National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
Notice; issuance of an incidental harassment authorization.
In accordance with the provisions of the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to Eglin Air Force Base (EAFB) to take marine mammals by Level B harassment incidental to Naval Explosive Ordnance Disposal School (NEODS) training operations, which include up to 30 detonations per year of small C-4 charges, off Santa Rosa Island (SRI) at EAFB.
Effective from August 1, 2005, through July 31, 2006.
A copy of the IHA and the application are available by writing to Steve Leathery, 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 references used in this document may be obtained by writing to this address, by telephoning the contact listed here (see FOR FURTHER INFORMATION CONTACT) or online at: http://www.nmfs.noaa.gov/prot_res/PR2/Small_Take/Start Printed Page 51342smalltake_info.htm#applications. Documents cited in this notice may be viewed, by appointment, during regular business hours, at the aforementioned address.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Jolie Harrison, Office of Protected Resources, NMFS, (301) 713-2289, ext 166.End Further Info End Preamble Start Supplemental Information
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, notice of a proposed authorization is provided to the public for review.
Authorization for incidental takings may be granted if NMFS finds that the taking will have no more than 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, and that the permissible methods of taking and requirements pertaining to the monitoring and reporting of such taking 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. The National Defense Authorization Act of 2004 (NDAA) (Public Law 108-136) amended the definition of “harassment” in section 18(A) of the MMPA as it applies to a “military readiness activity” to read as follows:
(i) any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild [Level A Harassment]; or (ii) any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered [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 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 March 11, 2004, NMFS received an application from EAFB, under section 101(a)(5)(D) of the MMPA, requesting authorization for the harassment of Atlantic bottlenose dolphins (Tursiops truncatus) and Atlantic spotted dolphins (Stenella frontalis) incidental to NEODS training operations at EAFB, Florida, in the northern Gulf of Mexico (GOM). Each of up to six missions per year would include up to five live detonations of approximately 5-pound (2.3-kg) net explosive weight charges to occur in approximately 60-ft (18.3-m) deep water from 1-3 nm (1.9 to 5.6 km) off shore. Because this activity will be a multi-year activity, NMFS also plans to develop proposed regulations for NEODS training operations at EAFB.
The mission of NEODS is to train personnel to detect, recover, identify, evaluate, render safe, and dispose of unexploded ordnance (UXO) that constitutes a threat to people, material, installations, ships, aircraft, and operations. The NEODS proposes to utilize three areas within the Eglin Gulf Test and Training Range (EGTTR), consisting of approximately 86,000 square miles within the GOM and the airspace above, for Mine Countermeasures (MCM) detonations, which involve mine-hunting and mine-clearance operations. The detonation of small, live explosive charges disables the function of the mines, which are inert for training purposes. The proposed training would occur approximately one to three nautical miles (nm) (1.9 to 5.6 km) offshore of SRI six times annually, at varying times within the year.
Each of the six training classes would include one or two “Live Demolition Days.” During each set of Live Demolition Days, five inert mines would be placed in a compact area on the sea floor in approximately 60 ft (18.3 m) of water. Divers would locate the mines by hand-held sonars. The AN/PQS-2A acoustic locator has a sound pressure level (SPL) of 178.5 re 1 microPascal at 1 meter and the Dukane Underwater Acoustic Locator has a SPL of 157-160.5 re 1 microPascal at 1 meter. Because these sonar ranges are below any current threshold for protected species, noise impacts are not anticipated and are not addressed further in this analysis.
Five charges packed with five lbs (2.3 kg) of C-4 explosive material will be set up adjacent to each of the mines. No more than five charges will be detonated over the 2-day period. Detonation times will begin no earlier than 2 hours after sunrise and end no later than 2 hours before dusk and charges utilized within the same hour period will have a maximum separation time of 20 minutes. Mine shapes and debris will be recovered and removed from the water when training is completed. A more detailed description of the work proposed for 2005 and 2006 is contained in the application which is available upon request (see ADDRESSES).
Military Readiness Activity
NEODS supports the Naval Fleet by providing training to personnel from all four armed
services, civil officials, and military students from over 70 countries. The NEODS facility supports the Department of Defense Joint Service Explosive Ordnance Disposal training mission. The Navy and the Marine Corps believe that the ability of Sailors and Marines to detect, characterize, and neutralize mines from their operating areas at sea, on the shore, and inland, is vital to their doctrines.
