Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing Activities in the Hawaii-Southern California Training and Testing Study Area
Federal RegisterDec 24, 2013
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Parts 216 and 218
[Docket No. 130107014-3969-02]
RIN 0648-BC52-X
Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing Activities in the Hawaii-Southern California Training and Testing Study Area
AGENCY:
National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION:
Final rule.
SUMMARY:
Upon application from the U.S. Navy (Navy), we (the National Marine Fisheries Service) are issuing regulations under the Marine Mammal Protection Act (MMPA) to govern the unintentional taking of marine mammals incidental to training and testing activities conducted in the Hawaii-Southern California Training and Testing (HSTT) Study Area from December 2013 through December 2018. These regulations allow us to issue Letters of Authorization (LOAs) for the incidental take of marine mammals during the Navy's specified activities and timeframes, set forth the permissible methods of taking, set forth other means of effecting the least practicable adverse impact on marine mammal species or stocks and their habitat, and set forth requirements pertaining to the monitoring and reporting of the incidental take.
DATES:
Effective December 24, 2013, through December 24, 2018.
ADDRESSES:
To obtain an electronic copy of the Navy's application or other referenced documents, visit the Internet at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Documents cited in this notice may also be viewed, by appointment, during regular business hours, at 1315 East-West Highway, SSMC III, Silver Spring, MD 20912.
FOR FURTHER INFORMATION CONTACT:
Michelle Magliocca, Office of Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of the Navy's application may be obtained by visiting the Internet at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
The Navy's Final Environmental Impact Statement/Overseas Environmental Impact Statement (FEIS/OEIS) for HSTT may be viewed at
http://www.hstteis.com.
Documents cited in this notice may also be viewed, by appointment, during regular business hours, at the aforementioned address (see
ADDRESSES
).
Background
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1361
et seq.
) directs the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and regulations are issued. We are required to grant authorization for the incidental taking of marine mammals if we find that the total taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses (where relevant). We must also set forth the permissible methods of taking and requirements pertaining to the mitigation, monitoring, and reporting of such takings. 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.”
The National Defense Authorization Act of 2004 (NDAA) (Pub. L. 108-136) amended section 101(a)(5)(A) of the MMPA by removing the small numbers and specified geographical region provisions and amending the definition of “harassment” as it applies to a “military readiness activity” to read as follows (section 3(18)(B) of the MMPA): “(i) Any act that injures or has the significant potential to injure a marine mammal or marine mammal stock in the wild [Level A Harassment]; or (ii) any act that disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing disruption of natural behavioral patterns, including, but not limited to, migration, surfacing, nursing, breeding, feeding, or sheltering, to a point where such behavioral patterns are abandoned or significantly altered [Level B Harassment].”
Summary of Request
On April 13, 2012, NMFS received an application from the Navy requesting two LOAs for the take of 39 species of marine mammals incidental to Navy training and testing activities to be conducted in the HSTT Study Area over 5 years. The Navy submitted an addendum on September 24, 2012 and NMFS considered the application complete. The Navy requests authorization to take marine mammals by Level A and Level B harassment and mortality during training and testing activities. The Study Area includes three existing range complexes (Southern California (SOCAL) Range Complex, Hawaii Range Complex (HRC), and Silver Strand Training Complex (SSTC)) plus pierside locations and areas on the high seas where maintenance, training, or testing may occur. These activities are considered military readiness activities. Marine mammals present in the Study Area may be exposed to sound from active sonar, underwater detonations, airguns, and/or pile driving and removal. In addition, incidental takes of marine mammals may occur from ship strikes. The Navy requests authorization to take 39 marine mammal species by Level B harassment and 24 marine mammal species by Level A harassment or mortality.
The Navy's application and the HSTT FEIS/OEIS contain acoustic thresholds that, in some instances, represent changes from what NMFS has used to evaluate the Navy's activities for previous authorizations. The revised thresholds, which the Navy developed in coordination with NMFS, are based on the evaluation and inclusion of new information from recent scientific studies; a detailed explanation of how they were derived is provided in the HSTT FEIS/OEIS Criteria and Thresholds Technical Report (available at
http://www.hstteis.com
). The revised thresholds are adopted for this rulemaking after providing the public with an opportunity for review and comment via the proposed rule for this action, which published on January 31, 2013 (78 FR 6978).
Further, more generally, NMFS is committed to the use of the best available science. NMFS uses an adaptive transparent process that allows for both timely scientific updates and public input into agency decisions regarding the use of acoustic research and thresholds. NMFS is currently in the process of re-evaluating acoustic thresholds based on the best available science, as well as how these thresholds are applied in the application of the MMPA standards for all activity types (not just for Navy activities). This re-evaluation could potentially result in changes to the acoustic thresholds or their application as they apply to future Navy activities. However, it is important to note that while changes in acoustic criteria may affect the enumeration of
“takes,” they do not necessarily significantly change the evaluation of population level effects or the outcome of the negligible impact analysis. Further, while acoustic criteria may also inform mitigation and monitoring decisions, the Navy has a robust adaptive management program that regularly addresses new information and allows for modification of mitigation and/or monitoring measures as appropriate.
Description of Specified Activities
The proposed rule (78 FR 6978, January 31, 2013) and HSTT FEIS/OEIS include a complete description of the Navy's specified activities that are being authorized in this final rule. Sonar use, underwater detonations, airguns, pile driving and removal, and ship strike are the stressors most likely to result in impacts on marine mammals that could rise to the level of harassment, thus necessitating MMPA authorization. Below we summarize the description of the specified activities.
Overview of Training Activities
Training activities are categorized into eight functional warfare areas (anti-air warfare; amphibious warfare; strike warfare; anti-surface warfare; anti-submarine warfare; electronic warfare; mine warfare; and naval special warfare). The Navy determined that the following stressors used in these warfare areas are most likely to result in impacts on marine mammals:
• Amphibious warfare (underwater detonations, pile driving and removal)
• Anti-surface warfare (underwater detonations)
• Anti-submarine warfare (active sonar, underwater detonations)
• Mine warfare (active sonar, underwater detonations, and marine mammal systems (see description below))
• Naval special warfare (underwater detonations)
The Navy's activities in anti-air warfare, strike warfare, and electronic warfare do not involve stressors that could result in harassment of marine mammals. Therefore, these activities are not discussed further.
Overview of Testing Activities
Testing activities may occur independently of or in conjunction with training activities. Many testing activities are conducted similarly to Navy training activities and are also categorized under one of the primary mission areas. Other testing activities are unique and are described within their specific testing categories. The Navy determined that stressors used during the following testing activities are most likely to result in impacts on marine mammals:
Naval Air Systems Command (NAVAIR) Testing
• Anti-surface warfare testing (underwater detonations)
• Anti-submarine warfare testing (active sonar, underwater detonations)
• Mine warfare testing (active sonar, underwater detonations)
• Naval Sea Systems Command (NAVSEA) Testing
• New ship construction (active sonar, underwater detonations)
• Life cycle activities (active sonar, underwater detonations)
• Anti-surface warfare/anti-submarine warfare testing (active sonar, underwater detonations)
• Mine warfare testing (active sonar, underwater detonations)
• Ship protection systems and swimmer defense testing (active sonar, airguns)
• Unmanned vehicle testing (active sonar)
• Other testing (active sonar)
Space and Naval Warfare Systems Commands (SPAWAR) Testing
• SPAWAR research, development, test, and evaluation (active sonar)
Office of Naval Research (ONR) and Naval Research Laboratory (NRL) Testing
• ONR/NRL research, development, test, and evaluation (active sonar)
Other Navy testing activities do not involve stressors that could result in marine mammal harassment. Therefore, these activities are not discussed further.
Classification of Non-Impulsive and Impulsive Sources Analyzed
In order to better organize and facilitate the analysis of about 300 sources of underwater non-impulsive sound or impulsive energy, the Navy developed a series of source classifications, or source bins. This method of analysis provides the following benefits:
• Allows for new sources to be covered under existing authorizations, as long as those sources fall within the parameters of a “bin;”
• Simplifies the data collection and reporting requirements anticipated under the MMPA;
• Ensures a conservative approach to all impact analysis because all sources in a single bin are modeled as the loudest source (e.g., lowest frequency, highest source level, longest duty cycle, or largest net explosive weight within that bin);
• Allows analysis to be conducted more efficiently, without compromising the results;
• Provides a framework to support the reallocation of source usage (hours/explosives) between different source bins, as long as the total number and severity of marine mammal takes remain within the overall analyzed and authorized limits. This flexibility is required to support evolving Navy training and testing requirements, which are linked to real world events.
A description of each source classification is provided in Tables 1, 2, and 3. Non-impulsive sources are grouped into bins based on the frequency, source level when warranted, and how the source would be used. Impulsive bins are based on the net explosive weight of the munitions or explosive devices. The following factors further describe how non-impulsive sources are divided:
Frequency of the non-impulsive source:
• Low-frequency sources operate below 1 kilohertz (kHz)
• Mid-frequency sources operate at or above 1 kHz, up to and including 10 kHz
• High-frequency sources operate above 10 kHz, up to and including 100 kHz
• Very high-frequency sources operate above 100 kHz, but below 200 kHz
Source level of the non-impulsive source:
• Greater than 160 decibels (dB), but less than 180 dB
• Equal to 180 dB and up to 200 dB
• Greater than 200 dB
How a sensor is used determines how the sensor's acoustic emissions are analyzed. Factors to consider include pulse length (time source is on); beam pattern (whether sound is emitted as a narrow, focused beam, or, as with most explosives, in all directions); and duty cycle (how often a transmission occurs in a given time period during an event).
There are also non-impulsive sources with characteristics that are not anticipated to result in takes of marine mammals. These sources have low source levels, narrow beam widths, downward directed transmission, short pulse lengths, frequencies beyond known hearing ranges of marine mammals, or some combination of these factors. These sources were not modeled by the Navy, but are qualitatively analyzed in Table 1-4 of the LOA application and the HSTT FEIS/OEIS. In addition, impulsive sources with explosive weights less than 0.1 lb net explosive weight (less than bin E1) were not modeled.
Table 1—Impulsive Training and Testing Source Classes Analyzed
Source class
Representative munitions
Net explosive weight (lbs)
E1
Medium-caliber projectiles
0.1-0.25 (45.4-113.4 g).
E2
Medium-caliber projectiles
0.26-0.5 (117.9-226.8 g).
E3
Large-caliber projectiles
>0.5-2.5 (>226.8 g-1.1 kg).
E4
Improved Extended Echo Ranging Sonobuoy
>2.5-5.0 (1.1-2.3 kg).
E5
5 in. (12.7 cm) projectiles
>5-10 (>2.3-4.5 kg).
E6
15 lb. (6.8 kg) shaped charge
>10-20 (>4.5-9.1 kg).
E7
40 lb. (18.1 kg) demo block/shaped charge
>20-60 (>9.1-27.2 kg).
E8
250 lb. (113.4 kg) bomb
>60-100 (>27.2-45.4 kg).
E9
500 lb. (226.8 kg) bomb
>100-250 (>45.4-113.4 kg).
E10
1,000 lb. (453.6 kg) bomb
>250-500 (>113.4-226.8 kg).
E11
650 lb. (294.8 kg) mine
>500-650 (>226.8-294.8 kg).
E12
2,000 lb. (907.2 kg) bomb
>650-1,000 (>294.8-453.6 kg).
E13
1,200 lb. (544.3 kg) HBX charge
>1,000-1,740 (>453.6-789.3 kg).
Table 2—Non-Impulsive Training Source Classes Analyzed
Source class category
Source class
Description
Mid-Frequency (MF): Tactical and non-tactical sources that produce mid-frequency (1 to 10 kHz) signals
MF1
Active hull-mounted surface ship sonar (e.g., AN/SQS-53C and AN/SQS-60).
MF1K
Kingfisher object avoidance mode associated with MF1 sonar.
MF2
Active hull-mounted surface ship sonar (e.g., AN/SQS-56).
MF2K
Kingfisher mode associated with MF2 sonar.
MF3
Active hull-mounted submarine sonar (e.g., AN/BQQ-10).
MF4
Active helicopter-deployed dipping sonar (e.g., AN/AQS-22 and AN/AQS-13).
MF5
Active acoustic sonobuoys (e.g., AN/SSQ-62 DICASS).
MF6
Active underwater sound signal devices (e.g., MK-84).
MF11
Hull-mounted surface ship sonar with an active duty cycle greater than 80%.
MF12
High duty cycle—variable depth sonar.
High-Frequency (HF) and Very High-Frequency (VHF): Tactical and non-tactical sources that produce high-frequency (greater than 10 kHz but less than 200 kHz) signals
HF1
Active hull-mounted submarine sonar (e.g., AN/BQQ-15).
HF4
Active mine detection, classification, and neutralization sonar (e.g., AN/SQS-20).
Anti-Submarine Warfare (ASW): Tactical sources such as active sonobuoys and acoustic countermeasures systems used during ASW training activities
ASW1
MF active Deep Water Active Distributed System (DWADS).
ASW2
MF active Multistatic Active Coherent (MAC) sonobuoy (e.g., AN/SSQ-125).
ASW3
MF active towed active acoustic countermeasure systems (e.g., AN/SLQ-25 NIXIE).
ASW4
MF active expendable active acoustic device countermeasures (e.g., MK-3).
Torpedoes (TORP): Source classes associated with active acoustic signals produced by torpedoes
TORP1
HF active lightweight torpedo sonar (e.g., MK-46, MK-54, or Anti-Torpedo Torpedo).
TORP2
HF active heavyweight torpedo sonar (e.g., MK-48).
Table 3—Non-Impulsive Testing Source Classes Analyzed
Source class category
Source class
Description
Low-Frequency (LF): Sources that produce low-frequency (less than 1 kilohertz [kHz]) signals
1
LF4
Low-frequency sources equal to 180 dB and up to 200 dB
LF5
Low-frequency sources less than 180 dB
LF6
Low-frequency sonar currently in development (e.g., anti-submarine warfare sonar associated with the Littoral Combat Ship).
Mid-Frequency (MF): Tactical and non-tactical sources that produce mid-frequency (1 to 10 kHz) signals
MF1
Hull-mounted surface ship sonar (e.g., AN/SQS-53C and AN/SQS-60).
MF1K
Kingfisher mode associated with MF1 sonar (Sound Navigation and Ranging).
MF2
Hull-mounted surface ship sonar (e.g., AN/SQS-56).
MF3
Hull-mounted submarine sonar (e.g., AN/BQQ-10).
MF4
Helicopter-deployed dipping sonar (e.g., AN/AQS-22 and AN/AQS-13).
MF5
Active acoustic sonobuoys (e.g., DICASS).
MF6
Active underwater sound signal devices (e.g., MK-84).
MF8
Active sources (greater than 200 dB).
MF9
Active sources (equal to 180 dB and up to 200 dB).
MF10
Active sources (greater than 160 dB, but less than 180 dB) not otherwise binned.
MF12
High duty cycle—variable depth sonar.
High-Frequency (HF) and Very High-Frequency (VHF):
Tactical and non-tactical sources that produce high-frequency (greater than 10 kHz but less than 200 kHz) signals
HF1
Hull-mounted submarine sonar (e.g., AN/BQQ-10).
HF3
Hull-mounted submarine sonar (classified).
HF4
Mine detection, classification, and neutralization sonar (e.g., AN/SQS-20).
HF5
Active sources (greater than 200 dB).
HF6
Active sources (equal to 180 dB and up to 200 dB).
Anti-Submarine Warfare (ASW): Tactical sources such as active sonobuoys and acoustic countermeasures systems used during the conduct of anti-submarine warfare testing activities
ASW1
Mid-frequency Deep Water Active Distributed System (DWADS).
ASW2
Mid-frequency Multistatic Active Coherent sonobuoy (e.g., AN/SSQ-125)—sources analyzed by number of items (sonobuoys).
