The primary potential impact to the Atlantic bottlenose dolphins occurring in the Port of Miami action area from the proposed detonations is Level B harassment incidental to noise generated by explosives. In the absence of any monitoring or mitigation measures, there is a very small chance that a marine mammal could be injured, seriously injured, or killed when exposed to the energy generated from an explosive force on the sea floor. However, the ACOE and NMFS believes that the proposed monitoring and mitigation measures will preclude this possibility in the case of this particular proposed activity.

Non-lethal injurious impacts (Level A harassment) are defined in this proposed IHA as TM rupture and the onset of slight lung injury. The threshold for Level A harassment corresponds to a 50 percent rate of TM rupture, which can be stated in terms of an energy flux density (EFD) value of 205 dB re 1 μPa 2 s. TM rupture is well-correlated with permanent hearing impairment (Ketten, 1998) indicates a 30 percent incidence of permanent threshold shift (PTS) at the same threshold. The farthest distance from the source at which an animal is exposed to the EFD level for the Level A harassment threshold is unknown at this time.

Level B (non-injurious) harassment includes temporary (auditory) threshold shift (TTS), a slight, recoverable loss of hearing sensitivity. One criterion used for TTS is 182 dB re 1 μPa² s maximum EFD level in any 1/3 -octave band above 100 Hz for toothed whales ( e.g., dolphins). A second criterion, 23 psi, has been established by NMFS to provide a more conservative range of TTS when the explosive or animals approaches the sea surface, in which case explosive energy is reduced, but the peak pressure is not. For the proposed project in Miami Harbor, the distance from the blast array at which the 23 psi threshold could be met for various charge detonation weights can be, and has been calculated.

Level B harassment may also include behavioral modifications resulting from repeated noise exposures (below TTS) to the same animals (usually resident) over a relatively short period of times. Threshold criteria for this particular type of harassment are currently still being considered. One recommendation is a level of 6 dB below TTS (see 69 FR 21816, April 22, 2004), which would be 177 dB re 1 μPa 2 s. The Level B harassment (behavioral) threshold criteria would not apply to the ACOE's proposed activity because there will only two blasting events a day, and the multiple (staggered) detonations are within a few microseconds of each other and do not last more than a few seconds in total duration per a blasting event.

For an open-water, unconfined blast, the pressure edge of the danger zone is expected to be 23 psi. For a fully confined blast, the pressure at the edge of the danger zone is expected to be 6 psi. Utilizing the pressure data collected the Miami Harbor Phase II project in 2005, for a maximum charge weight of 450 lbs in a fully confined blast, the pressure is expected to be 22 psi approximately 700 ft (213.4 m) from the blast, which is below the threshold for Level B harassment ( i.e., 23 psi criteria for explosives less than 2,000 lb). However to ensure the protection of marine mammals, and in case of an incident where a detonation is not fully confined, the ACOE assumes that any animal within the boundaries of a designated “danger zone” would be taken by Level B harassment.

The ACOE is planning to implement a series of monitoring and mitigation measures to protect marine mammals from the potential impacts of the proposed blasting activities. The ACOE has designated a “danger zone” as the area within which the potential for Level B harassment occurs, and the “exclusion zone” as the area within which if an animal crosses and enters that zone then the blast will be delayed until the animal leaves the zone of its own volition. The exclusion zone is larger than the area where the ACOE has determined that Level B harassment will occur, so if the monitoring and mitigation measures implemented are successful as expected, and no detonation occurs when an animals is inside of the exclusion zone, no take by Level B harassment is likely to occur. However, to be conservative, the ACOE has calculated the potential exists for Level B harassment and is pursuing an IHA from NMFS. More information on how the danger and exclusion zones are determined is included in the “Proposed Mitigation” section of this document (see below).

It has been noted on one previous occasion at the ACOE's Miami Harbor Phase II project in 2005 that a bottlenose dolphin outside the exclusion zone, in the deeper water channel, exhibited a startle response immediately following a blast. Details of that event from the monitoring report are included below:

Individual dolphins from other stocks and within the Biscayne Bay and Western North Atlantic Central Florida Coastal stocks potentially move both inshore and offshore of Biscayne Bay due to the openness of this bay system and closeness of the outer continental shelf. These movements are not fully understood and the possibility exists that these other stocks may be affected in the same manner as the Biscayne Bay and Western North Atlantic Central Florida Coastal stocks.

Based on the data from the Miami Harbor project in 2005 and the implementation of the proposed monitoring and mitigation measures, the ACOE and NMFS expects limited potential effects of the proposed construction and blasting activities on marine mammals in the Port of Miami action area.

The ACOE and NMFS are unable to determine if resident bottlenose dolphins in the proposed action area utilize the inner and outer channels, walls, and substrate of the Port of Miami as habitat for feeding, resting, mating, or other biologically significant functions. The bottom of the channel has been previously blasted, and the rock and sand dredged. The walls of the channels are composed of vertical rock. The ACOE acknowledges that while the port may not be suitable foraging habitat for bottlenose dolphins in Biscayne Bay, it is likely that dolphins may use the area to traverse to and from North Biscayne Bay or offshore via the main channel ( i.e., Government Cut).

The ACOE and NMFS are unable to determine how the temporary modification of the action area by the proposed construction and blasting activities will potentially impact the two stocks of bottlenose dolphins expected to be present in the Port of Miami. If animals are using the Port of Miami to travel from south to north Biscayne Bay or vice-versa and/or exiting the bay via the main shipping channel, the proposed construction and blasting activities may delay or detour their movements.

Blasting within the boundaries of the Port of Miami will be limited both spatially and temporally. The explosives utilized in the proposed blasting operations are water soluble and non-toxic. If an explosive charge is unable to be fired and must be left in the drill hole, it is designed to break down. Also, each drill hole has a booster with detonator and detonation cord. Most of the detonation cord is recovered onto the drill barge by pulling it back onboard the drill barge after the blasting event. Small amounts of detonation cord may remain in the water after the blasting event has taken place, and will be recovered by small vessels with scoop nets. Any material left in the drill hole after the blast event will be recovered through the dredging process, when the cutterhead dredge excavates the fractured rock material.

With regard to prey species (mainly fish), a very small number of fish are expected to be impacted by the proposed Miami Harbor project, based on the results of the 2005 blasting project in Miami Harbor. That project consisted of 40 blast events over a 38 day time frame. Of these 40 blast events, 23 were monitored (57.5% of the total) by the state and injured and dead fish were collected after the all clear was given (the “all-clear” is normally at least two to three min after the shot is fired, since seagulls and frigate birds quickly learned to approach the blast site and swoop in to eat some of the stunned, injured, and dead fish floating on the surface of the water). State biologists and volunteers collected the carcasses of the floating fish (note that not all dead fish float after a blasting event, and due to safety concerns, there are no plans to put divers on the bottom of the channel in the blast zone to collect non-floating fish carcasses. The fish were described to the lowest taxonomic level possible (usually species) and the injury types were categorized. The data forms are available from the FWC and ACOE upon request.

A summary of those data shows that 24 different genera were collected during the previous Miami Harbor blasting project. The species with the highest abundance were white grunts ( Haemulon plumier, N = 51), scrawled cowfish ( Lactophrys quadricornis, N = 43), and pygmy filefish ( Monocanthus setifer, N = 30). The total fish collected during the 23 blasts was 288 or an average of 12.5 fish per blast (range 3 to 38). In observation of the three blasts with the greatest number of fish killed (see Table 4 of ACOE's application) and reviewing the maximum charge weight per delay for the Miami Harbor project, it appears that there is no direct correlation between the charge weight and fish killed that can be determined from such a small sample. Reviewing the 23 blasting events where dead and injured fish were collected after the “all-clear” signal was given, no discernable pattern exists. Factors that affect fish mortality include, but are not limited to fish size, body shape (fusiform, etc. ), proximity of the blast to a vertical structure like a bulkhead ( e.g., see the August 10, 2005 blast event, a much smaller charge weight resulted in a higher fish kill due to the closeness of a bulkhead).

In the past, to reduce the potential for fish to be injured or killed by the blasting, the resource agencies have requested, and ACOE has allowed that blasting contractors utilize a small, unconfined explosive charge, usually a 1 lb (0.5 kg) booster, detonated about 30 seconds before the main blast, to drive fish away from the blasting zone. It is assumed that noise or pressure generated by the small charge will drive fish from the immediate area, thereby reducing impacts from the larger and potentially more-damaging blast. Blasting companies use this method as a “good faith effort” to reduce the potential impacts to aquatic natural resources. The explosives industry recommends firing a “warning shot” to frighten fish out of the area before seismic exploration work is begun (Anonymous, 1978 in Keevin et al., 1997).

There are limited data available on the effectiveness of fish scare charges at actually reducing the magnitude of fish kills, and the effectiveness may be based on the fish's life history. Keevin et al. (1997) conducted a study to rest if fish scare charges are effective in moving fishes away from blast zones. They used three freshwater species ( i.e., largemouth bass ( Micropterus salmoides ), channel catfish ( Ictalurus punctatus ), and flathead catfish ( Pylodictis olivaris ), equipping each fish with an internal radio tag to allow the fishes movements to be tracked before and after the scare charge. Fish movement was compared with a predicted lethal dose (LD) 0% mortality distance for an open water shot (no confinement) for a variety of charge weights. Largemouth bass showed little response to repelling charges and none would have moved from the kill zone calculated for any explosive size. Only one of the flathead catfish and two of the channel catfish would have moved to a safe distance for any blast. This means that only 11% of the fish used in the study would have survived the blast events.

These results call into question the true effectiveness of this minimization methodology; however, some argue that based on the monetary value of fish (American Fishery Society, 1992 in Keevin et al., 1997), including the high value commercial or recreational species like snook ( Centropomus undecimalis ) and tarpon ( Megalops atlanticus ) found in southeast Florida inlets like Port Everglades, the low cost associated with repelling charge use would be offset if only a few fish moved from the kill zone (Keevin et al., 1997).

To calculate the potential loss of prey species from the proposed project area as an impact of the blasting events, the ACOE used a 12.5 fish kill per blasting event estimate based on the Miami Harbor 2005 project, and multiplied it by the 40 shots, reaching a total estimate of 500 floating fish. As stated previously, not all carcasses float to the surface and there is no way to estimate how many carcasses did not float. Using an estimate of 12.5 fish kill per blasting event, and the maximum 600 detonations for the entire multi-year proposed project, the minimum number of fish expected to be killed by the proposed project is approximately 7,500 fish across the entire 28,500 ft (8,686.8 m) long channel footprint, assuming the worst case scenario and the entire channel needs to be blasted.

NMFS anticipates that the proposed action will result in no significant impacts to marine mammal habitat beyond rendering the areas immediately around the Port of Miami less desirable shortly after each blasting event and during dredging operations and potentially eliminating a relatively small amount of locally available prey. The impacts will be localized and instantaneous. Impacts to marine mammal habitat, as well as invertebrate and fish species are not expected to be significantly detrimental.

In order to issue an Incidental Take Authorization (ITA) under section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods of taking pursuant to such activity, and other means of effecting the least practicable adverse impact on such species or stock and its habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of such species or stock for taking for certain subsistence uses.

Over the last 10 years, the ACOE's Jacksonville District has been collecting data concerning the effects of confined blasting projects on marine mammals. This effort began in the early 1990's when the ACOE contracted with Dr. Calvin Koyna, Precision Blasting Services, to review previous ACOE blasting projects. The ACOE also received recommendations from the Florida Fish and Wildlife Conservation Commission (FWC, then known as the Florida Department of Natural Resources) and the USFWS to prepare for a harbor deepening project at Port Everglades, Florida, which was conducted in the mid-1980's. The recommendations prepared for the project were specifically aimed at protecting endangered manatees and endangered and threatened sea turtles.

The ACOE will develop and implement four zones as protective measures that are based on the use of an unconfined blast. The use of unconfined blast in development of these protective zones for a confined blast will increase the conservation measures afforded marine mammals in the proposed action area. These four zones are referred to as the danger zone ( i.e., inner most zone, located closest to the blast), the exclusion zone ( i.e., the danger zone plus 500 ft (152.4 m) to add an additional layer of conservatism for marine mammals), the safety zone ( i.e., the third zone), and the watch zone ( i.e., the outer most zone). All of these zones are noted in Figure 11 of ACOE's IHA application and described in further detail in this section of the document (see below). Of these four zones, only the danger zone, is associated with an MMPA threshold. The danger zone has been determined to be larger than or equal to the threshold for Level B harassment, as defined by the MMPA. Injury (Level A harassment), serious injury, or mortality, as defined by the MMPA, are expected to occur at closer distances to the blasting array within the danger zone.

These four zone calculations will be included as part of the specifications package that the contractors will bid on before the project is awarded.

As part of the ACOE's Miami Harbor Phase II project, the ACOE monitored the blasting project and collected data on the pressures associated with confined blasts, while employing a formula to calculate buffer and exclusion zones that would protect marine mammals. Results from the pressure monitoring at Miami Harbor Phase II demonstrate that stemming each drill hole reduces the blast pressure entering the water (Nedwell and Thandavamoorthy, 1992; Hemen et al., 2005; Hempen et al., 2007).

The following standard conditions have been incorporated into the proposed project specifications to reduce the risk to marine mammals in the proposed project area. While this application is specific to bottlenose dolphins, these specifications are written for all protected species that may be in the proposed project area.

If blasting is proposed during the period of November 1 through March 31, significant operational delays should be expected due to the increased likelihood of manatees being present within the proposed project area. If possible, avoid scheduling proposed blasting during the period from November 1 through March 31. In the area where blasting could occur or any area where blasting is required to obtain channel design depth, the following marine mammal protective measures shall be employed, before, during, and after each blast:

(A) The FWC, the USFWS, and NMFS must review the contractor's approved Blasting Plan prior to any blasting activities. Copies of this blasting plan shall be provided to FDEP and FWC as a matter of comity. This blasting proposal must include information concerning a watch program and details of the blasting events. This information must be submitted at least 30 days prior to the proposed date of the blast(s) to the following addresses:

(1) FWC-ISM, 620 South Meridian Street, Mail Stop 6A, Tallahassee, FL 32399-1600 or ImperiledSpecies@myfwc.com.

(2) NMFS Office of Protected Resources, 1315 East-West Highway, Silver Spring, MD 20910.

(3) USFWS, 1339 20th Street, Vero Beach, Florida 32960-3559 or 6620 Southpoint Drive South, Suite 310, Jacksonville, FL 32216-0912 (project location dependent).

(4) NMFS Southeast Regional Office, Protected Species Management Branch, 263 13th Avenue South, St. Petersburg, FL 33701.

In addition to plan review, Dr. Allen Foley should be notified at the initiation and completion of all in-water blasting ( allen.foley@myfwc.com ).

(B) The proposed project specifications shall include at least the following information:

(1) A list of Protected Species Observers (PSOs), their qualifications, and positions for the watch, including a map depicting the proposed locations for boat or land-based PSOs. Qualified PSOs must have prior on-the-job experience observing for protected species during previous in-water blasting events where the blasting activities were similar in nature to this project.

(2) The amount of explosive charge proposed, the explosive charge's equivalency in TNT, how it will be executed (depth of drilling, stemming, in-water, etc. ), a drawing depicting the placement of the charges, size of the exclusion zone, and how it will be marked (also depicted on a map), tide tables for the blasting event(s), and estimates of times and days for blasting events (with an understanding this is an estimate, and may change due to weather, equipment, etc. ).

(C) For each explosive charge placed, three zones will be calculated, denoted on monitoring reports and provided to PSOs before each blast for incorporation in the watch plan for each planned detonation. All of the zones will be noted by buoys for each of the blasts. These zones are:

(1) Danger Zone: The danger zone radius is equal to 260 (79.25 m) times the cube root of the weight of the explosive charge in lbs per delay (equivalent weight of tetryl or TNT). The radius of the danger zone has been determined to be equal to or larger than the distance from the charge to a location where a marine mammal would experience Level B harassment.

