Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Dock Replacement Project, 9447-9458 [2016-03998]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 81, Number 37 (Thursday, February 25, 2016)]
[Notices]
[Pages 9447-9458]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-03998]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE340


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Dock Replacement Project

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that we have issued an incidental harassment authorization (IHA) to 
UniSea, Inc. (UniSea) to incidentally harass, by Level B harassment 
only, small numbers of marine mammals during construction activities 
associated with a dock replacement project in Iliuliuk Harbor, 
Unalaska, AK.

DATES: This authorization is effective from March 1, 2016, through 
February 28, 2017.

FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

    An electronic copy of UniSea's application and supporting 
documents, as well as a list of the references cited in this document, 
may be obtained by visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/. In case of problems accessing these documents, 
please call the contact listed under FOR FURTHER INFORMATION CONTACT.

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 by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified area, the incidental, but not intentional, 
taking of small numbers of marine mammals, providing that certain 
findings are made and the necessary prescriptions are established.
    The incidental taking of small numbers of marine mammals may be 
allowed only if NMFS (through authority delegated by the Secretary) 
finds that the total taking by the specified activity during the 
specified time period will (i) have a negligible impact on the species 
or stock(s) and (ii) not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant). Further, the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such taking 
must be set forth.
    The allowance of such incidental taking under section 101(a)(5)(A), 
by harassment, serious injury, death, or a combination thereof, 
requires that regulations be established. Subsequently, a Letter of 
Authorization may be issued pursuant to the prescriptions established 
in such regulations, providing that the level of taking will be 
consistent with the findings made for the total taking allowable under 
the specific regulations. Under section 101(a)(5)(D), NMFS may 
authorize such incidental taking by harassment only, for periods of not 
more than one year, pursuant to requirements and conditions contained 
within an IHA. The establishment of these prescriptions requires notice 
and opportunity for public comment.
    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, section 3(18) of 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 June 10, 2015, we received a request from UniSea for 
authorization to take marine mammals incidental to pile driving and 
pile removal associated with construction of a commercial fishing dock 
in Iliuliuk Harbor, a small harbor in the Aleutian Islands. UniSea 
submitted revised versions of the request on September 28, 2015, and 
December 2, 2015. The latter of these was deemed adequate and complete. 
UniSea proposed to replace the existing dock with an 80 foot by 400 
foot open cell sheet pile dock, between March 1, 2016 and February 28, 
2017.

[[Page 9448]]

    The use of both vibratory and impact pile driving is expected to 
produce underwater sound at levels that have the potential to result in 
behavioral harassment of marine mammals. Species with the expected 
potential to be present during all or a portion of the in-water work 
window include the Steller sea lion (Eumetopias jubatus) and harbor 
seal (Phoca vitulina). These species may occur year-round in Iliuliuk 
Harbor.

Description of the Specified Activity

    A detailed description of the proposed G1 dock construction project 
is provided in the Federal Register notice for the proposed IHA (80 FR 
79822; December 23, 2015). Since that time, no changes have been made 
to the proposed dock construction activities. Therefore, a detailed 
description is not provided here. Please refer to that Federal Register 
notice for the description of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to UniSea was published 
in the Federal Register on December 23, 2015 (80 FR 79822). That notice 
described, in detail, UniSea's activity, the marine mammal species that 
may be affected by the activity, and the anticipated effects on marine 
mammals. During the 30-day public comment period, NMFS received 
comments from the Marine Mammal Commission. The Marine Mammal 
Commission recommended that NMFS issue the IHA, subject to inclusion of 
the proposed mitigation, monitoring, and reporting measures.

Description of Marine Mammals in the Area of the Specified Activity

    Marine waters near Unalaska Island support many species of marine 
mammals, including pinnipeds and cetaceans; however, the number of 
species regularly occurring near the project location is limited. There 
are three marine mammal species under NMFS' jurisdiction with recorded 
occurrence in Iliuliuk Harbor during the past 15 years, including one 
cetacean and two pinnipeds. Steller sea lions are the most common 
marine mammals in the project area and are part of the western Distinct 
Population Segment (DPS) that is listed as Endangered under the 
Endangered Species Act (ESA). Harbor seals (Phoca vitulina) may also 
occur in the project area, though less frequently and in lower 
abundance than Steller sea lions. The humpback whale (Megaptera 
novaeangliae), although seasonally abundant in Unalaska Bay, is not 
typically present in Iliuliuk Harbor. A single humpback whale was 
observed beneath the bridge that connects Amaknak Island and Unalaska 
Island, moving in the direction of Iliuliuk Harbor, in September 2015 
(pers. comm., L. Baughman, PND Engineers, to J. Carduner, NMFS, Oct. 
12, 2015); no other sightings of humpback whales in Iliuliuk Harbor 
have been recorded and no records are found in the literature. In the 
summer months, the majority of humpback whales from the central North 
Pacific stock are found in the feeding grounds of the Aleutian Islands, 
Bering Sea, Gulf of Alaska, and Southeast Alaska/northern British 
Columbia, with high densities of whales found in the eastern Aleutian 
Islands, including along the north side of Unalaska Island (Allen and 
Angliss 2014). Despite their relatively high abundance in Unalaska Bay 
during summer months, their presence within Iliuliuk Harbor is 
sufficiently rare that we do not believe there is a reasonable 
likelihood of their occurrence in the project area during the period of 
validity for the IHA. Thus the incidental harassment of humpback whales 
as a result of the G1 dock construction project is not authorized in 
the IHA; as such, the humpback whale is not carried forward for further 
analysis beyond this section.
    We have reviewed UniSea's detailed species descriptions, including 
life history information, for accuracy and completeness and refer the 
reader to Sections 3 and 4 of UniSea's application, rather than 
reprinting the information here. In addition, a detailed description of 
the species likely to be affected by the UniSea G1 dock construction 
project, including brief introductions to the species and relevant 
stocks as well as available information regarding population trends and 
threats, and information regarding local occurrence, were provided in 
the Federal Register notice for the proposed IHA (80 FR 79822; December 
23, 2015); since that time, we are not aware of any changes in the 
status of these species and stocks; therefore, detailed descriptions 
are not provided here. Please refer to that Federal Register notice for 
these descriptions. Please also refer to NMFS' Web site 
(www.nmfs.noaa.gov/pr/species/mammals/) for generalized species 
accounts.
    Table 1 lists the marine mammal species with expected potential for 
occurrence in the vicinity of the project during the project timeframe 
and summarizes key information regarding stock status and abundance. 
Taxonomically, we follow Committee on Taxonomy (2015). Please see NMFS' 
Stock Assessment Reports (SAR), available at www.nmfs.noaa.gov/pr/sars, 
for more detailed accounts of these stocks' status and abundance. The 
harbor seal and Steller sea lion are addressed in the Alaska SARs 
(e.g., Allen and Angliss, 2012, 2014).

