[Federal Register Volume 65, Number 165 (Thursday, August 24, 2000)]
[Proposed Rules]
[Pages 51584-51587]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-21679]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 216

[Docket No. 000801223-0223-01; I.D. 062000A]
RIN 0648-AO24


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Operation of a Low Frequency Sound Source by the North 
Pacific Acoustic Laboratory

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Advance notice of proposed rulemaking; receipt of an 
application for a small take exemption; request for comment and 
information.

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SUMMARY: NMFS has received a request from the University of California 
San Diego, Scripps Institution of Oceanography (Scripps), for a small 
take of marine mammals incidental to the continued operation of a low 
frequency (LF) sound source previously installed off the north shore of 
Kauai by the Acoustic Thermometry of Ocean Climate (ATOC) project. As a 
result of that request, NMFS is considering whether to propose 
regulations that would authorize the incidental taking of a small 
number of marine mammals. In order to issue regulations for this 
taking, NMFS must determine that this taking will have no more than a 
negligible impact on the affected species and stocks of marine mammals. 
NMFS invites comment on the application and suggestions on the content 
of the regulations.

DATES: Comments and information must be postmarked no later than 
September 25, 2000. Comments will not be accepted if submitted via e-
mail or the Internet.

ADDRESSES: Comments should be addressed to Donna Wieting, Chief, Marine 
Mammal Conservation Division, Office of Protected Resources, National 
Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 
20910-3226. A copy of the application, which contains the references 
used in this document, may be obtained by writing to this address, or 
by telephoning the contact listed here (see FOR FURTHER INFORMATION 
CONTACT). A copy of the draft environmental impact statement (DEIS) may 
be obtained from Marine Acoustics Inc., 809 Aquidneck Ave., Middletown, 
RI 02842, attn. Kathy Vigness Reposa, 401-847-7508.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead (301) 713-
2055, ext. 128.

SUPPLEMENTARY INFORMATION:

Background

    Section 101(a)(5)(A) of the Marine Mammal Protection Act (16 U.S.C. 
1361 et seq.) (MMPA) directs the Secretary of Commerce (Secretary) to 
allow, upon request, the incidental, but not intentional taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and regulations are 
issued.
    Permission may be granted for periods of 5 years or less if the 
Secretary finds that the taking will be small, will have no more than a 
negligible impact on the species or stock(s), and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for Arctic Ocean subsistence uses, and if regulations are 
prescribed setting forth the permissible methods of taking and the 
requirements pertaining to the monitoring and reporting of such taking.

Summary of Request

    On May 21, 2000, NMFS received an application for an incidental, 
small take authorization under section 101(a)(5)(A) of the MMPA from 
Scripps to take marine mammals incidental to the continued operation of 
a LF sound source previously installed off the north shore of Kauai by 
the ATOC project. An alternative source location under consideration in 
the DEIS and here is for Midway Island. A final decision on whether to 
re-use the ATOC source (or to install a new source and cable at 
Midway), in order to combine a second phase of research on the 
feasibility and value of large-scale acoustic thermometry with long 
range underwater sound transmission studies and marine mammal 
monitoring and studies will be made based, in part, on findings and 
determinations made under the National Environmental Policy Act (NEPA). 
As the principal funding agency for the proposed action, a DEIS has 
been prepared by the Office of Naval Research (ONR). NMFS is a

[[Page 51585]]

cooperating agency in the preparation of this DEIS.