ASW2
Mid-frequency sonobuoy (e.g., high duty cycle)—Sources that are analyzed by hours.
ASW3
Mid-frequency towed active acoustic countermeasure systems (e.g., AN/SLQ-25).
ASW4
Mid-frequency expendable active acoustic device countermeasures (e.g., MK-3).
Torpedoes (TORP): Source classes associated with the active acoustic signals produced by torpedoes
TORP1
Lightweight torpedo (e.g., MK-46, MK-54, or Surface Ship Defense System).
TORP2
Heavyweight torpedo (e.g., MK-48).
Acoustic Modems (M): Systems used to transmit data acoustically through water
M3
Mid-frequency acoustic modems (greater than 190 dB).
Swimmer Detection Sonar (SD): Systems used to detect divers and submerged swimmers
SD1—SD2
High-frequency sources with short pulse lengths, used for the detection of swimmers and other objects for the purpose of port security.
Airguns (AG): Underwater airguns are used during swimmer defense and diver deterrent training and testing activities
AG
Up to 60 cubic inch airguns (e.g., Sercel Mini-G).
Synthetic Aperture Sonar (SAS): Sonar in which active acoustic signals are post-processed to form high-resolution images of the seafloor
SAS1
MF SAS systems.
SAS2
HF SAS systems.
SAS3
VHF SAS systems.
1
This source class category does not include the SURTASS LFA system, which is authorized under a separate rulemaking and EIS/OEIS.
Authorized Action
Training—Table 4 describes the annual number of impulsive source detonations during training activities within the HSTT Study Area, and Table 5 describes the annual number of hours or items of non-impulsive sources used during training within the HSTT Study Area.
Table 4—Annual Number of Impulsive Source Detonations During Training in the HSTT Study Area
Explosive class
Net explosive weight
(NEW)
Annual
in-water
detonations
(training)
E1
(0.1 lb.-0.25 lb.)
19,840
E2
(0.26 lb.-0.5 lb.)
1,044
E3
(>0.5 lb.-2.5 lb.)
3,020
E4
(>2.5 lb.-5 lb.)
668
E5
(>5 lb.-10 lb.)
8,154
E6
(>10 lb.-20 lb.)
538
E7
(>20 lb.-60 lb.)
407
E8
(>60 lb.-100 lb.)
64
E9
(>100 lb.-250 lb.)
16
E10
(>250 lb.-500 lb.)
19
E11
(>500 lb.-650 lb.)
8
E12
(>650 lb.-1,000 lb.)
224
E13
(>1,000 lb.-1,740 lb.)
9
Table 5—Annual Hours and Items of Non-Impulsive Sources Used During Training
Within the HSTT Study Area
Source class category
Source class
Annual Use
Mid-Frequency (MF) Active sources from 1 to 10 kHz
MF1
11,588 hours.
MF1K
88 hours.
MF2
3,060 hours.
MF2K
34 hours.
MF3
2,336 hours.
MF4
888 hours.
MF5
13,718 items.
MF11
1,120 hours.
MF12
1,094 hours.
High-Frequency (HF) and Very High-Frequency (VHF) Tactical and non-tactical sources that produce signals greater than 10kHz but less than 200kHz
HF1
HF4
1,754 hours
4,848 hours.
Anti-Submarine Warfare (ASW)—Active ASW sources
ASW1
224 hours.
ASW2
1,800 items.
ASW3
16,561 hours.
ASW4
1,540 items.
Torpedoes (TORP)—Active torpedo sonar
TORP1
170 items.
TORP2
400 items.
Testing—Table 6 describes the annual number of impulsive source detonations during testing activities within the HSTT Study Area, and Table 7 describes the annual number of hours or items of non-impulsive sources used during testing within the HSTT Study Area.
Table 6—Annual Number of Impulsive Source Detonations During Testing Activities
Within the HSTT Study Area
Explosive class
Net explosive weight
(NEW)
Annual
in-water
detonations
(testing)
E1
(0.1 lb.-0.25 lb.)
14,501
E2
(0.26 lb.-0.5 lb.)
0
E3
(>0.5 lb.-2.5 lb.)
2,990
E4
(>2.5 lb.-5 lb.)
753
E5
(>5 lb.-10 lb.)
202
E6
(>10 lb.-20 lb.)
37
E7
(>20 lb.-60 lb.)
21
E8
(>60 lb.-100 lb.)
12
E9
(>100 lb.-250 lb.)
0
E10
(>250 lb.-500 lb.)
31
E11
(>500 lb.-650 lb.)
14
E12
(>650 lb.-1,000 lb.)
0
E13
(>1,000 lb.-1,740 lb.)
0
Table 7—Annual Hours and Items of Non-Impulsive Sources Used During Testing
Within the HSTT Study Area
Source class category
Source class
Annual use
Low-Frequency (LF) Sources that produce signals less than 1 kHz
1
LF4
52 hours.
LF5
2,160 hours.
LF6
192 hours.
Mid-Frequency (MF) Tactical and non-tactical sources that produce signals from 1 to 10 kHz
MF1
180 hours.
MF1K
18 hours.
MF2
84 hours.
MF3
392 hours.
MF4
693 hours.
MF5
5,024 items.
MF6
540 items.
MF8
2 hours.
MF9
3,039 hours.
MF10
35 hours.
MF12
336 hours.
High-Frequency (HF) and Very High-Frequency (VHF): Tactical and non-tactical sources that produce signals greater than 10kHz but less than 200kHz
HF1
1,025 hours.
HF3
273 hours.
HF4
1,336 hours.
HF5
1,094 hours.
HF6
3,460 hours.
Anti-Submarine Warfare (ASW) Tactical sources used during anti-submarine warfare training and testing activities
ASW1
224 hours.
ASW2
2,260 items.
ASW2
255 hours.
ASW3
1,278 hours.
ASW4
477 items.
Torpedoes (TORP) Source classes associated with active acoustic signals produced by torpedoes
TORP1
701 items.
TORP2
732 items.
Acoustic Modems (M) Transmit data acoustically through the water
M3
4,995 hours.
Swimmer Detection Sonar (SD) Used to detect divers and submerged swimmers
SD1
38 hours.
Airguns (AG) Used during swimmer defense and diver deterrent training and testing activities
AG
5 uses.
Synthetic Aperture Sonar (SAS): Sonar in which active acoustic signals are post-processed to form high-resolution images of the seafloor
SAS1
2,700 hours.
SAS2
4,956 hours.
SAS3
3,360 hours.
1
This source class category does not include the SURTASS LFA system, which is authorized under a separate rulemaking and EIS/OEIS.
Vessels—Representative Navy vessel types, lengths, and speeds used in both training and testing activities are shown in Table 8. While these speeds are representative, some vessels operate outside of these speeds due to unique training, testing, or safety requirements for a given event. Examples include increased speeds needed for flight operations, full speed runs to test engineering equipment, time critical positioning needs, etc. Examples of decreased speeds include speeds less than 5 knots or completely stopped for launching small boats, certain tactical maneuvers, target launch or retrievals, unmanned underwater vehicles, etc.
Table 8—Typical Navy Boat and Vessel Types With Length Greater Than 18 Meters
Used Within the HSTT Study Area
Vessel Type
(>18 m)
Example(s) (specifications in meters (m) for length, metric tons (mt) for mass, and knots for speed)
Typical operating speed
(knots)
Aircraft Carrier
Aircraft Carrier (CVN) length: 333 m beam: 41 m draft: 12 m displacement: 81,284 mt max. speed: 30+ knots
10 to 15.
Surface Combatants
Cruiser (CG) length: 173 m beam: 17 m draft: 10 m displacement: 9,754 mt max. speed: 30+ knots
10 to 15.
Destroyer (DDG) length: 155 m beam: 18 m draft: 9 m displacement: 9,648 mt max. speed: 30+ knots
Frigate (FFG) length: 136 m beam: 14 m draft: 7 m displacement: 4,166 mt max. speed: 30+ knots
Littoral Combat Ship (LCS) length: 115 m beam: 18 m draft: 4 m displacement: 3,000 mt max. speed: 40+ knots
Amphibious Warfare Ships
Amphibious Assault Ship (LHA, LHD) length: 253 m beam: 32 m draft: 8 m displacement: 42,442 mt max. speed: 20+ knots
10 to 15.
Amphibious Transport Dock (LPD) length: 208 m beam: 32 m draft: 7 m displacement: 25,997 mt max. speed: 20+ knots
Dock Landing Ship (LSD) length: 186 m beam: 26 m draft: 6 m displacement: 16,976 mt max. speed: 20+ knots
Mine Warship Ship
Mine Countermeasures Ship (MCM) length: 68 m beam: 12 m draft: 4 m displacement: 1,333 max. speed: 14 knots
5 to 8.
Submarines
Attack Submarine (SSN) length: 115 m beam: 12 m draft: 9 m displacement: 12,353 mt max. speed: 20+ knots
8 to 13.
Guided Missile Submarine (SSGN) length: 171 m beam: 13 m draft: 12 m displacement: 19,000 mt max. speed: 20+ knots
Combat Logistics Force Ships *
Fast Combat Support Ship (T-AOE) length: 230 m beam: 33 m draft: 12 m displacement: 49,583 max. speed: 25 knots
8 to 12.
Dry Cargo/Ammunition Ship (T-AKE) length: 210 m beam: 32 m draft: 9 m displacement: 41,658 mt max speed: 20 knots
Fleet Replenishment Oilers (T-AO) length: 206 m beam: 30 m draft: 11 displacement: 42,674 mt max. speed: 20 knots
Fleet Ocean Tugs (T-ATF) length: 69 m beam: 13 m draft: 5 m displacement: 2,297 max. speed: 14 knots
Support Craft/Other
Landing Craft, Utility (LCU) length: 41m beam: 9 m draft: 2 m displacement: 381 mt max. speed: 11 knots
3 to 5.
Landing Craft, Mechanized (LCM) length: 23 m beam: 6 m draft: 1 m displacement: 107 mt max. speed: 11 knots
Support Craft/Other Specialized High Speed
MK V Special Operations Craft length: 25 m beam: 5 m displacement: 52 mt max. speed: 50 knots
Variable.
* CLF vessels are not homeported in Pearl Harbor or San Diego, but are frequently used for various fleet support and training support events in the HSTT Study Area.
Duration and Location
The description of the location of authorized activities has not changed from what was provided in the proposed rule and HSTT FEIS/OEIS (78 FR 6978, January 31, 2013; pages 6987-6988;
http://www.hstteis.com
). For a complete description, please see those documents. Training and testing activities will be conducted in the HSTT Study Area from December 2013 through December 2018. The Study Area includes three existing range complexes: the Hawaii Range Complex (HRC), the Southern California (SOCAL) Range Complex, and the Silver Strand Training Complex (SSTC). Each range complex is an organized and designated set of specifically bounded geographic areas, which includes a water component (above and below the surface), airspace, and sometimes a land component. Operating areas (OPAREAs) and special use airspace are established within each range complex. In addition to Navy range complexes, the Study Area includes other areas where training and testing activities occur, including pierside locations in San Diego Bay and Pearl Harbor, the transit corridor between SOCAL and Hawaii, and throughout the San Diego Bay. The majority of active sonar activities occur in SOCAL and the HRC, while the SSTC is used primarily for explosive activities and pile driving. However, hull mounted mid-frequency active sonar during Major Training Events (MTEs) is not typically used in the San Diego Arc area or in areas of high humpback whale density around Hawaii (with the exception of water adjacent to the Pacific Missile Range Facility). Much less sonar activity and no explosive activities are conducted within the transit corridors.
Description of Marine Mammals in the Area of the Specified Activities
Thirty-nine marine mammal species are known to occur in the Study Area, including seven mysticetes (baleen whales), 25 odontocetes (dolphins and toothed whales), six pinnipeds (seals and sea lions), and the Southern sea otter. Among these species, there are 72 stocks managed by NMFS or the U.S. Fish and Wildlife Service (USFWS) in the U.S. Exclusive Economic Zone (EEZ). To address a public comment on population structure, and consistent with NMFS most recent Pacific Stock Assessment Report, a single species may include multiple stocks recognized for management purposes (e.g., spinner dolphin), while other species are grouped into a single stock due to limited species-specific information (e.g., beaked whales belonging to the genus
Mesoplodon
). However, when there is sufficient information available, the Navy's take estimates and NMFS' negligible impact determination are based on stock-specific numbers. Eight of the 39 marine mammal species are endangered and one of the 39 marine mammal species are threatened under the Endangered Species Act of 1978 (ESA; 16 U.S.C. 1531
et seq.
).
The Description of Marine Mammals in the Area of the Specified Activities section has not changed from what was in the proposed rule (78 FR 6978, January 31, 2013; pages 6988-6994). Table 9 of the proposed rule provided a list of marine mammals with possible or confirmed occurrence within the HSTT Study Area, including stock, abundance, and status. Since publishing the proposed rule, NMFS released new stock assessment reports for some of the marine mammal species occurring within the HSTT Study Area. The new species abundance estimates were considered in making our final determinations. Table 3.4-1 of the HSTT FEIS/OEIS includes a table with the revised species abundance estimates. Although not repeated in this final rule, we have reviewed these data, determined them to be the best available scientific information for the purposes of the rulemaking, and consider this information part of the administrative record for this action.
The proposed rule (78 FR 6978, January 31, 2013; pages 6994-6995), the Navy's LOA application and the HSTT FEIS/OEIS include a complete description of information on the status, distribution, abundance, vocalizations, density estimates, and general biology of marine mammal species.
Potential Effects of Specified Activities on Marine Mammals
For the purpose of MMPA authorizations, NMFS' effects assessments serve five primary purposes: (1) To prescribe the permissible methods of taking (i.e., Level B harassment (behavioral harassment), Level A harassment (injury), or mortality, including an identification of the number and types of take that could occur by harassment or mortality), (2) to prescribe other means of effecting the least practicable adverse impact on such species or stock and its habitat (i.e., mitigation); (3) to determine whether the specified activity would have a negligible impact on the affected species or stocks of marine mammals (based on the likelihood that the activity would adversely affect the species or stock through effects on annual rates of recruitment or survival); (4) to determine whether the specified activity would have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses; and (5) to prescribe requirements pertaining to monitoring and reporting.
In the Potential Effects of Specified Activities on Marine Mammals section of the proposed rule, we included a qualitative discussion of the different ways that Navy training and testing activities may potentially affect marine mammals without consideration of mitigation and monitoring measures (78 FR 6978, January 31, 2013; pages 6997-7011). Marine mammals may experience direct physiological effects (e.g., threshold shift and non-acoustic injury), acoustic masking, impaired communication, stress responses, behavioral disturbance, stranding, behavioral responses from vessel movement, and injury or death from vessel collisions. NMFS made no changes to the information contained in that section of the proposed rule, and it adopts that discussion for purposes of this final rule.
NMFS is constantly evaluating new science and how to best incorporate it into our decisions. This process involves careful consideration of new data and how it is best interpreted
within the context of a given management framework. Since publication of the proposed rule, a few studies have been published regarding behavioral responses that are relevant to the proposed activities and energy sources: Moore and Barlow, 2013; DeRuiter
et al.,
2013; and Goldbogen
et al.,
2013, among others. These articles are specifically addressed in the Comments and Responses section of this document. Each of these articles emphasizes the importance of context (e.g., behavioral state of the animals, distance from the sound source, etc.) in evaluating behavioral responses of marine mammals to acoustic sources. In addition, New
et al.,
2013, Houser
et al.,
2013, and Claridge, 2013 were recently published.
New
et al.
uses energetic models to investigate the survival and reproduction of beaked whales. The model suggests that impacts to habitat quality may affect adult female beaked whales' ability to reproduce; and therefore, a reduction in energy intake over a long period of time may have the potential to impact reproduction. However, the SOCAL Range Complex continues to support high densities of beaked whales and there is no data to suggest a decline in this population.
