6376 Federal Register / Vol. 81, No. 24 / Friday, February 5, 2016 / Notices 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

RIN 0648–XE403 

Takes of Marine Mammals Incidental to 

Specified Activities; Taking Marine 

Mammals Incidental to Geophysical 

and Geotechnical Survey in Cook Inlet, 

Alaska 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Notice; proposed incidental 

harassment authorization; request for 

comments. 

SUMMARY: NMFS has received an 

application from ExxonMobil Alaska 

LNG LLC (EMALL) for an Incidental 

Harassment Authorization (IHA) to take 

marine mammals, by harassment, 

incidental to a geophysical and 

geotechnical survey in Cook Inlet, 

Alaska. This action is proposed to occur 

for 16 weeks. Pursuant to the Marine 

Mammal Protection Act (MMPA), NMFS 

is requesting comments on its proposal 

to issue an IHA to EMALL to 

incidentally take, by Level B 

Harassment only, marine mammals 

during the specified activity. 

DATES: Comments and information must 

be received no later than March 7, 2016. 

ADDRESSES: Comments on the 

application should be addressed to Jolie 

Harrison, Chief, Permits and 

Conservation Division, Office of 

Protected Resources, National Marine 

Fisheries Service, 1315 East-West 

Highway, Silver Spring, MD 20910. The 

mailbox address for providing email 

comments is itp.young@noaa.gov. 

Comments sent via email, including all 

attachments, must not exceed a 25- 

megabyte file size. NMFS is not 

responsible for comments sent to 

addresses other than those provided 

here. 

Instructions: All comments received 

are a part of the public record and will 

generally be posted to http:// 

www.nmfs.noaa.gov/pr/permits/

incidental.htm without change. All 

Personal Identifying Information (for 

example, name, address, etc.) 

voluntarily submitted by the commenter 

may be publicly accessible. Do not 

submit Confidential Business 

Information or otherwise sensitive or 

protected information. 

An electronic copy of the application 

may be obtained by writing to the 

address specified above, telephoning the 

contact listed below (see FOR FURTHER

INFORMATION CONTACT), or visiting the 

internet at: http://www.nmfs.noaa.gov/

pr/permits/incidental.htm. The 

following associated documents are also 

available at the same internet address: 

Draft Environmental Assessment. 

FOR FURTHER INFORMATION CONTACT: Sara 

Young, Office of Protected Resources, 

NMFS, (301) 427–8484. 

SUPPLEMENTARY INFORMATION: 

Background 

Sections 101(a)(5)(A) and (D) of the 

MMPA (16 U.S.C. 1361 et seq.) direct 

the Secretary of Commerce to allow, 

upon request, the incidental, but not 

intentional, taking of small numbers of 

marine mammals by U.S. citizens who 

engage in a specified activity (other than 

commercial fishing) within a specified 

geographical region if certain findings 

are made and either regulations are 

issued or, if the taking is limited to 

harassment, a notice of a proposed 

authorization is provided to the public 

for review. 

An 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 October 5, 2015, NMFS received 

an application from EMALL for the 

taking of marine mammals incidental to 

a geotechnical and geophysical survey 

in Cook Inlet, Alaska. NMFS determined 

that the application was adequate and 

complete on December 22, 2015. 

EMALL proposes to conduct a 

geophysical and geotechnical survey in 

Cook Inlet to investigate the technical 

suitability of a pipeline study corridor 

across Cook Inlet and potential marine 

terminal locations near Nikiski. The 

proposed activity would occur for 16 

weeks during the 2016 open water 

season beginning on March 1, 2016. The 

following specific aspects of the 

proposed activities are likely to result in 

the take of marine mammals: Use of a 

seismic airgun, sub-bottom profiler 

(chirp and boomer), and a vibracore. 

Take, by Level B Harassment only, of 

individuals of four species of marine 

mammals is anticipated to result from 

the specified activities. 

EMALL received an Authorization for 

2015 to conduct a similar suite of 

activities using the same technologies. 

The Authorization was issued for 84 

days beginning August 14, 2015 (80 FR 

50989). 

Description of the Specified Activity 

Overview 

The planned geophysical surveys 

involve remote sensors including single 

beam echo sounder, multibeam echo 

sounder, sub-bottom profiler (chirp and 

boomer), 0.983 L (60 in3) airgun array, 

side scan sonar, geophysical resistivity 

meters, and magnetometer to 

characterize the bottom surface and 

subsurface. The planned shallow 

geotechnical investigations include 

vibracoring, sediment grab sampling, 

and piezo-cone penetration testing 

(PCPT) to directly evaluate seabed 

features and soil conditions. 

Geotechnical borings are planned at 

potential shoreline crossings and in the 

terminal boring subarea within the 

Marine Terminal survey area, and will 

be used to collect information on the 

mechanical properties of in-situ soils to 

support feasibility studies for 

construction crossing techniques and 

decisions on siting and design of 

pilings, dolphins, and other marine 

structures. Geophysical resistivity 

imaging will be conducted at the 

potential shoreline crossings. Shear 

wave velocity profiles (downhole 

geophysics) will be conducted within 

some of the boreholes. Further details of 

the planned operations are provided 

below. 

Dates and Duration 

EMALL expects operations to occur 

102 days during the 2016 open-water 

season between March 2016 and 

November 2016. Operations in the 

pipeline survey area would occur for 

approximately 46 days, and operations 

in the marine facilities survey area and 

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LNG carrier (LNGC) approach survey 

area would occur for a total of 

approximately 56 days. Approximately 

100 km (62 mi) of transect line (the 

linear distance traveled by the survey 

vessel) would be surveyed on an average 

day. The use of an air gun from a 

stationary platform would occur over an 

estimated 24 days in the marine 

facilities survey area. Vibracoring would 

occur approximately 120 times 

(estimated 60 days) during the 2016 

open-water season between March 2016 

and November 2016. It is expected that 

on average, two vibracores would be 

conducted each day depending on tides 

and currents, with the sound source 

operating for a few minutes each time 

the equipment is deployed. The survey 

days may not be consecutive, given 

operational limitations including but 

not limited to tides, currents, hours of 

daylight, vessel resupply, personnel 

fatigue days, weather, and simultaneous 

operations. The activities would be 

scheduled in such a manner as to 

minimize potential effects to marine 

mammals, subsistence activities, and 

other users of the Cook Inlet. EMALL 

will engage with NMFS should the 

program require additional time to 

complete. 

Specified Geographic Region 

Three separate areas will be surveyed 

in Cook Inlet. The survey areas are 

shown in Figure 1 of the application. 

The survey areas were sized to provide 

siting flexibility for future infrastructure 

to avoid existing hazards. 

The pipeline survey area (Figure 2 in 

the application) extends in the marine 

waters of Cook Inlet from the northwest 

shoreline of Upper Cook Inlet near the 

communities of Tyonek and Beluga to 

the southeast shoreline of Upper Cook 

Inlet near Boulder Point on the Kenai 

Peninsula. This survey area is 

approximately 47 km (29 mi) in length 

and averages approximately 16 km (10 

mi) wide. The pipeline survey area is 

795 km2 (307 mi2). 

The marine facilities survey area and 

LNGC approach survey areas (Figure 3 

in the application) are located in the 

marine waters of Cook Inlet near the 

eastern shoreline of what is defined as 

the northern region of Lower Cook Inlet, 

south of the Forelands and adjacent to 

Nikiski on the Kenai Peninsula. The 

marine facilities survey area 

encompasses 109 km2 (42 mi2) and the 

LNGC approach survey area 

encompasses 79 km2 (30 mi2). 

In the LNGC approach survey area, 

the chirp and boomer sub-bottom 

profilers will be operated 

simultaneously. The marine facilities 

survey area will be surveyed twice: 

Once with the chirp and boomer subbottom profilers operated 

simultaneously, and once with the air 

gun and chirp subbottom profiler 

operated simultaneously. The pipeline 

survey area will also be surveyed twice: 

Once with the chirp and boomer subbottom profilers operated 

simultaneously and once with the 

boomer sub-bottom profiler and air gun 

operated simultaneously. Use of an air 

gun from a stationary platform will be 

conducted only in the marine facilities 

survey area. Vibracoring may be 

conducted throughout all of the survey 

areas. 

Detailed Description of Activities 

The details of this activity are broken 

down into two categories for further 

description and analysis: Geophysical 

surveys and geotechnical surveys. 

Geophysical Surveys 

The types of acoustical geophysical 

equipment planned for use in the Cook 

Inlet 2016 G&G Program are indicated in 

Table 1 in the application. The 

equipment includes: Sub-bottom 

profilers (chirp and boomer), 0.983 L (60 

in3) airgun, and vibracore. 

Downhole geophysics is included in 

the table as a sound source, but is not 

considered further in this assessment as 

the energy source will not generate 

significant sound energy within the 

water column since the equipment will 

be located downhole within the 

geotechnical boreholes. The transmitter 

(source) and receiver are both housed 

within the same probe or tool that is 

lowered into the hole on a wireline. The 

suspension log transmitter is an 

electromechanical device. It consists of 

a metallic barrel (the hammer) disposed 

horizontally in the tool and actuated by 

an electromagnet (solenoid) to hit the 

inside of tool body (the plate). The 

fundamental H1 mode is at about 4.5 

KHz, and H2 is at 9 KHz. An extra 

resonance (unknown) mode is also 

present at about 15 Khz. An analysis 

performed to estimate the expected 

sound level of the proposed borehole 

logging equipment scaled the sound 

produced by a steel pile driven by a 

hammer (given that both are cylindrical 

noise sources and produce impulsive 

sounds) and concluded that the sound 

level produced at 25 m by the borehole 

logging equipment would be less than 

142 dB. This is not considering the 

confining effect of the borehole which 

would lower the sound level even 

further (I&R, 2015). 

The other types of geophysical 

equipment proposed for the 2015 

program will generate impulsive sound 

in the water column and are described 

below Information on the acoustic 

characteristics of geophysical and 

geotechnical sound sources is also 

summarized in Table 2 in the 

application, followed by a 

corresponding description of each piece 

of equipment to be used. 

Sub-Bottom Profiler—Chirp 

The chirp sub-bottom profiler 

planned for use in this program is a 

precisely controlled ‘‘chirp’’ system that 

emits high-energy sounds with a 

resolution of one millisecond (ms) and 

is used to penetrate and profile the 

shallow sediments near the sea floor. At 

operating frequencies of 2 to 16 kHz 

(Table 2 in application), this system will 

be operating at the lower end of the 

hearing range of beluga whales and well 

below the most sensitive hearing range 

of beluga whales (45–80 kHz, Castellote 

et al. 2014), killer whales (18–42 kHz; 

Szymanski et al. 1999) and harbor 

porpoises (16–140 kHz; Kastelein et al. 

2002). The source level is estimated at 

202 dB re 1 mPa-m (rms). The beam 

width is 24 degrees and pointed 

downward. The chirp will be used in 

combination with the boomer, and 

separately in combination with the air 

gun. 

Sub-Bottom Profiler—Boomer 

A boomer sub-bottom profiling system 

with a penetration depth of up to 600 

ms and resolution of 2 to 10 ms will be 

used to penetrate and profile the Cook 

Inlet sediments to an intermediate 

depth. The system will be towed behind 

the vessel. With a sound energy source 

level of about 205 dB re 1 mPa-m (rms) 

at frequencies of 0.5 to 6 kHz (Table 2 

in application), most of the sound 

energy generated by the boomer will be 

at frequencies that are well below peak 

hearing sensitivities of beluga whales 

(45–80 kHz; Castellote et al. 2014), but 

would still be detectable by these 

animals. The boomer is pointed 

downward but the equipment is omnidirectional so the physical orientation is 

irrelevant. 

Airgun 

A 0.983 L (60 in3) airgun or airgun 

array of equal or lesser volume will be 

used to gather high resolution profiling 

at greater depths below the seafloor. The 

published source level from Sercel (the 

manufacturer) for a 0.983 L (60 in3) 

airgun is 216 dB re 1 mPa-m (equating 

to about 206 dB re 1 mPa-m (rms). These 

airguns typically produce sound levels 

at frequencies of less than 1 kHz 

(Richardson et al. 1995, Zykov and Carr 

2012), or below the most sensitive 

hearing of beluga whales (45–80 kHz; 

Castellote et al. 2014), but within the 

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functional hearing of these animals (>75 

Hz; Southall et al. 2007). The airgun 

will only be used during geophysical 

surveys conducted in the Marine 

Facilities area (Lower Inlet). 

Geotechnical Surveys 

Shallow Geotechnical Investigations— 

Vibracores 

Vibracoring is conducted to obtain 

cores of the seafloor sediment from the 

surface down to a depth of about 6.1 m 

(20 ft). The cores are later analyzed in 

the laboratory for moisture, organic and 

carbonate content, shear strength, and 

grain size. Vibracore samplers consist of 

a 10-cm (4.0-in) diameter core barrel 

and a vibratory driving mechanism 

mounted on a four-legged frame, which 

is lowered to the seafloor. The electric 

motor driving mechanism oscillates the 

core barrel into the sediment where a 

core sample is then extracted. The 

duration of the operation varies with 

substrate type, but generally the sound 

source (driving mechanism) is operable 

for only the one or two minutes it takes 

to complete the 6.1-m (20-ft) bore and 

the entire setup process often takes less 

than one hour. 

Chorney et al. (2011) conducted 

sound measurements on an operating 

vibracorer in Alaska and found that it 

emitted a sound pressure level at 1-m 

source of 187.4 dB re 1 mPa-m (rms), 

with a frequency range of between 10 

Hz and 20 kHz (Table 2). Vibracoring 

will result in the largest zone of 

influence (ZOI; area ensonified by 

sound energy greater than the 120 dB 

threshold) among the continuous sound 

sources. Vibracoring would also have a 

very small effect on the benthic habitat. 

Vibracoring will be conducted 

approximately 120 times over 60 days. 

Because of the very brief duration 

within a day (each event lasting 1 or 2- 

minute periods) of this continuous, nonimpulsive sound, combined with the 

small number of days the source will be 

used overall, NMFS does not believe 

that the vibracore operations will result 

in the take of marine mammals. 

However, because the applicant 

requested take from this source and 

included a quantitative analysis in their 

application, that analysis will be 

included here for reference and 

opportunity for public comment. 

Vessels 

Vessels used in the program will be 

approximately 15–42 m (50–140 ft) in 

length and 4.5–15 m (15–50 ft) in width 

(beam) with approximately 750–1500 

horsepower. When used in combination, 

the air gun and chirp and boomer subbottom profilers will typically be 

deployed from the same survey vessel. 

Vibracoring may be conducted from a 

separate survey vessel. The air gun may 

also be used from a stationary platform 

or barge. 

Description of Marine Mammals in the 

Area of the Specified Activity 

Marine mammals that regularly 

inhabit upper Cook Inlet and Nikiski 

activity areas are the beluga whale 

(Delphinapterus leucas), harbor 

porpoise (Phocoena phocoena), and 

harbor seal (Phoca vitulina) (Table 6). 

However, these species are found there 

in relatively low numbers, and generally 

only during the summer fish runs 

(Nemeth et al. 2007, Boveng et al. 2012). 

Killer whales (Orcinus orca) are 

occasionally observed in upper Cook 

Inlet where they have been observed 

attempting to prey on beluga whales 

(Shelden et al. 2003). Based on a 

number of factors, Shelden et al. (2003) 

concluded that the killer whales found 

in upper Cook Inlet to date are the 

transient type, while resident types 

occasionally enter lower Cook Inlet. 

Marine mammals occasionally found in 

lower Cook Inlet include humpback 

whales (Megaptera novaeangliae), gray 

whales (Eschrichtius robustus), minke 

whales (Balaenoptera acutorostrata), 

Dall’s porpoise (Phocoena dalli), and 

Steller sea lion (Eumetopias jubatus). 

Background information of species 

found in Upper Cook Inlet is detailed in 

Table 1 below. 

TABLE 1—MARINE MAMMALS INHABITING THE COOK INLET ACTION AREA

Species Stock 

ESA/MMPA 

status1; 

strategic 

(Y/N) 

Stock abundance 

(CV, Nmin, most recent abundance 

survey) 2

Relative occurrence in Cook Inlet; 

season of occurrence 

Killer whale ............ Alaska Resident ...

Alaska Transient ...

–;N ........................

–:N ........................

2,347 (N/A; 2,084; 2009) .....................

345 (N/A; 303; 2003) ...........................

Occasionally sighted in Lower Cook 

Inlet. 

Beluga whale ......... Cook Inlet ............. E/D;Y .................... 312 (0.10; 280; 2012) .......................... Use upper Inlet in summer and lower 

in winter: Annual. 

Harbor porpoise ..... Gulf of Alaska ....... –;Y ........................ 31,046 (0.214; 25,987; 1998) .............. Widespread in the Inlet: Annual (less 

in winter). 

Harbor seal ............ Cook Inlet/Shelikof –;N ........................ 22,900 (0.053; 21,896; 2006) .............. Frequently found in upper and lower 

inlet; annual (more in northern Inlet 

in summer). 

1ESA 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 certain stocks, 

abundance estimates are actual counts of animals and there is no associated CV. The most recent abundance survey that is reflected in the 

abundance estimate is presented; there may be more recent surveys that have not yet been incorporated into the estimate. 

Beluga Whale (Delphinapterus leucas) 

The Cook Inlet beluga whale Distinct 

Population Segment (DPS) is a small 

geographically isolated population that 

is separated from other beluga 

populations by the Alaska Peninsula. 

The population is genetically (mtDNA) 

distinct from other Alaska populations, 

suggesting that the Peninsula is an 

effective barrier to genetic exchange 

(O’Corry-Crowe et al. 1997) and that 

these whales may have been separated 

from other stocks at least since the last 

ice age. Laidre et al. (2000) examined 

data from over 20 marine mammal 

surveys conducted in the northern Gulf 

of Alaska and found that sightings of 

belugas outside Cook Inlet were 

exceedingly rare, and these were 

composed of a few stragglers from the 

Cook Inlet DPS observed at Kodiak 

Island, Prince William Sound, and 

Yakutat Bay. Several marine mammal 

surveys specific to Cook Inlet (Laidre et 

al. 2000, Speckman and Piatt 2000), 

including those that concentrated on 

beluga whales (Rugh et al. 2000, 2005a), 

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clearly indicate that this stock largely 

confines itself to Cook Inlet. There is no 

indication that these whales make 

forays into the Bering Sea where they 

might intermix with other Alaskan 

stocks. 

The Cook Inlet beluga DPS was 

originally estimated at 1,300 whales in 

1979 (Calkins 1989) and has been the 

focus of management concerns since 

experiencing a dramatic decline in the 

1990s. Between 1994 and 1998 the stock 

declined 47%, which has been 

attributed to overharvesting by 

subsistence hunting. During that period, 

subsistence hunting was estimated to 

have annually removed 10–15% of the 

population. Only five belugas have been 

harvested since 1999, yet the population 

has continued to decline (Allen and 

Angliss 2014), with the most recent 

estimate at only 312 animals (Allen and 

Angliss 2014). The NMFS listed the 

population as ‘‘depleted’’ in 2000 as a 

consequence of the decline, and as 

‘‘endangered’’ under the ESA in 2008 

when the population failed to recover 

following a moratorium on subsistence 

harvest. In April 2011, the NMFS 

designated critical habitat for the Cook 

Inlet beluga whale under the ESA 

(Figure 2 in the application). 

Prior to the decline, this DPS was 

believed to range throughout Cook Inlet 

and occasionally into Prince William 

Sound and Yakutat (Nemeth et al. 

2007). However, the range has 

contracted coincident with the 

population reduction (Speckman and 

Piatt 2000). During the summer and fall, 

beluga whales are concentrated near the 

Susitna River mouth, Knik Arm, 

Turnagain Arm, and Chickaloon Bay 

(Nemeth et al. 2007) where they feed on 

migrating eulachon (Thaleichthys 

pacificus) and salmon (Onchorhynchus 

spp.) (Moore et al. 2000). The limits of 

Critical Habitat Area 1 reflect the 

summer distribution (Figure 4 in the 

application). During the winter, beluga 

whales concentrate in deeper waters in 

the mid-inlet to Kalgin Island, and in 

the shallow waters along the west shore 

of Cook Inlet to Kamishak Bay. The 

limits of Critical Habitat Area 2 reflect 

the winter distribution. Some whales 

may also winter in and near Kachemak 

Bay. 

Goetz et al. (2012) modeled beluga 

use in Cook Inlet based on the NMFS 

aerial surveys conducted between 1994 

and 2008. The combined model results 

shown in Figure 3 in the application 

indicate a very clumped distribution of 

summering beluga whales, and that 

lower densities of belugas are expected 

to occur in most of the pipeline survey 

area (but not necessarily specific G&G 

survey locations; see Section 6.3 in the 

application) and the vicinity of the 

proposed Marine Terminal. However, 

Cook Inlet beluga whales begin moving 

into Knik Arm around August 15 where 

they spend about a month feeding on 

Eagle River salmon. The area between 

Nikiski, Kenai, and Kalgin Island 

provides important wintering habitat for 

Cook Inlet beluga whales. Use of this 

area would be expected between fall 

and spring, with animals largely absent 

during the summer months when G&G 

surveys would occur (Goetz et al. 2012). 

Killer Whale (Orcinus orca) 

Two different stocks of killer whales 

inhabit the Cook Inlet region of Alaska: 

The Alaska Resident Stock and the Gulf 

of Alaska, Aleutian Islands, Bering Sea 

Transient Stock (Allen and Angliss 

2014). The Alaska Resident killer whale 

stock is estimated at 2,347 animals and 

occurs from Southeast Alaska to the 

Bering Sea (Allen and Angliss 2014). 

Resident killer whales feed exclusively 

on fish and are genetically distinct from 

transient whales (Saulitis et al. 2000). 

The transient killer whales feed 

primarily on marine mammals (Saulitis 

et al. 2000). The transient population 

inhabiting the Gulf of Alaska shares 

mitochondrial DNA haplotypes with 

whales found along the Aleutian Islands 

and the Bering Sea, suggesting a 

common stock, although there appears 

to be some subpopulation genetic 

structuring occurring to suggest the gene 

flow between groups is limited (see 

Allen and Angliss 2014). For the three 

regions combined, the transient 

population has been estimated at 587 

animals (Allen and Angliss 2014). 

Killer whales are occasionally 

observed in lower Cook Inlet, especially 

near Homer and Port Graham (Shelden 

et al. 2003, Rugh et al. 2005a). The few 

whales that have been photographically 

identified in lower Cook Inlet belong to 

resident groups more commonly found 

in nearby Kenai Fjords and Prince 

William Sound (Shelden et al. 2003). 

Prior to the 1980s, killer whale sightings 

in upper Cook Inlet were very rare. 

During aerial surveys conducted 

between 1993 and 2004, killer whales 

were observed on only three flights, all 

in the Kachemak and English Bay area 

(Rugh et al. 2005a). However, anecdotal 

reports of killer whales feeding on 

belugas in upper Cook Inlet began 

increasing in the 1990s, possibly in 

response to declines in sea lion and 

harbor seal prey elsewhere (Shelden et 

al. 2003). These sporadic ventures of 

transient killer whales into beluga 

summering grounds have been 

implicated as a possible contributor to 

the decline of Cook Inlet belugas in the 

1990s, although the number of 

confirmed mortalities from killer whales 

is small (Shelden et al. 2003). If killer 

whales were to venture into upper Cook 

Inlet in 2015, they might be encountered 

during the G&G Program. 

