Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to U.S. Navy Pier Construction Activities at Naval Submarine Base New London, 36773-36791 [2018-15938]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 83, Number 147 (Tuesday, July 31, 2018)]
[Rules and Regulations]
[Pages 36773-36791]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-15938]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 170908887-8622-02]
RIN 0648-BH24


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to U.S. Navy Pier Construction Activities at Naval Submarine 
Base New London

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

ACTION: Final rule.

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SUMMARY: Upon application from the U.S. Navy (Navy), NMFS is issuing 
regulations under the Marine Mammal Protection Act for the taking of 
marine mammals incidental to the pier construction activities conducted 
at the Naval Submarine Base New London in Groton, Connecticut, over the 
course of five years (2020-2025). These regulations allow NMFS to issue 
a Letter of Authorization (LOA) for the incidental take of marine 
mammals during the specified construction activities carried out during 
the rule's period of effectiveness, 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 March 1, 2020 through February 28, 2025.

ADDRESSES: To obtain an electronic copy of the Navy's LOA application 
or other referenced documents, visit the internet at: 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of 
problems accessing these documents, please call the contact listed 
below (see FOR FURTHER INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected 
Resources, NMFS; phone: (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Purpose and Need for Regulatory Action

    This final rule establishes a framework under the authority of the 
MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of take of 
marine mammals incidental to the Navy's construction activities related 
to marine structure maintenance and pile replacement at a facility in 
Groton, Connecticut.
    We received an application from the Navy requesting five-year 
regulations and authorization to take multiple species of marine 
mammals. Take would occur by Level A and Level B harassment incidental 
to impact and vibratory pile driving. Please see ``Background'' below 
for definitions of harassment.

Legal Authority for the Proposed Action

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) 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 for up to five years 
if, after notice and public comment, the agency makes certain findings 
and issues regulations that set forth permissible methods of taking 
pursuant

[[Page 36774]]

to that activity and other means of effecting the ``least practicable 
adverse impact'' on the affected species or stocks and their habitat 
(see the discussion below in the ``Proposed Mitigation'' section), as 
well as monitoring and reporting requirements. Section 101(a)(5)(A) of 
the MMPA and the implementing regulations at 50 CFR part 216, subpart 
I, provide the legal basis for issuing this proposed rule containing 
five-year regulations, and for any subsequent letters of authorization 
(LOAs). As directed by this legal authority, this final rule contains 
mitigation, monitoring, and reporting requirements.

Summary of Major Provisions Within the Final Rule

    Following is a summary of the major provisions of this final rule 
regarding Navy construction activities. These measures include:
     Required monitoring of the construction areas to detect 
the presence of marine mammals before beginning construction 
activities.
     Shutdown of construction activities under certain 
circumstances to avoid injury of marine mammals.
     Soft start for impact pile driving to allow marine mammals 
the opportunity to leave the area prior to beginning impact pile 
driving at full power.

Background

    Sections 101(a)(5)(A) and (D) of the Marine Mammal Protection Act 
of 1972, as amended (MMPA; 16 U.S.C. 1361 et seq.) direct the Secretary 
of Commerce (Secretary) to allow, upon request, the incidental, but not 
intentional taking of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) if certain findings 
are made and regulations are issued or, if the taking is limited to 
harassment, notice of a proposed authorization is provided to the 
public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such taking 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal. Except with respect to certain activities not pertinent here, 
the MMPA defines ``harassment'' as any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

Summary of Request

    On March 22, 2017, NMFS received an application from the Navy 
requesting authorization to incidentally take harbor and gray seals, by 
Level A and Level B harassment, incidental to noise exposure resulting 
from conducting pier construction activities at the Navy Submarine Base 
New London in Groton, Connecticut, from October 2018 to March 2022. 
These regulations would be valid for a period of five years. On August 
31, 2017, NMFS deemed the application adequate and complete. On May 23, 
2018, the Navy requested that the rule be valid between March 1, 2020, 
and February 28, 2025, due to construction schedule changes.
    The use of sound sources such as those described in the application 
(e.g., piledriving) may result in the take of marine mammals through 
disruption of behavioral patterns or may cause auditory injury of 
marine mammals. Therefore, incidental take authorization under the MMPA 
is warranted.

Description of the Specified Activity

Overview

    The Navy is planning to demolish Pier 32 and Pier 10 and construct 
a new Pier 32 at Naval Submarine Base New London (SUBASE), Groton, 
Connecticut.
    Recent Global Shore Infrastructure Plans and Regional Shore 
Infrastructure Plans identified a requirement for 11 adequate submarine 
berths at SUBASE. There are currently six adequate berths available via 
Piers 6, 17, and 31, leaving a shortfall of five adequate berths. The 
remaining submarine berthing piers (8, 10, 12, 32, and 33) are 
classified as inadequate because of their narrow width and short length 
compared to current SSN (hull classification) berthing design standards 
(Unified Facilities Criteria 4-152-01, Design Standards for Piers and 
Wharves).
    The Proposed Action is to demolish Pier 32 and Pier 10, and replace 
them with a new Pier 32 that meets all current Navy SSN pier standards 
to accommodate Virginia Class submarines. The Proposed Action includes:
     Construction of a new, larger Pier 32 to be located 
approximately 150 feet (ft) north of the current location.
     Upgrade of the quaywall, north of Pier 32, may be required 
to accommodate a crane weight test area.
     Demolition of existing Pier 32 and Pier 10.
     Dredging of the sediment mounds beneath the existing Pier 
32 (approximately 9,400 cubic yards [cy]) and the existing Pier 10 
(approximately 10,000 cy) to a depth of 36 ft below mean lower low 
water (-36 ft MLLW) plus 2 ft of over dredge (additional dredge depth 
that allows for varying degrees of accuracy of different types of 
dredging equipment). Any remaining timber piles beneath the existing 
piers would be pulled with a strap.
     Dredging of the berthing areas alongside the proposed new 
Pier 32 (approximately 74,000 sq ft) to a depth of -38 feet MLLW plus 2 
feet of over dredge.
     Dredging of two additional areas (approximately 10,200 cy 
and 31,100 cy) in the Thames River navigation channel to a depth of -36 
ft MLLW plus 2 ft of over dredge.
    Two species of marine mammals are expected to potentially be 
present in the Thames River near SUBASE: Harbor seal (Phoca vitulina) 
and gray seal (Halichoeris grypus). Harbor seals and gray seals are 
more likely to occur at SUBASE from September to May.

Dates and Duration

    Pile installation for the new Pier 32 and pile removal associated 
with the demolition of the existing Piers 32 and 10 is expected to take 
a total of approximately 3.5 years. Construction and demolition 
activities are expected to begin no earlier than March 2020 and proceed 
to completion in February 2025.
    In-water activities expected to result in incidental takes of 
marine mammals would occur during approximately 35 non-consecutive 
months of the project beginning in March 2020. The estimated duration 
of pile installation and removal, including duration of the vibratory 
and impact hammer activities, is provided in Table 1 below for each 
year of construction and demolition. Also included in the Table are the 
durations for wood piles and steel fender piles to be pulled by a crane 
using a sling or strap attached to the pile. The durations of proposed 
pile driving/removal activities are primarily

[[Page 36775]]

derived from information provided by Naval Facilities Engineering 
Command (NAVFAC) Mid-Atlantic Public Works Department, Facilities 
Engineering and Acquisition Department (FEAD) Design Manager and the 
record of pile driving activities documented during the construction of 
SUBASE Pier 31 (American Bridge 2010-2011). The proposed new Pier 32 
would be comparable to Pier 31 in design and location and would have 
similar sub-surface geological conditions along this reach of the 
Thames River.

Specified Geographical Region

    SUBASE is located in the towns of Groton and Ledyard in New London 
County, Connecticut. SUBASE occupies approximately 687 acres along the 
east bank of the Thames River, 6 mi north of the river's mouth at Long 
Island Sound (Figure 1-1 in LOA application). The Thames River is the 
easternmost of Connecticut's three major rivers and is formed by the 
confluence of the Shetucket and Yantic rivers in Norwich, from which it 
flows south for 12 mi to New London Harbor. The Thames River discharges 
freshwater and sediment from the interior of eastern Connecticut into 
Long Island Sound. It is the main drainage of the Thames River Major 
Drainage Basin, which encompasses approximately 3,900 square mi of 
eastern Connecticut and central Massachusetts (USACE 2015). The lower 
Thames River and New London Harbor sustains a variety of military, 
commercial, and recreational vessel usage. New London Harbor provides 
protection to a number of these.

