8652 Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 

pursuant to the provisions of the 

Foreign-Trade Zones Act, as amended 

(19 U.S.C. 81a–81u), and the regulations 

of the Board (15 CFR part 400). It was 

formally filed on February 16, 2010. 

The Luigi Bormioli facility (35 

employees, 19 acres, $11.5 million in 

annual shipments) is located at 1656 

Fuldner Rd. (Joey Zorn Blvd.), Barnwell, 

South Carolina. The facility is used for 

the storage and distribution of glass 

fragrance containers and glass tableware 

products (duty rate ranges from 3 to 

38%). 

FTZ procedures could exempt Luigi 

Bormioli from customs duty payments 

on foreign products that are re-exported 

(approximately 2 percent of shipments). 

On its domestic sales, the company 

would be able to defer duty payments 

until merchandise is shipped from the 

plant and entered for consumption. FTZ 

designation would further allow Luigi 

Bormioli to realize logistical benefits 

through the use of weekly customs entry 

procedures. The request indicates that 

the savings from FTZ procedures would 

help improve the facility’s international 

competitiveness. 

In accordance with the Board’s 

regulations, Maureen Hinman of the 

FTZ Staff is designated examiner to 

evaluate and analyze the facts and 

information presented in the application 

and case record and to report findings 

and recommendations to the Board. 

Public comment is invited from 

interested parties. Submissions (original 

and 3 copies) shall be addressed to the 

Board’s Executive Secretary at the 

address below. The closing period for 

their receipt is April 26, 2010. Rebuttal 

comments in response to material 

submitted during the foregoing period 

may be submitted during the subsequent 

15-day period to May 11, 2010. 

A copy of the application will be 

available for public inspection at the 

Office of the Executive Secretary, 

Foreign-Trade Zones Board, Room 2111, 

U.S. Department of Commerce, 1401 

Constitution Avenue, NW., Washington, 

DC 20230–0002, and in the ‘‘Reading 

Room’’ section of the Board’s Web site, 

which is accessible via www.trade.gov/ 

ftz. 

For further information, contact 

Maureen Hinman at 

maureen.hinman@trade.gov or (202) 

482–0627. 

Dated: February 16, 2010. 

Andrew McGilvray, 

Executive Secretary. 

[FR Doc. 2010–3861 Filed 2–24–10; 8:45 am] 

BILLING CODE P 

DEPARTMENT OF COMMERCE 

Foreign-Trade Zones Board 

[Docket 11–2010] 

Foreign-Trade Zone 59—Lincoln, NE 

Application for Subzone CNH America, 

LLC (Agricultural Machinery 

Manufacturing) Grand Island, NE 

An application has been submitted to 

the Foreign-Trade Zones Board (the 

Board) by the Lincoln Foreign Trade 

Zone, Inc., grantee of FTZ 59, requesting 

special-purpose subzone status for the 

agricultural combine and hay tools 

manufacturing facilities of CNH 

America, LLC (CNH), located in Grand 

Island, Nebraska. The application was 

submitted pursuant to the provisions of 

the Foreign-Trade Zones Act, as 

amended (19 U.S.C. 81a–81u), and the 

regulations of the Board (15 CFR part 

400). It was formally filed on February 

16, 2010. 

The CNH facilities (1,274 employees) 

consist of two sites in Grand Island, 

Nebraska on approximately 171.5 acres: 

Site 1 (132.52 acres)—main plant 

located at 3445 W. Stolley Park Road; 

and Site 2 (38.93 acres)—warehouse 

located at 1011 Claude Road. The 

facilities are used for the manufacture, 

testing, warehousing and distribution of 

combines and hay tools. The CNH 

facilities annually can produce up to 

5,960 combines and 4,600 hay tools. 

Components and materials sourced from 

abroad (representing 10% of the value of 

the finished product) include: Articles 

of plastic (incl. tubes, hoses, fittings, 

stoppers and lids); articles of rubber 

(incl. belts, tubes, hoses, grommets, 

plugs, mountings, sheets, strips); tires; 

gaskets; washers; safety glass; iron 

tubes; pipes and fittings; cable; 

fasteners; springs; articles of steel; sign 

plates; internal-combustion engines and 

parts; pumps; filters; parts for 

agricultural equipment; valves; bearings; 

transmission shafts; electric motors; 

generators; clutches; brakes; ignitions; 

electromagnetic couplings; gears; 

flywheels; pulleys; electrical lighting or 

signaling equipment; loudspeakers; 

heaters; defrosters; resistors; switches; 

relays; lamps; wires; cables; locks and 

keys; thermostats and measuring 

instruments (duty rates range from free 

to 9%). 

FTZ procedures could exempt CNH 

from customs duty payments on the 

foreign components used in export 

production. The company anticipates 

that some 30 percent of the plant’s 

shipments will be exported. On its 

domestic sales, CNH would be able to 

choose the duty rates during customs 

entry procedures that apply to combines 

and hay tools (duty-free) for the foreign 

inputs noted above. FTZ designation 

would further allow CNH to realize 

logistical benefits through the use of 

certain customs entry procedures. The 

request indicates that the savings from 

FTZ procedures would help improve 

the plant’s international 

competitiveness. 

In accordance with the Board’s 

regulations, Diane Finver of the FTZ 

Staff is designated examiner to evaluate 

and analyze the facts and information 

presented in the application and case 

record and to report findings and 

recommendations to the Board. 

Public comment is invited from 

interested parties. Submissions (original 

and 3 copies) shall be addressed to the 

Board’s Executive Secretary at the 

address below. The closing period for 

their receipt is April 26, 2010. Rebuttal 

comments in response to material 

submitted during the foregoing period 

may be submitted during the subsequent 

15-day period to May 11, 2010. 

A copy of the application will be 

available for public inspection at the 

Office of the Executive Secretary, 

Foreign-Trade Zones Board, Room 2111, 

U.S. Department of Commerce, 1401 

Constitution Avenue, NW., Washington, 

DC 20230–0002, and in the ‘‘Reading 

Room’’ section of the Board’s Web site, 

which is accessible via www.trade.gov/ 

ftz. 

For further information, contact Diane 

Finver at Diane.Finver@trade.gov or 

(202) 482–1367. 

Dated: February 16, 2010. 

Andrew McGilvray, 

Executive Secretary. 

[FR Doc. 2010–3883 Filed 2–24–10; 8:45 am] 

BILLING CODE P 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

RIN 0648–XT57 

Incidental Takes of Marine Mammals 

During Specified Activities; Marine 

Geophysical Survey in the 

Commonwealth of the Northern 

Mariana Islands, April to June 2010 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Notice; proposed incidental take 

authorization; request for comments. 

SUMMARY: NMFS has received an 

application from the Lamont-Doherty 

Earth Observatory (L–DEO), a part of 


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Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 8653 

Columbia University, for an Incidental 

Harassment Authorization (IHA) to take 

small numbers of marine mammals, by 

harassment, incidental to conducting a 

marine seismic survey in the 

Commonwealth of the Northern Mariana 

Islands (CNMI) during April to June 

2010. Pursuant to the Marine Mammal 

Protection Act (MMPA), NMFS requests 

comments on its proposal to authorize 

L–DEO to incidentally take, by Level B 

harassment only, small numbers of 

marine mammals during the 

aforementioned activity. 

DATES: Comments and information must 

be received no later than March 29, 

2010. 

ADDRESSES: Comments on the 

application should be addressed to P. 

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–XT57@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. 

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. Documents cited in this 

notice may be viewed, by appointment, 

during regular business hours, at the 

aforementioned address. 

FOR FURTHER INFORMATION CONTACT: 

Howard Goldstein or Jolie Harrison, 

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 (Secretary) 

to allow, upon request, the incidental, 

but not intentional, taking of marine 

mammals by United States citizens who 

engage in a specified activity (other than 

commercial fishing) within a specified 

geographical region if certain findings 

are made and either regulations are 

issued or, if the taking is limited to 

harassment, a notice of a proposed 

authorization is provided to the public 

for review. 

An authorization for incidental taking 

of small numbers of marine mammals 

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, 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.’’ The 

authorization must also set forth 

permissible methods of taking, other 

means of affecting the least practicable 

adverse impact on the species or stock 

and its habitat and requirements for 

monitoring and reporting such takings. 

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

established an expedited process by 

which citizens of the United States can 

apply for an authorization not to exceed 

one year to incidentally take small 

numbers of marine mammals by 

harassment. Except with respect to 

certain activities not pertinent here, the 

MMPA defines ‘‘harassment’’ as: 

any act of pursuit, torment, or annoyance 

which (i) has the potential to injure a marine 

mammal or marine mammal stock in the wild 

[‘‘Level A harassment’’]; or (ii) has the 

potential to disturb a marine mammal or 

marine mammal stock in the wild by causing 

disruption of behavioral patterns, including, 

but not limited to, migration, breathing, 

nursing, breeding, feeding, or sheltering 

[‘‘Level B harassment’’]. 

16 U.S.C. 1362(18) 

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 for any 

proposed authorizations for the 

incidental harassment of marine 

mammals. Within 45 days of the close 

of the comment period, NMFS, on 

behalf of the Secretary, makes the 

findings set forth in clause 

101(a)(5)(D)(i) of the MMPA and must 

either issue the authorization with 

appropriate conditions to meet the 

requirements of clause 101(a)(5)(D)(ii) or 

deny it. NMFS will publish notice of 

issuance or denial of the authorization 

within thirty days of issuance or denial. 

Summary of Request 

On December 16, 2009, NMFS 

received an IHA application and an 

Environmental Assessment (EA) from 

L–DEO for the taking, by Level B 

harassment only, of small numbers of 

several species of marine mammals 

incidental to conducting, with research 

funding from the National Science 

Foundation (NSF), a marine seismic 

survey in the CNMI during April to 

June, 2010. The CNMI is a 

commonwealth in a political union with 

the U.S. The survey will take place in 

the Exclusive Economic Zone (EEZ) of 

the U.S. in water depths greater than 

2,000 m (6,561.7 ft). The seismic study 

will use a towed array of 36 airguns 

with a total discharge volume of 

approximately 6,600 in3. 

Description of the Specified Activity 

L–DEO plans to conduct a seismic 

survey in the CNMI. The survey will 

occur in the area 16.5° to 19° North, 

146.5° to 150° East within the EEZ (see 

Figure 1 of L–DEO’s application). The 

project is scheduled to occur from April 

25 to June 6, 2010. Some minor 

deviation of these dates is possible, 

depending on logistics and weather (i.e., 

the cruise may depart earlier to be 

extended due to poor weather; there 

could be extra days (up to three) of 

seismic operations if collected data are 

of substandard quality. 

L–DEO plans to conduct the seismic 

survey over the Mariana outer forearc, 

the trench and the outer rise of the 

subducting and bending Pacific plate. 

The objective is to understand the water 

cycle within subduction-systems. 

Subduction systems are where the basic 

building blocks of continental crust are 

made and where Earth’s great 

earthquakes occur. Little is known about 

either of these processes, but water 

cycling through the system is thought to 

be the primary controlling factor in both 

arc-crust generation and megathrust 

seismicity. 

An important new hypothesis has 

recently been suggested that, if correct, 

will transform our understanding of the 

water budget of subduction systems. 

This hypothesis holds that cracking 

attributable to bending of the 

subducting plate enables water to 

penetrate through the subducting crust 

into the mantle, where it hydrates the 

mantle by forming the hydrous mineral 

phase serpentine. This phase is stable to 

greater depths than the hydrous clay 

minerals of the crust, where most of the 

subducting water was previously 

believed to be held. Thus, if this 


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8654 Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 

hypothesis is correct, it provides a 

mechanism for transporting water far 

beneath the mantle wedge, where it 

promotes melting and crust formation, 

and possibly even deeper into the 

mantle, providing a whole-earth 

hydration mechanism that promotes the 

continued operation of plate tectonics, 

without which our planet would likely 

be unable to support life. 

The scientists involved in this 

program will test this hypothesis by 

measuring mantle seismic sounds 

speeds, which vary with degree of 

serpentinization. By comparing these 

measurements from the Mariana system, 

which is old and cold with the Costa 

Rica system, which is young and warm 

and where similar measurements have 

recently been made, we should be able 

to definitively determine whether or not 

substantial water is taken up by the 

mantle of subducting plates near the 

outer rise of seafloor trenches. 

The planned survey will involve one 

source vessel, the R/V Marcus G. 

Langseth (Langseth), which will occur 

in the CNMI. The Langseth will deploy 

an array of 36 airguns (6,600 in3) as an 

energy source at a tow depth of 9 m (30 

ft). The receiving system will consist of 

a 6 km (3.7 mi) hydrophone streamer 

and approximately 85 ocean bottom 

seismometers (OBSs). As the airgun 

array is towed along the survey lines, 

the hydrophone streamer will receive 

the returning acoustic signals and 

transfer the data to the on-board 

processing system. The OBSs record the 

returning acoustic signals internally for 

later analysis. The OBSs to be used for 

the 2010 program will be deployed and 

most (approximately 60) will be 

retrieved during the cruise, whereas 25 

will be left in place for one year. 

