Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Conducting Air-to-Surface Gunnery Missions in the Gulf of Mexico, 29974-29982 [E7-10372]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 72, Number 103 (Wednesday, May 30, 2007)]
[Notices]
[Pages 29974-29982]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-10372]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 021607A]


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Conducting Air-to-Surface Gunnery Missions in the Gulf of 
Mexico

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

ACTION: Notice of proposed issuance of an incidental take 
authorization; request for comments and information.

-----------------------------------------------------------------------

SUMMARY: NMFS has received a request from Eglin Air Force Base (Eglin 
AFB), for renewal of an authorization to harass marine mammals, 
incidental to conducting air-to-surface (A-S) gunnery missions in the 
Gulf of Mexico (GOM). As a result of this request, NMFS is proposing to 
reissue a 1-year authorization to take marine mammals by Level B 
harassment incidental to this activity. Under the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an authorization to Eglin AFB to incidentally take, by 
harassment, several species of cetaceans for a period of 1 year.

DATES: Comments and information must be postmarked no later than June 
29, 2007.

ADDRESSES: Comments should be addressed to Michael Payne, Chief, 
Permits, Conservation and Education Division, Office of Protected 
Resources, National Marine Fisheries Service, 1315 East-West Highway, 
Silver Spring, MD 20910-3226. The mailbox address for providing email 
comments on this action is PR1.021607A@noaa.gov. Comments sent via 
email, including all attachments, must not exceed a 10-megabyte file 
size. A copy of Eglin's original 2003 application and its December, 
2006 letter updating its request may be obtained by writing to this 
address, by telephoning the contact listed here (see FOR FURTHER 
INFORMATION CONTACT) and is also available at: https://
www.nmfs.noaa.gov/prot_res/PR2/Small_Take/smalltake_
info.htm#applications. A copy of the Final Programmatic Environmental 
Assessment (Final PEA) is available by writing to the Department of the 
Air Force, AAC/EMSN, Natural Resources Branch, 501 DeLeon St., Suite 
101, Eglin AFB, FL 32542-5133.

FOR FURTHER INFORMATION CONTACT: Kenneth R. Hollingshead, NMFS, 301-
713-2289, ext 128.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and 101(a)(5)(D) of the Marine Mammal 
Protection Act (16 U.S.C. 1361 et seq.)(MMPA) 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.
    Permission may be granted if NMFS finds that the taking will have a 
negligible impact on the species or stock(s), will not (where relevant) 
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

[[Page 29975]]

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. For 
the purposes of ``military readiness activities'' harassment is defined 
as:
    (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

    Eglin AFB originally petitioned NMFS on February 13, 2003, as a 
precautionary measure, for an authorization under section 101(a)(5) of 
the MMPA for the taking, by harassment, of marine mammals incidental to 
programmatic mission activities within the Eglin Gulf Test and Training 
Range (EGTTR). The EGTTR is described as the airspace over the GOM that 
is controlled by Eglin AFB. A notice of receipt of Eglin's application 
and proposed IHA and request for 30-day public comment was published on 
January 23, 2006 (71 FR 3474). A 1-year IHA was subsequently issued to 
Eglin AFB for this activity on May 3, 2006 (71 FR 27695, May 12, 2006). 
A description of Eglin AFB's A-S gunnery activity follows.

Description of Activities

    A-S gunnery missions, a ``military readiness activity,'' involve 
surface impacts of projectiles and small underwater detonations with 
the potential to affect cetaceans that may occur within the EGTTR. 
These missions typically involve the use of 25-mm (0.98 in), 40-mm 
(1.57 in), and 105-mm (4.13 in) gunnery rounds containing, 0.0662 lb 
(1.1 oz 30 g), 0.865 lb (13.8 oz, 392 g), and 4.7 lbs (2.1 kg) of 
explosive, respectively. Live rounds must be used to produce a visible 
surface splash that must be used to ``score'' the round; the impact of 
inert rounds on the sea surface would not be detected. The Air Force 
has developed a 105-mm training round (TR) that contains less than 10 
percent of the amount of explosive material (0.35 lb; 0.16 kg) as 
compared to the ``Full-Up'' (FU) 105-mm (4.13 in) round. The TR was 
developed as one method to mitigate effects on marine life during 
night-time A/S gunnery exercises when visibility at the water surface 
would be poor. However, the TR cannot be used in daytime since the 
amount of explosive material is insufficient to be detected from the 
aircraft.
    Water ranges within the EGTTR that are typically used for the 
gunnery operations are located in the GOM offshore from the Florida 
Panhandle (areas W-151A, W-151B, W-151C, and W-151D as shown in Figure 
1 in Eglin's 2003 application). Data indicate that W-151A is the most 
frequently used water range due to its proximity to Hurlburt Field, but 
activities may occur anywhere within the EGTTR.
    The AC-130 gunship aircraft normally transit from Hurlburt Field, 
FL to the water range at a minimum of 4,000 ft (1.2 km) above surface 
level. The AC-130 conducts at least two complete orbits at a minimum 
safe airspeed around a prospective target area at a maximum altitude of 
1,500 ft (457 m), with a NMFS recommended to an operational altitude of 
approximately 4,500 to 10,000 ft (1372-3048 m). Ascent occurs over a 
10-15 minute period. Eglin AFB has noted that the search area for these 
orbits ensures that no vessels (or protected species) are within an 
area of 5 nm (9.3 km) of the target. The AC-130 continues orbiting the 
selected target point as it climbs to the mission-testing altitude. 
During the low altitude orbits and the climb to testing altitude, 
aircraft crew visually scan the sea surface within the aircraft's orbit 
circle for the presence of vessels and protected species. Primary 
responsibility for the surface scan is on the flight crew in the 
cockpit and personnel stationed in the tail observer bubble and 
starboard viewing window. The AC-130's optical and electronic sensors 
are also employed for target clearance. If any marine mammals are 
detected within the AC-130's orbit circle, either during initial 
clearance or after commencement of live firing, the aircraft will 
relocate to another target area and repeat the clearance procedures. A 
typical distance from the coast for this activity is at least 15 mi (24 
km).
    When offshore, the crews can scan a 5-nm (9.3-km) radius around the 
potential impact area to ensure it is clear of surface craft, marine 
mammals, and sea turtles. Scanning is accomplished using radar, all-
light television (TV), infrared sensors (IR), and visual means. An 
alternative area would be selected if any cetaceans or vessels were 
detected within a 5-nm (9.3 km) search area. Once the scan is 
completed, Mk-25 flares are dropped and the firing sequence is 
initiated.
    A typical gunship mission lasts approximately 5 hours without 
refueling and 6 hours when air-to-air refueling is accomplished. A 
typical mission includes: (1) 30 minutes for take off and to perform 
airborne sensor alignment, align electro-optical sensors (IR and TV) to 
heads-up display; (2) 1.5 to 2 hours of dry fire (no ordnance 
expended), and includes transition time; (3) 1.5 to 2 hours of live 
fire, and includes clearing the area and transiting to and from the 
range (actual firing activities typically do not exceed 30 minutes); 
(4) 1 hour air-to-air refueling, if and when performed; and (5) 30 
minutes of transition work (take-offs, approaches, and landings-pattern 
work).
    The guns are fired during the live-fire phase of the mission. The 
actual firing can last from 30 minutes to 1.5 hours but is typically 
completed in 30 minutes. The number and type of A-S gunnery munitions 
deployed during a mission varies with each type of mission flown. In 
addition to the 25-, 40-, and 105-mm rounds, marking flares are also 
deployed as targets. All guns are fired at a specific target in the 
water, usually an Mk-25 flare, starting with the lowest caliber 
ordnance or action with the least impact and proceeding to greater 
caliber sizes. To establish the test target area, two Mk-25 flares are 
deployed into the center of the 5-nm (9.3-km) radius cleared area 
(visually clear of aircraft, ships, and surface marine species) on the 
water's surface. The flare's burn time normally lasts 10 to 20 minutes 
but could be much less if actually hit with one of the ordnance 
projectiles; however, some flares have burned as long as 40 minutes. 
Live fires are a continuous event with pauses during the firing usually 
well under a minute and rarely from 2 to 5 minutes. Firing pauses would 
only exceed 10 minutes if surface boat traffic or marine protected 
species caused the mission to relocate; if aircraft, gun, or targeting 
system problems existed; or if more flares needed to be deployed. The 
Eglin Safety Office has described the gunnery missions as having 95-
percent containment with a 99-percent confidence level within a 5-m 
(16.4-ft) area around the established flare target test area.