Houser
et al.
performed a controlled exposure study involving California sea lions exposed to a simulated mid-frequency sonar signal. The purpose of this Navy-sponsored study was to determine the probability and magnitude of behavioral responses by California sea lions exposed to differing intensities of simulated mid-frequency sonar signals. Houser
et al.'
s findings are consistent with current scientific studies and criteria development concerning marine mammal reactions to mid-frequency sonar sounds.
Claridge published her Ph.D. thesis, which investigated the potential effects exposure to mid-frequency active sonar could have on beaked whale demographics. In summary, Claridge suggested that lower reproductive rates observed at the Navy's Atlantic Undersea Test and Evaluation Center (AUTEC), when compared to a control site, were due to stressors associated with frequent and repeated use of Navy sonar. However, the author noted that there may be other unknown differences between the sites. It is also important to note that there were some relevant shortcomings of this study. For example, all of the re-sighted whales during the 5-year study at both sites were female, which Claridge acknowledged can lead to a negative bias in the abundance estimation. There was also a reduced effort and shorter overall study period at the AUTEC site that failed to capture some of the emigration/immigration trends identified at the control site. Furthermore, Claridge assumed that the two sites were identical and therefore should have equal potential abundances; when in reality, there were notable physical differences. All of the aforementioned studies were considered in NMFS' determination to issue regulations and associated LOAs to the Navy for their proposed activities in the HSTT Study Area.
Also, since the publication of the proposed rule, the Independent Scientific Review Panel investigating potential contributing factors to a 2008 mass stranding of melon-headed whales (
Peponocephala electra
) in Antsohihy, Madagascar released its final report. This report suggests that the operation of a commercial high-powered 12 kHz multi-beam echosounder during an industry seismic survey was a plausible and likely initial trigger that caused a large group of melon-headed whales to leave their typical habitat and then ultimately strand as a result of secondary factors such as malnourishment and dehydration. The report indicates that the risk of this particular convergence of factors and ultimate outcome is likely very low, but recommends that the potential be considered in environmental planning. Because of the association between tactical mid-frequency active sonar use and a small number of marine mammal strandings, the Navy and NMFS have been considering and addressing the potential for strandings in association with Navy activities for years. In addition to a suite of mitigation intended to more broadly minimize impacts to marine mammals, the Navy and NMFS have a detailed Stranding Response Plan that outlines reporting, communication, and response protocols intended both to minimize the impacts of, and enhance the analysis of, any potential stranding in areas where the Navy operates.
Mitigation
In order to issue regulations and LOAs under section 101(a)(5)(A) 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.” NMFS' duty under this “least practicable adverse impact” standard is to prescribe mitigation reasonably designed to minimize, to the extent practicable, any adverse population-level impacts, as well as habitat impacts. While population-level impacts can be minimized only by reducing impacts on individual marine mammals, not all takes translate to population-level impacts. NMFS' objective under the “least practicable adverse impact” standard is to design mitigation targeting those impacts on individual marine mammals that are most likely to lead to adverse population-level effects.
The NDAA of 2004 amended the MMPA as it relates to military readiness activities and the Incidental Take Authorization (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 and testing activities described in the Navy's LOA application are considered military readiness activities.
NMFS reviewed the proposed activities and the suite of proposed mitigation measures as described in the Navy's LOA application to determine if they would result in the least practicable adverse effect on marine mammal species and stocks and their habitat, which includes a careful balancing of the degree to which the mitigation measures are expected to reduce the likelihood and/or magnitude of adverse impacts to marine mammal species or stocks and their habitat with the likely effect of the measures on personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity. Included below are the mitigation measures the Navy proposed in their LOA application.
NMFS described the Navy's proposed mitigation measures in detail in the proposed rule (78 FR 6978, January 31, 2013; pages 7011-7017), and they have not changed. NMFS worked with the Navy in the development of the Navy's initially proposed measures, and they are informed by years of experience and monitoring. As described in the mitigation conclusions below and in responses to comments, and in the HSTT EIS, additional measures were considered and analyzed, but ultimately not chosen for implementation. However, the Navy's low use of mid-frequency active sonar in certain areas of particular importance to marine mammals has been clarified in the Comments and Responses section of this document. Below are the mitigation measures as agreed upon by the Navy and NMFS.
• At least one Lookout during training and testing activities;
• Mitigation zones during impulse and non-impulsive sources to avoid or reduce the potential for onset of the lowest level of injury, PTS, out to the predicted maximum range (Tables 11 and 12);
• Mitigation zones of 500 yards (yd) (457 meters(m)) for whales and 200 yd (183 m) for all other marine mammals (except bow riding dolphins) during vessel movement;
• A mitigation zone of 250 yd (229 m) for marine mammals during use of towed in-water devices being towed from manned platforms;
• A mitigation zone of 200 yd (183 m) around the intended impact location during non-explosive gunnery exercises (all calibers) and small and medium caliber explosive gunnery exercises;
• A mitigation zone of 600 yd (549 m) around the intended impact location during large caliber explosive gunnery exercises;
• A mitigation zone of 1,000 yd (914 m) around the intended impact location during non-explosive bombing exercises;
• A mitigation zone of 1.5 miles (mi) (2.3 kilometers (km)) for explosive bombing exercises;
• Standard operating procedures to limit the low risk of disease transmission during Navy Marine Mammal Program operations; and
• Humpback whale cautionary area requiring high-level clearance if training or testing use of mid-frequency active sonar is necessary between December 15 and April 15.
Table 11—Predicted Ranges to TTS, PTS, and Recommended Mitigation Zones
Activity category
Bin (representative source) *
Predicted average (longest) range to TTS
Predicted average (longest) range to PTS
Predicted maximum range to PTS
Recommended
mitigation zone
Non-Impulsive Sound
Low-Frequency and Hull-Mounted Mid-Frequency Active Sonar
1
MF1 (SQS-53 ASW hull-mounted sonar)
3,821 yd (3.5 km) for one ping
100 yd (91 m) for one ping
N/A
6 dB power down at 1,000 yd. (914 m); 4 dB power down at 500 yd. (457 m); and shutdown at 200 yd. (183 m).
High-Frequency and Non-Hull Mounted Mid-Frequency Active Sonar
MF4 (AQS-22 ASW dipping sonar)
230 yd (210 m) for one ping
20 yd (18 m) for one ping
N/A
200 yd. (183 m).
Explosive and Impulsive Sound
Improved Extended Echo Ranging Sonobuoys
E4 (Explosive sonobuoy)
434 yd (397 m)
156 yd (143 m)
563 yd (515 m)
600 yd (549 m).
Explosive Sonobuoys using 0.5-2.25 lb. NEW
E3 (Explosive sonobuoy)
290 yd (265 m)
113 yd (103 m)
309 yd (283 m)
350 yd (320 m).
Anti-Swimmer Grenades
E2 (Up to 0.5 lb. NEW)
190 yd (174 m)
83 yd (76 m)
182 yd (167 m)
200 yd (183 m).
Mine Countermeasure and Neutralization Activities Using Positive Control Firing Devices
NEW dependent (see Table 12)
Mine Neutralization Diver-Placed Mines Using Time-Delay Firing Devices
E7 (29 lb. NEW only)
846 yd (774 m)
286 yd (262 m)
541 yd (495 m)
1,000 yd (915 m).
Gunnery Exercises—Small-and Medium-Caliber (Surface Target)
E2 (40 mm projectile)
190 yd (174 m)
83 yd (76 m)
182 yd (167 m)
200 yd (183 m).
Gunnery Exercises—Large-Caliber (Surface Target)
E5 (5 in. projectiles at the surface ***)
453 yd (414 m)
186 yd (170 m)
526 yd (481 m)
600 yd (549 m).
Missile Exercises up to 250 lb. NEW (Surface Target)
E9 (Maverick missile)
949 yd (868 m)
398 yd (364 m)
699 yd (639 m)
900 yd (823 m).
Missile Exercises up to 500 lb. NEW (Surface Target)
E10 (Harpoon missile)
1,832 yd (1.7 km)
731 yd (668 m)
1,883 yd (1.7 k m)
2,000 yd (1.8 km).
Bombing Exercises
E12 (MK-84 2,000 lb. bomb)
2,513 yd (2.3 km)
991 yd (906 m)
2,474 yd (2.3 km)
2,500 yd (2.3 km).**
Torpedo (Explosive) Testing
E11 (MK-48 torpedo)
1,632 yd (1.5 km)
697 yd (637 m)
2,021 yd (1.8 km)
2,100 yd (1.9 km).
Sinking Exercises
E12 (Various sources up to the MK-84 2,000 lb. bomb)
2,513 yd (2.3 km)
991 yd (906 m)
2,474 yd (2.3 km)
2.5 nm.
At-Sea Explosive Testing
E5 (Various sources less than 10 lb. NEW at various depths ***)
525 yd (480 m)
204 yd (187 m)
649 yd (593 m)
1,600 yd (1.4 km).**
Elevated Causeway System—Pile Driving
24 in. steel impact hammer
1,094 yd (1 k m)
51 yd (46 m)
51 yd (46 m)
60 yd (55 m).
Note:
The predicted average and maximum ranges have been updated for bins MF1 and MF4 since the proposed rules. These distances are consistent with the HSTT FEIS and do not change the recommended mitigation zones. ASW: anti-submarine warfare; NEW: net explosive weight; PTS: permanent threshold shift; TTS: temporary threshold shift.
1
The mitigation zone would be 200 yd for sources not able to be powered down (e.g., LF4 and LF5).
* This table does not provide an inclusive list of source bins; bins presented here represent the source bin with the largest range to effects within the given activity category.
** Recommended mitigation zones are larger than the modeled injury zones to account for multiple types of sources or charges being used.
*** The representative source bin E5 has different range to effects depending on the depth of activity occurrence (at the surface or at various depths).
Table 12—Predicted Ranges to Effects and Mitigation Zone Radius for Mine Countermeasure and Neutralization Activities Using Positive Control Firing Devices
Charge size
Net explosive weight
(bins)
General mine countermeasure and
Neutralization activities using positive control firing devices *
Predicted average range to TTS
Predicted average range to PTS
Predicted maximum range to PTS
Recommended mitigation zone
Mine countermeasure and neutralization
Activities using diver placed charges under positive control**
Predicted average range to TTS
Predicted average range to PTS
Predicted maximum range to PTS
Recommended mitigation zone
2.6-5 lb (1.2-2.3 kg) (E4)
434 yd
197 yd
563 yd
600 yd
545 yd
169 yd
301 yd
350 yd.
(397 m)
(180 m)
(515 m)
(549 m)
(498 m)
(155 m)
(275 m)
(320 m).
6-10 lb (2.7-4.5 kg) (E5)
525 yd
204 yd
649 yd
800 yd
587 yd
203 yd
464 yd
500 yd.
(480 m)
(187 m)
(593 m)
(732 m)
(537 m)
(185 m)
(424 m)
(457 m).
11-20 lb (5-9.1 kg) (E6)
766 yd
288 yd
648 yd
800 yd
647 yd
232 yd
469 yd
500 yd.
(700 m)
(263 m)
(593 m)
(732 m)
(592 m)
(212 m)
(429 m)
(457 m).
21-60 lb (9.5-27.2 kg) (E7) ***
1,670 yd
581 yd
964 yd
1,200 yd.
1,532 yd
473 yd
789 yd
800 yd.
(1.5 km)
(531 m)
(882 m)
(1.1 km)
(1.4 km)
(432 m)
(721 m)
(732 m).
61-100 lb (27.7-45.4 kg) (E8) ****
878 yd
383 yd
996 yd
1,600 yd.
969 yd
438 yd
850 yd
850 yd.
(802 m)
(351 m)
(911 m)
(1.4 m)
(886 m)
(400 m)
(777 m)
(777 m).
250-500 lb (113.4-226.8 kg) (E10)
1,832 yd
731 yd
1,883 yd
2,000 yd.
700 yd (640 m).*****
(1,675 m)
(668 m)
(1,721 m)
(1.8 km)
*
501-650 lb (227.3-294.8) (E11)
1,632 yd
697 yd
2,021 yd
2,100 yd.
N/A.
(1,492 m)
(637 m)
(1,848 m)
(1.9 km)
PTS: permanent threshold shift; TTS: temporary threshold shift.
* These mitigation zones are applicable to all mine countermeasure and neutralization activities conducted in all locations that Tables 2.8-1 through 2.8-5 in the HSTT FEIS/OEIS specifies.
** These mitigation zones are only applicable to mine countermeasure and neutralization activities involving the use of diver placed charges. These activities are conducted in shallow-water and the mitigation zones are based only on the functional hearing groups with species that occur in these areas (mid-frequency cetaceans and sea turtles).
*** The E7 bin was only modeled in shallow-water locations so there is no difference for the diver placed charges category.
**** The E8 bin was only modeled for surface explosions, so some of the ranges are shorter than for sources modeled in the E7 bin which occur at depth.
***** The mitigation zone for the E10 charge applies only to very shallow water detonations and is based on empirical data as described in section 5.3.2.1.2.4 of the HSTT FEIS/OEIS (Mine Countermeasure and Neutralization Activities Using Positive Control Firing Devices).
Time-Delay Firing Devices
When mine neutralization activities using diver placed charges (up to a 29 lb NEW) are conducted with a time-delay firing device, the detonation is fused with a specified time-delay by the personnel conducting the activity and is not authorized until the area is clear at the time the fuse is initiated. During these activities, the detonation cannot be terminated once the fuse is initiated due to human safety concerns. During activities using up to a 29 lb NEW (bin E7) detonation, the Navy will have four Lookouts and two small rigid hull inflatable boats (two Lookouts positioned in each of the two boats) monitoring a 1,000-yd (915-m) mitigation zone. In addition, when aircraft are used, the pilot or member of the aircrew will serve as an additional Lookout. The Navy will monitor the mitigation zone for 30 minutes before, during, and 30 minutes after the activity to ensure that the area is clear of marine mammals and time-delay firing device events will only be conducted during daylight hours.
Vessel Strike
Naval vessels will maneuver to keep at least 500 yd (457 m) away from any observed whale in the vessel's path and avoid approaching whales head-on. These requirements do not apply if a vessel's safety is threatened, such as
when change of course will create an imminent and serious threat to a person, vessel, or aircraft, and to the extent vessels are restricted in their ability to maneuver. Restricted maneuverability includes, but is not limited to, situations when vessels are engaged in dredging, submerged activities, launching and recovering aircraft or landing craft, minesweeping activities, replenishment while underway and towing activities that severely restrict a vessel's ability to deviate course. Vessels will take reasonable steps to alert other vessels in the vicinity of the whale. Given rapid swimming speeds and maneuverability of many dolphin species, naval vessels would maintain normal course and speed on sighting dolphins unless some condition indicated a need for the vessel to maneuver. Vessels will take all practical steps to alert other vessels in the vicinity of a whale.
If a large whale surfaces within 500 yd (457 m) of a Navy vessel (or if a vessel is within this distance of a large whale for any other reason), the vessel should exercise caution, increase vigilance, and consider slower speed if operationally supportable and does not interfere with safety of navigation until the vessel has moved beyond a 500 yd (457 m) radius of the observed whale, or any subsequently observed whales (whales often travel in pairs within several body lengths of one another (fin/blue) and humpbacks in feeding aggregations).