                                   Table 1--Marine Mammals Potentially Present in the Vicinity of the Project Location
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                                                                                     Stock abundance (CV;                         Relative occurrence in
              Species                         Stock             ESA/MMPA status;       Nmin; most recent     PBR \3\   Annual M/     Iliuliuk Harbor;
                                                              strategic (Y/N) \1\    abundance survey) \2\               SI \4\    season of occurrence
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                                                         Order Carnivora--Superfamily Pinnipedia
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                                                      Family Otariidae (eared seals and sea lions)
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Steller sea lion...................  Western U.S...........  E/D; N                 55,422 (n/a; 48,676;          292      234.7  common; year-round
                                                                                     2008-11).                                     (greater abundance in
                                                                                                                                   summer).
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[[Page 9449]]

 
                                                             Family Phocidae (earless seals)
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Harbor seal........................  Aleutian Islands......  -; N                   \5\ 3,579 (0.092;              99       93.1  occasional; year-
                                                                                     3,313; 2004).                                 round.
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\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
  designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR (see
  footnote 3) or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For killer whales, the
  abundance values represent direct counts of individually identifiable animals; therefore there is only a single abundance estimate with no associated
  CV. For certain stocks of pinnipeds, abundance estimates are based upon observations of animals (often pups) ashore multiplied by some correction
  factor derived from knowledge of the species (or similar species) life history to arrive at a best abundance estimate; therefore, there is no
  associated CV. In these cases, the minimum abundance may represent actual counts of all animals ashore.
\3\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
  marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP).
\4\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value.
\5\ Abundance estimate for this stock is greater than ten years old and is therefore not considered current. We nevertheless present the most recent
  abundance estimate, as this represents the best available information for use in this document.

Potential Effects of the Specified Activity on Marine Mammals

    The effects of underwater noise from in-water construction 
activities for the UniSea G1 dock construction project have the 
potential to result in behavioral harassment of marine mammals in the 
vicinity of the action area. The Federal Register notice for the 
proposed IHA (80 FR 79822; December 23, 2015) included a discussion of 
the effects of anthropogenic noise on marine mammals, therefore that 
information is not repeated here; please refer to that Federal Register 
notice for that information. No instances of hearing threshold shifts, 
injury, serious injury, or mortality are expected as a result of the 
in-water construction activities.

Anticipated Effects on Habitat

    The main impact associated with the UniSea G1 dock construction 
project would be temporarily elevated sound levels and the associated 
direct effects on marine mammals. The project would not result in 
permanent impacts to habitats used directly by marine mammals, such as 
haul-out sites, but may have potential short-term impacts to food 
sources such as forage fish and salmonids, and minor impacts to the 
immediate substrate during installation and removal of piles during the 
dock construction project. These potential effects are discussed in 
detail in the Federal Register notice for the proposed IHA (80 FR 
79822; December 23, 2015), therefore that information is not repeated 
here; please refer to that Federal Register notice for that 
information.

Mitigation Measures

    In order to issue an IHA 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 on 
the availability of such species or stock for taking for certain 
subsistence uses.
    For the G1 dock construction project, NMFS is requiring UniSea to 
implement the following mitigation measures to minimize potential 
impacts to marine mammals in the project vicinity as a result of in-
water construction activities.

Monitoring and Shutdown for Pile Driving

    Measurements from similar pile driving events were coupled with 
practical spreading loss to estimate Level A and Level B harassment 
zones (see ``Estimated Take by Incidental Harassment''). These values 
were then used to develop mitigation measures for pile driving 
activities. The Level A zone effectively represents the mitigation zone 
that would be established around each pile to prevent Level A 
harassment to marine mammals, while the Level B zone provides estimates 
of the areas within which Level B harassment might occur as a result of 
noise associated with in-water construction. While the Level A and 
Level B harassment zones vary between different types of construction 
methods, UniSea will establish mitigation zones for the maximum 
possible Level A and Level B zones for all construction activities 
conducted in support of the project. Note that in the Federal Register 
notice for the proposed IHA (80 FR 79822; December 23, 2015), the 
mitigation and monitoring zones were referred to as the ``exclusion 
zone'' and ``zone of influence''; we have since changed the names of 
the zones for clarity.
    The following measures would apply to UniSea's mitigation through 
the Level A and Level B harassment zones:
    Level A Zone--For all pile driving activities, UniSea will 
establish a Level A zone intended to contain the area in which SPLs 
equal or exceed the 190 dB rms acoustic injury criteria for pinnipeds. 
The purpose of the Level A zone is to define an area within which 
shutdown of construction activity would occur upon sighting of a marine 
mammal within that area (or in anticipation of an animal entering that 
area), thus preventing potential injury of marine mammals. Modeled 
distances to the Level A threshold are shown in Table 3. UniSea would 
implement a minimum 10 m radius Level A zone for all pile driving and 
down-the-hole drilling activities. See Appendix B in the IHA 
application for figures showing the Level A zones overlaid on satellite 
images of the project area.
    Level B Zones--The Level B zones refer to the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for pulsed and non-pulsed 
continuous sound, respectively). Level B zones provide utility for 
monitoring that is conducted for mitigation purposes (i.e., shutdown 
monitoring) by establishing monitoring protocols for areas adjacent to 
the Level A zone. Monitoring of the Level B zones enable observers to 
be aware of, and communicate about, the presence of marine mammals 
within the

[[Page 9450]]

project area but outside the Level A zone, and thus prepare for 
potential shutdowns of activity should those marine mammals approach 
the Level A zone. However, the primary purpose of monitoring in the 
Level B zones is to allow documentation of incidents of Level B 
harassment; monitoring of Level B zones is discussed in greater detail 
in the Marine Mammal Monitoring Plan which, available at: 
www.nmfs.noaa.gov/pr/permits/incidental/. The modeled radial distances 
for Level B zones for impact and vibratory pile driving and removal 
(not taking into account landmasses which are expected to limit the 
actual Level B zone radii) are shown in Table 3.
    In order to document observed incidents of harassment, monitors 
will record all marine mammals observed within the modeled Level B 
zones. Modeling was performed to estimate the Level B zone for impact 
pile driving (the areas in which SPLs are expected to equal or exceed 
160 dB rms during impact driving) and for vibratory pile driving (the 
areas in which SPLs are expected to equal or exceed 120 dB rms during 
vibratory driving and removal). Results of this modeling showed the 
Level B zone for impact driving would extend to a radius of 900 m from 
the pile being driven, the Level B zone for vibratory pile driving and 
down-the-hole drilling (if it occurs) would extend to a radius of 
10,000 m from the pile being driven, and the Level B zone for vibratory 
pile removal would extend to a radius of 7,400 m from the pile being 
removed. However, due to the geography of the project area, landmasses 
surrounding Iliuliuk Harbor are expected to limit the propagation of 
sound from construction activities such that the actual distances to 
the extents of the Level B zones for all construction activities will 
be substantially smaller than those described above. Modeling results 
of the ensonified areas, taking into account the attenuation provided 
by landmasses, suggest the actual Level B zones will extend to a 
maximum distance of 1,300 m from the G1 dock, at the furthest point 
(for vibratory driving). Due to this relatively small modeled Level B 
zones, and due to the monitoring locations chosen by UniSea, we expect 
that monitors will be able to observe the entire modeled Level B zones 
for both impact and vibratory pile driving, and thus we expect data 
collected on incidents of Level B harassment to be relatively accurate. 
The modeled areas of the Level B zones for impact and vibratory 
driving, taking into account the attenuation provided by landmasses in 
attenuating sound from the construction project, and the monitoring 
locations, are shown in Marine Mammal Monitoring Plan, available at: 
www.nmfs.noaa.gov/pr/permits/incidental/.

