[Federal Register Volume 83, Number 147 (Tuesday, July 31, 2018)]
[Rules and Regulations]
[Pages 36773-36791]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-15938]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 170908887-8622-02]
RIN 0648-BH24
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to U.S. Navy Pier Construction Activities at Naval Submarine
Base New London
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Final rule.
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SUMMARY: Upon application from the U.S. Navy (Navy), NMFS is issuing
regulations under the Marine Mammal Protection Act for the taking of
marine mammals incidental to the pier construction activities conducted
at the Naval Submarine Base New London in Groton, Connecticut, over the
course of five years (2020-2025). These regulations allow NMFS to issue
a Letter of Authorization (LOA) for the incidental take of marine
mammals during the specified construction activities carried out during
the rule's period of effectiveness, set forth the permissible methods
of taking, set forth other means of effecting the least practicable
adverse impact on marine mammal species or stocks and their habitat,
and set forth requirements pertaining to the monitoring and reporting
of the incidental take.
DATES: Effective March 1, 2020 through February 28, 2025.
ADDRESSES: To obtain an electronic copy of the Navy's LOA application
or other referenced documents, visit the internet at:
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of
problems accessing these documents, please call the contact listed
below (see FOR FURTHER INFORMATION CONTACT).
FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected
Resources, NMFS; phone: (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Purpose and Need for Regulatory Action
This final rule establishes a framework under the authority of the
MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of take of
marine mammals incidental to the Navy's construction activities related
to marine structure maintenance and pile replacement at a facility in
Groton, Connecticut.
We received an application from the Navy requesting five-year
regulations and authorization to take multiple species of marine
mammals. Take would occur by Level A and Level B harassment incidental
to impact and vibratory pile driving. Please see ``Background'' below
for definitions of harassment.
Legal Authority for the Proposed Action
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
the Secretary of Commerce to allow, upon request, the incidental, but
not intentional taking of small numbers of marine mammals by U.S.
citizens who engage in a specified activity (other than commercial
fishing) within a specified geographical region for up to five years
if, after notice and public comment, the agency makes certain findings
and issues regulations that set forth permissible methods of taking
pursuant
[[Page 36774]]
to that activity and other means of effecting the ``least practicable
adverse impact'' on the affected species or stocks and their habitat
(see the discussion below in the ``Proposed Mitigation'' section), as
well as monitoring and reporting requirements. Section 101(a)(5)(A) of
the MMPA and the implementing regulations at 50 CFR part 216, subpart
I, provide the legal basis for issuing this proposed rule containing
five-year regulations, and for any subsequent letters of authorization
(LOAs). As directed by this legal authority, this final rule contains
mitigation, monitoring, and reporting requirements.
Summary of Major Provisions Within the Final Rule
Following is a summary of the major provisions of this final rule
regarding Navy construction activities. These measures include:
Required monitoring of the construction areas to detect
the presence of marine mammals before beginning construction
activities.
Shutdown of construction activities under certain
circumstances to avoid injury of marine mammals.
Soft start for impact pile driving to allow marine mammals
the opportunity to leave the area prior to beginning impact pile
driving at full power.
Background
Sections 101(a)(5)(A) and (D) of the Marine Mammal Protection Act
of 1972, as amended (MMPA; 16 U.S.C. 1361 et seq.) direct the Secretary
of Commerce (Secretary) to allow, upon request, the incidental, but not
intentional taking of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) if certain findings
are made and regulations are issued or, if the taking is limited to
harassment, notice of a proposed authorization is provided to the
public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such taking
are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an
impact resulting from the specified activity that cannot be reasonably
expected to, and is not reasonably likely to, adversely affect the
species or stock through effects on annual rates of recruitment or
survival.
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal. Except with respect to certain activities not pertinent here,
the MMPA defines ``harassment'' as any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild (Level A harassment); or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering (Level B harassment).
Summary of Request
On March 22, 2017, NMFS received an application from the Navy
requesting authorization to incidentally take harbor and gray seals, by
Level A and Level B harassment, incidental to noise exposure resulting
from conducting pier construction activities at the Navy Submarine Base
New London in Groton, Connecticut, from October 2018 to March 2022.
These regulations would be valid for a period of five years. On August
31, 2017, NMFS deemed the application adequate and complete. On May 23,
2018, the Navy requested that the rule be valid between March 1, 2020,
and February 28, 2025, due to construction schedule changes.
The use of sound sources such as those described in the application
(e.g., piledriving) may result in the take of marine mammals through
disruption of behavioral patterns or may cause auditory injury of
marine mammals. Therefore, incidental take authorization under the MMPA
is warranted.
Description of the Specified Activity
Overview
The Navy is planning to demolish Pier 32 and Pier 10 and construct
a new Pier 32 at Naval Submarine Base New London (SUBASE), Groton,
Connecticut.
Recent Global Shore Infrastructure Plans and Regional Shore
Infrastructure Plans identified a requirement for 11 adequate submarine
berths at SUBASE. There are currently six adequate berths available via
Piers 6, 17, and 31, leaving a shortfall of five adequate berths. The
remaining submarine berthing piers (8, 10, 12, 32, and 33) are
classified as inadequate because of their narrow width and short length
compared to current SSN (hull classification) berthing design standards
(Unified Facilities Criteria 4-152-01, Design Standards for Piers and
Wharves).
The Proposed Action is to demolish Pier 32 and Pier 10, and replace
them with a new Pier 32 that meets all current Navy SSN pier standards
to accommodate Virginia Class submarines. The Proposed Action includes:
Construction of a new, larger Pier 32 to be located
approximately 150 feet (ft) north of the current location.
Upgrade of the quaywall, north of Pier 32, may be required
to accommodate a crane weight test area.
Demolition of existing Pier 32 and Pier 10.
Dredging of the sediment mounds beneath the existing Pier
32 (approximately 9,400 cubic yards [cy]) and the existing Pier 10
(approximately 10,000 cy) to a depth of 36 ft below mean lower low
water (-36 ft MLLW) plus 2 ft of over dredge (additional dredge depth
that allows for varying degrees of accuracy of different types of
dredging equipment). Any remaining timber piles beneath the existing
piers would be pulled with a strap.
Dredging of the berthing areas alongside the proposed new
Pier 32 (approximately 74,000 sq ft) to a depth of -38 feet MLLW plus 2
feet of over dredge.
Dredging of two additional areas (approximately 10,200 cy
and 31,100 cy) in the Thames River navigation channel to a depth of -36
ft MLLW plus 2 ft of over dredge.
Two species of marine mammals are expected to potentially be
present in the Thames River near SUBASE: Harbor seal (Phoca vitulina)
and gray seal (Halichoeris grypus). Harbor seals and gray seals are
more likely to occur at SUBASE from September to May.
Dates and Duration
Pile installation for the new Pier 32 and pile removal associated
with the demolition of the existing Piers 32 and 10 is expected to take
a total of approximately 3.5 years. Construction and demolition
activities are expected to begin no earlier than March 2020 and proceed
to completion in February 2025.
In-water activities expected to result in incidental takes of
marine mammals would occur during approximately 35 non-consecutive
months of the project beginning in March 2020. The estimated duration
of pile installation and removal, including duration of the vibratory
and impact hammer activities, is provided in Table 1 below for each
year of construction and demolition. Also included in the Table are the
durations for wood piles and steel fender piles to be pulled by a crane
using a sling or strap attached to the pile. The durations of proposed
pile driving/removal activities are primarily
[[Page 36775]]
derived from information provided by Naval Facilities Engineering
Command (NAVFAC) Mid-Atlantic Public Works Department, Facilities
Engineering and Acquisition Department (FEAD) Design Manager and the
record of pile driving activities documented during the construction of
SUBASE Pier 31 (American Bridge 2010-2011). The proposed new Pier 32
would be comparable to Pier 31 in design and location and would have
similar sub-surface geological conditions along this reach of the
Thames River.
Specified Geographical Region
SUBASE is located in the towns of Groton and Ledyard in New London
County, Connecticut. SUBASE occupies approximately 687 acres along the
east bank of the Thames River, 6 mi north of the river's mouth at Long
Island Sound (Figure 1-1 in LOA application). The Thames River is the
easternmost of Connecticut's three major rivers and is formed by the
confluence of the Shetucket and Yantic rivers in Norwich, from which it
flows south for 12 mi to New London Harbor. The Thames River discharges
freshwater and sediment from the interior of eastern Connecticut into
Long Island Sound. It is the main drainage of the Thames River Major
Drainage Basin, which encompasses approximately 3,900 square mi of
eastern Connecticut and central Massachusetts (USACE 2015). The lower
Thames River and New London Harbor sustains a variety of military,
commercial, and recreational vessel usage. New London Harbor provides
protection to a number of these.
Detailed Description of Specified Activity
1. Construction of New Pier 32
Pile driving would most likely be conducted using a barge and
crane. However, the contractor may choose to use a temporary pile-
supported work trestle that would be constructed by driving
approximately 60 steel 14-inch diameter H-piles.
Structural support piles for Pier 32 would consist of approximately
120 concrete-filled steel pipe piles measuring 36 inches in diameter.
The piles would be driven between 40 ft below the mudline near the
shore and 150 ft below the mudline at the end of the pier. Fender piles
would also be installed and would consist of approximately 194
fiberglass-reinforced plastic piles measuring 16 inches in diameter.
Special construction features would include drilling rock sockets
into bedrock in an estimated 60 places to hold the piles. A rotary
drill using a rock core barrel and rock muck bucket would be used
inside of the steel pipe piles to drill a minimum of 2 ft down into
bedrock to create the rock socket that would be filled with concrete.
Sediment would be lifted out and re-deposited within 10 ft of the pipe
pile during rock socket drilling. Underwater noise from the rock drill
as it is operated inside a steel pipe would be much less than that
produced by vibratory and impact pile driving of the steel pipes
(Martin et al. 2012).
Impact and vibratory hammers would be used for installing piles
where rock sockets are not required. Based on previous construction
projects at SUBASE, it is estimated that an average of one 36-inch pile
per week (with driving on multiple days) and two plastic piles per day
would be installed. The per-pile drive time for each pile type and
method will vary based on environmental conditions (including
substrate) where each pile is driven. Impact or vibratory pile driving
may result in harassment of marine mammals.
Construction of Pier 32 may also require upgrade of the quaywall
north of Pier 32 to provide the reinforcement needed to support a crane
weight test area. Because there is potential that a work trestle would
be used and the requirement for the upgrade will not be determined
until final design, the pile driving is included in the analyzed
activities. The quaywall upgrade would include up to approximately
eighteen 30-inch diameter concrete-filled steel pipe piles that would
be installed into rock sockets driven into bedrock adjacent and
parallel to the existing steel sheet pile wall. Pile caps and a
concrete deck would be installed above the piles. A fender system
composed of approximately nine 16-inch diameter plastic piles would
also be installed into rock sockets approximately 2 ft in front of the
new deck.
2. Demolition and Removal of Pier 32 and Pier 10
When the new Pier 32 is operational, the existing Pier 32 would be
demolished using a floating crane and a series of barges. Pier 10 would
be demolished after the demolition of existing Pier 32. The concrete
decks of the piers would be cut into pieces and placed on the barges.
