Exclusive Economic Zone
(EEZ), and out to 556 km (300.2 nmi) offshore of California, Oregon,
and Washington, was conducted in the summer and fall of 2005 by NMFS
(Forney, 2007). Many other regional surveys have also been conducted
(Carretta, 2003). Becker (2007) analyzed data from vessel surveys
conducted since 1986, and compiled marine mammal densities. There are
30 cetacean and 6 pinniped species with ranges that are known to occur
in the Eastern North Pacific Ocean waters of the project area. These
include the North Pacific right whale, Bryde's whale (Balaenoptera
edeni), dwarf sperm whale (Kogia sima), harbor porpoise (Phocoena
phocoena), Steller sea lion (Eumatopias jubatus), and Guadalupe fur
seal. However, these species are extremely rare, found in the Channel
Islands, or are primarily found north or south of the Santa Barbara
Channel, and are unlikely to be found in the proposed action area. The
harbor porpoise occurs north of Point Conception, California. Bryde's
whales are extremely rare in the Southern California Bight, with fewer
than ten confirmed sightings from August 2006 to September 2010
(Smultea et al., 2012). Guadalupe fur seals are most common at
Guadalupe Island, Mexico, which is their primary breeding ground (Melin
and Delong, 1999). Although adult and juvenile males have been observed
at San Miguel Island, California, since the mid-1960's, and in the late
1990's a pup was born on the islands (Melin and Delong, 1999), more
recent sightings are extremely rare. These species are not considered
further in this document. Table 3 (below) presents information on the
occurrence, abundance, distribution, population status, and
conservation status of the species of marine mammals that may occur in
the proposed project area during August to November 2014.
[[Page 36749]]
Table 3--The Habitat, Occurrence, Range, Regional Abundance, and Conservation Status of Marine Mammals That May Occur in or Near the Proposed Pipe
Installation Project Area Off the Coast of California in the Pacific Ocean
[See text and Tables 3-1 in ExxonMobil's IHA application for further details]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Best population
Species Habitat Occurrence Range estimate ESA \2\ MMPA \3\
(minimum) \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
North Pacific right whale Coastal and Rare.............. North Pacific NA (26)--Eastern EN................ D.
(Eubalaena japonica). pelagic. Ocean between 20 North Pacific
to 60[deg] North. stock.
Gray whale (Eschrichtius Coastal and shelf. Transient during North Pacific 19,126 (18,107)-- DL--Eastern North NC--Eastern North
robustus). seasonal Ocean, Gulf of Eastern North Pacific stock. Pacific stock.
migrations. California to Pacific stock. EN--Western North D--Western North
Arctic--Eastern 155 (142)--Western Pacific Pacific
North Pacific North Pacific population. population.
stock. population..
Humpback whale (Megaptera Pelagic, nearshore Seasonal, Cosmopolitan...... 1,918 (1,876)-- EN................ D.
novaeangliae). waters, and banks. sightings near California/Oregon/
northern Channel Washington (CA/OR/
Islands. WA) stock.
Minke whale (Balaenoptera Pelagic and Less common in Tropics and sub- 478 (202)--CA/OR/ NL................ NC.
acutorostrata). coastal. summer, small tropics to ice WA stock.
number around edges.
northern Channel
Islands.
Bryde's whale (Balaenoptera Pelagic and Rare, infrequent Tropical and sub- NA................ NL................ NC.
edeni). coastal. summer off tropical zones
California. between 40[deg]
North and 40[deg]
South.
Sei whale (Balaenoptera Primarily Rare, infrequent Tropical to polar 126 (83)--Eastern EN................ D.
borealis). offshore, pelagic. summer off zones, favor mid- North Pacific
California. latitude stock.
temperate areas.
Fin whale (Balaenoptera Continental slope, Year-round Tropical, 3,051 (2,598)--CA/ EN................ D.
physalus). pelagic. presence. temperate, and OR/WA stock.
polar zones of
all oceans.
Blue whale (Balaenoptera Pelagic, shelf, Seasonal, arrive Tropical waters to 1,647 (1,551)-- EN................ D.
musculus). coastal. April to May, pack ice edges. Eastern North
common late- Pacific stock.
summer to fall
off Southern
California.
Odontocetes:
Sperm whale (Physeter Pelagic, deep sea. Common year-round, Tropical waters to 971 (751)--CA/OR/ EN................ D.
macrocephalus). more likely in pack ice edges. WA stock.
waters >1,000 m.
Pygmy sperm whale (Kogia Pelagic, slope.... Seaward of 500 to Tropical to warm 579 (271)--CA/OR/ NL................ NC.
breviceps). 1,000 m, Limited temperate zones WA stock.
sightings in (temperate
Southern preference).
California Bight.
Dwarf sperm whale (Kogia Deep waters off Rare.............. Tropical to warm NA--CA/OR/WA stock NL................ NC.
sima). the shelf. temperate zones
(warmer
preference).
Baird's beaked whale Pelagic........... Primarily along North Pacific 847 (466)--CA/OR/ NL................ NC.
(Berardius bairdii). continental slope Ocean and WA stock.
late spring to adjacent seas.
early fall.
Cuvier's beaked whale Pelagic........... Possible year- Cosmopolitan...... 6,950 (4,481)--CA/ NL................ NC.
(Ziphius cavirostris). round occurrence. OR/WA stock.
Blainville's beaked whale Pelagic........... Rare, continental Temperate and 694 (389)-- NL................ NC.
(Mesoplodon densirostris). slope region, tropical waters Mesoplodon spp.
generally seaward worldwide. CA/OR/WA stock.
of 500 to 1,000 m
depth.
Perrin's beaked whale Pelagic........... Rare, continental North Pacific 694 (389)-- NL................ NC.
(Mesoplodon perrini). slope region, Ocean. Mesoplodon spp.
generally seaward CA/OR/WA stock.
of 500 to 1,000 m
depth.
Lesser beaked whale Pelagic........... Rare, continental Temperate and 694 (389)-- NL................ NC.
(Mesoplodon peruvianis). slope region, tropical waters Mesoplodon spp.
generally seaward Eastern Pacific CA/OR/WA stock.
of 500 to 1,000 m Ocean.
depth.
Stejneger's beaked whale Pelagic........... Rare, continental North Pacific 694 (389)-- NL................ NC.
(Mesoplodon stejnegeri). slope region, Ocean. Mesoplodon spp.
generally seaward CA/OR/WA stock.
of 500 to 1,000 m
depth.
Ginkgo-toothed beaked whale Pelagic........... Rare, continental Temperate and 694 (389)-- NL................ NC.
(Mesoplodon ginkgodens). slope region, tropical waters Mesoplodon spp.
generally seaward Indo-Pacific CA/OR/WA stock.
of 500 to 1,000 m Ocean.
depth.
Hubbs' beaked (Mesoplodon Pelagic........... Rare, continental North Pacific 694 (389)-- NL................ NC.
carlhubbsi). slope region, Ocean. Mesoplodon spp.
generally seaward CA/OR/WA stock.
of 500 to 1,000 m
depth.
[[Page 36750]]
Killer whale (Orcinus orca). Pelagic, shelf, Varies on inter- Cosmopolitan...... 240 (162)--Eastern NL................ NC.
coastal, pack ice. annual basis, North Pacific
likely in winter Offshore stock.
(January to 346 (346)--Eastern
February). North Pacific
Transient stock..
354 (354)--West
Coast Transient
stock..
Short-finned pilot whale Pelagic, shelf, Uncommon, more Warm temperate to 760 (465)--CA/OR/ NL................ NC.
(Globicephala coastal. common before tropical waters, WA stock.
macrorhynchus). 1982. ~50[deg] North to
40[deg] South.
Bottlenose dolphin (Tursiops Offshore, inshore, Offshore stock-- Tropical and 1,006 (684)--CA/OR/ NL................ NC.
truncatus). coastal, Year-round temperate waters WA Offshore stock.
estuaries. presence. between 45[deg] 323 (290)--
Coastal stock-- North and South. California
Limited, small Coastal stock..
population within
1 km of shore.
Striped dolphin (Stenella Off continental Occasional visitor Tropical to 10,908 (8,231)--CA/ NL................ NC.
coeruleoalba). shelf. temperate waters, OR/WA stock.
50[deg] North to
40[deg] South.
Short-beaked common dolphin Shelf, pelagic, Common, more Tropical to 411,211 (343,990)-- NL................ NC.
(Delphinus delphis). seamounts. abundant in temperate waters CA/OR/WA stock.
summer. of Atlantic and
Pacific Ocean.
Long-beaked common dolphin Inshore........... Common, more Nearshore and 107,016 (76,224)-- NL................ NC.
(Delphinus capensis). inshore tropical waters. California stock.
distribution,
year-round
presence.
Pacific white-sided dolphin Offshore, slope... Common, year- Temperate waters 26,930 (21,406)-- NL................ NC.
(Lagenorhynchus round, more of North Pacific CA/OR/WA,
obliquidens). abundant November Ocean. Northern and
to April. Southern stock.
Northern right whale dolphin Pelagic........... Common, more North Pacific 8,334 (6,019)--CA/ NL................ NC.
(Lissodelphis borealis). abundant November Ocean, 30 to OR/WA stock.
to April. 50[deg] North.
Risso's dolphin (Grampus Deep water, Common, present in Continental slope 6,272 (4,913)--CA/ NL................ NC.
griseus). seamounts. summer, more and outer shelf OR/WA stock.
abundant November of tropical to
to April. temperate waters.
Dall's porpoise Shelf, slope, Common, more North Pacific 42,000 (32,106)-- NL................ NC.
(Phocoenoides dalli). offshore. abundant November Ocean, 30 to CA/OR/WA stock.
to April. 62[deg] North.
Harbor porpoise (Phocoena Coastal and inland AK to Point Shallow temperate NA................ NL................ NC.
phocoena). waters. Conception, CA. to sub-polar
waters of
Northern
Hemisphere.
Pinnipeds:
California sea lion Coastal, shelf.... Common, Channel Eastern North 296,750 (153,337)-- NL................ NC.
(Zalophus californianus). Island breeding Pacific Ocean-- U.S. stock.
sites in summer. Alaska to Mexico.
Steller sea lion (Eumetopias Coastal, shelf.... Rare.............. North Pacific 49,685 (45,916)-- EN--Western stock. D.
jubatus). Ocean--Central Western stock. DL--Eastern stock.
California to 58,334 to 72,223
Korea. (52,847)--Eastern
stock..
Pacific harbor seal (Phoca Coastal........... Common, haul-outs Coastal temperate 30,196 (26,667)-- NL................ NC.
vitulina richardii). and rookeries in to polar regions California stock.
Channel Islands, in Northern
bulk of stock Hemisphere.
north of Point
Conception.
Northern elephant seal Coastal, pelagic Common, haul-outs Eastern and 124,000 (74,913)-- NL................ NC.
(Mirounga angustirostris). when not and rookeries in Central North California
migrating. Channel Islands, Pacific Ocean-- breeding stock.
December to March Alaska to Mexico.
and April to
August, spend 8
to 10 months at
sea.
Northern fur seal Pelagic, offshore. Common, small North Pacific 12,844 (6,722)-- NL................ NC.
(Callorhinus ursinus). population breeds Ocean--Mexico to California stock.
on San Miguel Japan.
Island May to
October.
Guadalupe fur seal Coastal, shelf.... Rare, observed in California to Baja 7,408 (3,028)-- T................. D.
(Arctocephalus townsendi). Channel Islands. California, Mexico to
Mexico. California stock.
[[Page 36751]]
Fissipeds:
Southern sea otter (Enhydra Coastal........... Mainland coastline North Pacific Rim-- 2,826 (2,723)-- T................. D.
lutris nereis). from San Mateo Japan to Mexico. California stock.
County to Santa
Barbara County,
CA San Nicolas
Island.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ NMFS Marine Mammal Stock Assessment Reports.
\2\ U.S. Endangered Species Act: EN = Endangered, T = Threatened, DL = Delisted, and NL = Not listed.
\3\ U.S. Marine Mammal Protection Act: D = Depleted, S = Strategic, and NC = Not Classified.
Further detailed information regarding the biology, distribution,
seasonality, life history, and occurrence of these marine mammal
species in the proposed project area can be found in sections 3 and 4
of ExxonMobil's IHA application. NMFS has reviewed these data and
determined them to be the best available scientific information for the
purposes of the proposed IHA.
Potential Effects of the Specified Activity on Marine Mammals
This section includes a summary and discussion of the ways that the
types of stressors associated with the specified activity (e.g., impact
hammer pile-driving) have been observed to impact marine mammals. This
discussion may also include reactions that we consider to rise to the
level of a take and those that we do not consider to revise to the
level of take (for example, with acoustics), we may include a
discussion of studies that showed animals not reacting at all to sound
or exhibiting barely measureable avoidance). This section is intended
as a background of potential effects and does not consider either the
specific manner in which this activity will be carried out or the
mitigation that will be implemented, and how either of those will shape
the anticipated impacts from this specific activity. The ``Estimated
Take by Incidental Harassment'' section later in this document will
include a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The ``Negligible Impact
Analysis'' section will include the analysis of how this specific
activity will impact marine mammals and will consider the content of
this section, the ``Estimated Take by Incidental Harassment'' section,
the ``Proposed Mitigation'' section, and the ``Anticipated Effects on
Marine Mammal Habitat'' section to draw conclusions regarding the
likely impacts of this activity on the reproductive success or
survivorship of individuals and from that on the affected marine mammal
populations or stocks.