Live-fire Event: 25-mm Round

    The 25-mm (0.98-in) firing event in a typical mission includes 
approximately 500 to 1000 rounds. These rounds are first in short 
bursts. These bursts last approximately 2-3 seconds with approximately 
100 rounds per burst. Based on the very tight target area and extremely 
small miss distance, these bursts of rounds all enter the

[[Page 29976]]

water within a 5-m (16.4-ft) area. Therefore, when calculations of the 
marine mammal Zone of Impact (ZOI) and take estimates are made later in 
this document for the 25-mm rounds, calculations will be based on the 
total number of rounds fired per year divided by 100.

Live-fire Event: 40-mm Round

    The 40-mm (1.57 in) firing event of a typical mission includes 
approximately 10 seconds with approximately 20 rounds per burst. Based 
on the very tight target area and extremely small ``miss'' distance, 
these bursts of rounds all enter the water within a 5-m (16.4 ft) area. 
Therefore, when calculations of the marine mammal ZOI and take 
estimates are made later in this document for the 40-mm rounds, 
calculations will be based on the total number of rounds fired per year 
divided by 20.

Live-fire Event: 105-mm Round

    The 105-mm firing event of a typical mission includes approximately 
20 rounds. These rounds are not fired in bursts, but as single shots. 
The 105-mm firing event lasts approximately 5 minutes with 
approximately two rounds per minute. Due to the single firing event of 
the 105-mm round, the peak pressure of each single 105-mm round is 
measured at a given distance (90 m (295 ft)) for the 105mm TR and 216 m 
(709 ft) for the 105mm FU).
    As described in Eglin's 2003 application, gunnery testing in this 
request includes historical baseline yearly amounts in addition to 
proposed nighttime gunnery missions. Daytime gunnery testing uses the 
105-mm FU round and nighttime gunnery training is proposed using the 
105-mm TR. The number of 105-mm rounds including nighttime operations 
would amount to 1,742. As shown in detail in Tables 1 and 2 (see 71 FR 
27695, May 12, 2006), Eglin proposes to conduct a total of 28 daytime 
missions and 263 nighttime missions annually, expending 3,832 rounds in 
daytime and 30,802 rounds nighttime (242 105-mm FU and 1,500 rounds 
would be the 105-mm TR).

Description of Marine Mammals Affected by the Activity

    There are 29 species of marine mammals documented as occurring in 
Federal waters of the GOM. General information on these species can be 
found in Wursig et al. (2000) and in the NMFS Stock Assessment Reports 
(Waring et al., 2007). This latter document is available at: https://
www.nefsc.noaa.gov/nefsc/publications/tm/tm201/
 Of these 29 species of marine mammals, approximately 21 may be 
found within the EGTTR. These species are the Bryde's whale, sperm 
whale, dwarf sperm whale, pygmy sperm whale, Atlantic bottlenose 
dolphin, Atlantic spotted dolphin, pan-tropical spotted dolphin, 
Blainville's beaked whale, Cuvier's beaked whale, Gervais' beaked 
whale, Clymene dolphin, spinner dolphin, striped dolphin, killer whale, 
false killer whale, pygmy killer whales, Risso's dolphin, Fraser's 
dolphin, melon-headed whale, rough-toothed dolphin, and pilot whale. 
Supplementary information on those species that may be impacted by the 
A/S gunnery exercises are discussed in the Eglin application (Eglin 
AFB, 2003) and the Eglin's Final PEA.

Potential Impacts to Marine Mammals

    A/S gunnery operations may potentially impact marine mammals at the 
water surface. Marine mammals could potentially be harassed, injured or 
killed by exploding and non-exploding projectiles, and falling debris 
(Eglin, 2002 (Final PEA)). However, based on analyses provided in the 
Eglin Final PEA and in Eglin's Supplemental Information Request 
(2003)), NMFS concurs with Eglin that gunnery exercises are not likely 
to result in any injury or mortality to marine mammals.
    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

Direct Physical Impacts (DPI)

