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Notice

Small Takes of Marine Mammals Incidental to Specified Activities; Oceanographic Surveys in the Eastern Tropical Pacific Ocean

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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 authorization; request for comments.

SUMMARY:

NMFS has received an application from the Scripps Institution of Oceanography (SIO), a part of the University of California, for an Incidental Harassment Authorization (IHA) to take small numbers of marine mammals, by harassment, incidental to conducting oceanographic surveys in the Eastern Tropical Pacific Ocean (ETP). Under the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an incidental take authorization to SIO to incidentally take, by harassment, small numbers of several species of cetaceans and pinnipeds for a limited period of time within a one-year period.

DATES:

Comments and information must be received no later than September 25, 2003.

ADDRESSES:

Comments on the application should be addressed to the Acting 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. A copy of the application containing a list of the references used in this document may be obtained by writing to this address or by telephoning the contact listed here. Comments cannot be accepted if submitted via e-mail or the Internet.

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FOR FURTHER INFORMATION CONTACT:

Sarah C. Hagedorn, Office of Protected Resources, NMFS, (301) 713-2322, ext 117.

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SUPPLEMENTARY INFORMATION:

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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).

Section 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 June 16, 2003, NMFS received an application from SIO for the taking, by harassment, of several species of marine mammals incidental to conducting a seismic survey program in international waters of the ETP and in several Exclusive Economic Zones (EEZ) of several coastal states (Mexico, Costa Rica, Panama, Columbia, Ecuador, and Peru), from which permission to conduct this type of scientific research has been requested. SIO's R/V Roger Revelle is scheduled to undertake a multidisciplinary research cruise, including some seismic reflection profiling and echo-sounding studies, in the ETP from September 2003 to February 2004, primarily 100-400 nautical miles (nm) (185 - 741 km) west of northern Peru and 200-1000 nm (370 - 1852 km) west of the Galapagos Islands. None of these operations would be in U.S. territorial waters or in the U.S. EEZ. A low-energy seismic reflection profiler with a small airgun sound source will be used on 3 of the 8 legs of the cruise. The purpose of this survey is to study the shape and structure of the sediment-buried oceanic crust in this part of the ETP.

Description of the Activity

SIO's seismic surveys will involve one vessel, the R/V Roger Revelle (under a cooperative agreement with the U.S. Navy, owner of the vessel). The Roger Revelle will deploy two airguns as an energy source, plus a single short (300 m or 984 ft) towed streamer of hydrophones to receive the returning acoustic signals, that can be retrieved and deployed in less than 20 minutes.

The bubble-generating chambers of the two small General-Injector airguns have a combined volume of 90 cubic inches (1475 cubic centimeters (cc)), contrasting with 3000-9000 cubic inches (49,161-147,484 cc) of the large gun arrays typical of academic and commercial seismic surveys. The primary seismic pulse is produced by a 45-in3 (737 cc) generator chamber, while compressed air from a 105-in3 (1721 cc) injector chamber is used to maintain the shape of the bubble and reduce its sound-making oscillation. The pair of simultaneously fired airguns would have a peak-to-peak (p-p) amplitude of 236 dB re 1 μPa. In addition, a hull-mounted mid-frequency multibeam echo-sounder sonar for seafloor mapping will be routinely operated whenever the Revelle is underway. The Kongsberg-Simard EM-120 sonar images the seafloor over a 120-140 degree-wide swath (about 10-20 km, or 5-10 nm wide), using very short (15 msec) transmit pulses with a 10-20 second repetition rate and a 11.25-12.60 kHz frequency sweep. Source level in deep water is 240 dB rms, but the brevity, directivity, and narrow beam-width (1 degree fore-and-aft) of the transmit pulses make it unlikely that operation of this depth sonar will affect marine mammals.