The planned seismic survey will 

consist of approximately 2,800 km 

(1,739.8 mi) of transect lines within the 

CNMI (see Figure 1 of L–DEO’s 

application). The survey will take place 

in water depths greater than 2,000 m 

(6,561.7 ft). All planned geophysical 

data acquisition activities will be 

conducted by L–DEO with onboard 

assistance by the scientists who have 

proposed the study. The scientific team 

consists of Dr. Doug Wiens (Washington 

University, St. Louis, MO) and Daniel 

Lizarralde (Woods Hole Oceanographic 

Institution [WHOI], Woods Hole, MA). 

The vessel will be self-contained, and 

the crew will live aboard the vessel for 

the entire cruise. 

In addition to the operations of the 

airgun array, a Kongsberg EM 

multibeam echosounder (MBES) and a 

Knudsen 320B sub-bottom profiler 

(SBP) will be operated from the 

Langseth continuously throughout the 

CNMI cruise. 

Vessel Specifications 

The Langseth will be used as the 

source vessel. The Langseth will tow the 

36 airgun array along predetermined 

lines. The Langseth will also tow the 

hydrophone streamer, retrieve OBSs, 

and may also deploy OBSs. When the 

Langseth is towing the airgun array as 

well as the hydrophone streamer, the 

turning rate of the vessel while the gear 

is deployed is limited to five degrees per 

minute. Thus, the maneuverability of 

the vessel is limited during operations 

with the streamer. 

The Langseth has a length of 71.5 m 

(234.6 ft), a beam of 17 m (55.8 ft), and 

a maximum draft of 5.9 m (19.4 ft). The 

ship was designed as a seismic research 

vessel, with a propulsion system 

designed to be as quiet as possible to 

avoid interference with the seismic 

signals. The ship is powered by two 

Bergen BRG–6 diesel engines, each 

producing 3,550 horse-power (hp), that 

drive the two propellers directly. Each 

propeller has four blades, and the shaft 

typically rotates at 750 revolutions per 

minute (rpm). The vessel also has an 

800 hp bowthruster, which is not used 

during seismic acquisition. The 

operation speed during seismic 

acquisition is typically 7.4 to 9.3 km/hr 

(4 to 5 kt). When not towing seismic 

survey gear, the Langseth can cruise at 

20 to 24 km/hr (11 to 13 kt). The 

Langseth has a range of 25,000 km 

(15,534 mi), which is the distance the 

vessel can travel without refueling. The 

Langseth will also serve as the platform 

from which vessel-based Protected 

Species Observers (PSOs) will watch for 

marine animals before and during 

airgun operations. NMFS believes that 

the realistic possibility of a ship-strike 

of a marine mammal by the vessel 

during research operations and intransit during the proposed survey is 

discountable. 

Acoustic Source Specifications— 

Seismic Airguns 

During the proposed survey, the 

airgun array to be used will consist of 

36 airguns, with a total volume of 

approximately 6,600 in3. The airgun 

array will consist of a mixture of Bolt 

1500LL and 1900LL airguns. The 

airguns array will be configured as four 

identical linear arrays or ‘‘strings’’ (see 

Figure 2 in L–DEO’s application). Each 

string will have 10 airguns; the first and 

last airguns in the strings are spaced 16 

m (52.5 ft) apart. Nine airguns in each 

string will be fired simultaneously, 

while the tenth is kept in reserve as a 

spare, to be turned on in case of failure 

of another airgun. The four airgun 

strings will be distributed across an 

approximate area of 24 × 16 m (78.7 × 

52.5 ft) behind the Langseth and will be 

towed approximately 140 m (459 ft) 

behind the vessel. The shot interval will 

be 37.5 m (123.0 ft) or 150 m (492.1 ft) 

during the study. The shot interval will 

be relatively short (approximately 37.5 

m or approximately 15 to 18 seconds [s]) 

for multi-channel seismic surveying 

with the hydrophone streamer, and 

relatively long (approximately 150 m or 

approximately 58 to 73 s) when 

recording data on the OBSs. The firing 

pressure of the array is 1,900 pounds 

per square inch (psi). During firing, a 

brief (approximately 0.1 s) pulse of 

sound is emitted. The airguns will be 

silent during the intervening periods. 

Because the actual source is a 

distributed source (36 airguns) rather 

than a single point source, the highest 

sound levels measurable at any location 

in the water will be less than the 

nominal source (265 dB re 1 μ Pa·m, 

peak-to-peak [pk-pk]). In addition, the 

effective source level for sound 

propagating in near-horizontal 

directions will be substantially lower 

than the nominal source level 

applicable to downward propagation 

because of the directional nature of the 

sound from the airgun array. 

TABLE 1—DISTANCES TO WHICH SOUND LEVELS GREATER THAN OR EQUAL TO 190, 180, AND 160 DB RE 1 μPa (RMS) 

COULD BE RECEIVED IN DEEP (GREATER THAN 1,000 M) WATER DURING THE PROPOSED SURVEY IN THE CNMI, 

APRIL 25 TO JUNE 6, 2010 

Source and volume Tow depth (m) Water depth 

Predicted RMS distances (m) 

190 dB 180 dB 160 dB 

Single Bolt airgun (40 in3) ................. 9 Deep (>1,000 m) .............................. 12 40 385 

4 strings, 36 airguns (6,600 in3) ....... 9 Deep (>1,000 m) .............................. 400 940 3,850 


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Acoustic Source Specifications— 

Multibeam Echosounder (MBES) and 

Sub-bottom Profiler (SBP) 

Along with the airgun operations, two 

additional acoustical data acquisition 

systems will be operated during the 

survey. The ocean floor will be mapped 

with Kongsberg EM 122 MBES and 

Knudsen 320 SBP. These sound sources 

will be operated from the Langseth 

continuously throughout the cruise. 

The Kongsberg EM 122 MBES 

operates at 10.5 to 13 (usually 12) kHz 

and is hull-mounted on the Langseth. 

The transmitting beamwidth is 1° or 2° 

fore-aft and 150° athwartship. The 

maximum source level is 242 dB re 1 

μPam (rms). Each ‘‘ping’’ consists of 

eight (in water greater than 1,000 m 

deep) or four (less than 1,000 m) 

successive fan-shaped transmissions, 

each ensonifying a sector that extends 1° 

fore-aft. Continuous-wave (CW) pulses 

increase from two to 15 ms long in 

water depths up to 2,600 m (8,530 ft), 

and FM chirp pulses up to 100 ms long 

are used in water greater than 2,600 m. 

The successive transmissions span an 

overall cross-track angular extent of 

about 150°, with 2 ms gaps between 

pulses for successive sectors. 

The Knudsen 320B SBP is normally 

operated to provide information about 

the sedimentary features and the bottom 

topography that is being mapped 

simultaneously by the MBES. The SBP 

beam is transmitted as a 27 degree cone, 

which is directed downward by a 3.5 

kHz transducer in the hull of the 

Langseth. The maximum output is 1,000 

watts (204 dB), but in practice, the 

output varies with water depth. The 

pulse interval is 1 s, but a common 

mode of operation is to broadcast five 

pulses at 1 s intervals followed by a 5 

s pause. 

OBS Description and Deployment 

Approximately 85 OBSs will be 

deployed by the Langseth before the 

survey, in water depths 3,100 to 8,100 

m (10,170.6 to 26,574.8 ft). There are 

three types of OBS deployment: 

(1) Approximately 20 broad-band 

OBSs located on the bottom in a wide 

two-dimensional (2D) array with a 

spacing of no more than 100 km (62.1 

mi); 

(2) Approximately five short-period 

OBSs tethered in the water column 

above the trench areas deeper than 6 

km; and 

(3) Approximately 60 short-period 

OBSs located on the bottom in a 2D 

array with a spacing of about 75 km 

(46.6 mi). 

The first two types will be left in 

place for one year for passive recording, 

and the third type will be retrieved after 

the seismic operations. OBSs deployed 

in water deeper than 5,500 m (18,044.6 

ft) will require a tether to keep the 

instruments at a depth of 5,500 to 6,000 

m (18,044.6 to 19,685 ft), as the 

instruments are rated to a maximum 

depth of 6,000 m. The lengths of the 

tethers will vary from 65 to 2,600 m 

(213.3 to 8,530.2 ft). The tether will fall 

to the seafloor when the OBS is 

released. 

Two different types of OBSs may be 

used during the 2010 program. The 

WHOI ‘‘D2’’ OBS has a height of 

approximately 1 m (3.3 ft) and a 

maximum diameter of 50 cm (19.7 in). 

The anchor is made of hot-rolled steel 

and weighs 23 kg (50.7 lb). The anchor 

dimensions are 2.5x30.5x38.1 cm. The 

LC4x4 OBS from the Scripps Institution 

of Oceanography (SIO) has a volume of 

approximately 1 m3, with an anchor that 

consists of a large piece of steel grating 

(approximately 1 m2). Once an OBS is 

ready to be retrieved, an acoustic release 

transponder interrogates the OBS at a 

frequency of 9 to 11 kHz, and a response 

is received at a frequency of 9 to 13 kHz. 

The burn-wire release assembly is then 

activated, and the instrument is released 

from the anchor to float to the surface. 

The anchors will remain on the sea 

floor. 

Proposed Dates, Duration, and Specific 

Geographic Area 

The survey will occur in the following 

specific geographic area: 16.5° to 19° 

North, 146.5° to 150° East within the 

EEZ of the U.S. (see Figure 1 of L–DEO’s 

application). Water depths in the survey 

area range from greater than 2,000 m to 

greater than 8,000 m (26,246.7 ft). The 

closest that the vessel will approach to 

any island is approximately 50 km (31.1 

mi) from Alamagan. The exact dates of 

the activities depend on logistics and 

weather conditions. The Langseth will 

depart from Guam on April 25, 2010 

and return to Guam on June 6, 2010. 

Seismic operations will be carried out 

for 16 days, with the balance of the 

cruise occupied in transit 

(approximately 2 days) and in 

deployment and retrieval of OBSs and 

maintenance (25 days). 

Description of Marine Mammals in the 

Proposed Activity Area 

A total of 27 cetacean species, 

including 20 odontocete (dolphins and 

small- and large-toothed whales) species 

and nine mysticetes (baleen whales) are 

known to occur in the area affected by 

the specified activities associated with 

the proposed CNMI marine geophysical 

survey (see Table 2 of L–DEO’s 

application). Cetaceans and pinnipeds, 

which are the subject of this IHA 

application, are protected by the MMPA 

and managed by NMFS in accordance 

with its requirements. Information on 

the occurrence, distribution, population 

size, and conservation status for each of 

the 27 marine mammal species that may 

occur in the proposed project area is 

presented in the Table 2 of L–DEO’s 

application as well as here in the table 

below (Table 2). The status of certain 

marine mammal species as threatened 

or endangered is based on evaluation 

and listing procedures under the U.S. 

Endangered Species Act (ESA), the 

International Union for Conservation of 

Nature (IUCN) Red List of Threatened 

Species, and Convention on 

International Trade in Endangered 

Species (CITES). Several marine 

mammal species that may be affected by 

the proposed IHA are listed as 

Endangered under Section 4 of the ESA, 

including the North Pacific right, sperm, 

humpback, fin, sei, and blue whales. 

There are no reported sightings of 

pinnipeds in the CNMI (e.g., DON, 

2005). The dugong (Dugong dugon), also 

listed under the ESA as Endangered, is 

distributed throughout most of the IndoPacific region between approximately 

27° North and south of the equator 

(Marsh, 2002); it seems unlikely that 

dugongs have ever inhabited the 

Mariana Islands (Nishiwaki et al., 1979). 

There have been some extralimital 

sightings in Guam, including a single 

dugong in Cocos Lagoon in 1974 

(Randall et al., 1975) and several 

sightings of an individual in 1985 along 

the southeastern coast (Eldredge, 2003). 

Table 2 below outlines the cetacean 

species, their habitat and abundance in 

the proposed project area, and the 

requested take levels. Additional 

information regarding the distribution of 

these species expected to be found in 

the project area and how the estimated 

densities were calculated may be found 

in L–DEO’s application. 


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TABLE 2—THE HABITAT, REGIONAL ABUNDANCE, CONSERVATION STATUS, AND BEST AND MAXIMUM DENSITY ESTIMATES

OF MARINE MAMMALS THAT COULD OCCUR IN OR NEAR THE PROPOSED SEISMIC SURVEY AREA IN THE CNMI. See 

TABLES 2 TO 4 IN L–DEO’S APPLICATION FOR FURTHER DETAIL

Species Habitat 

Regional 

population 

size a

ESAb

Density/ 

1000 km2

(best) c

Density/ 

1000 km2

(max) d

Mysticetes: 

North Pacific right whale (Eubalaena japonica) ....... Pelagic and coastal ...................... Few 100s ......... EN ..... 0.01 0.01 

Humpback whale (Megaptera novaeangliae) .......... Mainly nearshore waters and 

banks.

938–1107 e ...... EN ..... 0.01 0.02 

Minke whale (Balaenoptera acutorostrata) .............. Pelagic and coastal ...................... 25,000 f ............ NL ..... 0.01 0.02 

Bryde’s whale Balaenoptera brydei) ........................ Pelagic and coastal ...................... 20,000–30,000 NL ..... 0.41 0.62 

Sei whale (Balaenoptera borealis) ........................... Primarily offshore, pelagic ............ 7,260–12,620 g EN ..... 0.29 0.44 

Fin whale (Balaenoptera physalus) .......................... Continental slope, mostly pelagic 13.620– 

18.680 h.