Shutdown Measures

    UniSea will implement shutdown measures if a Steller sea lion or 
harbor seal is sighted in, or approaching, the Level A zone. In-water 
construction activities would be suspended until the Steller sea lion 
or harbor seal is observed leaving the Level A zone voluntarily and has 
been visually confirmed beyond the Level A zone, or 15 minutes has 
elapsed without re-detection of the animal in the Level A zone. 
Shutdown of construction operations will also occur if a species for 
which authorization has not been granted (including humpback whales) 
approaches or is observed within the Level B harassment zone; in-water 
construction activities would be suspended until the animal is observed 
leaving the Level B zone voluntarily and has been visually confirmed 
beyond the Level B harassment zone, or 15 minutes (in the case of 
pinnipeds) or 30 minutes (in the case of cetaceans) has elapsed without 
re-detection of the animal in the Level B harassment zone. In addition, 
shutdown of construction operations will also occur if the number of 
takes authorized for Steller sea lions or harbor seals have been met, 
and a Steller sea lion or harbor seal approaches, or is observed 
within, the Level B harassment zone; in-water construction activities 
would be suspended until the Steller sea lion or harbor seal is 
observed leaving the Level B zone voluntarily and has been visually 
confirmed beyond the Level B harassment zone, or 15 minutes has elapsed 
without re-detection of the animal in the Level B harassment zone.
    Observations of Steller sea lions and harbor seals outside the 
Level A zone will not result in shutdown of construction operations, 
unless the Steller sea lion or harbor seal approaches or enters the 
Level A zone, or unless authorized take numbers for Steller sea lions 
or harbor seals has already been exceeded as described above, at which 
point all pile driving activities will be halted.
    Monitoring Protocols--Monitoring will be conducted before, during, 
and after pile driving activities. Monitoring will take place from 30 
minutes prior to initiation of pile driving or pile removal through 30 
minutes post-completion of pile driving or removal activities. Pile 
driving and removal activities include the time to remove a single pile 
or series of piles, as long as the time elapsed between uses of the 
pile driving equipment is no more than thirty minutes. Please see the 
Marine Mammal Monitoring Plan (available at www.nmfs.noaa.gov/pr/permits/incidental/), for full details of the monitoring protocols.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown procedures when applicable by 
calling for the shutdown to the hammer operator. Qualified observers 
are will have the following minimum qualifications:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance;
     Experience and ability to conduct field observations and 
collect data according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors, with ability 
to accurately identify marine mammals in Alaskan waters to species;
     Sufficient training, orientation or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    (2) Prior to the start of pile driving activity, the Level A and 
Level B zone will be monitored for thirty minutes to ensure that the 
Level A zone is clear of all marine mammals and the Level B zone is 
clear of marine mammals other than Steller sea lions and harbor seals. 
Pile driving will only commence once observers have declared the Level 
A zone is clear of all marine mammals and the Level B zone is clear of 
all marine mammals under NMFS jurisdiction with the exception of 
Steller sea lions and harbor seals; animals will be allowed to remain 
in the respective exclusion zones (i.e., must leave of their own 
volition) and their behavior will be monitored and documented. The 
respective exclusion zones may only be declared clear, and pile driving 
started, when the entire Level B zone is visible (i.e., when not 
obscured by dark, rain, fog, etc.). In addition, if such conditions 
should arise during impact pile driving that is already underway, the 
activity will be halted.

[[Page 9451]]

    (3) If a Steller sea lion or harbor seal enters or approaches the 
Level A zone, or, if a marine mammal other than Steller sea lion or 
harbor seal enters or approaches the Level B zone, during the course of 
pile driving operations, activity will be halted and delayed until 
either the animal has voluntarily left the respective zone and been 
visually confirmed beyond the respective zone, or fifteen minutes have 
passed without re-detection of the animal in the case of pinnipeds, or 
thirty minutes have passed without re-detection of the animal in the 
case of cetaceans. Monitoring will be conducted throughout the time 
required to drive a pile.

Sound Attenuation Devices

    UniSea will use bubble curtains, which create a column of air 
bubbles rising around a pile from the substrate to the water's surface, 
as a sound attenuation device. The air bubbles absorb and scatter sound 
waves emanating from the pile, thereby reducing the sound energy. 
Unconfined bubble curtains will be used during all impact pile driving 
associated with the G1 dock construction project. A discussion of 
bubble curtains and their anticipated effectiveness is included in the 
Federal Register notice for the proposed IHA (80 FR 79822; December 23, 
2015), therefore that information is not repeated here; please refer to 
that Federal Register notice for that information.

Soft Start

    The use of a ``soft-start'' procedure is believed to provide 
additional protection to marine mammals by providing a warning and an 
opportunity to leave the area prior to the hammer operating at full 
capacity. For vibratory hammers, the soft start technique will initiate 
noise from the hammer for 15 seconds at a reduced energy level, 
followed by 1-minute waiting period and repeat the procedure two 
additional times. For impact hammers, the soft start technique will 
initiate three strikes at a reduced energy level, followed by a 30-
second waiting period. This procedure would also be repeated two 
additional times. The actual number of strikes at reduced energy will 
vary because operating the hammer at less than full power results in 
``bouncing'' of the hammer as it strikes the pile, resulting in 
multiple ``strikes.'' Soft start for impact driving will be required at 
the beginning of each day's pile driving work and at any time following 
a cessation of impact pile driving of thirty minutes or longer.
    We have carefully evaluated UniSea's proposed mitigation measures 
and considered their likely effectiveness relative to implementation of 
similar mitigation measures in previously issued IHAs to determine 
whether they are likely to affect the least practicable impact on the 
affected marine mammal species and stocks and their habitat. Our 
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.
    Any mitigation measure(s) we prescribe 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 number (total number or number at 
biologically important time or location) of individual marine mammals 
exposed to stimuli expected to result in incidental take (this goal may 
contribute to 1, above, or to reducing takes by behavioral harassment 
only).
    (3) A reduction in the number (total number or number at 
biologically important time or location) of times any individual marine 
mammal would be exposed to stimuli expected to result in incidental 
take (this goal may contribute to 1, above, or to reducing takes by 
behavioral harassment only).
    (4) A reduction in the intensity of exposure to stimuli expected to 
result in incidental take (this goal may contribute to 1, above, or to 
reducing the severity of behavioral harassment only).
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying particular attention to the prey base, blockage or 
limitation of passage to or from biologically important areas, 
permanent destruction of habitat, or temporary 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 our evaluation of UniSea's proposed measures, we have 
determined that the mitigation measures provide the means of affecting 
the least practicable impact on marine mammal species or stocks and 
their habitat.

Monitoring and Reporting

    In order to issue an IHA 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 
incidental take authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting that will 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 project area.
    Any monitoring requirement we prescribe should accomplish one or 
more of the following general goals:
    1. An increase in the probability of detecting marine mammals, both 
within defined zones of effect (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 stimuli that we associate with specific adverse 
effects, such as behavioral harassment or hearing threshold shifts;
    3. An increase in our understanding of how marine mammals respond 
to stimuli expected to result in incidental take and how anticipated 
adverse effects on individuals may impact the population, stock, or 
species (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 pertinent information, e.g., received level, 
distance from source);
     Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict pertinent information, e.g., received level, 
distance from source); and
     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; or

[[Page 9452]]

    5. An increase in our understanding of the effectiveness of certain 
mitigation and monitoring measures.
    UniSea submitted a marine mammal monitoring plan as part of their 
IHA application (the monitoring plan can be viewed online at: 
www.nmfs.noaa.gov/pr/permits/incidental/). UniSea's marine mammal 
monitoring plan was created with input from NMFS and was based on 
similar plans that have been successfully implemented by other action 
proponents under previous IHAs for pile driving projects.