    Potential impacts resulting from air-to-surface test operations 
include DPI resulting from ordnance. DPI could result from inert bombs, 
gunnery ammunition, and shrapnel from live missiles falling into the 
water. Marine mammals and sea turtles swimming at the surface could 
potentially be injured or killed by projectiles and falling debris if 
not sighted and firing discontinued. Small arms gunnery operations may 
offer a worst case scenario for evaluating DPI of EGTTR operations, 
mainly due to the comparatively large number of rounds expended. Some 
contain small amounts of explosives, but the majority do not. The 
assumptions made by Eglin for DPI calculations can be found in Eglin's 
Final PEA under Alternative 1 for this action. Approximately 606 small-
arms gunnery firing events comprise the estimated level of potential 
DPI events, as shown in Table 4 in the Federal Register notice for the 
previous IHA on this action (71 FR 27695, May 12, 2006).
    DPI impacts are anticipated to affect only marine species at or 
very near the ocean surface. As a result, to calculate impacts, Eglin 
used corrected species densities (Table 4-23 in Eglin's Final PEA) to 
reflect the surface interval population, which is approximately 10 
percent of densities calculated for distribution in the total water 
column. As shown in Table 5 in the Federal Register notice for the 
previous IHA on this action (71 FR 27695, May 12, 2006) and correcting 
PEA Table 4-23), the impacts to marine mammals and sea turtles at the 
surface that could potentially be injured or killed by projectiles and 
falling debris was determined to be very low, and mitigation measures 
that Eglin will employ under this action would reduce even these low 
levels.
    In addition to small arms, Eglin calculated the potential for other 
non-explosive items (inert bombs, missiles, and drones) to impact 
marine mammals and sea turtles. The number of annual events expected 
are 551 bombs, 1183 missiles, and 99 drones (Table 6). As shown in 
Eglin's Final PEA and Table 7 in the Federal Register notice for the 
previous IHA on this action (71 FR 27695, May 12, 2006), the potential 
for any DPI to marine mammals and sea turtles is extremely remote and 
can, therefore, be discounted.
    Similar to non-gunnery/non-small arms DPI impacts, DPI impacts from 
gunnery activities may also affect marine mammals and sea turtles in 
the surface zone. Again, DPI impacts are anticipated to affect only 
marine species at or near the ocean surface. Tables 8 and 9 in the 
Federal Register notice for the previous IHA on this action (71 FR 
27695, May 12, 2006) demonstrate that the potential for any DPI from 
gunnery activities are extremely remote and can be discounted.

Marine Mammal Take Estimates from Gunnery Activities

    Estimating the impacts to marine mammals from underwater 
detonations is difficult due to complexities of the physics of 
explosive sound under water and the limited understanding with respect 
to hearing in marine mammals. Detailed assessments were made in the 
notice for the previous IHA on this action (71 FR 27695, May 12, 2006) 
and in this Federal Register notice. These assessments used, and 
improved upon, the criteria and thresholds for marine mammal impacts 
that were developed

[[Page 29977]]

for the shock trials of the USS SEAWOLF submarine and the destroyer USS 
Winston S. Churchill (DDG-81) (Navy, 1998; 2001). The criteria and 
thresholds used in those actions were adopted by NMFS for use in 
calculating incidental takes from explosives. Criteria for assessing 
impacts include: (1) Mortality, as determined by exposure to a certain 
level of positive impulse pressure (expressed as pounds per square inch 
per millisecond or psi-msec); (2) injury, both hearing-related and non-
hearing related; and (3) harassment, as determined by a temporary loss 
of some hearing ability and behavioral reactions. Due to the small 
amounts of net explosive weight for each of the rounds fired in the 
EGTTR and the mitigation measures, mortality resulting from sounds 
generated in the water column was determined to be highly unlikely and 
was not considered further by Eglin AFB or NMFS.
    Criteria and methods for calculation for permanent and temporary 
threshold shift and Level B harassment (behavioral response) to noise 
from the air-to-surface gunnery exercises was provided by NMFS in 
detail in its Federal Register notices on the previous IHA for this 
action (71 FR 3474 (January 23, 2006), 71 FR 27695 (May 12, 2006). 
Criteria for assessing impacts include: (1) mortality, as determined by 
exposure to a certain level of positive impulse pressure (expressed as 
pounds per square inch per millisecond or psi-msec); (2) injury, both 
hearing-related and non-hearing related; and (3) harassment, as 
determined by a temporary loss of some hearing ability and behavioral 
reactions. Due to the small amounts of net explosive weight (NEW) for 
each of the rounds fired in the EGTTR and the mitigation measures, 
mortality resulting from sounds generated in the water column was 
determined to be highly unlikely and is not considered further.
    Permanent hearing loss is considered an injury and is termed 
permanent threshold shift (PTS). NMFS, therefore, categorizes PTS as 
Level A harassment. Temporary loss of hearing ability is termed a 
temporary threshold shift (TTS), meaning a temporary reduction of 
hearing sensitivity which abates following noise exposure. TTS is 
considered non-injurious and is categorized as a Level B type of 
harassment. NMFS recognizes dual criteria for TTS, one based on peak 
pressure and one based on the greatest 1/3 octave sound exposure level 
(SEL) or energy flux density level (EFDL), with the more conservative 
(i.e., larger) of the two criteria being selected for impacts analysis 
(note: SEL and EFDL are used interchangeably, but with increasing 
scientific preference for SEL). The peak pressure metric used in the 
shock trials to represent TTS was 12 pounds per square inch (psi) 
which, for the NEW used, resulted in a zone of possible Level B 
harassment approximately equal to that obtained by using a 182 decibel 
(dB) re 1 microPa\2\-s, total EFDL/SEL metric. The 12-psi metric is 
largely based on anatomical studies and extrapolations from terrestrial 
mammal data (see Ketten, 1995; Navy, 1999 (Appendix E, Churchill FEIS; 
and 70 FR 48675 (August 19, 2005)) for background information). 
However, the results of a more recent investigation involving marine 
mammals suggest that, for charges considerably smaller than those used 
in the Navy shock trials, the 12-psi metric is not an adequate 
predictor of the onset of TTS.
    Finneran et al. (2002) measured TTS in a bottlenose dolphin and a 
beluga whale exposed to single underwater impulses produced by a 
seismic water gun in San Diego Bay. The water gun was chosen over other 
seismic sources, such as air guns, because the impulses contain more 
energy at high frequencies where odontocete hearing thresholds are 
relatively low (i.e., more sensitive). Hearing thresholds were measured 
at 0.4, 4, and 30 kilohertz (kHz). A relatively small and short-term 
level of masked TTS (MTTS)(7 dB at 0.4 kHz and 6 dB at 30 kHz) occurred 
in the beluga whale at a peak pressure of 160 kilopascals (kPa), which 
is equivalent to 23 psi, 226 dB re 1 micro Pa peak-peak pressure, and 
186 dB re 1 microPa\2\-s. The maximum experimental peak pressure 
exposure of 207 kPa (30 psi, 228 dB re 1 microPa peak-peak pressure, 
188 dB re 1 microPa\2\-s) did not cause any measurable masked TTS in 
the bottlenose dolphin. The results of these field experiments 
represent the most current science available for the relationship 
between peak pressure and TTS in marine mammals. It is also considered 
precautionary for this project since the bottlenose dolphin did not 
incur an MTTS at the higher level of 30 psi. Therefore, until 
additional information becomes available, 23 psi is considered an 
appropriate and conservative metric for predicting the onset of 
pressure-related TTS from small explosive charges.
    Documented behavioral reactions occur at noise levels below those 
considered to cause TTS in marine mammals (Finneran et al., 2002; 
Schlundt et al., 2000; Finneran and Schlundt, 2004). In controlled 
experimental situations, behavioral effects are typically defined as 
alterations of trained behaviors. Behavioral effects in wild animals 
are more difficult to define but may include decreased ability to feed, 
communicate, migrate, or reproduce. Abandonment of an area due to 
repeated noise exposure is also considered a behavioral effect. 
Analyses in subsequent sections of this document refer to such 
behavioral effects as ``sub-TTS Level B harassment.'' Schlundt et al. 
(2000) exposed bottlenose dolphins and beluga whales to various pure-
tone sound frequencies and intensities in order to measure underwater 
hearing thresholds. Masking is considered to have occurred because of 
ambient noise environment in which the experiments took place. Sound 
levels were progressively increased until behavioral alterations were 
noted (at which point the onset of TTS was presumed). It was found that 
decreasing the sound intensity by 4 to 6 dB greatly decreased the 
occurrence of anomalous behaviors. The lowest sound pressure levels, 
over all frequencies, at which altered behaviors were observed, ranged 
from 178 to 193 dB re 1 micro Pa for the bottlenose dolphins and from 
180 to 196 dB re 1 micro Pa for the beluga whales. Thus, it is 
reasonable to consider that sub-TTS (behavioral) effects occur at 
approximately 6 dB below the TTS-inducing sound level, or at 
approximately 176 dB in the greatest 1/3 octave band EFDL/SEL.
    Table 10 in the Federal Register notice for the previous IHA on 
this action (71 FR 27695, May 12, 2006) summarizes the relevant 
thresholds for levels of noise that may result in injury, TTS or 
behavioral harassment to marine mammals. Mortality and injury 
thresholds are designed to be conservative by considering the impacts 
that would occur to the most sensitive life stage (e.g., a dolphin 
calf). Table 11 published in the Federal Register notice for the 
previous IHA on this action (71 FR 27695, May 12, 2006) provides the 
estimated ZOI radii for the EGTTR ordnance. At this time, there is no 
empirical data or information that would allow NMFS to establish a peak 
pressure criterion for sub-TTS behavioral disruption.
    As mentioned previously, the EGTTR live fire events are continuous 
events with pauses during the firing usually well under a minute and 
rarely from 2 to 5 minutes. Live fire typically occurs within a 30 
minute time frame, including all ordnance fired: 25-mm (Phase I), 40-mm 
(Phase II), and 105-mm (Phase III), and where the 105-mm ordnance are 
fired as separate rounds with up to 30-second intervals, the 25-mm and 
the 40-mm are often fired in