Danger Zone Development: The radius of the danger zone will be calculated to determine the maximum distance from the blast at which mortality to marine mammals is likely to occur. The danger zone was determined by the amount of explosives used within each delay (which can contain multiple boreholes). The original basis of this calculation was to protect human U.S. Navy Seal divers from underwater detonations of underwater mines (Goertner, 1982). Goertner's calculations were based on impacts to terrestrial animals in water when exposed to a detonation suspended in the water column (unconfined blast) as researched by the U.S. Navy in the 1970's (Yelverton et al., 1973; Richmond et al., 1973). Additionally, observations of sea turtle injury and mortality associated with unconfined blasts for the cutting of oil rig structures in the Gulf of Mexico (Young, 1991; Young and O'Keefe, 1994) were also incorporated in this radius beyond its use by the Navy. The State of Florida has adopted this method for the protection of marine mammals (particularly the Florida manatee) within state waters (FWC, 2005) in the document entitled, “May 2005 Guidelines for the Protection of Marine Mammals and Sea Turtles during the Use of Explosives in the Waters of the State of Florida.”

The U.S. Navy Dive Manual and the FWC Guidelines (2005) set the danger zone formula for an unconfined blast suspended in the water column, which is as follows:

(2) Exclusion Zone: The exclusion zone radius is equal to the danger zone plus a buffer of 500 ft. Detonation will not occur if a marine mammal is known to be (or based on previous sightings, may be) within the exclusion zone.

Exclusion Zone Development: The exclusion zone is not associated with any threshold of take, as defined by the MMPA, as it is larger than the danger zone, where Level B harassment is expected. The exclusion zone was developed during consultations with the FWC during the 2005 to 2006 Phase II dredging and blasting project in Miami Harbor. FWC requested a larger “no blast” radius due to the high number of manatees documented in the vicinity of the Port of Miami, particularly utilizing the Bill Sadowski Wildlife Area directly south of the port and north of Virginia Key. The ACOE concurred with this request and added a second zone with an additional 500 ft radius above the calculated radius of the danger zone. To be consistent with the previous blasting activities at Miami Harbor, and since the blasting will take place in the same area, with the same concerns about the proximity of manatees to the blasting sites along Fisherman's Channel, the ACOE proposes to maintain the exclusion zone.

(3) Safety Zone: The safety zone is equal to 520 (158.50 m) times the cube root of the weight of the explosive charge in lbs per delay (equivalent weight of tetryl or TNT).

Safety Zone Development: The safety zone is not associated with any threshold of take, as defined by the MMPA, as it is larger than the danger zone, where Level B harassment is expected. The safety zone was developed to be an area of “heightened awareness” of protected species ( e.g. dolphins, manatees, and sea turtles) entering the blast area, without triggering a shut-down. This area triggers individual specific monitoring of each individual or group of animals as they transit in, out, or through the designated zones.

(4) Watch Zone: The watch zone is three times the radius of the danger zone to ensure that animals entering or traveling close to the exclusion zone are sighted and appropriate actions can be implemented before or as the animal enters the any impact areas ( i.e., a delay in blasting activities).

Watch Zone Development: The watch zone is not associated to any threshold of take, as defined by the MMPA, as it is larger than the danger zone, where Level B harassment is expected. The watch zone is the area that can be typically covered by a small helicopter based on the blasting site, flight speed, flight height, and available fuel to ensure effective mitigation-monitoring of the proposed project area.

(D) The watch program shall begin at least one hour prior to the scheduled start of blasting to identify the possible presence of marine mammals. The watch program shall continue for at least 30 minutes (min) after detonations are complete.

(E) The watch program shall consist of a minimum of six PSOs. Each PSO shall be equipped with a two-way radio that shall be dedicated exclusively to the watch. Extra radios should be available in case of failures. All of the PSOs shall be in close communication with the blasting sub-contractor in order to halt the blast event if the need arises. If all PSOs do not have working radios and cannot contact the primary PSO and the blasting sub-contractor during the pre-blast watch, the blast shall be postponed until all PSOs are in radio contact. PSOs will also be equipped with polarized sunglasses, binoculars, a red flag for back-up visual communication, and a sighting log with a map to record sightings. All blasting events will be weather dependent. Climatic conditions must be suitable for optimal viewing conditions, to be determined by the PSOs.

(F) The watch program shall include a continuous aerial survey to be conducted by aircraft, as approved by the Federal Aviation Administration (FAA). The blasting event shall be halted if an animal(s) is sighted within the exclusion zone, within the five min before the explosives are scheduled to be detonated. An “all clear” signal must be obtained from the aerial PSO before the detonation can occur. The blasting event shall be halted immediately upon request of any of the PSOs. If animals are sighted, the blast event shall not take place until the animal(s) moves out of the exclusion zone under its own volition. Animals shall not be herded away or intentionally harassed into leaving. Specifically, the animals must not be intentionally approached by project watercraft or aircraft. If the animal(s) is not sighted a second time, the event may resume 30 min after the last sighting.

(G) An actual delay in blasting only occurs when a marine mammal was located within the exclusion zone at the point where the blast countdown reaches the T-minus five min. At that time, if an animal is in or near the safety zone, the countdown is put on hold until the zone is completely clear of marine mammals and all 30 min sighting holds have expired. Animal movements into the safety zone prior to that point are monitored closely, but do not necessarily stop the countdown. The exception to this would be stationary animals that do not appear to be moving out of the area or animals that begin moving into the safety zone late in the countdown. For these cases, holds on the T-minus 15 min may be called to keep the shipping channel open and minimize the impact on the Port of Miami operations.

(H) The PSOs and contractors shall evaluate any problems encountered during blasting events and logistical solutions shall be presented during blasting events and logistical solutions shall be presented to the Contracting Officer. Corrections to the watch shall be made prior to the next blasting event. If any one of the aforementioned conditions is not met prior to or during the blasting, the watch PSOs shall have the authority to terminate the blasting event, until resolution can be reached with the Contracting Officer. The Contracting Officer will contact FWC, USFWS, and NMFS.

(I) If an injured or dead marine mammal is sighted after the blast event, the PSOs on watch shall contact the ACOE and the ACOE will then contact the proper Federal and/or state natural resource agencies.

The PSOs shall maintain contact with the injured or dead marine mammal until authorities have arrived. Blasting shall be postponed until consultations are reinitiated and completed, and determinations can be made of the cause of injury or mortality. If blasting injuries are documented, all demolition activities shall cease. The ACOE will then submit a revised blasting plan to FWC, USFWS, and NMFS for review.

(J) Within 30 days after completion of all blasting events, the primary PSO shall submit a report the ACOE, who will provide it to the FWC, USFWS, and NMFS, providing a description of the event, number and location of animals seen and what actions were taken when animals were seen. Any problems associated with the event and suggestions for improvements shall also be documented in the report.

The ACOE will rely upon the same monitoring protocol developed for the Port of Miami project in 2005 (Barkaszi, 2005) and published in Jordan et al. (2007), which can be found online at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. The monitoring protocol is summarized here:

A watch plan will be formulated based on the required monitoring radii and optimal observation locations. The watch plan will consist of at least five PSOs including at least one aerial PSO, two boat-based PSOs, and two PSOs stationed on the drill barge (see Figures 13, 14, 15, and 16 of the ACOE's IHA application). This watch plan will be consistent with the program that was utilized successfully at Miami Harbor in 2005. The sixth PSO will be placed in the most optimal observation location (boat, barge, or aircraft) on a day-by-day basis depending on the location of the blast and the placement of dredging equipment. This process will ensure complete coverage of the four zones as well as any critical areas. The watch will begin at least one hour prior to each blast and continue for one half hour after each blast (Jordan et al., 2007).

The aerial PSO will fly in a turbine engine helicopter (bell jet ranger) with the doors removed. This provided maximum visibility of the watch and safety zones as well as exceptional maneuverability and the needed flexibility for continual surveillance without fuel stops or down time, minimization of delays due to weather or visibility and the ability to deliver post-blast assistance. Additionally, at least six commercial helicopter, small Cessna, and ultra-light companies operate on Key Biscayne, immediately south of the Port of Miami and offer “flight-seeing” operations over downtown Miami, Bayfront, and the Port of Miami. Recreational use of ultra-lights launching from Key Biscayne is also common in the area, as are overflights of commercial seaplanes, jet aircraft, and helicopters. The proposed action area being monitored is a high traffic area, surrounded by an urban environment where animals are potentially exposed to multiple overflights daily. ACOE conferred with Mary Jo Barkaszi, owner and chief PSO of ECOES, Inc., a protected species monitoring company with 25 years experience, and has worked on the last five blasting events involving marine mammal concerns for the ACOE throughout the country. All of these blasting events had bottlenose dolphins commonly occur in the project area. Ms. Barkaszi states that in her experience, she has not observed bottlenose dolphins diving or fleeing the area because a helicopter is hovering nearby at 500 ft (pers. comm., September 12, 2011). During monitoring events, the helicopter hovers at 500 ft above the watch zone and only drops below that level when helping to confirm identification of something small in the water, like a sea turtle. The ACOE and NMFS do not expect the incidental take of bottlenose dolphins, by Level B harassment, from helicopter-based monitoring of the blasting operations and the ACOE is not requesting take.

Boat-based PSOs are placed on one of two vessels, both of which have attached platforms that place the PSOs eyes at least 10 ft (3 m) above the water surface enabling optimal visibility of the water from the vessels. The boat-based PSOs cover the safety zone where waters are deep enough to safely operate the boats without any impacts to seagrass resources. The shallow seagrass beds south of the proposed project site relegate the PSO boats mainly to the channel east and west of the blast zone. At no time are any of the PSO boats allowed in shallow areas where propellers could potentially impact the fragile seagrass.

At times, turbidity in the water may be high and visibility through the water column may be reduced so that animals are not seen below the surface as they should be under normal conditions. This may be more common on an ebb tide. However, animals surfacing in these conditions are still routinely sighted from the air and from the boats, thus the overall PSO program is not compromised, only the degree to which animals were tracked below the surface. Adjustments to the program are made accordingly so that all protected species are confirmed out of the safety zone prior to the T-minus five min, just as they are under normal visual conditions. The waters within the proposed project area are exceptional for observation so that the decreased visibility below the surface during turbid conditions make the waters more typical of other port facilities where PSO programs are also effective throughout the U.S., for example New York and Boston harbors, where this monitoring method has also been employed.

All PSOs are equipped with marine-band VHF radios, maps of the blast zone, polarized sunglasses, and appropriate data sheets. Communications among PSOs and with the blaster is of critical importance to the success of the watch plan. The aerial-based PSO is in contact with vessel and drill barge-based PSOs and the drill barge with regular 15 min radio checks throughout the watch period. Constant tracking of animals spotted by any PSO is possible due to the amount and type of PSO coverage and the excellent communications plan. Watch hours are restricted to between two hours after sunrise and one hour before sunset. The watch begins at least one hour prior to the scheduled blast and is continuous throughout the blast. Watch continues for at least 30 min post blast at which time any animals that were seen prior to the blast are visually relocated whenever possible and all PSOs in boats and in the aircraft assisted in cleaning up any blast debris.

If any marine mammals are spotted during the watch, the PSO notifies the aerial-based PSO and/or the other PSOs via radio. The animals is located by the aerial-based PSO to determine its range and bearing from the blast array. Initial locations and all subsequent re-acquisitions are plotted on maps. Animals within or approaching the safety zone are tracked by the aerial and boat-based PSOs until they exited the safety zone. Anytime animals are sighted near the safety zone, the drill barge is alerted as to the animal's proximity and some indication of any potential delays it might cause.

If any animal(s) is sighted inside the safety zone and not re-acquired, no blasting is authorized until at least 30 min has elapsed since the last sighting of that animal(s). The PSOs on watch will continue the countdown up until the T-minus five min point. At this time, the aerial-based PSO confirms that all animals are outside the safety zone and that all holds have expired prior to clearing the drill barge for the T-minus five min notice. A fish scare charge will be fired at T-minus five min and T-minus one min to minimize effects of the blast on fish that may be in the same area of the blast array by scaring them from the blast area.

An actual delay in blasting only occurs when a marine mammal is located within the exclusion zone at the point where the blast countdown reaches the T-minus five min. At that time, if an animal is in or near the safety zone, the countdown is put on hold until the zone is completely clear of marine mammals and all 30 min sighting holds have expired. Animal movements into the safety zone prior to that point are monitored closely, but do not necessarily stop the countdown. The exception to this would be stationary animals that do not appear to be moving out of the area or animals that begin moving into the safety zone late in the countdown. For these cases, holds on the T-minus 15 min may be called for to keep the shipping channel open and minimize the impact on the Port of Miami operations.

In order to issue an ITA for an activity, section 101(a)(5)(D) of the MMPA states that NMFS must set forth “requirements pertaining to the monitoring and reporting of such taking.” The MMPA implanting regulations at 50 CFR 216.104 (a)(13) indicate that requests for IHAs must include the suggested means of accomplishing the necessary monitoring and reporting that will result in increased knowledge of the species and of the level of taking or impacts on populations of marine mammals that are expected to be present in the action area.

The ACOE will be conducting a study on fish kill associated with confined underwater blasting that will provide information on the effects of confined underwater blasting on prey species for dolphins in the proposed project area. This study will determine the maximum distance from the blast array, based on charge weight, that fish will not be killed, or injured (the “lethal dose of zero” distance) by confined underwater blasting. Similar studies have been completed for open water (unconfined) blasts as cited by Hempen and Keevin (1995), Keevin et al. (1995a, 1995b, and 1997), and Keevin (1998), but no such studies have been conducted for confined underwater blasting. This data will be useful for future confined blasting projects where pisciverous marine mammals are found, since it will allow resource managers to assess the impacts of the blasting activities on marine mammal prey, where species composition and density data have been collected for that project.

Additionally, ACOE will provide sighting data for each blast to researchers at NMFS Southeast Fisheries Science Center's marine mammal program and any other researchers working on dolphins in the project area to add to their database of animal usage of the proposed project area. The ACOE will rely upon the same monitoring protocol developed for the Port of Miami project in 2005 (Barkaszi, 2005) and published in Jordan et al. (2007).

The ACOE plan to coordinate monitoring with the appropriate Federal and state resource agencies, and will provide copies of all relevant monitoring reports prepared by their contractors. After completion of all detonation and dredging events, the ACOE would submit a summary report to regulatory agencies.

Within 30 days after completion of all proposed blasting events, the lead PSO shall submit a report to the ACOE, who will provide it to NMFS. The report will contain the PSO's logs (including names and positions during the blasting events), provide a description of the events, environmental conditions, number and location of animals sighted, the behavioral observations of the marine mammals, and what actions were taken when animals were sighted in the action area of the proposed project. Any problems associated with the even and suggestions for improvements shall also be documented in the report. A draft final report must be submitted to NMFS within 90 days after the conclusion of the proposed blasting activities. The report would include a summary of the information gathered pursuant to the monitoring requirements set forth in the IHA, including dates and times of detonations as well as pre- and post-blasting monitoring observations. A final report must be submitted to the Regional Administrator within 30 days after receiving comments from NMFS on the draft final report. If no comments are received from NMFS, the draft final report would be considered to be the final report.

In the unanticipated event that the specified activity clearly causes the take of a marine mammal in a manner prohibited by this IHA, such as an injury, serious injury or mortality, ACOE will immediately cease the specified activities and immediately report the incident to the Chief of the Permits and Conservation, Office of Protected Resources, NMFS at (301) 427-8401 and/or by email to Michael.Payne@noaa.gov and Howard.Goldstein@noaa.gov , and the NMFS Southeast Region Marine Mammal Stranding Network at (877) 433-8299 ( Blair.Mase@noaa.gov and Erin.Fougeres@noaa.gov ) (Florida Marine Mammal Stranding Hotline at (888) 404-3922). The report must include the following information:

• Time, date, and location (latitude/longitude) of the incident;

• Description of the incident;

• Status of all noise-generating source use in the 24 hours preceding the incident;

• Water depth;

• Environmental conditions ( e.g., wind speed and direction, Beaufort sea state, cloud cover, and visibility);

• Description of all marine mammal observations in the 24 hours preceding the incident;

• Species identification or description of the animal(s) involved;

• Fate of the animal(s); and

• Photographs or video footage of the animal(s) (if equipment is available).

Activities shall not resume until NMFS is able to review the circumstances of the prohibited take. NMFS shall work with ACOE to determine what is necessary to minimize the likelihood of further prohibited take and ensure MMPA compliance. ACOE may not resume their activities until notified by NMFS via letter or email, or telephone.