Demolition debris would be sorted and removed by barge and recycled to
the maximum extent practicable. Any residual waste would be disposed of
offsite in accordance with applicable federal, state, and local
regulations. Once the decks are removed, the steel H piles and pipe
piles that support the existing pier would be pulled using a vibratory
extraction method (hammer). The vibratory hammer would be attached to
the pile head with a clamp. Once attached, vibration would be applied
to the pile that would liquefy the adjacent sediment allowing the pile
to be removed.
Demolition of existing Pier 32 would include the removal by
vibratory driver-extractor (hammer) of approximately 60 steel piles
from the temporary work trestle, 120 concrete-encased steel H-piles,
and 70 steel H-piles. Fifty-six wood piles would be pulled with a
sling. Demolition of Pier 10 would include the removal by vibratory
hammer of 24 concrete-encased, steel H-piles and 166 cast-in-place,
reinforced concrete piles. Eighty-four steel fender piles and 41 wood
piles would be pulled with a sling. A total of 440 piles would be
removed by vibratory hammer for both piers and the work trestle.
3. Dredging of Pier Areas and Navigation Channel
The Proposed Action would also include dredging of approximately
60,000 cy of sediment in two areas of the Thames River navigation
channel near Pier 32, the berthing areas alongside the new Pier 32, and
underneath existing Pier 32 and Pier 10 after demolition. All dredging
for the Proposed Action would support safe maneuvering for entry and
departure of submarines at the proposed new Pier 32 and existing Piers
8, 12, 17, and 31. The proposed design dredge depth in all areas to be
dredged is -36 ft relative to MLLW plus 2 ft of over dredge.
Dredging would be conducted in two phases. Dredging of the new Pier
32 area and the northern portion of the channel dredge areas would be
conducted in the first construction year. The footprints of the
demolished Pier 32 and Pier 10 and the southern portions of the channel
dredge areas would be dredged after demolition of the existing piers in
the fourth year of construction. Dredging would occur only during the
period between October 1 and January 31 to avoid potential impacts on
shellfish and fisheries resources in the area. Each dredging and
disposal phase would take approximately 2 weeks to complete.
After the demolition of Pier 32, any remnant timber piles present
underneath existing Pier 32 would be pulled with a strap. The sediment
mound that has formed beneath the pier would be dredged (approximately
9,400 cy) to the design depth. Dredging would also be required
immediately west of Piers 31 and 32 (approximately 10,200 cy) and along
the eastern edge
[[Page 36776]]
(approximately 31,100 cy) of the navigation channel to achieve the
required minimum depths to maneuver the submarines. Once the existing
Pier 10 and any remnant timber piles are removed, the sediment mound
beneath the old pier would be dredged (approximately 10,000 cy).
Since dredging and disposal activities would be slow moving and
conspicuous to marine mammals, they pose negligible risks of physical
injury. An environmental bucket would be used for dredging to minimize
turbidity compared with the turbidity generated by hydraulic dredging.
Noise emitted by dredging equipment is broadband, with most energy
below 1 kilohertz (kHz), and would be similar to that generated by
vessels and maritime industrial activities that regularly operate
within the action area (Clarke et al. 2002; Todd et al. 2015). Due to
the low noise output and slow and steady transiting nature of the
dredging activity, NMFS does not consider it would result to the level
of harassment under the MMPA. Therefore, dredging is not considered
further in this document.
Table 1--Summary of Construction Activities for the Navy Submarine Base New London
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Total
Activity Pile No. Pile type Method Piles/day driving Strike number (impact) Duration
days or duration(s) per pile
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Year 1
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Pier 32 construction............ 60 14'' steel H-pile Impact............ 4 15 1,000 strikes.......... 3 weeks.
temp. work trestle.
60 36'' x 100' Vibratory hammer & 0.5 120 1,200 seconds.......... 6 months.
concrete-filled rock socket
steel pipe piles. drilling.
20 36'' x 180' Vibratory hammer.. 0.2 100 1,800 seconds.......... 5 months.
concrete-filled
steel piles.
20 36'' x 180' Impact hammer to 2.5 8 1,000 strikes.......... 2 weeks.
concrete-filled last 20-40 ft.
steel piles.
Quaywall upgrade................ 18 30'' x 100' Rock socket 0.5 36 15,000 seconds......... Concurrent with
concrete-filled drilling. Pier 32.
steel pipe piles.
9 16'' fiberglass Rock socket 0.5 18 7,500 seconds..........
reinforced plastic drilling.
piles.
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Year 2
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Pier 32 construction............ 40 36'' x 180' Vibratory hammer.. 0.2 200 1,800 seconds.......... 10 months.
concrete-filled
steel piles.
40 36'' x 180' Impact hammer to 2.5 16 1,000 strikes.......... 3.5 weeks.
concrete-filled drive last 20-40
steel piles. ft.
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Year 3
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Pier 32 construction............ 194 16'' fiberglass Vibratory hammer.. 2 97 1,200 seconds.......... 5 months.
reinforced plastic
piles.
64 16'' fiberglass Impact hammer to 2.5 26 1,000 strikes.......... 1.5 months.
reinforced plastic drive last 20-40
piles. ft.
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Year 4
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Pier 32 demolition.............. 60 14'' steel H-piles Vibratory hammer 5 14 1,200 seconds.......... 3 weeks.
temp. work trestle. (removal).
24 33'' concrete- Vibratory hammer 2 12 1,200 seconds.......... 3.5 months.
encased steel H (removal).
piles.
96 24'' concrete- Vibratory hammer 2 48 1,200 seconds..........
encased steel H (removal).
piles.
70 14'' steel H piles. Vibratory hammer 5 14 1,200 seconds..........
(removal).
Pier 10 demolition.............. 24 24'' concrete- Vibratory hammer 9.5 2.5 1,200 seconds.......... 0.5 month.
encased steel H (removal).
piles.
166 24'' cast-in-place Vibratory hammer 9.5 17.5 1,200 seconds.......... 0.5 month.
reinforced (removal).
concrete piles.
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Prescribed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see ``Mitigation''
and ``Monitoring and Reporting'').
Comments and Responses
NMFS published a proposed rule in the Federal Register on April 13,
2018 (83 FR 16027). During the 30-day public comment period on the
proposed rule, NMFS received comments from the Marine Mammal Commission
(Commission). We did not receive other comments.
Comment 1: The Commission recommends that NMFS require the Navy to
conduct sound source verification (SSV) and the size of Level B
harassment zone measurements for certain piles that data are lacking
and where the zones are not based on modeling. These acoustic
measurements include:
Vibratory and impact installation of at least five 16-in
fiberglass-reinforced plastic piles--measurements for source levels;
Rock socket drilling of at least three 30-in and three 16-
in piles--measurements for source levels and the extent of the Level B
harassment zones;
Vibratory installation of at least three 36-in steel
piles--measurements for the extent of the Level B harassment zone; and
Vibratory removal of at least three 24-in concrete and
three 33-in concrete piles--measurements for source levels and the
extent of the Level B harassment zones.
Response: NMFS discussed these recommendation with the Navy and the
Navy agreed to conduct SSVs on the piles for which source level data
are not already available. SSV measurements to be conducted are:
Vibratory and impact installation of at least 5 16-in
fiberglass reinforced plastic piles, and
[[Page 36777]]
Rock socket drilling of at least 3 30-in and 3 16-in
piles.
However, the Navy did not agree to conduct acoustic measurements to
the extent of the Level B harassment zones. The Navy indicated that
conducting hydroacoustic monitoring to the extent of the Level B
harassment zones is not a common requirement based on the five most
recent active IHAs, including U.S. Army Corps of Engineers' (USACE)
Tampa Harbor Big Bend Channel expansion project, the City of Astoria's
waterfront bridge replacement project, the Navy's Bravo wharf
recapitalization project, and U.S. Coast Guard's (USCG) Monterey
waterfront repair project. Instead, the Navy offered to conduct
hydroacoustic measurements at several points between 10 and 500 m from
the source and extrapolate the distance of the Level B harassment zone.
While being able to determine the extent of Level B harassment
zones is critical to accurately assess the potential impacts to marine
mammals, these zones can be determined by means other than direct
measurements recommended by the Commission. Therefore, NMFS considers
the Navy's proposal of extrapolating the Level B harassment zone using
near- and far-field measurement data a valid approach.
Therefore, in the final rule, NMFS requires the Navy to conduct
SSVs on the piles listed above and to conduct measurements on several
locations between 10 and 500 m from the source to determine the Level B
harassment zones for those zones that were not based on modeling.
These requirements are included in the final rule.
Comment 2: The Commission recommends that NMFS require the Navy to
include certain metrics in the hydroacoustic monitoring report for
measurements being conducted. These metrics include:
Root-mean-square sound pressure levels
(SPLrms), 1-sec sound exposure levels (SELs), duration of
recordings used to derive SELs, cumulative SEL (SELcum)
based on the number of piles and driving duration for each scenario,
and SEL source spectra for vibratory pile driving/removal source level
measurements;
Peak SPLs (SPLpeak), SPLrms,
integration time/pulse duration for SPLrms, single-strike
SPLs (SPLs-s), SELcum based on the number of
piles and driving duration for each scenario, and SELs-s
spectra for impact pile driving source level measurements;
The measured (or extrapolated, if not reached) distances
at which the SPLrms decays to 120 dB re 1 [mu]Pa or to
ambient, whichever is higher, and integration time/pulse duration for
SPLrms for verification of the extent to the Level B
harassment zones;
All sound levels via medians, means, minimums, and
maximums and linear average (i.e., averaging the sound intensity/
pressure before converting to dB); and
Sediment type, water depth, hydrophone depth, etc.
Response: NMFS discussed this with the Navy and the Navy agreed to
report these metrics in the acoustic monitoring report. These
requirements are included in the final rule.
Comment 3: The Commission recommends that NMFS revise its draft
rounding criteria and share it with the Commission.
Response: NMFS appreciates the Commission's ongoing concern in this
matter. Calculating predicted takes is not an exact science and there
are arguments for taking different mathematical approaches in different
situations, and for making qualitative adjustments in other situations.
We believe, however, that the methodology used for take calculation in
this LOA remains appropriate and is not at odds with the 24-hour reset
policy the Commission references. We look forward to continued
discussion with the Commission on this matter and will share the
rounding guidance as soon as is appropriate.
Description of Marine Mammals in the Area of the Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history, of the potentially affected species.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical
and behavioral descriptions) may be found on NMFS's website (https://www.fisheries.noaa.gov/seals-sea-lions).
Table 2 lists all species with expected potential for occurrence in
location and summarizes information related to the population or stock,
including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. For taxonomy, we follow
Committee on Taxonomy (2017). PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS's
SARs). While no mortality is anticipated or authorized here, PBR and
annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Atlantic SARs (Waring et al., 2017). All values presented
in Table 2 are the most recent available at the time of publication and
are available in the draft 2017 SARs (Hayes et al., 2017).
