[Federal Register Volume 64, Number 204 (Friday, October 22, 1999)]
[Proposed Rules]
[Pages 57026-57029]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-27579]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 216

[Docket No. 990927266-9266-01; I.D. 072699A]
RIN 0648-AM62


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Navy Operations of Surveillance Towed Array Sensor System 
Low Frequency Active Sonar

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

ACTION: Advance Notice of Proposed Rulemaking; request for comment and 
information.

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SUMMARY: NMFS has received a request for a Letter of Authorization 
(LOA) from the U.S. Navy for the take of small numbers of marine 
mammals by harassment incidental to Navy operations of Surveillance 
Towed Array Sensor System (SURTASS) Low Frequency Active (LFA) Sonar. 
In order to issue an LOA, NMFS must promulgate regulations and 
determine that these takings will have a negligible impact on the 
affected species and stocks of marine mammals and will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses. NMFS invites comment on the application, 
and suggestions on the content of the regulations.

DATES: Comments and information must be postmarked no later than 
November 22, 1999.

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 may be obtained by writing to 
this address or by telephoning one of the contacts listed here (see FOR 
FURTHER INFORMATION CONTACT). A copy of the draft environmental impact 
statement (DEIS) for SURTASS LFA sonar may be obtained by contacting 
Mr. J.S. Johnson, SURTASS-LFA Sonar Program Manager, 901 North Stewart 
Street, Suit 708, Arlington, VA 22203. Comments on the DEIS will be 
accepted at this address until October 28, 1999.

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 (MMPA) (16 
U.S.C. 1361 et seq.) directs the Secretary of Commerce (Secretary) 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 regulations are issued.
    Permission may be granted for periods of 5 years or less if the 
Secretary finds that the taking will have a negligible impact on the 
species or stock(s) of affected marine mammals, will not have an 
unmitigable adverse impact on the availability of the species or 
stock(s) for subsistence uses, and 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 August 12, 1999, NMFS received an application from the U.S. Navy 
requesting a small take exemption under section 101(a)(5)(A) of the 
MMPA for the taking of marine mammals by harassment incidental to 
operation of the SURTASS LFA sonar for a period of time not to exceed 5 
years, beginning in FY 2000. SURTASS LFA sonar will operate a maximum 
of 4 ship systems in the ten geographic operating regions in which 
SURTASS LFA sonar could potentially operate. There would be a maximum 
of four SURTASS LFA sonar systems with a nominal maximum of two systems 
at sea at any one time.

Description of the Activity

    The SURTASS LFA sonar system is a long-range, low frequency 
(between 100 and 500 Hertz) sonar that has both active and passive 
components. It does not rely on detection of noise generated by the 
target. The active component of the system is a set of low frequency 
(LF) acoustic transmitting source elements (called projectors) 
suspended from a cable from underneath a ship. The projectors are 
devices that produce the active sound or pulse.
    The typical SURTASS LFA sonar signal is not a constant tone, but 
rather a transmission of various waveforms that vary in frequency and 
duration. A complete sequence of sound transmissions is referred to as 
a ``ping'' and can last for as short as 6 seconds (sec) to as long as 
100 sec. The time between pings is typically from 6 to 15 minutes. 
Average duty cycle (ratio of sound ``on'' time to total time) can be 
controlled but is less than 20 percent; typical duty cycle is between 
10 and 20 percent.
    The passive or listening component of the system is SURTASS, which 
detects returning echoes from submerged objects, such as submarines, 
through the use of hydrophones. The hydrophones are mounted on a 
horizontal array that is towed behind the ship. The SURTASS LFA sonar 
ship maintains a minimum speed of 5.6 km/hr (3.0 knots).
    The Navy anticipates that a nominal, or typical SURTASS LFA sonar 
deployment schedule for a single vessel would involve about 270 days/
year at sea (underway). A typical at-sea mission would occur over a 30-
day period, made up of two 9-day exercise segments. Active sonar 
operations could be conducted up to 20 hrs during an exercise day, 
although the system would actually be transmitting for only a

