E6-21979. Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Surf Zone Testing/Training and Amphibious Vehicle Training and Weapons Testing

AGENCY:

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

ACTION:

Notice of issuance of an incidental harassment authorization.

SUMMARY:

In accordance with provisions of the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that an Incidental Harassment Authorization (IHA) to take marine mammals, by harassment, incidental to conducting surf zone testing/training and amphibious vehicle training and weapons testing off the coast of Santa Rosa Island (SRI) has been issued to the U.S. Air Force Eglin Air Force Base (Eglin AFB) for a period of 1 year. NMFS may propose regulations at a later date that would govern these incidental takes under a Letter of Authorization (LOA) issued to Eglin for a period of up to 5 years after the 1-year IHA expires.

DATES:

This authorization is effective from December 11, 2006 until December 10, 2007.

ADDRESSES:

A copy of the application, IHA, the Santa Rosa Island Mission Utilization Plan Programmatic Environmental Assessment (SRI Mission PEA), and/or a list of references used in this document may be obtained 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 one of the contacts listed here (see FOR FURTHER INFORMATION CONTACT). The application and the SRI Mission PEA is also available at: http://www.nmfs.noaa.gov/​pr/​permits/​incidental.htm.

FOR FURTHER INFORMATION CONTACT:

Shane Guan, NMFS, [phone], ext 137.

SUPPLEMENTARY INFORMATION:

Background

Sections 101(a)(5)(A) and 101(a)(5)(D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce (Secretary) to allow, upon request, the incidental, but not intentional taking of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

An authorization shall 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 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 “...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 marine mammals by harassment. With respect to “military readiness activities,” the MMPA defines “harassment” 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].

Summary of Request

On November 21, 2005, Eglin AFB petitioned NMFS for an authorization under section 101(a)(5) of the MMPA for the taking, by harassment, of marine mammals incidental to programmatic mission activities on Eglin's SRI property, including the shoreline of the Gulf of Mexico (Gulf or GOM) to a depth of 30 feet (9.1 meters). The distance from the island shoreline that corresponds to this depth varies from approximately 0.5 mile (0.8 km) at the western side of the Air Force property to 1.5 miles (2.4 km) at the eastern side, extending out into the inner continental shelf.

Activities conducted within the action area are addressed in the Estuarine and Riverine Areas Programmatic Environmental Assessment (U.S. Air Force, 2003a). The proposed action is for the 46th Test Wing Commander to establish a mission utilization plan for SRI based on historical and anticipated future use. Current and future operations are categorized as either testing or training and include: 1) Surf Zone Testing/Training; 2) Landing Craft Air Cushion (LCAC) Training and Weapons Testing; 3) Amphibious Assaults; and 4) Special Operations Training.

Description of Activities

The activities proposed by Eglin AFB include surf zone testing/training and amphibious vehicle training and weapon testing. A detailed description of these activities was published in the Federal Register on June 22, 2006 (71 FR 35870). No change was made to these proposed activities.

Surf zone testing/training activities and amphibious vehicle testing/training activities would be intermittent yet ongoing, and therefore Eglin AFB has also made a request for a take authorization under section 10(a)(5)(A) of the MMPA for a time period of five years. These activities would occur within the proposed action area, which includes the Gulf-side shoreline of SRI seaward to a depth of 30 feet (91 m). The distance from the shoreline that corresponds to this depth varies from approximately 0.5 mile (0.8 km) at the western side of the Air Force property to 1.5 miles (2.4 km) at the eastern side, extending into the inner continental shelf.

Training involving live fire exercises would be carried out a maximum twice per year (one during daytime and/or one at night). These missions would involve special operations personnel, an LCAC, or an AAV on the north shore of the island or in Santa Rosa Sound firing at a target located on SRI. The target would be a hardended structure of steel or wood. The angle of firing would be toward the ground and ricocheting would be minimal due to the sandy substrate. The NSWCPC would use low-range, high-fragmentation munitions at the maneuver areas to allow for more realistic training scenarios. The NSWCPC would direct live fire toward the Gulf.

Comments and Responses

A notice of receipt and request for 30-day public comment on the application and proposed authorization was published on June 22, 2006 (71 FR 35870). During the 30-day public comment period, NMFS received the following comments from the Humane Society of the United States (HSUS) and the Marine Mammal Commission (Commission).

Comment 1: The HSUS stated that the bottlenose dolphin stocks in the area are likely declining as a result of recent die-offs and can ill afford additional impacts. The HSUS argues that the population estimates were outdated and the relatively high number of bottlenose dolphin deaths that have occurred since 1990 raises the concern that not only are some of the stocks “stressed,” but they may even be in decline. HSUS further suggested that dolphins near Santa Rosa were also affected in the 1999 mass stranding event near St. Joseph Bay. Therefore, HSUS argues that the estimated impacts of bottlenose dolphins cannot be assumed to apply merely to those animals sighted in the Santa Rosa area.

