Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Operation and Maintenance of a Liquefied Natural Gas Facility Off Massachusetts, 80260-80286 [2010-31769]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 75, Number 244 (Tuesday, December 21, 2010)]
[Proposed Rules]
[Pages 80260-80286]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-31769]



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Part V





Department of Commerce





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National Oceanic and Atmospheric Administration



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50 CFR Part 217



Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to Operation and Maintenance of a Liquefied Natural Gas Facility Off 
Massachusetts; Proposed Rule

Federal Register / Vol. 75 , No. 244 / Tuesday, December 21, 2010 / 
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 0808041026-9015-01]
RIN 0648-AX09


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Operation and Maintenance of a Liquefied Natural Gas 
Facility Off Massachusetts

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

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS has received a request from Neptune LNG LLC (Neptune) for 
authorization for the take of marine mammals, by harassment, incidental 
to port commissioning and operations, including maintenance and repair 
activities, at its Neptune Deepwater Port (the Port) in Massachusetts 
Bay for the period of July 2011 through July 2016. Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS is proposing regulations to 
govern that take and requests information, suggestions, and comments on 
these proposed regulations.

DATES: Comments and information must be received no later than February 
4, 2011.

ADDRESSES: You may submit comments, identified by 0648-AX09, by any one 
of the following methods:
     Electronic Submissions: Submit all electronic public 
comments via the Federal eRulemaking Portal: https://www.regulations.gov.
     Hand delivery or mailing of paper, disk, or CD-ROM 
comments should be addressed to Michael Payne, Chief, Permits, 
Conservation and Education Division, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Silver 
Spring, MD 20910.
    Comments regarding any aspect of the collection of information 
requirement contained in this proposed rule should be sent to NMFS via 
one of the means stated here and to the Office of Information and 
Regulatory Affairs, NEOB-10202, Office of Management and Budget (OMB), 
Attn: Desk Office, Washington, DC 20503, OIRA@omb.eop.gov.
    Instructions: All comments received are a part of the public record 
and will generally be posted to https://www.regulations.gov 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.
    NMFS will accept anonymous comments (enter N/A in the required 
fields if you wish to remain anonymous). Attachments to electronic 
comments will be accepted in Microsoft Word, Excel, WordPerfect, or 
Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: Candace Nachman, Office of Protected 
Resources, NMFS, (301) 713-2289, ext 156.

SUPPLEMENTARY INFORMATION:

Availability

    A copy of Neptune's application may be obtained by writing to the 
address specified above (see ADDRESSES), calling the contact listed 
above (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet 
at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. To help NMFS 
process and review comments more efficiently, please use only one 
method to submit comments.
    The Final Environmental Impact Statement (Final EIS) on the Neptune 
Deepwater Port License Application authored by the Maritime 
Administration (MARAD) and U.S. Coast Guard (USCG) is available for 
viewing at https://www.regulations.gov by entering the search words 
``Neptune LNG.''

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 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 December 14, 2009, NMFS received an application from Neptune for 
the taking, by harassment, of marine mammals incidental to port 
commissioning and operations, including maintenance and repair 
activities, at its Neptune Deepwater Port (Port) facility in 
Massachusetts Bay. NMFS reviewed Neptune's application and identified a 
number of issues requiring further clarification. After addressing 
comments from NMFS, Neptune modified its application and submitted a 
revised application on March 11, 2010. The March 11, 2010, application 
is the one available for public comment (see ADDRESSES) and which was 
considered by NMFS for these proposed regulations.
    Neptune submitted its first complete application to NMFS on 
December 27, 2007, for the take of small numbers of marine mammals, by 
harassment, incidental to the construction phase of the Neptune LNG 
Port Facility. In June 2008, NMFS issued a 1-year Incidental Harassment 
Authorization (IHA) to Neptune for the construction of the Port (73 FR 
33400, June 12, 2008). This authorization expired on June 30, 2009. 
NMFS issued a second 1-year IHA to Neptune for the completion of 
construction and beginning of Port operations on June 26, 2009 (74 FR 
31926, July 6, 2009), which expired on June 30, 2010.
    On July 12, 2010, NMFS issued a third IHA to Neptune based on the 
request in its March 11, 2010, application (75 FR 41440, July 16, 
2010). This latest IHA is effective through July 11, 2011. During the 
period of this third IHA, Neptune intends to commission its second 
shuttle and regasification vessel (SRV) and conduct limited port 
operations. There is also a

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chance that some maintenance and repairs may be conducted on the Port 
facility.
    During the period of these proposed regulations (July 2011-July 
2016), Neptune intends to continue port operations and conduct 
maintenance and repairs, as needed. The Neptune Port is located 
approximately 22 mi (35 km) northeast of Boston, Massachusetts, in 
Federal waters approximately 260 ft (79 m) in depth. The purpose of the 
Port is to import liquefied natural gas (LNG) into the New England 
region. Take of marine mammals may occur during port operations from 
thruster use during maneuvering of the SRVs while docking and 
undocking, occasional weathervaning (turning of a vessel at anchor from 
one direction to another under the influence of wind or currents) at 
the Port, and during thruster use of dynamic positioning (DP) 
maintenance vessels should a major repair be necessary. Neptune has 
requested an authorization to take 12 marine mammal species by Level B 
harassment. The species are: North Atlantic right whale; humpback 
whale; fin whale; sei whale; minke whale; long-finned pilot whale; 
Atlantic white-sided dolphin; harbor porpoise; common dolphin; Risso's 
dolphin; bottlenose dolphin; and harbor seal. In the 2009 and 2010 
IHAs, NMFS also authorized take of killer whales and gray seals. NMFS 
has preliminarily determined that it would be appropriate in this 
proposed rule to authorize take, by Level B harassment only, incidental 
to operations and maintenance activities of these two species as well.