Harbor Porpoise (Phocoena phocoena) 

Harbor porpoise are small 

(approximately 1.2 m [4 ft] in length), 

relatively inconspicuous toothed 

whales. The Gulf of Alaska Stock is 

distributed from Cape Suckling to 

Unimak Pass and was most recently 

estimated at 31,046 animals (Allen and 

Angliss 2014). They are found primarily 

in coastal waters less than 100 m (328 

ft) deep (Hobbs and Waite 2010) where 

they feed on Pacific herring (Clupea 

pallasii), other schooling fishes, and 

cephalopods. 

Although they have been frequently 

observed during aerial surveys in Cook 

Inlet, most sightings of harbor porpoise 

are of single animals, and are 

concentrated at Chinitna and Tuxedni 

bays on the west side of lower Cook 

Inlet (Rugh et al. 2005a). Dahlheim et al. 

(2000) estimated the 1991 Cook Inletwide population at only 136 animals. 

Also, during marine mammal 

monitoring efforts conducted in upper 

Cook Inlet by Apache from 2012 to 

2014, harbor porpoise represented less 

than 2% of all marine mammal 

sightings. However, they are one of the 

three marine mammals (besides belugas 

and harbor seals) regularly seen in 

upper Cook Inlet (Nemeth et al. 2007), 

especially during spring eulachon and 

summer salmon runs. Because harbor 

porpoise have been observed throughout 

Cook Inlet during the summer months, 

including mid-inlet waters, they 

represent species that might be 

encountered during G&G Program 

surveys in upper Cook Inlet. 

Harbor Seal (Phoca vitulina) 

At over 150,000 animals state-wide 

(Allen and Angliss 2014), harbor seals 

are one of the more common marine 

mammal species in Alaskan waters. 

They are most commonly seen hauled 

out at tidal flats and rocky areas. Harbor 

seals feed largely on schooling fish such 

as Alaska Pollock, Pacific cod, salmon, 

Pacific herring, eulachon, and squid. 

Although harbor seals may make 

seasonal movements in response to 

prey, they are resident to Alaska and do 

not migrate. 

The Cook Inlet/Shelikof Stock, 

ranging from approximately Anchorage 

down along the south side of the Alaska 

Peninsula to Unimak Pass, has been 

recently estimated at a stable 22,900 

(Allen and Angliss 2014). Large 

numbers concentrate at the river mouths 

and embayments of lower Cook Inlet, 

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including the Fox River mouth in 

Kachemak Bay (Rugh et al. 2005a). 

Montgomery et al. (2007) recorded over 

200 haulout sites in lower Cook Inlet 

alone. However, only a few dozen to a 

couple hundred seals seasonally occur 

in upper Cook Inlet (Rugh et al. 2005a), 

mostly at the mouth of the Susitna River 

where their numbers vary with the 

spring eulachon and summer salmon 

runs (Nemeth et al. 2007, Boveng et al. 

2012). Review of NMFS aerial survey 

data collected from 1993–2012 (Shelden 

et al. 2013) finds that the annual high 

counts of seals hauled out in Cook Inlet 

ranged from about 100–380, with most 

of these animals hauling out at the 

mouths of the Theodore and Lewis 

Rivers. There are certainly thousands of 

harbor seals occurring in lower Cook 

Inlet, but no references have been found 

showing more than about 400 harbor 

seals occurring seasonally in upper 

Cook Inlet. In 2012, up to 100 harbor 

seals were observed hauled out at the 

mouths of the Theodore and Lewis 

rivers (located about 16 km [10 mi] 

northeast of the pipeline survey area) 

during monitoring activity associated 

with Apache’s 2012 Cook Inlet seismic 

program, and harbor seals constituted 

60 percent of all marine mammal 

sightings by Apache observers during 

2012 to 2014 survey and monitoring 

efforts (L. Parker, Apache, pers. comm.). 

Montgomery et al. (2007) also found 

that seals elsewhere in Cook Inlet move 

in response to local steelhead 

(Onchorhynchus mykiss) and salmon 

runs. Harbor seals may be encountered 

during G&G surveys in Cook Inlet. 

Humpback Whale (Megaptera 

novaeangliae) 

Although there is considerable 

distributional overlap in the humpback 

whale stocks that use Alaska, the whales 

seasonally found in lower Cook Inlet are 

probably of the Central North Pacific 

stock. Listed as endangered under the 

ESA, this stock has recently been 

estimated at 7,469, with the portion of 

the stock that feeds in the Gulf of Alaska 

estimated at 2,845 animals (Allen and 

Angliss 2014). The Central North Pacific 

stock winters in Hawaii and summers 

from British Columbia to the Aleutian 

Islands (Calambokidis et al. 1997), 

including Cook Inlet. 

Humpback use of Cook Inlet is largely 

confined to lower Cook Inlet. They have 

been regularly seen near Kachemak Bay 

during the summer months (Rugh et al. 

2005a), and there is a whale-watching 

venture in Homer capitalizing on this 

seasonal event. There are anecdotal 

observations of humpback whales as far 

north as Anchor Point, with recent 

summer observations extending to Cape 

Starichkof (Owl Ridge 2014). Because of 

the southern distribution of humpbacks 

in Cook Inlet, it is unlikely that they 

will be encountered during this activity 

in close enough proximity to cause 

Level B harassment. Therefore, no take 

is authorized for humpback whales. 

Gray Whale (Eschrichtius robustus) 

Each spring, the Eastern North Pacific 

stock of gray whale migrates 8,000 

kilometers (5,000 miles) northward from 

breeding lagoons in Baja California to 

feeding grounds in the Bering and 

Chukchi seas, reversing their travel 

again in the fall (Rice and Wolman 

1971). Their migration route is for the 

most part coastal until they reach the 

feeding grounds. A small portion of 

whales do not annually complete the 

full circuit, as small numbers can be 

found in the summer feeding along the 

Oregon, Washington, British Columbia, 

and Alaskan coasts (Rice et al. 1984, 

Moore et al. 2007). 

Human exploitation reduced this 

stock to an estimated ‘‘few thousand’’ 

animals (Jones and Schwartz 2002). 

However, by the late 1980s, the stock 

was appearing to reach carrying 

capacity and estimated to be at 26,600 

animals (Jones and Schwartz 2002). By 

2002, that stock had been reduced to 

about 16,000 animals, especially 

following unusually high mortality 

events in 1999 and 2000 (Allen and 

Angliss 2014). The stock has continued 

to grow since then and is currently 

estimated at 19,126 animals with a 

minimum estimate of 18,017 (Carretta et 

al. 2013). 

Most gray whales migrate past the 

mouth of Cook Inlet to and from 

northern feeding grounds. However, 

small numbers of summering gray 

whales have been noted by fisherman 

near Kachemak Bay and north of 

Anchor Point. Further, summering gray 

whales were seen offshore of Cape 

Starichkof by marine mammal observers 

monitoring Buccaneer’s Cosmopolitan 

drilling program in 2013 (Owl Ridge 

2014). Regardless, gray whales are not 

expected to be encountered in upper 

Cook Inlet, where the activity is 

concentrated, north of Kachemak Bay. 

Therefore, it is unlikely that they will be 

encountered during this activity in close 

enough proximity to cause Level B 

harassment and are not considered 

further in this final Authorization 

notice. 

Minke Whale (Balaenoptera 

acutorostrata) 

Minke whales are the smallest of the 

rorqual group of baleen whales reaching 

lengths of up to 35 feet. They are also 

the most common of the baleen whales, 

although there are no population 

estimates for the North Pacific, although 

estimates have been made for some 

portions of Alaska. Zerbini et al. (2006) 

estimated the coastal population 

between Kenai Fjords and the Aleutian 

Islands at 1,233 animals. 

During Cook Inlet-wide aerial surveys 

conducted from 1993 to 2004, minke 

whales were encountered only twice 

(1998, 1999), both times off Anchor 

Point 16 miles northwest of Homer. 

Recently, several minke whales were 

recorded off Cape Starichkof in early 

summer 2013 during exploratory 

drilling conducted there (Owl Ridge 

2014). There are no records north of 

Cape Starichkof, and this species is 

unlikely to be seen in upper Cook Inlet. 

There is little chance of encountering a 

minke whale during these activities. 

Therefore, no take of minke whales is 

authorized. 

Dall’s Porpoise (Phocoenoides dalli) 

Dall’s porpoise are widely distributed 

throughout the North Pacific Ocean 

including Alaska, although they are not 

found in upper Cook Inlet and the 

shallower waters of the Bering, Chukchi, 

and Beaufort Seas (Allen and Angliss 

2014). Compared to harbor porpoise, 

Dall’s porpoise prefer the deep offshore 

and shelf slope waters. The Alaskan 

population has been estimated at 83,400 

animals (Allen and Angliss 2014), 

making it one of the more common 

cetaceans in the state. Dall’s porpoise 

have been observed in lower Cook Inlet, 

including Kachemak Bay and near 

Anchor Point (Owl Ridge 2014), but 

sightings there are rare. The 

concentration of sightings of Dall’s 

porpoise in a southerly part of the Inlet 

suggest it is unlikely they will be 

encountered during EMALL’s activities. 

Therefore, no take of Dall’s porpoise is 

authorized. 

Steller Sea Lion (Eumetopias jubatus) 

The Western Stock of the Steller sea 

lion is defined as all populations west 

of longitude 144°W to the western end 

of the Aleutian Islands. The most recent 

estimate for this stock is 45,649 animals 

(Allen and Angliss 2014), considerably 

less than that estimated 140,000 animals 

in the 1950s (Merrick et al. 1987). 

Because of this dramatic decline, the 

stock was listed under the ESA as a 

threatened DPS in 1990, and relisted as 

endangered in 1997. Critical habitat was 

designated in 1993, and is defined as a 

20-nautical-mile radius around all major 

rookeries and haulout sites. The 20- 

nautical-mile buffer was established 

based on telemetry data that indicated 

these sea lions concentrated their 

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summer foraging effort within this 

distance of rookeries and haul outs. 

Steller sea lions inhabit lower Cook 

Inlet, especially in the vicinity of Shaw 

Island and Elizabeth Island (Nagahut 

Rocks) haulout sites (Rugh et al. 2005a), 

but are rarely seen in upper Cook Inlet 

(Nemeth et al. 2007). Of the 42 Steller 

sea lion groups recorded during Cook 

Inlet aerial surveys between 1993 and 

2004, none were recorded north of 

Anchor Point and only one in the 

vicinity of Kachemak Bay (Rugh et al. 

2005a). Marine mammal observers 

associated with Buccaneer’s drilling 

project off Cape Starichkof did observe 

seven Steller sea lions during the 

summer of 2013 (Owl Ridge 2014). 

The upper reaches of Cook Inlet may 

not provide adequate foraging 

conditions for sea lions for establishing 

a major haul out presence. Steller sea 

lions feed largely on walleye pollock, 

salmon and arrowtooth flounder during 

the summer, and walleye pollock and 

Pacific cod during the winter (Sinclair 

and Zeppelin 2002), none of which, 

except for salmon, are found in 

abundance in upper Cook Inlet (Nemeth 

et al. 2007). Steller sea lions are unlikely 

to be encountered during operations in 

upper Cook Inlet, as they are primarily 

encountered along the Kenai Peninsula, 

especially closer to Anchor Point. 

Therefore, no take of Steller sea lion is 

authorized. 

Potential Effects of the Specified 

Activity on Marine Mammals 

This section includes a summary and 

discussion of the ways that components 

(seismic airgun operations, sub-bottom 

profiler chirper and boomer, vibracore) 

of the specified activity may impact 

marine mammals. The ‘‘Estimated Take 

by Incidental Harassment’’ section later 

in this document will include a 

quantitative analysis of the number of 

individuals that NMFS expects to be 

taken by this activity. The ‘‘Negligible 

Impact Analysis’’ section will include 

the analysis of how this specific 

proposed activity would impact marine 

mammals and will consider the content 

of this section, the ‘‘Estimated Take by 

Incidental Harassment’’ section, the 

‘‘Mitigation’’ section, and the 

‘‘Anticipated Effects on Marine Mammal 

Habitat’’ section to draw conclusions 

regarding the likely impacts of this 

activity on the reproductive success or 

survivorship of individuals and from 

that on the affected marine mammal 

populations or stocks. 

NMFS intends to provide a 

background of potential effects of 

EMALL’s activities in this section. 

Operating active acoustic sources have 

the potential for adverse effects on 

marine mammals. The majority of 

anticipated impacts would be from the 

use of active acoustic sources. 

Acoustic Impacts 

When considering the influence of 

various kinds of sound on the marine 

environment, it is necessary to 

understand that different kinds of 

marine life are sensitive to different 

frequencies of sound. Current data 

indicate that not all marine mammal 

species have equal hearing capabilities 

(Richardson et al., 1995; Southall et al., 

1997; Wartzok and Ketten, 1999; Au and 

Hastings, 2008). 

Southall et al. (2007) designated 

‘‘Functional hearing groups’’ for marine 

mammals based on available behavioral 

data; audiograms derived from auditory 

evoked potentials; anatomical modeling; 

and other data. Southall et al. (2007) 

also estimated the lower and upper 

frequencies of functional hearing for 

each group. However, animals are less 

sensitive to sounds at the outer edges of 

their functional hearing range and are 

more sensitive to a range of frequencies 

within the middle of their functional 

hearing range. 

The functional groups and the 

associated frequencies are: 

• Low frequency cetaceans (13 

species of mysticetes): Functional 

hearing estimates occur between 

approximately 7 Hertz (Hz) and 25 kHz 

(extended from 22 kHz based on data 

indicating that some mysticetes can hear 

above 22 kHz; Au et al., 2006; Lucifredi 

and Stein, 2007; Ketten and Mountain, 

2009; Tubelli et al., 2012); 

• Mid-frequency cetaceans (32 

species of dolphins, six species of larger 

toothed whales, and 19 species of 

beaked and bottlenose whales): 

Functional hearing estimates 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 estimates occur 

between approximately 200 Hz and 180 

kHz; and 

• Pinnipeds in Water: Phocid (true 

seals) functional hearing estimates occur 

between approximately 75 Hz and 100 

kHz (Hemila et al., 2006; Mulsow et al., 

2011; Reichmuth et al., 2013) and 

otariid (seals and sea lions) functional 

hearing estimates occur between 

approximately 100 Hz to 40 kHz. 

As mentioned previously in this 

document, Cook Inlet beluga whales, 

harbor porpoise, killer whales, and 

harbor seals (3 odontocetes and 1 

phocid) would likely occur in the action 

area. Table 2 presents the classification 

of these species into their respective 

functional hearing group. NMFS 

consider a species’ functional hearing 

group when analyzing the effects of 

exposure to sound on marine mammals. 

TABLE 2—CLASSIFICATION OF MARINE

MAMMALS THAT COULD POTENTIALLY OCCUR IN THE PROPOSED

ACTIVITY AREA IN COOK INLET, 

2015 BY FUNCTIONAL HEARING

GROUP

[Southall et al., 2007] 

Mid-Frequency Hearing Range.Beluga whale, killer 

whale. 

High Frequency Hearing Range.Harbor porpoise. 

Pinnipeds in Water 

Hearing Range.

Harbor seal. 

1. Potential Effects of Airgun Sounds on 

Marine Mammals 

The effects of sounds from airgun 

operations might include one or more of 

the following: Tolerance, masking of 

natural sounds, behavioral disturbance, 

temporary or permanent impairment, or 

non-auditory physical or physiological 

effects (Richardson et al., 1995; Gordon 

et al., 2003; Nowacek et al., 2007; 

Southall et al., 2007). The effects of 

noise on marine mammals are highly 

variable, often depending on species 

and contextual factors (based on 

Richardson et al., 1995). 

Tolerance 

Studies on marine mammals’ 

tolerance to sound in the natural 

environment are relatively rare. 

Richardson et al. (1995) defined 

tolerance as the occurrence of marine 

mammals in areas where they are 

exposed to human activities or 

manmade noise. In many cases, 

tolerance develops by the animal 

habituating to the stimulus (i.e., the 

gradual waning of responses to a 

repeated or ongoing stimulus) 

(Richardson, et al., 1995), but because of 

ecological or physiological 

requirements, many marine animals 

may need to remain in areas where they 

are exposed to chronic stimuli 

(Richardson, et al., 1995). 

Numerous studies have shown that 

pulsed sounds from airguns are often 

readily detectable in the water at 

distances of many kilometers. Several 

studies have also shown that marine 

mammals at distances of more than a 

few kilometers from operating seismic 

vessels often show no apparent 

response. That is often true even in 

cases when the pulsed sounds must be 

readily audible to the animals based on 

measured received levels and the 

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hearing sensitivity of the marine 

mammal group. Although various 

baleen whales and toothed whales, and 

(less frequently) pinnipeds have been 

shown to react behaviorally to airgun 

pulses under some conditions, at other 

times marine mammals of all three types 

have shown no overt reactions (Stone, 

2003; Stone and Tasker, 2006; Moulton 

et al. 2005, 2006) and (MacLean and 

Koski, 2005; Bain and Williams, 2006). 

Weir (2008) observed marine mammal 

responses to seismic pulses from a 24 

airgun array firing a total volume of 

either 5,085 in3 or 3,147 in3 in Angolan 

waters between August 2004 and May 

2005. Weir (2008) recorded a total of 

207 sightings of humpback whales (n = 

66), sperm whales (n = 124), and 

Atlantic spotted dolphins (n = 17) and 

reported that there were no significant 

differences in encounter rates (sightings 

per hour) for humpback and sperm 

whales according to the airgun array’s 

operational status (i.e., active versus 

silent). 

Bain and Williams (2006) examined 

the effects of a large airgun array 

(maximum total discharge volume of 

1,100 in3) on six species in shallow 

waters off British Columbia and 

Washington: harbor seal, California sea 

lion, Steller sea lion, gray whale, Dall’s 

porpoise, and harbor porpoise. Harbor 

porpoises showed reactions at received 

levels less than 155 dB re: 1 mPa at a 

distance of greater than 70 km (43 mi) 

from the seismic source (Bain and 

Williams, 2006). However, the tendency 

for greater responsiveness by harbor 

porpoise is consistent with their relative 

responsiveness to boat traffic and some 

other acoustic sources (Richardson, et 

al., 1995; Southall, et al., 2007). In 

contrast, the authors reported that gray 

whales seemed to tolerate exposures to 

sound up to approximately 170 dB re: 

1 mPa (Bain and Williams, 2006) and 

Dall’s porpoises occupied and tolerated 

areas receiving exposures of 170–180 dB 

re: 1 mPa (Bain and Williams, 2006; 

Parsons, et al., 2009). The authors 

observed several gray whales that 

moved away from the airguns toward 

deeper water where sound levels were 

higher due to propagation effects 

resulting in higher noise exposures 

(Bain and Williams, 2006). However, it 

is unclear whether their movements 

reflected a response to the sounds (Bain 

and Williams, 2006). Thus, the authors 

surmised that the lack of gray whale 

responses to higher received sound 

levels were ambiguous at best because 

one expects the species to be the most 

sensitive to the low-frequency sound 

emanating from the airguns (Bain and 

Williams, 2006). 

Pirotta et al. (2014) observed shortterm responses of harbor porpoises to a 

two-dimensional (2–D) seismic survey 

in an enclosed bay in northeast Scotland 

which did not result in broad-scale 

displacement. The harbor porpoises that 

remained in the enclosed bay area 

reduced their buzzing activity by 15 

percent during the seismic survey 

(Pirotta, et al., 2014). Thus, the authors 

suggest that animals exposed to 

anthropogenic disturbance may make 

trade-offs between perceived risks and 

the cost of leaving disturbed areas 

(Pirotta, et al., 2014). 

Masking 

Marine mammals use acoustic signals 

for a variety of purposes, which differ 

among species, but include 

communication between individuals, 

navigation, foraging, reproduction, 

avoiding predators, and learning about 

their environment (Erbe and Farmer, 

2000; Tyack, 2000). 

The term masking refers to the 

inability of an animal to recognize the 

occurrence of an acoustic stimulus 

because of interference of another 

acoustic stimulus (Clark et al., 2009). 

Thus, masking is the obscuring of 

sounds of interest by other sounds, often 

at similar frequencies. It is a 

phenomenon that affects animals that 

are trying to receive acoustic 

information about their environment, 

including sounds from other members 

of their species, predators, prey, and 

sounds that allow them to orient in their 

environment. Masking these acoustic 

signals can disturb the behavior of 

individual animals, groups of animals, 

or entire populations in certain 

circumstances. 

Introduced underwater sound may, 

through masking, reduce the effective 

communication distance of a marine 

mammal species if the frequency of the 

source is close to that used as a signal 

by the marine mammal, and if the 

anthropogenic sound is present for a 

significant fraction of the time 

(Richardson et al., 1995). 

Marine mammals are thought to be 

able to compensate for masking by 

adjusting their acoustic behavior 

through shifting call frequencies, 

increasing call volume, and increasing 

vocalization rates. For example in one 

study, blue whales increased call rates 

when exposed to noise from seismic 

surveys in the St. Lawrence Estuary (Di 

Iorio and Clark, 2010). Other studies 

reported that some North Atlantic right 

whales exposed to high shipping noise 

increased call frequency (Parks et al., 

2007) and some humpback whales 

responded to low-frequency active sonar 

playbacks by increasing song length 

(Miller et al., 2000). Additionally, 

beluga whales change their 

vocalizations in the presence of high 

background noise possibly to avoid 

masking calls (Au et al., 1985; Lesage et 

al., 1999; Scheifele et al., 2005). 

Studies have shown that some baleen 

and toothed whales continue calling in 

the presence of seismic pulses, and 

some researchers have heard these calls 

between the seismic pulses (e.g., 

McDonald et al., 1995; Greene et al., 

1999; Nieukirk et al., 2004; Smultea et 

al., 2004; Holst et al., 2005a, 2005b, 

2006; and Dunn and Hernandez, 2009). 

In contrast, Clark and Gagnon (2006) 

reported that fin whales in the northeast 

Pacific Ocean went silent for an 

extended period starting soon after the 

onset of a seismic survey in the area. 

Similarly, NMFS is aware of one report 

that observed sperm whales ceased calls 

when exposed to pulses from a very 

distant seismic ship (Bowles et al., 

1994). However, more recent studies 

have found that sperm whales 

continued calling in the presence of 

seismic pulses (Madsen et al., 2002; 

Tyack et al., 2003; Smultea et al., 2004; 

Holst et al., 2006; and Jochens et al., 

2008). 