Cetacean and Sound Mapping
NMFS Office of Protected Resources routinely considers available information about marine mammal habitat use to inform discussions with applicants regarding potential spatio-temporal limitations on their activities that might help effect the least practicable adverse impact on species or stocks and their habitat (e.g., Humpback Whale Cautionary Area). Through the Cetacean and Sound Mapping effort (
cetsound.noaa.gov
), NOAA's Cetacean Density and Distribution Mapping Working Group (CetMap) is currently involved in a process to compile available literature and solicit expert review to identify areas and times where species are known to concentrate for specific behaviors (e.g., feeding, breeding/calving, or migration) or be range-limited (e.g., small resident populations). These areas, called Biologically Important Areas (BIAs), are useful tools for planning and impact assessments and are being provided to the public via the CetSound Web site, along with a summary of the supporting information. While these BIAs are useful tools for analysts, any decisions regarding protective measures based on these areas must go through the normal MMPA evaluation process (or any other statutory process that the BIAs are used to inform)—the designation of a BIA does not pre-suppose any specific management decision associated with those areas. Additionally, the BIA process is iterative and the areas will be updated as new information becomes available. Currently, NMFS has published some BIAs in Hawaii (which are considered in the Comments and Responses section of this document). The BIAs in other regions, such as the Atlantic and West Coast of the continental U.S., are preliminary and are being prepared for submission to a peer-reviewed journal for review. NMFS and the Navy have discussed the draft BIAs, what Navy activities take place in these areas (in the context of what their effects on marine mammals might be or whether additional mitigation is necessary), and what measures could be implemented to reduce impacts in these areas (in the context of their potential to reduce marine mammal impacts and their practicability). As we learn more about marine mammal density, distribution, and habitat use (and the BIAs are updated), NMFS and the Navy will continue to reevaluate appropriate time-area measures through the Adaptive Management process outlined in these regulations.
Stranding Response Plan
NMFS and the Navy developed a Stranding Response Plan for the HRC and SOCAL Range Complexes in 2009 as part of previous incidental take authorizations (ITAs). The Stranding Response Plans are specifically intended to outline applicable requirements in the event that a marine mammal stranding is reported in the HRC or SOCAL Range Complex during a major training exercise. NMFS considers all plausible causes within the course of a stranding investigation and these plans in no way presume that any strandings in a Navy range complex are related to, or caused by, Navy training and testing activities, absent a determination made during investigation. The plans are designed to address mitigation, monitoring, and compliance. The Navy is currently working with NMFS to refine these plans for the new HSTT Study Area (to include regionally specific plans that include more logistical detail) and revised plans will be made available here:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Modifications to the Stranding Response Plan may also be made through the adaptive management process.
Mitigation Conclusions
NMFS has carefully evaluated the Navy's proposed suite of mitigation measures and considered a broad range of other measures (including those recommended during the public comment period) 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: the manner in which, and the degree to which, the successful implementation of the required mitigation measures is expected to reduce the likelihood and/or magnitude of adverse impacts to marine mammal species and stocks and their habitat; the proven or likely efficacy of the measures; and the practicability of the suite of measures for applicant implementation, including consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity.
In some cases, additional mitigation measures are required beyond those that the applicant proposes. NMFS may consider the practicability of implementing a particular mitigation measure if the best available science indicates that the measure (either alone or in combination with other mitigation measures) has a reasonable likelihood of accomplishing or contributing to the accomplishment of one or more of the goals listed below, which in turn would be expected to lessen the likelihood and/or magnitude of adverse impacts on marine mammal species or stocks and their habitat:
(a) Avoidance or minimization of injury or death of marine mammals wherever possible (goals b, c, and d may contribute to this goal).
(b) A reduction in the numbers of marine mammals (total number or number at biologically important time or location) exposed to received levels of active sonar, underwater detonations, or other activities expected to result in the take of marine mammals (this goal may contribute to a, above, or to reducing harassment takes only).
(c) A reduction in the number of times (total number or number at biologically important time or location) individuals would be exposed to received levels of active sonar, underwater detonations, or other activities expected to result in the take of marine mammals (this goal may contribute to a, above, or to reducing harassment takes only).
(d) A reduction in the intensity of exposures (either total number or number at biologically important time or location) to received levels of MFAS/HFAS, underwater detonations, or other activities expected to result in the take of marine mammals (this goal may contribute to a, above, or to reducing the severity of harassment takes only).
(e) Avoidance or minimization of adverse effects to marine mammal habitat, paying special attention to the food base, activities that block or limit passage to or from biologically important areas, permanent destruction of habitat, or temporary destruction/disturbance of habitat during a biologically important time.
(f) For monitoring directly related to mitigation—an increase in the probability of detecting marine mammals, thus allowing for more effective implementation of the mitigation (shut-down zone, etc.).
Based on our evaluation of the Navy's proposed measures, as well as other measures considered by NMFS or recommended by the public, NMFS has determined that the Navy's proposed mitigation measures (especially when the adaptive management component is taken into consideration (see Adaptive Management, below)), along with the additions detailed in the Mitigation section above, are adequate 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.
Monitoring
Section 101(a)(5)(A) of the MMPA states that in order to issue an incidental take authorization for an activity, 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 LOAs 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:
• An increase in the probability of detecting marine mammals, both within the mitigation zone (thus allowing for more effective implementation of the mitigation) and in general to generate more data to contribute to the analyses mentioned below;
• An increase in our understanding of how many marine mammals are likely to be exposed to levels of active sonar (or in-water explosives or other stimuli) that we associate with specific adverse effects, such as behavioral harassment, TTS, or PTS;
• An increase in our understanding of how marine mammals respond to active sonar (at specific received levels), underwater explosives, or other stimuli expected to result in take and how anticipated adverse effects on 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) through any of the following methods:
○ Behavioral observations in the presence of active sonar compared to observations in the absence of sonar (need to be able to accurately predict received level and report bathymetric conditions, distance from source, and other pertinent information);
○ Physiological measurements in the presence of active sonar compared to observations in the absence of tactical sonar (need to be able to accurately predict received level and report bathymetric conditions, distance from source, and other pertinent information);
○ Pre-planned and thorough investigation of stranding events that occur coincident to naval activities; and
○ Distribution and/or abundance comparisons in times or areas with concentrated active sonar versus times or areas without active sonar.
• An increased knowledge of the affected species; and
• An increase in our understanding of the effectiveness of certain mitigation and monitoring measures.
NMFS described an overview of Navy monitoring and research, highlighted recent findings, and explained the Navy's new approach to monitoring in the proposed rule (78 FR 6978, January 31, 2013; pages 7017-7020). Below is a summary of the Navy's Integrated Comprehensive Monitoring Program (ICMP) and the Navy's Strategic Planning Process for Marine Species Monitoring. A summary of the Navy's potential HSTT projects in 2014 is included in Response 2 of the Comments and Responses section of this document and will be detailedthrough the Navy Marine Species Monitoring web portal (
http://www.navymarinespeciesmonitoring.us/
).
Integrated Comprehensive Monitoring Program (ICMP)
—The Navy's ICMP is intended to coordinate monitoring efforts across all regions and to allocate the most appropriate level and type of effort for each range complex based on a set of standardized objectives, and in acknowledgement of regional expertise and resource availability. The ICMP is designed to be flexible, scalable, and adaptable through the adaptive management and strategic planning processes to periodically assess progress and reevaluate objectives. Although the ICMP does not specify actual monitoring field work or projects, it does establish top-level goals that have been developed in coordination with NMFS. As the ICMP is implemented, detailed and specific studies will be developed which support the Navy's top-level monitoring goals. In essence, the ICMP directs that monitoring activities relating to the effects of Navy training and testing activities on marine species should be designed to accomplish one or more top-level goals. Monitoring will address the ICMP top-level goals through a collection of specific regional and ocean basin studies based on scientific objectives. Quantitative metrics of monitoring effort (e.g., 20 days of aerial surveys) will not be a specific requirement. The adaptive management process and reporting requirements will serve as the basis for evaluating performance and compliance, primarily considering the quality of the work and results produced, as well as peer review and publications, and public dissemination of information, reports and data. Details of the current ICMP are available online (
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
and at
http://www.navymarinespeciesmonitoring.us/
).
Strategic Planning Process for Marine Species Monitoring
—The Navy also developed the Strategic Planning Process for Marine Species Monitoring, which establishes the guidelines and processes necessary to develop, evaluate, and fund individual projects based on objective scientific study questions. The process uses an underlying framework designed around top-level goals, a conceptual framework incorporating a progression of knowledge, and in consultation with the Scientific Advisory Group and other regional experts. The Strategic Planning Process for Marine Species Monitoring
will be used to set intermediate scientific objectives, identify potential species of interest at a regional scale, and evaluate and select specific monitoring projects to fund or continue supporting for a given fiscal year. This process will also address relative investments to different range complexes based on goals across all range complexes, and monitoring would leverage multiple techniques for data acquisition and analysis whenever possible. The Strategic Planning Process for Marine Species Monitoring is also available on our Web site (
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
) and at
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
Past and Current Monitoring in the HSTT Study Area
NMFS has received multiple years' worth of annual exercise and monitoring reports addressing active sonar use and explosive detonations within the HRC, SOCAL Range Complex, and the SSTC. The data and information contained in these reports have been considered in developing mitigation and monitoring measures for the training and testing activities within the HSTT Study Area. The Navy's annual exercise and monitoring reports may be viewed at:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
and
http://www.navymarinespeciesmonitoring.us.
NMFS' summary of the Navy's monitoring reports was included in the proposed rule (78 FR 6978, January 31, 2013; pages 7018-7019).
Monitoring for the HSTT Study Area
2014 will be a transitional year for Navy monitoring so that ongoing data collection from the Navy's current HRC and SOCAL rulemakings can be completed. Therefore, monitoring in 2014 will be a combination of previously funded Fiscal Year 2013 (FY-13) “carry-over” projects and new FY-14 project starts. A more detailed description of the Navy's planned projects starting in 2014 (and some continuing from previous years) is available on NMFS Web site (
www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
). The Navy will update the status of its monitoring program and funded projects through their Navy Marine Species Monitoring web portal:
http://www.navymarinespeciesmonitoring.us/.
Potential HSTT projects for 2014 are summarized in Response 2 of the Comments and Responses section of this document. NMFS will provide one public comment period on the Navy's monitoring program during the 5-year regulations. At this time, the public will have an opportunity (likely in the second year) to comment specifically on the Navy's HSTT monitoring projects and data collection to date, as well as planned projects for the remainder of the regulations.
Through the adaptive management process (including annual meetings), the Navy will coordinate with NMFS and the Marine Mammal Commission (Commission) to review and provide input for projects that will meet the scientific objectives that are used to guide development of individual monitoring projects. The adaptive management process will continue to serve as the primary venue for both NMFS and the Commission to provide input on the Navy's monitoring program, including ongoing work, future priorities, and potential new projects. The Navy will continue to submit annual monitoring reports to NMFS as part of the HSTT rulemaking and LOA requirements. Each annual report will contain a section describing the adaptive management process and summarize the Navy's anticipated monitoring projects for the next reporting year. Following annual report submission to NMFS, the final rule language mandates a 3-month NMFS review prior to each report being finalized. This will provide ample time for NMFS and the Commission to comment on the next year's planned projects as well as ongoing regional projects or proposed new starts. Comments will be received by the Navy prior to the annual adaptive management meeting to facilitate a meaningful and productive discussion. NMFS and the Commission will also have the opportunity for involvement at the annual monitoring program science review meetings and/or regional Scientific Advisory Group meetings. This will help NMFS and the Commission stay informed and understand the scientific considerations and limitations involved with planning and executing various monitoring projects.
Adaptive Management
Although substantial improvements have been made in our understanding of the effects of Navy training and testing activities (e.g., sonar, underwater detonations) on marine mammals, the science in this field is evolving fairly quickly. These circumstances make the inclusion of an adaptive management component both valuable and necessary within the context of 5-year regulations.
The reporting requirements associated with this rule are designed to provide NMFS with monitoring data from the previous year to allow us to consider whether any changes are appropriate. NMFS, the Navy, and the Commission will meet to discuss the monitoring reports, Navy R&D developments, current science, and whether mitigation or monitoring modifications are appropriate. The use of adaptive management allows NMFS to consider new information from different sources to determine (with input from the Navy regarding practicability) on an annual or biennial basis if mitigation or monitoring measures should be modified (including additions or deletions). Mitigation measures could be modified if new data suggests that such modifications would have a reasonable likelihood of reducing adverse effects to marine mammals species or stocks and their habitat and if the measures are practicable.
The following are some of the possible sources of applicable data to be considered through the adaptive management process: (1) Results from monitoring and exercise and testing reports, as required by MMPA authorizations; (2) compiled results of Navy funded R&D studies; (3) results from specific stranding investigations; (4) results from general marine mammal and sound research; and (5) any information which reveals that marine mammals may have been taken in a manner, extent, or number not authorized by these regulations or subsequent LOAs.
Reporting
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.” Effective reporting is critical both to compliance as well as ensuring that the most value is obtained from the required monitoring. NMFS described the proposed Navy reporting requirements in the proposed rule (78 FR 6978, January 31, 2013; page 7021). Since then, the Navy has expanded on those reports to include specific language for testing activities, which is detailed in the regulatory text at the end of this document. Reports from individual monitoring events, results of analyses, publications, and periodic progress reports for specific monitoring projects will be posted to the Navy's Marine Species Monitoring web portal:
http://www.navymarinespeciesmonitoring.us
and NMFS' Web site:
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
There are several different reporting requirements
that are further detailed in the regulatory text at the end of this document and summarized below.
General Notification of Injured or Dead Marine Mammals
Navy personnel will ensure that NMFS (the appropriate Regional Stranding Coordinator) is notified immediately (or as soon as clearance procedures allow) if an injured or dead marine mammal is found during or shortly after, and in the vicinity of, any Navy training or testing activities utilizing active sonar or underwater explosive detonations. The Navy will provide NMFS with species identification or a description of the animal(s), the condition of the animal(s) (including carcass condition if the animal is dead), location, time of first discovery, observed behaviors (if alive), and photographs or video (if available). The HSTT Stranding Response Plan contains further reporting requirements for specific circumstances (
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
).
Vessel Strike
Since the proposed rule, NMFS has added the following language to address monitoring and reporting measures specific to vessel strike. Most of this language comes directly from the Stranding Response Plan. This section has also been included in the regulatory text at the end of this document. In the event that a Navy vessel strikes a whale, the Navy shall do the following:
Immediately report to NMFS (pursuant to the established Communication Protocol) the:
• Species identification (if known);
• Location (latitude/longitude) of the animal (or location of the strike if the animal has disappeared);
• Whether the animal is alive or dead (or unknown); and
• The time of the strike.
As soon as feasible, the Navy shall report to or provide to NMFS, the:
• Size, length, and description (critical if species is not known) of animal;
• An estimate of the injury status (e.g., dead, injured but alive, injured and moving, blood or tissue observed in the water, status unknown, disappeared, etc.);
• Description of the behavior of the whale during event, immediately after the strike, and following the strike (until the report is made or the animal is no longer sighted);
• Vessel class/type and operational status;
• Vessel length;
• Vessel speed and heading; and
• To the best extent possible, obtain a photo or video of the struck animal, if the animal is still in view.
Within 2 weeks of the strike, provide NMFS:
• A detailed description of the specific actions of the vessel in the 30-minute timeframe immediately preceding the strike, during the event, and immediately after the strike (e.g., the speed and changes in speed, the direction and changes in direction, other maneuvers, sonar use, etc., if not classified);
• A narrative description of marine mammal sightings during the event and immediately after, and any information as to sightings prior to the strike, if available; and use established Navy shipboard procedures to make a camera available to attempt to capture photographs following a ship strike.
NMFS and the Navy will coordinate to determine the services the Navy may provide to assist NMFS with the investigation of the strike. The response and support activities to be provided by the Navy are dependent on resource availability, must be consistent with military security, and must be logistically feasible without compromising Navy personnel safety. Assistance requested and provided may vary based on distance of strike from shore, the nature of the vessel that hit the whale, available nearby Navy resources, operational and installation commitments, or other factors.
