Federal Register / Vol. 75, No. 171 / Friday, September 3, 2010 / Notices 54095 

LIST OF PETITIONS RECEIVED BY EDA FOR CERTIFICATION OF ELIGIBILITY TO APPLY FOR TRADE ADJUSTMENT 8/17/2010 

THROUGH 8/27/2010 

Firm name Address Date accepted 

for filing Products 

American Standard Circuits, 

Inc.

475 Industrial Drive, West Chicago, IL 60185.08/18/10 The company is a manufacturer of printed circuit boards for 

the military, aerospace, industrial, commercial, medical, 

telecommunications, computer, radar and transportation industries. 

Diamond Roltran, LLC ............. 59 Porter Road, Littleton, MA 

01460.

08/27/10 The company manufactures roll rings. Roll rings transfer 

power, data and signals over rotary interfaces. They are 

custom designed, although there are four basic types: 

Flexures, couplers, roll blocks and flex wheels. 

Manchester Wood, Inc ............ 180 North Street, Granville, 

NY 12832–9438.

08/18/10 The company produces wooded furniture for the retailing industry including TV tray tables, kitchen gourmet carts and 

Adirondack style furniture. 

McVan, Inc .............................. 35 Frank Mossberg Drive, Attleboro, MA 02703.08/23/10 The company manufactures gold, silver and pewter jewelry 

and religious products. Their manufacturing process consists of stamping and casting. 

Any party having a substantial 

interest in these proceedings may 

request a public hearing on the matter. 

A written request for a hearing must be 

submitted to the Trade Adjustment 

Assistance for Firms Division, Room 

7106, Economic Development 

Administration, U.S. Department of 

Commerce, Washington, DC 20230, no 

later than ten (10) calendar days 

following publication of this notice. 

Please follow the procedures set forth 

in Section 315.9 of EDA’s final rule (71 

FR 56704) for procedures for requesting 

a public hearing. The Catalog of Federal 

Domestic Assistance official program 

number and title of the program under 

which these petitions are submitted is 

11.313, Trade Adjustment Assistance. 

Dated: August 27, 2010. 

Miriam J. Kearse, 

Program Team Lead. 

[FR Doc. 2010–22123 Filed 9–2–10; 8:45 am] 

BILLING CODE 3510–24–P 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

RIN 0648–XY12 

Takes of Marine Mammals Incidental to 

Specified Activities; Low-Energy 

Marine Seismic Survey in the Eastern 

Tropical Pacific Ocean Off Central and 

South America, October–November 

2010 

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 the Scripps Institution 

of Oceanography (SIO) of the University 

of California for an Incidental 

Harassment Authorization (IHA) to take 

marine mammals, by harassment, 

incidental to conducting a low-energy 

marine seismic survey. Pursuant to the 

Marine Mammal Protection Act 

(MMPA), NMFS is requesting comments 

on its proposal to issue an IHA to SIO 

to take, by Level B Harassment only, 21 

species of marine mammals during the 

specified activity. 

DATES: Comments and information must 

be received no later than October 4, 

2010. 

ADDRESSES: Comments on the 

application should be addressed to 

Michael Payne, Chief, Permits, 

Conservation and Education Division, 

Office of Protected Resources, National 

Marine Fisheries Service, 1315 EastWest Highway, Silver Spring, MD 

20910. The mailbox address for 

providing e-mail comments is 

PR1.0648–XY12@noaa.gov. NMFS is not 

responsible for e-mail comments sent to 

addresses other than the one provided 

here. Comments sent via e-mail, 

including all attachments, must not 

exceed a 10-megabyte file size. 

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. 

A copy of the application containing 

a list of the references used in this 

document 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 National Science 

Foundation (NSF), which is providing 

funding for the proposed action, has 

prepared a draft Environmental 

Assessment (EA) titled ‘‘Marine 

Geophysical Survey by the R/V Melville 

in the Pacific Ocean off Central and 

South America, October–November 

2010’’. The NSF draft EA incorporates 

an ‘‘Environmental Assessment of a 

Marine Geophysical Survey by the R/V 

Melville in the Pacific Ocean off Central 

and South America, October–November 

2010’’, prepared by LGL Limited, 

Environmental Research Associates, on 

behalf of NSF. These associated 

documents, prepared in compliance 

with the National Environmental Policy 

Act (NEPA), are also available at the 

same Internet address. Documents cited 

in this notice may also be viewed, by 

appointment, during regular business 

hours, at the aforementioned address. 

FOR FURTHER INFORMATION CONTACT: Ben 

Laws or Candace Nachman, Office of 

Protected Resources, NMFS, (301) 713– 

2289. 

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 


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authorization is provided to the public 

for review. 

Authorization for incidental takings 

shall be granted if NMFS finds that the 

taking will have a negligible impact on 

the species or stock(s), will not have an 

unmitigable adverse impact on the 

availability of the species or stock(s) for 

subsistence uses (where relevant), and if 

the permissible methods of taking and 

requirements pertaining to the 

mitigation, monitoring and reporting of 

such takings are set forth. NMFS has 

defined ‘‘negligible impact’’ in 50 CFR 

216.103 as ‘‘* * * an impact resulting 

from the specified activity that cannot 

be reasonably expected to, and is not 

reasonably likely to, adversely affect the 

species or stock through effects on 

annual rates of recruitment or survival.’’ 

Section 101(a)(5)(D) of the MMPA 

established an expedited process by 

which citizens of the U.S. can apply for 

an authorization to incidentally take 

small numbers of marine mammals by 

harassment. Section 101(a)(5)(D) 

establishes a 45-day time limit for 

NMFS review of an application 

followed by a 30-day public notice and 

comment period on any proposed 

authorizations for the incidental 

harassment of marine mammals. Within 

45 days of the close of the comment 

period, NMFS must either issue or deny 

the authorization. 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 

NMFS received an application on 

May 28, 2010 from SIO for the taking, 

by harassment, of marine mammals 

incidental to conducting, in 

collaboration with Texas A&M 

University and with research funding 

provided by the National Science 

Foundation, a low-energy marine 

seismic survey. NMFS reviewed SIO’s 

application and identified a number of 

issues requiring further clarification. 

After addressing comments from NMFS, 

SIO modified its application and 

submitted a revised application on July 

14, 2010. NMFS carefully evaluated 

SIO’s application, including their 

analyses, and determined that the 

application is complete and provides 

sufficient data for NMFS to make the 

necessary preliminary determinations 

pursuant to the MMPA. The July 14, 

2010 application is the one available for 

public comment (see ADDRESSES) and 

considered by NMFS for this proposed 

IHA. 

The proposed survey will occur in the 

Eastern Tropical Pacific Ocean (ETP), 

encompassing the area from 

approximately 8° N–12° S and 80–91° 

W, off the coasts of Costa Rica, Panama, 

Colombia, Ecuador, and Peru, in 

International Waters and within the 

Exclusive Economic Zones (EEZs) of 

Costa Rica, Panama, Colombia, and 

Ecuador, and is scheduled to occur from 

October 19–November 14, 2010. Some 

minor deviation from these dates is 

possible, depending on logistics and 

weather. The survey will use a pair of 

Generator Injector (GI) airguns, each 

with a discharge volume of 45 in3. 

Seismic airgun operations are expected 

to result in the incidental take, by Level 

B harassment only, of up to 21 species 

of marine mammals. These species 

include: Bryde’s whale; blue whale; 

sperm whale; humpback whale; Cuvier’s 

beaked whale; Blainville’s beaked 

whale; pygmy beaked whale; gingkotoothed beaked whale; rough-toothed 

dolphin; bottlenose dolphin; 

pantropical spotted dolphin; spinner 

dolphin; striped dolphin; Fraser’s 

dolphin; short-beaked common dolphin; 

Risso’s dolphin; melon-headed whale; 

pygmy killer whale; false killer whale; 

killer whale; and short-finned pilot 

whale. 

Description of the Specified Activity 

SIO plans to conduct a seismic survey 

as part of an integrated geophysical and 

geochemical study. In addition to the GI 

airguns, a multibeam echosounder 

(MBES) and a sub-bottom profiler (SBP) 

will be utilized for research purposes. 

The planned survey will involve one 

source vessel, the R/V Melville 

(Melville). 

The purpose of this project is to better 

understand how marine sediments 

record paleo-oceanographic 

information. The deposition of 

sediments in the upper 500 m (1640.4 

ft) of the sediment column will be 

studied using known seismic horizons 

in the sediment column to estimate rates 

of deposition downstream from 

potential sediment sources on the 

topographic highs and to estimate loss 

from the ridges. The seismic survey and 

associated coring and water sampling 

will allow comparisons of geophysical 

estimates of the level of erosion from 

marine ridges and highs with 

geochemical estimates of sediment 

focusing based upon the distribution of 

Th-230, a particle-reactive isotope 

produced by the decay of dissolved 

uranium in the water column. In 

addition, the study will examine 

whether there are sediment sources for 

Th-230 in slowly-accumulating 

sediments. 

The Melville is expected to depart 

Puntarenas, Costa Rica, on October 19, 

2010, and spend approximately 15 days 

conducting seismic surveys, 10 days 

collecting water and core samples, and 

approximately 2 days in transit, arriving 

at Arica, Chile, on November 14, 2010. 

At each of four sites (see Figure 1 of 

SIO’s application), seismic operations 

will be conducted for approximately 2 

days, and each water sampling and 

coring station will be occupied for 1–2 

days. Some minor deviation from these 

dates is possible, depending on logistics 

and weather. 

The source vessel, the Melville, will 

deploy a pair of low-energy GI airguns 

as an energy source at a depth of 2 m 

(each with a discharge volume of 45 

in3), plus either of two towed 

hydrophone streamers, one 725 m 

(2378.6 ft) long with 40 channels, and 

the other 350 m (1148.3 ft) long with 16 

channels. Hydrophone streamers are 

towed at adjustable depth to afford best 

reception of returning seismic signals, 

depending upon surface conditions, but 

are typically towed in at approximately 

10 m. The energy to the GI airgun is 

compressed air supplied by compressors 

onboard the source vessel. As the GI 

airgun is towed along the survey lines, 

the receiving systems will receive the 

returning acoustic signals. 

In addition to the GI airguns, an 

MBES and an SBP will be used 

throughout the cruise, except while at 

water/core stations, to help verify 

seafloor conditions at possible coring 

sites and to collect additional seafloor 

bathymetric data. Passive geophysical 

sensors (a gravimeter and a 

magnetometer) will also be operated 

continuously throughout the entire 

cruise. 

All potential incidental take, by 

harassment only, is expected to result 

from the operation of the GI airguns. 

Take is not expected to result from the 

use of the MBES or SBP, for reasons 

discussed below, or from collision with 

the vessel because it is a single vessel, 

moving at a relatively slow speed 

(operational speeds of approximately 11 

km/hr [6 knots] during seismic 

acquisition within the survey areas and 

15–18.5 km/hr [8–10 knots] between 

survey areas and stations), for a 

relatively short period of time 

(approximately 30 days). It is likely that 

any marine mammal would be able to 

avoid the vessel. 

The seismic program will consist of 

approximately 5475 km (3402 mi) of 


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survey lines, including turns (see Figure 

1 of SIO’s application). Water depths at 

the seismic survey locations are 

approximately 1000–4800 m (3280.8– 

15,748 ft). The GI airguns will be 

operated on a small grid for 

approximately 45 hours at each of four 

sites (see Figure 1 of SIO’s application) 

where the 40-channel streamer will be 

used, and for most of the time during 

transits between the sites, to the first 

site, and after the last site, where the 12- 

channel streamer will be used. There 

will be additional seismic operations 

associated with equipment testing, 

startup, and possible line changes or 

repeat coverage of any areas where 

initial data quality is sub-standard. 

Those additional operations are allowed 

for in the estimated total line-kilometers 

given above. The Melville is expected to 

depart Puntarenas, Costa Rica, on 

October 19, 2010 and spend 

approximately 15 days conducting 

seismic surveys, 10 days collecting 

water and core samples, and 

approximately 2 days in transit, arriving 

at Arica, Chile, on November 14, 2010. 

All planned geophysical data 

acquisition activities will be conducted 

by SIO with on-board assistance by the 

scientists who have proposed the study. 

The Chief Scientist is Dr. Franco 

Marcantonio of Texas A&M University. 

The vessel will be self-contained, and 

the crew will live aboard the vessel for 

the entire cruise. 

Vessel Specifications 

The Melville has a length of 85 m 

(278.9 ft), a beam of 14 m (45.9 ft), and 

a maximum draft of 5 m (16.4 ft). The 

ship is powered by two 1385-hp diesel 

engines and a 900-hp retracting 

azimuthing bow thruster. Operation 

speeds of approximately 11 km/hr (5.9 

knots) and 15–18.5 km/hr (8.1–10 knots) 

will be used during seismic acquisition 

within the survey areas and between the 

areas and stations, respectively. When 

not towing seismic survey gear, the 

Melville cruises at 21.7 km/hr (11.7 

knots) and has a maximum speed of 

25.9 km/hr (14 knots). The Melville will 

also serve as the platform from which 

vessel-based protected species observers 

(PSOs) will watch for animals before 

and during airgun operations (discussed 

later in this document). 

Acoustic Source Specifications 

(1) Seismic Airguns 

The Melville will tow a pair of 45-in3

Sercel GI airguns and a streamer 

containing hydrophones along 

predetermined lines. Seismic pulses 

will be emitted at intervals of 8–10 s. At 

speeds of approximately 11–18.5 km/hr 

(5.9–10 knots), the 8–10 s spacing 

corresponds to shot intervals of 

approximately 25–50 m (82–164 ft). 

The generator chamber of each GI 

airgun, responsible for introducing the 

sound pulse into the ocean, is 45 in3. 

The larger (105-in3) injector chamber 

injects air into the previously-generated 

bubble to maintain its shape and does 

not introduce more sound into the 

water. The two 45-in3 GI airguns will be 

towed 8 m (26.2 ft) apart side by side, 

21 m (68.9 ft) behind the Melville, at a 

depth of 2 m (6.6 ft). 

As the GI airgun is towed along the 

survey line, the towed hydrophone 

array in the streamer receives the 

reflected signals and transfers the data 

to the on-board processing system. 

Given the relatively short streamer 

length behind the vessel, the turning 

rate of the vessel while the gear is 

deployed is much higher than the limit 

of five degrees per minute for a seismic 

vessel towing a streamer of more typical 

length (greater than l km (0.6 mi)). Thus, 

the maneuverability of the vessel is not 

limited much during operations. 

The root mean square (rms) received 

levels that are used as impact criteria for 

marine mammals are not directly 

comparable to the peak (pk or 0-pk) or 

peak-to-peak (pk-pk) values normally 

used to characterize source levels of 

airgun arrays. The measurement units 

used to describe airgun sources, peak or 

peak-to-peak decibels, are always higher 

than the rms decibels referred to in 

biological literature. A measured 

received level of 160 dB re 1 μPa (rms) 

in the far field would typically 

correspond to a peak measurement of 

approximately 170 dB and to a peak-topeak measurement of approximately 

176–178 dB, as measured for the same 

pulse received at the same location 

(Greene, 1997; McCauley et al., 1998, 

2000). The precise difference between 

rms and peak or peak-to-peak values 

depends on the frequency content and 

duration of the pulse, among other 

factors. However, the rms level is 

always lower than the peak or peak-topeak level for an airgun-type source. 

The actual received level at any location 

in the water near the GI airguns will not 

exceed the source level of the strongest 

individual source. In this case, that will 

be about 224.6 dB re 1 μPa-m peak or 

229.8 dB re 1 μPa-m peak-to-peak. The 

dominant frequency components of the 

GI airguns are 0–188 Hertz (Hz). 

Received sound levels have been 

modeled by Lamont-Doherty Earth 

Observatory (L–DEO) for a number of 

airgun configurations, including two 45 

in3 Nucleus G. Guns, in relation to 

distance and direction from the airgun 

(see Figure 2 of SIO’s application). The 

model does not allow for bottom 

interactions and is most directly 

applicable to deep water. Based on the 

modeling, estimates of the maximum 

distances from the GI airguns where 

sound levels of 190, 180, and 160 dB re 

1 μPa (rms) are predicted to be received 

in deep (>1,000 m (3280.8 ft)) water are 

shown in Table 1 below. Because the 

model results are for G. Guns, which 

have more energy than GI airguns of the 

same size, the distances in Table 1 

overestimate the distances for the 45 in3

GI airguns. 