The Navy believes that an array of transnational, rogue, and subnational adversaries now pose the most immediate threat to American interests. Because of their relative low cost and ease of use, mines will be among the adversaries' weapons of choice in shallow-water situations, and they will be deployed in an asymmetrical and asynchronous manner. The Navy needs organic means to clear mines and obstacles rapidly in three challenging environments: shallow water; the surf zone; and the beach zone. The Navy also needs a capability for rapid clandestine surveillance and reconnaissance of minefields and obstacles in these environments. The NEODS mission in the GOM offshore of EAFB is considered a military readiness activity pursuant to the NDAA (Public Law 108-136).
Comments and Responses
A notice of receipt of the EAFB application and proposed IHA was published in the Federal Register on June 7, 2005 (70 FR 33122). During the comment period, NMFS received comments from the Marine Mammal Commission (Commission) and one individual.
Comment 1: The Commission notes that the proposed weapons test appears Start Printed Page 51343to fit within the definition of a “military readiness activity” as defined in section 315(f) of Public Law 107-314, which includes “the adequate and realistic testing of military equipment, vehicles, weapons, and sensors for proper operation and suitability for combat use.” As such, the revised definition of harassment adopted in the NDAA (Public Law 108-136) would seem to be applicable in this instance. However, NMFS' analysis of the small take request does not seem to have employed this definition. If NMFS' preliminary conclusion that “no take by serious 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 (proposed) mitigation measures is correct, it may be that no taking by harassment can be expected and that no authorization is needed. The Commission therefore recommends that NMFS analyze the request for an IHA and the small take regulations being contemplated in light of the applicable definition of the term “harassment.” Although the Commission appreciates NMFS has yet to promulgate regulations or take other steps to implement the new definition, the statutory change cannot be ignored.
Response: In the preamble to the notice of proposed authorization and in this document, NMFS cited the NDAA definition of Level B harassment for military readiness activities. While NMFS believes that the monitoring to be implemented by EAFB will ensure that Level A harassment or mortality is highly unlikely, an authorization under section 101(a)(5) of the MMPA is warranted because some animals could be injured (estimate is 0.4 animals per year) if the mitigation and monitoring overlooks an animal.
Given the uncertainty associated with predicting animal presence and behavior in the field, NMFS accords some deference to applicants requesting an MMPA authorization for an activity that might fall slightly below the NDAA definition of harassment, so that they are covered for impacts that may rise to the level of take. Equally important, such an authorization also carries with it responsibilities to implement mitigation and monitoring measures to protect marine mammals.
Comment 2: The Commission remains concerned that NMFS assessment of potential harassment levels fails to apply the statutory definition of “harassment” in the MMPA. It is the Commission's view that an across-the-board definition of temporary threshold shift (TTS) as constituting no more than Level B Harassment inappropriately dismisses possible injury and biologically significant behavioral effects to the affected animals.
Response: As mentioned in previous Federal Register documents, second level impacts due to a marine mammal having a temporary hearing impairment cannot be predicted and are, therefore, speculative. The principal reason that second level impacts are not considered in classification is that any Level B disruption of behavior could, with suppositions, be seen as potentially dangerous and, therefore, considered potential Level A harassment or even lethal. Similarly, Level A injuries could be seen as being accompanied by some disruption of behavior and, therefore, Level B disturbances as well as Level A injuries. Such reasoning blurs the distinctions that the definitions of harassment attempt to make. NMFS believes that Level B harassment, if of sufficient degree and duration, can be very serious and require consideration, as has been done here. Moderate TTS does not necessarily mean that the animal cannot hear, only that its threshold of hearing is raised above its normal level. The extent of time that this impairment remains is dependent upon the amount of initial threshold shift which in turn depends on the strength of the received sound and whether the TTS is in a frequency range that the animal depends on for receiving cues that would benefit survival. It should be noted that increased ambient noise levels, due to biologics, storms, shipping, and tectonic events may also result in short-term decreases in an animal's ability to hear normally. NMFS scientists believe that marine mammals have likely adopted behavioral responses, such as decreased spatial separation, slower swimming speeds, and cessation of socialization to compensate for increased ambient noise or shifts in hearing threshold levels.