Description of the Specified Activity

    On March 23, 2007, Neptune received a license from MARAD to own, 
construct, and operate a deepwater port. The Port, which is located in 
Massachusetts Bay, consists of a submerged buoy system to dock 
specifically designed LNG carriers approximately 22 mi (35 km) 
northeast of Boston, Massachusetts, in Federal waters approximately 260 
ft (79 m) in depth. The two buoys are separated from one another by a 
distance of approximately 2.1 mi (3.4 km). The locations of the Neptune 
Port and the associated pipeline are shown in Figure 2-1 in Neptune's 
application (see ADDRESSES).
    All construction of the Neptune Port was completed in November 
2009. The first SRV was commissioned in February-March 2010. 
Commissioning of the second SRV is scheduled to occur in early 2011 and 
so would occur under the current IHA. Between July 2011 and July 2016, 
(the requested time period for these proposed regulations), Neptune 
plans to continue Port operations and also plans to conduct any 
necessary maintenance and repairs of the Port facility.
    Neptune will be capable of mooring LNG SRVs with a capacity of 
approximately 183,113 cubic yards (yd\3\; 140,000 cubic meters (m\3\)). 
Up to two SRVs will temporarily moor at the Port by means of a 
submerged unloading buoy system. Two separate buoys will allow natural 
gas to be delivered in a continuous flow, without interruption, by 
having a brief overlap between arriving and departing SRVs. The annual 
average throughput capacity will be around 500 million standard cubic 
feet per day (mmscfd) with an initial throughput of 400 mmscfd and a 
peak capacity of approximately 750 mmscfd.
    The SRVs will be equipped to store, transport, and vaporize LNG and 
to odorize, meter and send out natural gas by means of two 16-in (40.6-
cm) flexible risers and one 24-in (61-cm) subsea flowline. These risers 
and flowline will lead to a 24-in (61-cm) gas transmission pipeline 
connecting the deepwater port to the existing 30-in (76.2-cm) Algonquin 
Hubline\SM\ (Hubline\SM\) located approximately 9 mi (14.5 km) west of 
the Neptune deepwater port location. The Port will have an expected 
operating life of approximately 25 years. Figure 1-1 of Neptune's 
application shows an isometric view of the Port (see ADDRESSES). The 
following subsections describe the operational activities for the Port.

Description of Port Operations

    During Neptune Port operations, sound will be generated by the 
regasification of the LNG aboard the SRVs and the use of thrusters by 
vessels maneuvering and maintaining position at the port. Large 
construction-type DP vessels used for major repairs of the subsea 
pipeline or unloading facility may be another potential sound source, 
although these types of repairs are unlikely to occur. Of these 
potential operations and maintenance/repair sound sources, thruster use 
for DP is the most significant. The following text describes the 
activities that will occur at the port upon its commissioning.
(1) Vessel Activity
    The SRVs will approach the Port using the Boston Harbor Traffic 
Separation Scheme (TSS), entering the TSS within the Great South 
Channel (GSC) and remaining in the TSS until they reach the Boston 
Harbor Precautionary Area. At the Boston Lighted Horn Buoy B (at the 
center of the Boston Harbor Precautionary Area), the SRV will be met by 
a pilot vessel and a support vessel. A pilot will board the SRV, and 
the support vessel will accompany the SRV to the port. SRVs carrying 
LNG typically travel at speeds up to 19.5 knots (36 km/hr); however, 
Neptune SRVs will reduce speed to 10 knots (18.5 km/hr) within the TSS 
year-round in the Off Race Point Seasonal Management Area (SMA) and 
will maintain a maximum of 10 knots (18.5 km/hr) when traveling to and 
from the buoys once exiting the shipping lanes at the Boston Harbor 
Precautionary Area. In addition, Neptune is committed to reducing speed 
to 10 knots (18.5 km/hr) in the GSC SMA from April 1 to July 31 each 
year.
    To supply a continuous flow of natural gas into the pipeline, an 
average of about 50 roundtrip SRV transits will take place annually 
(one transit every 3.65 days). As an SRV approaches the Port, vessel 
speed will gradually be reduced. Upon arrival at the Port, one of the 
submerged unloading buoys will be located and retrieved from its 
submerged position by means of a winch and recovery line. The SRV is 
designed for operation in harsh environments and can connect to the 
unloading buoy in up to 11.5 ft (3.5 m) significant wave heights and 
remain operational in up to 36 ft (11 m) significant wave heights, 
providing high operational availability.
    The vessel's aft/forward thrusters will be used intermittently. 
Neptune SRVs will use both bow and stern thrusters when approaching the 
unloading buoy and when docking the buoy inside the Submerged Turret 
Loading (STL) compartment, as well as when releasing the buoy after the 
regasifying process is finished. The thrusters will be energized for up 
to 2 hours during the docking process and up to 1 hour during the 
undocking/release process. When energized, the thrusters will rotate at 
a constant RPM with the blades set at zero pitch. There will be little 
cavitation when the thruster propellers idle in this mode. The sound 
levels in this operating mode are expected to be approximately 8 
decibels (dB) less than at 100 percent load, based on measured data 
from other vessels.
    When the thrusters are engaged, the pitch of the blades will be 
adjusted in short bursts for the amount of thrust needed. These short 
bursts will cause cavitation and elevated sound levels. The maximum 
sound level with two thrusters operating at 100 percent load will be 
180 dB re 1 [mu]Pa at 1m. This is not the normal operating mode, but a 
worst-case scenario. Typically, thrusters are operated for only seconds 
at a time and not at continuous full loading. These thrusters will be 
engaged for no

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more than 20 minutes, in total, when docking at the buoy. The same 
applies for the undocking scenario.
    During normal conditions, the vessel will be allowed to weathervane 
on the single-point mooring system. However, aft thrusters may be used 
under certain conditions to maintain the vessel's heading into the wind 
when competing tides operate to push the vessel broadside to the wind. 
Neptune has assumed a total of 200 hr/yr operating under these 
conditions. In these circumstances, the ambient sound will already be 
high because of the wind and associated wave sound.
(2) Regasification System
    Once an SRV is connected to a buoy, the vaporization of LNG and 
send-out of natural gas can begin. Each SRV will be equipped with three 
vaporization units, each with the capacity to vaporize 250 mmscfd. 
Under normal operation, two units will be in service simultaneously. 
The third vaporization unit will be on standby mode, although all three 
units could operate simultaneously.
(3) Maintenance and Repairs
    Routine maintenance activities typically are short in duration 
(several days or less) and require small vessels (less than 300 gross 
tons) to perform. Activities include attaching and detaching and/or 
cleaning the buoy pick up line to the STL buoy, performing surveys and 
inspections with a remotely operated vehicle, and cleaning or replacing 
parts (e.g., bulbs, batteries, etc.) on the floating navigation buoys. 
Every 7-10 years, Neptune will run an intelligent pig (a gauging/
cleaning device) down the pipeline to assess its condition. This 
particular activity will require several larger, construction-type 
vessels and several weeks to complete.
    Unplanned repairs can be either relatively minor, or in some cases, 
major, requiring several large, construction-type vessels and a 
mitigation program similar to that employed during the construction 
phase of the project. Minor repairs are typically shorter in duration 
and could include fixing flange or valve leaks, replacing faulty 
pressure transducers, or repairing a stuck valve. These kinds of 
repairs require one diver support vessel with three or four anchors to 
hold its position. Minor repairs could take from a few days to 1-2 
weeks depending on the nature of the problem.
    Major repairs are longer in duration and typically require large 
construction vessels similar to those used to install the pipeline and 
set the buoy and anchoring system. These vessels will typically 
mobilize from local ports or the Gulf of Mexico. Major repairs require 
upfront planning, equipment procurement, and mobilization of vessels 
and saturation divers. Examples of major repairs--although unlikely to 
occur--include damage to a riser or umbilical and their possible 
replacement, damage to the pipeline and manifolds, or anchor chain 
replacement. These types of repairs could take 1-4 weeks and possibly 
longer.