None of the 3 research legs for which an IHA is requested will be a dedicated seismic reflection survey of the sort typically conducted by a specialized seismic vessel. The seismic reflection profiler will be used as just one tool in integrated marine geology and geophysical studies that also employ bathymetric echo-sounders, passive geophysical sensors (such as a gravimeter and magnetometer), and geologic sampling tools (like rock dredges and cores). Typical operating procedure during these three legs of the cruise will be to conduct seismic profiling, at a ship speed of 9-11 knots for periods of 8-12 hours, interspersed with episodes of geologic sampling and periods of faster steaming with no profiling system deployed. In a few instances (1-3 per leg), longer profiles will need to be collected, requiring up to 36 hours of continuous airgun operation. The objective is not to image deep crustal structureor the stratigraphy of thick sedimentary units (the typical goals of seismic surveys); instead the purpose is to measure the varying thickness of the 100-400 m-thick (328-1312 ft) cover of pelagic sediment that buries and obscures the igneous oceanic crust in our study areas, because establishing the relief of the buried crust is essential for interpreting the bathymetric, magnetic and gravity data. For this limited objective, the large powerful sound sources and hydrophone streamers several kilometers long that typify dedicated seismic surveys are not required. Nor will any broad ocean volume be ensonified by profiling on closely-spaced seismic lines.

Leg 1 of the cruise, from San Diego to Puerto Caldera, Costa Rica, is planned for September 27-October 9, 2003. This will be primarily a staging and instrument testing and calibration leg, but with 2 days of seismic reflection profiling and rock-dredging 40-80 nm (74-148 km) off the coast of Costa Rica. In addition to the approximately 24 hours of seismic profiling, it is also planned during this leg to test and calibrate new components of the system, and train shipboard technicians in their use, with 2 or 3 12-18 hour test runs along parts of the transit track. Because these test profiles may obtain scientifically useful data, specific sites that are of interest to Mexican researchers have been targeted, in partial fulfillment of SIO's foreign-Start Printed Page 51242clearance obligation to collect data of value to coastal states.

Leg 2, from Puerto Caldera, Costa Rica, to Manta, Ecuador, is planned for October 10-November 6, 2003. The plan for this leg is to (i) conduct a 2-day seismic reflection plus rock dredging survey of Cobia Ridge, south of Panama, (ii) collect a north-south seismic reflection plus magnetics profile across the eastern Panama Basin, and (iii) conduct a 14-day seismic reflection plus bathymetry plus rock dredging survey off northern Peru. A total of 200-250 hours of seismic reflection profiling is anticipated for this leg of the cruise.

Leg 5, from Callao, Peru, to Puerto Caldera, Costa Rica, is planned to take place from December 28-February 23, 2003. Primary survey tools will be a multibeam echo-sounder and a new magnetometer system. Seismic reflection profiling will have a subsidiary role, imaging the relief of the igneous crust in the approximately 20 percent of the survey area that has a significant cover of structure-obscuring sediment. A total of 150-200 hours of profiling is anticipated for this leg of the cruise. All three legs will use the same bathymetric sonar and seismic profiling system, described above.

All planned geophysical data acquisition activities are funded by the National Science Foundation (NSF) and will be conducted by SIO scientists, with a specific Principal Investigator aboard the vessel. Additional information on the airgun array and bathymetric multibeam sonar is contained in the application, which is available upon request (see ADDRESSES).