Annual Monitoring and Exercise and Testing Reports
As noted above, reports from individual monitoring events, results of analyses, publications, and periodic progress reports for specific monitoring projects will be posted to the
Navy's Marine Species Monitoring web portal
and NMFS' Web site as they become available. Progress and results from all monitoring activity conducted within the HSTT Study Area, as well as required Major Training Event exercise and testing activity, will be summarized in an annual report.
In the past, each annual report has summarized data for a single year. At the Navy's suggestion, the annual reports under this final rule will take a cumulative approach in that each report will compare data from that year to all previous years. For example, the third annual report will include data from the third year and compare it to data from the first and second years. This will provide an ongoing cumulative look at the Navy's annual monitoring and exercise and testing reports and eliminate the need for a separate comprehensive monitoring and exercise summary report (as included in the proposed rule) at the end of the 5-year period. A draft of the annual reports will be submitted to NMFS for review in April of each year in order to cover the entire reporting period for the authorization. NMFS will review the reports and provide comments for incorporation within 3 months.
Comments and Responses
On January 13, 2013 (78 FR 6978), NMFS published a proposed rule in response to the Navy's request to take marine mammals incidental to training and testing activities in the HSTT Study Area and requested comments, information, and suggestions concerning the request. During the 30-day public comment period, NMFS received over 200 comments from private citizens, the Marine Mammal Commission (Commission), and several non-governmental organizations, including the Natural Resources Defense Council (NRDC), the Cascadia Research Collective (CRC), and Earthjustice (on behalf of the Center for Biological Diversity and Ocean Mammal Institute). Comments specific to section 101(a)(5)(A) of the MMPA and NMFS' analysis of impacts to marine mammals are summarized, sorted into general topic areas, and addressed below and/or throughout the final rule. Comments specific to the FEIS/OEIS, which NMFS participated in developing as a cooperating agency and adopted, or that were also submitted to the Navy during the DEIS/OEIS public comment period are addressed in Appendix E (Public Participation) of the FEIS/OEIS. Last, some commenters presented technical comments on the general behavioral risk function that are largely identical to those posed during the comment period for the HRC proposed rule, one of the predecessors to the HSTT rule. The behavioral risk function remains unchanged since then, and here we incorporate our responses to those initial technical comments (74 FR 1455, Acoustic Threshold for Behavioral Harassment section, page 1473). Full copies of the comment letters may be accessed at
http://www.regulations.gov.
Monitoring and Reporting
Comment 1:
The Commission recommended that we require the Navy to use passive and active acoustics to supplement visual monitoring during implementation of mitigation measures for all activities that could cause Level A harassment or mortality. Specifically, the Commission questioned why passive and active acoustic monitoring used during the Navy's Surveillance Towed Array Sensory System Low
Frequency Active (SURTASS LFA) activities is not applied here.
Response 1:
The Navy requested Level A take of marine mammals for impulse and non-impulse sources during training and testing based on its acoustic analysis. The Navy also requested take of marine mammals by mortality for impulse sources, unspecified sources (impulse or non-impulse), and vessel strike. While it is impractical for the Navy to conduct passive acoustic monitoring during all training and testing activities, the Navy has engineered the use of passive acoustic detection for monitoring purposes, taking into consideration where the largest impacts could potentially occur, and the effectiveness and practicality of installing or using these devices. The Navy will use passive acoustic monitoring to supplement visual observations during Improved Extended Echo Ranging (IEER) sonobuoy activities, explosive sonobuoys using 0.6-2.5 pound (lb) net explosive weight, torpedo (explosive) testing, and sinking exercises, to detect marine mammal vocalizations. However, it is important to note that passive acoustic detections do not provide range or bearing to detected animals, and therefore cannot provide locations of these animals. Passive acoustic detections will be reported to Lookouts to increase vigilance of the visual surveillance.
The active sonar system used by SURTASS LFA is unique to the platforms that use SURTASS LFA. Moreover, this system requires the platforms that carry SURTASS LFA to travel at very slow speeds for the system to be effective. For both of these reasons it is not possible for the Navy to use this system for the platforms analyzed in the HSTT EIS/OEIS.
NMFS believes that the Navy's suite of mitigation measures (which include mitigation zones that exceed or meet the predicted maximum distance to PTS) will typically ensure that animals will not be exposed to injurious levels of sound. To date, the Navy has conducted and submitted 22 post-explosive monitoring reports for the HRC between 2009 and 2012, none of which show any evidence of injured marine mammals. In addition, within the SSTC portion of the HSTT Study Area, the Navy has conducted eight post-explosive monitoring events between 2012 and 2013, none of which show any evidence of injured marine mammals.
Comment 2:
The Commission recommended that NMFS require the Navy to submit a proposed monitoring plan for public review and comment prior to issuance of final regulations.
Response 2:
NMFS provided an overview of the Navy's Integrated Comprehensive Monitoring Program (ICMP) in the proposed rule (78 FR 6978, January 31, 2013). While the ICMP does not specify actual monitoring field work or projects, it does establish top-level goals that have been developed by the Navy and NMFS. As explained in the proposed rule, detailed and specific studies will be developed as the ICMP is implemented and funding is allocated.
Since the proposed rule was published, the Navy has provided a more detailed short-term plan for the first year of the rule. 2014 will be a transitional year with ongoing data collection straddling the shift from Phase I (metric-based) to Phase II Compliance Monitoring. Therefore, monitoring in 2014 will be a combination of previously funded FY-13 “carry-over” projects from Phase I and new FY-14 project starts under the vision for Phase II monitoring. A more detailed description of the Navy's planned projects starting in 2014 (and some continuing from previous years) is available on NMFS Web site (
www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
).
Additionally, NMFS will provide one public comment period on the Navy's monitoring program during the 5-year regulations. At this time, the public will have an opportunity (likely in the second year) to comment specifically on the Navy's HSTT monitoring projects and data collection to date, as well as planned projects for the remainder of the regulations.
In summary, HSTT projects in 2014 may include analysis of passive acoustic data from Ecological Acoustic Recorders (EARs) around Niihau and Kaula Island; an exposure and response study of species exposed to mid-frequency active sonar during Naval training events around Kauai; post-training event aerial shoreline surveys for stranded marine mammals around Niihau and Kauai; post-training event ground-based shoreline surveys for stranded marine mammals following a Navy training event around Niihau; a pre-training event visual survey, cetacean tagging, and passive acoustic monitoring around Kauai and Kaula Island; a glider survey of the HRC; the use of marine mammal observers on guided missile destroyers and at Puuloa during underwater detonations. In addition, two SOCAL projects were already funded in FY-13 and field work will continue through 2014. Details of already funded projects are available through the Navy Marine Species Monitoring web portal (
http://www.navymarinespeciesmonitoring.us
/). The Navy will update the status of their monitoring projects through this site, which serves as a public portal for information regarding all aspects of the Navy's monitoring program, including background and guidance documents, access to reports and data, and specific information on current monitoring projects. The public will also have the opportunity to review the Navy's monitoring reports, which will be posted and available for download every year form the Navy's Marine Species Monitoring web portal (
http://www.navymarinespeciesmonitoring.us/
).
Through the adaptive management process (including annual meetings), the Navy will coordinate with NMFS and the Commission to review and revise, if required, the list of intermediate scientific objectives that are used to guide development of individual monitoring projects. As described previously in the Monitoring section of this document, NMFS and the Commission will also have the opportunity to attend monitoring program science review meetings and/or regional Scientific Advisory Group meetings.
The Navy will continue to submit annual monitoring reports to NMFS, which will describe the results of the adaptive management process and summarize the Navy's anticipated monitoring projects for the next reporting year. NMFS will have a 3-month review period to comment on the next year's planned projects, ongoing regional projects, and proposed new project starts. NMFS' comments will be submitted to the Navy prior to the annual adaptive management meeting to facilitate a meaningful and productive discussion between NMFS, the Navy, and the Commission.
Comment 3:
One commenter recommended the use of remote control underwater video cameras to help monitor for marine mammals.
Response 3:
The use of remote control underwater video cameras is not a practical means of monitoring during Navy training and testing activities due to the inability to observe a large enough range to protect marine mammals from acoustic or explosive effects; expansive monitoring areas; the lack of personnel and resources available; and safety and security concerns.
Comment 4:
One commenter asked about the qualifications, training, and time schedules of observers.
Response 4:
The Navy has Lookouts stationed onboard ships whose primary duty is to detect objects in the water, estimate the distance from the ship, and identify them as any number of
inanimate or animate objects that are significant to a Navy activity or as a marine mammal so that the mitigation measure can be implemented. Navy Lookouts undergo extensive training to learn these skills and the Navy's Marine Species Awareness Training is used to make them more aware of marine mammal species and behaviors. Detailed information on the Navy's Marine Species Awareness Training program, which speaks to qualifications and training, is also provided in Chapter 5 of the HSTT FEIS/OEIS. Lookouts are used continuously, throughout the duration of activities that involve the following: active sonar, Improved Extended Echo Ranging (IEER) sonobuoys, anti-swimmer grenades, positive control firing devices, time-delay firing devices, gunnery exercises (surface target), missile exercises (surface target), bombing exercises, torpedo (explosive) testing, sinking exercises, at-sea explosives testing, pile driving, vessels underway, towed in-water devices, and non-explosive practice munitions.
Comment 5:
Several commenters proposed the use of seabed listening stations, modification of sonobuoys for passive acoustic detection, or other Navy detection devices to enhance marine mammal monitoring.
Response 5:
While there are some established bottom-mounted hydrophone arrays in the Pacific Ocean, they cover a very small portion of the HSTT Study Area. The Navy has used passive acoustics in the past and continues to use arrays such as the Pacific Missile Range Facility in Hawaii and the Southern California Anti-Submarine Warfare Range in California to study animal movements and behavioral response to Navy training activities. Results from these studies are available in the Navy's annual monitoring reports through our Web site (
http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications
) or the Navy's (
http://www.navymarinespeciesmonitoring.us/
).
Passive acoustic monitoring will also be conducted with Navy assets, such as sonobuoys, already participating in an activity (e.g., sinking exercises, torpedo (explosive) testing, and improved extended echo ranging sonobuoys). These assets would only detect vocalizing marine mammals within the frequency bands monitored by Navy personnel. Passive acoustic detections would not provide range or bearing to detected animals, and therefore cannot provide locations of these animals. However, passive acoustic detections would be reported to Lookouts posted in aircraft to increase vigilance of their visual observation. Modifying sonobuoys to increase the bandwidth is considered impractical for the Navy because it would require significant modification to the sonobuoy receiving equipment at a substantial cost and reduce the effectiveness of the sonobuoy system's primary purpose—to detect submarines. It is impractical for the Navy to construct and maintain additional passive acoustic monitoring systems for each training and testing activity.
Comment 6:
One commenter shared concerns about how sequestration will affect the Navy's marine mammal monitoring program and research efforts.
Response 6:
The Navy is required to comply with the terms of the regulations and LOAs regardless of sequestration.
Comment 7:
One commenter suggested that Navy Lookouts should be dedicated solely to the observation of marine mammals and turtles.
Response 7:
The Navy has Lookouts stationed onboard ships whose primary duty is to detect objects in the water, estimate the distance from the ship, and identify them as any number of inanimate or animate objects that are significant to a Navy activity or as a marine mammal so that the mitigation measure can be implemented. Navy Lookouts undergo extensive training to learn these skills and the Navy's Marine Species Awareness Training is used to make them more aware of marine mammal species and behaviors. However, because Lookouts must be able to detect and identify multiple objects in the water to ensure the safety of the ship, they are not expected to solely observe for marine mammals and sea turtles.
Comment 8:
One commenter suggested that small Rigid Hull Inflatable Boats (RHIBs) are not adequate for monitoring 900 or 1,200-meter mitigation zones.
Response 8:
The only activity with a mitigation zone of larger than 900 yd where RHIBs are the primary means of monitoring the mitigation zone is for time-delay firing devices (TDFDs), which have a mitigation zone of 1,000 yd. All other diver-placed charges, which are the vast majority of underwater detonations, have smaller mitigation zones. All other activities with mitigation zones larger than 900 yd (i.e., missile exercises, bombing exercises, torpedo testing, etc.) use aircraft, larger surface craft, or a combination of assets (not just RHIBs) for monitoring.
For the TDFD mitigation zone, the Navy considered 1,000 yd (914 m) to be the maximum distance that Lookouts in two small boats can effectively and realistically monitor. The Navy considered this limitation when proposing mitigation zones and available assets for each of their activities. Navy Lookouts are trained to detect objects in the water and it is in the Navy's best interest (for safety, security, and compliance with the MMPA) to ensure that mitigation zones can be properly monitored from each available vessel or boat. RHIBs are used during particular nearshore underwater detonation training activities. The Navy's RHIBs are agile enough and the boat drivers are experienced enough to conduct frequent circular sweeps around a given mitigation zone looking for marine mammals. Also, these kinds of training activities are not typically conducted if sea state is above a level 3.
Comment 9:
NRDC recommended that the Navy use all available range assets for marine mammal monitoring.
Response 9:
NMFS has worked with the Navy over the years to help develop the most effective mitigation protocols using the platforms and assets that are available for monitoring. The required mitigation measures in this document represent the maximum level of effort (e.g., numbers of Lookouts and passive sonobuoys) that the Navy can commit to observing mitigation zones given the number of personnel that will be involved and the number and type of assets and resources available. The Navy has determined that it is impractical to increase visual and passive acoustic observations for the purpose of mitigation.
The National Defense Authorization Act of 2004 amended the MMPA as it relates to military readiness activities (which these Navy activities are) and the incidental take authorization 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.” As explained in Chapter 5 of the HSTT FEIS/OEIS, it is impractical for the Navy to increase the level of marine mammal monitoring. The Navy has a limited number of resources (e.g., personnel and other assets) and the monitoring requirements in this rulemaking represent the maximum level of effort that the Navy can commit to marine mammal monitoring.
Mitigation
Comment 10:
The Commission requested that NMFS require the Navy to cease use of sound sources and not reinitiate them for (1) at least 15
minutes if small odontocetes or pinnipeds enter the mitigation zone and are not observed to leave; and (2) relevant time periods based on the maximum dive times of mysticetes or large- or medium-sized odontocetes if they enter the mitigation zone and are not observed to leave. Other commenters also suggested that activities should not resume until the animal is observed to exit the mitigation zone or the target has been repositioned more than 400 yd (366 m) away from the last marine mammal sighting; and that monitoring the mitigation zone for 30 minutes, before, during, and after the activity is insufficient for deep-diving species.
Response 10:
Section 5.3.2 of the HSTT FEIS/OEIS details the mitigation measures in place for each type of activity. These mitigation measures are also provided in the regulatory text at the end of this document. In summary, depending on the specific activity type and following the shutdown or delay of acoustic activities, the Navy may resume activities if any one of the following conditions are met: (1) The animal is observed exiting the mitigation zone; (2) the animal is thought to have exited the mitigation zone based on a determination of its course and speed and the relative motion between the animal and the source; (3) the mitigation zone has been clear from any additional sightings for a period of 10 or 30 minutes (depending on whether aircraft is involved and specific fuel restrictions); (4) the intended target location has been repositioned more than 400 yd (366 m) away from the location of the last sighting; (5) the ship has transited more than 140 yd (128 m) (large-caliber gunnery exercises) or 2,000 yd (1.8 km) (active sonar) beyond the location of the last sighting; or (6) dolphins are bow riding and there are no other marine mammal sightings within the mitigation zone.
The Commission expressed concern regarding the Navy's ability to determine the relative position of an animal. Understanding relative motion is a critical skill for Navy personnel, who receive training in target and contact tracking, target and contact interception, multi-ship maneuvering drills, etc. While an animal may occasionally act unpredictably, it is more likely that the animal will be seen leaving the mitigation zone or Navy personnel will be able to track the animal's location.