Response: In NMFS' 2006 stock assessment report, NMFS stated that there is not sufficient data to determine population trends for all the Gulf of Mexico bay, sound and estuary bottlenose dolphin communities (Waring et al., 2006). NMFS acknowledges that the relatively high number of bottlenose dolphin deaths which occurred during the mortality events since 1990 and agrees that some of these stocks may be stressed. However, this is not relevant to the issuance of the IHA, since Eglin AFB's surf zone activities will take place a maximum of only once a year for surf zone testing/training mission and a maximum of a couple of times per year for live fire operations, with no serious injury or mortality expected. NMFS believes that Eglin's activities are unlikely to add to existing mortality levels. As a result, NMFS does not believe that authorizing the taking of bottlenose dolphins by Level B harassment will have more than a negligible impact on the affected dolphin stocks. Additionally, NMFS will require mitigation and monitoring measures to further reduce potential impacts to these marine mammal species and stocks. Although it is difficult to interpret these mass stranding events, bottlenose dolphins are known to become entangled in recreational and commercial fishing gear (Wells and Scott, 1994; Wells et al., 1998; Gorzelany, 1998) and some are struck by recreational and commercial vessels (Wells and Scott, 1997). Waring et al. (2006) estimated that as many as 172 bottlenose dolphins could have been taken in the GOM menhaden fishery alone between 1992 and 1995.

Comment 2: The HSUS is concerned that the density for bottlenose dolphins and spotted dolphins are based on outdated data. The HSUS believes that the population estimates for the various stocks of these species are substantially lower and the stocks thus more vulnerable to adverse impacts. The HSUS stated that it is reasonable to presume that there has been some redistribution of animals, which further complicates understanding of distribution and density and calls into question the density estimates used in this application to calculate risk.

Response: The combined estimated abundance for the Atlantic spotted dolphin in the northern GOM, pooled from 1998 through 2001, for the outer continental shelf shipboard surveys was 30,772 (Fulling et al., 2003). NMFS has relied upon the best scientific information available and does not believe these five-year old data are outdated.

The population survey of the three GOM bay, sound, and estuarine bottlenose dolphin stocks were last conducted more than 8 years ago. While the data relied upon were developed in 1998, NMFS continuous to believe that these data sets comprise the best available information. The abundance for the northern coastal, the Pensacola Bay/East Bay, and the Choctawhatchee Bay bottlenose dolphins stocks were estimated at 9,912, 33, and 242 animals, respectively (Waring et al., 2006). NMFS scientists in the Southeast Region have confirmed that this is the best available information to date.

Comment 3: The HSUS questions the methodology that used 30 percent of the time dolphin spent at the surface to calculate the density estimate. The HSUS stated that according to Dr. Randall Wells, a more appropriate estimate would be 5 percent of the time being spent at the surface. The HSUS also is concerned that since bottlenose dolphins rarely travel as singles, the impacts will likely be on groups of animals rather than on individuals.

Response: NMFS agrees with HSUS' assessment that bottlenose dolphins may spend up to 95 percent of their time under the sea surface, though one study conducted on a single adult female bottlenose dolphin showed that this individual spent approximately 87.1 ± 0.6 percent of its time submerged (Mate et al., 1995). However, the 30 percent dive profile used by Eglin AFB to calculate bottlenose dolphin density is to compensate for the presence of submerged and uncounted animals. As mentioned in the Federal Register notice (71 FR 35870, June 22, 2006), the water clarity in the northeastern GOM is typically very high, and it is often possible to view the entire water column in the water depth that defines the action area (30 ft or 9.1 m). Research on inshore bottlenose dolphin behavior off the western coast of Florida showed that dolphins were sighted 92 percent time in the water column in 4.5 m (14.8 ft) or less (Shane, 1990). Therefore, NMFS believes it is likely that all animals will be detected during the marine mammal monitoring, regardless whether the animals are at the surface or submerged.

NMFS does not agree with HSUS' assessment that since dolphins rarely travel as singles, the impacts will likely be on groups of animals rather than on individuals. As noted in the Federal Register notice (71 FR 35870, June 22, 2006), since dolphins tend to stay in groups, it makes much easier to detect animals in the field as different individuals don't always surface at the same time. The mitigation measures require that no activities be carried out when an animal is detected within the safety zone. NMFS believes that no animals, either in groups or solitary, will likely to be impacted by more than Level B harassment. Because activities would be halted if there is a sighting of individual animals or a group.

Comment 4: The HSUS is concerned that the estimation of the number of animals affected by blast trauma seems low, in regards to HSUS' density estimates for marine mammals and the likelihood of detecting animals that spend little time at the surface. The HSUS also questioned NMFS' determination that no animals will be injured or killed by detonation and live fire operations.

Response: If the HSUS' statement in Comment 2 that the population estimates for the various stocks of these dolphin species are substantially lower is true, then the number of animals affected by blast trauma would be even lower than NMFS' assessment. As stated in the Federal Register notice (71 FR 35870, June 22, 2006), the estimated number of mammal takes is carefully calculated by applying marine mammal density to the zone of influence (ZOI) for each detonation type. Live-fire operations will use small caliber weapons between 5.56 mm and .50 caliber with low-range munitions, and will be conducted on SRI in an area of less than 1 km (0.62 mile) wide. Live-fire exercise involves firing at a hardened structure of steel or wood, and angle of firing would be toward the ground and ricocheting would be minimal due to sandy substrate on SRI. Therefore, it is extremely unlikely that a dolphin would be hit by a stray projectile that misses the target and passes the firing range on SRI into the GOM. Species density is based on adjusted GulfCet II aerial survey data, which is the best available data to date.

Comment 5: The HSUS noted that the calculation of noise impacts from the proposed activities is based on spherical propagation of sound in deep water. The HSUS thinks that shallow water reflection of pressure waves off the bottom can result in both pressure wave impacts and acoustic impacts well beyond a radius predicted by spherical spreading, as the HSUS cited NMFS' assessment on the onset of slight lung injury by precision strike weapons using Goertner model (70 FR 48675).