Description of Habitat and Marine Mammals Affected by the Activity

A detailed description of the ETP and its associated marine mammals can be found in the SIO application (as updated by Peter Lonsdale) and in a number of documents referenced therein. That information is not repeated here. Throughout the entire proposed study regions during the fall and winter months of 2003, approximately 21 species of cetaceans and four species of pinnipeds are likely to occur. These species are the sperm whale (Physeter macrocephalus), pygmy sperm whale (Kogia breviceps), dwarf sperm whale (Kogia sima), Cuvier's beaked whale (Ziphius cavirostris), rough-toothed dolphin (Steno bredanensis), bottlenose dolphin (Tursiops truncatus), pantropical spotted dolphin (Stenella attenuata), spinner dolphin (Stenella longirostris), striped dolphin (Stenella coeruleoalba), short-beaked common dolphin (Delphinus delphis), Pacific white-sided dolphin (Lagenorhynchus obliquidis), Risso's dolphin (Grampus griseus), melon-headed whale (Peponocephala electra), pygmy killer whale (Feresa attenuata), false killer whale (Pseudorca crassidens), killer whale (Orcinus orca), short-finned pilot whale (Globicephala macrorhynchus), humpback whale (Megaptera novaeangliae), minke whale (Balaenoptera acutorostrata), Bryde's whale (Balaenoptera edeni), blue whale (Balaenoptera musculus), Guadalupe fur seal (Arctocephalus townsendi), northern elephant seal (Mirounga angusirostris), South American sea lion (Otaria flavescens), and California sea lions (Zalophus californianus). It is also possible that four species of beaked whales may be encountered within the proposed survey areas: Longman's beaked whale (Indopacetus pacificus), pygmy beaked whale (Mesoplodon peruvianus), Ginkgo-toothed beaked whale (Mesoplodon ginkgodens), and Blainville's beaked whale (Mesoplodon densirostris). In addition, four other species of cetaceans have been reported in the area of the proposed surveys, but have been rarely or never seen during NMFS population assessments. These species are the dusky dolphin (Lagenorhynchus obscurus), Fraser's dolphin (Lagenodelphis hosei), fin whale (Balaenoptera physalus), and Baird's beaked whale (Berardius bairdii). Additional information on most of these species can be found in the application, but is also contained in Caretta et al. (2001, 2002) which are available at: http://www.nmfs.noaa.gov/​prot_​res/​PR2/​Stock_​Assessment_​Program/​sars.html.

Potential Effects on Marine Mammals

NMFS described the characteristics of acoustic sources from airguns and from mid-frequency sonar and, in general, the anticipated effects on marine mammals including masking, disturbance, and potential hearing impairment and other physical effects in another Notice of Receipt of an IHA application and proposed IHA involving seismic survey activities, published on April 14, 2003 (68 FR 17909). That information is not repeated here. The SIO application also provides information on what is known about the effects on marine mammals from the types of seismic operations planned by SIO.

Estimates of Take by Harassment for the ETP Cruise

As described previously (68 FR 17909), animals subjected to sound levels ≥160 dB may alter their behavior or distribution, and therefore might be considered taken by Level B harassment.

The estimates of takes by harassment are based on the number of marine mammals that might be found within the 160 dB isopleth radius and potentially disturbed by operations with the 2 GI-guns planned for the project. Based on summer/fall marine mammal density calculations by Ferguson and Barlow (2001), SIO used their average marine mammal densities from the ETP to compute a “best estimate” of the number of marine mammals that may be exposed to seismic sounds ≥160 dB re 1μPa (rms) (NMFS' current criterion for onset of Level B harassment). The average densities were then converted to per-km abundances and multiplied (for the appropriate region) by the area that is planned to be ensonified at levels ≥160 dB re 1 μPa (rms) during the proposed seismic survey program. Where abundance estimates for certain species (pacific white-sided dolphins, pygmy sperm whales, minke whales, and humpback whales) were not readily available for stocks found within the proposed survey areas, minimum population estimates were taken from individual Marine Mammal Stock Assessment Reports, which are available online as mentioned previously.

SIO did not estimate numbers of pinnipeds potentially vulnerable to harassment due to insufficient data on distribution, seasonal abundance, and pinniped response. However, SIO determined that it is unlikely to encounter significant numbers of any of the pinniped species that live, at least part of the year, in the area of the proposed activity. We preliminarily agree.

Based on this method, Table 3 in the application gives the best estimates of numbers for each species of cetacean that might be exposed to received levels ≥160 dB re 1 μPa (rms), and thus potentially taken by Level B harassment, during seismic surveys in the proposed study areas of the ETP.

Eight species of delphinidae would account for 95 percent of the overall estimate for potential taking by harassment. Common dolphins are the most abundant delphinid in the proposed seismic survey areas, representing 71 percent of the total estimate for potential taking by harassment. Most of the remaining 5 percent of the overall estimate for potential taking by harassment consists of pilot whales, dwarf sperm whales, and five species of beaked whales.