Table 2--Marine Mammals That May Occur Within Navy Submarine Base New London Area
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Stock abundance best/
Common name Scientific name Stock ESA/MMPA status minimum population Occurrence in study area
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Order Carnivora
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Suborder Pinnipedia
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Family Phocidae (true seals):
Gray seal..................... Halichoerus grypus... Western North ..................... 505,000 *........... Thames River.
Atlantic.
Harbor seal................... Phoca vitulina....... Western North ..................... 75,834 (0.15)/66,884 Thames River.
Atlantic.
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* There are an estimated 27,131 seals in U.S. waters; however, gray seals form one population not distinguished on the basis of the U.S./Canada boundary
(Waring et al., 2017).
[[Page 36778]]
All species that could potentially occur in the proposed survey
areas are included in table 2. As described below, all two species
(with two managed stocks) temporally and spatially co-occur with the
activity to the degree that take is reasonably likely to occur, and we
have proposed authorizing it.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65 dB
threshold from the normalized composite audiograms, with the exception
for lower limits for low-frequency cetaceans where the lower bound was
deemed to be biologically implausible and the lower bound from Southall
et al. (2007) retained. The functional groups and the associated
frequencies are indicated below (note that these frequency ranges
correspond to the range for the composite group, with the entire range
not necessarily reflecting the capabilities of every species within
that group):
Low-frequency cetaceans (mysticetes): Generalized hearing
is estimated to occur between approximately 7 Hz and 35 kHz;
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Generalized hearing is estimated to occur
between approximately 150 Hz and 160 kHz;
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, on the basis of recent echolocation data
and genetic data): Generalized hearing is estimated to occur between
approximately 275 Hz and 160 kHz.
Pinnipeds in water; Phocidae (true seals): Generalized
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
Pinnipeds in water; Otariidae (eared seals): Generalized
hearing is estimated to occur between 60 Hz and 39 kHz.
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2016) for a review of available information.
Two marine mammal species (both phocid species) have the reasonable
potential to co-occur with the proposed survey activities. Please refer
to Table 2.
Potential Impacts to Marine Mammals
The Navy's Submarine Base New London pier construction using in-
water pile driving and pile removal could adversely affect marine
mammal species and stocks by exposing them to elevated noise levels in
the vicinity of the activity area.
Exposure to high intensity sound for a sufficient duration may
result in auditory effects such as a noise-induced threshold shift
(TS)--an increase in the auditory threshold after exposure to noise
(Finneran et al., 2005). Factors that influence the amount of threshold
shift include the amplitude, duration, frequency content, temporal
pattern, and energy distribution of noise exposure. The magnitude of
hearing threshold shift normally decreases over time following
cessation of the noise exposure. The amount of TS just after exposure
is the initial TS. If the TS eventually returns to zero (i.e., the
threshold returns to the pre-exposure value), it is a temporary
threshold shift (TTS) (Southall et al., 2007).
Threshold Shift (noise-induced loss of hearing)--When animals
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an
animal to detect them) following exposure to an intense sound or sound
for long duration, it is referred to as a noise-induced TS. An animal
can experience TTS or permanent threshold shift (PTS). TTS can last
from minutes or hours to days (i.e., there is complete recovery), can
occur in specific frequency ranges (i.e., an animal might only have a
temporary loss of hearing sensitivity between the frequencies of 1 and
10 kHz), and can be of varying amounts (for example, an animal's
hearing sensitivity might be reduced initially by only 6 dB or reduced
by 30 dB). PTS is permanent, but some recovery is possible. PTS can
also occur in a specific frequency range and amount as mentioned above
for TTS.
For marine mammals, published data are limited to the captive
bottlenose dolphin, beluga, harbor porpoise, and Yangtze finless
porpoise (Finneran, 2015). For pinnipeds in water, data are limited to
measurements of TTS in harbor seals, an elephant seal, and California
sea lions (Kastak et al., 1999, 2005; Kastelein et al., 2012b).
Lucke et al. (2009) found a TS of a harbor porpoise after exposing
it to airgun noise with a received sound pressure level (SPL) at 200.2
dB (peak-to-peak) re: 1 micropascal ([mu]Pa), which corresponds to a
sound exposure level of 164.5 dB re: 1 [mu]Pa\2\ s after integrating
exposure. Because the airgun noise is a broadband impulse, one cannot
directly determine the equivalent of root mean square (rms) SPL from
the reported peak-to-peak SPLs. However, applying a conservative
conversion factor of 16 dB for broadband signals from seismic surveys
(McCauley, et al., 2000) to correct for the difference between peak-to-
peak levels reported in Lucke et al. (2009) and rms SPLs, the rms SPL
for TTS would be approximately 184 dB re: 1 [mu]Pa, and the received
levels associated with PTS (Level A harassment) would be higher.
Therefore, based on these studies, NMFS recognizes that TTS of harbor
porpoises is lower than other cetacean species empirically tested
(Finneran & Schlundt, 2010; Finneran et al., 2002; Kastelein and
Jennings, 2012).
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS, and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to serious
(similar to those discussed in auditory masking, below). For example, a
marine mammal may be able to readily compensate for a brief, relatively
small amount of TTS in a non-critical frequency range that occurs
during a time where ambient noise is lower and there are not as many
competing sounds present. Alternatively, a larger amount and longer
duration of TTS sustained during time when communication is critical
for successful mother/calf interactions could have more serious
[[Page 36779]]
impacts. Also, depending on the degree and frequency range, the effects
of PTS on an animal could range in severity, although it is considered
generally more serious because it is a permanent condition. Of note,
reduced hearing sensitivity as a simple function of aging has been
observed in marine mammals, as well as humans and other taxa (Southall
et al., 2007), so one can infer that strategies exist for coping with
this condition to some degree, though likely not without cost.
In addition, chronic exposure to excessive, though not high-
intensity, noise could cause masking at particular frequencies for
marine mammals, which utilize sound for vital biological functions
(Clark et al., 2009). Acoustic masking is when other noises such as
from human sources interfere with animal detection of acoustic signals
such as communication calls, echolocation sounds, and environmental
sounds important to marine mammals. Therefore, under certain
circumstances, marine mammals whose acoustical sensors or environment
are being severely masked could also be impaired from maximizing their
performance fitness in survival and reproduction.
Masking occurs at the frequency band that the animals utilize.
Therefore, since noise generated from vibratory pile driving is mostly
concentrated at low frequency ranges, it may have less effect on high
frequency echolocation sounds by odontocetes (toothed whales). However,
lower frequency man-made noises are more likely to affect detection of
communication calls and other potentially important natural sounds such
as surf and prey noise. It may also affect communication signals when
they occur near the noise band and thus reduce the communication space
of animals (e.g., Clark et al., 2009) and cause increased stress levels
(e.g., Foote et al., 2004; Holt et al., 2009).
Unlike TS, masking, which can occur over large temporal and spatial
scales, can potentially affect the species at population, community, or
even ecosystem levels, as well as individual levels. Masking affects
both senders and receivers of the signals and could have long-term
chronic effects on marine mammal species and populations. Recent
science suggests that low frequency ambient sound levels have increased
by as much as 20 dB (more than three times in terms of sound pressure
level) in the world's ocean from pre-industrial periods, and most of
these increases are from distant shipping (Hildebrand, 2009). For the
Navy's Submarine Base New London pier construction, noises from
vibratory pile driving and pile removal contribute to the elevated
ambient noise levels in the project area, thus increasing potential for
or severity of masking. Baseline ambient noise levels in the vicinity
of project area are high due to ongoing shipping, construction and
other activities in the Thames River.
Finally, marine mammals' exposure to certain sounds could lead to
behavioral disturbance (Richardson et al., 1995), such as: Changing
durations of surfacing and dives, number of blows per surfacing, or
moving direction and/or speed; reduced/increased vocal activities;
changing/cessation of certain behavioral activities (such as
socializing or feeding); visible startle response or aggressive
behavior (such as tail/fluke slapping or jaw clapping); avoidance of
areas where noise sources are located; and/or flight responses (e.g.,
pinnipeds flushing into water from haulouts or rookeries).
The onset of behavioral disturbance from anthropogenic noise
depends on both external factors (characteristics of noise sources and
their paths) and the receiving animals (hearing, motivation,
experience, demography) and is also difficult to predict (Southall et
al., 2007). Currently NMFS uses a received level of 160 dB re 1 [mu]Pa
(rms) to predict the onset of behavioral harassment from impulse noises
(such as impact pile driving), and 120 dB re 1 [mu]Pa (rms) for
continuous noises (such as vibratory pile driving). For the Navy's
Submarine Base New London pier construction, both 160- and 120-dB
levels are considered for effects analysis because the Navy plans to
use both impact pile driving and vibratory pile driving and pile
removal.
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be biologically significant if the change affects
growth, survival, and/or reproduction, which depends on the severity,
duration, and context of the effects.
Potential Effects on Marine Mammal Habitat
The primary potential impacts to marine mammal habitat are
associated with elevated sound levels produced by vibratory pile
removal and pile driving in the area. However, other potential impacts
to the surrounding habitat from physical disturbance are also possible.
With regard to fish as a prey source for cetaceans and pinnipeds,
fish are known to hear and react to sounds and to use sound to
communicate (Tavolga et al., 1981) and possibly avoid predators (Wilson
and Dill, 2002). Experiments have shown that fish can sense both the
strength and direction of sound (Hawkins, 1981). Primary factors
determining whether a fish can sense a sound signal, and potentially
react to it, are the frequency of the signal and the strength of the
signal in relation to the natural background noise level.
The level of sound at which a fish will react or alter its behavior
is usually well above the detection level. Fish have been found to
react to sounds when the sound level increased to about 20 dB above the
detection level of 120 dB (Ona, 1988); however, the response threshold
can depend on the time of year and the fish's physiological condition
(Engas et al., 1993). In general, fish react more strongly to pulses of
sound (such as noise from impact pile driving) rather than continuous
signals (such as noise from vibratory pile driving) (Blaxter et al.,
1981), and a quicker alarm response is elicited when the sound signal
intensity rises rapidly compared to sound rising more slowly to the
same level.
During in-water pile driving only a small fraction of the available
habitat would be ensonified at any given time. Disturbance to fish
species would be short-term and fish would return to their pre-
disturbance behavior once the pile driving activity ceases. Thus, the
proposed construction would have little, if any, impact on marine
mammals' prey availability in the area where construction work is
planned.
Disposal of dredged material in the confined aquatic disposal (CAD)
cell would have a direct impact to the benthos as a result of burial
and suffocation. Most, if not all, sessile marine invertebrates are not
expected to survive burial. Some motile marine organisms would be
buried and unable to survive, while others such as burrowing
specialists, may survive. Survival rates would depend primarily on
burial depth. From 2010 through 2012, biannual benthic sampling of the
CAD cell area was conducted to assess the timeframe for recovery of
benthic populations of the CAD cells, in accordance with Water Quality
Certificate conditions for the 2010 waterfront maintenance dredging
project at the submarine base. The sampling results of the CAD cell
were compared to sampling results of an undisturbed reference site
located upriver. The degree of similarity of population and community
structures was assessed. The results of the three year survey program
indicated that a progressive recovery to a stable benthic population
was occurring at the CAD cell. As demonstrated by the biannual
[[Page 36780]]
benthic survey, benthic assemblages are anticipated to recover within
three to five years after the completion of the project, and disposal
impacts would not be significant (CardnoTEC 2015).