Response: One should not be confused by the difference between the overpressures and acoustics impacts upon marine mammals. The former is a wave of pressure in the water column caused by underwater explosions, and the latter is the noise generated by the explosions. Injury ranges determined by the Goertner (1982) model are most appropriate for use in regions close to the explosive charge, while the proposed surf zone detonation will ensure that no marine mammals as present in the area where Level A harassment could occur. It is correct that calculation based on spherical propagation of noise impacts does not precisely fit the proposed activity. It is also true that shallow-water mine-clearing systems are comprised of lines or multiple blocks of explosive and would typically produce non-spherical zones of influence, therefore, all NET explosive weights in the systems analyzed by Eglin AFB were totaled and a single point of detonation assumed for each system. This approach provides a simplified but conservative analysis. In addition, bottom absorption is likely to reduce much of the acoustic energy that is reflected back into water column.

Comment 6: The HSUS is concerned that the noise effects from activities involving amphibious vehicles would not be negligible. The HSUS states that noise penetrates the surface of the water when the surface is disrupted by waves and chop. The HSUS is also concerned that dolphins will be able to hear the noise and be disturbed when they are at surface.

Response: NMFS agrees that some noise from the landing craft could penetrate into the water column when the surface is disrupted by wind and wave, however, much of the acoustic energy will be reflected at the surface due to different acoustic impedance between air and water. In addition, there is no evidence that the maximum noise level (98 dBA) from the LCAC's engine in air will cause more than a momentary disturbance in dolphins. If the noise level is high enough to cause disturbances to marine mammals, it is most likely that marine mammals in the vicinity will move away from the noise source quickly.

Comment 7: The HSUS argues that the ZOI for this type of activity would be far greater than 2 km (1.24 miles) and thus far more than 68 dolphins without mitigation measures (71 FR 35870, June 22, 2006) would be harassed. The HSUS states that it is difficult to conceive only a few dozen dolphins would hear and be disturbed by the noise. The HSUS also states that it seems far more likely that every dolphin within a several-mile radius will hear the explosions, rumbles, and rockets and will at the least temporarily abandon their activities and move away from the noise.

Response: The Federal Register notice (71 FR 35870, June 22, 2006) provided detailed description and analyses on the calculation of ZOI relative to different munitions and are not repeated here. The results of these analyses point out that the radii of safety zones and the estimated number of takes that could occur are scientifically sound and are supported by the Committee of Scientific Advisors of the Commission. There is no evidence that the ZOI for this type of activity would be far greater than 2 km (1.24 miles) and more than 68 dolphins without mitigation measures (71 FR 35870, June 22, 2006) would be harassed. While it is possible that dolphins within a several-mile radius of the action area could detect explosions, these noises would be so low at these distances and would most likely be masked by the prevailing ambient noise from waves, surf, vessels, and bubbles. Therefore, NMFS believes it is highly unlikely that marine mammals outside the safety zone will abandon their activities and move away.

Comment 8: The HSUS is concerned about the effectiveness of mitigation and monitoring measures that rely on clarity of water, the Beaufort sea state, and the visibility of bottlenose dolphins surface activity.

Response: Clarity of water, Beaufort sea state under 3, and using trained marine mammal observers to monitor the action area prior to proposed activity are only three of the several requirements in the IHA. Other mitigation and monitoring measures that are required for the proposed activity, include: (1) limiting surf zone testing/training missions under daylight conditions; and (2) limiting surf zone testing between November 1 and March 1 to avoid takes of manatees and sea turtles. NMFS scientists believe that these mitigation and monitoring measures are effective for the proposed activity and would result in the least practicable adverse impact, and this determination is supported by the Committee of Scientific Advisors of the Commission.

Comment 9: The HSUS stated that vessels on the water have a more limited field of view than helicopters. The HSUS questions the justification for use of one type of monitoring platform and not the other in various activities, and requests that Eglin AFB be required to use the most effective (as opposed to the most expedient) platform for detecting dolphins, manatees and turtles in the area for all activities.

Response: The effectiveness of platforms used in detecting marine mammals depends on a number of conditions, such as the size of the monitored area and the height of the platform above the water. For monitoring activities during surf zone detonation, the area could reach a 2.3 km (1.4 mile) radius, therefore, a helicopter is believed to be more effective in monitoring this area. However, the live-fire operations are conducted in a much smaller area of the SRI beach, and monitoring would only focus on this limited zone. NMFS believes that small vessels can provide more effective monitoring of this area.

Comment 10: The HSUS questions the speed of helicopters as it stated that “the speed of the aircraft has a significant effect on the observer's ability to detect animals.” The HSUS also stated that the expertise of personnel is crucial to the effectiveness of this mitigation measure.

Response: Eglin AFB has not identified a need to specify a maximum or minimum speed at which survey helicopters may operate. All NMFS-approved MMOs are qualified aerial surveyors and are familiar with area of operations as well as the protected species that occur in the region. MMOs are aware of the effect of helicopter speed on survey effectiveness and operate at speeds that maximize the likelihood of animal detection.

Comment 11: The HSUS is concerned that mitigation will not be possible when live-fire exercises are conducted at night. The HSUS requests that mitigation be required during night-time exercise, and if not, night-time activity should not be permitted.