Acoustic Impacts
When considering the influence of various kinds of sound on the
marine environment, it is necessary to understand that different kinds
of marine life are sensitive to different frequencies of sound. Based
on available behavioral data, audiograms have been derived using
auditory evoked potentials, anatomical modeling, and other data,
Southall et al. (2007) designate ``functional hearing groups'' for
marine mammals and estimate the lower and upper frequencies of
functional hearing of the groups. The functional groups and the
associated frequencies are indicated below (though animals are less
sensitive to sounds at the outer edge of their functional range and
most sensitive to sounds of frequencies within a smaller range
somewhere in the middle of their functional hearing range):
Low-frequency cetaceans (13 species of mysticetes):
Functional hearing is estimated to occur between approximately 7 Hz and
30 kHz;
Mid-frequency cetaceans (32 species of dolphins, six
species of larger toothed whales, and 19 species of beaked and
bottlenose whales): Functional hearing is estimated to occur between
approximately 150 Hz and 160 kHz;
High-frequency cetaceans (eight species of true porpoises,
six species of river dolphins, Kogia spp., the franciscana (Pontoporia
blainvillei), and four species of cephalorhynchids): Functional hearing
is estimated to occur between approximately 200 Hz and 180 kHz; and
Phocid pinnipeds in water: Functional hearing is estimated
to occur between approximately 75 Hz and 100 kHz;
Otariid pinnipeds in water: Functional hearing is
estimated to occur between approximately 100 Hz and 40 kHz.
As mentioned previously in this document, 30 marine mammal species
managed under NMFS jurisdiction (26 cetacean and 4 pinniped species)
are likely to occur in the proposed action area. Of the 26 cetacean
species likely to occur in ExxonMobil's proposed action area, 6 are
classified as low-frequency cetaceans (i.e., gray, humpback, minke,
sei, fin, and blue whale), 18 are classified as mid-frequency cetaceans
(i.e., sperm, Baird's beaked, Cuvier's beaked, Blainville's beaked,
Perrin's beaked, Lesser beaked, Stejneger's beaked, Ginkgo-toothed
beaked, Hubb's beaked, killer, and short-finned pilot whale, as well as
bottlenose, striped, short-beaked common, long-beaked common, Pacific
white-sided, northern right whale, and Risso's dolphin), 2 are
classified as high-frequency cetaceans (i.e., pygmy sperm whale and
Dall's porpoise), 2 are classified as phocids (i.e., harbor and
northern elephant seal), and 2 are classified as otariid pinnipeds
(i.e., California sea lion and northern fur seal) (Southall et al.,
2007). A species' functional hearing group is a consideration when we
analyze the effects of exposure to sound on marine mammals.
Current NMFS practice, regarding exposure of marine mammals to
high-level underwater sounds is that cetaceans and pinnipeds exposed to
impulsive sounds at or above 180 and 190 dB (rms), respectively, have
the potential to be injured (i.e., Level A harassment). NMFS considers
the potential for Level B (behavioral) harassment to occur when marine
mammals are exposed to sounds below injury thresholds but at or above
the 160 dB (rms) threshold for impulse sounds (e.g., impact pile-
driving) and the 120 dB (rms) threshold for continuous noise
[[Page 36752]]
(e.g., vibratory pile-driving). No vibratory pile-driving is planned
for ExxonMobil's proposed activity in the Santa Barbara Channel.
Current NMFS practice, regarding exposure of marine mammals to high-
level in-air sounds, as a threshold for potential Level B harassment,
is at or above 90 dB re 20 [micro]Pa for harbor seals and at or above
100 dB re 20 [micro]Pa for all other pinniped species (Lawson et al.,
2002; Southall et al., 2007). NMFS has not established a threshold for
Level A harassment for marine mammals exposed to in-air noise; however,
Southall et al. (2007) recommends 149 dB re 20 [micro]Pa (peak) (flat)
as the potential threshold for injury from in-air noise for all
pinnipeds.
Acoustic stimuli generated by the conductor pipe installation
activities, which introduce sound into the marine environment and in-
air, may have the potential to cause Level B harassment of marine
mammals in the proposed action area. The effects of sounds from impact
hammer pile-driving activities might include one or more of the
following: tolerance, masking of natural sounds, behavioral
disturbance, temporary or permanent hearing impairment, or non-auditory
physical or physiological effects (Richardson et al., 1995; Gordon et
al., 2004; Nowacek et al., 2007; Southall et al., 2007). Permanent
hearing impairment, in the unlikely event that it occurred, would
constitute injury, but temporary threshold shift (TTS) is not an injury
(Southall et al., 2007). Although the possibility cannot be entirely
excluded, it is unlikely that the proposed project would result in any
cases of temporary or permanent hearing impairment, or any significant
non-auditory physical or physiological effects. Based on the available
data and studies described here, some behavioral disturbance is
expected.
The effects of pile-driving on marine mammals depend on several
factors, including the size, type, and depth of the animal; the depth,
intensity, and duration of the pile-driving sound; the depth of the
water column; the substrate of the habitat; the standoff distance
between the pile and the animals; and the sound propagation properties
of the environment. Impacts to marine mammals from pile-driving
activities are expected to result primarily from acoustic pathways. As
such, the degree of effect is intrinsically related to the received
level and duration of the sound exposure, which are in turn influenced
by the distance between the animal and the source. The further away
from the source, the less intense the exposure should be. The substrate
and depth of the habitat affect the sound propagation properties of the
environment. Shallow environments are typically more structurally
complex, which leads to rapid sound attenuation. In addition,
substrates that are soft (e.g., sand) would absorb or attenuate the
sound more readily than hard substrates (e.g., rock), which may reflect
the acoustic wave. Soft porous substrates would also likely require
less time to drive the pipe, and possibly less forceful equipment,
which would ultimately decrease the intensity of the acoustic source.
In the absence of mitigation, impacts to marine mammal species may
result from physiological and behavioral responses to both the type and
strength of the acoustic signature (Viada et al., 2008). The type and
severity of behavioral impacts are difficult to define due to limited
studies addressing the behavioral effects of impulse sounds on marine
mammals. Potential effects from impulsive sound sources can range in
severity, ranging from effects such as behavioral disturbance, tactile
perception, physical discomfort, slight injury, of the internal organs
and the auditory system, to mortality (Yelverton et al., 1973).
Tolerance
Richardson et al. (1995) defines tolerance as the occurrence of
marine mammals in areas where they are exposed to human activities or
man-made noise. In many cases, tolerance develops by the animal
habituating to the stimulus (i.e., the gradual waning of responses to a
repeated or ongoing stimulus) (Richardson, et al., 1995; Thorpe, 1963),
but because of ecological or physiological requirements, many marine
animals may need to remain in areas where they are exposed to chronic
stimuli (Richardson, et al., 1995).
Numerous studies have shown that pulsed underwater sounds from
industry activities are often readily detectable in the water at
distances of many kilometers. Several studies have shown that marine
mammals at distances more than a few kilometers often show no apparent
response (Miller et al., 2005; Bain and Williams, 2006). That is often
true even in cases when the pulsed sounds must be readily audible to
the animals based on measured received levels and the hearing
sensitivity of the marine mammal group. Although various baleen whales
and toothed whales, and (less frequently) pinnipeds have been shown to
react behaviorally to airgun pulses under some conditions, at other
times marine mammals of all three types have shown no overt reactions
(e.g., Malme et al., 1986; Richardson et al., 1995; Madsen and Mohl,
2000; Croll et al., 2001; Jacobs and Terhune, 2002; Madsen et al.,
2002; Miller et al., 2005). The relative responsiveness of baleen and
toothed whales are quite variable.
Masking
The term masking refers to the inability of a subject to recognize
the occurrence of an acoustic stimulus as a result of the interference
of another acoustic stimulus (Clark et al., 2009). Introduced
underwater sound may, through masking, reduce the effective
communication distance of a marine mammal species if the frequency of
the source is close to that used as a signal by the marine mammal, and
if the anthropogenic sound is present for a significant fraction of the
time (Richardson et al., 1995).
Natural and artificial sounds can disrupt behavior by masking, or
interfering with, a marine mammal's ability to hear other sounds.
Masking occurs when the receipt of a sound is interfered with by
another coincident sound at similar frequencies and at similar or
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular frequencies for
marine mammals that utilize sound for vital biological functions.
Masking can interfere with detection of acoustic signals such as
communication calls, echolocation sounds, and environmental sounds
important to marine mammals. Therefore, under certain circumstances,
marine mammals whose acoustic sensors or environment are being severely
masked could also be impaired from maximizing their performance fitness
in survival and reproduction. If the coincident (masking) sound were
man-made, it could be potentially harassing if it disrupted hearing-
related behavior. It is important to distinguish TTS and PTS, which
persist after the sound exposure, from masking, which occurs during the
sound exposure. Because masking (without resulting in threshold shift)
is not associated with abnormal physiological function, it is not
considered a physiological effect, but rather a potential behavioral
effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. Because sound
generated from in-water pile-driving is mostly concentrated at low
frequency ranges, it may have less effect on high frequency
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls
and other potentially important natural sounds such as surf and prey
sound. It
[[Page 36753]]
may also affect communication signals when they occur near the sound
band and thus reduce the communication space of animals (e.g., Clark et
al., 2009) and cause increased stress levels (e.g., Foote et al., 2004;
Holt et al., 2009).
Masking has the potential to impact species at population,
community, or even ecosystem levels, as well as at individual levels.
Masking affects both senders and receivers of the signals and can
potentially have long-term chronic effects on marine mammal species and
populations. Recent research suggests that low frequency ambient sound
levels have increased by as much as 20 dB (more than three times in
terms of SPL) in the world's ocean from pre-industrial periods, and
that most of these increases are from distant shipping (Hildebrand,
2009). All anthropogenic sound sources, such as those from vessel
traffic, pile-driving, and dredging activities, contribute to the
elevated ambient sound levels, thus intensifying masking. However, much
of the sound generated from the proposed activities is not expected to
contribute significantly to increased ocean ambient sound.
Given that the energy distribution of pile-driving covers a broad
frequency spectrum, sound from these sources would likely be within the
audible range of marine mammals present in the proposed action area.
Impact pile-driving activity is relatively short-term, with rapid
pulses occurring for the duration of the driving event. The probability
that impact pile-driving resulting from this proposed action would mask
acoustic signals important to the behavior and survival of marine
mammal species is likely to be discountable. Any masking event that
could possibly rise to Level B harassment under the MMPA would occur
concurrently within the zones of behavioral harassment already
estimated for impact pile-driving, and which have already been taken
into account in the exposure analysis.
Behavioral Disturbance
Marine mammals may behaviorally react to sound when exposed to
anthropogenic noise. Disturbance includes a variety of effects,
including subtle to conspicuous changes in behavior, movement, and
displacement. Behavioral responses to sound are highly variable and
context-specific and reactions, if any, depend on species, state of
maturity, experience, current activity, reproductive state, time of
day, and many other factors (Richardson et al., 1995; Wartzok et al.,
2004; Southall et al., 2007; Weilgart, 2007).
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure. Behavioral state may affect the type of response as well. For
example, animals that are resting may show greater behavioral change in
response to disturbing sound levels than animals that are highly
motivated to remain in an area for feeding (Richardson et al., 1995;
NRC, 2003; Wartzok et al., 2003).
Controlled experiments involving exposure to loud impulse sound
sources with captive marine mammals showed pronounced behavioral
reactions, including avoidance of loud sound sources (Ridgeway et al.,
1997; Finneran et al., 2003). Observed responses of wild marine mammals
to loud pulsed sound sources (typically seismic airguns or acoustic
harassment devices, but also including impact pile-driving) have been
varied but often consist of avoidance behavior or other behavioral
changes suggesting discomfort (Morton and Symonds, 2002; Thorson and
Reyff, 2006; see also Gordon et al., 2004; Wartzok et al., 2003;
Nowacek et al., 2007).
It is likely that the onset of pile-driving could result in
temporary, short-term changes in an animal's typical behavior and/or
avoidance of the affected action area. These behavioral reactions are
often shown as: Changing durations of surfacing and dives, number of
blows per surfacing, or moving direction and/or speed; reduced/
increased vocal activities; changing/cessation of certain behavioral
activities (such as socializing or feeding); visible startle response
or aggressive behavior (such as tail/fluke slapping or jaw clapping);
avoidance of areas where noise sources are located; and/or flight
responses (e.g., pinnipeds flushing into the water from haul-outs or
rookeries). If a marine mammal does react briefly to an underwater
sound by changing its behavior or moving a small distance, the impacts
of the change are unlikely to be significant to the individual, let
alone the stock or population. However, if a sound source displaces
marine mammals from an important feeding or breeding area for a
prolonged period, impacts on individuals and populations could be
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be expected to be biologically significant if the
change affects growth, survival, and/or reproduction. Some of these
significant behavioral modifications that could potentially lead to
effects on growth, survival, or reproduction include:
Change in diving/surfacing patterns (such as those thought
to be causing beaked whale stranding due to exposure to military mid-
frequency tactical sonar);
Habitat abandonment due to loss of desirable acoustic
environment; and
Cessation of feeding or social interaction.
The onset of behavioral disturbance from anthropogenic noise
depends on both external factors (characteristics of noise sources and
their paths) and the specific characteristics of receiving animals
(hearing, motivation, experience, demography) and is also difficult to
predict (Richardson et al., 1995; Southall et al., 2007). Given the
many uncertainties in predicting the quantity and types of impacts of
noise on marine mammals, it is common practice to estimate how many
mammals would be present within a particular distance of industrial
activities and/or exposed to a particular level of sound. In most
cases, this approach likely overestimates the numbers of marine mammals
that would be affected in some biologically-important manner.
Hearing Impairment and Other Physical Effects
Marine mammals exposed to high intensity sound repeatedly or for
prolonged periods can experience hearing threshold shift, which is the
loss of hearing sensitivity at certain frequency ranges (Kastak et al.,
1999; Schlundt et al., 2000; Finneran et al., 2002, 2005). Threshold
shift can be permanent (PTS), in which case the loss of hearing
sensitivity is not recoverable, or temporary (TTS), in which case the
animal's hearing threshold would recover over time (Southall et al.,
2007). Marine mammals depend on acoustic cues for vital biological
functions (e.g., orientation, communication, finding prey, avoiding
predators); thus, TTS may result in reduced fitness in survival and
reproduction. However, this depends on the frequency and duration of
TTS, as well as the biological context in which it occurs. TTS of
limited duration, occurring in a frequency range that does not coincide
with that used for recognition of important acoustic cues, would have
little to no effect on an
[[Page 36754]]
animal's fitness. Repeated sound exposures that lead to TTS could cause
PTS. PTS, in the unlikely event that it occurred, would constitute
injury, but TTS is not considered injury (Southall et al., 2007). It is
unlikely that the project would result in any cases of temporary or
especially permanent hearing impairment or any significant non-auditory
physical or physiological effects for reasons discussed later in this
document. Some behavioral disturbance is expected, but it is likely
that this would be localized and short-term because of the short
duration of the proposed action.
