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Small Takes of Marine Mammals Incidental to Specified Activities; Low-Energy Marine Seismic Survey in the Northeastern Pacific Ocean, September 2007

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Information about this document as published in the Federal Register.

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


Notice; issuance of incidental harassment authorization.


In accordance with the Marine Mammal Protection Act (MMPA) regulations, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to Scripps Institution of Oceanography (SIO) for the take of marine mammals, by Level B harassment only, incidental to conducting a low-energy marine seismic survey in the northeastern Pacific Ocean during September, 2007.


Effective September 5, 2007, through September 30, 2007.


A copy of the IHA and application are available by writing to P. Michael Payne, Chief, Permits, Conservation and Education 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 the address specified above, telephoning the contact listed below (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet at:​pr/​permits/​incidental.htm#applications. Documents cited in this notice may be viewed, by appointment, during regular business hours, at the aforementioned address.

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Candace Nachman or Jolie Harrison, Office of Protected Resources, NMFS, (301) 713-2289.

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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.

Authorization shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s), will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (where relevant), and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring, and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as ” 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.”

Section 101(a)(5)(D) of the MMPA established an expedited process by which citizens of the U.S. can apply for an authorization to incidentally take small numbers of marine mammals by harassment. Except with respect to certain activities not pertinent here, 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 [Level A harassment]; 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 [Level B harassment].

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 marine mammals. Within 45 days of the close of the comment period, NMFS must either approve or deny the authorization.

Summary of Request

On May 4, 2007, NMFS received an application from SIO for the taking, by Level B harassment only, of eight species of marine mammals incidental to conducting, with research funding from the National Science Foundation (NSF), an ocean-bottom seismograph (OBS) deployment and a magnetic, bathymetric, and seismic survey program off the Oregon coast in the northeastern Pacific Ocean during September, 2007. The purpose of the research program was outlined in NMFS' notice of the proposed IHA (72 FR 42045, August 1, 2007).Start Printed Page 51623

Description of the Activity

The seismic surveys will involve one vessel, the R/V Wecoma (Wecoma), which is scheduled to depart from Newport, OR on September 5, 2007 and return on September 11, 2007. The exact dates of the activities may vary by a few days because of weather conditions, repositioning, OBS and streamer operations and adjustments, GI-gun deployment, or the need to repeat some lines if data quality is substandard. The seismic surveys will take place off the Oregon coast in the northeastern Pacific Ocean. The overall area within which the seismic surveys will occur is located between approximately 44° and 45° N. and 124.5° and 126o W. (Figure 1 in the application). The surveys will occur approximately 25-110 km (15.5-68.4 mi) offshore from Oregon in water depths between approximately 110 and 3,050 m (361 and 10,007 ft), entirely within the Exclusive Economic Zone of the U.S.

The Wecoma will deploy a single low-energy Generator-Injector (GI) airgun as an energy source (with a discharge volume of 45 in3), 16 OBSs that will remain in place for a year, and a 300 m-long (984 ft-long), 16-channel, towed hydrophone streamer. The program will consist of approximately 21 km (13 mi) of surveys over each of the 16 OBSs. The GI gun will be operated on a small grid for approximately 2 hours at each of 16 OBS sites over an approximately 7-day period during September, 2007. In addition to the operations of the GI gun, a 3.5-kHz sub-bottom profiler, a Knudsen 320BR sub-bottom profiler, and a magnetometer may be run on the transit between OBS locations.

A more detailed description of the authorized action, including vessel and acoustic source specifications, was included in the notice of the proposed IHA (72 FR 42045, August 1, 2007).

Safety Radii

Received sound levels have been modeled by Lamont-Doherty Earth Observatory (L-DEO) for a number of airgun configurations, including one 45-in3 GI gun, in relation to distance and direction from the airgun(s). The model does not allow for bottom interactions and is most directly applicable to deep water. Based on the modeling, estimates of the maximum distances from the GI gun where sound levels of 190, 180, and 160 dB re 1 μPa (rms) are predicted to be received in deep (>1000-m, 3280-ft) water are 8, 23, and 220 m (26.2, 75.5, and 721.8 ft), respectively and 12, 35, and 330 m (39.4, 115, and 1,082.7 ft), respectively for intermediate water depths (100-1000m, 328-3,280 ft). Because the model results are for a 2.5-m (8.2-ft) tow depth, the above distances slightly underestimate the distances for the 45-in3 GI gun towed at 4-m (13-ft) depth.