Response: The proposed live fire exercise that might occur at night would be conducted on the firing range on SRI. Eglin's proposal was developed to take into account potential impacts to marine mammals. As part of this proposed action, Eglin will require the following measures that are designed to lessen impacts. These include: (1) firing at a hardened structure of steel or wood so the bullets do not penetrate the target and continue into the GOM; (2) firing at an angle toward the ground so ricocheting would be minimal due to sandy substrate on SRI; and (3) using small caliber weapons between 5.56 mm and .50 caliber with low-range munitions. In addition, there will be a maximum of 1 live-fire night-time exercise per year. Therefore, it is extremely unlikely that a dolphin would be hit by a stray bullet.

Comment 12: The HSUS noted that the permit application stated that the activity being conducted could require closure to vessels of some areas of the GOM to accommodate a 2.5 mile (4.0 km), 110-degree safety fan (71 FR 35870, June 22, 2006, page 35871). The HSUS also noted that the risk analysis presumed for dolphins stated the risk is largely in a range that does not exceed 1 km (0.62 mile) (71 FR 35870, June 22, 2006, page 35874). The HSUS requests a greater degree of precaution for dolphins.

Response: The 2.5-mile (4.0 km), 110-degree safety fan refers specifically to the cleared water surface area that is associated with SABRE system testing. This safety fan does not apply to other activities. SABRE system testing involves a rocket-propelled launch of a line of explosives into the air. If conducted at the eastern end of Eglin's SRI property, which is in close proximity to a large civilian population (both residents and tourists), human safety would be a concern. Therefore, a relatively large area of the water surface would be closed to non-military vessels during testing. Safety considerations in this case result from potential above-water impacts due to rocket motor, charge line, or shrapnel/debris strikes.

Conversely, the potential risk to dolphins results from underwater impacts, primarily underwater noise produced by detonations. Table 1 of the Federal Register notice (71 FR 35870, June 22, 2006, page 35873) provides the range of various types of impacts due to underwater noise. These distances range from 42 m (138 ft) to 1.8 km (5906 ft), depending on the threshold evaluated and the net explosive weight used. Above-water human safety zones and in-water noise impact zones are not directly comparable.

Comment 13: The HSUS noted that post-activity monitoring was only specified for detonation activity, but not other activity. The HSUS is also concerned that a 15-minute helicopter post-activity monitoring is insufficient because any animal that is injured but does not immediately die and float to the surface will be undetected.

Response: Post-activity monitoring measures are required for all activities under this IHA. Due to the small size of the impact area (maximum radius of 2.3 km, or 1.4 miles for surf zone detonation), NMFS believes that 15 minutes is sufficient to detect any marine mammals within the area immediately following each detonation. Post-activity for actions other than surf zone detonation will be conducted by boats. In addition, due to mitigation and monitoring required by the IHA, no marine mammals are expected to be killed or injured by the proposed activities on SRI.

Comment 14: The HSUS questions the monitoring measure that includes coordination with marine mammal stranding networks because the stranding networks do not regularly survey the coastline for carcasses and, when discovered in the Florida Panhandle, they are often in a state of decomposition such that cause of death is not readily ascertained. The HSUS is also concerned that because this area has recently been subject to mortality events, carcasses seen along beaches may not necessarily be linked to the Naval activity unless pointed necropsies are done. The HSUS states that this is something that will not be possible for most carcasses, therefore, even if the cause of death is related to Naval activities, it may remain undetected.

Response: The Eglin AFB is required to monitor the target area prior to, during, and immediately after the proposed activity, and is required to contact the marine mammal stranding networks for any beached animals within the Eglin AFB property. The concern regarding the recent dolphin mortality events and whether the death of dolphins results from Naval activities is not relevant to the issuance of this IHA. As stated previously and concurred by the scientists of the Commission, the proposed activities are expected to result in no more than the incidental taking by Level B harassment of marine mammals.

Comment 15: The HSUS argues that the Federal Register notice (71 FR 35870, June 22, 2006) does not appear to be in compliance with NEPA requirements. The HSUS stated that NMFS must study, develop, and describe appropriate alternatives to recommended courses of action, and discuss alternatives it has considered. The HSUS is concerned that under the proposed scheme, stakeholders and the public were not provided an opportunity to comment on a NMFS “NEPA document” that might be prepared after the close of this comment period and associated with issuance of an IHA.

Response: NMFS does not agree with HSUS's comment. As described in the Federal Register notice (71 FR 35870, June 22, 2006), the USAF prepared the SRI Mission PEA. The SRI Mission PEA was available for public review during the 30-day comment period and is available upon written request to NMFS Office of Protected Resources (OPR), or by downloading from OPR's website at http://www.nmfs.noaa.gov/​pr/​pdfs/​permits/​sri_​iha_​ea.pdf. NMFS staff reviewed Eglin's PEA and determined that it meets the standards under the NMFS regulations and NOAA's Administrator Order 216-6 for the issuance of this IHA. NMFS believes this is consistent with the Council on Environmental Quality's regulations for implementing the procedural provisions of the NEPA. NMFS has issued a Finding of No Significant Impact statement.

Comment 16: The Commission requests that NMFS assess the likelihood of detecting marine mammals at or below the water surface within zones of potential impacts, particularly when operations are conducted at night.

Response: As described in the Federal Register notice (71 FR 35870, June 22, 2006), marine mammal detection within zones of potential impacts will be conducted prior to planned mission activities. After reviewing the Eglin AFB's marine mammal monitoring protocols, NMFS determined that monitoring measures developed by Eglin AFB are highly effective in detecting marine mammals at or below the water surface within zones of potential impacts during daylight hours. However, since no mitigation measures for marine mammals would be feasible for night-time missions, night-time operations will not be monitored, as they are only associated with live-fire exercises conducted on designated on-shore firing ranges on SRI.