Visual Marine Mammal Observations

    UniSea will collect sighting data and will record behavioral 
responses to construction activities for marine mammal species observed 
in the project location during the period of activity. All marine 
mammal observers (MMOs) will be trained in marine mammal identification 
and behaviors and are required to have no other construction-related 
tasks while conducting monitoring. UniSea will monitor the Level A and 
Level B harassment zones before, during, and after pile driving, with 
observers located at the best practicable vantage points. See Figure 2 
in the Marine Mammal Monitoring Plan for the observer locations planned 
for use during construction. Based on our requirements, the Marine 
Mammal Monitoring Plan would implement the following procedures for 
pile driving:
     Observers will report directly to the monitoring 
coordinator if/when a shutdown is deemed necessary due to marine 
mammals approaching the Level A or Level B harassment zones. An 
employee of the construction contractor will be identified as the 
monitoring coordinator at the start of each construction day. Shutdowns 
will be implemented immediately upon an observer reporting a marine 
mammal in, or approaching, the Level A zone; or, upon an observer 
reporting a marine mammal under NMFS's jurisdiction other than a 
Steller sea lion or harbor seal in, or approaching, the Level B zone.
     MMOs will be located at the best vantage point(s) in order 
to properly observe the entire Level A and Level B zones. A minimum of 
two MMOs will be on duty during all pile driving activity, with one of 
these MMOs having full time responsibility for monitoring the Level A 
zone.
     During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals.
     If the Level A or Level B zones are obscured by fog or 
poor lighting conditions, pile driving will not be initiated until the 
Level A and Level B zones are clearly visible. Should such conditions 
arise while impact driving is underway, the activity would be halted.
     The Level A or Level B zones will be monitored for the 
presence of marine mammals before, during, and after any pile driving 
or removal activity.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. MMOs will use their best 
professional judgment throughout implementation and seek improvements 
to these methods when deemed appropriate. Any modifications to protocol 
will be coordinated between NMFS and UniSea.

Data Collection

    We require that observers use approved data forms. Among other 
pieces of information, UniSea will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile being driven, a description of specific actions that ensued, 
and resulting behavior of the animal, if any. In addition, UniSea will 
attempt to distinguish between the number of individual animals taken 
and the number of incidents of take, when possible. We require that, at 
a minimum, the following information be collected on sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and (if possible) sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from marine mammal(s) to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    A draft report will be submitted within 90 calendar days of the 
completion of the activity, or within 45 calendar days prior to the 
effective date of a subsequent IHA (if applicable). The report will 
include information on marine mammal observations pre-activity, during-
activity, and post-activity during pile driving days, and will provide 
descriptions of any behavioral responses to construction activities by 
marine mammals and a complete description of any mitigation shutdowns 
and results of those actions, as well as an estimate of total take 
based on the number of marine mammals observed during the course of 
construction. A final report must be submitted within 30 days following 
resolution of comments from NMFS on the draft report.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner not authorized by the 
IHA, such as a Level A harassment, or a take of a marine mammal species 
other than those authorized, UniSea will immediately cease the 
specified activities and immediately report the incident to the Chief 
of the Permits and Conservation Division, Office of Protected 
Resources. The report would include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     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 would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with UniSea to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. UniSea would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that UniSea discovers an injured or dead marine 
mammal, and the lead MMO 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), UniSea would immediately report the 
incident to mail to: The Chief of the Permits and Conservation 
Division, Office of Protected Resources, NMFS, and the Alaska Stranding 
Coordinator.
    The report would include the same information identified in the 
paragraph above. Construction related activities would be able to 
continue while NMFS reviews the circumstances of the incident. NMFS 
would work with UniSea to determine whether

[[Page 9453]]

modifications in the activities are appropriate.
    In the event that UniSea discovers an injured or dead marine 
mammal, and the lead MMO 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 to advanced 
decomposition, or scavenger damage), UniSea would report the incident 
to the Chief of the Permits and Conservation Division, Office of 
Protected Resources, NMFS, and the Alaska Stranding Coordinator, within 
24 hours of the discovery. UniSea would provide photographs or video 
footage (if available) or other documentation of the stranded animal 
sighting to NMFS and the Marine Mammal Stranding Network.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, 
section 3(18) of 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].''
    All anticipated takes would be by Level B harassment, resulting 
from vibratory and impact pile driving and involving temporary changes 
in behavior. Based on the best available information, the activities--
vibratory and impact pile driving--would not result in serious injuries 
or mortalities to marine mammals even in the absence of the mitigation 
and monitoring measures. However, the mitigation and monitoring 
measures are expected to minimize the potential for injury, such that 
take by Level A harassment is considered discountable.
    If a marine mammal responds to a stimulus by changing its behavior 
(e.g., through relatively minor changes in locomotion direction/speed 
or vocalization behavior), the response may or may not constitute 
taking at the individual level, and is unlikely to affect the stock or 
the species as a whole. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on animals or on the stock or species could potentially 
be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007). Given 
the many uncertainties in predicting the quantity and types of impacts 
of sound on marine mammals, it is common practice to estimate how many 
animals are likely to be present within a particular distance of a 
given activity, or exposed to a particular level of sound.
    This practice potentially overestimates the numbers of marine 
mammals taken, as it is often difficult to distinguish between the 
individual animals harassed and incidences of harassment. In 
particular, for stationary activities, it is more likely that some 
smaller number of individuals may accrue a number of incidences of 
harassment per individual than for each incidence to accrue to a new 
individual, especially if those individuals display some degree of 
residency or site fidelity and the impetus to use the site (e.g., 
because of foraging opportunities) is stronger than the deterrence 
presented by the harassing activity. The Steller sea lions and harbor 
seals expected to occur in the project area are not branded, thus we 
expect that the identification of individual animals, even by 
experienced MMOs, would be extremely difficult. This would further 
increase the likelihood that repeated exposures of an individual, even 
within the same day, could be recorded as multiple takes.
    UniSea requested authorization for the incidental taking of small 
numbers of Steller sea lions and harbor seals that may result from pile 
driving activities associated with the dock construction project 
described previously in this document. In order to estimate the 
incidents of take that may occur incidental to the specified activity, 
we must first estimate the extent of the sound field that may be 
produced by the activity and then incorporate information about marine 
mammal density or abundance in the project area. We first provide 
information on applicable sound thresholds for determining effects to 
marine mammals before describing the information used in estimating the 
sound fields, the available marine mammal density or abundance 
information, and the method of estimating incidences of take.

