Proposed Rule2021-21426
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Navy Construction at Naval Station Newport in Newport, Rhode Island
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
October 13, 2021
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the U.S. Navy (Navy) for authorization to take marine mammals incidental to construction activities for bulkhead replacement and repairs at Naval Station Newport (NAVSTA Newport) over the course of five years (2022-2027). As required by the Marine Mammal Protection Act (MMPA), NMFS is proposing regulations to govern that take, and requests comments on the proposed regulations. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorization and agency responses will be summarized in the final notice of our decision.
Full Text
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<title>Federal Register, Volume 86 Issue 195 (Wednesday, October 13, 2021)</title>
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[Federal Register Volume 86, Number 195 (Wednesday, October 13, 2021)]
[Proposed Rules]
[Pages 56857-56884]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-21426]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 210924-0196]
RIN 0648-BK69
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to U.S. Navy Construction at Naval
Station Newport in Newport, Rhode Island
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to construction
activities for bulkhead replacement and repairs at Naval Station
Newport (NAVSTA Newport) over the course of five years (2022-2027). As
required by the Marine Mammal Protection Act (MMPA), NMFS is proposing
regulations to govern that take, and requests comments on the proposed
regulations. NMFS will consider public comments prior to making any
final decision on the issuance of the requested MMPA authorization and
agency responses will be summarized in the final notice of our
decision.
DATES: Comments and information must be received no later than November
12, 2021.
ADDRESSES: You may submit comments on this document, identified by
NOAA-NMFS-2021-0096, by the following method:
<bullet> Electronic submission: Submit all electronic public
comments via the Federal e-Rulemaking Portal. Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a> and enter NOAA-NMFS-2021-0096 in the Search box,
click the ``Comment'' icon, complete the required fields, and enter or
attach your comments.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
<a href="http://www.regulations.gov">www.regulations.gov</a> without change. All personal identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
Attachments to electronic comments will be accepted in Microsoft Word,
Excel, or Adobe PDF file formats only.
FOR FURTHER INFORMATION CONTACT: Stephanie Egger, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of the Navy's application and any supporting documents, as
well as a list of the references cited in this document, may be
obtained online at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-construction-naval-station-newport-rhode-island">https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-construction-naval-station-newport-rhode-island</a>. In case of problems accessing these documents, please call the
contact listed above (see FOR FURTHER INFORMATION CONTACT).
Purpose and Need for Regulatory Action
This proposed rule would establish a framework under the authority
of the MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of
take of marine mammals incidental to the Navy's construction activities
for bulkhead replacement and repairs at NAVSTA Newport.
We received an application from the Navy requesting five-year
regulations and authorization to take multiple species of marine
mammals. Take would occur by Level A and Level B harassment incidental
to impact and vibratory pile driving. Please see Background below for
definitions of harassment.
Legal Authority for the Proposed Action
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
the Secretary of Commerce to allow, upon request, the incidental, but
not intentional taking of small numbers of marine mammals by U.S.
citizens who engage in a specified activity (other than commercial
fishing) within a specified geographical region for up to five years
if, after notice and public comment, the agency makes certain findings
and issues regulations that set forth permissible methods of taking
pursuant to that activity and other means of effecting the ``least
practicable adverse impact'' on the affected species or stocks and
their habitat (see the discussion below in the Proposed Mitigation
section), as well as monitoring and reporting requirements. Section
101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR
part 216, subpart R provide the legal basis for issuing this proposed
rule containing five-year regulations, and for any subsequent letters
of authorization (LOAs). As directed by this legal authority, this
proposed rule contains mitigation, monitoring, and reporting
requirements.
Summary of Major Provisions Within the Proposed Rule
Following is a summary of the major provisions of this proposed
rule regarding Navy construction activities. These measures include:
<bullet> Required monitoring of the construction areas to detect
the presence of marine mammals before beginning construction
activities;
<bullet> Shutdown of construction activities under certain
circumstances to avoid injury of marine mammals; and
<bullet> 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
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1361 et seq.) directs
the Secretary of Commerce (as delegated to NMFS) to allow, upon
request, the incidental, but not intentional, taking of small numbers
of marine mammals by U.S. citizens who engage in a specified activity
(other than commercial fishing) within a specified geographical region
if certain findings are made, regulations are issued, and notice is
provided to the public.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
[[Page 56858]]
availability of the species or stock(s) for taking for subsistence uses
(where relevant), and if the permissible methods of taking and
requirements pertaining to the mitigation, monitoring and reporting of
the takings 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.
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild (Level A harassment); or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering (Level B harassment).
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the promulgation of
regulations and subsequent issuance of an incidental take
authorization) with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 of the Companion Manual for NOAA
Administrative Order 216-6A, which do not individually or cumulatively
have the potential for significant impacts on the quality of the human
environment and for which we have not identified any extraordinary
circumstances that would preclude this categorical exclusion.
Accordingly, NMFS has preliminarily determined that the issuance of
this proposed rule qualifies to be categorically excluded from further
NEPA review.
Information in the Navy's application and this document
collectively provide the environmental information related to proposed
issuance of these regulations and subsequent incidental take
authorization for public review and comment. We will review all
comments submitted in response to this document prior to concluding our
NEPA process or making a final decision on the request for incidental
take authorization.
Summary of Request
In July 2020, NMFS received a request from the Navy requesting
authorization to take small numbers of seven species of marine mammals
incidental to construction activities including bulkhead replacement
and repairs at NAVSTA Newport. The Navy has requested regulations that
would establish a process for authorizing such take via a LOA. NMFS
reviewed the Navy's application, and the Navy provided responses
addressing NMFS' questions and comments on February 22, 2021. The
application was deemed adequate and complete and published for public
review and comment on May 19, 2021 (86 FR 27069). We did not receive
substantive comments on that notice and request for comments and
information.
The Navy requests authorization to take a small number of seven
species of marine mammals by Level A and B harassment. Neither the Navy
nor NMFS expects serious injury or mortality to result from this
activity. The proposed regulations would be valid for five years (2022-
2027).
Description of Proposed Activity
Overview
The Navy proposes to replace or repair several sections of
deteriorating, unstable, hazardous, and eroding bulkhead, sheet pile,
and revetment (approximately 2,730 total linear feet (ft)) along the
Coddington Cove waterfront of NAVSTA Newport. Over time, the existing
storm sewer systems and bulkheads along the Coddington Cove waterfront
have severely degraded due to erosion from under-capacity stormwater
system piping and aging infrastructure. This impacts the ability of the
installation to minimize shoreline erosion and minimize safety risks
from associated upland subsidence, while also maintaining potential
berthing space. The Navy plans to conduct necessary work, including
impact and vibratory pile driving, to repair and replace bulkheads over
five years.
Dates and Duration
The proposed regulations would be valid for a period of five years
(2022-2027). The specified activities may occur at any time during the
5-year period of validity of the proposed regulations. The Navy expects
pile driving to occur on approximately 222 non-consecutive in-water
pile driving days over the five-year duration. Pile driving activities
are anticipated to be completed within 4 years. However, because the
proposed construction is dependent on the allocation of funding, the
Navy is requesting that the LOA be issued for the entire 5-year
construction period to ensure flexibility in the project schedule.
Table 1 provides the anticipated construction schedule for the proposed
activities.
Table 1--Coddington Cove Bulkhead Replacement and Repair Summary Schedule
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Revetment
Section ID Bulkhead replacement (lf) replacement Outfalls replaced Dredging area Dredging Construction start date
(lf) (ft2) volume (cy)
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S45................................... 310......................... 250 Yes (3).................... 8,400 650 May 15, 2022.
S366.................................. 90.......................... 0 Yes (1).................... 1,350 100 October 15, 2023.
Pier 1................................ 100......................... 0 No......................... 1,500 120 October 15, 2023.
LNG................................... 650......................... 0 Yes (2).................... 9,750 760 October 15, 2024.
S499/Pier 2........................... 510......................... 90 Yes (5).................... 9,000 700 October 15, 2025.
S50................................... 730 (repair)................ 0 Yes (2).................... 0 0 October 15, 2026.
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Source: NAVFAC Mid-Atlantic 2018.
Specific Geographic Region
NAVSTA Newport, encompasses 1,399 acres extending 6-7 mi along the
western shore of Aquidneck Island in the towns of Portsmouth, Rhode
Island, and Middletown, Rhode Island, and the City of Newport, Rhode
Island. The base footprint also includes the northern third of Gould
Island in the town of Jamestown, Rhode Island. The base is located in
the southern part of the state near where Narragansett Bay adjoins the
Atlantic Ocean. The locations of the proposed bulkhead repairs at
Coddington Cove are identified in Figure 1.
[[Page 56859]]
Narragansett Bay is one of Rhode Island's principle water features.
Narragansett Bay is approximately 22 nautical miles (nmi) (40
kilometers (km)) long and 7 nmi (16 km) wide. The average depth of
Narragansett Bay is 29 ft. The Narragansett Bay's most prominent
bathymetric feature is a submarine valley that runs between Conanicut
and Aquidneck Islands to Rhode Island Sound, and defines the East
Passage of Narragansett Bay. The shipping channel in the East Passage
serves as the primary shipping channel for the rest of Narragansett Bay
and is generally 100 ft deep. The shipping channel from the lower East
Passage splits just south of Gould Island with the western shipping
channel heading to Quonset Point and the eastern shipping channel
heading to Providence and Fall River (Navy, 2008).
Coddington Cove is located on the western side of Aquidneck Island
and is a protected embayment formed by Coddington Point to the south
and a 4,000 ft long rubble-mound breakwater to the north. It covers an
area of 1.6 square nmi with water depths up to 50 ft The area is a
Restricted Area and is closed to all commercial and recreational vessel
traffic, unless authorized by the appropriate personnel (Navy, 2008).
According to a 2015 bathymetric survey of Coddington Cove, water depths
in the proposed project area are less than 34 ft mean lower low water.
Water depths in the pier are artificially deep to accommodate the
berthing of large ships (NAVFAC, 2015).
BILLING CODE 3510-22-P
[[Page 56860]]
[GRAPHIC] [TIFF OMITTED] TP13OC21.000
BILLING CODE 3510-22-C
Detailed Description of Specific Activity
The proposed project is the replacement or repair of several
sections of deteriorating, unstable, hazardous, and eroding bulkhead
along the Coddington Cove waterfront of NAVSTA Newport. As part of the
replacement/repairs, existing stormwater outfalls in the repair areas
would also be replaced or improved. Improvements would include changing
outfall pipe material and/or changing outfall pipe diameter. Stormwater
outfall improvements would reduce flooding and improve conveyance, as
well as minimize shoreline erosion and associated sedimentation of
adjacent receiving waters. The specific sections proposed for bulkhead
repair and replacement are described from north to
[[Page 56861]]
south in the following paragraphs and are summarized in Table 2 at the
end of this section.
Section S499/Pier 2: Currently, this section of bulkhead is in
serious condition and has a high priority for replacement/repair
because the steel sheet pile has widespread moderate-to-advanced
corrosion across multiple zones. There are also significant section
losses of steel sheet pile and timber planking occurring at multiple
locations. In addition, the protective coatings have separated and
failed along the bulkhead.
Replacement and repair of Section S499/Pier 2 includes the
demolition of the existing north marginal wharf; excavation and
replacement of approximately 310 ft of existing steel bulkhead
underneath and north of Pier 2; and replacement of approximately 90 ft
of rip rap revetment north of Pier 2. Demolition of the marginal wharf
would include the removal of approximately 8,500 square ft (ft\2\) of
concrete decking and the demolition of 80 (36-inch (in) diameter)
concrete encased piles.