With regard to maximum dive times, NMFS disagrees that the clearance time should be lengthened for deep-diving species for the following reasons: (1) Just because an animal can dive for longer than 30 minutes does not mean that they always do, so a longer delay would only potentially add value in instances when animals had remained underwater for more than 30 minutes; and (2) The animal would need to have stayed in the immediate vicinity of the sound source for more than 30 minutes. Considering the maximum area that both the vessel and the animal could cover in that amount of time, it is improbable that this would randomly occur. For example, during a 1-hour dive by a beaked whale or sperm whale, a mid-frequency active sonar ship moving at a nominal speed of 10 knots could transit up to 10 nautical miles from its original location. Additionally, the times when marine mammals are diving deep (i.e., the times when they are under the water for longer periods of time) are the same times that a large portion of their motion is in the vertical direction, which means that they are far less likely to keep pace with a horizontally moving vessel. Moreover, considering that many animals have been shown to avoid both acoustic sources and ships without acoustic sources, it is improbable that a deep-diving cetacean (as opposed to a dolphin that might bow ride) would choose to remain in the immediate vicinity of the acoustic source; (3) Visual observers are not always able to differentiate species to the degree that would be necessary to implement this measure; and (4) Increasing clearance time is not operationally feasible for Navy activities that require aircraft surveillance because of fuel limitations. NMFS does not believe that increasing the clearance time based on maximum dive times will add to the protection of marine mammals in the vast majority of cases, and therefore, we have not required it.
Comment 11:
The Commission recommended that NMFS require the Navy to either (1) adjust the size of the mitigation zone for mine neutralization activities using the average swim speed of the fastest swimming marine mammal occurring in the area where time-delay firing devices will be used and ensure that the zone is adequately monitored; or (2) authorize all model-estimated takes for Level A harassment and mortality for mine neutralization activities in which divers use time-delay firing devices.
Response 11:
The Navy proposed a mitigation zone of 1,000 yards for all charge sizes (5, 10, and 29 lb) and for a maximum time-delay of 10 minutes. This is the maximum distance that Lookouts in two small boats can realistically monitor. The use of more than two boats for monitoring during time-delay firing device events is impractical due to the Navy's limited personnel resources. The Navy's proposed mitigation zone covers the potential for mortality up to a 9-minute time delay (but not 10-minute). The proposed mitigation zone also covers the potential for injury up to a 5-minute time-delay for 10 and 29 lb charges, and a 6-minute time-delay for 5 lb charges, but not for time delays greater than 6 minutes for any charge size. As a result of the mitigation zone restriction and the Commission's recommendation, and based on the Navy's modeling results and mitigation effectiveness, the Navy has requested seven mortalities and 56 Level A injuries for any training or testing event (not just underwater detonations), in case of an unavoidable incident.
Comment 12:
A few commenters recommended that the leeward side of the island of Hawaii out to a depth of 3,281 yd (3,000 m) should be off limits to Navy training and testing activities.
Response 12:
As described in the proposed rule, there is evidence suggesting that several resident populations of marine mammals may be present off the leeward side of Hawaii. NMFS considers the nature, level, and spatial extent of activities expected to co-occur with resident populations in both the analysis and in the development of mitigation measures. Time-area restrictions may be considered in order to help ensure that these small populations, limited to a small area of preferred habitat, are not exposed to concentrations of activities within their ranges that have the potential to impact a large portion of the stock/species over longer amounts of time that could have detrimental consequences to the stock/species. Here, NMFS has reviewed the Navy's exercise reports and considered/discussed their historical level of activity in the area where resident populations of marine mammals are concentrated, found that it is very low, and concluded that time/area restrictions in this area would not further reduce the likelihood or magnitude of adverse impacts on marine mammal species or stocks in this location and are not necessary at this point. However, if future monitoring and exercise and testing reports suggest that increased operations overlap with these resident populations, NMFS will revisit the consideration of area limitations around these populations.
Comment 13:
One commenter suggested that an alternate industrial shipping route could be created to reduce the risk of vessel strike to blue whales if the Navy would allow
shipping lanes south of the northern Channel Islands.
Response 13:
The U.S. Coast Guard, rather than the Navy, designates commercial shipping lanes. The Channel Islands are north of the SOCAL Range Complex and are not part of the HSTT Study Area. Furthermore, there has not been a Navy ship strike to any marine mammal north of the SOCAL Range Complex over the last 10 years.
However, NOAA National Marine Sanctuaries recently worked with the U.S. Coast Guard to modify the International Maritime Organization's shipping lane approaches to the Los Angeles, Long Beach, and San Francisco Bay ports in order to reduce the co-occurrence of ships and whales in the Santa Barbara Channel and the San Francisco Bay area.
Comment 14:
Several commenters suggested that the proposed mitigation measures were inadequate because observers do not always detect marine mammals and cannot see as far as sound travels.
Response 14:
It is the duty of Navy Lookouts to detect marine mammals in the water and estimate the distance from the ship so that the mitigation measures (shutdown, powerdown, etc.) can be implemented. Navy Lookouts undergo extensive training to learn these skills and the Marine Species Awareness Training is used to augment this general training with information specific to marine mammals. However, the mitigation measures the Navy is implementing are designed primarily to avoid and minimize the likelihood of mortality and injury, which are associated with acoustic exposures above a certain level, and therefore it is not necessary to see as far as sound travels to successfully implement the mitigation measures.
Comment 15:
Earthjustice suggested that NMFS did not propose any additional mitigation measures beyond what the Navy included in their application.
Response 15:
NMFS worked closely with the Navy in the development of mitigation for training and testing both in the first 5-year rules and for this 2013 proposal. The measures that the Navy proposed reflect years of experience and consideration of extensive monitoring results. NMFS and the Navy considered a wide array of additional measures, both before and after the public comment period. A description of some of the additional measures that were considered, and how they were analyzed in the context of the “least practicable adverse impact on the species and/or stock” finding, is included in this document (see Comments and Responses and Mitigation sections) as well as the Navy's HSTT FEIS/OEIS. As described, NMFS has determined that the Navy's proposed mitigation measures (especially when the adaptive management component is taken into consideration (see previous Adaptive Management discussion)), along with the additions detailed in the Mitigation section, are adequate means of effecting the least practicable adverse impacts on marine mammal 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.
Comment 16:
Earthjustice suggested that Navy training and testing activities should be prohibited in the Hawaiian Islands Humpback National Marine Sanctuary during critical calving and mating months.
Response 16:
Scientific evidence shows that there are well-known areas of high density for humpback whales within the Hawaiian Islands Humpback National Marine Sanctuary and in nearshore areas of the Main Hawaiian Islands. In recognition of the significance of the Hawaiian Islands for humpback whales, the Navy will continue their designation of a humpback whale cautionary area in Hawaiian waters. As explained in the proposed rule, this area consists of a 5-kilometer (3.1-mile) buffer zone having one of the highest concentrations of humpback whales during winter months. The Navy has to receive a very high level of clearance if training or testing use of mid-frequency active sonar is necessary between December 15 and April 15. To date, the Navy has never requested approval to conduct training or testing use of mid-frequency active sonar in the area during this time period. Additionally, the fact that high concentrations of marine mammals make conducting training and testing activities difficult and unsafe reduces the likelihood that the Navy will conduct training or testing in the higher density areas (with the exception of the PMRF Range, an essential training and testing asset) unless absolutely necessary.
The Navy has been collecting hull-mounted mid-frequency active sonar usage data in many areas of high-density humpback whale concentrations since 2009 and reporting to NMFS since 2010. The Navy has verified that, with the exception of the Pacific Missile Range Facility, there is limited use of any hull-mounted sonar (from training and testing activities) overlapping with humpback whale high-density areas around the Main Hawaiian Islands.
Comment 17:
Several commenters recommended that the Navy use more than one Lookout during all training and testing activities.
Response 17:
The Navy will have more than one Lookout for several higher risk training and testing activities or where the ensonified area is larger, such as during mine countermeasure and neutralization activities involving time-delay firing devices; for some vessels using low-frequency active sonar or hull-mounted mid-frequency active sonar associated with ASW activities, depending on the size and status/location of the vessel; during mine neutralization activities involving diver placed charges of up to 100 lb (45 kg) net explosive weight; and during sinking exercises. Aircrew and divers may also be used as additional observers during mine countermeasure and neutralization activities. However, for the reasons stated below, the Navy cannot use more than one Lookout for all training and testing activities—however, a minimum of one Lookout would always be required.
The National Defense Authorization Act of 2004 amended the MMPA as it relates to military readiness activities (which these Navy activities are) and the incidental take authorization 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.” As explained in Chapter 5 of the HSTT FEIS/OEIS, it is impractical for the Navy to increase visual observations for the purpose of mitigation beyond the amounts that have already been worked out in coordination with NMFS here. The Navy has a limited number of resources (e.g., personnel and other assets) and the mitigation requirements in this rulemaking represent the maximum level of effort that the Navy can commit to observing mitigation zones. Also, the use of additional Lookouts in association with lower risk activities with smaller ensonified areas would not be expected to provide as much of an additional protective value as is provided for the activities mentioned above.
Comment 18:
Several commenters suggested that the Navy limit their activities to periods of good visibility. More specifically, NRDC suggested that all weapons firing in missile, bombing, and sinking exercises involving detonations exceeding 20 lb. net explosive weight take place during the
period 1 hour after sunrise to 30 minutes before sunset.
Response 18:
The Navy explained in Chapter 5 of the HSTT FEIS/OEIS that avoiding or reducing active sonar at night and during periods of low visibility for the purpose of mitigation would result in an unacceptable impact on readiness. In summary, the Navy must train and test in a variety of conditions (including at night and in low-visibility) to adequately train for military operations and test systems and equipment in all appropriate conditions and ensure that systems and equipment operate as intended. However, certain activities, such as those involving explosives greater than 20 lb net explosive weight, are currently conducted during daylight hours only. The Navy does not anticipate impacts to the training or testing programs, as long as training or testing requirements do not change; however, the Navy needs to retain the ability to conduct these activities at night if emergent requirements dictate the need for this capability.
The Navy will use passive acoustic monitoring to supplement visual observations during Improved Extended Echo Ranging (IEER) sonobuoy activities, explosive sonouboys using 0.6-2.5 lb net explosive weight, torpedo (explosive) testing, and sinking exercises, to detect marine mammal vocalizations. However, it is important to note that passive acoustic detections do not provide range or bearing to detected animals, and therefore cannot provide locations of these animals. Passive acoustic detections will be reported to Lookouts to increase vigilance of the visual surveillance.
Comment 19:
One commenter suggested that Navy training and testing activities could be significantly reduced while still maintaining military readiness.
Response 19:
The Navy has identified the level of training and testing requirements that are necessary to meet its legally mandated requirements. NMFS must decide whether to authorize the take of marine mammals incidental to an applicant's proposed action based on the factors contained in the MMPA; NMFS does not permit or authorize the underlying action itself. In this case, NMFS has determined that the Navy's training and testing activities will have a negligible impact on the affected species or stocks and has met all other statutory requirements, therefore, we plan to issue the requested MMPA authorization.
Comment 20:
NRDC and other commenters recommended an expansion of the Navy's mitigation zones during the use of mid-frequency active sonar to reflect international best practice (4 km) or the standard prescribed by the California Coastal Commission (2 km).
Response 20:
The Navy developed mitigation zones to avoid or reduce the potential for onset of the lowest level of injury, PTS, out to the predicted maximum range. For mid-frequency active sonar, the Navy will implement a 6 dB power down at 1,000 yd (914 m), an additional 4 dB (total 10 dB) power down at 500 yd (457 m), and shutdown at 200 yd (183 m). Both powerdown criteria exceed the predicted average and maximum ranges to PTS. NMFS believes that these mitigation zone distances will help avoid the potential for onset of PTS in marine mammals and reduce the potential for TTS. These shutdown zones, combined with other mitigation measures, are expected to effect the least practicable adverse impact on marine mammal species or stocks and their habitat.
Furthermore, the Navy's mitigation zones represent the maximum area the Navy can observe based on the platform of observation, number of personnel that will be involved, and the number and types of assets and resources available. Increasing the size of observed mitigation zones for the purposes of mitigation would be impractical with regard to implementation of military readiness activities and result in an unacceptable impact on readiness.
Comment 21:
NRDC recommended that the Navy use sonar and other active acoustic sources at the lowest practicable source level.
Response 21:
The Navy utilizes sonar and other active acoustic sources to support a variety of missions. Primary uses of sonar include detection of and defense against submarines (anti-submarine warfare) and mines (mine warfare); safe navigation and effective communications; and oceanographic surveys. The source levels must be adequate to perform these tasks, but mitigation measures (e.g., powerdown and shutdown) will be implemented if marine mammals are within or approaching established zones. The Navy will submit annual exercise and testing reports to NMFS that summarize major training exercises, sinking exercises, and sound sources used. These reports will be made available to the public via NMFS' Web site and the U.S. Navy Marine Species Monitoring web portal.
Comment 22:
NRDC suggested that the Navy delay or relocate activities when beaked whales are detected through passive acoustic monitoring, even if potentially occurring beyond the established mitigation zone.
Response 22:
This recommendation is impractical for the Navy because operators of passive acoustic systems may not be able to identify whether a vocalization is from a beaked whale. As stated previously, passive acoustic monitoring can neither provide range or bearing to detected animals, and therefore cannot provide locations of these animals. However, all passive acoustic detections will be reported to Lookouts to increase vigilance of the visual surveillance.
Comment 23:
NRDC suggested that the Navy use gliders or other platforms for pre-activity monitoring to avoid significant aggregations of marine mammals and delay or relocate activities when significant aggregations of marine mammals are detected within the vicinity of an exercise.
Response 23:
The development of passive acoustic detectors on gliders and other platforms is still in the research and development stages under funding from the Office of Naval Research and the Navy's new Living Marine Resources programs. While promising, many of the various technologies are still being tested and not ready for transition to compliance monitoring where a higher degree of performance is needed. Gliders, even if able to report in real-time, or even delayed near real-time, would only be able to document the presence of marine mammals, not the marine mammal distance from the glider or individual animal movement. In many places where Navy activity occurs, there are almost near constant small odontocete passive acoustic detections. Finally, gliders would only provide an indication that animals are in the area, but these same animals could easily move substantial distances over the course of just a few hours. In some cases, use of gliders in and around where Navy submarines also operate is an underwater safety hazard to the submarine and to the glider. Gliders and other passive acoustic platforms, therefore, are more appropriate for broad area searches within Navy ranges to document marine mammal seasonal occurrence, but are not practical as a mitigation tool.
The Navy will implement mitigation measures for all marine mammals regardless of species, if they approach or enter a mitigation zone, which were calculated to help avoid the potential for onset of PTS and reduce the potential for TTS.
Comment 24:
NRDC suggested that the Navy use simulated geography and planning of ship tracks to reduce or
eliminate chokepoint exercises in near-coastal environments, particularly within canyons and channels or other important habitat. Similarly, NRDC suggested the use of dedicated aerial monitors during chokepoint exercises, major exercises, and near-coastal exercises.
Response 24:
For decades, the Navy has been using simulated electronic depictions of land in some of its at-sea exercises. However, the types of exercises the commenter refers to are critical to realistic and effective training due to the unique sound propagation characteristics and they cannot be replicated by simulated geography. The Navy will implement mitigation for all training and testing activities to minimize any potential effects.
Specific aerial monitoring is not typically feasible given the limited duration of typical monitoring flights (less than 4 hours). In addition, there are significant flight safety considerations and airspace restrictions during major exercises when larger groups of military aircraft are present in high numbers at various altitudes.