Conclusions-effects on Cetaceans

Baleen whales have been seen to avoid operating airguns with avoidance Start Printed Page 51243radii that are quite variable, while some baleen whales show considerable tolerance of seismic pulses. Whales are often reported to show no overt reactions to airgun pulses at distances beyond a few kilometers, even though the pulses remain well above ambient noise levels out to much longer distances. However, recent studies of humpback and especially bowhead whales show that reactions, including avoidance, sometimes extend to greater distances than documented earlier, possibly even exceeding the distances at which boat-based observers can see whales. Strong avoidance reactions by several species of mysticetes to seismic vessels have been observed at ranges up to 6 to 8 km (3.2 to 4.3 n.mi.) and occasionally as far as 20-30 km (10.8-16.2 n.mi.) from the source vessel. Some bowhead whales avoided waters within 30 km (16.2 n.mi.) of the seismic operation. However, reactions at such long distances appear to be atypical of other species of mysticetes, and even for bowheads may only apply during migration.

Odontocete reactions to seismic pulses, or at least those of dolphins, are expected to extend to lesser distances than those of mysticetes. Odontocete low-frequency hearing is less sensitive than that of mysticetes, and dolphins are often seen from seismic vessels, occasionally even at close distances. In fact, there are documented instances of dolphins approaching active seismic vessels. However, dolphins as well as some other types of odontocetes sometimes show avoidance responses and/or other changes in behavior when near operating seismic vessels. In the cases of mysticetes, these reactions are expected to involve small numbers of individual cetaceans because few mysticetes occur in the area where seismic surveys are proposed.

For most species, including endangered sperm and blue whales, the total estimated “take by harassment” by species presented in Table 3 of the application (Scripps 2003) represents less than 1.0 percent of the eastern tropical Pacific population of any of these species. For the remaining three cetacean species, the total estimated “take by harassment” are 1.8 percent of the estimated pygmy sperm whale population in and adjacent to the study area, 6.2 percent of the dwarf sperm whale population, and 1.8 percent of endangered humpback whales would receive seismic sounds >160 dB. Although the absolute numbers of odontocetes that may be harassed by the proposed activities may be large, the population sizes of the main species are also large; therefore, the numbers potentially affected are small relative to the population sizes.

Taking account of the mitigation measures that are planned, effects on cetaceans are generally expected to be limited to avoidance of the area around the seismic operation and short-term changes in behavior, falling within the MMPA definition of “Level B harassment.” Based on the relatively low numbers of marine mammals that will be exposed at levels >160 dB and the expected impacts at these levels, NMFS has preliminarily determined that this action will have a negligible impact on the affected species or stocks of cetaceans.

Conclusions-effects on Pinnipeds

Responses of pinnipeds to acoustic disturbance are variable, but usually quite limited. Early observations provided considerable evidence that pinnipeds are often quite tolerant of strong pulsed sounds. Visual monitoring from seismic vessels has shown only slight (if any) avoidance of airguns by pinnipeds, and only slight (if any) changes in behavior. These studies show that pinnipeds frequently do not avoid the area within a few hundred meters of an operating airgun array. Even so, results from initial telemetry studies suggest that avoidance and other behavioral reactions may be stronger than has been evident from visual studies.

Very few, if any, pinnipeds are expected to be encountered during the proposed seismic survey in the ETP, and it is therefore unlikely that the seismic vessel will encounter significant numbers of any of the four pinniped species that live, for at least part of the year, in the area of proposed seismic profiling.

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. Effects are expected to be limited to short-term and localized behavioral changes falling within the MMPA definition of Level B harassment. Therefore, NMFS' preliminary determination is that impacts will be negligible.

Mitigation

For the proposed seismic operations in the ETP, SIO will use 2-GI guns with a total volume of 90 in3 (1475 cc). These airguns will be spread out horizontally, so that the energy from the array will be directed mostly downward. The following mitigation measures, as well as marine mammal monitoring, will be adopted during the proposed ETP seismic survey program.

Shutdown Procedures

SIO proposes to shut down seismic sources whenever marine mammals are observed close enough to the vessel that they are at risk of exposure to sound levels greater than 180 dB (rms), where there is a possibility of Level A harassment. Airgun operations will be suspended immediately when marine mammals are observed within, or about to enter, this designated safety zone. Current NMFS guidance dictates that cetaceans and pinnipeds should not be exposed to impulsive sounds exceeding 180 and 190 dB rms (the level for the potential for Level A harassment), respectively. SIO will adopt a 180-dB threshold for all marine mammals because pinnipeds have less developed (or less documented) avoidance behaviors, and because of the low liklihood that pinnipeds will be encountered.