Many marine mammals are likely to show some avoidance of the
proposed action area where received levels of pile-driving sound high
enough that hearing impairment could potentially occur. In those cases,
the avoidance responses of the animals themselves would reduce or (most
likely) avoid any possibility of hearing impairment. Non-auditory
physical effects may also occur in marine mammals exposed to strong
underwater pulsed sound.
Temporary Threshold Shift--TTS is the mildest form of hearing
impairment that can occur during exposure to a strong sound (Kryter,
1985). While experiencing TTS, the hearing threshold rises and a sound
must be stronger in order to be heard. At least in terrestrial mammals,
TTS can last from minutes or hours to (in cases of strong TTS) days.
For sound exposures at or somewhat above the TTS threshold, hearing
sensitivity in both terrestrial and marine mammals recovers rapidly
after exposure to the noise ends. Few data on sound levels and
durations necessary to elicit mild TTS have been obtained for marine
mammals, and none of the published data concern TTS elicited by
exposure to multiple pulses of sound. Available data on TTS in marine
mammals are summarized in Southall et al. (2007). Table 2 (above)
presents the estimated distances from the impact hammer during pile-
driving activities at which the received energy level (per pulse, flat-
weighted) would be expected to be greater than or equal to 180 and 190
dB re 1 [micro]Pa (rms).
To avoid the potential for injury (Level A harassment), NMFS (1995,
2000) concluded that cetaceans and pinnipeds should not be exposed to
pulsed underwater noise at received levels exceeding 180 and 190 dB re
1 [mu]Pa (rms), respectively. The established 180 and 190 dB (rms)
criteria are not considered to be the levels above which TTS might
occur. Rather, they are the received levels above which, in the view of
a panel of bioacoustics specialists convened by NMFS before TTS
measurements for marine mammals started to become available, one could
not be certain that there would be no injurious effects, auditory or
otherwise, to marine mammals. NMFS also assumes that cetaceans and
pinnipeds exposed to levels exceeding 160 dB re 1 [mu]Pa (rms) may
experience Level B harassment.
For toothed whales, researchers have derived TTS information for
odontocetes from studies on the bottlenose dolphin and beluga whale
(Delphinapterus leucas). The experiments show that exposure to a single
impulse at a received level of 207 kPa (or 30 psi, p-p), which is
equivalent to 228 dB re 1 Pa (p-p), resulted in a 7 and 6 dB TTS in the
beluga whale at 0.4 and 30 kHz, respectively. Thresholds returned to
within 2 dB of the pre-exposure level within 4 minutes of the exposure
(Finneran et al., 2002). For the one harbor porpoise tested, the
received level of airgun sound that elicited onset of TTS was lower
(Lucke et al., 2009). If these results from a single animal are
representative, it is inappropriate to assume that onset of TTS occurs
at similar received levels in all odontocetes (cf. Southall et al.,
2007). Some cetaceans apparently can incur TTS at considerably lower
sound exposures than are necessary to elicit TTS in the bottlenose
dolphin or beluga whale.
For baleen whales, there are no data, direct or indirect, on levels
or properties of sound that are required to induce TTS. The frequencies
to which baleen whales are most sensitive are assumed to be lower than
those to which odontocetes are most sensitive, and natural background
noise levels at those low frequencies tend to be higher. As a result,
auditory thresholds of baleen whales within their frequency band of
best hearing are believed to be higher (less sensitive) than are those
of odontocetes at their best frequencies (Clark and Ellison, 2004).
From this, it is suspected that received levels causing TTS onset may
also be higher in baleen whales than those of odontocetes (Southall et
al., 2007).
In pinnipeds, researchers have not measured TTS thresholds
associated with exposure to brief pulses (single or multiple) of
underwater sound. Initial evidence from more prolonged (non-pulse)
exposures suggested that some pinnipeds (harbor seals in particular)
incur TTS at somewhat lower received levels than do small odontocetes
exposed for similar durations (Kastak et al., 1999, 2005; Ketten et
al., 2001). The TTS threshold for pulsed sounds has been indirectly
estimated as being an SEL of approximately 171 dB re 1 [mu]Pa
\2\[middot]s (Southall et al., 2007) which would be equivalent to a
single pulse with a received level of approximately 181 to 186 dB re 1
[mu]Pa (rms), or a series of pulses for which the highest rms values
are a few dB lower. Corresponding values for California sea lions and
northern elephant seals are likely to be higher (Kastak et al., 2005).
Permanent Threshold Shift--When PTS occurs, there is physical
damage to the sound receptors in the ear. In severe cases, there can be
total or partial deafness, whereas in other cases, the animal has an
impaired ability to hear sounds in specific frequency ranges (Kryter,
1985). There is no specific evidence that exposure to pulses of airgun
or pile-driving sound can cause PTS in any marine mammal. However,
given the possibility that mammals close to an airgun array might incur
at least mild TTS, there has been further speculation about the
possibility that some individuals occurring very close to airguns might
incur PTS (e.g., Richardson et al., 1995, p. 372ff; Gedamke et al.,
2008). Single or occasional occurrences of mild TTS are not indicative
of permanent auditory damage, but repeated or (in some cases) single
exposures to a level well above that causing TTS onset might elicit
PTS.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals but are assumed to be similar to those in humans and
other terrestrial mammals (Southall et al., 2007). PTS might occur at a
received sound level at least several dBs above that inducing mild TTS
if the animal were exposed to strong sound pulses with rapid rise
times. Based on data from terrestrial mammals, a precautionary
assumption is that the PTS threshold for impulse sounds (such as an
impact hammer pile-driving as received close to the source) is at least
6 dB higher than the TTS threshold on a peak-pressure basis, and
probably greater than 6 dB (Southall et al., 2007).
Given the higher level of sound necessary to cause PTS as compared
with TTS, it is considerably less likely that PTS would occur. Baleen
whales generally avoid the immediate area around operating sound
sources, as do some other marine mammals.
Non-auditory Physiological Effects--Non-auditory physiological
effects or injuries that theoretically might occur in marine mammals
exposed to strong underwater sound include stress, neurological
effects, bubble formation, resonance, and other types of organ or
tissue damage (Cox et al., 2006; Southall et al., 2007). Studies
examining such effects are limited.
[[Page 36755]]
In general, very little is known about the potential for pile-
driving sounds (or other types of strong underwater sounds) to cause
non-auditory physical effects in marine mammals. Such effects, if they
occur at all, would presumably be limited to short distances from the
sound source and to activities that extend over a prolonged period. The
available data do not allow identification of a specific exposure level
above which non-auditory effects can be expected (Southall et al.,
2007), or any meaningful quantitative predictions of the numbers (if
any) of marine mammals that might be affected in those ways. Marine
mammals that show behavioral avoidance of pile-driving, including most
baleen whales, some odontocetes, and some pinnipeds, are especially
unlikely to incur auditory impairment or non-auditory physical effects.
Airborne Sound Effects
Marine mammals that occur in the proposed project area could be
exposed to airborne sounds associated with pile-driving that have the
potential to cause harassment, depending on their distance from pile-
driving activities. Airborne pile-driving sound would have less impact
on cetaceans than pinnipeds because sound from atmospheric sources does
not transmit well underwater (Richardson et al., 1995); thus, airborne
sound would only be an issue for pinnipeds in the proposed action area,
whether hauled-out or in the water with their heads in the air. Most
likely, a sound would cause behavioral responses similar to those
discussed above in relation to underwater sound. For instance,
anthropogenic sound could cause hauled-out pinnipeds to exhibit changes
in their normal behavior, such as reduction in vocalizations, or cause
them to temporarily abandon their habitat and move further from the
source. Studies by Blackwell et al. (2004) and Moulton et al. (2005)
indicate a tolerance or lack of response to unweighted airborne sounds
as high as 112 dB peak and 96 dB rms.
The potential effects to marine mammals described in this section
of the document do not take into consideration the proposed monitoring
and mitigation measures described later in this document (see the
``Proposed Mitigation'' and ``Proposed Monitoring and Reporting''
sections) which, as noted are designed to effect the least practicable
impact on affected marine mammal species and stocks.
Anticipated Effects on Marine Mammal Habitat
The proposed activities at the Harmony Platform would not result in
permanent impacts to habitats used directly by marine mammals, but may
have potential short-term impacts to food sources such as forage fish
and invertebrates, and may affect acoustic habitat. There are no
rookeries or major haul-out sites, no known foraging hot-spots, or
other ocean bottom structure of significant biological importance to
marine mammals present in the marine waters in the vicinity of the
proposed action area. Therefore, the main impact issue associated with
the proposed activity would be temporarily elevated sound levels and
associated direct effects on marine mammals, as discussed previously in
this document. The most likely impact to marine mammal habitat occurs
from pile-driving effects on likely marine mammal prey near the Harmony
Platform and minor impacts to the immediate substrate during conductor
pipe installation.
Anticipated Effects on Potential Prey
Common prey for cetaceans and pinnipeds in the proposed action area
include a wide variety of nekton species spanning the water column
pelagic, epipelagic, benthopelagic and demersal zones. The most common
prey groups found in the area are hagfish, lampreys, cartilaginous, and
bony fish (including anchovies), and large free swimming invertebrates
(e.g., squids). Pinnipeds could also be considered prey for large
cetaceans (e.g., killer whales). Prey for baleen whales (e.g., blue
whale) include large zooplankton (e.g., krill), opportunistically
consumed during migration/transit through the Santa Barbara Channel.
Infaunal benthic amphipods exist in the proposed action area and are
common prey items for feeding gray whales, but the Santa Barbara
Channel is not known as a feeding ground for this species.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds. Short duration, sharp sounds can
cause overt or subtle changes in fish behavior and local distribution.
Hastings and Popper (2005) and Hastings (2009) identified several
studies that suggest fish may relocate to avoid certain areas of sound
energy. Additional studies have documented effects of pile-driving (or
other types of sounds) on fish, although several are based on studies
in support of large multi-year bridge construction projects (e.g.,
Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Sound pulses
at received levels of 160 dB re 1 [mu]Pa may cause subtle changes in
fish behavior. SPLs of 180 dB may cause noticeable changes in behavior
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient
strength have been known to cause injury to fish and fish mortality.
The most likely impact to fish from pile-driving activities in the
proposed action area would be temporary behavioral avoidance of the
area. The duration of fish avoidance of this area after pile-driving
stops is unknown, but a rapid return to normal recruitment,
distribution, and behavior is anticipated. In general, impacts to
marine mammal prey species are expected to be minor and temporary due
to the short timeframe for the proposed activities. However, adverse
impacts may occur to a few species of fish which may be present in the
proposed action area.
Anticipated Effects on Potential Foraging Habitat
The Harmony Platform has been in place for 20 years and the
addition of six conductor pipes to the existing 51 conductor pipes
within the platform structure would not produce a quantifiable impact
to marine mammals to their existing habitat. The additional six
conductor pipes are approved (permitted) as part of the original
Development Production Plan for Harmony Platform.
The area likely impacted by the project activities is relatively
small compared to the available habitat in the Santa Barbara Channel
waters. The likelihood for avoidance by potential prey (i.e., fish and
invertebrates) of the immediate area due to the temporary loss of this
foraging habitat is unknown, but a rapid return to normal recruitment,
distribution, and behavior is anticipated. Any behavioral avoidance by
fish of the disturbed area would still leave significantly large areas
of prey and marine mammal foraging habitat in the nearby vicinity.
Given the short hourly duration of sound associated with individual
pile-driving activities and the relatively small areas being affected,
pile-driving activities associated with the proposed action are not
likely to have a permanent, adverse effect on any fish habitat, or
populations of fish and invertebrate species. Therefore, pile-driving
is not likely to have a permanent, adverse effect on marine mammal
foraging habitat at the proposed action area. Furthermore, the area
around Harmony Platform in the Santa Barbara Channel, is already
altered by various shipping activities.
[[Page 36756]]
There would be no measureable loss of existing marine mammal water
column or benthic habitat resulting from the installation of six
conductor pipes at Harmony Platform. The impacts associated with the
proposed project are temporary and are not expected to have long term
effects on marine mammals or marine mammal habitat. The primary impact
of the activity on the local environment is from sound, above and below
water surface to a depth of 366 m. The transitory nature of sound would
not impact the habitat of the marine mammal populations. A secondary
impact from the activity would be the temporary suspension of bottom
sediment, resulting from the installation via hammer driving of six 26-
in diameter steel conductor pipes within the platform jacket structure.
The small amount of suspended sediment would quickly disperse and
resettle to the seafloor. No permanent impacts are expected to marine
mammals. The impacts are temporary in nature and are associated with
pile-driving and construction noise disturbance and would not require
restoration. Site conditions are anticipated to be unchanged from
existing conditions for marine mammals following project
implementation.
There is no potential for an oil spill from operations/activities
associated with this project. Potential impacts from an oil spill from
existing operations are addressed in an approved Oil Spill Response
Plan on file with BOEM for the Santa Ynez Production Unit, including
Harmony Platform. Any potential spill from the supply boats or
helicopters are already included in the approved operation and plan.
Based on the preceding discussion of potential types of impacts to
marine mammal habitat, overall, NMFS anticipates that the proposed
action is not expected to cause significant impacts on habitats used by
the marine mammal species in the proposed action area or on the food
sources that they utilize.
Proposed Mitigation
In order to issue an Incidental Take Authorization (ITA) under
section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible
methods of taking pursuant to such activity, and other means of
effecting the least practicable impact on such species or stock and its
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance, and the availability of such species or
stock for taking for certain subsistence uses (where relevant).
ExxonMobil has incorporated a suite of appropriate mitigation
measures into its project description (see Section 11 of the IHA
application).
To reduce the potential for disturbance from acoustic stimuli
associated with the proposed activities, ExxonMobil and/or its
designees have proposed to implement the following mitigation measures
for marine mammals:
(1) Proposed buffer and exclusion zones around the sound source;
(2) Hours of operation;
(3) Shut-down procedures; and
(4) Ramp-up procedures.