[[Page 29978]]

multiple bursts. These burst include multiple rounds (25 to 100) within 
a 10- to 20-second time frame. Eglin notes that even if animal 
avoidance once firing commences is not considered, an average swim 
speed (1.5 m/s) of animals would not allow sufficient time for new 
animals to re-enter the Level B harassment ZOI (23 psi) within the time 
frame of a single burst. As such, only the peak pressure of a single 
round is measured per burst and experienced at a given distance (49 m 
(161 ft; Phase I), 122 m (400 ft; Phase II)).
    For daytime firing it is assumed that the average swim speed per 
cetacean is approximately 3 knots or 1.5 m/sec. As a conservative 
scenario, Eglin assumes that there is one animal present within or near 
the 216-m ZOI (FU 105-mm round ZOI) which may be potentially ensonified 
within the 23-psi TTS exposure at the time that the 105-mm live firing 
begins. Density distributions have assumed an even distribution of 
approximately 4.38 animals/km2 or approximately 500 m (1640 ft) apart 
(all species) for the analyses for take estimates. At this density 
distribution and typical swim speed, the next available cetacean would 
approach the perimeter of the 216-m (709 ft) ZOI (23-psi TTS ZOI) in 
approximately 5.5 minutes, assuming a straight line path. With live 
fire events of the 105-mm occurring at a rate of approximately 2 rounds 
per minute, nearly one half (or 10 rounds) of the total 105-mm rounds 
(20 rounds) would potentially be expended within this 5.5 minute time 
frame. If the concept of marine mammal avoidance of an area once firing 
commences is not considered, an average swim speed of 1.5 m/s (4.9 f/s) 
would allow sufficient time for new animals to re-enter the 23-psi TTS 
impact area. Allowing for a potential 2 minute break in firing after 10 
rounds are expended, it is, therefore, conservative and reasonable to 
assume that nearly 3 to 4 individual animals could be exposed to the 
23-psi TTS sound level during a typical 20 round firing event. 
Therefore, the ZOI and Level B harassment take estimate calculations 
are based on the total number of rounds fired per year divided by 5, or 
approximately 20 percent. This approach assumes that although single 
animals may be ensonified more than once due to the time required to 
exit the 23 psi TTS ZOI, animals are not considered to be ``taken'' 
more than once for the purposes of estimating take levels.
    Similarly, as a conservative approach for nighttime firing, Eglin 
assumes that there is one animal present within or near the 90-m (295-
ft) ZOI (105-mm TR ZOI) which may be potentially ensonified within the 
23-psi TTS exposure zone at the time that the 105-mm round live firing 
phase begins. Density distributions have assumed an even distribution 
of approximately 4.38 animals/km\2\ (all species) for the approach of 
impact analyses for estimation of take. At this density distribution 
and typical swim speed, the next available cetacean would approach the 
perimeter of the 90-m (295-ft) ZOI (23-psi TTS ZOI) in approximately 
5.5 minutes or the same time as with the 216-m ZOI (used for the 105-mm 
FU). The difference is the amount of time it takes the animal to exit 
the ZOI or in other words, how long the animals resides within the ZOI 
on a straight line path. With live fire events of the 105-mm round 
occurring at a rate of approximately 2 rounds per minute, nearly one 
half (or 10 rounds) of the total 105-mm rounds (20 rounds) would 
potentially be expended within this 5.5-minute time frame. If the 
concept of marine mammal avoidance of an area once firing commences is 
not considered, an average swim speed (1.5 m/s) of animals would allow 
sufficient time for new animals to re-enter the 23-psi TTS impact area. 
Allowing for a potential 2-min break in firing after 10 rounds are 
expended, it is conservative and reasonable to assume that nearly 3 to 
4 individual animals may be potentially exposed to the 23-psi TTS sound 
level during a typical 20 round firing event. Therefore, the ZOI and 
take estimate calculations are based on the total number of rounds 
fired per year divided by 5, or approximately 20 percent. This approach 
assumes that, although single animals may be ensonified more than once 
due to the time required to exit the 23-psi TTS ZOI, individual animals 
are not considered to be ``taken'' more than once for the purposes of 
estimating take levels.
    Based on this discussion, Table 1 in this Federal Register document 
provides Eglin AFB's estimates of the annual number of marine mammals, 
by species, potentially taken by Level B harassment, by the gunnery 
mission noise. It should be noted that these estimates are derived 
without consideration of the effectiveness of Eglin AFB's proposed 
mitigation measures (except use of the training round (TR)), which are 
discussed in the next section.