In the event that ACOE discovers an injured or dead marine mammal, and the lead PSO determines that the cause of the injury or death is unknown and the death is relatively recent ( i.e., in less than a moderate state of decomposition as described in the next paragraph), ACOE will immediately report the incident to the Chief of the Permits and Conservation Division, Office of Protected Resources, NMFS, at (301) 427-8401, and/or by email to Michael.Payne@noaa.gov and Howard.Goldstein@noaa.gov , and the NMFS Southeast Region Marine Mammal Stranding Network (877) 433-8299) and/or by email to the Southeast Regional Stranding Coordinator ( Blair.Mase@noaa.gov ) and Southeast Regional Stranding Program Administrator ( Erin.Fougeres@noaa.gov ). The report must include the same information identified in the paragraph above. Activities may continue while NMFS reviews the circumstances of the incident. NMFS will work with ACOE to determine whether modifications in the activities are appropriate.

In the event that ACOE discovers an injured or dead marine mammal, and the lead PSO determines that the injury or death is not associated with or related to the activities authorized in the IHA ( e.g., previously wounded animal, carcass with moderate to advanced decomposition, or scavenger damage), ACOE will report the incident to the Chief of the Permits and Conservation Division, Office of Protected Resources, NMFS, at (301) 427-8401, and/or by email to Michael.Payne@noaa.gov and Howard.Goldstein@noaa.gov , and the NMFS Southeast Region Marine Mammal Stranding Network (877) 433-8299), and/or by email to the Southeast Regional Stranding Coordinator ( Blair.Mase@noaa.gov ) and Southeast Regional Stranding Program Administrator ( Erin.Fougeres@noaa.gov ), within 24 hours of discovery. ACOE will provide photographs or video footage (if available) or other documentation of the stranded animal sighting to NMFS and the Marine Mammal Stranding Network.

Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as:

The ACOE is requesting the take of Atlantic bottlenose dolphins, by Level B harassment only, incidental to proposed blasting activities at Miami Harbor. The ACOE notes that multiple IHAs (up to three) will likely be needed and requested for the proposed project due to the duration of the planned blasting activities. See Table 2 (above) for NMFS's threshold criteria and metrics utilized for impact analyses from the use of explosives.

The Biscayne Bay stock of Atlantic bottlenose dolphins is bounded by Haulover Inlet to the north and Card Sound Bridge to the south. Biscayne Bay is 428 square mi (mi 2 ) (1,108.5 square km [km 2 ]) in area. The Port of Miami channel, within the boundaries of Biscayne Bay, is approximately 7,200 ft (2,194.6 m) long by 500 ft (152.4 m) wide, with the 3,425 ft (1,044 m) long by 1,400 ft (426.7 m) wide Dodge-Lummus Island turning basin (total area 0.3 mi 2 [0.8 km 2 ]) at the western terminus of Fisherman's Channel. The Port of Miami's channels consist of approximately 0.1% of the entire area of Biscayne Bay. To determine the maximum area of Biscayne Bay in which bottlenose dolphins may experience pressure levels greater than or equal to the 23 psi threshold for explosives less than 2,000 lb (907.2 kg), which has the potential to result in Level B harassment due to temporary threshold shift (TTS) and associated behavioral disruption, the ACOE may utilize a maximum charge weight of 450 lb (204.1 kg) with a calculated danger zone of 1,995 ft (608.1 m). Using this radius, the total area of this zone is approximately 0.1% of Biscayne Bay (12,503,617 ft 2 [1,161,624 m 2 ]).

For an open-water, unconfined blast, the pressure edge of the danger zone is expected to be 23 psi. For a fully confined blast, the pressure at the edge of the danger zone is expected to be 6 psi. Utilizing the pressure data collected the Miami Harbor Phase II project in 2005, for a maximum charge weight of 450 lbs in a fully confined blast, the pressure is expected to be 22 psi approximately 700 ft (213.4 m) from the blast, which is below the threshold for Level B harassment ( i.e., 23 psi criteria for explosives less than 2,000 lb). However to ensure the protection of marine mammals, and in case of an incident where a detonation is not fully confined, the ACOE assumes that any animal within the boundaries of the danger zone would be taken by Level B harassment.

Litz (2007) identified 69 individuals of the Biscayne Bay stock that she classified as the “northern dolphins” meaning animals with a mean sighting history from 1994 to 2004 north of 25.61° North. The photo-ID study that Litz's data is based on encompassed an area of approximately 200 mi 2 (518 km 2 ), approximately 50% of Biscayne Bay. The estimated maximum population of animals that may be in the proposed project area is equal to the total number of uniquely identified animals for the entire photo-ID study of Biscayne Bay is 229 individuals (Waring et al., 2010). The best population estimate for Biscayne Bay is 157 individuals, which is based on SEFSC's most consistent survey effort conducted during the 2003 to 2007 photo-ID survey seasons (Waring et al., 2010).

Table 4 (below) presents the estimated incidental take, by Level B harassment, for varying charge weight delays likely to be used during the proposed blasting activities and the estimated impacts based on the population estimates used in this analysis. In all cases, less than one bottlenose dolphin is expected to be taken incidental to each blasting event (0.049 minimum to 0.162 maximum). This assumes that the distribution of bottlenose dolphins is equal throughout all of Biscayne Bay.

The ACOE accessed the NMFS SEFSC photo-ID survey data from 1990 to 2004 in Biscayne Bay via the OBIS-Seamap database ( http://seamap.env.duke.edu/ ) and downloaded the Google Earth overlay of the data. Figure 12 of the ACOE's IHA application shows the general area of the Port of Miami and hot spots of bottlenose dolphin sightings both north and south of Miami Harbor. The data were used to see if sightings across all parts of the Biscayne Bay were equal. This sighting frequency data was not used to calculate the potential take numbers of marine mammals incidental to the proposed blasting activities.

Reviewing the data from the Miami Harbor Phase II project in 2005, the ACOE noted that for the 40 detonations, 28% of all animals sighted within the proposed action area (Fisherman's Channel) were bottlenose dolphins (the other animals sighted were manatees and sea turtles). Bottlenose dolphins were sighted inside the exclusion zone 12 times with a total of 30 individuals, with an average of 2.5 animals per sighting out of the total 58 bottlenose dolphins recorded during the project; therefore, groups of dolphins entered the exclusion zone multiple times. Also, dolphins entered the exclusion zone during 30% of the blasting events. Not all of the incidents where dolphins entered the exclusion zone resulted in a project delay, it is dependent upon when during the countdown the animals cross the line demarcating the exclusion zone, and how long they stay in the exclusion zone.

During the Miami Harbor Phase II project in 2005, bottlenose dolphins in the exclusion zone triggered delays on four occasions during the 13 blasting events (31%). If the maximum 313 planned detonations for the duration of the one year IHA have an equal percentage of delays as the 2005 project (assuming construction starts in June with blasting June, 2012 to June, 2013 timeframe, with no blasting on Sundays), 94 of the detonations would be delayed for some period of time due to the presence of protected species and 29 of those delays would specifically be for bottlenose dolphins.

As a worst case, using the area of the danger zone, and recognizing that the Port of Miami is within the boundaries of the northern area described in Litz (2007), and that the danger zone of any blasting event using equal to or less than 450 lbs/delay will be approximately 0.1% of Biscayne Bay, the ACOE assumes that because animals are not evenly distributed throughout Biscayne Bay, that they travel as single individuals or in groups (as documented in the OBIS-Seamap data and the monitoring data from the Miami Harbor Phase II project in 2005), and that without any monitoring and mitigation measures to minimize potential impacts, up to three bottlenose dolphins from the Biscayne Bay stock may be taken, by Level B harassment, incidental to each blasting event.

Assuming that the delays will be spread equally across the proposed action area and using the calculation of 29 delays and that three bottlenose dolphins would be inside the danger zone, 15 of the delayed blasting events would take place in Biscayne Bay since it compromises 52% of the proposed action area. Three bottlenose dolphins times 15 detonations is equal to 45 bottlenose dolphins may be exposed to an underwater sound and pressure over a 1-year period for an IHA incidental to the proposed blasting activities at the Port of Miami.

The Western North Atlantic Central Florida Coastal stock of bottlenose dolphins is present in the coastal Atlantic waters shallower than 65.6 ft (20 m) in depth between latitude 29.4° North to the western end of Vaca Key (approximately 29.69° North to 81.11° West) where the stock boundary for the Florida Key stock begins, with an area of 3,007 mi 2 (7,789 km 2 ). The outer entrance channel of the Port of Miami is approximately 15,500 ft long (4,724.4 m) by 500 ft wide, which is approximately 0.28 mi 2 (0.73 km 2 ). The Port of Miami's channels consist of approximately 0.009% of the stocks boundaries.

The same calculations for assessing the potential impacts to bottlenose dolphins from the proposed blasting activities that were used for the Biscayne Bay stock were also applied to this stock. To determine the maximum area of the coastal Atlantic in which bottlenose dolphins may experience pressure levels greater than or equal to the 23 psi threshold for explosives less than 2,000 lb (907.2 kg), which has the potential to result in Level B harassment due to TTS and associated behavioral disruption, the ACOE may utilize a maximum charge weight of 450 lb (204.1 kg) with a calculated danger zone of 1,995 ft (608.1 m). Using this radius, the total area of this zone is approximately 0.015% of coastal Atlantic where this stock is expected to occur.

For an open-water, unconfined blast, the pressure edge of the danger zone is expected to be 23 psi. For a fully confined blast, the pressure at the edge of the danger zone is expected to be 6 psi. Utilizing the pressure data collected the Miami Harbor Phase II project in 2005, for a maximum charge weight of 450 lbs in a fully confined blast, the pressure is expected to be 22 psi approximately 700 ft (213.4 m) from the blast, which is below the threshold for Level B harassment ( i.e., 23 psi criteria for explosives less than 2,000 lb). However to ensure the protection of marine mammals, and in case of an incident where a detonation is not fully confined, the ACOE assumes that any animal within the boundaries of the danger zone would be taken by Level B harassment.

Waring et al. (2010) estimates the minimum population for the Western North Atlantic Central Florida stock to be 5,094 animals, and estimates the best population to be 6,318 animals.

Table 5 (below) presents the estimated incidental take, by Level B harassment, for varying charge weight delays likely to be used during the proposed blasting activities and the estimated impacts based on the population estimates used in this analysis. In all cases, less than one bottlenose dolphin is expected to be taken incidental to each blasting event (0.102 minimum to 0.948 maximum). This assumes that the distribution of bottlenose dolphins is equal throughout all of the stock's range.

Other than the aerial surveys conducted by NMFS used to develop the stock assessment report, the ACOE has not been able to locate any additional photo-ID or habitat usage analysis. As a result, the ACOE is unable to determine if animals are evenly distributed throughout the stock's range, particularly in the southernmost portion of the stock's range where the proposed action area is located.

To be conservative, the ACOE will use the same assumptions for the Western North Atlantic Central Florida Coastal stock as was used for the Biscayne Bay stock. Reviewing the data from the Miami Harbor Phase II project in 2005, the ACOE noted that for the 40 detonations, 28% of all animals sighted within the proposed action area (Fisherman's Channel) were bottlenose dolphins (the other animals sighted were manatees and sea turtles). Bottlenose dolphins were sighted inside the exclusion zone 12 times with a total of 30 individuals, with an average of 2.5 animals per sighting out of the total 58 bottlenose dolphins recorded during the project; therefore, groups of dolphins entered the exclusion zone multiple times. Also, dolphins entered the exclusion zone during 30% of the blasting events. Not all of the incidents where dolphins entered the exclusion zone resulted in a project delay, it is dependent upon when during the countdown the animals cross the line demarcating the exclusion zone, and how long they stay in the exclusion zone.

During the Miami Harbor Phase II project in 2005, bottlenose dolphins in the exclusion zone triggered delays on four occasions during the 13 blasting events (31%). If the maximum 313 planned detonations for the duration of the one year IHA have an equal percentage of delays as the 2005 project (assuming construction starts in June with blasting June, 2012 to June, 2013 timeframe, with no blasting on Sundays), 94 of the detonations would be delayed for some period of time due to the presence of protected species and 29 of those delays would specifically be for bottlenose dolphins.

As a worst case, using the area of the danger zone, and that the danger zone of any blasting event using equal to or less than 450 lbs/delay will be approximately 0.009% of the stock's range. The ACOE assumes that because animals are not evenly distributed throughout the stock's range, that they travel as single individuals or in groups (as documented in the monitoring data from the Miami Harbor Phase II project in 2005), and that without any monitoring and mitigation measures to minimize potential impacts, up to three bottlenose dolphins from the Western North Atlantic Central Florida Coastal stock may be taken, by Level B harassment, incidental to each blasting event.

Assuming that delays will be spread equally across the proposed action area and using the calculation of 29 delays and that three bottlenose dolphins would be inside the danger zone, 14 of the delayed blasting events would take place in Biscayne Bay since it compromises 48% of the proposed action area. Three bottlenose dolphins times 14 detonations is equal to 42 bottlenose dolphins may be exposed to underwater sound and pressure over a one year period for an IHA incidental to the proposed blasting activities at the Port of Miami.

Without the implementation of the proposed monitoring and mitigation measures, the ACOE has calculated up to 87 bottlenose dolphins (45 from the Biscayne Bay stock, 42 of the Western North Atlantic Central Florida stock) may be potentially taken, by Level B harassment, incidental to the proposed blasting operations over the course of the one year IHA. Due to the protective measures of confined blasts, the implementation of the proposed monitoring and mitigation measures ( i.e., danger, exclusion, safety, and watch zones, use of the confined blasting techniques, as well as PSOs), the ACOE is requesting the take, by Level B harassment only, of a total of 22 bottlenose dolphins (12 bottlenose dolphins from the Biscayne Bay stock and 10 bottlenose dolphins from the Western North Atlantic Central Florida Coastal stock).

The ACOE will coordinate monitoring with the appropriate Federal and state resource agencies, including NMFS Office of Protected Resources and NMFS Southeast Regional Office's (SERO) Protected Resources Division, and will provide copies of any monitoring reports prepared by the contractors.

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.” In making a negligible impact determination, NMFS evaluated factors such as:

(1) The number of anticipated injuries, serious injuries, or mortalities;

(2) The number, nature, and intensity, and duration of Level B harassment (all relatively limited);

(3) The context in which the takes occur ( i.e., impacts to areas of significance, impacts to local populations, and cumulative impacts when taking into account successive/contemporaneous actions when added to the baseline data);

(4) The status of stock or species of marine mammals ( i.e., depleted, not depleted, decreasing, increasing, stable, and impact relative to the size of the population);

(5) Impacts on habitat affecting rates of recruitment or survival; and

(6) The effectiveness of monitoring and mitigation measures ( i.e., the manner and degree in which the measure is likely to reduce adverse impacts to marine mammals, the likely effectiveness of the measures, and the practicability of implementation).

Tables 1, 4, and 5 in this document discloses the habitat, regional abundance, conservation status, density, and the number of individuals potentially exposed to sounds and pressure levels considered the threshold for Level B harassment. Also, there are no known important reproductive or feeding areas in the proposed action area.

For reasons stated previously in this document, the specified activities associated with the ACOE's blasting operations are not likely to cause PTS, or other non-auditory injury, serious injury, or death to affected marine mammals. As a result, no take by injury, serious injury, or death is anticipated or authorized, and the potential for temporary or permanent hearing impairment is very low and will be minimized through the incorporation of the proposed monitoring and mitigation measures.

No injuries or mortalities are anticipated to occur as a result of the ACOE's blasting operations, and none are proposed to be authorized by NMFS. Approximately 22 Atlantic bottlenose dolphins (12 from the Biscayne Bay stock, 10 from the Western North Atlantic Central Florida Coastal stock) are anticipated to incur short-term, minor, hearing impairment (TTS) and associated behavioral disruption due to the instantaneous duration of the blasting events. While some other species of marine mammals may occur in the proposed project area, only Atlantic bottlenose dolphins are anticipated to be potentially impacted by the ACOE's proposed blasting operations.

Many animals perform vital functions, such as feeding, resting, traveling, and socializing, on a diel cycle (24-hr cycle). Behavioral reactions to noise exposure (such as disruption of critical life functions, displacement, or avoidance of important habitat) are more likely to be significant if they last more than one diel cycle or recur on subsequent days (Southall et al., 2007). Consequently, a behavioral response lasting less than one day and not recurring on subsequent days is not considered particularly severe unless it could directly affect reproduction or survival (Southall et al., 2007). The ACOE's proposed action at Miami Harbor includes up to two planned blasting events per day, which are very short in duration, and may potentially result in momentary reactions by marine mammals in the proposed action area.

Atlantic bottlenose dolphins are the only species of marine mammals under NMFS jurisdiction that are likely to occur in the action area, they are not listed as threatened or endangered under the ESA, however both stocks are listed as depleted and considered strategic under the MMPA. To protect these marine mammals (and other protected species in the proposed action area), the ACOE must delay operations if animals enter designated zones. Due to the nature, degree, and context of the Level B harassment anticipated and described in this notice (see “Potential Effects on Marine Mammals” section above), the activity is not expected to impact rates of recruitment or survival for any affected species or stock.