Proposed Exclusion Zones--ExxonMobil uses radii to designate
exclusion and buffer zones and to estimate take for marine mammals.
Table 2 (presented earlier in this document) shows the distances at
which one would expect marine mammal exposures to three received sound
levels (160, 180, and 190 dB) from the impact hammer. The 180 and 190
dB level shut-down criteria are applicable to cetaceans and pinnipeds,
respectively, as specified by NMFS (2000). ExxonMobil used these levels
to establish the exclusion and buffer zones.
Based on the modeling, exclusion zones (for triggering a shut-down)
for Level A harassment would be established for cetaceans and pinnipeds
at 3.5 m (11.5 ft) and 10 m (32.8 ft) from the conductor pipe sound
source, respectively. These shut-down zones would be monitored by a
dedicated PSO. If the PSO detects a marine mammal(s) within or about to
enter the appropriate exclusion zone, the pile-driving activities would
be shut-down immediately. If marine mammals are present within the
shut-down zone before impact pile-driving activities begin, start of
operations would be delayed until the exclusion zones are clear for at
least 30 minutes. If marine mammals appear in the shut-down zone during
proposed pile-driving activities, the PSO would instruct the hammer
operator to halt all operations in a safe, but immediate manner. Pile-
driving activities would only resume once the exclusion zone has been
cleared for at least 30 minutes. In the unlikely event that the marine
mammal enters the exclusion zone during pile-driving activities, the
exposure and behaviors would be documented and reported by the PSO and
NMFS would be contacted within 24 hours. A non-PSO safety spotter would
also be assigned to the lower deck observation area. All personnel
operating at the lower observation levels would be required to wear
appropriate personal protective equipment.
Hours of Operation--The proposed activities would be conducted on a
continual 24-hour basis; therefore, some of the 2.5 to 3.3 hours of
active impact pile-driving periods would be expected to occur during
non-daylight hours. To facilitate visual monitoring during non-daylight
hours, the exclusion zones would be illuminated to permit more
effective viewing by the PSO. Lighting would not be expected to attract
marine mammals. The areas where the exclusion zones occur fall within
the jacket structure of the platform, and therefore could be easily
illuminated by lights and monitored during non-daylight hours. For the
buffer zone, which would extend out to 325 m (1,066.3 ft) from the
conductor pipe, PSOs would be stationed on an upper deck of the Harmony
Platform to monitor for marine mammals during the proposed pile-driving
activities. During non-daylight hours, PSOs would utilize night-vision
devices and other appropriate equipment to monitor marine mammals. If
nighttime visual aids are insufficient, ExxonMobil proposes to use
daytime visual counts of marine mammals as an estimate of the number of
marine mammals present during non-daylight hours (within a 24 hour
period), noting that diurnal activities for most marine mammals are
expected to vary somewhat.
Shut-down Procedures--ExxonMobil would shut-down the operating
hammer if a marine mammal is detected outside the exclusion zone, and
the sound source would be shut-down before the animal is within the
exclusion zone. Likewise, if a marine mammal is already within the
exclusion zone when first detected, the sound source would be shut-down
immediately.
Following a shut-down, ExxonMobil would not resume pile-driving
activities until the marine mammal has cleared the exclusion zone.
ExxonMobil would consider the animal to have cleared the exclusion zone
if:
A PSO has visually observed the animal leave the exclusion
zone, or
A PSO has not sighted the animal within the exclusion zone
for 15 minutes for species with shorter dive durations (i.e., small
odontocetes and pinnipeds), or 30 minutes for species with longer dive
durations (i.e., mysticetes and large odontocetes, including sperm,
pygmy and dwarf sperm, killer, and beaked whales).
All visual monitoring would be conducted by qualified PSOs. Visual
monitoring would be conducted continuously during active pile-driving
activities. PSOs would not have any tasks other than visual monitoring
and would conduct monitoring from the best
[[Page 36757]]
vantage point(s) practicable (e.g., on the Harmony Platform or other
suitable location) that provides 360[ordm] visibility of the Level A
harassment exclusion zones and Level B harassment buffer zone, as far
as possible. The PSO would be in radio communication with the hammer
operator during pile-driving activities, and would call for a shut-down
in the event a pinniped or cetacean appears to be headed toward its
respective exclusion zone for cetaceans and pinnipeds.
Ramp-Up Procedures--Ramp-up (sometimes referred to as a ``soft-
start'') of the impact hammer provides a gradual increase in sound
levels until the full sound level is achieved. The purpose of a ramp-up
is to ``warn'' marine mammals in the vicinity of the impact hammer and
to provide the time for them to leave the area avoiding any potential
injury or impairment of their hearing abilities. A ramp-up consists of
an initial set of three strikes from the impact hammer at 40% energy,
followed by a 30 second waiting period, then two subsequent three
strike sets.
The buffer zone would be monitored by PSOs beginning 30 minutes
before pile-driving activities, during pile-driving, and for 30 minutes
after pile-driving stops. During ramp-up, the PSOs would monitor the
exclusion zone, and if marine mammals are sighted, a shut-down would be
implemented.
If the complete exclusion zone has not been visible for at least 30
minutes prior to the start of operations in either daylight or
nighttime, ExxonMobil would not commence the ramp-up. ExxonMobil would
not initiate a ramp-up of the impact hammer if a marine mammal is
sighted within or near the applicable exclusion zones during the day or
close to the Harmony Platform at night.
Oil Spill Plan--ExxonMobil has developed an Oil Spill Response Plan
and it is on file with BOEM.
Mitigation Conclusions
NMFS has carefully evaluated the applicant's proposed mitigation
measures and has considered a range of other measures in the context of
ensuring that NMFS prescribes the means of effecting the least
practicable impact on the affected marine mammal species and stocks and
their habitat. NMFS's evaluation of potential measures included
consideration of the following factors in relation to one another:
(1) The manner in which, and the degree to which, the successful
implementation of the measure is expected to minimize adverse impacts
to marine mammals;
(2) The proven or likely efficacy of the specific measure to
minimize adverse impacts as planned; and
(3) The practicability of the measure for applicant implementation,
including consideration of personnel safety, practicality of
implementation, and impact on the effectiveness of the activity.
Any mitigation measure(s) prescribed by NMFS should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current science), or contribute to the accomplishment of one or more of
the general goals listed below:
(1) Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
(2) A reduction in the numbers of marine mammals (total number or
number at biologically important time or location) exposed to received
levels of hammer pile-driving, or other activities expected to result
in the take of marine mammals (this goal may contribute to 1, above, or
to reducing harassment takes only).
(3) A reduction in the number of times (total number or number at
biologically important time or location) individuals would be exposed
to received levels of hammer pile-driving, or other activities expected
to result in the take of marine mammals (this goal may contribute to 1,
above, or to reducing harassment takes only).
(4) A reduction in the intensity of exposures (either total number
or number at biologically important time or location) to received
levels of hammer pile-driving, or other activities expected to result
in the take of marine mammals (this goal may contribute to a, above, or
to reducing the severity of harassment takes only).
(5) Avoidance of minimization of adverse effects to marine mammal
habitat, paying special attention to the food base, activities that
block or limit passage to or from biologically important areas,
permanent destruction of habitat, or temporary destruction/disturbance
of habitat during a biologically important time.
(6) For monitoring directly related to mitigation--an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on NMFS's evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS or recommended by the public,
NMFS has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable impact on marine
mammal species or stocks and their habitat, paying particular attention
to rookeries, mating grounds, and areas of similar significance.
Proposed Monitoring and Reporting
In order to issue an ITA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth ``requirements pertaining to
the monitoring and reporting of such taking.'' The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for ITAs
must include the suggested means of accomplishing the necessary
monitoring and reporting that would result in increased knowledge of
the species and of the level of taking or impacts on populations of
marine mammals that are expected to be present in the proposed action
area. ExxonMobil submitted a marine mammal monitoring plan as part of
the IHA application. It can be found in Section 13 of the IHA
application. The plan may be modified or supplemented based on comments
or new information received from the public during the public comment
period or from the peer review panel (see the ``Monitoring Plan Peer
Review'' section later in this document).
Monitoring measures prescribed by NMFS should accomplish one or
more of the following general goals:
(1) An increase in the probability of detecting marine mammals,
both within the mitigation zone (thus allowing for more effective
implementation of the mitigation) and in general to generate more data
to contribute to the analyses mentioned below;
(2) An increase in our understanding of how many marine mammals are
likely to be exposed to levels of sound from impact hammer pile-driving
activities that we associate with specific adverse effects, such as
behavioral harassment, TTS or PTS;
(3) An increase in our understanding of how marine mammals respond
to stimuli expected to result in take and how anticipated adverse
effects on individuals (in different ways and to varying degrees) may
impact the population, species, or stock (specifically through effects
on annual rates of recruitment or survival) through any of the
following methods:
Behavioral observations in the presence of stimuli
compared to observations in the absence of stimuli (need to be able to
accurately predict received level, distance from source, and other
pertinent information);
Physiological measurements in the presence of stimuli
compared to observations in the absence of stimuli
[[Page 36758]]
(need to be able to accurately predict receive level, distance from the
source, and other pertinent information);
Distribution and/or abundance comparisons in times or
areas with concentrated stimuli versus times or areas without stimuli;
(4) An increased knowledge of the affected species; and
(5) An increase in our understanding of the effectiveness of
certain mitigation and monitoring measures.
Proposed Monitoring
ExxonMobil proposes to sponsor marine mammal monitoring during the
proposed project, in order to implement the proposed mitigation
measures that require real-time monitoring, and to satisfy the
anticipated monitoring requirements of the IHA. ExxonMobil's proposed
``Monitoring Plan'' is described below this section. ExxonMobil
understand that this monitoring plan would be subject to review by NMFS
and that refinements may be required. Two main types of monitoring
would be performed for this proposed project: (1) in-situ measurement
of sound pressure levels; and (2) visual observations of the number and
type of marine mammals that enter sound exposure zones. In-situ
acoustic data would be used to validate model predictions of sound
pressure levels near and with distance from the conductor pipe sound
source, including the predicted maximum distances for the buffer and
exclusion zones. If measured results differ from modeled results,
measured data would be used to revise buffer and exclusion zone
boundaries to reflect actual conditions during proposed project
activities. Data from visual monitoring would be used to validate take
estimate calculations.
Acoustic Monitoring
Acoustic monitoring using hydrophones and microphones would be
conducted to obtain and validate modeled in-water and in-air sound
levels during the proposed pile-driving activities. Each hydrophone
(in-water) and microphone (in-air) would be calibrated following the
manufacturer's recommendations prior to the start of the proposed
project and checked for accuracy and precision at the end of the data
collection for each conductor pipe or as practical during conductor
pipe installation activities. Environmental data would be collected to
supplement the acoustic monitoring and include: wind speed and
direction, air temperature, humidity, near-surface water temperature,
weather conditions, and other appropriate factors that could contribute
to influencing either in-air or in-water sound transmission levels.
Prior to deploying monitoring equipment, the acoustics specialist would
be provided with the hammer model and size, hammer energy settings, and
projected blows per minute for the conductor pipe segments requiring
hammer pile-driving. Background in-air and in-water sound levels would
be measured at Harmony Platform in the absence of pile-driving
activities to obtain an ambient noise level, and recorded over a
frequency range of 10 Hz to 20 kHz. Ambient noise level measurements
would be conducted before, during, and after the project. The measured
in-air and in-water sound data would be used to recalibrate and refine
the sound propagation model used to determine the buffer and exclusion
zones. Also, sound pressure levels associated with ramp-up techniques
would be measured.
In-Water Monitoring--Acoustic monitoring would be performed at a
minimum of two fixed stations located at 10 m (32.8 ft) and
approximately 325 m (1,066.3 ft) from the conductor pipe sound source.
These distances represent the 180 dB and 160 dB (rms) modeled sound
levels. The following general approach would be used to measure in-
water sound levels:
Acoustic monitoring would be conducted over the entire
pile-driving period for each conductor pipe, starting approximately 1
hour prior to pile-driving through 1 hour after impact hammering has
stopped. Pre- and post-hammer pile-driving data would be used to
determine ambient/background noise levels.
A stationary hydrophone system with the ability to measure
and record sound pressure levels would be deployed at a minimum of two
monitoring locations (stations). SPLs would be recorded in voltage,
converted to microPascals ([micro]Pa), and post-processed to decibels
(dB [re 1 [micro]Pa]). For the first conductor pipe installation,
hydrophones are placed at 10+/-1 m and at 325+/-33 m from the conductor
pipe at depths ranging from 10 to 30 m (32.8 to 98.4 ft) below the
water surface to avoid potential inferences for surface water energy,
and to target the depth range of maximum occurrence of marine mammals
most likely in the area during the project. The equipment would obtain
data for the most likely depth range of marine mammal occurrence.
Horizontal displacement of +/-10% may be expected for instrument
movement due to the water depth and forces from tides, currents, and
storms. Additional hydrophone mooring systems may be deployed at
additional distances and/or depths. Following each successive conductor
pipe installation, the water depth and geographical orientation of the
hydrophone may be changed to validate modeled SPLs at varying water
depths and direction.
At a minimum, the following sound data would be analyzed
(post-processed) from recorded sound levels: absolute peak overpressure
and under pressure levels for each conductor pipe; average, minimum,
and maximum sound pressure levels (rms), integrated from 3 Hz to 20
kHz; average duration of each hammer strike (blow), and total number of
strikes per continuous hammer pile-driving period for each conductor.
In the event that field measurements indicate different sound
pressure levels (rms) values than those predicted by modeling for
either the maximum distances of the buffer or exclusion zones from the
conductor sound source, corresponding boundaries for the buffer and
appropriate exclusion zones would be increased/decreased accordingly,
following NMFS notification, concurrence, and authorization.
In-Air Monitoring--Reference measurements would be made at
approximately 10 to 20 m (32.8 to 65.6 ft) from the initial hammer
strike position using a stationary microphone. The microphone would be
placed as far away from other large sound sources as practical. The in-
air buffer zone predicted for pinnipeds (non-harbor seal, 100 dB re 20
[micro]Pa) was estimated at 41 m (134.5 ft) from the hammer impact
point on the conductor pipe. In-air sound levels would be recorded at
several points around the base of the Harmony Platform at sea level to
validate modeled sound levels. Distances closer to the sound source may
be monitored for model validation purposes, but only if safety issues
are not introduced. Recorded data would be recorded as dB (re 20
[micro]Pa, A-weighted and unweighted) for comparison to in-air noise
thresholds for Level B harassment for pinnipeds.