Comment 17: The Commission requests 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 proposed activities.

Response: NMFS agrees, and the IHA will specify that operations be suspended immediately if a dead or seriously injured marine mammal is found in the vicinity of the operations potentially linked to Eglin's activity.

Comment 18: The Commission requests that NMFS revises its interpretation of temporary threshold shift (TTS) to indicate that it has the potential to injure marine mammals (and in the case of military readiness activities has a significant potential to injure marine mammals) and therefore constitutes Level A harassment due to the foreseeable secondary effects of temporary hearing loss.

Response: NMFS stated in a previous Federal Register notice (68 FR 64595, November 14, 2003) that the reclassification of TTS from Level B to Level A harassment requires support and scientific documentation, and not be based on speculation that TTS might result in increased predation, for example. In addition, it is irrelevant for this IHA, because sound levels will not be high since mitigation and monitoring requirements under the IHA is expected to prevent TTS. Also, while there has been discussion among scientists regarding whether a permanent shift in hearing threshold (PTS) can occur with repeated exposures of TTS, at least one study showed that long-term (4 - 7 years) noise exposure on three experimental pinniped species had caused no change on their underwater hearing thresholds at frequencies of 0.2 - 6.4 kHz (Southall et al., 2005).

Comment 19: The Commission requests that NMFS advise the Air Force, if it has not already done so, of the need to consult with the U.S. Fish and Wildlife Service (FWS) to confirm that manatees are not likely to occur in or near the vicinity of the test site at the time the tests are scheduled to be conducted.

Response: Eglin AFB has consulted with the FWS on the proposed mission activities in accordance with the Endangered Species Act (ESA, 16 USC 1531 et seq.). The FWS issued a Biological Opinion on December 1, 2005, and concluded that the proposed action is not likely to adversely affect West Indian manatees based on Eglin's commitment to incorporate measures to avoid and minimize impacts to the species.

Description of Marine Mammals Affected by the Activity

Marine mammal species potentially occurring within the proposed action area include the Atlantic bottlenose dolphin (Tursiops truncatus), the Atlantic spotted dolphin (Stenella frontalis), and the Florida manatee (Trichechus manatus latirostris). General information on these species and stocks are provided in the June 22, 2006, Federal Register (71 FR 35870). Therefore, it is not repeated here. More detailed information on Florida manatee can be found in the Florida Manatee Recovery Plan (US Fish and Wildlife Service, 2001). More detailed information on the Atlantic bottlenose and spotted dolphins can be found in the NMFS Stock Assessment Reports at: http://www.nmfs.noaa.gov/​pr/​sars/​species.htm.

Potential Impacts to Marine Mammals

Marine mammals may be impacted by underwater noise and direct physical impacts (DPI). Noise is produced by underwater detonations in the surf zone and by the operation of amphibious vehicles. DPI could result from collisions with amphibious vehicles and from ordnance live fire. However, with implementation of the mitigation measures discussed throughout this document, impacts to marine mammals are anticipated to be no more than negligible.

Explosive criteria and thresholds for assessing impacts of explosions on marine mammals were discussed by NMFS in detail in its issuance of an IHA for Eglin's Precision Strike Weapon testing activity (70 FR 48675, August 19, 2005) and are not repeated here. Please refer to that document for this background information.

Estimation of Take and Impact

Surf Zone Detonation

Surf zone detonation noise impacts are considered within two categories: overpressure and acoustics. Underwater explosive detonations produce a wave of pressure in the water column. This pressure wave potentially has lethal and injurious impacts, depending on the proximity to the source detonation. Humans and animals receive the acoustic signature of noise as sound. Beyond the physical impacts, acoustics may cause annoyance and behavior modifications (Goertner, 1982).

Impacts to marine mammals from underwater detonations were discussed by NMFS in detail in its notice of receipt of application for an IHA for Eglin's Air-to-Surface Gunnery mission in the Gulf (71 FR 3474, January 23, 2006) and is not repeated here. Please refer to that document for this background information.

A maximum of one surf zone testing/training mission would be completed per year. The impact areas of the proposed action are derived from mathematical calculations and models that predict the distances to which threshold noise levels would travel. The equations for the models consider the amount of net explosive, the properties of detonations under water, and environmental factors such as depth of the explosion, overall water depth, water temperature, and bottom type.

The end result of the analysis is an area known as the Zone of Influence (ZOI). A ZOI is based on an outward radial distance from the point of detonation, extending to the limit of a particular threshold level in a 360-degree area. Thus, there are separate ZOIs for mortality, injury (hearing-related injury and slight, non-fatal lung injury), and harassment (temporary threshold shift, or TTS, and sub-TTS). Given the radius, and assuming noise spreads outward in a spherical manner, the entire area ensonified (i.e., exposed to the specific noise level being analyzed) is estimated.

The radius of each threshold is shown for each shallow water surf zone mine clearing system in Table 1. The radius is assumed to extend from the point of detonation in all directions, allowing calculation of the affected area.

The number of takes is calculated by applying marine mammal density to the ZOI (area) for each detonation type. Species density for most cetaceans is based on adjusted GulfCet II aerial survey data, which is shown in Table 2. GulfCet II data were conservatively adjusted upward to approximately two standard deviations to obtain 99 percent confidence, and a submergence correction factor was applied to account for the presence of submerged, uncounted animals. However, the actual number of marine mammal takes would be even smaller, since up to half of the ZOI would be over land and very shallow surf, which is not considered marine mammal habitat.