EN ..... 0.01 0.02 

Blue whale (Balaenoptera musculus) ...................... Pelagic and coastal ...................... N.A. ................. EN ..... 0.01 0.02 

Odontocetes: 

Sperm whale (Physeter macrocephalus) ................. Usually pelagic and deep seas .... 29,674 i ............ EN ..... 1.23 1.85 

Pygmy sperm whale (Kogia breviceps) ................... Deep waters off shelf ................... N.A. ................. NL ..... 2.91 4.37 

Dwarf sperm whale (Kogia sima) ............................. Deep waters off the shelf ............. 11,200 j ............ NL ..... 7.14 10.71 

Cuvier’s beaked whale (Ziphius cavirostris) ............ Pelagic .......................................... 20,000 j ............ NL ..... 6.21 9.32 

Longman’s beaked whale (Indopacetus pacificus) .. Deep water ................................... N.A. ................. NL ..... 0.41 0.62 

Blainville’s beaked whale (Mesoplodon densirostris) Pelagic .......................................... 25,300 k ........... NL ..... 1.17 1.76 

Ginkgo-toothed beaked whale (Mesoplodon 

ginkgodens).

Pelagic .......................................... N.A. ................. NL ..... 0.01 0.02 

Rough-toothed dolphin (Steno bredanensis) ........... Deep water ................................... 146,000 ETPj .. NL ..... 0.29 0.44 

Common bottlenose dolphin (Tursiops truncatus) ... Coastal and oceanic, shelf break 243,500 ETPj .. NL ..... 0.21 0.32 

Pantropical spotted dolphin (Stenella attenuata) ..... Coastal and pelagic ...................... 800,000 ETPj .. NL ..... 22.60 33.90 

Spinner dolphin (Stenella longirostris) ..................... Coastal and pelagic ...................... 800,000 ETPj .. NL ..... 3.14 4.71 

Striped dolphin (Stenella coeruleoalba) ................... Off continental shelf ...................... 1,000,000 ETPj NL ..... 6.16 9.24 

Fraser’s dolphin (Lagenodelphis hosei) ................... Waters greater than 1,000 m ....... 289,000 ETPj .. NL ..... 4.17 6.26 

Short-beaked common dolphin (Delphinus delphis) Shelf and pelagic, seamounts ...... 3,000,000 ETPj NL ..... 0.01 0.01 

Risso’s dolphin (Grampus griseus) .......................... Waters greater than 1,000 m, 

seamounts.

175,000 ETPj .. NL ..... 0.97 1.46 

Melon-headed whale (Peponocephala electra) ....... Oceanic ......................................... 45,000 ETPj .... NL ..... 4.28 6.42 

Pygmy killer whale (Feresa attenuata) .................... Deep, pantropical waters .............. 39,000 ETPj .... NL ..... 0.14 0.21 

False killer whale (Pseudorca crassidens) .............. Pelagic .......................................... 40,000 j ............ NL ..... 1.11 0.21 

Killer whale (Orcinus orca) ....................................... Widely distributed ......................... 8,500 ETPj ...... NL ..... 0.14 0.21 

Short-finned pilot whale (Globicephala 

macrorhynchus).

Mostly pelagic, high-relief topography.500,000 ETPj .. NL ..... 1.59 2.39 

Sirenians: Dugong (Dugong dugon) ................................ Coastal .......................................... N.A. ................. EN ..... N.A. N.A. 

N.A.—Data not available or species status was not assessed, 

a North Pacific (Jefferson et al., 2008) unless otherwise indicated. b U.S. Endangered Species Act: EN = Endangered, NL = Not listed. 

cBest estimate as listed in Table 3 of the application. 

d Maximum estimate as listed in Table 3 of the application. 

eWestern North Pacific (Calambokidis et al., 2008). f Northwest Pacific and Okhotsk Sea (IWC, 2007a). 

g North Pacific (Tillman, 1977). 

h North Pacific (Ohsumi and Wada, 1974). 

iWestern North Pacific (Whitehead, 2002b). 

jEastern Tropical Pacific = ETP (Wade and Gerrodette, 1993). 

kETP; all Mesoplodon spp. (Wade and Gerodette, 1993). 

Potential Effects on Marine Mammals 

Potential Effects of Airgun Sounds 

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, or non-auditory physical or 

physiological effects (Richardson et al., 

1995; Gordon et al., 2004; Nowacek et 

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

Permanent hearing impairment, in the 

unlikely event that it occurred, would 

constitute injury, but temporary 

threshold shift (TTS) is not an injury 

(Southall et al., 2007). Although the 

possibility cannot be entirely excluded, 

it is unlikely that the project would 

result in any cases of temporary or 

especially permanent hearing 

impairment, or any significant nonauditory physical or physiological 

effects. Some behavioral disturbance is 

expected, but this would be localized 

and short-term. NMFS concurs with this 

determination. 

The root mean square (rms) received 

levels that are used as impact criteria for 

marine mammals are not directly 

comparable to the peak or peak-to-peak 

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 rms in the far field would 

typically correspond to a peak 

measurement of approximately 170 to 

172 dB, and to a peak-to-peak 

measurement of approximately 176 to 

178 dB, as measured for the same pulse 

received at the same location (Greene, 

1997; McCauley et al., 1998, 2000a). 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 


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than the peak or peak-to-peak level for 

an airgun-type source. 

Tolerance 

Numerous studies have shown that 

pulsed sounds from airguns are often 

readily detectable in the water at 

distances of many kilometers. For a 

summary of the characteristics of airgun 

pulses, see Appendix B (3) of the EA. 

Numerous studies have shown that 

marine mammals at distances more than 

a few kilometers from operating seismic 

vessels often show no apparent 

response—see Appendix B (5) of L– 

DEO’s application. 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 relative responsiveness 

of baleen and toothed whales being 

variable. 

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) 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 exceptional 

situations, reverberation occurs for 

much or all of the interval between 

pulses (Simard et al., 2005; Clark and 

Gagnon, 2006) which could mask calls. 

Some baleen and toothed whales are 

known to continue calling in the 

presence of seismic pulses. The airgun 

sounds are pulsed, with quiet periods 

between the pulses, and whale calls 

often can be heard between the seismic 

pulses (Richardson et al., 1986; 

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

1999; Nieukirk et al., 2004; Smultea et 

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

Dunn et al., 2009). In the northeast 

Pacific Ocean, blue whale calls have 

been recorded during a seismic survey 

off Oregon (McDonald et al., 1995). 

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 they continued 

calling 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). 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 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 B (4) of the L–DEO EA. 

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 does react to an underwater 

sound by changing its behavior or 

moving a small distance, the response 

may or may not rise to the level of 

‘‘harassment’’ to the individual, or affect 

the stock or the species population as a 

whole. However, if a sound source 

displaces marine mammals from an 

important feeding or breeding area for a 

prolonged period, impacts on 

individuals and populations could be 

significant (e.g., Lusseau and Bejder, 

2007; Weilgart, 2007). 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 industrial activities, and/or 

exposed to a particular level of 

industrial sound. In most cases, this 

practice potentially overestimates the 

numbers of marine mammals that would 

be affected in some biologicallyimportant manner. 

The sound exposure criteria used to 

estimate how many marine mammals 

might be disturbed to some biologicallyimportant degree by a seismic program 

are based primarily on behavioral 

observations of several species. 

However, information is lacking for 

many species. Detailed studies have 

been done on humpback, gray, 

bowhead, and sperm whales. 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. 

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 B (5) of the L–DEO EA, 

baleen whales exposed to strong noise 

pulses from airguns often react by 

deviating from their normal migration 

route and/or interrupting their feeding 

activities and moving away from the 

sound source. In the case of the 

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. 

Studies of gray, bowhead, and 

humpback whales have demonstrated 

that seismic pulses with received levels 

of 160 to 170 dB re 1 μPa (rms) 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 to 15 

km (2.8 to 9 mi) from the source. A 

substantial proportion of the baleen 

whales within those distances may 

show avoidance or other strong 

behavioral reactions to the airgun array. 

Subtle behavioral changes sometimes 

become evident at somewhat lower 

received levels, and studies summarized 

in Appendix B(5) of the L–DEO 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 to 170 dB re 1 μPa (rms). 

Responses of humpback whales to 

seismic surveys have been studied 

during migration, on the 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, 2,678 in3 array, and to a single 

20 in3 airgun with a source level of 227 


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dB re 1 μPam peak-to-peak. McCauley et 

al. (1998) documented that initial 

avoidance reactions began at 5 to 8 km 

(3.1 to 5 mi) from the array, and that 

those reactions kept most pods 

approximately 3 to 4 km (1.9 to 2.5 mi) 

from the operating seismic boat. 

McCauley et al. (2000a) noted localized 

displacement during migration of 4 to 5 

km (2.5 to 3.1 mi) by traveling pods and 

7 to 12 km (4.3 to 7.5 mi) by cow-calf 

pairs. Avoidance distances with respect 

to the single airgun were smaller (2 km 

[1.2 mi]) but consistent with the results 

from the full array in terms of received 

sound levels. The mean received level 

for initial avoidance of an approaching 

airgun was 140 dB re 1 μPa (rms) for 

humpback whale pods containing 

females, and at the mean closest point 

of approach (CPA) distance the received 

level was 143 dB re 1 μPa (rms). The 

initial avoidance response generally 

occurred at distances of 5 to 8 km (3.1 

to 5 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 to 400 m (328 

to 1,312 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 1.64– 

L (100 in3) airgun (Malme et al., 1985). 

Some humpbacks seemed ‘‘startled’’ at 

received levels of 150 to 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 

humpbacks 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, 2007:236). 

There are no data on reactions of right 

whales to seismic surveys, but results 

from the closely-related bowhead whale 

show that their responsiveness can be 

quite variable depending on the activity 

(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 to 30 km (12.4 to 18.6 

mi) from a medium-sized airgun source 

at received sound levels of around 120 

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

1999; Richardson et al., 1999; see 

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

more recent research on bowhead 

whales (Miller et al., 2005a; 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 a received level 

of about 152 to 178 dB re 1 μPa (rms) 

(Richardson et al., 1986, 1995; 

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

2005a). 

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. Malme et al. (1986, 

1988) 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 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). 

Various species of Balaenoptera (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 (e.g. 

McDonald et al., 1995; Dunn et al., 

2009). Sightings by observers on seismic 

vessels off the United Kingdom from 

1997 to 2000 suggest that, during 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 

(silent) (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 

of reactions) of cetaceans to impulsive 

noises are not necessarily indicative of 

long-term or biologically significant 

effects. It is not known whether 

impulsive sounds 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 Outlaw, 2008). 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). Similarly, 

bowhead whales have continued to 

travel to the eastern Beaufort Sea each 

summer, and their numbers have 

increased notably, despite seismic 

exploration in their summer and 

autumn range for many years 

(Richardson et al., 1987; Angliss and 

Outlaw, 2008). 

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 and (in more detail) 

in Appendix B or the EA have been 

reported for toothed whales. However, 

recent 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). There is an increasing 

amount of information about responses 


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of various odontocetes to seismic 

surveys based on monitoring studies 

(e.g., Stone, 2003; Smultea et al., 2004; 

Moulton and Miller, 2005; Bain and 

Williams, 2006; Holst et al., 2006; Stone 

and Tasker, 2006; Potter et al., 2007; 

Hauser et al., 2008; Holst and Smultea, 

2008; Weir, 2008; Barkaszi et al., 2009; 

Richardson et al., 2009). 

Seismic operators and observers 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; Barkaszi et al., 2009). 

However, 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 more often 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 is a 

species that (at least at times) shows 

long-distance avoidance of seismic 

vessels. Aerial surveys during seismic 

operations in the southeastern Beaufort 

Sea during summer found that sighting 

rates of beluga whales were significantly 

lower at distances 10 to 20 km (6.2 to 

12.4 mi) compared with 20 to 30 km 

(mi) from an operating airgun array, and 

observers on seismic boats in that area 

rarely see belugas (Miller et al., 2005; 

Harris et al., 2007). 

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; 

Finneran and Schlundt, 2004). 

However, the animals tolerated high 

received levels of sound before 

exhibiting aversive behaviors. 

Results for porpoises depend on 

species. The limited available data 

suggest that harbor porpoises show 

stronger avoidance of seismic operations 

than do Dall’s porpoises (Stone, 2003; 

Bain and Williams, 2006; Stone and 

Tasker, 2006). Dall’s porpoises seem 

relatively tolerant of airgun operations 

(MacLean and Koski, 2005; Bain and 

Williams, 2006), although they too have 

been observed to avoid large arrays of 

operations airguns (Calambokidis and 

Osmek, 1998; Bain and Williams, 2006). 

This apparent difference in 

responsiveness of these two porpoise 

species is consistent with their relative 

responsiveness to boat traffic and some 

other acoustic sources in general 

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

2007). 

Most studies of sperm whales exposed 

to airgun sounds indicate that the sperm 

whale 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 B in 

the L–DEO EA). However, controlled 

exposure experiments in the Gulf of 

Mexico indicate that foraging behavior 

was altered upon exposure to airgun 

sounds (Jochens et al., 2008; Miller et 

al., 2009; Tyack, 2009). 