(2) Multibeam Echosounder and SubBottom Profiler 

Along with the GI airgun operations, 

an MBES and a SBP will be operated 

from the source vessel at certain times 

during the planned study to help verify 

seafloor conditions at possible coring 

sites and to collect additional seafloor 

bathymetric data. 

The Kongsberg EM 122 MBES 

operates at 10.5–13 (usually 12) 

kilohertz (kHz) and is hull-mounted on 

the Melville. The transmitting 

beamwidth is 1° fore-aft and 150° 

athwartship. The maximum source level 

is 242 dB re 1 μPa-m (rms). Each ‘‘ping’’ 

consists of eight (in water >1000 m 

deep) or four (<1000 m deep) successive 

fan-shaped transmissions, each 

ensonifying a sector that extends 1° foreaft. Continuous-wave pulses increase 

from 2 to 15 ms long in water depths up 

to 2600 m (8530.2 ft), and FM chirp 

pulses up to 100 ms long are used in 

water >2600 m. The successive 

transmissions span an overall crosstrack angular extent of about 150°, with 

2-ms gaps between the pulses for 

successive sectors. 

The Knudsen Engineering Model 

320B/R SBP is a dual-frequency 

transceiver designed to operate at 3.5 

and/or 12 kHz. It is used in conjunction 

with the MBES to provide data about 

the sedimentary features that occur 

below the sea floor. The energy from the 

SBP is directed downward via a 3.5-kHz 

transducer array mounted in the hull of 

the Melville. The maximum power 

output of the 320B/R is 10 kilowatts for 

the 3.5-kHz section and 2 kilowatts for 

the 12-kHz section. The nominal 

beamwidth is 80°. 

The pulse length for the 3.5-kHz 

section of the 320B/R is 0.8–24 ms, 

controlled by the system operator in 

regards to water depth and reflectivity 

of the bottom sediments and will 

usually be 6, 12, or 24 ms at the water 

depths at the study sites and in transit 

from Puntarenas and to Arica. The 

system produces one sound pulse and 

then waits for its return before 

transmitting again. Thus, the pulse 


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interval is directly dependent upon 

water depth, and in this survey is 0.8– 

1.5 s. Using the Sonar Equations and 

assuming 100 percent efficiency in the 

system (impractical in real world 

applications), the source level for the 

320B/R is calculated to be 211 dB re 1 

μPa-m. In practice, the system is rarely 

operated above 80 percent power level. 

(3) Safety Radii 

NMFS has determined that for 

acoustic effects, using acoustic 

thresholds in combination with 

corresponding safety radii is an effective 

way to consistently apply measures to 

avoid or minimize the impacts of an 

action, and to quantitatively estimate 

the effects of an action. Thresholds are 

used in two ways: (1) To establish a 

mitigation shut-down or power-down 

zone, i.e., if an animal enters an area 

calculated to be ensonified above the 

level of an established threshold, a 

sound source is powered down or shut 

down; and (2) to calculate take, in that 

a model may be used to calculate the 

area around the sound source that will 

be ensonified to that level or above, 

then, based on the estimated density of 

animals and the distance that the sound 

source moves, NMFS can estimate the 

number of marine mammals that may be 

‘‘taken.’’ 

As a matter of past practice and based 

on the best available information at the 

time regarding the effects of marine 

sound, NMFS estimates that Level A 

harassment from acoustic sources may 

occur when animals are exposed to 

levels above 180 dB re 1 μPa (rms) level 

for cetaceans and 190 dB re 1 μPa (rms) 

for pinnipeds. A review of the available 

scientific data using an application of 

science-based extrapolation procedures 

(Southall et al., 2007) strongly suggests 

that Level A harassment (as well as 

temporary threshold shift (TTS)) from 

single sound exposure impulse events 

may occur at much higher levels than 

the levels previously estimated using 

very limited data. However, for 

purposes of this proposed action, SIO’s 

application sets forth, and NMFS is 

using, the more conservative 180 and 

190 dB re 1 μPa (rms) criteria. NMFS 

also considers 160 dB re 1 μPa (rms) as 

the criterion for estimating the onset of 

Level B harassment from acoustic 

sources producing impulse sounds, as 

in this seismic survey. 

Empirical data concerning the 180- 

and 160-dB distances have been 

acquired based on measurements during 

the acoustic verification study 

conducted by L–DEO in the northern 

Gulf of Mexico from May 27–June 3, 

2003 (Tolstoy et al., 2004). Although the 

results are limited, the data showed that 

radii around the airguns where the 

received level would be 180 dB re 1 μPa 

(rms), the safety criterion applicable to 

cetaceans (NMFS 2000), vary with water 

depth. Similar depth-related variation is 

likely in the 190 dB distances applicable 

to pinnipeds. Correction factors were 

developed for water depths 100–1000 m 

and <100 m. The proposed survey will 

occur in depths of approximately 1000– 

4800 m, so the correction factors for 

shallow water are not relevant here. All 

of the seismic operations will be in 

depths >1000 m. 

The empirical data indicate that, for 

deep water (>1000 m), the L–DEO 

model tends to overestimate the 

received sound levels at a given 

distance (Tolstoy et al., 2004). However, 

to be precautionary pending acquisition 

of additional empirical data, it is 

proposed that safety radii during GI 

airgun operations in deep water will be 

values predicted by L–DEO’s model (see 

Table 1 in this document). Therefore, 

the assumed 180- and 190-dB radii are 

40 m (131.2 ft) and 10 m (32.8 ft), 

respectively. 

TABLE 1—PREDICTED DISTANCES TO WHICH SOUND LEVELS ≥190, 180 AND 160 DB RE 1 μPA (RMS) MIGHT BE RECEIVED FROM TWO 45 IN3 GI AIRGUNS THAT WILL BE USED DURING THE SEISMIC SURVEYS IN THE EASTERN TROPICAL PACIFIC OCEAN DURING OCTOBER-NOVEMBER 2010 

[Distances are based on model results provided by L–DEO.] 

Source and volume Tow depth (m) Water depth 

Estimated distances at received levels (m) 

190 dB 180 dB 160 dB 

Two GI airguns, 45 in3 each 2 Deep (>1000 m) ............................ 10 40 400 

Description of Marine Mammals in the 

Area of the Specified Activity 

Forty-three species of marine 

mammals, including 29 odontocetes, 7 

mysticetes, 6 pinnipeds, and the marine 

sea otter (Enhydra lutris), are known to 

occur in the ETP. Of these, 23 cetacean 

species are likely to occur in the 

proposed survey areas in the ETP during 

October–November (see Table 2 in this 

document), and are considered further 

here. Three of these 23 cetacean species 

are listed under the Endangered Species 

Act (ESA) as Endangered: The sperm 

(Physeter macrocephalus), humpback 

(Megaptera novaeangliae), and blue 

(Balaenoptera musculus) whales. 

Nine cetacean species, although 

present in the wider ETP, likely would 

not be found in the proposed seismic 

survey areas because their ranges do not 

extend that far south or north. Pacific 

white-sided dolphins (Lagenorhynchus 

obliquidens) and Baird’s beaked whales 

(Berardius bairdii) are seen very 

occasionally in the northernmost 

portions of the ETP (Ferguson and 

Barlow, 2001). Long-beaked common 

dolphins (Delphinus capensis) are 

known to occur in the northernmost 

areas of the ETP off Baja California, 

Mexico, and off the coast of Peru 

(Heyning and Perrin, 1994). Southern 

right whales (Eubalaena australis) are 

seen on rare occasions off the coasts of 

Peru and Chile (Aguayo et al., 1992; 

Santillan et al., 2004). Gray’s beaked 

whales (Mesoplodon grayi) are 

distributed in the southernmost portions 

of the ETP and off the coast of southern 

Peru (Culik, 2010). Dusky dolphins 

(Lagenorhynchus obscurus), southern 

right whale dolphins (Lissodelphis 

peronii), Burmeister’s porpoises 

(Phocoena spinipinnis), and long-finned 

pilot whales (Globicephala melas) also 

occur near the Peruvian coast 

(Leatherwood et al., 1991; Van 

Waerebeek et al., 1991; Brownell and 

Clapham, 1999; Olson and Reilly, 2002). 

These nine species are not addressed in 

detail in SIO’s application and are not 

considered further in this Notice of 

Proposed IHA. 

Sei (Balaenoptera borealis) and fin (B. 

physalus) whales, listed as Endangered 

under the ESA, are known from the ETP 

but are considered very rare in the 

proposed survey area. Sei whales may 

have been sighted during surveys in the 

ETP (Wade and Gerrodette, 1993; 

Kinzey et al., 1999, 2000, 2001); 

however, it is difficult to distinguish sei 

whales from Bryde’s whales (B. edeni) at 

sea. Because sei whales generally have 

a more northerly and temperate 

distribution (Leatherwood et al., 1988), 

Wade and Gerrodette (1993) classified 


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any tentative sei whale observations in 

the ETP as Bryde’s whale sightings. Sei 

whales may also have been sighted near 

the Galapagos Islands (Clarke, 1962); 

although, Clarke and Aguayo (1965) 

suggested that those sightings could 

have been Bryde’s whales. Although the 

occurrence of sei whales is documented 

off Costa Rica (Rodriguez-Herrera et al., 

2002), the reliability of the 

identification is uncertain. Neither 

Ferguson and Barlow (2001) or Jackson 

et al. (2008) positively identified sei 

whales in or near the proposed project 

area during surveys conducted during 

July–December. Similarly, Rasmussen et 

al. (2004) did not report sei whales in 

8 years of surveys off Costa Rica or 

Panama. No sei whales were detected 

during L–DEO seismic surveys off Costa 

Rica or Nicaragua in November– 

December 2004 or February–March 2008 

(Holst et al., 2005b; Holst and Smultea, 

2008), in the Hess Deep approximately 

1100 km (683.5 mi) west of the 

Galapagos Islands in July 2003 (Smultea 

and Holst, 2003), or 1600–1950 km 

(994.2–1211.7 mi) west of the proposed 

survey area in April–August 2008 

(Hauser et al., 2008). 

No confirmed fin whale sightings 

were made in the proposed study area 

during 10 years of survey effort in July– 

December by Ferguson and Barlow 

(2001) or by Jackson et al. (2008) during 

July–December surveys in 2006. Despite 

>30 years of NMFS and other surveys, 

as well as stranding records from the 

Pacific coast of Costa Rica, there have 

been no confirmed records of fin whales 

(May-Collado et al., 2005). A possible 

sighting of a fin whale in this region 

occurred off the Osa Peninsula in 1997; 

however, the sighting was not 

confirmed (May-Collado et al., 2005), 

although Rodriguez-Herrera et al. (2002) 

list the fin whale as having been 

documented off Costa Rica. No fin 

whales were detected during L–DEO 

seismic surveys off Costa Rica or 

Nicaragua in November–December 2004 

or February–March 2008 (Holst et al., 

2005b; Holst and Smultea, 2008), in the 

Hess Deep approximately 1100 km 

(683.5 mi) west of the Galapagos Islands 

in July 2003 (Smultea and Holst, 2003), 

or 1600–1950 km (994.2–1211.7 mi) 

west of the proposed survey area in 

April–August 2008 (Hauser et al., 2008). 

Sei and fin whales are not considered 

further in this document. 

The general distribution of minke 

whales (Balaenoptera acutorostrata) 

includes the offshore waters of the study 

area (Reeves et al., 2002). However, 

minke whales are likely to be rare in the 

survey area. This species has been 

found off the coast of Costa Rica on 

occasion (Rodriguez-Herrera et al., 

2002). No minke whales were found in 

the proposed project region during July– 

December surveys during 1986–1996 by 

Ferguson and Barlow (2001) or in 2006 

by Jackson et al. (2008). Rasmussen et 

al. (2004) did not report seeing any 

minke whales in 8 years of surveys 

(1996–2003) off Costa Rica or in 2001– 

2003 off Panama. May-Collado et al. 

(2005) also did not report any minkes 

based on compiled sightings off Costa 

Rica during 1979–2001, nor have 

minkes been reported among compiled 

strandings off Costa Rica (RodriguezFonseca and Cubero-Pardo, 2001). 

Minke whales are unlikely to occur in 

the planned survey areas and are not 

considered further in this document. 

Longman’s beaked whale 

(Indopacetus pacificus), also known as 

the tropical bottlenose whale, is 

considered rare in the ETP. Although 

widespread throughout the tropical 

Pacific, the species is considered rare 

because of a scarcity of sightings despite 

a great deal of survey effort (Pitman et 

al., 1999). In the ETP, most tropical 

bottlenose whale sightings have been 

made between 3–10° N (Pitman et al., 

1999). Kinzey et al. (2001) reported one 

sighting of I. pacificus in the ETP at 

about 135° W. Jackson et al. (2008) also 

reported I. pacificus in the ETP well to 

the west of the proposed study area. No 

Longman’s beaked whales were reported 

by May-Collado et al. (2005) based on 

compiled sightings off Costa Rica from 

1979–2001. The species is very rare in 

the study area and is not considered 

further in this document. 

Dwarf (Kogia sima) and pygmy (K. 

breviceps) sperm whales may occur in 

the proposed survey area, although 

dwarf sperm whales are likely to be very 

rare and pygmy sperm whales are likely 

to be rare. No Kogia sp. were detected 

during L–DEO seismic surveys off Costa 

Rica and Nicaragua in November– 

December 2004 (Holst et al., 2005b) or 

in the Hess Deep approximately 1100 

km (683.5 mi) west of the Galapagos 

Islands in July 2003 (Smultea and Holst, 

2003). One sighting of a dwarf sperm 

whale and one sighting of two pygmy 

sperm whales were observed off the 

coast of Costa Rica in waters 

approximately 2000 m (6561.7 ft) and 

3500 m (11482.9 ft) deep, respectively, 

during an L–DEO seismic survey off 

Costa Rica and Nicaragua in February– 

March 2008 (Holst and Smultea, 2008), 

and one unidentified Kogia sp. was 

sighted during L–DEO seismic surveys 

1600–1950 km (994.2–1211.7 mi) west 

of the proposed survey area in April– 

August 2008 (Hauser et al., 2008). Due 

to the rarity of these species, no take has 

been requested and none will be 

authorized. 

Six species of pinnipeds are known to 

occur in the ETP: The Guadalupe fur 

seal (Arctocephalus townsendi), 

California sea lion (Zalophus 

californianus), Galapagos sea lion (Z. 

wollebaeki), Galapagos fur seal (A. 

galapagoensis), southern sea lion 

(Otaria flavescens), and the South 

American fur seal (A. australis). Ranges 

of the first two are substantially north of 

the proposed seismic survey areas, and 

the last four species are not expected to 

occur in the offshore waters of the study 

areas. The marine sea otter, which is 

managed by the U.S. Fish and Wildlife 

Service, is a coastal species and does 

not occur in offshore waters. Pinnipeds 

are highly unlikely to occur in the 

survey area and are not considered in 

further detail here. 

The ETP is a biologically productive 

area that supports a variety of cetacean 

species (Au and Perryman, 1985). 

Several studies of marine mammal 

distribution and abundance have been 

conducted in the wider ETP. The most 

extensive regional distribution and 

abundance data that encompass the 

study area come primarily from multiyear vessel surveys conducted in the 

wider ETP by the NMFS Southwest 

Fisheries Science Center (SWFSC). 

Information on the distribution of 

cetaceans inhabiting the ETP has been 

summarized in several studies 

(Polacheck, 1987; Wade and Gerrodette, 

1993; Ferguson and Barlow, 2001; 

Gerrodette et al., 2008). However, for 

some species, abundance in the 

proposed seismic survey area could be 

quite different from that of the wider 

ETP, depending on local oceanographic 

variability. 

In addition, procedures used during 

the various surveys that are cited have 

differed somewhat, and those 

differences could affect the results. For 

example, Ferguson and Barlow (2001) 

calculated cetacean densities in the ETP 

based on summer/fall research surveys 

in 1986–1996. Their densities are 

corrected for both changes in 

detectability of species with distance 

from the survey track line and for 

perception and availability bias. 

Gerrodette et al. (2008) calculated 

dolphin abundance in the ETP based on 

summer/fall research surveys in 1986– 

1990, 1998–2000, 2003, and 2006. Their 

estimates are corrected for the former 

but not the latter. 

Additional sighting records are 

available from recent surveys in the 

ETP. Jackson et al. (2008) described 

cetacean sightings data collected during 

a survey from July 28–December 7, 

2006. The survey area extended from 

30° N–18° S from the coastline to 153° 

W, overlapping with the proposed 


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seismic survey area. Rasmussen et al. 