It is important to note that the Navy does have a particular set of monitoring measures (intended to help reduce the chance of a stranding) that would be applied if circumstances are thought to make a stranding more likely (e.g., steep bathymetry, multiple vessels in a single area over an extended period of time, constricted channels or embayments). However, there are no areas with these features included in the HSTT Study Area.
Comment 25:
NRDC stated that the Navy did not account for reverberation in its modeling and also suggested the use of additional powerdowns when significant surface ducting conditions coincide with other conditions that elevate risk (such as during exercises involving the use of multiple systems or in beaked whale habitat).
Response 25:
The Navy's propagation model used for all non-impulsive modeling accommodates surface and bottom boundary interactions (including reverberation), but does not account for side reflections that would be a factor in a highly reverberant environment, such as a depression or canyon, or in a man-made structure, such as a dredged harbor. The details of the Navy's propagation models are provided in a supporting technical report for the HSTT EIS/OEIS (“The Determination of Acoustic Effects on Marine Mammals and Sea Turtles,”
hstteis.com
).
Based on the lessons learned from five beaked whale stranding events, all of which took place outside of the HSTT Study Area, and occurred over approximately a decade, exposure of beaked whales to mid-frequency active sonar in the presence of certain conditions (e.g., multiple units using tactical sonar, steep bathymetry, constricted channels, strong surface ducts, etc.) may result in strandings, potentially leading to mortality. Although these physical features are not present in the HSTT Study Area in aggregate, scientific uncertainty exists regarding what other factors, or combination of factors, may contribute to beaked whale strandings. To minimize risk to beaked whales, several conditions will be considered during exercise planning: (1) Areas of at least 1,000 m (1,094 yd) depth near a shoreline where there is rapid change in bathymetry on the order of 1,000-6,000 m (1,094-6,562 yd) occurring across a relatively short horizontal distance (e.g., 5 nm); (2) cases in which multiple ships or submarines (≥ 3) are operating active sonar in the same area over extended periods of time (≥ 6 hours) in close proximity (≤ 10 nm apart); (3) an area surrounded by land masses, separated by less than 35 nm and at least 10 nm in length, or an embayment, wherein operations involving multiple ships/submarines (≥ 3) employing active sonar near land may produce sound directed toward the channel or embayment that may cut off the lines of egress for marine mammals; and (4) though not as dominant a condition as bathymetric features, the historical presence of a strong surface duct (i.e., mixed layer of constant water temperature extending from the sea surface to 100 or more feet).
If a major exercise must occur in an area where the above conditions exist in the aggregate, these conditions must be fully analyzed in environmental planning documentation. The Navy will increase vigilance by undertaking the following additional protective measure: a dedicated aircraft (Navy asset or contracted aircraft) will undertake reconnaissance of the embayment or channel ahead of the exercise participants to detect marine mammals that may be in the area exposed to active sonar. Where practical, the advance survey should occur within about 2 hours prior to sonar use and periodic surveillance should continue for the duration of the exercise. Any unusual conditions (e.g., presence of marine mammals, groups of species milling out of habitat, and any stranded animals) shall be reported to the Officer in Tactical Command, who should give consideration to delaying, suspending, or altering the activity. All mitigation zone powerdown requirements described in the Mitigation section of this document will apply. Finally, the post-exercise report must include specific reference to any event conducted in areas where the above conditions exist, with exact location and time/duration of the event and noting results of surveys conducted.
Comment 26:
NRDC suggested the suspension or postponement of chokepoint exercises during surface ducting conditions and scheduling of such exercises during daylight hours.
Response 26:
See response to Comment 16, 18, 24, and 39.
Comment 27:
NRDC suggested the use of aerial surveys and ship-based surveys before, during, and after major exercises.
Response 27:
As proposed, and detailed in the HSTT FEIS/OEIS, the Navy will implement pre-exercise aerial or vessel-based observation as a mitigation measure for Improved Extended Echo Ranging (IEER) sonobuoys and explosive buoys using 0.6-2.5 lb net explosive weight, mine countermeasure and neutralization activities using positive control firing devices involving explosives in bin E11 (501-650 lb net explosive weight), sinking exercises, bombing exercises, gunnery exercises, and missile exercises. Monitoring will continue throughout the duration of these exercises. This amount of monitoring represents the maximum level of effort that the Navy can commit to observing mitigation zones given the number of personnel and assets available. Surveys before, during, and after major exercises would require an inordinate amount of resources that are not available and would have a significant impact on readiness.
In addition to the monitoring required to implement mitigation, the Navy is also committed to a robust marine mammal monitoring program designed to answer specific questions about the effects of the Navy's activities on marine mammals. The Navy uses visual surveys (by trained protected species observers; from aircraft and vessels), passive acoustic monitoring devices, and tagging as some of the methods to best detect and evaluate any effects. See the Navy's monitoring reports at
http://www.navymarinespeciesmonitoring.us/.
Comment 28:
NRDC suggested the use of NMFS-certified observers for marine mammal detection and several commenters requested further information on the Navy's Lookout effectiveness study. More specifically, NRDC suggested that the Navy complete a Lookout effectiveness study comparing the abilities of Navy vessel-based Lookouts and third-party protected species observers. If Navy Lookouts are significantly less likely to
detect marine mammals, NRDC recommends the use of NMFS-certified Lookouts or other monitoring enhancements.
Response 28:
The Navy has determined that the use of third-party observers (e.g., NMFS-certified protected species observers) in air or on surface platforms in lieu of or in addition to existing Navy Lookouts for the purposes of mitigation is impractical for the following reasons: the use of third-party observers would compromise security for some activities involving active sonar due to the requirement to provide advance notification of specific times and locations of Navy platforms; reliance on the availability of third-party personnel could impact training and testing flexibility; the presence of additional aircraft in the vicinity of naval activities would raise safety concerns; and there is limited space aboard Navy vessels. Furthermore, Navy personnel are extensively trained in spotting items on or near the water surface and receive more hours of training than many third-party personnel.
The Navy undertakes monitoring of marine mammals during training and testing activities and has mitigation procedures designed to minimize risk to these animals. One key component of this monitoring and mitigation is the shipboard Lookouts (also known as watchstanders), who are part of the standard operating procedure that ships use to detect objects (including marine mammals) within a specific area around the ship during events. The Lookouts are an element of the Navy's monitoring plan, as required by NMFS and specified in the LOAs. The goal is to detect marine mammals entering ranges of 200, 500, and 1,000 yd (183, 457, and 914 m) around the vessel, which correspond to distances at which various mitigation actions should be performed. In addition to the Lookouts, officers on the bridge search visually and sonar operators listen for marine mammal vocalizations. All of these observers together are referred to as the observation team.
In 2010, the Navy initiated a study designed to evaluate the effectiveness of the Navy Lookout team. The University of St. Andrews, Scotland, under contract to the Navy, developed an initial data collection protocol for use during the study. Between 2010 and 2012, trained Navy marine mammal observers collected data during nine field trials as part of a “proof of concept” phase. The goal of the proof of concept phase was to develop a statistically valid protocol for quantitatively analyzing the effectiveness of Lookouts during Navy training exercises. Field trials were conducted in the HRC, SOCAL Range Complex, and Jacksonville Range Complex onboard one frigate, one cruiser, and seven destroyers. Preliminary analysis of the proof of concept data is ongoing. The Navy is also working to finalize the data collection process for use during the next phase of the study. While data was collected as part of this proof of concept phase, those data are not fairly comparable because protocols were being changed and assessed, nor are those data statistically significant. Therefore, it is improper to use these data to draw any conclusions on the effectiveness of Navy Lookouts at this time.
In addition, given the distance from shore and especially the dynamic and moving nature of Major Training Events (MTEs) where sonar platforms can be widely dispersed and then move on to another area, aerial or ship-based civilian monitoring concurrent to MTEs would not be logistically practical or safe. Before and after surveys would only duplicate similar marine mammal sightings that have already been conducted under the previous HRC and SOCAL rulemakings. During the period from 2009 to 2012, the Navy has visually surveyed approximately 100,000 nm of ocean within HRC and SOCAL with marine mammal sightings described in annual monitoring reports as well as posted electronically on public online data portals. While contributing to the body of science on marine mammal occurrence, these broad area surveys are less informative for monitoring of Navy impacts to marine mammals. The Navy's revised HSTT monitoring plan consists of more focused objective-oriented studies to address both species-specific occurrence and determine impact or lack of impact from training and testing activities.
Comment 29:
NRDC recommended that the Navy comply with underwater detonation and gunnery exercise mitigation measures as set forth in NMFS' final rule for the SOCAL Range Complex.
Response 29:
The mitigation measures for underwater detonation and gunnery exercises in NMFS' final rule for the SOCAL Range Complex have been carried over to HSTT (i.e., buffer zones around the intended target, monitoring before and during the exercise, avoidance of sighted marine mammals). There have been some slight modifications to the TDFD mitigation to account for resource limitations in the number of available boats and Lookouts.
Comment 30:
NRDC recommended the use of dedicated aerial monitoring for all Navy explosive activities using time-delay firing devices and/or all activities involving explosives greater than 20 lb net explosive weight.
Response 30:
Time-delay firing device events can occur over several hours and the exact detonation time is dependent on multiple variables including, but not limited to, weather, background traffic, training requirements, delays for mitigation, etc., that make it impractical and unsafe to have aircraft surveys. Time-delay firing device events also typically occur near commercial and military airspace that would pose a serious risk to the survey and non-survey aircraft.
Mitigation during explosive events (greater than 20 lb net explosive weight) already includes the use of available aircraft for mitigation monitoring. However, these activities can occur offshore and over several hours duration, making a dedicated aerial survey platform unsafe and impractical. The Navy has mitigation zones in place designed to minimize potential effects from all explosive activities
Comment 31:
NRDC suggested avoidance and reduction in the use of time-delay firing devices in favor of explosives with positive controls.
Response 31:
The Navy has explained their use of time-delay firing devices in previous documents (LOA application for the Silver Strand Training Complex, LOA application for the Hawaii Range Complex, and the HSTT FEIS/OEIS). The Navy relies on both time-delay and positive control to initiate underwater detonations, depending on the training event and objectives. The Navy has cited time-delay firing devices as the simplest, safest, least expensive, most operationally acceptable method of initiating an underwater detonation. They are preferred due to their light weight, low magnetic signature, and reduced risk of accidental detonation from nearby radios or other electronics. Time-delay firing devices allow sufficient time for personnel to swim outside of the detonation plume radius and human safety buffer zone after the timer is set. The Navy considers it critical that personnel qualify annually with necessary time-delay certification, maintain proficiency, and train to face real-world scenarios that require the use of time-delay firing devices. However, the Navy does strive to use positive control detonation whenever feasible depending on the training need. Within the SSTC portion of HSTT for instance, during the last year of the 86 completed underwater detonations with charge weights between 10-20 lb net explosive
weight, only two TDFDs were used; the remaining 84 detonations used positive control.
Time-delay firing devices raised concern in 2011, when three or four long-beaked common dolphins were killed in an explosion during an underwater detonation training event. About 5 minutes remained on a time-delay fuse when a pod of long-beaked common dolphins was observed, but attempts to guide the dolphins away from the area were unsuccessful. Following the event, the Navy worked with NMFS to develop a more robust monitoring and mitigation plan to ensure that marine mammal mortality and injury would not occur during activities that involve time-delay firing devices. NMFS incorporated additional mitigation and monitoring measures into the appropriate authorizations. Those additions are being carried over to the HSTT rule, with some modifications to the mitigation zone and number of observers due to the impracticality of the initial changes. As detailed in the proposed rule, NMFS believes that the Navy's modifications will still reduce the potential for injury and mortality because (1) the mitigation zone exceeds the predicted ranges to TTS and PTS; (2) the number of Lookouts for a 1,000-yd (915-m) mitigation zone would not change; (3) the maximum net explosive weight would decrease; (4) monitoring 30 minutes before, during, and 30 minutes after the activity would still take place; and (5) time-delay firing device activities are only conducted during daylight hours.
Comment 32:
NRDC suggested that the Navy should evaluate before each major exercise whether reductions in sonar are possible, given the readiness status of the strike groups involved.
Response 32:
The Navy only uses active sonar for validated training requirements, so this type of pre-exercise evaluation is unnecessary.
Comment 33:
NRDC recommended that the Navy establish a plan and timetable for maximizing synthetic training in order to reduce the use of active sonar training.
Response 33:
As described in section 2.5.1.4 of the HSTT FEIS/OEIS, the Navy currently uses computer simulation for training and testing whenever possible. Computer simulation can provide familiarity and complement live training and testing; however, it cannot provide the fidelity and level of training necessary to prepare naval forces for deployment.
The Navy is required to provide a ready and capable force. In doing so, the Navy must operationally test major platforms, systems, and components of these platforms and systems in realistic combat conditions before full-scale production can occur. Substituting simulation for live training and testing fails to meet the Navy's statutory requirement to properly prepare forces for national defense.
Comment 34:
NRDC recommended that specific mitigation requirements be prescribed for individual classes (or sub-classes) of training and testing activities in order to maximize mitigation given varying sets of operational needs.
Response 34:
NMFS has already worked with the Navy to develop mitigation by activity type to reduce potential impacts on marine mammals. The regulatory text of this document details the different types of mitigation required for different activities.
Comment 35:
NRDC recommended that the Navy submit timely, regular reports to NMFS, state coastal management authorities, and the public to describe and verify use of mitigation measures during training and testing activities.
Response 35:
The Navy will be required to submit annual reports and the unclassified portions of these reports will be made available to the public through NMFS' Web site. The reports will include a description of the mitigation measures implemented during major training exercises and will also include an evaluation of the effectiveness of any mitigation measure implemented.
Comment 36:
One commenter suggested that there are sufficient resources to identify important areas off California for large whales and the potential impacts could be reduced if the Navy avoided using these areas.
Response 36:
As addressed in Response 12, while NMFS acknowledges that there are important areas for fin and blue whales that overlap with the SOCAL Range Complex, these areas are also adjacent to the Navy's only west coast underwater instrumented training range. This range has been in operation for decades and is considered mission-critical by the Navy for ASW training and testing. In addition, nearby infrastructure supports multiple warfare mission areas used concurrently with sonar and explosive use. The Navy has indicated that establishment of a time-area closure within this region is not practical. However, the Navy has also stated that given the closeness to shore, relatively shallow water, and lack of other nearby training infrastructure, Major Training Events (MTEs) are not typically planned in this vicinity. Additionally, the Navy has further strengthened mitigation measures intended to reduce the likelihood of a ship strike (adding at least a 500-yd (457-m) exclusion zone for whales during vessel movement), which are particularly important in areas where greater concentrations of marine mammals may be encountered.
NMFS has carefully evaluated the Navy's proposed suite of mitigation measures and considered a broad range of other measures (including those recommended during the public comment period) 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: the manner in which, and the degree to which, the successful implementation of the required mitigation measures is expected to reduce the likelihood and/or magnitude of adverse impacts to marine mammal species and stocks and their habitat; the proven or likely efficacy of the measures; and the practicability of the suite of measures for applicant implementation, including consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the military readiness activity.
The Navy's list of monitoring projects for the SOCAL Range Complex has been finalized and is available on the Navy's marine species monitoring Website (
http://www.navymarinespeciesmonitoring.us/
). This list of 2013-2014 projects includes studies of blue and fin whale vocalizations from numerous passive acoustic devices within the SOCAL Range Complex. In addition, long-term satellite tag tracking of fin and blue whales will enhance understanding of residence times within the SOCAL Range Complex as well as within other areas of their Pacific Ocean range. Through this data collection, review of other new science, and the Adaptive Management process, NMFS and the Navy will continue to regularly evaluate whether there are other appropriate practicable measures that could further reduce impacts to marine mammals in Southern California.
Comment 37:
Several commenters recommended additional mitigation, including exclusion zones and time-area closures, and suggested that NMFS did not provide any additional mitigation to the Navy's proposed measures in order to reduce impacts on marine mammals.