Operations Sound

    The acoustic effects of using the thrusters for maneuvering at the 
unloading buoys were modeled by JASCO Research Limited (2005). The 
analysis assumed the use of four thrusters (two bow, two stern) at 100 
percent power during all four seasons. The one-third (\1/3\)-octave 
band source levels for the thrusters ranged from 148.5 dB re 1 [mu]Pa 
at 1 m at 2,000 Hertz (Hz) to 174.5 dB re 1 [micro]Pa at 1 m at 10 Hz. 
Figures 1-2 through 1-5 in Neptune's application show the received 
sound level at 164-ft (50-m) depth at the south unloading buoy during 
each of the four seasons.
    The acoustic effects of operating the regasification system at the 
unloading buoys were also modeled by JASCO Research Limited (2005). In 
addition, supplemental analysis was performed to assess the potential 
underwater acoustic impacts of using the two aft thrusters after 
mooring for maintaining the heading of the vessel in situations when 
competing tides operate to push the vessel broadside to the wind. 
Additionally, Samsung performed an underwater noise study on the newly 
constructed SRV, and an evaluation of these data was performed by JASCO 
Applied Sciences. Additional details of all the modeling analyses can 
be found in Appendices B and C of Neptune's application (see 
ADDRESSES). The loudest source of sound during operations at the port 
will be the use of thrusters for dynamic positioning.

Maintenance/Repair Sound

    Acoustic modeling originally performed to predict received levels 
of underwater sound that could result from the construction of Neptune 
also could be applicable to major maintenance/repair during operations 
(see Appendices B and C in Neptune's application for a discussion of 
the acoustic modeling methodology employed). Activities considered to 
be potential sound sources during major maintenance/repair activities 
include excavation (jetting) of the flowline or main transmission 
pipeline routes and lowering of materials (pipe, anchors, and chains) 
to the sea floor. These analyses evaluated the potential impacts of 
construction of the flowline and pipeline using surrogate source levels 
for vessels that could be employed during Neptune's construction. One 
surrogate vessel used for modeling purposes was the Castoro II (and 
four accompanying vessels). Figures 1-6 and 1-7 in Neptune's 
application illustrate the worst-case received sound levels that would 
be associated with major maintenance/repair activities along the 
flowline between the two unloading buoys and along the pipeline route 
at the 164-ft (50-m) depth during the spring season if a vessel similar 
to the Castoro II were used.

Comments and Responses

    On May 6, 2010, NMFS published a notice of a proposed IHA and a 
notice of receipt of an application for a Letter of Authorization (LOA) 
in the Federal Register (75 FR 24906) and requested comments and 
information from the public for 30 days. NMFS received only one comment 
letter from the Marine Mammal Commission (MMC). The MMC's comments 
noted the need for monitoring and mitigation and for the reinitiation 
of section 7 consultation under the Endangered Species Act (ESA). NMFS 
included the proposed monitoring and mitigation measures in the 2010 
IHA and completed the required ESA section 7 consultation prior to 
issuance of the 2010 IHA. To see the full comments and responses, 
please refer to the IHA Federal Register notice of issuance (75 FR 
41440, July 16, 2010).

Description of Marine Mammals in the Area of the Specified Activity

    Massachusetts Bay (as well as the entire Atlantic Ocean) hosts a 
diverse assemblage of marine mammals, including the: North Atlantic 
right whale; blue whale; fin whale; sei whale; minke whale; humpback 
whale; killer whale; long-finned pilot whale; sperm whale; Atlantic 
white-beaked dolphin; Atlantic white-sided dolphin; bottlenose dolphin; 
common dolphin; harbor porpoise; Risso's dolphin; striped dolphin; gray 
seal; harbor seal; harp seal; and hooded seal. Table 3-1 in Neptune's 
application outlines the marine mammal species that occur in 
Massachusetts Bay and the likelihood of occurrence of each species. Of 
the species listed here, the North Atlantic right, blue, fin, sei, 
humpback, and sperm whales are all listed as endangered under the ESA 
and as depleted under the MMPA. The northern coastal stock of 
bottlenose dolphins is considered depleted under

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the MMPA. Certain stocks or populations of killer whales are listed as 
endangered under the ESA or depleted under the MMPA; however, none of 
those stocks or populations occurs in the proposed activity area.
    Of these species, 14 are expected to occur in the area of Neptune's 
proposed operations. These species include: The North Atlantic right, 
humpback, fin, sei, minke, killer, and long-finned pilot whales; 
Atlantic white-sided, common, Risso's, and bottlenose dolphins; harbor 
porpoise; and harbor and gray seals. Neptune used information from the 
Cetacean and Turtle Assessment Program (CETAP; 1982) and the U.S. 
Navy's Marine Resource Assessment (MRA) for the Northeast Operating 
Areas (DoN, 2005; available on the Internet at: https://portal.navfac.navy.mil/portal/page/portal/navfac/navfac_ww_pp/navfac_hq_pp/navfac_environmental/mra) to estimate densities of the 
species in the area. Nonetheless, NMFS used the data on cetacean 
distribution within Massachusetts Bay, such as those published by 
NOAA's National Centers for Coastal Ocean Science (NCCOS; 2006), to 
determine density estimates of several species of marine mammals in the 
vicinity of the project area. The explanation for those derivations and 
the actual density estimates are described later in this document (see 
the ``Estimated Take by Incidental Harassment'' section).
    Blue and sperm whales are not commonly found in Massachusetts Bay. 
The sperm whale is generally a deepwater animal, and its distribution 
off the northeastern U.S. is concentrated around the 13,280-ft (4,048-
m) depth contour, with sightings extending offshore beyond the 6,560-ft 
(2,000-m) depth contour. Sperm whales also can be seen in shallow water 
south of Cape Cod from May to November (CETAP, 1982). In the North 
Atlantic, blue whales are most commonly sighted in the waters off 
eastern Canada. Although they are rare in the shelf waters of the 
eastern U.S., occasional sightings of blue whales have been made off 
Cape Cod. Harp and hooded seals are seasonal visitors from much further 
north, seen mostly in the winter and early spring. Prior to 1990, harp 
and hooded seals were sighted only very occasionally in the Gulf of 
Maine, but recent sightings suggest increasing numbers of these species 
now visit these waters (Harris et al., 2001, 2002). However, these harp 
seal sightings are considered extralimital (Waring et al., 2009). While 
there have been some increased sightings of hooded seals off the east 
coast of the U.S., the southernmost portion of their spring migration 
is considered the Gulf of St. Lawrence (Waring et al., 2009). 
Therefore, their sightings in U.S. east coast waters are considered 
extralimital. Juveniles of a third seal species, the ringed seal, are 
seen on occasion as far south as Cape Cod in the winter, but this 
species is considered to be quite rare in these waters (Provincetown 
Center for Coastal Studies, 2005). Due to the rarity of these species 
in the proposed project area and the remote chance they would be 
affected by Neptune's proposed port operations, these species are not 
considered further in these proposed regulations.
    In addition to the 16 cetacean species listed in Table 3-1 in 
Neptune's application, 10 other cetacean species have been recorded for 
Massachusetts as rare vagrants or from strandings (Cardoza et al., 
1999). The following six species of beaked whale are all pelagic and 
recorded mostly as strandings: the northern bottlenose whale; Cuvier's 
beaked whale; Sowerby's beaked whale; Blainville's beaked whale; 
Gervais' beaked whale; and True's beaked whale. Vagrants include the 
beluga whale, a northern species with rare vagrants reported as far 
south as Long Island (Katona et al., 1993); the pantropical spotted 
dolphin and false killer whale, which are primarily tropical species 
with rare sightings in Massachusetts waters (Cardoza et al., 1999); and 
the pygmy sperm whale, which is generally an offshore species that 
occasionally wanders inshore. There have been occasional sightings of 
striped dolphins in the waters of the northeastern U.S. However, the 
majority of these sightings occurred in waters deeper than those of the 
Neptune Port project area (Waring et al., 2009). While some Atlantic 
white-beaked dolphins have been sighted in the western Gulf of Maine 
and off Cape Cod, their distribution in the area has been considered 
limited, mostly a factor of opportunistic feeding (Waring et al., 
2009). Due to the rarity of these species in the proposed project area 
and the remote chance they would be affected by Neptune's proposed port 
operations, these species are not considered further in these proposed 
regulations.
    Information on those species that may be impacted by this activity 
is provided in Neptune's application and sections 3.2.3 and 3.2.5 in 
the MARAD/USCG Final EIS on the Neptune LNG proposal (see ADDRESSES). 
Please refer to those documents for more information on these species. 
In addition, general information on these marine mammal species can 
also be found in the 2009 NMFS U.S. Atlantic and Gulf of Mexico Marine 
Mammal Stock Assessment Report (SAR; Waring et al., 2009) and the 2010 
Draft NMFS Atlantic and Gulf of Mexico Marine Mammal SAR (Waring et 
al., in prep.), which are available on the Internet at: https://www.nefsc.noaa.gov/publications/tm/tm213/ and https://www.nmfs.noaa.gov/pr/sars/draft.htm, respectively. A brief summary on several commonly 
sighted marine mammal species distribution and abundance in the 
vicinity of the action area is provided next.