As mentioned previously, NMFS estimates that one species of marine mammals under its jurisdiction could be potentially affected by Level B harassment over the course of the IHA. For each species, these numbers are estimated to be small ( i.e., 22 Atlantic bottlenose dolphins, 12 from the Biscayne Bay stock [17% of the estimated minimum population, 7.6% of the estimated best population, and 5.2% of the estimated maximum population], and 10 from the Western North Atlantic Central Florida Coastal stock [0.19% of the estimated minimum population and 0.15% of the estimated best population], less than 17 percent of any of the estimated population sizes based on data in this notice, and has been mitigated to the lowest level practicable through the incorporation of the monitoring and mitigation measures mentioned previously in this document.

NMFS had determined, provided that the aforementioned monitoring and mitigation measures are implemented, that the impact of conducting the proposed blasting activities in the Port of Miami from June, 2012 through May, 2012, may result, at worst in a temporary modification in behavior and/or low level physiological effects (Level B harassment) of small numbers of Atlantic bottlenose dolphins.

While behavioral modifications, including temporarily vacating the area immediately after blasting operations, may be made by these species to avoid the resultant underwater acoustic disturbance, the availability of alternate areas within these area and the instantaneous and sporadic duration of the blasting activities, have led NMFS to determine that this action will have a negligible impact on the specified geographic region.

Based on the analysis contained herein of the likely effects of the specified activity on marine mammals and their habitat, and taking into consideration the implementation of the mitigation and monitoring measures, NMFS has preliminarily determined that the ACOE`s planned blasting activities will result in the incidental take of small numbers of marine mammals, by Level B harassment only, and that the total taking from the blasting activities will have a negligible impact on the affected species or stocks of marine mammals; and the impacts to affected species or stocks of marine mammals have been mitigated to the lowest level practicable.

Section 101(a)(5)(D) also requires NMFS to determine that the authorization will not have an unmitigable adverse effect on the availability of marine mammal species or stocks for subsistence use. There is no subsistence hunting for marine mammals in the action area (waters off of the coast of southeast Florida) that implicates MMPA section 101(a)(5)(D).

Under section 7 of the ESA, the ACOE requested formal consultation with the NMFS SERO, on the proposed project to improve the Port of Miami on September 5, 2002, and reinitiated consultation on January 6, 2011. NMFS SERO determined that the proposed action is likely to adversely affect one ESA-listed species and prepared a Biological Opinion (BiOp) issued on September 8, 2011, that analyzes the project's effects on staghorn coral ( Acropora cervicornis ). It is NMFS's biological opinion that the action, as proposed, is likely to adversely affect staghorn coral, but is not likely to jeopardize its continued existence or adversely modify its designated critical habitat. Based upon NMFS SERO's updated analysis, NMFS no longer expects the proposed project is likely to adversely affect Johnson's seagrass ( Halophila johnsonii ) or its designated critical habitat. NMFS SERO has determined that the ESA-listed marine mammals (Blue, fin, sei, humpback, North Atlantic right, and sperm whales), smalltooth sawfish ( Pristis pectinata ), and leatherback sea turtles ( Dermochelys coriacea ) are not likely to be adversely affected by the proposed action. Previous NMFS biological opinions have determined that hopper dredges may affect hawksbill ( Eretmochelys imbricata ), Kemp's ridley ( Lepidochelys kempii ), green ( Chelonia mydas ), and loggerhead ( Caretta caretta ) sea turtles through entrainment by the draghead. Any incidental take of loggerhead, green, Kemp's ridley, or hawksbill sea turtles due to hopper dredging has been previously authorized in NMFS's 1997 South Atlantic Regional BiOp on hopper dredging along the South Atlantic coast. The ACOE is currently in re-initiation of consultation with NMFS on the South Atlantic Regional BiOp. When a new BiOp is issued by NMFS, the Terms and Conditions of that South Atlantic Regional BiOp will be incorporated into the proposed project.

The ACOE has prepared a “Final Environmental Impact Statement on the Navigation Study for Miami Harbor, Miami-Dade County, Florida,” and a Record of Decision for the proposed project was signed on May 22, 2006; however, this document does not analyze NMFS's action, the issuance of the IHA for the ACOE's proposed activity. NMFS, after independently reviewing and evaluating the document for sufficiency and compliance with the CEQ regulations and NOAA Administrative Order (NAO) 216-6 § 5.09(d), has begun conducting a separate NEPA analysis, which analyzes the project's purpose and need, alternatives, affected environment, and environmental effects for the proposed action. NMFS will decide whether or not to sign a Finding of No Significant Impact (FONSI) prior to making a determination on the issuance of the IHA.

NMFS proposes to issue an IHA to the ACOE for conducting blasting operations at the Port of Miami, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated. The duration of the IHA would not exceed one year from the date of its issuance.

NMFS requests interested persons to submit comments and information concerning this proposed project and NMFS's preliminary determination of issuing an IHA (see ADDRESSES ). Concurrent with the publication of this notice in the Federal Register , NMFS is forwarding copies of this application to the Marine Mammal Commission and its Committee of Scientific Advisors.

Air-to-surface training involves ordnance delivered from aircraft and aimed at targets on the water's surface or on land in the case of BT-11. A description of the types of targets used at MCAS Cherry Point is provided in the section on BTs above. There are four types of air-to-surface activities conducted within the MCAS Cherry Point BTs: Mine laying; bombing; gunnery or rocket exercises which are carried out via fixed wing or rotary wing aircraft.

Mine Warfare (MIW) includes the strategic, operational, and tactical use of mines and mine countermine measures. MIW is divided into two basic subdivisions: (a) The laying of mines to degrade the enemy's capabilities to wage land, air, and maritime warfare, and (b) the countering of enemy-laid mines to permit friendly maneuver or use of selected land or sea areas (DoN, 2007). MCAS Cherry Point would only engage in mine laying exercises as described below. No detonations of any mine device are involved with this training.

During mine laying, a fixed-wing or maritime patrol aircraft (P-3 or P-8) typically drops a series of about four inert mine shapes in an offensive or defensive pattern, making multiple passes along a pre-determined flight azimuth, and dropping one or more shapes each time. Mine simulation shapes include MK76, MK80 series, and BDU practice bombs ranging from 25 to 2,000 pounds in weight, There is an attempt to fly undetected to the area where the mines are laid with either a low or high altitude tactic flight. The shapes are scored for accuracy as they enter the water and the aircrew is later debriefed on their performance. The training shapes are inert (no detonations occur) and expendable. Mine laying operations are regularly conducted in the water in the vicinity of BT-9.

The purpose of bombing exercises is to train pilots in destroying or disabling enemy ships or boats. During training, fixed wing or rotary wing aircraft deliver bombs against surface maritime targets at BT-9 or BT-11, day or night, using either unguided or precision-guided munitions. Unguided munitions include MK-76 and BDU-45 inert training bombs, and MK-80 series of inert bombs (no cluster munitions authorized). Precision-guided munitions consist of laser-guided bombs (inert) and laser-guided training rounds (inert). Typically, two aircraft approach the target (principally BT-9) from an altitude of approximately 914 m (3,000 ft) up to 4,572 m (15,000 ft) and, when on an established range, the aircraft adhere to designated ingress and egress routes. Typical bomb release altitude is 914 m (3,000 ft) for unguided munitions or above 4,572 m (15,000 ft) and in excess of 1.8 km (1 nm) for precision-guided munitions. However, the lowest minimum altitude for ordnance delivery (inert bombs) would be 152 m (500 ft).

Onboard laser designators or laser designators from a support aircraft or ground support personnel are used to illuminate certified targets for use when using laser guided weapons. Due to target maintenance issues, live bombs have not been dropped at the BT-9 targets for the past few years although these munitions are authorized for use. For the effective IHA timeframe, no live bombs would be utilized. Live rockets and grenades; however, have been expended at BT-9.

Air-to-Surface bombing exercises have the potential to occur on a daily basis. The standard sortie consists of two aircraft per bombing run. The frequency of these exercises is dependent on squadron level training requirements, deployment status, and range availability; therefore, there is no set pattern or specific time of year or month when this training occurs. Normal operating hours for the range are 0800-2300, Monday through Friday; however, the range is available for use 365 days per year.

Rocket exercises are carried out similar to bombing exercises. Fixed- and rotary-wing aircraft crews launch rockets at surface maritime targets, day and night, to train for destroying or disabling enemy ships or boats. These operations employ 2.75-inch and 5-inch rockets.

The average number of rockets delivered per sortie is approximately 14. As with the bombing exercise, there is no set level or pattern of amount of sorties conducted.

During gunnery training, fixed- and rotary-wing aircraft expend smaller munitions targeted at the BTs with the purpose of hitting them. However, some small arms may land in the water. Rotary wing exercises involve either CH-53, UH-1, CH-46, MV-22, or H-60 rotary-wing aircraft with mounted 7.62 mm or .50 cal machine guns. Each gunner expends approximately 800 rounds of 7.62 mm and 200 rounds of .50 cal ammunition in each exercise. These may be live or inert.

Fixed wing gunnery exercises involve the flight of two aircraft that begin to descend to the target from an altitude of approximately 914 meters (m) (3,000 feet [ft]) while still several miles away. Within a distance of 1,219 m (4,000 ft) from the target, each aircraft fires a burst of approximately 30 rounds before reaching an altitude of 305 m (1,000 ft), then breaks off and repositions for another strafing run until each aircraft expends its exercise ordnance allowance of approximately 250 rounds. In total, about 8-12 passes are made by each aircraft per exercise. Typically these fixed wing exercise events involve an F/A-18 and AH-1 with Vulcan M61A1/A2, 20 mm cannon; AV-8 with GAU-12, 25 mm cannon.

A complete list of the ordnance authorized for use at BT-9 and BT-11 can be found in Tables 2 and 3, respectively. There are several varieties and net explosive weights (for live munition used at BT-9) can vary according to the variety. All practice bombs are inert and used to simulate the same ballistic properties of service type bombs. They are manufactured as either solid cast metal bodies or thin sheet metal containers. Since practice bombs contain no explosive filler, a practice bomb signal cartridge (smoke) is used for visual observation of weapon target impact. Practice bombs provide a low cost training device for pilot and ground handling crews. Due to the relatively small amount of explosive material in practice bombs (small signal charge), the availability of ranges for training is greatly increased.

When a high explosive detonates, it is converted almost instantly into a gas at very high pressure and temperature. Under the pressure of the gases thus generated, the weapon case expands and breaks into fragments. The air surrounding the casing is compressed and shock (blast) wave is transmitted into it. Typical initial values for a high-explosive weapon are 200 kilobars of pressure (1 bar = 1 atmosphere) and 5,000 degrees Celsius. There are five types of explosive sources used at BT-9: 2.75” Rocket High Explosives, 5” Rocket High Explosives, 30 mm High Explosives, 40 mm High Explosives, and G911 grenades. No live munitions are used at BT-11.

The amounts of all ordnance to be expended at BT-9 and BT-11 (both surface-to-surface and air-to-surface) are 897,932 and 1,109,955 rounds, respectively (see Table 4 and 5 below).

Forty marine mammal species occur within the nearshore and offshore waters of North Carolina; however, the majority of these species are solely oceanic in distribution. Only one marine mammal species, the bottlenose dolphin, has been repeatedly sighted in Pamlico Sound, while an additional species, the endangered West Indian manatee ( Trichechus manatus ), has been sighted rarely (Lefebvre et al., 2001; DoN 2003). The U.S. Fish and Wildlife Service oversees management of the manatee; therefore, authorization to harass manatees would not be included in any NMFS' authorization and will not be discussed further.

No sightings of the endangered North Atlantic right whale ( Eubalaena glacialis ) or other large whales have been observed within Pamlico Sound or in vicinity of the BTs (Kenney 2006). No suitable habitat exists for these species in the shallow Pamlico Sound or BT vicinity; therefore, whales would not be affected by the specified activities and will not be discussed further. Other dolphins, such as Atlantic spotted ( Stenella frontalis ) and common dolphins ( Delphinus delphis ), are oceanic in distribution and do not venture into the shallow, brackish waters of southern Pamlico Sound. Therefore, the specified activity has the potential to affect one marine mammal species under NMFS' jurisdiction: the bottlenose dolphin.

Coastal (or nearshore) and offshore stocks of bottlenose dolphins in the Western North Atlantic can be distinguished by genetics, diet, blood characteristics, and outward appearance (Duffield et al., 1983; Hersh and Duffield, 1990; Mead and Potter, 1995; Curry and Smith, 1997). Initially, a single stock of coastal morphotype bottlenose dolphins was thought to migrate seasonally between New Jersey (summer months) and central Florida based on seasonal patterns in strandings during a large scale mortality event occurring during 1987-1988 (Scott et al., 1988). However, re-analysis of stranding data (McLellan et al., 2003) and extensive analysis of genetic, photo-identification, satellite telemetry, and stable isotope studies demonstrate a complex mosaic of coastal bottlenose dolphin stocks (NMFS 2001) which may be migratory or resident (they do not migrate and occur within an area year round). Four out of the seven designated coastal stocks may occur in North Carolina waters at some part of the year: The Northern Migratory stock (NM; winter); the Southern Migratory stock (SM; winter); the Northern North Carolina Estuarine stock (NNCE; resident, year round); and the more recently identified Southern North Carolina Estuarine stock (SNCE; resident, year round). Stable isotope depleted oxygen signature (hypoxic conditions routinely develops during summer in North Carolina waters) (Cortese, 2000), satellite telemetry, and photo-identification (NMFS, 2001) support stock structure analysis. Dolphins encountered at the BTs likely belong to the NNCE and SNCE stock; however, this may not always be the case. NMFS' 2010 stock assessment report provides further detail on stock delineation. All stocks discussed here are considered depleted (and thus strategic) under the MMPA (Waring et al., 2010).

NMFS provides abundance estimates for the four aforementioned migratory and resident coastal stocks in its 2010 stock assessment report. The best available abundance estimate for the NNCE stock is the combined abundance from estuarine (Read et al., 2003) and coastal (aerial survey data dating from 2002) waters. This combined estimate is 1,387 (Waring et al., 2010). Similarly, the best available abundance estimate for the SNCE stock is the combined abundance from estuarine and coastal waters. This combined estimate is 2,595 (Waring et al., 2010). The best abundance estimate for the NM stock, resulting from 2002 aerial surveys, is 9,604 (Waring et al., 2010). Using the same information, the resulting best abundance estimate for the SM stock is 12,482 (Waring et al., 2010).

From July 2004 through April 2006, the NMFS' SEFSC conducted 41 aerial surveys to document the seasonal distribution and estimated density of sea turtles and dolphins within Core Sound and portions of Pamlico Sound, and coastal waters extending one mile offshore (Goodman et al., 2007). Pamlico Sound was divided into two survey areas: western (encompassing BT-9 and BT-11) and eastern (including Core Sound and the eastern portion of restricted air space R-5306). In total, 281 dolphins were sighted in the western range. To account for animals likely missed during sightings ( i.e., those below the surface), Goodman et al. (2007) estimate that, in reality, 415 dolphins were present. Densities for bottlenose dolphins in the western part of Pamlico Sound were calculated to be 0.0272/km 2 in winter; 0.2158/km 2 in autumn; 0.0371/km 2 in summer; and 0.0946/km 2 in summer (Goodman et al., 2007). Dolphins were sighted throughout the entire range when mean sea surface temperature (SST) was 7.60  °C to 30.82 °C, with fewer dolphins sighted as water temperatures increased. Like in Mayer (2003), dolphins were found in higher numbers around BT-11, a range where no live firing occurs.