The existing bulkhead structure would be replaced with a new
combined wall system (see Figure 1-3 of the application). Because of
the proximity of important buildings, a deadman and tie rod anchoring
system cannot be installed at this location. Approximately 140 (70
pairs) (31.5-in) sheet piles; 35 (42-in) steel pipe piles; and 79 (14-
in) H-piles would be installed approximately 12 in seaward of the
existing bulkhead using a vibratory and impact hammer, as necessary.
The existing bulkhead would be excavated landside and cut off
approximately 5 ft below ground level. The interstitial space would be
backfilled with stone.
Section S366: In its current condition, this section of bulkhead is
in a serious condition with a high priority for replacement/repair
because the steel sheet piling exhibits heavy corrosion with numerous
areas that exhibit 100 percent loss of section, as well as separation
of the protective coating, vegetation growth through the structure, and
rust pack. The timber planking protecting the concrete encasement has
rotted at the waterline in some areas.
Replacement of Section S366 would include the demolition and
replacement of approximately 90 ft of existing steel sheet pile
bulkhead just north of Pier 1. The existing bulkhead would then be
replaced with a new deadman anchored king pile system. The system would
consist of approximately 28 (14 pairs) (22.5-in) Z-shaped sheet piles;
15 (30-in) steel pipe piles; and 14 (14-in) H-piles. These piles would
be installed approximately 1ft in front of the existing bulkhead using
a combination of vibratory and impact hammers, as necessary. The
existing steel sheet pile wall would be excavated landside to a depth
of approximately 8-10 ft and cut off at the limit of excavation. An 8-
ft high concrete deadman anchor system would be installed approximately
50 ft behind the new bulkhead and would be connected to the bulkhead by
tie rods (see Figure 1-6 of the application). Stone would be used as
the backfill material to allow a rapid drop down of the water at the
back of the bulkhead after a severe storm.
Section Pier 1: Pier 1 was not accessible during the condition
assessment and is assumed to be in similar condition as S366. The
waterside inspection was limited due to the presence of vessels and
other obstacles that would not allow the inspection vessel to pass
(NAVFAC Mid-Atlantic, 2018).
Section Pier 1 includes demolition and replacement of approximately
100 ft of existing steel sheet pile bulkhead underneath Pier 1 (see
Figure 1-7 of the application). In order to access the bulkhead
underneath the pier, partial demolition of Pier 1 would occur.
Demolition would involve the removal of concrete decking, but the
removal of support piles is not anticipated.
Should demolition of the underlying support piles be required to
perform bulkhead replacement/repair, the use of impact or vibratory
hammers would not be required. Piles would be cut off at mudline or
extracted with a sling (i.e., dead pull). The existing steel sheet pile
wall would be excavated landside to a depth of approximately 13 ft
below ground surface and cut off at the limit of excavation. The
existing bulkhead would then be replaced with a new deadman and tie rod
anchored sheet pile system. The system would consist of approximately
54 (27 pairs) (22.5-in) Z-shaped sheet piles and approximately 26 (14-
in) H-piles. These piles would be installed approximately 1ft in front
of the existing bulkhead using a combination of vibratory and impact
hammers, as necessary. Bulkhead replacement would include shoreline
dredging to a depth of approximately 14 ft at the toe of the existing
bulkhead to ensure proper installation of the new bulkhead.
Section S45: In its current condition, this section of bulkhead is
in serious condition with a high priority for replacement/repair
because the steel sheet piles and cap exhibit heavy corrosion with
numerous areas that exhibit 100 percent loss of section resulting in
extensive landside erosion.
Replacement of Section S45 would include the demolition and
replacement of approximately 310 ft of existing steel sheet pile
bulkhead just south of Pier 1. The existing bulkhead would then be
replaced with a new deadman anchored king pile system. The system would
consist of approximately 4 (30-in) steel pipe piles; 160 (80 pairs)
(22.5-in) Z-shaped sheet piles; and approximately 76 (14-in) H-piles.
These piles would be installed approximately 1ft in front of the
existing bulkhead using a combination of vibratory and impact hammers,
as necessary. The existing steel sheet pile wall would be excavated
landside to a depth of approximately 10 ft below ground surface and cut
off at the limit of excavation (see Figure 1-8 of the application).
Section LNG: In its current condition, this section of bulkhead is
in serious condition with high priority for replacement/repair due to
heavy corrosion with numerous areas that exhibit 100 percent loss of
section. Where the steel sheet piling is in poor condition, there is
extensive landside erosion.
Section LNG includes excavation and replacement of approximately
650 ft of existing steel bulkhead south of the T-Pier. The existing
bulkhead would be replaced with a new deadman anchored sheet pile
system. The system would be similar to the system installed at Pier 1
and would consist of approximately 346 (173 pairs) (22.5-in) Z-shaped
sheet piles; and approximately 164 (14-in) H-piles. These piles would
be installed approximately 1ft in front of the existing bulkhead using
a combination of vibratory and impact hammers. The existing steel sheet
pile wall would be excavated landside to a depth of approximately 13ft
below ground surface and cut off at the limit of excavation.
[[Page 56862]]
Table 2--Bulkhead Pile Installation Activity
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Maximum Maximum
Vibratory number of number of
Facility Method of pile Pile type Pile Size Number of sheets Strikes per driving piles pile
driving (pairs)/piles pile minutes per installed driving
pile per day days
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S45.................. Vibratory/Impact. Z-shaped Steel 3.75 ft per pair/ 80 pair............. 530 13 10 27
Sheet Pile. 22.5-in each.
Impact........... Steel Pipe Pile.. 30-in............ 4................... 530 NA 2 4
Vibratory........ Steel H-pile..... 14-in............ 76.................. NA 10 12 13
S366................. Vibratory/Impact. Z-shaped Steel 3.75 ft per pair/ 14 pair............. 530 13 10 5
Sheet Pile. 22.5-in each.
Impact........... Steel pipe pile.. 30-in diameter... 15.................. 530 NA 2 15
Vibratory........ Steel H-pile..... 14-in............ 14.................. NA 10 12 3
S499/Pier 2.......... Vibratory/Impact. Z-shaped Steel 5.25 ft per pair/ 70 pair............. 530 13 8 23
Sheet Pile. 31.5-in each.
Impact........... Steel Pipe Pile.. 42-in............ 35.................. 530 NA 4 18
Vibratory........ Steel H-pile..... 14-in............ 79.................. NA 10 12 14
LNG Vibratory/Impact. Z-shaped Steel 3.75 ft per pair/ 173 pair............ 530 13 10 58
Sheet Pile. 22.5-in each.
Vibratory........ Steel H-pile..... 14-in............ 164................. NA 10 12 28
Pier 01.............. Vibratory/Impact. Z-shaped Steel 3.75 ft per pair/ 27 pair............. 530 13 10 9
Sheet Pile. 22.5-in each.
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Vibratory........ Steel H-pile..... 14-in............ 26.................. NA 10 12 5
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Total sheet piles 364/413..........
pairs/pipe and H-
piles installed.
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Total days pile ................. ................. ................. .................... ........... ........... ........... 222
driving.
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Legend: NA = not applicable, ft = foot; Start date of in-water work and duration are to be determined.
Pile installation would occur using land-based or barge-mounted
cranes, as appropriate. Cranes would be equipped with both vibratory
and impact hammers. Piles would be installed initially using vibratory
means and then finished with impact hammers, as necessary. Impact
hammers would also be used where obstructions or sediment conditions do
not permit the efficient use of vibratory hammers. Impact hammers would
utilize soft start techniques to minimize noise impacts in the water
column. The Navy does not yet know what type/size of hammers would be
used to complete the work. For purposes of this analysis, underwater
noise was modeled without accounting for potential noise minimization
measures.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the Navy's 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 (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 3 lists all species or stocks for which take is expected and
proposed for authorization, and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endangered Species Act (ESA) and potential biological removal (PBR),
where known. For taxonomy, we follow Committee on Taxonomy (2021). 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' 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' 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 and Gulf of Mexico SARs (e.g., Hayes et al. 2021).
All values presented in Table 3 are the most recent available at the
time of publication and are available in the 2020 SARs (Hayes et al.
2021).
[[Page 56863]]
Table 3--Marine Mammal Species Likely To Occur Near the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock abundance (CV,
ESA/MMPA status; Nmin, most recent Annual M/
Common name Scientific name Stock strategic (Y/N) 1 abundance survey) 2 PBR SI 3
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Atlantic white-sided dolphin.... Lagenorhynchus acutus.. Western North Atlantic. -, -; N 93,233 (0.71; 54,443; 544 26
2016).
Common dolphin.................. Delphinus delphis...... Western North Atlantic. -, -; N 172,974 (0.21; 1,452 399
145,216; 2016).
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Gulf of Maine/Bay of -, -; N 95,543 (0.31; 74,034; 851 217
Fundy. 2016).
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Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... Western North Atlantic. -,-; N 75,834 (0.15; 66,884, 2,006 350
2012).
Gray seal....................... Halichoerus grypus..... Western North Atlantic. -,-; N 27,131 (0.19, 23,158, 1,389 4,729
2016)\4\.
Harp seal....................... Pagophilus Western North Atlantic. -,-; N 7,400,000............. unknown 232,422
groenlandicus.
Hooded seal..................... Cystophora cristata.... Western North Atlantic. -,-; N 593,500............... unknown 1,680
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike). Annual Mortality/Serious Injury (M/SI) often cannot be determined precisely and is in some cases presented as a minimum value
or range. A CV associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ This abundance value and the associated PBR value reflect the U.S. population only. Estimated abundance for the entire Western North Atlantic stock,
including animals in Canada, is 451,131. The annual M/SI estimate is for the entire stock.
As indicated above, all seven species in Table 3 temporally and
spatially co-occur with the activity to the degree that take is
reasonably likely to occur, and we have proposed authorizing take.
Several depleted species of whales occur seasonally in the waters off
Rhode Island including Humpback (Megaptera novaeangliae), Fin
(Balaenoptera physalus), Sei (Balaenoptera borealis), Sperm (Physeter
macrocephalus) and North Atlantic Right whales (Eubaleana glacialis).
These whales are seasonally present in New England waters; however, due
to the depths of Narragansett Bay and near shore location of the
project area, these listed marine mammals are unlikely to occur.
Therefore, no takes were requested and none are anticipated or proposed
for authorization by NMFS and they are not discussed further.
Atlantic White-Sided Dolphin
Atlantic white-sided dolphins are found in the temperate waters of
the North Atlantic and specifically off the coast of North Carolina to
Maine in U.S. waters (NOAA Fisheries, 2020a). The Gulf of Maine
population of white-sided dolphin primarily occurs in continental shelf
waters from Hudson Canyon to Georges Bank, and in the Gulf of Maine and
lower Bay of Fundy. From January to May they occur in low numbers from
Georges Bank to Jeffreys Ledge (off New Hampshire). They are most
common from June through September from Georges Bank to lower Bay of
Fundy, with densities declining from October through December (Hayes et
al., 2019).
Since stranding recordings for the Atlantic white-sided dolphin
began in Rhode Island in the late 1960s, this species has become the
third most frequently recorded small cetacean. There are occasional
unconfirmed opportunistic reports of white-sided dolphins in
Narragansett Bay, typically in fall and winter. Atlantic white-sided
dolphins in Rhode Island are inhabitants of the continental shelf, with
a slight tendency to occur in shallower water in the spring when they
are most common (approximately 64 percent of records). Seasonal
occurrence of Atlantic white-sided dolphins decreases significantly
following spring with 21 percent of records in summer, 10 percent in
winter, and 7.6 percent in fall (Kenny and Vigness-Raposa, 2010).
