Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to U.S. Navy Pier Construction Activities at Naval Submarine Base New London, 16027-16043 [2018-07728]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 83, Number 72 (Friday, April 13, 2018)]
[Proposed Rules]
[Pages 16027-16043]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-07728]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 170908887-8328-01]
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.

[[Page 16028]]


ACTION: Proposed rule; request for comments and information.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization to take 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 (2018-
2023). As required by the Marine Mammal Protection Act (MMPA), NMFS is 
proposing regulations to govern that take, and requests comments on the 
proposed regulations. NMFS will consider public comments prior to 
making any final decision on the issuance of the requested MMPA 
authorization and agency responses will be summarized in the final 
notice of our decision.

DATES: Comments and information must be received no later than May 14, 
2018.

ADDRESSES: You may submit comments, identified by NOAA-NMFS-2018-0047, 
by any of the following methods:
     Electronic submissions: Submit all electronic public 
comments via the Federal eRulemaking Portal, Go to www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2018-0047, click the ``Comment Now!'' icon, 
complete the required fields, and enter or attach your comments.
     Mail: Submit comments to Jolie Harrison, Chief, Permits 
and Conservation Division, Office of Protected Resources, National 
Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 
20910-3225.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address, etc.), confidential business 
information, or otherwise sensitive information submitted voluntarily 
by the sender may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information. 
NMFS will accept anonymous comments (enter ``N/A'' in the required 
fields if you wish to remain anonymous). Attachments to electronic 
comments will be accepted in Microsoft Word, Excel, or Adobe PDF file 
formats only.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected 
Resources, NMFS; phone: (301) 427-8401. Electronic copies of the 
application and supporting documents, as well as a list of the 
references cited in this document, may be obtained online at: 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of 
problems accessing these documents, please call the contact listed 
above.

SUPPLEMENTARY INFORMATION: 

Purpose and Need for Regulatory Action

    This proposed rule would establish 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 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 
proposed rule contains mitigation, monitoring, and reporting 
requirements.

Summary of Major Provisions Within the Proposed Rule

    Following is a summary of the major provisions of this proposed 
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).

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

[[Page 16029]]

preliminarily 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. We will 
consider all public comments prior to making a final decision regarding 
application of CE B4.
    We will review all comments submitted in response to this notice as 
we complete the NEPA process, prior to making a final decision on the 
incidental take authorization request.

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.
    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; and
     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 in October 2018 and proceed to 
completion in March 2022.
    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 October 2018. 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 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

[[Page 16030]]

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 (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        Strike number
             Activity                 Pile         Pile type              Method        Piles/day   driving        (impact) or            Duration
                                     number                                                           days    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.

[[Page 16031]]

 
                                          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 Pier
                                               concrete-filled      drilling.                                                        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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         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.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Year 4
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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

Description of Marine Mammals in the Area of the Specified Activities

    Marine mammal species that could be present in the Study Area and 
their associated stocks are presented in Table 2 along with an 
abundance estimate, an associated coefficient of variation value, and 
best/minimum abundance estimates. There are other species of marine 
mammals, including a number of cetaceans, that are known to be present 
in nearby Long Island Sound. However, since received noise levels from 
the project are not expected to reach the mouth of the Thames River due 
to geographical boundaries, these species are excluded from further 
discussion. The Navy proposes to take individuals of harbor seal and 
gray seal by Level A and B harassment incidental to pier construction 
activities. Neither of these marine mammal species is listed as 
endangered or threatened under the Endangered Species Act (ESA).
    Information on the status, distribution, and abundance of these 
seal species in the Study Area may be viewed in the Navy's LOA 
application. Additional information on the general biology and ecology 
of marine mammals are included in the application. In addition, NMFS 
annually publishes Stock Assessment Reports (SARs) for all marine 
mammals in U.S. EEZ waters, including stocks that occur within the 
Study Area--U.S. Atlantic and Gulf of Mexico Marine Mammal Stock 
Assessment Reports (Hayes et al., 2017).

                Table 2--Marine Mammals That May Occur Within Navy Submarine Base New London Area
----------------------------------------------------------------------------------------------------------------
                                                                                Stock abundance
         Common name          Scientific name       Stock          ESA/MMPA      best/ minimum    Occurrence in
                                                                    status         population       study area
----------------------------------------------------------------------------------------------------------------
                                                 Order Carnivora
----------------------------------------------------------------------------------------------------------------
                                               Suborder Pinnipedia
----------------------------------------------------------------------------------------------------------------
                                          Family Phocidae (true seals)
----------------------------------------------------------------------------------------------------------------
Gray seal...................  Halichoerus      Western North    ..............  505,000 *......  Thames River.
                               grypus.          Atlantic.
Harbor seal.................  Phoca vitulina.  Western North    ..............  75,834 (0.15)/   Thames River.
                                                Atlantic.                        66,884.
----------------------------------------------------------------------------------------------------------------
* 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.