Risch et al. (2012) documented 

reductions in humpback whale 

vocalizations in the Stellwagen Bank 

National Marine Sanctuary concurrent 

with transmissions of the Ocean 

Acoustic Waveguide Remote Sensing 

(OAWRS) low-frequency fish sensor 

system at distances of 200 km (124 mi) 

from the source. The recorded OAWRS 

produced series of frequency modulated 

pulses and the signal received levels 

ranged from 88 to 110 dB re: 1 mPa 

(Risch, et al., 2012). The authors 

hypothesized that individuals did not 

leave the area but instead ceased singing 

and noted that the duration and 

frequency range of the OAWRS signals 

(a novel sound to the whales) were 

similar to those of natural humpback 

whale song components used during 

mating (Risch et al., 2012). Thus, the 

novelty of the sound to humpback 

whales in the study area provided a 

compelling contextual probability for 

the observed effects (Risch et al., 2012). 

However, the authors did not state or 

imply that these changes had long-term 

effects on individual animals or 

populations (Risch et al., 2012). 

Several studies have also reported 

hearing dolphins and porpoises calling 

while airguns were operating (e.g., 

Gordon et al., 2004; Smultea et al., 2004; 

Holst et al., 2005a, b; and Potter et al., 

2007). The sounds important to small 

odontocetes are predominantly at much 

higher frequencies than the dominant 

components of airgun sounds, thus 

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limiting the potential for masking in 

those species. 

Although some degree of masking is 

inevitable when high levels of manmade 

broadband sounds are present in the 

sea, marine mammals have evolved 

systems and behavior that function to 

reduce the impacts of masking. 

Odontocete conspecifics may readily 

detect structured signals, such as the 

echolocation click sequences of small 

toothed whales 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. 

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 

sounds by improving the effective 

signal-to-noise ratio. In the cases of 

higher 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 increase 

the source levels or alter the frequency 

of their calls in the presence of elevated 

sound levels (Dahlheim, 1987; Au, 1993; 

Lesage et al., 1993, 1999; Terhune, 1999; 

Foote et al., 2004; Parks et al., 2007, 

2009; Di Iorio and Clark, 2010; Holt et 

al., 2009). 

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. Studies have noted 

directional hearing at frequencies as low 

as 0.5–2 kHz in several marine 

mammals, including killer whales 

(Richardson et al., 1995a). This ability 

may be useful in reducing masking at 

these frequencies. In summary, high 

levels of sound 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. 

Behavioral Disturbance 

Marine mammals may behaviorally 

react to sound when exposed to 

anthropogenic noise. Reactions to 

sound, if any, depend on species, state 

of maturity, experience, current activity, 

reproductive state, time of day, and 

many other factors (Richardson et al., 

1995; D’Spain & Wartzok, 2004; 

Southall et al., 2007; Weilgart, 2007). 

Types of behavioral reactions can 

include the following: Changing 

durations of surfacing and dives, 

number of blows per surfacing, or 

moving direction and/or speed; 

reduced/increased vocal activities; 

changing/cessation of certain behavioral 

activities (such as socializing or 

feeding); visible startle response or 

aggressive behavior (such as tail/fluke 

slapping or jaw clapping); avoidance of 

areas where noise sources are located; 

and/or flight responses (e.g., pinnipeds 

flushing into water from haulouts or 

rookeries). 

The biological significance of many of 

these behavioral disturbances is difficult 

to predict, especially if the detected 

disturbances appear minor. However, 

one could expect the consequences of 

behavioral modification to be 

biologically significant if the change 

affects growth, survival, and/or 

reproduction (e.g., Lusseau and Bejder, 

2007; Weilgart, 2007). Examples of 

behavioral modifications that could 

impact growth, survival, or 

reproduction include: 

• Drastic changes in diving/surfacing 

patterns (such as those associated with 

beaked whale stranding related to 

exposure to military mid-frequency 

tactical sonar); 

• Permanent habitat abandonment 

due to loss of desirable acoustic 

environment; and 

• Disruption of feeding or social 

interaction resulting in significant 

energetic costs, inhibited breeding, or 

cow-calf separation. 

The onset of behavioral disturbance 

from anthropogenic noise depends on 

both external factors (characteristics of 

noise sources and their paths) and the 

receiving animals (hearing, motivation, 

experience, demography) and is also 

difficult to predict (Richardson et al., 

1995; Southall et al., 2007). Many 

studies have also shown that marine 

mammals at distances more than a few 

kilometers away often show no apparent 

response when exposed to seismic 

activities (e.g., Madsen & Mohl, 2000 for 

sperm whales; Malme et al., 1983, 1984 

for gray whales; and Richardson et al., 

1986 for bowhead whales). Other 

studies have shown that marine 

mammals continue important behaviors 

in the presence of seismic pulses (e.g., 

Dunn & Hernandez, 2009 for blue 

whales; Greene Jr. et al., 1999 for 

bowhead whales; Holst and Beland, 

2010; Holst and Smultea, 2008; Holst et 

al., 2005; Nieukirk et al., 2004; 

Richardson, et al., 1986; Smultea et al., 

2004). 

Baleen Whales: Studies have shown 

that underwater sounds from seismic 

activities are often readily detectable by 

baleen whales in the water at distances 

of many kilometers (Castellote et al., 

2012 for fin whales). 

Observers have seen various species 

of Balaenoptera (blue, sei, fin, and 

minke whales) in areas ensonified by 

airgun pulses (Stone, 2003; MacLean 

and Haley, 2004; Stone and Tasker, 

2006), and have localized calls from 

blue and fin whales in areas with airgun 

operations (e.g., McDonald et al., 1995; 

Dunn and Hernandez, 2009; Castellote 

et al., 2010). Sightings by observers on 

seismic vessels off the United Kingdom 

from 1997 to 2000 suggest that, during 

times of good visibility, sighting rates 

for mysticetes (mainly fin and sei 

whales) were similar when large arrays 

of airguns were shooting versus silent 

(Stone, 2003; Stone and Tasker, 2006). 

However, these whales tended to exhibit 

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localized avoidance, remaining 

significantly further (on average) from 

the airgun array during seismic 

operations compared with non-seismic 

periods (Stone and Tasker, 2006). 

Ship-based monitoring studies of 

baleen whales (including blue, fin, sei, 

minke, and humpback whales) in the 

northwest Atlantic found that overall, 

this group had lower sighting rates 

during seismic versus non-seismic 

periods (Moulton and Holst, 2010). The 

authors observed that baleen whales as 

a group were significantly farther from 

the vessel during seismic compared 

with non-seismic periods. Moreover, the 

authors observed that the whales swam 

away more often from the operating 

seismic vessel (Moulton and Holst, 

2010). Initial sightings of blue and 

minke whales were significantly farther 

from the vessel during seismic 

operations compared to non-seismic 

periods and the authors observed the 

same trend for fin whales (Moulton and 

Holst, 2010). Also, the authors observed 

that minke whales most often swam 

away from the vessel when seismic 

operations were underway (Moulton 

and Holst, 2010). 

Toothed Whales: Few systematic data 

are available describing reactions of 

toothed whales to noise pulses. 

However, systematic work on sperm 

whales is underway (e.g., Gordon et al., 

2006; Madsen et al., 2006; Winsor and 

Mate, 2006; Jochens et al., 2008; Miller 

et al., 2009) and there is an increasing 

amount of information about responses 

of various odontocetes, including killer 

whales and belugas, to seismic surveys 

based on monitoring studies (e.g., Stone, 

2003; Smultea et al., 2004; Moulton and 

Miller, 2005; Bain and Williams, 2006; 

Holst et al., 2006; Stone and Tasker, 

2006; Potter et al., 2007; Hauser et al., 

2008; Holst and Smultea, 2008; Weir, 

2008; Barkaszi et al., 2009; Richardson 

et al., 2009; Moulton and Holst, 2010). 

Reactions of toothed whales to large 

arrays of airguns are variable and, at 

least for delphinids, seem to be confined 

to a smaller radius than has been 

observed for mysticetes. 

Observers stationed on seismic 

vessels operating off the United 

Kingdom from 1997–2000 have 

provided data on the occurrence and 

behavior of various toothed whales 

exposed to seismic pulses (Stone, 2003; 

Gordon et al., 2004). The studies note 

that killer whales were significantly 

farther from large airgun arrays during 

periods of active airgun operations 

compared with periods of silence. The 

displacement of the median distance 

from the array was approximately 0.5 

km (0.3 mi) or more. Killer whales also 

appear to be more tolerant of seismic 

shooting in deeper water (Stone, 2003; 

Gordon et al., 2004). 

The beluga may be a species that (at 

least in certain geographic areas) shows 

long-distance avoidance of seismic 

vessels. Aerial surveys during seismic 

operations in the southeastern Beaufort 

Sea recorded much lower sighting rates 

of beluga whales within 10–20 km (6.2– 

12.4 mi) of an active seismic vessel. 

These results were consistent with the 

low number of beluga sightings reported 

by observers aboard the seismic vessel, 

suggesting that some belugas might have 

been avoiding the seismic operations at 

distances of 10–20 km (6.2–12.4 mi) 

(Miller et al., 2005). 

Delphinids 

Seismic operators and protected 

species observers (observers) on seismic 

vessels regularly see dolphins and other 

small toothed whales near operating 

airgun arrays, but in general there is a 

tendency for most delphinids to show 

some avoidance of operating seismic 

vessels (e.g., Goold, 1996a,b,c; 

Calambokidis and Osmek, 1998; Stone, 

2003; Moulton and Miller, 2005; Holst 

et al., 2006; Stone and Tasker, 2006; 

Weir, 2008; Richardson et al., 2009; 

Barkaszi et al., 2009; Moulton and 

Holst, 2010). Some dolphins seem to be 

attracted to the seismic vessel and 

floats, and some ride the bow wave of 

the seismic vessel even when large 

arrays of airguns are firing (e.g., 

Moulton and Miller, 2005). Nonetheless, 

there have been indications that small 

toothed whales sometimes move away 

or maintain a somewhat greater distance 

from the vessel when a large array of 

airguns is operating than when it is 

silent (e.g., Goold, 1996a,b,c; Stone and 

Tasker, 2006; Weir, 2008; Moulton and 

Holst, 2010). In most cases, the 

avoidance radii for delphinids appear to 

be small, on the order of one km or less, 

and some individuals show no apparent 

avoidance. 

Captive bottlenose dolphins exhibited 

changes in behavior when exposed to 

strong pulsed sounds similar in 

duration to those typically used in 

seismic surveys (Finneran et al., 2000, 

2002, 2005). However, the animals 

tolerated high received levels of sound 

(pk–pk level >200 dB re 1 mPa) before 

exhibiting aversive behaviors. 

Porpoises 

Results for porpoises depend upon 

the species. The limited available data 

suggest that harbor porpoises show 

stronger avoidance of seismic operations 

than do Dall’s porpoises (Stone, 2003; 

MacLean and Koski, 2005; Bain and 

Williams, 2006; Stone and Tasker, 

2006). Dall’s porpoises seem relatively 

tolerant of airgun operations (MacLean 

and Koski, 2005; Bain and Williams, 

2006), although they too have been 

observed to avoid large arrays of 

operating airguns (Calambokidis and 

Osmek, 1998; Bain and Williams, 2006). 

This apparent difference in 

responsiveness of these two porpoise 

species is consistent with their relative 

responsiveness to boat traffic and some 

other acoustic sources (Richardson et 

al., 1995; Southall et al., 2007). 

Pinnipeds 

Pinnipeds are not likely to show a 

strong avoidance reaction to the airgun 

sources proposed for use. Visual 

monitoring from seismic vessels has 

shown only slight (if any) avoidance of 

airguns by pinnipeds and only slight (if 

any) changes in behavior. Monitoring 

work in the Alaskan Beaufort Sea during 

1996–2001 provided considerable 

information regarding the behavior of 

Arctic ice seals exposed to seismic 

pulses (Harris et al., 2001; Moulton and 

Lawson, 2002). These seismic projects 

usually involved arrays of 6 to 16 

airguns with total volumes of 560 to 

1,500 in3. The combined results suggest 

that some seals avoid the immediate 

area around seismic vessels. In most 

survey years, ringed seal (Phoca 

hispida) sightings tended to be farther 

away from the seismic vessel when the 

airguns were operating than when they 

were not (Moulton and Lawson, 2002). 

However, these avoidance movements 

were relatively small, on the order of 

100 m (328 ft) to a few hundreds of 

meters, and many seals remained within 

100–200 m (328–656 ft) of the trackline 

as the operating airgun array passed by 

the animals. Seal sighting rates at the 

water surface were lower during airgun 

array operations than during no-airgun 

periods in each survey year except 1997. 

Similarly, seals are often very tolerant of 

pulsed sounds from seal-scaring devices 

(Mate and Harvey, 1987; Jefferson and 

Curry, 1994; Richardson et al., 1995). 

However, initial telemetry work 

suggests that avoidance and other 

behavioral reactions by two other 

species of seals to small airgun sources 

may at times be stronger than evident to 

date from visual studies of pinniped 

reactions to airguns (Thompson et al., 

1998). 

Hearing Impairment 

Exposure to high intensity sound for 

a sufficient duration may result in 

auditory effects such as a noise-induced 

threshold shift—an increase in the 

auditory threshold after exposure to 

noise (Finneran et al., 2005). Factors 

that influence the amount of threshold 

shift include the amplitude, duration, 

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frequency content, temporal pattern, 

and energy distribution of noise 

exposure. The magnitude of hearing 

threshold shift normally decreases over 

time following cessation of the noise 

exposure. The amount of threshold shift 

just after exposure is the initial 

threshold shift. If the threshold shift 

eventually returns to zero (i.e., the 

threshold returns to the pre-exposure 

value), it is a temporary threshold shift 

(Southall et al., 2007). 

Threshold Shift (noise-induced loss of 

hearing)—When animals exhibit 

reduced hearing sensitivity (i.e., sounds 

must be louder for an animal to detect 

them) following exposure to an intense 

sound or sound for long duration, it is 

referred to as a noise-induced threshold 

shift (TS). An animal can experience 

temporary threshold shift (TTS) or 

permanent threshold shift (PTS). TTS 

can last from minutes or hours to days 

(i.e., there is complete recovery), can 

occur in specific frequency ranges (i.e., 

an animal might only have a temporary 

loss of hearing sensitivity between the 

frequencies of 1 and 10 kHz), and can 

be of varying amounts (for example, an 

animal’s hearing sensitivity might be 

reduced initially by only 6 dB or 

reduced by 30 dB). PTS is permanent, 

but some recovery is possible. PTS can 

also occur in a specific frequency range 

and amount as mentioned above for 

TTS. 

The following physiological 

mechanisms are thought to play a role 

in inducing auditory TS: Effects to 

sensory hair cells in the inner ear that 

reduce their sensitivity, modification of 

the chemical environment within the 

sensory cells, residual muscular activity 

in the middle ear, displacement of 

certain inner ear membranes, increased 

blood flow, and post-stimulatory 

reduction in both efferent and sensory 

neural output (Southall et al., 2007). 

The amplitude, duration, frequency, 

temporal pattern, and energy 

distribution of sound exposure all can 

affect the amount of associated TS and 

the frequency range in which it occurs. 

As amplitude and duration of sound 

exposure increase, so, generally, does 

the amount of TS, along with the 

recovery time. For intermittent sounds, 

less TS could occur than compared to a 

continuous exposure with the same 

energy (some recovery could occur 

between intermittent exposures 

depending on the duty cycle between 

sounds) (Kryter et al., 1966; Ward, 

1997). For example, one short but loud 

(higher SPL) sound exposure may 

induce the same impairment as one 

longer but softer sound, which in turn 

may cause more impairment than a 

series of several intermittent softer 

sounds with the same total energy 

(Ward, 1997). Additionally, though TTS 

is temporary, prolonged exposure to 

sounds strong enough to elicit TTS, or 

shorter-term exposure to sound levels 

well above the TTS threshold, can cause 

PTS, at least in terrestrial mammals 

(Kryter, 1985). Although in the case of 

EMALL’s survey, NMFS does not expect 

that animals would experience levels 

high enough or durations long enough 

to result in PTS given that the airgun is 

a very low volume airgun, and the use 

of the airgun will be restricted to seven 

days in a small geographic area. 

PTS is considered auditory injury 

(Southall et al., 2007). Irreparable 

damage to the inner or outer cochlear 

hair cells may cause PTS; however, 

other mechanisms are also involved, 

such as exceeding the elastic limits of 

certain tissues and membranes in the 

middle and inner ears and resultant 

changes in the chemical composition of 

the inner ear fluids (Southall et al., 

2007). 

Although the published body of 

scientific literature contains numerous 

theoretical studies and discussion 

papers on hearing impairments that can 

occur with exposure to a loud sound, 

only a few studies provide empirical 

information on the levels at which 

noise-induced loss in hearing sensitivity 

occurs in non-human animals. 

Recent studies by Kujawa and 

Liberman (2009) and Lin et al. (2011) 

found that despite completely reversible 

threshold shifts that leave cochlear 

sensory cells intact, large threshold 

shifts could cause synaptic level 

changes and delayed cochlear nerve 

degeneration in mice and guinea pigs, 

respectively. NMFS notes that the high 

level of TTS that led to the synaptic 

changes shown in these studies is in the 

range of the high degree of TTS that 

Southall et al. (2007) used to calculate 

PTS levels. It is unknown whether 

smaller levels of TTS would lead to 

similar changes. NMFS, however, 

acknowledges the complexity of noise 

exposure on the nervous system, and 

will re-examine this issue as more data 

become available. 

For marine mammals, published data 

are limited to the captive bottlenose 

dolphin, beluga, harbor porpoise, and 

Yangtze finless porpoise (Finneran et 

al., 2000, 2002, 2003, 2005, 2007, 2010a, 

2010b; Finneran and Schlundt, 2010; 

Lucke et al., 2009; Mooney et al., 2009a, 

2009b; Popov et al., 2011a, 2011b; 

Kastelein et al., 2012a; Schlundt et al., 

2000; Nachtigall et al., 2003, 2004). For 

pinnipeds in water, data are limited to 

measurements of TTS in harbor seals, an 

elephant seal, and California sea lions 

(Kastak et al., 1999, 2005; Kastelein et 

al., 2012b). 

Lucke et al. (2009) found a threshold 

shift (TS) of a harbor porpoise after 

exposing it to airgun noise with a 

received sound pressure level (SPL) at 

200.2 dB (peak-to-peak) re: 1 mPa, which 

corresponds to a sound exposure level 

of 164.5 dB re: 1 mPa2 s after integrating 

exposure. NMFS currently uses the rootmean-square (rms) of received SPL at 

180 dB and 190 dB re: 1 mPa as the 

threshold above which permanent 

threshold shift (PTS) could occur for 

cetaceans and pinnipeds, respectively. 

Because the airgun noise is a broadband 

impulse, one cannot directly determine 

the equivalent of rms SPL from the 

reported peak-to-peak SPLs. However, 

applying a conservative conversion 

factor of 16 dB for broadband signals 

from seismic surveys (McCauley, et al., 

2000) to correct for the difference 

between peak-to-peak levels reported in 

Lucke et al. (2009) and rms SPLs, the 

rms SPL for TTS would be 

approximately 184 dB re: 1 mPa, and the 

received levels associated with PTS 

(Level A harassment) would be higher. 

This is still above NMFS’ current 180 

dB rms re: 1 mPa threshold for injury. 

However, NMFS recognizes that TTS of 

harbor porpoises is lower than other 

cetacean species empirically tested 

(Finneran & Schlundt, 2010; Finneran et 

al., 2002; Kastelein and Jennings, 2012). 

A recent study on bottlenose dolphins 

(Schlundt, et al., 2013) measured 

hearing thresholds at multiple 

frequencies to determine the amount of 

TTS induced before and after exposure 

to a sequence of impulses produced by 

a seismic air gun. The air gun volume 

and operating pressure varied from 40– 

150 in3 and 1000–2000 psi, respectively. 

After three years and 180 sessions, the 

authors observed no significant TTS at 

any test frequency, for any combinations 

of air gun volume, pressure, or 

proximity to the dolphin during 

behavioral tests (Schlundt, et al., 2013). 

Schlundt et al. (2013) suggest that the 

potential for airguns to cause hearing 

loss in dolphins is lower than 

previously predicted, perhaps as a result 

of the low-frequency content of air gun 

impulses compared to the highfrequency hearing ability of dolphins. 

Marine mammal hearing plays a 

critical role in communication with 

conspecifics, and interpretation of 

environmental cues for purposes such 

as predator avoidance and prey capture. 

Depending on the degree (elevation of 

threshold in dB), duration (i.e., recovery 

time), and frequency range of TTS, and 

the context in which it is experienced, 

TTS can have effects on marine 

mammals ranging from discountable to 

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serious (similar to those discussed in 

auditory masking, below). For example, 

a marine mammal may be able to readily 

compensate for a brief, relatively small 

amount of TTS in a non-critical 

frequency range that occurs during a 

time where ambient noise is lower and 

there are not as many competing sounds 

present. Alternatively, a larger amount 

and longer duration of TTS sustained 

during time when communication is 

critical for successful mother/calf 

interactions could have more serious 

impacts. Also, depending on the degree 

and frequency range, the effects of PTS 

on an animal could range in severity, 

although it is considered generally more 

serious because it is a permanent 

condition. Of note, reduced hearing 

sensitivity as a simple function of aging 

has been observed in marine mammals, 

as well as humans and other taxa 

(Southall et al., 2007), so one can infer 

that strategies exist for coping with this 

condition to some degree, though likely 

not without cost. 

Given the higher level of sound 

necessary to cause PTS as compared 

with TTS, it is considerably less likely 

that PTS would occur during the survey; 

TTS is also unlikely. Cetaceans 

generally avoid the immediate area 

around operating seismic vessels, as do 

some other marine mammals. Some 

pinnipeds show avoidance reactions to 

airguns, but their avoidance reactions 

are generally not as strong or consistent 

compared to cetacean reactions. 

Non-auditory Physical Effects: Nonauditory physical effects might occur in 

marine mammals exposed to strong 

underwater pulsed sound. Possible 

types of non-auditory physiological 

effects or injuries that theoretically 

might occur in mammals close to a 

strong sound source include stress, 

neurological effects, bubble formation, 

and other types of organ or tissue 

damage. Some marine mammal species 

(i.e., beaked whales) may be especially 

susceptible to injury and/or stranding 

when exposed to strong pulsed sounds. 

Classic stress responses begin when 

an animal’s central nervous system 

perceives a potential threat to its 

homeostasis. That perception triggers 

stress responses regardless of whether a 

stimulus actually threatens the animal; 

the mere perception of a threat is 

sufficient to trigger a stress response 

(Moberg, 2000; Sapolsky et al., 2005; 

Seyle, 1950). Once an animal’s central 

nervous system perceives a threat, it 

mounts a biological response or defense 

that consists of a combination of the 

four general biological defense 

responses: Behavioral responses; 

autonomic nervous system responses; 

neuroendocrine responses; or immune 

responses. 

In the case of many stressors, an 

animal’s first and most economical (in 

terms of biotic costs) response is 

behavioral avoidance of the potential 

stressor or avoidance of continued 

exposure to a stressor. An animal’s 

second line of defense to stressors 

involves the sympathetic part of the 

autonomic nervous system and the 

classical ‘‘fight or flight’’ response, 

which includes the cardiovascular 

system, the gastrointestinal system, the 

exocrine glands, and the adrenal 

medulla to produce changes in heart 

rate, blood pressure, and gastrointestinal 

activity that humans commonly 

associate with stress. These responses 

have a relatively short duration and may 

or may not have significant long-term 

effects on an animal’s welfare. 