Common Dolphin
The common dolphin is one of the most widely distributed species of
cetaceans, found world-wide in temperate and subtropical seas. In the
North Atlantic, they are common along the shoreline of Massachusetts
and at sea sightings have been concentrated over the continental shelf
between the 100-meter (m) and 2000-m isobaths over prominent underwater
topography and east to the mid-Atlantic Ridge. The common dolphin can
be found from Cape Hatteras northeast to Georges Bank from mid-January
to May and in Gulf of Maine from mid-summer to autumn (Hayes et al.,
2019).
Common dolphins occur in the Rhode Island waters (encompassing
Narragansett Bay, Block Island Sound, Rhode Island Sound, and nearby
coastal and continental shelf areas) year-round. They occur across much
of the shelf but most commonly in waters deeper than approximately 60
m. Seasonality is not particularly strong, but sightings are more
common in spring at approximately 35 percent of records followed by 26
percent in summer, 22 percent in winter, and 18 percent in fall (Kenny
and Vigness-Raposa, 2010).
Strandings occur year-round. In the stranding record for Rhode
Island, common dolphins are the second most frequently stranded
cetacean (exceeded only by harbor porpoises) and the most common
delphinid. There were 23 strandings in Rhode Island between 1972 and
2005 (Kenny and Vigness-Raposa, 2010). A common dolphin was
[[Page 56864]]
most recently recorded in Narragansett Bay in October of 2016 (Hayes et
al., 2019). There are no recent records of common dolphins far up
rivers, however such occurrences would only show up in the stranding
database if the stranding network responded, and there is no
centralized clearinghouse for opportunistic sightings of that type. In
Rhode Island, there are occasional opportunistic reports of common
dolphins in Narragansett Bay up as far as the Providence River, usually
in winter.
Harbor Porpoise
Harbor porpoises are found in northern temperate and subarctic
coastal and offshore waters in both the Atlantic and Pacific Oceans. In
the western North Atlantic, harbor porpoises are found in the northern
Gulf of Maine and southern Bay of Fundy region in waters generally less
than 150 m deep, primarily during the summer (July to September).
During fall (October to December) and spring (April to June), harbor
porpoises are widely dispersed between New Jersey and Maine. Lower
densities of harbor porpoises occur during the winter (January to
March) in waters off New York to New Brunswick, Canada (Hayes et al.,
2019).
Harbor Seal
Harbor seals occur in all nearshore waters of the North Atlantic
and North Pacific Oceans and adjoining seas above approximately
30[deg]N (Burns, 2009). They are year-round residents in the coastal
waters of eastern Canada and Maine, occurring seasonally from southern
New England to New Jersey from September through late May. Harbor
seals' northern movement occurs prior to pupping season that takes
place from May through June along the Maine coast. In autumn to early
winter, harbor seals move southward from the Bay of Fundy to southern
New England (Hayes et al., 2019). Overall, there are five recognized
subspecies of harbor seal, two of which occur in the Atlantic Ocean.
The western Atlantic harbor seal is the subspecies likely to occur in
the proposed project area. There is some uncertainly about the overall
population stock structure of harbor seals in the western North
Atlantic Ocean. However, it is theorized that harbor seals along the
eastern U.S. and Canada are all from a single population (Temte et al.,
1991).
Harbor seals are regularly observed around all coastal areas
throughout Rhode Island, and occasionally well inland up bays, rivers,
and streams. In general, rough estimates indicate that approximately
100,000 harbor seals can be found in New England waters (DeAngelis,
2020). It should be noted for all the seals that the available data are
strongly dominated by stranding records, which comprised 446 out of 507
total records for harbor seals (88 percent) (Kenny and Vigness-Raposa,
2010). Seals are very difficult to detect during surveys, since they
tend to be solitary and the usual sighting cue is only the seal's head
above the surface. Of the available records, 52.5 percent are in
spring, 31.2 percent in winter, 9.5 percent in summer, and 6.9 percent
in fall. In Rhode Island, there are no records offshore of the 90-m
isobath. Based on seasonal monitoring in Rhode Island, seals begin to
arrive in Narragansett Bay in September, with numbers slowly increasing
in March before dropping off sharply in April. By May, seals have left
Narragansett Bay (DeAngelis, 2020).
Seasonal nearshore marine mammal surveys were conducted at NAVSTA
Newport between May 2016 and February 2017. The surveys were conducted
along the western shoreline of Coasters Harbor Island northward to
Coggeshall Point and eastward to include Gould Island. The only species
that was sighted during the survey was harbor seal. During the spring
survey, one harbor seal was sighted on 12 May 2016. The seal was
observed near the surface of the water and engaged in several small
dives during the encounter. A group of three harbor seals was sighted
on 1 February 2017, during the winter survey. All three of the harbor
seals were at the surface and watched the vessel pass. One dead harbor
seal carcass was observed in the 12 May 2016 survey and reported to the
Mystic Aquarium Stranding Network (Moll et al., 2016, 2017; Navy,
2017b).
In Rhode Island waters, harbor seals prefer to haul out on well-
isolated intertidal rock ledges and outcrops. Numerous Naval Station
employees have reported seals hauled out on an intertidal rock ledge
north-northwest of Coddington Point named ``The Sisters'' that is 0.9
miles from the project area (see Figure 4-1 of the application) (NUWC
Division, 2011). This haulout has been studied by the NUWC Division
Newport since 2011 and has demonstrated a steady increase in use during
winter months when harbor seals are present in the bay. Harbor seals
are rarely observed at The Sisters haulout in the early fall
(September-October) but consistent numbers in mid-November (0-10
animals) are regularly observed with a gradual increase of 20+ animals
until peak numbers in the upper 40s occur during March, typically at
low tide. The number of harbor seals begins to drop off in April, and
by mid-May they are not observed hauled out at all (DeAngelis, 2020).
Haulout spaces at The Sisters haulout site is primarily influenced by
tide level, swell, and wind direction (splashing the haul out) (Moll et
al., 2017; DeAngelis, 2020).
Including The Sisters haulout, there are 22 haul out sites in
Narragansett Bay (see Figure 4-1 of the application); however, none of
these 22 other haulouts are within the project area. During a one-day
Narragansett Bay-wide count in 2018, there were at least 423 seals
observed, and all 22 haulout sites were represented. Preliminary
results from the bay-wide count for 2019 recorded 572 harbor seals;
this count also included counts from Block Island (DeAngelis, 2020).
Gray Seal
The Western North Atlantic stock of gray seal occurs in the project
area. The western North Atlantic stock is centered in Canadian waters,
including the Gulf of St. Lawrence and the Atlantic coasts of Nova
Scotia, Newfoundland, and Labrador, Canada, and the northeast U.S.
continental shelf (Hayes et al. 2017). In general, this species can be
found year-round in the coastal waters of the Gulf of Maine (Hayes et
al., 2019).
Gray seal occurrences in Rhode Island are mostly represented by
stranding records--155 of 193 total records (80 percent). Gray seal
records in the region are primarily from the spring (approximately 87
percent), with much smaller numbers in all other seasons (5.7 percent
in winter, 5.2 percent in summer, and 2.1 percent in fall). Strandings
were broadly distributed along ocean-facing beaches in Long Island and
Rhode Island, with a few spring records in Connecticut (Kenny and
Vigness-Raposa, 2010). As with other seals, habitat use by gray seals
in Rhode Island is poorly known. They are seen mainly when stranded or
hauled out and infrequently at sea. There are very few observations of
gray seals in Rhode Island other than strandings. The annual numbers of
gray seal strandings in the Rhode Island study area since 1993 have
fluctuated markedly, from a low of 1 in 1999 to a high of 24 in 2011
(Kenney, 2020). The very strong seasonality observed in gray seal
occurrence in Rhode Island between March and June is clearly related to
the timing of pupping in January-February. Most stranded individuals
encountered in Rhode Island area appear to be post-weaning juveniles
and starved or starving juveniles (Nawojchik, 2002; Kenney, 2005).
Annual informal surveys conducted since 1994 observed a small number of
gray seals in Narragansett Bay in 2016 (ecoRI News, 2016).
[[Page 56865]]
Harp Seal
The harp seal is a highly migratory species, and its range can
extend from the Canadian Arctic to New Jersey. In U.S. waters, the
species has an increasing presence in the coastal waters between Maine
and New Jersey and are considered members of the western North Atlantic
stock with general presence from January through May (Hayes et al.,
2019).
Harp seals in Rhode Island are known almost exclusively from
strandings (approximately 98 percent). Strandings are widespread on
ocean-facing beaches throughout Long Island and Rhode Island and the
records are almost entirely from spring (approximately 68 percent) and
winter (approximately 30 percent). Harp seals are nearly absent in
summer and fall. Harp seals also make occasional appearances well
inland up rivers (Kenny and Vigness-Raposa, 2010). During late winter
of 2020, a healthy harp seal was observed hauled out and resting near
``The Sisters'' haulout site (DeAngelis, 2020).
Hooded Seal
The hooded seal is a highly migratory species, and its range can
extend from the Canadian Arctic to as far south as Puerto Rico
(Mignucci-Giannoni and Odell, 2001 as cited in Hayes et al., 2019). In
U.S. waters, the species has an increasing presence in the coastal
waters between Maine and Florida. Hooded seals in the U.S. are
considered members of the western North Atlantic stock and generally
occur in New England waters from January through May and further south
off the southeast U.S. coast and in the Caribbean in the summer and
fall seasons (McAlpine et al. 1999; Harris et al. 2001; and Mignucci-
Giannoni and Odell, 2001 as cited in Hayes et al., 2019).
Hooded seal occurrences in Rhode Island are predominantly from
stranding records (approximately 99 percent). They are rare in summer
and fall but most common in the area during spring and winter (45
percent and 36 percent of all records, respectively) (Kenney, 2005;
Kenny and Vigness-Raposa, 2010). Hooded seal strandings are broadly
distributed across ocean-facing beaches in Rhode Island and they
occasionally occur well up rivers, but less often than harp seals.
Hooded seals have been recorded in Narragansett Bay but are considered
occasional visitors and are expected to be the least encountered seal
species in the bay (RICRMC, 2010).
Unusual Mortality Events
An unusual mortality event (UME) is defined under Section 410(6) of
the MMPA as a stranding that is unexpected; involves a significant die-
off of any marine mammal population; and demands immediate response.
There are no active UME investigations for species affected in the
project area.
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 (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (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. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 4.
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Generalized hearing range
Hearing group *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales). 7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales, bottlenose
whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus cruciger &
L. australis).
Phocid pinnipeds (PW) (underwater) (true 50 Hz to 86 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
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 (2018) for a review of available information.
Seven marine mammal species (three cetacean and four phocid pinniped
species) have the reasonable potential to co-occur with the proposed
construction activities. Please refer to Table 3. Of the cetacean
species that may be present, two are classified as a mid-frequency
cetacean (i.e., dolphins), and one is classified as a high-frequency
cetacean (i.e., harbor porpoise).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated
[[Page 56866]]
Take section, and the Proposed Mitigation section, to draw conclusions
regarding the likely impacts of these activities on the reproductive
success or survivorship of individuals and how those impacts on
individuals are likely to impact marine mammal species or stocks.
