Marine mammals: Incidental taking; authorization letters, etc. Lamont-Doherty Earth Observatory; Mid-Atlantic Ocean; oceanographic surveys,
FR, November 10, 2003 › Notices › National Oceanic and Atmospheric Administration
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Federal Register: November 10, 2003 (Volume 68, Number 217)NoticesPage 63761-63768From the Federal Register Online via GPO Access [wais.access.gpo.gov]
DOCID:fr10no03-22
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
I.D. 080803CSmall Takes of Marine Mammals Incidental to Specified Activities; Oceanographic Surveys in the Mid-Atlantic Ocean
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION: Notice of issuance of an incidental harassment authorization.
SUMMARY: In accordance with provisions of the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that an Incidental Harassment Authorization (IHA) to take small numbers of marine mammals, by harassment, incidental to conducting oceanographic surveys in the Mid-Atlantic Ocean has been issued to Lamont-Doherty Earth Observatory (LDEO).
DATES: Effective from October 23, 2003 through October 22, 2004.
ADDRESSES: The application, a list of references used in this document, and/or the IHA are available by writing to P. Michael Payne, Chief, Marine Mammal Conservation Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225, or by telephoning the contact listed here.
FOR FURTHER INFORMATION CONTACT: Sarah C. Hagedorn, Office of Protected Resources, NMFS, (301) 713-2322, ext 117.
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 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, a 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) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses and that the permissible methods of taking and requirements pertaining to the 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.''
Subsection 101(a)(5)(D) of the MMPA 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. Under Section 3(18)(A), 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; 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.
The term ``Level A harassment'' means harassment described in subparagraph (A)(i). The term ``Level B harassment'' means harassment described in subparagraph (A)(ii).
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 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 21, 2003, NMFS received an application from LDEO for the taking,
[Page 63762]by harassment, of several species of marine mammals incidental to conducting a seismic survey program. As presently scheduled, two seismic surveys will be conducted in the Mid-Atlantic Ocean. The Trans- Atlantic Geotransect (TAG) cruise will be centered at 26[deg]N and 45[deg]W in the Mid-Atlantic Ocean during late October 2003, for a total of six days of seismic surveying. The Atlantic Deep Western Boundary Current (ADWBC) cruise will occur between 39[deg] and 42[deg]N and between 45[deg] and 52.5[deg]W, during July and August of 2004 for a total of approximately 20 days of surveying. These operations will take place in international waters.
The seismic survey work conducted during the TAG cruise is part of a multi-disciplinary experiment, taking place in the TAG Active Mound area over a period of nine months. The TAG active mound (26[deg]N on the Mid-Atlantic Ridge), which is one of the largest hydrothermal deposits found to date on the seafloor, is a large, focused mineral deposit on a slow-spreading ridge. The purpose of the TAG cruise is to delineate the nature, position, and size of any heat sources (low- velocity zones) that might drive convection at the TAG active mound, and more generally, to provide an understanding of crustal architecture in the TAG region. More specifically, the TAG experiment will address key issues at the TAG site: (1) the nature of the heat source driving circulation, (2) the relationship between faulting on the eastern flank and fluid flow at the mound, (3) the possible existence of a low- velocity zone beneath the rise axis, and (4) the hydraulic connectivity of the shallow TAG mound.
The ADWBC cruise will determine the configuration, age, and paleoceanographic significance of the sedimentary sequences on J Anomaly Ridge and Southeast Newfoundland Ridge, which may show evidence for strong boundary currents dating to the early Paleocene. Proposed tracklines for the seismic survey were chosen with four primary objectives in mind: (1) to map the main reflection sequences across the full extent of the ridges and onto the edges of adjacent abyssal plains, (2) to obtain continuity in tracing sequences by profiling around major interruptions (seamounts) and optimizing track crossings, (3) to provide abundant crossing lines in areas where existing seismic and bathymetric data suggest that there are outcrops of pre-Neogene strata, and (4) to take advantage of good-quality seismic data, where they exist (e.g., Conrad 2510 MCS), in order to make loop correlations between tracks.