A general discussion of acoustic thresholds and safety radii, as well as further discussion of the modeling conducted by L-DEO, was included in the notice of the proposed IHA (72 FR 42045, August 1, 2007).

Comments and Responses

A notice of receipt of the SIO application and proposed IHA was published in the Federal Register on August 1, 2007 (72 FR 42045). During the comment period, NMFS received comments from the Marine Mammal Commission (MMC) and one individual. One individual expressed the opinion that this authorization should be denied because this type of activity is much more harmful than the “profiteers” admit, causing extreme harm to the animals, such as brain hemorrhages which cause the death of the animals. No supporting information was provided for these assertions, and NMFS believes that the contrary analyses presented in the EA and Federal Register Notice remain correct.

MMC Comment: The MMC states that because the applicant is requesting authority to take marine mammals by harassment only, NMFS should require that operations be suspended immediately if a dead or seriously injured marine mammal is found in the vicinity of the operations and the death or injury could have occurred incidental to the seismic survey. The MMC further recommends that any such suspension should remain in place until NMFS has: (1) reviewed the situation and determined that further mortalities or serious injuries are unlikely to occur; or (2) issued regulations authorizing such takes under section 101(a)(5)(A) of the MMPA.

Response: NMFS concurs with MMC's recommendations and has included a requirement to this effect in the IHA.

Description of Marine Mammals in the Activity Area

Thirty-two marine mammal species, including 19 odontocete (dolphins and small and large toothed whales) species, seven mysticete (baleen whales) species, five pinniped species, and the sea otter, may occur or have been documented to occur in the marine waters off Oregon and Washington, excluding extralimital sightings or strandings (Table 1 here). Six of the species that may occur in the project area are listed under the U.S. Endangered Species Act (ESA) as Endangered, including sperm, humpback, blue, fin, sei, and North Pacific right whales. One other species listed as Threatened may occur in the project area: the Steller sea lion.

Additional information regarding the status and distribution of the marine mammals in the area and how the densities were calculated was included in the notice of the proposed IHA (72 FR 42045, August 1, 2007) and may be found in SIO's application.

SpeciesHabitatAbundance1Auth Take
North Pacific right whale (Eubalaena japonica)*Inshore, occasionally offshoreN.A.20
Humpback whale (Megaptera novaeangliae)*Mainly nearshore waters and banks13910
Minke whale (Balaenoptera acutorostrata)Pelagic and coastal10150
Sei whale (Balaenoptera borealis)*Primarily offshore, pelagic560
Fin whale (Balaenoptera physalus)*Continental slope, mostly pelagic32790
Blue whale (Balaenoptera musculus)*Pelagic and coastal17440
Sperm whale (Physeter macrocephalus)*Usually pelagic and deep seas12330
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Pygmy sperm whale (Kogia breviceps)Deep waters off the shelf2471
Dwarf sperm whale (Kogia sima)Deep waters off the shelfN.A.0
Cuvier's beaked whale (Ziphius cavirostris)Pelagic18840
Baird's beaked whale (Berardius bairdii)Pelagic2280
Blainville's beaked whale (Mesoplodon densirostris)Slope, offshore124730
Hubb's beaked whale (Mesoplodon carlhubbsi)Slope, offshore124730
Stejneger's beaked whale (Mesoplodon stejnegeri)Slope, offshore1247 30
Offshore bottlenose dolphin (Tursiops truncatus)Offshore, slope5,0650
Striped dolphin (Stenella coeruleoalba)Off continental shelf13,9340
Short-beaked common dolphin (Delphinus delphis)Shelf and pelagic, seamounts449,8464
Pacific white-sided dolphin (Lagenorhynchus obliquidens)Offshore, slope59,2746
Northern right whale dolphin (Lissodelphis borealis)Slope, offshore waters20,3625
Risso's dolphin (Grampus griseus)Shelf, slope, seamounts16,0663
False killer whale (Pseudorca crassidens)Pelagic, occasionally inshoreN.A.0
Killer whale (Orcinus orca)Widely distributed466 (Offshore)0
Short-finned pilot whale (Globicephala macrorhynchus)Mostly pelagic, high-relief topography3040
Harbor porpoise (Phocoena phocoena)Coastal and inland waters39,586 (OR/WA)0
Dall's porpoise (Phocoenoides dalli)Shelf, slope, offshore99,51739
Northern fur seal (Callorhinus ursinus)Pelagic, offshore688,02823
California sea lion (Zalophus californianus californianus)Coastal, shelf237,000-244,0000
Steller sea lion (Eumetopias jubatus)*Coastal, shelf44,9962 Eastern US0
Harbor seal (Phoca vitulina richardsi)Coastal24,732 (OR/WA)1
Northern elephant seal (Mirounga angustirostris)Coastal, pelagic when migrating101,000 (CA)0
Table 1. Species expected to be encountered (and potentially harassed) during SIO's Pacific Ocean cruise. The far right column indicates the number of takes authorized by the IHA.
N.A. - Data not available or species status was not assessed.
* Species are listed as threatened or endangered under the Endangered Species Act.
1 Abundance given for U.S., Eastern North Pacific, or California/Oregon/Washington Stock, whichever is included in the 2005 U.S. Pacific Marine Mammal Stock Assessments (Carretta et al. 2006), unless otherwise stated.
2 Angliss and Outlaw (2005).
3 All mesoplodont whales