Ship strikes of whales by large vessels suggest that at least certain species of large whales do not use vessel sounds to avoid interactions. Also, there is no indication that smaller whales and dolphins with TTS would modify behavior significantly enough to be struck by an approaching vessel. Finally, a hypothesis that marine mammals would be subject to increased predation presumes that the predators would either not be similarly affected by the detonation or would travel from areas outside the impact zone, indicating recognition between the signal of a single detonation at distance and potentially debilitated food sources. Therefore, NMFS does not believe the evidence warrants that all (or an unknown percentage) of the estimated numbers of Level B harassment be considered as Level A harassment or as potential mortalities.
Comment 3: The Commission believes that NMFS needs to provide a better explanation of, and justification for, using the dual criteria established for determining non-lethal injury (i.e., the onset of slight lung hemorrhage and a 50 percent probability for eardrum rupture).
Response: Explanation and justification were provided in detail in both the SEAWOLF and CHURCHILL Final EISs (DoN 1998 and DoN 2001). An updated summary for using the dual injury criteria from those documents was provided in a recent Federal Register notice, published August 19, 2005, announcing the issuance of an IHA for the Navy's Precision Strike Weapons.
Comment 4: The Commission states that defining Level B acoustic harassment from explosive detonation events in terms off TTS exclusively (i.e., behavioral changes related to temporary hearing impairment), like NMFS does, implies that behavioral changes not related to TTS would not constitute harassment as defined in the MMPA, which is inconsistent with the term “harassment” as it is defined generally in the MMPA.
Response: NMFS justification for the way Level B Harassment is defined as related to explosive detonations is addressed in detail in a recent Federal Register notice, published August 19, 2005, announcing the issuance of an IHA for the Navy's Precision Strike Weapons.
Comment 5: The Commission believes that additional clarification and justification is needed concerning the threshold for “non-injurious behavioral response” proposed in the application (6 dB below TTS (i.e., 176 dB re 1 microPa2-sec).
Response: Based on the science used to develop the CHURCHILL criteria, for single detonations a significant response by a marine mammal is not expected to occur other than by TTS. As noted in the proposed authorization, NEODS training operations consist of six training sessions a year, and each session consists of five single small detonations over the course of 2 days. Due to the infrequent test events, the potential variability in target locations, and the continuous movement of marine mammals in the GOM, NMFS does not anticipate sub-TTS behavioral modification because the same animal will not be repeatedly exposed. The discussion in the application and Federal Register notice is relevant to actions involving multiple detonations. Start Printed Page 51344 NMFS will address comments on this threshold criterion in an applicable proposed IHA application with multiple detonations.
Comment 6: The Commission believes that NMFS should provide a better explanation of and justification for using the 23 psi criterion (versus 12 psi) for estimating the TTS pressure threshold.
Response: This issue remains under review by the Navy, the U.S. Air Force and NMFS. Navy acousticians believe that Ketten (1995), which summarized earlier acoustic research, does not fully support using a 12-psi peak pressure threshold for TTS for underwater explosion impacts on marine mammals from small detonations. The original basis in Ketten (1995) for the use of the 12-psi threshold for the SEAWOLF and CHURCHILL actions (which were 10,000 lb (4,536 kg) detonations) is the use of a combination of in-air and in-water peak pressure measurements without adjustment for the medium. A re-examination of the basis for the 12-psi threshold by Navy acousticians indicates that, for underwater explosions of small charges, a higher threshold may be warranted. This led the Navy and Eglin to suggest scaling 12 psi for small charges, which was used in the proposed authorization notice and analysis. Although this issue remains under review by NMFS and the Navy for future rulemaking actions, as an interim criterion for this IHA and for the Navy Precision Strike Weapon (PSW) IHA, NMFS is adopting the experimental findings of Finneran et al. (2002) that TTS can be induced at a pressure level of 23 psi (at least in belugas). As explained here, this is considered conservative since a 23-psi pressure level was below the level that induced TTS in bottlenose dolphins.