(2004) and Calambokidis et al. (2010) 

described cetacean sightings resulting 

from humpback whale surveys off Costa 

Rica and surrounding waters from 

January to March in 1996–2003 and 

2010. Recent at-sea monitoring for L– 

DEO in the ETP also provided sighting 

records for cetaceans during seismic 

programs. Seismic monitoring programs 

took place at the Hess Deep in July 

2003, approximately 1100 km (683.5 mi) 

west of the Galapagos Islands (Smultea 

and Holst, 2003); from Costa Rica to El 

Salvador in November–December 2004, 

mainly within approximately 100 km 

(62.1 mi) of the coast in water depths 

extending to 5000 m (16,404.2 ft) (Holst 

et al., 2005b); from Costa Rica to 

Nicaragua in March–April 2008, up to 

approximately 200 km (124.3 mi) from 

the coast in water depths extending to 

5000 m (Holst and Smultea, 2008); and 

approximately 1600–1900 km (994.2– 

1,180.6 mi) west of the study area in 

April–August 2008 (Hauser et al., 2008). 

Information on the occurrence, 

distribution, population size, and 

conservation status for each of the 23 

cetacean species that may occur in the 

proposed project area during October– 

November is presented in Table 2 in this 

document. The five species of marine 

mammals expected to be most common 

in the waters of the project area, all 

delphinids, include the short beaked 

common dolphin (Delphinus delphis), 

pantropical spotted dolphin (Stenella 

attenuata), bottlenose dolphin (Tursiops 

truncatus), Risso’s dolphin (Grampus 

griseus), and short-finned pilot whale 

(Globicephala macrorhynchus). 

Additional information regarding the 

abundance and distribution, population 

status, and life history and behavior of 

these species expected to be found in 

the project area and how the estimated 

densities were calculated may be found 

in SIO’s application. NMFS has 

reviewed these data and determined 

them to be the best available scientific 

information for the purposes of the 

proposed IHA. Please refer to the 

application for that information (see 

ADDRESSES). Additional information can 

also be found in the NMFS Stock 

Assessment Report (SAR). The Pacific 

2009 SAR is available at: http:// 

www.nmfs.noaa.gov/pr/pdfs/sars/ 

po2009.pdf. 

TABLE 2—THE OCCURRENCE, HABITAT, REGIONAL ABUNDANCE, CONSERVATION STATUS, AND BEST AND MAXIMUM DENSITY ESTIMATES FOR MARINE MAMMALS IN OR NEAR THE PROPOSED LOW-ENERGY SEISMIC SURVEY AREA IN THE

EASTERN TROPICAL PACIFIC OCEAN. CETACEAN DENSITIES ARE BASED ON NMFS SWFSC SHIP TRANSECT SURVEYS CONDUCTED IN 1986–2006 FROM PREDICTIVE MODELING (BARLOW ET AL. 2009; READ ET AL. 2009) OR IN

1986–1996 FROM FERGUSON AND BARLOW (2003) 

[See text and Tables 2–4 in SIO’s application for further detail.] 

Species 

Occurrence in survey area during 

Oct–Nov 

Habitat Regional population 

size 1 ESA2 Density 

(best) 3

Density 

(max) 4

Mysticetes: 

Bryde’s Whale, (Balaenoptera edeni) ... Uncommon ............. Pelagic and coastal 13,000 5 .................. NL ..... 0.53 1.15 

Blue whale, (Balaenoptera musculus) .. Uncommon ............. Pelagic and coastal 1415 6 ..................... EN .... 0.13 0.23 

Humpback whale, (Megaptera 

novaeangliae).

Uncommon ............. Mainly nearshore 

waters and banks.

NE Pacific 1392 13; 

SE Pacific 

2900 14.

EN .... 15 0.1 15 0.2 

Odontocetes: 

Sperm whale, (Physeter 

macrocephalus).

Common ................ Usually deep pelagic, steep topography.26,053 7 .................. EN .... 3.95 15.20 

Pygmy sperm whale, (Kogia breviceps) Rare ....................... Deep waters off 

shelf.

NA8 ........................ NL ..... 16 0.01 16 0.02 

Dwarf sperm whale, (Kogia sima) ........ Very rare ................ Deep waters off 

shelf.

11,200 9 .................. NL ..... 16 0.01 16 0.02 

Cuvier’s beaked whale, (Ziphius 

cavirostris).

Common ................ Slope and pelagic .. 20,000 6 .................. NL ..... 1.83 3.70 

Blainville’s beaked whale, (Mesoplodon 

densirostris).

Uncommon ............. Pelagic ................... 25,300 10 ................ NL ..... 17 0.21 17 0.37 

Pygmy beaked whale, (Mesoplodon 

peruvianus).

Uncommon ............. Pelagic ................... 25,300 10 ................ NL ..... 17 0.21 17 0.37 

Gingko-toothed beaked whale, 

(Mesoplodon stejnegeri).

Very rare ................ Pelagic ................... 25,300 10 ................ NL ..... 17 0.21 17 0.37 

Bottlenose dolphin, (Tursiops 

truncatus).

Very common ......... Coastal, shelf, pelagic.335,834 .................. NL ..... 15.14 23.09 

Rough-toothed dolphin, (Steno 

bredanensis).

Common ................ Mainly pelagic ........ 107,633 .................. NL ..... 1.60 2.34 

Short-beaked common dolphin, 

(Delphinus delphis).

Very common ......... Shelf, pelagic, high 

relief.

3,127,203 ............... NL ..... 143.21 242.80 

Pantropical spotted dolphin, (Stenella 

attenuata).

Very common ......... Coastal and pelagic 857,884 .................. NL ..... 12.43 22.53 

Risso’s dolphin, (Grampus griseus) ..... Very common ......... Shelf, slope, 

seamounts.

110,457 .................. NL ..... 10.21 37.40 

Spinner dolphin, (Stenella longirostris) Very common ......... Coastal and pelagic 1,797,716 ............... NL ..... 3.81 5.74 

Striped dolphin, (Stenella coeruleoalba) Very common ......... Off continental shelf 964,362 .................. NL ..... 35.23 53.67 

Fraser’s dolphin, (Lagenodelphis hosei) Common ................ Pelagic ................... 289,300 6 ................ NL ..... 1.03 5.60 

Melon-headed whale, (Peponocephala 

electra).

Common ................ Pelagic ................... 45,400 6 .................. NL ..... 2.80 9.30 

Pygmy killer whale, (Feresa attenuata) Uncommon ............. Pelagic ................... 38,900 6 .................. NL ..... 0.60 1.80 

False killer whale, (Pseudorca 

crassidens).

Uncommon ............. Pelagic ................... 39,800 6 .................. NL ..... 0.39 2.10 

Killer whale, (Orcinus orca) .................. Uncommon ............. Widely distributed .. 8,500 11 .................. NL ..... 0.85 4.00 


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TABLE 2—THE OCCURRENCE, HABITAT, REGIONAL ABUNDANCE, CONSERVATION STATUS, AND BEST AND MAXIMUM DENSITY ESTIMATES FOR MARINE MAMMALS IN OR NEAR THE PROPOSED LOW-ENERGY SEISMIC SURVEY AREA IN THE

EASTERN TROPICAL PACIFIC OCEAN. CETACEAN DENSITIES ARE BASED ON NMFS SWFSC SHIP TRANSECT SURVEYS CONDUCTED IN 1986–2006 FROM PREDICTIVE MODELING (BARLOW ET AL. 2009; READ ET AL. 2009) OR IN

1986–1996 FROM FERGUSON AND BARLOW (2003)—Continued 

[See text and Tables 2–4 in SIO’s application for further detail.] 

Species 

Occurrence in survey area during 

Oct–Nov 

Habitat Regional population 

size 1 ESA2 Density 

(best) 3

Density 

(max) 4

Short-finned pilot whale, (Globicephala 

macrorhynchus).

Common ................ Mostly pelagic, 

high-relief.

589,315 12 .............. NL ..... 6.29 11.74 

NA—Data not available or species status was not assessed. For density estimates, NA indicates that estimates would be lower than the lowest 

estimate in this table. 1Abundance from Gerrodette et al. (2008) unless otherwise stated. 2 U.S. Endangered Species Act: EN = Endangered, T = Threatened, NL = Not listed. 

3Best density (#/1000km2) estimate as listed in Table 3 of the application. Cetecean densities are based on NMFS SWFSC ship transect surveys conducted in 1986–2006 from predictive modeling (Barlow et al. 2009; Read et al. 2009) or in 1986–1996 from Ferguson and Barlow 

(2003). 4 Maximum density (#/1000km2) estimate as listed in Table 3 of the application. 5This estimate is mainly for Balaenoptera edeni but may include some B. borealis. 6ETP (Wade and Gerrodette 1993). 

7Eastern temperate North Pacific (Whitehead 2002). 

8 California/Oregon/Washington (Carretta et al. 2010). 9This abundance estimate is mostly for Kogia sima but may also include some K. breviceps. Density estimates for Kogia spp. combined. 10Estimates for population size and for density include all species of the genus Mesoplodon in the ETP (Ferguson and Barlow 2001). 11ETP (Ford 2002). 12This estimate is for Globicephala macrorhynchus and G. melas in the ETP (Gerrodette and Forcada 2002). 13 U.S. west coast (Carretta et al. 2010). 14Southeast Pacific; Felix et al. (2005). 15Approximate estimates. 16 Density estimates are combined for pygmy and dwarf sperm whales. 17 Density estimates are combined for species of the genus Mesoplodon. 

Marine Mammal Hearing 

The primary effect on marine 

mammals anticipated from the specified 

activities will result from exposure of 

animals to underwater sound. Exposure 

to sound can affect marine mammal 

hearing. When considering the 

influence of various kinds of sound on 

the marine environment, it is necessary 

to understand that different kinds of 

marine life are sensitive to different 

frequencies of sound. Based on available 

behavioral data, audiograms derived 

using auditory evoked potential 

techniques, anatomical modeling, and 

other data, Southall et al. (2007) 

designate ‘‘functional hearing groups’’ 

for marine mammals and estimate the 

lower and upper frequencies of 

functional hearing of the groups. The 

functional groups and the associated 

frequencies are indicated below (though 

animals are less sensitive to sounds at 

the outer edge of their functional range 

and most sensitive to sounds of 

frequencies within a smaller range 

somewhere in the middle of their 

functional hearing range): 

• Low frequency cetaceans (13 

species of mysticetes): Functional 

hearing is estimated to occur between 

approximately 7 Hz and 22 kHz; 

• Mid-frequency cetaceans (32 

species of dolphins, six species of larger 

toothed whales, and 19 species of 

beaked and bottlenose whales): 

Functional hearing is estimated to occur 

between approximately 150 Hz and 160 

kHz; 

• High frequency cetaceans (six 

species of true porpoises, four species of 

river dolphins, two members of the 

genus Kogia, and four dolphin species 

of the genus Cephalorhynchus): 

Functional hearing is estimated to occur 

between approximately 200 Hz and 180 

kHz; and 

• Pinnipeds in water: Functional 

hearing is estimated to occur between 

approximately 75 Hz and 75 kHz, with 

the greatest sensitivity between 

approximately 700 Hz and 20 kHz. 

As mentioned previously in this 

document, 21 cetacean species are likely 

to occur in the proposed survey area. Of 

the 21 species likely to occur in SIO’s 

project area, two are classified as low 

frequency cetaceans (Bryde’s, 

humpback, and blue whales) and 18 are 

classified as mid-frequency cetaceans 

(sperm, Cuvier’s beaked, Blainville’s 

beaked, pygmy beaked, gingko-toothed 

beaked, melon-headed, pygmy killer, 

false killer, killer, and short-finned pilot 

whales and rough-toothed, bottlenose, 

pantropical spotted, spinner, striped, 

Fraser’s, short-beaked common, and 

Risso’s dolphins) (Southall et al., 2007). 

Potential Effects of the Specified 

Activity on Marine Mammals 

Potential Effects of Airguns 

The effects of sounds from airguns 

might result in one or more of the 

following: Tolerance, masking of natural 

sounds, behavioral disturbances, 

temporary or permanent hearing 

impairment, and non-auditory physical 

or physiological effects (Richardson et 

al., 1995; Gordon et al., 2004; Nowacek 

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

Permanent hearing impairment, or PTS, 

in the unlikely event that it occurred, 

would constitute injury, but temporary 

threshold shift (TTS) is not an injury 

(Southall et al., 2007). It is unlikely that 

the project would result in any cases of 

temporary or especially permanent 

hearing impairment or any significant 

non-auditory physical or physiological 

effects for reasons discussed later in this 

document. Some behavioral disturbance 

is expected, but it is expected that this 

would be localized and short-term 

because of the short amount of time that 

would be spent at any particular site 

within the survey area (approximately 

two days of seismic data acquisition at 

any one site). 

(1) Tolerance 

Numerous studies have shown that 

pulsed sounds from airguns are often 

readily detectable in the water at 


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distances of many kilometers. For a brief 

summary of the characteristics of airgun 

pulses, see Appendix A(3) of the 

supporting EA (see ADDRESSES). 

However, it should be noted that most 

of the measurements are for airguns that 

would be detectable considerably 

farther away than the GI airgun planned 

for use in the present project. 

Several studies have shown that 

marine mammals at distances more than 

a few kilometers from operating seismic 

vessels often show no apparent 

response; see Appendix A(5) of the EA. 

That is often true even in cases when 

the pulsed sounds must be readily 

audible to the animals based on 

measured received levels and the 

hearing sensitivity of the mammal 

group. Although various baleen whales, 

toothed whales, and (less frequently) 

pinnipeds have been shown to react 

behaviorally to airgun pulses under 

some conditions, at other times, 

mammals of all three types have shown 

no overt reactions. In general, pinnipeds 

usually seem to be more tolerant of 

exposure to airgun pulses than are 

cetaceans, with the relative 

responsiveness of baleen and toothed 

whales being variable. Given the 

relatively small and low-energy GI 

airgun source planned for use in this 

project, mammals are expected to 

tolerate being closer to this source than 

would be the case for a larger airgun 

source typical of most seismic surveys. 

(2) Masking 

Obscuring of sounds of interest by 

interfering sounds, generally at similar 

frequencies, is known as masking. 

Masking effects of pulsed sounds (even 

from large arrays of airguns, much larger 

than that proposed for use in this 

survey) on marine mammal calls and 

other natural sounds are expected to be 

limited, although there are few specific 

data of relevance. Because of the 

intermittent nature and low duty cycle 

of seismic pulses, animals can emit and 

receive sounds in the relatively quiet 

intervals between pulses. However, in 

some situations, multi-path arrivals and 

reverberation cause airgun sound to 

arrive for much or all of the interval 

between pulses (Simard et al., 2005; 

Clark and Gagnon, 2006), which could 

mask calls. Whale calls often can be 

heard between the seismic pulses 

(Richardson et al., 1986; McDonald et 

al., 1995; Greene et al., 1999a,b; 

Nieukirk et al., 2004; Smultea et al., 

2004; Holst et al., 2005a,b, 2006; Dunn 

and Hernandez, 2009), and certain 

baleen and toothed whales are known to 

continue calling in the presence of 

seismic pulses. However, 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, there has been 

one report that sperm whales ceased 

calling when exposed to pulses from a 

very distant seismic ship (Bowles et al., 

1994). However, more recent studies 

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; 

Jochens et al., 2008). Given the small 

source planned for use during the 

proposed survey, there is even less 

potential for masking of baleen or sperm 

whale calls during the present study 

than in most seismic surveys. Masking 

effects of seismic pulses are expected to 

be negligible in the case of small 

odontocetes, given the intermittent 

nature of seismic pulses. Dolphins and 

porpoises commonly are heard calling 

while airguns are operating (Gordon et 

al., 2004; Smultea et al., 2004; Holst et 

al., 2005a,b; Potter et al., 2007). The 

sounds important to small odontocetes 

are predominantly at much higher 

frequencies than are the dominant 

components of airgun sounds, thus 

limiting the potential for masking. In 

general, masking effects of seismic 

pulses are expected to be minor, given 

the normally intermittent nature of 

seismic pulses. Masking effects on 

marine mammals are discussed further 

in Appendix A(4) of the EA. 