Acoustic effects on marine mammals during the specified activity
can occur from vibratory and impact pile driving. The effects of
underwater noise from the Navy's proposed activities have the potential
to result in Level A and Level B harassment of marine mammals in the
action area.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
background sound in a given place and is usually a composite of sound
from many sources both near and far. The sound level of an area is
defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., waves, wind,
precipitation, earthquakes, ice, atmospheric sound), biological (e.g.,
sounds produced by marine mammals, fish, and invertebrates), and
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ambient sound--depends not
only on the source levels (as determined by current weather conditions
and levels of biological and shipping activity) but also on the ability
of sound to propagate through the environment. In turn, sound
propagation is dependent on the spatially and temporally varying
properties of the water column and sea floor, and is frequency-
dependent. As a result of the dependence on a large number of varying
factors, ambient sound levels can be expected to vary widely over both
coarse and fine spatial and temporal scales. Sound levels at a given
frequency and location can vary by 10-20 dB from day to day (Richardson
et al. 1995). The result is that, depending on the source type and its
intensity, sound from the specified activity may be a negligible
addition to the local environment or could form a distinctive signal
that may affect marine mammals.
In-water construction activities associated with the project would
include impact pile driving and vibratory pile driving. The sounds
produced by these activities fall into one of two general sound types:
Impulsive and non-impulsive. Impulsive sounds (e.g., explosions,
gunshots, sonic booms, impact pile driving) are typically transient,
brief (less than 1 second), broadband, and consist of high peak sound
pressure with rapid rise time and rapid decay (ANSI 1986; NIOSH 1998;
ANSI 2005; NMFS 2018a). Non-impulsive sounds (e.g. aircraft, machinery
operations such as drilling or dredging, vibratory pile driving, and
active sonar systems) can be broadband, narrowband or tonal, brief or
prolonged (continuous or intermittent), and typically do not have the
high peak sound pressure with raid rise/decay time that impulsive
sounds do (ANSI 1995; NIOSH 1998; NMFS 2018a). The distinction between
these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward 1997 in Southall et al. 2007).
Two types of pile hammers would be used on this project: Impact and
vibratory. Impact hammers operate by repeatedly dropping a heavy piston
onto a pile to drive the pile into the substrate. Sound generated by
impact hammers is characterized by rapid rise times and high peak
levels, a potentially injurious combination (Hastings and Popper 2005).
Vibratory hammers install piles by vibrating them and allowing the
weight of the hammer to push them into the sediment. Vibratory hammers
produce significantly less sound than impact hammers. Peak sound
pressure levels (SPLs) may be 180 dB or greater, but are generally 10
to 20 dB lower than SPLs generated during impact pile driving of the
same-sized pile (Oestman et al. 2009). Rise time is slower, reducing
the probability and severity of injury, and sound energy is distributed
over a greater amount of time (Nedwell and Edwards 2002; Carlson et al.
2005).
The likely or possible impacts of the Navy's proposed activity on
marine mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors could result from the physical
presence of the equipment and personnel. However, any impacts to marine
mammals are expected to primarily be acoustic in nature. Acoustic
stressors include effects of heavy equipment operation during pile
driving.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving is the primary means by which marine
mammals may be harassed from the Navy's specified activity. In general,
animals exposed to natural or anthropogenic sound may experience
physical and psychological effects, ranging in magnitude from none to
severe (Southall et al. 2007). In general, exposure to pile driving
noise has the potential to result in auditory threshold shifts and
behavioral reactions (e.g., avoidance, temporary cessation of foraging
and vocalizing, changes in dive behavior). Exposure to anthropogenic
noise can also lead to non-observable physiological responses such an
increase in stress hormones. Additional noise in a marine mammal's
habitat can mask acoustic cues used by marine mammals to carry out
daily functions such as communication and predator and prey detection.
The effects of pile driving noise on marine mammals are dependent on
several factors, including, but not limited to, sound type (e.g.,
impulsive vs. non-impulsive), the species, age and sex class (e.g.,
adult male vs. mom with calf), duration of exposure, the distance
between the pile and the animal, received levels, behavior at time of
exposure, and previous history with exposure (Wartzok et al. 2004;
Southall et al. 2007). Here we discuss physical auditory effects
(threshold shifts), followed by behavioral effects and potential
impacts on habitat.
NMFS defines a noise-induced threshold shift (TS) as a change,
usually an increase, in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). The amount of
threshold shift is customarily expressed in dB. A TS can be permanent
or temporary. As described in NMFS (2018), there are numerous factors
to consider when examining the consequence of TS, including, but not
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), the likelihood an individual would be exposed for a long
enough duration or to a high enough level to induce a TS, the magnitude
of the TS, the time to recovery (seconds to minutes or hours to days),
the frequency range of the exposure (i.e., spectral content), the
hearing and vocalization frequency range of the exposed species
relative to the signal's frequency spectrum (i.e., how an animal uses
sound within the frequency band of the signal; e.g., Kastelein et al.
2014), and the overlap between the animal and the source (e.g.,
spatial, temporal, and spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals
[[Page 56867]]
indicate that a 40 dB threshold shift approximates PTS onset (see Ward
et al. 1958, 1959; Ward 1960; Kryter et al. 1966; Miller 1974; Ahroon
et al. 1996; Henderson et al. 2008). PTS levels for marine mammals are
estimates, and, with the exception of a single study unintentionally
inducing PTS in a harbor seal (Kastak et al. 2008), there are no
empirical data measuring PTS in marine mammals, largely due to the fact
that, for various ethical reasons, experiments involving anthropogenic
noise exposure at levels inducing PTS are not typically pursued or
authorized (NMFS 2018).
Temporary Threshold Shift (TTS)--TTS is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS 2018). Based on data from cetacean TTS
measurements (see Southall et al. 2007), a TTS of 6 dB is considered
the minimum threshold shift clearly larger than any day-to-day or
session-to-session variation in a subject's normal hearing ability
(Schlundt et al. 2000; Finneran et al. 2000, 2002). As described in
Finneran (2015), marine mammal studies have shown the amount of TTS
increases with cumulative sound exposure level (SELcum) in an
accelerating fashion: At low exposures with lower SELcum, the amount of
TTS is typically small and the growth curves have shallow slopes. At
exposures with higher SELcum, the growth curves become steeper and
approach linear relationships with the noise SEL.
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 takes place during a time when the animal
is traveling through the open ocean, 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 a time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that 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 we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis))
and five species of pinnipeds exposed to a limited number of sound
sources (i.e., mostly tones and octave-band noise) in laboratory
settings (Finneran 2015). TTS was not observed in trained spotted
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive
noise at levels matching previous predictions of TTS onset (Reichmuth
et al. 2016). In general, harbor seals and harbor porpoises have a
lower TTS onset than other measured pinniped or cetacean species
(Finneran 2015). Additionally, the existing marine mammal TTS data come
from a limited number of individuals within these species. No data are
available on noise-induced hearing loss for mysticetes. For summaries
of data on TTS in marine mammals or for further discussion of TTS onset
thresholds, please see Southall et al. (2007), Finneran and Jenkins
(2012), Finneran (2015), and Table 5 in NMFS (2018). Installing piles
requires a combination of impact pile driving and vibratory pile
driving. For this project, these activities would not occur at the same
time and there would be pauses in activities producing the sound during
each day. Given these pauses and that many marine mammals are likely
moving through the ensonified area and not remaining for extended
periods of time, the potential for TS declines.
Behavioral Harassment--Exposure to noise from pile driving and
removal also has the potential to behaviorally disturb marine mammals.
Available studies show wide variation in response to underwater sound;
therefore, it is difficult to predict specifically how any given sound
in a particular instance might affect marine mammals perceiving the
signal. If a marine mammal does react briefly to an underwater sound by
changing its behavior or moving a small distance, the impacts of the
change are unlikely to be significant to the individual, let alone the
stock or population. However, if a sound source displaces marine
mammals from an important feeding or breeding area for a prolonged
period, impacts on individuals and populations could be significant
(e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 2005).
Disturbance may result in 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 sound sources are located.
Pinnipeds may increase their haulout time, possibly to avoid in-water
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are
highly variable and context-specific and any reactions depend on
numerous intrinsic and extrinsic factors (e.g., species, state of
maturity, experience, current activity, reproductive state, auditory
sensitivity, time of day), as well as the interplay between factors
(e.g., Richardson et al. 1995; Wartzok et al. 2003; Southall et al.
2007; Weilgart 2007; Archer et al. 2010). Behavioral reactions can vary
not only among individuals but also within an individual, depending on
previous experience with a sound source, context, and numerous other
factors (Ellison et al. 2012), and can vary depending on
characteristics associated with the sound source (e.g., whether it is
moving or stationary, number of sources, distance from the source). In
general, pinnipeds seem more tolerant of, or at least habituate more
quickly to, potentially disturbing underwater sound than do cetaceans,
and generally seem to be less responsive to exposure to industrial
sound than most cetaceans. Please see Appendices B-C of Southall et al.
(2007) for a review of studies involving marine mammal behavioral
responses to sound.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.
2001; Nowacek et al. 2004; Madsen et al. 2006; Yazvenko et al. 2007). A
determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral
[[Page 56868]]
responses, autonomic nervous system responses, neuroendocrine
responses, or immune responses (e.g., Seyle 1950; Moberg 2000). In many
cases, an animal's first and sometimes most economical (in terms of
energetic costs) response is behavioral avoidance of the potential
stressor. Autonomic nervous system responses to stress typically
involve changes in heart rate, blood pressure, and gastrointestinal
activity. These responses have a relatively short duration and may or
may not have a significant long-term effect on an animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al. 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and distress is the cost of the
response. During a stress response, an animal uses glycogen stores that
can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This is a state
of distress, and it will last until the animal replenishes its
energetic reserves sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al. 1996; Hood et al. 1998; Jessop et al. 2003;
Krausman et al. 2004; Lankford et al. 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker 2000; Romano
et al. 2002b) and, more rarely, studied in wild populations (e.g.,
Romano et al. 2002a). For example, Rolland et al. (2012) found that
noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these stress
responses would be classified as distress. In addition, any animal
experiencing TTS would likely also experience stress responses (NRC,
2003), however distress is an unlikely result of this project, based on
observations of marine mammals during previous, similar projects in the
area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al. 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked.
Airborne Acoustic Effects--Although pinnipeds are known to haul out
regularly in Narraganset Bay and some in the vicinity of the project
area, we believe that incidents of take resulting solely from airborne
sound are unlikely. There is a possibility that an animal could surface
in-water, but with head out, within the area in which airborne sound
exceeds relevant thresholds and thereby be exposed to levels of
airborne sound that NMFS associates with harassment, but any such
occurrence would likely be accounted for in our estimation of
incidental take from underwater sound. Therefore, authorization of
incidental take resulting from airborne sound for pinnipeds is not
warranted, and airborne sound is not discussed further here. Cetaceans
are not expected to be exposed to airborne sounds that would result in
harassment as defined under the MMPA.
Marine Mammal Habitat Effects
The Navy's construction activities could have localized, temporary
impacts on marine mammal habitat by increasing in-water sound pressure
levels and slightly decreasing water quality. Construction activities
are of short duration and would likely have temporary impacts on marine
mammal habitat through increases in underwater sound. Increased noise
levels may affect acoustic habitat (see masking discussion above) and
adversely affect marine mammal prey in the vicinity of the project area
(see discussion below). During impact and vibratory pile driving,
elevated levels of underwater noise would ensonify the project area
where both fish and mammals may occur and could affect foraging
success. Additionally, marine mammals may avoid the area during
construction, however, displacement due to noise is expected to be
temporary and is not expected to result in long-term effects to the
individuals or populations.