Project activities would temporarily disturb benthic and water
column habitats and change bottom topography to a minor degree, but
effects on prey availability and foraging conditions for marine mammals
would be temporary and limited to the immediate area of pier
demolition/construction, dredging, and disposal. The new surfaces of
piles and exposed concrete on the new pier would likely result in
establishment of fouling communities on the new structures, and may
attract fish and benthic organisms, resulting in small scale shifts in
prey distribution.
There are no known haul outs within the vicinity of the Proposed
Action.
The project activities would not permanently modify existing marine
mammal habitat. The activities may kill some fish and cause other fish
to leave the area temporarily, thus impacting marine mammals' foraging
opportunities in a limited portion of the foraging range; but, because
of the short duration of the activities and the relatively small area
of the habitat that may be affected, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences. Therefore, given the consideration of potential impacts
to marine mammal prey species and their physical environment, the
Navy's proposed construction activity at the submarine base would not
adversely affect marine mammal habitat.
Estimated Take
Except with respect to certain activities not pertinent here,
section 3(18) of the MMPA defines ``harassment'' as: Any act of
pursuit, torment, or annoyance which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment). Harassment is the only
type of take expected to result from these activities.
Authorized takes would be by Level A and Level B harassments, in
the form of mild permanent hearing threshold shift (Level A) and
disruption of behavioral patterns (Level B) for individual marine
mammals resulting from exposure to noise generated from impact pile
driving and vibratory pile driving and removal. Based on the nature of
the activity and the anticipated effectiveness of the mitigation
measures (e.g., shutdown measures--discussed in detail below in
Mitigation section), serious injury or mortality is neither anticipated
nor authorized.
As described previously, no mortality is anticipated or authorized
for this activity. Below we describe how the take is estimated.
Described in the most basic way, we estimate take by considering:
(1) Acoustic thresholds above which NMFS believes the best available
science indicates marine mammals will be behaviorally harassed or incur
some degree of permanent hearing impairment; (2) the area or volume of
water that will be ensonified above these levels in a day; (3) the
density or occurrence of marine mammals within these ensonified areas;
and, (4) and the number of days of activities. Below, we describe these
components in more detail and present the take estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment).
Level B Harassment for non-explosive sources--Though significantly
driven by received level, the onset of behavioral disturbance from
anthropogenic noise exposure is also informed to varying degrees by
other factors related to the source (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2011). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals are
likely to be behaviorally harassed in a manner we consider Level B
harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g.,
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms)
for non-explosive impulsive (e.g., seismic airguns) or intermittent
(e.g., scientific sonar) sources.
Applicant's proposed activity includes the use of continuous
(vibratory pile driving and removal) and impulsive (impact pile
driving) sources, and therefore the 120 and 160 dB re 1 [mu]Pa (rms)
levels are applicable.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Technical Guidance, 2016) identifies dual criteria to
assess auditory injury (Level A harassment) to five different marine
mammal groups (based on hearing sensitivity) as a result of exposure to
noise from two different types of sources (impulsive or non-impulsive).
Applicant's proposed activity includes the use of non-impulsive
(vibratory pile driving and pile removal) sources.
These thresholds were developed by compiling and synthesizing the
best available science and soliciting input multiple times from both
the public and peer reviewers to inform the final product, and are
provided in the table below. The references, analysis, and methodology
used in the development of the thresholds are described in NMFS' 2016
Technical Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
Table 3--Current Acoustic Exposure Criteria for Non-Explosive Sound Underwater
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds Behavioral thresholds
Hearing group ----------------------------------------------------------------------------------
Impulsive Non-impulsive Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans. Lpk,flat: 219 dB LE,LF,24h: 199 Lrms,flat: 160 dB.... Lrms,flat: 120 dB
LE,LF,24h: 183 dB.
dB.
Mid-Frequency (MF) Cetaceans. Lpk,flat: 230 dB LE,MF,24h: 198
LE,MF,24h: 185 dB.
dB.
High-Frequency (HF) Cetaceans Lpk,flat: 202 dB LE,HF,24h: 173
LE,HF,24h: 155 dB.
dB.
[[Page 36781]]
Phocid Pinnipeds (PW)........ Lpk,flat: 218 dB LE,PW,24h: 201
(Underwater)................. LE,PW,24h: 185 dB.
dB.
Otariid Pinnipeds (OW)....... Lpk,flat: 232 dB LE,OW,24h: 219
(Underwater)................. LE,OW,24h: 203 dB.
dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]Pa2s. In this Table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds.
Source Levels
The project includes impact pile driving and vibratory pile driving
and removal of various piles. Source levels of pile driving and removal
activities are based on reviews of measurements of the same or similar
types and dimensions of piles available in the literature (Caltrans,
2015; Martin et al., 2012; Dazey et al., 2012; WSDOT, 2007, 2012;
NAVFAC Southwest, 2014). Based on this review, the following source
levels are assumed for the underwater noise produced by construction
activities:
Impact driving of 14-inch steel H-piles for the temporary
trestle is assumed to generate a peak SPL of 208 dB re 1[mu]Pa, and a
root-mean-squared (rms) SPL of 187 dB re 1 [mu]Pa, based on adding 10
dB to a single-strike SEL of 177 dB re 1 [mu]Pa\2\-sec at 10 m (33 ft)
reported by Caltrans (2015). This assumption is based on differences
between SEL and rms values of other piles reported by Caltrans (2015).
Impact driving of 36-inch steel piles would be assumed to
generate an instantaneous peak SPL of 209 dB, an rms SPL of 198 dB, and
a SEL of 183 dB at the 10 m (33 ft) distance, based on the weighted
average of similar pile driving at the Bangor Naval Base, Naval Base
Point Loma, Washington State Department of Transportation (WSDOT)
Anacortes Ferry Terminal, and WSDOT Mukilteo Ferry Terminal.
Vibratory driving of 36-inch steel piles would be assumed
to generate a 168 dB SPLrms and a 168 dB SEL at 10 m (33 ft), based on
the weighted average of similar pile driving measured at Bangor Naval
Base, Naval Base Point Loma, and WSDOT Anacortes Ferry Terminal.
Impact driving of the 16-inch plastic piles, for which no
data specific to that size and composition are available, are assumed
to be similar to available data on 13-inch plastic piles: 166 dB peak
SPL and 153 dB rms SPL. No SEL measurements were made, but the SEL at
10 m (33 ft) can be assumed to be 9 dB less than the rms value (based
on differences of rms and SEL values of in-water impact pile-driving
data of other piles summarized by Caltrans 2015), which would put the
SEL value for the plastic piles at 144 dB. For vibratory pile driving
of the same plastic piles, the SPL rms of impact driving is used as a
proxy due to lack of measurement.
Vibratory removal of 14-inch steel H-piles is
conservatively assumed to have rms and SEL values of 158 dB based on a
relatively large set of measurements from the vibratory installation of
14-inch H-piles.
Drilling the rock sockets is assumed to be an
intermittent, non-impulsive, broadband noise source, similar to
vibratory pile driving, but using a rotary drill inside a pipe or
casing, which is expected to reduce sound levels below those of typical
pile driving (Martin et al. 2012). Measurements made during a pile
drilling project in 1-5 m (3-16 ft) depths at Santa Rosa Island, CA, by
Dazey et al. (2012) appear to provide reasonable proxy source levels
for the proposed activities. Dazey et al. (2012) reported average rms
source levels ranging from 151 to 157 dB re 1[micro]Pa, normalized to a
distance of 1 m (3 ft) from the pile, during activities that included
casing removal and installation as well as drilling, with an average of
154 dB re 1[micro]Pa during 62 days that spanned all related drilling
activities during a single season.
Since no source level data are available for vibratory
extraction of concrete or concrete encased 24-inch and 33-inch steel H-
piles, conservative proxy source levels were based on the summary
values reported for vibratory driving of 24-inch steel sheet piles by
Caltrans (2015). There are two reasons for using 24-in steel sheet pile
driving source level as a proxy: (1) In general, pile extraction
generates less noise in comparison to pile driving, and (2) piling of
concrete or concrete encased piles generated less noise in comparison
to steel piles. Since there are no source levels available for
extraction of the 24-in concrete or concrete encased piles and 33-in
steel H-piles, we defer to the pile driving source level of 24-in steel
sheet pile reported by Caltrans (2015). The Caltrans (2015) typical
source level of 160 dB rms and SEL was used for vibratory removal of
24-inch concrete piles and 24-inch concrete encased steel H-piles,
whereas the loudest source level of 165 dB rms and SEL was used for
vibratory removal of 33-inch concrete encased steel piles.
A summary of source levels from different pile driving and pile
removal activities is provided in Table 4.
[[Page 36782]]
Table 4--Summary of In-Water Pile Driving Source Levels
[At 10 m from source]
----------------------------------------------------------------------------------------------------------------
SPLpk (dB re 1 SPLrms (dB re
Method Pile type/size [micro] Pa) 1 [micro] Pa) SEL (dB re 1
[micro] Pa\2\-s)
----------------------------------------------------------------------------------------------------------------
Impact driving.................... 14-in steel H pile........ 208 187 177
Impact driving.................... 36-in concrete-filled 209 198 183
steel pile.
Vibratory driving................. 30- and 36-in concrete- NA 168 168
filled steel pipe pile;
16-in fiberglass plastic
pile.
Impact driving.................... 16-in fiberglass plastic 166 153 144
pile.
Vibratory driving................. 16-in fiberglass plastic NA 153 153
pile.
Rock socket drilling.............. 30-in steel pile & 16-in NA 154 154
plastic pile.
Vibratory removal................. 14-in steel H pile........ NA 158 158
Vibratory removal................. 24-in concrete-encased NA 160 160
steel H pile.
Vibratory removal................. 33-in concrete-encased NA 165 165
steel H pile.
----------------------------------------------------------------------------------------------------------------
These source levels are used to compute the Level A injury zones
and to estimate the Level B harassment zones. For Level A harassment
zones, since the peak source levels for both pile driving methods are
below the injury thresholds, cumulative SEL were used to do the
calculations using the NMFS acoustic guidance (NMFS 2016).
Estimating Injury Zones
When NMFS' Technical Guidance (2016) was published, in recognition
of the fact that ensonified area/volume could be more technically
challenging to predict because of the duration component in the new
thresholds, we developed a User Spreadsheet that includes tools to help
predict a simple isopleth that can be used in conjunction with marine
mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced are typically going
to be overestimates of some degree, which will result in some degree of
overestimate of Level A take. However, these tools offer the best way
to predict appropriate isopleths when more sophisticated 3D modeling
methods are not available, and NMFS continues to develop ways to
quantitatively refine these tools, and will qualitatively address the
output where appropriate.