Humpback Whale

    The highest abundance for humpback whales is distributed primarily 
along a relatively narrow corridor following the 328-ft (100-m) isobath 
across the southern Gulf of Maine from the northwestern slope of 
Georges Bank, south to the GSC, and northward alongside Cape Cod to 
Stellwagen Bank and Jeffreys Ledge. The relative abundance of whales 
increases in the spring with the highest occurrence along the slope 
waters (between the 131- and 459-ft, 40- and 140-m, isobaths) off Cape 
Cod and Davis Bank, Stellwagen Basin and Tillies Basin and between the 
164- and 656-ft (50- and 200-m) isobaths along the inner slope of 
Georges Bank. High abundance was also estimated for the waters around 
Platts Bank. In the summer months, abundance increases markedly over 
the shallow waters (< 164 ft, or < 50 m) of Stellwagen Bank, the waters 
(328-656 ft, 100-200 m) between Platts Bank and Jeffreys Ledge, the 
steep slopes (between the 98- and 525-ft isobaths, 30- and 160-m 
isobaths) of Phelps and Davis Bank north of the GSC towards Cape Cod, 
and between the 164- and 328-ft (50- and 100-m) isobath for almost the 
entire length of the steeply sloping northern edge of Georges Bank. 
This general distribution pattern persists in all seasons except winter 
when humpbacks remain at high abundance in only a few locations, 
including Porpoise and Neddick Basins adjacent to Jeffreys Ledge, 
northern Stellwagen Bank and Tillies Basin, and the GSC. The best 
estimate of abundance for Gulf of Maine, formerly western North 
Atlantic, humpback whales is 847 animals (Waring et al., 2009). Current 
data suggest that the Gulf of Maine humpback whale stock is steadily 
increasing in size, which is consistent with an estimated average trend 
of 3.1 percent in the North Atlantic population overall for the period 
1979-1993 (Stevick et al., 2003, cited in Waring et al., 2009).

Fin Whale

    Spatial patterns of habitat utilization by fin whales are very 
similar to those of humpback whales. Spring and

[[Page 80264]]

summer high-use areas follow the 328-ft (100-m) isobath along the 
northern edge of Georges Bank (between the 164- and 656-ft, 50- and 
200-m, isobaths), and northward from the GSC (between the 164- and 525-
ft, 50- and 160-m, isobaths). Waters around Cashes Ledge, Platts Bank, 
and Jeffreys Ledge are all high-use areas in the summer months. 
Stellwagen Bank is a high-use area for fin whales in all seasons, with 
highest abundance occurring over the southern Stellwagen Bank in the 
summer months. In fact, the southern portion of Stellwagen Bank 
National Marine Sanctuary (SBNMS) is used more frequently than the 
northern portion in all months except winter, when high abundance is 
recorded over the northern tip of Stellwagen Bank. In addition to 
Stellwagen Bank, high abundance in winter is estimated for Jeffreys 
Ledge and the adjacent Porpoise Basin (328- to 525-ft, isobaths), as 
well as Georges Basin and northern Georges Bank. The best estimate of 
abundance for the western North Atlantic stock of fin whales is 3,985, 
which is the sum of the estimate derived from an August 2006 Gulf of 
Maine survey and the sum of the estimate derived from a July-August 
2007 northern Labrador to Scotian Shelf survey (Waring et al., in 
prep.). Currently, there are insufficient data to determine population 
trends for this species.

Minke Whale

    Like other piscivorus baleen whales, the highest abundance for 
minke whale is strongly associated with regions between the 164- and 
328-ft (50- and 100-m) isobaths, but with a slightly stronger 
preference for the shallower waters along the slopes of Davis Bank, 
Phelps Bank, GSC, and Georges Shoals on Georges Bank. Minke whales are 
sighted in SBNMS in all seasons, with highest abundance estimated for 
the shallow waters (approximately 131 ft, 40 m) over southern 
Stellwagen Bank in the summer and fall months. Platts Bank, Cashes 
Ledge, Jeffreys Ledge, and the adjacent basins (Neddick, Porpoise, and 
Scantium) also support high relative abundance. Very low densities of 
minke whales remain throughout most of the southern Gulf of Maine in 
winter. The best estimate of abundance for the Canadian East Coast 
stock of minke whales, which occurs from the western half of the Davis 
Strait to the Gulf of Mexico, is 8,987 animals, which is the sum of the 
estimate derived from an August 2006 Gulf of Maine survey and the sum 
of the estimate derived from a July-August 2007 northern Labrador to 
Scotian Shelf survey (Waring et al., in prep.). A population trend 
analysis for this species has not been conducted (Waring et al., in 
prep.).