[[Page 57027]]

maximum of 4 hrs/day (resulting in 432 hrs of active transmission time 
per year for each SURTASS LFA sonar system in operation based on a 
maximum duty cycle of 20 percent). The remaining 12 days of the at-sea 
mission would be spent in transit or repositioning the vessel. In a 
nominal year there could be a maximum of 9 missions, six of which would 
involve the employment of SURTASS LFA sonar in the active mode and 
three of which would employ the SURTASS LFA sonar in the passive mode. 
Between missions, an estimated 95 days would be spent in port for 
upkeep and repair. With two vessels in the Pacific-Indian Ocean area 
and two vessels in the Atlantic Ocean-Mediterranean Sea area, there 
could be up to 12 operations in each area per year.
    At present, only one SURTASS LFA sonar system is operational. A 
second SURTASS LFA sonar system is expected to be operational in FY 
2000. The third and fourth systems are tentatively planned for FY 2003 
and FY 2004, but their delivery may be postponed until after FY 2005. 
With 4 systems, a nominal maximum of two vessels would be at sea at any 
one time. As a result, under 5-year regulations NMFS would propose to 
authorize marine mammal harassment takings for 2 SURTASS LFA sonar 
vessels for FY 2000 through FY 2002, 3 vessels for FY 2003, and 4 
vessels for FY 2004.

Affected Marine Mammal Species

    In their DEIS analysis and small take application, the Navy 
excluded from take consideration those marine mammal species that 
either do not inhabit the areas wherein SURTASS LFA sonar would operate 
or do not possess sensory mechanisms that allow the mammal to perceive 
low frequency (LF) sounds. Where data was not available or was 
insufficient for one species, comparable data for a related species was 
used, if available. Because all species of baleen whales produce LF 
sounds, and anatomical evidence strongly suggests that their inner ears 
are well adapted for LF hearing, all species are considered sensitive 
to LF sound and at risk from exposure to LF sounds. The ten species of 
baleen whales that may be affected by SURTASS LFA sonar are: blue 
(Balaenoptera musculus), fin (Balaenoptera physalus), minke 
(Balaenoptera acutorostrata), Bryde's (Balaenoptera borealis), sei 
(Balaenoptera borealis), humpback (Megaptera novaeangliae), northern 
right (Eubalaena glacialis), southern right (Eubalaena australis), 
pygmy right (Capera marginata), and gray whales (Eschrichtius 
robustus).
    The odontocetes (toothed whales) that may be affected because they 
inhabit the deeper, offshore waters where SURTASS LFA sonar might 
operate include both the pelagic (oceanic) whales and dolphins and 
those coastal species that also occur in deep water including Stenella 
spp., Risso's dolphin (Grampus griseus), rough-toothed dolphin (Steno 
bredanensis), Fraser's dolphin (Lagenodelphis hosei), right-whale 
dolphin (Lissodelphis spp.), Lagenorhynchus spp., Cephalorhynchus spp., 
bottlenose dolphin (Tursiops truncatus), common dolphin (Delphinus 
delphis), Dall's porpoise (Phocoenoides dalli), melon-headed whale 
(Peponocephala spp.), beaked whales (Berardius spp., Hyperoodon spp., 
Mesoplodon spp., Cuvier's beaked whale (Ziphius cavirostris), Shepard's 
beaked whale (Tasmacetus shepherdi), Longman's beaked whale 
(Indopacetus pacificus), killer whale (Orcinus orca), false killer 
whale (Pseudorca crassidens), pygmy killer whale (Feresa attenuata), 
sperm whale (Physeter macrocephalus, Kogia spp.), and pilot whale 
(Globicephala spp.).
    Potentially affected pinnipeds include: 8 phocid (true seal) 
species including, the Hawaiian and Mediterranean monk seals (Monachus 
spp.), harbor seals (Phoca spp), and elephant seals (Mirounga spp.); 8 
species of fur seals (Arctocephalus spp., Callorhinus ursinus); and 5 
species of sea lions, including the Steller sea lion (Eumetopias 
jubatus) and California sea lion (Zalophus californianus).
    A description of affected marine mammal species and the criteria 
used to determine those species that have the potential for taking by 
harassment are provided and explained in detail in the Navy application 
and DEIS and need not be repeated here.