An animal’s third line of defense to 

stressors involves its neuroendocrine or 

sympathetic nervous systems; the 

system that has received the most study 

has been the hypothalmus-pituitaryadrenal (HPA) system (also known as 

the HPA axis in mammals or the 

hypothalamus-pituitary-interrenal axis 

in fish and some reptiles). Unlike stress 

responses associated with the 

autonomic nervous system, the pituitary 

hormones regulate virtually all 

neuroendocrine functions affected by 

stress—including immune competence, 

reproduction, metabolism, and 

behavior. Stress-induced changes in the 

secretion of pituitary hormones have 

been implicated in failed reproduction 

(Moberg, 1987; Rivier, 1995), altered 

metabolism (Elasser et al., 2000), and 

reduced immune competence (Blecha, 

2000). Increases in the circulation of 

glucocorticosteroids (cortisol, 

corticosterone, and aldosterone in 

marine mammals; see Romano et al., 

2004) have been equated with stress for 

many years. 

The primary distinction between 

stress (which is adaptive and does not 

normally place an animal at risk) and 

distress is the biotic cost of the 

response. During a stress response, an 

animal uses glycogen stores that the 

body quickly replenishes after 

alleviation of the stressor. In such 

circumstances, the cost of the stress 

response would not pose a risk to the 

animal’s welfare. However, when an 

animal does not have sufficient energy 

reserves to satisfy the energetic costs of 

a stress response, it diverts energy 

resources from other biotic functions, 

which impair those functions that 

experience the diversion. For example, 

when mounting a stress response diverts 

energy away from growth in young 

animals, those animals may experience 

stunted growth (McEwen and Wingfield, 

2003). When mounting a stress response 

diverts energy from a fetus, an animal’s 

reproductive success and fitness will 

suffer. In these cases, the animals will 

have entered a pre-pathological or 

pathological state called ‘‘distress’’ 

(sensu Seyle, 1950) or ‘‘allostatic 

loading’’ (sensu McEwen and Wingfield, 

2003). This pathological state will last 

until the animal replenishes its biotic 

reserves sufficient to restore normal 

function. Note that these examples 

involved a long-term (days or weeks) 

stress response exposure to stimuli. 

Relationships between these 

physiological mechanisms, animal 

behavior, and the costs of stress 

responses have also been documented 

fairly well through controlled 

experiment; because this physiology 

exists in every vertebrate that has been 

studied, it is not surprising that stress 

responses and their costs have been 

documented in both laboratory and freeliving animals (for examples see, 

Holberton et al., 1996; Hood et al., 1998; 

Jessop et al., 2003; Krausman et al., 

2004; Lankford et al., 2005; Reneerkens 

et al., 2002; Thompson and Hamer, 

2000). Although no information has 

been collected on the physiological 

responses of marine mammals to 

anthropogenic sound exposure, studies 

of other marine animals and terrestrial 

animals would lead us to expect some 

marine mammals to experience 

physiological stress responses and, 

perhaps, physiological responses that 

would be classified as ‘‘distress’’ upon 

exposure to anthropogenic sounds. 

For example, Jansen (1998) reported 

on the relationship between acoustic 

exposures and physiological responses 

that are indicative of stress responses in 

humans (e.g., elevated respiration and 

increased heart rates). Jones (1998) 

reported on reductions in human 

performance when faced with acute, 

repetitive exposures to acoustic 

disturbance. Trimper et al. (1998) 

reported on the physiological stress 

responses of osprey to low-level aircraft 

noise while Krausman et al. (2004) 

reported on the auditory and physiology 

stress responses of endangered Sonoran 

pronghorn to military overflights. Smith 

et al. (2004a, 2004b) identified noiseinduced physiological transient stress 

responses in hearing-specialist fish (i.e., 

goldfish) that accompanied short- and 

long-term hearing losses. Welch and 

Welch (1970) reported physiological 

and behavioral stress responses that 

accompanied damage to the inner ears 

of fish and several mammals. 

Hearing is one of the primary senses 

marine mammals use to gather 

information about their environment 

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and communicate with conspecifics. 

Although empirical information on the 

relationship between sensory 

impairment (TTS, PTS, and acoustic 

masking) on marine mammals remains 

limited, we assume that reducing a 

marine mammal’s ability to gather 

information about its environment and 

communicate with other members of its 

species would induce stress, based on 

data that terrestrial animals exhibit 

those responses under similar 

conditions (NRC, 2003) and because 

marine mammals use hearing as their 

primary sensory mechanism. Therefore, 

NMFS assumes that acoustic exposures 

sufficient to trigger onset PTS or TTS 

would be accompanied by physiological 

stress responses. More importantly, 

marine mammals might experience 

stress responses at received levels lower 

than those necessary to trigger onset 

TTS. Based on empirical studies of the 

time required to recover from stress 

responses (Moberg, 2000), NMFS also 

assumes that stress responses could 

persist beyond the time interval 

required for animals to recover from 

TTS and might result in pathological 

and pre-pathological states that would 

be as significant as behavioral responses 

to TTS. 

Resonance effects (Gentry, 2002) and 

direct noise-induced bubble formations 

(Crum et al., 2005) are implausible in 

the case of exposure to an impulsive 

broadband source like an airgun array. 

If seismic surveys disrupt diving 

patterns of deep-diving species, this 

might result in bubble formation and a 

form of the bends, as speculated to 

occur in beaked whales exposed to 

sonar. However, there is no specific 

evidence of this upon exposure to 

airgun pulses. 

In general, there are few data about 

the potential for strong, anthropogenic 

underwater sounds to cause nonauditory physical effects in marine 

mammals. Such effects, if they occur at 

all, would presumably be limited to 

short distances and to activities that 

extend over a prolonged period. The 

available data do not allow 

identification of a specific exposure 

level above which non-auditory effects 

can be expected (Southall et al., 2007) 

or any meaningful quantitative 

predictions of the numbers (if any) of 

marine mammals that might be affected 

in those ways. There is no definitive 

evidence that any of these effects occur 

even for marine mammals in close 

proximity to large arrays of airguns. In 

addition, marine mammals that show 

behavioral avoidance of seismic vessels, 

including some pinnipeds, are unlikely 

to incur non-auditory impairment or 

other physical effects. The low volume 

of the airgun proposed for this activity 

combined with the limited scope of use 

makes non-auditory physical effects 

from airgun use, including stress, 

unlikely. Therefore, we do not 

anticipate such effects would occur 

given the brief duration of exposure 

during the survey. 

Stranding and Mortality 

When a living or dead marine 

mammal swims or floats onto shore and 

becomes ‘‘beached’’ or incapable of 

returning to sea, the event is a 

‘‘stranding’’ (Geraci et al., 1999; Perrin 

and Geraci, 2002; Geraci and 

Lounsbury, 2005; NMFS, 2007). The 

legal definition for a stranding under the 

MMPA is that ‘‘(A) a marine mammal is 

dead and is (i) on a beach or shore of 

the United States; or (ii) in waters under 

the jurisdiction of the United States 

(including any navigable waters); or (B) 

a marine mammal is alive and is (i) on 

a beach or shore of the United States 

and is unable to return to the water; (ii) 

on a beach or shore of the United States 

and, although able to return to the 

water, is in need of apparent medical 

attention; or (iii) in the waters under the 

jurisdiction of the United States 

(including any navigable waters), but is 

unable to return to its natural habitat 

under its own power or without 

assistance.’’ 

Marine mammals strand for a variety 

of reasons, such as infectious agents, 

biotoxicosis, starvation, fishery 

interaction, ship strike, unusual 

oceanographic or weather events, sound 

exposure, or combinations of these 

stressors sustained concurrently or in 

series. However, the cause or causes of 

most strandings are unknown (Geraci et 

al., 1976; Eaton, 1979; Odell et al., 1980; 

Best, 1982). Numerous studies suggest 

that the physiology, behavior, habitat 

relationships, age, or condition of 

cetaceans may cause them to strand or 

might pre-dispose them to strand when 

exposed to another phenomenon. These 

suggestions are consistent with the 

conclusions of numerous other studies 

that have demonstrated that 

combinations of dissimilar stressors 

commonly combine to kill an animal or 

dramatically reduce its fitness, even 

though one exposure without the other 

does not produce the same result 

(Chroussos, 2000; Creel, 2005; DeVries 

et al., 2003; Fair and Becker, 2000; Foley 

et al., 2001; Moberg, 2000; Relyea, 

2005a; 2005b, Romero, 2004; Sih et al., 

2004). Given the low volume and source 

level of the proposed airgun, standing 

and mortality are not anticipated due to 

use of the airgun proposed for this 

activity. 

2. Potential Effects of Other Acoustic 

Devices 

Sub-Bottom Profiler 

EMALL would also operate a subbottom profiler chirp and boomer from 

the source vessel during the proposed 

survey. The chirp’s sounds are very 

short pulses, occurring for one ms, six 

times per second. Most of the energy in 

the sound pulses emitted by the profiler 

is at 2–6 kHz, and the beam is directed 

downward. The chirp has a maximum 

source level of 202 dB re: 1 mPa, with 

a tilt angle of 90 degrees below 

horizontal and a beam width of 24 

degrees. The sub-bottom profiler boomer 

will shoot approximately every 3.125 m, 

with shots lasting 1.5 to 2 seconds. Most 

of the energy in the sound pulses 

emitted by the boomer is concentrated 

between 0.5 and 6 kHz, with a source 

level of 205 dB re: 1 mPa. The tilt of the 

boomer is 90 degrees below horizontal, 

but the emission is omnidirectional. 

Kremser et al. (2005) noted that the 

probability of a cetacean swimming 

through the area of exposure when a 

bottom profiler emits a pulse is small— 

because if the animal was in the area, it 

would have to pass the transducer at 

close range in order to be subjected to 

sound levels that could cause temporary 

threshold shift and would likely exhibit 

avoidance behavior to the area near the 

transducer rather than swim through at 

such a close range. 

Masking: Both the chirper and boomer 

sub-bottom profilers produce impulsive 

sound exceeding 160 dB re: 1 mPa-m 

(rms). The louder boomer operates at a 

source value of 205 dB re: 1 mPa-m 

(rms), but with a frequency between 0.5 

and 6 kHz, which is lower than the 

maximum sensitivity hearing range of 

any the local species (belugas—40–130 

kHz;, killer whales—7–30 kHz; harbor 

porpoise—100–140 kHz; and harbor 

seals—10–30 kHz; Wartzok and Ketten 

1999, Southall et al. 2007, Kastelein et 

al. 2002). While the chirper is not as 

loud (202 dB re 1 mPa-m [rms]), it does 

operate at a higher frequency range (2– 

16 kHz), and within the maximum 

sensitive range of all of the local species 

except beluga whales. 

Marine mammal communications 

would not likely be masked appreciably 

by the profiler’s signals given the 

directionality of the signal and the brief 

period when an individual mammal is 

likely to be within its beam. 

Furthermore, despite the fact that the 

profiler overlaps with hearing ranges of 

many marine mammal species in the 

area, the profiler’s signals do not 

overlap with the predominant 

frequencies in the calls, which would 

avoid significant masking. 

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Behavioral Responses: Responses to 

the profiler are likely to be similar to the 

other pulsed sources discussed earlier if 

received at the same levels. The 

behavioral response of local marine 

mammals to the operation of the subbottom profilers is expected to be 

similar to that of the small airgun. The 

odontocetes are likely to avoid the subbottom profiler activity, especially the 

naturally shy harbor porpoise, while the 

harbor seals might be attracted to them 

out of curiosity. However, because the 

sub-bottom profilers operate from a 

moving vessel, and the maximum radius 

to the 160 dB harassment threshold is 

only 263 m (863 ft), the area and time 

that this equipment would be affecting 

a given location is very small. 

Hearing Impairment and Other 

Physical Effects: It is unlikely that the 

sub-bottom profilers produce sound 

levels strong enough to cause hearing 

impairment or other physical injuries 

even in an animal that is (briefly) in a 

position near the source (Wood et al. 

2012). The likelihood of marine 

mammals moving away from the source 

make if further unlikely that a marine 

mammal would be able to approach 

close to the transducers. 

Animals may avoid the area around 

the survey vessels, thereby reducing 

exposure. Any disturbance to marine 

mammals is likely to be in the form of 

temporary avoidance or alteration of 

opportunistic foraging behavior near the 

survey location. 

Vibracore 

EMALL would conduct vibracoring in 

a portion of Cook Inlet for a total of 120 

vibracoring occurrences. While duration 

is dependent on sediment type, the 

driving mechanism, which emits sound 

at a source level of 187dB re: 1 mPa, will 

only bore for 1 to 2 minutes. The sound 

is emitted at a frequency of 10 Hz to 20 

kHz. 

Masking: It is unlikely that masking 

will occur due to vibracore operations. 

Chorney et al. (2011) conducted sound 

measurements on an operating 

vibracorer in Alaska and found that it 

emitted a sound pressure level at 1-m 

source of 188 dB re 1 mPa-m (rms), with 

a frequency range of between 10 Hz and 

20 kHz. While the frequency range 

overlaps the lower ends of the 

maximum sensitivity hearing ranges of 

harbor porpoises, killer whales, and 

harbor seals, and the continuous sound 

extends 2.54 km (1.6 mi) to the 120 dB 

threshold, the vibracorer will operate 

about the one or two minutes it takes to 

drive the core pipe 7 m (20 ft) into the 

sediment, and approximately twice per 

day. Therefore, there is very little 

opportunity for this activity to mask the 

communication of local marine 

mammals. 

Behavioral Response: It is unlikely 

that vibracoring will elicit behavioral 

responses that rise to the level of a take 

from marine mammal species in the 

area. A review of similar survey activity 

in New Zealand by their Department of 

Conservation classified the likely effects 

from vibracore and similar activity to be 

some habitat degradation and prey 

species effects, but primarily behavioral 

responses, although the species in the 

analyzed area were different to those 

found in Cook Inlet (Thompson, 2012). 

The category of behavioral responses 

covered a suite of behaviors including 

altered respiration and dive patterns, 

disruption of foraging or nursing, and 

temporary displacement from particular 

habitats. 

There are no data on the behavioral 

response to vibracore activity of marine 

mammals in Cook Inlet. The closest 

analog to vibracoring might be 

exploratory drilling, although there is a 

notable difference in magnitude 

between an oil and gas drilling 

operation and collecting sediment 

samples with a vibracorer. Thomas et al. 

(1990) played back drilling sound to 

four captive beluga whales and found 

no statistical difference in swim 

patterns, social groups, respiration and 

dive rates, or stress hormone levels 

before and during playbacks. There is 

no reason to believe that beluga whales 

or any other marine mammal exposed to 

vibracoring sound would behave any 

differently, especially since vibracoring 

occurs for only one or two minutes. 

Hearing Impairment and Other 

Physical Effects: The vibracorer operates 

for only one or two minutes at a time 

with a 1-m source of 187.4 dB re 1 mPam (rms). It is neither loud enough nor 

does it operate for a long enough 

duration to induce either TTS or PTS. 

Stranding and Mortality 

Stress, Stranding, and Mortality 

Safety zones will be established to 

prevent acoustical injury to local marine 

mammals, especially injury that could 

indirectly lead to mortality. Also, G&G 

sound is not expected to cause resonate 

effects to gas-filled spaces or airspaces 

in marine mammals based on the 

research of Finneran (2003) on beluga 

whales showing that the tissue and 

other body masses dampen any 

potential effects of resonance on ear 

cavities, lungs, and intestines. Chronic 

exposure to sound could lead to 

physiological stress eventually causing 

hormonal imbalances (NRC 2005). If 

survival demands are already high, and/ 

or additional stressors are present, the 

ability of the animal to cope decreases, 

leading to pathological conditions or 

death (NRC 2005). Potential effects may 

be greatest where sound disturbance can 

disrupt feeding patterns including 

displacement from critical feeding 

grounds. However, all G&G exposure to 

marine mammals would be of duration 

measured in minutes. 

Specific sound-related processes that 

lead to strandings and mortality are not 

well documented, but may include (1) 

swimming in avoidance of a sound into 

shallow water; (2) a change in behavior 

(such as a change in diving behavior) 

that might contribute to tissue damage, 

gas bubble formation, hypoxia, cardiac 

arrhythmia, hypertensive hemorrhage, 

or other forms of trauma; (3) a 

physiological change such as a 

vestibular response leading to a 

behavioral change or stress-induced 

hemorrhagic diathesis, leading in turn 

to tissue damage; and, (4) tissue damage 

directly from sound exposure, such as 

through acoustically mediated bubble 

formation and growth or acoustic 

resonance of tissues (Wood et al. 2012). 

Some of these mechanisms are unlikely 

to apply in the case of impulse G&G 

sounds, especially since airguns and 

sub-bottom profilers produce broadband 

sound with low pressure rise. 

Strandings to date which have been 

attributed to sound exposure related to 

date from military exercises using 

narrowband mid-frequency sonar with a 

much greater likelihood to cause 

physical damage (Balcomb and Claridge 

2001, NOAA and USN, 2001, 

Hildebrand 2005). 

The low intensity, low frequency, 

broadband sound associated with 

airguns and sub-bottom profilers, 

combined with the shutdown safety 

zone mitigation measure for the airgun 

would prevent physical damage to 

marine mammals. The vibracoring 

would also be unlikely to have the 

capability of causing physical damage to 

marine mammals because of its low 

intensity and short duration. 

3. Potential Effects of Vessel Movement 

and Collisions 

Vessel movement in the vicinity of 

marine mammals has the potential to 

result in either a behavioral response or 

a direct physical interaction. We discuss 

both scenarios here. 

Behavioral Responses to Vessel 

Movement: There are limited data 

concerning marine mammal behavioral 

responses to vessel traffic and vessel 

noise, and a lack of consensus among 

scientists with respect to what these 

responses mean or whether they result 

in short-term or long-term adverse 

effects. In those cases where there is a 

busy shipping lane or where there is a 

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large amount of vessel traffic, marine 

mammals may experience acoustic 

masking (Hildebrand, 2005) if they are 

present in the area (e.g., killer whales in 

Puget Sound; Foote et al., 2004; Holt et 

al., 2008). In cases where vessels 

actively approach marine mammals 

(e.g., whale watching or dolphin 

watching boats), scientists have 

documented that animals exhibit altered 

behavior such as increased swimming 

speed, erratic movement, and active 

avoidance behavior (Bursk, 1983; 

Acevedo, 1991; Baker and MacGibbon, 

1991; Trites and Bain, 2000; Williams et 

al., 2002; Constantine et al., 2003), 

reduced blow interval (Ritcher et al., 

2003), disruption of normal social 

behaviors (Lusseau, 2003; 2006), and the 

shift of behavioral activities which may 

increase energetic costs (Constantine et 

al., 2003; 2004). A detailed review of 

marine mammal reactions to ships and 

boats is available in Richardson et al. 

(1995). For each of the marine mammal 

taxonomy groups, Richardson et al. 

(1995) provides the following 

assessment regarding reactions to vessel 

traffic: 

Pinnipeds: Reactions by pinnipeds to 

vessel disturbance largely involve 

relocation. Harbor seals hauled out on 

mud flats have been documented 

returning to the water in response to 

nearing boat traffic. Vessels that 

approach haulouts slowly may also 

elicit alert reactions without flushing 

from the haulout. Small boats with 

slow, constant speed elicit the least 

noticeable reactions. However, in 

Alaska specifically, harbor seals are 

documented to tolerate fishing vessels 

with no discernable reactions, and 

habituation is common (Burns in 

Johnson et al., 1989). 

Porpoises: Harbor porpoises are often 

seen changing direction in the presence 

of vessel traffic. Avoidance has been 

documented up to 1km away from an 

approaching vessel, but the avoidance 

response is strengthened in closer 

proximity to vessels (Barlow, 1998; 

Palka, 1993). This avoidance behavior is 

not consistent across all porpoises, as 

Dall’s porpoises have been observed 

approaching boats. 

Toothed whales: In summary, toothed 

whales sometimes show no avoidance 

reaction to vessels, or even approach 

them. However, avoidance can occur, 

especially in response to vessels of 

types used to chase or hunt the animals. 

This may cause temporary 

displacement, but we know of no clear 

evidence that toothed whales have 

abandoned significant parts of their 

range because of vessel traffic. 

Behavioral responses to stimuli are 

complex and influenced to varying 

degrees by a number of factors, such as 

species, behavioral contexts, 

geographical regions, source 

characteristics (moving or stationary, 

speed, direction, etc.), prior experience 

of the animal and physical status of the 

animal. For example, studies have 

shown that beluga whales’ reactions 

varied when exposed to vessel noise 

and traffic. In some cases, naive beluga 

whales exhibited rapid swimming from 

ice-breaking vessels up to 80 km (49.7 

mi) away, and showed changes in 

surfacing, breathing, diving, and group 

composition in the Canadian high 

Arctic where vessel traffic is rare (Finley 

et al., 1990). In other cases, beluga 

whales were more tolerant of vessels, 

but responded differentially to certain 

vessels and operating characteristics by 

reducing their calling rates (especially 

older animals) in the St. Lawrence River 

where vessel traffic is common (Blane 

and Jaakson, 1994). In Bristol Bay, 

Alaska, beluga whales continued to feed 

when surrounded by fishing vessels and 

resisted dispersal even when 

purposefully harassed (Fish and Vania, 

1971). 

In reviewing more than 25 years of 

whale observation data, Watkins (1986) 

concluded that whale reactions to vessel 

traffic were ‘‘modified by their previous 

experience and current activity: 

Habituation often occurred rapidly, 

attention to other stimuli or 

preoccupation with other activities 

sometimes overcame their interest or 

wariness of stimuli.’’ Watkins noticed 

that over the years of exposure to ships 

in the Cape Cod area, minke whales 

changed from frequent positive interest 

(e.g., approaching vessels) to generally 

uninterested reactions; fin whales 

changed from mostly negative (e.g., 

avoidance) to uninterested reactions; 

right whales apparently continued the 

same variety of responses (negative, 

uninterested, and positive responses) 

with little change; and humpbacks 

dramatically changed from mixed 

responses that were often negative to 

reactions that were often strongly 

positive. Watkins (1986) summarized 

that ‘‘whales near shore, even in regions 

with low vessel traffic, generally have 

become less wary of boats and their 

noises, and they have appeared to be 

less easily disturbed than previously. In 

particular locations with intense 

shipping and repeated approaches by 

boats (such as the whale-watching areas 

of Stellwagen Bank), more and more 

whales had positive reactions to familiar 

vessels, and they also occasionally 

approached other boats and yachts in 

the same ways.’’ 

Vessel Strike 

Ship strikes of cetaceans can cause 

major wounds, which may lead to the 

death of the animal. An animal at the 

surface could be struck directly by a 

vessel, a surfacing animal could hit the 

bottom of a vessel, or a vessel’s 

propeller could injure an animal just 

below the surface. The severity of 

injuries typically depends on the size 

and speed of the vessel (Knowlton and 

Kraus, 2001; Laist et al., 2001; 

Vanderlaan and Taggart, 2007). 