In 2000, Duke University Marine Lab (DUML), conducted a boat-based mark-recapture survey throughout the estuaries, bays and sounds of North Carolina (Read et al., 2003). This summer survey yielded a dolphin density of 0.183/km 2 (0.071 mi 2 ) based on an estimate of 919 dolphins for the northern inshore waters divided by an estimated 5,015 km 2 (1,936 mi 2 ) survey area. Additionally, from July 2002-June 2003, the USMC supported DUML to conduct dolphin surveys specifically in and around BT-9 and BT-11. During these surveys, one sighting in the restricted area surrounding BT-9 and two sightings in proximity to BT-11 were observed, as well as seven sightings in waters adjacent to the BTs. In total, 276 bottlenose dolphins were sighted ranging in group size from two to 70 animals with mean dolphin density in BT-11 more than twice as large as the density of any of the other areas; however, the daily densities were not significantly different (Maher, 2003). Estimated dolphin density at BT-9 and BT-11 based on these surveys were calculated to be 0.11 dolphins/km 2 , and 1.23 dolphins/km 2 , respectively, based on boat surveys conducted from July 2002 through June 2003 (excluding April, May, Sept. and Jan.). However, the USMC choose to estimate take of dolphins based on the higher density reported from the summer 2000 surveys (0.183/km 2 ). Although the aerial surveys were conducted year round and therefore provide for seasonal density estimates, the average year-round density from the aerial surveys is 0.0936, lower than the 0.183/km 2 density chosen to calculate take for purposes of this MMPA authorization. Additionally, Goodman et al. (2007) acknowledged that boat based density estimates may be more accurate than the uncorrected estimates derived from the aerial surveys.

In Pamlico Sound, bottlenose dolphins concentrate in shallow water habitats along shorelines, and few, if any, individuals are present in the central portions of the sounds (Gannon, 2003; Read et al., 2003a, 2003b). The dolphins utilize shallow habitats, such as tributary creeks and the edges of the Neuse River, where the bottom depth is less than 3.5 m (Gannon, 2003). Fine-scale distribution of dolphins seems to relate to the presence of topography or vertical structure, such as the steeply-sloping bottom near the shore and oyster reefs, which may be used to facilitate prey capture (Gannon, 2003). Results of a passive acoustic monitoring effort conducted from 2006-2007 by Duke University researchers validated this information. Vocalizations of dolphins in the BT-11 vicinity were higher in August and September than vocalization detection at BT-9, an open water area (Read et al., 2007). Additionally, detected vocalizations of dolphins were more frequent at night for the BT-9 area and during early morning hours at BT-11.

Unlike migrating whales which display strong temporal foraging and mating/birthing periods, many bottlenose dolphins in Pamlico Sound are residents and mate year round. However, dolphins in the southeast U.S. do display some reproductive seasonality. Based on neonate stranding records, sighting data, and births by known females, the populations of dolphins that frequent the North Carolina estuarine waters have calving peaks in spring but calving continues throughout the summer and is followed by a smaller number of fall births (Thayer et al., 2003).

Bottlenose dolphins can typically hear within a broad frequency range of 0.04 to 160 kHz (Au, 1993; Turl, 1993). Electrophysiological experiments suggest that the bottlenose dolphin brain has a dual analysis system: one specialized for ultrasonic clicks and another for lower-frequency sounds, such as whistles (Ridgway, 2000). Scientists have reported a range of highest sensitivity between 25 and 70 kHz, with peaks in sensitivity at 25 and 50 kHz (Nachtigall et al., 2000). Recent research on the same individuals indicates that auditory thresholds obtained by electrophysiological methods correlate well with those obtained in behavior studies, except at some lower (10 kHz) and higher (80 and 100 kHz) frequencies (Finneran and Houser, 2006).

Sounds emitted by bottlenose dolphins have been classified into two broad categories: pulsed sounds (including clicks and burst-pulses) and narrow-band continuous sounds (whistles), which usually are frequency modulated. Clicks have a dominant frequency range of 110 to 130 kiloHertz (kHz) and a source level of 218 to 228 dB re 1 μPa (peak-to-peak) (Au, 1993) and 3.4 to 14.5 kHz at 125 to 173 dB re 1 μPa (peak-to-peak) (Ketten, 1998). Whistles are primarily associated with communication and can serve to identify specific individuals ( i.e., signature whistles) (Caldwell and Caldwell, 1965; Janik et al., 2006). Up to 52 percent of whistles produced by bottlenose dolphin groups with mother-calf pairs can be classified as signature whistles (Cook et al., 2004). Sound production is also influenced by group type (single or multiple individuals), habitat, and behavior (Nowacek, 2005). Bray calls (low-frequency vocalizations; majority of energy below 4 kHz), for example, are used when capturing fish, specifically sea trout (Salmo trutta) and Atlantic salmon (Salmo salar), in some regions ( i.e., Moray Firth, Scotland) (Janik, 2000). Additionally, whistle production has been observed to increase while feeding (Acevedo-Gutiérrez and Stienessen, 2004; Cook et al., 2004).

As mentioned previously, with respect to military readiness activities, Section 3(18)(B) of the MMPA defines “harassment” 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].

The USMC has concluded that harassment to marine mammals may occur incidental to munitions firing noise and pressure at the BTs. These military readiness activities would result in increased noise levels, explosions, and munition debris within bottlenose dolphin habitat. NMFS also considered the potential for harassment from vessel and aircraft operation. NMFS' analysis of potential impacts from these factors, including consideration of the USMC's analysis in its application, is outlined below.

Marine mammals respond to various types of anthropogenic sounds introduced in the ocean environment. Responses are highly variable and depend on a suite of internal and external factors which in turn results in varying degrees of significance (NRC, 2003; Southall et al., 2007). Internal factors include: (1) Individual hearing sensitivity, activity pattern, and motivational and behavioral state ( e.g., feeding, traveling) at the time it receives the stimulus; (2) past exposure of the animal to the noise, which may lead to habituation or sensitization; (3) individual noise tolerance; and (4) demographic factors such as age, sex, and presence of dependent offspring. External factors include: (1) Non-acoustic characteristics of the sound source ( e.g., if it is moving or stationary); (2) environmental variables ( e.g., substrate) which influence sound transmission; and (3) habitat characteristics and location ( e.g., open ocean vs. confined area). To determine whether an animal perceives the sound, the received level, frequency, and duration of the sound are compared to ambient noise levels and the species' hearing sensitivity range. That is, if the frequency of an introduced sound is outside of the species' frequency hearing range, it cannot be heard. Similarly, if the frequency is on the upper or lower end of the species hearing range, the sound must be louder in order to be heard.

Marine mammal responses to anthropogenic noise are typically subtle and can include visible and acoustic reactions such as avoidance, altered dive patterns and cessation of pre-exposure activities and vocalization reactions such as increasing or decreasing call rates or shifting call frequency. Responses can also be unobservable, such as stress hormone production and auditory trauma or fatigue. It is not always known how these behavioral and physiological responses relate to significant effects ( e.g., long-term effects or individual/population consequences); however, individuals and populations can be monitored to provide some insight into the consequences of exposing marine mammals to noise. For example, Haviland-Howell et al . (2007) compared sighting rates of bottlenose dolphins within the Wilmington, NC stretch of the Atlantic Intracoastal Waterway (ICW) on weekends, when recreational vessel traffic was high, to weekdays, when vessel traffic was relatively minimal. The authors found that dolphins were less often sighted in the ICW during times of increased boat traffic ( i.e., on weekends) and theorized that because vessel noise falls within the frequencies of dolphin communication whistles and primary energy of most fish vocalizations, the continuous vessel traffic along that stretch of the ICW could result in social and foraging impacts. However, the extent to which these impacts affect individual health and population structure is unknown.

A full assessment of marine mammal responses and disturbances when exposed to anthropogenic sound can be found in NMFS' proposed rulemaking for the Navy Cherry Point Range Complex (74 FR 11057, March 16, 2009). That rulemaking was made final on June 15, 2009 (74 FR 28370). In summary, sound exposure may result in physiological impacts, stress responses, and behavioral responses which could affect proximate or ultimate life functions. Proximate life history functions are the functions that the animal is engaged in at the time of acoustic exposure. The ultimate life functions are those that enable an animal to contribute to the population (or stock, or species, etc. ).

In mammals, high-intensity sound may rupture the eardrum, damage the small bones in the middle ear, or over stimulate the electromechanical hair cells that convert the fluid motions caused by sound into neural impulses that are sent to the brain. Lower level exposures may cause a loss of hearing sensitivity, termed a threshold shift (TS) (Miller, 1974). Incidence of TS may be either permanent, referred to as permanent threshold shift (PTS), or temporary, referred to as temporary threshold shift (TTS). The amplitude, duration, frequency, and temporal pattern, and energy distribution of sound exposure all affect the amount of associated TS and the frequency range in which it occurs. As amplitude and duration of sound exposure increase, generally, so does the amount of TS and recovery time. Human non-impulsive noise exposure guidelines are based on exposures of equal energy (the same SEL) producing equal amounts of hearing impairment regardless of how the sound energy is distributed in time (NIOSH 1998). Until recently, previous marine mammal TTS studies have also generally supported this equal energy relationship (Southall et al., 2007). Three newer studies, two by Mooney et al. (2009a, 2009b) on a single bottlenose dolphin either exposed to playbacks of Navy MFAS or octave-band noise (4-8 kHz) and one by Kastak et al. (2007) on a single California sea lion exposed to airborne octave-band noise (centered at 2.5 kHz), concluded that for all noise exposure situations the equal energy relationship may not be the best indicator to predict TTS onset levels. Generally, with sound exposures of equal energy, those that were quieter (lower sound pressure level [SPL]) with longer duration were found to induce TTS onset more than those of louder (higher SPL) and shorter duration (more similar to noise from AS Cherry Point exercises). For intermittent sounds, less TS will occur than from a continuous exposure with the same energy (some recovery will occur between exposures) (Kryter et al., 1966; Ward, 1997). Additionally, though TTS is temporary, very prolonged exposure to sound strong enough to elicit TTS, or shorter-term exposure to sound levels well above the TTS threshold, can cause PTS, at least in terrestrial mammals (Kryter, 1985). However, these studies highlight the inherent complexity of predicting TTS onset in marine mammals, as well as the importance of considering exposure duration when assessing potential impacts.

PTS consists of non-recoverable physical damage to the sound receptors in the ear, which can include total or partial deafness, or an impaired ability to hear sounds in specific frequency ranges; PTS is considered Level A harassment. TTS is recoverable and is considered to result from temporary, non-injurious impacts to hearing-related tissues; TTS is considered Level B harassment.

Auditory trauma represents direct mechanical injury to hearing related structures, including tympanic membrane rupture, disarticulation of the middle ear ossicles, and trauma to the inner ear structures such as the organ of Corti and the associated hair cells. Auditory trauma is irreversible and considered to be an injury that could result in PTS. PTS results from exposure to intense sounds that cause a permanent loss of inner or outer cochlear hair cells or exceed the elastic limits of certain tissues and membranes in the middle and inner ears and result in changes in the chemical composition of the inner ear fluids. In some cases, there can be total or partial deafness across all frequencies, whereas in other cases, the animal has an impaired ability to hear sounds in specific frequency ranges. There is no empirical data for onset of PTS in any marine mammal, and therefore, PTS- onset must be estimated from TTS-onset measurements and from the rate of TTS growth with increasing exposure levels above the level eliciting TTS-onset. PTS is presumed to be likely if the hearing threshold is reduced by ≥ 40 dB ( i.e., 40 dB of TTS). Relationships between TTS and PTS thresholds have not been studied in marine mammals, but are assumed to be similar to those in humans and other terrestrial mammals.

TTS is the mildest form of hearing impairment that can occur during exposure to a loud sound (Kryter, 1985). Southall et al. (2007) indicate that although PTS is a tissue injury, TTS is not because the reduced hearing sensitivity following exposure to intense sound results primarily from fatigue, not loss, of cochlear hair cells and supporting structures and is reversible. Accordingly, NMFS classifies TTS as Level B Harassment, not Level A Harassment (injury); however, NMFS does not consider the onset of TTS to be the lowest level at which Level B Harassment may occur (see III. Behavior section below).

Southall et al. (2007) considers a 6 dB TTS ( i.e., baseline hearing thresholds are elevated by 6 dB) sufficient to be recognized as an unequivocal deviation and thus a sufficient definition of TTS onset. TTS in bottlenose dolphin hearing have been experimentally induced. For example, Finneran et al. (2002) exposed a trained captive bottlenose dolphin to a seismic watergun simulator with a single acoustic pulse. No TTS was observed in the dolphin at the highest exposure condition (peak: 207 kPa [30psi]; peak-to-peak: 228 dB re: 1 microPa; SEL: 188 dB re 1 microPa 2 -s). Schludt et al. (2000) demonstrated temporary shifts in masked hearing thresholds in five bottlenose dolphins occurring generally between 192 and 201 dB rms (192 and 201 dB SEL) after exposure to intense, non-pulse, 1-s tones at, 3kHz, 10kHz, and 20 kHz. TTS onset occurred at mean sound exposure level of 195 dB rms (195 dB SEL). At 0.4 kHz, no subjects exhibited threshold shifts after SPL exposures of 193dB re: 1 microPa (192 dB re: 1 microPa 2 -s). In the same study, at 75 kHz, one dolphin exhibited a TTS after exposure at 182 dB SPL re: 1 microPa but not at higher exposure levels. Another dolphin experienced no threshold shift after exposure to maximum SPL levels of 193 dB re: 1 microPa at the same frequency. Frequencies of explosives used at MCAS Cherry Point range from 1-25 kHz; the range where dolphin TTS onset occurred at 195 dB rms in the Schludt et al. (2000) study.

Preliminary research indicates that TTS and recovery after noise exposure are frequency dependent and that an inverse relationship exists between exposure time and sound pressure level associated with exposure (Mooney et al., 2005; Mooney, 2006). For example, Nachtigall et al. (2003) measured TTS in a bottlenose dolphin and found an average 11 dB shift following a 30 minute net exposure to OBN at a 7.5  kHz center frequency (max SPL of 179 dB re: 1 microPa; SEL: 212-214 dB re: 1 microPa 2 -s). No TTS was observed after exposure to the same duration and frequency noise with maximum SPLs of 165 and 171 dB re: 1 microPa. After 50 minutes of exposure to the same 7.5 kHz frequency OBN, Natchigall et al. (2004) measured a 4-8 dB shift (max SPL: 160dB re 1microPa; SEL: 193-195 dB re:1 microPa 2 -s). Finneran et al. (2005) concluded that a sound exposure level of 195 dB re 1 μPa2-s is a reasonable threshold for the onset of TTS in bottlenose dolphins exposed to mid-frequency tones.

An acoustic source is considered a potential stressor if, by its action on the animal, via auditory or non-auditory means, it may produce a stress response in the animal. Here, the stress response will refer to an increase in energetic expenditure that results from exposure to the stressor and which is predominantly characterized by either the stimulation of the sympathetic nervous system (SNS) or the hypothalamic-pituitary-adrenal (HPA) axis (Reeder and Kramer, 2005). The SNS response to a stressor is immediate and acute and is characterized by the release of the catecholamine neurohormones norepinephrine and epinephrine ( i.e., adrenaline). These hormones produce elevations in the heart and respiration rate, increase awareness, and increase the availability of glucose and lipids for energy. The HPA response is ultimately defined by increases in the secretion of the glucocorticoid steroid hormones, predominantly cortisol in mammals. The presence and magnitude of a stress response in an animal depends on a number of factors. These include the animal's life history stage ( e.g., neonate, juvenile, adult), the environmental conditions, reproductive or developmental state, and experience with the stressor. Not only will these factors be subject to individual variation, but they will also vary within an individual over time. The stress response may or may not result in a behavioral change, depending on the characteristics of the exposed animal. However, provided a stress response occurs, we assume that some contribution is made to the animal's allostatic load. Any immediate effect of exposure that produces an injury is assumed to also produce a stress response and contribute to the allostatic load. Allostasis is the ability of an animal to maintain stability through change by adjusting its physiology in response to both predictable and unpredictable events (McEwen and Wingfield, 2003). If the acoustic source does not produce tissue effects, is not perceived by the animal, or does not produce a stress response by any other means, we assume that the exposure does not contribute to the allostatic load. Additionally, without a stress response or auditory masking, it is assumed that there can be no behavioral change.

Changes in marine mammal behavior in response to anthropogenic noise may include altered travel directions, increased swimming speeds, changes in dive, surfacing, respiration and feeding patterns, and changes in vocalizations. As described above, lower level physiological stress responses could also co-occur with altered behavior; however, stress responses are more difficult to detect and fewer data exist relative to specific received levels of sound.