Detailed Description of Specified Activity

1. Construction of New Pier 32
    Pile driving would most likely be conducted using a barge and 
crane. However, the contractor may choose to use a temporary pile-
supported work trestle that would be constructed by driving 
approximately 60 steel 14-inch diameter H-piles.
    Structural support piles for Pier 32 would consist of approximately 
120 concrete-filled steel pipe piles measuring 36 inches in diameter. 
The piles would be driven between 40 ft below the mudline near the 
shore and 150 ft below the mudline at the end of the pier. Fender piles 
would also be installed and would consist of approximately 194 
fiberglass-reinforced plastic piles measuring 16 inches in diameter.
    Special construction features would include drilling rock sockets 
into bedrock in an estimated 60 places to hold the piles. A rotary 
drill using a rock core barrel and rock muck bucket would be used 
inside of the steel pipe piles to drill a minimum of 2 ft down into 
bedrock to create the rock socket that would be filled with concrete. 
Sediment would be lifted out and re-deposited within 10 ft of the pipe 
pile during rock socket drilling. Underwater noise from the rock drill 
as it is operated inside a steel pipe would be much less than that 
produced by vibratory and impact pile driving of the steel pipes 
(Martin et al. 2012).
    Impact and vibratory hammers would be used for installing piles 
where rock sockets are not required. Based on previous construction 
projects at SUBASE, it is estimated that an average of one 36-inch pile 
per week (with driving on multiple days) and two plastic piles per day 
would be installed. The per-pile drive time for each pile type and 
method will vary based on environmental conditions (including 
substrate) where each pile is driven. Impact or vibratory pile driving 
may result in harassment of marine mammals.
    Construction of Pier 32 may also require upgrade of the quaywall 
north of Pier 32 to provide the reinforcement needed to support a crane 
weight test area. Because there is potential that a work trestle would 
be used and the requirement for the upgrade will not be determined 
until final design, the pile driving is included in the analyzed 
activities. The quaywall upgrade would include up to approximately 
eighteen 30-inch diameter concrete-filled steel pipe piles that would 
be installed into rock sockets driven into bedrock adjacent and 
parallel to the existing steel sheet pile wall. Pile caps and a 
concrete deck would be installed above the piles. A fender system 
composed of approximately nine 16-inch diameter plastic piles would 
also be installed into rock sockets approximately 2 ft in front of the 
new deck.
2. Demolition and Removal of Pier 32 and Pier 10
    When the new Pier 32 is operational, the existing Pier 32 would be 
demolished using a floating crane and a series of barges. Pier 10 would 
be demolished after the demolition of existing Pier 32. The concrete 
decks of the piers would be cut into pieces and placed on the barges. 
Demolition debris would be sorted and removed by barge and recycled to 
the maximum extent practicable. Any residual waste would be disposed of 
offsite in accordance with applicable federal, state, and local 
regulations. Once the decks are removed, the steel H piles and pipe 
piles that support the existing pier would be pulled using a vibratory 
extraction method (hammer). The vibratory hammer would be attached to 
the pile head with a clamp. Once attached, vibration would be applied 
to the pile that would liquefy the adjacent sediment allowing the pile 
to be removed.
    Demolition of existing Pier 32 would include the removal by 
vibratory driver-extractor (hammer) of approximately 60 steel piles 
from the temporary work trestle, 120 concrete-encased steel H-piles, 
and 70 steel H-piles. Fifty-six wood piles would be pulled with a 
sling. Demolition of Pier 10 would include the removal by vibratory 
hammer of 24 concrete-encased, steel H-piles and 166 cast-in-place, 
reinforced concrete piles. Eighty-four steel fender piles and 41 wood 
piles would be pulled with a sling. A total of 440 piles would be 
removed by vibratory hammer for both piers and the work trestle.
3. Dredging of Pier Areas and Navigation Channel
    The Proposed Action would also include dredging of approximately 
60,000 cy of sediment in two areas of the Thames River navigation 
channel near Pier 32, the berthing areas alongside the new Pier 32, and 
underneath existing Pier 32 and Pier 10 after demolition. All dredging 
for the Proposed Action would support safe maneuvering for entry and 
departure of submarines at the proposed new Pier 32 and existing Piers 
8, 12, 17, and 31. The proposed design dredge depth in all areas to be 
dredged is -36 ft relative to MLLW plus 2 ft of over dredge.
    Dredging would be conducted in two phases. Dredging of the new Pier 
32 area and the northern portion of the channel dredge areas would be 
conducted in the first construction year. The footprints of the 
demolished Pier 32 and Pier 10 and the southern portions of the channel 
dredge areas would be dredged after demolition of the existing piers in 
the fourth year of construction. Dredging would occur only during the 
period between October 1 and January 31 to avoid potential impacts on 
shellfish and fisheries resources in the area. Each dredging and 
disposal phase would take approximately 2 weeks to complete.
    After the demolition of Pier 32, any remnant timber piles present 
underneath existing Pier 32 would be pulled with a strap. The sediment 
mound that has formed beneath the pier would be dredged (approximately 
9,400 cy) to the design depth. Dredging would also be required 
immediately west of Piers 31 and 32 (approximately 10,200 cy) and along 
the eastern edge

[[Page 36776]]

(approximately 31,100 cy) of the navigation channel to achieve the 
required minimum depths to maneuver the submarines. Once the existing 
Pier 10 and any remnant timber piles are removed, the sediment mound 
beneath the old pier would be dredged (approximately 10,000 cy).
    Since dredging and disposal activities would be slow moving and 
conspicuous to marine mammals, they pose negligible risks of physical 
injury. An environmental bucket would be used for dredging to minimize 
turbidity compared with the turbidity generated by hydraulic dredging. 
Noise emitted by dredging equipment is broadband, with most energy 
below 1 kilohertz (kHz), and would be similar to that generated by 
vessels and maritime industrial activities that regularly operate 
within the action area (Clarke et al. 2002; Todd et al. 2015). Due to 
the low noise output and slow and steady transiting nature of the 
dredging activity, NMFS does not consider it would result to the level 
of harassment under the MMPA. Therefore, dredging is not considered 
further in this document.

                                   Table 1--Summary of Construction Activities for the Navy Submarine Base New London
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                                                                                                   Total
            Activity               Pile No.       Pile type             Method        Piles/day   driving    Strike number (impact)        Duration
                                                                                                    days    or duration(s) per pile
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                                                                         Year 1
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Pier 32 construction............         60  14'' steel H-pile    Impact............          4         15  1,000 strikes..........  3 weeks.
                                              temp. work trestle.
                                         60  36'' x 100'          Vibratory hammer &        0.5        120  1,200 seconds..........  6 months.
                                              concrete-filled      rock socket
                                              steel pipe piles.    drilling.
                                         20  36'' x 180'          Vibratory hammer..        0.2        100  1,800 seconds..........  5 months.
                                              concrete-filled
                                              steel piles.
                                         20  36'' x 180'          Impact hammer to          2.5          8  1,000 strikes..........  2 weeks.
                                              concrete-filled      last 20-40 ft.
                                              steel piles.
Quaywall upgrade................         18  30'' x 100'          Rock socket               0.5         36  15,000 seconds.........  Concurrent with
                                              concrete-filled      drilling.                                                          Pier 32.
                                              steel pipe piles.
                                          9  16'' fiberglass      Rock socket               0.5         18  7,500 seconds..........
                                              reinforced plastic   drilling.
                                              piles.
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                                                                         Year 2
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Pier 32 construction............         40  36'' x 180'          Vibratory hammer..        0.2        200  1,800 seconds..........  10 months.
                                              concrete-filled
                                              steel piles.
                                         40  36'' x 180'          Impact hammer to          2.5         16  1,000 strikes..........  3.5 weeks.
                                              concrete-filled      drive last 20-40
                                              steel piles.         ft.
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                                                                         Year 3
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Pier 32 construction............        194  16'' fiberglass      Vibratory hammer..          2         97  1,200 seconds..........  5 months.
                                              reinforced plastic
                                              piles.
                                         64  16'' fiberglass      Impact hammer to          2.5         26  1,000 strikes..........  1.5 months.
                                              reinforced plastic   drive last 20-40
                                              piles.               ft.
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                                                                         Year 4
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Pier 32 demolition..............         60  14'' steel H-piles   Vibratory hammer            5         14  1,200 seconds..........  3 weeks.
                                              temp. work trestle.  (removal).
                                         24  33'' concrete-       Vibratory hammer            2         12  1,200 seconds..........  3.5 months.
                                              encased steel H      (removal).
                                              piles.
                                         96  24'' concrete-       Vibratory hammer            2         48  1,200 seconds..........
                                              encased steel H      (removal).
                                              piles.
                                         70  14'' steel H piles.  Vibratory hammer            5         14  1,200 seconds..........
                                                                   (removal).
Pier 10 demolition..............         24  24'' concrete-       Vibratory hammer          9.5        2.5  1,200 seconds..........  0.5 month.
                                              encased steel H      (removal).
                                              piles.
                                        166  24'' cast-in-place   Vibratory hammer          9.5       17.5  1,200 seconds..........  0.5 month.
                                              reinforced           (removal).
                                              concrete piles.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Prescribed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see ``Mitigation'' 
and ``Monitoring and Reporting'').

Comments and Responses

    NMFS published a proposed rule in the Federal Register on April 13, 
2018 (83 FR 16027). During the 30-day public comment period on the 
proposed rule, NMFS received comments from the Marine Mammal Commission 
(Commission). We did not receive other comments.
    Comment 1: The Commission recommends that NMFS require the Navy to 
conduct sound source verification (SSV) and the size of Level B 
harassment zone measurements for certain piles that data are lacking 
and where the zones are not based on modeling. These acoustic 
measurements include:
     Vibratory and impact installation of at least five 16-in 
fiberglass-reinforced plastic piles--measurements for source levels;
     Rock socket drilling of at least three 30-in and three 16-
in piles--measurements for source levels and the extent of the Level B 
harassment zones;
     Vibratory installation of at least three 36-in steel 
piles--measurements for the extent of the Level B harassment zone; and
     Vibratory removal of at least three 24-in concrete and 
three 33-in concrete piles--measurements for source levels and the 
extent of the Level B harassment zones.
    Response: NMFS discussed these recommendation with the Navy and the 
Navy agreed to conduct SSVs on the piles for which source level data 
are not already available. SSV measurements to be conducted are:
     Vibratory and impact installation of at least 5 16-in 
fiberglass reinforced plastic piles, and

[[Page 36777]]

     Rock socket drilling of at least 3 30-in and 3 16-in 
piles.
    However, the Navy did not agree to conduct acoustic measurements to 
the extent of the Level B harassment zones. The Navy indicated that 
conducting hydroacoustic monitoring to the extent of the Level B 
harassment zones is not a common requirement based on the five most 
recent active IHAs, including U.S. Army Corps of Engineers' (USACE) 
Tampa Harbor Big Bend Channel expansion project, the City of Astoria's 
waterfront bridge replacement project, the Navy's Bravo wharf 
recapitalization project, and U.S. Coast Guard's (USCG) Monterey 
waterfront repair project. Instead, the Navy offered to conduct 
hydroacoustic measurements at several points between 10 and 500 m from 
the source and extrapolate the distance of the Level B harassment zone.
    While being able to determine the extent of Level B harassment 
zones is critical to accurately assess the potential impacts to marine 
mammals, these zones can be determined by means other than direct 
measurements recommended by the Commission. Therefore, NMFS considers 
the Navy's proposal of extrapolating the Level B harassment zone using 
near- and far-field measurement data a valid approach.
    Therefore, in the final rule, NMFS requires the Navy to conduct 
SSVs on the piles listed above and to conduct measurements on several 
locations between 10 and 500 m from the source to determine the Level B 
harassment zones for those zones that were not based on modeling.
    These requirements are included in the final rule.
    Comment 2: The Commission recommends that NMFS require the Navy to 
include certain metrics in the hydroacoustic monitoring report for 
measurements being conducted. These metrics include:
     Root-mean-square sound pressure levels 
(SPLrms), 1-sec sound exposure levels (SELs), duration of 
recordings used to derive SELs, cumulative SEL (SELcum) 
based on the number of piles and driving duration for each scenario, 
and SEL source spectra for vibratory pile driving/removal source level 
measurements;
     Peak SPLs (SPLpeak), SPLrms, 
integration time/pulse duration for SPLrms, single-strike 
SPLs (SPLs-s), SELcum based on the number of 
piles and driving duration for each scenario, and SELs-s 
spectra for impact pile driving source level measurements;
     The measured (or extrapolated, if not reached) distances 
at which the SPLrms decays to 120 dB re 1 [mu]Pa or to 
ambient, whichever is higher, and integration time/pulse duration for 
SPLrms for verification of the extent to the Level B 
harassment zones;
     All sound levels via medians, means, minimums, and 
maximums and linear average (i.e., averaging the sound intensity/
pressure before converting to dB); and
     Sediment type, water depth, hydrophone depth, etc.
    Response: NMFS discussed this with the Navy and the Navy agreed to 
report these metrics in the acoustic monitoring report. These 
requirements are included in the final rule.
    Comment 3: The Commission recommends that NMFS revise its draft 
rounding criteria and share it with the Commission.
    Response: NMFS appreciates the Commission's ongoing concern in this 
matter. Calculating predicted takes is not an exact science and there 
are arguments for taking different mathematical approaches in different 
situations, and for making qualitative adjustments in other situations. 
We believe, however, that the methodology used for take calculation in 
this LOA remains appropriate and is not at odds with the 24-hour reset 
policy the Commission references. We look forward to continued 
discussion with the Commission on this matter and will share the 
rounding guidance as soon as is appropriate.