[[Page 16032]]

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;
     Phocidae (true seals): Generalized hearing is estimated to 
occur between approximately 50 Hz to 86 kHz;
     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. 
Only two marine mammal species (both are phocid species) have the 
reasonable potential to co-occur with the proposed construction 
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 et al., 2000, 2002, 2003, 2005, 2007, 2010a, 2010b; 
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et 
al., 2000; Nachtigall et al., 2003, 2004). 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 
impacts. Also, depending on the degree

[[Page 16033]]

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 benthic 
survey, benthic assemblages are

[[Page 16034]]

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 haulouts 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

    This section provides an estimate of the number of incidental takes 
proposed to be authorized through this rule, which will inform both 
NMFS' consideration of whether the number of takes is ``small'' and the 
negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. 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).
    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     LE,LF,24h: 199   Lrms,flat: 160 dB.....  Lrms,flat: 120 dB.
                                dB; LE,LF,24h:    dB.
                                183 dB.
Mid-Frequency (MF) Cetaceans.  Lpk,flat: 230     LE,MF,24h: 198
                                dB; LE,MF,24h:    dB.
                                185 dB.

[[Page 16035]]

 
High-Frequency (HF) Cetaceans  Lpk,flat: 202     LE,HF,24h: 173
                                dB; LE,HF,24h:    dB.
                                155 dB.
Phocid Pinnipeds (PW)          Lpk,flat: 218     LE,PW,24h: 201
 (Underwater).                  dB; LE,PW,24h:    dB.
                                185 dB.
Otariid Pinnipeds (OW)         Lpk,flat: 232     LE,OW,24h: 219
 (Underwater).                  dB; LE,OW,24h:    dB.
                                203 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 on13-inch plastic piles: 177 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 16036]]



                             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]Pa2-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                   177             153                 144
                                       plastic pile.
Vibratory driving...................  16-in fiberglass                    NA             153                 153
                                       plastic pile.
Rock socket drilling................  30-in steel pile & 16-              NA             154                 154
                                       in 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 10m.
    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.
    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
       Year            Activity description     @10m, dB (rms/   Level A distance (m)/    Level B distance (m)/
                                                     SEL)             area (km\2\)             area (km\2\)
----------------------------------------------------------------------------------------------------------------
1.................  Impact driving 14'' steel          187/177  536/0.4468.............  631/0.5468.
                     H-pile.
                    Vibratory & rock socket                168  <4/<0.0001.............  4,642/2.2002.
                     drilling installation of
                     36'' concrete-filled
                     steel piles.
                    Impact driving 36''                198/183  984/0.886..............  3,415/2.037.
                     concrete-filled steel
                     piles.
                                                               -------------------------------------------------
                    Rocket socket drilling of              154     Activity will occur concurrently with above
                     30'' concrete-filled                            activities that have much bigger zones.
                     steel piles and 16''
                     fiberglass reinforced
                     plastic piles.
                                                               -------------------------------------------------
2.................  Vibratory installation of              168  <4/<0.0001.............  4,642/2.2002.
                     36'' concrete-filled
                     steel piles.
                    Impact pile driving 36''           198/183  984/0.886..............  3,415/2.037.
                     concrete-filled steel
                     piles.
3.................  Vibratory installation of              153  0.9/<0.0001............  1,584/1.1584.
                     16'' fiberglass plastic
                     piles.
                    Impact installation of             153/144  2.5/<0.0001............  1/<0.000.
                     16'' fiberglass plastic
                     piles.
4.................  Vibratory removal of 14''              158  <4/<0.0001.............  2,415/1.8372.
                     steel H-piles.
                    Vibratory removal of 24''              160  2.7/<0.0001............  4,334/2.029.
                     concrete-filled steel
                     piles (Pier 32).
                    Vibratory removal of 30''              165  5.9/<0.0001............  4,334/2.029.
                     concrete-filled steel
                     piles (Pier 32).
                    Vibratory removal of 24''              160  7.7/<0.0001............  4,642/3.317.
                     concrete-filled steel
                     piles (Pier 10).
----------------------------------------------------------------------------------------------------------------


[[Page 16037]]

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).
    Based on the repeated sightings at the Submarine Base New London, 
the average presence of seals (harbor or gray) is estimated to be 4 per 
week or 0.6 per day from September through May. The majority (75 
percent) of these are likely to be harbor seals. There are no areas 
(haulouts) 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 percent harbor seals (0.45/km\2\) and 25 percent 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; and
     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 injury zones 
and the 10 m (33 ft) exclusion 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            0.15
                Gray seal.......               0              37              37          27,131            0.14
----------------------------------------------------------------------------------------------------------------


[[Page 16038]]

Proposed 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 would 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 Exclusion Zones
    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 
[mu]Pa for impulsive noise sources (impact pile driving) and 120 
dBrms re 1 [mu]Pa for non-impulsive noise sources (vibratory 
pile driving and pile removal).
    The Navy shall establish a 10-m (33-ft) exclusion zone for all in-
water construction and demolition work.
    If marine mammals are found within the exclusion 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 
exclusion zone.
    If pile driving of a segment ceases for 30 minutes or more and a 
marine mammal is sighted within the designated exclusion 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 exclusion zone. Operations may not resume until 
the marine mammal has exited the exclusion 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) exclusion zone.
    Further, the Navy shall implement shutdown measures if the number 
of authorized takes for any particular species reaches the limit under 
the LOA (if issued) 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.
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 impact driving with soft-
start procedures described above.
    Based on our evaluation of the required measures, NMFS has 
preliminarily 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.