Anthropogenic noise can interfere with, or mask, detection of acoustic signals such as communication calls, echolocation, and environmental sounds important to marine mammals. Southall et al. (2007) defines auditory masking as the partial or complete reduction in the audibility of signals due to the presence of interfering noise with the degree of masking depending on the spectral, temporal, and spatial relationships between signals and masking noise, as well as the respective received levels. Masking of sender communication space can be considered as the amount of change in a sender's communication space caused by the presence of other sounds, relative to a pre-industrial ambient noise condition (Clark et al., in press ). Unlike auditory fatigue, which always results in a stress response because the sensory tissues are being stimulated beyond their normal physiological range, masking may or may not result in a stress response, depending on the degree and duration of the masking effect. Masking may also result in a unique circumstance where an animal's ability to detect other sounds is compromised without the animal's knowledge. This could conceivably result in sensory impairment and subsequent behavior change; in this case, the change in behavior is the lack of a response that would normally be made if sensory impairment did not occur. For this reason, masking also may lead directly to behavior change without first causing a stress response. Projecting noise into the marine environment which causes acoustic masking is considered Level B harassment as it can disrupt natural behavioral patterns by interrupting or limiting the marine mammal's receipt or transmittal of important information or environmental cues. To compensate for masking, marine mammals, including bottlenose dolphins, are known to increase their levels of vocalization as a function of background noise by increasing call repetition and amplitude, shifting calls higher frequencies, and/or changing the structure of call content (Lesage et al., 1999; Scheifele et al., 2005; McIwem, 2006).

While it may occur temporarily, NMFS does not expect auditory masking to result in detrimental impacts to an individual's or population's survival, fitness, or reproductive success. Dolphins are not confined to the BT ranges; allowing for movement out of area to avoid masking impacts. The USMC would also conduct visual sweeps of the area before any training exercise and implement training delay mitigation measures if a dolphin is sighted within designated zones (see Proposed Mitigation Measures section below). As discussed previously, the USMC has been working with DUML to collect baseline information on dolphins in Pamlico Sound, specifically dolphin abundance and habitat use around the BTs. The USMC has also recently accepted a DUML proposal to investigate methods of dolphin acoustic detection around the BTs. NMFS would encourage the USMC to expand acoustic investigations to include the impacts of training exercises on vocalization properties ( e.g., call content, duration, frequency) and masking ( e.g., communication and foraging impairment) of the affected population of dolphins in Pamlico Sound.

MCAS Cherry Point plans to use five types of explosive sources during its training exercises: 2.75″ Rocket High Explosives, 5″ Rocket High Explosives, 30 mm High Explosives, 40 mm High Explosives, and G911 grenades. The underwater explosions from these weapons would send a shock wave and blast noise through the water, release gaseous by-products, create an oscillating bubble, and cause a plume of water to shoot up from the water surface. The shock wave and blast noise are of most concern to marine animals. In general, potential impacts from explosive detonations can range from brief effects (such as short term behavioral disturbance), tactile perception, physical discomfort, slight injury of the internal organs and the auditory system, to death of the animal (Yelverton et al., 1973; O'Keeffe and Young, 1984; DoN, 2001).

Explosives produce significant acoustic energy across several frequency decades of bandwidth ( i.e., broadband). Propagation loss is sufficiently sensitive to frequency as to require model estimates at several frequencies over such a wide band. The effects of an underwater explosion on a marine mammal depend on many factors, including the size, type, and depth of both the animal and the explosive charge; the depth of the water column; and the standoff distance between the charge and the animal, as well as the sound propagation properties of the environment. The net explosive weight (or NEW) of an explosive is the weight of TNT required to produce an equivalent explosive power. The detonation depth of an explosive is particularly important due to a propagation effect known as surface-image interference. For sources located near the sea surface, a distinct interference pattern arises from the coherent sum of the two paths that differ only by a single reflection from the pressure-release surface. As the source depth and/or the source frequency decreases, these two paths increasingly, destructively interfere with each other, reaching total cancellation at the surface (barring surface-reflection scattering loss). USMC conservatively estimates that all explosives would detonate at a 1.2 m (3.9 ft) water depth. This is the worst case scenario as the purpose of training is to hit the target, resulting in an in-air explosion.

The firing sequence for some of the munitions consists of a number of rapid bursts, often lasting a second or less. The maximum firing time is 10-15 second bursts. Due to the tight spacing in time, each burst can be treated as a single detonation. For the energy metrics, the impact area of a burst is computed using a source energy spectrum that is the source spectrum for a single detonation scaled by the number of rounds in a burst. For the pressure metrics, the impact area for a burst is the same as the impact area of a single round. For all metrics, the cumulative impact area of an event consisting of a certain number of bursts is merely the product of the impact area of a single burst and the number of bursts, as would be the case if the bursts are sufficiently spaced in time or location as to insure that each burst is affecting a different set of marine wildlife.

Physical damage of tissues resulting from a shock wave (from an explosive detonation) is classified as an injury. Blast effects are greatest at the gas-liquid interface (Landsberg, 2000) and gas containing organs, particularly the lungs and gastrointestinal tract, are especially susceptible to damage (Goertner, 1982; Hill 1978; Yelverton et al., 1973). Nasal sacs, larynx, pharynx, trachea, and lungs may be damaged by compression/expansion caused by the oscillations of the blast gas bubble (Reidenberg and Laitman, 2003). Severe damage (from the shock wave) to the ears can include tympanic membrane rupture, fracture of the ossicles, damage to the cochlea, hemorrhage, and cerebrospinal fluid leakage into the middle ear.

Non-lethal injury includes slight injury to internal organs and the auditory system; however, delayed lethality can be a result of individual or cumulative sublethal injuries (DoN, 2001). Immediate lethal injury would be a result of massive combined trauma to internal organs as a direct result of proximity to the point of detonation (DoN, 2001). Exposure to distance explosions could result only in behavioral changes. Masked underwater hearing thresholds in two bottlenose dolphins and one beluga whale have been measured before and after exposure to impulsive underwater sounds with waveforms resembling distant signatures of underwater explosions (Finneran et al., 2000). The authors found no temporary shifts in masked-hearing thresholds (MTTSs), defined as a 6-dB or larger increase in threshold over pre-exposure levels, had been observed at the highest impulse level generated (500 kg at 1.7 km, peak pressure 70 kPa); however, disruptions of the animals' trained behaviors began to occur at exposures corresponding to 5 kg at 9.3 km and 5 kg at 1.5 km for the dolphins and 500 kg at 1.9 km for the beluga whale.

Generally, the higher the level of impulse and pressure level exposure, the more severe the impact to an individual. While, in general, dolphins could sustain injury or mortality if within very close proximity to in-water explosion, monitoring and mitigation measures employed by the USMC before and during training exercises, as would be required under any ITA issued, are designed to avoid any firing if a marine mammal is sighted within designated BT zones (see Proposed Mitigation and Monitoring section below). No marine mammal injury or death has been attributed to the specified activities described in the application. As such, and due to implementation of the proposed mitigation and monitoring measures, bottlenose dolphin injury or mortality is not anticipated nor would any be authorized.

The potential risk to marine mammals from non-explosive ordnance entails two possible sources of impacts: Elevated sound levels or the ordnance physically hitting an animal. The latter is discussed below in the Munition Presence section below. The USMC provided information that the noise fields generated in water by the firing of non-explosive ordnance indicate that the energy radiated is about 1 to 2 percent of the total kinetic energy of the impact. This energy level (and likely peak pressure levels) is well below the TTS-energy threshold, even at 1-m from the impact and is not expected to be audible to marine mammals. As such, the noise generated by the in-water impact of non-explosive ordnance will not result in take of marine mammals.

In addition to behavioral and physiological impacts from live fire and ammunition testing, NMFS has preliminarily analyzed impacts from presence of munition debris in the water, as described in the USMC's application and 2009 EA. These impacts include falling debris, ingestion of expended ordnance, and entanglement in parachute debris.

Ingestion of marine debris by marine mammals can cause digestive tract blockages or damage the digestive system (Gorzelany, 1998; Stamper et al., 2006). Debris could be either the expended ordnance or non-munition related products such as chaff and self protection flares. Expended ordnance would be small and sink to the bottom. Chaff is composed of either aluminum foil or aluminum-coated glass fibers designed to act as a visual smoke screen; hiding the aircraft from enemy radar. Chaff also serves as a decoy for radar detection, allowing aircraft to maneuver or egress from the area. The foil type currently used is no longer manufactured, although it remains in the inventory and is used primarily by B-52 bombers. Both types of chaff are cut into dipoles ranging in length from 0.3 to over 2.0 inches. The aluminum foil dipoles are 0.45 mils (0.00045 inches) thick and 6 to 8 mils wide. The glass fiber dipoles are generally 1 mil (25.4 microns) in diameter, including the aluminum coating. Chaff is packed into about 4-ounce bundles. The major components of chaff are silica, aluminum, and stearic acid; all naturally prevalent in the environment.

Based on the dispersion characteristics of chaff, concentrations around the BTs would be low. For example, Hullar et al. (1999) calculated that a 4.97-mile by 7.46-mile area (37.1 km 2 ) would be affected by deployment of a single cartridge containing 150 grams of chaff; however, concentration would only be about 5.4 grams per square nautical mile. This corresponds to fewer than 179,000 fibers per square nautical mile or fewer than 0.005 fibers per square foot.

Self-protection flares are deployed to mislead or confuse heat-sensitive or heat-seeking anti-aircraft systems. The flares are magnesium pellets that, when ignited, burn for a short period of time (less than 10 seconds) at 2,000 degrees Fahrenheit. Air-deployed LUU-2 high-intensity illumination flares are used to illuminate targets, enhancing a pilot's ability to see targets while using Night Vision Goggles. The LUU-2B Flare has a light output rating of 1.8 x 10(6) candlepower and at 1,000 feet altitude illuminates a circle on the ground of 500 meters. The LUU-2 is housed in a pod or canister and is deployed by ejection. The mechanism has a timer on it that deploys the parachute and ignites the flare candle. The flare candle burns magnesium at high temperature, emitting an intense bright white light. The LUU-2 has a burn time of approximately 5 minutes while suspended from a parachute. The pyrotechnic candle consumes the flare housing, reducing flare weight, which in turn slows the rate of fall during the last 2 minutes of burn time. At candle burnout an explosive bolt is fired, releasing one parachute support cable, which causes the parachute to collapse.

Ingestion of debris by dolphins is not likely, as dolphins typically eat fish and other moving prey items. NMFS solicited information on evidence of debris ingestion from two marine mammal veterinarians who have performed many necropsies on the protected species of North Carolina's waters. In their experience, no necropsies of bottlenose dolphins have revealed evidence of munition, parachute, or chaff ingestion (pers. comm., Drs. C. Harms and D. Rostein, November 14, 2009). However, it was noted evidence of chaff ingestion would be difficult to detect. In the chance that dolphins do ingest chaff, the filaments are so fine they would likely pass through the digestive system without complication. However, if the chaff is durable enough, it might act as a linear foreign body. In such case, the intestines bunch up on the line restricting movement of the line resulting in an obstruction. The peristalsis on an immovable thin line can cause intestinal lacerations and perforations (pers. comm., C. Harms, November 14, 2009. This is a well known complication in cats when they ingest thread and which occurs occasionally with sea turtles ingesting fishing line. The longevity of chaff filaments, based upon dispersion rates, is unclear. Chaff exposed to synthetic seawater and aqueous environments in the pH range of 4-10 exhibited varying levels of degradation suggesting a short lifespan for the outer aluminum coating (Farrell and Siciliano, 1998). The underlying filament is a flexible silica core and composed of primarily silica dioxide. While no studies have been conducted to evaluate the effects of chaff ingestion on marine mammals, the effects are expected to be negligible based upon chaff concentration in the environment, size of fibers, and available toxicity data on fiberglass and aluminum. Given that the size of chaff fibers are no more than 2 inches long, tidal flushing reduces concentration in the environment, and chaff degradation rate, the chance of chaff ingestions is unlikely; however, if swallowed, impacts would be negligible.

Given that there is no evidence that dolphins ingest military debris; dolphins in the Sound forage on moving prey suspended in the water column while expended munition would sink; the property and dispersion characteristics of chaff make potential for ingestion discountable; and that Pamlico Sound is a tidal body of water with continuing flushing, NMFS has preliminarily determined that the presence of training debris would not have an effect on dolphins in Pamlico Sound.

Although sometimes large, expended parachutes ( e.g., those from the flares) are flimsy and structurally simple and NMFS has determined that the probability of entanglement with a dolphin is low. There are no known reports of live or stranded dolphins entangled in parachute gear; fishing gear is usually the culprit of reported entanglements. The NMFS' Marine Mammal Stranding Network (Network) has established protocol for reporting marine mammals in peril. Should any injured, stranded or entangled marine mammal be observed by USMC personnel during training exercises, the sighting would be reported to the Network within 24 hours of the observation.

The marine mammals most vulnerable to vessel strikes are slow-moving and/or spend extended periods of time at the surface in order to restore oxygen levels within their tissues after deep dives ( e.g., right whales, fin whales, sperm whales). Smaller marine mammals such as bottlenose dolphins (the only marine mammal that would be encountered at the BTs) are agile and move more quickly through the water, making them less susceptible to ship strikes. NMFS is not aware of any vessel strikes of bottlenose dolphins in Pamlico Sound. Therefore, NMFS does not anticipate that USMC vessels engaged in the specified activity would strike any marine mammals and no take from ship strike would be authorized in the proposed IHA.

Behaviorally, marine mammals may or may not respond to the operation of vessels and associated noise. Responses to vessels vary widely among marine mammals in general, but also among different species of small cetaceans. Responses may include attraction to the vessel (Richardson et al., 1995); altering travel patterns to avoid vessels (Constantine, 2001; Nowacek et al., 2001; Lusseau, 2003, 2006); relocating to other areas (Allen and Read, 2000); cessation of feeding, resting, and social interaction (Baker et al., 1983; Bauer and Herman, 1986; Hall, 1982; Krieger and Wing, 1984; Lusseau, 2003; Constantine et al., 2004); abandoning feeding, resting, and nursing areas (Jurasz and Jurasz 1979; Dean et al., 1985; Glockner-Ferrari and Ferrari 1985, 1990; Lusseau, 2005; Norris et al., 1985; Salden, 1988; Forest, 2001; Morton and Symonds, 2002; Courbis, 2004; Bejder, 2006); stress (Romano et al., 2004); and changes in acoustic behavior (Van Parijs and Corkeron, 2001). However, in some studies marine mammals display no reaction to vessels (Watkins, 1986; Nowacek et al., 2003) and many odontocetes show considerable tolerance to vessel traffic (Richardson et al., 1995). Dolphins may actually reduce the energetic cost of traveling by riding the bow or stern waves of vessels (Williams et al., 1992; Richardson et al., 1995).

Dolphins within Pamlico Sound are continually exposed to recreational, commercial, and military vessels. Richardson et al. (1995) addresses in detail three responses that marine mammals may experience when exposed to anthropogenic activities: Tolerance; habituation; and sensitization. More recent publications provide variations on these themes rather than new data (NRC 2003). Marine mammals are often seen in regions with much human activity; thus, certain individuals or populations exhibit some tolerance of anthropogenic noise and other stimuli. Animals will tolerate a stimulus they might otherwise avoid if the benefits in terms of feeding, mating, migrating to traditional habitats, or other factors outweigh the negative aspects of the stimulus (NRC, 2003). In many cases, tolerance develops as a result of habituation. The NRC (2003) defines habituation as a gradual waning of behavioral responsiveness over time as animals learn that a repeated or ongoing stimulus lacks significant consequences for the animals. Contrarily, sensitization occurs when an animal links a stimulus with some degree of negative consequence and as a result increases responsiveness to that human activity over time (Richardson et al., 1995). For example, seals and whales are known to avoid previously encountered vessels involved in subsistence hunts (Walker, 1949; Ash 1962; Terhune, 1985) and bottlenose dolphins that had previously been captured and released from a 7.3 m boat involved in health studies were documented to flee when that boat approached closer than 400 m, whereas dolphins that had not been involved in the capture did not display signs of avoidance of the vessel (Irvine et al., 1981). Because dolphins in Pamlico Sound are continually exposed to vessel traffic that does not present immediate danger to them, it is likely animals are both tolerant and habituated to vessels.

The specified activities also involve aircraft, which marine mammals are known to react (Richardson et al., 1995). Aircraft produce noise at frequencies that are well within the frequency range of cetacean hearing and also produce visual signals such as the aircraft itself and its shadow (Richardson et al., 1995, Richardson & Würsig, 1997). A major difference between aircraft noise and noise caused by other anthropogenic sources is that the sound is generated in the air, transmitted through the water surface and then propagates underwater to the receiver, diminishing the received levels to significantly below what is heard above the water's surface. Sound transmission from air to water is greatest in a sound cone 26 degrees directly under the aircraft.