The most vulnerable marine mammals 

are those that spend extended periods of 

time at the surface in order to restore 

oxygen levels within their tissues after 

deep dives (e.g., the sperm whale). In 

addition, some baleen whales, such as 

the North Atlantic right whale, seem 

generally unresponsive to vessel sound, 

making them more susceptible to vessel 

collisions (Nowacek et al., 2004). These 

species are primarily large, slow moving 

whales. Smaller marine mammals (e.g., 

bottlenose dolphin) move quickly 

through the water column and are often 

seen riding the bow wave of large ships. 

Marine mammal responses to vessels 

may include avoidance and changes in 

dive pattern (NRC, 2003). 

An examination of all known ship 

strikes from all shipping sources 

(civilian and military) indicates vessel 

speed is a principal factor in whether a 

vessel strike results in death (Knowlton 

and Kraus, 2001; Laist et al., 2001; 

Jensen and Silber, 2003; Vanderlaan and 

Taggart, 2007). In assessing records with 

known vessel speeds, Laist et al. (2001) 

found a direct relationship between the 

occurrence of a whale strike and the 

speed of the vessel involved in the 

collision. The authors concluded that 

most deaths occurred when a vessel was 

traveling in excess of 24.1 km/h (14.9 

mph; 13 kts). Given the slow vessel 

speeds necessary for data acquisition, 

ship strike is unlikely to occur during 

this survey. 

Entanglement 

Entanglement can occur if wildlife 

becomes immobilized in survey lines, 

cables, nets, or other equipment that is 

moving through the water column. The 

proposed survey would require towing 

approximately 150 ft of cables. This size 

of the array generally carries a lower 

risk of entanglement for marine 

mammals. Wildlife, especially slow 

moving individuals, such as large 

whales, have a low probability of 

entanglement due to the low amount of 

slack in the lines, slow speed of the 

survey vessel, and onboard monitoring. 

Pinnipeds and porpoises are the least 

likely to entangle in equipment, as most 

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documented cases of entanglement 

involve fishing gear and prey species 

(Gales et al., 2003). There are no 

reported cases of entanglement from 

geophysical equipment in the Cook Inlet 

area. 

Anticipated Effects on Marine Mammal 

Habitat 

The G&G Program survey areas are 

within upper Cook Inlet, primarily 

north of the Forelands although the 

Marine Terminal survey area is located 

near Nikiski just south of the East 

Foreland, which includes habitat for 

prey species of marine mammals, 

including fish as well as invertebrates 

eaten by Cook Inlet beluga whales. This 

area contains Critical Habitat for Cook 

Inlet belugas, is near the breeding 

grounds for the local harbor seal 

population, and serves as an occasional 

feeding ground for killer whales and 

harbor porpoises. Cook Inlet is a large 

subarctic estuary roughly 299 km (186 

mi) in length and averaging 96 km (60 

mi) in width. It extends from the city of 

Anchorage at its northern end and flows 

into the Gulf of Alaska at its 

southernmost end. For descriptive 

purposes, Cook Inlet is separated into 

unique upper and lower sections, 

divided at the East and West Forelands, 

where the opposing peninsulas create a 

natural waistline in the length of the 

waterway, measuring approximately 16 

km (10 mi) across (Mulherin et al., 

2001). 

Potential effects on beluga habitat 

would be limited to noise effects on 

prey; direct impact to benthic habitat 

from jack-up platform leg placement, 

and sampling with grabs, coring, and 

boring; and small discharges of drill 

cuttings and drilling mud associated 

with the borings. Portions of the survey 

areas include waters of Cook Inlet that 

are <9.1 m (30 ft) in depth and within 

8.0 km (5.0 mi) of anadromous streams. 

Several anadromous streams (Threemile Creek, Indian Creek, and two 

unnamed streams) enter the Cook Inlet 

within the survey areas. Other 

anadromous streams are located within 

8.0 km (5.0 mi) of the survey areas. The 

survey program will not prevent beluga 

access to the mouths of these streams 

and will result in no short-term or longterm loss of intertidal or subtidal waters 

that are <9.1 m (30 ft) in depth and 

within 8.0 km (5.0 mi) of anadromous 

streams. Minor seafloor impacts will 

occur in these areas from grab samples, 

PCPTs, vibracores, or geotechnical 

borings but will have no effect on the 

area as beluga habitat once the vessel or 

jack-up platform has left. The survey 

program will have no effect on this 

habitat. 

Cook Inlet beluga whales may avoid 

areas ensonified by the geophysical or 

geotechnical activities that generate 

sound with frequencies within the 

beluga hearing range and at levels above 

threshold values. This includes the 

chirp sub-bottom profiler with a radius 

of 631 m, the boomer sub-bottom 

profiler with a radius of 1 km, the 

airgun with a radius of 300 m and the 

vibracore with a radius of 6.2 m. The 

sub-bottom profilers and the airgun will 

be operated from a vessel moving at 

speeds of about 4 kt. The chirp may also 

be operated concurrently with an 

airgun. The airgun may also be used as 

a stationary source in the Marine 

Facilities area. The operation of a 

vibracore has a duration of 

approximately 1–2 minutes. All of these 

activities will be conducted in relatively 

open areas of the Cook Inlet within 

Critical Habitat Area 2. Given the size 

and openness of the Cook Inlet in the 

survey areas, and the relatively small 

area and mobile/temporary nature of the 

zones of ensonification, the generation 

of sound by the G&G activities is not 

expected to result in any restriction of 

passage of belugas within or between 

critical habitat areas. The jack-up 

platform from which the geotechnical 

borings will be conducted will be 

attached to the seafloor with legs, and 

will be in place at a given location for 

up to 4–5 days, but given its small size 

(Table 4 in the application) would not 

result in any obstruction of passage by 

belugas. 

Upper Cook Inlet comprises the area 

between Point Campbell (Anchorage) 

down to the Forelands, and is roughly 

95 km (59 mi) in length and 24.9 km 

(15.5 mi) in width (Mulherin et al., 

2001). Five major rivers (Knik, 

Matanuska, Susitna, Little Susitna, and 

Beluga) deliver freshwater to upper 

Cook Inlet, carrying a heavy annual 

sediment load of over 40 million tons of 

eroded materials and glacial silt (Brabets 

1999). As a result, upper Cook Inlet is 

relatively shallow, averaging 18.3 m (60 

ft) in depth. It is characterized by 

shoals, mudflats, and a wide coastal 

shelf, less than 17.9 m (59 ft) deep, 

extending from the eastern shore. A 

deep trough exists between Trading Bay 

and the Middle Ground Shoal, ranging 

from 35 to 77 m (114–253 ft) deep 

(NOAA Nautical Chart 16660). The 

substrate consists of a mixture of coarse 

gravels, cobbles, pebbles, sand, clay, 

and silt (Bouma et al. 1978, Rappeport 

1982). 

Upper Cook Inlet experiences some of 

the most extreme tides in the world, 

demonstrated by a mean tidal range 

from 4.0 m (13 ft) at the Gulf of Alaska 

end to 8.8 m (29 ft) near Anchorage 

(U.S. Army Corps of Engineers 2013). 

Tidal currents reach 3.9 kts per second 

(Mulherin et al., 2001) in upper Cook 

Inlet, increasing to 5.7–7.7 kts per 

second near the Forelands where the 

inlet is constricted. Each tidal cycle 

creates significant turbulence and 

vertical mixing of the water column in 

the upper inlet (U.S. Army Corps of 

Engineers 2013), and are reversing, 

meaning that they are marked by a 

period of slack tide followed an 

acceleration in the opposite direction 

(Mulherin et al,. 2001). 

Because of scouring, mixing, and 

sediment transport from these currents, 

the marine invertebrate community is 

very limited (Pentec 2005). Of the 50 

stations sampled by Saupe et al. 2005 

for marine invertebrates in Southcentral 

Alaska, their upper Cook Inlet station 

had by far the lowest abundance and 

diversity. Further, the fish community 

of upper Cook Inlet is characterized 

largely by migratory fish—eulachon and 

Pacific salmon—returning to spawning 

rivers, or outmigrating salmon smolts. 

Moulton (1997) documented only 18 

fish species in upper Cook Inlet 

compared to at least 50 species found in 

lower Cook Inlet (Robards et al. 1999). 

Lower Cook Inlet extends from the 

Forelands southwest to the inlet mouth 

demarked by an approximate line 

between Cape Douglas and English Bay. 

Water circulation in lower Cook Inlet is 

dominated by the Alaska Coastal 

Current (ACC) that flows northward 

along the shores of the Kenai Peninsula 

until it turns westward and is mixed by 

the combined influences of freshwater 

input from upper Cook Inlet, wind, 

topography, tidal surges, and the 

coriolis effect (Field and Walker 2003, 

MMS 1996). Upwelling by the ACC 

brings nutrient-rich waters to lower 

Cook Inlet and contributes to a 

biologically rich and productive ecology 

(Sambrotto and Lorenzen 1986). Tidal 

currents average 2–3 kt per second and 

are rotary in that they do not completely 

go slack before rotating around into an 

opposite direction (Gatto 1976, 

Mulherin et al. 2001). Depths in the 

central portion of lower Cook Inlet are 

60–80 m (197–262 ft) and decrease 

steadily toward the shores (Muench 

1981). Bottom sediments in the lower 

inlet are coarse gravel and sand that 

grade to finer sand and mud toward the 

south (Bouma 1978). 

Coarser substrate support a wide 

variety of invertebrates and fish 

including Pacific halibut, Dungeness 

crab, tanner crab, pandalid shrimp, 

Pacific cod, and rock sole, while the 

soft-bottom sand and silt communities 

are dominated by polychaetes, bivalves 

and other flatfish (Field and Walker 

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2003). These species constitute prey 

species for several marine mammals in 

Cook Inlet, including pinnipeds and 

Cook Inlet belugas. Sea urchins and sea 

cucumbers are important otter prey and 

are found in shell debris communities. 

Razor clams are found all along the 

beaches of the Kenai Peninsula. In 

general, the lower Cook Inlet marine 

invertebrate community is of low 

abundance, dominated by polychaetes, 

until reaching the mouth of the inlet 

(Saupe et al. 2005). Overall, the lower 

Cook Inlet marine ecosystem is fed by 

midwater communities of 

phytoplankton and zooplankton, with 

the latter composed mostly of copepods 

and barnacle and crab larvae (Damkaer 

1977, English 1980). 

G&G Program activities that could 

potentially impact marine mammal 

habitats include sediment sampling 

(vibracore, boring, grab sampling) on the 

sea bottom, placement of the jack-up 

platform spud cans, and acoustical 

injury of prey resources. However, there 

are few benthic resources in the survey 

area that could be impacted by 

collection of the small samples (Saupe 

et al. 2005). These activities are 

temporary in nature and for short 

durations. 

Acoustical effects to marine mammal 

prey resources are also limited. 

Christian et al. (2004) studied seismic 

energy impacts on male snow crabs and 

found no significant increases in 

physiological stress due to exposure to 

high sound pressure levels. No 

acoustical impact studies have been 

conducted to date on the above fish 

species, but studies have been 

conducted on Atlantic cod and sardine. 

Davis et al. (1998) cited various studies 

that found no effects to Atlantic cod 

eggs, larvae, and fry when received 

levels were 222 dB. Effects found were 

to larval fish within about 5.0 m (16 ft), 

and from air guns with volumes 

between 49,661 and 65,548 cm3 (3,000 

and 4,000 in3). Similarly, effects to 

sardine were greatest on eggs and 2-day 

larvae, but these effects were greatest at 

0.5 m (1.6 ft), and again confined to 5.0 

m (16 ft). Further, Greenlaw et al. (1988) 

found no evidence of gross histological 

damage to eggs and larvae of northern 

anchovy exposed to seismic air guns, 

and concluded that noticeable effects 

would result only from multiple, close 

exposures. Based on these results, much 

lower energy impulsive geophysical 

equipment planned for this program 

would not damage larval fish or any 

other marine mammal prey resource. 

Potential damage to the Cook Inlet 

benthic community will be limited to 

the actual surface area of the four spud 

cans that form the ‘‘foot’’ of each 0.762- 

m (30-in) diameter leg, the 42 0.1524-m 

(6-in) diameter borings, and the 55 

0.0762-m (3-in) diameter vibracore 

samplings (plus several grab and PCPT 

samples). Collectively, these samples 

would temporarily damage about a 

hundred square meters of benthic 

habitat relative to the size (nearly 21,000 

km2/8,108 mi2) of Cook Inlet. Overall, 

sediment sampling and acoustical 

effects on prey resources will have a 

negligible effect at most on the marine 

mammal habitat within the G&G 

Program survey area. Some prey 

resources might be temporarily 

displaced, but no long-term effects are 

expected. 

The Cook Inlet 2015 G&G Program 

will result in a number of minor 

discharges to the waters of Cook Inlet. 

Discharges associated with the 

geotechnical borings will include: (1) 

The discharge of drill cuttings and 

drilling fluids and (2) the discharge of 

deck drainage (runoff of precipitation 

and deck wash water) from the 

geotechnical drilling platform. Other 

vessels associated with the G&G surveys 

will discharge wastewaters that are 

normally associated with the operation 

of vessels in transit including deck 

drainage, ballast water, bilge water, noncontact cooling water, and gray water. 

The discharges of drill cuttings, 

drilling fluids, and deck drainage 

associated with the geotechnical borings 

will be within limitations authorized by 

the Alaska Department of 

Environmental Conservation under the 

Alaska Pollutant Discharge Elimination 

System. The drill cuttings consist of 

natural geologic materials of the seafloor 

sediments brought to the surface via the 

drill bit/drill stem of the rotary drilling 

operation, will be relatively minor in 

volume, and deposit over a very small 

area of Cook Inlet seafloor. The drilling 

fluids which are used to lubricate the 

bit, stabilize the hole, and viscosify the 

slurry for transport of the solids to the 

surface will consist of seawater and guar 

gum. Guar gum is a high-molecular 

weight polysaccharide (galactose and 

mannose units) derived from the ground 

seeds of the plant Cyampsis gonolobus. 

It is a non-toxic fluid also used as a food 

additive in soups, drinks, breads, and 

meat products. 

Vessel discharges will be authorized 

under the U.S. Environmental 

Protection Agency’s (EPA’s) National 

Pollutant Discharge Elimination System 

(NPDES) Vessel General Permit (VGP) 

for Discharges Incidental to the Normal 

Operation of Vessels. Each vessel will 

have obtained authorization under the 

VGP and will discharge according to the 

conditions and limitations mandated by 

the permit. As required by statute and 

regulation, the EPA has made a 

determination that such discharges will 

not result in any unreasonable 

degradation of the marine environment, 

including: 

• Significant adverse changes in 

ecosystem diversity, productivity and 

stability of the biological community 

within the area of discharge and 

surrounding biological communities, 

• Threat to human health through 

direct exposure to pollutants or through 

consumption of exposed aquatic 

organisms, or 

• Loss of aesthetic, recreational, 

scientific or economic values which is 

unreasonable in relation to the benefit 

derived from the discharge. 

Proposed Mitigation 

In order to issue an incidental take 

authorization 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 adverse 

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 

(where relevant). 

EMALL has proposed the following 

mitigation measures. To mitigate 

potential acoustical impacts to local 

marine mammals, Protected Species 

Observers (PSOs) will operate aboard 

the vessels from which the chirper, 

boomer, airgun, and vibracorer will be 

deployed. The PSOs will implement the 

mitigation measures described in the 

Marine Mammal Monitoring and 

Mitigation Plan (Appendix A of the 

application). These mitigations include: 

(1) Establishing safety zones to ensure 

marine mammals are not injured by 

sound pressure levels exceeding Level A 

injury thresholds; (2) shutting down the 

airgun when required to avoid 

harassment of beluga whales 

approaching the 160–dB disturbance 

zone; and (3) timing survey activity to 

avoid concentrations of beluga whales 

on a seasonal basis. 

Before chirper, boomer, airgun, and 

vibracoring operations begin each day 

and before restarting operations after a 

shutdown of 15 minutes or greater, the 

PSOs will ‘‘clear’’ both the Level A and 

Level B Zones of Influence (ZOIs—area 

from the source to the 160dB or 180/ 

190dB isopleths) of marine mammals by 

intensively surveying these ZOIs prior 

to activity to confirm that marine 

mammals are not seen in the applicable 

area. All three geophysical activities 

(boomer, chirp, airgun) will be shut 

down in mid-operation at the approach 

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to any marine mammal to the Level A 

safety zone, and at the approach of an 

ESA-listed beluga whale to the Level B 

harassment zone for these sources. The 

geotechnical vibracoring lasts only one 

or two minutes and shutdowns are 

likely impossible. Finally, the G&G 

Program will be planned to avoid high 

beluga whale density areas. This would 

be achieved by conducting surveys at 

the Marine Terminal and the southern 

end of the pipeline survey area when 

beluga whales are farther north, feeding 

near the Susitna Delta, and completing 

activities in the northern portion of the 

pipeline survey area when the Cook 

Inlet beluga whales have begun to 

disperse from the Susitna Delta and 

other summer concentration areas. 

Vessel-Based Visual Mitigation 

Monitoring 

EMALL will hire qualified and 

NMFS-approved PSOs. These PSOs will 

be stationed aboard the geophysical 

survey source or support vessels during 

sub-bottom profiling, air gun, and 

vibracoring operations. A single senior 

PSO will be assigned to oversee all 

Marine Mammal Mitigation and 

Monitoring Program mandates and 

function as the on-site person-inchargeimplementing the 4MP. 

Generally, two PSOs will work on a 

rotational basis during daylight hours 

with shifts of 4 to 6 hours, and one PSO 

on duty on each source vessel at all 

times. Work days for an individual PSO 

will not exceed 12 hours in duration. 

Sufficient numbers of PSOs will be 

available and provided to meet 

requirements. 

Roles and responsibilities of all PSOs 

include the following: 

• Accurately observe and record 

sensitive marine mammal species; 

• Follow monitoring and data 

collection procedures; and 

• Ensure mitigation measures are 

followed. 

PSOs will be stationed at the best 

available vantage point on the source 

vessels. PSOs will scan systematically 

with the unaided eye and 7x50 reticle 

binoculars. As necessary, new PSOs will 

be paired with experienced PSOs to 

ensure that the quality of marine 

mammal observations and data 

recording are consistent. 

All field data collected will be entered 

by the end of the day into a custom 

database using a notebook computer. 

Weather data relative to viewing 

conditions will be collected hourly, on 

rotation, and when sightings occur and 

include the following: 

• Sea state; 

• Wind speed and direction; 

• Sun position; and 

• Percent glare. 

The following data will be collected 

for all marine mammal sightings: 

• Bearing and distance to the 

sighting; 

• Species identification; 

• Behavior at the time of sighting 

(e.g., travel, spy-hop, breach, etc.); 

• Direction and speed relative to 

vessel; 

• Reaction to activities—changes in 

behavior (e.g., none, avoidance, 

approach, paralleling, etc.); 

• Group size; 

• Orientation when sighted (e.g., 

toward, away, parallel, etc.); 

• Closest point of approach; 

• Sighting cue (e.g., animal, splash, 

birds, etc.); 

• Physical description of features that 

were observed or determined not to be 

present in the case of unknown or 

unidentified animals; 

• Time of sighting; 

• Location, speed, and activity of the 

source and mitigation vessels, sea state, 

ice cover, visibility, and sun glare; and 

positions of other vessel(s) in the 

vicinity, and 

• Mitigation measure taken—if any. 

All observations and shut downs will 

be recorded in a standardized format 

and data entered into a custom database 

using a notebook computer. Accuracy of 

all data will be verified daily by the 

person in charge (PIC) or designated 

PSO by a manual verification. These 

procedures will reduce errors, allow the 

preparation of short-term data 

summaries, and facilitate transfer of the 

data to statistical, graphical, or other 

programs for further processing and 

archiving. PSOs will conduct 

monitoring during daylight periods 

(weather permitting) during G&G 

activities, and during most daylight 

periods when G&G activities are 

temporarily suspended. 

Shutdown Procedures 

If any marine mammal is seen 

approaching the Level A injury zone for 

the air gun, chirp, or boomer, these 

sources will be shut down. If ESA-listed 

marine mammals (e.g., beluga whales) 

are observed approaching the Level B 

harassment zone for the air gun, chirp, 

or boomer, these sources will be shut 

down. The PSOs will ensure that the 

harassment zone is clear of marine 

mammal activity before vibracoring will 

occur, using observers near the 

vibracore as well as PSOs from a 

monitoring vessel. Given that 

vibracoring lasts only about a minute or 

two, shutdown actions are not 

practicable. 

Resuming Airgun Operations After a 

Shutdown 

A full ramp-up after a shutdown will 

not begin until there has been a 

minimum of 30 minutes of observation 

of the applicable exclusion zone by 

PSOs to assure that no marine mammals 

are present. The entire exclusion zone 

must be visible during the 30-minute 

lead-in to a full ramp up. If the entire 

exclusion zone is not visible, then rampup from a cold start cannot begin. If a 

marine mammal(s) is sighted within the 

injury exclusion zone during the 30- 

minute watch prior to ramp-up, rampup will be delayed until the marine 

mammal(s) is sighted outside of the 

zone or the animal(s) is not sighted for 

at least 15–30 minutes: 15 Minutes for 

small odontocetes and pinnipeds (e.g. 

harbor porpoises, harbor seals), or 30 

minutes for large odontocetes (e.g., 

killer whales and beluga whales). 

Speed and Course Alterations 

If a marine mammal is detected 

outside the Level A injury exclusion 

zone and, based on its position and the 

relative motion, is likely to enter that 

zone, the vessel’s speed and/or direct 

course may, when practical and safe, be 

changed to also minimize the effect on 

the survey program. The marine 

mammal activities and movements 

relative to the sound source and support 

vessels will be closely monitored to 

ensure that the marine mammal does 

not approach within the applicable 

exclusion radius. If the mammal appears 

likely to enter the exclusion radius, 

further mitigative actions will be taken, 

i.e., either further course alterations or 

shut down of the active sound sources 

considered in this Authorization. 

Mitigation Proposed by NMFS 

Special Procedures for Situations or 

Species of Concern 

The following additional protective 

measures for beluga whales and groups 

of five or more killer whales and harbor 

porpoises are required. Specifically, a 

160-dB vessel monitoring zone would 

be established and monitored in Cook 

Inlet during all seismic surveys. If a 

beluga whale or groups of five or more 

killer whales and/or harbor porpoises 

are visually sighted approaching or 

within the 160-dB disturbance zone, 

survey activity would not commence 

until the animals are no longer present 

within the 160-dB disturbance zone. 

Whenever Cook Inlet beluga whales or 

groups of five or more killer whales 

and/or harbor porpoises are detected 

approaching or within the 160-dB 

disturbance zone, the boomer, chirp, 

and airgun may be powered down 

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before the animal is within the 160-dB 

disturbance zone, as an alternative to a 

complete shutdown. If the PSO 

determines a power down is not 

sufficient, the sound source(s) shall be 

shut-down until the animals are no 

longer present within the 160-dB zone. 