Proposed 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

[[Page 16039]]

     Mitigation and monitoring effectiveness.

Proposed 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. 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 exclusion 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, 
impact pile driving would be halted but vibratory pile driving or 
extraction would be allowed to continue;
     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 exclusion zone will be monitored for 15 minutes prior to in-
water construction/demolition activities. If a marine mammal is present 
within the 10-m exclusion zone, the activity will be delayed until the 
animal(s) leave the exclusion 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 exclusion zone. If a marine mammal is 
observed approaching the exclusion 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 exclusion zone, the pile segment being worked on 
will be completed without cessation, unless the animal enters or 
approaches the exclusion zone, at which point all pile driving 
activities will be halted. If an animal is observed within the 
exclusion 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 exclusion zone of its own volition or 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.

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 would 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. NMFS would provide comments within 30 days after receiving 
these reports, and the Navy should 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 (if issued), whichever comes earlier. This 
report would 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 would provide comments 
within 30 days after receiving this report, and the Navy should 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 would require 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 would report the same 
information as listed above to NMFS as soon as operationally feasible.

[[Page 16040]]

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 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 
haulouts, 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'' section.
    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 preliminarily 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 preliminarily 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.

[[Page 16041]]

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.

Request for Information

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning the Navy request and the proposed 
regulations (see ADDRESSES). All comments will be reviewed and 
evaluated as we prepare a final rule and make final determinations on 
whether to issue the requested authorization. This notice and 
referenced documents provide all environmental information relating to 
our proposed action for public review.

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 218

    Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine 
mammals, Navy, Penalties, Reporting and recordkeeping requirements, 
Seafood, Sonar, Transportation.

    Dated: April 10, 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 proposed 
to be amended as follows:

PART 218--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.

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 [EFFECTIVE DATE OF FINAL 
RULE] through [DATE 5 YEARS AFTER EFFECTIVE DATE OF FINAL RULE].


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 of 
this chapter 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
    (d) 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 exclusion zones:
    (1) For all relevant in-water construction and demolition activity, 
the Navy shall implement shutdown zones with radial distances as 
identified in any LOA issued under Sec.  216.106 of this chapter and 
Sec.  217.96. If a marine mammal comes within or approaches the 
shutdown zone, such operations shall cease;

[[Page 16042]]

    (2) For all relevant in-water construction and demolition activity, 
the Navy shall designate monitoring zones with radial distances as 
identified in any LOA issued under Sec.  216.106 of this chapter and 
Sec.  217.96; and
    (3) For all in-water construction and demolition activity, the Navy 
shall implement a minimum shutdown zone of a 10 meter (m) radius around 
the pile. If a marine mammal comes within or approaches the shutdown 
zone, such operations shall cease;
    (c) Shutdown Measures. (1) The Navy shall deploy three protected 
species observers (PSO) 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.
    (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, 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 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) Monitoring shall be conducted by trained observers, who shall 
have no other assigned tasks during monitoring periods. Trained 
observers 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. The 
Navy shall adhere to the following additional observer qualifications:
    (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 (degree in 
biological science or related field) or training for experience;
    (iv) Where a team of three or more observers are required, one 
observer shall be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer; and
    (v) The Navy shall submit observer CVs for approval by NMFS;
    (5) 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.
    (c) 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 Protocols. The Navy shall conduct 
briefings between construction supervisors and crews and the observer 
team prior to the start of all pile driving and removal activities, and 
when new personnel join the work. Trained observers shall receive a 
general environmental awareness briefing conducted by Navy staff. At 
minimum, training shall include identification of marine mammals that 
may occur in the project vicinity and relevant mitigation and 
monitoring requirements. All observers shall have no other 
construction-related tasks while conducting monitoring.
    (b) Pile driving or removal shall only take place when the 
exclusion and Level A zones are visible and can be adequately 
monitored. If conditions (e.g., fog) prevent the visual detection of 
marine mammals, activities shall not be initiated. If such conditions 
arise after the activity has begun, impact pile driving would be halted 
but vibratory pile driving or removal would be allowed to continue.
    (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 would 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) NMFS would 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);

[[Page 16043]]

    (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) 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) of this subpart.
    (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 LOA(s) expires prior to the expiration date of these 
regulations, the Navy may apply for and obtain a renewal of the LOA(s).
    (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 LOA(s) 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 LOA(s) 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 subchapter 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 LOA(s) 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 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. 2018-07728 Filed 4-12-18; 8:45 am]
BILLING CODE 3510-22-P