A temporary and localized increase in turbidity near the seafloor
would occur in the immediate area surrounding the area where piles are
installed. The sediments on the sea floor will be disturbed during pile
driving; however, suspension will be brief and localized and is
unlikely to measurably affect marine mammals or their prey in the area.
In general, turbidity associated with pile installation is localized to
about a 25-ft (7.6-m) radius around the pile (Everitt et al. 1980).
Cetaceans are not expected to be close enough to the pile driving areas
to experience effects of turbidity, and any pinnipeds could avoid
localized areas of turbidity. Therefore, we expect the impact from
increased turbidity levels to be discountable to marine mammals and do
not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat
The proposed activities would not result in permanent impacts to
habitats used directly by marine mammals except for the actual
footprint of the project. The total seafloor area affected by pile
installation is a very small area compared to the vast foraging area
[[Page 56869]]
available to marine mammals in the surrounding area.
Avoidance by potential prey (i.e., fish) of the immediate area due
to the temporary loss of this foraging habitat is also possible. The
duration of fish avoidance of this area after pile driving stops is
unknown, but we anticipate a rapid return to normal recruitment,
distribution and behavior. Any behavioral avoidance by fish of the
disturbed area would still leave large areas of fish and marine mammal
foraging habitat in the nearby vicinity in the project area.
Effects on Potential Prey
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., fish). Marine mammal
prey varies by species, season, and location. Here, we describe studies
regarding the effects of noise on known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al. 1999; Fay, 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al. 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. Short duration, sharp
sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the
physiological state of the fish, past exposures, motivation (e.g.,
feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish
may relocate to avoid certain areas of sound energy. Additional studies
have documented effects of pile driving on fish, although several are
based on studies in support of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings,
2009). Several studies have demonstrated that impulse sounds might
affect the distribution and behavior of some fishes, potentially
impacting foraging opportunities or increasing energetic costs (e.g.,
Fewtrell and McCauley, 2012; Pearson et al. 1992; Skalski et al. 1992;
Santulli et al. 1999; Paxton et al. 2017). However, some studies have
shown no or slight reaction to impulse sounds (e.g., Pena et al. 2013;
Wardle et al. 2001; Jorgenson and Gyselman, 2009; Cott et al. 2012).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al. 2012b; Casper et al. 2013).
The most likely impact to fish from pile driving activities at the
project areas would be temporary behavioral avoidance of the area. The
duration of fish avoidance of an area after pile driving stops is
unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated.
The area impacted by the project is relatively small compared to
the available habitat in the remainder of the project area and
surrounding waters, and there are no areas of particular importance
that would be impacted by this project. Any behavioral avoidance by
fish of the disturbed area would still leave significantly large areas
of fish and marine mammal foraging habitat in the nearby vicinity. As
described in the preceding paragraphs, the potential for the Navy's
construction to affect the availability of prey to marine mammals or to
meaningfully impact the quality of physical or acoustic habitat is
considered to be insignificant.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization, which will inform both NMFS' consideration
of small numbers and the negligible impact determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would be by Level A and B harassment, in the form
of disruption of behavioral patterns and potential TTS and PTS for
individual marine mammals resulting from exposure to pile driving and
removal. As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the take is estimated.
Generally speaking, 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) the
number of days of activities. We note that while these factors can
contribute to a basic calculation to provide an initial prediction of
takes, additional information that can qualitatively inform take
estimates is also sometimes available (e.g., previous monitoring
results or average group size). Below, we describe the factors
considered here in more detail and present the proposed take estimate.
Acoustic Thresholds
NMFS recommends the use of 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--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. 2012). Based on what the
available
[[Page 56870]]
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) (reference pressure
microPascal, root mean square) 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.
The Navy's construction includes the use of continuous (vibratory
pile driving) and impulsive (impact pile driving) sources, and
therefore the level of 120 and 160 dB re 1 [mu]Pa (rms) is applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) 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. The
technical guidance identifies the received levels, or thresholds, above
which individual marine mammals are predicted to experience changes in
their hearing sensitivity for all underwater anthropogenic sound
sources, and reflects the best available science on the potential for
noise to affect auditory sensitivity. The technical guidance does this
by identifying threshholds in the follow manner:
[ssquf] Dividing sound sources into two groups (i.e., impulsive and
non-impulsive) based on their potential to affect hearing sensitivity;
[ssquf] Choosing metrics that best address the impacts of noise on
hearing sensitivity, i.e., sound pressure level (peak SPL) and sound
exposure level (SEL) (also accounting for duration of exposure); and
[ssquf] Dividing marine mammals into hearing groups and developing
auditory weighting functions based on the science supporting the fact
that not all marine mammals hear and use sound in the same manner.
These thresholds were developed by compiling and synthesizing the
best available science, and are provided in Table 5 below. The
references, analysis, and methodology used in the development of the
thresholds are described in NMFS 2018 Technical Guidance, which may be
accessed at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection">https://www.fisheries.noaa.gov/national/marine-mammal-protection</a>.
The Navy's proposed construction includes the use of impulsive
(impact pile driving) and non-impulsive (vibratory pile driving)
sources.
Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 217 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. 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, which include source levels transmission loss
coefficient.
Sound Propagation
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * log<INF>10</INF>(R<INF>1</INF>/R<INF>2</INF>),
where
B = transmission loss coefficient (assumed to be 15)
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions, including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6 dB reduction in sound level for each doubling of
distance from the source (20*log(range)). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log(range)). As is
common practice in coastal waters, here we assume practical spreading
(4.5 dB reduction in sound level for each doubling of distance).
Practical spreading is a compromise that is often used under conditions
where water depth increases as the receiver moves away from the
shoreline, resulting in an
[[Page 56871]]
expected propagation environment that would lie between spherical and
cylindrical spreading loss conditions. Practical spreading was used to
determine sound propagation for this project.
Sound source levels
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles, hammers, and the physical
environment in which the activity takes place. There are sound source
level (SSL) measurements available for certain pile types and sizes
from the similar environments from other Navy pile driving projects
that were evaluated and used as proxy sound source levels to determine
reasonable sound source levels likely to result from the pile driving
and removal activities (Table 6). Some of the proxy source levels are
expected to be conservative, as the values are from larger pile sizes.
Table 6--Underwater Noise Sound Source Levels Modeled for Impact and Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Sound pressure levels (SPL) or sound exposure
level (SEL) at 10 m distance
Pile size, type Method -----------------------------------------------
Peak SPL RMS SPL SEL L
----------------------------------------------------------------------------------------------------------------
42-in Diameter Steel Pipe \1\......... Impact.................. 211 196 181
30-in Diameter Steel Pipe \2\......... Impact.................. 211 196 181
14-in Steel H-pile \3\................ Vibratory............... NA 158 158
31.5-in Z-shaped Steel Sheet \4\...... Impact.................. 211 196 181
31.5-in Z-shaped Steel Sheet \5\...... Vibratory............... NA 163 163
22.5-in Z-shaped Steel Sheet \3\...... Impact.................. 205 190 180
22.5-in Z-shaped Steel Sheet \5\...... Vibratory............... NA 163 163
----------------------------------------------------------------------------------------------------------------
Legend: All sound pressure levels (SPLs) are unattenuated; dB = decibels; rms = root mean square, SEL = sound
exposure level; NA = Not applicable; NR = Not reported.
Notes:
\1\ = Navy pers comm. 2021.
\2\ = Navy San Diego Bay Acoustic Compendium (NAVFAC SW 2020).
\3\ = Caltrans 2015.
\4\ = A proxy value for 31-in sheet piles could not be found for impact driving so the proxy for a 30-in steel
pipe pile has been used from NAVFAC SW (2020). This value was also used for Z-shaped steel sheets for the
Navy's Dry Dock 1 Modification and Expansion, Portsmouth Naval Shipyard, Kittery, Maine 2021 IHA (86 FR 14598;
March 17, 2021).
\5\ = For vibratory driving of 31-in sheet piles and 22.5-in Z-shaped steel sheet piles, 163 dB SPL was used
based on measurements conducted by the Naval Facilities Engineering Command Mid-Atlantic (NAVFAC Mid-Atlantic)
in the Technical Memorandum Nearshore Marine Mammal Surveys, Portsmouth Naval Shipyard (2018).
For 42-in steel piles, a SSL of 181 db SEL was used for impact
driving and is similar to SSL of 180 dB SEL for 36-in piles in CALTRANS
(2015). There are no SSL values for 42-in piles in CALTRANS, the
nearest values are for 36-in and 60-in steel pipe piles. For 30-in
steel pipe piles, a SSL of 181 dB SEL was used for impact pile driving
as a proxy from the Navy's San Diego Bay Acoustic Compendium (NAVFAC SW
2020) (the median value from the greatest sound levels recorded for 30-
in steel piles). The SSL used for 30-in steel piles during impact pile
driving is also more conservative than the SSL of 177 dB SEL for 30-in
steel piles in CALTRANS (2015). For 31.5-in sheet piles, a SSL of 181
dB SEL was used for impact pile driving as a proxy from 30-in steel
pipe piles (NAVFAC SW 2020), which is also slightly more conservative
than a SSL of 180 dB SEL for 24-in piles in CALTRANS (2015) (no larger
sheet piles are described in CALTRANS 2015). During vibratory pile
driving of 31.5-in sheet piles, the Navy used a SSL of 163 dB SPL,
which is also more conservative than a SSL of 160 dB SPL for 24-in
sheet piles in CALTRANS (2015) (no large sheet piles are described in
CALTRANS 2015). For 22.5-in Z-shaped steel sheet piles, a SSL of 180 dB
SEL was used for impact pile driving and is also equivalent to 24-in
sheet piles in CALTRANS (2015). During vibratory pile driving, a SSL of
163 dB SPL is a proxy from NAVFAC Mid-Atlantic (2018) and is also more
conservative than 24-in sheet piles in CALTRANS (2015) where the SSL is
160 dB SPL for 24-in sheet piles (no larger sheet piles are described
in CALTRANS (2015). For 14-in steel H-piles, a SSL of 158 dB SPL was
used from CALTRANS (2015).
Level A Harassment
In conjunction with the NMFS Technical Guidance (2018), 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, NMFS 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 may result in some
degree of overestimation of Level A harassment 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 stationary
sources (such as from impact and vibratory pile driving), the NMFS User
Spreadsheet (2020) predicts the closest distance at which, if a marine
mammal remained at that distance the whole duration of the activity, it
would not incur PTS. Inputs used in the User Spreadsheet (Tables 7 and
8), and the resulting isopleths are reported below (Table 9).
[[Page 56872]]
Table 7--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Vibratory Pile
Driving
[User spreadsheet input--Vibratory Pile Driving Spreadsheet Tab A.1 Vibratory Pile Driving Used.]
----------------------------------------------------------------------------------------------------------------
22.5-in Z- 31.5-in Z-
14-in steel H- shaped sheet shaped sheet
pile piles piles
----------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL).......................................... 158 163 163
Weighting Factor Adjustment (kHz)............................... 2.5 2.5 2.5
Number of piles within 24-hr period............................. 12 10 8
Duration to drive a single pile (min)........................... 10 13 13
Propagation (xLogR)............................................. 15 15 15
Distance of source level measurement (m)........................ 10 10 10
----------------------------------------------------------------------------------------------------------------
Table 8--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Impact Pile
Driving
[User spreadsheet input--Impact Pile Driving Spreadsheet Tab E.1 Impact Pile Driving Used.]