Mitigation Exclusion Zones 

NMFS requires that EMALL will not 

operate the chirp, boomer, vibracore, or 

airgun within 10 miles (16 km) of the 

mean higher high water (MHHW) line of 

the Susitna Delta (Beluga River to the 

Little Susitna River) between April 15 

and October 15. The purpose of this 

mitigation measure is to protect beluga 

whales in the designated critical habitat 

in this area that is important for beluga 

whale feeding and calving during the 

spring and fall months. The range of the 

setback required by NMFS was 

designated to protect this important 

habitat area and also to create an 

effective buffer where sound does not 

encroach on this habitat. This seasonal 

exclusion will be in effect from April 

15th to October 15th annually. 

Activities can occur within this area 

from October 16th–April 14th. 

Passive Acoustic Monitoring 

To allow the use of vibracoring in 

low-light and nighttime conditions, 

NMFS would require use of passive 

acoustic monitoring to acoustically 

‘‘clear’’ the relevant 120 or 160-dB 

disturbance zone. A specifically trained 

Passive Acoustic Monitoring (PAM) 

operator will deploy the hydrophone 

and listen for vocalizations of marine 

mammals. If no vocalizations are 

detected in 30 minutes of listening, the 

area can be considered clear and 

operations can ramp up. 

Mitigation Conclusions 

NMFS has carefully evaluated 

EMALL’s mitigation measures and 

considered additional measures in the 

context of ensuring that we prescribe 

the means of effecting 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: 

• The manner in which, and the 

degree to which, the successful 

implementation of the measure is 

expected to minimize adverse impacts 

to marine mammals; 

• The proven or likely efficacy of the 

specific measure to minimize adverse 

impacts as planned; and 

• The practicability of the measure 

for applicant implementation. 

Any mitigation measure(s) prescribed 

by NMFS should be able to accomplish, 

have a reasonable likelihood of 

accomplishing (based on current 

science), or contribute to the 

accomplishment of one or more of the 

general goals listed here: 

• Avoidance or minimization of 

injury or death of marine mammals 

wherever possible (goals 2, 3, and 4 may 

contribute to this goal). 

• A reduction in the numbers of 

marine mammals (total number or 

number at biologically important time 

or location) exposed to sub-bottom 

profiler or airgun operations that we 

expect to result in the take of marine 

mammals (this goal may contribute to 1, 

above, or to reducing harassment takes 

only). 

• A reduction in the number of times 

(total number or number at biologically 

important time or location) individuals 

would be exposed to sub-bottom profiler 

or airgun operations that we expect to 

result in the take of marine mammals 

(this goal may contribute to 1, above, or 

to reducing harassment takes only). 

• A reduction in the intensity of 

exposures (either total number or 

number at biologically important time 

or location) to airgun operations that we 

expect to result in the take of marine 

mammals (this goal may contribute to a, 

above, or to reducing the severity of 

harassment takes only). 

• Avoidance or minimization of 

adverse effects to marine mammal 

habitat, paying special attention to the 

food base, activities that block or limit 

passage to or from biologically 

important areas, permanent destruction 

of habitat, or temporary destruction/ 

disturbance of habitat during a 

biologically important time. 

• 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 the evaluation of EMALL’s 

measures, as well as other measures 

required by NMFS, NMFS has 

determined that the mitigation measures 

provide the means of effecting the least 

practicable impact on marine mammal 

species or stocks and their habitat, 

paying particular attention to rookeries, 

mating grounds, and areas of similar 

significance. Measures to ensure 

availability of such species or stock for 

taking for certain subsistence uses are 

discussed later in this document (see 

‘‘Impact on Availability of Affected 

Species or Stock for Taking for 

Subsistence Uses’’ section). 

Proposed 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 proposed action area. 

Any monitoring requirement we 

prescribe should improve our 

understanding of one or more of the 

following: 

• Occurrence of marine mammal 

species in action area (e.g., presence, 

abundance, distribution, density). 

• Nature, scope, or context of likely 

marine mammal exposure to potential 

stressors/impacts (individual or 

cumulative, acute or chronic), through 

better understanding of: (1) Action or 

environment (e.g., source 

characterization, propagation, ambient 

noise); (2) Affected species (e.g., life 

history, dive patterns); (3) Cooccurrence of marine mammal species 

with the action; or (4) Biological or 

behavioral context of exposure (e.g., age, 

calving, breeding, or feeding areas). 

• Individual responses to acute 

stressors, or impacts of chronic 

exposures (behavioral or physiological). 

• How anticipated responses to 

stressors impact either: (1) Long-term 

fitness and survival of an individual; or 

(2) Population, species, or stock. 

• Effects on marine mammal habitat 

and resultant impacts to marine 

mammals. 

• Mitigation and monitoring 

effectiveness. 

EMALL submitted a marine mammal 

monitoring plan as part of the IHA 

application. It can be found in 

Appendix A. The plan may be modified 

or supplemented based on comments or 

new information received from the 

public during the public comment 

period. 

Weekly Field Reports 

Weekly reports will be submitted to 

NMFS no later than the close of 

business (Alaska Time) each Thursday 

during the weeks when in-water G&G 

activities take place. The reports will 

cover information collected from 

Wednesday of the previous week 

through Tuesday of the current week. 

The field reports will summarize 

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species detected, in-water activity 

occurring at the time of the sighting, 

behavioral reactions to in-water 

activities, and the number of marine 

mammals exposed to harassment level 

noise. The weekly reports will also 

contain information about which km2

grid cells that EMALL has operated in 

that week, along with the corresponding 

densities from the Goetz et al. 2012 

model to indicate how many belugas 

may have been taken by these 

operations. The weekly report will also 

include the number of belugas that may 

have been taken from previous weeks to 

track when EMALL is approaching their 

cap of 34 belugas. 

Monthly Field Reports 

Monthly reports will be submitted to 

NMFS for all months during which inwater G&G activities take place. The 

reports will be submitted to NMFS no 

later than five business days after the 

end of the month. The monthly report 

will contain and summarize the 

following information: 

• Dates, times, locations, heading, 

speed, weather, sea conditions 

(including Beaufort Sea state and wind 

force), and associated activities during 

the G&G Program and marine mammal 

sightings. 

• Species, number, location, distance 

from the vessel, and behavior of any 

sighted marine mammals, as well as 

associated G&G activity (number of shut 

downs), observed throughout all 

monitoring activities. 

• An estimate of the number (by 

species) of: (i) Pinnipeds that have been 

exposed to the authorized geophysical 

or geotechnical activity (based on visual 

observation) at received levels greater 

than or equal to 160 dB re 1 mPa (rms) 

and/or 190 dB re 1 mPa (rms) with a 

discussion of any specific behaviors 

those individuals exhibited; and (ii) 

cetaceans that have been exposed to the 

geophysical activity (based on visual 

observation) at received levels greater 

than or equal to 160 dB re 1 mPa (rms) 

and/or 180 dB re 1 mPa (rms) with a 

discussion of any specific behaviors 

those individuals exhibited. 

• An estimate of the number (by 

species) of pinnipeds and cetaceans that 

have been exposed to the geotechnical 

activity (based on visual observation) at 

received levels greater than or equal to 

120 dB re 1 mPa (rms) with a discussion 

of any specific behaviors those 

individuals exhibited. 

• A description of the 

implementation and effectiveness of the: 

(i) Terms and conditions of the 

Biological Opinion’s Incidental Take 

Statement; and (ii) mitigation measures 

of the IHA. For the Biological Opinion, 

the report shall confirm the 

implementation of each Term and 

Condition, as well as any conservation 

recommendations, and describe their 

effectiveness, for minimizing the 

adverse effects of the action on ESAlisted marine mammals. 

90-Day Technical Report 

A report will be submitted to NMFS 

within 90 days after the end of the 

project or at least 60 days before the 

request for another IHA for the next 

open water season to enable NMFS to 

incorporate observation data into the 

next Authorization. The report will 

summarize all activities and monitoring 

results (i.e., vessel-based visual 

monitoring) conducted during in-water 

G&G surveys. The Technical Report will 

include the following: 

• Summaries of monitoring effort 

(e.g., total hours, total distances, and 

marine mammal distribution through 

the study period, accounting for sea 

state and other factors affecting 

visibility and detectability of marine 

mammals). 

• Analyses of the effects of various 

factors influencing detectability of 

marine mammals (e.g., sea state, number 

of observers, and fog/glare). 

• Species composition, occurrence, 

and distribution of marine mammal 

sightings, including date, water depth, 

numbers, age/size/gender categories (if 

determinable), group sizes, and ice 

cover. 

• Analyses of the effects of survey 

operations. 

• Sighting rates of marine mammals 

during periods with and without G&G 

survey activities (and other variables 

that could affect detectability), such as: 

(i) Initial sighting distances versus 

survey activity state; (ii) closest point of 

approach versus survey activity state; 

(iii) observed behaviors and types of 

movements versus survey activity state; 

(iv) numbers of sightings/individuals 

seen versus survey activity state; (v) 

distribution around the source vessels 

versus survey activity state; and (vi) 

estimates of Level B harassment based 

on presence in the 120 or 160 dB 

harassment zone. 

Notification of Injured or Dead Marine 

Mammals 

In the unanticipated event that the 

specified activity leads to an injury of a 

marine mammal (Level A harassment) 

or mortality (e.g., ship-strike, gear 

interaction, and/or entanglement), 

EMALL would immediately cease the 

specified activities and immediately 

report the incident to the Chief of the 

Permits and Conservation Division, 

Office of Protected Resources, and the 

Alaska Regional Stranding Coordinators 

at NMFS. The report would include the 

following information: 

• Time, date, and location (latitude/

longitude) of the incident; 

• Name and type of vessel involved; 

• Vessel’s speed during and leading 

up to the incident; 

• Description of the incident; 

• Status of all sound source use in the 

24 hours preceding the incident; 

• Water depth; 

• Environmental conditions (e.g., 

wind speed and direction, Beaufort sea 

state, cloud cover, and visibility); 

• Description of all marine mammal 

observations in the 24 hours preceding 

the incident; 

• Species identification or 

description of the animal(s) involved; 

• Fate of the animal(s); and 

• Photographs or video footage of the 

animal(s) (if equipment is available). 

Activities would not resume until 

NMFS is able to review the 

circumstances of the event. EMALL 

would work with NMFS to minimize 

reoccurrence of such an event in the 

future. The G&G Program would not 

resume activities until formally notified 

by NMFS via letter, email, or telephone. 

In the event that the G&G Program 

discovers an injured or dead marine 

mammal, and the lead PSO determines 

that the cause of the injury or death is 

unknown and the death is relatively 

recent (i.e., in less than a moderate state 

of decomposition as described in the 

next paragraph), the Applicant would 

immediately report the incident to the 

Chief of the Permits and Conservation 

Division, Office of Protected Resources, 

NMFS, and the NMFS Alaska Stranding 

Hotline and/or by email to the Alaska 

Regional Stranding Coordinators. The 

report would include the same 

information identified in the paragraph 

above. Activities would be able to 

continue while NMFS reviews the 

circumstances of the incident. NMFS 

would work with the Applicant to 

determine if modifications in the 

activities are appropriate. 

In the event that the G&G Program 

discovers an injured or dead marine 

mammal, and the lead PSO determines 

that the injury or death is not associated 

with or related to the activities 

authorized in the IHA (e.g., previously 

wounded animal, carcass with moderate 

to advanced decomposition, or 

scavenger damage), EMALL would 

report the incident to the Chief of the 

Permits and Conservation Division, 

Office of Protected Resources, NMFS, 

and the NMFS Alaska Stranding Hotline 

and/or by email to the Alaska Regional 

Stranding Coordinators, within 24 hours 

of the discovery. EMALL would provide 

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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, 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]. 

Acoustic stimuli (i.e., increased 

underwater sound) generated during the 

operation of the airgun or the subbottom profiler have the potential to 

result in the behavioral disturbance of 

some marine mammals. NMFS believes 

that take from the operation of the 

vibracore is unlikely but possible and is 

issuing take at the request of the 

applicant. Thus, NMFS proposes to 

authorize take by Level B harassment 

resulting from the operation of the 

sound sources for the proposed survey 

based upon the current acoustic 

exposure criteria shown in Table 3. 

TABLE 3—NMFS’ CURRENT ACOUSTIC EXPOSURE CRITERIA

Criterion Criterion definition Threshold 

Level A Harassment (Injury) .............................. Permanent Threshold Shift (PTS) (Any level 

above that which is known to cause TTS).

180 dB re 1 microPa-m (cetaceans)/190 dB re 

1 microPa-m (pinnipeds) root mean square 

(rms). 

Level B Harassment .......................................... Behavioral Disruption (for impulse noises) ...... 160 dB re 1 microPa-m (rms). 

Behavioral Disruption (for continuous noises) 120 dB re 1 microPa-m (rms). 

NMFS’ practice is to apply the 120 or 

160 dB re: 1 mPa received level 

threshold (whichever is appropriate) for 

underwater impulse sound levels to 

determine whether take by Level B 

harassment is likely to occur. 

All four types of survey equipment 

addressed in the application will be 

operated from the geophysical source 

vessels that will either be moving 

steadily across the ocean surface 

(chirper, boomer, airgun), or from 

station to station (airgun, vibracoring). 

The numbers of marine mammals that 

might be exposed to sound pressure 

levels exceeding NMFS Level B 

harassment threshold levels due to G&G 

surveys, without mitigation, were 

determined by multiplying the average 

raw density for each species by the daily 

ensonified area, and then multiplying 

that figure by the number of days each 

sound source is estimated to be in use. 

The chirp is always used 

simultaneously with either the boomer 

or the airgun and therefore was removed 

from calculation because they will be 

operating concurrently, using the daily 

ensonified area of the boomer or airgun, 

as it is a slightly larger isopleth. The 

exposure estimates for each activity 

were then summed to provide total 

exposures for the duration of the 

project. The exposure estimates for the 

activity are detailed below. Although 

NMFS believes that take of marine 

mammals from vibracore is extremely 

unlikely, it has been included in this 

authorization out of an abundance of 

caution and at the request of the 

applicant. 

Ensonified Area 

The ZOI is the area ensonified by a 

particular sound source greater than 

threshold levels (120 dB for continuous 

and 160 dB for impulsive). The radius 

of the ZOI for airguns was determined 

by applying the source sound pressure 

levels described in Table 6 of the 

application to Collins et al.’s (2007) 

attenuation model of 18.4 Log(r)— 

0.00188 derived from Cook Inlet. For the 

boomer and vibracore, which are less 

studied sound sources, the geometric 

spreading model of 15 Log(r) was used. 

For those equipment generating loud 

underwater sound within the audible 

hearing range of marine mammals (<200 

kHz), the distance to threshold ranges 

between 44 m and 1 km (Table 4). 

TABLE 4—SUMMARY OF DISTANCES TO THE NMFS THRESHOLDS AND ASSOCIATED ZOIS

Survey equipment 

Distance to 160/120 dB 

isopleth 1

Km2

160/120 dB ZOI 

km2

Sub-bottom Profiler (Chirp) .......................................................................................................... 0.631(160 dB) 127 (160 dB) 

Sub-bottom Profiler (Boomer) ...................................................................................................... 1.00 (160 dB) 203(160 dB) 

Airgun ........................................................................................................................................... 0.3 (160 dB) 60 (160 dB) 

Vibracore ...................................................................................................................................... 20.57 (120 dB) 1328.61 (120 dB) 

1 Calculated by applying Collins et al. (2007) spreading formula or geometrical spreading to source levels in Table 2. 

Marine Mammal Densities 

Density estimates were derived for 

harbor porpoises, killer whales, and 

harbor seals from NMFS 2002–2012 

Cook Inlet survey data as described 

below in Section 6.1.2.1 and shown in 

Table 8. The beluga whale densities 

were extracted from Goetz et al. (2012) 

as described in Section 6.1.2.2 of the 

application. 

Harbor Porpoise, Killer Whale, Harbor 

Seal 

Density estimates were calculated for 

all marine mammals (except beluga 

whales) by using aerial survey data 

collected by NMFS in Cook Inlet 

between 2002 and 2012 (Rugh et al. 

2002, 2003, 2004a, 2004b, 2005a, 2005b, 

2005c, 2006, 2007; Shelden et al. 2008, 

2009, 2010; Hobbs et al. 2011, Shelden 

et al. 2012) and compiled by Apache, 

Inc. (Apache IHA application 2014). To 

estimate the average raw densities of 

marine mammals, the total number of 

animals for each species observed over 

the 11-year survey period was divided 

by the total area of 65,889 km2 (25,540 

mi2) surveyed over the 11 years. The 

aerial survey marine mammal sightings, 

survey effort (area), and derived average 

raw densities are provided in Table 5. 

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TABLE 5—RAW DENSITY ESTIMATES FOR COOK INLET MARINE MAMMALS BASED ON NMFS AERIAL SURVEYS

Species Number of 

animals 

NMFS 

survey area 

km2 (mi2) 

Mean raw density 

animals/km2

(animals/mi2) 

Harbor Porpoise ......................................................................................................... 249 65,889 (25,440) 0.0033 (0.0098) 

Killer Whale 1 ............................................................................................................. 42 65,889 (25,440) 0.0008 (0.0017) 

Harbor Seal ................................................................................................................ 16,117 65,889 (25,440) 0.28 (0.6335) 

1 Density is for all killer whales regardless of the stock although all killer whales in the upper Cook Inlet are thought to be transient. 

These raw densities were not 

corrected for animals missed during the 

aerial surveys as no accurate correction 

factors are currently available for these 

species; however, observer error may be 

limited as the NMFS surveyors often 

circled marine mammal groups to get an 

accurate count of group size. The harbor 

seal densities are probably biased 

upwards given that a large number of 

the animals recorded were of large 

groups hauled out at river mouths, and 

do not represent the distribution in the 

waters where the G&G activity will 

actually occur. However, these data are 

the most comprehensive available for 

Cook Inlet harbor seals and therefore 

constitute the best available science. 

Beluga Whale 

Goetz et al. (2012) modeled aerial 

survey data collected by the NMFS 

between 1993 and 2008 and developed 

specific beluga summer densities for 

each 1-km2 cell of Cook Inlet. The 

results provide a more precise estimate 

of beluga density at a given location 

than simply multiplying all aerial 

observations by the total survey effort 

given the clumped distribution of 

beluga whales during the summer 

months. To develop a density estimate 

associated with planned action areas 

(i.e., Marine Terminal and pipeline 

survey areas), the ensonified area 

associated with each activity was 

overlain a map of the 1-km density cells, 

the cells falling within each ensonified 

area were quantified, and an average 

cell density was calculated. The 

summary of the density results is found 

in Table 9 in the application. The 

associated ensonified areas and beluga 

density contours relative to the action 

areas are shown in Table 6. 

TABLE 6—MEAN RAW DENSITIES OF BELUGA WHALES WITHIN THE ACTION AREAS BASED ON GOETZ ET AL. (2012) COOK

INLET BELUGA WHALE DISTRIBUTION MODELING

Action area Number of cells Mean density 

(animals/km2) 

Density range 

(animals/km2) 

Marine Facilities Area ................................................................................................ 141 0.00014 0.00002–0.00069 

LNGC Approach Area ................................................................................................ 95 .00016 0.00003–0.00052 

Pipeline Survey Area ................................................................................................. 880 0.0139 0.00028–0.15672 

Activity Duration 

The Cook Inlet 2015 G&G Program is 

expected to require approximately 16 

weeks (102 days) to complete. Table 7 

below outlines which technologies will 

be used and for how many days. 

TABLE 7—ESTIMATED ACTIVITY DURATIONS FOR 2016 G&G PROGRAM

Survey area 

Survey equipment Unit Marine 

facilities 

LNGC 

Approach Pipeline Total 

Sub-bottom profiler—boomer .............................................. Days ............... 28 14 30 72 

Air gun ................................................................................. Days ............... 14 0 16 30 

Subtotal ................................................................................ Days ............... 42 14 46 102 

Vibracore ............................................................................. Days ............... 30 10 20 60 

Air gun (stationary) .............................................................. Days ............... 24 0 0 24 

In the 46 days of activity in the 

pipeline area, the chirp and boomer will 

operate concurrently for 30 days while 

the chirp and airgun will operate 

concurrently for 16 days. In the 42 days 

of activity in the Marine Facilities area, 

the chirp and boom will operate 

concurrently for 28 days and the chirp 

will operate concurrently with the 

airgun for 14 days. In the 14 days of 

operation in the LNGC approach area, 

the chirp and boom will operate 

concurrently for all days. 

Exposure Calculations 

The numbers of marine mammals that 

might be exposed to sound pressure 

levels exceeding NMFS Level B 

harassment threshold levels due to G&G 

surveys, without mitigation, were 

determined by multiplying the average 

raw density for each species by the daily 

ensonified area, then multiplying by the 

number of days each sound source is 

estimated to be in use. While this 

method produces a good estimate of the 

number of instances of take, it is likely 

an overestimate of the number of 

individual marine mammals taken 

because it assumes that entirely new 

individuals are taken on subsequent 

days and that no animals are taken more 

than once. The chirp and boomer 

activities were combined to calculate 

exposure from days of activities in the 

Upper Cook Inlet area and the Lower 

Cook Inlet area because they will be 

operating concurrently. The exposure 

estimates for each activity were then 

summed to provide total exposures for 

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the duration of the project. The exposure estimates for the activity are 

detailed below. 

TABLE 8—EXPOSURE ESTIMATES FOR ACTIVITY IN INSTANCES, NOT NUMBER OF INDIVIDUALS

[Also not accounting for management of total beluga takes] 

Total exposures 

Boomer Airgun 

Stationary 

airgun Total Marine 

facilities LNGC Pipeline Marine facilities LNGC Pipeline 

Harbor porpoise 18.71 9.36 20.05 2.78 0.00 3.17 0.02 54.09 

Harbor seal ...... 1606.15 803.08 1720.88 238.32 0.00 272.36 1.92 4642.81 

Killer whale ....... 4.66 2.33 5.00 0.69 0.00 0.79 0.01 13.48 

Beluga .............. 0.80 0.46 80.38 0.12 0.00 12.72 0.00 1 94.48 

* Vibracore totals are not proposed to be authorized because NMFS has determined take due to vibracoring is unlikely to occur. 

1This calculation of beluga takes is from the ensonified area and densities of those areas, and does not incorporate mitigation. NMFS will require a cap of 34 takes on the activity and would not authorize this number of takes. 

NMFS recognizes that in addition to 

what was mentioned above, there are 

other factors that contribute to an 

overestimate of exposures e.g., the fact 

that many of these technologies will be 

operating simultaneously, and not 

exposing animals in separate instances 

for the duration of the survey period. 

Additionally, the beamwidth and tilt 

angle of the sub-bottom profiler are not 

factored into the characterization of the 

sound field, making it conservative and 

large, creating additional overestimates 

in take estimation. 

NMFS calculated the exposures from 

vibracore and found they would 

increase take by 580 percent and 

recognizes that the take calculated for 

vibracore is high when compared to take 

calculated from other portions of the 

activity. It is unlikely that many 

instances of take will occur from an 

activity with a source level of 187.4 dB 

for a duration of 60–90 seconds. This is 

largely attributed to the size of the 

isopleth (20 km) due to the use of 

geometrical spreading to model the ZOI. 