Description of the Activity
The TAG seismic survey will involve a single vessel which will conduct the seismic work, the R/V Maurice Ewing, operated by LDEO under a cooperative agreement with the U.S. National Science Foundation (NSF), owner of the vessel. The Maurice Ewing will deploy an array of 20 airguns as an energy source, and will deploy and retrieve Ocean Bottom Hydrophones (OBHs). A hydrophone streamer will not be towed during the TAG cruise. The energy to the airgun array is compressed air supplied by compressors on board the source vessel. As the airgun array is towed along the survey lines, the OBHs and Ocean Bottom Seismometers (OBSs) will receive the reflected signals and transfer the data to the onboard processing system. All planned geophysical data acquisition activities will be conducted by LDEO scientists with onboard assistance by the scientists who proposed the study. The TAG program will consist of 185 km (100 n.mi.) of survey lines. There will be a total of three seismic lines, two along- and one across-axis of the TAG. Water depths in the area will vary from 1500 to 4500 m (4921-14,764 ft).
The ADWBC cruise will involve the oceanographic research vessel R/V Knorr, a U.S. Navy-owned ship operated by the Woods Hole Oceanographic Institution (WHOI), and will use a portable LDEO seismic system to conduct the seismic survey. The vessel will deploy 2 General Injector (GI)-guns as an energy source plus a towed streamer containing hydrophones to receive the returning acoustic signals. The hydrophone array will consist of a 600-m (1969 ft) solid state streamer with a 200-m (656 ft) tow leader. The energy to the airgun array is compressed air supplied by compressors on board the source vessel. As the 2 GI- guns are towed along the survey line, the hydrophone array will receive the returning signals and transfer the data to the onboard processing system. All planned geophysical activities will be conducted by the scientists who have proposed the study, while LDEO will provide the portable high-resolution seismic system that will support the seismic surveys for the proposed study. The ADWBC program will consist of 4334 km (2340 n.mi.) of seismic profiles that will be shot over a period of 20 days. The most detailed grids of seismic lines are proposed for the southern end of J Anomaly Ridge and for moats around seamounts on the crest of the Southeast Newfoundland Ridge - both are areas where there appear to be extensive pre-Neogene outcrops. Water depths in the area will vary from 4000 - 5000 m (13,124-16,405 ft).
The procedures to be used for the two seismic studies will be similar to those used during previous seismic surveys by LDEO, e.g., in the equatorial Pacific Ocean (Carbotte et al., 1998, 2000). The proposed seismic surveys will use conventional seismic methodology with a towed airgun array as the energy source, and either a towed hydrophone streamer or OBH and OBS receivers placed on the bottom to receive the reflected signals. For the TAG survey, eighteen OBHs will be deployed (and recovered) by the Maurice Ewing - eight along each of the long axis lines and two on the across axis line. After the seismic lines are shot, the data will be downloaded and the OBSs will be retrieved during an, as of yet, unscheduled cruise in the summer of 2004 (during which no seismic sound sources will be used). Along three selected seismic lines, 13 OBS receivers will be placed in the proposed study area by the R/V Alvin from 7-24 June 2003, before the arrival of the Maurice Ewing. In addition, a multi-beam bathymetric sonar will be operated from the source vessel continuously throughout both cruises, and a lower-energy sub-bottom profiler will also be operated during most of both surveys. During the ADWBC study, coring of numerous sedimentary outcrops known to exist on the ridges will also take place. During both cruises, there will be additional operations associated with equipment testing, startup, line changes, and repeat coverage of any areas where initial data quality is sub-standard.
The R/V Maurice Ewing will be used as the source vessel during the TAG cruise, and the R/V Knorr will be used as the source vessel during the ADWBC cruise. Both vessels will tow airgun arrays along predetermined lines, and will also serve as platforms from which vessel-based marine mammal observers will watch for marine mammals before and during airgun operations.
During TAG-study airgun operations, the vessel will travel at 7.4- 9.3 km/hr (4-5 knots), and seismic pulses will be emitted at intervals of 60-90 seconds (OBS lines during the TAG cruise). The 60-90 sec. spacing along OBS lines is to minimize reverberation from previous shot noise during OBS data acquisition, and the exact spacing will depend on water depth. The airgun array to be used will consist of 20 2000-psi Bolt airguns, towed at a depth of 7.5 m (24.5 ft). The 20-gun array will include airguns ranging in chamber volume from 80 to 850 in\3\, with a total volume of 8,575 in\3\.
[Page 63763]These airguns will be spaced in an approximate rectangle with dimensions of 35 m (115 ft) (across track) by 9 m (30 ft) (along track).