Impacts to Marine Mammals

    The analysis of potential impacts on marine mammals was developed 
by the Navy based on the results of a literature review, the Navy's LF 
Sound Scientific Research Program (LFS SRP), and a complex, 
comprehensive program of underwater acoustical modeling. To assess 
potential impact of the SURTASS LFA sonar source on marine mammals 
operating at a given site, it was necessary for the Navy 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 total acoustic exposure for each animal in the modeled population, 
(4) converting 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) converting 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 received level (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 LFS SRP results, the acoustical modeling, and 
the risk assessment, provide an estimate of potential environmental 
impacts to marine mammals.
    The acoustical modeling process was accomplished using the 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 to 
estimate mammal sound exposures and essentially integrates simulated 
movements (including dive patterns) of marine mammals, a schedule of 
SURTASS LFA sonar transmissions, and the predicted sound field for each 
transmission to estimate acoustic exposure during a hypothetical 
SURTASS LFA sonar operation. Description of the PE and AIM models, 
including AIM input parameters for animal movement, diving behavior, 
and marine mammal distribution, abundance, and density are described in 
detail in the Navy application and the DEIS and are not discussed 
further in this document.
    Using the AIM model, the Navy developed 31 acoustic modeling 
scenarios for the major ocean regions (which are described in the 
application and DEIS). Locations were carefully selected to represent 
reasonable ``worst case'' scenarios for each of the three major ocean 
acoustic regimes where SURTASS LFA sonar would be employed. These 
acoustic regimes were (1) deep-water convergence propagation zone, (2) 
near surface duct propagation zone, and (3) shallow water bottom 
interaction propagation zone. These scenarios represent the condition 
under

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which, on average, the greatest number of animals could be exposed to 
the greatest number of pings at the highest RLs and were considered the 
most severe conditions that could be expected from operation of the 
SURTASS LFA sonar system. Thus, if SURTASS LFA sonar operations were 
conducted in an area that was not acoustically modeled, the potential 
effects would almost certainly be less than those obtained from the 
most similar scenario in the analysis.

Risk Analysis

    The Navy interprets the results of the LFS SRP to justify use of 
unlimited exposure during a mission to 120 dB as the lowest value for 
risk. Below this level, there is no risk of prolonged biologically 
significant responses from marine mammals. It is important to note that 
risk varies with both level and number of exposures.
    The Navy calculated the risks for take by injury based on criteria 
of 180 dB RL, which is a conservative value for the onset of a minor 
temporary threshold (TTS) shift in hearing (see Ridgway et al. (1997)). 
Ridgway et al.'s (1997) measurement at one second duration implies that 
the TTS threshold for a 100-second signal lies between 182 and 172 dB, 
depending upon the formula used. The Navy believes that the 180-dB 
single ping criterion can be considered conservative. However, the RL 
for serious injury would be much higher, and the marine mammal would 
have to be much closer to the array than the 2 km (1.1 nm) radius 
around the vertical array delineating the 180 dB sound field. With 
three levels of mitigation monitoring for marine mammals (described 
later in this document), it is unlikely that any marine mammal would 
get that close before either turning away from the annoyance, or being 
detected and the SURTASS LFA sonar shut down (see Mitigation). However, 
because the probability is not zero, the Navy has included this 
scenario in its authorization request.