There are almost no specific data on 

the behavioral reactions of beaked 

whales to seismic surveys. However, 

northern bottlenose whales (Hyperodon 

ampullatus) continued to produce highfrequency clicks when exposed to sound 

pulses from distant seismic surveys 

(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). It is likely 

that these beaked whales would 

normally show strong avoidance of an 

approaching seismic vessel, but 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, belugas, and harbor 

porpoises (Appendix B of the L–DEO 

EA). 

Hearing Impairment and Other Physical 

Effects 

Temporary or permanent hearing 

impairment is a possibility when marine 

mammals are exposed to very strong 

sounds, but there has been no specific 

documentation of this for marine 

mammals exposed to sequences of 

airgun pulses. 

NMFS will be developing new noise 

exposure criteria for marine mammals 

that take account of the now-available 

scientific data on temporary threshold 

shift (TTS), the expected offset between 

the TTS and permanent threshold shift 

(PTS) thresholds, differences in the 

acoustic frequencies to which different 

marine mammal groups are sensitive, 

and other relevant factors. Detailed 

recommendations for new science-based 

noise exposure criteria were published 

in late 2007 (Southall et al., 2007). 

Several aspects of the planned 

monitoring and mitigation measures for 

this project (see below) 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 such 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 

might (in theory) occur in mammals 

close to a strong sound source include 

stress, neurological effects, bubble 

formation, 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 below, 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 effects of 

these types would occur during the 

present project given the brief duration 

of exposure of any given mammal, the 

deep water in the study area, and the 

proposed monitoring and mitigation 

measures (see below). The following 

subsections discuss in somewhat more 

detail the possibilities of TTS, 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 


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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). Based on these data, the 

received energy 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 SEL or 

approximately 196 to 201 re 1 μPa [rms]) 

in order to produce brief, mild TTS. 

Exposure to several strong seismic 

pulses that each have received levels 

near 190 re 1 μPa (rms) 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; however, this ‘equal energy’ 

concept is an oversimplification. The 

distance from the Langseth’s airguns at 

which the received energy level (per 

pulse, flat-weighted) would be expected 

to be greater than or equal to 190 dB re 

1 μPa (rms) are estimated in Table 1 of 

L–DEO’s application and above. Levels 

greater than or equal to 190 dB re 1 μPa 

(rms) are expected to be restricted to 

radii no more than 400 m. For an 

odontocete closer to the surface, the 

maximum radius with greater than or 

equal to 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. For 

the one harbor porpoise tested, the 

received level of airgun sound that 

elicited onset of TTS was lower (Lucke 

et al., 2009). If these results from a 

single animal are representative, it is 

inappropriate to assume that onset of 

TTS occurs at similar received levels in 

all odontocetes (Southall et al., 2007). 

Some cetaceans apparently can incur 

TTS at considerably lower sound 

exposures than are necessary to elicit 

TTS in the beluga or bottlenose dolphin. 

For baleen whales, there are no data, 

direct or indirect, on levels or properties 

of sound required to induce TTS. The 

frequencies to which baleen whales are 

most sensitive are lower than those to 

which odontocetes are more sensitive, 

and natural background noise levels at 

those low frequencies tend to be higher. 

As a result, auditory thresholds of 

baleen whales within their frequency 

band of best hearing are believed to be 

higher (less sensitive) than are those of 

odontocetes at their best frequencies 

(Clark and Ellison, 2004). From this, it 

is suspected that received levels causing 

TTS onset may also be higher in baleen 

whales (Southall et al., 2007). In any 

event, no cases of TTS are expected 

given three considerations: 

(1) The relatively low abundance of 

baleen whales expected in the planned 

study areas; 

(2) The strong likelihood that baleen 

whales would avoid the approaching 

airguns (or vessel) before being exposed 

to levels high enough for there to be any 

possibility of TTS; and 

(3) The mitigation measures that are 

planned. 

To avoid the potential for injury, 

NMFS (1995, 2000) concluded that 

cetaceans and pinnipeds should not be 

exposed to pulsed underwater noise at 

received levels exceeding 180 and 190 

dB re 1 μPa (rms), respectively. This 

sound level is not considered to be the 

level above which TTS might occur. 

Rather, it was the received levels above 

which, in the view of a panel of 

bioacoustics specialists convened by 

NMFS before TTS measurements for 

marine mammals started to become 

available, one could not be certain that 

there would be no injurious effects, 

auditory or otherwise, to cetaceans. As 

summarized above and in Southall et al. 

(2007), data that are now available 

imply that TTS is unlikely to occur in 

most odontocetes (and probably 

mysticetes as well) unless they are 

exposed to a sequence of several airgun 

pulses stronger than 190 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, whereas in other cases, the 

animal has an impaired ability to hear 

sounds in specific frequency ranges 

(Kryter, 1985). 

There is no specific evidence that 

exposure to pulses of airgun 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 at 

least mild 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 B (6) of the L–DEO 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 greater than 6 dB (Southall 

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

et al. (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 they 

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 

Mmf -weighted TTS threshold, in a 

beluga, for a watergun impulse), where 

the SEL value is cumulated over the 

sequence of pulses. 

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. 

Thus PTS might be expected upon 

exposure of cetaceans to either SEL 

greater than or equal to 198 dB re 1 

μPa2·s or peak pressure greater than or 

equal to 230 dB re 1 μPa. Corresponding 

proposed dual criteria for pinnipeds (at 

least harbor seals) are greater than or 

equal to 186 dB SEL and greater than or 

equal to 218 dB peak pressure (Southall 

et al., 2007). These estimates are all first 

approximations, given the limited 

underlying data, assumptions, species 

differences, and evidence that the ‘‘equal 

energy’’ model may not be entirely 

correct. A peak pressure of 230 dB re 1 

μPa (3.2 bar · m, 0-pk), which would 

only be found within a few meters of the 

largest (360 in3) airguns in the planned 

airgun array (Caldwell and Dragoset, 

2000). 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. 

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. The 

planned monitoring and mitigation 

measures, including visual monitoring, 

passive acoustic monitoring (PAM) to 

complement visual observations (if 

practicable), power-downs, and shutdowns of the airguns when mammals 

are seen within or approaching the EZs 

will further reduce the probability of 

exposure of marine mammals to sounds 

strong enough to induce PTS. 


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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 waters for 

commercial seismic surveys or (with 

rare exceptions) for seismic research; 

they 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 proof that they can cause 

serious 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 B(6) of 

the L–DEO 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 

vetibular 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. 

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 

supersaturated tissue by a behavioral 

response to acoustic exposure, could be 

a pathologic mechanism for the 

strandings and mortality of some deepdiving 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 signals 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 to 10 kHz, 

generally with a relatively narrow 

bandwidth at any one time. Thus, it is 

not appropriate to assume that there is 

a direct connection between the effects 

of military sonar and 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; 

Ferna ́ndez et al., 2004, 2005a; Cox et al., 

2006) suggests that caution is warranted 

when dealing with exposure of marine 

mammals to any high-intensity 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) was not well founded based 

on available data (IAGC, 2004; IWC, 

2007b). In September 2002, there was a 

stranding of two Cuvier’s beaked whales 

in the Gulf of California, Mexico, when 

the L–DEO vessel R/V Maurice Ewing 

(Ewing) was operating a 20 airgun, 

8,490 in3 array in the general area. The 

link between the stranding and the 

seismic survey 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 any 

beaked whales nearby would avoid the 

approaching vessel before being 

exposed to high sound levels; 

(2) The proposed monitoring and 

mitigation measures; and 

(3) Differences between the sound 

sources operated by L–DEO and those 

involved in the naval exercises 

associated with strandings. 

Non-auditory Physiological Effects— 

non-auditory physiological effects or 

injuries that theoretically might occur in 

marine mammals exposed to strong 

underwater sound include stress, 

neurological effects, bubble formation, 

resonance, and other types of organ or 

tissue damage (Cox et al., 2006; Southall 

et al., 2007). Studies examining such 

effects are limited. However, resonance 

effects (Gentry, 2002) and direct noiseinduced bubble formation (Crum et al., 

2005) are implausible in the case of 

exposure to an impulsive broadband 

source like an airgun array. If seismic 

surveys disrupt diving patterns of deepdiving 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, very little is known about 

the potential for seismic survey sounds 

(or other types of strong underwater 

sounds) to cause non-auditory physical 

effects in marine mammals. Such 

effects, if they occur at all, would 

presumably be limited to short distances 

and to activities that extend over a 

prolonged period. The available data do 

not allow identification of a specific 

exposure level above which nonauditory 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 and some 

odontocetes, are especially unlikely to 

incur non-auditory physical effects. 

Also, the planned monitoring and 

mitigation measures, including shutdown of the airguns, will reduce any 

such effects that might otherwise occur. 

Potential Effects of Other Acoustic 

Devices—MBES Signals 

The Kongsberg EM 122 MBES will be 

operated from the source vessel during 

the planned study. Sounds from the 

MBES are very short pulses, occurring 

for 2 to 15 ms once every 5 to 20 s, 

depending on water depth. Most of the 

energy in the sound pulses emitted by 

the MBES is at frequencies centered at 

12 kHz, and the maximum source level 

is 242 dB re 1 μPa (rms). The beam is 

narrow (1 to 2°) in fore-aft extent and 

wide (150°) in the cross-track extent. 

Each ping consists of eight (in water 

greater than 1,000 m deep) or four 

(greater than 1,000 m deep) successive 

fan-shaped transmissions (segments) at 

different cross-track angles. Any given 

mammal at depth near the trackline 

would be in the main beam for only one 

or two of the nine segments. Also, 

marine mammals that encounter the 

MBES are unlikely to be subjected to 


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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 to 15 ms pulse (or two pulses 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 in order to receive the 

multiple pulses that might result in 

sufficient exposure to cause TTS. 

Burkhardt et al. (2007) concluded that 

immediate direct auditory injury was 

possible only if a cetacean dived under 

the vessel into the immediate vicinity of 

the transducer. 

Navy sonars that have been linked to 

avoidance reactions and stranding of 

cetaceans (1) generally have a longer 

pulse duration that the Kongsberg EM 

122, and (2) 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 a Navy 

sonar. During L–DEO’s operations, the 

individual pulses will be very short, and 

a given marine mammal would not 

receive many of the downward-directed 

pulses as the vessel passes by. 

Marine mammal communications will 

not be masked appreciably by the MBES 

signals given its low duty cycle and the 

brief period when an individual 

mammal is likely to be within its beam. 

Furthermore, in the case of baleen 

whales, the signals (12 kHz) do not 

overlap with the predominant 

frequencies in the calls, which would 

avoid 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 (Rendell and Gordon, 

1999), and the previously-mentioned 

beachings by beaked whales. During 

exposure to a 21 to 25 kHz ‘‘whalefinding’’ sonar with a source level of 215 

dB re 1 μPam, gray whales reacted by 

orienting slightly away from the source 

and being deflected from their course by 

approximately 200 m (656 ft) (Frankel, 

2005). When a 38 kHz echosounder and 

a 150 kHz acoustic Doppler current 

profiler were transmitting during 

studies in the Eastern Tropical Pacific, 

baleen whales showed no significant 

responses, while spotted and spinner 

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 L–DEO, 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 free-ranging odontocetes is 

uncertain, and in any case, the test 

sounds were quite different in either 

duration as compared with those from 

an MBES. 

NMFS believes that the brief exposure 

of marine mammals to one pulse, or 

small numbers of signals, from the 

MBES are not likely to result in the 

harassment of marine mammals. 

Potential Effects of Other Acoustic 

Devices—SBP Signals 

A SBP will be operated from the 

source vessel during the planned study. 

Sounds from the SBP are very short 

pulses, occurring for 1 to 4 ms once 

every second. Most of the energy in the 

sound pulses emitted by the SBP is at 

3.5 kHz, and the cone-shaped beam is 

directed downward. The SBP on the 

Langseth has a maximum source level of 

204 dB re 1 μPam. 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—even for an SBP more powerful 

than that on the Langseth—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 of the 

signal and the brief period when an 

individual mammal is likely to be 

within its beam. 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 are 

discussed above, and responses to the 

SBP are likely to be similar to those for 

other pulsed sources if received at the 

same levels. The pulsed signals from the 

SBP are somewhat weaker than those 

from the MBES. Therefore, behavioral 

responses are not expected unless 

marine mammals are very close to the 

source. 

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 operated simultaneously 

with other higher-power acoustic 

sources, including the airguns. 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. In the case of mammals that do not 

avoid the approaching vessel and its 

various sound sources, monitoring and 

mitigation measures that would be 

applied to minimize effects of other 

sources would further reduce or 

eliminate any minor effects of the SBP. 

NMFS believes that to avoid the 

potential for permanent physiological 

damage (Level A harassment), cetaceans 

and pinnipeds should not be exposed to 

pulsed underwater noise at received 

levels exceeding, respectively, 180 and 

190 dB re 1 μPa (rms). The 

precautionary nature of these criteria is 

discussed in the L–DEO 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 harassment. 

Possible Effects of Acoustic Release 

Signals 

The acoustic release transponder used 

to communicate with the OBSs uses 

frequencies of 9 to 13 kHz. These signals 

will be used very intermittently. It is 

unlikely that the acoustic release signals 

would have significant effects on marine 

mammals through masking, disturbance, 

or hearing impairment. Any effects 

likely would be negligible given the 

brief exposure at presumable low levels. 