----------------------------------------------------------------------------------------------------------------
22-in Z-shaped 31.5-in Z-
piles shaped piles 30-in pile 42-in pile
----------------------------------------------------------------------------------------------------------------
Source Level (Single Strike/shot SEL)........... 180 181 181 181
Weighting Factor Adjustment (kHz)............... 2 2 2 2
Number of strikes per pile...................... 530 530 530 530
Number of piles per day......................... 10 8 2 4
Propagation (xLogR)............................. 15 15 15 15
Distance of source level measurement (m)........ 10 10 10 10
----------------------------------------------------------------------------------------------------------------
Table 9--NMFS Technical Guidance (2020) User Spreadsheet Outputs To Calculate Level A Harassment PTS Isopleths
[User spreadsheet output]
--------------------------------------------------------------------------------------------------------------------------------------------------------
PTS isopleths (m)
-------------------------------------------------------------------------------
Level A harassment
Activity Sound source level at 10 m -------------------------------------------------------------------------------
High-
Low-frequency Mid-frequency frequency Phocid Otariid
cetaceans cetaceans cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch H-pile........................ 158 SPL......................... 6.8 0.6 10.1 4.2 0.3
22.5-in Z-shaped sheet piles.......... 163 SPL......................... 15.5 1.4 23.0 9.4 0.7
31.5-in Z-shaped sheet piles.......... 163 SPL......................... 13.4 1.2 19.8 8.1 0.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
22.5-in Z-shaped sheet piles.......... 180 SEL/190 SPL................. 1,915.4 68.1 2,281.5 1,025.0 74.6
31.5-in Z-shaped sheet piles.......... 181 SEL/196 SPL................. 1,942.5 68.4 2,292.4 1,029.9 75.0
30-in pile............................ 181 SEL/196 SPL................. 763.7 27.2 909.7 408.7 29.8
42-in pile............................ 181 SEL/196 SPL................. 1,212 43.1 1,444.1 648.8 47.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level B Harassment
Utilizing the practical spreading model, NMFS determined underwater
noise will fall below the behavioral effects threshold of 120 dB rms
for marine mammals at the distances shown in Table 10 for vibratory
pile driving. With these radial distances, the largest Level B
harassment zone calculated was 7,356 m for sheet piles. However, this
distance would be truncated due to the presence of intersecting land
masses. For calculating the Level B harassment zone for impact driving,
the practical spreading loss model was used with a behavioral threshold
of 160 dB rms. The maximum radial distance of the Level B harassment
zone for impact piling equaled 2,512 m for 30-in piles, 42-in piles and
31.5-in sheet piles. Table 10 below provides all Level B harassment
radial distances (m) and ensonified areas (km\2\) during the Navy's
proposed activities.
[[Page 56873]]
Table 10--Distances to Relevant Behavioral Isopleths and Ensonified Areas
----------------------------------------------------------------------------------------------------------------
Level B
Year (section) Activity Received level at 10 m harassment zone
(m/km\2\) *
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Year 1 (S45)........................... 14-in H-piles............ 158 SPL.................. 3,415 m/5.6 km\2\
Year 2 (S366), Year 2 (Pier 1)......... 14-in H-piles............ 158 SPL.................. 3,415 m/5.8 km\2\
Year 3 (LNG)........................... 14-in H-piles............ 158 SPL.................. 3,415 m/5.8 km\2\
Year 4 (S499/Pier 2)................... 14-in H-piles............ 158 SPL.................. 3,415 m/5.7 km\2\
Year 1 (S45)........................... 22.5-in Z-shaped sheet 163 SPL.................. 7,356 m/7.9 km\2\
piles.
Year 2 (S366), Year 2 (Pier 1)......... 22.5-in Z-shaped sheet 163 SPL.................. 7,356 m/8.3 km\2\
piles.
Year 3 (LNG)........................... 22.5-in Z-shaped sheet 163 SPL.................. 7,356 m/7.5 km\2\
piles.
Year 4 (S499/Pier 2)................... 22.5-in Z-shaped sheet 163 SPL.................. 7,356 m/7.5 km\2\
piles.
Year 4 (S499/Pier 2)................... 31.5-in Z-shaped sheet 163 SPL.................. 7,356 m/9.5.km\2\
piles.
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
Year 1 (S45)........................... 22.5-in Z-shaped sheet 180 SEL/190 SPL.......... 1,000 m/1.1 km\2\
piles.
Year 2 (S366), Year 2 (Pier 1)......... 22.5-in Z-shaped sheet 180 SEL/190 SPL.......... 1,000 m/1.3 km\2\
piles.
Year 3 (LNG)........................... 22.5-in Z-shaped sheet 180 SEL/190 SPL.......... 1,000 m/0.7 km\2\
piles.
Year 4 (S499/Pier 2)................... 31.5-in Z-shaped sheet 181 SEL/196 SPL.......... 2,512 m/3.8 km\2\
piles.
Year 1 (S45)........................... 30-in piles.............. 181 SEL/196 SPL.......... 2,512 m/3.8 km\2\
Year 2 (S366).......................... 30-in piles.............. 181 SEL/196 SPL.......... 2,512 m/4.0 km\2\
Year 4 (S499/Pier 2)................... 42-in piles.............. 181 SEL/196 SPL.......... 2,512 m/3.8 km\2\
----------------------------------------------------------------------------------------------------------------
* Note: Distances to the Level B harassment zone may vary slightly of the same pile size, due to the section of
work being conducted and how the produced sound would be directed (see Figures 6-1 through 6-4 of the Navy's
application).
Marine Mammal Occurrence and Take Calculation and Estimation
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations. Potential exposures to impact pile and vibratory pile
driving noise for each acoustic threshold were estimated using marine
mammal density estimates (N) from the Navy Marine Species Density
Database NMSDD (Navy 2017) for which data of monthly densities of
species were evaluated in terms of minimum, maximum, and average annual
densities within Narragansett Bay and multiplied by the zone of
influence (ZOI) and the maximum days of pile driving (take estimate = N
x ZOI x days of pile driving). The pile type, size, and installation
method that produce the largest ZOI were used to estimate exposure of
marine mammals to noise impacts. We describe how the information
provided above is brought together to produce a quantitative take
estimate in the species sections below.
Atlantic White-Sided Dolphins
Atlantic white-sided dolphins occur seasonally, occurring primarily
along the continental shelf with occasional unconfirmed opportunistic
sightings in Narragansett Bay in fall and winter. The most recent
observation of a pod of dolphins in Narragansett Bay was in October
2007 (NUWC Division, 2011). Construction activity could occur at any
time of year and would be short-term and intermittent. Therefore, the
average species density was determined to be appropriate for estimating
takes of Atlantic white-sided dolphin. Based on density data for
Narragansett Bay (Navy 2017), the average density of Atlantic white-
sided dolphin was determined to be 0.003/km\2\. This density was used
to estimate abundance of animals that could be present in the area for
exposure. Using this information, 1 take was calculated for Years 1, 3,
and 4 and 0 takes in Year 2 (Table 11). However, the annual take by
Level B harassment proposed for Atlantic white-sided dolphins has been
increased to the average group size (16) (NAVSEA NUWC 2017) for Years
1, 3, and 4, because the calculated annual take is below the average
group size. Therefore, the Navy requested and NMFS proposes 16 takes
annually in Years 1, 3, and 4 (0 in Year 2) for a total of 48 takes by
Level B harassment of Atlantic white-sided dolphin (Table 11). No takes
by Level A harassment of Atlantic white-sided dolphin are anticipated.
Because this species' regular occurrence is in much deeper waters than
the extent of the ZOI (Hayes et al., 2019), expected takes of this
species are extremely low.
Table 11--Proposed Take for Atlantic White-Sided Dolphin
------------------------------------------------------------------------
Calculated
Construction year Level B Proposed Level
harassment B harassment
------------------------------------------------------------------------
Year 1 (S45)............................ 1 16
Year 2 (S366 and Pier 01)............... 0 0
Year 3 (LNG)............................ 1 16
Year 4 (S499/Pier 2).................... 1 16
-------------------------------
Total............................... 3 48
------------------------------------------------------------------------
[[Page 56874]]
Common Dolphin
Common dolphins are the most likely dolphin species to be spotted
in Narragansett Bay, and usually occur in late fall or winter (Kenney,
2013). The most recent sighting of a common dolphin recorded in
Narragansett Bay was in October of 2016 (Hayes et al., 2019).
Construction activity could occur at any time of year and would be
short-term and intermittent. Based on density data for Narragansett Bay
(NMSDD, Navy, 2017), the average density of common dolphin was
determined to be 0.011/km\2\. Using this information, 3 takes by Level
B harassment were calculated for Years 1 and 4, 2 takes for Year 2 and
6 takes for Year 3 (Table 12). Because the calculated annual take is
below the average group size, the annual take by Level B harassment
proposed for common dolphin has been increased to the average group
size (28) (NAVSEA NUWC 2017). Therefore, the Navy requested and NMFS
proposes 28 takes annually (with the exception of Year 2, for which it
was doubled to 56 takes as a conservative approach to account for more
vibratory and impact pile driving activities that occur during that
year in two sections (S366 and Pier 1)) for a total of 140 takes by
Level B harassment of common dolphin (Table 12). No takes by Level A
harassment of common dolphin are anticipated. Because this species'
regular occurrence is in much deeper waters than the extent of the ZOI
(Hayes et al., 2019), takes of this species are expected to be
extremely low.
Table 12--Proposed Take for Common Dolphin
------------------------------------------------------------------------
Calculated
Construction year Level B Proposed Level
harassment B harassment
------------------------------------------------------------------------
Year 1 (S45)............................ 3 28
Year 2 (S366 and Pier 01)............... 2 56
Year 3 (LNG)............................ 6 28
Year 4 (S499/Pier 2).................... 3 28
-------------------------------
Total............................... 14 140
------------------------------------------------------------------------
Harbor Porpoise
Harbor porpoise are not common to Narragansett Bay but may occur,
especially in winter and spring months (Kinney 2013). Harbor porpoise
is the most stranded cetacean in Rhode Island, with a strong seasonal
occurrence in the spring. Construction activity could occur at any time
of year and would be short-term and intermittent. Therefore, the
average species density was determined to be appropriate for estimating
takes of harbor porpoise. Based on density data for Narragansett Bay
(NMSDD, Navy 2017), the average density of harbor porpoise was
determined to be 0.012/km\2\. Using this information, 4 takes by Level
B harassment were calculated for Years 1 and 4, 2 takes for Year 2, and
7 takes for Year 3 (Table 13). Because the calculated take in Year 2
was less than the group size, the annual take by Level B harassment
proposed for harbor porpoise has been increased to the average group
size (3) and multiplied by two for 6 takes (NAVSEA NUWC 2017) as a
conservative approach to account for more vibratory and impact pile
driving activities that occur during that year in two sections (S366
and Pier 1)). Therefore, the Navy requested and NMFS proposes 4 takes
in Years 1 and 4, 6 takes in Year 2, and 7 takes in Year 3, and a total
of 21 takes by Level B harassment of harbor porpoise (Table 13). Level
A harassment could occur during years 1, 3 and 4 (Table 13).