Platform-Based Visual Monitoring
PSOs would be based aboard the Harmony Platform and would watch for
marine mammals near the platform during conductor pipe installation
activities during daytime and nighttime pile-driving activities. Visual
monitoring for marine mammals would be performed at a minimum during
periods of active hammer pile-driving throughout the proposed project
following general procedures in Baker et al. (2013). Monitoring by PSOs
would begin at least 30 minutes before the start of impact hammer pile-
driving, continue through an estimated 2.5 to 3.3 hours of pile-
driving, and conclude 30
[[Page 36759]]
minutes after pile-driving stops (up to 4.3 hours of monitoring per a
period of pile-driving). Five to 7 periods of impact hammer pile-
driving would be required for each conductor pipe. When feasible, PSOs
would conduct observations during periods when the impact hammer pile-
driving is not operating for comparison of sighting rates and behavior
with and without operations and between pile-driving periods. In
addition to monitoring during pile-driving activities, baseline
monitoring of marine mammals would be performed up to one week before
and one week after conductor pipe installation, as well as selected
periods in between impact hammer pile-driving activities.
The exclusion zone would be monitored to prevent injury to marine
mammal species. Based on PSO observations, the impact hammer pile-
driving would be shut-down when marine mammals are observed within or
about to enter the designated exclusion zone. The exclusion zone is a
region in which a possibility exists of adverse effects on animal
hearing or physical effects. A comprehensive monitoring plan would be
developed to ensure compliance with the IHA for this proposed project.
Methods--There would be a team of 3 PSOs based aboard Harmony
Platform conducting monitoring during active hammer pile-driving
periods. Visual observations would take place during active hammering
periods which includes both daylight and nighttime operations. This
monitoring would occur for approximately 4.3 hours (3.3 hour monitoring
plus 0.5 hour pre- and post-hammering) during a single hammering phase
followed by approximately 6.3 hours of off-duty rest. A total of 5 to 7
observation periods corresponding to the driving of the pipe segments
would be anticipated for each of the six conductors. It is possible
that an impact hammer pile-driving session would take less than 3.3
hours and that the ``rest interval'' for the visual monitors separating
driving segments would be less than 6.3 hours. If driving and rest
intervals are reduced and additional segments are added (e.g., seven
instead of five), two alternating teams of three PSOs may be required.
At the conclusion of impact hammer pile-driving activities for a single
conductor pipe, PSOs may be transferred to shore to await the next
active pile-driving phase.
PSOs would be placed at the best practicable vantage point(s)
(e.g., lower platform level, upper platform level) to monitor the
applicable buffer and exclusion zones for marine mammals. The PSOs
would have authority to implement shut-down/delay ramp-up procedures,
if applicable, by calling the hammer operator for a shut-down via radio
communication. For the buffer zone, two PSOs would be stationed on an
upper platform deck where they have a clear view of the monitoring
area. They would be approximately 180 degrees apart and each would
monitor approximately one-half of the corresponding buffer zone and
beyond with binoculars and other appropriate equipment. For exclusion
zone area, one PSO would concurrently monitor the applicable radii for
pinnipeds and cetaceans, respectively, from a lower level observation
post that provides a clear view of the sea surface around the actively
driven conductor pipe. The lower observation area would be illuminated
during nighttime observations. Visual aids may be used but would not be
required, providing the PSO has a clear view of the sea surface with
the naked eye. A non-PSO safety spotter would also be assigned to the
lower deck observation area. The safety spotter would be available to
deter errant California sea lions using NMFS-recommended methods (see
below) (NMFS, 2008).
All personnel operating on the Harmony Platform would be required
to receive required training and wear appropriate personal protective
equipment. Personal protective equipment is specific to the task,
location, and environmental conditions (e.g., weather, operations
risks). It includes items such as floatation vests, hard hats, steel-
toed shoes, gloves, fire-resistant clothing, gear, eye protection, and
other protective equipment. Details on specific personal protective
equipment items required for PSO and acoustic monitoring would be
determined via the regular work risk assessment process, and would be
presented in the associated monitoring plans for the project.
Equipment for monitoring would include hearing protection from
where observations are made from high noise areas of the platform,
marine radios with headsets, time keeping device (e.g., watch or cell
phone), day and night range finding binoculars (7 x 50 or greater),
notebooks with standardized recording forms, species identification
guides, and a project-specific monitoring plan approved by NMFS (to be
submitted separately).
PSO Qualifications--Monitoring would be conducted by qualified PSOs
defined in Baker et al. (2013) and approved by NMFS. PSOs dedicated to
the proposed project would have no other activity-related tasks.
PSO Data and Documentation
PSOs would record data to estimate the numbers of marine mammals
exposed to various received sound levels and to document apparent
disturbance reactions or lack thereof. Data would be used to estimate
numbers of animals potentially ``taken'' by harassment (as defined in
the MMPA). They would also provide information needed to order a shut-
down of the impact hammer when a marine mammal is within or near the
exclusion zone. Visual observations would also be made during pile-
driving activities as well as daytime periods from the Harmony Platform
when the regular operations would be underway without pile-driving
activities to collect baseline biological data.
When a sighting is made, the following information about the
sighting would be recorded:
1. Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from platform, sighting cue, apparent
reaction to the sound source (e.g., none, avoidance, approach,
paralleling, etc., and including responses to ramp-up), speed of
travel, and duration of presence.
2. Date, time, location, heading, speed, activity of the conductor
pipe installation activities, weather conditions, Beaufort sea state
and wind force, visibility, and sun glare.
The data listed under (2) would also be recorded at the start and
end of each observation watch, and during a watch whenever there is a
change in one or more of the variables.
All observations, as well as information regarding ramp-ups or
shut-downs would be recorded in a standardized format.
Results from the platform-based visual observations would provide
the following information:
1. The basis for real-time mitigation (impact hammer shut-down).
2. Information needed to estimate the number of marine mammals
potentially taken by harassment, which must be reported to NMFS.
3. Data on the occurrence, distribution, and activities of marine
mammals in the area where the conductor pipe installation activities
are conducted.
4. Information to compare the distance and distribution of marine
mammals relative to the source platform at times with and without pile-
driving activities.
5. Data on the behavior and movement patterns of marine mammals
[[Page 36760]]
seen at times with and without pile-driving activities.
Proposed Reporting
ExxonMobil would submit a comprehensive report to NMFS within 90
days after the end of the conductor pipe installation activities and
the expiration of the IHA (if issued). The report would describe the
proposed pile-driving activities that were conducted and sightings of
marine mammals near the operations. The report submitted to NMFS would
provide full documentation of methods, results, and interpretation
pertaining to all monitoring. The 90-day report would summarize the
dates and location of impact hammer pile-driving activities and all
marine mammal sightings (i.e., dates, times, locations, activities, and
associated seismic survey activities). The report would minimally
include:
Summaries of monitoring effort--total hours, total
distances, and distribution of marine mammals through the activity
period accounting for Beaufort sea state and other factors affecting
visibility and detectability of marine mammals;
Analyses of the effects of various factors influencing
detectability of marine mammals including Beaufort sea state, number of
PSOs, and fog/glare;
Species composition, occurrence, and distribution of
marine mammals sightings including date, water depth, numbers, age/
size/gender, and group sizes; and analyses of the effects of
activities;
Sighting rates of marine mammals during periods with and
without impact hammer pile-driving activities (and other variables that
could affect detectability);
Initial sighting distances versus operational activity
state;
Closest point of approach versus operational activity
state;
Observed behaviors and types of movements versus
operational activity state;
Numbers of sightings/individuals seen versus operational
activity state; and
Distribution around the platform versus operational
activity state.
The report would also include estimates of the number and nature of
exposures that could result in ``takes'' of marine mammals by
harassment or in other ways (based on presence in the buffer and/or
exclusion zones). After the report is considered final, it would be
publicly available on the NMFS Web site at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
Reporting Prohibited Take--In the unanticipated event that the
specified activity clearly causes the take of a marine mammal in a
manner prohibited by this IHA, such as an injury (Level A harassment),
serious injury, or mortality (e.g., ship-strike, gear interaction, and/
or entanglement), ExxonMobil would immediately cease the specified
activities and immediately report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS
at 301-427-8401 and/or by email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov and the West Coast Regional Stranding
Coordinator (Justin.Greenman@noaa.gov). The report must include the
following information:
Time, date, and location (latitude/longitude) of the
incident;
Type of activity involved;
Description of the circumstances during and leading up to
the incident;
Status of all sound source use in the 24 hours preceding
the incident;
Water depth;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities shall not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS shall work with ExxonMobil
to determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. ExxonMobil may not resume
their activities until notified by NMFS via letter or email, or
telephone.
Reporting an Injured or Dead Marine Mammal with an Unknown Cause of
Death--In the event that ExxonMobil discovers an injured or dead marine
mammal, and the lead PSO determines that the cause of the injury or
death is unknown and the death is relatively recent (i.e., in less than
a moderate state of decomposition as described in the next paragraph),
ExxonMobil would immediately report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
at 301-427-8401, and/or by email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov, and the NMFS West Coast Regional Office (1-
866-767-6114) and/or by email to the West Coast Regional Stranding
Coordinator (Justin.Greenman@noaa.gov). The report must include the
same information identified in the paragraph above. Activities may
continue while NMFS reviews the circumstances of the incident. NMFS
would work with ExxonMobil to determine whether modifications to the
activities are appropriate.
Reporting an Injured or Dead Marine Mammal Not Related to the
Activities--In the event that ExxonMobil discovers an injured or dead
marine mammal, and the lead PSO determines that the injury or death is
not associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate or advanced
decomposition, or scavenger damage), ExxonMobil would report the
incident to the Chief of the Permits and Conservation Division, Office
of Protected Resources, NMFS, at 301-427-8401, and/or by email to
Jolie.Harrison@noaa.gov and Howard.Goldstein@noaa.gov, and the NMFS
West coast Regional Office (1-866-767-6114) and/or by email to the West
Coast Regional Stranding Coordinator (Justin.Greenman@noaa.gov), within
24 hours of discovery. ExxonMobil would provide photographs or video
footage (if available) or other documentation of the stranded animal
sighting to NMFS and the Marine Mammal Stranding Network. Activities
may continue while NMFS reviews the circumstances of the incident.
Estimated Take by Incidental Harassment
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment].
[[Page 36761]]
Table 4--NMFS's Current Underwater and In-Air Acoustic Exposure Criteria
------------------------------------------------------------------------
Criterion Criterion definition Threshold
------------------------------------------------------------------------
Impulsive (Non-Explosive) Sound
------------------------------------------------------------------------
Level A harassment (injury). Permanent threshold 180 dB re 1
shift (PTS) (Any [micro]Pa-m (root
level above that means square [rms])
which is known to (cetaceans)
cause TTS). 190 dB re 1
[micro]Pa-m (rms)
(pinnipeds).
Level B harassment.......... Behavioral 160 dB re 1
disruption (for [micro]Pa-m (rms).
impulsive noise).
Level B harassment.......... Behavioral 120 dB re 1
disruption (for [micro]Pa-m (rms).
continuous noise).
------------------------------------------------------------------------
In-Air Sound
------------------------------------------------------------------------
Level A harassment.......... NA.................. NA.
Level B harassment.......... Behavioral 90 dB re 20
disruption. [micro]Pa (harbor
seals).
100 dB re 20
[micro]Pa (all
other pinniped
species).
NA (cetaceans).
------------------------------------------------------------------------
Level B harassment is anticipated and proposed to be authorized as
a result of the proposed conductor pipe installation activities at the
Harmony Platform in the Santa Barbara Channel offshore of California.
Acoustic stimuli (i.e., increased underwater and in-air sound)
generated during the pile-driving activities are expected to result in
the behavioral disturbance of some marine mammals. There is no evidence
that the planned activities could result in injury, serious injury, or
mortality for which ExxonMobil seeks the IHA. The required mitigation
and monitoring measures would minimize any potential risk for injury,
serious injury, or mortality.
The following sections describe ExxonMobil's methods to estimate
take by incidental harassment and present the applicant's estimates of
the numbers of marine mammals that could be affected during the
proposed conductor pipe installation activities at the Harmony Platform
in the Santa Barbara Channel offshore of California. The estimated
takes were calculated using information on sound source levels, sound
propagation, maximum distances from the sound source to Level A and
Level B harassment exposure thresholds, and estimated density of marine
mammals in the action area. Take estimates were calculated for in-water
(cetaceans and pinnipeds) and in-air (pinnipeds only). The estimates
are based on the following information:
Thresholds for marine mammals to in-water and in-air
noise;
Sound levels at the conductor pipe from hammer strike;
Sound propagation (transmission/spreading loss) through
the environment (i.e., air, water);
Maximum distances from the sound sources to the
corresponding impact zones (based on Level A and Level B harassment
thresholds) for marine mammals;
Density estimate for each species of marine mammals
(calculated as stock abundance divided by 12,592 km\2\ [3,671.2 nmi\2\]
area [except where noted]); and
Number of takes for each species of marine mammals within
a group (calculated as density multiplied by buffer/exclusion zone
multiplied by days of activity).
Sound levels for impulsive (impact) pile-driving by the hammer and
propagation through water and in-air at the Harmony Platform were
modeled by JASCO Applied Sciences, Ltd. The modeling results are
presented in JASCO's acoustic modeling report as an addendum to the IHA
application titled ``Assessment of Airborne and Underwater Noise from
Pile Driving Activities at the Harmony Platform.'' Methods used to
estimate marine mammal densities and takes for the proposed action area
in the Santa Barbara Channel are presented in Sections 6.1.5 and 6.1.6
of the IHA application for likely exposures to species of marine
mammals.