            Table 1. Yearly Estimated Number of Marine Mammals Affected by the Gunnery Mission Noise
----------------------------------------------------------------------------------------------------------------
                                                     Level A          Level B                         Level B
                                    Adjusted        Harassment    Harassment Non-     Level B     Harassment Non-
            Species                  Density      Injurious 205    injurious 182  Harassment Non-  Injurious 176
                                   (/   dB* EFD For Ear    dB* EFD for    Injurious 23     dB* EFD For
                                     km\2\)          Rupture            TTS         psi For TTS      Behavior
----------------------------------------------------------------------------------------------------------------
Bryde's whale                    0.007           <0.001           0.010           0.4             0.041
----------------------------------------------------------------------------------------------------------------
Sperm whale                      0.011           <0.001           0.016           0.0             0.064
----------------------------------------------------------------------------------------------------------------
Dwarf/pygmy sperm whale          0.024           <0.001           0.035           1.5             0.139
----------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale            0.10            <0.001           0.015           0.6             0.058
----------------------------------------------------------------------------------------------------------------
Mesoplodon spp.                  0.019           <0.001           0.028           1.2             0.110
----------------------------------------------------------------------------------------------------------------
Pygmy killer whale               0.030           <0.001           0.044           1.9             0.174
----------------------------------------------------------------------------------------------------------------
False killer whale               0.026           <0.001           0.038           1.6             0.151
----------------------------------------------------------------------------------------------------------------
Short-finned pilot whale         0.027           <0.001           0.039           1.7             0.157
----------------------------------------------------------------------------------------------------------------
Rough-toothed dolphin            0.028           <0.001           0.041           1.7             0.163
----------------------------------------------------------------------------------------------------------------
Bottlenose dolphin               0.810           0.006            1.177           50.1            4.706
----------------------------------------------------------------------------------------------------------------

[[Page 29979]]

 
Risso's dolphin                  0.113           0.001            0.164           7.0             0.657
----------------------------------------------------------------------------------------------------------------
Atlantic spotted dolphin         0.677           0.005            0.984           41.9            3.934
----------------------------------------------------------------------------------------------------------------
Pantropical spotted dolphin      1.077           0.008            1.565           66.7            6.258
----------------------------------------------------------------------------------------------------------------
Striped dolphin                  0.237           0.002            0.344           14.7            1.377
----------------------------------------------------------------------------------------------------------------
Spinner dolphin                  0.915           0.007            1.330           56.6            5.316
----------------------------------------------------------------------------------------------------------------
Clymene dolphin                  0.253           0.002            0.368           15.7            1.470
----------------------------------------------------------------------------------------------------------------
Unidentified dolphin**           0.053           <0.001           0.077           3.3             0.308
----------------------------------------------------------------------------------------------------------------
Unidentified whale               0.008           <0.001           0.012           0.5             0.046
----------------------------------------------------------------------------------------------------------------
All marine mammals               4.325           0.032            6.29            271.1           25.13
----------------------------------------------------------------------------------------------------------------
km\2\=square kilometers; NA=not applicable
dB-dB re 1 microPa\2\ -s
**Bottlenose dolphin/Atlantic spotted dolphin

Proposed Mitigation Measures

    Under its recent IHA, Eglin AFB employed a number of mitigation 
measures in an effort to substantially decrease the number of animals 
potentially affected. The proposed mitigation for this proposed IHA is 
substantially similar with a few modifications. Eglin AFB states that 
it is committed to assessing the mission activity for opportunities to 
provide operational mitigation (i.e., ramping up and using nighttime 
training rounds), while potentially sacrificing some mission 
flexibility.

Visual Mitigation

    Areas to be used in gunnery missions are visually monitored for 
marine mammal presence from the AC-130 aircraft prior to commencement 
of the mission. If the presence of one or more marine mammals is 
detected, the target area will be avoided. In addition, monitoring will 
continue during the mission. If marine mammals are detected at any 
time, the mission will be either immediately halted and/or relocated as 
necessary or suspended until the marine mammal has left the area. 
Daytime and nighttime visual monitoring will be supplemented with IR 
and TV monitoring. As nighttime visual monitoring is generally 
considered to be ineffective at any height, the EGTTR missions will 
incorporate the TR.

Development of the TR

    The largest type of ammunition used during typical gunnery missions 
is the 105-mm (4.13-in) round containing 4.7 lbs (2.1 kg) of high 
explosive (HE). This is several times more HE than that found in the 
next largest round (40 mm/1.57 in). As a mitigation technique, the Air 
Force developed a 105-mm TR that contains only 0.35 lb (0.16 kg) of HE. 
The TR was developed to significantly reduce the effects of nighttime 
operations, when visual surveying for marine mammals is of limited 
effectiveness. Use of the TR at night dramatically reduces the risk of 
harassment, and Eglin AFB anticipates a 96 percent reduction in impact 
by using the 105-mm TR.

Ramp-Up

    Eglin incorporated a ramp-up procedure by beginning with the 
smallest round (or the round having least impact) and proceeding to 
subsequently larger size rounds (in this case the lowest caliber of 
munition up to the 105-mm FU round). Theoretically, this allows animals 
to perceive steadily increasing sounds and to react, if necessary. 
Alerting animals in advance of injurious sound waves by transmitting 
low-power ``warning'' signals a short time before the action provides a 
safeguard where there is a potential for the risk of injury.