Table 13--Proposed Take for Harbor Porpoise
----------------------------------------------------------------------------------------------------------------
Calculated
Construction year Proposed Level Level B Proposed Level
A harassment harassment B harassment
----------------------------------------------------------------------------------------------------------------
Year 1 (S45).................................................... 1 4 4
Year 2 (S366 and Pier 01)....................................... 0 2 6
Year 3 (LNG).................................................... 2 7 7
Year 4 (S499/Pier 2)............................................ 1 4 4
-----------------------------------------------
Total....................................................... 4 17 21
----------------------------------------------------------------------------------------------------------------
Harbor Seal
Harbor seals are the most common seal in Narragansett Bay, which is
a well-known winter feeding ground for the species (Moll et al., 2017).
Seals are commonly observed from late September through April (Moll et.
al., 2017; DeAngelis, 2020). Of the 22 known haulouts within
Narragansett Bay, The Sisters is the nearest haulout to the project
area (0.9 mi). Harbor seals are rarely observed at The Sisters haulout
in the early fall (September-October) but consistent numbers are
regularly observed in mid-November (0-10 animals). These numbers
gradually increase with peak numbers in the upper 40s occurring in
March, typically at low tide (DeAngelis, 2020). The NMSDD (Navy, 2017a)
models harbor and gray seals as a guild due to the difficulty in
distinguishing these species at sea. Harbor seal is expected to be the
most common pinniped in Narragansett Bay with year-round occurrence
(Kenney and Vigness-Raposa, 2010). Therefore, the maximum species
density for the harbor-gray seal guild was determined to be appropriate
for estimating takes of harbor seal. Based on density data for
Narragansett Bay (Navy, 2017a), the maximum density of seals was
determined to be 0.623/km\2\. This density value is for all seals
(harbor and gray seals as a guild); therefore, this density value
results in some degree of overestimation when applied to harbor seals
only. The Navy requested and NMFS proposes a high of 25 takes by Level
A harassment and 353 takes by Level B harassment during Year 3, and a
low of 13 takes by Level A harassment
[[Page 56875]]
and 138 takes by Level B harassment during Year 2 (Table 14).
Table 14--Proposed Take for Harbor Seal
------------------------------------------------------------------------
Calculated/
Construction year Proposed Level proposed Level
A harassment B harassment
------------------------------------------------------------------------
Year 1 (S45)............................ 15 188
Year 2 (S366 and Pier 01)............... 13 138
Year 3 (LNG)............................ 25 353
Year 4 (S499/Pier 2).................... 25 221
-------------------------------
Total............................... 78 900
------------------------------------------------------------------------
Gray Seal
Based on stranding records, gray seals are seasonally present in
Rhode Island with the largest populations occurring from February
through June with a sharp peak in March and April. The NMSDD (Navy,
2017a) provides combined densities for harbor seal and gray seal (as
discussed above). Gray seals are the second most likely seal to be
observed in Rhode Island waters, next to harbor seals, and more of an
occasional visitor (Kenney, 2020); therefore, the average species
density for the harbor-gray seal guild was determined to be appropriate
for determining takes of gray seal. Based on density data for
Narragansett Bay (Navy, 2017a), the average density of seals was
determined to be 0.131/km\2\. This density value is for all seals
(harbor and gray seals as a guild); therefore, it results in some
degree of overestimation when applied to gray seals only. Calculated
takes by Level A harassment and Level B harassment may occur each
construction year with up to 5 takes by Level A harassment and 74 takes
by Level B harassment during Year 3. Fewer annual takes were calculated
for Year 2 and 3 by Level A harassment and 28 takes by Level B (Table
15). Because the calculated annual take is below the average group
size, the annual take by Level B harassment proposed for gray seal has
been increased to the average group size (50 gray seals) (NAVSEA NUWC
2017) and conservatively doubled for Year 1, 2, and 4, during which
years calculated takes were less than group size. Therefore, the Navy
requested and NMFS proposes 100 takes of gray seals in Years 1, 2 and
4, and 74 takes in Year 3, and a total of 374 takes by Level B
harassment of gray seals. A total of 17 takes of gray seals by Level A
harassment is also proposed.
Table 15--Proposed Take for Gray Seal
----------------------------------------------------------------------------------------------------------------
Calculated
Construction year Proposed Level Level B Proposed Level
A harassment harassment B harassment
----------------------------------------------------------------------------------------------------------------
Year 1 (S45).................................................... 3 40 100
Year 2 (S366 and Pier 01)....................................... 3 28 100
Year 3 (LNG).................................................... 5 74 74
Year 4 (S499/Pier 2)............................................ 6 41 100
-----------------------------------------------
Total....................................................... 17 183 374
----------------------------------------------------------------------------------------------------------------
Harp Seal
Harp seals may be present in the project vicinity January through
May. In general, harp seals are much rarer than the harbor seal and
gray seal in Narragansett Bay and are rarely observed in the bay
(Kenney, 2015). Therefore, the minimum species density was determined
to be appropriate for determining takes of harp seal. Based on density
data for Narragansett Bay obtained from the NMSDD (Navy 2017), the
minimum density of harp seal was determined to be 0.050/km\2\. The Navy
requested and NMFS proposes that 2 takes by Level A harassment could
occur in Year 3, and 1 take by Level A harassment in Years 1, 2, and 4,
for a total of 5 takes (Table 16). Calculated takes by Level B
harassment range from 11 to 29 and total 72 takes over the project
(Table 16).
Table 16--Proposed Take for Harp Seal
------------------------------------------------------------------------
Calculated/
Construction year Proposed Level proposed Level
A harassment B harassment
------------------------------------------------------------------------
Year 1 (S45)............................ 1 16
Year 2 (S366 and Pier 1)................ 1 11
Year 3 (LNG)............................ 2 29
Year 4 (S499/Pier 2).................... 2 18
-------------------------------
Total............................... 6 74
------------------------------------------------------------------------
[[Page 56876]]
Hooded Seal
Hooded seals may be present in the project vicinity from January
through May, although their exact seasonal densities are unknown. In
general, hooded seals are much rarer than the harbor seal and gray seal
in Narragansett Bay and are rarely observed in the Bay (Kenney, 2005).
Based on density data for Narragansett Bay obtained from the NMSDD, the
minimum density of hooded seal was determined to be 0.001/km\2\. Hooded
seals have the potential to occur but are considered the least likely
seal to be present in Narragansett Bay. No Level A (PTS onset) or Level
B (behavioral) takes are anticipated during any construction year.
However, in order to guard against unauthorized take, the Navy is
requesting and NMFS is proposing 1 Level B (behavioral) take of hooded
seal per month of construction when this species may occur (Jan through
May) for each construction year for a total of 20 takes by Level B
harassment (Table 17). No take by Level A harassment is anticipated or
proposed for authorization for this species.
Table 17--Proposed Take for Hooded Seal
------------------------------------------------------------------------
Proposed Level
Construction year B harassment
------------------------------------------------------------------------
Year 1 (S45)............................................ 5
Year 2 (S366 and Pier 1)................................ 5
Year 3 (LNG)............................................ 5
Year 4 (S499/Pier 2).................................... 5
---------------
Total............................................... 20
------------------------------------------------------------------------
Table 18 below summarizes the proposed authorized take for all the
species described above as a percentage of stock abundance.
Table 18--Take Estimates as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
Level A Level B
Species Stock (NEST) harassment harassment Percent of stock
----------------------------------------------------------------------------------------------------------------
Atlantic White-sided Dolphin...... Western North 0 48 Less than 1 percent.
Atlantic (93,233).
Common Dolphin.................... Western North 0 140 Less than 1 percent.
Atlantic (172,974).
Harbor Porpoise................... Gulf of Maine/Bay of 4 21 Less than 1 percent.
Fundy (95,543).
Harbor Seal....................... Western North 78 900 Less than 2 percent.
Atlantic (75,834).
Gray Seal......................... Western North 17 374 Less than 1 percent.
Atlantic (451,131).
Harp Seal......................... Western North 6 74 Less than 1 percent.
Atlantic (unknown).
Hooded Seal....................... Western North 0 20 Less than 1 percent.
Atlantic (unknown).
----------------------------------------------------------------------------------------------------------------
Proposed Mitigation
Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the
permissible methods of taking pursuant to the activity, and other means
of effecting the least practicable adverse impact on the species or
stock and its habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance, and on the availability of
the 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 the 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, 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, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
The following mitigation measures are proposed for the Navy's in-
water construction activities.
General
The Navy will follow mitigation procedures as described below. In
general, if poor environmental conditions restrict full visibility of
the shutdown zone, pile driving activities would be delayed.
Training
The Navy will ensure that construction supervisors and crews, the
monitoring team, and relevant Navy staff are trained and prior to the
start of construction activity subject to this rule, so that
responsibilities, communication procedures, monitoring protocols, and
operational procedures are clearly understood. New personnel joining
during the project will be trained prior to commencing work.
Avoiding Direct Physical Interaction
The Navy will avoid direct physical interaction with marine mammals
during construction activity. If a marine mammal comes within 10 m of
such activity, operations will cease and vessels will reduce speed to
the minimum level required to maintain steerage and safe working
conditions, as necessary to avoid direct physical interaction.
Shutdown Zones
The Navy will establish shutdown zones for all pile driving
activities. The purpose of a shutdown zone is generally to define an
area within which shutdown of the activity would occur upon sighting of
a marine mammal (or in anticipation of an animal entering the defined
area). Shutdown zones will vary based on the activity type and marine
mammal hearing group (Table 19). For those activities with larger Level
A (PTS onset) harassment zones, the shutdown zone would be limited to
150 m from the point of noise generation to ensure adequate monitoring
for each bulkhead section and the remaining area would be considered
part of the ``disturbance zone.'' A take will be recorded if a marine
mammal enters the disturbance zone but does not approach or enter the
shutdown zone. The disturbance zone is the Level B harassment zone and,
where
[[Page 56877]]
present, the Level A harassment zone (PTS onset) beyond 150 m from the
point of noise generation (see Figures 6-1 through 6-4 of the Navy's
application). For activities where the Level A (PTS onset) harassment
zones are smaller, the disturbance zone would include the entire region
of influence (ROI) and is the full extent of potential underwater noise
impact (Level A and Level B calculated harassment zones). Work will be
allowed to proceed without cessation while marine mammals are in the
disturbance zone and marine mammal behavior within the disturbance zone
will be monitored and documented.
Table 19--Pile Driving Shutdown Zone and Disturbance Zones During Project Activities
----------------------------------------------------------------------------------------------------------------
Installation Shut down zone Shut down zone Disturbance
Pile type method Pile diameter for cetaceans for pinnipeds zone
----------------------------------------------------------------------------------------------------------------
Steel pipe...................... Impact 30-in 150 m 150 m 2,500 m
Impact 42-in 150 m 50 m 2,500 m
Steel H......................... Vibratory 14-in 10 m 10 m ROI
Vibratory 22.5-in 30 m 10 m ROI
Z-Shaped Steel Sheet............ Impact 22.5-in 150 m 150 m 2,500 m
Vibratory 31.5-in 20 m 10 m ROI
Impact 31.5-in 150 m 150 m 2,500 m
----------------------------------------------------------------------------------------------------------------
* ROI = region of influence and is the full extent of potential underwater noise impact (Level A and Level B
calculated harassment zones).
Soft Start
The Navy will use soft start techniques when impact pile driving.
Soft start requires contractors to provide an initial set of three
strikes from the hammer at reduced energy, followed by a 30-second
waiting period. Then two subsequent reduced-energy strike sets would
occur. A soft start will be implemented at the start of each day's
impact pile driving and at any time following cessation of impact pile
driving for a period of 30 minutes or longer. Soft start is not
required during vibratory pile driving activities.