(3) Disturbance Reactions 

Disturbance includes a variety of 

effects, including subtle changes in 

behavior, more conspicuous changes in 

activities, and displacement. 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; Wartzok et al., 2004; Southall 

et al., 2007; Weilgart, 2007). If a marine 

mammal responds to an underwater 

sound by changing its behavior or 

moving a small distance, the response 

may or may not rise to the level of 

‘‘taking’’, or affect the stock or the 

species as a whole. However, if a sound 

source displaces marine mammals from 

an important feeding or breeding area 

for a prolonged period, impacts on 

animals or on the stock or species could 

potentially be significant (Lusseau and 

Bejder, 2007; Weilgart, 2007). Given the 

many uncertainties in predicting the 

quantity and types of impacts of noise 

on marine mammals, it is common 

practice to estimate how many 

mammals are likely to be present within 

a particular distance of a given activity, 

or exposed to a particular level of 

sound. This practice potentially 

overestimates the numbers of marine 

mammals that are affected in some 

biologically-important manner. 

The sound exposure thresholds that 

are used to estimate how many marine 

mammals might be harassed by a 

seismic survey are based on behavioral 

observations during studies of several 

species. However, information is lacking 

for many species. Detailed studies have 

been done on humpback, gray 

(Eschrichtius robustus), bowhead 

(Balaena mysticetus), and sperm 

whales, and on ringed seals (Phoca 

hispida). Less detailed data are available 

for some other species of baleen whales, 

small toothed whales, and sea otters, but 

for many species there are no data on 

responses to marine seismic surveys. 

Most of those studies have concerned 

reactions to much larger airgun sources 

than planned for use in the proposed 

SIO project. Thus, effects are expected 

to be limited to considerably smaller 

distances and shorter periods of 

exposure in the present project than in 

most of the previous work concerning 

marine mammal reactions to airguns. 

Baleen Whales—Baleen whales 

generally tend to avoid operating 

airguns, but avoidance radii are quite 

variable. Whales are often reported to 

show no overt reactions to pulses from 

large arrays of airguns at distances 

beyond a few kilometers, even though 

the airgun pulses remain well above 

ambient noise levels out to much longer 

distances. However, as reviewed in 

Appendix A(5) of the EA, baleen whales 

exposed to strong noise pulses from 

airguns often react by deviating from 

their normal migration route 

(Richardson et al., 1999) and/or 

interrupting their feeding activities and 

moving away from the sound source. In 

the cases of migrating gray and bowhead 

whales, the observed changes in 

behavior appeared to be of little or no 

biological consequence to the animals. 

They simply avoided the sound source 

by displacing their migration route to 

varying degrees, but within the natural 

boundaries of the migration corridors 

(Schick and Urban, 2000; Richardson et 

al., 1999; Malme et al., 1983). 

Studies of gray, bowhead, and 

humpback whales have shown that 

seismic pulses with received levels of 

pulses in the 160–170 dB re 1 μPa (rms) 

range seem to cause obvious avoidance 

behavior in a substantial fraction of the 

animals exposed (Richardson et al., 

1995). In many areas, seismic pulses 

from large arrays of airguns diminish to 

those levels at distances ranging from 

4.5–14.5 km (2.8–9 mi) from the source. 

A substantial proportion of the baleen 

whales within those distances may 

show avoidance or other strong 


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disturbance reactions to the airgun 

array. Subtle behavioral changes 

sometimes become evident at somewhat 

lower received levels, and studies 

summarized in Appendix A(5) of the EA 

have shown that some species of baleen 

whales, notably bowhead and 

humpback whales, at times show strong 

avoidance at received levels lower than 

160–170 dB re 1 μPa (rms). Reaction 

distances would be considerably smaller 

during the proposed project, for which 

the 160 dB radius is predicted to be 400 

m (1312.3 ft) (see Table 1 in this 

document), as compared with several 

kilometers when a large array of airguns 

is operating. 

Responses of humpback whales to 

seismic surveys have been studied 

during migration, on summer feeding 

grounds, and on Angolan winter 

breeding grounds; there has also been 

discussion of effects on the Brazilian 

wintering grounds. McCauley et al. 

(1998, 2000a) studied the responses of 

humpback whales off Western Australia 

to a full-scale seismic survey with a 

16-airgun, 2678-in 3 array, and to a 

single 20-in 3 airgun with a source level 

of 227 dB re 1 μPa-m peak-to-peak. 

McCauley et al. (1998) documented that 

initial avoidance reactions began at 5– 

8 km (3.1–5 mi) from the array, and that 

those reactions kept most pods 

approximately 3–4 km (1.9–2.5 mi) from 

the operating seismic boat. McCauley et 

al. (2000a) noted localized displacement 

during migration of 4–5 km (2.5–3.1 mi) 

by traveling pods and 7–12 km (4.3–7.5 

mi) by cow-calf pairs. Avoidance 

distances with respect to the single 

airgun were smaller but consistent with 

the results from the full array in terms 

of received sound levels. The mean 

received level for initial avoidance 

reactions to an approaching airgun was 

140 dB re 1 μPa (rms) for humpback 

whale pods containing females. The 

standoff range, i.e., the mean closest 

point of approach of the whales to the 

airgun, corresponded to a received level 

of 143 dB re 1 μPa (rms). The initial 

avoidance response generally occurred 

at distances of 5–8 km (3.1–5.0 mi) from 

the airgun array and 2 km (1.2 mi) from 

the single airgun. However, some 

individual humpback whales, especially 

males, approached within distances of 

100–400 m (328.1–1312.3 ft), where the 

maximum received level was 179 dB re 

1 μPa (rms). 

Humpback whales on their summer 

feeding grounds in southeast Alaska did 

not exhibit persistent avoidance when 

exposed to seismic pulses from a 100- 

in 3 airgun (Malme et al., 1985). Some 

humpbacks seemed ‘‘startled’’ at 

received levels of 150–169 dB re 1 μPa 

on an (approximate) rms basis. Malme et 

al. (1985) concluded that there was no 

clear evidence of avoidance, despite the 

possibility of subtle effects, at received 

levels up to 172 re 1 μPa on an 

(approximate) rms basis. 

It has been suggested that South 

Atlantic humpback whales wintering off 

Brazil may be displaced or even strand 

upon exposure to seismic surveys (Engel 

et al., 2004). The evidence for this was 

circumstantial and subject to alternative 

explanations (IAGC 2004). Also, the 

evidence was not consistent with 

subsequent results from the same area of 

Brazil (Parente et al., 2006), or with 

results from direct studies of humpback 

whales exposed to seismic surveys in 

other areas and seasons. After allowance 

for data from subsequent years, there 

was ‘‘no observable direct correlation’’ 

between strandings and seismic surveys 

(IWC 2007). 

Studies of bowhead whales show that 

their responsiveness can be quite 

variable depending on the activity (e.g., 

migrating vs. feeding). Bowhead whales 

migrating west across the Alaskan 

Beaufort Sea in autumn, in particular, 

are unusually responsive, with 

substantial avoidance occurring out to 

distances of 20–30 km (12.4–18.6 mi) 

from a medium-sized airgun source at 

received sound levels of around 120– 

130 dB re 1 μPa (rms) (Miller et al., 

1999; Richardson et al., 1999; see also 

Appendix A (5) of the EA). However, 

more recent research on bowhead 

whales (Miller et al., 2005; Harris et al., 

2007) corroborates earlier evidence that, 

during the summer feeding season, 

bowheads are not as sensitive to seismic 

sources. Nonetheless, subtle but 

statistically significant changes in 

surfacing-respiration-dive cycles were 

evident upon statistical analysis 

(Richardson et al., 1986). In summer, 

bowheads typically begin to show 

avoidance reactions at received levels of 

about 152–178 dB re 1 μPa (rms) 

(Richardson et al., 1986, 1995; 

Ljungblad et al., 1988; Miller et al., 

2005). 

Reactions of migrating and feeding 

(but not wintering) gray whales to 

seismic surveys have been studied. 

Malme et al. (1986, 1988) studied the 

responses of feeding Eastern Pacific gray 

whales to pulses from a single 100-in3

airgun off St. Lawrence Island in the 

northern Bering Sea. They estimated, 

based on small sample sizes, that 50 

percent of feeding gray whales ceased 

feeding at an average received pressure 

level of 173 dB re 1 μPa on an 

(approximate) rms basis and that 10 

percent of feeding whales interrupted 

feeding at received levels of 163 dB re 

1 μPa (rms). Those findings were 

generally consistent with the results of 

experiments conducted on larger 

numbers of gray whales that were 

migrating along the California coast 

(Malme et al., 1984; Malme and Miles, 

1985) and with observations of Western 

Pacific gray whales feeding off Sakhalin 

Island, Russia, when a seismic survey 

was underway just offshore of their 

feeding area (Wursig et al., 1999; Gailey 

et al., 2007; Johnson et al., 2007; 

Yazvenko et al., 2007a,b), along with 

data on gray whales off British 

Columbia (Bain and Williams, 2006). 

Gray whales typically show no 

conspicuous responses to airgun pulses 

with received levels up to 150 to 160 dB 

re 1 μPa (rms), but are increasingly 

likely to show avoidance as received 

levels increase above that range. While 

neither bowhead nor gray whales are 

present in the study area, these studies 

can be used to draw general inference 

about the potential reactions of other 

baleen whales to underwater sound. 

Various species of the genus 

Balaenoptera (e.g., blue, sei, fin, 

Bryde’s, and minke whales) have 

occasionally been reported in areas 

ensonified by airgun pulses (Stone, 

2003; MacLean and Haley, 2004; Stone 

and Tasker, 2006), and calls from blue 

and fin whales have been localized in 

areas with airgun operations (McDonald 

et al., 1995; Dunn and Hernandez, 

2009). Sightings by observers on seismic 

vessels off the United Kingdom from 

1997–2000 suggest that, at times of good 

sightability, sighting rates for mysticetes 

(mainly fin and sei whales) were similar 

when large arrays of airguns were 

shooting and not shooting (Stone, 2003; 

Stone and Tasker, 2006). However, these 

whales tended to exhibit localized 

avoidance, remaining significantly 

further (on average) from the airgun 

array during seismic operations 

compared with non-seismic periods 

(Stone and Tasker, 2006). In a study off 

Nova Scotia, Moulton and Miller (2005) 

found little difference in sighting rates 

(after accounting for water depth) and 

initial sighting distances of 

balaenopterid whales when airguns 

were operating vs. silent. However, 

there were indications that these whales 

were more likely to be moving away 

when seen during airgun operations. 

Similarly, ship-based monitoring 

studies of blue, fin, sei, and minke 

whales offshore of Newfoundland 

(Orphan Basin and Laurentian Subbasin) found no more than small 

differences in sighting rates and swim 

direction during seismic vs. non-seismic 

periods (Moulton et al., 2005, 2006a,b). 

Data on short-term reactions, or lack 

thereof, by cetaceans to impulsive 

noises do not necessarily provide 

information about long-term effects. It is 


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not known whether impulsive noises 

affect reproductive rate or distribution 

and habitat use in subsequent days or 

years. However, gray whales continued 

to migrate annually along the west coast 

of North America with substantial 

increases in the population over recent 

years, despite intermittent seismic 

exploration (and much ship traffic) in 

that area for decades (see Appendix A 

in Malme et al., 1984; Richardson et al., 

1995; Angliss and Allen, 2009). The 

Western Pacific gray whale population 

did not seem affected by a seismic 

survey in its feeding ground during a 

prior year (Johnson et al., 2007). 

Bowhead whales have continued to 

travel to the eastern Beaufort Sea each 

summer, and their numbers have 

increased notably (3.4 percent annually 

for nearly a decade), despite seismic 

exploration in their summer and 

autumn range for many years 

(Richardson et al., 1987; Angliss and 

Allen 2009). In any event, brief 

exposures to sound pulses from the 

proposed airgun source are highly 

unlikely to result in prolonged effects. 

Toothed Whales—Little systematic 

information is available about reactions 

of toothed whales to noise pulses. Few 

studies similar to the more extensive 

baleen whale/seismic pulse work 

summarized above have been reported 

for toothed whales. However, systematic 

studies on sperm whales have been 

done (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 

to seismic surveys based on monitoring 

studies (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). 

Seismic operators and PSOs on 

seismic vessels regularly see dolphins 

and other small toothed whales near 

operating airgun arrays, but, in general, 

there seems to be a tendency for most 

delphinids to show some avoidance of 

operating seismic vessels (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; see also Barkaszi et al., 2009). 

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 airgun arrays are firing 

(Moulton and Miller, 2005). 

Nonetheless, there have been 

indications that small toothed whales 

sometimes tend to head away, or to 

maintain a somewhat greater distance 

from the vessel, when a large array of 

airguns is operating than when it is 

silent (Stone and Tasker, 2006; Weir, 

2008). In most cases, the avoidance radii 

for delphinids appear to be small, on the 

order of 1 km (0.62 mi) or less, and 

some individuals show no apparent 

avoidance. The beluga whale 

(Delphinapterus leucas) is a species that 

(at least at times) shows long-distance 

avoidance of seismic vessels. Aerial 

surveys conducted during seismic 

operations in the southeastern Beaufort 

Sea during summer recorded much 

lower sighting rates of beluga whales 

within 10–20 km (6.2–12.4 mi) 

compared with 20–30 km (12.4–18.6 mi) 

from an operating airgun array, and 

observers on seismic boats in that area 

rarely see beluga whales (Miller et al., 

2005; Harris et al., 2007). However, 

beluga whales are not found in SIO’s 

proposed project area. 

Captive bottlenose dolphins and 

beluga whales 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). The 

animals tolerated high received levels of 

sound before exhibiting aversive 

behaviors. 

Most studies of sperm whales exposed 

to airgun sounds indicate that this 

species shows considerable tolerance of 

airgun pulses (Stone, 2003; Moulton et 

al., 2005, 2006a; Stone and Tasker, 

2006; Weir, 2008). In most cases the 

whales do not show strong avoidance 

and continue to call (see Appendix A of 

the EA for review). However, controlled 

exposure experiments in the Gulf of 

Mexico indicate that foraging effort is 

somewhat altered upon exposure to 

airgun sound (Jochens et al., 2008; 

Miller et al., 2009; Tyack, 2009). 

There are almost no specific data on 

the behavioral reactions of beaked 

whales (Family Ziphiidae) to seismic 

surveys. However, northern bottlenose 

whales (Hyperoodon ampullatus) 

continued to produce high-frequency 

clicks when exposed to sound pulses 

from distant seismic surveys (Gosselin 

and Lawson, 2004; Laurinolli and 

Cochrane, 2005; Simard et al., 2005). 

Most beaked whales tend to avoid 

approaching vessels of other types 

(Wursig et al., 1998). They may also 

dive for an extended period when 

approached by a vessel (Kasuya, 1986), 

although it is uncertain how much 

longer such dives may be as compared 

to dives by undisturbed beaked whales, 

which also are often quite long (Baird 

et al., 2006; Tyack et al., 2006). In any 

event, it is likely that most beaked 

whales would also show strong 

avoidance of an approaching seismic 

vessel, although this has not been 

documented explicitly. 

Odontocete reactions to large arrays of 

airguns are variable and, at least for 

delphinids and Dall’s porpoises, seem to 

be confined to a smaller radius than has 

been observed for the more responsive 

of the mysticetes, beluga whales, and 

harbor porpoises (Appendix A of the 

EA). 

Additional details on the behavioral 

reactions (or the lack thereof) by all 

types of marine mammals to seismic 

vessels can be found in Appendix A (5) 

of the EA. 

(4) Hearing Impairment and Other 

Physical Effects 

Temporary (TTS) or permanent (PTS) 

hearing impairment is a possibility 

when marine mammals are exposed to 

very strong sounds. TTS has been 

demonstrated and studied in certain 

captive odontocetes and pinnipeds 

exposed to strong sounds (reviewed in 

Southall et al., 2007). However, there 

has been no specific documentation of 

this for marine mammals exposed to 

sequences of airgun pulses. 

Several aspects of the planned 

monitoring and mitigation measures for 

this project (see the ‘‘Proposed 

Mitigation’’ and ‘‘Proposed Monitoring 

and Reporting’’ sections later in this 

document) are designed to detect 

marine mammals occurring near the 

airguns to avoid exposing them to sound 

pulses that might, at least in theory, 

cause hearing impairment. In addition, 

many cetaceans are likely to show some 

avoidance of the area where received 

levels of airgun sound are high enough 

that hearing impairment could 

potentially occur. In those cases, the 

avoidance responses of the animals 

themselves will reduce or (most likely) 

avoid any possibility of hearing 

impairment. 

Non-auditory physical effects may 

also occur in marine mammals exposed 

to strong underwater pulsed sound. 