For cumulative SEL (LE), distances to marine mammal injury
thresholds were estimated using NMFS' Optional User Spreadsheet based
on the noise exposure guidance. For impact pile driving, the single
strike SEL/pulse equivalent was used, and for vibratory pile driving,
the rms SPL source level was used. Per the NMFS Spreadsheet, default
Weighting Factor Adjustments (WFA) were used for calculating PTS from
both vibratory and impact pile driving, using 2.5 kHz and 2.0 KHz,
respectively. These WFAs are acknowledged by NMFS as conservative. A
transmission loss coefficient of 15 is used with reported source levels
measured at 10 m.
Estimating Behavioral Harassment Zones
Isopleths to Level B behavioral zones are based on rms SPL
(SPLrms) that are specific for non-impulse (vibratory pile
driving) sources. Distances to marine mammal behavior thresholds were
calculated using practical spreading.
In addition, based on the number of piers and high density of
pilings along the shoreline, the Navy concluded that underwater sound
transmission through these structures would be impeded similar to the
interruption of sound transmission by natural projections of the
shoreline. Using this assumption, the resulting Level B behavioral
harassment zone for marine mammal disturbance for most project
activities would be limited to the middle reaches of the Thames River,
extending no farther south than the Amtrak Bridge, 3 miles (4,642 m)
upstream from the mouth of the river.
A summary of the measured and modeled harassment zones is provided
in Table 5. In modeling transmission loss from the project area, the
conventional assumption would be made that acoustic propagation from
the source is impeded by natural and manmade features that extend into
the water, resulting in acoustic shadows behind such features. While
not solid structures, given the density of structural pilings under the
many pile-supported piers located south of Piers 32 and 10, coupled
with the docking of submarines at these piers, the piers are presumed
to disrupt sound propagation southward in the river.
Table 5--Calculated Areas of Zone of Influence and Maximum Distances
----------------------------------------------------------------------------------------------------------------
Source level @10m, Level A distance (m)/area Level B distance (m)/area
Year Activity description dB (rms/SEL) (km\2\) (km\2\)
----------------------------------------------------------------------------------------------------------------
1............. Impact driving 14'' 187/177 536/0.4468............... 631/0.5468.
steel H-pile 1,000
strikes per pile, 4
piles/day.
Vibratory & rock 168 <4/<0.0001............... 4,642/2.2002.
socket drilling
installation of 36''
concrete-filled
steel piles; average
10 minutes/day.
Impact driving 36'' 198/183 984/0.886................ 3,415/2.037.
concrete-filled
steel piles; 1,000
strikes per pile;
average 2.5 piles
per day.
------------------------------------------------------
Rocket socket 154 Activity will occur concurrently with above
drilling of 30'' activities that have much bigger zones
concrete-filled
steel piles and 16''
fiberglass
reinforced plastic
piles; average 1.04
hours/day.
------------------------------------------------------
2............. Vibratory 168 <4/<0.0001............... 4,642/2.2002.
installation of 36''
concrete-filled
steel piles; average
6 minutes/day.
[[Page 36783]]
Impact pile driving 198/183 984/0.886................ 3,415/2.037.
36'' concrete-filled
steel piles; 1,000
strikes per pile;
average 2.5 piles
per day.
3............. Vibratory 153 0.9/<0.0001.............. 1,584/1.1584.
installation of 16''
fiberglass plastic
piles; 40 minutes/
day.
Impact installation 153/144 2.5/<0.0001.............. 1/<0.000.
of 16'' fiberglass
plastic piles; 1,000
strikes per pile;
average 2.5 piles
per day.
4............. Vibratory removal of 158 <4/<0.0001............... 3,415/1.8372.
14'' steel H-piles;
average 100 minutes/
day.
Vibratory removal of 160 2.7/<0.0001.............. 4,642/2.2002.
24'' concrete-filled
steel piles (Pier
32); average 190
minutes/day.
Vibratory removal of 165 5.9/<0.0001.............. 4,642/2.2002.
30'' concrete-filled
steel piles (Pier
32); average 40
minutes/day.
Vibratory removal of 160 7.7/<0.0001.............. 4,642/2.2002.
24'' concrete-filled
steel piles (Pier
10); average 40
minutes/day.
----------------------------------------------------------------------------------------------------------------
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
The Navy's Marine Species Density Database (NMSDD) has density
estimates for harbor and gray seals that occur in Long Island Sound.
The NMSDD density estimates for harbor seals and gray seals are the
same, 0.0703/km\2\ during fall, winter, and spring, and 0.0174/km\2\
during summer months. These estimates, however, are based on broad-
scale oceanic surveys, which have not extended up the Thames River.
Marine mammal surveys were conducted in fall 2014 and winter,
spring, and summer of 2015 as part of a nearshore biological survey at
Submarine Base New London. No marine mammals were observed (Tetra Tech
2016). Harbor seals have been sighted in the Thames River near the
submarine base by Navy personnel. Both gray and harbor seals have
rookeries in Long Island Sound. A two-year detailed, systematic survey
of marine mammals in the Thames River began in January 2017. During the
first nine months of the survey through September, one pinniped (gray
seal) was observed approximately 2\3/4\ miles downstream of SUBASE at a
fishing dock near the ferry terminal, approximately 3,000 feet south of
the Gold Star Memorial Bridge (I-95).
There are no survey-based estimates of the relative abundances of
the two species in the Thames River. Up to two harbor seals have been
observed near the submarine base by base personnel. No gray seals have
been observed by the Navy close to the submarine base. However, the
Navy states that during preparation of the LOA they have learned that
since the population of gray seals is generally growing in the region
that gray seals are likely to also occur in the area of effect by the
first year of construction, 2020, but in smaller numbers. A ratio of 3
to 1 harbor seals to gray seals was identified as a reasonable
approximation of their relative abundance. No evidence is available to
suggest a different ratio. There are no areas (haul outs) where seals
are known to be concentrated nor have there been contemporary sightings
of larger numbers of seals along this stretch of the river, and the
animals seen at the submarine base are likely to move up and down as
well as across the river. Given that the Thames River is about 500 m
(1,640 ft) wide at the Submarine Base New London, and similarly
developed areas extend about 1 km (3,280 ft) up and down the river, the
Navy believes it is reasonable to extrapolate the observations at the
Submarine Base New London to an area of about 1 km\2\ for the purpose
of estimating density. This would result in an average density of 0.45
harbor and 0.15 gray seals per km\2\ within the project ZOIs from
September through May. Very few animals were sighted outside the
September through May time frame. Therefore, the September through May
data is used for density estimates to be conservative.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate. For both harbor and
gray seals, estimated takes are calculated based on ensonified area for
a specific pile driving activity multiplied by the marine mammal
density in the action area, multiplied by the number of pile driving
(or removal) days. Distances to and areas of different harassment zones
are listed in Table 4.
For both Level A and Level B harassment, take calculations and
assumptions are as follows:
Number of takes per activity = density (average number of
seals per km\2\) * area of ZOI (km\2\) * number of days, rounded to the
nearest whole number.
Seal density in the project area is estimated as 0.6/km\2\
from September through May (zero from June through August), consisting
of 75% harbor seals (0.45/km\2\) and 25% gray seals (0.15/km\2\).
Assumes as a worst case that activities will occur up to a
maximum of 180 workdays (5 days per week) when seals are present
(September through May) during each full construction year.
Assumes vibratory and impact hammer pile driving would not
occur on the same days.
Level A and Level B takes are calculated separately based
on the respective ZOIs for each type of activity, providing a maximum
estimate for each type of take which corresponds to the authorization
requested under the MMPA.
Assumes that the effective implementation of a 10 m
shutdown zone will prevent non-acoustic injuries and will prevent
animals from entering acoustic harassment ZOIs that extend less than 10
m from the source.
The maximum extent of the potential injury zone (for impact pile
driving of steel piles) is 984 m (3,228 ft) from the source for 36-inch
concrete-filled steel piles and 536 m (1,758 ft) for 14-inch steel H-
piles; other potential acoustic injury ZOIs for vibratory pile
extraction and installation are only 1 to 7.7 m (3 to 25 ft) from the
source (Table 4). Seals within about 10 m (33 ft) of in-water
construction or demolition may also be at risk of injury from
interaction with construction equipment. These potential
[[Page 36784]]
injury zones and the 10 m (33 ft) shutdown distance would be monitored
during all in-water construction/demolition activities, and the
activities would be halted if a marine mammal were to approach within
these distances.
The estimated numbers of instances of acoustic harassment (takes)
by year, species and severity (Level A or Level B) are shown in Table
6. Total Level A takes are estimated as 12 harbor seals and 4 gray
seals (total 16), and Level B takes are estimated as 504 harbor seals
and 168 gray seals (total 672).
Table 6--Estimated Numbers of Marine Mammals That May Be Exposed to Received Noise Levels That Cause Level A and Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated Estimated Estimated
Year Species Level A take Level B take total take Abundance Percentage
--------------------------------------------------------------------------------------------------------------------------------------------------------
1......................................... Harbor seal................. 6 166 172 75,834 0.23
Gray seal................... 2 55 57 27,131 0.21
2......................................... Harbor seal................. 6 177 183 75,834 0.24
Gray seal................... 2 59 61 505,000 0.01
3......................................... Harbor seal................. 0 51 51 75,834 0.07
Gray seal................... 0 17 17 27,131 0.06
4......................................... Harbor seal................. 0 110 110 75,834 0.13
Gray seal................... 0 37 37 27,131 0.12
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mitigation
In order to issue an LOA under section 101(a)(5)(A) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned) the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost and impact on
operations.
Mitigation for Marine Mammals and Their Habitat
1. Time Restriction.
Work will occur only during daylight hours, when visual monitoring
of marine mammals can be conducted.
2. Establishing and Monitoring Level A and Level B Harassment
Zones, and Shutdown Zones. These zones may be adjusted as appropriate
on the basis of the acoustic monitoring described below.
Before the commencement of in-water construction activities, which
include impact pile driving and vibratory pile driving and pile
removal, the Navy shall establish Level A harassment zones where
received underwater SELcum could cause PTS (see Table 5
above).
The Navy shall also establish Level B harassment zones where
received underwater SPLs are higher than 160 dBrms re 1
[micro]Pa for impulsive noise sources (impact pile driving) and 120
dBrms re 1 [micro]Pa for non-impulsive noise sources
(vibratory pile driving and pile removal).
The Navy shall establish a 10-m (33-ft) shutdown zone for all in-
water construction and demolition work.
If marine mammals are found within the shutdown zone, pile driving
of the segment would be delayed until they move out of the area. If a
marine mammal is seen above water and then dives below, the contractor
would wait 15 minutes. If no marine mammals are seen by the observer in
that time it can be assumed that the animal has moved beyond the
shutdown zone.
If pile driving of a segment ceases for 30 minutes or more and a
marine mammal is sighted within the designated shutdown zone prior to
commencement of pile driving, the observer(s) must notify the pile
driving operator (or other authorized individual) immediately and
continue to monitor the shutdown zone. Operations may not resume until
the marine mammal has exited the shutdown zone or 15 minutes have
elapsed since the last sighting.