Sound Thresholds

    We use generic sound exposure thresholds to determine when an 
activity that produces sound might result in impacts to a marine mammal 
such that a ``take'' by harassment might occur. To date, no studies 
have been conducted that explicitly examine impacts to marine mammals 
from pile driving sounds or from which empirical sound thresholds have 
been established. These thresholds should be considered guidelines for 
estimating when harassment may occur (i.e., when an animal is exposed 
to levels equal to or exceeding the relevant criterion) in specific 
contexts; however, useful contextual information that may inform our 
assessment of effects is typically lacking and we consider these 
thresholds as step functions. NMFS is currently revising these acoustic 
guidelines; for more information on that process, please see: 
www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

            Table 2--Current NMFS Acoustic Exposure Criteria
------------------------------------------------------------------------
           Criterion                Definition           Threshold
------------------------------------------------------------------------
Level A harassment              Injury (PTS--any   180 dB (cetaceans)/
 (underwater).                   level above that   190 dB (pinnipeds)
                                 which is known     (rms).
                                 to cause TTS).
Level B harassment              Behavioral         160 dB (impulsive
 (underwater).                   disruption.        source *)/120 dB
                                                    (continuous source
                                                    *) (rms).
Level B harassment (airborne)   Behavioral         90 dB (harbor seals)/
 **.                             disruption.        100 dB (other
                                                    pinnipeds)
                                                    (unweighted).
------------------------------------------------------------------------
* Impact pile driving produces impulsive noise; vibratory pile driving
  produces non-pulsed (continuous) noise.
** NMFS has not established any formal criteria for harassment resulting
  from exposure to airborne sound. However, these thresholds represent
  the best available information regarding the effects of pinniped
  exposure to such sound and NMFS' practice is to associate exposure at
  these levels with Level B harassment.

Distance to Sound Thresholds

    Underwater Sound Propagation Formula--Pile driving generates 
underwater noise that can potentially result in disturbance to marine 
mammals in the project area. Transmission loss (TL) is the decrease in 
acoustic intensity as an acoustic pressure wave propagates out from a 
source. TL parameters vary with frequency, temperature, sea conditions,

[[Page 9454]]

current, source and receiver depth, water depth, water chemistry, and 
bottom composition and topography. The general formula for underwater 
TL is:

TL = B * log10(R1/R2),

Where

R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement


    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]). A 
practical spreading value of fifteen is often used under conditions, 
such as Iliuliuk Harbor, where water depth increases as the receiver 
moves away from the shoreline, resulting in an expected propagation 
environment that would lie between spherical and cylindrical spreading 
loss conditions. Practical spreading loss (4.5 dB reduction in sound 
level for each doubling of distance) is assumed here.
    Underwater Sound--The intensity of pile driving sounds is greatly 
influenced by factors such as the type of piles, hammers, and the 
physical environment in which the activity occurs. A large quantity of 
literature regarding SPLs recorded from pile driving projects is 
available for consideration. In order to determine reasonable SPLs and 
their associated effects on marine mammals that are likely to result 
from pile driving at the UniSea dock, studies with similar properties 
to the specified activity were evaluated. See Section 5 of UniSea's IHA 
application for a detailed description of the information considered in 
determining reasonable proxy source level values. UniSea used 
representative source levels of 165 dB rms for installation of steel 
sheet piles using a vibratory hammer (CalTrans 2012), 163 dB rms for 
vibratory removal and installation of a 24-inch steel pile (Rodkin 
2013), 189 dB rms for impact pile driving of a 24-inch steel pile 
(CalTrans 2012), and 165 dB (re: 1 [mu]Pa at 1m) at 200 Hz for down-
the-hole drilling (URS 2011). The representative source level of 189 dB 
rms for impact pile driving of a 24-inch steel pile represents a change 
from the proposed IHA published in the Federal Register on December 23, 
2015 (80 FR 79822), in which a representative source level of 184 dB 
rms was proposed as a proxy source level; during the 30 day public 
comment period, NMFS determined that the best available information 
suggested 189 dB represented a more accurate source level for impact 
pile driving (CalTrans 2012).

   Table 3--Modeled Distances From G1 Dock to NMFS Level A and Level B
 Harassment Thresholds (Isopleths) During Pile Installation and Removal
------------------------------------------------------------------------
                                                               Distance
                          Threshold                           (meters) *
------------------------------------------------------------------------
Impact driving, pinniped injury (190 dB)....................      ** 8.6
Impact driving, pinniped disturbance (160 dB)...............         900
Vibratory driving, pinniped injury (190 dB).................    ** 0.215
Vibratory driving or down-the-hole drilling, pinniped             10,000
 disturbance (120 dB).......................................
Vibratory removal, pinniped injury (160 dB).................    ** 0.158
Vibratory removal, pinniped disturbance (120 dB)............       7,400
------------------------------------------------------------------------
* Distances shown are modeled maximum distances and do not account for
  landmasses which are expected to reduce the actual distances to sound
  thresholds.
** These are modeled distances to the Level A harassment threshold,
  however the Level A zone will conservatively extend to 10 m radius,
  thus any marine mammal within, or approaching, a 10 m radius of the
  pile being driven would trigger a shutdown of construction.

    Iliuliuk Harbor does not represent open water, or free field, 
conditions. Therefore, sounds would attenuate as they encounter land 
masses. As a result, and as described above, pile driving noise in the 
project area is not expected to propagate to the calculated distances 
for the 160 dB or 120 dB thresholds as shown in Table 3. See Appendix B 
of UniSea's IHA application for figures depicting the actual extents of 
areas in which each underwater sound threshold is predicted to occur at 
the project area due to pile driving, taking into account the 
attenuation provided by landmasses.
    Airborne Sound--Pile driving can generate airborne sound that could 
potentially result in disturbance to pinnipeds that are hauled out or 
at the water's surface. As a result, UniSea analyzed the potential for 
pinnipeds hauled out or swimming at the surface near the G1 dock to be 
exposed to airborne SPLs that could result in Level B behavioral 
harassment. A spherical spreading loss model (i.e., 6 dB reduction in 
sound level for each doubling of distance from the source), in which 
there is a perfectly unobstructed (free-field) environment not limited 
by depth or water surface, is appropriate for use with airborne sound 
and was used to estimate the distance to the airborne thresholds.
    As discussed above regarding underwater sound from pile driving, 
the intensity of pile driving sounds is greatly influenced by factors 
such as the type of piles, hammers, and the physical environment in 
which the activity occurs. In order to determine reasonable airborne 
SPLs and their associated effects on marine mammals that are likely to 
result from pile driving at Iliuliuk Harbor, studies with similar 
properties to the UniSea G1 dock construction project, as described 
previously, were evaluated. UniSea used representative source levels of 
100 dB Leq/rms at 22 m for vibratory removal and installation of a 24-
inch steel pile and 100 dB Leq/rms at 26 m for impact driven 24-inch 
steel piles. Please see Section 5 of UniSea's IHA application for 
details of the information considered. These values result in a 
disturbance zone (radial distance) of 3.16 m for harbor seals and 1.0 m 
for Steller sea lions. No data was found for the airborne sound levels 
expected from the installation of steel sheet piles or 18-inch steel 
piles, but sound levels from the installation of steel sheet piles and 
18-inch steel piles are likely to be within a similar range as sound 
levels mentioned above.
    Despite the modeled distances described above, no incidents of 
incidental take resulting solely from airborne sound are likely, as 
distances to the harassment thresholds would not reach areas where 
pinnipeds are known to haul out in the area of the project. Harbor seal 
haulout locations may change slightly depending on weather patterns, 
human disturbance, or prey availability, but the closest known harbor 
seal haulout to the project location is on the north side of Hog 
island, located west of Amaknak Island in Unalaska Bay, approximately 3 
km from the G1 dock (pers. comm., L. Fritz, NMML, to J. Carduner, NMFS, 
Oct 30, 2015). Steller sea lions have greater site fidelity than harbor 
seals; the closest known Steller sea lion haulout is at Priest Rock, a 
point that juts into the Bering Sea on the northeastern corner of 
Unalaska Bay, approximately 20 km from the project site (pers. comm., 
L.