North Atlantic Right Whale

    North Atlantic right whales are generally distributed widely across 
the southern Gulf of Maine in spring with highest abundance located 
over the deeper waters (328- to 525-ft, 100- to 160-m, isobaths) on the 
northern edge of the GSC and deep waters (328-984 ft 100-300 m) 
parallel to the 328-ft (100-m) isobath of northern Georges Bank and 
Georges Basin. High abundance was also found in the shallowest waters 
(< 98 ft, <30 m) of Cape Cod Bay (CCB), over Platts Bank and around 
Cashes Ledge. Lower relative abundance is estimated over deep-water 
basins including Wilkinson Basin, Rodgers Basin, and Franklin Basin. In 
the summer months, right whales move almost entirely away from the 
coast to deep waters over basins in the central Gulf of Maine 
(Wilkinson Basin, Cashes Basin between the 525- and 656-ft, 160- and 
200-m, isobaths) and north of Georges Bank (Rogers, Crowell, and 
Georges Basins). Highest abundance is found north of the 328-ft (100-m 
isobath at the GSC and over the deep slope waters and basins along the 
northern edge of Georges Bank. The waters between Fippennies Ledge and 
Cashes Ledge are also estimated as high-use areas. In the fall months, 
right whales are sighted infrequently in the Gulf of Maine, with 
highest densities over Jeffreys Ledge and over deeper waters near 
Cashes Ledge and Wilkinson Basin. In winter, CCB, Scantum Basin, 
Jeffreys Ledge, and Cashes Ledge are the main high-use areas. Although 
SBNMS does not appear to support the highest abundance of right whales, 
sightings within SBNMS are reported for all four seasons, albeit at low 
relative abundance. The highest rate of sighting within SBNMS occurs 
along the southern edge of the Bank.
    The western North Atlantic population size was estimated to be at 
least 361 individuals in 2005 based on a census of individual whales 
identified using photo-identification techniques (Waring et al., in 
prep.). This value is a minimum and does not include animals that were 
alive prior to 2005 but not recorded in the individual sightings 
database as seen from December 1, 2004, to June 24, 2009. It also does 
not include some calves known to be born during 2005 or any other 
individual whale seen during 2005 but not yet entered into the catalog 
(Waring et al., in prep.). Examination of the minimum number alive 
population index calculated from the individual sightings database, as 
it existed on June 24, 2009, for the years 1990-2005 suggests a 
positive trend in population size. These data reveal a significant 
increase in the number of catalogued whales alive during this period 
but with significant variation due to apparent losses exceeding gains 
during 1998-1999. Mean growth rate for the period 1990-2005 was 2.1 
percent (Waring et al., in prep.).

Long-finned Pilot Whale

    The long-finned pilot whale is more generally found along the edge 
of the continental shelf (a depth of 328 to 3,280 ft, or 100 to 1,000 
m), choosing areas of high relief or submerged banks in cold or 
temperate shoreline waters. This species is split into two subspecies: 
the Northern and Southern subspecies. The Southern subspecies is 
circumpolar with northern limits of Brazil and South Africa. The 
Northern subspecies, which could be encountered during operation of the 
Neptune Port facility, ranges from North Carolina to Greenland (Reeves 
et al., 2002; Wilson and Ruff, 1999). In the western North Atlantic, 
long-finned pilot whales are pelagic, occurring in especially high 
densities in winter and spring over the continental slope, then moving 
inshore and onto the shelf in summer and autumn following squid and 
mackerel populations (Reeves et al., 2002). They frequently travel into 
the central and northern Georges Bank, GSC, and Gulf of Maine areas 
during the summer and early fall (May and October; NOAA, 1993). The 
best population estimate for the western North Atlantic stock of long-
finned pilot whale is 12,619 individuals (Waring et al., in prep.). 
Currently, there are insufficient data to determine population trends 
for the long-finned pilot whale.

Sei Whale

    The sei whale is the least likely of all the baleen whale species 
to occur near the Neptune Port. However, there were a couple of 
sightings in the general vicinity of the port facility during the 
construction phase (Neptune Marine Mammal Monitoring Weekly Reports, 
2008). The Nova Scotia stock of sei whales ranges from the continental 
shelf waters of the northeastern U.S. and extends northeastward to 
south of Newfoundland. The southern portion of the species range during 
spring and summer includes the northern portions of the U.S. Atlantic 
Exclusive Economic Zone (i.e., the Gulf of Maine and Georges Bank). Sei 
whales are most abundant in U.S. waters during the spring, with 
sightings concentrated along the eastern margin of Georges Bank and 
into the Northeast Channel area and along the southwestern edge of

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Georges Bank in the area of Hydrographer Canyon (CETAP, 1982). The best 
estimate of abundance for this stock is 386 animals (Waring et al., 
2009). A population trend analysis has not been done for this species.

Atlantic White-Sided Dolphin

    In spring, summer and fall, Atlantic white-sided dolphins are 
widespread throughout the southern Gulf of Maine, with the high-use 
areas widely located on either side of the 328-ft (100-m) isobath along 
the northern edge of Georges Bank, and north from the GSC to Stellwagen 
Bank, Jeffreys Ledge, Platts Bank, and Cashes Ledge. In spring, high-
use areas exist in the GSC, northern Georges Bank, the steeply sloping 
edge of Davis Bank, Cape Cod, southern Stellwagen Bank, and the waters 
between Jeffreys Ledge and Platts Bank. In summer, there is a shift and 
expansion of habitat toward the east and northeast. High-use areas 
occur along most of the northern edge of Georges Bank between the 164- 
and 656-ft (50- and 200-m) isobaths and northward from the GSC along 
the slopes of Davis Bank and Cape Cod. High sightings are also recorded 
over Truxton Swell, Wilkinson Basin, Cashes Ledge and the 
bathymetrically complex area northeast of Platts Bank. High numbers of 
sightings of white-sided dolphin are recorded within SBNMS in all 
seasons, with highest density in summer, and the most widespread 
distribution in spring is located mainly over the southern end of 
Stellwagen Bank. In winter, high sightings were recorded at the 
northern tip of Stellwagen Bank and Tillies Basin.
    A comparison of spatial distribution patterns for all baleen whales 
and all porpoises and dolphins combined showed that both groups have 
very similar spatial patterns of high- and low-use areas. The baleen 
whales, whether piscivorus or planktivorous, are more concentrated than 
the dolphins and porpoises. They utilize a corridor that extends 
broadly along the most linear and steeply sloping edges in the southern 
Gulf of Maine indicated broadly by the 328-ft (100-m) isobath. 
Stellwagen Bank and Jeffreys Ledge support a high abundance of baleen 
whales throughout the year. Species richness maps indicate that high-
use areas for individual whales and dolphin species co-occurred, 
resulting in similar patterns of species richness primarily along the 
southern portion of the 328-ft (100-m) isobath extending northeast and 
northwest from the GSC. The southern edge of Stellwagen Bank and the 
waters around the northern tip of Cape Cod are also highlighted as 
supporting high cetacean species richness. Intermediate to high numbers 
of species are also calculated for the waters surrounding Jeffreys 
Ledge, the entire Stellwagen Bank, Platts Bank, Fippennies Ledge, and 
Cashes Ledge. The best estimate of abundance for the western North 
Atlantic stock of white-sided dolphins is 63,368 (Waring et al., 2009). 
A trend analysis has not been conducted for this species.