Response 37:
Exclusion zones (termed “mitigation zones” in the proposed rule and this document) are already in place for the Navy's training and testing activities. Training and testing activities require continuous access to large areas consisting potentially of thousands of square miles of ocean and air space to provide naval personnel the ability to train with and develop competence and confidence in their capabilities and their entire suite of weapons and sensors. Exercises may change mid-stream based on evaluators' assessment of performance and other conditions including weather or mechanical issues. This means that the designation of time-area closures is not practicable in some cases, and NMFS and the Navy evaluate mitigation of this nature on a case-by-case basis and within the context of the Navy's overall suite of mitigation.
NMFS has been heavily involved in developing the Navy's suite of mitigation measures since 2007. Many of the Navy's proposed mitigation measures were a result of NMFS' input over the past 5 years. It is also important to note that the NDAA of 2004 amended the MMPA to require the consideration of personnel safety, practicality of implementation, and impact on the effectiveness of the “military readiness activity” when determining the “least practicable adverse impact.” Mitigation measures that the Navy considered, but could not implement, are included in the FEIS/OEIS.
However, the Navy has designated a Humpback Whale Cautionary Area that is effective between December 15 and April 15, which essentially restricts certain Navy activities within a certain time and location. Conducting exercises with mid-frequency active sonar within the Humpback Whale Cautionary Area between December 15 and April 15 requires approval for the use of hull-mounted mid-frequency active sonar from a four-star Admiral, the highest ranking officer in the U.S. Pacific Fleet. Since 2009 (when the current rule for the HRC was issued), the Navy has never requested this approval.
The Navy addresses numerous other mitigation measures in section 5.3 of the HSTT FEIS/OEIS that were considered but eliminated for various reasons. We address other areas that were considered off Hawaii and Southern California in responses to Comments 12, 16, and 36 above.
Comment 38:
Several commenters suggested that the Navy's activities should be moved to pelagic sea depths, away from continental shelves and islands to reduce impacts on marine mammals.
Response 38:
As stated in section 5.3 of the HSTT FEIS/OEIS, the Navy has eliminated from consideration alternative training and testing locations because there are no other potential locations where land ranges, operating areas, undersea terrain and ranges, testing ranges, and military airspace combine to provide the venues necessary for the training and testing realism and effectiveness required to train and certify naval forces ready for combat operations. Training and testing in shallow water is an essential component to maintaining military readiness. Sound propagates differently in shallow water and operators must learn to train in this environment. Additionally, submarines have become quieter through the use of improved technology and have learned to hide in the higher ambient noise levels of shallow coastal waters. In real world events, it is likely that sailors would be working in, and therefore must train in, and use systems that have been tested in, these types of environments.
However, as described in Response 28 above, in order to reduce impacts to humpback whales in the Hawaiian Islands, the Navy has designated the Humpback Whale Cautionary area between December 15 and April 15, which includes shallow water environments. In addition, following the implementation of the rule and issuance of LOAs, the adaptive management process will also provide a mechanism for considering if modifications to mitigation measures are necessary in the future.
Comment 39:
NRDC recommended that the Navy avoid or reduce their activities during months with historically significant surface ducting conditions.
Response 39:
The Navy's activities must be conducted during all months and in a variety of conditions in order for the Navy to meet its mission. The Navy's training schedules are driven by deployment requirements, which are established by the Department of Defense and the President of the United States. These schedules are dynamic, based on real-world events, ship availability, and numerous others factors that prevent the Navy's activities from being able to limit at sea training to only certain months. Similarly, Navy testing schedules are driven by Fleet maintenance, repair, and modernization needs; and the delivery of Navy ships, aircraft, and systems to support these training and deployment requirement, and cannot be limited to certain months. Therefore, the Navy's MMPA authorization must support year-round training and testing.
Comment 40:
NRDC recommended that the Navy delay activities or implement powerdowns during significant surface ducting conditions.
Response 40:
Avoiding or reducing active sonar during strong surface ducts for the purpose of mitigation would increase safety risks to personnel, be impractical with regard to implementation of military readiness activities, and result in unacceptable impacts on readiness for the following reasons: The Navy must train in the same manner as it will fight. Anti-submarine warfare can require a significant amount of time to develop the “tactical picture,” or an understanding of the battle space (e.g., area searched or unsearched, identifying false contacts, and understanding the water conditions). Training in surface ducting conditions is a critical component to military readiness because sonar operators need to learn how sonar transmissions are altered due to surface ducting, how submarines may take advantage of them, and how to operate sonar effectively in this environment. Furthermore, avoiding surface ducting would be impractical to implement because ocean conditions contributing to surface ducting change frequently, and surface ducts can be of varying duration. Surface ducting can also lack uniformity and may or may not extend over a large geographic area, making it difficult to determine where to reduce power and for what periods.
Comment 41:
NRDC recommended that the Navy plan their ship tracks to avoid embayments and provide escape routes for marine mammals.
Response 41:
As noted in Response 15, the Navy has a particular set of monitoring measures (intended to help reduce the chance of a stranding) that would be applied if circumstances are thought to make a stranding more likely (e.g., steep bathymetry, multiple vessels in a single area over an extended period of time, constricted channels or embayments). However, there are no areas with these features in aggregate included in the HSTT Study Area.
Comment 42:
NRDC recommended that the Navy be required to implement mitigation prescribed by state regulators, by the courts, by other navies or research centers, or from past Navy actions.
Response 42:
NMFS and the Navy have worked together on developing a comprehensive suite of mitigation measures to reduce the impacts from Navy training and testing activities on marine mammal species or stocks and their habitat. During the process of developing mitigation measures, NMFS and the Navy considered all potentially
applicable mitigation measures. NMFS has determined that the Navy's proposed mitigation measures, along with the Planning Awareness Areas, Stranding Response Plan, and Adaptive Management are adequate means of effecting the least practicable adverse impacts on marine mammal 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 justification for this conclusion is discussed in the Mitigation Conclusions section of the proposed rule (78 FR 6978, January 31, 2013; page 7016).
Comment 43:
One commenter stated that there is no compelling case for why Navy activities need to occur in areas of high humpback whale concentrations around Hawaii.
Response 43:
Due to the combination of installed MIW targets, range instrumentation, and unique shallow water bathymetry, these areas represent an important training and testing capability within the HRC and must be available to support deploying forces year round. However, it is likely that the demonstrated low use of hull-mounted mid-frequency active sonar within these areas will continue in the foreseeable future. See Response 7 of this section.
Acoustic Thresholds
Comment 44:
The Commission recommended that NMFS require the Navy to adjust all acoustic and explosive thresholds for low-, mid-, and high-frequency cetaceans by the appropriate amplitude factor (e.g., 16.5 or 19.4 dB), if the Type II weighting functions from Figure 6 of Finneran and Jenkins (2012) are to be used.
Response 44:
The acoustic and explosive thresholds were adjusted based on weighting the exposures from the original research from which the thresholds were derived with the Type II weighing functions. The weighted threshold is not derived by a simple amplitude shift.
The high-frequency cetacean onset TTS threshold is based on the onset-TTS threshold derived from data in Lucke
et al.
(2009) for impulsive exposures. This threshold was subsequently adjusted in Finneran and Jenkins (2012) to reflect Type II high-frequency cetacean weighting. Therefore, a simple 19.4 dB adjustment to the thresholds presented in Southall
et al.
(2007) is not appropriate.
At the time the acoustic criteria and thresholds were developed, no direct measurements of TTS due to non-impulsive sound exposures were available for any high-frequency cetacean; therefore, the relationship between onset-TTS sound exposure level (SEL)-based thresholds (Type II weighted) for mid-frequency cetaceans exposed to impulsive and non-impulsive sounds (beluga data) was used to derive the onset-TTS threshold for high-frequency cetaceans exposed to non-impulsive sounds (6-dB difference). The derived high-frequency cetacean non-impulsive onset TTS threshold is consistent with data recently published by Kastelein,
et al.
(2012) on TTS measured after exposing a harbor porpoise to non-impulsive sounds.
Comment 45:
The Commission requested an explanation of why data from Kastak
et al.
(2005) was used as the basis for explosive thresholds in pinnipeds and for the extrapolation process and factors used as the basis for associated TTS thresholds.
Response 45:
The same offset between impulsive and non-impulsive TTS found for the only species where both types of sound were tested (beluga) was used to convert the Kastak
et al.
(2005) data (which used non-impulsive tones) to an impulsive threshold. This method is explained in Finneran and Jenkins (2012) and Southall
et al.
(2007).
Comment 46:
The Commission recommended that NMFS require the Navy to provide the predicted average and maximum ranges for all impact criteria (behavioral response, TTS, PTS, onset slight lung injury, onset slight gastrointestinal injury, and onset mortality), all activities, and all functional hearing groups.
Response 46:
The Navy discusses range to effects in sections 3.4.3.2.1.1 and 3.4.3.2.2.1 of the HSTT FEIS/OEIS. The active acoustic tables in section 3.4.3.2.1.1 illustrate the ranges to PTS, TTS, and behavioral response. The active acoustic tables for PTS and TTS show ranges for all functional hearing groups and the tables for behavioral response show ranges for low-, mid-, and high-frequency cetaceans. The active acoustic source class bins used to assess range to effects represent some of the most powerful sonar sources and are often the dominant source in an activity. The explosives table in section 3.4.3.2.2.2 illustrates the range to effects for onset mortality, onset slight lung injury, onset slight gastrointestinal tract injury, PTS, TTS, and behavioral response. The explosives table shows ranges for all functional hearing groups. The source class bins used for explosives range from the smallest to largest amount of net explosive weight. These ranges represent conservative estimates (i.e., longer ranges) based on assuming all impulses are 1-second in duration. In fact, most impulses are much shorter and contain less energy. Therefore, these ranges provide realistic maximum distances over which the specific effects would be possible.
NMFS believes that these representative sources provide adequate information to analyze potential effects on marine mammals. Because the Navy conducts training and testing in a variety of environments having variable acoustic propagation conditions, variations in acoustic propagation conditions are considered in the Navy's acoustic modeling and the quantitative analysis of acoustic impacts. Average ranges to effect are provided in the HSTT FEIS/OEIS to show the reader typical zones of impact around representative sources.
Comment 47:
One commenter suggested, based on Kastelein
et al.
(2012), that using sound exposure level (SEL) may sometimes underestimate the amount of TTS experienced by a marine mammal.
Response 47:
The basic assumption of using the SEL metric with TTS thresholds is that the equal energy hypothesis (EEH) holds true in all situations (i.e., if the SELs of two sources are similar, a sound from a lower level source with a longer exposure duration may have similar risks to a sound from a higher level source with a shorter exposure duration). It is known from marine mammal and terrestrial mammal data that this is not always the case, especially in situations of long exposure periods with lower sound pressure levels. However, the EEH also does not account for any possible recovery between intermittent exposures and that non-impulsive, intermittent sources typically require higher SELs to induce TTS compared to continuous exposures of the same duration (Mooney
et al.,
2009; Finneran
et al.,
2010). Additionally, Kastelein
et al.
(2012b) expose animals to continuous durations of 7.5 minutes and longer, which do not necessarily reflect exposure durations expected for the majority of Navy sources.
Comment 48:
One commenter claimed that a statement in the proposed rule suggested that NMFS believes that data from bottlenose dolphins and beluga whales represent the full diversity of mid-frequency cetaceans.
Response 48:
The commenter is referring to a paper by Finneran and Jenkins (2012) titled “Criteria and Thresholds for Navy Acoustic Effects Analysis.” The authors do not claim that bottlenose dolphins and belugas
encompass the full diversity of mid-frequency odontocetes. Rather, they state that these two species are diverse. Because both species showed similar TTS thresholds, and because TTS data has not been collected for other mid-frequency cetaceans, the TTS thresholds for bottlenose dolphins and belugas were applied to all mid-frequency cetaceans.
Comment 49:
One commenter suggested that low-frequency cetaceans should be split into two groups because the blue and fin whales (and possibly sei whales) are more low-frequency specialists than others.
Response 49:
NMFS does not plan on splitting low-frequency cetaceans into two groups. Although there is some variation among the 13 species of marine mammals identified in the proposed rule as “low-frequency” cetaceans, these species all fall within the “low-frequency” functional hearing group identified by Southall
et al.
(2007) where functional hearing is estimated to occur between approximately 7 Hz and 22 kHz.
Comment 50:
One commenter referred specifically to the criteria and thresholds used for TTS as described in a paper by Finneran and Jenkins (2012): “Criteria and Thresholds for Navy Acoustic Effects Analysis Technical Report.” The commenter believes that scientific literature is at odds with the conclusions made in the Navy document and referred to the following quote on page 18 of the technical report: “This means the (Type I) weighted exposure SEL for harbor seals under water is 183 dB re 1 μPa2•s.” However, Kastelein
et al.
(2012a) note for harbor seals that “[while] TTS onset (6 dB) is predicted to occur at 183 dB re 1 μPa2•s . . . [i]n the present study, statistically significant TTS, at ca. 2.5 dB, began to occur at SELs of ~170 [136 dB SPL, 60 min.] and 178 dB re 1 μPa2•s [148 dB SPL, 15 min.], but actual TTS onset is probably at lower SELs.” The Kastelein
et al.
(2012a) study used two young (4-5 year old) female harbor seals, whereas the 183 dB figure originates from a study (Kastak
et al.
2005) using one male that was 14 years old. Kastelein
et al.
(2012a) found that even for the same seal, “thresholds changed [hearing became slightly less sensitive (3 dB) for 4 kHz test signals and slightly more sensitive (2 dB) for 5.7 kHz test signals] over time in the control sessions.” The commenter claims the authors caution that “[m]odeling TTS from exposure SPLs and duration (as done by Finneran
et al.
2010) would require more data points, e.g., at lower and higher exposure SPLs, to find the SPL and duration thresholds at which TTS starts. It would be risky to fit a formula to the 14 SEL data points found in the present study because the TTS results of the two seals differ, and because this study shows that harbor seals' TTSs may reach asymptote after certain exposure durations.” The highest TTS in the Kastelein
et al.
(2012a) study was 10 dB produced by 148 dB re 1 μPa at 120 and 240 minute exposures. The authors also stressed that the TTS may have an ecological impact, “ . . . reduc[ing] the audibility of ecologically and socially important sounds for seals. For example, a TTS of 6 dB would halve the distance at which the seal suffering that TTS would be able to detect another seal, a vociferous fish, or a predator acoustically. . . ”
Response 50:
There are some distinct differences between the Kastelein
et al.
(2012a) study and the Kastak
et al.
(2005) study, from which the current pinniped TTS onset criterion was derived, including differences associated with the sex and age of individuals tested, different background noise levels, and differences in experimental procedure, as well as different center frequency of exposure stimuli. It should be noted that a threshold shift of 6 dB is considered the minimum threshold shift clearly larger than any day-to-day or session-to-session variation in a subject's normal hearing ability (Schlundt
et al.
2000; Finneran
et al.
2000; Finneran
et al.
2002). Southall
et al.
(2007) also defined TTS onset as a 6 dB shift in threshold. Similarly, for humans, the National Institute for Occupational Safety and Health (1998) regards the range of audiometric testing variability to be approximately 5 dB. Additionally, despite Kastelein
et al.
(2012a) indicating possible ecological impacts associated with TTS, they also say “Recovery from small TTSs (up to 10 dB), such as those caused by the sound exposures in the present study, is very fast (within_60 min). Reduced hearing for such a short period probably has little effect on the total foraging period of a seal, as long as TTS occurs infrequently.”
It should also be noted that the Navy's acoustic analysis indicated that predicted TTS in harbor seals was typically caused by higher sound pressure levels (greater than 160 dB re 1µPa) over much shorter total durations (on the order of a few
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