Estimated Take of Marine Mammals by 

Incidental Harassment 

All anticipated takes would be ‘‘takes 

by Level B harassment,’’ involving 

temporary changes in behavior. The 

proposed monitoring and mitigation 

measures are expected to minimize the 

possibility of injurious takes or 

mortality. However, as noted earlier, 

there is no specific information 


jlentini on DSKJ8SOYB1PROD with NOTICES
Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 8663 

demonstrating that injurious ‘‘takes’’ or 

mortality would occur even in the 

absence of the planned mitigation 

measures. NMFS believes, therefore, 

that injurious take or mortality to the 

affected species marine mammals is 

extremely unlikely to occur as a result 

of the specified activities within the 

specified geographic area for which L– 

DEO seeks the IHA. The sections below 

describe methods to estimate ‘‘take by 

harassment’’, and present estimates of 

the numbers of marine mammals that 

could be affected during the proposed 

seismic program. The estimates of ‘‘take 

by harassment’’ are based on 

consideration of the number of marine 

mammals that might be disturbed 

appreciably by operations with the 36 

airgun array to be used during 

approximately 2,800 km of seismic 

surveys in the CNMI study area. The 

sources of distributional and numerical 

data used in deriving the estimates are 

described below. 

It is assumed that, during 

simultaneous operations of the airgun 

array and the other sources, any marine 

mammals close enough to be affected by 

the MBES and SBP would already be 

affected by the airguns. However, 

whether or not the airguns 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. Such reactions are 

not considered to constitute ‘‘taking’’ 

(NMFS, 2001). Therefore, no additional 

allowance is included for animals that 

could be affected by sound sources 

other than airguns. 

The only systematic marine mammal 

survey conducted in the CNMI was a 

ship-based survey conducted by the 

U.S. Navy during January to April, 2007 

in four legs: January 16 to February 2, 

February 6 to 25, March 1 to 20, and 

March 24 to April 12 (SRS—Parsons et 

al., 2007). The cruise area was defined 

by the boundaries 10° to 18° North, 142° 

to 148° East, encompassing an area 

approximately 585,000 km2 including 

the islands of Guam and the southern 

CNMI almost as far north as Pagan. The 

systematic line-transect survey effort 

was conducted from the flying bridge 

(10.5 m or 34.5 ft above sea level) of the 

56 m (183.7 ft) long M/V Kahana using 

standard line-transect protocols 

developed by NMFS Southwest 

Fisheries Science Center (SWFSC). 

Observers visually surveyed 11,033 km 

(6,855.6 mi) of tracklines, mostly in high 

sea states (88 percent of the time in 

Beaufort Sea states 4 to 6). 

L–DEO used the densities calculated 

in SRS—Parsons et al. (2007) for the 12 

species sighted in that survey. For eight 

species not sighted in that survey, but 

expected to occur in the CNMI, relevant 

densities are available for the ‘‘outer EEZ 

stratum’’ of Hawaiian waters, based on 

a 13,500 km (mi) survey conducted by 

NMFS SWFSC in August to November, 

2002 (Barlow, 2006). Another potential 

source of relevant densities is the 

SWFSC surveys conducted in the ETP 

during summer/fall 1986 to 1996 

(Ferguson and Barlow, 2001). However, 

for five of the remaining seven species 

that could occur in the survey area, 

there were no sightings in offshore 

tropical strata during those surveys, and 

for another (the humpback whale), there 

was only one sighting in more than 50 

offshore tropical (less than 20° latitude) 

5° x 5° strata. For those six species, an 

arbitrary low density was assigned. The 

short-beaked common dolphin was 

sighted in a number of offshore tropical 

strata, so its density was calculated as 

the mean of densities in the 17 offshore 

5° x 5° strata between 10° North and 20° 

North. 

The densities mentioned above had 

been corrected, by the original authors, 

for detectability bias, and in two of the 

three areas, for availability bias. 

Detectability bias is associated with 

diminishing sightability with increasing 

lateral distance from the track line 

[ƒ(0)]. Availability bias refers to the fact 

that there is less than 100 percent 

probability of sighting an animal that is 

present along the survey track line, and 

it is measured by g(0). SRS—Parsons et 

al. (2007) did not correct the Marianas 

densities for g(0), which for all but large 

(greater than 20) groups of dolphins 

[where g(0) = 1], resulted in 

underestimates of density. 

There is some uncertainty about the 

representativeness of the density data 

and the assumptions used in the 

calculations. For example, the timing of 

the surveys was either before (Marianas) 

or after (Hawaii and ETP) the proposed 

surveys. Also, most of the Marianas 

survey was in high sea states that would 

have prevented detection of many 

marine mammals, especially cryptic 

species such as beaked whales and 

Kogia spp. However, the approach used 

here is believed to be the best available 

approach. To provide some allowance 

for these uncertainties, particularly 

underestimates of densities present and 

numbers of marine mammals potentially 

affected have been derived; maximum 

estimates are 1.5x the best estimates. 

Densities calculated or estimated as 

described above are given in Table 3 of 

L–DEO’s application. 

The estimated numbers of individuals 

potentially exposed are based on the 

160 dB re 1 Pa (rms) Level B harassment 

exposure threshold for all cetaceans, see 

Table 4 of L–DEO’s application. It is 

assumed that the species of marine 

mammals affected by the proposed 

survey, if exposed to airgun sounds at 

these levels, might change their 

behavior sufficiently to be considered 

‘‘take by Level B harassment.’’ 

It should be noted that the following 

estimates of exposures to various sound 

levels and related incidental takes by 

Level B harassment assume that the 

proposed marine geophysical surveys 

will be completed. As is typical during 

offshore ship surveys, inclement 

weather and equipment malfunctions 

are likely to cause delays and may limit 

the number of useful line-km of seismic 

operations that can be undertaken. 

Furthermore, any marine mammals 

sightings within or near the designated 

EZs will result in the power-down or 

shut-down of seismic operations as a 

mitigation measure. Thus the following 

estimates of the numbers of marine 

mammals potentially exposed to 160 dB 

re 1 μPam (rms) sounds are 

precautionary and probably 

overestimate the actual numbers of 

marine mammals that might be 

involved. These estimates assume that 

there will be no weather, equipment, or 

mitigation delays, which is highly 

unlikely. 

Table 4 of L–DEO’s application shows 

the best and maximum estimated 

number of exposures and the number of 

different individuals potentially 

exposed during the seismic survey if no 

animals moved away from the survey 

vessel. The requested take 

authorization, given in the far right 

column of Table 4 of L–DEO’s 

application, is based on the maximum 

estimates rather than the best estimates 

of the numbers of individuals exposed, 

because of uncertainties associated with 

applying density data from one area to 

another. 

The number of different individuals 

that may be exposed to 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. 

The number of possible exposures 

(including repeated exposures of the 

same individuals) can be estimated by 

considering the total marine area that 

would be within the 160 dB radius 

around the operating airguns, including 

areas of overlap. In the proposed survey, 

the seismic lines are widely spaced in 

the proposed survey area, so an 


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8664 Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 

individual mammal would most likely 

not be exposed numerous times during 

the survey; the area including overlap is 

only 1.4x the area excluding overlap. 

Moreover, it is unlikely that a particular 

animal would stay in the area during the 

entire survey. 

The number of different individuals 

potentially exposed to received levels 

≥160 dB re 1 μPa (rms) was calculated 

by multiplying: 

• The expected species density, either 

‘‘mean’’ (i.e., best estimate) or 

‘‘maximum,’’ times, 

• The anticipated minimum area to 

be ensonified to that level during airgun 

operations excluding overlap 

(exposures), or 

• The anticipated area to be 

ensonified to that level during airgun 

operations excluding overlap 

(individuals). 

The area expected to be ensonified 

was determined by entering the planned 

survey lines into a MapInfo Geographic 

Information System (GIS), using the GIS 

to identify the relevant areas by 

‘‘drawing’’ the applicable 160 dB buffer 

(see Table 1 of L–DEO’s application) 

around each seismic line, and then 

calculating the total area within the 

buffers. Areas where overlap were 

included only once when estimating the 

number of individuals exposed. 

Applying the approach described 

above, approximately 15,685 km2 (6,056 

mi2) would be within the 160 dB 

isopleth on one or more occasions 

during the survey, where as 21,415 km2

(8,268.4 mi2) is the area ensonified to 

greater than or equal to 160 dB when 

overlap is included. Because this 

approach does not allow for turnover in 

the mammal populations in the study 

area during the course of the survey, the 

actual number of individuals exposed 

could be underestimated. However, the 

approach assumes that no cetaceans will 

move away from or toward the trackline 

as the Langseth approaches in response 

to increasing sound levels prior to the 

time the levels reach 160 dB, which will 

result in overestimates for those species 

known to avoid seismic vessels. 

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

THAN OR EQUAL TO 160 DB DURING L–DEO’S PROPOSED SEISMIC SURVEY IN THE CNMI IN APRIL TO JUNE, 2010* 

Species 

No. of individuals exposed 

(best) 1

No. of individuals exposed 

(max) 1

Approx. percent of regional population (best) 2

Mysticetes: 

...............................................................................................................................................

North Pacific right whale ......................................................................................................

(Eubalaena japonica) ............................................................................................................ 0 1 0 

Humpback whale ..................................................................................................................

(Megaptera novaeangliae) .................................................................................................... 0 2 0 

Minke whale ..........................................................................................................................

(Balaenoptera acutorostrata) ................................................................................................ 0 0 0 

Bryde’s whale .......................................................................................................................

(Balaenoptera brydei) ........................................................................................................... 6 10 0.03 

Sei whale ..............................................................................................................................

(Balaenoptera borealis) ........................................................................................................ 5 7 0.05 

Fin whale ..............................................................................................................................

(Balaenoptera physalus) ....................................................................................................... 0 2 0 

Blue whale ............................................................................................................................

(Balaenoptera musculus) ...................................................................................................... 0 2 0 

Odontocetes: 

...............................................................................................................................................

Sperm whale .........................................................................................................................

(Physeter macrocephalus) .................................................................................................... 19 29 0.07 

Pygmy sperm whale .............................................................................................................

(Kogia breviceps) .................................................................................................................. 46 68 N.A. 

Dwarf sperm whale ...............................................................................................................

(Kogia sima) ......................................................................................................................... 112 168 <0.01 

Cuvier’s beaked whale .........................................................................................................

(Ziphius cavirostris) .............................................................................................................. 97 146 0.49 

Longman’s beaked whale .....................................................................................................

(Indopacetus pacificus) ......................................................................................................... 9 13 N.A. 

Blainville’s beaked whale .....................................................................................................

(Mesoplodon densirostris) .................................................................................................... 18 28 0.07 

Ginkgo-toothed beaked whale ..............................................................................................

(Mesoplodon ginkgodens) .................................................................................................... 0 0 N.A. 

Rough-toothed dolphin .........................................................................................................

(Steno bredanensis) ............................................................................................................. 5 7 <0.01 

Bottlenose dolphin ................................................................................................................

(Tursiops truncatus) .............................................................................................................. 3 5 <0.01 

Pantropical spotted dolphin ..................................................................................................

(Stenella attenuata) .............................................................................................................. 355 532 0.04 

Spinner dolphin .....................................................................................................................

(Stenella longirostris) ............................................................................................................ 49 74 <0.01 

Striped dolphin ......................................................................................................................

(Stenella coeruleoalba) ......................................................................................................... 97 145 0.01 

Fraser’s dolphin ....................................................................................................................

(Lagenodelphis hosei) .......................................................................................................... 65 98 0.02 

Short-beaked common dolphin ............................................................................................

(Delphinus delphis) ............................................................................................................... 0 0 0 


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

THAN OR EQUAL TO 160 DB DURING L–DEO’S PROPOSED SEISMIC SURVEY IN THE CNMI IN APRIL TO JUNE, 

2010*—Continued 

Species 

No. of individuals exposed 

(best) 1

No. of individuals exposed 

(max) 1

Approx. percent of regional population (best) 2

Risso’s dolphin .....................................................................................................................

(Grampus griseus) ................................................................................................................ 15 23 0.01 

Melon-headed whale ............................................................................................................

(Peponocephala electra) ...................................................................................................... 67 101 0.15 

Pygmy killer whale ................................................................................................................

(Feresa attenuata) ................................................................................................................ 2 3 <0.01 

False killer whale ..................................................................................................................

(Pseudorca crassidens) ........................................................................................................ 17 26 <0.01 

Killer whale ...........................................................................................................................

(Orcinus orca) ....................................................................................................................... 2 3 0.04

Short-finned pilot whale ........................................................................................................

(Globicephala macrorhynchus) ............................................................................................. 25 37 <0.01 

Sirenians: Dugong .......................................................................................................................

(Dugong dugon) ........................................................................................................................... 0 0 N.A. 

* The proposed sound source consists of a 36 airgun, 6,600 in3 array. 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 to 4 in L–DEO’s application for further detail. 

N.A.—Data not available or species status was not assessed 

1Best estimate and maximum density estimates are from Table 3 of L–DEO’s application. 

2 Regional population size estimates are from Table 2. 

Table 4 of L–DEO’s application shows 

the best and maximum estimates of the 

number of exposures and the number of 

different individual marine mammals 

that potentially could be exposed to 

greater than or equal to 160 dB re 1 μPa 

(rms) during the seismic survey if no 

animals moved away from the survey 

vessel. For ESA listed species, the 

maximum estimate and Requested Take 

Authorization have been increased to 

the mean group size for the particular 

species in cases where the calculated 

maximum number of individuals 

exposed was between 0.05 and the mean 

group size (i.e., for North Pacific, right, 

humpback, fin, and blue whales). 