Description of Marine Mammals in the Area of the Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical 
and behavioral descriptions) may be found on NMFS's website (https://www.fisheries.noaa.gov/seals-sea-lions).
    Table 2 lists all species with expected potential for occurrence in 
location and summarizes information related to the population or stock, 
including regulatory status under the MMPA and ESA and potential 
biological removal (PBR), where known. For taxonomy, we follow 
Committee on Taxonomy (2017). PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS's 
SARs). While no mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Atlantic SARs (Waring et al., 2017). All values presented 
in Table 2 are the most recent available at the time of publication and 
are available in the draft 2017 SARs (Hayes et al., 2017).

                                    Table 2--Marine Mammals That May Occur Within Navy Submarine Base New London Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         Stock abundance best/
            Common name                Scientific name             Stock             ESA/MMPA status       minimum population   Occurrence in study area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Order Carnivora
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Suborder Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (true seals):
    Gray seal.....................  Halichoerus grypus...  Western North          .....................  505,000 *...........  Thames River.
                                                            Atlantic.
    Harbor seal...................  Phoca vitulina.......  Western North          .....................  75,834 (0.15)/66,884  Thames River.
                                                            Atlantic.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* There are an estimated 27,131 seals in U.S. waters; however, gray seals form one population not distinguished on the basis of the U.S./Canada boundary
  (Waring et al., 2017).


[[Page 36778]]

    All species that could potentially occur in the proposed survey 
areas are included in table 2. As described below, all two species 
(with two managed stocks) temporally and spatially co-occur with the 
activity to the degree that take is reasonably likely to occur, and we 
have proposed authorizing it.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Two marine mammal species (both phocid species) have the reasonable 
potential to co-occur with the proposed survey activities. Please refer 
to Table 2.

Potential Impacts to Marine Mammals

    The Navy's Submarine Base New London pier construction using in-
water pile driving and pile removal could adversely affect marine 
mammal species and stocks by exposing them to elevated noise levels in 
the vicinity of the activity area.
    Exposure to high intensity sound for a sufficient duration may 
result in auditory effects such as a noise-induced threshold shift 
(TS)--an increase in the auditory threshold after exposure to noise 
(Finneran et al., 2005). Factors that influence the amount of threshold 
shift include the amplitude, duration, frequency content, temporal 
pattern, and energy distribution of noise exposure. The magnitude of 
hearing threshold shift normally decreases over time following 
cessation of the noise exposure. The amount of TS just after exposure 
is the initial TS. If the TS eventually returns to zero (i.e., the 
threshold returns to the pre-exposure value), it is a temporary 
threshold shift (TTS) (Southall et al., 2007).
    Threshold Shift (noise-induced loss of hearing)--When animals 
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an 
animal to detect them) following exposure to an intense sound or sound 
for long duration, it is referred to as a noise-induced TS. An animal 
can experience TTS or permanent threshold shift (PTS). TTS can last 
from minutes or hours to days (i.e., there is complete recovery), can 
occur in specific frequency ranges (i.e., an animal might only have a 
temporary loss of hearing sensitivity between the frequencies of 1 and 
10 kHz), and can be of varying amounts (for example, an animal's 
hearing sensitivity might be reduced initially by only 6 dB or reduced 
by 30 dB). PTS is permanent, but some recovery is possible. PTS can 
also occur in a specific frequency range and amount as mentioned above 
for TTS.
    For marine mammals, published data are limited to the captive 
bottlenose dolphin, beluga, harbor porpoise, and Yangtze finless 
porpoise (Finneran, 2015). For pinnipeds in water, data are limited to 
measurements of TTS in harbor seals, an elephant seal, and California 
sea lions (Kastak et al., 1999, 2005; Kastelein et al., 2012b).
    Lucke et al. (2009) found a TS of a harbor porpoise after exposing 
it to airgun noise with a received sound pressure level (SPL) at 200.2 
dB (peak-to-peak) re: 1 micropascal ([mu]Pa), which corresponds to a 
sound exposure level of 164.5 dB re: 1 [mu]Pa\2\ s after integrating 
exposure. Because the airgun noise is a broadband impulse, one cannot 
directly determine the equivalent of root mean square (rms) SPL from 
the reported peak-to-peak SPLs. However, applying a conservative 
conversion factor of 16 dB for broadband signals from seismic surveys 
(McCauley, et al., 2000) to correct for the difference between peak-to-
peak levels reported in Lucke et al. (2009) and rms SPLs, the rms SPL 
for TTS would be approximately 184 dB re: 1 [mu]Pa, and the received 
levels associated with PTS (Level A harassment) would be higher. 
Therefore, based on these studies, NMFS recognizes that TTS of harbor 
porpoises is lower than other cetacean species empirically tested 
(Finneran & Schlundt, 2010; Finneran et al., 2002; Kastelein and 
Jennings, 2012).
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
(similar to those discussed in auditory masking, below). For example, a 
marine mammal may be able to readily compensate for a brief, relatively 
small amount of TTS in a non-critical frequency range that occurs 
during a time where ambient noise is lower and there are not as many 
competing sounds present. Alternatively, a larger amount and longer 
duration of TTS sustained during time when communication is critical 
for successful mother/calf interactions could have more serious

[[Page 36779]]

impacts. Also, depending on the degree and frequency range, the effects 
of PTS on an animal could range in severity, although it is considered 
generally more serious because it is a permanent condition. Of note, 
reduced hearing sensitivity as a simple function of aging has been 
observed in marine mammals, as well as humans and other taxa (Southall 
et al., 2007), so one can infer that strategies exist for coping with 
this condition to some degree, though likely not without cost.
    In addition, chronic exposure to excessive, though not high-
intensity, noise could cause masking at particular frequencies for 
marine mammals, which utilize sound for vital biological functions 
(Clark et al., 2009). Acoustic masking is when other noises such as 
from human sources interfere with animal detection of acoustic signals 
such as communication calls, echolocation sounds, and environmental 
sounds important to marine mammals. Therefore, under certain 
circumstances, marine mammals whose acoustical sensors or environment 
are being severely masked could also be impaired from maximizing their 
performance fitness in survival and reproduction.
    Masking occurs at the frequency band that the animals utilize. 
Therefore, since noise generated from vibratory pile driving is mostly 
concentrated at low frequency ranges, it may have less effect on high 
frequency echolocation sounds by odontocetes (toothed whales). However, 
lower frequency man-made noises are more likely to affect detection of 
communication calls and other potentially important natural sounds such 
as surf and prey noise. It may also affect communication signals when 
they occur near the noise band and thus reduce the communication space 
of animals (e.g., Clark et al., 2009) and cause increased stress levels 
(e.g., Foote et al., 2004; Holt et al., 2009).
    Unlike TS, masking, which can occur over large temporal and spatial 
scales, can potentially affect the species at population, community, or 
even ecosystem levels, as well as individual levels. Masking affects 
both senders and receivers of the signals and could have long-term 
chronic effects on marine mammal species and populations. Recent 
science suggests that low frequency ambient sound levels have increased 
by as much as 20 dB (more than three times in terms of sound pressure 
level) in the world's ocean from pre-industrial periods, and most of 
these increases are from distant shipping (Hildebrand, 2009). For the 
Navy's Submarine Base New London pier construction, noises from 
vibratory pile driving and pile removal contribute to the elevated 
ambient noise levels in the project area, thus increasing potential for 
or severity of masking. Baseline ambient noise levels in the vicinity 
of project area are high due to ongoing shipping, construction and 
other activities in the Thames River.
    Finally, marine mammals' exposure to certain sounds could lead to 
behavioral disturbance (Richardson et al., 1995), such as: Changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities; 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where noise sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haulouts or rookeries).
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Southall et 
al., 2007). Currently NMFS uses a received level of 160 dB re 1 [mu]Pa 
(rms) to predict the onset of behavioral harassment from impulse noises 
(such as impact pile driving), and 120 dB re 1 [mu]Pa (rms) for 
continuous noises (such as vibratory pile driving). For the Navy's 
Submarine Base New London pier construction, both 160- and 120-dB 
levels are considered for effects analysis because the Navy plans to 
use both impact pile driving and vibratory pile driving and pile 
removal.
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be biologically significant if the change affects 
growth, survival, and/or reproduction, which depends on the severity, 
duration, and context of the effects.

Potential Effects on Marine Mammal Habitat

    The primary potential impacts to marine mammal habitat are 
associated with elevated sound levels produced by vibratory pile 
removal and pile driving in the area. However, other potential impacts 
to the surrounding habitat from physical disturbance are also possible.
    With regard to fish as a prey source for cetaceans and pinnipeds, 
fish are known to hear and react to sounds and to use sound to 
communicate (Tavolga et al., 1981) and possibly avoid predators (Wilson 
and Dill, 2002). Experiments have shown that fish can sense both the 
strength and direction of sound (Hawkins, 1981). Primary factors 
determining whether a fish can sense a sound signal, and potentially 
react to it, are the frequency of the signal and the strength of the 
signal in relation to the natural background noise level.
    The level of sound at which a fish will react or alter its behavior 
is usually well above the detection level. Fish have been found to 
react to sounds when the sound level increased to about 20 dB above the 
detection level of 120 dB (Ona, 1988); however, the response threshold 
can depend on the time of year and the fish's physiological condition 
(Engas et al., 1993). In general, fish react more strongly to pulses of 
sound (such as noise from impact pile driving) rather than continuous 
signals (such as noise from vibratory pile driving) (Blaxter et al., 
1981), and a quicker alarm response is elicited when the sound signal 
intensity rises rapidly compared to sound rising more slowly to the 
same level.
    During in-water pile driving only a small fraction of the available 
habitat would be ensonified at any given time. Disturbance to fish 
species would be short-term and fish would return to their pre-
disturbance behavior once the pile driving activity ceases. Thus, the 
proposed construction would have little, if any, impact on marine 
mammals' prey availability in the area where construction work is 
planned.
    Disposal of dredged material in the confined aquatic disposal (CAD) 
cell would have a direct impact to the benthos as a result of burial 
and suffocation. Most, if not all, sessile marine invertebrates are not 
expected to survive burial. Some motile marine organisms would be 
buried and unable to survive, while others such as burrowing 
specialists, may survive. Survival rates would depend primarily on 
burial depth. From 2010 through 2012, biannual benthic sampling of the 
CAD cell area was conducted to assess the timeframe for recovery of 
benthic populations of the CAD cells, in accordance with Water Quality 
Certificate conditions for the 2010 waterfront maintenance dredging 
project at the submarine base. The sampling results of the CAD cell 
were compared to sampling results of an undisturbed reference site 
located upriver. The degree of similarity of population and community 
structures was assessed. The results of the three year survey program 
indicated that a progressive recovery to a stable benthic population 
was occurring at the CAD cell. As demonstrated by the biannual

[[Page 36780]]

benthic survey, benthic assemblages are anticipated to recover within 
three to five years after the completion of the project, and disposal 
impacts would not be significant (CardnoTEC 2015).
    Project activities would temporarily disturb benthic and water 
column habitats and change bottom topography to a minor degree, but 
effects on prey availability and foraging conditions for marine mammals 
would be temporary and limited to the immediate area of pier 
demolition/construction, dredging, and disposal. The new surfaces of 
piles and exposed concrete on the new pier would likely result in 
establishment of fouling communities on the new structures, and may 
attract fish and benthic organisms, resulting in small scale shifts in 
prey distribution.
    There are no known haul outs within the vicinity of the Proposed 
Action.
    The project activities would not permanently modify existing marine 
mammal habitat. The activities may kill some fish and cause other fish 
to leave the area temporarily, thus impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and the relatively small area 
of the habitat that may be affected, the impacts to marine mammal 
habitat are not expected to cause significant or long-term negative 
consequences. Therefore, given the consideration of potential impacts 
to marine mammal prey species and their physical environment, the 
Navy's proposed construction activity at the submarine base would not 
adversely affect marine mammal habitat.