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, resonance effects, and other 

types of organ or tissue damage. It is 

possible that some marine mammal 

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

especially susceptible to injury and/or 

stranding when exposed to strong 

pulsed sounds. However, as discussed 

later in this document, there is no 

definitive evidence that any of these 

effects occur even for marine mammals 

in close proximity to large arrays of 

airguns. It is especially unlikely that any 


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effects of these types would occur 

during the present project given the 

brief duration of exposure for any given 

individual and the planned monitoring 

and mitigation measures (see the 

‘‘Proposed Mitigation’’ and ‘‘Proposed 

Monitoring and Reporting’’ sections later 

in this document). The following 

subsections discuss in somewhat more 

detail the possibilities of TTS, 

permanent threshold shift (PTS), and 

non-auditory physical effects. 

Temporary Threshold Shift—TTS is 

the mildest form of hearing impairment 

that can occur during exposure to a 

strong sound (Kryter, 1985). While 

experiencing TTS, the hearing threshold 

rises, and a sound must be stronger in 

order to be heard. At least in terrestrial 

mammals, TTS can last from minutes or 

hours to (in cases of strong TTS) days. 

For sound exposures at or somewhat 

above the TTS threshold, hearing 

sensitivity in both terrestrial and marine 

mammals recovers rapidly after 

exposure to the noise ends. Few data on 

sound levels and durations necessary to 

elicit mild TTS have been obtained for 

marine mammals, and none of the 

published data concern TTS elicited by 

exposure to multiple pulses of sound. 

Available data on TTS in marine 

mammals are summarized in Southall et 

al., (2007). The distances from the 

Melville’s airguns at which the received 

energy level (per pulse, flat-weighted) 

that would be expected to be greater 

than or equal to 180 dB re 1 μPa are 

estimated in Table 1. 

Given the available data, the received 

level of a single seismic pulse (with no 

frequency weighting) might need to be 

approximately 186 dB re 1 μPa2-s (i.e., 

186 dB sound exposure level (SEL) or 

approximately 221–226 dB pk-pk) in 

order to produce brief, mild TTS. 

Exposure to several strong seismic 

pulses that each have received levels 

near 190 dB re 1 μPa (rms) (175–180 dB 

SEL) might result in cumulative 

exposure of approximately 186 dB SEL 

and thus slight TTS in a small 

odontocete, assuming the TTS threshold 

is (to a first approximation) a function 

of the total received pulse energy. 

Levels ≥190 dB re 1 μPa (rms) are 

expected to be restricted to radii no 

more than 15 m (49.2 ft) from the 

Melville’s GI airguns. For an odontocete 

closer to the surface, the maximum 

radius with ≥190 dB re 1 μPa (rms) 

would be smaller. 

The above TTS information for 

odontocetes is derived from studies on 

the bottlenose dolphin and beluga 

whale. There is not published TTS 

information for other species of 

cetaceans. However, preliminary 

evidence from a harbor porpoise 

exposed to airgun sound suggests that 

its TTS threshold may have been lower 

(Lucke et al., 2009). 

For baleen whales, there are no data, 

direct or indirect, on levels or properties 

for any sound source required to induce 

TTS. The frequencies to which baleen 

whales are most sensitive are lower than 

those for odontocetes, and natural 

background noise levels at those low 

frequencies tend to be higher. Marine 

mammals can hear sounds at varying 

frequency levels. However, sounds that 

are produced in the frequency range at 

which an animal hears the best do not 

need to be as loud as sounds in less 

functional frequencies to be detected by 

the animal. As a result, auditory 

thresholds of baleen whales within their 

frequency band of best hearing are 

believed to be higher (less sensitive) 

than are those of odontocetes at their 

best frequencies (Clark and Ellison, 

2004), meaning that baleen whales 

require sounds to be louder (i.e., higher 

dB levels) than odontocetes in the 

frequency ranges at which each group 

hears the best. From this, it is suspected 

that received levels causing TTS onset 

may also be higher in baleen whales 

(Southall et al., 2007). Since current 

NMFS practice assumes the same 

thresholds for the onset of hearing 

impairment in both odontocetes and 

mysticetes, the threshold is likely 

conservative for mysticetes. In any 

event, no cases of TTS are expected 

given two considerations: (1) The small 

size of the GI airgun source (a total 

discharge volume of approximately 90 

in3 as opposed to arrays of much larger 

volumes up to 6,600 in3); and (2) the 

strong likelihood that baleen whales 

would avoid the approaching airguns 

(i.e., the vessel) before being exposed to 

levels high enough for TTS to possibly 

occur (as discussed previously in this 

document). 

As noted above, most cetacean species 

tend to avoid operating airguns, 

although not all individuals do so. In 

addition, ramping up airgun arrays, 

which is standard operational protocol 

for large airgun arrays and proposed for 

the much smaller airgun array for this 

action, should allow cetaceans to move 

away from the seismic source and avoid 

being exposed to the full acoustic 

output of the airgun array. Even with a 

large airgun array, it is unlikely that the 

cetaceans would be exposed to airgun 

pulses at a sufficiently high level for a 

sufficiently long period to cause more 

than mild TTS, given the relative 

movement of the vessel and the marine 

mammal. The potential for TTS is much 

lower in this project because of the 

much smaller airgun array proposed to 

be used. With a large array of airguns, 

TTS would be most likely in any 

odontocetes that bow-ride or otherwise 

linger near the airguns. While bowriding, odontocetes would be at or above 

the surface, and thus not exposed to 

strong pulses given the pressure-release 

effect at the surface. However, bowriding animals generally dive below the 

surface intermittently. If they did so 

while bow-riding near airguns, they 

would be exposed to strong sound 

pulses, possibly repeatedly. If some 

cetaceans did incur TTS through 

exposure to airgun sounds, this would 

very likely be mild, temporary, and 

reversible. 

To avoid the potential for injury, 

NMFS has determined that cetaceans 

should not be exposed to pulsed 

underwater noise at received levels 

exceeding 180 dB re 1 μPa (rms). As 

summarized above, data that are now 

available imply that TTS is unlikely to 

occur unless odontocetes (and probably 

mysticetes as well) are exposed to 

airgun pulses stronger than 180 dB re 1 

μPa (rms). 

Permanent Threshold Shift—When 

PTS occurs, there is physical damage to 

the sound receptors in the ear. In severe 

cases, there can be total or partial 

deafness, while in other cases the 

animal has an impaired ability to hear 

sounds in specific frequency ranges 

(Kryter, 1985). 

There is no specific evidence that 

exposure to pulses of airgun sound can 

cause PTS in any marine mammal, even 

with large arrays of airguns. However, 

given the possibility that mammals 

close to an airgun array might incur 

TTS, there has been further speculation 

about the possibility that some 

individuals occurring very close to 

airguns might incur PTS (Richardson et 

al., 1995, Gedamke et al., 2008). Single 

or occasional occurrences of mild TTS 

are not indicative of permanent auditory 

damage, but repeated or (in some cases) 

single exposures to a level well above 

that causing TTS onset might elicit PTS. 

Relationships between TTS and PTS 

thresholds have not been studied in 

marine mammals but are assumed to be 

similar to those in humans and other 

terrestrial mammals. PTS might occur at 

a received sound level at least several 

decibels above that inducing mild TTS 

if the animal were exposed to strong 

sound pulses with rapid rise time (see 

Appendix A (6) of the EA). Based on 

data from terrestrial mammals, a 

precautionary assumption is that the 

PTS threshold for impulse sounds (such 

as airgun pulses as received close to the 

source) is at least 6 dB higher than the 

TTS threshold on a peak-pressure basis 

and probably > 6 dB (Southall et al., 

2007). On an SEL basis, Southall et al., 


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(2007) estimated that received levels 

would need to exceed the TTS threshold 

by at least 15 dB for there to be risk of 

PTS. Thus, for cetaceans, Southall et al. 

estimate that the PTS threshold might 

be an M-weighted SEL (for the sequence 

of received pulses) of approximately 198 

dB re 1 μPa2-s (15 dB higher than the 

TTS threshold for an impulse). 

Southall et al. (2007) also note that, 

regardless of the SEL, there is concern 

about the possibility of PTS if a cetacean 

or pinniped receives one or more pulses 

with peak pressure exceeding 230 or 

218 dB re 1 μPa (peak), respectively. A 

peak pressure of 230 dB re 1 μPa (3.2 

bar -m, 0-pk) would only be found 

within a meter from a GI gun, which has 

a peak pressure of 224.6 dB re 1μPa-m. 

A peak pressure of 218 dB re 1 μPa 

could be received somewhat farther 

away; to estimate that specific distance, 

one would need to apply a model that 

accurately calculates peak pressures in 

the near-field around an array of 

airguns. However, no pinnipeds are 

expected in the proposed survey areas. 

Given the higher level of sound 

necessary to cause PTS as compared 

with TTS, it is considerably less likely 

that PTS could occur. Baleen whales 

generally avoid the immediate area 

around operating seismic vessels, as do 

some other marine mammals. 

Non-auditory Physiological Effects— 

Non-auditory physiological effects or 

injuries that theoretically might occur in 

marine mammals exposed to strong 

underwater sound include stress, 

neurological effects, bubble formation, 

resonance effects, and other types of 

organ or tissue damage (Cox et al., 2006; 

Southall et al., 2007). Studies examining 

such effects are limited. However, 

resonance (Gentry 2002) and direct 

noise-induced bubble formation (Crum 

et al., 2005) are not expected in the case 

of an impulsive source like an airgun 

array. If seismic surveys disrupt diving 

patterns of deep diving species, this 

might perhaps 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, little is known about the 

potential for seismic survey sounds to 

cause auditory impairment or other 

physical effects in marine mammals. 

Available data suggest that such effects, 

if they occur at all, would presumably 

be limited to short distances from the 

sound source and to activities that 

extend over a prolonged period. The 

available data do not allow 

identification of a specific exposure 

level above which non-auditory effects 

can be expected (Southall et al., 2007) 

or any meaningful quantitative 

predictions of the numbers (if any) of 

marine mammals that might be affected 

in those ways. Marine mammals that 

show behavioral avoidance of seismic 

vessels, including most baleen whales, 

some odontocetes, and some pinnipeds, 

are especially unlikely to incur auditory 

impairment or non-auditory physical 

effects. 

(5) Strandings and Mortality 

Marine mammals close to underwater 

detonations of high explosives can be 

killed or severely injured, and their 

auditory organs are especially 

susceptible to injury (Ketten et al., 1993; 

Ketten, 1995). However, explosives are 

no longer used for marine seismic 

research or commercial seismic surveys 

and have been replaced entirely by 

airguns or related non-explosive pulse 

generators. Airgun pulses are less 

energetic and have slower rise times, 

and there is no specific evidence that 

they can cause injury, death, or 

stranding even in the case of large 

airgun arrays. However, the association 

of mass strandings of beaked whales 

with naval exercises and, in one case, an 

L–DEO seismic survey (Malakoff, 2002; 

Cox et al., 2006) has raised the 

possibility that beaked whales exposed 

to strong ‘‘pulsed’’ sounds may be 

especially susceptible to injury and/or 

behavioral reactions that can lead to 

stranding (Hildebrand, 2005; Southall et 

al., 2007). Appendix A (6) of the EA 

provides additional details. 

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. As noted in SIO’s 

application, some of these mechanisms 

are unlikely to apply in the case of 

impulse sounds. However, there are 

increasing indications that gas-bubble 

disease (analogous to ‘‘the bends’’), 

induced in super-saturated tissue by a 

behavioral response to acoustic 

exposure, could be a pathologic 

mechanism for the strandings and 

mortality of some deep-diving cetaceans 

exposed to sonar. The evidence for this 

remains circumstantial and associated 

with exposure to naval mid-frequency 

sonar, not seismic surveys (Cox et al., 

2006; Southall et al., 2007). 

Seismic pulses and mid-frequency 

sonar pulses are quite different, and 

some mechanisms by which sonar 

sounds have been hypothesized to affect 

beaked whales are unlikely to apply to 

airgun pulses. Sounds produced by 

airgun arrays are broadband impulses 

with most of the energy below 1 kHz. 

Typical military mid-frequency sonars 

operate at frequencies of 2–10 kHz, 

generally with a relatively narrow 

bandwidth at any one time. A further 

difference between seismic surveys and 

naval exercises is that naval exercises 

can involve sound sources on more than 

one vessel. Thus, it is not appropriate to 

assume that there is a direct correlation 

between the effects of military sonar and 

those of seismic surveys on marine 

mammals. However, evidence that sonar 

pulses can, in special circumstances, 

lead (at least indirectly) to physical 

damage and mortality (Balcomb and 

Claridge, 2001; NOAA and USN, 2001; 

Jepson et al., 2003; Fernandez et al., 

2004, 2005; Hildebrand, 2005; Cox et 

al., 2006) suggests that caution is 

warranted when dealing with exposure 

of marine mammals to any highintensity pulsed sound. 

There is no conclusive evidence of 

cetacean strandings or deaths at sea as 

a result of exposure to seismic surveys, 

but a few cases of strandings in the 

general area where a seismic survey was 

ongoing have led to speculation 

concerning a possible link between 

seismic surveys and strandings. 

Suggestions that there was a link 

between seismic surveys and strandings 

of humpback whales in Brazil (Engel et 

al., 2004) were not well founded based 

on available data (IAGC, 2004; IWC, 

2007). In September 2002, there was a 

stranding of two Cuvier’s beaked whales 

(Ziphius cavirostris) in the Gulf of 

California, Mexico, when the L–DEO 

vessel R/V Maurice Ewing was operating 

a 20-airgun, 8490-in3 array in the 

general area. The link between the 

stranding and the seismic surveys was 

inconclusive and not based on any 

physical evidence (Hogarth, 2002; 

Yoder, 2002). Nonetheless, the Gulf of 

California incident plus the beaked 

whale strandings near naval exercises 

involving use of mid-frequency sonar 

suggests a need for caution when 

conducting seismic surveys in areas 

occupied by beaked whales until more 

is known about effects of seismic 

surveys on those species (Hildebrand, 

2005). No injuries of beaked whales are 

anticipated during the proposed study 

because of (1) the high likelihood that 


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any beaked whales nearby would avoid 

the approaching vessel before being 

exposed to high sound levels, and (2) 

differences between the sound sources 

operated by SIO and those involved in 

the naval exercises associated with 

strandings. 

Potential Effects of Other Acoustic 

Devices 

(1) Multi-Beam Echosounder Signals 

The Kongsberg EM 122 12-kHz MBES 

will be operated from the source vessel 

at some times during the planned study. 

Information about this equipment was 

provided earlier in this document. Any 

given mammal at depth near the 

trackline would be in the main beam for 

only one or two of the segments. Also, 

marine mammals that encounter the 

Kongsberg EM 122 are unlikely to be 

subjected to repeated pulses because of 

the narrow fore-aft width of the beam 

and will receive only limited amounts 

of pulse energy because of the short 

pulses. Animals close to the ship (where 

the beam is narrowest) are especially 

unlikely to be ensonified for more than 

one 2–15 ms pulse or 100-ms chirp (or 

two pulses or chirps if in the overlap 

area). Similarly, Kremser et al. (2005) 

noted that the probability of a cetacean 

swimming through the area of exposure 

when an MBES emits a pulse is small. 

The animal would have to pass the 

transducer at close range and be 

swimming at speeds similar to the 

vessel in order to receive the multiple 

pulses that might result in sufficient 

exposure to cause TTS. 

Navy sonars that have been linked to 

avoidance reactions and stranding of 

cetaceans generally have longer pulse 

durations than the Kongsberg EM 122 

and are often directed close to 

horizontally vs. more downward for the 

MBES. The area of possible influence of 

the MBES is much smaller—a narrow 

band below the source vessel. The 

duration of exposure for a given marine 

mammal can be much longer for Navy 

sonar. During SIO’s operations, the 

individual pulses will be very short, and 

a given mammal would not receive 

many of the downward-directed pulses 

as the vessel passes by. Possible effects 

of an MBES on marine mammals are 

outlined below. 

Marine mammal communications will 

not be masked appreciably by the MBES 

signals given the low duty cycle of the 

echosounder and the brief period when 

an individual mammal is likely to be 

within its beam. Furthermore, in the 

case of baleen whales, the echosounder 

signals (12 kHz) do not overlap with the 

predominant frequencies in the calls, 

which would avoid any significant 

masking. 