Killer Whale, Common Dolphin, Bottlenose Dolphin, Risso's Dolphin, and 
Harbor Porpoise

    Although these five species are some of the most widely distributed 
small cetacean species in the world (Jefferson et al., 1993), they are 
not commonly seen in the vicinity of the project area in Massachusetts 
Bay (Wiley et al., 1994; NCCOS, 2006; Northeast Gateway Marine Mammal 
Monitoring Weekly Reports, 2007; Neptune Marine Mammal Monitoring 
Weekly Reports, 2008). The total number of killer whales off the 
eastern U.S. coast is unknown, and present data are insufficient to 
calculate a minimum population estimate or to determine the population 
trends for this stock (Blaylock et al., 1995). The best estimate of 
abundance for the western North Atlantic stock of common dolphins is 
120,743 animals, and a trend analysis has not been conducted for this 
species (Waring et al., 2007). There are several stocks of bottlenose 
dolphins found along the eastern U.S. from Maine to Florida. The stock 
that may occur in the area of the Neptune Port is the western North 
Atlantic coastal northern migratory stock of bottlenose dolphins. The 
best estimate of abundance for this stock is 9,604 animals (Waring et 
al., in prep.). There are insufficient data to determine the population 
trend for this stock. The best estimate of abundance for the western 
North Atlantic stock of Risso's dolphins is 20,479 animals (Waring et 
al., 2009). There are insufficient data to determine the population 
trend for this stock. The best estimate of abundance for the Gulf of 
Maine/Bay of Fundy stock of harbor porpoise is 89,054 animals (Waring 
et al., 2009). A trend analysis has not been conducted for this 
species.

Harbor and Gray Seals

    In the U.S. western North Atlantic, both harbor and gray seals are 
usually found from the coast of Maine south to southern New England and 
New York (Waring et al., 2007).
    Along the southern New England and New York coasts, harbor seals 
occur seasonally from September through late May (Schneider and Payne, 
1983). In recent years, their seasonal interval along the southern New 
England to New Jersey coasts has increased (deHart, 2002). In U.S. 
waters, harbor seal breeding and pupping normally occur in waters north 
of the New Hampshire/Maine border, although breeding has occurred as 
far south as Cape Cod in the early part of the 20th century (Temte et 
al., 1991; Katona et al., 1993). Between 1981 and 2001, the uncorrected 
counts of seals increased from 10,543 to 38,014, an annual rate of 6.6 
percent (Gilbert et al., 2005, cited in Waring et al., 2009). However, 
present data are insufficient to calculate a minimum population 
estimate for this stock or to determine a population trend for this 
stock (Waring et al., in prep.).
    Although gray seals are often seen off the coast from New England 
to Labrador, within U.S. waters, only small numbers of gray seals have 
been observed pupping on several isolated islands along the Maine coast 
and in Nantucket-Vineyard Sound, Massachusetts (Katona et al., 1993; 
Rough, 1995). In the late 1990s, a year-round breeding population of 
approximately 400 gray seals was documented on outer Cape Cod and 
Muskeget Island (Waring et al., 2007). Depending on the model used, the 
minimum estimate for the Canadian gray seal population ranged between 
125,541 and 169,064 animals (Trzcinski et al., 2005, cited in Waring et 
al., 2009); however, present data are insufficient to calculate the 
minimum population estimate for U.S. waters. Waring et al. (2009) note 
that gray seal abundance in the U.S. Atlantic is likely increasing, but 
the rate of increase is unknown.

Brief Background on Marine Mammal Hearing

    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 derived using auditory evoked 
potential techniques, 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

[[Page 80266]]

hearing is estimated to occur between approximately 7 Hz and 22 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, the franciscana, and four species 
of cephalorhynchids): functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz; and
     Pinnipeds in Water: functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
    As mentioned previously in this document, 14 marine mammal species 
(12 cetacean and two pinniped species) are likely to occur in the 
Neptune Port area. Of the 12 cetacean species likely to occur in 
Neptune's project area, five are classified as low frequency cetaceans 
(i.e., North Atlantic right, humpback, fin, minke, and sei whales), six 
are classified as mid-frequency cetaceans (i.e., killer and pilot 
whales and bottlenose, common, Risso's, and Atlantic white-sided 
dolphins), and one is classified as a high-frequency cetacean (i.e., 
harbor porpoise) (Southall et al., 2007).

Potential Effects of the Specified Activity on Marine Mammals

    Potential effects of Neptune's proposed port operations and 
maintenance/repair activities would most likely be acoustic in nature. 
LNG port operations and maintenance/repair activities introduce sound 
into the marine environment. Potential acoustic effects on marine 
mammals relate to sound produced by thrusters during maneuvering of the 
SRVs while docking and undocking, occasional weathervaning at the port, 
and during thruster use of DP maintenance vessels should a major repair 
be necessary. The potential effects of sound from the proposed 
activities associated with the Neptune Port might include one or more 
of the following: Tolerance; masking of natural sounds; behavioral 
disturbance; non-auditory physical effects; and, at least in theory, 
temporary or permanent hearing impairment (Richardson et al., 1995). 
However, for reasons discussed later in this document, it is unlikely 
that there would be any cases of temporary, or especially permanent, 
hearing impairment resulting from these activities. As outlined in 
previous NMFS documents, the effects of noise on marine mammals are 
highly variable, and can be categorized as follows (based on Richardson 
et al., 1995):
    (1) The noise may be too weak to be heard at the location of the 
animal (i.e., lower than the prevailing ambient noise level, the 
hearing threshold of the animal at relevant frequencies, or both);
    (2) The noise may be audible but not strong enough to elicit any 
overt behavioral response;
    (3) The noise may elicit reactions of variable conspicuousness and 
variable relevance to the well being of the marine mammal; these can 
range from temporary alert responses to active avoidance reactions such 
as vacating an area at least until the noise event ceases but 
potentially for longer periods of time;
    (4) Upon repeated exposure, a marine mammal may exhibit diminishing 
responsiveness (habituation), or disturbance effects may persist; the 
latter is most likely with sounds that are highly variable in 
characteristics, infrequent, and unpredictable in occurrence, and 
associated with situations that a marine mammal perceives as a threat;
    (5) Any anthropogenic noise that is strong enough to be heard has 
the potential to reduce (mask) the ability of a marine mammal to hear 
natural sounds at similar frequencies, including calls from 
conspecifics, and underwater environmental sounds such as surf noise;
    (6) If mammals remain in an area because it is important for 
feeding, breeding, or some other biologically important purpose even 
though there is chronic exposure to noise, it is possible that there 
could be noise-induced physiological stress; this might in turn have 
negative effects on the well-being or reproduction of the animals 
involved; and
    (7) Very strong sounds have the potential to cause a temporary or 
permanent reduction in hearing sensitivity. In terrestrial mammals, and 
presumably marine mammals, received sound levels must far exceed the 
animal's hearing threshold for there to be any temporary threshold 
shift (TTS) in its hearing ability. For transient sounds, the sound 
level necessary to cause TTS is inversely related to the duration of 
the sound. Received sound levels must be even higher for there to be 
risk of permanent hearing impairment. In addition, intense acoustic or 
explosive events may cause trauma to tissues associated with organs 
vital for hearing, sound production, respiration and other functions. 
This trauma may include minor to severe hemorrhage.