Potential Effects on Marine Mammals

The effects of sounds from airguns might include one or more of the following: tolerance, masking of natural sounds, behavioral disturbance, and temporary or permanent hearing impairment or non-auditory physical or physiological effects (Richardson et al., 1995; Gordon et al., 2004). To avoid injury, NMFS has determined that cetaceans and pinnipeds should not be exposed to pulsed underwater noise at received levels exceeding, respectively, 180 and 190 dB re 1 μPa (rms). The predicted 180- and 190-dB distances for the GI gun operated by SIO are 35 m (115 ft) and 12 m (39.4 ft), respectively, for intermediate water depths and 23 m (75.5 ft) and 8 m (26.2 ft), respectively, for deep water. Given the small size of the gun (one 45-in3 GI gun) planned for the present project and the required mitigation and monitoring measures, effects are anticipated to be considerably less than would be the case with a large array of airguns. It is very unlikely that there would be any cases of temporary or, especially, permanent hearing impairment or any Start Printed Page 51625significant non-auditory physical or physiological effects. Also, behavioral disturbance is expected to be limited to relatively short distances.

The notice of the proposed IHA (72 FR 42045, August 1, 2007) included a discussion of the effects of sounds from airguns on mysticetes, odontocetes, and pinnipeds, including tolerance, masking, behavioral disturbance, hearing impairment, and other non-auditory physical effects. Additional information on the behavioral reactions (or lack thereof) by all types of marine mammals to seismic vessels can be found in Appendix A (e) of SIO's applicaiton.

The notice of the proposed IHA also included a discussion of the potential effects of the sub-bottom profiler. Because of the shape of the beams and the power of the bottom profiler, NMFS believes it unlikely that marine mammals will be exposed to the sub-bottom profiler at levels at or above those likely to cause harassment.

Estimated Take by Incidental Harassment

The notice of the proposed IHA (72 FR 42045, August 1, 2007) included an in-depth discussion of the methods used to calculate the densities of the marine mammals in the area of the seismic survey and the take estimates. Additional information was included in SIO's application. A summary of the total take authorized is included here.

All anticipated takes authorized by this IHA are Level B harassment only, involving temporary changes in behavior. The far right column in Table 1, “Auth Take”, displays the numbers for which take is authorized. Take calculations were based on maximum exposure estimates (based on maximum density estimates) vs. best estimates and are based on the 160-dB isopleth of a larger array of airguns. Given these considerations, the predicted number of marine mammals that might be exposed to sounds 160 dB may be somewhat overestimated.

Extensive systematic aircraft- and ship-based surveys have been conducted for marine mammals offshore of Oregon and Washington (Bonnell et al., 1992; Green et al., 1992, 1993; Barlow, 1997, 2003; Barlow and Taylor, 2001; Calambokidis and Barlow, 2004). The most comprehensive and recent density data available for cetacean species off slope and offshore waters of Oregon are from the 1996 and 2001 NMFS SWFSC “ORCAWALE” ship surveys as synthesized by Barlow (2003). The surveys were conducted from late July to early November (1996) or early December (2001). They were conducted up to approximately 556 km (1,824 ft) offshore from Oregon and Washington. Systematic, offshore, at-sea survey data for pinnipeds are more limited. The most comprehensive such studies are reported by Bonnell et al. (1992) and Green et al. (1993) based on systematic aerial surveys conducted in 1989 1990 and 1992, primarily from coastal to slope waters with some offshore effort as well.

Since the take estimates authorized in this IHA are no more than 0.4 percent of any cetacean species and no more than 0.01 percent of any pinniped species found along the Oregon coast, NMFS believes that the estimated take numbers for these species and stocks are small relative to both the worldwide abundance of these species and to numbers taken in other activities that have been authorized for incidental take of these species.