Project Description

    Acoustic thermometry is a method for obtaining information about 
the temperature field in the ocean from precise measurements of the 
travel times of sound pulses transmitted through the ocean. It is also 
a technique for acoustic remote sensing of the ocean interior, in which 
the properties of the ocean between the acoustic sources and receivers 
are determined, rather than the properties of the ocean at the 
instruments as is the case for conventional thermometers and current 
meters. Acoustic thermometry in the ocean is closely related to 
seismology, in which properties of the Earth's interior are inferred 
from travel times of earthquake waves.
    Under the proposed action, the seabed power cable and sound source 
from the ATOC project would remain in their present locations on Kauai, 
and transmissions would continue with approximately the same signal 
parameters and transmission schedule used in the earlier ATOC project. 
The typical schedule consists of six 20-minute (min) transmissions (one 
every 4 hours), every fourth day, with each transmission preceded by a 
5-min ramp-up period during which the signal intensity was gradually 
increased, representing an average duty cycle of 2 percent. With the 
possible exception of short duration testing with duty cycles of up to 
8 percent, or equipment failure, this schedule would continue for a 
period of 5 years. The signals transmitted by the source would have a 
center frequency of 75 Hertz (Hz) and a bandwidth of approximately 35 
Hz (i.e., sound transmissions are in the frequency band of 57.5-92.5 
Hz). Approximately 260 watts of acoustic power would be radiated during 
transmission. At 1 meter (m)(33 feet (ft)) from the source (at 807 m 
(2,648 ft) water depth at the Kauai location), sound intensity (i.e., 
source level) would be about 195 decibels (dB) referenced to the 
intensity of a signal with a sound pressure level (SPL) of 1 
microPascal (1 Pa). According to Scripps, the signal 
parameters and source level have been found in the ATOC project to 
provide adequate, but not excessive, signal-to-noise ratios in the 
receiver ranges of interest.
    While the proposed action involves the continued operation of the 
source installed at the Kauai, HI location, an alternative location 
under consideration in the ONR DEIS would be installing a sound source 
and cable at a location off the coast of Midway Island.

Marine Mammals

    A summary of the marine mammal species that may potentially be 
found in the vicinity of the ATOC source at either Kauai or Midway is 
presented here. For more detail on marine mammal abundance, density and 
the methods used to obtain this information, reviewers are requested to 
refer to the ONR DEIS. For general information on North Pacific Ocean 
marine mammals, reviewers may refer to Barlow et al. (1997).
    Six species of baleen whales, humpback (Megaptera novaengliae), fin 
Balaenoptera physalus), blue B. musculus), Bryde'sB. borealis), minke 
(B. acutorostrata), and right (Eubalaena glacialis) whales, may occur 
in the Kauai or Midway Atoll areas. Although not reported near Midway 
Atoll, the humpback whale is the only balaenopterid whale known to be 
present in reasonably large numbers. Humpback whales are considered 
abundant in coastal waters of the main Hawaiian Islands from November 
through April. Fin whales and blue whales have the potential to occur 
in the area; however, their distribution and abundance in the region is 
believed to be uncommon (Balcomb, 1987), although only a single fin 
whale was observed during recent ATOC marine mammal research. Right 
whales in the North Pacific Ocean are extremely rare and therefore, 
would also be rare in the Hawaiian Islands. Bryde's whales, and minke 
whales may be occasionally seen in the area of Midway Atoll 
(Leatherwood et al., 1988), but are not usually found off Kauai.
    Sixteen species of odontocetes (toothed whales, dolphins and 
porpoises) may be found in the Kauai and Midway areas. These species 
are sperm whales (Physeter macrocephalus), short-finned pilot whales 
(Globicephala macrorhynchus), beaked whales (Ziphius cavirostris, 
Berardius bairdi, and Mesoplodon spp.), spinner dolphins (Stenella 
longirostris), spotted dolphin (Stenella attenuata), striped dolphin 
(Stenella coeruleoalba), bottlenose dolphins (Tursiops truncatus), 
rough-toothed dolphin (Steno bredanensis), pygmy sperm whale (Kogia 
breviceps), dwarf sperm whale (Kogia simus), killer whales (Orcinus 
orca), false killer whale (Pseudorca crassidens), pygmy killer whale 
(Feresa attenuata), and melon-headed whale (Peponocephala electra). It 
should be noted, however, that the latter 7 species were not sighted in 
or near the proposed Kauai area during marine mammal surveys conducted 
between 1993 and 1998.
    The Hawaiian monk seal (Monachus schauinslandi) occurs in the area 
of the Leeward Hawaiian Islands.