Tolerance

    Numerous studies have shown that underwater sounds from industry 
activities are often readily detectable by marine mammals in the water 
at distances of many kilometers. Numerous studies have also shown that 
marine mammals at distances more than a few kilometers away often show 
no apparent response to industry activities of various types (Miller et 
al., 2005). This is often true even in cases when the sounds must be 
readily audible to the animals based on measured received levels and 
the hearing sensitivity of that mammal group. Although various baleen 
whales, toothed whales, and (less frequently) pinnipeds have been shown 
to react behaviorally to underwater sound such as airgun pulses or 
vessels under some conditions, at other times, 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). In 
general, pinnipeds and small odontocetes seem to be more tolerant of 
exposure to some types of underwater sound than are baleen whales. 
Richardson et al. (1995) found that vessel noise does not seem to 
strongly affect pinnipeds that are already in the water. Richardson et 
al. (1995) went on to explain that seals on haul-outs sometimes respond 
strongly to the presence of vessels and at other times appear to show 
considerable tolerance of vessels, and Brueggeman et al. (1992; cited 
in Richardson et al., 1995) observed ringed seals hauled out on ice 
pans displaying short-term escape reactions when a ship approached 
within 0.16-0.31 mi (0.25-0.5 km).

Masking

    Masking is the obscuring of sounds of interest by other sounds, 
often at similar frequencies. Marine mammals are highly dependent on 
sound, and their ability to recognize sound signals amid other noise is 
important in communication, predator and prey detection, and, in the 
case of toothed whales, echolocation. Even in the absence of manmade 
sounds, the sea is usually noisy. Background ambient noise often 
interferes with or masks the ability of an animal to detect a sound 
signal even when that signal is above its absolute hearing threshold. 
Natural ambient noise includes contributions from wind, waves, 
precipitation, other animals, and (at frequencies above 30 kHz) thermal 
noise resulting from molecular agitation (Richardson et al., 1995). 
Background noise also can

[[Page 80267]]

include sounds from human activities. Masking of natural sounds can 
result when human activities produce high levels of background noise. 
Conversely, if the background level of underwater noise is high (e.g., 
on a day with strong wind and high waves), an anthropogenic noise 
source will not be detectable as far away as would be possible under 
quieter conditions and will itself be masked. Ambient noise is highly 
variable on continental shelves (Thompson, 1965; Myrberg, 1978; Chapman 
et al., 1998; Desharnais et al., 1999). This inevitably results in a 
high degree of variability in the range at which marine mammals can 
detect anthropogenic sounds.
    Although masking is a natural phenomenon to which marine mammals 
must adapt, the introduction of strong sounds into the sea at 
frequencies important to marine mammals increases the severity and 
frequency of occurrence of masking. For example, if a baleen whale is 
exposed to continuous low-frequency noise from an industrial source, 
this will reduce the size of the area around that whale within which it 
can hear the calls of another whale. In general, little is known about 
the importance to marine mammals of detecting sounds from conspecifics, 
predators, prey, or other natural sources. In the absence of much 
information about the importance of detecting these natural sounds, it 
is not possible to predict the impacts if marine mammals are unable to 
hear these sounds as often, or from as far away, because of masking by 
industrial noise (Richardson et al., 1995). In general, masking effects 
are expected to be less severe when sounds are transient than when they 
are continuous.
    Although some degree of masking is inevitable when high levels of 
manmade broadband sounds are introduced into the sea, marine mammals 
have evolved systems and behavior that function to reduce the impacts 
of masking. Structured signals, such as the echolocation click 
sequences of small toothed whales, may be readily detected even in the 
presence of strong background noise because their frequency content and 
temporal features usually differ strongly from those of the background 
noise (Au and Moore, 1988, 1990). The components of background noise 
that are similar in frequency to the sound signal in question primarily 
determine the degree of masking of that signal. Low-frequency 
industrial noise, such as shipping, has little or no masking effect on 
high frequency echolocation sounds.
    Redundancy and context can also facilitate detection of weak 
signals. These phenomena may help marine mammals detect weak sounds in 
the presence of natural or manmade noise. Most masking studies in 
marine mammals present the test signal and the masking noise from the 
same direction. The sound localization abilities of marine mammals 
suggest that, if signal and noise come from different directions, 
masking would not be as severe as the usual types of masking studies 
might suggest (Richardson et al., 1995). The dominant background noise 
may be highly directional if it comes from a particular anthropogenic 
source such as a ship or industrial site. Directional hearing may 
significantly reduce the masking effects of these noises by improving 
the effective signal-to-noise ratio. In the cases of high-frequency 
hearing by the bottlenose dolphin, beluga whale, and killer whale, 
empirical evidence confirms that masking depends strongly on the 
relative directions of arrival of sound signals and the masking noise 
(Penner et al., 1986; Dubrovskiy, 1990; Bain et al., 1993; Bain and 
Dahlheim, 1994). Toothed whales, and probably other marine mammals as 
well, have additional capabilities besides directional hearing that can 
facilitate detection of sounds in the presence of background noise. 
There is evidence that some toothed whales can shift the dominant 
frequencies of their echolocation signals from a frequency range with a 
lot of ambient noise toward frequencies with less noise (Au et al., 
1974, 1985; Moore and Pawloski, 1990; Thomas and Turl, 1990; Romanenko 
and Kitain, 1992; Lesage et al., 1999). A few marine mammal species are 
known to increase the source levels of their calls in the presence of 
elevated sound levels (Dahlheim, 1987; Au, 1993; Lesage et al., 1999; 
Terhune, 1999).
    These data demonstrating adaptations for reduced masking pertain 
mainly to the very high frequency echolocation signals of toothed 
whales. There is less information about the existence of corresponding 
mechanisms at moderate or low frequencies or in other types of marine 
mammals. For example, Zaitseva et al. (1980) found that, for the 
bottlenose dolphin, the angular separation between a sound source and a 
masking noise source had little effect on the degree of masking when 
the sound frequency was 18 kHz, in contrast to the pronounced effect at 
higher frequencies. Directional hearing has been demonstrated at 
frequencies as low as 0.5-2 kHz in several marine mammals, including 
killer whales (Richardson et al., 1995). This ability may be useful in 
reducing masking at these frequencies. In summary, high levels of noise 
generated by anthropogenic activities may act to mask the detection of 
weaker biologically important sounds by some marine mammals. This 
masking may be more prominent for lower frequencies. For higher 
frequencies, such as that used in echolocation by toothed whales, 
several mechanisms are available that may allow them to reduce the 
effects of such masking.