The ADWBC seismic survey will be high-resolution, consisting of two 105 in3 GI airguns with a total volume of approximately 210 in3, spaced 7.8 m (26 ft) apart, and towed 37 m (121 ft) behind the vessel at a depth of 2-3 m (7-10 ft). Towing airguns at this shallow depth is accomplished by suspending the guns from floats, and the resulting short-period free surface ``ghosting'' keeps the spectral content broad with usable signals up to 300-350 Hz. These airguns produce an unusually clean impulse with sufficient energy to penetrate many hundreds of meters of sediment. Airgun firing, timing, and synchronizing is handled by a LDEO-built controller, which is integrated with a SUN workstation-based DGPS navigation, data logging, and fire control system. The air is produced by a standalone Price Co. 2000 psi compressor, and the seismic signals are detected by a solid state ITI hydrophone ``Stealtharray'', with 48 12.5-m (41 ft) long channels, and a total length of 600 m (1969 ft).
The dominant frequency components for both airgun arrays is 0 - 188 Hz. The 2-airgun array will have a peak sound source output level of 237 dB re 1 microPa or 243 dB peak-to-peak (P-P). The 20-airgun array will have a peak sound source output level of 255 dB re 1 microPa or 262 dB P-P. Because the actual source is a distributed sound source (2 or 20 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 level. Also, because of the downward directional nature of the sound from these airgun arrays, the effective source level for sound propagating in near-horizontal directions will be substantially lower.
Along with the airgun operations, several additional acoustical data acquisition systems will be operated during most or all of the cruises. The ocean floor will be mapped with an Atlas Hydrosweep DS-2 multi-beam 15.5-kHz bathymetric sonar, and/or a 3.5-kHz sub-bottom profiler. These mid-frequency sound sources are commonly operated from research vessels simultaneous with airgun arrays as well as in the absence of airgun activity.
The Atlas Hydrosweep sonar will be used during cruises by the R/V Maurice Ewing, is mounted in the hull of the vessel, and operates in three modes depending on the water depth. The first is a shallow-water mode when water depth is 160 dB and the expected impacts at these levels, NMFS has determined that this action will have a negligible impact on the affected species or stocks.
Larger numbers of odontocetes may be affected by the seismic activities, but the populations sizes of most of the species are large and the numbers potentially affected are small relative to the population sizes. The best estimate of the total number of odontocetes that might be exposed to [gteqt]160 dB re 1 microPa (rms) in the proposed survey areas in the Mid-Atlantic Ocean is 746 for the TAG cruise, and 991 for the ADWBC cruise. Of these, 709 (TAG cruise) and 943 (ADWBC cruise) are Delphinidae, and of these about 204 (TAG cruise) and 322 (ADWBC cruise) might be exposed to [gteqt]170 dB. Approximately 316 and 419 common dolphins (the most abundant delphinid in the proposed survey areas) are expected to be exposed to seismic sounds
[gteqt] 160 dB in the TAG and
[Page 63768]ADWBC seismic survey areas, respectively. These figures represent considerably less than 0.2 and 0.3 percent of the North Atlantic population of common dolphins, respectively. Of these, 91 and 144, respectively, might be exposed to [gteqt]170 dB. These figures are much less than 0.1 percent of the North Atlantic population and the 170-dB values (91 and 144) are believed to be a more accurate estimate of the number potentially affected. Smaller numbers of other species of dolphins will be exposed to seismic sounds [gteqt]160 dB during the surveys, and the numbers for each species represent considerably less than 0.1 to 0.7 percent of each population. The numbers that might be exposed to [gteqt]170 dB are even smaller and represent considerably less than 0.1 to 0.2 percent of each population; these latter percentages are believed to be a more accurate estimate of the numbers potentially affected. Based on the relatively low numbers of marine mammals that will be exposed at levels [gteqt]160 dB and the expected impacts at these levels, NMFS has determined that this action will have a negligible impact on the affected species or stocks.
Altogether, the mitigation measures explained in this document (See Mitigation) will reduce short-term reactions to disturbance, and minimize any effects on hearing sensitivity.
Effects on Pinnipeds
Very few if any pinnipeds are expected to be encountered during the proposed seismic surveys in the Mid-Atlantic Ocean. Most have a coastal distribution or are distributed along the pack-ice edge. Therefore, it is unlikely that pinnipeds will be encountered in either study area. However, if pinnipeds are encountered, they are more likely to be seen during the ADWBC cruise in the northern Mid-Atlantic than during the TAG cruise. A few gray seals, which are normally found in coastal areas might be seen during the ADWBC cruise. In addition, a few vagrant harbor seals, harp seals, or hooded seals might be encountered. None of the pinniped species is endangered or depleted.