Potential Impacts on Marine Mammals

    The effects of underwater noise on marine mammals are highly 
variable, and can be categorized as follows (based on Richardson et 
al., 1995): (1) The noise may be too weak to be heard at the location 
of the animal (i.e. lower than the prevailing ambient noise level, the 
hearing threshold of the animal at relevant frequencies, or both); (2) 
the noise may be audible but not strong enough to elicit any overt 
behavioral response; (3) the noise may elicit behavioral reactions of 
variable conspicuousness and variable relevance to the well being of 
the animal; these can range from subtle effects on respiration or other 
behaviors (detectable only by statistical analysis) to active avoidance 
reactions; (4) upon repeated exposure, animals may exhibit diminishing 
responsiveness (habituation), or disturbance effects may persist (the 
latter is most likely with sounds that are highly variable in 
characteristics, unpredictable in occurrence, and associated with 
situations that the animal perceives as a threat); (5) any man-made 
noise that is strong enough to be heard has the potential to reduce 
(mask) the ability of marine mammals to hear natural sounds at similar 
frequencies, including calls from conspecifics and/or echolocation 
sounds, and environmental sounds such as ice or surf noise; and (6) 
very strong sounds have the potential to cause either a temporary or a 
permanent reduction in hearing sensitivity (referred to respectively as 
temporary threshold shift (TTS) or permanent threshold shift (PTS). Few 
data on the effects of non-explosive sounds on hearing thresholds of 
marine mammals have been obtained, however, in terrestrial mammals, and 
presumably in marine mammals, received sound levels must far exceed the 
animal's hearing threshold for there to be any TTS. Received levels 
must be even higher for there to be risk of PTS.
    For this project, Scripps has established the threshold for risk of 
harm as a single ping at 180 dB re 1 Parms (180 
dB). Harm is defined in this context as onset TTS, or the lower end of 
Level A harassment. Although recently some scientists have questioned 
whether TTS is actually an injury (see Navy, 1999, Appendix E-1, 
Criteria for Marine Mammal Auditory Shift), in this action, TTS is 
being categorized as the onset for a Level A harassment take. In this 
proposed action, a marine mammal would have to receive one ping greater 
than, or equal

[[Page 51586]]