Behavioral reactions of free-ranging 

marine mammals to sonars, 

echosounders, and other sound sources 

appear to vary by species and 

circumstance. Observed reactions have 

included silencing and dispersal by 

sperm whales (Watkins et al., 1985), 

increased vocalizations and no dispersal 

by pilot whales (Globicephala spp.) 

(Rendell and Gordon, 1999), and the 

previously-mentioned beachings by 

beaked whales. During exposure to a 

21–25 kHz ‘‘whale-finding’’ sonar with a 

source level of 215 dB re 1 μPa-m, gray 

whales reacted by orienting slightly 

away from the source and being 

deflected from their course by 

approximately 200 m (656.2 ft) (Frankel, 

2005). When a 38-kHz echosounder and 

a 150-kHz acoustic Doppler current 

profiler were transmitting during 

studies in the ETP, baleen whales 

showed no significant responses, while 

spotted (Stenella spp.) and spinner 

(Stenella longirostris) dolphins were 

detected slightly more often and beaked 

whales less often during visual surveys 

(Gerrodette and Pettis, 2005). 

Captive bottlenose dolphins and a 

beluga whale exhibited changes in 

behavior when exposed to 1-s tonal 

signals at frequencies similar to those 

that will be emitted by the MBES used 

by SIO, and to shorter broadband pulsed 

signals. Behavioral changes typically 

involved what appeared to be deliberate 

attempts to avoid the sound exposure 

(Schlundt et al., 2000; Finneran et al., 

2002; Finneran and Schlundt, 2004). 

The relevance of those data to freeranging odontocetes is uncertain, and in 

any case, the test sounds were quite 

different in duration as compared with 

those from an MBES. 

Given recent stranding events that 

have been associated with the operation 

of naval sonar, there is concern that 

mid-frequency sonar sounds can cause 

serious impacts to marine mammals (see 

above). However, the MBES proposed 

for use by SIO is quite different than 

sonar used for Navy operations. Pulse 

duration of the MBES is very short 

relative to naval sonar. Also, at any 

given location, an individual marine 

mammal would be in the beam of the 

MBES for much less time given the 

generally downward orientation of the 

beam and its narrow fore-aft beamwidth; 

Navy sonar often use near-horizontally 

directed sound. Those factors would all 

reduce the sound energy received from 

the MBES relative to that from the sonar 

used by the Navy. 

As noted earlier in this document, 

animals are unlikely to be exposed to 

levels that would result in TTS or Level 

B harassment because of the shape of 

the beam, the duration of the signal, and 

the likelihood that they will be avoiding 

the vessel at greater horizontal distance 

when airguns are operating. 

(2) Sub-Bottom Profiler Signals 

A SBP will be operated from the 

source vessel during the planned study. 

Details about this equipment were 

provided earlier in this document. The 

SBP on the Melville has a maximum 

source level of 211 dB re 1 μPa-m. 

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, 

and—even for an SBP more powerful 

than those on the Melville—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 TTS. 

Marine mammal communications will 

not be masked appreciably by the SBP 

signals given their directionality and the 

brief period when an individual 

mammal is likely to be within their 

beams. Furthermore, in the case of most 

baleen whales, the SBP signals do not 

overlap with the predominant 

frequencies in the calls, which would 

avoid significant masking. 

Marine mammal behavioral reactions 

to other pulsed sound sources were 

discussed previously, and responses to 

the SBP are likely to be similar to those 

for other pulsed sources if received at 

the same levels. However, the pulsed 

signals from the SBPs are considerably 

weaker than those from the MBES. 

Therefore, behavioral responses are not 

expected unless marine mammals are 

within 10 m of the source, which is not 

expected to occur. 

The source levels of the SBP are much 

lower than those of the airguns. It is 

unlikely that the SBP produces pulse 

levels strong enough to cause hearing 

impairment or other physical injuries 

even in an animal that is (briefly) in a 

position near the source. The SBP is 

usually operated simultaneously with 

other higher-power acoustic sources. 

Many marine mammals will move away 

in response to the approaching higherpower sources or the vessel itself before 

the mammals would be close enough for 

there to be any possibility of effects 

from the less intense sounds from the 

SBP. Because of the shape of the beams 

of these sources and their power, NMFS 

believes it unlikely that marine 

mammals will be exposed to either the 

MBES or the SBP at levels at or above 

those likely to cause harassment. 

Further, NMFS believes that the brief 

exposure of cetaceans to a few signals 

from the multi-beam bathymetric sonar 


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system is not likely to result in the 

harassment of marine mammals. 

As stated above, current NMFS 

practice assumes that the onset of Level 

A harassment corresponds to 180 dB re 

1 μPa (rms) for cetaceans. The 

precautionary nature of these criteria is 

discussed in Appendix A (5) of the 

supporting EA, including the fact that 

the minimum sound level necessary to 

cause permanent hearing impairment is 

higher, by a variable and generally 

unknown amount, than the level that 

induces barely-detectable TTS, and the 

level associated with the onset of TTS 

is often considered to be a level below 

which there is no danger of permanent 

damage. NMFS also assumes that 

cetaceans or pinnipeds exposed to 

levels exceeding 160 dB re 1 μPa (rms) 

may experience Level B (behavioral) 

harassment. 

Potential Effects on Marine Mammal 

Habitat 

The proposed SIO seismic survey will 

not result in any permanent impact to 

habitats used by marine mammals or to 

their food sources, and there will be no 

physical damage to any habitat. While it 

is anticipated that the specified activity 

may result in marine mammals avoiding 

certain areas due to temporary 

ensonification, this impact to habitat is 

temporary and reversible and was 

considered in further detail earlier in 

this document, as behavioral 

modification. The main impact issue 

associated with the proposed activity 

will be temporarily elevated noise levels 

and the associated direct effects on 

marine mammals, as described 

previously. 

Effects on Fish and Invertebrates 

The existing body of information on 

the impacts of seismic survey sound on 

marine fish and invertebrates is very 

limited. Furthermore, the available 

information on the impacts of seismic 

surveys on fish and invertebrates is from 

studies of individuals or portions of a 

population; there have been no studies 

at the population scale. Thus, available 

information provides limited insight on 

possible real-world effects at the ocean 

or population scale. This makes drawing 

conclusions about impacts problematic 

because ultimately, the most important 

aspect of potential impacts relates to 

how exposure to seismic survey sound 

affects populations and their viability, 

including their availability to fisheries. 

However, there is some unpublished 

and very limited evidence of the 

potential for adverse effects on fish and 

invertebrates, thereby justifying further 

discussion and analysis of this issue. 

The three types of potential effects of 

exposure to seismic surveys on fish and 

marine invertebrates are pathological, 

physiological, and behavioral. 

Pathological effects involve lethal and 

temporary or permanent sublethal 

injury. Physiological effects involve 

temporary and permanent primary and 

secondary stress responses, such as 

changes in levels of enzymes and 

proteins. Behavioral effects refer to 

temporary and (if they occur) permanent 

changes in exhibited behavior (e.g., 

startle and avoidance behavior). The 

three categories are interrelated in 

complex ways. For example, it is 

possible that certain physiological and 

behavioral changes potentially could 

lead to an ultimate pathological effect 

on individuals (i.e., mortality). The 

specific received sound levels at which 

permanent adverse effects to fish 

potentially could occur are little studied 

and largely unknown. 

Based on the physical structure of 

their sensory organs, marine 

invertebrates appear to be specialized to 

respond to particle displacement 

components of an impinging sound field 

and not to the pressure component 

(Popper et al., 2001; see also Appendix 

D of the EA). More details concerning 

the effects of airguns on fish and 

invertebrates are included in SIO’s 

application and the associated EA. In 

conclusion, NMFS has preliminarily 

determined that SIO’s proposed seismic 

survey operations are not expected to 

have any habitat-related effects that 

could cause significant or long-term 

consequences for individual marine 

mammals or on the food sources they 

utilize. 

Proposed Mitigation 

In order to issue an incidental take 

authorization (ITA) under Sections 

101(a)(5)(A) and (D) of the MMPA, 

NMFS must, where applicable, 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). 

Mitigation and monitoring measures 

proposed to be implemented for the 

proposed seismic survey have been 

developed and refined during previous 

SIO seismic studies and associated EAs, 

IHA applications, and IHAs. The 

mitigation and monitoring measures 

described herein represent a 

combination of procedures required by 

past IHAs for other similar projects and 

on best practices recommended in 

Richardson et al. (1995), Pierson et al. 

(1998), and Weir and Dolman (2007). 

The measures are described in detail 

below. 

Mitigation measures proposed by SIO 

for adoption during the proposed survey 

include (1) visual monitoring by 

protected species observers (discussed 

later in this document), (2) 

establishment of an exclusion zone (EZ), 

(3) speed or course alteration, provided 

that doing so will not compromise 

operational safety requirements, (4) GI 

airgun shut down procedures, and (5) 

ramp-up procedures. Although powerdown procedures are often standard 

operating practice for seismic surveys, 

they will not be used here because 

powering down from two airguns to one 

airgun would make only a small 

difference in the 180-dB safety radius. 

The difference is not enough to allow 

continued one-airgun operations if a 

mammal came within the safety radius 

for two airguns. 

Exclusion Zones—As discussed 

previously in this document, NMFS has 

determined that for acoustic effects, 

using acoustic thresholds in 

combination with corresponding safety 

radii is an effective way to consistently 

apply measures to avoid or minimize 

the impacts of an action. Thresholds are 

used to establish a mitigation shutdown, or exclusion, zone, i.e., if an 

animal enters an area calculated to be 

ensonified above the level of an 

established threshold, a sound source is 

shut down. 

As a matter of past practice and based 

on the best available information at the 

time regarding the effects of marine 

sound, NMFS estimates that Level A 

harassment from acoustic sources may 

occur when cetaceans are exposed to 

levels above 180 dB re 1 μPa (rms) level. 

NMFS also considers 160 dB re 1 μPa 

(rms) as the criterion for estimating the 

onset of Level B harassment from 

acoustic sources producing impulse 

sounds, as in this seismic survey. 

Empirical data concerning the 180- 

and 160-dB distances have been 

acquired based on measurements during 

the acoustic verification study 

conducted by L–DEO in the northern 

Gulf of Mexico from May 27–June 3, 

2003 (Tolstoy et al., 2004). The 

empirical data indicate that, for this 

survey, the assumed 180- and 160-dB 

radii are 40 m (131.2 ft) and 400 m 

(1312.3 ft), respectively (see Table 1 in 

this document). 

Speed or Course Alteration—If a 

marine mammal is detected outside the 

EZ but is likely to enter it based on 

relative movement of the vessel and the 

animal, and if safety and scientific 

objectives allow, the vessel speed and/ 


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or course will be adjusted to minimize 

the likelihood of the animal entering the 

EZ. In the event that safety and/or 

scientific objectives do not allow for 

alteration of speed and/or course as a 

needed mitigation measure, shut-down 

procedures will still be utilized (see 

below). Major course and speed 

adjustments are often impractical when 

towing long seismic streamers and large 

source arrays but are possible in this 

case because only a small source and 

short streamers will be used. 

Shut-down Procedures—If a marine 

mammal is detected by PSOs outside 

the EZ but is likely to enter the EZ, and 

if the vessel’s speed and/or course 

cannot be changed to avoid having the 

animal enter the EZ, the airgun array, 

MBES, and SBP will be shut down 

before the animal is within the EZ. 

Likewise, if a marine mammal is already 

within the EZ when first detected, the 

airgun array, MBES, and SBP will be 

shut down immediately. Following a 

shut down, seismic activity will not 

resume until the marine mammal has 

cleared the EZ. The animal will be 

considered to have cleared the EZ if it 

(a) is visually observed to have left the 

EZ, or (b) has not been seen within the 

EZ for 15 min in the case of small 

odontocetes, or has not been seen 

within the EZ for 30 min in the case of 

mysticetes and large odontocetes, 

including sperm and beaked whales. 

Ramp-up Procedures—A ramp-up 

procedure will be followed when the GI 

airguns begin operating after a specified 

period without GI airgun operations. It 

is proposed that, for the present cruise, 

this period would be approximately 1– 

2 min. This period is based on the 180- 

dB radii for the GI airguns (see Table 1 

in this document) in relation to the 

planned speed of the Melville while 

shooting. Ramp-up will begin with a 

single GI airgun (45 in3). The second GI 

airgun (45 in3) will be added after 5 

min. During ramp up, the PSOs will 

monitor the exclusion zone, and, if 

marine mammals are sighted, a shutdown will be implemented as though 

both GI airguns were operational. 

If the complete EZ has not been 

visible for at least 30 min prior to the 

start of operations in either daylight or 

nighttime, ramp-up will not commence. 

If one GI airgun has operated, ramp-up 

to full power will be permissible at 

night or in poor visibility on the 

assumption that marine mammals will 

be alerted to the approaching seismic 

vessel by the sounds from the single GI 

airgun and could move away if they 

choose. A ramp-up from a shut-down 

may occur at night, but only when the 

entire EZ is visible, and it has been 

determined from the pre-ramp up watch 

that the EZ is clear of marine mammals. 

Ramp-up of the GI airguns will not be 

initiated if a marine mammal is sighted 

within or near the applicable EZ during 

day or night. 

NMFS has carefully evaluated the 

applicant’s proposed mitigation 

measures and considered a range of 

other measures in the context of 

ensuring that NMFS prescribes the 

means of effecting the least practicable 

impact on the affected marine mammal 

species and stocks and their habitat. 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. 

Based on our evaluation of the 

applicant’s proposed measures, as well 

as other measures considered by NMFS, 

NMFS has preliminarily determined 

that the proposed mitigation measures 

provide the means of effecting the least 

practicable impact on marine mammal 

species or stocks and their habitat, 

paying particular attention to rookeries, 

mating grounds, and areas of similar 

significance. 

Proposed Monitoring and Reporting 

In order to issue an ITA for an 

activity, Section 101(a)(5)(D) of the 

MMPA states that NMFS must set forth 

‘‘requirements pertaining to the 

monitoring and reporting of such 

taking’’. The MMPA implementing 

regulations at 50 CFR 216.104(a)(13) 

indicate that requests for ITAs must 

include the suggested means of 

accomplishing the necessary monitoring 

and reporting that 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. 

SIO proposes to sponsor marine 

mammal monitoring during the present 

project in order to implement the 

proposed mitigation measures that 

require real-time monitoring and to 

satisfy the anticipated monitoring 

requirements of the IHA. SIO’s proposed 

Monitoring Plan is described next. The 

monitoring work described here has 

been planned as a self-contained project 

independent of any other related 

monitoring projects that may be 

occurring simultaneously in the same 

regions. SIO is prepared to discuss 

coordination of its monitoring program 

with any related work that might be 

done by other groups insofar as this is 

practical and desirable. 

Vessel-based Visual Monitoring 

Three protected species observers 

(PSOs) will be based aboard the seismic 

source vessel for the duration of the 

cruise and will watch for marine 

mammals near the vessel during 

daytime airgun operations and during 

start-up of airguns at any time. Watches 

will be conducted by at least one 

observer 100% of the time during 

seismic surveys in daylight hours. 

Daylight observation by at least one 

observer will continue during nonseismic periods, as long as weather 

conditions make observations 

meaningful, for comparison of sighting 

rates and animal behavior during 

periods with vs. without airgun 

operations. PSOs will be appointed by 

SIO with NMFS concurrence after a 

review of their qualifications. 

The Melville is a suitable platform for 

marine mammal observations. The 

observer platform is located one deck 

below and forward of the bridge (12.46 

meters (40.88 ft) above the waterline), 

affording a relatively unobstructed 180- 

degree forward view. Aft views can be 

obtained along the port and starboard 

decks. During daytime hours, the 

observer(s) will scan the area 

systematically using reticulated 25x150 

big-eye binoculars and 7x50 hand-held 

binoculars to determine bearing and 

distance of sightings. A clinometer is 

used to determine distances of animals 

in close proximity to the vessel. Handheld fixed rangefinders and distance 

marks on the ship’s side rails are used 

to measure the exact location of the 

safety zone. Laser rangefinders, which 

have proven to be less reliable for open 

water sighting, are also provided. 

During darkness, night-vision 

equipment will be available. The PSOs 

will be in wireless communication with 

ship’s officers on the bridge and 

scientists in the vessel’s operations 

laboratory, so they can advise promptly 

of the need for avoidance maneuvers or 

GI airgun shut down. 