Estimated Take

    Except with respect to certain activities not pertinent here, 
section 3(18) of the MMPA defines ``harassment'' as: Any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment). Harassment is the only 
type of take expected to result from these activities.
    Authorized takes would be by Level A and Level B harassments, in 
the form of mild permanent hearing threshold shift (Level A) and 
disruption of behavioral patterns (Level B) for individual marine 
mammals resulting from exposure to noise generated from impact pile 
driving and vibratory pile driving and removal. Based on the nature of 
the activity and the anticipated effectiveness of the mitigation 
measures (e.g., shutdown measures--discussed in detail below in 
Mitigation section), serious injury or mortality is neither anticipated 
nor authorized.
    As described previously, no mortality is anticipated or authorized 
for this activity. Below we describe how the take is estimated.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed or incur 
some degree of permanent hearing impairment; (2) the area or volume of 
water that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and, (4) and the number of days of activities. Below, we describe these 
components in more detail and present the take estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2011). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources.
    Applicant's proposed activity includes the use of continuous 
(vibratory pile driving and removal) and impulsive (impact pile 
driving) sources, and therefore the 120 and 160 dB re 1 [mu]Pa (rms) 
levels are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Technical Guidance, 2016) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
Applicant's proposed activity includes the use of non-impulsive 
(vibratory pile driving and pile removal) sources.
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product, and are 
provided in the table below. The references, analysis, and methodology 
used in the development of the thresholds are described in NMFS' 2016 
Technical Guidance, which may be accessed at: https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

                 Table 3--Current Acoustic Exposure Criteria for Non-Explosive Sound Underwater
----------------------------------------------------------------------------------------------------------------
                                      PTS onset thresholds                     Behavioral thresholds
        Hearing group         ----------------------------------------------------------------------------------
                                   Impulsive       Non-impulsive         Impulsive             Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.  Lpk,flat: 219 dB  LE,LF,24h: 199    Lrms,flat: 160 dB....  Lrms,flat: 120 dB
                               LE,LF,24h: 183     dB.
                                dB.
Mid-Frequency (MF) Cetaceans.  Lpk,flat: 230 dB  LE,MF,24h: 198
                               LE,MF,24h: 185     dB.
                                dB.
High-Frequency (HF) Cetaceans  Lpk,flat: 202 dB  LE,HF,24h: 173
                               LE,HF,24h: 155     dB.
                                dB.

[[Page 36781]]

 
Phocid Pinnipeds (PW)........  Lpk,flat: 218 dB  LE,PW,24h: 201
(Underwater).................  LE,PW,24h: 185     dB.
                                dB.
Otariid Pinnipeds (OW).......  Lpk,flat: 232 dB  LE,OW,24h: 219
(Underwater).................  LE,OW,24h: 203     dB.
                                dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa2s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds.
Source Levels
    The project includes impact pile driving and vibratory pile driving 
and removal of various piles. Source levels of pile driving and removal 
activities are based on reviews of measurements of the same or similar 
types and dimensions of piles available in the literature (Caltrans, 
2015; Martin et al., 2012; Dazey et al., 2012; WSDOT, 2007, 2012; 
NAVFAC Southwest, 2014). Based on this review, the following source 
levels are assumed for the underwater noise produced by construction 
activities:
     Impact driving of 14-inch steel H-piles for the temporary 
trestle is assumed to generate a peak SPL of 208 dB re 1[mu]Pa, and a 
root-mean-squared (rms) SPL of 187 dB re 1 [mu]Pa, based on adding 10 
dB to a single-strike SEL of 177 dB re 1 [mu]Pa\2\-sec at 10 m (33 ft) 
reported by Caltrans (2015). This assumption is based on differences 
between SEL and rms values of other piles reported by Caltrans (2015).
     Impact driving of 36-inch steel piles would be assumed to 
generate an instantaneous peak SPL of 209 dB, an rms SPL of 198 dB, and 
a SEL of 183 dB at the 10 m (33 ft) distance, based on the weighted 
average of similar pile driving at the Bangor Naval Base, Naval Base 
Point Loma, Washington State Department of Transportation (WSDOT) 
Anacortes Ferry Terminal, and WSDOT Mukilteo Ferry Terminal.
     Vibratory driving of 36-inch steel piles would be assumed 
to generate a 168 dB SPLrms and a 168 dB SEL at 10 m (33 ft), based on 
the weighted average of similar pile driving measured at Bangor Naval 
Base, Naval Base Point Loma, and WSDOT Anacortes Ferry Terminal.
     Impact driving of the 16-inch plastic piles, for which no 
data specific to that size and composition are available, are assumed 
to be similar to available data on 13-inch plastic piles: 166 dB peak 
SPL and 153 dB rms SPL. No SEL measurements were made, but the SEL at 
10 m (33 ft) can be assumed to be 9 dB less than the rms value (based 
on differences of rms and SEL values of in-water impact pile-driving 
data of other piles summarized by Caltrans 2015), which would put the 
SEL value for the plastic piles at 144 dB. For vibratory pile driving 
of the same plastic piles, the SPL rms of impact driving is used as a 
proxy due to lack of measurement.
     Vibratory removal of 14-inch steel H-piles is 
conservatively assumed to have rms and SEL values of 158 dB based on a 
relatively large set of measurements from the vibratory installation of 
14-inch H-piles.
     Drilling the rock sockets is assumed to be an 
intermittent, non-impulsive, broadband noise source, similar to 
vibratory pile driving, but using a rotary drill inside a pipe or 
casing, which is expected to reduce sound levels below those of typical 
pile driving (Martin et al. 2012). Measurements made during a pile 
drilling project in 1-5 m (3-16 ft) depths at Santa Rosa Island, CA, by 
Dazey et al. (2012) appear to provide reasonable proxy source levels 
for the proposed activities. Dazey et al. (2012) reported average rms 
source levels ranging from 151 to 157 dB re 1[micro]Pa, normalized to a 
distance of 1 m (3 ft) from the pile, during activities that included 
casing removal and installation as well as drilling, with an average of 
154 dB re 1[micro]Pa during 62 days that spanned all related drilling 
activities during a single season.
     Since no source level data are available for vibratory 
extraction of concrete or concrete encased 24-inch and 33-inch steel H-
piles, conservative proxy source levels were based on the summary 
values reported for vibratory driving of 24-inch steel sheet piles by 
Caltrans (2015). There are two reasons for using 24-in steel sheet pile 
driving source level as a proxy: (1) In general, pile extraction 
generates less noise in comparison to pile driving, and (2) piling of 
concrete or concrete encased piles generated less noise in comparison 
to steel piles. Since there are no source levels available for 
extraction of the 24-in concrete or concrete encased piles and 33-in 
steel H-piles, we defer to the pile driving source level of 24-in steel 
sheet pile reported by Caltrans (2015). The Caltrans (2015) typical 
source level of 160 dB rms and SEL was used for vibratory removal of 
24-inch concrete piles and 24-inch concrete encased steel H-piles, 
whereas the loudest source level of 165 dB rms and SEL was used for 
vibratory removal of 33-inch concrete encased steel piles.
    A summary of source levels from different pile driving and pile 
removal activities is provided in Table 4.

[[Page 36782]]



                             Table 4--Summary of In-Water Pile Driving Source Levels
                                              [At 10 m from source]
----------------------------------------------------------------------------------------------------------------
                                                                SPLpk (dB re 1   SPLrms (dB re
              Method                      Pile type/size          [micro] Pa)    1 [micro] Pa)    SEL (dB re 1
                                                                                                [micro] Pa\2\-s)
----------------------------------------------------------------------------------------------------------------
Impact driving....................  14-in steel H pile........             208             187               177
Impact driving....................  36-in concrete-filled                  209             198               183
                                     steel pile.
Vibratory driving.................  30- and 36-in concrete-                 NA             168               168
                                     filled steel pipe pile;
                                     16-in fiberglass plastic
                                     pile.
Impact driving....................  16-in fiberglass plastic               166             153               144
                                     pile.
Vibratory driving.................  16-in fiberglass plastic                NA             153               153
                                     pile.
Rock socket drilling..............  30-in steel pile & 16-in                NA             154               154
                                     plastic pile.
Vibratory removal.................  14-in steel H pile........              NA             158               158
Vibratory removal.................  24-in concrete-encased                  NA             160               160
                                     steel H pile.
Vibratory removal.................  33-in concrete-encased                  NA             165               165
                                     steel H pile.
----------------------------------------------------------------------------------------------------------------

    These source levels are used to compute the Level A injury zones 
and to estimate the Level B harassment zones. For Level A harassment 
zones, since the peak source levels for both pile driving methods are 
below the injury thresholds, cumulative SEL were used to do the 
calculations using the NMFS acoustic guidance (NMFS 2016).

Estimating Injury Zones

    When NMFS' Technical Guidance (2016) was published, in recognition 
of the fact that ensonified area/volume could be more technically 
challenging to predict because of the duration component in the new 
thresholds, we developed a User Spreadsheet that includes tools to help 
predict a simple isopleth that can be used in conjunction with marine 
mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which will result in some degree of 
overestimate of Level A take. However, these tools offer the best way 
to predict appropriate isopleths when more sophisticated 3D modeling 
methods are not available, and NMFS continues to develop ways to 
quantitatively refine these tools, and will qualitatively address the 
output where appropriate.
    For cumulative SEL (LE), distances to marine mammal injury 
thresholds were estimated using NMFS' Optional User Spreadsheet based 
on the noise exposure guidance. For impact pile driving, the single 
strike SEL/pulse equivalent was used, and for vibratory pile driving, 
the rms SPL source level was used. Per the NMFS Spreadsheet, default 
Weighting Factor Adjustments (WFA) were used for calculating PTS from 
both vibratory and impact pile driving, using 2.5 kHz and 2.0 KHz, 
respectively. These WFAs are acknowledged by NMFS as conservative. A 
transmission loss coefficient of 15 is used with reported source levels 
measured at 10 m.