Table 1. Zones of Impact for Underwater Explosive from Four Mine Clearing Systems (Acoustic units are re 1 microPa²)

Threshold	Criteria	ZOI Radius (m)
		SABRE 232 lb NEW	MK-5 MCS 1,750 lb NEW	DET 130 lb	MK-82 ARRAY 1,372 lb
176 dB 1/3 Octave SEL*	Level B Behavior	1,440	2,299	1,252	2,207
182 dB 1/3 Octave SEL	Level B TTS Dual Criterion	961	1,658	796	1,544
205 dB SEL	Level A PTS	200	478	155	436
23 psi	Level B Dual Criteria	857	1,788	761	1,557
13 psi-msec	Level A Injury	60	100	58	86
30.5 psi-msec	Mortality	45	68	42	60
* SEL - Sound energy level

Table 2. Cetacean Densities for Gulf of Mexico Shelf Region

Species	Individuals/km2	Dive profile - % at surface	Adjusted density (Individuals/km2)*
Bottlenose dolphin	0.148	30	0.810
Atlantic spotted dolphin	0.089	30	0.677
Bottlenose or Atlantic spotted dolphin	0.007	30	0.053
Total	0.244		1.54
* Adjusted for undetected submerged animals to approximately two standard deviations.

Table 3. Preferred Alternative Take Estimates from Noise Impacts to Dolphins (Acoustic units are re 1 microPa²)

Threshold	Criteria	SABRE	MK-5 MCS	DET	MK-82 Array	Total Takes*
176 dB 1/3 Octave SEL	Sub-TTS	10	26	8	24	68
182 dB 1/3 Octave SEL	Level B Harassment TTS (dual criterion)	5	13	3	12	33
23 psi	Level B TTS (dual criterion)	4	15	3	12	34
205 dB Total SEL	Level A PTS	0	1	0	1	2
13 psi-msec	Level A Non-lethal Injury	0	0	0	0	0
30.5 psi-msec	Mortality	0	0	0	0	0
* Estimated exposure with no mitigation measures in place.

Table 3 lists the noise-related dolphin take estimates resulting from surf zone detonations associated with the Perferred Alternative of the PEA. The take numbers represent the combined total of Atlantic bottlenose and Atlantic spotted dolphins, and do not consider any mitigation measures. Implementation of mitigation measures discussed below could significantly decrease the number of takes. Discussion of the amount of take reduction is provided below.

Noise from LCAC

Noise resulting from LCAC operations was considered under a transit mode of operation. The LCAC uses rotary air screw technology to power the craft over the water, therefore, noise from the engine is not emitted directly into the water. The Navy's acoustic in-water noise characterization studies show the noise emitted from the LCAC into the water is very similar to that of the MH-53 helicopter operating at low altitudes. Based on the Air Force's Excess Sound Attenuation Model for the LCAC's engines under ground runup condition, the data estimate that the maximum noise level (98 dBA) is at a point 45 degrees from the bow of the craft at a distance of 61 m (200 ft) in air. Maximum noise levels fall below 90 dBA at a point less than 122 meters (400 ft) from the craft in air (U.S. Air Force, 1999).

Due to the large difference of acoustic impedance between air and water, much of the acoustic energy would be reflected at the surface. Therefore, the effects of noise from LCAC to marine mammals would be negligible.

Collision with Vessels

During the time that amphibious vehicles are operating in (or, in the case of LCACs, just above) the water, encounters with marine mammals are possible. A slight possibility exists that such encounters could result in a vessel physically striking an animal. However, this scenario is considered very unlikely. Dolphins are extremely mobile and have keen hearing and would likely leave the vicinity of any vehicle traffic. The largest vehicles that would be moving are LCACs, and their beam measurement can be used for conservative impact analyses. The operation which potentially uses the largest number of LCACs is Amphibious Ready Group/Marine Expeditionary Unit (ARG/MEU) training. Based on analysis in the ARG/MEU Readiness Training Environmental Assessment (U.S. Air Force, 2003b), LCAC activities (over 10 days) could potentially impact 22.25 square miles of the total water surface area. The estimated number of bottlenose dolphins in this area is 6.9, with an approximately equal number of Atlantic spotted dolphins. These species would easily avoid collision because the LCACs produce noise that would be detected some distance away, and therefore would be avoided as any other boat in the Gulf. In addition, AAVs move very slowly and would be easily avoided. The potential for amphibious craft colliding with marine mammals and causing injury or death is therefore considered remote.

Live Fire Operations

Live-fire operations with munitions directed towards the Gulf have the potential to impact marine mammals (primarily bottlenose and Atlantic spotted dolphins). Cetacean abundance estimates for the study area are derived from GulfCet II aerial surveys in the eastern Gulf waters (Davis et al., 2000). To provide a more conservative impact analysis, density estimates have been adjusted to account for submerged individuals. The percent of time that an animal is submerged versus at the surface was obtained from Moore and Clarke (1998), and used to determine an adjusted density for each species. The result shows an estimated animal density of 1.54 animals/km² (Table 2).