Before commencing seismic 

operations during daylight hours, two 

observers will maintain a 360-degree 

watch for all marine mammals for at 

least 30 minutes prior to the start of 

seismic operations after an extended 

shutdown of the airguns (1–2 minutes, 

depending on vessel speed). If no 

marine mammals are observed within 

the EZ during this time, the observers 

will notify the seismic personnel of an 

‘‘all clear’’ status. Watch periods are 

scheduled as a 2-hour rotation. The 


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observers continually scan the water 

from the horizon to the ship’s hull, and 

forward of 90 degrees from the port and 

starboard beams. Based on PSO 

observations, the GI airgun will be shut 

down (as described earlier in this 

document) when marine mammals are 

detected within or about to enter a 

designated EZ that corresponds to the 

180-dB re 1 μPa (rms) isopleths. The 

PSOs will continue to maintain watch to 

determine when the animal(s) are 

outside the EZ, and airgun operations 

will not resume until the animal has left 

that EZ. The predicted distance for the 

180-dB EZ is listed in Table 1 earlier in 

this document. Seismic operations will 

resume only after the animals are seen 

to exit the safety radius or after no 

further visual detection of the animal for 

15 minutes (for small odontocetes and 

pinnipeds) or 30 minutes (for mysticetes 

and large odontocetes, including beaked 

whales). 

The bridge officers and other crew 

will be instructed to alert the observer 

on watch of any suspected marine 

mammal sighting. If needed, the bridge 

will be contacted in order to maneuver 

the ship to avoid interception with 

approaching marine mammals. 

PSO Data and Documentation 

PSOs will record data to estimate the 

numbers of marine mammals exposed to 

various received sound levels and to 

document reactions or lack thereof. Data 

will be used to estimate numbers of 

animals potentially ‘taken’ by 

harassment (as defined in the MMPA). 

They will also provide information 

needed to order a shutdown of the 

seismic source when a marine mammal 

is within or near the EZ. When a 

sighting is made, the following 

information about the sighting will be 

recorded: 

• Species, group size, and 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 seismic source or vessel (e.g., none, 

avoidance, approach, paralleling, etc.); 

and behavioral pace; and 

• Time, location, heading, speed, 

activity of the vessel, sea state, 

visibility, cloud cover, and sun glare. 

The data will also be recorded at the 

start and end of each observation watch 

and during a watch whenever there is a 

change in one or more of the variables. 

All observations, as well as 

information regarding seismic source 

shutdown, will be recorded in a 

standardized format. Data collection 

procedures are adapted from the linetransect protocols developed by the 

SWFSC for their marine mammal 

abundance research cruises. A laptop 

computer is located on the observer 

platform for ease of data entry. The 

computer is connected to the ship’s 

Global Positioning System, which 

allows a record of time and position to 

be made at 3-minute intervals and for 

each event entered (such as sightings, 

weather updates and effort changes). 

Data accuracy will be verified by the 

PSOs at sea and preliminary reports will 

be prepared during the field program 

and summaries forwarded to the SIO’s 

shore facility and to NSF weekly or 

more frequently. PSO observations will 

provide the following information: 

• The basis for decisions about 

shutting down the airgun arrays; 

• Information needed to estimate the 

number of marine mammals potentially 

‘taken by harassment’, which will be 

reported to NMFS; 

• Data on the occurrence, 

distribution, and activities of marine 

mammals in the area where the seismic 

study is conducted; and 

• Data on the behavior and movement 

patterns of marine mammals seen at 

times with and without seismic activity. 

A report will be submitted to NMFS 

within 90 days after the end of the 

cruise. The report will describe the 

operations that were conducted and 

sightings of marine mammals near the 

operations. The report will be submitted 

to NMFS, providing full documentation 

of methods, results, and interpretation 

pertaining to all monitoring. The 90-day 

report will summarize the dates and 

locations of seismic operations and all 

marine mammal sightings (dates, times, 

locations, activities, associated seismic 

survey activities). The report will also 

include estimates of the amount and 

nature of potential ‘‘take’’ of marine 

mammals by harassment or in other 

ways. All injured or dead marine 

mammals (regardless of cause) will be 

reported to NMFS as soon as 

practicable. The report should include 

species or description of animal, 

condition of animal, location, time first 

found, observed behaviors (if alive), and 

photo or video, if available. 

Estimated Takes by Incidental 

Harassment 

With respect to the activities described 

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]. 

All anticipated takes would be by 

Level B harassment, involving 

temporary changes in behavior. The 

proposed mitigation and monitoring 

measures are expected to minimize the 

possibility of injurious or lethal takes 

such that take by Level A harassment, 

serious injury or mortality is considered 

remote. However, as noted earlier, there 

is no specific information demonstrating 

that injurious or lethal ‘‘takes’’ would 

occur even in the absence of the 

planned mitigation and monitoring 

measures. The sections here describe 

methods to estimate ‘‘take by Level B 

harassment’’ and present estimates of 

the numbers of marine mammals that 

might be affected during the proposed 

seismic program. The estimates of ‘‘take’’ 

are based on data collected in the ETP 

by NMFS SWFSC during 12 ship-based 

cetacean and ecosystem assessment 

surveys conducted during July– 

December from 1986–2006. 

It is assumed that, during 

simultaneous operations of the seismic 

sources and the other sources, any 

marine mammals close enough to be 

affected by the MBES or SBP would 

already be affected by the seismic 

sources. However, whether or not the 

seismic sources are operating 

simultaneously with the other sources, 

marine mammals are expected to exhibit 

no more than short-term and 

inconsequential responses to the MBES 

and SBP given their characteristics (e.g., 

narrow downward-directed beam) and 

other considerations described above, 

such as the unlikelihood of being 

exposed to the source at higher levels 

and the fact that it would likely only be 

for one or two pulses. Such reactions are 

not considered to constitute ‘‘taking’’ 

(NMFS, 2001). Therefore, no additional 

allowance is included for animals that 

might be affected by sound sources 

other than the seismic sources (i.e., air 

guns). 

Extensive systematic ship-based 

surveys have been conducted by NMFS 

SWFSC for marine mammals in the ETP. 

SWFSC has recently developed habitat 

modeling as a method to estimate 

cetacean densities on a finer spatial 

scale than traditional line-transect 

analyses by using a continuous function 

of habitat variables, e.g., sea surface 

temperature, depth, distance from shore, 

and prey density (Barlow et al., 2009). 

The models have been incorporated into 

a Web-based Geographic Information 

System (GIS) developed by Duke 

University’s Department of Defense 

Strategic Environmental Research and 

Development Program (SERDP) team in 

close collaboration with the SWFSC 

SERDP team (Read et al., 2009). The GIS 

was used to obtain densities for the 11 


srobinson on DSKHWCL6B1PROD with NOTICES
Federal Register / Vol. 75, No. 171 / Friday, September 3, 2010 / Notices 54111 

cetaceans in the model (Bryde’s whale, 

blue whale, Kogia spp., Mesoplodon 

spp., rough-toothed, bottlenose, 

pantropical spotted, spinner, striped, 

and short-beaked common dolphins, 

and short-finned pilot whale) in each of 

eight areas: the four proposed survey 

areas (see Figure 1 in SIO’s application), 

and corridors 1° wide and centered on 

the tracklines between the survey areas 

and from the southernmost survey area 

to the EEZ of Peru. For species sighted 

in SWFSC surveys whose sample sizes 

were too small to model density (sperm 

whale, humpback whale, Cuvier’s 

beaked whale, Fraser’s dolphin, Risso’s 

dolphin, melon-headed, pygmy killer, 

false killer, and killer whales), SIO used 

densities from the surveys conducted 

during summer and fall 1986–1996, as 

summarized by Ferguson and Barlow 

(2001). Densities were calculated from 

Ferguson and Barlow (2003) for 5° x 5° 

blocks that include the proposed survey 

areas and corridors. Those blocks 

included 27,275 km (16,947.9 mi) of 

survey effort in Beaufort sea states 0–5 

and 2564 km (1593.2 mi) of survey effort 

in Beaufort sea states 0–2. Densities 

were obtained for an additional eight 

species that were sighted in one or more 

of those blocks. 

Oceanographic conditions, including 

occasional El Nino and La Nina events, 

influence the distribution and numbers 

of marine mammals present in the ETP, 

resulting in considerable year-to-year 

variation in the distribution and 

abundance of many marine mammal 

species (Escorza-Trevino, 2009). Thus, 

for some species, the densities derived 

from recent surveys (see Table 2 of this 

document) may not be representative of 

the densities that will be encountered 

during the proposed seismic survey. 

Table 3 in SIO’s application gives the 

average (or ‘‘best’’) and maximum 

densities for each species of cetacean 

likely to occur in the study area, i.e., 

species for which densities were 

obtained or assigned. These densities 

have been corrected for both 

detectability and availability bias by the 

study authors. Detectability bias is 

associated with diminishing sightability 

with increasing lateral distance from the 

trackline. Availability bias refers to the 

fact that there is less than 100 percent 

probability of sighting an animal that is 

present along the survey trackline. 

The estimated numbers of individuals 

potentially exposed are presented next 

based on the 160-dB re 1 μPa (rms) 

Level B harassment criterion for all 

cetaceans. It is assumed that marine 

mammals exposed to airgun sounds at 

that level might change their behavior 

sufficiently to be considered ‘‘taken by 

harassment’’. 

It should be noted that the following 

estimates of ‘‘takes by harassment’’ 

assume that the surveys will be 

undertaken and completed; in fact, the 

planned number of line-kilometers has 

been increased to accommodate lines 

that may need to be repeated, 

equipment testing, etc. As is typical on 

offshore ship surveys, inclement 

weather and equipment malfunctions 

are likely to cause delays and may limit 

the number of useful line-kilometers of 

seismic operations that can be 

undertaken. Furthermore, any marine 

mammal sightings within or near the 

designated EZ will result in the 

shutdown of seismic operations as a 

mitigation measure. Thus, the following 

estimates of the numbers of marine 

mammals potentially exposed to 160-dB 

re 1 μPa (rms) sounds are precautionary 

and probably overestimate the actual 

numbers of marine mammals that might 

be taken. These estimates assume that 

there will be no weather, equipment, or 

mitigation delays, which is highly 

unlikely. 

There is some uncertainty about the 

representativeness of the data and the 

assumptions used in the calculations 

presented here. However, the approach 

used here is believed to be the best 

available approach. Also, to provide 

some allowance for these uncertainties, 

‘‘maximum estimates’’ as well as ‘‘best 

estimates’’ of the densities present and 

numbers potentially affected have been 

derived. Best estimates of density are 

the mean densities weighted by effort in 

the eight survey areas or corridors from 

Read et al. (2009) or the nine 5° x 5° 

blocks from Ferguson and Barlow (2001, 

2003), whereas maximum estimates of 

density are the highest densities in any 

of those survey areas/corridors or 

blocks. 

The number of different individuals 

that may be exposed to GI airgun sounds 

with received levels ≥160 dB re 1 μPa 

(rms) on one or more occasions was 

estimated by considering the total 

marine area that would be within the 

160-dB radius around the operating 

airgun array on at least one occasion, 

along with the expected density of 

animals in the area. The proposed 

seismic lines do not run parallel to each 

other in close proximity, which 

minimizes the number of times an 

individual mammal may be exposed 

during the survey; in this case, an 

individual could be exposed 1.01 times 

on average. The numbers of different 

individuals potentially exposed to ≥160 

dB re 1 μPa (rms) were calculated by 

multiplying the expected species 

density, either ‘‘mean’’ (i.e., best 

estimate) or ‘‘maximum’’, times the 

anticipated area to be ensonified to that 

level during GI airgun operations. 

The area expected to be ensonified 

was determined by entering the planned 

survey lines into a MapInfo GIS, using 

the GIS to identify the relevant areas by 

‘‘drawing’’ the applicable 160-dB buffer 

(see Table 1 in this document) around 

each seismic line, and then calculating 

the total area within the buffers. Areas 

where overlap occurred (because of 

intersecting lines) were included only 

once when estimating the number of 

individuals exposed. 

Applying the approach described 

here, approximately 4340 km2 (1675.7 

mi2) would be within the 160-dB 

isopleth on one or more occasions 

during the surveys. This approach does 

not allow for turnover in the mammal 

populations in the study area during the 

course of the survey. That might 

underestimate actual numbers of 

individuals exposed, although the 

conservative distances used to calculate 

the area may offset this. In addition, the 

approach assumes that no cetaceans will 

move away or toward the trackline as 

the Melville approaches in response to 

increasing sound levels prior to the time 

the levels reach 160 dB. Another way of 

interpreting the estimates that follow 

(Table 3 in this document) is that they 

represent the number of individuals that 

are expected (in the absence of a seismic 

program) to occur in the waters that will 

be exposed to ≥160 dB re 1 μPa (rms). 

The take estimates presented here do 

not take the proposed mitigation 

measures into consideration and thus 

are likely to be overestimates. 


srobinson on DSKHWCL6B1PROD with NOTICES
54112 Federal Register / Vol. 75, No. 171 / Friday, September 3, 2010 / Notices 

TABLE 3—THE ESTIMATES OF THE POSSIBLE NUMBERS OF MARINE MAMMALS EXPOSED TO SOUND LEVELS GREATER

THAN OR EQUAL TO 160 DB DURING SIO’S PROPOSED SEISMIC SURVEY IN THE EASTERN TROPICAL PACIFIC OCEAN

IN OCT–NOV 2010. THE PROPOSED SOUND SOURCE IS A PAIR OF GI AIRGUNS. RECEIVED LEVELS ARE EXPRESSED

IN DB RE 1 μPA (RMS) (AVERAGED OVER PULSE DURATION), CONSISTENT WITH NMFS’ PRACTICE. NOT ALL MARINE

MAMMALS WILL CHANGE THEIR BEHAVIOR WHEN EXPOSED TO THESE SOUND LEVELS, BUT SOME MAY ALTER THEIR

BEHAVIOR WHEN LEVELS ARE LOWER (SEE TEXT) 

[See Tables 2–4 in SIO’s Application for Further Detail] 

Species 

Number of individuals exposed 

(best) 1

Number of individuals exposed 

(max) 1

Approx. % regional population 

(best) 2

Requested take 

authorization 

Mysticetes: 

Bryde’s whale, (Balaenoptera edeni) ....................................... 3 6 0.02 3 

Blue whale, (Balaenoptera musculus) ...................................... 1 1 0.05 * 2 

Humpback whale, (Megaptera novaeangliae) .......................... 1 1 3 NA * 2 

Odontocetes: 

Sperm whale, (Physeter macrocephalus) ................................ 23 82 0.09 23 

Cuvier’s beaked whale, (Ziphius cavirostris) ............................ 10 20 0.05 10 

Mesoplodon sp. (unidentified) .................................................. 1 2 <0.01 1 

Rough-toothed dolphin, (Steno bredanensis) .......................... 9 13 0.01 * 15 

Pantropical spotted dolphin, (Stenella attenuata) .................... 67 122 0.01 * 131 

Spinner dolphin, (Stenella longirostris) .................................... 21 31 <0.01 * 109 

Bottlenose dolphin, (Tursiops truncatus) .................................. 82 125 0.02 82 

Striped dolphin, (Stenella coeruleoalba) .................................. 6 291 <0.01 6 

Fraser’s dolphin, (Lagenodelphis hosei) .................................. 6 30 <0.01 * 440 

Short-beaked common dolphin, (Delphinus delphis) ............... 777 1317 0.02 777 

Pygmy killer whale, (Feresa attenuata) .................................... 3 10 0.01 * 30 

Melon-headed whale, (Peponocephala electra) ....................... 15 50 0.03 * 258 

Risso’s dolphin, (Grampus griseus) ......................................... 55 203 0.05 55 

False killer whale, (Pseudorca crassidens) .............................. 2 11 0.01 * 11 

Killer whale, (Orcinus orca) ...................................................... 5 22 0.05 5 

Short-finned pilot whale, (Globicephala macrorhynchus) ......... 34 64 0.01 34 

* Requested take authorization increased from ‘best’ exposure estimate to mean group size as reported in Ferguson et al. (2006). 1Best estimate and maximum estimate density are from Table 3 of SIO’s application; therefore, takes are not anticipated for sei, fin, humpback, minke, Longman’s beaked whales, pygmy sperm whales, and dwarf sperm whales. Humpback whale estimates calculated independently 

using methodology described previously. 2 Regional population size estimates are from Table 2 in this document. 

3Southern Hemisphere population sizes are poorly understood. However, the number of individuals potentially exposed is low relative to regional population. 