Other Mitigation

    Under the previous IHA, NMFS required additional mitigation 
measures to protect marine life. These requirements are:
    (1) Test firing will be conducted only when sea surface conditions 
are sea state 3.5 or less on the Beaufort scale.
    (2) Prior to each firing event, the aircraft crew will conduct a 
visual survey of the 5-nm (9.3-km) wide prospective target area to 
attempt to sight any protected species that may be present (e.g., 
marine mammals, sea turtles, and Sargassum rafts). The AC-130 gunship 
will conduct at least two complete orbits at a minimum safe airspeed 
around a prospective target area at a maximum altitude of 1,500 ft (457 
m), with a recommended altitude of 1,000 ft (305 m). Provided protected 
species are not detected, the AC-130 can then continue orbiting the 
selected target point as it climbs to the mission testing altitude. 
During the low altitude orbits and the climb to testing altitude, the 
aircraft crew will visually scan the sea surface within the aircraft's 
orbit circle for the presence of listed and non-listed marine mammals 
and sea turtles. Primary emphasis for the surface scan will be upon the 
flight crew in the cockpit and personnel stationed in the tail observer 
bubble and starboard viewing window. The AC-130's optical and 
electronic sensors will also be employed for target clearance. If any 
marine mammals are detected within the AC-130's orbit circle, either 
during initial clearance or after commencement of live firing, the 
aircraft will relocate to another target and repeat the clearance 
procedures. If multiple firing events occur within the same flight, 
these clearance procedures will precede each event.
    (3) The aircrews of the air-to-ground gunnery missions will 
initiate location and surveillance of a suitable firing site 
immediately after exiting U.S. territorial waters (> 12 nm, 22 km). 
This would potentially restrict most gunnery

[[Page 29980]]

activities to the shallower continental shelf waters of the GOM where 
marine mammal densities are typically lower, and thus potentially avoid 
the slope waters where the more sensitive species (e.g., endangered 
sperm whales) typically reside.
    (4) Observations will be accomplished using all-light TV, IR 
sensors, and visual means for at least 60 minutes prior to each 
exercise.
    (5) Aircrews will utilize visual, night vision goggles (NVGs), and 
other onboard sensors to search for marine mammals while performing 
area clearance procedures during night-time pre-mission activities.
    (6) If any marine mammals are sighted during pre-mission surveys or 
during the mission, activities will be immediately halted until the 
area is clear of all marine mammals for 60 minutes or the mission 
location relocated and resurveyed.

Monitoring and Reporting

    The NMFS Biological Opinion on this action recommended certain 
monitoring measures to protect marine life. As a result, NMFS imposed 
these same requirements under the previous IHA:
    (1) Eglin will develop and implement a marine species observer-
training program in coordination with NMFS. This program will primarily 
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, the A-S gunnery mission 
aircrews will participate in the species observation training. As a 
result, designated crew members will be selected to receive training as 
protected species observers. Observers will receive training in 
protected species survey and identification techniques through a NMFS-
approved training program.
    (2) Aircrews will initiate the post-mission clearance procedures 
beginning at the operational altitude of approximately 15,000 to 20,000 
ft (4572 to 6096 m) elevation, and initiating a spiraling descent down 
to an observation altitude of approximately 1,500 ft. (457 m) 
elevation. Rates of descent will occur over a 3 to 5 minute time frame.
    (3) Eglin will track their use of the EGTR for test firing missions 
and protected species observations, through the use of mission 
reporting forms.
    (4) A-S gunnery missions will coordinate with next-day flight 
activities to provide supplemental post-mission observations for marine 
mammals in the operations area of the previous day.
    (5) A summary annual report of marine mammal observations and A-S 
activities will be submitted to the NMFS Southeast Regional Office 
(SERO) and the Office of Protected Resources either at the time of a 
request for renewal of an IHA or 90 days after expiration of the 
current IHA if a new IHA is not requested.
    (6) If any dead or injured marine mammals are observed or detected 
prior to testing, or injured or killed during live fire, a report must 
be made to the NMFS by the following business day.
    (7) Any unauthorized takes of marine mammals (i.e., injury or 
mortality) must be immediately reported to the NMFS represent-ative and 
to the respective stranding network representative.

Proposed Modifications to the Mitigation and Monitoring Requirements

    Eglin AFB has requested several modifications to its IHA to be 
incorporated into the new IHA.
    As of October 27, 2006, two A-S gunnery missions have been 
attempted (one of the missions was ultimately aborted due to sea 
state). As a result of flying live missions over the ocean, aircrews 
have requested a modification to three components of the 2006 IHA 
requirements. These components are: (1) protected species surveys, (2) 
ramp-up procedures, and (3) sea state restrictions.

Protected Species Surveys-Altitude and Equipment

    Currently, pre-mission surveys for marine mammals and other 
protected species must be commenced at a maximum altitude of 1,500 ft 
(457 m)(with 1,000 ft (305 m) recommended) during the day and at 2,000 
ft (610 m)(1,500 ft (457 m) recommended) at night. Visual scans, as 
well as all applicable instruments, are to be used to survey for 
protected species at the water surface. Aircrews have reported that 
these altitudes are not safe, and that the onboard instrumentation used 
for surveys actually performs better at a higher altitude.
    The propeller-driven AC-130 aircraft, which is used for all A-S 
gunnery missions, is among the largest and heaviest in the Air Force, 
weighing up to approximately 150,000 lbs (68040 kg) depending on 
equipment configuration. If an emergency situation, such as a 
malfunction of one or more engines, occurred during the protected 
species surveys, the aircraft would likely lose altitude initially. The 
AC-130 does not perform well with less than a full compliment of 
engines. At 1,000 to 2,000 ft (305 to 610 m), the pilots would have 
little time to recover before striking the water surface, which would 
result in potential human fatalities and certain loss of the aircraft. 
The AC-130 is typically flown at a minimum altitude of 4,500 ft (1372 
m). Eglin AFB notes that the 2004 National Defense Authorization Act 
amendments to the MMPA explicitly require consideration of personnel 
safety during military readiness activities.
    AC-130 gunships are equipped with low-light TV cameras and ANIAAQ-
26 Infrared Detection Sets (IDS). The TV cameras operate in a range of 
electromagnetic radiation of 532 to 980 nanometers (visible and near-
visible light), and the IDS system operates in the IR portion of 7.5 to 
11.7 micrometers. IR systems are capable of detecting differences in 
temperature from thermal energy (heat) radiated from living bodies, or 
from reflected and scattered thermal energy. In contrast to typical 
night-vision devices, visible light is not necessary for object 
detection. IR systems are equally effective during day or night use.
    The ANIAAQ-26 IDS system produces a composite video signal which is 
displayed on an onboard television monitor. The IDS provides imagery 
and accurate line-of-sight information for an operator to detect, 
acquire, identify, and track targets. Additional capabilities include 
providing imagery suitable for reconnaissance and low-level navigation. 
The IDS is capable of detecting very small thermal differences (the 
exact thermal sensitivity is classified). Three fields-of-view (FOV) 
are available for the IDS. All are typically used during a mission to 
survey the area and acquire targets. These are:
     Wide FOV (1.80 magnification) aides in low altitude 
flight, navigation, and area search, and also provides sufficient 
resolution to recognize typical terrain features such as roads, rivers, 
and bridges.
     Medium FOV (10.8 magnification) provides for immediate 
target area orientation and target detection.
     Narrow FOV (42.9 magnification) provides small target 
identification, target recognition, and precise line-of-sight angular 
adjustments. A 2X FOV (85.80 magnification) provides electronic 
magnification of the Narrow FOV.
    The IDS provides pointing information regarding its optical line-
of-sight, and features a continuous 360-degree azimuth Field of Regard 
(FOR) and +60 degree up-look to -105 degree down-look elevation FOR. 
The line-of-sight is inertial-stabilized with regard to