Potential Effects on Habitat

A detailed discussion of the potential effects of this action on marine mammal habitat, including physiological and behavioral effects on marine fish and invertebrates, was included in the notice of the proposed IHA (72 FR 42045, August 1, 2007). Based on the discussion in the proposed IHA and the nature of the activities (small airgun and limited duration), the authorized operations are not expected to have any habitat-related effects that could cause significant or long-term consequences for individual marine mammals or their populations or stocks.


Vessel-based marine mammal visual observers (MMVOs) will be based aboard the seismic source vessel and will watch for marine mammals near the vessel during all daytime GI gun operations and during start-ups of the gun at night. MMVOs will also watch for marine mammals near the seismic vessel for at least 30 minutes prior to the start of GI gun operations. When feasible, MMVOs will also make observations during daytime periods when the seismic system is not operating for comparison of animal abundance and behavior. Based on MMVO observations, the airgun will be shut down when marine mammals are observed within or about to enter a designated exclusion zone (EZ; safety radius). The EZ is a region in which a possibility exists of adverse effects on animal hearing or other physical effects.

MMVOs will be appointed by the academic institution conducting the research cruise, with NMFS Office of Protected Resources concurrence. At least one MMVO will monitor the EZ during daytime GI gun operations and any nighttime startups. MMVOs will normally work in shifts of 4 hours duration or less. The vessel crew will also be instructed to assist in detecting marine mammals.

The Wecoma is a suitable platform for marine mammal observations. Observing stations will be on the bridge wings, with observers' eyes approximately 6.5 m (21.3 ft) above the water line and a 180° view outboard from either side, on the whaleback deck in front of the bridge, with observers' eyes approximately 7.5 m (24.6 ft) above the waterline and an approximate 200° view forward, and on the aft control station, with observers' eyes approximately 5.5 m (18 ft) above the waterline and an approximate 180° view aft that includes the 40-m (131-ft; 180-dB) radius area around the GI gun. The eyes of the bridge watch will be at a height of approximately 6.5 m (21.3 ft). MMVOs will repair to the enclosed bridge during any inclement weather.

Standard equipment for MMVOs will be 7 x 50 reticule binoculars and optical range finders. At night, night-vision equipment will be available. Observers will be in wireless communication with ship officers on the bridge and scientists in the ship's operations laboratory, so they can advise promptly of the need for avoidance maneuvers or GI gun shut down.

MMVOs will record data to estimate the numbers of marine mammals exposed to various received sound levels and to document any apparent disturbance reactions. Data will be used to estimate the numbers of mammals potentially “taken” by harassment. It will also provide the information needed to order a shutdown of the GI gun when a marine mammal is within or near the EZ. When a 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 the GI gun or seismic vessel (e.g., none, avoidance, approach, paralleling, etc.), and behavioral pace.

(2) Time, location, heading, speed, activity of the vessel (shooting or not), sea state, visibility, cloud cover, and sun glare.

The data listed under (2) will also be recorded at the start and end of each observation watch and during a watch, whenever there is a change in one or more of the variables.Start Printed Page 51626

All mammal observations and airgun shutdowns will be recorded in a standardized format. Data accuracy will be verified by the MMVOs at sea, and preliminary reports will be prepared during the field program and summaries forwarded to the operating institution's shore facility and to NSF weekly or more frequently. MMVO observations will provide the following information:

(1) The basis for decisions about shutting down the GI gun.

(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) Data on the behavior and movement patterns of marine mammals seen at times with and without seismic activity.


Mitigation and monitoring measures proposed to be implemented for the proposed seismic survey have been developed and refined during previous SIO and L-DEO seismic studies and associated EAs, IHA applications, and IHAs. The mitigation and monitoring measures described herein represent a combination of the procedures required by past IHAs for other SIO and L-DEO projects. The measures are described in detail below.

The number of individual animals expected to be approached closely during the proposed activity will be small in relation to regional population sizes. With the proposed monitoring and shut-down provisions (see below), any effects on individuals are expected to be limited to behavioral disturbance and will have only negligible impacts on the species and stocks.

Mitigation measures that will be adopted will include: (1) vessel speed or course alteration, provided that doing so will not compromise operational safety requirements, (2) GI gun shut down, and (3) minimizing approach to slopes and submarine canyons, if possible, because of sensitivity of beaked whales. Two other standard mitigation measures airgun array power down and airgun array ramp up are not possible because only one, low-volume GI gun will be used for the surveys.