Table 4 in SIO’s application shows 

the best and maximum estimates of the 

number of exposures and the number of 

individual marine mammals that 

potentially could be exposed to ≥160 dB 

re 1 μPa (rms) during the seismic survey 

if no animals moved away from the 

survey vessel. Proposed take 

authorizations are based on best 

estimates, calculated according to the 

methodology described previously. The 

best estimate of the number of 

individual cetaceans that could be 

exposed to seismic sounds with 

received levels ≥160 dB re 1 μPa (rms) 

(but below Level A harassment 

thresholds) during the survey is shown 

in Table 4 of SIO’s application and 

Table 3 here. That total includes 25 

endangered whales: 1 blue whale 

(0.05% of the regional population), 1 

humpback whale, and 23 sperm whales 

(0.09%). Percentage of regional 

population for humpback whale is not 

listed because Southern Hemisphere 

population numbers are poorly 

understood; however, the authorized 

take is low compared to regional 

population. It should be noted that the 

applicant did not initially request take 

authorization for humpback whales, 

believing that migrating individuals 

would depart the proposed study area 

prior to the activity dates. In subsequent 

discussions between NMFS and the 

applicant, it was agreed that there was 

some reasonable chance that latemigrant Southern Hemisphere 

individuals could be present in one or 

more of the study areas. The proposed 

take authorization for humpback whales 

reflects this decision. Most (96.8%) of 

the cetaceans potentially exposed are 

delphinids; short-beaked common, 

pantropical spotted, bottlenose, and 

Risso’s dolphins and short-finned pilot 

whales are estimated to be the most 

common species in the area, with best 

estimates of 777 (0.02% of the regional 

population), 67 (0.01%), 82 (0.02%), 55 

(0.05%), and 34 (0.01%) exposed to 

≥160 dB re 1 μPa (rms), respectively. For 

certain species where the calculated 

number of individuals exposed was 

between 1 and the mean group size, the 

requested take authorization has been 

increased to the mean group size as 

observed in the ETP (Ferguson et al., 

2006). 

Negligible Impact and Small Numbers 

Analysis and Preliminary 

Determination 

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.’’ 

In making a negligible impact 

determination, NMFS considers a 

variety of factors, including but not 

limited to: (1) The number of 

anticipated mortalities; (2) the number 

and nature of anticipated injuries; (3) 

the number, nature, intensity, and 

duration of Level B harassment; and (4) 

the context in which the take occurs. 

NMFS has preliminarily determined 

that the impact of conducting the lowenergy marine seismic survey in the 

ETP may result, at worst, in a temporary 

modification in behavior (Level B 

harassment) of small numbers of marine 

mammals. No mortality or injuries are 


srobinson on DSKHWCL6B1PROD with NOTICES
Federal Register / Vol. 75, No. 171 / Friday, September 3, 2010 / Notices 54113 

anticipated as a result of the specified 

activity, and none are proposed to be 

authorized. Additionally, animals in the 

area are not expected to incur hearing 

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

the nature, degree, and context of 

behavioral harassment anticipated, the 

activity is not expected to impact rates 

of recruitment or survival. This activity 

is expected to result in a negligible 

impact on the affected species or stocks. 

Many animals perform vital functions, 

such as feeding, resting, traveling, and 

socializing, on a diel cycle (24-hr cycle). 

Behavioral reactions to noise exposure 

(such as disruption of critical life 

functions, displacement, or avoidance of 

important habitat) are more likely to be 

significant if they last more than one 

diel cycle or recur on subsequent days 

(Southall et al., 2007). Consequently, a 

behavioral response lasting less than 

one day and not recurring on 

subsequent days is not considered 

particularly severe unless it could 

directly affect reproduction or survival 

(Southall et al., 2007). Seismic 

operations are only scheduled to occur 

at each site for approximately 2 days. 

Additionally, the source vessel will be 

constantly moving and will not remain 

in any one spot for a prolonged period 

of time. Survey operations will be 

conducted solely in deep-water areas of 

no specifically-known (e.g., breeding) 

importance for the species described. 

Several species for which take 

authorization is requested are either 

ESA-listed and/or are considered 

‘‘Depleted’’ under the MMPA. Blue, 

sperm, and humpback whales are listed 

as Endangered under the ESA (as well 

as MMPA–Depleted). Along the 

California coast blue whale abundance 

has been increasing during the past two 

decades (Calambokidis et al., 1990; 

Barlow, 1994; Calambokidis, 1995). 

Though the magnitude of this apparent 

increase is too large to be accounted for 

by population growth alone and, 

therefore, is assumed to partly result 

from a shift in distribution, there is an 

apparent increasing trend. Some 

individuals from this stock may be 

present year-round on the Costa Rica 

Dome (Reilly and Thayer, 1990). 

Although the population in the North 

Pacific is expected to have grown since 

being given protected status in 1966, 

there is no evidence showing that the 

eastern North Pacific stock is currently 

growing, and no information exists on 

the rate of growth of blue whale 

populations in the Pacific (Best, 1993). 

Slightly more information is available 

for sperm whales, and it has been 

suggested that ETP animals of this 

species may form a distinct stock 

(Dufault and Whitehead 1995; Jaquet et 

al., 2003). However, little is known 

about population trends and growth 

rates in the survey area. Again, 

populations are assumed to have 

increased since the species gained 

protection. Humpback whales 

potentially seen in the survey area 

would likely be late migrant individuals 

belonging to Southern Hemisphere 

stocks, where the International Whaling 

Commission has designated seven major 

breeding stocks linked to seven major 

feeding areas. In most areas for which 

there are good data, humpback whales 

have shown evidence of strong recovery 

towards their unexploited size, with 

annual increase rates of about 10% 

being recorded in a number of areas 

including off South America. The total 

Southern Hemisphere abundance is 

probably at least 60,000, although little 

data on which to base this number 

exists. The eastern spinner dolphin (S. 

l. orientalis), considered an offshore 

species and common in the survey area, 

is considered a Depleted stock under the 

MMPA. The long-term trend is flat for 

this stock. For all of these species, the 

levels of requested take are small 

relative to the regional population (see 

Table 3 in this document). 

For reasons stated previously in this 

document, the negligible impact 

determination is also supported by the 

likelihood that, given sufficient ‘‘notice’’ 

through relatively slow ship speed, 

marine mammals are expected to move 

away from a noise source that is 

annoying prior to its becoming 

potentially injurious; the fact that 

cetaceans would have to be closer than 

40 m (131.2 ft) in deep water when the 

GI airgun is in use from the vessel to be 

exposed to levels of sound (180 dB) 

believed to have even a minimal chance 

of causing PTS; and the likelihood that 

marine mammal detection ability by 

trained observers is high at that short 

distance from the vessel, enabling the 

implementation of shut-downs to avoid 

injury, serious injury, or mortality. As a 

result, no take by injury or death is 

anticipated, and the potential for 

temporary or permanent hearing 

impairment is very low and will be 

avoided through the incorporation of 

the proposed mitigation measures. 

While the number of marine 

mammals potentially incidentally 

harassed will depend on the 

distribution and abundance of marine 

mammals in the vicinity of the survey 

activity, the number of potential 

harassment takings is estimated to be 

small, less than one percent of any of 

the estimated population sizes, and has 

been mitigated to the lowest level 

practicable through incorporation of the 

proposed mitigation and monitoring 

measures mentioned previously in this 

document. 

Based on the analysis contained 

herein of the likely effects of the 

specified activity on marine mammals 

and their habitat, and taking into 

consideration the implementation of the 

mitigation and monitoring measures, 

NMFS preliminarily finds that the 

proposed SIO seismic survey will result 

in the incidental take of small numbers 

of marine mammal, by Level B 

harassment only, and that the total 

taking from the seismic survey will have 

a negligible impact on the affected 

species or stocks. 

Impact on Availability of Affected 

Species or Stock for Taking for 

Subsistence Uses 

Subsistence whaling of several 

species of small cetaceans, including the 

bottlenose dolphin, takes place in 

territorial coastal waters of Peru (Read et 

al., 1998). This hunt is mainly for 

human consumption and uses gill nets, 

purse seines, and harpoons. Read et al. 

(1998) estimated that approximately 

10,000 dolphins and porpoises were 

landed in Peru in 1985. Because the 

seismic surveys are in offshore waters, 

the proposed activities will not have 

any impact on the availability of the 

species or stocks for subsistence users. 

However, there are no relevant 

subsistence uses of marine mammals 

implicated by this action. 

Endangered Species Act (ESA) 

There are six marine mammal species 

that are listed as endangered under the 

ESA with confirmed or possible 

occurrence in the study area: The 

humpback whale, South Pacific right 

whale, sei whale, fin whale, blue whale, 

and sperm whale. Under section 7 of the 

ESA, SIO has begun consultation with 

NMFS on the proposed seismic survey. 

NMFS will also consult internally on 

the issuance of an IHA under section 

101(a)(5)(D) of the MMPA for this 

activity. As discussed previously in this 

document, take is requested only for 

species likely to occur in the survey area 

during the project timeframe (blue, 

humpback, and sperm whales), and 

consultation will consider these three 

species. Consultation will be concluded 

prior to a determination on the issuance 

of an IHA. 

National Environmental Policy Act 

(NEPA) 

On behalf of NSF, LGL Limited, 

Environmental Research Associates, 

prepared an EA titled ‘‘Environmental 

Assessment of a Marine Geophysical 

Survey by the R/V Melville in the Pacific 


srobinson on DSKHWCL6B1PROD with NOTICES
54114 Federal Register / Vol. 75, No. 171 / Friday, September 3, 2010 / Notices 

Ocean off Central and South America, 

October-November 2010’’. NMFS, after 

independently reviewing and evaluating 

the document for sufficiency and 

compliance with the Council on 

Environmental Quality regulations and 

NOAA Administrative Order 216–6, 

will either adopt NSF’s EA or conduct 

a separate NEPA analysis, as necessary, 

prior to making a determination on the 

issuance of the IHA. 

Proposed Authorization 

As a result of these preliminary 

determinations, NMFS proposes to issue 

an IHA for Level B harassment, at levels 

specified in Table 3 of this document, 

to SIO incidental to conducting a lowenergy marine seismic survey in the 

ETP during the period OctoberNovember 2010, provided the 

previously mentioned mitigation, 

monitoring, and reporting requirements 

are incorporated. 

Dated: August 30, 2010. 

James H. Lecky, 

Director, Office of Protected Resources, 

National Marine Fisheries Service. 

[FR Doc. 2010–22080 Filed 9–2–10; 8:45 am] 

BILLING CODE 3510–22–P 

COMMITTEE FOR PURCHASE FROM 

PEOPLE WHO ARE BLIND OR 

SEVERELY DISABLED 

Procurement List Additions 

AGENCY: Committee for Purchase From 

People Who Are Blind or Severely 

Disabled. 

ACTION: Additions to the Procurement 

List. 

SUMMARY: This action adds products and 

services to the Procurement List that 

will be furnished by nonprofit agencies 

employing persons who are blind or 

have other severe disabilities. 

DATES: Effective Date: 10/4/2010. 

ADDRESSES: Committee for Purchase 

From People Who Are Blind or Severely 

Disabled, Jefferson Plaza 2, Suite 10800, 

1421 Jefferson Davis Highway, 

Arlington, Virginia 22202–3259. 

FOR FURTHER INFORMATION CONTACT: 

Barry S. Lineback, Telephone: (703) 

603–7740, Fax: (703) 603–0655, or email CMTEFedReg@AbilityOne.gov. 

SUPPLEMENTARY INFORMATION: 

Additions 

On 7/2/2010 (75 FR 38467–38468) 

and 7/9/2010 (75 FR 39497–39499), the 

Committee for Purchase From People 

Who Are Blind or Severely Disabled 

published Notices of proposed additions 

to the Procurement List. 

Comments were received from a 

nonprofit agency that was not selected 

as the designated nonprofit agency to 

perform the Janitorial and Grounds 

Service at the Alan Bible Federal 

Building and Lloyd George U.S. 

Courthouse in Las Vegas, NV. In its 

comments, the nonprofit agency 

questions the fairness of the process 

used by the central nonprofit agency to 

identify the nonprofit agency to perform 

this project. 

The Committee for Purchase From 

People Who Are Blind or Severely 

Disabled (Committee) operates pursuant 

to statutory and regulatory 

requirements. In accordance with these 

requirements, the Committee has 

designated central nonprofit agencies to 

perform certain duties, including 

facilitating the distribution of 

Government orders for goods and 

services among qualified nonprofit 

agencies. The central nonprofit agencies 

have established order distribution 

procedures which include dispute 

resolution processes. Accordingly, in 

this instance, if a qualified nonprofit 

agency questions the fairness of the 

order distribution process conducted by 

the central nonprofit agency, they must 

utilize the established dispute 

resolution process. 

After consideration of the material 

presented to it concerning capability of 

qualified nonprofit agencies to provide 

the products and services and impact of 

the additions on the current or most 

recent contractors, the Committee has 

determined that the products and 

services listed below are suitable for 

procurement by the Federal Government 

under 41 U.S.C. 46–48c and 41 CFR 51– 

2.4. 

Regulatory Flexibility Act Certification 

I certify that the following action will 

not have a significant impact on a 

substantial number of small entities. 

The major factors considered for this 

certification were: 

1. The action will not result in any 

additional reporting, recordkeeping or 

other compliance requirements for small 

entities other than the small 

organizations that will furnish the 

products and services to the 

Government. 

2. The action will result in 

authorizing small entities to furnish the 

products and services to the 

Government. 

3. There are no known regulatory 

alternatives which would accomplish 

the objectives of the Javits-WagnerO’Day Act (41 U.S.C. 46–48c) in 

connection with the products and 

services proposed for addition to the 

Procurement List. 

End of Certification 

Accordingly, the following products 

and services are added to the 

Procurement List: 

Products 

NSN: 7220–00–NIB–0367—Disposable Urinal 

Floor Mat. 

NSN: 7220–00–NIB–0368—Disposable Toilet 

Floor Mat. 

NPA: NewView Oklahoma, Inc., Oklahoma 

City, OK. 

Contracting Activity: GSA/Federal 

Acquisition Service, Fort Worth, TX. 

Coverage: B-List for the Broad Government 

Requirement as aggregated by the 

General Services Administration. 

NSN: 7520–01–377–9534—Cord Connector/ 

Rotator, Telephone, Twisstop, Black. 

NSN: 7520–00–NIB–2084—Shoulder Rest, 

Telephone, Black, Softak II. 

NSN: 7520–00–NIB–2085—Shoulder Rest, 

Telephone, Black. 

Coverage: A-List for the Total Government 

Requirement as aggregated by the 

General Services Administration. 

NSN: 7520–01–253–1283—Shoulder Rest, 

Telephone, Beige, 21⁄4′′ W × 7′′ L. 

NSN: 7520–01–377–9533—Cord Connector/ 

Rotator, Telephone, Twisstop, Clear. 

Coverage: B-List for the Broad Government 

Requirement as aggregated by the 

General Services Administration. 

NPA: Bestwork Industries for the Blind, Inc., 

Runnemede, NJ. 

Contracting Activity: GSA/Federal 

Acquisition Service, New York, NY. 

NSN: 7910–00–NIB–0236—Surface Prep pad 

13.’’ 

NSN: 7910–00–NIB–0240—Surface Prep pad 

17.’’ 

NSN: 7910–00–NIB–0243—Surface Prep pad 

20.’’ 

NPA: Beacon Lighthouse, Inc., Wichita Falls, 

TX. 

Contracting Activity: Department of Veteran 

Affairs, National Acquisition Center, 

Hines, IL. 

Coverage: C-List for 100% of the 

requirement of the Department of Veterans 

Affairs as aggregated by the Department of 

Veterans Affairs National Acquisition Center, 

Hines, IL. 

NSN: 8415–00–NIB–0210—Pants, United 

States Coast Guard Running Suit, Size 

XS. 

NSN: 8415–00–NIB–0778—Pants, United 

States Coast Guard Running Suit, Size 

SM. 

NSN: 8415–00–NIB–0779—Pants, United 

States Coast Guard Running Suit, Size 

MD. 

NSN: 8415–00–NIB–0780—Pants, United 

States Coast Guard Running Suit, Size 

LG. 

NSN: 8415–00–NIB–0781—Pants, United 

States Coast Guard Running Suit, Size 

X–LG. 

NSN: 8415–00–NIB–0782—Pants, United 

States Coast Guard Running Suit, Size 

XX–LG. 

NPA: Association for the Blind & Visually 

Impaired & Goodwill Ind. of Greater 

Rochester, Rochester, NY. 

Contracting Activity: Department of 


srobinson on DSKHWCL6B1PROD with NOTICES