The vibracore produces noise of a much 

shorter duration than those sources used 

to determine the 120dB threshold,. 

NMFS believes implementation of the 

mitigation and monitoring measures 

mentioned in the above section, in 

combination with the short duration of 

the sound, will not result in take by 

Level B harassment. 

The possibility of Level A exposure 

was analyzed, however the distances to 

180 dB/190 dB isopleths are incredibly 

small, ranging from 3 to 47 meters. The 

number of exposures, without 

accounting for mitigation or likely 

avoidance of louder sounds, is small for 

these zones, and with mitigation and the 

likelihood of detecting marine mammals 

within this small area combined with 

the likelihood of avoidance, it is likely 

these takes can be avoided. The only 

technology that would not shutdown is 

the vibracore, which has a distance to 

Level A isopleth (180 dB) of 3 meters. 

Therefore, authorization of Level A take 

is not necessary. 

NMFS recognizes that the calculations 

of take by Level B harassment of beluga 

whales for the entire activity is higher 

than NMFS would issue for an 

endangered population that is not 

recovering despite the moratorium on 

subsistence hunting. Given that the 

factors contributing to the lack of 

recovery remain unknown, NMFS 

proposes to limit the number of Level B 

takes of Cook Inlet beluga to 34, or 10 

percent of the population. This cap can 

be implemented in a method similar to 

that used in SAE’s 2015 IHA or the 

Apache proposed rulemaking. 

In order to estimate when 34 

individuals is reached, EMALL will use 

a formula based on the total potential 

area of each survey project zone 

(including the 160 dB buffer) and the 

average density of beluga whales for 

each zone. Daily take is calculated as 

the product of the daily ensonified area 

times the beluga density in that area, as 

extracted from the Goetz et al 2012 

model. Then daily take is summed 

across all the days of the survey until 

the survey approaches 34 takes. 

EMALL will limit surveying in the 

seismic survey area as not to exceed a 

maximum of 34 beluga takes during the 

open water season. In order to ensure 

that EMALL does not exceed 34 beluga 

whale takes, the following equation is 

being used: 

This formula also allows EMALL to 

have flexibility to prioritize survey 

locations in response to local weather, 

ice, and operational constraints. EMALL 

may choose to survey portions of a zone 

or a zone in its entirety, and the analysis 

in this Authorization takes this into 

account. 

Operations are required to cease once 

EMALL has conducted seismic data 

acquisition in an area where 

multiplying the applicable density by 

the total ensonified area out to the 160- 

dB isopleth equaled 34 beluga whales, 

using the equation provided above. If 34 

belugas are visually observed within the 

ZOI before the calculation reaches 34 

belugas, EMALL is also required to 

cease survey activity. 

NMFS proposes to authorize the 

following takes by Level B harassment: 


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TABLE 9—PROPOSED TAKE AUTHORIZATION

Species Exposure 

estimate 

Take 

authorized 

Percent of stock 

or population Population trend 

Beluga ............................................................................................. 94.48 34 10 ........................... Decreasing. 

Killer whale ...................................................................................... 13.48 13 3.77 transient ......... Transient—Stable. 

Harbor seal ...................................................................................... 4,642.81 4,643 20.27 ...................... Stable. 

Harbor porpoise .............................................................................. 54.09 54 0.17 ........................ No reliable info. 

Analysis and Preliminary 

Determinations 

Negligible Impact 

Negligible impact is ‘‘an impact 

resulting from the specified activity that 

cannot be reasonably expected to, and is 

not reasonably likely to, adversely affect 

the species or stock through effects on 

annual rates of recruitment or survival’’ 

(50 CFR 216.103). The lack of likely 

adverse effects on annual rates of 

recruitment or survival (i.e., population 

level effects) forms the basis of a 

negligible impact finding. Thus, an 

estimate of the number of takes, alone, 

is not enough information on which to 

base an impact determination. In 

addition to considering estimates of the 

number of marine mammals that might 

be ‘‘taken’’ through behavioral 

harassment, NMFS must consider other 

factors, such as the likely nature of any 

responses (their intensity, duration, 

etc.), the context of any responses 

(critical reproductive time or location, 

migration, etc.), as well as the number 

and nature of estimated Level A 

harassment takes, the number of 

estimated mortalities, effects on habitat, 

and the status of the species. 

To avoid repetition, except where 

otherwise identified, the discussion of 

our analyses applies to all the species 

listed in Table 8, given that the 

anticipated effects of this project on 

marine mammals are expected to be 

relatively similar in nature. Where there 

is information about specific impacts to, 

or about the size, status, or structure of, 

any species or stock that would lead to 

a different analysis for this activity, 

species-specific factors are identified 

and analyzed. 

In making a negligible impact 

determination, NMFS considers: 

• The number of anticipated injuries, 

serious injuries, or mortalities; 

• The number, nature, and intensity, 

and duration of Level B harassment; and 

• The context in which the takes 

occur (e.g., impacts to areas of 

significance, impacts to local 

populations, and cumulative impacts 

when taking into account successive/

contemporaneous actions when added 

to baseline data); 

• The status of stock or species of 

marine mammals (i.e., depleted, not 

depleted, decreasing, increasing, stable, 

impact relative to the size of the 

population); 

• Impacts on habitat affecting rates of 

recruitment/survival; and 

• The effectiveness of monitoring and 

mitigation measures to reduce the 

number or severity of incidental take. 

As discussed in the Potential Effects 

section, temporary or permanent 

threshold shift, non-auditory physical or 

physiological effects, ship strike, 

entanglement are not expected to occur. 

Given the required mitigation and 

related monitoring, no injuries or 

mortalities are anticipated to occur to 

any species as a result of EMALL’s 

proposed survey in Cook Inlet, and none 

are authorized. Animals in the area are 

not expected to incur hearing 

impairment (i.e., TTS or PTS) or nonauditory physiological effects due to 

low source levels and the fact that most 

marine mammals would more likely 

avoid a loud sound source rather than 

swim in such close proximity as to 

result in TTS or PTS. The most likely 

effect from the proposed action is 

localized, short-term behavioral 

disturbance from active acoustic 

sources. The number of takes that are 

anticipated and authorized are expected 

to be limited to short-term Level B 

behavioral harassment for all stocks for 

which take is authorized. This is largely 

due to the short time scale of the 

proposed activity, the low source levels 

for many of the technologies proposed 

to be used, as well as the required 

mitigation. The technologies do not 

operate continuously over a 24-hour 

period. Rather, airguns are operational 

for a few hours at a time for 30 days, 

with the sub-bottom profiler boomer 

operating for 72 days, and the vibracore 

operating over 60 days. 

The addition of five vessels, and noise 

due to vessel operations associated with 

the survey, would not be outside the 

present experience of marine mammals 

in Cook Inlet, although levels may 

increase locally. Potential impacts to 

marine mammal habitat were discussed 

previously in this document (see the 

‘‘Anticipated Effects on Habitat’’ 

section). Although some disturbance is 

possible to food sources of marine 

mammals, the impacts are anticipated to 

be minor enough as to not affect annual 

rates of recruitment or survival of 

marine mammals in the area. Based on 

the size of Cook Inlet where feeding by 

marine mammals occurs versus the 

localized area of the marine survey 

activities, any missed feeding 

opportunities in the direct project area 

would be minor based on the fact that 

other feeding areas exist elsewhere. 

Taking into account the mitigation 

measures that are planned, effects on 

cetaceans are generally expected to be 

restricted to avoidance of a limited area 

around the survey operation and shortterm changes in behavior, falling within 

the MMPA definition of ‘‘Level B 

harassment.’’ Shut-downs are required 

for belugas and groups of killer whales 

or harbor porpoises when they approach 

the 160dB disturbance zone, to further 

reduce potential impacts to these 

populations. Visual observation by 

trained PSOs is also implemented to 

reduce the impact of the proposed 

activity by informing operators of 

marine mammals approaching the 

relevant disturbance or injury zones. 

Animals are not expected to 

permanently abandon any area that is 

surveyed, and any behaviors that are 

interrupted during the activity are 

expected to resume once the activity 

ceases. Only a small portion of marine 

mammal habitat will be affected at any 

time, and other areas within Cook Inlet 

will be available for necessary biological 

functions. 

Odontocete (including Cook Inlet 

beluga whales, killer whales, and harbor 

porpoises) reactions to seismic energy 

pulses are usually assumed to be limited 

to shorter distances from the airgun(s) 

than are those of mysticetes, in part 

because odontocete low-frequency 

hearing is assumed to be less sensitive 

than that of mysticetes. This 

information supports the idea that the 

numerated takes for odonotocetes are 

likely on the lower end of severity in the 

terms of responses that rise to the level 

of a take. 

Beluga Whales 

Cook Inlet beluga whales are listed as 

endangered under the ESA. This stock 

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is also considered depleted under the 

MMPA. The estimated annual rate of 

decline for Cook Inlet beluga whales 

was 0.6 percent between 2002 and 2012. 

The authorization of take by Level B 

harassment of 34 Cook Inlet beluga 

whales represents 10 percent of the 

population. 

Belugas in the Canadian Beaufort Sea 

in summer appear to be fairly 

responsive to seismic energy, with few 

being sighted within 10–20 km (6–12 

mi) of seismic vessels during aerial 

surveys (Miller et al., 2005). However, 

as noted above, Cook Inlet belugas are 

more accustomed to anthropogenic 

sound than beluga whales in the 

Beaufort Sea. Therefore, the results from 

the Beaufort Sea surveys are not 

necessarily applicable to potential 

reactions of Cook Inlet beluga whales. 

Also, due to the dispersed distribution 

of beluga whales in Cook Inlet during 

winter and the concentration of beluga 

whales in upper Cook Inlet from late 

April through early fall, belugas would 

likely occur in small numbers in the 

majority of EMALL’s proposed survey 

area during the majority of EMALL’s 

annual operational timeframe of March 

through December. For the same reason, 

as well as the mitigation measure that 

requires shutting down for belugas seen 

approaching the 160 dB disturbance 

zone, and the likelihood of avoidance at 

high levels, it is unlikely that animals 

would be exposed to received levels 

capable of causing injury. 

Given the large number of vessels in 

Cook Inlet and the apparent habituation 

to vessels by Cook Inlet beluga whales 

and the other marine mammals that may 

occur in the area, vessel activity from 

the two source vessels, tug and jack-up 

rig and associated vessel noise is not 

expected to have effects that could 

cause significant or long-term 

consequences for individual marine 

mammals or their populations, given 

that vessels will operate for a maximum 

of 102 days. 

In addition, NMFS has seasonally 

restricted survey operations in the area 

known to be important for beluga whale 

feeding, calving, or nursing. The 

primary location for these biological life 

functions occurs in the Susitna Delta 

region of upper Cook Inlet. NMFS 

required EMALL to implement a 16 km 

(10 mi) seasonal exclusion from survey 

operations in this region from April 15– 

October 15. The highest concentrations 

of belugas are typically found in this 

area from early May through September 

each year. NMFS has incorporated a 2- 

week buffer on each end of this seasonal 

use timeframe to account for any 

anomalies in distribution and marine 

mammal usage. 

Killer Whales 

The authorization of take by Level B 

harassment of 13 killer whales 

represents only 3.77 percent of the 

population. Killer whales are not 

encountered as frequently in Cook Inlet 

as some of the other species in this 

analysis, however when sighted they are 

usually in groups. The addition of a 

mitigation measure to shutdown if a 

group of 5 or more killer whales is seen 

approaching the 160 dB zone is 

intended to minimize any impact to an 

aggregation of killer whales if 

encountered. The killer whales in the 

survey area are also thought to be 

transient killer whales and therefore 

rely on the habitat in the EMALL survey 

area less than other resident species. 

Harbor Porpoise 

The authorization of take by Level B 

harassment for 54 harbor porpoises 

represents only 0.17 percent of the 

population. Harbor porpoises are among 

the most sensitive marine mammal 

species with regard to behavioral 

response and anthropogenic noise. They 

are known to exhibit behavioral 

responses to operation of seismic 

airguns, pingers, and other technologies 

at low thresholds. However, they are 

abundant in Cook Inlet and therefore the 

authorized take is unlikely to affect 

recruitment or status of the population 

in any way. In addition, mitigation 

measures include shutdowns for groups 

of more than 5 harbor porpoises that 

will minimize the amount of take to the 

local harbor porpoise population. This 

mitigation as well as the short duration 

and low source levels of the proposed 

activity will reduce the impact to the 

harbor porpoises found in Cook Inlet. 

Harbor Seal 

The authorization of take by Level B 

harassment for 4,643 harbor seals 

represents 20.27 percent of a stable 

population. Observations during other 

anthropogenic activities in Cook Inlet 

have reported large congregations of 

harbor seals hauling out in upper Cook 

Inlet. However, mitigation measures, 

such as vessel speed, course alteration, 

and visual monitoring, and time-area 

restrictions will be implemented to help 

reduce impacts to the animals. 

Additionally, this activity does not 

encompass a large number of known 

harbor seal haulouts, particularly as this 

activity proposes operations traversing 

across the Inlet, as opposed to entirely 

nearshore activities. While some harbor 

seals will likely be exposed, the 

required mitigation along with their 

smaller aggregations in water than on 

shore should minimize impacts to the 

harbor seal population. Additionally, 

the short duration of the survey, and the 

use of visual observers to inform 

shutdowns and ramp up delays should 

further reduce the severity of behavioral 

reactions to Cook Inlet harbor seals. 

Therefore, the exposure of pinnipeds to 

sounds produced by this phase of 

EMALL’s proposed survey is not 

anticipated to have an effect on annual 

rates of recruitment or survival on those 

species or stocks. 

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 

required monitoring and mitigation 

measures, NMFS finds that the total 

annual marine mammal take from 

EMALL’s proposed survey will have a 

negligible impact on the affected marine 

mammal species or stocks (see Table 8). 

Although NMFS believes it is unlikely 

the operation of the vibracore would 

result in the take of marine mammals 

and does not propose to authorize take 

by vibracore in the Federal Register, the 

analysis has been included in this 

document for public comment. The 

vibracoring activity is proposed to occur 

at 60 locations across the Inlet from the 

Forelands, north to the upper end of 

Cook Inlet. However, the actual noiseproducing activity will only occur for 

only 90 seconds at a time, during which 

PSOs will be observing for marine 

mammals and passive acoustic 

monitoring will be required during 

nighttime vibracoring. The limited 

scope and duration of vibracoring makes 

it extremely unlikely that take by Level 

B harassment would occur during the 

vibracore portion of the operation. 

Nonetheless, we included the potential 

take from vibracore in our analysis 

above. 

Small Numbers Analysis 

The requested takes authorized 

annually represent 10 percent of the 

Cook Inlet beluga whale population of 

approximately 340 animals (Shelden et 

al., 2015), 3.77 percent of the Gulf of 

Alaska, Aleutian Island and Bering Sea 

stock of killer whales (345 transients), 

and 0.17 percent of the Gulf of Alaska 

stock of approximately 31,046 harbor 

porpoises. The take requests presented 

for harbor seals represent 20.27 percent 

of the Cook Inlet/Shelikof stock of 

approximately 22,900 animals. These 

take estimates represent small numbers 

relative to the affected species or stock 

sizes as shown in Table 8. 

In addition to the quantitative 

methods used to estimate take, NMFS 

also considered qualitative factors that 

further support the ‘‘small numbers’’ 

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determination, including: (1) The 

seasonal distribution and habitat use 

patterns of Cook Inlet beluga whales, 

which suggest that for much of the time 

only a small portion of the population 

would be accessible to impacts from 

EMALL’s activity, as most animals are 

found in the Susitna Delta region of 

Upper Cook Inlet from early May 

through September; (2) other cetacean 

species are not common in the survey 

area; (3) the required mitigation 

requirements, which provide spatiotemporal limitations that avoid impacts 

to large numbers of belugas feeding and 

calving in the Susitna Delta; (4) the 

required monitoring requirements and 

mitigation measures described earlier in 

this document for all marine mammal 

species that will reduce the amount of 

takes; and (5) monitoring results from 

previous activities that indicated low 

numbers of beluga whale sightings 

within the Level B disturbance 

exclusion zone and low levels of Level 

B harassment takes of other marine 

mammals. Therefore, NMFS determined 

that the numbers of animals likely to be 

taken are small. 

Impact on Availability of Affected 

Species for Taking for Subsistence Uses 

Relevant Subsistence Uses 

The subsistence harvest of marine 

mammals transcends the nutritional and 

economic values attributed to the 

animal and is an integral part of the 

cultural identity of the region’s Alaska 

Native communities. Inedible parts of 

the whale provide Native artisans with 

materials for cultural handicrafts, and 

the hunting itself perpetuates Native 

traditions by transmitting traditional 

skills and knowledge to younger 

generations (NOAA, 2007). 

The Cook Inlet beluga whale has 

traditionally been hunted by Alaska 

Natives for subsistence purposes. For 

several decades prior to the 1980s, the 

Native Village of Tyonek residents were 

the primary subsistence hunters of Cook 

Inlet beluga whales. During the 1980s 

and 1990s, Alaska Natives from villages 

in the western, northwestern, and North 

Slope regions of Alaska either moved to 

or visited the south central region and 

participated in the yearly subsistence 

harvest (Stanek, 1994). From 1994 to 

1998, NMFS estimated 65 whales per 

year (range 21–123) were taken in this 

harvest, including those successfully 

taken for food and those struck and lost. 

NMFS concluded that this number was 

high enough to account for the 

estimated 14 percent annual decline in 

the population during this time (Hobbs 

et al., 2008). Actual mortality may have 

been higher, given the difficulty of 

estimating the number of whales struck 

and lost during the hunts. In 1999, a 

moratorium was enacted (Pub. L. 106– 

31) prohibiting the subsistence take of 

Cook Inlet beluga whales except through 

a cooperative agreement between NMFS 

and the affected Alaska Native 

organizations. Since the Cook Inlet 

beluga whale harvest was regulated in 

1999 requiring cooperative agreements, 

five beluga whales have been struck and 

harvested. Those beluga whales were 

harvested in 2001 (one animal), 2002 

(one animal), 2003 (one animal), and 

2005 (two animals). The Native Village 

of Tyonek agreed not to hunt or request 

a hunt in 2007, when no comanagement agreement was to be signed 

(NMFS, 2008a). 

On October 15, 2008, NMFS 

published a final rule that established 

long-term harvest limits on Cook Inlet 

beluga whales that may be taken by 

Alaska Natives for subsistence purposes 

(73 FR 60976). That rule prohibits 

harvest for a 5-year interval period if the 

average stock abundance of Cook Inlet 

beluga whales over the prior five-year 

interval is below 350 whales. Harvest 

levels for the current 5-year planning 

interval (2013–2017) are zero because 

the average stock abundance for the 

previous five-year period (2008–2012) 

was below 350 whales. Based on the 

average abundance over the 2002–2007 

period, no hunt occurred between 2008 

and 2012 (NMFS, 2008a). The Cook 

Inlet Marine Mammal Council, which 

managed the Alaska Native Subsistence 

fishery with NMFS, was disbanded by a 

unanimous vote of the Tribes’ 

representatives on June 20, 2012. At this 

time, no harvest is expected in 2015 or, 

likely, in 2016. 

Data on the harvest of other marine 

mammals in Cook Inlet are lacking. 

Some data are available on the 

subsistence harvest of harbor seals, 

harbor porpoises, and killer whales in 

Alaska in the marine mammal stock 

assessments. However, these numbers 

are for the Gulf of Alaska including 

Cook Inlet, and they are not indicative 

of the harvest in Cook Inlet. 

There is a low level of subsistence 

hunting for harbor seals in Cook Inlet. 

Seal hunting occurs opportunistically 

among Alaska Natives who may be 

fishing or travelling in the upper Inlet 

near the mouths of the Susitna River, 

Beluga River, and Little Susitna. Some 

detailed information on the subsistence 

harvest of harbor seals is available from 

past studies conducted by the Alaska 

Department of Fish & Game (Wolfe et 

al., 2009). In 2008, 33 harbor seals were 

taken for harvest in the Upper KenaiCook Inlet area. In the same study, 

reports from hunters stated that harbor 

seal populations in the area were 

increasing (28.6%) or remaining stable 

(71.4%). The specific hunting regions 

identified were Anchorage, Homer, 

Kenai, and Tyonek, and hunting 

generally peaks in March, September, 

and November (Wolfe et al., 2009). 

Potential Impacts on Availability for 

Subsistence Uses 

Section 101(a)(5)(D) also requires 

NMFS to determine that the taking will 

not have an unmitigable adverse effect 

on the availability of marine mammal 

species or stocks for subsistence use. 

NMFS has defined ‘‘unmitigable adverse 

impact’’ in 50 CFR 216.103 as an impact 

resulting from the specified activity: (1) 

That is likely to reduce the availability 

of the species to a level insufficient for 

a harvest to meet subsistence needs by: 

(i) Causing the marine mammals to 

abandon or avoid hunting areas; (ii) 

Directly displacing subsistence users; or 

(iii) Placing physical barriers between 

the marine mammals and the 

subsistence hunters; and (2) That cannot 

be sufficiently mitigated by other 

measures to increase the availability of 

marine mammals to allow subsistence 

needs to be met. 

The primary concern is the 

disturbance of marine mammals through 

the introduction of anthropogenic sound 

into the marine environment during the 

proposed survey. Marine mammals 

could be behaviorally harassed and 

either become more difficult to hunt or 

temporarily abandon traditional hunting 

grounds. However, the proposed survey 

will not have any impacts to beluga 

harvests as none currently occur in 

Cook Inlet. Additionally, subsistence 

harvests of other marine mammal 

species are limited in Cook Inlet. 

Plan of Cooperation or Measures To 

Minimize Impacts to Subsistence Hunts 

50 CFR 216.04(a)(12) requires IHA 

applicants for activities that take place 

in Arctic waters to provide Plan of 

Cooperation or information that 

identifies what measures have been 

taken and/or will be taken to minimize 

adverse effects on the availability of 

marine mammals for subsistence uses. 

The entire upper Cook unit and a 

portion of the lower Cook unit falls 

north of 60° N, or within the region 

NMFS has designated as an Arctic 

subsistence use area. EMALL provided 

detailed information in Section 8 of 

their application regarding their plan to 

cooperate with local subsistence users 

and stakeholders regarding the potential 

effects of their proposed activity. There 

are several villages in EMALL’s 

proposed project area that have 

traditionally hunted marine mammals, 

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Federal Register / Vol. 81, No. 24 / Friday, February 5, 2016 / Notices 6401 

primarily harbor seals. Tyonek is the 

only tribal village in upper Cook Inlet 

with a tradition of hunting marine 

mammals, in this case harbor seals and 

beluga whales. However, for either 

species the annual recorded harvest 

since the 1980s has averaged about one 

or fewer of either species (Fall et al. 

1984, Wolfe et al. 2009, SRBA and HC 

2011), and there is currently a 

moratorium on subsistence harvest of 

belugas. Further, many of the seals that 

are harvested are done incidentally to 

salmon fishing or moose hunting (Fall et 

al. 1984, Merrill and Orpheim 2013), 

often near the mouths of the Susitna 

Delta rivers (Fall et al. 1984) north of 

EMALL’s proposed seismic survey area. 