[[Page 29981]]

airplane angular motions and is directed to pointing angles via 
programmed commands, operator commands, or position commands from the 
avionics systems.
    IR and low-light TV systems are used during both daytime and 
nighttime missions (ambient light is sufficient for the TV system at 
night). The IDS is the primary detection system and is used during all 
gunship missions. Low-light TV and visual surveys are used to 
supplement the IDS system as appropriate. The magnification of the TV 
system is comparable to that of the IDS. Although the IDS is capable of 
detecting infrared emissions at altitudes in excess of 12,500 ft (3810 
m), an altitude range of 6,000 to 9,000 ft (1829 to 2743 m) affords the 
optimal slant range for overall sensor performance and target 
orientation.
    The sensor suite is considered superior to the human eye for 
detecting targets on the water surface, even at altitudes as low as 
1,000 ft (305 m). This is particularly true for night observations. IR 
systems havc been used to detect whales and dolphins (Baldacci et al., 
2005). Although the central portion of cetacean bodies are insulated 
with blubber, peripheral areas such as the flukes and fins are 
relatively poorly insulated. These areas may be detected thermally. 
Also, the movement of a cetacean's body at the surface causes heat to 
be radiated at different angles, resulting in an apparent temperature 
difference that can be detected by IR sensors. Additional areas of 
thermal discrimination include the blowhole, the blow, and areas of 
water disturbance where water of different temperatures is mixed. 
However, high humidity, rain, fog, high waves, and whitecap conditions 
can decrease the effectiveness of IR detection. Figure 1 in Eglin's 
January 22, 2007 renewal request shows examples of all FOVs for the IDS 
system, as an operator would see them on a monitor. All examples 
represent a 7.8-ft (2.4 m) dolphin at 6,000 ft (1829 m) altitude (above 
ground level, or AGL) and at a slant range of 8,000 ft (2438 m). All 
four FOVs would be used during protected species surveys. Based on the 
above discussion, the AC-130 aircrews recommend a protected species 
survey altitude of 6,000 ft (1829 m), using all sensors, for both day 
and night missions.
    The gunship sensor suite provides the best daytime and nighttime 
performance in normal weather and sea conditions at this altitude 
range. At lower altitudes, the sensors' area of coverage is smaller for 
any given field of view. In addition, the sensors' effectiveness is 
diminished due to magnification factors. For example, at an altitude of 
1,000 ft (305 m), the 2X and Narrow FOV settings would cause over-
magnification, resulting in decreased ability to discriminate targets. 
In addition to considerations of sensor performance, a 6,000-ft (1829-
m) survey altitude would be significantly safer than the current 1,000- 
to 2,000-ft (305- to 610-m)range.
    Eglin AFB therefore proposes a revised protocol for protected 
species surveys. The AC-130 gunship would travel to a potential mission 
location at an altitude of 6,000 ft (1829 m). After arriving at the 
site, the aircrew would initiate a surface vessel and protected species 
survey at a 6,000 ft (1829 m) altitude. The aircraft would circle the 
target site and continue the survey for 15 minutes. During the survey, 
aircrews would use the ANIAAQ-26 IDS to search the water surface for 
vessels and marine species. The low-light TV system would be used to 
supplement the IDS system. For missions conducted during daylight 
hours, the aircrew would visually scan the water surface as well. The 
live fire phase of the mission would not begin until the site is 
determined to be clear of vessels and protected species during the 15-
minute survey. If a marine mammal, sea turtle or Sargassum bed is 
identified during the pre-mission survey or during the mission, or if 
any object besides the target is detected but cannot conclusively be 
identified, the mission would be paused or relocated as appropriate. 
Aircrews would conduct a post-mission survey for 5 minutes at an 
altitude of 6,000 ft (1829 m) using the IDS and low-light television 
systems and, for daytime missions, visual scans. Eglin AFB considers 
that the protocol described here would provide effective mitigation to 
the risks posed to protected species during A-S gunnery missions. In 
summary, Eglin AFB believes that sensor-based observation effectiveness 
at 6,000 ft (1829 m) altitude is superior to visual survey 
effectiveness at 1,000 ft (305 m) altitude and should replace the 
previous mitigation measure.

Ramp-up Procedures

    The 2006-2007 IHA stipulates that ramp-up procedures are to be used 
during A-S gunnery missions. This process involves beginning with the 
smallest gunnery round, which has the least impact, and proceeding to 
subsequently larger size rounds. The rationale is that this process may 
allow animals to perceive steadily increasing noise levels and to 
react, if necessary, before the noise reaches a threshold of 
significance. The gunships' weapons are used in two activity phases. 
First, the guns are checked for functionality and calibrated. This step 
requires an abbreviated period of live fire. After the guns are 
determined to be ready for use, the mission proceeds under various test 
and training scenarios. This second phase involves a more extended 
period of live fire and can incorporate use of one or any combination 
of the munitions available (25-, 40-, and 105-millimeter rounds). Eglin 
AFB believes the 2006-2007 IHA is somewhat ambiguous regarding whether 
the ramp-up procedure is required only for the first (calibrating) 
phase or throughout the entire mission. Eglin AFB proposes that the 
ramp-up procedure be required for the initial gun calibration, and that 
after this phase the guns may be fired in any order. Eglin believes 
this process complies with the intent of the ramp-up requirement. 
Marine species will have opportunity to respond to increasing noise 
levels. If an animal leaves the area during ramp-up, it is unlikely to 
return while the live-fire mission is proceeding. This protocol would 
allow a more realistic training experience. In combat situations, 
gunship crews would not likely fire the complete ammunition load of a 
given caliber gun before proceeding to another gun. Rather, a 
combination of guns would likely be used as required by an evolving 
situation. An additional benefit of this protocol is that mechanical or 
ammunition problems on an individual gun can be resolved while live 
fire continues with functioning weapons. This diminishes the 
possibility of a lengthy pause in live fire which, if greater than 10 
minutes, would necessitate re-initiation of protected species surveys.