Reactions of odontocetes to aircraft have been reported less often than those of pinnipeds. Responses to aircraft include diving, slapping the water with pectoral fins or tail fluke, or swimming away from the track of the aircraft (Richardson et al., 1995). The nature and degree of the response, or the lack thereof, are dependent upon nature of the flight ( e.g., type of aircraft, altitude, straight vs. circular flight pattern). Würsig et al. (1998) assessed the responses of cetaceans to aerial surveys in the northcentral and western Gulf of Mexico using a DeHavilland Twin Otter fixed-wing airplane. The plane flew at an altitude of 229 m at 204 km/hr. A minimum of 305 m straight line distance from the cetaceans was maintained. Water depth was 100-1000m. Bottlenose dolphins most commonly responded by diving (48 percent), while 14 percent responded by moving away. Other species ( e.g., beluga whale, sperm whale) show considerable variation in reactions to aircraft but diving or swimming away from the aircraft are the most common reactions to low flights (less than 500 m).

Detonations of live ordnance would result in temporary modification to water properties. As described above, an underwater explosion from these weapon would send a shock wave and blast noise through the water, release gaseous by-products, create an oscillating bubble, and cause a plume of water to shoot up from the water surface. However, these would be temporary and not expected to last more than a few seconds. Because dolphins are not expected to be in the area during live firing, due to monitoring and mitigation measure implementation, they would not be subject to any short term habitat alterations.

Similarly, no long term impacts with regard to hazardous constituents are expected to occur. MCAS Cherry Point has an active Range Environmental Vulnerability Assessment (REVA) program in place to monitor impacts to habitat from its activities. One goal of REVA is to determine the horizontal and vertical concentration profiles of heavy metals, explosives constituents, perchlorate nutrients, and dissolved salts in the sediment and seawater surrounding BT-9 and BT-11. The preliminary results of the sampling indicate that explosive constituents ( e.g., trinitrotoluene (TNT), cyclotrimethylenetrinitramine (RDX), and hexahydro-trinitro-triazine (HMX), as described in Hazardous Constituents [Subchapter 3.2.7.2] of the MCAS Cherry Point Range Operations EA, were not detected in any sediment or water sample surrounding the BTs. Metals were not present above toxicity screening values. Perchlorate was detected in a few sediment samples above the detection limit (0.21 ppm), but below the reporting limit (0.6 ppm). The ongoing REVA would continue to evaluate potential munitions constituent migration from operational range areas to off-range areas and MCAS Cherry Point.

USMC complied with the mitigation and monitoring required under the previous authorization. In accordance with the 2010-11 IHA, USMC submitted a final monitoring report, which described the activities conducted and observations made. USMC did not record observations of any marine mammals during training exercises. The only recorded observations—which were of bottlenose dolphins—were on two occasions by maintenance vessels engaged in target maintenance. No marine mammals were observed during range sweeps, air to ground activities, surface to surface activities (small boats), or ad hoc via range cameras. Table 6 details the number of sorties conducted, by air and water, at each target. The number of sorties conducted does not relate to the total amount of munitions expended, as the training requirements for the specific military unit conducting the sortie determine the munitions loading for the air platform or watercraft during each sortie. In addition, munitions expenditures may be determined by the loading specifications of the specific aircraft and vessels used in the training exercise.

The total amount of ordnance expended at BT-9 and BT-11 under the 2010-11 IHA was 878,625 and 693,612 respectively (Table 7). These amounts represent 98 and 62 percent of the estimated annual maximum ordnance expenditures. The amounts of ordnance expended at the BTs account for all use of the targets. There are five types of explosive sources used at BT-9: 2.75” Rocket High Explosives, 5” Rocket High Explosives, 30 mm High Explosives, 40 mm High Explosives, and G911 grenades. No explosive munitions are used at BT-11.

In order to issue an incidental take authorization (ITA) under Section 101(a)(5)(D) of the MMPA, NMFS must set forth the “permissible methods of taking pursuant to such activity, and other means of effecting the least practicable adverse impact on such species or stock and its habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance.” The NDAA of 2004 amended the MMPA as it relates to military-readiness activities and the ITA process such that “least practicable adverse impact” shall include consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. The training activities described in the USMC's application are considered military readiness activities.

NMFS has carefully evaluated the applicant's proposed mitigation measures and considered a range of other measures in the context of ensuring that NMFS prescribes the means of effecting the least practicable adverse impact on the affected marine mammal species and stocks and their habitat. Our evaluation of potential measures included consideration of the following factors in relation to one another: (1) The manner in which, and the degree to which, the successful implementation of the measure is expected to minimize adverse impacts to marine mammals; (2) the proven or likely efficacy of the specific measure to minimize adverse impacts as planned; (3) the practicability of the measure for applicant implementation, including consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. NMFS has preliminarily determined that the proposed mitigation measures provide the means of effecting the least practicable adverse impacts on marine mammals species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance while also considering personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity.

The USMC, in collaboration with NMFS, has worked to identify potential practicable and effective mitigation measures, which include a careful balancing of the likely benefit of any particular measure to the marine mammals with the likely effect of that measure on personnel safety, practicality of implementation, and impact on the “military-readiness activity”. These proposed mitigation measures are listed below.

(1) Range Sweeps: The VMR-1 squadron, stationed at MCAS Cherry Point, includes three specially equipped HH-46D helicopters. The primary mission of these aircraft, known as PEDRO, is to provide search and rescue for downed 2 d Marine Air Wing aircrews. On-board are a pilot, co-pilot, crew chief, search and rescue swimmer, and a medical corpsman. Each crew member has received extensive training in search and rescue techniques, and is therefore particularly capable at spotting objects floating in the water.

PEDRO crew would conduct a range sweep the morning of each exercise day prior to the commencement of range operations. The primary goal of the pre-exercise sweep is to ensure that the target area is clear of fisherman, other personnel, and protected species. The sweep is flown at 100-300 meters above the water surface, at airspeeds between 60-100 knots. The path of the sweep runs down the western side of BT-11, circles around BT-9 and then continues down the eastern side of BT-9 before leaving. The sweep typically takes 20-30 minutes to complete. The PEDRO crew is able to communicate directly with range personnel and can provide immediate notification to range operators. The PEDRO aircraft would remain in the area of a sighting until clear if possible or as mission requirements dictate.

If marine mammals are sighted during a range sweep, sighting data will be collected and entered into the US Marine Corps sighting database, web-interface, or report generator and this information would be relayed to the training Commander. Sighting data includes the following (collected to the best of the observer's ability): (1) Species identification; (2) group size; (3) the behavior of marine mammals ( e.g., milling, travel, social, foraging); (4) location and relative distance from the BT; (5) date, time and visual conditions ( e.g., Beaufort sea state, weather) associated with each observation; (6) direction of travel relative to the BT; and (7) duration of the observation.

(2) Cold Passes: All aircraft participating in an air-to-surface exercise would be required to perform a “cold pass” immediately prior to ordnance delivery at the BTs both day and night. That is, prior to granting a “First Pass Hot” (use of ordnance), pilots would be directed to perform a low, cold (no ordnance delivered) first pass which serves as a visual sweep of the targets prior to ordnance delivery to determine if unauthorized civilian vessels or personnel, or protected species, are present. The cold pass is conducted with the aircraft (helicopter or fixed-winged) flying straight and level at altitudes of 200-3000 feet over the target area. The viewing angle is approximately 15 degrees. A blind spot exists to the immediate rear of the aircraft. Based upon prevailing visibility, a pilot can see more than one mile forward upon approach. The aircrew and range personnel make every attempt to ensure clearance of the area via visual inspection and remotely operated camera operations (see Proposed Monitoring and Reporting section below). The Range Controller may deny or approve the First Pass Hot clearance as conditions warrant.

(3) Delay of Exercises: An active range would be considered “fouled” and not available for use if a marine mammal is present within 1000 yards (914 m) of the target area at BT-9 or anywhere within Rattan Bay (BT-11). Therefore, if a marine mammal is sighted within 1000 yards (914 m) of the target at BT-9 or anywhere within Rattan Bay at BT-11 during the cold pass or from range camera detection, training would be delayed until the marine mammal moves beyond and on a path away from 1000 yards (914 m) from the BT-9 target or out of Rattan Bay at BT-11. This mitigation applies to both air-to-surface and surface-to-surface exercises.

(4) Range Camera Use: To increase the safety of persons or property near the targets, Range Operation and Control personnel monitor the target area through tower mounted safety and surveillance cameras. The remotely operated range cameras are high resolution and, according to range personnel, allow a clear visual of a duck floating near the target. The cameras allow viewers to see animals at the surface and breaking the surface, but not underwater.

A new, enhanced camera system has been purchased and will be installed on BT-11 towers 3 and 7, and on both towers at BT-9. The new camera system has night vision capabilities with resolution levels near those during daytime. Lenses on the camera system have focal lengths of 40 mm to 2200 mm (56x), with view angles of 18°10′ and 13°41′, respectively. The field of view when zoomed in on the Rattan Bay targets will be 23′ wide by 17′ high, and on the mouth of Rattan Bay itself 87′ wide by 66′ high.

Again, in the event that a marine mammal is sighted within 1000 yards (914 m) of the BT-9 target, or anywhere within Rattan Bay, the target would be declared fouled. Operations may commence in the fouled area after the animal(s) have moved 1000 yards (914 m) from the BT-9 target and/or out of Rattan Bay.

(5) Vessel Operation: All vessels used during training operations would abide by the NMFS' Southeast Regional Viewing Guidelines designed to prevent harassment to marine mammals ( http://www.nmfs.noaa.gov/pr/education/southeast /).

(6) Stranding Network Coordination: The USMC would coordinate with the local NMFS Stranding Coordinator for any unusual marine mammal behavior and any stranding, beached live/dead, or floating marine mammals that may occur at any time during training activities or within 24 hours after completion of training.

In order to issue an ITA for an activity, Section 101(a)(5)(A) of the MMPA states that NMFS must set forth “requirements pertaining to the monitoring and reporting of such taking”. The MMPA implementing regulations at 50 CFR 216.104(a)(13) indicate that requests for incidental take authorizations must include the suggested means of accomplishing the necessary monitoring and reporting that will result in increased knowledge of the species and of the level of taking or impacts on populations of marine mammals that are expected to be present. Monitoring measures prescribed by NMFS should accomplish one or more of the following general goals: (a) An increase in our understanding of how many marine mammals are likely to be exposed to munition noise and explosions that we associate with specific adverse effects, such as behavioral harassment, TTS, or PTS; (b) an increase in our understanding of how individual marine mammals respond (behaviorally or physiologically) to gunnery and bombing exercises (at specific received levels) expected to result in take; (c) an increase in our understanding of how anticipated takes of individuals (in different ways and to varying degrees) may impact the population, species, or stock (specifically through effects on annual rates of recruitment or survival); (d) an increased knowledge of the affected species; (e) an increase in our understanding of the effectiveness of certain mitigation and monitoring measures; (f) a better understanding and record of the manner in which the authorized entity complies with the incidental take authorization; (g) an increase in the probability of detecting marine mammals, both within the safety zone (thus allowing for more effective implementation of the mitigation) and in general to better achieve the above goals.

The suggested means of accomplishing the necessary monitoring and reporting that will result in increased knowledge of the species and of the level of taking or impacts on populations of marine mammals expected to be present within the action area are as follows:

(1) Marine Mammal Observer Training: Pilots, operators of small boats, and other personnel monitoring for marine mammals would be required to take the Marine Species Awareness Training (Version 2), maintained and promoted by the Department of the Navy. This training would make personnel knowledgeable of marine mammals, protected species, and visual cues related to the presence of marine mammals and protected species.

(2) Weekly and Post-Exercise Monitoring: Post-exercise monitoring would be conducted concomitant to the next regularly scheduled pre-exercise sweep. Weekly monitoring events would include a maximum of five pre-exercise and four post-exercise sweeps. The maximum number of days that would elapse between pre- and post-exercise monitoring events would be approximately 3 days, and would normally occur on weekends. If marine mammals are observed during this monitoring, sighting data identical to those collected by PEDRO crew would be recorded.

(3) Long-Term Monitoring: The USMC has awarded DUML duties to obtain abundance, group dynamics ( e.g., group size, age census), behavior, habitat use, and acoustic data on the bottlenose dolphins which inhabit Pamlico Sound, specifically those around BT-9 and BT-11. DUML began conducting boat-based surveys and passive acoustic monitoring of bottlenose dolphins in Pamlico Sound in 2000 (Read et al., 2003) and specifically at BT-9 and BT-11 in 2003 (Mayer, 2003). To date, boat-based surveys indicate that bottlenose dolphins may be resident to Pamlico Sound and use BT restricted areas on a frequent basis. Passive acoustic monitoring (PAM) is providing more detailed insight into how dolphins use the two ranges, by monitoring for their vocalizations year-round, regardless of weather conditions or darkness. In addition to these surveys, DUML scientists are testing a real-time passive acoustic monitoring system at BT-9 that will allow automated detection of bottlenose dolphin whistles, providing yet another method of detecting dolphins prior to training operations. Although it is unlikely this PAM system would be active for purposes of implementing mitigation measures before an exercise prior to expiration of the proposed IHA, it would be operational for future MMPA incidental take authorizations.

(4) Reporting: The USMC would submit a report to NMFS within 90 days after expiration of the IHA or, if a subsequent incidental take authorization is requested, within 120 days prior to expiration of the IHA. The report would summarize the type and amount of training exercises conducted, all marine mammal observations made during monitoring, and if mitigation measures were implemented. The report would also address the effectiveness of the monitoring plan in detecting marine mammals.

The following provides the USMC's model for take of dolphins from explosives (without consideration of mitigation and the conservative assumption that all explosives would land in the water and not on the targets or land) and potential for direct hits and NMFS' analysis of potential harassment from small vessel and aircraft operations.

For the purposes of an MMPA incidental take authorization, three levels of take are identified: Level B harassment; Level A harassment; and mortality (or serious injury leading to mortality). The categories of marine mammal responses (physiological and behavioral) that fall into harassment categories were described previously in this notice. A method to estimate the number of individuals that will be taken, pursuant to the MMPA, based on the proposed action has been derived. To this end, NMFS uses acoustic criteria that estimate at what received level Level B harassment, Level A harassment, and mortality of marine mammals would occur. The acoustic criteria for underwater detonations are comprehensively explained in NMFS' proposed and final rulemakings for the U.S. Navy's Cherry Point Range Operations (74 FR 11057; 74 FR 28370) and are summarized here:

Criteria and thresholds for estimating the exposures from a single explosive activity on marine mammals were established for the Seawolf Submarine Shock Test Final Environmental Impact Statement (FEIS) (“Seawolf”) and subsequently used in the USS Winston S. Churchill (DDG 81) Ship Shock FEIS (“Churchill”) (DoN, 1998 and 2001). NMFS adopted these criteria and thresholds in its final rule on the unintentional taking of marine animals occurring incidental to the shock testing which involved large explosives (65 FR 77546; December 12, 2000). Because no large explosives (> 1000 lbs NEW) would be used at Cherry Point during the specified activities, a revised acoustic criterion for small underwater explosions ( i.e., 23 pounds per square inch [psi] instead of previous acoustic criteria of 12 psi for peak pressure over all exposures) has been established to predict onset of TTS.

For injury, NMFS uses dual criteria, eardrum rupture ( i.e., tympanic-membrane injury) and onset of slight lung injury, to indicate the onset of injury. The threshold for tympanic-membrane (TM) rupture corresponds to a 50 percent rate of rupture ( i.e., 50 percent of animals exposed to the level are expected to suffer TM rupture). This value is stated in terms of an Energy Flux Density Level (EL) value of 1.17 inch pounds per square inch (in-lb/in2), approximately 205 dB re 1 microPa 2 - sec.

The threshold for onset of slight lung injury is calculated for a small animal (a dolphin calf weighing 26.9 lbs), and is given in terms of the “Goertner modified positive impulse,” indexed to 13 psi-msec (DoN, 2001). This threshold is conservative since the positive impulse needed to cause injury is proportional to animal mass, and therefore, larger animals require a higher impulse to cause the onset of injury. This analysis assumed the marine species populations were 100 percent small animals. The criterion with the largest potential impact range (most conservative), either TM rupture (energy threshold) or onset of slight lung injury (peak pressure), will be used in the analysis to determine Level A exposures for single explosive events.