to 180 dB in order to be considered receiving a non-serious injury 
(Level A harassment) or many pings at a received level (RL) slightly 
lower than 180 dB in order to potentially incur a significant 
biological response (Level B harassment).
    In order to understand the biological significance of the risk of 
Level A or Level B harassment, it is necessary to determine how this 
risk might affect a population of marine mammals, starting with 
acoustic criteria. First, the marine mammal must be able to hear LF 
sound. Second, the animal must incur a reaction to the LF sound that is 
more than momentary. Third, any effect from LF sound must involve a 
significant behavioral change in a biologically important activity, 
such as feeding, breeding, or migration, all of which are potentially 
important for reproductive success of the population.
    Based on California and Hawaii ATOC Marine Mammal Research Program 
(MMRP), Scripps found no overt or obvious short-term changes (1) in the 
abundance and distribution of marine mammals in response to the ATOC 
transmissions (intensive statistical analyses of aerial survey data 
showed some subtle shifts in distribution of humpback (and possibly 
sperm) whales away from the California site (Calambokidis et al., 1998) 
and humpback whales away from the Kauai site); (2) in the behavior of 
humpback whales or elephant seals in response to the playback of ATOC-
like sounds (intensive statistical analyses revealed some subtle 
changes in the behavior of humpback whales (Frankel and Clark, 1998; 
1999b); or (3) in the singing behavior of humpback whales in the 
vicinity of the Kauai ATOC sound source. Bioacoustic experts concluded 
that these subtle effects would not adversely affect the survival of an 
individual whale or the status of the North Pacific humpback whale 
population (Frankel and Clark, 1999a).
    To assess the potential environmental impact of the North Pacific 
Acoustic Laboratory (NPAL) sound source on marine mammals, it was 
necessary for Scripps to predict the sound field that a given marine 
mammal species could be exposed to over time. This is a multi-part 
process involving (1) the ability to measure or estimate an animal's 
location in space and time, (2) the ability to measure or estimate the 
three-dimensional sound field at these times and locations, (3) the 
integration of these two data sets to estimate the potential impact of 
the sound field on a specific animal in the modeled population, (4) the 
conversion of the resultant cumulative exposures for a modeled 
population into an estimate of the risk from a prolonged disruption of 
a biologically important behavior, and (5) the conversion of these 
estimates of behavioral risk into an assessment of risk in terms of the 
level of potential biological removal.
    Next, a relationship for converting the resultant cumulative 
exposures for a modeled population into an estimate of the risk to the 
entire population of a prolonged disruption of a biologically important 
behavior and of injury was developed. This process assessed risk in 
relation to RL and repeated exposure. The resultant risk 
continuum is based on the assumption that the threshold of 
risk is variable and occurs over a range of conditions rather than at a 
single threshold.
    Taken together, the recent results on marine mammals from LF 
sounds, the acoustical modeling, and the risk assessment, provide an 
estimate of potential environmental impacts to marine mammals.
    The acoustical modeling process was accomplished by Scripps using 
the U.S. Navy's standard acoustical performance prediction transmission 
loss model-Parabolic Equation (PE) version 3.4. The results of this 
model are the primary input to the Acoustic Integration Model (AIM). 
AIM was used in this analysis to estimate mammal sound exposures and 
integrate simulated characteristics of marine mammals (e.g., species 
distribution, density, dive profiles, and general movement, NPAL sound 
transmissions (e.g., duty cycle, transmission length), and the 
predicted sound field for each transmission to estimate acoustic 
exposure during a typical NPAL source transmission. A description of 
the PE and AIM models (including AIM input parameters for animal 
movement, diving behavior, and marine mammal distribution, abundance, 
and density) and the risk continuum analysis are described in detail in 
the Scripps application and the ONR DEIS and are not discussed further 
in this document. At this time, NMFS recommends reviewers read these 
documents if additional information is desired. If NMFS proceeds with 
rulemaking on this action, that rulemaking document will discuss the 
risk continuum and estimates of affected marine mammal populations in 
greater detail.
    Scripps, however, has drawn some general conclusions from the 
relative abundance of various marine mammal species in relationship to 
the NPAL sound field. Under the proposed alternative (utilizing the 
ATOC sound source at Kauai), the only mysticete (baleen) whale species 
expected in the area in substantial numbers is the humpback whale, and 
Scripps believes that because they usually prefer nearshore locations 
(inside the 100-fathom (188 m) depth contour), few are expected to be 
exposed to received levels greater than 120 dB (i.e, the SPL level 
presumed by Scripps to be zero for marine mammals having the potential 
to incur a prolonged disturbance of biologically important behavior). 
Similarly, sperm whales are the most common deep-diving odontocete 
(toothed) whale in the area, but because they usually prefer offshore 
waters (i.e., water depths greater than 4,000 m (12,700 ft)), few are 
expected to be exposed to received levels greater than 120 dB. 
According to Scripps, these distributional preferences are supported by 
the Kauai ATOC MMRP (Mobley, 1999a).
    Using the risk continuum and acoustic modeling Scripps estimated 
the potential for biologically significant reactions by marine mammals 
under the proposed action. Scripps determined that only humpback whales 
that remain in the vicinity of the sound source for a full day of 
transmissions may potentially experience any effect from the source 
transmissions. However, humpback whales typically travel parallel to 
the coast of Kauai, and, therefore, Scripps believes, would probably 
not receive sound from more than a single transmission.
    At the Midway site, the mysticete whale expected in greatest 
abundance is the Bryde's whale. Because they usually prefer nearshore 
locations, Scripps expects few animals would be exposed to RLs greater 
than 120 dB. Similarly, sperm whales are the most common deep-diving 
odontocetes in the area, but because they usually prefer offshore 
waters (i.e., water depths greater than 4,000 m (12,700 ft)), few are 
expected to be exposed to received levels greater than 120 dB. A much 
higher abundance of Hawaiian monk seals is expected near Midway Island 
than Kauai since this species prefers the small, mostly uninhabited 
chain of islands and atolls northwest of the main Hawaiian Islands.
    Using the risk continuum and acoustic modeling Scripps determined 
that there would be no potential for biologically significant effects 
on marine mammals from source transmissions at Midway Island, although 
some subtle effects may occur.

