Small Takes of Marine Mammals Incidental to Specified Activities; Haro Strait Oceanographic Experiment; Additional Information

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 032296A]

Small Takes of Marine Mammals Incidental to Specified Activities;

Haro Strait Oceanographic Experiment; Additional Information

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

Atmospheric Administration (NOAA), Commerce.

ACTION: Notice of proposed authorization for a small take exemption;

request for comment.

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SUMMARY: On March 28, 1995, NMFS published a notice of a proposed

authorization for a small take exemption. The notice did not include

information provided in the application that described the mitigation

measures that the applicant planned to undertake to reduce the

incidental harassment of those marine mammals found within the activity

area. That information is herewith provided.

DATES: Comments and information must be received on or before April 29,

1996.

ADDRESSES: Comments on the application should be addressed to Chief,

Marine Mammal Division, Office of Protected Resources, National Marine

Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-

3225. A copy of the application and other documents mentioned in the

March 28, 1996, notice may be obtained by writing to this address or by

telephoning one of the contacts listed below.

FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead, Office of

Protected Resources at 301-713-2055, or Brent Norberg, Northwest

Regional Office at 206-526-6733.

SUPPLEMENTARY INFORMATION:

For information on the application for an incidental harassment

authorization under section 101(a)(5)(D) of the Marine Mammal

Protection Act and the proposal by NMFS to issue an authorization to

take small numbers of marine mammals by harassment incidental to

conducting a physical oceanography experiment that uses sound to study

the flow field and mixing processes in Haro Strait, Puget Sound, WA,

please refer to the earlier notice (61 FR 13847, March 28, 1996).

Pre-Experiment Mitigation Measures

Mitigation measures that have already been undertaken include: (1)

Developing and incorporating a ramp-up of sound sources A and C over

0.25 sec; (2) incorporating a coded sequence mechanism for shutting off

source D; (3) hardwiring the maximum output of source A down from 185

dB (re 1Pa) to 170 dB @ 1 m. and (4) developing a protocol for

shutting down sources upon the approach of killer whales in order to

use the vertical arrays to record and analyze their sounds.

Mitigation Measures

In order for the experiment to have the least practicable impact on

marine mammals, the applicant has incorporated the following protocols

for mitigation: (1) A scientific oversight review committee consisting

of marine mammal scientists operating in the experimental area; (2)

statistical criteria for determination for review of impacts to harbor

porpoise and killer whales by the oversight committee; and (3)

procedures for emergency shutdown whenever necessary.

Mitigation Measures Established for Harbor Porpoise

There is a risk that the sound sources may displace harbor porpoise

from important habitat on the western side of Haro Strait, Puget Sound,

WA. A shore station on Sidney Island will be used to estimate the

occurrence, abundance and distribution of harbor porpoise in this

habitat. The monitoring plan will provide a baseline data set of

sufficient sample size to detect a large drop in harbor porpoise

abundance.

Sighting data will be collected for the first 4 days of the

experiment. At the end of this period, and daily thereafter, these

sighting data will be analyzed and exposure sightings will be compared

with baseline data. A drop in exposure sightings will trigger a

mitigation review by the oversight committee. If the committee

concludes that there is a likelihood that harbor porpoise will be taken

(through habitat exclusion or by injury), the experiment will be

stopped for 2 or 3 days to allow the ecosystem to recover. After 2 to 3

days, the

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experiment will be allowed to resume for an additional 4 days. If the

observed effects are noted in the next four-day period, the committee

will consider the new data and will again reach a conclusion on the

impact to individual harbor porpoise or on the stock. The committee may

either recommend stopping the experiment permanently or for a 2- to 3-

day period as before.

If the committee concludes that there is no likelihood that harbor

porpoise will be injured, the experiment will be allowed to continue

for 4 more days, with a new collection of sightings data. If abundance

is still significantly below baseline with a confidence level of 99

percent, the committee will again review the data as before. This data

collection, analysis and possible review by the committee will continue

throughout the experiment.

Mitigation Measures Established for Killer Whales

The applicant will monitor killer whale behavior in the area of the

experiment using the Speiden Island shore station, by boat and by

hydrophone. Monitoring, which will begin approximately 25 days prior to

the start of the experiment, will include the travel behavior of the

killer whales as they approach the area of the experiment. Using both

base-line and historical data, a measure of the probability that a

given pod of killer whales will travel through the area will be made.

After the experiment has run for several days, if the applicant

determines that the probability of any given pod of killer whales

passing Turn Point on Stuart Island drops to zero for four approaches

to the 80 percent turn-around point (the location where 80 percent of

the time killer whale pods reverse direction), the scientific committee

will review the data. The committee will review the collected travel

and behavioral data and information from other locations to determine

if there is a likelihood that killer whales will be injured by the

change in behavior caused by the sound sources. If they determine that

injury is likely, the sources will be turned off whenever killer whales

are observed to approach and remain within 1 km of the study area's

zone of responsiveness for killer whales.

If the committee determines that there is no likelihood of injury

to killer whales, the experiment will be allowed to continue for four

additional approaches to the study area. A probability of zero for

these approaches will again trigger the review described above.

Emergency Shut-off Mitigation Measure

If observations are made that (1) one or more marine mammals are

attempting to beach themselves when the sound sources are operating;

and/or (2) either a marine mammal listed as endangered or threatened

under the Endangered Species Act, or a marine mammal for which an

incidental harassment authorization has not been issued, approaches the

sources, the sound sources will be immediately shut off. The protocol

for this mitigation measure is described in detail in the application

and need not be repeated here.

Dead Marine Mammals

Upon notification by a local stranding network that a marine mammal

has been found dead within the waters of the San Juan Archipelago, the

committee will investigate the stranding to determine whether a

reasonable chance exists that the experiment caused the animal's death.

If the committee determines that there is a reasonable chance that the

death was due to the sound sources, the experiment will be stopped

until completion of the necropsy. The necropsy results will be reviewed

by the scientific oversight committee. If that committee determines

that the death was likely due to the sound sources, the experiment will

be turned off and will not resume until the sound sources are altered

in some way to eliminate the potential for future deaths. In addition,

because a section 101(a)(5)(D) authorization, if issued, does not

authorize taking by death, consultation with NMFS will be necessary

before restarting the experiment.

Dated: April 3, 1996.

Patricia A. Montanio,

Deputy Director, Office of Protected Resources, National Marine

Fisheries Service.

[FR Doc. 96-8705 Filed 4-8-96; 8:45 am]

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