The ‘‘best estimate’’ of the total 

number of individual marine mammals 

that could be exposed to seismic sounds 

with received levels greater than or 

equal to 160 dB re 1 μPa (rms) during 

the survey is 1,011 animals and is 

shown in Table 4 of L–DEO’s 

application and Table 3 (shown above). 

These estimates were derived from the 

best density estimates calculated for 

these species in the area. That total 

includes 11 baleen whales, five of 

which are ESA-listed sei whales, or 0.05 

percent of the regional population. In 

addition, 19 ESA-listed sperm whales or 

0.07 percent of the regional population 

could be exposed during the survey, and 

121 beaked whales including Cuvier’s, 

Longman’s, and Blainville’s beaked 

whales. Most (69.4 percent) of the 

cetaceans exposed are delphinids; 

pantropical spotted, striped, and 

Fraser’s dolphins and melon-headed 

whales are estimated to be the most 

common species in the area, with best 

estimates of 355 (0.04 percent of the 

regional population), 97 (0.01 percent), 

65 (0.02 percent), and 67 (0.15 percent) 

exposed to greater or equal to 160 dB re 

1 μPa (rms) respectively. 

Potential Effects on Marine Mammal 

Habitat 

The proposed L–DEO seismic survey 

will not result in any permanent impact 

on habitats used by marine mammals, 

including the food sources they use. 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 above. The following sections 

briefly review effects of airguns on fish 

and invertebrates, and more details are 

included in Appendices C and D of the 

L–DEO EA, respectively. 

Potential Effects on Fish 

One reason for the adoption of airguns 

as the standard energy source for marine 

seismic surveys is that, unlike 

explosives, they have not been 

associated with large-scale fish kills. 

However, existing information on the 

impacts of seismic surveys on marine 

fish populations is limited (see 

Appendix D of the EA). There are three 

types of potential effects on fish and 

invertebrates from exposure to seismic 

surveys: 

(1) Pathological, 

(2) Physiological, and 

(3) Behavioral. 

Pathological effects involve lethal and 

temporary or permanent sub-lethal 

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. Furthermore, the 

available information on the impacts of 

seismic surveys on marine fish is from 

studies of individuals or portions of a 

population; there have been no studies 

at the population scale. The studies of 

individual fish have often been on caged 

fish that were exposed to airgun pulses 

in situations not representative of an 

actual seismic survey. Thus, available 

information provides limited insight on 

possible real-world effects at the ocean 

or population scale. This makes drawing 

conclusions about impacts on fish 

problematic because ultimately, the 

most important aspect of potential 

impacts relates to how exposure to 

seismic survey sound affects marine fish 

populations and their viability, 

including their availability to fisheries. 


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Hastings and Popper (2005), Popper 

(2009), and Popper and Hastings 

(2009a,b) provided recent critical 

reviews of the known effects of sound 

on fish. The following sections provide 

a general synopsis of available 

information on the effects of exposure to 

seismic and other anthropogenic sound 

as relevant to fish. The information 

comprises results from scientific studies 

of varying degrees of rigor plus some 

anecdotal information. Some of the data 

sources may have serious shortcomings 

in methods, analysis, interpretation, and 

reproducibility that must be considered 

when interpreting their results (see 

Hastings and Popper, 2005). Potential 

adverse effects of the program’s sound 

sources on marine fish are then noted. 

Pathological Effects—The potential 

for pathological damage to hearing 

structures in fish depends on the energy 

level of the received sound and the 

physiology and hearing capability of the 

species in question (see Appendix D of 

the L–DEO EA). For a given sound to 

result in hearing loss, the sound must 

exceed, by some substantial amount, the 

hearing threshold of the fish for that 

sound (Popper, 2005). The 

consequences of temporary or 

permanent hearing loss in individual 

fish on a fish population are unknown; 

however, they likely depend on the 

number of individuals affected and 

whether critical behaviors involving 

sound (e.g., predator avoidance, prey 

capture, orientation and navigation, 

reproduction, etc.) are adversely 

affected. 

Little is known about the mechanisms 

and characteristics of damage to fish 

that may be inflicted by exposure to 

seismic survey sounds. Few data have 

been presented in the peer-reviewed 

scientific literature. There are only two 

known valid papers with proper 

experimental methods, controls, and 

careful pathological investigation 

implicating sounds produced by actual 

seismic survey airguns with adverse 

anatomical effects. One such study 

indicated anatomical damage and the 

second indicated TTS in fish hearing. 

The anatomical case is McCauley et al. 

(2003), who found that exposure to 

airgun sound caused observable 

anatomical damage to the auditory 

maculae of ‘‘pink snapper’’ (Pagrus 

auratus). This damage in the ears had 

not been repaired in fish sacrificed and 

examined almost two months after 

exposure. On the other hand, Popper et 

al. (2005) documented only TTS (as 

determined by auditory brainstem 

response) in two of three fish species 

from the Mackenzie River Delta. This 

study found that broad whitefish 

(Coreogonus nasus) that received a 

sound exposure level of 177 dB re 1 

μPa2·s showed no hearing loss. During 

both studies, the repetitive exposure to 

sound was greater than would have 

occurred during a typical seismic 

survey. However, the substantial lowfrequency energy produced by the 

airgun arrays [less than approximately 

400 Hz in the study by McCauley et al. 

(2003) and less than approximately 200 

Hz in Popper et al. (2005)] likely did not 

propagate to the fish because the water 

in the study areas was very shallow 

(approximately 9 m in the former case 

and less than 2 m in the latter). Water 

depth sets a lower limit on the lowest 

sound frequency that will propagate (the 

‘‘cut-off frequency’’) at about one-quarter 

wavelength (Urick, 1983; Rogers and 

Cox, 1988). 

Wardle et al. (2001) suggested that in 

water, acute injury and death of 

organisms exposed to seismic energy 

depends primarily on two features of 

the sound source: (1) The received peak 

pressure, and (2) the time required for 

the pressure to rise and decay. 

Generally, as received pressure 

increases, the period for the pressure to 

rise and decay decreases, and the 

chance of acute pathological effects 

increases. According to Buchanan et al. 

(2004), for the types of seismic airguns 

and arrays involved with the proposed 

program, the pathological (mortality) 

zone for fish and invertebrates would be 

expected to be within a few meters of 

the seismic source. Numerous other 

studies provide examples of no fish 

mortality upon exposure to seismic 

sources (Falk and Lawrence, 1973; 

Holliday et al., 1987; La Bella et al., 

1996; Santulli et al., 1999; McCauley et 

al., 2000a,b, 2003; Bjarti, 2002; 

Thomsen, 2002; Hassel et al., 2003; 

Popper et al., 2005; Boeger et al., 2006). 

Some studies have reported, some 

equivocally, that mortality of fish, fish 

eggs, or larvae can occur close to 

seismic sources (Kostyuchenko, 1973; 

Dalen and Knutsen, 1986; Booman et 

al., 1996; Dalen et al., 1996). Some of 

the reports claimed seismic effects from 

treatments quite different from actual 

seismic survey sounds or even 

reasonable surrogates. However, Payne 

et al. (2009) reported no statistical 

differences in morality/morbidity 

between control and exposed groups of 

capelin eggs or monkfish larvae. Saetre 

and Ona (1996) applied a ‘worst-case 

scenario’ mathematical model to 

investigate the effects of seismic energy 

on fish eggs and larvae. They concluded 

that mortality rates caused by exposure 

to seismic surveys are so low, as 

compared to natural mortality rates, that 

the impact of seismic surveying on 

recruitment to a fish stock must be 

regarded as insignificant. 

Physiological Effects—Physiological 

effects refer to cellular and/or 

biochemical responses of fish to 

acoustic stress. Such stress potentially 

could affect fish populations by 

increasing mortality or reducing 

reproductive success. Primary and 

secondary stress responses of fish after 

exposure to seismic survey sound 

appear to be temporary in all studies 

done to date (Sverdrup et al., 1994; 

McCauley et al., 2000a, 2000b). The 

periods necessary for the biochemical 

changes to return to normal are variable, 

and depend on numerous aspects of the 

biology of the species and of the sound 

stimulus (see Appendix D of the EA). 

Behavioral Effects—Behavioral effects 

include changes in the distribution, 

migration, mating, and catchability of 

fish populations. Studies investigating 

the possible effects of sound (including 

seismic survey sound) on fish behavior 

have been conducted on both uncaged 

and caged individuals (Chapman and 

Hawkins, 1969; Pearson et al., 1992; 

Santulli et al., 1999; Wardle et al., 2001; 

Hassel et al., 2003). Typically, in these 

studies fish exhibited a sharp ‘‘startle’’ 

response at the onset of a sound 

followed by habituation and a return to 

normal behavior after the sound ceased. 

There is general concern about 

potential adverse effects of seismic 

operations on fisheries, namely a 

potential reduction in the ‘‘catchability’’ 

of fish involved in fisheries. Although 

reduced catch rates have been observed 

in some marine fisheries during seismic 

testing, in a number of cases the 

findings are confounded by other 

sources of disturbance (Dalen and 

Raknes, 1985; Dalen and Knutsen, 1986; 

L<kkeborg, 1991; Skalski et al., 1992; 

Engas et al., 1996). In other airgun 

experiments, there was no change in 

catch per unit effort (CPUE) of fish 

when airgun pulses were emitted, 

particularly in the immediate vicinity of 

the seismic survey (Pickett et al., 1994; 

La Bella et al., 1996). For some species, 

reductions in catch may have resulted 

from a change in behavior of the fish, 

e.g., a change in vertical or horizontal 

distribution, as reported in Slotte et al., 

(2004). 

In general, any adverse effects on fish 

behavior or fisheries attributable to 

seismic testing may depend on the 

species in question and the nature of the 

fishery (season, duration, fishing 

method). They may also depend on the 

age of the fish, its motivational state, its 

size, and numerous other factors that are 

difficult, if not impossible, to quantify at 

this point, given such limited data on 


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Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 8667 

effects of airguns on fish, particularly 

under realistic at-sea conditions. 

Potential Effects on Invertebrates 

The existing body of information on 

the impacts of seismic survey sound on 

marine invertebrates is very limited. 

However, there is some unpublished 

and very limited evidence of the 

potential for adverse effects on 

invertebrates, thereby justifying further 

discussion and analysis of this issue. 

The three types of potential effects of 

exposure to seismic surveys on marine 

invertebrates are pathological, 

physiological, and behavioral. 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 Appendix E of the L–DEO 

EA). 

The only information available on the 

impacts of seismic surveys on marine 

invertebrates involves studies of 

individuals; there have been no studies 

at the population scale. Thus, available 

information provides limited insight on 

possible real-world effects at the 

regional or ocean scale. The most 

important aspect of potential impacts 

concerns how exposure to seismic 

survey sound ultimately affects 

invertebrate populations and their 

viability, including availability to 

fisheries. 

Literature reviews of the effects of 

seismic and other underwater sound on 

invertebrates were provided by 

Moriyasu et al. (2004) and Payne et al. 

(2008). The following sections provide a 

synopsis of available information on the 

effects of exposure to seismic survey 

sound on species of decapod 

crustaceans and cephalopods, the two 

taxonomic groups of invertebrates on 

which most such studies have been 

conducted. The available information is 

from studies with variable degrees of 

scientific soundness and from anecdotal 

information. A more detailed review of 

the literature on the effects of seismic 

survey sound on invertebrates is 

provided in Appendix E of the L–DEO 

EA. 

Pathological Effects—In water, lethal 

and sub-lethal injury to organisms 

exposed to seismic survey sound 

appears to depend on at least two 

features of the sound source: (1) the 

received peak pressure, and (2) the time 

required for the pressure to rise and 

decay. Generally, as received pressure 

increases, the period for the pressure to 

rise and decay decreases, and the 

chance of acute pathological effects 

increases. For the type of airgun array 

planned for the proposed program, the 

pathological (mortality) zone for 

crustaceans and cephalopods is 

expected to be within a few meters of 

the seismic source, at most; however, 

very few specific data are available on 

levels of seismic signals that might 

damage these animals. This premise is 

based on the peak pressure and rise/ 

decay time characteristics of seismic 

airgun arrays currently in use around 

the world. 

Some studies have suggested that 

seismic survey sound has a limited 

pathological impact on early 

developmental stages of crustaceans 

(Pearson et al., 1994; Christian et al., 

2003; DFO, 2004). However, the impacts 

appear to be either temporary or 

insignificant compared to what occurs 

under natural conditions. Controlled 

field experiments on adult crustaceans 

(Christian et al., 2003, 2004; DFO, 2004) 

and adult cephalopods (McCauley et al., 

2000a,b) exposed to seismic survey 

sound have not resulted in any 

significant pathological impacts on the 

animals. It has been suggested that 

exposure to commercial seismic survey 

activities has injured giant squid 

(Guerra et al., 2004), but there is no 

evidence to support such claims. 

Physiological Effects—Physiological 

effects refer mainly to biochemical 

responses by marine invertebrates to 

acoustic stress. Such stress potentially 

could affect invertebrate populations by 

increasing mortality or reducing 

reproductive success. Primary and 

secondary stress responses (i.e., changes 

in haemolymph levels of enzymes, 

proteins, etc.) of crustaceans have been 

noted several days or months after 

exposure to seismic survey sounds 

(Payne et al., 2007). The periods 

necessary for these biochemical changes 

to return to normal are variable and 

depend on numerous aspects of the 

biology of the species and of the sound 

stimulus. 