Densities of marine mammal species likely to occur in the proposed
action area of the Santa Barbara Channel were taken directly from
scientific literature or calculated using corresponding abundances in
NMFS Stock Assessment Reports. Density estimates for the blue, fin, and
humpback whale were taken directly from Redfern et al. (2013), using
the upper limit reported for the density contour that includes the
Harmony Platform. Redfern et al. (2013) estimated densities for these
three species using NMFS sightings collected from primarily August
through November over a period from 1991 to 2009 throughout the Santa
Barbara Channel. Results for blue, fin, and humpback whales are
presented in Figures 6-3, 6-4, and 6-5 of the IHA application. These
densities are considered more accurate than those based on reported
stock abundances because even though they are for the same monthly
period and geographical location, they include a correction factor to
correct for non-observational periods. For calculated densities of
likely affected marine mammal species, stock abundances, which
generally range from the state of Washington to northern Baja
California, Mexico, were assumed to be concentrated within the 12,593
km\2\ (3,671.5 nmi\2\) proposed action area in the Santa Barbara
Channel. The proposed action area includes the Harmony Platform, and
extends 18 km (9.7 nmi) to the north, 60 km (32.4 nmi) to the west, and
70 km (37.8 nmi) to the south of Point Conception, California. The
eastern boundary is 35 km (18.9 nmi) east of Anacapa Island. Use of
this area produces a conservative density estimate because the
geographical range of each marine mammal species evaluated is much
greater than 70 km (nmi) of the coastline selected to represent the
proposed action area, including season-specific ranges for species that
migrate (e.g., gray whale). For marine mammal species potentially
exposed to in-air noise, pinniped densities were calculated by dividing
the stock abundance for each marine mammal species by the 1,130 m\2\
(12,163.2 ft\2\) impact area of the Harmony Platform near sea level
where the animals could potentially haul-out and/or have their heads
out of the water. Tables 6-7 and 6-8 of the IHA application describe
the calculated densities and estimated take by marine mammal species as
well as associated data for the in-water and in-air sound thresholds,
respectively. Although there is some uncertainty about the
representativeness of the data and the assumptions used in the
calculations below, the approach used here is believed to be the best
available approach.
[[Page 36762]]
Table 5--Estimated Densities and Possible Number of Marine Mammal Species That Might Be Exposed to Greater Than or Equal to 160 dB (Pile-Driving
Activities) During ExxonMobil's Proposed Conductor Pipe Installation Activities in the Santa Barbara Channel Offshore of California
--------------------------------------------------------------------------------------------------------------------------------------------------------
Calculated take
from pile-
Calculated driving
take from pile- activities in-
driving air (i.e.,
activities in- estimated number Approximate
Density in water (i.e., of individuals Total requested percentage of
Species action area estimated exposed to sound take Abundance \5\ population/ Population trend
(/ number of levels >=90 dB authorization\4\ stock \5\
km\2\) \1\ individuals re 20 [mu]Pa for estimate \6\
exposed to harbor seals and
sound levels 90 dB re 20
>=160 dB re 1 [mu]Pa for all
[mu]Pa) \2\ other pinnipeds)
\3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mysticetes:
North Pacific right whale.. NA 0 0 0 NA (18 to 21)-- NA NA.
Eastern North
Pacific stock.
Gray whale................. 0.5067 0.693 0 10 19,126 (18,107)-- 0.05 Increasing over
Eastern North past several
Pacific stock. decades--Eastern
155 (142)--Western North Pacific
North Pacific stock.
population.
Humpback whale............. 0.0055 0.007 0 1 1,918 (1,876)--CA/ 0.05 Increasing.
OR/WA stock.
Minke whale................ 0.04 0.055 0 1 478 (202)--CA/OR/ 0.2 NA.
WA stock.
Bryde's whale.............. NA 0 0 0 NA................ NA NA.
Sei whale.................. 0.01 0.014 0 1 126 (83)--Eastern 0.8 NA.
North Pacific
stock.
Fin whale.................. 0.004 0.005 0 1 3,051 (2,598)--CA/ 0.03 Increasing.
OR/WA stock.
Blue whale................. 0.008 0.011 0 1 1,647 (1,551)-- 0.06 NA.
Eastern North
Pacific stock.
Odontocetes:
Sperm whale................ 0.08 0.109 0 1 971 (751)--CA/OR/ 0.1 NA.
WA stock.
Pygmy sperm whale.......... 0.05 0.068 0 1 579 (271)--CA/OR/ 0.17 NA.
WA stock.
Dwarf sperm whale.......... NA 0 0 0 NA--CA/OR/WA stock NA NA.
Baird's beaked whale....... 0.07 0.096 0 1 847 (466)--CA/OR/ 0.12 NA.
WA stock.
Cuvier's beaked whale...... 0.17 0.233 0 1 6,950 (4,481)--CA/ 0.01 Declining off CA/
OR/WA stock. OR/WA.
Mesoplodon beaked whale.... 0.08 0.109 0 1 694 (389)--CA/OR/ 0.14 Declining off CA/
WA stock. OR/WA.
Killer whale............... 0.05 0.068 0 1 240 (162)--Eastern 0.42/0.29/0.28 NA--Eastern North
North Pacific Pacific Offshore
stock. stock; NA--
346 (346)--Eastern Eastern North
North Pacific Pacific Transient
Transient stock. stock;
354 (354)--West Increasing--West
Coast Transient Coast Transient
stock. stock.
Short-finned pilot whale... 0.06 0.082 0 1 760 (465)--CA/OR/ 0.13 NA.
WA stock.
Bottlenose dolphin......... 0.11 0.151 0 10 1,006 (684)--CA/OR/ 0.1 NA--CA/OR/WA
WA stock. Offshore stock;
NA--CA Coastal
stock.
Striped dolphin............ 0.87 1.191 0 20 10,908 (8,231)--CA/ 0.18 NA.
OR/WA stock.
Short-beaked common dolphin 32.65 44.691 0 45 411,211 (343,990)-- 0.01 Varies with
CA/OR/WA stock. oceanographic
conditions.
Long-beaked common dolphin. 8.5 11.635 0 120 107,016 (76,224)-- 0.11 Increasing over
CA stock. last 30 years.
Pacific white-sided dolphin 2.14 2.929 0 30 26,930 (21,406)-- 0.11 NA.
CA/OR/WA stock.
Northern right whale 0.66 0.903 0 1 8,334 (6,019)--CA/ 0.01 NA.
dolphin. OR/WA stock.
Risso's dolphin............ 0.5 0.684 0 10 6,272 (4,913)--CA/ 0.16 NA.
OR/WA stock.
Dall's porpoise............ 3.34 4.572 0 50 42,000 (32,106)-- 0.12 NA.
CA/OR/WA stock.
Harbor porpoise............ 0 0 0 0 NA................ NA NA.
Pinnipeds:
California sea lion........ 23.6 32.249 0 33 296,750 (153,337)-- 0.01 Increasing.
U.S. stock.
[[Page 36763]]
Steller sea lion........... NA 0 0 0 49,685 (42,366)-- NA Declining--Western
Western stock. stock;
58,334 (72,223)-- Increasing--Easte
Eastern stock. rn stock;
Declining in CA.
Pacific harbor seal........ 2.4 3.285 0.011 4 30,196 (26,667)-- 0.01 Increased 1981 to
CA stock. 2004.
Northern elephant seal..... 9.85 13.483 0 14 124,000 (74,913)-- 0.01 Increasing through
CA breeding stock. 2005.
Northern fur seal.......... 0.79 1.081 0 2 12,844 (6,722)-- 0.02 Increasing.
California stock.
Guadalupe fur seal......... NA 0 0 0 7,408 (3,028)-- NA Increasing.
Mexico to CA
stock.
--------------------------------------------------------------------------------------------------------------------------------------------------------
NA = Not available or not assessed.
\1\ Proposed action area (12,593 km\2\) in the Santa Barbara Channel off the coast of California.
\2\ Calculated take is the estimated number of animals in the in-water ensonified buffer zone multiplied by the number of days.
\3\ Calculated take is the estimated number of animals in the in-air ensonified buffer zone multiplied by the number of days.
\4\ Requested Take Authorization includes calculated takes for animals in the ensonified in-water and in-air buffer zones.
\5\ NMFS Marine Mammal Stock Assessment Reports.
\6\ Total requested (and calculated) takes expressed as percentages of the species or stock.
Numbers of marine mammals that might be present and potentially
disturbed are estimated based on the available data about marine mammal
distribution and densities in the proposed Santa Barbara Channel action
area. ExxonMobil estimated the number of different individuals of
marine mammal species that may be exposed to in-water and in-air sounds
with received levels greater than or equal to 160 dB re 1 [micro]Pa
(rms) and in-air sounds with received levels greater than or equal to
90 dB re 20 [micro]Pa (rms) (for harbor seals)/100 dB re 20 [micro]Pa
(rms) (for all other pinniped species) for impact hammer pile-driving
activities on one or more occasions by considering the total marine
area that would be within the 160 dB in-water radius and 90 dB (for
harbor seals)/100 dB (for all other pinniped species) in-air radius
around the impact hammer pile-driving on at least one occasion and the
expected density of marine mammals in the area (in the absence of the
conductor pipe installation activities). The number of possible
exposures can be estimated by considering the total marine area that
would be within the in-water 160 dB radius and in-air 90 dB (for harbor
seals)/100 dB (for all other pinniped species) radius around the impact
hammer pile-driving activities. The in-water 160 dB and in-air 90 dB
(harbor seal)/100 dB (for all other pinniped species) radii are based
on acoustic modeling data for the impact hammer pile-driving activities
that may be used during the proposed action (see of the addendum to the
IHA application). It is unlikely that a particular animal would stay in
the area during the entire impact hammer pile-driving activities.
The number of different individuals potentially exposed to received
levels greater than or equal to 160 dB re 1 [micro]Pa (rms) for in-
water noise and 90 dB re 20 [micro]Pa (rms) (for harbor seals)/100 dB
re 20 [micro]Pa (rms) (for all other pinniped species) for in-air noise
from impact hammer pile-driving activities was calculated by
multiplying:
(1) The expected species density (in number/km\2\), times
(2) The anticipated area to be ensonified to that level during
conductor pipe installation (buffer zone = [pi] x [maximum
distance]\2\), times
(3) The number of days of the conductor pipe installation
activities.
Applying the approach described above, approximately 0.3318 km\2\
would be ensonified within the in-water 160 dB isopleth and
approximately 0.0053 km\2\/0.0475 km\2\ would be ensonified within the
in-air 90 dB (harbor seals)/100 dB (for all other pinniped species)
isopleths for impact hammer pile-driving activities (assuming
omnidirectional spreading of sound from the conductor pipe) during the
proposed conductor pipe installation activities. The take calculations
within the proposed action area account for animals in the initial
density snapshot and account for new (i.e., turnover) or previously
exposed animals over an approximate 4-day period that approach and
enter the area ensonified above or equal to the 160 dB isopleth for in-
water noise and 90/100 dB isopleth for in-air noise from the impact
hammer pile-driving activities; however, studies suggest that many
marine mammals would avoid exposing themselves to sounds at these
level, which suggests that there would not necessarily be a large
number of new animals entering the proposed action area once the
conductor pipe installation activities started. Also, the approach
assumes that no cetaceans or pinnipeds would move away or toward the
Harmony Platform. The take estimates represent the number of
individuals that are expected (in absence of a conductor pipe
installation activities) to occur over an approximate 4-day period of
time in the waters that would be exposed to greater than or equal to
160 dB (rms) in-water and greater than or equal to 90/100 dB (rms) in-
air for impact hammer pile-driving activities.
ExxonMobil's estimates of exposures to various sound levels assume
that the proposed activities would be carried out in full. The
estimates of the numbers of marine mammals potentially exposed to 160
dB (rms) for in-water noise and 90 dB re 20 [micro]Pa (rms) (for harbor
seals)/100
[[Page 36764]]
dB re 20 [micro]Pa (rms) (for all other pinniped species) for in-air
noise received levels are precautionary and probably overestimate the
actual numbers of marine mammals that could be involved. These
estimates include standard contingencies for weather, equipment, or
mitigation delays in the time planned for the proposed activities.
Table 5 shows the estimates of the number of different individual
marine mammals anticipated to be exposed to greater than or equal to
160 dB re 1 [mu]Pa (rms) for the conductor pipe installation activities
if no animals moved away from the Harmony Platform. No takes by Level A
harassment have been requested. The total requested take authorization
is given in the fifth column of Table 5.
Encouraging and Coordinating Research
ExxonMobil would coordinate the planned marine mammal monitoring
program associated with the proposed conductor pipe installation
activities with researchers and other parties that express interest in
this activity, area, and anthropogenic sound effects on marine mammals.
ExxonMobil would coordinate with applicable U.S. agencies (e.g., NMFS),
and would comply with their requirements.
ExxonMobil supports research on marine mammals and sound in the
environment through academic, industry, and private sector
collaborations. ExxonMobil is a founding member and largest contributor
to the Sound and Marine Life Joint Industry Program (JIP) through the
International Oil and Gas Producers (OGP), and the International
Association of Geophysical Contractors (IAGC). Through JIP and other
venues, ExxonMobil provides annual funding and support for fundamental
and applied scientific research to better understand the effects of
anthropogenic sound on marine life. ExxonMobil also conducts internal
research and monitoring programs specific to sound effects from
exploration and production activities. These efforts have helped
produce effective mitigation strategies and techniques to reduce
potential sound effects on marine mammals from their operations and
those from the oil and gas industry as a whole. More information on
selected examples of ExxonMobil's involvement and contributions to
scientific research on marine mammals and sound can be found in section
14 of the IHA application.
Impact on Availability of Affected Species or Stock for Taking for
Subsistence Uses
Section 101(a)(5)(D) of the MMPA also requires NMFS to determine
that the authorization would not have an unmitigable adverse effect on
the availability of marine mammal species or stocks for subsistence
use. There are no relevant subsistence uses of marine mammals
implicated by this action. Therefore, NMFS has determined that the
total taking of affected species or stocks would not have an
unmitigable adverse impact on the availability of such species or
stocks for taking for subsistence purposes.