3. Shutdown Measures.
The Navy shall implement shutdown measures if a marine mammal is
detected moving towards or entered the 10-m (33-ft) shutdown zone.
Further, the Navy shall implement shutdown measures if the number
of authorized takes for any particular species reaches the limit under
the LOA and such marine mammals are sighted within the vicinity of the
project area and are approaching the Level B harassment zone during in-
water construction activities.
In addition, the Navy shall implement shutdown measures if species
not authorized to take are sighted within the vicinity of the project
area and are approaching the Level B harassment zone during in-water
construction activities.
4. Soft Start.
The Navy shall implement soft start techniques for impact pile
driving. The Navy shall conduct an initial set of three strikes from
the impact hammer at 40 percent energy, followed by a 1-minute waiting
period, then two subsequent three strike sets. Soft start shall be
required for any impact driving, including at the beginning of the day,
and at any time following a cessation of impact pile driving of thirty
minutes or longer.
Whenever there has been downtime of 30 minutes or more without
impact driving, the contractor shall initiate
[[Page 36785]]
impact driving with soft-start procedures described above.
Based on our evaluation of the required measures, NMFS has
determined that the prescribed mitigation measures provide the means
effecting the least practicable adverse impact on the affected species
or stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an LOA for an activity, section 101(a)(5)(A) of
the MMPA states that NMFS must set forth, ``requirements pertaining to
the monitoring and reporting of such taking.'' The MMPA implementing
regulations at 50 CFR 216.104(a)(13) state that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Monitoring Measures
The Navy shall employ trained protected species observers (PSOs) to
conduct marine mammal monitoring for its Submarine Base New London pier
construction project. The purposes of marine mammal monitoring are to
implement mitigation measures and learn more about impacts to marine
mammals from the Navy's construction activities. The PSOs will observe
and collect data on marine mammals in and around the project area for
15 minutes before, during, and for 30 minutes after all pile removal
and pile installation work.
Protected Species Observer Qualifications
NMFS-approved PSOs shall meet the following requirements:
1. Independent observers (i.e., not construction personnel) are
required;
2. At least one observer must have prior experience working as an
observer;
3. Other observers may substitute education (undergraduate degree
in biological science or related field) or training for experience;
4. Where a team of three or more observers are required, one
observer should be designated as lead observer or monitoring
coordinator. The lead observer must have prior experience working as an
observer; and
5. NMFS will require submission and approval of observer CVs.
Marine Mammal Monitoring Protocols
The Navy shall conduct briefings between construction supervisors
and crews and the PSO team prior to the start of all pile driving
activities, and when new personnel join the work, in order to explain
responsibilities, communication procedures, marine mammal monitoring
protocol, and operational procedures. All personnel working in the
project area shall watch the Navy's Marine Species Awareness Training
video. An informal guide shall be included with the monitoring plan to
aid in identifying species if they are observed in the vicinity of the
project area.
The Navy will monitor the Level A and Level B harassment zones
before, during, and after pile driving activities for all in-water
constructions. The Marine Mammal Monitoring Plan would include the
following procedures:
PSOs will be primarily located on boats, docks, and piers
at the best vantage point(s) in order to properly see the entire
shutdown zone(s).
PSOs will be located at the best vantage point(s) to
observe the zone associated with behavioral impact thresholds.
During all observation periods, PSOs will use high-
magnification (25X), as well as standard handheld (7X) binoculars, and
the naked eye to search continuously for marine mammals.
Monitoring distances will be measured with range finders.
Distances to animals will be based on the best estimate of the PSO,
relative to known distances to objects in the vicinity of the PSO.
Bearings to animals will be determined using a compass.
Pile driving shall only take place when the shutdown and
Level A zones are visible and can be adequately monitored. If
conditions (e.g., fog) prevent the visual detection of marine mammals,
activities with the potential to result in Level A harassment shall not
be initiated. If such conditions arise after the activity has begun,
pile driving or pile removal activities shall be halted if the 10-m
shutdown zone is not visible.
Three (3) PSOs shall be posted to monitor marine mammals
during in-water pile driving and pile removal. One PSO will be located
on land and two will be located in a boat to monitor the farther
locations.
Pre-Activity Monitoring:
The shutdown zone will be monitored for 15 minutes prior to in-
water construction/demolition activities. If a marine mammal is present
within the 10-m shutdown zone, the activity will be delayed until the
animal(s) leave the shutdown zone. Activity will resume only after the
PSO has determined that, through sighting or by waiting 15 minutes, the
animal(s) has moved outside the shutdown zone. If a marine mammal is
observed approaching the shutdown zone, the PSO who sighted that animal
will notify all other PSOs of its presence.
During Activity Monitoring:
If a marine mammal is observed entering the Level A or Level B
zones outside the 10-m shutdown zone, the pile segment being worked on
will be completed without cessation, unless the animal enters or
approaches the shutdown zone, at which point all pile driving
activities will be halted. If an animal is observed within the shutdown
zone during pile driving, then pile driving will be stopped as soon as
it is safe to do so. Pile driving can only resume once the animal has
left the shutdown zone of its own volition or
[[Page 36786]]
has not been re-sighted for a period of 15 minutes.
Post-Activity Monitoring:
Monitoring of all zones will continue for 30 minutes following the
completion of the activity.
Acoustic Monitoring
(1) Sound Source Verification
The Navy shall conduct pile driving sound source verification for
the types and sizes of piles with no prior measurements. These piles
include:
Vibratory and impact installation of at least 5 16-in
fiberglass reinforced plastic piles, and
Rock socket drilling of at least 3 30-in and 3 16-in
piles.
Sound source measurements of these piles sound be conducted at
distances approximately 10 m from the source.
For vibratory pile driving/removal source level measurements,
reports should include 1-s sound exposure level (SEL), source spectrum,
duration of recordings used to derived the SEL, and 24-hour cumulative
SEL extrapolated from measurements.
For impact pile driving source level measurements, report should
include peak sound pressure level (SPLpk), root-mean-square
SPL (SPLrms), single strike SEL (SELss),
integration time for SPLrms, SELss spectrum, and
24-hour cumulative SEL extrapolated from measurements.
(2) Level B Harassment Distance Verification
The Navy shall empirically determine the Level B harassment
distance either by extrapolating from in situ measurements conducted at
several points between 10 and 500 m from the source, or by direct
measurements at far distance to locate the distance where the received
levels reach 120 dB or below, or at the ambient noise level.
Level B behavioral harassment zones need to be empirically
determined include:
Rock socket drilling of at least 3 30-in and 3 16-in
piles,
Vibratory installation of at least 3 36-in steel piles,
and
Vibratory removal of at least 3 24-in concrete and 3 33-in
concrete piles.
For extent of Level B distance verification, the Navy shall report
the measured or extrapolated distances where the received levels
SPLrms decay to 120-dB or to the ambient noise level,
whichever is higher, as well as integration time for such
SPLrms.
The sound levels reported should be in median and linear average
(i.e., taking averages of sound intensity before converting to dB).
The acoustic monitoring reports shall also include sediment type
where measurements are made.
Reporting Measures
The Navy is required to submit an annual report within 90 days
after each activity year, starting from the date when the LOA is issued
(for the first annual report) or from the date when the previous annual
report ended. These reports will detail the monitoring protocol,
summarize the data recorded during monitoring, and estimate the number
of marine mammals that may have been harassed during the period of the
report. Results from acoustic monitoring should also be included within
the monitoring report, as discussed above. NMFS will provide comments
within 30 days after receiving these reports, and the Navy shall
address the comments and submit revisions within 30 days after
receiving NMFS comments. If no comment is received from NMFS within 30
days, the annual report is considered completed.
The Navy is also required to submit a draft monitoring report
within 90 days after completion of the construction work or the
expiration of the final LOA, whichever comes earlier. This report will
synthesize all data recorded during marine mammal monitoring, and
estimate the number of marine mammals that may have been harassed
through the entire project. NMFS will provide comments within 30 days
after receiving this report, and the Navy shall address the comments
and submit revisions within 30 days after receiving NMFS comments. If
no comment is received from NMFS within 30 days, the monitoring report
is considered as final.
In addition, NMFS requires the Navy to notify NMFS' Office of
Protected Resources and NMFS' Greater Atlantic Stranding Coordinator
within 48 hours of sighting an injured or dead marine mammal in the
construction site. The Navy shall provide NMFS and the Stranding
Network with the species or description of the animal(s), the condition
of the animal(s) (including carcass condition, if the animal is dead),
location, time of first discovery, observed behaviors (if alive), and
photo or video (if available).
In the event that the Navy finds an injured or dead marine mammal
that is not in the construction area, the Navy will report the same
information as listed above to NMFS as soon as operationally feasible.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as ``an impact resulting from
the specified activity that cannot be reasonably expected to, and is
not reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival'' (50 CFR 216.103).
A negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
To avoid repetition, this introductory discussion of our analyses
applies to both of the species listed in Table 2, given that the
anticipated effects of the Navy's Submarine Base New London pier
construction project activities involving pile driving and pile removal
on marine mammals are expected to be relatively similar in nature.
There is no information about the nature or severity of the impacts, or
the size, status, or structure of any species or stock that would lead
to a different analysis by species for this activity, or else species-
specific factors would be identified and analyzed.
Although a few individual seals (6 harbor seals and 2 gray seals
each in year 1 and year 2) are estimated to experience Level A
harassment in the form of PTS if they stay within the Level A
harassment zone during the entire pile driving for the day, the degree
of injury is expected to be mild and is not likely to affect the
reproduction or survival of the individual animals. It is expected
that, if hearing impairments occurs, most likely the affected animal
would lose a few dB in its hearing sensitivity, which in most cases is
not likely to affect its survival and
[[Page 36787]]
recruitment. Hearing impairment that might occur for these individual
animals would be limited to the dominant frequency of the noise
sources, i.e., in the low-frequency region below 2 kHz. Nevertheless,
as for all marine mammal species, it is known that in general these
pinnipeds will avoid areas where sound levels could cause hearing
impairment. Therefore it is not likely that an animal would stay in an
area with intense noise that could cause severe levels of hearing
damage.
Under the majority of the circumstances, anticipated takes are
expected to be limited to short-term Level B harassment. Marine mammals
present in the vicinity of the action area and taken by Level B
harassment would most likely show overt brief disturbance (startle
reaction) and avoidance of the area from elevated noise levels during
pile driving and pile removal. Given the limited estimated number of
incidents of Level A and Level B harassment and the limited, short-term
nature of the responses by the individuals, the impacts of the
estimated take cannot be reasonably expected to, and are not reasonably
likely to, rise to the level that they would adversely affect either
species at the population level, through effects on annual rates of
recruitment or survival.
There are no known important habitats, such as rookeries or haul-
outs, in the vicinity of the Navy's proposed Submarine Base New London
pier construction project. The project also is not expected to have
significant adverse effects on affected marine mammals' habitat,
including prey, as analyzed in detail in the ``Anticipated Effects on
Marine Mammal Habitat'' subsection.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS finds that the total take from the proposed
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under section 101(a)(5)(A) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers and so, in practice, NMFS compares the number of
individuals taken to the most appropriate estimation of abundance of
the relevant species or stock in our determination of whether an
authorization is limited to small numbers of marine mammals.