Behavioral Effects—There is 

increasing interest in assessing the 

possible direct and indirect effects of 

seismic and other sounds on 

invertebrate behavior, particularly in 

relation to the consequences for 

fisheries. Changes in behavior could 

potentially affect such aspects as 

reproductive success, distribution, 

susceptibility to predation, and 

catchability by fisheries. Studies 

investigating the possible behavioral 

effect of exposure to seismic survey 

sound on crustaceans and cephalopods 

have been conducted on both uncaged 

and caged animals. In some cases, 

invertebrates exhibited startle responses 

(e.g., squid in McCauley et al., 2000a,b). 

In other cases, no behavioral impacts 

were noted (e.g., crustaceans in 

Christian et al., 2003, 2004; DFO, 2004). 

There have been anecdotal reports of 

reduced catch rates of shrimp shortly 

after exposure to seismic surveys; 

however, other studies have not 

observed any significant changes in 

shrimp catch rate (Andriguetto-Filho et 

al., 2005). Similarly, Parry and Gason 

(2006) did not find any evidence that 

lobster catch rates were affected by 

seismic surveys. Any adverse effects on 

crustacean and cephalopod behavior or 

fisheries attributable to seismic survey 

sound depend on the species in 

question and the nature of the fishery 

(season, duration, fishing method). 

During the proposed study, only a 

small fraction of the available habitat 

would be ensonified at any given time, 

and fish species would return to their 

pre-disturbance behavior once the 

seismic activity ceased. The proposed 

seismic program is predicted to have 

negligible to low behavioral effects on 

the various life stages of the fish and 

invertebrates during its relatively short 

duration and extent. 

Because of the reasons noted above 

and the nature of the proposed 

activities, the proposed operations are 

not expected to have any habitat-related 

effects that could cause significant or 

long-term consequences for individual 

marine mammals or their populations or 

stocks. Similarly, any effects to food 

sources are expected to be negligible. 

Proposed Mitigation 

In order to issue an Incidental Take 

Authorization (ITA) for small numbers 

of marine mammals under Section 

101(a)(5)(D) of the MMPA, NMFS must 

set forth the permissible methods of 

taking pursuant to such activity and 

other means of effecting the least 

practicable adverse impact on such 

species or stock and its habitat, paying 

particular attention to rookeries, mating 

grounds, and areas of similar 

significance, and on the availability of 

such species or stock for taking for 

certain subsistence uses. As noted, 

NMFS has determined that the proposed 

IHA would not impact marine mammals 

for purposes of their use for subsistence. 

Mitigation and monitoring measures 

and procedures described herein to be 

implemented for the proposed seismic 

survey have been developed and refined 

during previous L–DEO seismic 

research cruises as approved by NMFS, 

and associated environmental 

assessments (EAs), IHA applications, 

and IHAs, and on recommended best 

practices in Richardson et al. (1995), 

Pierson et al. (1998), and Weir and 

Dolman (2007). The following 

information provides more detailed 


jlentini on DSKJ8SOYB1PROD with NOTICES
8668 Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 

information about the mitigation 

measures that would be an integral part 

of the planned activities designed to 

affect the least practicable impact on 

stocks and species of affected marine 

mammals and their habitat. The 

measures are described in detail below. 

Planning Phase 

In designing the proposed seismic 

survey, L–DEO and NSF have 

considered potential environmental 

impacts including seasonal, biological, 

and weather factors; ship schedules; and 

equipment availability during a 

preliminary assessment carried out 

when ship schedules were still flexible. 

Part of the considerations was whether 

the research objectives could be met 

with a smaller source or with a different 

survey design that involves less 

prolonged seismic operations. 

Proposed Exclusion Zones (EZ) 

Received sound levels have been 

predicted by L–DEO, in relation to 

distance and direction from the airguns, 

for the 36 airgun array and for a single 

1900LL 40 in3 airgun, which will be 

used during power-downs. Results were 

recently reported for propagation 

measurements of pulses from the 36 

airgun array in two water depths 

(approximately 1,600 m and 50 m) in 

the Gulf of Mexico in 2007 to 2008 

(Tolstoy et al., 2009). It would be 

prudent to use the empirical values that 

resulted to determine EZs for the airgun 

array. Measurements were not reported 

for the mitigation airgun, so model 

results will not be used. 

Results of the propagation 

measurements (Tolstoy et al., 2009) 

showed that radii around the airguns for 

various received levels varied with 

water depth. During the proposed study, 

all survey effort will take place in deep 

(greater than 1,000 m) water, so 

propagation in shallow water is not 

relevant here. However, the depth of the 

array was different in the Gulf of Mexico 

calibration study (6 m or 20 ft) than in 

the proposed survey (9 m or 30 ft). 

Because propagation varies with array 

depth, correction factors have been 

applied to the distances reported by 

Tolstoy et al. (2009). The correction 

factors used were the ratios of the 160, 

180, and 190 dB distances from the 

modeled results for the 6,600 in3 airgun 

array towed at 6 m and 9 m depths; 

these distances were used for the L– 

DEO seismic survey in the Northeast 

Pacific Ocean (see Table 1 in LGL Ltd., 

2009). The factors are 1.34 to 1.38 for 

the 180 to 190 dB distances, and 1.29 for 

the 160 dB distance. Using the corrected 

measurements (array) or model 

(mitigation gun), Table 1 shows the 

distances at which four rms sound 

levels are expected to be received from 

the 36 airgun array and a single airgun. 

The 180 and 190 dB levels are shutdown criteria applicable to cetaceans 

and pinnipeds, respectively, as 

specified by NMFS (2000); these levels 

were used to establish the EZs. If the 

PSVO detects marine mammal(s) within 

or about to enter the appropriate EZ, the 

airguns will be powered-down (or shutdown if necessary) immediately (see 

below). 

Detailed recommendations for new 

science-based noise exposure criteria 

were published in early 2008 (Southall 

et al., 2007). L–DEO will be prepared to 

revise its procedures for estimating 

numbers of mammals ‘‘taken,’’ EZs, etc., 

as may be required by any new 

guidelines that result. As yet, NMFS has 

not specified a new procedure for 

determining EZs. Such procedures, if 

applicable would be implemented 

through a modification to the IHA if 

issued. 

Mitigation measures that will be 

adopted during the proposed CNMI 

survey include: 

(1) Power-down procedures; 

(2) Shut-down procedures; and 

(3) Ramp-up procedures; 

Power-down Procedures—A powerdown involves reducing the number of 

airguns in use such that the radius of 

the 180 dB (or 190 dB) zone is decreased 

to the extent that marine mammals are 

no longer in or about to enter the EZ. A 

power-down of the airgun array can also 

occur when the vessel is moving from 

one seismic line to another. During a 

power-down for mitigation, one airgun 

will be operated. The continued 

operation of one airgun is intended to 

alert marine mammals to the presence of 

the seismic vessel in the area. In 

contrast, a shut-down occurs when all 

airgun activity is suspended. 

If a marine mammal (other than right 

whales [immediate shut-down, see end 

of section]) is detected outside the EZ 

but is likely to enter the EZ, the airguns 

will be powered-down to a single airgun 

before the animal is within the EZ. 

Likewise, if a mammal is already within 

the EZ when first detected, the airguns 

will be powered-down immediately. 

During a power-down of the airgun 

array, the 40 in3 airgun will be operated. 

If a marine mammal is detected within 

or near the smaller EZ around that 

single airgun (see Table 1 of L–DEO’s 

application and Table 1 above), all 

airguns will be shut down (see next 

subsection). 

Following a power-down, airgun 

activity will not resume until the marine 

mammal is outside the EZ for the full 

array. The animal will be considered to 

have cleared the EZ if it: 

(1) Is visually observed to have left 

the EZ, or 

(2) Has not been seen within the EZ 

for 15 minutes in the case for species 

with shorter dive durations (e.g., small 

odontocetes); or 

(3) Has not been seen within the EZ 

for 30 minutes in the case for species 

with longer dive durations (e.g., 

mysticetes and large odontocetes, 

including sperm, pygmy sperm, dwarf 

sperm, killer, and beaked whales). 

During airgun operations following a 

power-down (or shut-down) whose 

duration has exceeded the limits 

specified above and subsequent animal 

departures, the airgun array will be 

ramped-up gradually. Ramp-up 

procedures are described below. 

Shut-down Procedures—The 

operating airguns(s) will be shut-down 

if a marine mammal is detected within 

or approaching the EZ for a single 

airgun source. Shut-downs will be 

implemented (1) if an animal enters the 

EZ of the single airgun after a powerdown has been initiated, or (2) if an 

animal is initially seen within the EZ of 

a single airgun when more than one 

airgun (typically the full array) is 

operating. Airgun activity will not 

resume until the marine mammal has 

cleared the EZ, or until the PSVO is 

confident that the animal has left the 

vicinity of the vessel (or the PSVO not 

observing the animal(s) within the EZ 

for 15 or 30 min depending upon the 

species). Criteria for judging that the 

animal has cleared the EZ will be as 

described in the preceding subsection. 

Ramp-up Procedures—A ramp-up 

procedure will be followed when the 

airgun array begins operating after a 

specified period without airgun 

operations or when a power-down has 

exceeded that period. It is proposed 

that, for the present cruise, this period 

would be approximately 8 minutes. This 

period is based on the largest modeled 

180 dB radius for the 36 airgun array 

(940 m or 3,084 ft) in relation to the 

minimum planned speed of the 

Langseth while shooting (7.4 km/hr or 

4.6 mi/hr). Similar periods 

(approximately 8 to 10 minutes) were 

used during previous L–DEO surveys. 

Ramp-up will begin with the smallest 

airgun in the array (40 in3). Airguns will 

be added in a sequence such that the 

source level of the array will increase in 

steps not exceeding 6 dB per 5 min 

period over a total duration of 

approximately 35 minutes. During 

ramp-up, the PSVOs will monitor the 

EZ, and if marine mammals are sighted, 

a power-down or shut-down will be 


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implemented as though the full array 

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 

unless at least one airgun (40 in3 or 

similar) has been operating during the 

interruption of seismic survey 

operations. Given these provisions, it is 

likely that the airgun array will not be 

ramped-up from a complete shut-down 

at night or in thick fog, because the 

outer part of the EZ for that array will 

not be visible during those conditions. 

If one airgun has operated during a 

power-down period, 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 airgun and could 

move away if they choose. Ramp-up of 

the airguns will not be initiated if a 

marine mammal is sighted within or 

near the applicable EZ during the day or 

close to the vessel at night. 

Procedures for Species of Particular 

Concern—One species of particular 

concern could occur in the study area. 

Considering the conservation status 

for North Pacific right whales, the 

airgun(s) will be shut-down 

immediately in the unlikely event that 

this species is observed, regardless of 

the distance from the Langseth. Rampup will only begin if the right whale has 

not been seen for 30 minutes. 

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) 

require that requests for IHAs 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. 

L–DEO proposes to sponsor marine 

mammal monitoring during the 

proposed project, in order to implement 

the proposed mitigation measures that 

require real-time monitoring, and to 

satisfy the anticipated monitoring 

requirements of the IHA. L–DEO’s 

proposed Monitoring Plan is described 

below as well as in their IHA 

application. L–DEO understands that 

this Monitoring Plan will be subject to 

review by NMFS, and that refinements 

may be required as part of the MMPA 

consultation process. 

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. L–DEO 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 

Protected Species Visual Observers 

(PSVOs) will be based aboard the 

seismic source vessel and will watch for 

marine mammals and other protected 

species near the vessel during daytime 

airgun operations and during start-ups 

of airguns at night. PSVOs will also 

watch for marine mammals near the 

seismic vessel for at least 30 minutes 

prior to the start of airgun operations 

and after an extended shut-down of the 

airguns. When feasible, PSVOs will also 

observe during daytime periods when 

the seismic system is not operating for 

comparison of sighting rates and animal 

behavior with vs. without airgun 

operations. Based on PSVO 

observations, the airguns will be 

powered-down or shut-down (see 

below) when marine mammals are 

detected within or about to enter a 

designated EZ, and in the case of the 

North Pacific right whale immediately 

when any individuals of that species is 

spotted at any distance. The PSVOs will 

continue to maintain watch to 

determine when the animal(s) are 

outside the EZ in accordance with the 

criteria established above in the 

mitigation section, and airgun 

operations will not resume until the 

animal has left that EZ. The predicted 

distances for the safety radius are listed 

according to the sound source, water 

depth, and received isopleths in Table 

1. The EZ is a region in which a 

possibility exists of adverse effects on 

animal hearing or other physical effects. 

During seismic operations in CNMI, 

five PSOs will be based aboard the 

Langseth. PSOs will be appointed by L– 

DEO with NMFS concurrence. At least 

one PSVO, and when practical two 

PSVOs, will monitor for marine 

mammals and other specified protected 

species near the seismic vessel during 

ongoing daytime operations and 

nighttime start-ups of the airguns. Use 

of two simultaneous PSVOs will 

increase the effectiveness of detecting 

animals near the sound source. PSVO(s) 

will be on duty in shift of duration no 

longer than 4 hours. The vessel crew 

will also be instructed to assist in 

detecting marine mammals and other 

specified protected species, and 

implementing mitigation measures (if 

practical). Before the start of the seismic 

survey the crew will be given additional 

instruction regarding how to do so. 