Mitigation

    Scripps' proposed action includes mitigation that would minimize 
the potential effects of the NPAL sound source to marine mammals. 
First, the sound source would operate at the

[[Page 51587]]

minimum duty cycle necessary to support the large-scale acoustic 
thermometry and long-range propagation objectives. Transmissions would 
contiue with approximately the same transmission schedule as that used 
during the first feasibility phase of the ATOC study. Second, any 
increases in the duty cycle beyond the nominal 2 percent (with a 
maximum of 8 percent) would not occur during the peak humpback whale 
season (January-April). The proposed action includes the possibility of 
an 8-percent duty cycle for up to 2 months out of each year; this 
action, however, would not occur during the period of time humpback 
whales inhabit Hawaiian waters. Third, the sound source would operate 
at the minimum power level necessary to support large-scale acoustic 
thermometry and long-range sound transmission objectives. The fourth 
mitigation measure proposed is to ramp-up the NPAL sound source 
transmissions over a 5-min period. This is believed to reduce the 
potential for startling marine mammals in the vicinity of the NPAL 
sound source and provides them an opportunity to move away from the 
sound source before transmitting at the maximum power levels.

Monitoring and Reporting

    In an effort to understand the potential for long-term effects of 
man-made sound on marine mammals, Scripps proposes to monitor the 
distribution and abundance of marine mammals in the vicinity of the 
sound source, by conducting a total of 4 aerial surveys during each 
humpback whale season. The data collected will be compared with data 
collected during the Kauai ATOC Marine Mammal Research Program. Reports 
on the aerial survey results will be available to the public in 
reports. A report on activites will be provided to NMFS annually.

NEPA

    The ONR has released a DEIS under NEPA (see ADDRESSES). NMFS is a 
cooperating agency, as defined by the Council on Environmental Quality 
(40 CFR 1501.6), in the preparation of this DEIS.

Endangered Species Act (ESA)

    NMFS will be consulting with the ONR under section 7 of the ESA on 
this action. In that regard, the ONR has submitted to NMFS a Biological 
Assessment under the ESA. This consultation will be concluded prior to 
a determination on issuance of a final rule and exemption.

Classification

    This action has been determined to be not significant under 
Executive Order 12866.

Information Solicited

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning the request and the structure and content of 
the regulations to allow the taking. NMFS requests that commenters 
review the ONR DEIS and/or Scripps' small take application and not 
submit comments based solely on this document. NMFS will consider 
information submitted in developing proposed regulations to authorize 
the taking. If NMFS proposes regulations to allow this take, interested 
parties will be given ample time and opportunity to comment on the 
proposed rule.

    Dated: August 15, 2000.
Penelope D. Dalton,
Assistant Administrator for Fisheries, National Marine Fisheries 
Service.
[FR Doc. 00-21679 Filed 8-23-00; 8:45 am]
Billing Code: 3510-22-S