For mortality, NMFS uses the criterion corresponding to the onset of extensive lung injury. This is conservative in that it corresponds to a 1 percent chance of mortal injury, and yet any animal experiencing onset severe lung injury is counted as a lethal exposure. For small animals, the threshold is given in terms of the Goertner modified positive impulse, indexed to 30.5 psi-msec. Since the Goertner approach depends on propagation, source/animal depths, and animal mass in a complex way, the actual impulse value corresponding to the 30.5 psi-msec index is a complicated calculation. To be conservative, the analysis used the mass of a calf dolphin (at 26.9 lbs) for 100 percent of the populations.

For multiple explosions, the Churchill approach had to be extended to cover multiple sound events at the same training site. For multiple exposures, accumulated energy over the entire training time is the natural extension for energy thresholds since energy accumulates with each subsequent shot (detonation); this is consistent with the treatment of multiple arrivals in Churchill. For positive impulse, it is consistent with the Churchill final rule to use the maximum value over all impulses received.

To determine the onset of TTS (non-injurious harassment)—a slight, recoverable loss of hearing sensitivity, there are dual criteria: An energy threshold and a peak pressure threshold. The criterion with the largest potential impact range (most conservative), either the energy or peak pressure threshold, will be used in the analysis to determine Level B TTS exposures. The thresholds for each criterion are described below.

The TTS energy threshold for explosives is derived from the Space and Naval Warfare Systems Center (SSC) pure-tone tests for TTS (Schlundt et al., 2000; Finneran and Schlundt, 2004). The pure-tone threshold (192 dB as the lowest value) is modified for explosives by (a) interpreting it as an energy metric, (b) reducing it by 10 dB to account for the time constant of the mammal ear, and (c) measuring the energy in 1/3-octave bands, the natural filter band of the ear. The resulting threshold is 182 dB re 1 microPa 2 -sec in any 1/3-octave band.

The second threshold applies to all species and is stated in terms of peak pressure at 23 psi (about 225 dB re 1 microPa). This criterion was adopted for Precision Strike Weapons (PSW) Testing and Training by Eglin Air Force Base in the Gulf of Mexico (NMFS, 2005). It is important to note that for small shots near the surface (such as in this analysis), the 23-psi peak pressure threshold generally will produce longer impact ranges than the 182-dB energy metric. Furthermore, it is not unusual for the TTS impact range for the 23-psi pressure metric to actually exceed the without-TTS (behavioral change without onset of TTS) impact range for the 177-dB energy metric.

For a single explosion, to be consistent with Churchill, TTS is the criterion for Level B harassment. In other words, because behavioral disturbance for a single explosion is likely to be limited to a short-lived startle reaction, use of the TTS criterion is considered sufficient protection and therefore behavioral effects (Level B behavioral harassment without onset of TTS) are not expected for single explosions.

For multiple explosions, the Churchill approach had to be extended to cover multiple sound events at the same training site. For multiple exposures, accumulated energy over the entire uninterrupted firing time is the natural extension for energy thresholds since energy accumulates with each subsequent shot (detonation); this is consistent with the treatment of multiple arrivals in Churchill. Because multiple explosions could occur within a discrete time period, a new acoustic criterion-behavioral disturbance without TTS is used to account for behavioral effects significant enough to be judged as harassment, but occurring at lower noise levels than those that may cause TTS.

The threshold is based on test results published in Schlundt et al. (2000), with derivation following the approach of the Churchill FEIS for the energy-based TTS threshold. The original Schlundt et al. (2000) data and the report of Finneran and Schlundt (2004) are the basis for thresholds for behavioral disturbance without TTS. During this study, instances of altered behavior sometimes began at lower exposures than those causing TTS; however, there were many instances when subjects exhibited no altered behavior at levels above the onset-TTS levels. Regardless of reactions at higher or lower levels, all instances of altered behavior were included in the statistical summary. The behavioral disturbance without TTS threshold for tones is derived from the SSC tests, and is found to be 5 dB below the threshold for TTS, or 177 dB re 1 microPa 2 -sec maximum energy flux density level in any 1/3-octave band at frequencies above 100 Hz for cetaceans.

The effects, criteria, and thresholds used in the assessment for impulsive sounds are summarized in Table 8. The criteria for behavioral effects without physiological effects used in this analysis are based on use of multiple explosives from live, explosive firing at BT-9 only; no live firing occurs at BT-11.

The USMC conservatively modeled that all explosives would detonate at a 1.2 m (3.9 ft) water depth despite the training goal of hitting the target, resulting in an above water or on land explosion. For sources that are detonated at shallow depths, it is frequently the case that the explosion may breech the surface with some of the acoustic energy escaping the water column. The source levels presented in the table above have not been adjusted for possible venting nor does the subsequent analysis take this into account. Properties of explosive sources used at BT-9, including NEW, peak one-third-octave (OTO) source level, the approximate frequency at which the peak occurs, and rounds per burst are described in Table 9. Distances to NMFS harassment threshold levels from these sources are outlined in Table 10.

To calculate take, the distances to which animals may be harassed were considered along with dolphin density. The density estimate from Read et al . (2003) was used to calculate take from munition firing. As described in the Description of Marine Mammals in the Area of the Specified Activity section above, this density, 0.183/km 2 , was derived from boat based surveys in 2000 which covered all inland North Carolina waters. Note that estimated density of dolphins at BT-9 and BT-11, specifically, were calculated to be 0.11 dolphins/km 2 , and 1.23 dolphins/km 2 respectively (Maher 2003), based on boat surveys conducted from July 2002 through June 2003 (excluding April, May, Sept. and Jan.). However, the USMC chose to estimate take of dolphins based on the higher density reported from the summer 2000 surveys (0.183/km 2 ). Additionally, take calculations for munition firing are based on 100 percent water detonation, although the goal of training is to hit the targets, and no pre-exercise monitoring or mitigation. Therefore, take estimates can be considered conservative.

Based on dolphin density and amount of munitions expended, there is very low potential for Level A harassment and mortality and monitoring and mitigation measures are anticipated to further negate this potential. Accordingly, NMFS is not proposing to issue these levels of take. As portrayed in Table 9, the largest harassment zone (Level B) is within 209 m of a detonation in water; however, the USMC has implemented a 1000 m “foul” zone for BT-9 and anywhere within Rattan Bay for BT-11. In total, from firing of explosive ordnances, the USMC is requesting, and NMFS is proposing to issue, the incidental take of 25 bottlenose dolphins from Level B harassment (Table 11).

The potential risk of a direct hit to an animal in the target area is estimated to be so low it is discountable. A Range Air Installation Compatible Use Zone (RAICUZ) study generated the surface area or footprints of weapon impact areas associated with air-to-ground ordnance delivery (USMC 2001). Statistically, a weapon safety footprint describes the area needed to contain 99.99 percent of initial and ricochet impacts at the 95-percent confidence interval for each type of aircraft and ordnance utilized on the BTs. At both BT-9 and BT-11 the probability of deployed ordnance landing in the impact footprint is essentially 1.0, since the footprints were designed to contain 99.99 percent of impacts, including ricochets. However, only 36 percent of the weapon footprint for BT-11 is over water in Rattan Bay, so the likelihood of a weapon striking an animal at the BT in Rattan Bay is 64 percent less. Water depths in Rattan Bay range from 3 m (10 ft) in the deepest part of the bay to 0.5 m (1.6 m) close to shore, so that nearly the entire habitat in Rattan Bay is suitable for marine mammal use (or 36 percent of the weapon footprint).

The estimated potential risk of a direct hit to an animal in the target area is extremely low. The probability of hitting a bottlenose dolphin at the BTs can be derived as follows: Probability = dolphin's dorsal surface area * density of dolphins. The estimated dorsal surface area of a bottlenose dolphin is 1.425 m 2 (or the average length of 2.85 m times the average body width of 0.5 m). Thus, using Read et al. (2003)'s density estimate of 0.183 dolphins/km 2 , without consideration of mitigation and monitoring implementation, the probability of a dolphin being hit in the waters of BT-9 is 2.61 × 10 −7 and of BT-11 is 9.4 × 10 −8 . Using the proposed levels of ordnance expenditures at each in-water BT (Tables 4 and 5) and taking into account that only 36 percent of the ordnance deployed at BT-11 is over water, as described in the application, the estimated potential number of ordnance strikes on a marine mammal per year is 0.263 at BT-9 and 0.034 at BT-11. It would take approximately three years of ordnance deployment at the BTs before it would be likely or probable that one bottlenose dolphin would be struck by deployed inert ordnance. Again, these estimates are without consideration to proposed monitoring and mitigation measures.

Vessel movement is associated with surface-to-surface exercises, as described in the Specified Activities section above, which primarily occurs within BT-11. The USMC is not requesting takes specific to the act of maneuvering small boats within the BTs; however, NMFS has analyzed the potential for take from this activity.

The potential impacts from exposure to vessels are described in the Vessel and Aircraft Presence section above. Interactions with vessels are not a new experience for bottlenose dolphins in Pamlico Sound. Pamlico Sound is heavily used by recreational, commercial (fishing, daily ferry service, tugs, etc. ), and military (including the Navy, Air Force, and Coast Guard) vessels year-round. The NMFS' Southeast Regional Office has developed marine mammal viewing guidelines to educate the public on how to responsibly view marine mammals in the wild and avoid causing a take ( http://www.nmfs.noaa.gov/pr/education/southeast ). The guidelines recommend that vessels should remain a minimum of 50 yards from a dolphin, operate vessels in a predictable manner, avoid excessive speed or sudden changes in speed or direction in the vicinity of animals, and not to pursue, chase, or separate a group of animals. The USMC would abide by these guidelines to the fullest extent practicable. The USMC would not engage in high speed exercises should a marine mammal be detected within the immediate area of the BTs prior to training commencement and would never closely approach, chase, or pursue dolphins. Detection of marine mammals would be facilitated by personnel monitoring on the vessels and those marking success rate of target hits and monitoring of remote camera on the BTs (see Proposed Monitoring and Reporting section).

Based on the description of the action, the other activities regularly occurring in the area, the species that may be exposed to the activity and their observed behaviors in the presence of vessel traffic, and the implementation of measures to avoid vessel strikes, NMFS believes it is unlikely that the operation of vessels during surface-to-surface maneuvers will result in the take of any marine mammals, in the form of either behavioral harassment or injury.

Aircraft would move swiftly through the area and would typically fly approximately 914 m from the water's surface before dropping unguided munitions and above 4,572 m for precision-guided munition bombing. While the aircraft may approach as low as 152 m (500 ft) to drop a bomb this is not the norm and would never been done around marine mammals. Regional whale watching guidelines advise aircraft to maintain a minimum altitude of 300 m (1,000 ft) above all marine mammals, including small odontocetes, and to not circle or hover over the animals to avoid harassment. NMFS' approach regulations limit aircraft from flying below 300 m (1,000 ft) over a humpback whale ( Megaptera novaeangliae ) in Hawaii, a known calving ground, and limit aircraft from flying over North Atlantic right whales closer than 460 m (1509 ft). Given USMC aircraft would not fly below 300 m on the approach, would not engage in hovering or circling the animals, and would not drop to the minimal altitude of 152 m if a marine mammal is in the area, NMFS believes it is unlikely that the operation of aircraft, as described above, will result in take of bottlenose dolphins in Pamlico Sound.

Pursuant to NMFS' regulations implementing the MMPA, an applicant is required to estimate the number of animals that will be “taken” by the specified activities ( i.e., takes by harassment only, or takes by harassment, injury, and/or death). This estimate informs the analysis that NMFS must perform to determine whether the activity will have a “negligible impact” on the species or stock. 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.” A negligible impact finding is based on the lack of likely adverse effects on annual rates of recruitment or survival ( i.e., population-level effects). An estimate of the number and manner of takes, alone, is not enough information on which to base a negligible impact determination. NMFS must also consider other factors, such as the likely nature of any responses (their intensity, duration, etc. ), the context of any responses (critical reproductive time or location, migration, etc. ), or any of the other variables mentioned in the first paragraph (if known), as well as the number and nature of estimated Level A takes, the number of estimated mortalities, and effects on habitat.

The USMC has been conducting gunnery and bombing training exercises at BT-9 and BT-11 for years and, to date, no dolphin injury or mortality has been attributed these military training exercises. The USMC has a history of notifying the NMFS stranding network when any injured or stranded animal comes ashore or is spotted by personnel on the water. Therefore, stranded animals have been examined by stranding responders, further confirming that it is unlikely training contributes to marine mammal injuries or deaths. Due to the implementation of the aforementioned mitigation measures, no take by Level A harassment or serious injury or mortality is anticipated nor would any be authorized in the IHA. NMFS is proposing; however, to authorize 25 Level B harassment takes associated with training exercises.

The USMC has proposed a 1000 yard (914 m) safety zone around BT-9 despite the fact that the distance to NMFS explosive Level B harassment threshold is 228 yards (209 m). They also would consider an area fouled if any dolphins are spotted within Raritan Bay (where BT-11 is located). The Level B harassment takes allowed for in the IHA would be of very low intensity and would likely result in dolphins being temporarily behaviorally affected by bombing or gunnery exercises. In addition, takes may be attributed to animals not using the area when exercises are occurring; however, this is difficult to calculate. Instead, NMFS looks to if the specified activities occur during and within habitat important to vital life functions to better inform its negligible impact determination.

Read et al. (2003) concluded that dolphins rarely occur in open waters in the middle of North Carolina sounds and large estuaries, but instead are concentrated in shallow water habitats along shorelines. However, no specific areas have been identified as vital reproduction or foraging habitat. Scientific boat based surveys conducted throughout Pamlico Sound conclude that dolphins use the areas around the BTs more frequently than other portions of Pamlico Sound (Maher, 2003) despite the USMC actively training in a manner identical to the specified activities described here for years.

As described in the Affected Species section of this notice, bottlenose dolphin stock segregation is complex with stocks overlapping throughout the coastal and estuarine waters of North Carolina. It is not possible for the USMC to determine to which stock any individual dolphin taken during training activities belong as this can only be accomplished through genetic testing. However, it is likely that many of the dolphins encountered would belong to the NNCE or SNCE stock. These stocks have a population estimate of 1,387 and 2,595, respectively. NMFS is proposing to authorize 25 takes of bottlenose dolphins in total; therefore, this number represents 1.8 and 1.0 percent, respectively, of those populations.

Based on the analysis contained herein of the likely effects of the specified activity on marine mammals and their habitat, and taking into consideration the implementation of the mitigation and monitoring measures, NMFS preliminarily finds that the specified USMC AS Cherry Point BT-9 and BT-11 training activities will result in the incidental take of marine mammals, by Level B harassment only, and that the total taking from will have a negligible impact on the affected species or stocks.

Marine mammals are not taken for subsistence use within Pamlico Sound; therefore, issuance of an IHA to the USMC for MCAS Cherry Point training exercises would not have an unmitigable adverse impact on the availability of the affected species or stocks for subsistence use.

No ESA-listed marine mammals are known to occur within the action area. Therefore, there is no requirement for NMFS to consult under Section 7 of the ESA on the issuance of an IHA under section 101(a)(5)(D) of the MMPA. However, ESA-listed sea turtles may be present within the action area.

On September 27, 2002, NMFS issued a Biological Opinion (BiOp) on Ongoing Ordnance Delivery at Bombing Target 9 (BT-9) and Bombing Target 11 (BT-11) at Marine Corps Air Station, Cherry Point, North Carolina. The BiOp, which is still in effect, concluded that the USMC's proposed action will not result in adverse impacts to any ESA-listed marine mammals and is not likely to jeopardize the continued existence of the endangered green turtle ( Chelonia mydas ), leatherback turtle ( Dermochelys coriacea ), Kemp's ridley turtle ( Lepidochelys kempii ), or threatened loggerhead turtle ( Caretta caretta ). No critical habitat has been designated for these species in the action area; therefore, none will be affected.

On February 11, 2009, the USMC issued a Finding of No Significant Impact for its Environmental Assessment (EA) on MCAS Cherry Point Range Operations. Based on the analysis of the EA, the USMC determined that the proposed action will not have a significant impact on the human environment. NMFS adopted USMC's EA and signed a FONSI on August 31, 2010. NMFS has reviewed the proposed application and preliminarily determined that there are no substantial changes to the proposed action or new environmental impacts or concerns. Therefore, NMFS has determined that a new or supplemental EA or Environmental Impact Statement is likely unnecessary. Before making a final determination in this regard, NMFS will review public comments and information submitted by the public and others in response to this notice. The EA referenced above is available for review at http://www.nmfs.noaa.gov/pr/permits/incidental.htm.