Villages in lower Cook Inlet adjacent 

to EMALL’s proposed survey area 

(Kenai, Salamatof, and Nikiski) have 

either not traditionally hunted beluga 

whales, or at least not in recent years, 

and rarely do they harvest sea lions. 

These villages more commonly harvest 

harbor seals, with Kenai reporting an 

average of about 13 per year between 

1992 and 2008 (Wolfe et al. 2009). 

According to Fall et al. (1984), many of 

the seals harvested by hunters from 

these villages were taken on the west 

side of the inlet during hunting 

excursions for moose and black bears. 

Although marine mammals remain an 

important subsistence resource in Cook 

Inlet, the number of animals annually 

harvested is low, and are primarily 

harbor seals. Much of the harbor seal 

harvest occurs incidental to other 

fishing and hunting activities, and at 

areas outside of the EMALL’s proposed 

survey areas such as the Susitna Delta 

or the west side of lower Cook Inlet. 

Also, EMALL is unlikely to conduct 

activity in the vicinity of any of the river 

mouths where large numbers of seals 

haul out. 

EMALL and NMFS recognize the 

importance of ensuring that Alaska 

Natives and federally recognized tribes 

are informed, engaged, and involved 

during the permitting process and will 

continue to work with the Alaska 

Natives and tribes to discuss operations 

and activities. 

Prior to offshore activities EMALL 

will to consult with nearby 

communities such as Tyonek, 

Salamatof, and the Kenaitze Indian 

Tribe to attend and present the program 

description prior to operations within 

those areas. 

If a conflict does occur with project 

activities involving subsistence or 

fishing, the project manager will 

immediately contact the affected party 

to resolve the conflict. 

Unmitigable Adverse Impact Analysis 

and Determination 

The project will not have any effect 

on beluga whale harvests because no 

beluga harvest will take place in 2016. 

Additionally, the proposed seismic 

survey area is not an important native 

subsistence site for other subsistence 

species of marine mammals thus, the 

number harvested is expected to be 

extremely low. The timing and location 

of subsistence harvest of Cook Inlet 

harbor seals may coincide with 

EMALL’s project, but because this 

subsistence hunt is conducted 

opportunistically and at such a low 

level (NMFS, 2013c), EMALL’s program 

is not expected to have an impact on the 

subsistence use of harbor seals. 

Moreover, the proposed survey would 

result in only temporary disturbances. 

Accordingly, the specified activity 

would not impact the availability of 

these other marine mammal species for 

subsistence uses. 

NMFS anticipates that any effects 

from EMALL’s proposed survey on 

marine mammals, especially harbor 

seals and Cook Inlet beluga whales, 

which are or have been taken for 

subsistence uses, would be short-term, 

site specific, and limited to 

inconsequential changes in behavior 

and mild stress responses. NMFS does 

not anticipate that the authorized taking 

of affected species or stocks will reduce 

the availability of the species to a level 

insufficient for a harvest to meet 

subsistence needs by: (1) Causing the 

marine mammals to abandon or avoid 

hunting areas; (2) directly displacing 

subsistence users; or (3) placing 

physical barriers between the marine 

mammals and the subsistence hunters; 

and that cannot be sufficiently mitigated 

by other measures to increase the 

availability of marine mammals to allow 

subsistence needs to be met. Based on 

the description of the specified activity, 

the measures described to minimize 

adverse effects on the availability of 

marine mammals for subsistence 

purposes, and the required mitigation 

and monitoring measures, NMFS has 

determined that there will not be an 

unmitigable adverse impact on 

subsistence uses from EMALL’s 

proposed activities. 

Endangered Species Act 

There is one marine mammal species 

listed as endangered under the ESA 

with confirmed or possible occurrence 

in the proposed project area: The Cook 

Inlet beluga whale. In addition, the 

proposed action could occur within 10 

miles of designated critical habitat for 

the Cook Inlet beluga whale. NMFS’s 

Permits and Conservation Division has 

initiated consultation with NMFS’ 

Alaska Region Protected Resources 

Division under section 7 of the ESA. 

This consultation will be concluded 

prior to issuing any final authorization. 

National Environmental Policy Act 

NMFS has prepared a Draft 

Environmental Assessment (EA) for the 

take of marine mammals incidental to 

issuance of IHAs for the proposed oil 

and gas activities in Cook Inlet. The 

Draft EA has been made available for 

public comment concurrently with this 

proposed authorization (see ADDRESSES). 

NMFS will finalize the EA and either 

conclude with a finding of no 

significant impact (FONSI) or prepare 

an Environmental Impact Statement 

prior to issuance of the final 

authorization (if issued). 

Proposed Authorization 

As a result of these preliminary 

determinations, we propose to issue an 

IHA to EMALL for taking marine 

mammals incidental to a geophysical 

and geotechnical survey in Cook Inlet, 

Alaska, provided the previously 

mentioned mitigation, monitoring, and 

reporting requirements are incorporated. 

The proposed IHA language is provided 

next. 

This section contains a draft of the 

IHA itself. The wording contained in 

this section is proposed for inclusion in 

the IHA (if issued). 

Incidental Harassment Authorization 

Exxon Mobil Alaska LNG LLC 

(EMALL), 3201 C Street; Suite 506, 

Anchorage, Alaska 99501, is hereby 

authorized under section 101(a)(5)(D) of 

the Marine Mammal Protection Act 

(MMPA; 16 U.S.C. 1371(a)(5)(D)), to 

harass small numbers of marine 

mammals incidental to specified 

activities associated with a marine 

geophysical and geotechnical survey in 

Cook Inlet, Alaska, contingent upon the 

following conditions: 

1. This Authorization is valid from 

March 1, 2016, through December 31, 

2016. 

2. This Authorization is valid only for 

EMALL’s activities associated with 

survey operations that shall occur 

within the areas denoted as Marine 

Terminal Survey Area and Pipeline 

Survey Area as depicted in the attached 

Figure 1 of EMALL’s October 2015 

application to the National Marine 

Fisheries Service. 

3. Species Authorized and Level of 

Take 

(a) The incidental taking of marine 

mammals, by Level B harassment only, 

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is limited to the following species in the 

waters of Cook Inlet: 

(i) Odontocetes: see Table 1 (attached) 

for authorized species and take 

numbers. 

(ii) Pinnipeds: see Table 1 (attached) 

for authorized species and take 

numbers. 

(iii) If any marine mammal species are 

encountered during activities that are 

not listed in Table 1 (attached) for 

authorized taking and are likely to be 

exposed to sound pressure levels (SPLs) 

greater than or equal to 160 dB re 1 mPa 

(rms) for impulsive sound of 120 dB re 

1mPa (rms), then the Holder of this 

Authorization must alter speed or 

course or shut-down the sound source 

to avoid take. 

(b) The taking by injury (Level A 

harassment), serious injury, or death of 

any of the species listed in Table 1 or 

the taking of any other species of marine 

mammal is prohibited and may result in 

the modification, suspension or 

revocation of this Authorization. 

(c) If the number of detected takes of 

any marine mammal species listed in 

Table 1 is met or exceeded, EMALL 

shall immediately cease survey 

operations involving the use of active 

sound sources (e.g., airguns, profilers 

etc.) and notify NMFS. 

4. The authorization for taking by 

harassment is limited to the following 

acoustic sources (or sources with 

comparable frequency and intensity) 

absent an amendment to this 

Authorization: 

(a) EdgeTech3200 Sub-bottom profiler 

chirp; 

(b) Applied Acoustics AA301 Subbottom profiler boomer; 

(c) A 60 in3 airgun; 

5. The taking of any marine mammal 

in a manner prohibited under this 

Authorization must be reported 

immediately to the Chief, Permits and 

Conservation Division, Office of 

Protected Resources, NMFS or her 

designee at (301) 427–8401. 

6. The holder of this Authorization 

must notify the Chief of the Permits and 

Conservation Division, Office of 

Protected Resources, or her designee at 

least 48 hours prior to the start of survey 

activities (unless constrained by the 

date of issuance of this Authorization in 

which case notification shall be made as 

soon as possible) at 301–427–8484 or to 

Sara.Young@noaa.gov. 

7. Mitigation and Monitoring 

Requirements: The Holder of this 

Authorization is required to implement 

the following mitigation and monitoring 

requirements when conducting the 

specified activities to achieve the least 

practicable impact on affected marine 

mammal species or stocks: 

(a) Utilize a minimum of two NMFSqualified PSOs per source vessel (one on 

duty and one off-duty) to visually watch 

for and monitor marine mammals near 

the seismic source vessels during 

daytime operations (from nautical 

twilight-dawn to nautical twilight-dusk) 

and before and during start-ups of 

sound sources day or night. Two PSVOs 

will be on each source vessel, and two 

PSVOs will be on a support vessel to 

observe the exclusion and disturbance 

zones. PSVOs shall have access to 

reticle binoculars (7x50) and long-range 

binoculars (40x80). PSVO shifts shall 

last no longer than 4 hours at a time. 

PSVOs shall also make observations 

during daytime periods when the sound 

sources are not operating for 

comparison of animal abundance and 

behavior, when feasible. When 

practicable, as an additional means of 

visual observation, EMALL’s vessel 

crew may also assist in detecting marine 

mammals. 

(b) Record the following information 

when a marine mammal is sighted: 

(i) Species, group size, age/size/sex 

categories (if determinable), behavior 

when first sighted and after initial 

sighting, heading (if consistent), bearing 

and distance from seismic vessel, 

sighting cue, apparent reaction to the 

airguns or vessel (e.g., none, avoidance, 

approach, paralleling, etc.), and 

behavioral pace; 

(ii) Time, location, heading, speed, 

activity of the vessel (including type of 

equipment operating), Beaufort sea state 

and wind force, visibility, and sun glare; 

and 

(iii) The data listed under Condition 

7(d)(ii) shall also be recorded at the start 

and end of each observation watch and 

during a watch whenever there is a 

change in one or more of the variables. 

(c) Establish a 160 dB re 1 mPa (rms) 

‘‘disturbance zone’’ for belugas, and 

groups of five or more harbor porpoises 

and killer whales as well as a 180 dB re 

1 mPa (rms) and 190 dB re 1 mPa (rms) 

‘‘exclusion zone’’ (EZ) for cetaceans and 

pinnipeds respectively before 

equipment is in operation. 

(d) Visually observe the entire extent 

of the EZ (180 dB re 1 mPa [rms] for 

cetaceans and 190 dB re 1 mPa [rms] for 

pinnipeds) using NMFS-qualified 

PSVOs, for at least 30 minutes (min) 

prior to starting the survey (day or 

night). If the PSVO finds a marine 

mammal within the EZ, EMALL must 

delay the seismic survey until the 

marine mammal(s) has left the area. If 

the PSVO sees a marine mammal that 

surfaces, then dives below the surface, 

the PSVO shall wait 30 min. If the PSVO 

sees no marine mammals during that 

time, they should assume that the 

animal has moved beyond the EZ. If for 

any reason the entire radius cannot be 

seen for the entire 30 min (i.e., rough 

seas, fog, darkness), or if marine 

mammals are near, approaching, or in 

the EZ, the sound sources may not be 

started. 

(e) Alter speed or course during 

survey operations if a marine mammal, 

based on its position and relative 

motion, appears likely to enter the 

relevant EZ. If speed or course alteration 

is not safe or practicable, or if after 

alteration the marine mammal still 

appears likely to enter the EZ, further 

mitigation measures, such as a 

shutdown, shall be taken. 

(f) Shutdown the sound source(s) if a 

marine mammal is detected within, 

approaches, or enters the relevant EZ. A 

shutdown means all operating sound 

sources are shut down (i.e., turned off). 

(g) Survey activity shall not resume 

until the PSVO has visually observed 

the marine mammal(s) exiting the EZ 

and is not likely to return, or has not 

been seen within the EZ for 15 min for 

species with shorter dive durations 

(small odontocetes and pinnipeds) or 30 

min for species with longer dive 

durations (large odontocetes, including 

killer whales and beluga whales). 

(h) Marine geophysical surveys may 

continue into night and low-light hours 

if such segment(s) of the survey is 

initiated when the entire relevant EZs 

can be effectively monitored visually 

(i.e., PSVO(s) must be able to see the 

extent of the entire relevant EZ). 

(i) No initiation of survey operations 

involving the use of sound sources is 

permitted from a shutdown position at 

night or during low-light hours (such as 

in dense fog or heavy rain). 

(j) If a beluga whale is visually sighted 

approaching or within the 

relevant160dB disturbance zone, survey 

activity will not commence or the sound 

source(s) shall be shut down until the 

animals are no longer present within the 

160-dB zone. 

(h) Whenever aggregations or groups 

of killer whales and/or harbor porpoises 

are detected approaching or within the 

160-dB disturbance zone, survey 

activity will not commence or the sound 

source(s) shall be shut-down until the 

animals are no longer present within the 

160-dB zone. An aggregation or group of 

whales/porpoises shall consist of five or 

more individuals of any age/sex class. 

(i) EMALL must not operate within 10 

miles (16 km) of the mean higher high 

water (MHHW) line of the Susitna Delta 

(Beluga River to the Little Susitna River) 

between April 15 and October 15 (to 

avoid any effects to belugas in an 

important feeding and breeding area). 

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(j) Survey operations involving the 

use of airguns, sub-bottom profiler, or 

vibracore must cease if takes of any 

marine mammal are met or exceeded. 

8. Reporting Requirements: The 

Holder of this Authorization is required 

to: 

(a) Submit a weekly field report, no 

later than close of business (Alaska 

time) each Thursday during the weeks 

when in-water survey activities take 

place. The field reports will summarize 

species detected, in-water activity 

occurring at the time of the sighting, 

behavioral reactions to in-water 

activities, and the number of marine 

mammals taken. The weekly reports 

will also contain information about 

which km2 grid cells that EMALL has 

operated in that week, along with the 

corresponding densities from the Goetz 

et al 2012 model to indicate how many 

belugas may have been taken by these 

operations. The weekly report will also 

include the number of belugas that may 

have been taken from previous weeks to 

track when EMALL is approaching their 

cap of 34 belugas. 

(b) Submit a monthly report, no later 

than the 15th of each month, to NMFS’ 

Permits and Conservation Division for 

all months during which in-water 

seismic survey activities occur. These 

reports must contain and summarize the 

following information: 

(i) Dates, times, locations, heading, 

speed, weather, sea conditions 

(including Beaufort sea state and wind 

force), and associated activities during 

all operations and marine mammal 

sightings; 

(ii) Species, number, location, 

distance from the vessel, and behavior 

of any marine mammals, as well as 

associated activity (type of equipment in 

use and number of shutdowns), 

observed throughout all monitoring 

activities; 

(iii) An estimate of the number (by 

species) of: (A) pinnipeds that have 

been exposed to the activity (based on 

visual observation) at received levels 

greater than or equal to 160 dB re 1 mPa 

(rms) and/or 190 dB re 1 mPa (rms) with 

a discussion of any specific behaviors 

those individuals exhibited; and (B) 

cetaceans that have been exposed to the 

activity (based on visual observation) at 

received levels greater than or equal to 

120 dB or 160 dB re 1 mPa (rms) and/ 

or 180 dB re 1 mPa (rms) with a 

discussion of any specific behaviors 

those individuals exhibited. 

(iv) A description of the 

implementation and effectiveness of the: 

(A) terms and conditions of the 

Biological Opinion’s Incidental Take 

Statement (ITS); and (B) mitigation 

measures of this Authorization. For the 

Biological Opinion, the report shall 

confirm the implementation of each 

Term and Condition, as well as any 

conservation recommendations, and 

describe their effectiveness, for 

minimizing the adverse effects of the 

action on Endangered Species Act-listed 

marine mammals. 

(c) Submit a draft Technical Report on 

all activities and monitoring results to 

NMFS’ Permits and Conservation 

Division within 90 days of the 

completion of the seismic survey. The 

Technical Report will include the 

following information: 

(i) Summaries of monitoring effort 

(e.g., total hours, total distances, and 

marine mammal distribution through 

the study period, accounting for sea 

state and other factors affecting 

visibility and detectability of marine 

mammals); 

(ii) Analyses of the effects of various 

factors influencing detectability of 

marine mammals (e.g., sea state, number 

of observers, and fog/glare); 

(iii) Species composition, occurrence, 

and distribution of marine mammal 

sightings, including date, water depth, 

numbers, age/size/gender categories (if 

determinable), group sizes, and ice 

cover; 

(iv) Analyses of the effects of survey 

operations; and 

(v) Sighting rates of marine mammals 

during periods with and without survey 

activities (and other variables that could 

affect detectability), such as: (A) initial 

sighting distances versus survey activity 

state; (B) closest point of approach 

versus survey activity state; (C) observed 

behaviors and types of movements 

versus survey activity state; (D) numbers 

of sightings/individuals seen versus 

survey activity state; (E) distribution 

around the source vessels versus survey 

activity state; and (F) estimates of take 

by Level B harassment based on 

presence in the relevant 120 dB or 160 

dB harassment zone. 

(d) Submit a final report to the Chief, 

Permits and Conservation Division, 

Office of Protected Resources, NMFS, 

within 30 days after receiving comments 

from NMFS on the draft report. If NMFS 

decides that the draft report needs no 

comments, the draft report shall be 

considered to be the final report. 

(e) EMALL must immediately report 

to NMFS if 25 belugas are detected 

within the relevant 120 dB or 160 dB re 

1 mPa (rms) disturbance zone during 

survey operations to allow NMFS to 

consider making necessary adjustments 

to monitoring and mitigation. 

9. (a) In the unanticipated event that 

the specified activity clearly causes the 

take of a marine mammal in a manner 

prohibited by this Authorization, such 

as an injury (Level A harassment), 

serious injury or mortality (e.g., shipstrike, gear interaction, and/or 

entanglement), EMALL shall 

immediately cease the specified 

activities and immediately report the 

incident to the Chief of the Permits and 

Conservation Division, Office of 

Protected Resources, NMFS, or her 

designees by phone or email (telephone: 

301–427–8401 or Sara.Young@

noaa.gov), the Alaska Regional Office 

(telephone: 907–271–1332 or 

Barbara.Mahoney@noaa.gov), and the 

Alaska Regional Stranding Coordinators 

(telephone: 907–586–7248 or 

Aleria.Jensen@noaa.gov or 

Barbara.Mahoney@noaa.gov). The 

report must include the following 

information: 

(i) Time, date, and location (latitude/ 

longitude) of the incident; 

(ii) The name and type of vessel 

involved; 

(iii) The vessel’s speed during and 

leading up to the incident; 

(iv) Description of the incident; 

(v) Status of all sound source use in 

the 24 hours preceding the incident; 

(vi) Water depth; 

(vii) Environmental conditions (e.g., 

wind speed and direction, Beaufort sea 

state, cloud cover, and visibility); 

(viii) Description of marine mammal 

observations in the 24 hours preceding 

the incident; 

(ix) Species identification or 

description of the animal(s) involved; 

(x) The fate of the animal(s); and 

(xi) Photographs or video footage of 

the animal (if equipment is available). 

Activities shall not resume until 

NMFS is able to review the 

circumstances of the prohibited take. 

NMFS shall work with EMALL to 

determine what is necessary to 

minimize the likelihood of further 

prohibited take and ensure MMPA 

compliance. EMALL may not resume 

their activities until notified by NMFS 

via letter or email, or telephone. 

(b) In the event that EMALL discovers 

an injured or dead marine mammal, and 

the lead PSO determines that the cause 

of the injury or death is unknown and 

the death is relatively recent (i.e., in less 

than a moderate state of decomposition 

as described in the next paragraph), 

EMALL will immediately report the 

incident to the Chief of the Permits and 

Conservation Division, Office of 

Protected Resources, NMFS, her 

designees, and the NMFS Alaska 

Stranding Hotline (see contact 

information in Condition 9(a)). The 

report must include the same 

information identified in the Condition 

9(a) above. Activities may continue 

while NMFS reviews the circumstances 

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of the incident. NMFS will work with 

EMALL to determine whether 

modifications in the activities are 

appropriate. 

(c) In the event that EMALL discovers 

an injured or dead marine mammal, and 

the lead PSO determines that the injury 

or death is not associated with or related 

to the activities authorized in Condition 

2 of this Authorization (e.g., previously 

wounded animal, carcass with moderate 

to advanced decomposition, or 

scavenger damage), EMALL shall report 

the incident to the Chief of the Permits 

and Conservation Division, Office of 

Protected Resources, NMFS, her 

designees, the NMFS Alaska Stranding 

Hotline (1–877–925–7773), and the 

Alaska Regional Stranding Coordinators 

within 24 hours of the discovery (see 

contact information in Condition 9(a)). 

EMALL shall provide photographs or 

video footage (if available) or other 

documentation of the stranded animal 

sighting to NMFS and the Marine 

Mammal Stranding Network. Activities 

may continue while NMFS reviews the 

circumstances of the incident. 

10. EMALL is required to comply 

with the Reasonable and Prudent 

Measures and Terms and Conditions of 

the ITS corresponding to NMFS’ 

Biological Opinion issued to both U.S. 

Army Corps of Engineers and NMFS’ 

Office of Protected Resources. 

11. A copy of this Authorization and 

the ITS must be in the possession of all 

contractors and PSOs operating under 

the authority of this Incidental 

Harassment Authorization. 

12. Penalties and Permit Sanctions: 

Any person who violates any provision 

of this Incidental Harassment 

Authorization is subject to civil and 

criminal penalties, permit sanctions, 

and forfeiture as authorized under the 

MMPA. 

13. This Authorization may be 

modified, suspended or withdrawn if 

the Holder fails to abide by the 

conditions prescribed herein or if the 

authorized taking is having more than a 

negligible impact on the species or stock 

of affected marine mammals, or if there 

is an unmitigable adverse impact on the 

availability of such species or stocks for 

subsistence uses. 

TABLE 1—AUTHORIZED TAKE NUMBERS FOR EACH MARINE MAMMAL

SPECIES IN COOK INLET

Species 

Authorized 

take in the 

Cook Inlet 

action area 

Odontocetes 

Beluga whale (Delphinapterus 

leucas) ................................. 34 

TABLE 1—AUTHORIZED TAKE NUMBERS FOR EACH MARINE MAMMAL

SPECIES IN COOK INLET—Continued 

Species 

Authorized 

take in the 

Cook Inlet 

action area 

Killer whale (Orcinus orca) ..... 13 

Harbor porpoise (Phocoena 

phocoena) ........................... 54 

Pinnipeds 

Harbor seal (Phoca vitulina 

richardsi) ............................. 4,643 

Request for Public Comments 

We request comment on our analysis, 

the draft authorization, and any other 

aspect of the Notice of Proposed IHA for 

EMALL. Please include with your 

comments any supporting data or 

literature citations to help inform our 

final decision on EMALL’s request for 

an MMPA authorization. 

Dated: January 29, 2016. 

Perry F. Gayaldo, 

Deputy Director, Office of Protected 

Resources, National Marine Fisheries Service. 

[FR Doc. 2016–01967 Filed 2–4–16; 8:45 am] 

BILLING CODE 3510–22–P 

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