Finneran et al. (2000; as described in Finneran et al. (2002)) conducted a study designed to measure masked TTS (MTTS) in bottlenose dolphins and belugas exposed to single underwater impulses. This study used an “explosion simulator” (ES) to generate impulsive sounds with pressure waveforms resembling those produced by distant underwater explosions. No substantial (i.e., 6 dB or larger) threshold shifts were observed in any of the subjects (two bottlenose dolphins and 1 beluga) at the highest received level produced by the ES: approximately 70 kPa (10 psi) peak pressure, 221 dB re re 1 micro Pa peak-to-peak (pk-pk) pressure, and 179 dB re 1 microPa2-s total EFD. In Finneran et al. (2002), a watergun was substituted for the ES because it is capable of producing impulses with higher peak pressures and total energy fluxes than the pressure waveforms produced using the ES. It was also preferable to other seismic sources because its impulses contain more energy at higher frequencies, where odontocete hearing thresholds are relatively low (i.e., more sensitive). Hearing thresholds were measured at 0.4, 4 and 30 kHz. MTTSs of 7 and 6 dB were observed in the beluga at 0.4 and 30 kHz, respectively, approximately 2 minutes following exposure to single impulses with peak pressures of 160 kPa (23 psi), pk-pk pressures of 226 dB re 1 microPa, and total EFD of 186 dB re 1 microPa2-s. Thresholds returned to within 2 dB of the pre-exposure value approximately 4 minutes post exposure. No MTTS was observed in the single bottlenose dolphin tested at the highest exposure conditions: peak pressure of 207 kPa (30 psi), 228 dB re 1 microPa pk-pk pressure, and 188 dB re 1 microPa2-s total energy flux. Therefore, until more scientific information is obtained, NMFS has determined that the pressure criterion for small explosions can be raised from 12 psi to 23 psi. At this time, NMFS believes that setting the pressure metric at 23 psi is conservative.
Analyses indicate that the ranges for the 23-psi TTS metric at depths of 60 ft (18.3 m) (depth of NEODS missions) are slightly less conservative than the originally provided ranges for the 182-dB (re 1 microPa2-s) TTS energy metric. For the NEODS activity, NMFS will use the more conservative values to determine impacts and areas that need to be monitored.
Comment 7: Based on the information contained in the application and Federal Register notice, the Commission believes that NMFS' preliminary determinations are reasonable, provided that the proposed mitigation and monitoring activities are adequate to detect all marine mammals in the vicinity of the proposed operations and sufficient to ensure that marine mammals are not being taken in unanticipated ways or numbers. The Commission notes however, that even under the best of conditions and using experienced observers, there is greater than an 80-percent likelihood that small cetaceans will not be observed if they are in the vicinity of the test site. Thus, although there may be a low probability that certain marine mammal species will be within the area where mortalities are considered possible at the time of weapon deployment, it is unclear that the proposed monitoring effort will be adequate to detect them if they are present. This being the case, the proposed monitoring activities may be insufficient to provide assurance that marine mammals are not being exposed to sound pressures or energy levels that could cause lethal injuries. Thus, NMFS, before issuing the requested authorization, should further explain its rationale for determining that the takings will only be by harassment.
Response: The vessel monitoring effort for NEODS is similar to that used in previous Navy ship-shock actions, with the differences being that the zone of influence is significantly smaller and the water is shallower, both of which make it even more likely that a marine animal will be detected. In these past ship-shock actions, detonations of 10,000 lbs (4536 kg) were used without any serious injuries or mortalities being noted during extensive follow-up monitoring. Though aerial surveys were also incorporated into the ship-shock monitoring measures, they were considered less effective than vessel monitoring for NEODS, and in fact, the Navy found that detection of bottlenose dolphins and spotted dolphins by shipboard observers was 100 percent (DON, 1999, Appendix C). Since, for safety reasons, the observer vessel will need to move out of the testing area immediately prior to the detonation (but will continue to monitor the ZOI), we can probably assume that the detection of dolphins within the ZOI is somewhat less than 100 percent. However, since the estimated (based on density estimates) number of any marine mammals that could potentially be exposed to energy levels that may cause Level A Harassment or death during the course of the 30 individual detonations per year, without any observers present, is only 0.4, NMFS is confident that no marine mammals will be killed as a result of EAFB's NEODS training operations.