Estimating Behavioral Harassment Zones

    Isopleths to Level B behavioral zones are based on rms SPL 
(SPLrms) that are specific for non-impulse (vibratory pile 
driving) sources. Distances to marine mammal behavior thresholds were 
calculated using practical spreading.
    In addition, based on the number of piers and high density of 
pilings along the shoreline, the Navy concluded that underwater sound 
transmission through these structures would be impeded similar to the 
interruption of sound transmission by natural projections of the 
shoreline. Using this assumption, the resulting Level B behavioral 
harassment zone for marine mammal disturbance for most project 
activities would be limited to the middle reaches of the Thames River, 
extending no farther south than the Amtrak Bridge, 3 miles (4,642 m) 
upstream from the mouth of the river.
    A summary of the measured and modeled harassment zones is provided 
in Table 5. In modeling transmission loss from the project area, the 
conventional assumption would be made that acoustic propagation from 
the source is impeded by natural and manmade features that extend into 
the water, resulting in acoustic shadows behind such features. While 
not solid structures, given the density of structural pilings under the 
many pile-supported piers located south of Piers 32 and 10, coupled 
with the docking of submarines at these piers, the piers are presumed 
to disrupt sound propagation southward in the river.

                      Table 5--Calculated Areas of Zone of Influence and Maximum Distances
----------------------------------------------------------------------------------------------------------------
                                       Source level @10m,  Level A distance (m)/area   Level B distance (m)/area
     Year        Activity description     dB (rms/SEL)              (km\2\)                     (km\2\)
----------------------------------------------------------------------------------------------------------------
1.............  Impact driving 14''               187/177  536/0.4468...............  631/0.5468.
                 steel H-pile 1,000
                 strikes per pile, 4
                 piles/day.
                Vibratory & rock                      168  <4/<0.0001...............  4,642/2.2002.
                 socket drilling
                 installation of 36''
                 concrete-filled
                 steel piles; average
                 10 minutes/day.
                Impact driving 36''               198/183  984/0.886................  3,415/2.037.
                 concrete-filled
                 steel piles; 1,000
                 strikes per pile;
                 average 2.5 piles
                 per day.
                                                          ------------------------------------------------------
                Rocket socket                         154       Activity will occur concurrently with above
                 drilling of 30''                                  activities that have much bigger zones
                 concrete-filled
                 steel piles and 16''
                 fiberglass
                 reinforced plastic
                 piles; average 1.04
                 hours/day.
                                                          ------------------------------------------------------
2.............  Vibratory                             168  <4/<0.0001...............  4,642/2.2002.
                 installation of 36''
                 concrete-filled
                 steel piles; average
                 6 minutes/day.

[[Page 36783]]

 
                Impact pile driving               198/183  984/0.886................  3,415/2.037.
                 36'' concrete-filled
                 steel piles; 1,000
                 strikes per pile;
                 average 2.5 piles
                 per day.
3.............  Vibratory                             153  0.9/<0.0001..............  1,584/1.1584.
                 installation of 16''
                 fiberglass plastic
                 piles; 40 minutes/
                 day.
                Impact installation               153/144  2.5/<0.0001..............  1/<0.000.
                 of 16'' fiberglass
                 plastic piles; 1,000
                 strikes per pile;
                 average 2.5 piles
                 per day.
4.............  Vibratory removal of                  158  <4/<0.0001...............  3,415/1.8372.
                 14'' steel H-piles;
                 average 100 minutes/
                 day.
                Vibratory removal of                  160  2.7/<0.0001..............  4,642/2.2002.
                 24'' concrete-filled
                 steel piles (Pier
                 32); average 190
                 minutes/day.
                Vibratory removal of                  165  5.9/<0.0001..............  4,642/2.2002.
                 30'' concrete-filled
                 steel piles (Pier
                 32); average 40
                 minutes/day.
                Vibratory removal of                  160  7.7/<0.0001..............  4,642/2.2002.
                 24'' concrete-filled
                 steel piles (Pier
                 10); average 40
                 minutes/day.
----------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    The Navy's Marine Species Density Database (NMSDD) has density 
estimates for harbor and gray seals that occur in Long Island Sound. 
The NMSDD density estimates for harbor seals and gray seals are the 
same, 0.0703/km\2\ during fall, winter, and spring, and 0.0174/km\2\ 
during summer months. These estimates, however, are based on broad-
scale oceanic surveys, which have not extended up the Thames River.
    Marine mammal surveys were conducted in fall 2014 and winter, 
spring, and summer of 2015 as part of a nearshore biological survey at 
Submarine Base New London. No marine mammals were observed (Tetra Tech 
2016). Harbor seals have been sighted in the Thames River near the 
submarine base by Navy personnel. Both gray and harbor seals have 
rookeries in Long Island Sound. A two-year detailed, systematic survey 
of marine mammals in the Thames River began in January 2017. During the 
first nine months of the survey through September, one pinniped (gray 
seal) was observed approximately 2\3/4\ miles downstream of SUBASE at a 
fishing dock near the ferry terminal, approximately 3,000 feet south of 
the Gold Star Memorial Bridge (I-95).
    There are no survey-based estimates of the relative abundances of 
the two species in the Thames River. Up to two harbor seals have been 
observed near the submarine base by base personnel. No gray seals have 
been observed by the Navy close to the submarine base. However, the 
Navy states that during preparation of the LOA they have learned that 
since the population of gray seals is generally growing in the region 
that gray seals are likely to also occur in the area of effect by the 
first year of construction, 2020, but in smaller numbers. A ratio of 3 
to 1 harbor seals to gray seals was identified as a reasonable 
approximation of their relative abundance. No evidence is available to 
suggest a different ratio. There are no areas (haul outs) where seals 
are known to be concentrated nor have there been contemporary sightings 
of larger numbers of seals along this stretch of the river, and the 
animals seen at the submarine base are likely to move up and down as 
well as across the river. Given that the Thames River is about 500 m 
(1,640 ft) wide at the Submarine Base New London, and similarly 
developed areas extend about 1 km (3,280 ft) up and down the river, the 
Navy believes it is reasonable to extrapolate the observations at the 
Submarine Base New London to an area of about 1 km\2\ for the purpose 
of estimating density. This would result in an average density of 0.45 
harbor and 0.15 gray seals per km\2\ within the project ZOIs from 
September through May. Very few animals were sighted outside the 
September through May time frame. Therefore, the September through May 
data is used for density estimates to be conservative.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. For both harbor and 
gray seals, estimated takes are calculated based on ensonified area for 
a specific pile driving activity multiplied by the marine mammal 
density in the action area, multiplied by the number of pile driving 
(or removal) days. Distances to and areas of different harassment zones 
are listed in Table 4.
    For both Level A and Level B harassment, take calculations and 
assumptions are as follows:
     Number of takes per activity = density (average number of 
seals per km\2\) * area of ZOI (km\2\) * number of days, rounded to the 
nearest whole number.
     Seal density in the project area is estimated as 0.6/km\2\ 
from September through May (zero from June through August), consisting 
of 75% harbor seals (0.45/km\2\) and 25% gray seals (0.15/km\2\).
     Assumes as a worst case that activities will occur up to a 
maximum of 180 workdays (5 days per week) when seals are present 
(September through May) during each full construction year.
     Assumes vibratory and impact hammer pile driving would not 
occur on the same days.
     Level A and Level B takes are calculated separately based 
on the respective ZOIs for each type of activity, providing a maximum 
estimate for each type of take which corresponds to the authorization 
requested under the MMPA.
     Assumes that the effective implementation of a 10 m 
shutdown zone will prevent non-acoustic injuries and will prevent 
animals from entering acoustic harassment ZOIs that extend less than 10 
m from the source.
    The maximum extent of the potential injury zone (for impact pile 
driving of steel piles) is 984 m (3,228 ft) from the source for 36-inch 
concrete-filled steel piles and 536 m (1,758 ft) for 14-inch steel H-
piles; other potential acoustic injury ZOIs for vibratory pile 
extraction and installation are only 1 to 7.7 m (3 to 25 ft) from the 
source (Table 4). Seals within about 10 m (33 ft) of in-water 
construction or demolition may also be at risk of injury from 
interaction with construction equipment. These potential

[[Page 36784]]

injury zones and the 10 m (33 ft) shutdown distance would be monitored 
during all in-water construction/demolition activities, and the 
activities would be halted if a marine mammal were to approach within 
these distances.
    The estimated numbers of instances of acoustic harassment (takes) 
by year, species and severity (Level A or Level B) are shown in Table 
6. Total Level A takes are estimated as 12 harbor seals and 4 gray 
seals (total 16), and Level B takes are estimated as 504 harbor seals 
and 168 gray seals (total 672).

           Table 6--Estimated Numbers of Marine Mammals That May Be Exposed to Received Noise Levels That Cause Level A and Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Estimated       Estimated       Estimated
                   Year                                Species             Level A take    Level B take     total take       Abundance      Percentage
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.........................................  Harbor seal.................               6             166             172          75,834            0.23
                                            Gray seal...................               2              55              57          27,131            0.21
2.........................................  Harbor seal.................               6             177             183          75,834            0.24
                                            Gray seal...................               2              59              61         505,000            0.01
3.........................................  Harbor seal.................               0              51              51          75,834            0.07
                                            Gray seal...................               0              17              17          27,131            0.06
4.........................................  Harbor seal.................               0             110             110          75,834            0.13
                                            Gray seal...................               0              37              37          27,131            0.12
--------------------------------------------------------------------------------------------------------------------------------------------------------

Mitigation

    In order to issue an LOA 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 impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost and impact on 
operations.