Disturbance

    Disturbance can induce a variety of effects, such as subtle changes 
in behavior, more conspicuous dramatic changes in activities, and 
displacement. Disturbance is one of the main concerns of the potential 
impacts of manmade noise on marine mammals. For many species and 
situations, there is no detailed information about reactions to noise. 
While there are no specific studies available on the reactions of 
marine mammals to sounds produced by a LNG facility, information from 
studies of marine mammal reactions to other types of continuous and 
transient anthropogenic sound (e.g., drillships) are described here as 
a proxy.
    Behavioral reactions of marine mammals to sound are difficult to 
predict because they are dependent on numerous factors, including 
species, state of maturity, experience, current activity, reproductive 
state, time of day, and weather. If a marine mammal does react to an 
underwater sound by changing its behavior or moving a small distance, 
the impacts of that change may not be important to the individual, 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 the animals could be important. Based on 
the literature reviewed in Richardson et al. (1995), it is apparent 
that most small and medium-sized toothed whales exposed to prolonged or 
repeated underwater sounds are unlikely to be displaced unless the 
overall received level is at least 140 dB re 1 [micro]Pa (rms). The 
limited available data indicate that the sperm whale is sometimes, 
though not always, more responsive to underwater sounds than other 
toothed whales. Baleen whales probably have better hearing 
sensitivities at lower sound frequencies, and in several studies have 
been shown to react to continuous sounds at received sound levels of 
approximately 120 dB re 1 [micro]Pa (rms). Toothed whales appear to 
exhibit a greater variety of reactions to manmade underwater noise than 
do baleen whales. Toothed whale reactions can vary from approaching

[[Page 80268]]

vessels (e.g., to bow ride) to strong avoidance, while baleen whale 
reactions range from neutral (little or no change in behavior) to 
strong avoidance. In general, pinnipeds seem more tolerant of, or at 
least habituate more quickly to, potentially disturbing underwater 
noise than do cetaceans.
    Baleen Whales--Baleen whales sometimes show behavioral changes in 
response to received broadband drillship noises of 120 dB (rms) or 
greater. On their summer range in the Beaufort Sea, bowhead whales (a 
species closely related to the right whale) were observed reacting to 
drillship noises within 2.5-5 mi (4-8 km) of the drillship at received 
levels 20 dB above ambient, or about 118 dB (Richardson et al., 1990). 
Reactions were stronger at the onset of the sound (Richardson et al., 
1995). Migrating bowhead whales avoided an area with a radius of 6.2-
12.4 mi (10-20 km around drillships and their associated support 
vessels, corresponding to a received noise level around 115 dB (Greene, 
1987; Koski and Johnson, 1987; Hall et al., 1994; Davies, 1997; Schick 
and Urban, 2000). For gray whales off California, the predicted 
reaction zone around a semi-submersible drill rig was less than 0.62 mi 
(1 km), at received levels of approximately 120 dB (Malme et al., 1983, 
1984). Humpback whales showed no obvious avoidance response to 
broadband drillship noises at a received level of 116 dB (Malme et al., 
1985).
    Reactions of baleen whales to boat noises include changes in 
swimming direction and speed, blow rate, and the frequency and kinds of 
vocalizations (Richardson et al., 1995). Baleen whales, especially 
minke whales, occasionally approach stationary or slow-moving boats, 
but more commonly avoid boats. Avoidance is strongest when boats 
approach directly or when vessel noise changes abruptly (Watkins, 1986; 
Beach and Weinrich, 1989). Humpback whales responded to boats at 
distances of at least 0.31-0.62 mi (0.5-1 km), and avoidance and other 
reactions have been noted in several areas at distances of several 
kilometers (Jurasz and Jurasz, 1979; Dean et al., 1985; Bauer, 1986; 
Bauer and Herman, 1986).
    During some activities and at some locations, humpbacks exhibit 
little or no reaction to boats (Watkins, 1986). Some baleen whales seem 
to show habituation to frequent boat traffic. Over 25 years of 
observations in Cape Cod waters, minke whales' reactions to boats 
changed from frequent positive interactions (i.e., reactions of 
apparent curiosity or reactions that appeared to provide some reward to 
the animal) to a general lack of interest (i.e., ignored the stimuli), 
while humpback whales' reactions changed from being often negative to 
being often positive, and fin whales' reactions changed from being 
mostly negative (i.e., sudden changes from activity to inactivity or a 
display of agonistic responses) to being mostly uninterested (Watkins, 
1986).
    North Atlantic right whales also display variable responses to 
boats. There may be an initial orientation away from a boat, followed 
by a lack of observable reaction (Atkins and Swartz, 1989). A slowly 
moving boat can approach a right whale, but an abrupt change in course 
or engine speed usually elicits a reaction (Goodyear, 1989; Mayo and 
Marx, 1990; Gaskin, 1991). When approached by a boat, right whale 
mothers will interpose themselves between the vessel and calf and will 
maintain a low profile (Richardson et al., 1995). In a long-term study 
of baleen whale reactions to boats, while other baleen whale species 
appeared to habituate to boat presence over the 25-year period, right 
whales continued to show either uninterested or negative reactions to 
boats with no change over time (Watkins, 1986).
    Biassoni et al. (2000) and Miller et al. (2000) reported behavioral 
observations for humpback whales exposed to a low-frequency sonar 
stimulus (160- to 330-Hz frequency band; 42-s tonal signal repeated 
every 6 min; source levels 170 to 200 dB) during playback experiments. 
Exposure to measured received levels ranging from 120 to 150 dB 
resulted in variability in humpback singing behavior. Croll et al. 
(2001) investigated responses of foraging fin and blue whales to the 
same low frequency active sonar stimulus off souther