Comment 8: The Commission recommends that, if NMFS determines that the potential for lethal injuries is sufficiently remote to warrant the issuance of an authorization under section 101(a)(5)(D) of the MMPA, any such authorization explicitly require that operations be suspended immediately if a dead or seriously injured animal is found in the vicinity of the test site, pending authorization to proceed or issuance of regulations authorizing such takes under section 101(a)(5)(A) of the MMPA.
Response: NMFS concurs with the Commission's recommendation and has included the requirement in the IHA.
Description of Marine Mammals and Habitat Affected by the Activity
Marine mammal species that potentially occur within the EGTTR include several species of cetaceans and Start Printed Page 51345the West Indian manatee. While a few manatees may migrate as far north as Louisiana in the summer from southern Florida (where there are generally confined in the winter), they primarily inhabit coastal and inshore waters and rarely venture offshore. NEODS missions are conducted at a distance of between 1 and 3 nm (5.6 km) from shore and effects on manatees are therefore considered very unlikely and not discussed further in this analysis.
Cetacean abundance estimates for the project area are derived from GulfCet II aerial surveys conducted from 1996 to 1998 over a 70,470 km2 area, including nearly the entire continental shelf region of the EGTTR, which extends approximately 9 nm (16.7 km) from shore. The dwarf and pygmy sperm whales are not included in this analysis because their potential for being found near the project site is remote. Although Atlantic spotted dolphins do not normally inhabit nearshore waters, they are included in the analysis to ensure conservative mitigation measures are applied. The two marine mammal species expected to be affected by these activities are the bottlenose dolphin (Tursiops truncatus) and the Atlantic spotted dolphin (Stenella frontalis). Descriptions of the biology and local distribution of these species can be found in the application (see ADDRESSES for availability), other sources such as Wursig et al. (2000), and the NMFS Stock Assessments, which can be viewed at: http://www.NMFS.noaa.gov/pr/PR2/Stock_Assessment_Program/sars.html.
The habitat at the NEODS test sites is approximately 60-ft (18.3-m) deep open water. The EGTTR contains many reefs, both natural and artificial, but the closest reef to the NEODS test site is an artificial reef over 2 mi (3.2 km) away.
Atlantic Bottlenose Dolphins
Atlantic bottlenose dolphins are distributed worldwide in tropical and temperate waters and occur in the slope, shelf, and inshore waters of the GOM. Based on a combination of geography and ecological and genetic research, Atlantic bottlenose dolphins have been divided into many separate stocks within the GOM. The exact structure of these stocks is complex and continues to be revised as research is completed. For now, bottlenose dolphins inhabiting waters less than 20 m (66 ft) deep in the U.S. GOM are believed to constitute 36 inshore or coastal stocks, and those inhabiting waters from 20 to 200 m (66 to 656 ft) deep in the northern GOM from the U.S.-Mexican border to the Florida Keys are considered the continental shelf stock (Waring et al., 2004). The proposed action would occur on the ocean floor at a depth of approximately 60 ft (18 m) and therefore has the potential to affect both the continental shelf and inshore stocks.
Continental shelf stock assessments were estimated using data from vessel surveys conducted between 1998 and 2001 (at 20- to 200-m (66- to 656-ft) depths). The minimum population estimate for the northern GOM continental shelf stock of the Atlantic bottlenose dolphin is 20,414 (Waring et al., 2004).
The most recent inshore stock assessment surveys were conducted aerially in 1993 and covered the area from the shore or bay boundaries out to 9.3 km (5.0 nm) past the 18.3 m-depth (60.0 nm-depth) isobath (a slightly different area than that defined as inshore in the more recent stock assessment above). The minimum population estimate of the northern GOM coastal stock of the Atlantic bottlenose dolphin was 3,518 dolphins (Waring et al., 1997).
Texas A&M University and the NMFS conducted GulfCet II aerial surveys in an area including the EGTTR from 1996 to 1998. Density estimates were calculated using abundance data collected from the continental shelf area of the EGTTR. In an effort to provide better species conservation and protection, estimates were adjusted to incorporate temporal and spatial variations, surface and submerged variations, and overall density confidence. The adjusted density estimate for Atlantic bottlenose dolphins within the project area is 0.810 individuals/km2. A small number of dolphins could not be identified specifically as Atlantic bottlenose or Atlantic spotted and their estimated density was 0.053 individuals/km2.
