Small Takes of Marine Mammals Incidental to Specified Activities; Seismic Hazards Investigations in Puget Sound

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 080697A]

Small Takes of Marine Mammals Incidental to Specified Activities;

Seismic Hazards Investigations in Puget Sound

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and

Atmospheric Administration (NOAA), Commerce.

ACTION: Notice of receipt of application and proposed authorization for

a small take exemption; request for comments.

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SUMMARY: NMFS has received a request from the U.S.Geological Survey

(USGS) for an authorization to take small numbers of marine mammals by

harassment incidental to collecting deep-crustal marine seismic data in

the Puget Sound/Straits of Juan de Fuca region of Washington State.

Under the Marine Mammal Protection Act (MMPA), NMFS is requesting

comments on its proposal to authorize USGS to incidentally take, by

harassment, small numbers of marine mammals in the above mentioned area

during late February or March 1998.

DATES: Comments and information must be received no later than October

17, 1997.

ADDRESSES: Comments on the application should be addressed to Michael

Payne, Chief, Marine Mammal Division, Office of Protected Resources,

NMFS, 1315 East-West Highway, Silver Spring, MD 20910-3225. A copy of

the application, and a draft environmental assessment (EA), which

includes a list of references used in this document, may be obtained by

writing to this address or by telephoning one of the contacts listed

below.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, Office of

Protected Resources, NMFS, (301) 713-2055, or Brent Norberg, Northwest

Regional Office, NMFS, (206) 526-6733.

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SUPPLEMENTARY INFORMATION:

Background

Section 101(a)(5) (A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)

directs the Secretary of Commerce to allow, upon request, the

incidental, but not intentional, taking of marine mammals by U.S.

citizens who engage in a specified activity (other than commercial

fishing) within a specified geographical region if certain findings are

made and either regulations are issued or, if the taking is limited to

harassment, notice of a proposed authorization is provided to the

public for review.

Permission may 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 the permissible methods of taking

and requirements pertaining to the monitoring and reporting of such

taking 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.''

New section 101(a)(5)(D) of the Marine Mammal Protection Act

established an expedited process by which citizens of the United States

can apply for an authorization to incidentally take small numbers of

marine mammals by harassment. The MMPA now defines ``harassment'' as:

* * * any act of pursuit, torment, or annoyance which (a) has

the potential to injure a marine mammal or marine mammal stock in

the wild; or (b) 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.

New subsection 101(a)(5)(D) establishes a 45-day time limit for

NMFS review of an application followed by a 30-day public notice and

comment period on any proposed authorizations for the incidental

harassment of small numbers of marine mammals. Within 45 days of the

close of the comment period, NMFS must either issue or deny issuance of

the authorization.

Summary of Request

On July 2, 1997, NMFS received an application from the USGS, on

behalf of the Seismic Hazards Investigations in Puget Sound (SHIPS)

project, requesting an authorization for the possible harassment of

small numbers of several species of marine mammals incidental to

conducting marine seismic surveys in Puget Sound, WA. The survey is to

collect data on the earthquake hazards of the Puget Sound area.

Geological features around the Puget Sound that might produce

earthquakes lie obscured beneath water, city, forest, and thick glacial

deposits. As a result, investigators must use sound waves that are

produced by an array of airguns to indirectly view these features.

Because seismic noise from the proposed survey's airguns could

potentially affect marine mammals due to disturbance by sound (i.e.,

acoustic harassment), an incidental harassment authorization under the

MMPA is warranted.

The main goals of the SHIPS project concern understanding

earthquake processes and mitigating a potential disaster, not

earthquake prediction. Geologists have clear evidence for past

earthquakes, but basic geological information about earthquake

processes is lacking. To close this critical information gap, the SHIPS

consortium will collect seismic reflection and seismic refraction data

in and near Puget Sound. Seismic reflection data will help locate

potential earthquake faults, and seismic refraction data will show the

speed of sound waves in deep rocks. These data together will reveal the

structure and physical properties of rocks where earthquakes are likely

to occur. Information from onshore seismometers will reveal where deep

rocks could focus earthquake waves at the surface and where surface

sediment is weak.