Sea State Restrictions

    The 2006-2007 IHA states that air-to-surface gunnery missions are 
to be conducted only in sea states of 3 or less on the Beaufort scale. 
A sea state of 3 or less, with a maximum wind speed of 10 knots (11.5 
mph, 18.5 km/hr) which is considered a gentle breeze, is fairly common 
off the Gulf coast of Florida; however, a large portion of time can be 
categorized as a sea state of 4 (1-16 knots (13-18 mph, 21-29 km/hr) 
which is considered a moderate breeze). Therefore, the availability of 
the EGTTR for gunship use is limited during anything over sea state 3, 
especially during the winter. Eglin AFB proposes gunship missions be 
allowed in sea states up to 4 on the Beaufort scale. This sea state 
encompasses wind speed up to a maximum of 16 knots (18 mph, 29 km/hr). 
Under these conditions, whitecaps are fairly frequent on the sea 
surface,

[[Page 29982]]

but sea spray does not occur. Sea spray, whitecaps, and large waves can 
decrease the effectiveness of LR detection. However, missions are not 
conducted if such conditions make observation of the gunnery target 
problematic. It is expected that marine species can be observed in 
weather conditions that allow observation of the gunnery target flare. 
Wave height is difficult to determine from the air, particularly at 
night. Therefore, Eglin proposes that wind speed, as provided by 
accepted forecasting outlets such as the National Weather Service, be 
considered the determining factor for weather restrictions.

Preliminary Conclusions

    For reasons described in this Federal Register document, NMFS has 
preliminarily determined that Esglin AFB's A-S Gunnery activity will 
not result in the mortality or serious injury of marine mammals and, 
would result in, at worst, a temporary elevation in hearing sensitivity 
(known as temporary threshold shift or TTS). As indicated in Table 1, 
Eglin AFB and NMFS estimated in 2006 that up to 271 marine mammals may 
incur this form of Level B harassment annually. Also, these gunnery 
exercises have the potential to result in a temporary modification in 
behavior by marine mammals. In 2006, NMFS estimated that up 25 marine 
mammals may experience a behavioral response to these exercises during 
the time-frame of an IHA (see Table 1). These air-to-surface gunnery 
activities are expected to have a negligible impact on the affected 
species or stocks. In addition, the potential for TTS is very low and 
will be mitigated to the lowest level practicable through the 
incorporation of the mitigation measures mentioned in this document. 
NMFS believes that the proposed modifications to the current mitigation 
requirements will not result in an increase in Level B harassment 
levels estimated in 2006. the previously discussed modifications 
(protected species survey altitude, ramp-up procedures and sea state 
conditions) to the mitigation measures in Eglin's existing IHA for the 
A-S gunnery exercises in the EGTTR, is unlikely to change NMFS' 2006 
determination.

Endangered Species Act (ESA)

    Consultation under section 7 of the ESA on Eglin AFB's A-S Gunnery 
Missions in the EGTTR was completed on December 18, 1998. Consultation 
was reinitiated by Eglin AFB with NMFS on February 13, 2003, and 
concluded on October 20, 2004. A NMFS Biological Opinion issued on 
October 20, 2004, concluded that the A-S gunnery exercises in the EGTTR 
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. NMFS has preliminary determined that 
this action, including the modifications to the mitigation and 
monitoring measures, does not have effects beyond that which was 
analyzed in that previous consultation, it is within the scope of that 
action and reinitiation of consultation is not necessary. However, 
prior to issuance of this IHA, NMFS will make a final determination 
whether additional consultation is necessary.

National Environmental Policy Act (NEPA)

    The U.S. Air Force (USAF) made a Finding of No Significant Impact 
(FONSI) determination on August 18, 2003, based on information 
contained within its November, 2002 Final PEA, that implementation of 
the subject action is not a major Federal action having significant 
effects on the environment within the meaning of NEPA. The USAF 
determined, therefore, that an environmental impact statement (EIS) 
would not be prepared. NMFS noted that Eglin AFB had prepared a Final 
PEA for the EGTTR activity and made this Final PEA available upon 
request on January 23, 2006 (71 FR 3474). In accordance with NOAA 
Administrative Order 216-6 (Environmental Review Procedures for 
Implementing the National Environmental Policy Act, May 20, 1999), NMFS 
reviewed the information contained in Eglin AFB's Final PEA and 
determined that Eglin AFB's Final PEA accurately and completely 
describes the proposed action, the alternatives to the proposed action, 
and the potential impacts on marine mammals, endangered species, and 
other marine life that could be impacted by the preferred alternative 
and the other alternatives. Accordingly, NMFS adopted Eglin AFB's Final 
PEA under 40 CFR 1506.3 and made its own FONSI. The NMFS FONSI also 
took into consideration updated data and information contained in the 
NMFS' Federal Register document noting issuance of an IHA to Eglin AFB 
for this activity (71 FR 27695, May 12, 2006), and previous notices (71 
FR 3474 (January 23, 2006); 70 FR 48675 (August 19, 2005)). NMFS has 
preliminarily determined that the current proposed action will not 
result in a significant modification in the previously reviewed 
activity and, therefore, a new EA, supplemental EA or an EIS for the 
issuance of an IHA to Eglin AFB for this activity is not necessary.

Proposed Authorization

    NMFS proposes to reissue an IHA to Eglin AFB for conducting A-S 
gunnery exercises within the EGTTR in the northern GOM provided the 
mitigation, monitoring, and reporting requirements described in this 
Federal Register notice are incorporated. NMFS has preliminarily 
determined that the proposed activity is unlikely to result in injury 
or mortality to marine mammals, and would have a negligible impact on 
the affected marine mammal species or stocks. The MMPA provision 
relating to impacts on subsistence are not relevant.

Information Solicited

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

    Dated: May 24, 2007.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. E7-10372 Filed 5-29-07; 8:45 am]
BILLING CODE 3510-22-S