Atlantic Spotted Dolphins
Atlantic spotted dolphins are endemic to the tropical and warm temperate waters of the Atlantic Ocean and can be found from the latitude of Cape May, New Jersey south along mainland shores to Venezuela, including the GOM and Lesser Antilles. In the GOM, Atlantic spotted dolphins occur primarily in continental shelf waters 10 to 200 m (33 to 656 ft) deep out to continental slope waters less than 500 m (1640.4 ft) deep. One recent study presents strong genetic support for differentiation between GOM and western North Atlantic management stocks, but the Gulf of Mexico stock has not yet been further subdivided.
Abundance was estimated in the most recent assessment of the northern GOM stock of the Atlantic spotted dolphin using combined data from continental shelf surveys (20 to 200 m (66 to 656 ft) deep) and oceanic surveys (200 m (656 ft)) to the offshore extent of U.S. Exclusive Economic Zone) conducted from 1996 to 2001. The minimum population estimate for the northern GOM is 24,752 Atlantic spotted dolphins (Waring et al., 2004).
Density estimates for the Atlantic spotted dolphin within the EGTTR were calculated using abundance data collected during the GulfCet II aerial surveys. In an effort to provide better species conservation and protection, estimates were adjusted to incorporate temporal and spatial variations, surface and submerged variations, and overall density confidence. The adjusted density estimate for Atlantic spotted dolphins within the project area is 0.677 individuals/km2. A small number of dolphins could not be identified specifically as Atlantic bottlenose or Atlantic spotted and their estimated density was 0.053 individuals/km2.
Potential Effects of Activities on Marine Mammals
The primary potential impact to the Atlantic bottlenose and the Atlantic spotted dolphins occurring in the EGTTR from the proposed detonations is Level B harassment from noise. There is a slight potential, absent mitigation, that a few mammals would be injured or killed due to the energy generated from an explosive force on the sea floor. Analysis of NEODS noise impacts to cetaceans was based on criteria and thresholds presented in both Finneran et al., 2002, and in the U.S. Navy Environmental Impact Statements for ship shock trials of the SEAWOLF submarine and the WINSTON CHURCHILL vessel and subsequently adopted by NMFS.
Non-lethal injurious impacts (Level A Harassment) are defined in as tympanic membrane (TM) rupture and the onset of slight lung injury. The threshold for Level A Harassment corresponds to a 50 percent rate of TM rupture, which can be stated in terms of an energy flux density (EFD) value of 205 dB re 1 microPa2 s. TM rupture is well-correlated with permanent hearing impairment (Ketten (1998) indicates a 30-percent incidence of permanent threshold shift (PTS) at the same threshold). The zone of influence (ZOI)(farthest distance from the source at which an animal is exposed to the EFD level referred to) for the Level A Harassment threshold is 52.2 m (171.6 ft).
Level B (non-injurious) Harassment includes temporary (auditory) threshold shift (TTS), a slight, recoverable loss of Start Printed Page 51346hearing sensitivity. The energy criterion used for TTS is 182 dB re 1 microPa2's maximum EFD level in any 1/3-octave band above 100 Hz for toothed whales (e.g., dolphins). The ZOI for this threshold is 229.8 m (754.0 ft). The pressure criterion, 23 psi, has recently been established by NMFS based on the more current work of Finneran et al., 2002. The ZOI for 23 psi is 222 m (728 ft). A detailed justification for the recent change in NMFS' pressure exposure criteria may be found in the Federal Register notice for the issuance of an IHA to the Navy for Precision Strike Weapons, published August 19, 2005.
Level B Harassment also includes behavioral modifications resulting from repeated noise exposures (below TTS) to the same animals (usually resident) over a relatively short period of time. No strictly sub-TTS behavioral responses (i.e., Level B harassment) are anticipated with the NEODS training activities because there are no successive detonations (5 small detonations in the course of 2 days, some of which may be separated by less than 20 minutes, but which would be in separate locations) which could provide causation for a behavioral disruption rising to the level of a significant alteration or abandonment of behavioral patterns without also causing TTS. Also, repetitive exposures (below TTS) to the same resident animals are highly unlikely due to the infrequent NEODS training sessions (6 sessions per year), the potential variability in target locations, and the continuous movement of marine mammals in the northern GOM.