[[Page 9455]]

Fritz, NMML, to J. Carduner, NMFS, Oct 30, 2015).
    We recognize that pinnipeds in the water could be exposed to 
airborne sound that may result in behavioral harassment when their 
heads are above the water's surface. However, these animals would 
previously have been ``taken'' as a result of exposure to underwater 
sound above the behavioral harassment thresholds, which are in all 
cases larger than those associated with airborne sound. Thus, the 
behavioral harassment of these animals is already accounted for in 
these estimates of potential take. Multiple incidents of exposure to 
sound above NMFS' thresholds for behavioral harassment are not believed 
to result in increased behavioral disturbance, in either nature or 
intensity of disturbance reaction. Therefore, authorization of 
incidental take resulting from airborne sound for pinnipeds is not 
warranted, and airborne sound is not discussed further.

Marine Mammal Occurrence

    The most appropriate information available was used to estimate the 
number of potential incidences of take. Density estimates for Steller 
sea lions and harbor seals in Iliuliuk Harbor, and more broadly in the 
waters surrounding Unalaska Island, are not readily available. 
Likewise, we were not able to find any published literature or reports 
describing densities or estimating abundance of either species in the 
project area. As such, data collected from marine mammal surveys 
represent the best available information on the occurrence of both 
species in the project area.
    Beginning in April 2015, UniSea personnel began conducting marine 
mammal surveys of Iliuliuk Harbor under the direction of an ecological 
consultant. Observers recorded data on all marine mammals that were 
observed, including Steller sea lions, whales, and harbor seals. Both 
stationary and roving observations occurred within a 1,000 m radius of 
the project site (see Figure 9 in the IHA application for a depiction 
of survey points and marine mammal observations). A combination of two 
of the stationary observation points were surveyed each day, for a 
total of 15 minutes at each point, and the roving route was checked 
once per day over a time span of 15 minutes, covering areas between the 
docks that were too difficult to see from the stationary points. The 
survey recorded the number of animals observed, the species, their 
primary activity, and any additional notes. From January through 
October 2015, a total of 323 Steller sea lions and 33 harbor seals were 
observed during 1,432 separate observations over the course of 358 
hours of surveys. These surveys represent the most recent data on 
marine mammal occurrence in the harbor, and represent the only targeted 
marine mammal surveys of the project area that we are aware of.
    Data from bird surveys of Iliuliuk Harbor conducted by the U.S. 
Army Corps of Engineers (USACE) from 2001-2007, which included 
observations of marine mammals in the harbor, were also available; 
however, we determined that these data were unreliable as a basis for 
prediction of marine mammal abundance in the project location as the 
goal of the USACE surveys was to develop a snapshot of waterfowl and 
seabird location and abundance in the harbor, thus the surveys would 
have been designed and carried out differently if the goal had been to 
document marine mammal use of the harbor (pers. comm., C. Hoffman, 
USACE, to J. Carduner, NMFS, October 26, 2015). Additionally, USACE 
surveys occurred only in winter; as Steller sea lion abundance is 
expected to vary significantly between the breeding and the non-
breeding season in the project location, data that were collected only 
during the non-breeding season have limited utility in predicting year-
round abundance. As such, we determined that the data from the surveys 
commissioned by UniSea in 2015 represents the best available 
information on marine mammals in the project location.

Description of Take Calculation

    The take calculations presented here rely on the best data 
currently available for marine mammal populations in the project 
location. Density data for marine mammal species in the project 
location is not available. Therefore the data collected from marine 
mammal surveys of Iliuliuk Harbor in 2015 represent the best available 
information on marine mammal populations in the project location, and 
this data was used to estimate take. As such, the zones that have been 
calculated to contain the areas ensonified to the Level A and Level B 
thresholds for pinnipeds have been calculated for mitigation and 
monitoring purposes and were not used in the calculation of take. See 
Table 4 for total estimated incidents of take. Estimates were based on 
the following assumptions:
     All marine mammals estimated to be in areas ensonified by 
noise exceeding the Level B harassment threshold for impact and 
vibratory driving (as shown in Appendix B of the IHA application) are 
assumed to be in the water 100% of the time. This assumption is based 
on the fact that there are no haulouts or rookeries within the area 
predicted to be ensonified to the Level B harassment threshold based on 
modeling.
     Predicted exposures were based on total estimated total 
duration of pile driving/removal hours, which are estimated at 1,080 
hours over the entire project. This estimate is based on a 180 day 
project time frame, an average work day of 12 hours (work days may be 
longer than 12 hours in summer and shorter than 12 hours in winter), 
and an estimate that approximately 50% of time during those work days 
will include pile driving and removal activities (with the other 50% of 
work days spent on non-pile driving activities which will not result in 
marine mammal take, such as installing templating and bracing, moving 
equipment, etc.).
     Vibratory or impact driving could occur at any time during 
the ``duration'' and our approach to take calculation assumes a rate of 
occurrence that is the same for any of the calculated zones.
     The hourly marine mammal observation rate recorded during 
marine mammal surveys of Iliuliuk Harbor in 2015 is reflective of the 
hourly rate that will be observed during the construction project.
     Takes were calculated based on estimated rates of 
occurrence for each species in the project area and this rate was 
assumed to be the same regardless of the size of the zone (for impact 
or vibratory driving/removal).
     Activities that may be accomplished by either impact 
driving or down-the-hole drilling (i.e. fender support/pin piles, 
miscellaneous support piles, and temporary support piles) were assumed 
to be accomplished via impact driving. If any of these activities are 
ultimately accomplished via down-the-hole drilling instead of impact 
driving, this would not result in a change in the amount of overall 
effort (as they will be accomplished via down-the-hole drilling instead 
of, and not in addition to, impact driving). As take estimates are 
calculated based on effort and not marine mammal densities, this would 
not change the take estimate.
    Take estimates for Steller sea lions and harbor seals were 
calculated using the following series of steps:
    1. The average hourly rate of animals observed during 2015 marine 
mammal surveys of Iliuliuk Harbor was calculated separately for both 
species (``Observation Rate''). Thus ``Observation Rate'' (OR) = No. of 
individuals observed/hours of observation;
    2. The 95% confidence interval was calculated for the data set, and 
the