Where these conditions of focusing and sediment weakness overlap,

buildings and other infrastructure are at elevated risk of damage or

destruction during a major earthquake. SHIPS will provide information

needed to make maps, for city planners, to show areas of potentially

strong ground motion so that scarce funds for seismic retrofitting can

be allocated on a rational basis. Prime candidates for retrofitting are

schools and hospitals. Freeway interchanges and major bridges as well

as structures housing police and firefighters must withstand

earthquakes so that survivors receive prompt assistance.

Dependent upon ship scheduling, the seismic survey is expected to

take approximately two weeks sometime during late February and March

1998. A detailed description of the work planned is contained in the

application (USGS 1997) and the draft EA. These documents are available

upon request (see ADDRESSES). Description of Habitat and Marine Mammals

Affected by the Activity

A description of the Puget Sound ecosystem and its associated

marine mammals can be found in the USGS application and associated

draft EA.

Marine Mammals

The species of marine mammals that are likely to be present in

Puget Sound and Straits of Juan de Fuca include the harbor porpoise

(Phocoena phocoena), killer whale (Orcinus orca), Dall's porpoise

(Phocoenoides dalli), and harbor seal (Phoca vitulina). Additional

species that are rare or only occasionally seen in the area at the time

of the survey include: Minke whale (Balaenoptera acutorostrata),

elephant seal (Mirounga angustirostris) Pacific white-sided dolphin

(Lagenorhynchus obliquidens), northern sea lion (Eumetopias jubatus),

California sea lion (Zalophus californianus), humpback whale (Megaptera

novaengliae), and gray whale (Eschrichtius robustus). General

information on these latter species can be found in Barlow et al.

(1995). Information relevant to the distribution, abundance, and

behavior of those species most likely to be impacted by the experiment

in Puget Sound and the Straits of Juan de Fuca is provided in the

application and draft EA. Please refer to those documents for

information on the biology, distribution, and abundance of these

species.

Potential Effects of Seismic Surveys on Marine Mammals

Discussion

Deep seismic surveys are used to obtain data about rock formations

several thousands of feet deep. These surveys are accomplished by

transmitting sound waves into the earth, which are reflected off

subsurface formations and recorded with detectors in the water column.

A typical marine seismic source is an airgun array, which releases

compressed air into the water creating an acoustical energy pulse that

is directed downwards toward the seabed. Hydrophones spaced along a

streamer cable just below the surface of the water receive the

reflected energy from the subsurface formations and transmit data to

the seismic vessel. Onboard the vessel, the signals are amplified,

digitized, and recorded on magnetic tape.

Disturbance by seismic noise is the principal means of taking by

this activity. Vessel noise may provide a secondary source. Also, the

physical presence of vessel(s) could also lead to some non-acoustic

effects involving visual or other cues.

Depending upon ambient conditions and the sensitivity of the

receptor,

[[Page 48819]]

underwater sounds produced by open-water seismic operations may be

detectable some substantial distance away from the activity. Any sound

that is detectable is (at least in theory) capable of eliciting a

disturbance reaction by a marine mammal or masking a signal of

comparable frequency. An incidental harassment take is presumed to

occur when marine mammals in the vicinity of the seismic source (or

vessel) react to the generated sounds or visual cues.

Seismic pulses are known to cause some species of whales, including

gray and bowhead whales, to behaviorally respond within a distance of

several kilometers (Richardson et al. 1995). Although some limited

masking of low-frequency sounds is a possibility for those species of

whales using low frequencies for communication, the intermittent nature

of seismic source pulses will limit the extent of masking. Bowhead

whales, for example, are known to continue calling in the presence of

seismic survey sounds, and their calls can be heard between seismic

pulses (Richardson et al. 1986).

When the received levels of noise exceed some behavioral reaction

threshold, cetaceans will show disturbance reactions. The levels,

frequencies, and types of noise that will elicit a response vary

between and within species, individuals, locations and season.

Behavioral changes may be subtle alterations in surface-dive-

respiration cycles. More conspicuous responses, include changes in

activity or aerial displays, movement away from the sound source, or

complete avoidance of the area. The reaction threshold and degree of

response are related to the activity of the animal at the time of the

disturbance. Whales engaged in active behaviors such as feeding,

socializing or mating are less likely than resting animals to show

overt behavioral reactions, unless the disturbance is directly

threatening.