Analysis and Preliminary Determinations
Negligible Impact
Negligible impact is ``an impact resulting from the specified
activity that cannot be reasonably expected to, and is not reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival'' (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes,
alone, is not enough information on which to base an impact
determination. In addition to considering estimates of the number of
marine mammals that might be ``taken'' through behavioral harassment,
NMFS must consider other factors such as the likely nature of any
responses (their intensity, duration, etc.), the context of any
responses (critical reproductive time or location, migration, etc.), as
well as the number and nature of estimated Level A harassment takes,
the number of estimated mortalities, and effects on habitat.
In making a negligible impact determination, NMFS evaluated factors
such as:
(1) The number of anticipated injuries, serious injuries, or
mortalities;
(2) The number, nature, and intensity, and duration of Level B
harassment (all relatively limited); and
(3) The context in which the takes occur (i.e., impacts to areas of
significance, impacts to local populations, and cumulative impacts when
taking into account successive/contemporaneous actions when added to
baseline data);
(4) The status of stock or species of marine mammals (i.e.,
depleted, not depleted, decreasing, increasing, stable, impact relative
to the size of the population);
(5) Impacts on habitat affecting rates of recruitment/survival; and
(6) The effectiveness of monitoring and mitigation measures.
As described above and based on the following factors, the
specified activities associated with the conductor pipe installation
activities are not likely to cause PTS, or other non-auditory injury,
serious injury, or death. The factors include:
(1) The likelihood that marine mammals are expected to move away
from a noise source that is annoying prior to its becoming potentially
injurious;
(2) The potential for temporary or permanent hearing impairment is
relatively low and would likely be avoided through the implementation
of the required monitoring and mitigation (i.e., shut-down) measures;
(3) The fact that cetaceans and pinnipeds would have to be closer
than 10 m and 3.5 m, respectively, during impact hammer pile-driving
activities to be exposed to levels of underwater sound believed to have
a minimal chance of causing a permanent threshold shift (PTS; i.e.,
Level A harassment); and
(4) The likelihood that marine mammal detection ability by trained
PSOs is high at close proximity to the platform.
No injuries, serious injuries, or mortalities are anticipated to
occur as a result of ExxonMobil's planned conductor pipe installation
activities, and none are proposed to be authorized by NMFS. Table 5 of
this document outlines the number of requested Level B harassment takes
that are anticipated as a result of these activities. NMFS's practice
has been to apply the 160 dB re 1 [micro]Pa (rms) received level
threshold for underwater impulse sound levels to determine whether take
by Level B harassment occurs. Southall et al. (2007) provide a severity
scale for ranking observed behavioral responses of both free-ranging
marine mammals and laboratory subjects to various types of
anthropogenic sound (see Table 4 in Southall et al. [2007]). Current
NMFS practice, regarding exposure of marine mammals to high-level in-
air sounds, as a threshold for potential Level B harassment, is at or
above 90 dB re 20 [micro]Pa for habor seals and at or above 100 dB re
20 [micro]Pa for all other pinniped species (Lawson et al., 2002;
Southall et al., 2007). NMFS has not determined Level A harassment
thresholds for marine mammals for in-air noise.
As mentioned previously, NMFS estimates that 30 species of marine
mammals under its jurisdiction could be potentially affected by Level B
[[Page 36765]]
harassment over the course of the IHA. The population estimates for the
marine mammal species that may be taken by Level B harassment were
provided in Table 3 and 5 of this document. Due to the nature, degree,
and context of Level B (behavioral) harassment anticipated and
described (see ``Potential Effects on Marine Mammals'' section above)
in this notice, the proposed activity is not expected to impact rates
of annual recruitment or survival for any affected species or stock,
particularly given NMFS's and the applicant's proposal to implement
mitigation, monitoring, and reporting measures to minimize impacts to
marine mammals. Additionally, the proposed conductor pipe installation
activities would not adversely impact marine mammal habitat.
For the marine mammal species that may occur within the proposed
action area, there are no known designated or important feeding and/or
reproductive areas. Many animals perform vital functions, such as
feeding, resting, traveling, and socializing, on a diel cycle (i.e., 24
hr cycle). Behavioral reactions to noise exposure (such as disruption
of critical life functions, displacement, or avoidance of important
habitat) are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Potential impacts are not likely to be significant from the proposed
pile-driving activities as the use of the impact hammer would occur
over 30 intermittent intervals of 2.5 to 3.3 hours each for a combined
total of about 4 days spread out over a 91-day period. Additionally,
the conductor pipe installation activities would be increasing sound
levels in the marine environment in a relatively small area surrounding
the Harmony Platform (compared to the range of the animals), and some
animals may only be exposed to and harassed by sound for less than a
day.
Of the 36 marine mammal species under NMFS jurisdiction that may or
are known to likely to occur in the proposed action area, seven are
listed as threatened or endangered under the ESA: North Pacific right,
humpback, sei, fin, blue, and sperm whale and Guadalupe fur seal. These
species are also considered depleted under the MMPA. Of these ESA-
listed species, incidental take has been requested to be authorized for
humpback, sei, fin, blue, and sperm whales. There is generally
insufficient data to determine population trends for the other depleted
species in the action area. To protect these animals (and other marine
mammals in the action area), ExxonMobil must cease impact hammer pile-
driving activities if any marine mammal enters designated exclusion
zones. No injury, serious injury, or mortality is expected to occur and
due to the nature, degree, and context of the Level B harassment
anticipated, and the activities are not expected to impact rates of
recruitment or survival.
NMFS has preliminarily determined, provided that the aforementioned
mitigation and monitoring measures are implemented, the impact of
conducting pile-driving activities in the Santa Barbara Channel off the
coast of California, may result, at worst, in a modification in
behavior and/or low-level physiological effects (Level B harassment) of
certain species of marine mammals.
Changes in diving/surfacing patterns, habitat abandonment due to
loss of desirable acoustic environment, and cessation of feeding or
social interaction are some of the significant behavioral modifications
that could potentially occur as a result of the proposed conductor pipe
installation activities. While behavioral modifications, including
temporarily vacating the area during the impact hammer pile-driving
activities, may be made by these marine mammal species to avoid the
resultant acoustic disturbance, the availability of alternate areas
within these areas for species and the short and sporadic duration of
the conductor pipe installation activities, have led NMFS to
preliminary determine that the taking by Level B harassment from the
specified activity would have a negligible impact on the affected
species in the specified geographic region. NMFS believes that the
length of the conductor pipe installation activities (duration of
approximately 4 days total), the requirement to implement mitigation
measures (e.g., shut-down of impact hammer pile-driving activities),
and the inclusion of the monitoring and reporting measures, would
reduce the amount and severity of the potential impacts from the
activity to the degree that it would have a negligible impact on the
species or stocks in the proposed action area. Based on the analysis
contained herein of the likely effects of the specified activity on
marine mammals and their habitat, and taking into consideration the
implementation of the proposed monitoring and mitigation measures, NMFS
preliminarily finds that the total marine mammal take from ExxonMobil's
proposed conductor pipe installation activities would have a negligible
impact on the affected marine mammal species or stocks.
Small Numbers
The estimate of the number of individual cetaceans and pinnipeds
that could be exposed to pile-driving sounds with received levels
greater than or equal to 160 dB re 1 [mu]Pa (rms) for all marine
mammals for in-water sound levels and at or above 90 dB re 20 [micro]Pa
for harbor seals and at or above 100 dB re 20 [micro]Pa for all other
pinniped species for in-air sound levels during the proposed conductor
pipe installation activities is in Table 5 of this document.
In total, 10 gray, 1 humpback, 1 minke, 1 sei, 1 fin, 1 blue, and 1
sperm whale could be taken by Level B harassment during the proposed
seismic survey, which would represent 0.05, 0.05, 0.2, 0.8, 0.03, 0.06,
and 0.1% of the stock populations, respectively. Some of the cetaceans
potentially taken by Level B harassment are delphinids and porpoises
with estimates of 1 pygmy sperm, 1 Baird's beaked, 1 Cuvier's beaked 1
Mesoplodon spp. Beaked, 1 killer, and 1 short-finned pilot whale, 10
bottlenose, 20 striped, 45 short-beaked common, 120 long-beaked common,
20 Pacific white-sided, 1 northern right whale, and 10 Risso's dolphin
as well as 50 Dall's porpoise, which would represent 0.17, 0.12, 0.01,
0.14, 0.42/0.29/0.28, 0.13, 0.1, 0.18, 0.01, 0.11, 0.11, 0.01, 0.16,
and 0.12% of the affected stock populations, respectively. The
pinnipeds that could potentially be taken by Level B harassment are the
California sea lion, Pacific harbor and northern elephant seal, and
northern fur seal with estimates of 33, 4, 14, and 2 individuals, which
would represent 0.01, 0.01, 0.01, and 0.02% of the affected stock
populations, respectively.
NMFS has preliminary determined that the requested take estimates
represent small numbers relative to the affected species or stocks
sizes (i.e., all are less than 1%). Based on the analysis contained
herein of the likely effects of the specified activity on marine
mammals and their habitat, and taking into consideration the
implementation of the mitigation and monitoring measures, NMFS
preliminarily finds that small numbers of marine mammals would be taken
relative to the populations of the affected species or stocks. See
Table 5 for the requested authorized take numbers of marine mammals.
Endangered Species Act
Of the species of marine mammals that may occur in the proposed
action area, several are listed as threatened or endangered under the
ESA, including the North Pacific right, humpback, sei, fin, blue, and
sperm whale and
[[Page 36766]]
Guadalupe fur seal. ExxonMobil did not request take of endangered North
Pacific right whales or the Guadalupe fur seals due to the low
likelihood of encountering this species during the proposed pile-
driving activities. NMFS's Office of Protected Resources, Permits and
Conservation Division, has initiated formal consultation under section
7 of the ESA with NMFS's West Coast Regional Office, Protected
Resources Division, to obtain a Biological Opinion evaluating the
effects of issuing the IHA to ExxonMobil under section 101(a)(5)(D) of
the MMPA on threatened and endangered marine mammals and, if
appropriate, authorizing incidental take. NMFS would conclude formal
section 7 consultation prior to making a determination on whether or
not to issue the IHA. If the IHA is issued, ExxonMobil, in addition to
the mitigation and monitoring requirements included in the IHA, would
be required to comply with the Terms and Conditions of the Incidental
Take Statement corresponding to NMFS's Biological Opinion issued to
both ExxonMobil and NMFS's Office of Protected Resources.
National Environmental Policy Act
To meet National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et
seq.) requirements, NMFS will conduct a NEPA analysis to evaluate the
effects of authorizing the proposed take of marine mammals prior to
making a final determination on the issuance of the IHA. This notice,
and referenced documents, including the IHA application provide the
environmental issues and information relevant to the proposed conductor
pipe installation activities as well as those specific to NMFS's
issuance of the IHA. NMFS's NEPA analysis will be completed prior to
the issuance or denial of this proposed IHA.
Proposed Authorization
As a result of these preliminary determinations, NMFS propose to
issue an IHA to ExxonMobil for conducting the pipe installation
activities at the Harmony Platform in the Santa Barbara Channel
offshore of California, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated. The proposed
IHA language is provided below:
ExxonMobil Production Company, P.O. Box 4358, Houston, Texas 77210-
4358, is hereby authorized under section 101(a)(5)(D) of the Marine
Mammal Protection Act (MMPA) (16 U.S.C. 1371(a)(5)(D)), to harass small
numbers of marine mammals incidental to conducting conductor pipe
installation activities at the Harmony Platform in the Santa Barbara
Channel off the coast of California:
1. This Authorization is valid from August 15, 2014 through August
14, 2015.
2. This Authorization is valid only for ExxonMobil's activities
associated with conductor pipe installation activities that shall occur
in the following specified geographic area:
In the Santa Barbara Channel offshore of California, the Harmony
Platform is located at 34[deg]22'35.906'' North, 120[deg]10'04.486''
West. The water depth at the action area is 366 m on the continental
slope below a relatively steep descent, and 4.7 km from the shelf
break. The conductor pipe installation activities would be conducted 10
km off the California coast, between Point Conception and the city of
Santa Barbara, in the U.S. Exclusive Economic Zone, as specified in
ExxonMobil's Incidental Harassment Authorization application and
addendum.
3. Species Authorized and Level of Takes
(a) The incidental taking of marine mammals, by Level B harassment
only, is limited to the following species in the waters of the Pacific
Ocean off the coast of California:
(i) Mysticetes--see Table 5 (above) for authorized species and take
numbers.
(ii) Odontocetes--see Table 5 (above) for authorized species and
take numbers.
(iii) Pinnipeds--see Table 5 (above) for authorized species and
take numbers.
(iv) If any marine mammal species is encountered during pile-
driving activities that is not listed in Table 2 (attached) for
authorized taking and is likely to be exposed to sound pressure levels
(SPLs) greater than or equal to 160 dB re 1 [mu]Pa (rms) for impulse
underwater noise from impact hammer pile-driving and/or at or above 100
dB re 20 [mu]Pa (rms) for all pinnipeds species except harbor seals
(which is at or above 90 dB re 20 [mu]Pa (rms) for in-air noise, then
ExxonMobil must shut-down the operations to avoid take.
(b) The taking by injury (Level A harassment), serious injury, or
death of any of the species listed in Condition 3(a) above and the
taking of any kind of any other species of marine mammal is prohibited
and may result in the modification, suspension or revocation of this
IHA.
4. The methods authorized for taking by Level B harassment are
limited to the following acoustic sources without an amendment to this
IHA:
(a) Pile-driving using impact hammer (i.e., installation);
5. The taking of any marine mammal in a manner prohibited under
this Authorization must be reported immediately to the Office of
Protected Resources, National Marine Fisheries Service (NMFS), at 301-
427-8401.
6. Mitigation and Monitoring Requirements
ExxonMobil is required to implement the following mitigation and
monitoring requirements when conducting the specified activities to
achieve the least practicable impact on affected marine mammal species
or stocks:
(a) Establish a 160 dB re 1 [mu]Pa (rms) buffer zone for cetaceans
and pinnipeds and a 180 dB re 1 [mu]Pa (rms) exclusion zone for
cetaceans and a 190 dB re 1 [mu]Pa (rms) exclusion zone for pinnipeds
for in-water sounds before the conductor pipe installation activities
begin so that underwater sounds associated with operations no longer
exceed levels that are potentially harmful to marine mammals. See Table
2 (above) for distances and buffer and exclusion zones.