Because of mitigation measures proposed, NMFS anticipates that only Level B harassment will occur incidental to the NEODS training operations and that these events will result in no more than a negligible impact on marine mammal species or their habitats.
Mitigation and Monitoring
Mitigation will consist primarily of surveying and taking action to avoid detonating charges when protected species are within the ZOI. A trained, NMFS-approved observerwill be staged from the highest point possible on a support ship and have proper lines of communication to the Officer in Tactical Command. The survey area will be 460 m (1509 ft) in every direction from the target, which is twice the radius of the ZOI for Level B Harassment (230 m (755 ft)). To ensure visibility of marine mammals to observers, NEODS missions will be delayed if whitecaps cover more than 50 percent of the surface or if the waves are greater than 3 feet (Beaufort Sea State 4).
Pre-mission monitoring will be used to evaluate the test site for environmental suitability of the mission. Visual surveys will be conducted 2 hours, 1 hour, and 5 minutes prior to the mission to verify that the ZOI (230 m (755 ft)) is free of visually detectable marine mammals, sea turtles, large schools of fish, large flocks of birds, large Sargassum mats, or large concentrations of jellyfish and that the weather is adequate to support visual surveys. The observer will plot and record sightings, bearing, and time for all marine mammals detected, which would allow the observer to determine if the animal is likely to enter the test area during detonation. If an animal appears likely to enter the test area during detonation, if marine mammals, sea turtles, large schools of fish, large flocks of birds, large Sargassum mats, or large concentrations of jellyfish are present, or if the weather is inadequate to support monitoring, the observer will declare the range fouled and the tactical officer will implement a hold until monitoring indicates that the test area is and will remain clear of detectable marine mammals or sea turtles.
Monitoring of the test area will continue throughout the mission until the last detonation is complete. The mission would be postponed if:
(1) Any marine mammal is visually detected within the ZOI (230 m (755 ft)). The delay would continue until the animal that caused the postponement is confirmed to be outside the ZOI (visually observed swimming out of the range).
(2) Any marine mammal or sea turtle is detected in the ZOI and subsequently is not seen again. The mission would not continue until the last verified location is outside of the ZOI and the animal is moving away from the mission area.
(3) Large Sargassum rafts or large concentrations of jellyfish are observed within the ZOI. The delay would continue until the Sargassum rafts or jellyfish that caused the postponement are confirmed to be outside of the ZOI either due to the current and/or wind moving them out of the mission area.
(4) Large schools of fish are observed in the water within of the ZOI. The delay would continue until large fish schools are confirmed to be outside the ZOI.
In the event of a postponement, pre-mission monitoring would continue as long as weather and daylight hours allow. If a charge failed to explode, mitigation measures would continue while operations personnel attempted to recognize and solve the problem (detonate the charge).
Post-mission monitoring is designed to determine the effectiveness of pre-mission mitigation by reporting any sightings of dead or injured marine mammals or sea turtles. Post-detonation monitoring, concentrating on the area down current of the test site, will commence immediately following each detonation and continue for at least two hours after the last detonation. The monitoring team will document and report to the appropriate marine animal stranding network any marine mammals or turtles killed or injured during the test and, if practicable, recover and examine any dead animals. The species, number, location, and behavior of any animals observed by the teams would be documented and reported to the Officer in Tactical Command.
EAFB will notify NMFS 2 weeks prior to initiation of each training session. Any takes of marine mammals other than those authorized by the IHA, as well as any injuries or deaths of marine mammals, will be reported to the Southeast Regional Administrator, NMFS, by the next working day. A summary of mission observations and test results, including dates, times, and locations of detonations as well as pre- and post-mission monitoring observations, will be submitted to the Division of Permits, Conservation, and Education, Office of Protected Resources (NMFS) and the Southeast Regional Office (NMFS) within 90 days after the completion of the last training session.