Hearing damage is not expected to occur during the project. While

it is not known whether a marine mammal very close to an airgun array

would be at risk of temporary or permanent hearing impairment,

temporary threshold shift (TTS) is a theoretical possibility for

animals within a few hundred meters (Richardson et al. 1995). However,

planned monitoring and mitigation measures (described below) are

designed to detect marine mammals occurring near the seismic array and

to avoid, to the greatest extent practicable, exposing them to sound

pulses that have any possibility of causing hearing damage.

Estimates of Harassment Take Levels

Based upon analyses provided in the application and draft EA, the

USGS estimates that the number of potential harassment takings

resulting from the 1998 Puget Sound marine seismic survey will be as

follows:

Harbor porpoise........................... 1,000.

Killer whale.............................. 40.

Dall's porpoise........................... 1,000.

Harbor seals.............................. 4,500 in Puget Sound, 1,200

in Hood Canal, 5,000 in the

Strait of Juan de Fuca.

California sea lions...................... 2,000.

Northern sea lions........................ 0.

Elephant seals:........................... 50.

Gray whale................................ 20.

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Potential Effect on Habitat

As described in detail in the draft EA, no impact on the habitat or

food sources of marine mammals are likely from this short-term marine

seismic survey.

Mitigation

Several mitigation measures to reduce the potential for marine

mammal harassment will be implemented by USGS as part of their proposed

activity. These include:

(1) Scheduling the survey for the period of February/March, when

marine mammal abundance in Puget Sound/Straits of Juan de Fuca is low;

(2) To avoid potential Level A harassment of, or injury to, marine

mammals, safety zones will be established and monitored continuously

(during daylight hours). Whenever the seismic vessel approaches a

marine mammal closer than the distance mentioned below and described in

more detail in both the application and the draft EA, the USGS would

shut off airguns.

(3) For gray, minke, and humpback whales, the marine mammal species

that are considered to be most sensitive to the frequency and intensity

of sound that will be emitted by the airgun array, airgun operations

will cease when members of these species approach within 500 m (1,640

ft) of the seismic vessel.

(4) For odontocetes, with their lower sensitivity to low frequency

sound, airgun operations will cease when these animals approach a

safety zone of 200 m (656 ft), twice the calculated radius for

preventing TTS.

(5) For pinnipeds (seals and sealions), if the SHIPS seismic vessel

approaches a pinniped, a safety radius of 100 m (328 ft) will be

maintained from the animal(s). However, if a pinniped approaches the

towed airgun array, the USGS will not be required to shutdown the

airguns. Experience indicates that pinnipeds will come from great

distances to scrutinize seismic operations. Seals have been observed

swimming within airgun bubbles, 10 m (33 ft) away from active arrays

and, more recently, Canadian scientists, who were using a high-

frequency seismic system that produced sound closer to pinniped hearing

than will the USGS airgun array, describe how seals frequently

approached close to the seismic source, presumably out of curiosity.

Therefore, because the seismic survey could be severely hampered by

delays, because turning across marine traffic lanes to resume work

after a shutdown will be risky and costly, and because pinnipeds

indicate no reaction to seismic noise, the above-mentioned mitigation

plan has been proposed. Instead, the USGS will gather information on

how often pinnipeds approach the airgun array on their own volition,

and what effect the airguns appear to have on them.

(6) To ensure no marine mammals are inadvertently harmed, when data

collection first begins, or resumes, after operations have ceased, the

airguns will be turned on sequentially at a rate no greater than 6 dB/

minute, so that peak power is achieved gradually to give marine mammals

a chance to move away from the source.

(7) During seismic survey operations, the ship's speed will be 4 to

5 knots so that when the airguns are being discharged, nearby marine

mammals will have gradual warning of the ship's approach and can move

away.

(8) The USGS plans to have marine biologists onboard the seismic

vessel who will have the authority to stop airgun operations when a

mammal enters the safety zone. These observers will monitor the safety

zone to ensure no marine mammals enter the zone, and record

observations on marine mammal abundance and behavior.

(9) Emergency shut-down. If observations are made that one or more

marine mammals of any species are attempting to beach themselves when

the seismic source is operating in the vicinity of the beaching, the

airgun array will be immediately shut off and NMFS contacted.