The Langseth is a suitable platform for 

observations for marine mammals and 

other protected species. When stationed 

on the observation platform, the eye 

level will be approximately 21.5 m (70.5 

ft) above sea level, and the observer will 

have a good view around the entire 

vessel. During the daytime, the PSVO(s) 

will scan the area around the vessel 

systematically with reticle binoculars 

(e.g., 7x50 Fujinon), Big-eye binoculars 

(25x150), and with the naked eye. 

During darkness, night vision devices 

(NVDs) will be available (ITT F500 

Series Generation 3 binocular-image 

intensifier or equivalent), when 

required. Laser rangefinding binoculars 

(Leica LRF 1200 laser rangefinder or 

equivalent) will be available to assist 

with distance estimation. Those are 

useful in training PSVOs to estimate 

distances visually, but are generally not 

useful in measuring distances to 

animals directly; that is done primarily 

with the reticles in the binoculars’ 

lenses. 

Passive Acoustic Monitoring (PAM) 

PAM will take place to complement 

the visual monitoring program, when 

practicable. Visual monitoring typically 

is not effective during periods of poor 

visibility (e.g., bad weather) or at night, 

and even with good visibility, is unable 

to detect marine mammals when they 

are below the surface or beyond visual 

range. Acoustical monitoring can be 

used in addition to visual observations 

to improve detection, identification, and 

localization of cetaceans. The acoustic 

monitoring will serve to alert visual 

observers (if on duty) when vocalizing 

cetaceans are detected. It is only useful 

when marine mammals call, but it can 

be effective either by day or by night 

and does not depend on good visibility. 

It will be monitored in real time so that 

the visual observers can be advised 

when cetaceans are detected. When 

bearings (primary and mirror-image) to 

calling cetacean(s) are determined, the 

bearings will be relayed to the visual 

observer to help him/her sight the 

calling animal(s). 

The PAM system consists of hardware 

(i.e., hydrophones) and software. The 

‘‘wet end’’ of the system consists of a 

low-noise, towed hydrophone array that 

is connected to the vessel by a ‘‘hairy’’ 

faired cable. The array will be deployed 

from a winch located on the back deck. 

A deck cable will connect from the 

winch to the main computer lab where 

the acoustic station and signal condition 

and processing system will be located. 

The lead-in from the hydrophone array 


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8670 Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 

is approximately 400 m (1,312 ft) long, 

and the active part of the hydrophone is 

approximately 56 m (184 ft) long. The 

hydrophone array is typically towed at 

depths less than 20 m (65.6 ft). 

The towed hydrophone array will be 

monitored 24 hours per day while at the 

survey area during airgun operations, 

and during most periods when the 

Langseth is underway while the airguns 

are not operating. One Protected Species 

Observer will monitor the acoustic 

detection system at any one time, by 

listening to the signals from two 

channels via headphones and/or 

speakers and watching the real time 

spectrographic display for frequency 

ranges produced by cetaceans. PSOs 

monitoring the acoustical data will be 

on a shift for one to six hours. Besides 

the visual PSOs, an additional PSO with 

primary responsibility for PAM will also 

be aboard. All PSOs are expected to 

rotate through the PAM position, 

although the most experienced with 

acoustics will be on PAM duty more 

frequently. 

When a vocalization is detected while 

visual observations are in progress, the 

acoustic PSO will contact the PSVO 

immediately to alert him/her to the 

presence of the cetacean(s) (if they have 

not already been seen), and to allow a 

power-down or shut-down to be 

initiated, if required. The information 

regarding the vocalization will be 

entered into a database. The data to be 

entered include an acoustic encounter 

identification number, whether it was 

linked with a visual sighting, date, time 

when first and last heard and whenever 

any additional information was 

recorded, position and water depth 

when first detected, bearing if 

determinable, species or species group 

(e.g., unidentified dolphin, sperm 

whale), types and nature of sounds 

heard (e.g., clicks, continuous, sporadic, 

whistles, creaks, burst pulses, strength 

of signal, etc.), and any other notable 

information. The acoustic detection can 

also be recorded for further analysis. 

L–DEO will coordinate the planned 

protected species monitoring program 

associated with the CNMI seismic 

survey with other parties that may have 

interest in the area and/or be conducting 

marine mammal studies in the same 

region during the proposed seismic 

survey. L–DEO and NSF will coordinate 

with applicable U.S. agencies (e.g., 

NMFS), and will comply with their 

requirements. 

PSVO Data and Documentation 

PSVOs will record data to estimate 

the numbers of marine mammals 

exposed to various received sound 

levels and to document apparent 

disturbance reactions or lack thereof. 

Data 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 power-down or 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: 

(1) 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. 

(2) Time, location, heading, speed, 

activity of the vessel, sea state, 

visibility, and sun glare. 

The data listed under (2) above 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 

power-downs and shut-downs, will be 

recorded in a standardized format. The 

accuracy of data entry will be verified 

by computerized data validity checks as 

the data are entered and by subsequent 

manual checking of the database. These 

procedures will allow initial summaries 

of data to be prepared during and 

shortly after the field program, and will 

facilitate transfer of the data to 

statistical, graphical, and other 

programs for further processing and 

archiving. 

Results for the vessel-based 

observations will provide: 

(1) The basis for real-time mitigation 

(airgun power-down or shut-down). 

(2) Information needed to estimate the 

number of marine mammals potentially 

taken by harassment, which must be 

reported to NMFS per terms of MMPA 

authorizations or regulations. 

(3) Data on the occurrence, 

distribution, and activities of marine 

mammals in the area where the seismic 

study is conducted. 

(4) Information to compare the 

distance and distribution of marine 

mammals relative to the source vessel at 

times with and without seismic activity. 

(5) 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 

and NSF 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 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. 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. 

Negligible Impact and Small Numbers 

of Marine Mammals Analysis and 

Determination 

The Secretary, in accordance with 

paragraph 101(a)(5)(D) of the MMPA, 

shall authorize the take of small 

numbers of marine mammals incidental 

to specified activities other than 

commercial fishing within a specific 

geographic region if, among other 

things, he determines that the 

authorized incidental take will have a 

‘‘negligible impact’’ on species or stocks 

affected by the authorization. NMFS 

implementing regulations codified at 50 

CFR 216.103 states that a ‘‘negligible 

impact is an impact resulting from the 

specified activity that cannot be 

reasonably expected to, and is not 

reasonably likely to, adversely affect the 

species or stock through effects on 

annual rates of recruitment or survival.’’ 

Based on the analysis contained 

herein, of the likely effects of the 

specified activity on marine mammals 

and their habitat within the specific area 

of study for the CNMI marine 

geophysical survey, and taking into 

consideration the implementation of the 

mitigation and monitoring measures, 

NMFS, on behalf the Secretary, 

preliminarily finds that L–DEO’s 

proposed activities would result in the 

incidental take of small numbers of 

marine mammals, by Level B 

harassment only, and that the total 

taking from the proposed seismic survey 

would have a negligible impact on the 

affected species or stocks of marine 

mammals. 

Impact on Availability of Affected 

Species for Taking for Subsistence Uses 

There is no subsistence hunting for 

marine mammals in the waters off of the 

coast of the CNMI that implicates 

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


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Federal Register / Vol. 75, No. 37 / Thursday, February 25, 2010 / Notices 8671 

Endangered Species Act (ESA) 

Under Section 7 of the ESA, NSF has 

initiated formal consultation with the 

NMFS, Office of Protected Resources, 

Endangered Species Division, on this 

proposed seismic survey. NMFS Office 

of Protected Resources, Permits, 

Conservation and Education Division, 

has initiated formal consultation under 

Section 7 of the ESA with NMFS Office 

of Protected Resources, Endangered 

Species Division, to obtain a Biological 

Opinion evaluating the effects of issuing 

the IHA on threatened and endangered 

marine mammals and, if appropriate, 

authorizing incidental take. NMFS will 

conclude formal Section 7 consultation 

prior to making a determination on 

whether or not to issue the IHA. If the 

IHA is issued, L–DEO will be required 

to comply with the Terms and 

Conditions of the Incidental Take 

Statement corresponding to NMFS’ 

Biological Opinion issued to both NSF 

and NMFS Office of Protected 

Resources. 

National Environmental Policy Act 

(NEPA) 

With its complete application, L–DEO 

provided NMFS an EA analyzing the 

direct, indirect and cumulative 

environmental impacts of the proposed 

specified activities on marine mammals 

including those listed as threatened or 

endangered under the ESA. The EA, 

prepared by LGL Environmental 

Research Associated (LGL) on behalf of 

NSF and L–DEO is entitled 

Environmental Assessment of a Marine 

Geophysical Survey by the R/V Marcus 

G. Langseth in the Commonwealth of 

the Northern Mariana Islands, April– 

June 2010 (L–DEO EA). Prior to making 

a final decision on the IHA application, 

NMFS will either prepare an 

independent EA, or, after review and 

evaluation of the L–DEO EA for 

consistency with the regulations 

published by the Council of 

Environmental Quality (CEQ) and 

NOAA Administrative Order 216–6, 

Environmental Review Procedures for 

Implementing the National 

Environmental Policy Act, adopt the 

L–DEO EA and make a decision of 

whether or not to issue a Finding of No 

Significant Impact (FONSI). 

Preliminary Determinations 

NMFS has preliminarily determined 

that the impact of conducting the 

specific seismic survey activities 

described in this notice and the IHA 

request in the specific geographic region 

within the U.S. EEZ within the CNMI 

may result, at worst, in a temporary 

modification in behavior (Level B 

harassment) of small numbers of marine 

mammals. Further, this activity is 

expected to result in a negligible impact 

on the affected species or stocks of 

marine mammals. The provision 

requiring that the activity not have an 

unmitigable impact on the availability 

of the affected species or stock of marine 

mammals for subsistence uses is not 

implicated for this proposed action. 

For reasons stated previously in this 

document, the specified activities 

associated with the proposed survey are 

not likely to cause TTS, PTS or other 

non-auditory injury, serious injury, or 

death to affected marine mammals 

because: 

(1) 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; 

(2) The fact that cetaceans would have 

to be closer than 940 m (0.6 mi) in deep 

water when the full array is in use at a 

9 m (29.5 ft) tow depth from the vessel 

to be exposed to levels of sound (180 

dB) believed to have even a minimal 

chance of causing PTS; 

(3) The fact that marine mammals 

would have to be closer than 3,850 m 

(2.4 mi) in deep water when the full 

array is in use at a 9 m (29.5 ft) tow 

depth from the vessel to be exposed to 

levels of sound (160 dB) believed to 

have even a minimal chance at causing 

TTS; and 

(4) The likelihood that marine 

mammal detection ability by trained 

observers is high at that short distance 

from the vessel. 

As a result, no take by injury, serious 

injury, or death is anticipated or 

authorized, and the potential for 

temporary or permanent hearing 

impairment is very low and will be 

avoided through the incorporation of 

the proposed monitoring and 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 Level 

B incidental harassment takings (see 

Table 3 above) is estimated to be small, 

less than a few percent of any of the 

estimated population sizes based on the 

data disclosed in Table 2 of this notice, 

and has been mitigated to the lowest 

level practicable through incorporation 

of the monitoring and mitigation 

measures mentioned previously in this 

document. Also, there are no known 

important reproduction or feeding areas 

in the proposed action area. 

Proposed Authorization 

As a result of these preliminary 

determinations, NMFS proposes to issue 

an IHA to L–DEO for conducting a 

marine geophysical survey in the CNMI 

from April to June, 2010, provided the 

previously mentioned mitigation, 

monitoring, and reporting requirements 

are incorporated. The duration of the 

IHA would not exceed one year from the 

date of its issuance. 

Information Solicited 

NMFS requests interested persons to 

submit comments and information 

concerning this proposed project and 

NMFS’ preliminary determination of 

issuing an IHA (see ADDRESSES). 

Concurrent with the publication of this 

notice in the Federal Register, NMFS is 

forwarding copies of this application to 

the Marine Mammal Commission and 

its Committee of Scientific Advisors. 

Dated: February 19, 2010. 

James H. Lecky, 

Director, Office of Protected Resources, 

National Marine Fisheries Service. 

[FR Doc. 2010–3869 Filed 2–24–10; 8:45 am] 

BILLING CODE 3510–22–P 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

RIN 0648–XU21 

Magnuson-Stevens Act Provisions; 

General Provisions for Domestic 

Fisheries; Application for Exempted 

Fishing Permit 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Notice; request for comments. 

SUMMARY: The Assistant Regional 

Administrator for Sustainable Fisheries, 

Northeast Region, NMFS (Assistant 

Regional Administrator), has made a 

preliminary determination that the 

subject Exempted Fishing Permit (EFP) 

application for the Northeast Fisheries 

Science Center’s (NEFSC) Study Fleet 

Program contains all of the required 

information and warrants further 

consideration. The EFP would exempt 

fishing vessels from minimum fish sizes 

and possession and landing limits for 

the purpose of collecting fishery 

dependent catch data and biological 

samples. 

Regulations under the MagnusonStevens Fishery Conservation and 

Management Act require publication of 

this notification to provide interested 


jlentini on DSKJ8SOYB1PROD with NOTICES