Mitigation and Monitoring

    SURTASS LFA sonar operations would be conducted to ensure that the 
sound field does not exceed 180 dB re 1 Parms 
(i.e., the zone of potential injury for marine mammals) within 22 km 
(12 nm) of any coastline, nor in offshore biologically important areas 
that are outside the 22 km (12 nm) zone during the biologically 
important season(s) for that particular area.
    SURTASS LFA sonar operators would estimate sound pressure levels 
prior to and during operations to provide the information necessary to 
modify operations, including delay or suspension of transmissions, in 
order not to exceed the sound field criteria. Please refer to the 
Navy's application for the criteria used to determine biologically 
important areas.
    In order to minimize risks to potentially affected marine mammals 
that may be present in waters surrounding SURTASS LFA sonar, the Navy 
will: (1) Conduct visual monitoring from the ship's bridge during 
daylight hours, (2) use passive (LF) SURTASS LFA sonar to listen for 
vocalizing marine mammals; and (3) use high frequency (HF) active sonar 
(i.e., commercial fish finder) to monitor/locate/track marine mammals 
in relation to the SURTASS LFA sonar vessel and the sound field 
produced by the SURTASS LFA sonar source array.
    Through observation, acoustic tracking and establishment of shut-
down criteria, the Navy will ensure that no marine mammals approach the 
SURTASS LFA sonar source close enough to be subjected to potentially 
harmful sound levels (inside the 180 dB re 1 Parms 
sound field; approximately 2 km (1.1 nm) from the source). The Navy 
estimates that the probability of detecting a marine mammal within the 
180 dB sound field of the source array by at least one of these 
monitoring methods is estimated to be between 70 and 99 percent. 
However, nominally, an effectiveness of 80 percent is used in the take 
calculations. This assumption incorporates the 70 percent effectiveness 
of the HF sonar, and an additional conservative 5- percent contribution 
each for visual and passive monitoring. In general, small, solitary 
marine mammals would be the most difficult to detect, while large 
whales and dolphin schools would be much easier to detect.

Reporting

    During routine operations of SURTASS LFA sonar, technical and 
environmental data would be collected and recorded. These would include 
data from visual and acoustic monitoring, ocean environmental 
measurements, and technical operational inputs. This information would 
become part of the data required from the Long Term Monitoring (LTM) 
Program.

Research

    The Navy proposes to provide a LTM program to conduct annual 
assessments of the potential cumulative impact of SURTASS LFA sonar 
operations on the marine environment, provide the necessary reporting 
to increase knowledge of the species, and to coordinate research 
opportunities and activities. This would include cumulative impact 
analyses of the annually tabulated injuries (if any) and harassments 
over the next 5 years.
    While research conducted to date is sufficient to assess impacts on 
marine mammals, it is prudent to continue research over the course of 
the first 5 years of the Navy's operations of SURTASS LFA sonar.
    The purpose of the LTM program would be to continue scientific data 
collection once SURTASS LFA sonar is deployed.

Conclusions

    Based on the scientific analyses detailed in the Navy application 
and further supported by the DEIS for SURTASS LFA sonar operations, the 
Navy concludes that the incidental taking of marine mammals resulting 
from SURTASS LFA sonar operations would be small and have no more than 
a negligible impact on the affected marine mammal stocks or habitats. 
This conclusion is particularly supported by the proposed mitigation 
measures that would be implemented for all SURTASS LFA sonar operations 
and the proposed LTM program. The former includes geographic 
restrictions, monitoring and reporting that would result in increased 
knowledge of marine mammal species. The latter offers means of learning 
of, encouraging, and coordinating research opportunities, plans, and 
activities relating to reducing the incidental taking of marine mammals 
from anthropogenic underwater sound, and evaluating the possible long-
term effects from exposing marine mammals to anthropogenic underwater 
sound.

Information Solicited

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning the Navy's request for a single LOA valid 
for SURTASS LFA sonar operations in all 10 biogeographic regions, and 
the structure and content of the regulations to allow takings by LFA 
sonar operations. NMFS would propose a single set of regulations, 
effective for a period of time up to 5 years, that would govern 
incidental takings for LFA sonar operations. All commenters are 
requested to review the DEIS and/or the application prior to submitting 
comments and, because of its brevity, not submit comments solely on 
this Federal Register document.
    NMFS is also requesting comment on an alternative proposal to issue 
annual LOAs to each vessel as it becomes operational. Based upon 
applications for annual LOAs, individual vessel LOAs

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may specify which of the 10 operating areas were scheduled for the 
upcoming year. For security reasons, locations and times for certain 
operations may be classified and not provided to the public.
    If NMFS proposes regulations governing the taking, interested 
parties will be provided a 45-day comment period on the content of the 
proposed rule.
    This action has been determined to be not significant for purposes 
of Executive Order 12866.

    Dated: October 15, 1999.
Andrew A. Rosenberg,
Deputy Assistant Administrator for Fisheries, National Marine Fisheries 
Service.
[FR Doc. 99-27579 Filed 10-21-99; 8:45 am]
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