A maximum of two live-fire operations would be conducted in a year, and are associated with expanded Special Operations training on SRI. Small caliber weapons between 5.56 mm and .50 caliber with low-range munitions would be allowed only within designated live-fire areas. The average range of the munitions is approximately 1 km (0.54 nm). If a given live-fire area was 1 km (0.54 nm) wide, then approximately 1.5 dolphins could be vulnerable to a munitions strike. However, even the largest live-fire area on SRI is considerably less than 1 km (0.54 nm) wide. If live fire is conservatively estimated to originate from a section of beach 0.2 km (0.11 nm) wide, only 0.3 dolphins would be within the area of potential DPI. Moreover, the mitigation measures discussed below would further reduce the likelihood of direct impacts to marine mammals due to live-fire operations.

Therefore, given the infrequency of the surf-zone detonation (maximum of once per year), amphibious vehicle testing, and live-fire weapons testing (maximum of twice per year), NMFS believes there is no potential for long-term displacement or behavioral impacts of marine mammals within the proposed action area.

Mitigation

Eglin AFB would employ a number of mitigation measures in order to substantially decrease the number of marine mammals potentially affected. Visual monitoring of the operational area can be a very effective means of detecting the presence of marine mammals. This is particularly true of the two species most likely to be present (bottlenose and Atlantic spotted dolphins) due to their tendency to occur in groups, their relatively short dive time, and their relatively high level of surface activity. In addition, the water clarity in the northeastern GOM is typically very high. It is often possible to view the entire water column in the water depth that defines the study area (30 feet or 9.1 m).

For the surf zone testing/training, missions would only be conducted under daylight conditions of suitable visibility and Beaufort sea state three or less. Prior to the mission, a trained MMO aboard a helicopter would survey (visually monitor) the test area, which is a very effective method for detecting sea turtles and cetaceans. In addition, shipboard personnel would provide supplemental observations when available. The size of the area to be surveyed would depend on the specific test system, but it would correspond to the ZOI for Level B behavior harassment (176 dB 1/3 octave SEL) listed in Table 1. The survey would be conducted approximately 250 feet (76 m) above the sea surface to allow observers to scan a large distance. If a marine mammal is sighted within the ZOI, the mission would be suspended until the animal is clear of this area. In addition, to reduce the potential impacts to sea turtles and manatees, surf zone testing would be conducted between 1 November and 1 March whenever possible.

Navy personnel (NSWCPC) would only conduct live-fire testing with Beaufort sea surface conditions of 3 or less, which is when there is about 33 - 50 percent of surface whitecaps with 0.6 - 0.9 m (2 - 3 ft) waves. During daytime missions, small boats would be used to survey for marine mammals in the proposed action area before and after the operations. If a marine mammal is sighted within the target or closely adjacent areas, the mission would be suspended until the area is clear. No mitigation for marine mammals would be feasible for nighttime mission, however, given the remoteness of impact, however, the potential that a marine mammal is injured or killed is unlikely and will not be authorized.

Monitoring and Reporting

The Eglin AFB will train personnel to conduct aerial surveys for protected species. The aerial survey/monitoring team would consist of an observer and a pilot familiar with flying transect patterns. A helicopter provides a preferable viewing platform for detection of protected marine species. The aerial observer must be experienced in marine mammal surveying and be familiar with species that may occur in the area. The observer would be responsible for relaying the location (latitude and longitude), the species if known, and the number of animals sighted. The aerial team would also identify large schools of fish, jellyfish aggregations, and any large accumulation of Sargassum that could potentially drift into the ZOI. Standard line-transect aerial surveying methods would be used. Observed marine mammals and sea turtles would be identified to species or the lowest possible taxonomic level possible.

The aerial and (potential) shipboard monitoring teams would have proper lines of communication to avoid communication deficiencies. Observers would have direct communication via radio with the Lead Scientist. The Lead Scientist reviews the range conditions and recommends a Go/No-Go decision to the Officer in Tactical Command, who makes the final Go/No-Go decision.

Stepwise mitigation procedures for SRI surf zone missions are outlined below. All zones (mortality, injury, TTS) would be monitored.

Pre-mission Monitoring:

The purposes of pre-mission monitoring are to (1) evaluate the test site for environmental suitability of the mission (e.g., relatively low numbers of marine mammals and turtles, few or no patches of Sargassum, etc.) and (2) verify that the ZOI is free of visually detectable marine mammals, sea turtles, large schools of fish, large flocks of birds, large Sargassum mats, and large concentrations of jellyfish (the latter two are possible indicators of turtle presence). On the morning of the test, the lead scientist would confirm that the test site can support the mission and that the weather is adequate to support observations.

(1) One Hour Prior to Mission

Approximately one hour prior to the mission, or at daybreak, the appropriate vessel(s) would be on-site near the location of the earliest planned mission point. Personnel onboard the vessel would assess the suitability of the test site, based on visual observation of marine mammals and sea turtles. This information would be relayed to the Lead Scientist.

(2) Fifteen Minutes Prior to Mission

Aerial monitoring would commence at the test site 15 minutes prior to the start of the mission. The entire ZOI would be surveyed by flying transects through the area. Shipboard personnel would also monitor the area as available. All marine mammal sightings would be reported to the Lead Scientist, who would enter all pertinent data into a sighting database.

(3) Go/No-Go Decision Process

The Lead Scientist would record sightings and bearing for all protected species detected. This would depict animal sightings relative to the mission area. The Lead Scientist would have the authority to declare the range fouled and recommend a hold until monitoring indicates that the ZOI is and will remain clear of detectable animals.