(b) Utilize three, NMFS-qualified, vessel-based Protected Species
Observer (PSO) to visually watch for and monitor marine mammals near
the impact hammer source during daytime and nighttime pile-driving
activities. The Harmony Platform's crew shall also assist in detecting
marine mammals, when practicable. PSOs shall be stationed at the best
practicable vantage point(s) (on the lower platform level, and upper
platform level) of the Harmony Platform to monitor the applicable
buffer and exclusion zone for marine mammals during the conductor pipe
installation activities. For the buffer zone, two PSOs shall be
stationed on the upper platform level. For the exclusion zone, one PSO
shall be concurrently stationed on the lower platform level. The lower
platform level shall be illuminated during nighttime visual
observations. PSOs shall have access to reticle binoculars (7 x 50
Fujinon) and night-vision devices. PSO shifts shall last no longer than
5 hours at a time. PSOs shall also make observations during daytime
periods when the pile-driving activities are not occurring for
comparison of animal abundance and behavior, when feasible. In addition
to monitoring during pile-driving activities, baseline monitoring for
marine mammals shall be performed up to one week before and one week
after conductor pipe installation activities, as well as selected
periods in between impact hammer pile-driving activities.
[[Page 36767]]
(c) A PSO shall record the following information when a marine
mammal is sighted:
(i) Species, group size, age/size/sex categories (if determinable),
behavior when first sighted and after initial sighting, heading (if
consistent), bearing and distance from platform, sighting cue, apparent
reaction to the conductor pipe installation activities (e.g., none,
avoidance, approach, paralleling, etc., and including responses to
ramp-up), speed of travel, and duration of presence; and
(ii) Date, time, location, activity of the conductor pipe
installation activities (including whether in state of ramp-up or shut-
down), monitoring and mitigation measures implemented (or not
implemented), weather conditions, Beaufort sea state and wind force,
visibility, and sun glare; and
(iii) The data listed under Condition 6(c)(ii) shall also be
recorded at the start and end of each observation watch, and during a
watch whenever there is a change in one or more of the variables.
(iv.) If inclement weather conditions (i.e., fog, rain, or rough
Beaufort sea state) limits or impairs the PSO's visibility of the
water's surface to less than 30.5 m (100 ft) within the action area,
then all noise-generating conductor pipe installation activities shall
be stopped until visibility improves.
(d) Visually observe the entire extent of the in-water buffer zone
(160 dB re 1 [mu]Pa [rms]) for cetaceans and pinnipeds and in-water
exclusion zone (180 dB re 1 [mu]Pa [rms] for cetaceans and 190 dB re 1
[mu]Pa [rms] for pinnipeds as well as the in-air buffer zone for harbor
seals (90 dB re 20 [mu]Pa) and for all other pinnipeds (100 dB re 20
[mu]Pa); see Table 2 [above] for distances) using NMFS-qualified PSOs,
for at least 30 minutes prior to starting the impact hammer (day or
night). If the PSO finds a marine mammal within the exclusion zone,
ExxonMobil must delay the pile-driving activities until the marine
mammal(s) has left the area. If the PSO sees a marine mammal that
surfaces, then dives below the surface, the PSO shall wait 30 minutes.
If the PSO sees no marine mammals during that time, they should assume
that the animal has moved beyond the exclusion zone. If for any reason
the entire exclusion zone radius cannot be seen for the entire 30
minutes (i.e., rough seas, fog, darkness), or if marine mammals are
near, approaching, or in the exclusion zone, the impact hammer may not
be ramped-up.
(e) Implement a ``ramp-up'' procedure when starting up at the
beginning of pile-driving activities, which means starting with an
initial set of three strikes from the impact hammer at 40% energy,
followed by a 30 second waiting period, then two subsequent three
strike sets. During ramp-up, the PSOs shall monitor the exclusion zone,
and if marine mammals are sighted, a shut-down shall be implemented.
Therefore, initiation of ramp-up procedures from shut-down requires
that the PSOs be able to view the full exclusion zone as described in
Condition 6(a) (above).
(f) Shut-down the pile-driving activities if a marine mammal is
detected approaching, about to enter, or located within the relevant
exclusion zone (as defined in Table 2, above). A shut-down means all
operating impact hammers are shut-down (i.e., turned off). If any
marine mammal is sighted within the relevant exclusion zone prior to
pile-driving activities, the hammer operator (or other authorized
individual) shall delay conductor pipe installation activities until
the animal has moved outside the exclusion zone or the animal is not
resighted within for 15 minutes for species with shorter dive durations
(small odontocetes and pinnipeds) or 30 minutes for species with longer
dive durations (mysticetes and large odontocetes, including sperm,
pygmy and dwarf sperm, killer, and beaked whales).
(g) Following a shut-down, the conductor pipe installation
activities shall not resume until the PSO has visually observed the
marine mammal(s) exiting the exclusion zone and is not likely to
return, or has not been seen within the exclusion zone for 15 minutes
for species with shorter dive durations (small odontocetes and
pinnipeds) or 30 minutes for species with longer dive durations
(mysticetes and large odontocetes, including sperm, pygmy and dwarf
sperm, killer, and beaked whales).
(h) Following a shut-down and subsequent animal departure,
conductor pipe installation activities may resume following ramp-up
procedures described in Condition 6(e).
(i) To facilitate visual monitoring during non-daylight hours, the
exclusion zones shall be illuminated by lights to allow for more
effective viewing of the area by the PSO on-duty.
(j) In-Water Monitoring--Acoustic monitoring shall be performed at
a minimum of two fixed stations located at 10 m and approximately 325 m
from the conductor pipe sound source. The following general approach
shall be used to measure in-water sound levels:
(k) Acoustic monitoring shall be conducted over the entire pile-
driving period for each conductor pipe, starting approximately 1 hour
prior to pile-driving through 1 hour after impact hammering has
stopped. Pre- and post-hammer pile-driving data shall be used to
determine ambient/background noise levels.
(i) A stationary hydrophone system with the ability to measure and
record sound pressure levels (SPL) shall be deployed at a minimum of
two monitoring locations. SPLs shall be recorded in voltage, converted
to microPascals ([mu]Pa), and post-processed to decibels (dB [re 1
[mu]Pa]). For the first conductor pipe installation, hydrophones shall
be placed at 101 m and at 32533 m from the
conductor pipe at depths ranging from 10 to 30 m below the water
surface to avoid potential interferences for surface water energy, and
to target the depth range of maximum occurrence of marine mammal most
likely in the area during the project. If necessary, additional
hydrophone mooring systems shall be deployed at additional distances
and/or depths. Following each successive conductor pipe installation,
the water depth and geographical orientation of the hydrophone may be
changed to validate modeled SPLs at varying water depths and direction.
(ii) At a minimum, the following sound data shall be analyzed
(post-processed) from recorded sound levels: Absolute peak overpressure
and under pressure levels for each conductor pipe; average, minimum,
and maximum sound pressure levels (rms), integrated from 3 Hz to 20
kHz; average duration of each hammer strike, and total number of
strikes per continuous hammer pile-driving period for each conductor
pipe.
(iii) In the event that field measurements indicate different SPL
(rms) values than those predicted by modeling for either the maximum
distances of the buffer or exclusion zones from the sound source,
corresponding boundaries for the buffer and exclusion zones shall be
increased/decreased accordingly, following NMFS notification and
concurrence.
(l) In-Air Monitoring--Reference measurements shall be made
approximately 10 to 20 m from the initial hammer strike position using
a stationary microphone. The microphone shall be placed as far away
from other large sound sources as practical. In-air sound levels shall
be recorded at several points around the base of the Harmony Platform
at sea level to validate modeled sound levels. Recorded data shall be
recorded as dB (re 20 [mu]Pa) for comparison to in-air noise thresholds
for Level B harassment for pinnipeds.
7. Reporting Requirements
ExxonMobil is required to:
[[Page 36768]]
(a) Submit a draft report on all activities and monitoring results
to the Office of Protected Resources, NMFS, within 90 days of the
completion of ExxonMobil's conductor pipe installation activities at
the Harmony Platform in the Santa Barbara Channel off the coast of
California. This report must contain and summarize the following
information:
(i) Dates, times, locations, weather, sea conditions (including
Beaufort sea state and wind force), and associated activities during
all conductor pipe installation activities and marine mammal sightings;
(ii) Species, number, location, distance from the platform, and
behavior of any marine mammals, as well as associated conductor pipe
installation activities (e.g., number of ramp-ups and shut-downs),
observed throughout all monitoring activities.
(iii) An estimate of the number (by species) of marine mammals
that: (A) Are known to have been exposed to the pile-driving activities
(based on visual observation) at received levels greater than or equal
to 160 dB re 1 [mu]Pa (rms), and/or 180 dB re 1 [mu]Pa (rms) for
cetaceans and greater than or equal to 190 dB re 1 [mu]Pa (rms) for
pinnipeds with a discussion of any specific behaviors those individuals
exhibited; and (B) may have been exposed (based on modeled values for
the impact hammer) to the pile-driving activities at received levels
greater than or equal to 160 dB re 1 [mu]Pa (rms), and/or 180 dB re 1
[mu]Pa (rms) for cetaceans and greater than or equal to 190 dB re 1
[mu]Pa (rms) for pinnipeds with a discussion of the nature of the
probable consequences of that exposure on the individuals that have
been exposed.
(iv) A description of the implementation and effectiveness of the:
(A) Terms and Conditions of the Biological Opinion's Incidental Take
Statement (ITS) (attached); and (B) mitigation measures of the
Incidental Harassment Authorization. For the Biological Opinion, the
report shall confirm the implementation of each Term and Condition, as
well as any conservation recommendations, and describe their
effectiveness for minimizing the adverse effects of the action on
Endangered Species Act-listed marine mammals.
(l) Submit a final report to the Chief, Permits and Conservation
Division, Office of Protected Resources, NMFS, within 30 days after
receiving comments from NMFS on the draft report. If NMFS decides that
the draft report needs no comments, the draft report shall be
considered to be the final report.
8. Reporting Prohibited Take
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by this
Authorization, such as an injury (Level A harassment), serious injury
or mortality (e.g., equipment interaction, and/or entanglement),
ExxonMobil shall immediately cease the specified activities and
immediately report the incident to the Chief of the Permits and
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401 and/or by email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov and the West Coast Regional Stranding
Coordinator (Justin.Greenman@noaa.gov). The report must include the
following information:
(a) Time, date, and location (latitude/longitude) of the incident;
description of the circumstances during and leading up to the incident;
status of all sound source use in the 24 hours preceding the incident;
water depth; environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility); description of marine
mammal observations in the 24 hours preceding the incident; species
identification or description of the animal(s) involved; the fate of
the animal(s); and photographs or video footage of the animal (if
equipment is available).
Activities shall not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS shall work with ExxonMobil
to determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. ExxonMobil may not resume
their activities until notified by NMFS via letter, email, or
telephone.
Reporting an Injured or Dead Marine Mammal with an Unknown Cause of
Death--In the event that ExxonMobil discovers an injured or dead marine
mammal, and the lead PSO determines that the cause of the injury or
death is unknown and the death is relatively recent (i.e., in less than
a moderate state of decomposition as described in the next paragraph),
ExxonMobil shall immediately report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
at 301-427-8401, and/or by email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov, and the NMFS West Coast Regional Office (1-
866-767-6114) and/or by email to the West Coast Regional Stranding
Coordinator (Justin.Greenman@noaa.gov). The report must include the
same information identified in Condition 8(a) above. Activities may
continue while NMFS reviews the circumstances of the incident. NMFS
shall work with ExxonMobil to determine whether modifications in the
activities are appropriate.
Reporting an Injured or Dead Marine mammal Not Related to the
Activities--In the event that ExxonMobil discovers an injured or dead
marine mammal, and the lead PSO determines that the injury or death is
not associated with or related to the activities authorized in
Condition 2 of this Authorization (e.g., previously wounded animal,
carcass with moderate to advanced decomposition, or scavenger damage),
ExxonMobil shall report the incident to the Chief of the Permits and
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401, and/or by email to Jolie.Harrison@noaa.gov and
Howard.Goldstein@noaa.gov, and the NMFS West Coast Regional Office (1-
866-767-6114) and/or by email to the West Coast Regional Stranding
Coordinator (Justin.Greenman@noaa.gov), within 24 hours of the
discovery. ExxonMobil shall provide photographs or video footage (if
available) or other documentation of the stranded animal sighting to
NMFS and the Marine Mammal Stranding Network. Activities may continue
while NMFS reviews the circumstances of the incident.
9. Endangered Species Act Biological Opinion and Incidental Take
Statement ExxonMobil is required to comply with the Terms and
Conditions of the ITS corresponding to NMFS's Biological Opinion issued
to both ExxonMobil and NMFS's Office of Protected Resources (attached).
10. A copy of this Authorization and the ITS must be in the
possession of all contractors and PSO(s) operating under the authority
of this Incidental Harassment Authorization.
11. Penalties and Permit Sanctions--Any person who violates any
provision of this IHA is subject to civil and criminal penalties,
permit sanctions, and forfeiture as authorized under the MMPA.
12. This IHA may be modified, suspended or withdrawn if ExxonMobil
fails to abide by the conditions prescribed herein or if the authorized
taking is having more than a negligible impact on the species or stock
of affected marine mammals, or if there is an unmitigable adverse
impact on the availability of such species or stocks for subsistence
uses.
Request for Public Comments
NMFS requests comments on our analysis, the draft authorization,
and
[[Page 36769]]
any other aspect of the notice of proposed IHA for ExxonMobil's
proposed installation of conductor pipes via hydraulic hammer driving
at Harmony Platform, Santa Ynez Production Unit, located in the Santa
Barbara Channel offshore of California. Please include with your
comments any supporting data or literature citations to help inform our
final decision on ExxonMobil's request for an MMPA authorization.
Concurrent with the publication of this notice in the Federal
Register, NMFS is forwarding copies of this application to the Marine
Mammal Commission and its Committee of Scientific Advisors.
Dated: June 25, 2014.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2014-15224 Filed 6-27-14; 8:45 am]
BILLING CODE 3510-22-P