[[Page 9456]]

upper bound of the 95% confidence interval was added to the Observation 
Rate to account for variability of the small data set (``Exposure 
Rate''). Thus ``Exposure Rate'' (XR) = [mu]OR + 
CI95 (where [mu]OR = average of monthly 
observation rates and CI95 = 95% confidence interval (normal 
distribution);
    3. The total estimated hours of pile driving work over the entire 
project was calculated, as described above (``Duration''); Thus 
``Duration'' = total number of work days (180) * average work hours per 
day (12) * percentage of pile driving time during work days (0.5) = 
total work hours for the project (1,080); and
    4. The estimated number of exposures was calculated by multiplying 
the ``Duration'' by the estimated ``Exposure Rate'' for each species. 
Thus, estimated takes = Duration * XR.
    Please refer to Appendix G of the IHA application for a more 
thorough description of the statistical analysis of the observation 
data from marine mammal surveys.
    Steller Sea Lion--Steller sea lion density data for the project 
area is not available. Steller sea lions occur year-round in the 
Aleutian Islands and within Unalaska Bay and Iliuliuk Harbor. As 
described above, local abundance in the non-breeding season (winter 
months) is generally lower overall; data from surveys conducted by 
UniSea in 2015 revealed Steller sea lions were present in Iliuliuk 
Harbor in all months that surveys occurred. We assume, based on marine 
mammal surveys of Iliuliuk Harbor, and based on the best available 
information on seasonal abundance patterns of the species including 
over 20 years of NMML survey data collected in Unalaska, that Steller 
sea lions will be regularly observed in the project area during all 
months of construction. As described above, all Steller sea lions in 
the project area at a given time are assumed to be in the water, thus 
any sea lion within the modeled area of ensonification exceeding the 
Level B harassment threshold would be recorded as taken by Level B 
harassment.
    Estimated take of Steller sea lions was calculated using the 
equations described above, as follows:

[mu]OR = 1.219 individuals/hr
CI95 = 0.798
XR = 2.016
Estimated exposures (Level B harassment) = 2.016 * 1,080 = 2,177

    Thus we estimate that a total of 2,177 Steller sea lion takes will 
occur as a result of the UniSea G1 dock construction project (Table 4).
    Harbor Seal--Harbor seal density data for the project location is 
not available. We assume, based on the best on the best available 
information, that harbor seals will be encountered in low numbers 
throughout the duration of the project. We relied on the best available 
information to estimate take of harbor seals, which in this case was 
survey data collected from the 2015 marine mammal surveys of Iliuliuk 
Harbor as described above. That survey data showed harbor seals are 
present in the harbor only occasionally, with only 33 seals observed 
over the entire survey. NMML surveys have not been performed in 
Iliuliuk Harbor, but the most recent NMML surveys of Unalaska Bay 
confirm that harbor seals are present in the area in relatively small 
numbers, with the most recent haulout counts in Unalaska Bay (2008-11) 
recording no more than 19 individuals at the three known haulouts 
there. NMML surveys have been limited to the months of July and August, 
so it is not known whether harbor seal abundance in the project area 
varies seasonally. The 2015 marine mammal surveys of Iliuliuk Harbor 
showed numbers of harbor seals in the harbor increasing from July 
through October, but the sample size for those months was extremely 
small (n=30). As described above, all harbor seals in the project area 
at a given time are assumed to be in the water, thus any harbor seals 
within the modeled area of ensonification exceeding the Level B 
harassment threshold would be recorded as taken by Level B harassment.
    Estimated take of harbor seals was calculated using the equations 
described above, as follows:

[mu]OR = 0.171 individuals/hr
CI95 = 0.185
XR = 0.356
Estimated exposures (Level B harassment) = 0.356 * 1,080 hours = 385

    Thus we estimate that a total of 385 harbor seal takes will occur 
as a result of the UniSea G1 dock construction project (Table 4).
    We therefore authorize the take, by Level B harassment only, of a 
total of 2,177 Steller sea lions (western DPS) and 385 harbor seals 
(Aleutian Islands stock) as a result of the UniSea G1 dock construction 
project. These take estimates are considered reasonable estimates of 
the number of marine mammal exposures to sound above the Level B 
harassment threshold that are likely to occur over the course of the 
project, and not the number of individual animals exposed. For 
instance, for pinnipeds that associate fishing boats in Iliuliuk Harbor 
with reliable sources of food, there will almost certainly be some 
overlap in individuals present day-to-day depending on the number of 
vessels entering the harbor, however each instance of exposure for 
these individuals will be recorded as a separate, additional take. 
Moreover, because we anticipate that marine mammal observers will 
typically be unable to determine from field observations whether the 
same or different individuals are being exposed over the course of a 
workday, each observation of a marine mammal will be recorded as a new 
take, although an individual theoretically would only be considered as 
taken once in a given day.

Table 4--Number of Authorized Incidental Takes of Marine Mammals, and Percentage of Stock Abundance, as a Result
                                       of the G1 Dock Construction Project
----------------------------------------------------------------------------------------------------------------
                                                                           Underwater *
                                                                 --------------------------------  Percentage of
                             Species                                               Level B (120        stock
                                                                      Level A           dB)          abundance
----------------------------------------------------------------------------------------------------------------
Steller sea lion................................................               0           2,177               4
Harbor seal.....................................................               0             385              11
----------------------------------------------------------------------------------------------------------------
* We assume, for reasons described earlier, that no takes would occur as a result of airborne noise.


[[Page 9457]]