Mitigation for Marine Mammals and Their Habitat

    1. Time Restriction.
    Work will occur only during daylight hours, when visual monitoring 
of marine mammals can be conducted.
    2. Establishing and Monitoring Level A and Level B Harassment 
Zones, and Shutdown Zones. These zones may be adjusted as appropriate 
on the basis of the acoustic monitoring described below.
    Before the commencement of in-water construction activities, which 
include impact pile driving and vibratory pile driving and pile 
removal, the Navy shall establish Level A harassment zones where 
received underwater SELcum could cause PTS (see Table 5 
above).
    The Navy shall also establish Level B harassment zones where 
received underwater SPLs are higher than 160 dBrms re 1 
[micro]Pa for impulsive noise sources (impact pile driving) and 120 
dBrms re 1 [micro]Pa for non-impulsive noise sources 
(vibratory pile driving and pile removal).
    The Navy shall establish a 10-m (33-ft) shutdown zone for all in-
water construction and demolition work.
    If marine mammals are found within the shutdown zone, pile driving 
of the segment would be delayed until they move out of the area. If a 
marine mammal is seen above water and then dives below, the contractor 
would wait 15 minutes. If no marine mammals are seen by the observer in 
that time it can be assumed that the animal has moved beyond the 
shutdown zone.
    If pile driving of a segment ceases for 30 minutes or more and a 
marine mammal is sighted within the designated shutdown zone prior to 
commencement of pile driving, the observer(s) must notify the pile 
driving operator (or other authorized individual) immediately and 
continue to monitor the shutdown zone. Operations may not resume until 
the marine mammal has exited the shutdown zone or 15 minutes have 
elapsed since the last sighting.
    3. Shutdown Measures.
    The Navy shall implement shutdown measures if a marine mammal is 
detected moving towards or entered the 10-m (33-ft) shutdown zone.
    Further, the Navy shall implement shutdown measures if the number 
of authorized takes for any particular species reaches the limit under 
the LOA and such marine mammals are sighted within the vicinity of the 
project area and are approaching the Level B harassment zone during in-
water construction activities.
    In addition, the Navy shall implement shutdown measures if species 
not authorized to take are sighted within the vicinity of the project 
area and are approaching the Level B harassment zone during in-water 
construction activities.
    4. Soft Start.
    The Navy shall implement soft start techniques for impact pile 
driving. The Navy shall conduct an initial set of three strikes from 
the impact hammer at 40 percent energy, followed by a 1-minute waiting 
period, then two subsequent three strike sets. Soft start shall be 
required for any impact driving, including at the beginning of the day, 
and at any time following a cessation of impact pile driving of thirty 
minutes or longer.
    Whenever there has been downtime of 30 minutes or more without 
impact driving, the contractor shall initiate

[[Page 36785]]

impact driving with soft-start procedures described above.
    Based on our evaluation of the required measures, NMFS has 
determined that the prescribed mitigation measures provide the means 
effecting the least practicable adverse impact on the affected species 
or stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

    In order to issue an LOA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth, ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) state that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Monitoring Measures

    The Navy shall employ trained protected species observers (PSOs) to 
conduct marine mammal monitoring for its Submarine Base New London pier 
construction project. The purposes of marine mammal monitoring are to 
implement mitigation measures and learn more about impacts to marine 
mammals from the Navy's construction activities. The PSOs will observe 
and collect data on marine mammals in and around the project area for 
15 minutes before, during, and for 30 minutes after all pile removal 
and pile installation work.
Protected Species Observer Qualifications
    NMFS-approved PSOs shall meet the following requirements:
    1. Independent observers (i.e., not construction personnel) are 
required;
    2. At least one observer must have prior experience working as an 
observer;
    3. Other observers may substitute education (undergraduate degree 
in biological science or related field) or training for experience;
    4. Where a team of three or more observers are required, one 
observer should be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer; and
    5. NMFS will require submission and approval of observer CVs.
Marine Mammal Monitoring Protocols
    The Navy shall conduct briefings between construction supervisors 
and crews and the PSO team prior to the start of all pile driving 
activities, and when new personnel join the work, in order to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures. All personnel working in the 
project area shall watch the Navy's Marine Species Awareness Training 
video. An informal guide shall be included with the monitoring plan to 
aid in identifying species if they are observed in the vicinity of the 
project area.
    The Navy will monitor the Level A and Level B harassment zones 
before, during, and after pile driving activities for all in-water 
constructions. The Marine Mammal Monitoring Plan would include the 
following procedures:
     PSOs will be primarily located on boats, docks, and piers 
at the best vantage point(s) in order to properly see the entire 
shutdown zone(s).
     PSOs will be located at the best vantage point(s) to 
observe the zone associated with behavioral impact thresholds.
     During all observation periods, PSOs will use high-
magnification (25X), as well as standard handheld (7X) binoculars, and 
the naked eye to search continuously for marine mammals.
     Monitoring distances will be measured with range finders. 
Distances to animals will be based on the best estimate of the PSO, 
relative to known distances to objects in the vicinity of the PSO.
     Bearings to animals will be determined using a compass.
     Pile driving shall only take place when the shutdown and 
Level A zones are visible and can be adequately monitored. If 
conditions (e.g., fog) prevent the visual detection of marine mammals, 
activities with the potential to result in Level A harassment shall not 
be initiated. If such conditions arise after the activity has begun, 
pile driving or pile removal activities shall be halted if the 10-m 
shutdown zone is not visible.
     Three (3) PSOs shall be posted to monitor marine mammals 
during in-water pile driving and pile removal. One PSO will be located 
on land and two will be located in a boat to monitor the farther 
locations.
     Pre-Activity Monitoring:
    The shutdown zone will be monitored for 15 minutes prior to in-
water construction/demolition activities. If a marine mammal is present 
within the 10-m shutdown zone, the activity will be delayed until the 
animal(s) leave the shutdown zone. Activity will resume only after the 
PSO has determined that, through sighting or by waiting 15 minutes, the 
animal(s) has moved outside the shutdown zone. If a marine mammal is 
observed approaching the shutdown zone, the PSO who sighted that animal 
will notify all other PSOs of its presence.
     During Activity Monitoring:
    If a marine mammal is observed entering the Level A or Level B 
zones outside the 10-m shutdown zone, the pile segment being worked on 
will be completed without cessation, unless the animal enters or 
approaches the shutdown zone, at which point all pile driving 
activities will be halted. If an animal is observed within the shutdown 
zone during pile driving, then pile driving will be stopped as soon as 
it is safe to do so. Pile driving can only resume once the animal has 
left the shutdown zone of its own volition or

[[Page 36786]]

has not been re-sighted for a period of 15 minutes.
     Post-Activity Monitoring:
    Monitoring of all zones will continue for 30 minutes following the 
completion of the activity.
Acoustic Monitoring
(1) Sound Source Verification
    The Navy shall conduct pile driving sound source verification for 
the types and sizes of piles with no prior measurements. These piles 
include:
     Vibratory and impact installation of at least 5 16-in 
fiberglass reinforced plastic piles, and
     Rock socket drilling of at least 3 30-in and 3 16-in 
piles.
    Sound source measurements of these piles sound be conducted at 
distances approximately 10 m from the source.
    For vibratory pile driving/removal source level measurements, 
reports should include 1-s sound exposure level (SEL), source spectrum, 
duration of recordings used to derived the SEL, and 24-hour cumulative 
SEL extrapolated from measurements.
    For impact pile driving source level measurements, report should 
include peak sound pressure level (SPLpk), root-mean-square 
SPL (SPLrms), single strike SEL (SELss), 
integration time for SPLrms, SELss spectrum, and 
24-hour cumulative SEL extrapolated from measurements.
(2) Level B Harassment Distance Verification
    The Navy shall empirically determine the Level B harassment 
distance either by extrapolating from in situ measurements conducted at 
several points between 10 and 500 m from the source, or by direct 
measurements at far distance to locate the distance where the received 
levels reach 120 dB or below, or at the ambient noise level.
    Level B behavioral harassment zones need to be empirically 
determined include:
     Rock socket drilling of at least 3 30-in and 3 16-in 
piles,
     Vibratory installation of at least 3 36-in steel piles, 
and
     Vibratory removal of at least 3 24-in concrete and 3 33-in 
concrete piles.
    For extent of Level B distance verification, the Navy shall report 
the measured or extrapolated distances where the received levels 
SPLrms decay to 120-dB or to the ambient noise level, 
whichever is higher, as well as integration time for such 
SPLrms.
    The sound levels reported should be in median and linear average 
(i.e., taking averages of sound intensity before converting to dB).
    The acoustic monitoring reports shall also include sediment type 
where measurements are made.

Reporting Measures

    The Navy is required to submit an annual report within 90 days 
after each activity year, starting from the date when the LOA is issued 
(for the first annual report) or from the date when the previous annual 
report ended. These reports will detail the monitoring protocol, 
summarize the data recorded during monitoring, and estimate the number 
of marine mammals that may have been harassed during the period of the 
report. Results from acoustic monitoring should also be included within 
the monitoring report, as discussed above. NMFS will provide comments 
within 30 days after receiving these reports, and the Navy shall 
address the comments and submit revisions within 30 days after 
receiving NMFS comments. If no comment is received from NMFS within 30 
days, the annual report is considered completed.
    The Navy is also required to submit a draft monitoring report 
within 90 days after completion of the construction work or the 
expiration of the final LOA, whichever comes earlier. This report will 
synthesize all data recorded during marine mammal monitoring, and 
estimate the number of marine mammals that may have been harassed 
through the entire project. NMFS will provide comments within 30 days 
after receiving this report, and the Navy shall address the comments 
and submit revisions within 30 days after receiving NMFS comments. If 
no comment is received from NMFS within 30 days, the monitoring report 
is considered as final.
    In addition, NMFS requires the Navy to notify NMFS' Office of 
Protected Resources and NMFS' Greater Atlantic Stranding Coordinator 
within 48 hours of sighting an injured or dead marine mammal in the 
construction site. The Navy shall provide NMFS and the Stranding 
Network with the species or 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 
photo or video (if available).
    In the event that the Navy finds an injured or dead marine mammal 
that is not in the construction area, the Navy will report the same 
information as listed above to NMFS as soon as operationally feasible.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact 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'' (50 CFR 216.103). 
A negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, this introductory discussion of our analyses 
applies to both of the species listed in Table 2, given that the 
anticipated effects of the Navy's Submarine Base New London pier 
construction project activities involving pile driving and pile removal 
on marine mammals are expected to be relatively similar in nature. 
There is no information about the nature or severity of the impacts, or 
the size, status, or structure of any species or stock that would lead 
to a different analysis by species for this activity, or else species-
specific factors would be identified and analyzed.
    Although a few individual seals (6 harbor seals and 2 gray seals 
each in year 1 and year 2) are estimated to experience Level A 
harassment in the form of PTS if they stay within the Level A 
harassment zone during the entire pile driving for the day, the degree 
of injury is expected to be mild and is not likely to affect the 
reproduction or survival of the individual animals. It is expected 
that, if hearing impairments occurs, most likely the affected animal 
would lose a few dB in its hearing sensitivity, which in most cases is 
not likely to affect its survival and

[[Page 36787]]

recruitment. Hearing impairment that might occur for these individual 
animals would be limited to the dominant frequency of the noise 
sources, i.e., in the low-frequency region below 2 kHz. Nevertheless, 
as for all marine mammal species, it is known that in general these 
pinnipeds will avoid areas where sound levels could cause hearing 
impairment. Therefore it is not likely that an animal would stay in an 
area with intense noise that could cause severe levels of hearing 
damage.
    Under the majority of the circumstances, anticipated takes are 
expected to be limited to short-term Level B harassment. Marine mammals 
present in the vicinity of the action area and taken by Level B 
harassment would most likely show overt brief disturbance (startle 
reaction) and avoidance of the area from elevated noise levels during 
pile driving and pile removal. Given the limited estimated number of 
incidents of Level A and Level B harassment and the limited, short-term 
nature of the responses by the individuals, the impacts of the 
estimated take cannot be reasonably expected to, and are not reasonably 
likely to, rise to the level that they would adversely affect either 
species at the population level, through effects on annual rates of 
recruitment or survival.
    There are no known important habitats, such as rookeries or haul-
outs, in the vicinity of the Navy's proposed Submarine Base New London 
pier construction project. The project also is not expected to have 
significant adverse effects on affected marine mammals' habitat, 
including prey, as analyzed in detail in the ``Anticipated Effects on 
Marine Mammal Habitat'' subsection.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS finds that the total take from the proposed 
activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under section 101(a)(5)(A) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, NMFS compares the number of 
individuals taken to the most appropriate estimation of abundance of 
the relevant species or stock in our determination of whether an 
authorization is limited to small numbers of marine mammals.
    The estimated takes are below one percent of the population for all 
marine mammals (Table 6).
    Based on the analysis contained herein of the proposed activity 
(including the prescribed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Subsistence Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
Navy maintenance construction activities would contain an adaptive 
management component.
    The reporting requirements associated with this proposed rule are 
designed to provide NMFS with monitoring data from the previous year to 
allow consideration of whether any changes 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 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 reports, as required by MMPA authorizations; (2) 
results from general marine mammal and sound research; and (3) 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.