The mission would be postponed if any marine mammal or sea turtle is visually detected within the ZOI for Level B behavioral harassment. The delay would continue until the marine mammal or sea turtle is confirmed to be outside the ZOI for Level B behavioral harassment.

In the event of a postponement, pre-mission monitoring would continue as long as weather and daylight hours allow. Aerial monitoring is limited by fuel and the on-station time of the monitoring aircraft.

Post-mission monitoring:

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 would commence immediately following each detonation and continue for 15 minutes. The helicopter would resume transects in the area of the detonation, concentrating on the area down current of the test site.

The monitoring team would attempt to document any marine mammals or turtles that were found dead or injured after the detonation, and, if practicable, recover and examine any dead animals. The species, number, location, and behavior of any animals observed by the observation teams would be documented and reported to the Lead Scientist.

Post-mission monitoring activities would also include coordination with marine animal stranding networks. The NMFS maintains stranding networks along coasts to collect and circulate information about marine mammal and sea turtle standings.

In addition, NMFS will require Eglin to monitor the target area for impacts to marine mammals and to report its activities on an annual basis. Accordingly, NMFS' Biological Opinion on this action has recommended certain monitoring measures to protect marine life. NMFS will require the same requirements under an IHA in order to conclude that this activity will result in no more than a negligible impacts on species and stocks of marine mammals:

(1) Eglin is working with NMFS to develop and implement a marine species observer-training program. This program will provide expertise to Eglin's testing and training community in the identification of protected marine species during surface and aerial mission activities in the GOM. Additionally, personnel involved in the surf zone and amphibious vehicle and weapon testing/training would participate in the proposed species observation training. Observers would receive training in protected species survey and identification techniques through a NMFS-approved training program.

(2) Eglin will track their use of the surf zone and amphibious vehicle and weapon testing/training for test firing missions and protected resources (marine mammal/sea turtle) observations, through the use of an observer training sheet.

(3) A summary annual report of marine mammal/sea turtle observations and surf zone and amphibious vehicle and weapon testing/training activities would be submitted to the NMFS Southeast Regional Office and the Office of Protected Resources within 90 days of the expiration of this IHA.

(4) If any marine mammal or sea turtle is observed or detected to be deceased prior to testing, or injured or killed during live fire, a report must be made to the NMFS by the following business day.

(5) Any unauthorized takes of marine mammals (i.e., serious injury or mortality) must be reported immediately to the NMFS representative and to the respective stranding network representative.

ESA

On March 18, 2005, NMFS Southeast Regional Office received a letter from the U.S. Air Force (USAF), Eglin AFB, requesting initiation of formal consultation on all potential environmental impacts to ESA-listed species from all Eglin AFB mission activities on SRI and within the surf zone near SRI. These missions include the surf zone detonation and amphibious vehicle and weapon testing/training. On October 12, 2005, NMFS issued a Biological Opinion, concluding that the surf zone and amphibious vehicle and weapon testing/training are unlikely to jeopardize the continued existence of species listed under the ESA that are within the jurisdiction of NMFS or destroy or adversely modify critical habitat. In addition, on March 18, 2005, Eglin AFB provided the FWS with a request for formal section 7 consultation for the SRI programmatic program regarding ESA-listed species and critical habitat under FWS jurisdiction. On December 1, 2005, FWS issued a Biological Opinion and concluded that the proposed mission activities are not likely to adversely affect these ESA-listed species based on Eglin's commitment to incorporate measures to avoid and minimize impacts to these species.

NEPA

In March, 2005, the USAF prepared the Santa Rosa Island Mission Utilization Plan Programmatic Environmental Assessment (SRI Mission PEA). NMFS reviewed this PEA and determined that it satisfies, in large part, the standards for an adequate statement under the NMFS regulations and is consistent with the Council on Environmental Quality's regulations and NOAA's Administrators Order 216-6 for implementing the procedural provisions of the NEPA (40 CFR 1508.3). NMFS supplemented the PEA with our own cumulative impacts analysis to better ascertain the cumulative effects of past, present, and reasonably foreseeable activities conducted within and around Santa Rosa Island. Therefore, NMFS decided to adopt this PEA with the supplemental cumulative impacts analysis for the issuance of the IHA and has issued a Finding of No Significant Impact statement.

Determinations

NMFS has determined that the surf zone and amphibious vehicle and weapon testing/training that are proposed by Eglin AFB off the coast of SRI, is unlikely to result in the mortality or serious injury of marine mammals (see Tables 2 and 3) and, would result in, at worst, a temporary modification in behavior by marine mammals. While behavioral modifications may be made by these species as a result of the surf zone detonation and amphibious vehicle training activities, any behavioral change is expected to have a negligible impact on the affected species or stocks. Also, given the infrequency of the testing/training missions (maximum of once per year for surf zone detonation and maximum of twice per year for amphibious assault training involving live fire), there is no potential for long-term displacement or long-lasting behavioral impacts of marine mammals within the proposed action area. In addition, the potential for temporary hearing impairment is very low and would be mitigated to the lowest level practicable through the incorporation of the mitigation measures mentioned in this document. There is no subsistence use of these marine mammal species in the action area.

Authorization

NMFS has issued an IHA, pursuant to MMPA section 101(a)(5)(D), to Eglin AFB for conducting surf zone and amphibious vehicle and weapon testing/training off the coast of SRI in the northern GOM provided the previously mentioned mitigation, monitoring, and reporting requirements are implemented.

Dated: December 18, 2006.

Donna Wieting

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