SIO has adopted conservative methods in defining safety zone calculations using (i) a 9-dB difference between p-p and rms, and (ii) spherical spreading of the sound, even though it is clear that at the low acoustic frequencies which dominate SIO's airgun output, the generated sound pulses have considerable directivity, favoring downward propagation over horizontal propagation (because in the near-horizontal direction the direct gun pulse is closely followed by the opposite-phased bounce off the sea surface, if the source is within an acoustic wavelength of the surface; this effect can reduce the effective near-horizontal output by as much as 10 dB). Because the actual seismic source is a distributed sound source 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.

As described earlier, the pair of simultaneously fired airguns would have a p-p amplitude of 236 dB re 1 μPa. Converting to a rms dB using the 9 dB difference between p-p and rms for a sine wave yields an output level of 227 dB rms. Therefore, SIO's modeled results for the 2-gun array indicate that, assuming spherical spreading, the paired guns would produce sound levels of 180 dB re 1 μPa (rms) at a range of about 225 m (738 ft); i.e., the radius around the 2-gun array where the received level would be 180 dB re 1 μ\Pa (rms), is estimated to be 225 m (738 ft). The effect of using a conservative calculation, which yields this safety zone for 180 dB rms sound, is to build a safety factor into the airgun Start Printed Page 51244shut-down radius; this is desirable because mammals may not be observed while submerged, and might move towards the acoustic sources during dives.

Airgun operations will not resume until the marine mammal is observed outside the safety radius or a minimum of 15 minutes has elapsed since the last sighting. Once the safety zone is clear of marine mammals, the observer will advise that seismic surveys can re-commence.

Gradual ramp-up of the output of the airgun array, a standard mitigation procedure during seismic surveys employing numerous guns of varying size, is inapplicable to the proposed operations which use only two small sound sources with a small total air discharge volume (90 in3).

Course Alteration

If a marine mammal is detected at any range beyond the 225 m (738 ft) safety radius but, based on its position and the relative motion, appears to be on a converging course with the ship while profiling is underway, the vessel will be maneuvered in an attempt to maintain a range greater than the shut-down radius. The marine mammal activities and movements relative to the seismic vessel will be closely monitored to ensure that the marine mammal does not approach within the safety radius. If the mammal appears likely to enter the safety radius, further mitigative actions will be taken, i.e., either further course alterations or shutdown of the airguns.

Because of the ineffectiveness of mammal observers during darkness (even though the vessel is equipped wit night-vision binoculars), seismic reflection profiling will be concentrated during daylight hours. As noted earlier, there are just 1-3 occasions on each leg when the scientific objectives require collection of seismic profiles that are too long to complete in a single daylight period, and limited nighttime profiling is needed to allow completion of the marine geophysical research. In no instance will seismic profiling be initiated during darkness, a situation where unobservable mammals would be at risk from the sudden onset of G.I.-gun noise.

Marine Mammal Monitoring

Effective implementation of these procedures requires surveillance by appropriately equipped skilled observers, who will monitor for marine mammals in the vicinity of the array. Each leg of the cruise will be staffed with two observers who have previously worked for the Southwest Fisheries Science Center of NMFS, and who are recommended by the Center. These observers will share surveillance duties during daylight hours, and be responsible for computer entry of their observations while off watch. They will be equipped with binoculars and have access to the 50X “big-eye” binoculars mounted on the Revelle's bridge (though their normal station, except in inclement weather will be outside on the upper deck). For estimating the range of marine mammals that are sighted, the observers will use the optical fixed-interval range-finder described by Heinemann (1981); this instrument relies on measuring the angle between the mammal and the visual horizon, by an observer at known height above sea-level. The observers will be in wireless communication with ship officers on the bridge and scientists in the vessel's operations laboratory, so they can advise promptly of the need for avoidance maneuvers or G.I. gun shut-down.