National Environmental Policy Act (NEPA)

    Issuance of an MMPA authorization requires compliance with NEPA.
    In accordance with NEPA (42 U.S.C. 4321 et seq.) and NOAA 
Administrative Order (NAO) 216-6A, we have determined that issuance of 
this rule and subsequent LOAs qualifies to be categorically excluded 
from further NEPA review. Issuance of the rule is consistent with 
categories of activities identified in CE B4 of the Companion Manual 
and we have not identified any extraordinary circumstances listed in 
Chapter 4 of the Companion Manual that would preclude use of this 
categorical exclusion.

Endangered Species Act (ESA)

    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Classification

    Pursuant to the procedures established to implement Executive Order 
12866, the Office of Management and Budget has determined that this 
proposed rule is not significant.
    Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA), 
the Chief Counsel for Regulation of the Department of Commerce has 
certified to the Chief Counsel for Advocacy of the Small Business 
Administration that this proposed rule, if adopted, would not have a 
significant economic impact on a substantial number of small entities. 
The U.S. Navy is the sole entity that would be subject to the 
requirements in these proposed regulations, and the Navy is not a small 
governmental jurisdiction, small organization, or small business, as 
defined by the RFA. Because of this certification, a regulatory 
flexibility analysis is not required and none has been prepared.
    This proposed rule does not contain a collection-of-information 
requirement subject to the provisions of the Paperwork Reduction Act 
(PRA) because the applicant is a federal agency. Notwithstanding any 
other provision of law, no person is required to respond to nor shall a 
person be subject to a penalty for failure to comply with a collection 
of information subject to the requirements of the PRA unless that 
collection of information displays a currently valid OMB control 
number. These requirements have been approved by OMB under control 
number 0648-0151 and include applications for regulations, subsequent 
LOAs, and reports.

List of Subjects in 50 CFR Part 217

    Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine

[[Page 36788]]

mammals, Navy, Penalties, Reporting and recordkeeping requirements, 
Seafood, Sonar, Transportation.

    Dated: July 20, 2018.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, 50 CFR part 217 is amended 
as follows:

PART 217--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 217 continues to read as follows:

    Authority:  16 U.S.C. 1361 et seq., unless otherwise noted.


0
2. Add subpart J to part 217 to read as follows:
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Submarine 
Base New London Pier Construction
Sec.
217.90 Specified activity and specified geographical region.
217.91 Effective dates.
217.92 Permissible methods of taking.
217.93 Prohibitions.
217.94 Mitigation requirements.
217.95 Requirements for monitoring and reporting.
217.96 Letters of Authorization.
217.97 Renewals and modifications of Letters of Authorization.
217.98 [Reserved]
217.99 [Reserved]

Subpart J--Taking and Importing Marine Mammals; U.S. Navy's 
Submarine Base New London Pier Construction


Sec.  217.90  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy (Navy) 
and those persons it authorizes or funds to conduct activities on its 
behalf for the taking of marine mammals that occurs in the area 
outlined in paragraph (b) of this section and that occurs incidental to 
the activities described in paragraph (c) of this section.
    (b) The taking of marine mammals by the Navy may be authorized in 
Letters of Authorization (LOAs) only if it occurs within the Navy 
Submarine Base New London Study Area, which is located in the towns of 
Groton and Ledyard in New London County, Connecticut.
    (c) The taking of marine mammals by the Navy is only authorized if 
it occurs incidental to the Navy's conducting in-water pier 
construction or demolition activities.


Sec.  217.91  Effective dates and definitions.

    Regulations in this subpart are effective March 1, 2020 through 
February 28, 2025.


Sec.  217.92  Permissible methods of taking.

    Under LOAs issued pursuant to Sec.  216.106 of this chapter and 
Sec.  217.96, the Holder of the LOAs (hereinafter ``Navy'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  217.90(b) by Level A harassment and Level B 
harassment associated with in-water pile driving and pile removal 
activities, provided the activity is in compliance with all terms, 
conditions, and requirements of the regulations in this subpart and the 
applicable LOAs.


Sec.  217.93  Prohibitions.

    Notwithstanding takings contemplated in Sec.  217.92 and authorized 
by LOAs issued under Sec.  216.106 of this chapter and Sec.  217.96, no 
person in connection with the activities described in Sec.  217.90 may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec.  216.106 of 
this chapter and Sec.  217.96;
    (b) Take any marine mammal not specified in such LOAs;
    (c) Take any marine mammal specified in such LOAs in any manner 
other than as specified;
    (d) Take a marine mammal specified in such LOAs if NMFS determines 
such taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (e) Take a marine mammal specified in such LOAs if NMFS determines 
such taking results in an unmitigable adverse impact on the 
availability of such species or stock of marine mammal for taking for 
subsistence uses.


Sec.  217.94  Mitigation requirements.

    When conducting the activities identified in Sec.  217.90(c), the 
mitigation measures contained in any LOAs issued under Sec.  216.106 of 
this chapter and Sec.  217.96 must be implemented. These mitigation 
measures shall include but are not limited to:
    (a) Time restriction. In-water construction and demolition work 
shall occur only during daylight hours.
    (b) Establishment of monitoring and shutdown zones. (1) For all 
relevant in-water construction and demolition activity, the Navy shall 
designate Level A harassment zones with radial distances as identified 
in any LOA issued under Sec.  216.106 of this chapter and Sec.  217.96.
    (2) For all relevant in-water construction and demolition activity, 
the Navy shall designate Level B harassment zones with radial distances 
as identified in any LOA issued under Sec.  216.106 of this chapter and 
Sec.  217.96.
    (3) For all in-water construction and demolition activity, the Navy 
shall implement a minimum shutdown zone of a 10-m radius around the 
pile. If a marine mammal comes within or approaches the shutdown zone, 
such operations shall cease.
    (c) Monitoring visibility. Pile driving shall only take place when 
the shutdown and Level A zones are visible and can be adequately 
monitored. If conditions (e.g., fog) prevent the visual detection of 
marine mammals, activities with the potential to result in Level A 
harassment shall not be initiated. If such conditions arise after the 
activity has begun, pile driving or pile removal activities shall be 
halted if the 10-m shutdown zone is not visible.
    (d) Shutdown measures. (1) The Navy shall deploy three protected 
species observers (PSOs) to monitor marine mammals during in-water pile 
driving and pile removal. One PSO shall be located on land and two 
shall be located in a boat to monitor the farther locations.
    (2) Monitoring shall take place from 15 minutes prior to initiation 
of pile driving or removal activity through 30 minutes post-completion 
of pile driving or removal activity. Pre-activity monitoring shall be 
conducted for 15 minutes to ensure that the shutdown zone is clear of 
marine mammals, and pile driving or removal may commence when observers 
have declared the shutdown zone clear of marine mammals. In the event 
of a delay or shutdown of activity resulting from marine mammals in the 
shutdown zone, animals shall be allowed to remain in the shutdown zone 
(i.e., must leave of their own volition) and their behavior shall be 
monitored and documented. Monitoring shall occur throughout the time 
required to drive or remove a pile. A determination that the shutdown 
zone is clear must be made during a period of good visibility (i.e., 
the entire shutdown zone and surrounding waters must be visible to the 
naked eye).
    (3) If a marine mammal approaches or enters the shutdown zone, or 
if a marine mammal not specified in the LOAs enters the Level B 
harassment zone, or if the take of a marine mammal species or stock has 
reached the take limits specified in any LOA issued under Sec.  216.106 
of this chapter and Sec.  217.96 and enters the Level B harassment 
zone, all pile driving or removal activities at that location shall be 
halted. If pile driving or removal is halted or delayed due to the 
presence of a marine

[[Page 36789]]

mammal, the activity may not commence or resume until either the animal 
has voluntarily left and been visually confirmed beyond the shutdown 
zone or fifteen minutes have passed without re-detection of the animal.
    (4) The Navy shall implement shutdown measures if the number of 
authorized takes for any particular species reaches the limit under the 
applicable LOA and if such marine mammals are sighted within the 
vicinity of the project area and are approaching the Level B harassment 
zone during in-water construction or demolition activities.
    (e) Soft start. (1) The Navy shall implement soft start techniques 
for impact pile driving. The Navy shall conduct an initial set of three 
strikes from the impact hammer at 40 percent energy, followed by a 1-
minute waiting period, then two subsequent three strike sets.
    (2) Soft start shall be required for any impact driving, including 
at the beginning of the day, and at any time following a cessation of 
impact pile driving of 30 minutes or longer.


Sec.  217.95  Requirements for monitoring and reporting.