Speed or Course Alteration - If a marine mammal is detected outside the EZ but is likely to enter it based on relative movement of the vessel and the animal, then if safety and scientific objectives allow, the vessel speed and/or direct course will be adjusted to minimize the likelihood of the animal entering the EZ. Major course and speed adjustments are often impractical when towing long seismic streamers and large source arrays but are possible in this case because only one GI gun and a short (300-m, 984-ft) streamer will be used. If the animal appears likely to enter the EZ, further mitigative actions will be taken, i.e., either further course alterations or shut down of the airgun.

Shut-down Procedures - If a marine mammal is within or about to enter the EZ for the single GI gun, it will be shut down immediately. Following a shut down, GI gun activity will not resume until the marine mammal is outside the EZ for the full array. The animal will be considered to have cleared the EZ if it: (1) is visually observed to have left the EZ; (2) has not been seen within the EZ for 15 minutes in the case of small odontocetes and pinnipeds; or (3) has not been seen within the EZ for 30 minutes in the case of mysticetes and large odontocetes, including sperm, pygmy sperm, dwarf sperm, and beaked whales.

Minimize Approach to Slopes and Submarine Canyons - Although sensitivity of beaked whales to airguns is not known, they appear to be sensitive to other sound sources (mid-frequency sonar; see section IV of SIO's application). Beaked whales tend to concentrate in continental slope areas and in areas where there are submarine canyons. Avoidance of airgun operations over or near submarine canyons has become a standard mitigation measure, but there are none within or near the study area. Four of the 16 OBS locations are on the continental slope, but the GI gun is low volume (45 in3), and it will operate only a short time (approximately 2 hours) at each location.


A report will be submitted to NMFS within 90 days after the end of the cruise. The report will describe the operations that were conducted and the marine mammals that were detected near the operations. The report will be submitted to NMFS, providing full documentation of methods, results, and interpretation pertaining to all monitoring. The 90-day report will summarize the dates and locations of seismic operations, all 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.


Pursuant to Section 7 of the ESA, the NSF has consulted informally with NMFS for this action since no take of listed species is anticipated or authorized. NMFS has also consulted internally pursuant to Section 7 of the ESA on the issuance of an IHA under Section 101(a)(5)(D) for this activity. NMFS Section 7 biologists issued a concurrence letter, which concluded that the risk of individuals listed under the ESA being adversely affected in this proposed project is reduced to discountable levels because of the: (1) type and short time frame of the proposed activity (single airgun source with nominal source level (peak to peak) of 230.7 dB re 1 μPa executed for a short period of time (16 sites, no more than two hours at each site, during a two week period); (2) unlikelihood of encountering listed species in the action area during the time of the proposed project; and (3) monitoring and minimization measures to be implemented as part of the proposed project.

National Environmental Policy Act (NEPA)

NSF prepared an Environmental Assessment of a Planned Low-Energy Marine Seismic Survey by the Scripps Institution of Oceanography in the Northeast Pacific Ocean, September 2007. NMFS has adopted NSF's EA and issued a Finding of No Significant Impact for the issuance of the IHA.


NMFS has determined that the impact of conducting the seismic survey in the northeast Pacific Ocean may result, at worst, in a temporary modification in behavior (Level B Harassment) of small numbers of eight species of marine mammals. Further, this activity is expected to result in a negligible impact on the affected species or stocks. The provision requiring that the activity not have an unmitigable adverse impact on the availability of the affected species or stock for subsistence uses does not apply for this action.

This determination is supported by: (1) the likelihood that, given sufficient notice through relatively slow ship speed, marine mammals are expected to move away from a noise source that is annoying prior to its becoming potentially injurious; (2) the fact that marine mammals would have to be closer than either 35 m (115 ft) in intermediate depths or 23 m (75.5 ft) in deep water from the vessel to be exposed to levels of sound (180 dB) believed to have even a minimal chance Start Printed Page 51627of causing TTS; and (3) the likelihood that marine mammal detection ability by trained observers is high at that short distance from the vessel. As a result, no take by injury or death is anticipated or authorized and the potential for temporary or permanent hearing impairment is very low and will be avoided through the incorporation of the required mitigation measures.

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, less than a percent of any of the estimated population sizes, and has been mitigated to the lowest level practicable through incorporation of the measures mentioned previously in this document.


As a result of these determinations, NMFS has issued an IHA to SIO for conducting a low-energy seismic survey in the Pacific Ocean during September, 2007, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated.

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Dated: September 4, 2007,

Helen Golde,

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

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[FR Doc. E7-17775 Filed 9-7-07; 8:45 am]