Numbers of Marine Mammals Expected to be Harassed
Estimates of the potential number of Atlantic bottlenose dolphins and Atlantic spotted dolphins to be harassed by the training were calculated using the number of distinct firing or test events (maximum 30 per year), the ZOI for noise exposure, and the density of animals that potentially occur in the ZOI. The take estimates provided here do not include mitigation measures, which are expected to further minimize impacts to protected species and make injury or death highly unlikely.
The estimated number of Atlantic bottlenose dolphins and Atlantic spotted dolphins that could potentially be exposed to the Level A Harassment threshold (205 dB re 1 microPa2 s) during one year is less than one (0.22 and 0.19, respectively).
For Level B Harassment, two separate criteria were established, one expressed in dB re 1 microPa2 s maximum EFD level in any 1/3-octave band above 100 Start Printed Page 51347Hz, and one expressed in psi. The estimated numbers of Atlantic bottlenose dolphins and Atlantic spotted dolphins potentially exposed to 182 dB and 23 psi, during one year, if mitigation measures were not effectively implemented within the 230-m (754 ft) ZOI, are 4 and 3 individuals.
Possible Effects of Activities on Marine Mammal Habitat
The Air Force anticipates no loss or modification to the habitat used by Atlantic bottlenose dolphins or Atlantic spotted dolphins in the EGTTR. The primary source of marine mammal habitat impact resulting from the NEODS missions is noise, which is intermittent (maximum 30 times per year) and of limited duration. NMFS does not anticipate that either debris (which will be recovered following test activities) or the minimal chemical residue from the detonated charges will affect marine mammal habitat.
Possible Effects of Activities on Subsistence Needs
There are no subsistence uses for Atlantic bottlenose dolphins Atlantic spotted dolphins in Florida waters, and thus, there are no anticipated effects on subsistence needs.
Endangered Species Act
In a Biological Opinion issued on October 25, 2004, NMFS concluded that the NEODS training missions and their associated actions are not likely to jeopardize the continued existence of threatened or endangered species under the jurisdiction of NMFS or destroy or adversely modify critical habitat that has been designated for those species. NMFS has issued an incidental take statement (ITS) for 4 species of sea turtles (leatherback sea turtle (Dermochelys coriacea), green sea turtle (Chelonia mydas), Kemp's ridley sea turtle (Lepidochelys kempii), and loggerhead sea turtle (Caretta caretta)) pursuant to section 7 of the Endangered Species Act. The ITS contains reasonable and prudent measures with implementing terms and conditions to minimize the effects of this take. This IHA action is within the scope of the previously analyzed action and does not change the action in a manner that was not considered previously.
National Environmental Policy Act
NMFS prepared an Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) on the Issuance of Authorizations to Take Marine Mammals, by Harassment, Incidental to Naval Explosive Ordnance Disposal School Training Operations at Eglin Air Force Base, Florida. Therefore, preparation of an EIS on this action is not required by section 102(2) of the NEPA or its implementing regulations. A copy of the EA and FONSI are available upon request (see ADDRESSES).
NMFS has determined that the NEODS training operations, as described in this document and in the application for an IHA, will result in no more than Level B harassment of Atlantic bottlenose dolphins and Atlantic spotted dolphins and will have no more than a negligible impact on these stocks. The effects of the NEODS training are expected to be limited to short-term and localized TTS-related behavioral changes, and these takes will be at the lowest level practicable due to incorporation of the mitigation measures mentioned previously in this document. With the application of the mitigation measures, as well as the potential density of dolphins in the area of the NEODS training operations, NMFS believes it highly unlikely that the proposed action will result in any injury or mortality of marine mammals. Additionally, the NEODS training operations will not have an unmitigable adverse impact on the availability of marine mammal stocks for subsistence use, as there are no subsistence uses for Atlantic bottlenose dolphins or Atlantic spotted dolphins in Florida waters.
NMFS has issued a 1-year IHA to EAFB for the take of Atlantic bottlenose dolphins and Atlantic spotted dolphins, by harassment, incidental to NEODS training operations, which include up to 30 detonations of small C-4 charges per year, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated.Start Signature
Dated: August 23, 2005.
Acting Director, Office of Protected Resources, National Marine Fisheries Service.
[FR Doc. 05-17224 Filed 8-29-05; 8:45 am]
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