The estimated takes are below one percent of the population for all
marine mammals (Table 6).
Based on the analysis contained herein of the proposed activity
(including the prescribed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS finds that small numbers of
marine mammals will be taken relative to the population size of the
affected species or stocks.
Unmitigable Adverse Impact Subsistence Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Adaptive Management
The regulations governing the take of marine mammals incidental to
Navy maintenance construction activities would contain an adaptive
management component.
The reporting requirements associated with this proposed rule are
designed to provide NMFS with monitoring data from the previous year to
allow consideration of whether any changes are appropriate. The use of
adaptive management allows NMFS to consider new information from
different sources to determine (with input from the Navy regarding
practicability) on an annual or biennial basis if mitigation or
monitoring measures should be modified (including additions or
deletions). Mitigation measures could be modified if new data suggests
that such modifications would have a reasonable likelihood of reducing
adverse effects to marine mammals and if the measures are practicable.
The following are some of the possible sources of applicable data
to be considered through the adaptive management process: (1) Results
from monitoring reports, as required by MMPA authorizations; (2)
results from general marine mammal and sound research; and (3) any
information which reveals that marine mammals may have been taken in a
manner, extent, or number not authorized by these regulations or
subsequent LOAs.
National Environmental Policy Act (NEPA)
Issuance of an MMPA authorization requires compliance with NEPA.
In accordance with NEPA (42 U.S.C. 4321 et seq.) and NOAA
Administrative Order (NAO) 216-6A, we have determined that issuance of
this rule and subsequent LOAs qualifies to be categorically excluded
from further NEPA review. Issuance of the rule is consistent with
categories of activities identified in CE B4 of the Companion Manual
and we have not identified any extraordinary circumstances listed in
Chapter 4 of the Companion Manual that would preclude use of this
categorical exclusion.
Endangered Species Act (ESA)
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Classification
Pursuant to the procedures established to implement Executive Order
12866, the Office of Management and Budget has determined that this
proposed rule is not significant.
Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA),
the Chief Counsel for Regulation of the Department of Commerce has
certified to the Chief Counsel for Advocacy of the Small Business
Administration that this proposed rule, if adopted, would not have a
significant economic impact on a substantial number of small entities.
The U.S. Navy is the sole entity that would be subject to the
requirements in these proposed regulations, and the Navy is not a small
governmental jurisdiction, small organization, or small business, as
defined by the RFA. Because of this certification, a regulatory
flexibility analysis is not required and none has been prepared.
This proposed rule does not contain a collection-of-information
requirement subject to the provisions of the Paperwork Reduction Act
(PRA) because the applicant is a federal agency. Notwithstanding any
other provision of law, no person is required to respond to nor shall a
person be subject to a penalty for failure to comply with a collection
of information subject to the requirements of the PRA unless that
collection of information displays a currently valid OMB control
number. These requirements have been approved by OMB under control
number 0648-0151 and include applications for regulations, subsequent
LOAs, and reports.
List of Subjects in 50 CFR Part 217
Exports, Fish, Imports, Incidental take, Indians, Labeling, Marine
[[Page 36788]]
mammals, Navy, Penalties, Reporting and recordkeeping requirements,
Seafood, Sonar, Transportation.
Dated: July 20, 2018.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For reasons set forth in the preamble, 50 CFR part 217 is amended
as follows:
PART 217--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
0
1. The authority citation for part 217 continues to read as follows:
Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.
0
2. Add subpart J to part 217 to read as follows:
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's Submarine
Base New London Pier Construction
Sec.
217.90 Specified activity and specified geographical region.
217.91 Effective dates.
217.92 Permissible methods of taking.
217.93 Prohibitions.
217.94 Mitigation requirements.
217.95 Requirements for monitoring and reporting.
217.96 Letters of Authorization.
217.97 Renewals and modifications of Letters of Authorization.
217.98 [Reserved]
217.99 [Reserved]
Subpart J--Taking and Importing Marine Mammals; U.S. Navy's
Submarine Base New London Pier Construction
Sec. 217.90 Specified activity and specified geographical region.
(a) Regulations in this subpart apply only to the U.S. Navy (Navy)
and those persons it authorizes or funds to conduct activities on its
behalf for the taking of marine mammals that occurs in the area
outlined in paragraph (b) of this section and that occurs incidental to
the activities described in paragraph (c) of this section.
(b) The taking of marine mammals by the Navy may be authorized in
Letters of Authorization (LOAs) only if it occurs within the Navy
Submarine Base New London Study Area, which is located in the towns of
Groton and Ledyard in New London County, Connecticut.
(c) The taking of marine mammals by the Navy is only authorized if
it occurs incidental to the Navy's conducting in-water pier
construction or demolition activities.
Sec. 217.91 Effective dates and definitions.
Regulations in this subpart are effective March 1, 2020 through
February 28, 2025.
Sec. 217.92 Permissible methods of taking.
Under LOAs issued pursuant to Sec. 216.106 of this chapter and
Sec. 217.96, the Holder of the LOAs (hereinafter ``Navy'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 217.90(b) by Level A harassment and Level B
harassment associated with in-water pile driving and pile removal
activities, provided the activity is in compliance with all terms,
conditions, and requirements of the regulations in this subpart and the
applicable LOAs.
Sec. 217.93 Prohibitions.
Notwithstanding takings contemplated in Sec. 217.92 and authorized
by LOAs issued under Sec. 216.106 of this chapter and Sec. 217.96, no
person in connection with the activities described in Sec. 217.90 may:
(a) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or a LOA issued under Sec. 216.106 of
this chapter and Sec. 217.96;
(b) Take any marine mammal not specified in such LOAs;
(c) Take any marine mammal specified in such LOAs in any manner
other than as specified;
(d) Take a marine mammal specified in such LOAs if NMFS determines
such taking results in more than a negligible impact on the species or
stocks of such marine mammal; or
(e) Take a marine mammal specified in such LOAs if NMFS determines
such taking results in an unmitigable adverse impact on the
availability of such species or stock of marine mammal for taking for
subsistence uses.
Sec. 217.94 Mitigation requirements.
When conducting the activities identified in Sec. 217.90(c), the
mitigation measures contained in any LOAs issued under Sec. 216.106 of
this chapter and Sec. 217.96 must be implemented. These mitigation
measures shall include but are not limited to:
(a) Time restriction. In-water construction and demolition work
shall occur only during daylight hours.
(b) Establishment of monitoring and shutdown zones. (1) For all
relevant in-water construction and demolition activity, the Navy shall
designate Level A harassment zones with radial distances as identified
in any LOA issued under Sec. 216.106 of this chapter and Sec. 217.96.
(2) For all relevant in-water construction and demolition activity,
the Navy shall designate Level B harassment zones with radial distances
as identified in any LOA issued under Sec. 216.106 of this chapter and
Sec. 217.96.
(3) For all in-water construction and demolition activity, the Navy
shall implement a minimum shutdown zone of a 10-m radius around the
pile. If a marine mammal comes within or approaches the shutdown zone,
such operations shall cease.
(c) Monitoring visibility. Pile driving shall only take place when
the shutdown and Level A zones are visible and can be adequately
monitored. If conditions (e.g., fog) prevent the visual detection of
marine mammals, activities with the potential to result in Level A
harassment shall not be initiated. If such conditions arise after the
activity has begun, pile driving or pile removal activities shall be
halted if the 10-m shutdown zone is not visible.
(d) Shutdown measures. (1) The Navy shall deploy three protected
species observers (PSOs) to monitor marine mammals during in-water pile
driving and pile removal. One PSO shall be located on land and two
shall be located in a boat to monitor the farther locations.
(2) Monitoring shall take place from 15 minutes prior to initiation
of pile driving or removal activity through 30 minutes post-completion
of pile driving or removal activity. Pre-activity monitoring shall be
conducted for 15 minutes to ensure that the shutdown zone is clear of
marine mammals, and pile driving or removal may commence when observers
have declared the shutdown zone clear of marine mammals. In the event
of a delay or shutdown of activity resulting from marine mammals in the
shutdown zone, animals shall be allowed to remain in the shutdown zone
(i.e., must leave of their own volition) and their behavior shall be
monitored and documented. Monitoring shall occur throughout the time
required to drive or remove a pile. A determination that the shutdown
zone is clear must be made during a period of good visibility (i.e.,
the entire shutdown zone and surrounding waters must be visible to the
naked eye).
(3) If a marine mammal approaches or enters the shutdown zone, or
if a marine mammal not specified in the LOAs enters the Level B
harassment zone, or if the take of a marine mammal species or stock has
reached the take limits specified in any LOA issued under Sec. 216.106
of this chapter and Sec. 217.96 and enters the Level B harassment
zone, all pile driving or removal activities at that location shall be
halted. If pile driving or removal is halted or delayed due to the
presence of a marine
[[Page 36789]]
mammal, the activity may not commence or resume until either the animal
has voluntarily left and been visually confirmed beyond the shutdown
zone or fifteen minutes have passed without re-detection of the animal.
(4) The Navy shall implement shutdown measures if the number of
authorized takes for any particular species reaches the limit under the
applicable LOA and if such marine mammals are sighted within the
vicinity of the project area and are approaching the Level B harassment
zone during in-water construction or demolition activities.
(e) Soft start. (1) The Navy shall implement soft start techniques
for impact pile driving. The Navy shall conduct an initial set of three
strikes from the impact hammer at 40 percent energy, followed by a 1-
minute waiting period, then two subsequent three strike sets.
(2) Soft start shall be required for any impact driving, including
at the beginning of the day, and at any time following a cessation of
impact pile driving of 30 minutes or longer.
Sec. 217.95 Requirements for monitoring and reporting.
(a) Marine mammal monitoring--(1) General requirements. The Navy
shall employ trained protected species observers (PSOs) to conduct
marine mammal monitoring for its Submarine Base New London pier
construction project. The PSOs shall observe and collect data on marine
mammals in and around the project area for 15 minutes before, during,
and for 30 minutes after all pile removal and pile installation work.
PSOs shall have no other assigned tasks during monitoring periods, and
shall be placed at the best vantage point(s) practicable to monitor for
marine mammals and implement shutdown or delay procedures when
applicable through communication with the equipment operator.
(2) Protected species observer qualifications. NMFS-approved PSOs
shall meet the following requirements:
(i) Independent observers (i.e., not construction personnel) are
required;
(ii) At least one observer must have prior experience working as an
observer;
(iii) Other observers may substitute education (undergraduate
degree in biological science or related field) or training for
experience;
(iv) Where a team of three or more observers are required, one
observer should be designated as lead observer or monitoring
coordinator. The lead observer must have prior experience working as an
observer; and
(v) NMFS will require submission and approval of observer CVs.