(10) Upon notification by a local stranding network that a marine

mammal has been found dead within the waters of Puget Sound, the San

Juan Archipelago, or the Straits of Juan de Fuca when the array is

operating within

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that body of water, NMFS will investigate the stranding to determine

whether a reasonable chance exists that the SHIPS project caused the

animal's death. If NMFS determines, based upon a necropsy of the

animal(s), that the death was likely due to the seismic source, the

survey must cease until procedures are altered to eliminate the

potential for future deaths.

Monitoring

The objectives of the proposed monitoring program will be: To

mitigate potential harassment of marine mammals, to document the number

of animals of each species present in the vicinity of the sound

transmissions, and to evaluate the reactions of marine mammals to these

transmissions. In addition, hydrophones will be used to measure sound

levels, to correlate mammal behavior with actual, received sound

levels. Focused surveys will be conducted in geographic areas of

particular concern, especially for gray whales that migrate past the

western entrance to the Straits of Juan de Fuca and other members of

this species that spend the summer in the survey area (near south

Whidbey Island and the Straits of Juan de Fuca), humpback whales near

Swiftsure Bank and the waters west of the Straits, harbor porpoise that

tend to congregate along western Whidbey Island and elsewhere, and

minke whales that frequent shallow banks in the Strait of Juan de Fuca.

All species of large whales (humpback, gray, minke, or killer whales)

will be photographed to identify the individual using the area.

It should be recognized that, at this time, the monitoring program

is unfunded and therefore may need to be modified in the future.

However, in order for an IHA to be issued, monitoring will need to be

conducted at a level which ensures that the activity will have no more

than a negligible impact on marine mammal species or stocks.

Reporting

The USGS will provide an initial report to NMFS within 90 days of

the completion of the 1998 phase of the marine seismic project. This

report will provide dates and locations of seismic operations, details

of marine mammal sightings, and estimates of the amount and nature of

all takes by harassment. A final technical report will be provided by

USGS within 1 year of completion of the 1998 phase of the Puget Sound

marine seismic project. The final technical report will contain a

description of the methods, results, and interpretation of all

monitoring tasks.

Consultation

Under section 7 of the Endangered Species Act, NMFS has begun

consultation on the proposed issuance of an incidental harassment

authorization. Consultation will be concluded upon completion of the

comment period and consideration of those comments in the final

determination on issuance of an authorization.

National Environmental Policy Act

In conjunction with this notice, NMFS has released a draft EA that

addresses the impacts on the human environment from issuance of the

authorization and the alternatives to the proposed action. A copy of

the draft EA is available upon request (see ADDRESSES).

Conclusions

NMFS has preliminarily determined that the short-term impact of

conducting deep crustal marine seismic surveys will result, at worst,

in a temporary modification in behavior by certain species of

pinnipeds, and possibly some individual cetaceans. While behavioral

modifications may be made by certain species of marine mammals to avoid

the resultant noise from airgun arrays, this behavioral change is

expected to have a negligible impact on the animals.

In addition, no take by injury and/or death is anticipated and

takes will be at the lowest level practicable due to incorporation of

the mitigation measures mentioned above. No known rookeries, mating

grounds, areas of concentrated feeding, or other areas of special

significance for marine mammals occur within or near the planned area

of operations during the season of operations.

Proposed Authorization

NMFS proposes to issue an incidental harassment authorization to

the USGS for the possible harassment of small numbers of several

species of marine mammals incidental to collecting deep-crustal marine

seismic data in the Puget Sound/Straits of Juan de Fuca region of

Washington State, provided the above-mentioned mitigation, monitoring,

and reporting requirements are incorporated. NMFS has preliminarily

determined that the proposed activities would result in the harassment

of only small numbers of each of several species of marine mammals and

will have no more than a negligible impact on these marine mammal

stocks.

Information Solicited

NMFS requests interested persons to submit comments, information,

and suggestions concerning this request (see ADDRESSES).

Dated: September 11, 1997.

Hilda Diaz-Soltero,

Director, Office of Protected Resources, National Marine Fisheries

Service.

[FR Doc. 97-24674 Filed 9-16-97; 8:45 am]

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