Monitoring and Reporting

Vessel-based Visual Monitoring

SIO proposes to conduct marine mammal monitoring of its seismic surveys in the ETP in order to satisfy the anticipated requirements of the IHA. Monitoring of marine mammals by experienced observers will occur during all daylight hours of the 3 legs of the cruise on the Revelle, whether or not G.I. guns are in operation. Except in bad weather, when they will occupy the bridge, observers will be stationed outside, forward on the 03 deck at a height of 9 m (30 ft) above the waterline; this has proved to be an effective station for marine mammal surveillance during previous mammal and seabird monitoring exercises from the Revelle.

Reporting

Observers will record their observations and range measurements on tape, for subsequent transcription into NMFS format. When a marine mammal sighting is made, the following information about the sighting will be recorded: (1) Species, group size, age/size/sex categories (if determinable), behavior when first sighted and after initial sighting, heading (if consistent), bearing and distance from seismic vessel, sighting cue, apparent reaction to seismic vessel (e.g., none, avoidance, approach, paralleling, etc.), and behavioral pace; and (2) time, location, heading, speed, activity of the vessel (seismic activity or not), sea state, visibility, cloud cover, and sun glare. The data listed under (2) above will also be recorded at the start and end of each observation watch and during a watch, and whenever there is a change in one or more of the variables.

Results from the vessel-based observations will provide: (1) the basis for real-time mitigation (airgun shutdown); (2) information needed to estimate the number of marine mammals potentially taken by harassment, which must be reported to NMFS; (3) data on the occurrence, distribution, and activities of marine mammals in the area where the seismic study is conducted; (4) information to compare the distance and distribution of marine mammals relative to the source vessel at times with and without seismic activity; and (5) data on the behavior and movement patterns of marine mammals seen at times with and without seismic activity.

A report will be submitted to NMFS within 90 days after the end of the seismic profiling program (before May 2004). The report will be submitted to NMFS, providing full documentation of methods, results, and interpretation pertaining to most all monitoring tasks. The 90-day report will summarize the dates and locations of seismic operations, sound measurement data, marine mammal sightings (dates, times, locations, activities, associated seismic survey activities), and estimates of the amount and nature of potential “take” of marine mammals by harassment or in other ways.

Endangered Species Act (ESA)

Under section 7 of the ESA, NMFS has begun consultation on the proposed issuance of an IHA under section 101(a)(5)(D) of the MMPA for this activity. Consultation will be concluded prior to the issuance of an IHA.

National Environmental Policy Act (NEPA)

An Environmental Assessment (EA) on a similar action for this area of the Pacific Ocean was prepared and released to the public on July 11, 2003 (68 FR 41314). The proposed acoustic survey described in this document will use acoustic instruments that are significantly less intense and will therefore have a significantly lower impact on the marine environment than acoustic sources addressed in the earlier EA. NMFS' analysis resulted in a Finding of No Significant Impact (FONSI). Therefore, based on that EA and the IHA application from Scripps, NMFS has preliminarily determined that this action will not have a significant impact on the human environment. Accordingly, this proposed action qualifies for a categorical exclusion under NEPA and NOAA Administrative Order 216-6 and Start Printed Page 51245is therefore exempted from further environmental review. A copy of relevant previous EA is available (see ADDRESSES).

Preliminary Conclusions

NMFS has preliminarily determined that the short-term impact of conducting a seismic survey program in the ETP will result, at worst, in a temporary modification in behavior by certain 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 in no more than a negligible impact on the affected species.

While the number of potential 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.

Proposed Authorization

NMFS proposes to issue an IHA to Scripps for conducting a 2-GI gun seismic survey program in the ETP, provided the proposed mitigation, monitoring, and reporting requirements are incorporated. NMFS has preliminarily determined that the proposed activity would result in the harassment of only small numbers of marine mammals; would have no more than a negligible impact on the affected marine mammal stocks; and would not have an unmitigable adverse impact on the availability of stocks for subsistence uses.

Information Solicited

NMFS requests interested persons to submit comments and information concerning this request (see ADDRESSES).

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Dated: August 20, 2003.

Donna Wieting,

Acting Director, Office of Protected Resources, National Marine Fisheries Service.

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[FR Doc. 03-21794 Filed 8-25-03; 8:45 am]

BILLING CODE 3510-22-S