    (a) Marine mammal monitoring--(1) General requirements. The Navy 
shall employ trained protected species observers (PSOs) to conduct 
marine mammal monitoring for its Submarine Base New London pier 
construction project. The PSOs shall observe and collect data on marine 
mammals in and around the project area for 15 minutes before, during, 
and for 30 minutes after all pile removal and pile installation work. 
PSOs shall have no other assigned tasks during monitoring periods, and 
shall be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown or delay procedures when 
applicable through communication with the equipment operator.
    (2) Protected species observer qualifications. NMFS-approved PSOs 
shall meet the following requirements:
    (i) Independent observers (i.e., not construction personnel) are 
required;
    (ii) At least one observer must have prior experience working as an 
observer;
    (iii) Other observers may substitute education (undergraduate 
degree in biological science or related field) or training for 
experience;
    (iv) Where a team of three or more observers are required, one 
observer should be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer; and
    (v) NMFS will require submission and approval of observer CVs.
    (3) Marine mammal monitoring protocols. (i) The Navy shall conduct 
briefings between construction supervisors and crews and the PSO team 
prior to the start of all pile driving activities, and when new 
personnel join the work, in order to explain responsibilities, 
communication procedures, marine mammal monitoring protocol, and 
operational procedures. All personnel working in the project area shall 
watch the Navy's Marine Species Awareness Training video. An informal 
guide shall be included with the monitoring plan to aid in identifying 
species if they are observed in the vicinity of the project area.
    (ii) The Navy shall monitor the Level A and Level B harassment 
zones before, during, and after pile driving activities for all in-
water constructions. The Marine Mammal Monitoring Plan shall include 
the following procedures:
    (A) PSO location. PSOs will be primarily located on boats, docks, 
and piers at the best vantage point(s) in order to properly see the 
entire shutdown zone(s).
    (B) PSO vantage point. PSOs will be located at the best vantage 
point(s) to observe the zone associated with behavioral impact 
thresholds.
    (C) Observation equipment. During all observation periods, PSOs 
will use high-magnification (25X), as well as standard handheld (7X) 
binoculars, and the naked eye to search continuously for marine 
mammals.
    (D) Ranging equipment. Monitoring distances will be measured with 
range finders. Distances to animals will be based on the best estimate 
of the PSO, relative to known distances to objects in the vicinity of 
the PSO.
    (E) Bearing. Bearings to animals will be determined using a 
compass.
    (F) Pre-activity monitoring. The shutdown zone will be monitored 
for 15 minutes prior to in-water construction/demolition activities. If 
a marine mammal is present within the 10-m shutdown zone, the activity 
will be delayed until the animal(s) leaves the shutdown zone. Activity 
will resume only after the PSO has determined that, through sighting or 
by waiting 15 minutes, the animal(s) has moved outside the shutdown 
zone. If a marine mammal is observed approaching the shutdown zone, the 
PSO who sighted that animal will notify all other PSOs of its presence.
    (G) During activity monitoring. If a marine mammal is observed 
entering the Level A or Level B harassment zones outside the 10-m 
shutdown zone, the pile segment being worked on will be completed 
without cessation, unless the animal enters or approaches the shutdown 
zone, at which point all pile driving activities will be halted. If an 
animal is observed within the shutdown zone during pile driving, then 
pile driving will be stopped as soon as it is safe to do so. Pile 
driving can only resume once the animal has left the shutdown zone of 
its own volition or has not been re-sighted for a period of 15 minutes.
    (H) Post-activity monitoring. Monitoring of all zones will continue 
for 30 minutes following the completion of the activity.
    (b) Acoustic monitoring--(1) Sound source verification. (i) The 
Navy shall conduct pile driving sound source verification for the 
following types and sizes of piles:
    (A) Vibratory and impact installation of at least 5 16-in 
fiberglass reinforced plastic piles; and
    (B) Rock socket drilling of at least 3 30-in and 3 16-in piles.
    (ii) Sound source measurements of these piles sound shall be 
conducted at distances approximately 10 m from the source.
    (iii) For vibratory pile driving/removal source level measurements, 
reports shall include 1-s sound exposure level (SEL), source spectrum, 
duration of recordings used to derived the SEL, and 24-hour cumulative 
SEL extrapolated from measurements.
    (iv) For impact pile driving source level measurements, report 
should include peak sound pressure level (SPLpk), root-mean-
square SPL (SPLrms), single strike SEL (SELss), 
integration time for SPLrms, SELss spectrum, and 
24-hour cumulative SEL extrapolated from measurements.
    (2) Level B harassment distance verification. (i) The Navy shall 
empirically determine the Level B harassment distance either by 
extrapolating from in situ measurements conducted at several points 
between 10 and 500 m from the source, or by direct measurements to 
locate the distance where the received levels reach 120 dB or below, or 
at the ambient noise level.
    (ii) Level B harassment zones to be empirically verified include:
    (A) Rock socket drilling of at least 3 30-in and 3 16-in piles;
    (B) Vibratory installation of at least 3 36-in steel piles; and
    (C) Vibratory removal of at least 3 24-in concrete and 3 33-in 
concrete piles.
    (iii) For extent of Level B harassment zone verification, the Navy 
shall report the measured or extrapolated distances where the received 
levels SPLrms decay to 120-dB or to the ambient noise level,

[[Page 36790]]

whichever is higher, as well as integration time for such 
SPLrms.
    (3) Source level calculation. The sound levels reported should be 
in median and linear average (i.e., taking averages of sound intensity 
before converting to dB).
    (4) Sediment type. The passive acoustic monitoring reports shall 
also include sediment type where measurements are made.
    (c) Reporting measures--(1) Annual reports. (i) The Navy shall 
submit an annual report within 90 days after each activity year, 
starting from the date when the LOA is issued (for the first annual 
report) or from the date when the previous annual report ended.
    (ii) Annual reports shall detail the monitoring protocol, summarize 
the data recorded during monitoring, and estimate the number of marine 
mammals that may have been harassed during the period of the report.
    (iii) Annual reports shall also include results from acoustic 
monitoring detailed in paragraph (b) of this section.
    (iv) NMFS shall provide comments within 30 days after receiving 
annual reports, and the Navy shall address the comments and submit 
revisions within 30 days after receiving NMFS comments. If no comment 
is received from the NMFS within 30 days, the annual report is 
considered completed.
    (2) Final report. (i) The Navy shall submit a comprehensive summary 
report to NMFS not later than 90 days following the conclusion of 
marine mammal monitoring efforts described in this subpart.
    (ii) The final report shall synthesize all data recorded during 
marine mammal monitoring, and estimate the number of marine mammals 
that may have been harassed through the entire project.
    (iii) NMFS would provide comments within 30 days after receiving 
this report, and the Navy shall address the comments and submit 
revisions within 30 days after receiving NMFS comments. If no comment 
is received from the NMFS within 30 days, the final report is 
considered as final.
    (3) Reporting of injured or dead marine mammals. (i) In the 
unanticipated event that the construction or demolition activities 
clearly cause the take of a marine mammal in a prohibited manner, such 
as an injury, serious injury, or mortality, the Navy shall immediately 
cease all operations and immediately report the incident to the NMFS 
Office of Protected Resources, NMFS, and the Greater Atlantic Region 
Stranding Coordinators. The report must include the following 
information:
    (A) Time, date, and location (latitude/longitude) of the incident;
    (B) Description of the incident;
    (C) Status of all sound source use in the 24 hours preceding the 
incident;
    (D) Environmental conditions (e.g., wind speed and direction, sea 
state, cloud cover, visibility, and water depth);
    (E) Description of marine mammal observations in the 24 hours 
preceding the incident;
    (F) Species identification or description of the animal(s) 
involved;
    (G) The fate of the animal(s); and
    (H) Photographs or video footage of the animal (if equipment is 
available).
    (ii) Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with the Navy to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. The Navy may not resume 
their activities until notified by NMFS via letter, email, or 
telephone.
    (iii) In the event that the Navy discovers an injured or dead 
marine mammal, and the lead PSO determines that the cause of the injury 
or death is unknown and the death is relatively recent (i.e., in less 
than a moderate state of decomposition as described in the next 
paragraph), the Navy will immediately report the incident to the NMFS 
Office of Protected Resources, NMFS, and the Greater Atlantic Regional 
Stranding Coordinators. The report must include the same information 
identified in paragraph (c)(3)(i)(A) of this section. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
will work with the Navy to determine whether modifications in the 
activities are appropriate.
    (iv) In the event that the Navy discovers an injured or dead marine 
mammal, and the lead protected species observer determines that the 
injury or death is not associated with or related to the activities 
authorized in the IHA (e.g., previously wounded animal, carcass with 
moderate to advanced decomposition, or scavenger damage), the Navy 
shall report the incident to the NMFS Office of Protected Resources, 
NMFS, and the Greater Atlantic Regional Stranding Coordinators, within 
24 hours of the discovery. The Navy shall provide photographs or video 
footage (if available) or other documentation of the stranded animal 
sighting to NMFS and the Marine Mammal Stranding Network. The Navy can 
continue its operations under such a case.


Sec.  217.96  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, the Navy must apply for and obtain LOAs in accordance with 
Sec.  216.106 of this chapter for conducting the activity identified in 
Sec.  217.90(c).
    (b) LOAs, unless suspended or revoked, may be effective for a 
period of time not to extend beyond the expiration date of these 
regulations.
    (c) If an LOAs expires prior to the expiration date of these 
regulations, the Navy may apply for and obtain a renewal of the LOAs.
    (d) In the event of projected changes to the activity or to 
mitigation, monitoring, reporting (excluding changes made pursuant to 
the adaptive management provision of Sec.  217.97(c)(1)) required by an 
LOA, the Navy must apply for and obtain a modification of LOAs as 
described in Sec.  217.97.
    (e) Each LOA shall set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, their habitat, and the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (f) Issuance of the LOAs shall be based on a determination that the 
level of taking shall be consistent with the findings made for the 
total taking allowable under these regulations.
    (g) Notice of issuance or denial of the LOAs shall be published in 
the Federal Register within 30 days of a determination.


Sec.  217.97  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec.  216.106 of this chapter and Sec.  
217.96 for the activity identified in Sec.  217.90(c) shall be renewed 
or modified upon request by the applicant, provided that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for these regulations (excluding changes 
made pursuant to the adaptive management provision in paragraph (c)(1) 
of this section); and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOAs under these regulations were 
implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting measures (excluding changes made pursuant to

[[Page 36791]]

the adaptive management provision in paragraph (c)(1) of this section) 
that do not change the findings made for the regulations or result in 
no more than a minor change in the total estimated number of takes (or 
distribution by species or years), NMFS may publish a notice of 
proposed LOA in the Federal Register, including the associated analysis 
of the change, and solicit public comment before issuing the LOA.
    (c) An LOA issued under Sec.  216.106 of this chapter and Sec.  
217.96 for the activity identified in Sec.  217.90(c) may be modified 
by NMFS under the following circumstances:
    (1) Adaptive management. After consulting with the Navy regarding 
the practicability of the modifications, NMFS may modify (including by 
adding or removing measures) the existing mitigation, monitoring, or 
reporting measures if doing so creates a reasonable likelihood of more 
effectively accomplishing the goals of the mitigation and monitoring 
set forth in the preamble for these regulations.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in an LOA:
    (A) Results from the Navy's monitoring from the previous year(s);
    (B) Results from other marine mammal and/or sound research or 
studies; or
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent or number not authorized by these regulations or 
subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
shall publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies. If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in LOAs issued pursuant to Sec.  216.106 of 
this chapter and Sec.  217.96, an LOA may be modified without prior 
notice or opportunity for public comment. Notice would be published in 
the Federal Register within thirty days of the action.


Sec.  217.98  [Reserved]


Sec.  217.99  [Reserved]

[FR Doc. 2018-15938 Filed 7-30-18; 8:45 am]
 BILLING CODE 3510-22-P