Because no seismic surveys will take place in coastal and nearshore areas, the best estimate of the numbers of each of the more common (but still unlikely) species that might be taken by Level B harassment is no more than 2 and is most likely 0. For the other less-common species the best estimate is zero. If pinnipeds are encountered, the proposed seismic activities would have, at most, a short-term effect on their behavior and no long-term impacts on individual seals or their populations. Responses of pinnipeds to acoustic disturbance are variable, but usually quite limited. Effects are expected to be limited to short-term and localized behavioral changes falling within the MMPA definition of Level B harassment. Therefore, based on these effects and the relatively low numbers of pinniped species that may be exposed, NMFS has determined that this action will have a negligible impact on the affected species or stocks.
Determinations
Based on the information contained in the LDEO application, the NSF EA, the September 17, 2003, proposed authorization notice (68 FR 54421) and this document, NMFS has determined that conducting two marine seismic surveys, one each by the Ewing and the Knorr, in the Mid- Atlantic Ocean by LDEO would result in the harassment of small numbers of marine mammals; would have no more than a negligible impact on the affected marine mammal species or stocks; and would not have an unmitigable adverse impact on the availability of stocks for subsistence uses. This activity will result, at worst, in a temporary modification in behavior by affected species of marine mammals. While behavioral modifications may be made by these species as a result of seismic survey activities, this behavioral change is expected to result n no more than a negligible impact on the affected species. Also, while the number of actual incidental harassment takes will depend on the distribution and abundance of marine mammals in the vicinity of the survey activity, the number of potential harassment takings is estimated to be small. In addition, no take by injury and/or death is anticipated, and the potential for temporary or permanent hearing impairment is low and will be avoided through the incorporation of the mitigation measures mentioned in this document and required under the IHA. For these reasons therefore, NMFS has determined that the requirements of section 101(a)(5)(D) of the MMPA have been met and the authorization can be issued.
Endangered Species Act (ESA)
NMFS has concluded consultation under section 7 of the ESA on NMFS' issuance of an IHA to take small numbers of marine mammals, by harassment, incidental to conducting two oceanographic seismic surveys in the Mid-Atlantic Ocean by LDEO. The consultation concluded with a biological opinion that this action is not likely to jeopardize the continued existence of marine species listed as threatened or endangered under the ESA. No critical habitat has been designated for these species in the equatorial Pacific Ocean; therefore, none will be affected. A copy of the Biological Opinion is available upon request (see ADDRESSES).
National Environmental Policy Act (NEPA)
On July 30, 2003, the NSF made a determination, based on information contained within its Environmental Assessment (EA), that implementation of the subject action is not a major Federal action having significant effects on the environment within the meaning of Executive Order 12114. NSF determined therefore, that an environmental impact statement would not be prepared. On September 17, 2003 (68 FR 54421), NMFS noted that the NSF had prepared an EA for the Mid-Atlantic surveys and made it available upon request. In accordance with NOAA Administrative Order 216-6 (Environmental Review Procedures for Implementing the National Environmental Policy Act, May 20, 1999), NMFS has reviewed the information contained in NSF's EA and determined that the NSF EA accurately and completely describes the proposed action alternative, reasonable additional alternatives, and the potential impacts on marine mammals, endangered species, and other marine life that could be impacted by the preferred alternative and the other alternatives. As a result, NMFS has determined that it is not necessary to issue either a new EA, supplemental EA or an environmental impact statement for the issuance of an IHA to LDEO for this activity. Therefore, based on this review and analysis, NMFS is adopting the NSF EA under
Authorization
NMFS has issued an IHA to take small numbers of marine mammals, by harassment, incidental to conducting two marine seismic surveys, one by the Ewing and one by the Knorr, in the Mid-Atlantic Ocean to LDEO for a 1-year period, provided the mitigation, monitoring, and reporting requirements described in this document and the IHA are undertaken.
Dated:October 23, 2003. Phil Williams, Acting Director, Office of Protected Resources, National Marine Fisheries Service.
FR Doc. 03-28129 Filed 11-7-03; 8:45 amBILLING CODE 3510-22-S
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