Analyses and Determinations

Negligible Impact Analysis

    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.'' 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, we consider other factors, such as the likely nature of any 
responses (e.g., intensity, duration), the context of any responses 
(e.g., critical reproductive time or location, migration), as well as 
the number and nature of estimated Level A harassment takes, the number 
of estimated mortalities, and effects on habitat.
    Pile driving activities associated with the UniSea G1 dock 
construction project, as outlined previously, have the potential to 
disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level B harassment 
(behavioral disturbance) only, from underwater sounds generated from 
pile driving. Takes could occur if marine mammals are present in the 
Level B harassment zone when pile driving is happening, which is likely 
to occur because: (1) Steller sea lions have established haulouts near 
Iliuliuk Harbor and are frequently observed in Iliuliuk Harbor, in 
varying numbers depending on season and prey availability, and probably 
associate fishing boats entering the harbor with reliable food sources; 
and (2) harbor seals are observed in Iliuliuk Harbor occasionally and 
are known to haulout at sites outside the harbor, including one site 
approximately 3 km from the project location.
    No serious injury or mortality of marine mammals would be 
anticipated as a result of vibratory and impact pile driving, 
regardless of mitigation and monitoring measures. Vibratory hammers do 
not have significant potential to cause injury to marine mammals due to 
the relatively low source levels produced (less than 180 dB rms) and 
the lack of potentially injurious source characteristics. Impact pile 
driving produces short, sharp pulses with higher peak levels than 
vibratory driving and much sharper rise time to reach those peaks. The 
potential for injury that may otherwise result from exposure to noise 
associated with impact pile driving will effectively be minimized 
through the implementation of the planned mitigation measures. These 
measures include: The implementation of a Level A ``exclusion zone'', 
which is expected to eliminate the likelihood of marine mammal exposure 
to noise at received levels that could result in injury; the use of 
``soft start'' before pile driving, which is expected to provide marine 
mammals near or within the zone of potential injury with sufficient 
time to vacate the area; and the use of a sound attenuation system 
which is expected to dampen the sharp, potentially injurious peaks 
associated with impact driving and to reduce the overall source level 
to some extent (it is difficult to predict the extent of attenuation 
provided as underwater recordings have not been performed for the type 
of bubble curtain proposed for use). We believe the required mitigation 
measures, which have been successfully implemented in similar pile 
driving projects, will minimize the possibility of injury that may 
otherwise exist as a result of impact pile driving.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from similar 
pile driving projects that have received incidental take authorizations 
from NMFS, will likely be limited to reactions such as increased 
swimming speeds, increased surfacing time, or decreased foraging. Most 
likely, individuals will simply move away from the sound source and be 
temporarily displaced from the area of pile driving (though even this 
reaction has been observed primarily in association with impact pile 
driving). In response to vibratory driving, harbor seals have been 
observed to orient towards and sometimes move towards the sound. 
Repeated exposures of individuals to levels of sound that may cause 
Level B harassment are unlikely to result in hearing impairment or to 
significantly disrupt foraging behavior. Thus, even repeated Level B 
harassment of some small subset of the overall stock is unlikely to 
result in any significant realized decrease in fitness to those 
individuals, and thus would not result in any adverse impact to the 
stock as a whole. Level B harassment will be reduced to the level of 
least practicable impact through use of mitigation measures described 
herein and, if sound produced by project activities is sufficiently 
disturbing, animals are likely to simply avoid the project area while 
the activity is occurring.
    No pinniped rookeries or haul-outs are present within the project 
area, and the project area is not known to provide foraging habitat of 
any special importance to either Steller sea lions or harbor seals 
(other than is afforded by the migration of salmonids to and from 
Iliuliuk Stream and the occasional availability of discarded fish from 
commercial fishing boats and fish processing facilities in the project 
area). No cetaceans are expected within the project area. While we are 
not aware of comparable construction projects in the project location, 
the pile driving activities analyzed here are similar to other in-water 
construction activities that have received incidental harassment 
authorizations previously, including projects at Naval Base Kitsap 
Bangor in Hood Canal, Washington, and at the Port of Friday Harbor in 
the San Juan Islands, which have occurred with no reported injuries or 
mortalities to marine mammals, and no known long-term adverse 
consequences to marine mammals from behavioral harassment.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of injury, serious injury, or 
mortality may reasonably be considered discountable; (2) the 
anticipated incidences of Level B harassment consist of, at worst, 
temporary modifications in behavior; (3) the absence of any major 
rookeries and only a few isolated haulout areas near the project site; 
(4) the absence of any other known areas or features of special 
significance for foraging or reproduction within the project area; and 
(5) the presumed efficacy of planned mitigation measures in reducing 
the effects of the specified activity to the level of least practicable 
impact. In combination, we believe that these factors, as well as the 
available body of evidence from other similar activities, demonstrate 
that the potential effects of the specified activity will have only 
short-term effects on individual animals. The specified activity is not 
expected to impact rates of recruitment or survival and will therefore 
not result in population-level impacts. 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 monitoring and mitigation measures, we find that 
the total marine mammal take from UniSea's dock construction activities 
in Iliuliuk Harbor will have a negligible impact on the affected marine 
mammal species or stocks.

[[Page 9458]]

Small Numbers Analysis

    The numbers of animals authorized to be taken would be considered 
small relative to the relevant stocks or populations (4 percent and 11 
percent for Steller sea lions and harbor seals, respectively) even if 
each estimated taking occurred to a new individual. However, the 
likelihood that each take would occur to a new individual is extremely 
low. As described above, for those sea lions that associate fishing 
boats with reliable sources of food, there will almost certainly be 
some overlap in individuals present day-to-day depending on the number 
of vessels entering the harbor. It is expected that operations at a 
separate, nearby UniSea dock and the associated UniSea processing 
facilities, as well as at seafood processing facilities owned by other 
companies based in Iliuliuk Harbor, will continue as usual during 
construction on the G1 dock, so it is likely that sea lions accustomed 
to seeking food at these facilities will continue to be attracted to 
the area during portions of the construction activities.
    Further, these takes are likely to occur only within some small 
portion of the overall regional stock. For example, of the estimated 
55,422 western DPS Steller sea lions throughout Alaska, there are 
probably no more than 300 individuals with site fidelity to the three 
haulouts located nearest to the project location, based on over twenty 
years of NMML survey data (see ``Description of Marine Mammals in the 
Area of the Specified Activity'' above). For harbor seals, NMML survey 
data suggest there are likely no more than 60 individuals that use the 
three haulouts nearest to the project location (the only haulouts in 
Unalaska Bay). Thus the estimate of take is an estimate of the number 
of anticipated exposures, rather than an estimate of the number of 
individuals that will be taken, as we expect the majority of exposures 
would be repeat exposures that would accrue to the same individuals. As 
such, the authorized takes represent a much smaller number of 
individuals of both Steller sea lions and harbor seals, in relation to 
total stock sizes.
    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, we find that small numbers of marine mammals will be taken 
relative to the populations of the affected species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    Subsistence hunting and fishing is an important part of the history 
and culture of Unalaska Island. However, the number of Steller sea 
lions and harbor seals harvested in Unalaska decreased from 1994 
through 2008; in 2008, the last year for which data is available, there 
were no Steller sea lions or harbor seals reported as harvested for 
subsistence use. Data on pinnipeds hunted for subsistence use in 
Unalaska has not been collected since 2008. For a summary of data on 
pinniped harvests in Unalaska from 1994-2008, see Section 8 of the IHA 
application.
    Aside from the apparently decreasing rate of subsistence hunting in 
Unalaska, Iliuliuk Harbor is not likely to be used for subsistence 
hunting or fishing due to its industrial nature, with several fish 
processing facilities located along the shoreline of the harbor. In 
addition, the UniSea G1 dock construction project is likely to result 
only in short-term, temporary impacts to pinnipeds in the form of 
possible behavior changes, and is not expected to result in the injury 
or death of any marine mammal. As such, the project is not likely to 
adversely impact the availability of any marine mammal species or 
stocks that may otherwise be used for subsistence purposes.

National Environmental Policy Act (NEPA)

    NMFS prepared an Environmental Assessment (EA) in February, 2016, 
titled ``Issuance of an Incidental Harassment Authorization to UniSea, 
Inc., to Take Marine Mammals by Harassment Incidental to Construction 
Activities on Unalaska Island, Alaska, March 2016-February 2017.'' A 
Finding of No Significant Impact (FONSI) was signed on February 12, 
2016. In the FONSI, NMFS determined that the issuance of the IHA for 
the take, by harassment, of small numbers of marine mammals incidental 
to the UniSea's dock construction project in Unalaska, AK, will not 
significantly impact the quality of the human environment, as described 
in this document and in the UniSea EA. The EA and FONSI can be found 
at: https://www.nmfs.noaa.gov/pr/permits/incidental/.

Endangered Species Act (ESA)

    There is one marine mammal species (western DPS Steller sea lion) 
with confirmed occurrence in the project area that is listed as 
endangered under the ESA. The NMFS Alaska Regional Office Protected 
Resources Division issued a Biological Opinion on February 16, 2016, 
under section 7 of the ESA, on the issuance of an IHA to UniSea under 
section 101(a)(5)(D) of the MMPA by the NMFS Permits and Conservation 
Division. The Biological Opinion concluded that the proposed action is 
not likely to jeopardize the continued existence of western DPS Steller 
sea lions, and is not likely to destroy or adversely modify western DPS 
Steller sea lion critical habitat.

Authorization

    NMFS has issued an IHA to UniSea for the potential harassment of 
small numbers of two marine mammal species incidental to the G1 dock 
construction project in Unalaska, Alaska, provided the previously 
mentioned mitigation.

    Dated: February 19, 2016.
Perry Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2016-03998 Filed 2-24-16; 8:45 am]
BILLING CODE 3510-22-P