(3) Marine mammal monitoring protocols. (i) The Navy shall conduct
briefings between construction supervisors and crews and the PSO team
prior to the start of all pile driving activities, and when new
personnel join the work, in order to explain responsibilities,
communication procedures, marine mammal monitoring protocol, and
operational procedures. All personnel working in the project area shall
watch the Navy's Marine Species Awareness Training video. An informal
guide shall be included with the monitoring plan to aid in identifying
species if they are observed in the vicinity of the project area.
(ii) The Navy shall monitor the Level A and Level B harassment
zones before, during, and after pile driving activities for all in-
water constructions. The Marine Mammal Monitoring Plan shall include
the following procedures:
(A) PSO location. PSOs will be primarily located on boats, docks,
and piers at the best vantage point(s) in order to properly see the
entire shutdown zone(s).
(B) PSO vantage point. PSOs will be located at the best vantage
point(s) to observe the zone associated with behavioral impact
thresholds.
(C) Observation equipment. During all observation periods, PSOs
will use high-magnification (25X), as well as standard handheld (7X)
binoculars, and the naked eye to search continuously for marine
mammals.
(D) Ranging equipment. Monitoring distances will be measured with
range finders. Distances to animals will be based on the best estimate
of the PSO, relative to known distances to objects in the vicinity of
the PSO.
(E) Bearing. Bearings to animals will be determined using a
compass.
(F) Pre-activity monitoring. The shutdown zone will be monitored
for 15 minutes prior to in-water construction/demolition activities. If
a marine mammal is present within the 10-m shutdown zone, the activity
will be delayed until the animal(s) leaves the shutdown zone. Activity
will resume only after the PSO has determined that, through sighting or
by waiting 15 minutes, the animal(s) has moved outside the shutdown
zone. If a marine mammal is observed approaching the shutdown zone, the
PSO who sighted that animal will notify all other PSOs of its presence.
(G) During activity monitoring. If a marine mammal is observed
entering the Level A or Level B harassment zones outside the 10-m
shutdown zone, the pile segment being worked on will be completed
without cessation, unless the animal enters or approaches the shutdown
zone, at which point all pile driving activities will be halted. If an
animal is observed within the shutdown zone during pile driving, then
pile driving will be stopped as soon as it is safe to do so. Pile
driving can only resume once the animal has left the shutdown zone of
its own volition or has not been re-sighted for a period of 15 minutes.
(H) Post-activity monitoring. Monitoring of all zones will continue
for 30 minutes following the completion of the activity.
(b) Acoustic monitoring--(1) Sound source verification. (i) The
Navy shall conduct pile driving sound source verification for the
following types and sizes of piles:
(A) Vibratory and impact installation of at least 5 16-in
fiberglass reinforced plastic piles; and
(B) Rock socket drilling of at least 3 30-in and 3 16-in piles.
(ii) Sound source measurements of these piles sound shall be
conducted at distances approximately 10 m from the source.
(iii) For vibratory pile driving/removal source level measurements,
reports shall include 1-s sound exposure level (SEL), source spectrum,
duration of recordings used to derived the SEL, and 24-hour cumulative
SEL extrapolated from measurements.
(iv) For impact pile driving source level measurements, report
should include peak sound pressure level (SPLpk), root-mean-
square SPL (SPLrms), single strike SEL (SELss),
integration time for SPLrms, SELss spectrum, and
24-hour cumulative SEL extrapolated from measurements.
(2) Level B harassment distance verification. (i) The Navy shall
empirically determine the Level B harassment distance either by
extrapolating from in situ measurements conducted at several points
between 10 and 500 m from the source, or by direct measurements to
locate the distance where the received levels reach 120 dB or below, or
at the ambient noise level.
(ii) Level B harassment zones to be empirically verified include:
(A) Rock socket drilling of at least 3 30-in and 3 16-in piles;
(B) Vibratory installation of at least 3 36-in steel piles; and
(C) Vibratory removal of at least 3 24-in concrete and 3 33-in
concrete piles.
(iii) For extent of Level B harassment zone verification, the Navy
shall report the measured or extrapolated distances where the received
levels SPLrms decay to 120-dB or to the ambient noise level,
[[Page 36790]]
whichever is higher, as well as integration time for such
SPLrms.
(3) Source level calculation. The sound levels reported should be
in median and linear average (i.e., taking averages of sound intensity
before converting to dB).
(4) Sediment type. The passive acoustic monitoring reports shall
also include sediment type where measurements are made.
(c) Reporting measures--(1) Annual reports. (i) The Navy shall
submit an annual report within 90 days after each activity year,
starting from the date when the LOA is issued (for the first annual
report) or from the date when the previous annual report ended.
(ii) Annual reports shall detail the monitoring protocol, summarize
the data recorded during monitoring, and estimate the number of marine
mammals that may have been harassed during the period of the report.
(iii) Annual reports shall also include results from acoustic
monitoring detailed in paragraph (b) of this section.
(iv) NMFS shall provide comments within 30 days after receiving
annual reports, and the Navy shall address the comments and submit
revisions within 30 days after receiving NMFS comments. If no comment
is received from the NMFS within 30 days, the annual report is
considered completed.
(2) Final report. (i) The Navy shall submit a comprehensive summary
report to NMFS not later than 90 days following the conclusion of
marine mammal monitoring efforts described in this subpart.
(ii) The final report shall synthesize all data recorded during
marine mammal monitoring, and estimate the number of marine mammals
that may have been harassed through the entire project.
(iii) NMFS would provide comments within 30 days after receiving
this report, and the Navy shall address the comments and submit
revisions within 30 days after receiving NMFS comments. If no comment
is received from the NMFS within 30 days, the final report is
considered as final.
(3) Reporting of injured or dead marine mammals. (i) In the
unanticipated event that the construction or demolition activities
clearly cause the take of a marine mammal in a prohibited manner, such
as an injury, serious injury, or mortality, the Navy shall immediately
cease all operations and immediately report the incident to the NMFS
Office of Protected Resources, NMFS, and the Greater Atlantic Region
Stranding Coordinators. The report must include the following
information:
(A) Time, date, and location (latitude/longitude) of the incident;
(B) Description of the incident;
(C) Status of all sound source use in the 24 hours preceding the
incident;
(D) Environmental conditions (e.g., wind speed and direction, sea
state, cloud cover, visibility, and water depth);
(E) Description of marine mammal observations in the 24 hours
preceding the incident;
(F) Species identification or description of the animal(s)
involved;
(G) The fate of the animal(s); and
(H) Photographs or video footage of the animal (if equipment is
available).
(ii) Activities shall not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS shall work with the Navy to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. The Navy may not resume
their activities until notified by NMFS via letter, email, or
telephone.
(iii) In the event that the Navy discovers an injured or dead
marine mammal, and the lead PSO determines that the cause of the injury
or death is unknown and the death is relatively recent (i.e., in less
than a moderate state of decomposition as described in the next
paragraph), the Navy will immediately report the incident to the NMFS
Office of Protected Resources, NMFS, and the Greater Atlantic Regional
Stranding Coordinators. The report must include the same information
identified in paragraph (c)(3)(i)(A) of this section. Activities may
continue while NMFS reviews the circumstances of the incident. NMFS
will work with the Navy to determine whether modifications in the
activities are appropriate.
(iv) In the event that the Navy discovers an injured or dead marine
mammal, and the lead protected species observer determines that the
injury or death is not associated with or related to the activities
authorized in the IHA (e.g., previously wounded animal, carcass with
moderate to advanced decomposition, or scavenger damage), the Navy
shall report the incident to the NMFS Office of Protected Resources,
NMFS, and the Greater Atlantic Regional Stranding Coordinators, within
24 hours of the discovery. The Navy shall provide photographs or video
footage (if available) or other documentation of the stranded animal
sighting to NMFS and the Marine Mammal Stranding Network. The Navy can
continue its operations under such a case.
Sec. 217.96 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to these
regulations, the Navy must apply for and obtain LOAs in accordance with
Sec. 216.106 of this chapter for conducting the activity identified in
Sec. 217.90(c).
(b) LOAs, unless suspended or revoked, may be effective for a
period of time not to extend beyond the expiration date of these
regulations.
(c) If an LOAs expires prior to the expiration date of these
regulations, the Navy may apply for and obtain a renewal of the LOAs.
(d) In the event of projected changes to the activity or to
mitigation, monitoring, reporting (excluding changes made pursuant to
the adaptive management provision of Sec. 217.97(c)(1)) required by an
LOA, the Navy must apply for and obtain a modification of LOAs as
described in Sec. 217.97.
(e) Each LOA shall set forth:
(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact (i.e.,
mitigation) on the species, their habitat, and the availability of the
species for subsistence uses; and
(3) Requirements for monitoring and reporting.
(f) Issuance of the LOAs shall be based on a determination that the
level of taking shall be consistent with the findings made for the
total taking allowable under these regulations.
(g) Notice of issuance or denial of the LOAs shall be published in
the Federal Register within 30 days of a determination.
Sec. 217.97 Renewals and modifications of Letters of Authorization.
(a) An LOA issued under Sec. 216.106 of this chapter and Sec.
217.96 for the activity identified in Sec. 217.90(c) shall be renewed
or modified upon request by the applicant, provided that:
(1) The proposed specified activity and mitigation, monitoring, and
reporting measures, as well as the anticipated impacts, are the same as
those described and analyzed for these regulations (excluding changes
made pursuant to the adaptive management provision in paragraph (c)(1)
of this section); and
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOAs under these regulations were
implemented.
(b) For LOA modification or renewal requests by the applicant that
include changes to the activity or the mitigation, monitoring, or
reporting measures (excluding changes made pursuant to
[[Page 36791]]
the adaptive management provision in paragraph (c)(1) of this section)
that do not change the findings made for the regulations or result in
no more than a minor change in the total estimated number of takes (or
distribution by species or years), NMFS may publish a notice of
proposed LOA in the Federal Register, including the associated analysis
of the change, and solicit public comment before issuing the LOA.
(c) An LOA issued under Sec. 216.106 of this chapter and Sec.
217.96 for the activity identified in Sec. 217.90(c) may be modified
by NMFS under the following circumstances:
(1) Adaptive management. After consulting with the Navy regarding
the practicability of the modifications, NMFS may modify (including by
adding or removing measures) the existing mitigation, monitoring, or
reporting measures if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of the mitigation and monitoring
set forth in the preamble for these regulations.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA:
(A) Results from the Navy's monitoring from the previous year(s);
(B) Results from other marine mammal and/or sound research or
studies; or
(C) Any information that reveals marine mammals may have been taken
in a manner, extent or number not authorized by these regulations or
subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
shall publish a notice of proposed LOA in the Federal Register and
solicit public comment.
(2) Emergencies. If NMFS determines that an emergency exists that
poses a significant risk to the well-being of the species or stocks of
marine mammals specified in LOAs issued pursuant to Sec. 216.106 of
this chapter and Sec. 217.96, an LOA may be modified without prior
notice or opportunity for public comment. Notice would be published in
the Federal Register within thirty days of the action.
Sec. 217.98 [Reserved]
Sec. 217.99 [Reserved]
[FR Doc. 2018-15938 Filed 7-30-18; 8:45 am]
BILLING CODE 3510-22-P