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable adverse impact on
the affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate 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
action area. Effective reporting is critical both to compliance as well
as for 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:
[ssquf] Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
[ssquf] 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);
[ssquf] Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
[ssquf] How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
[ssquf] Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
[ssquf] Mitigation and monitoring effectiveness.
The Navy will submit a Marine Mammal Monitoring Plan to NMFS for
approval in advance of the start of construction.
Monitoring Zones
The Navy will conduct monitoring to include the area within the
Level B harassment zones (areas where SPLs are equal to or exceed the
160 dB rms threshold for impact driving and the 120 dB rms threshold
during vibratory pile driving) (see Disturbance Zones in Table 19).
These disturbance zones provide utility for monitoring conducted for
mitigation purposes (i.e., shutdown zone monitoring) by establishing
monitoring protocols for areas adjacent to the shutdown zones.
Monitoring of the disturbance zones enables observers to be aware of
and communicate the presence of marine mammals in the project area, but
outside the shutdown zone, and thus prepare for potential shutdowns of
activity.
Visual Monitoring
Monitoring must take place from 30 minutes (min) prior to
initiation of pile driving activity (i.e., pre-start clearance
monitoring) through 30 min post-completion of pile driving activity. If
a marine mammal is observed entering or within the shutdown zones, pile
driving will be delayed or halted. If pile driving is delayed or halted
due to the presence of a marine mammal, the activity may not commence
or resume until either the animal has voluntarily exited and been
visually confirmed beyond the shutdown zone or 15 min have passed
without re-detection of the animal. Pile driving activity will be
halted upon observation of either a species for which incidental take
is not authorized or a species for which incidental take has been
authorized but the authorized number of takes has been met, entering or
within the disturbance zone.
[[Page 56878]]
PSO Monitoring Requirements and Locations
PSOs will be responsible for monitoring, the shutdown zones, the
disturbance zones and the pre-clearance zones, as well as effectively
documenting Level A and B harassment take. As described in more detail
in the Reporting section below, they will also (1) document the
frequency at which marine mammals are present in the project area, (2)
document behavior and group composition, (3) record all construction
activities, and (4) document observed reactions (changes in behavior or
movement) of marine mammals during each sighting. The PSOs will monitor
for marine mammals during all in-water pile activities associated with
the project. The Navy will monitor the project area to the extent
possible based on the required number of PSOs, required monitoring
locations, and environmental conditions. Visual monitoring will be
conducted by, at a minimum, by two PSOs. It is assumed that two to
three PSOs would be sufficient to monitor the respective ROIs given the
abundance of suitable vantage points. Any activity that would result in
threshold exceedance at or more than 1,000 m would require a minimum of
three PSOs to effectively monitor the entire ROI. However, additional
monitors may be added if warranted by site conditions and/or the level
of marine mammal activity in the area. Trained PSOs will be placed at
the best vantage point(s) practicable such as on nearby breakwaters,
Gould Island, Coddington Point, or Taylor Point (see Figure 11-1 of the
Navy's application) to monitor for marine mammals and implement
shutdown/delay procedures when applicable. The PSOs must record all
observations of marine mammals, regardless of distance from the pile
being driven.
In addition, PSOs will work in shifts lasting no longer than 4 hrs
with at least a 1-hr break between shifts, and will not perform duties
as a PSO for more than 12 hrs in a 24[hyphen]hr period (to reduce PSO
fatigue).
Monitoring of pile driving will be conducted by qualified, NMFS-
approved PSOs. The Navy shall adhere to the following conditions when
selecting PSOs:
[ssquf] PSOs must be independent (i.e., not construction personnel)
and have no other assigned tasks during monitoring periods;
[ssquf] At least one PSO must have prior experience performing the
duties of a PSO during construction activities pursuant to a NMFS-
issued incidental take authorization;
[ssquf] Other PSOs may substitute other relevant experience,
education (degree in biological science or related field), or training;
[ssquf] Where a team of three PSOs are required, a lead observer or
monitoring coordinator shall be designated. The lead observer must have
prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization; and
[ssquf] PSOs must be approved by NMFS prior to beginning any
activity subject to this proposed rule.
The Navy will ensure that the PSOs have the following additional
qualifications:
[ssquf] Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
[ssquf] Experience and ability to conduct field observations and
collect data according to assigned protocols;
[ssquf] Experience or training in the field identification of
marine mammals, including the identification of behaviors;
[ssquf] Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
[ssquf] Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
[ssquf] Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
Acoustic Monitoring
The Navy intends to conduct a sound source verification (SSV) study
for all pile types and will follow accepted methodological standards to
achieve their objectives. The Navy will submit an acoustic monitoring
plan to NMFS for approval prior to the start of construction.
Reporting
The Navy would submit a draft report to NMFS within 90 workdays of
the completion of required monitoring for each portion of the project
as well as a comprehensive summary report at the end of the project.
The report will detail the monitoring protocol and summarize the data
recorded during monitoring. Final annual reports (each portion of the
project and comprehensive) must be prepared and submitted within 30
days following resolution of any NMFS comments on the draft report. If
no comments are received from NMFS within 30 days of receipt of the
draft report, the report shall be considered final. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments. All draft and final marine
mammal monitoring reports must be submitted to
<a href="/cdn-cgi/l/email-protection#e7b7b5c9aeb3b7c9aa88898e9388958e8980b5829788959394a789888686c9808891"><span class="__cf_email__" data-cfemail="86d6d4a8cfd2d6a8cbe9e8eff2e9f4efe8e1d4e3f6e9f4f2f5c6e8e9e7e7a8e1e9f0">[email protected]</span></a> and <a href="/cdn-cgi/l/email-protection#a5ecf1f58be0c2c2c0d7e5cbcac4c48bc2cad3"><span class="__cf_email__" data-cfemail="82cbd6d2acc7e5e5e7f0c2ecede3e3ace5edf4">[email protected]</span></a>. The reports
must contain the following informational elements, at minimum, (and be
included in the Marine Mammal Monitoring Plan), including:
[ssquf] Dates and times (begin and end) of all marine mammal
monitoring;
[ssquf] Construction activities occurring during each daily
observation period, including:
[cir] How many and what type of piles were driven and by what
method (e.g., impact or vibratory); and
[cir] Total duration of driving time for each pile (vibratory
driving) and number of strikes for each pile (impact driving);
[ssquf] PSO locations during marine mammal monitoring;
[ssquf] Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
[ssquf] Upon observation of a marine mammal, the following
information:
[cir] PSO who sighted the animal and PSO location and activity at
time of sighting;
[cir] Time of sighting;
[cir] Identification of the animal (e.g., genus/species, lowest
possible taxonomic level, or unidentified), PSO confidence in
identification, and the composition of the group if there is a mix of
species;
[cir] Distance and bearing of each marine mammal observed to the
pile being driven for each sighting (if pile driving was occurring at
time of sighting);
[cir] Estimated number of animals (minimum/maximum/best);
[cir] Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.;
[[Page 56879]]
[cir] Animal's closest point of approach and estimated time spent
within the harassment zone; and
[cir] Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses to the activity (e.g., no response
or changes in behavioral state such as ceasing feeding, changing
direction, flushing, or breaching);
[ssquf] Detailed information about implementation of any mitigation
(e.g., shutdowns and delays), a description of specific actions that
ensued, and resulting changes in behavior of the animal, if any; and
[ssquf] All PSO datasheets and/or raw sightings data.
Reporting of Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the Navy must report the
incident to NMFS Office of Protected Resources (OPR)
(<a href="/cdn-cgi/l/email-protection#d08082fe998480fe9dbfbeb9a4bfa2b9beb782b5a0bfa2a4a390bebfb1b1feb7bfa6"><span class="__cf_email__" data-cfemail="2474760a6d70740a694b4a4d504b564d4a437641544b565057644a4b45450a434b52">[email protected]</span></a>), NMFS (301-427-8401) and to the
Greater Atlantic Region New England/Mid-Atlantic Stranding Coordinator
(866-755-6622) as soon as feasible. If the death or injury was clearly
caused by the specified activity, the Navy must immediately cease the
specified activities until NMFS OPR is able to review the circumstances
of the incident and determine what, if any, additional measures are
appropriate to ensure compliance with the terms of this rule. The Navy
will not resume their activities until notified by NMFS. The report
must include the following information:
[ssquf] Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
[ssquf] Species identification (if known) or description of the
animal(s) involved;
[ssquf] Condition of the animal(s) (including carcass condition if
the animal is dead);
[ssquf] Observed behaviors of the animal(s), if alive;
[ssquf] If available, photographs or video footage of the
animal(s); and
[ssquf] General circumstances under which the animal was
discovered.
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' 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 all of the species listed in Table 3, given that many of the
anticipated effects of this project on different marine mammal stocks
are expected to be relatively similar in nature. Where there are
meaningful differences between species or stocks in anticipated
individual responses to activities, impacts of expected take on the
population due to differences in population status, or impacts on
habitat, they are described independently in the analysis below.
Pile driving activities associated with the project, as outlined
previously, have the potential to disturb or displace marine mammals.
Specifically, the specified activities may result in take, in the form
of Level A and Level B harassment from underwater sounds generated by
pile driving. Potential takes could occur if marine mammals are present
in zones ensonified above the thresholds for Level A and Level B
harassment, identified above, while activities are underway.
No serious injury or mortality would be expected even in the
absence of the proposed mitigation measures. During all impact driving,
implementation of soft start procedures and monitoring of established
shutdown zones will be required, significantly reducing the possibility
of injury. Given sufficient notice through use of soft start (for
impact driving), marine mammals are expected to move away from an
irritating sound source prior to it becoming potentially injurious. In
addition, PSOs will be stationed within the action area whenever pile
driving activities are underway. Depending on the activity, the Navy
will employ the use of at least two and up to three PSOs to ensure all
monitoring and shutdown zones are properly observed. For Atlantic
white-sided dolphins, common dolphins and hooded seals, no Level A
harassment is anticipated. Atlantic white-sided dolphin and common
dolphin are both species in which regular occurrence is in much deeper
waters than the project area, and, given the small Level A harassment
zone sizes for mid-frequency cetaceans, we do not anticipate take by
Level A harassment. For hooded seals, with the absence of any major
rookeries and only one pinniped haulout (The Sisters) within the
project area, and being a rare species in Narragansett Bay, we do not
anticipate any take by Level A harassment.
The Navy's proposed pile driving activities and associated impacts
will occur within a limited portion of the confluence of the
Narraganset Bay area. Exposures to elevated sound levels produced
during pile driving activities may cause behavioral disturbance of some
individuals, but they are expected to be mild and temporary. However,
as described previously, the mitigation and monitoring measures are
expected to further reduce the likelihood of injury as well as reduce
behavioral disturbances.
Effects on individuals that are taken by Level B harassment, as
enumerated in the Estimated Take section, on the basis of reports in
the literature as well as monitoring from other similar activities,
will likely be limited to reactions such as increased swimming speeds,
increased surfacing time, or decreased foraging (if such activity were
occurring) (e.g., Thorson and Reyff 2006). Most likely, individual
animals will simply move away from the sound source and be temporarily
displaced from the areas of pile driving, although even this reaction
has been observed primarily only in association with impact pile
driving. The pile driving activities analyzed here are similar to, or
less impactful than, numerous other construction activities conducted
along both Atlantic and Pacific coasts, which have taken place with no
known long-term adverse consequences from behavioral harassment. These
reactions and behavioral changes are expected to subside quickly when
the exposures cease. Level B harassment will be
[[Page 56880]]
minimized through use of mitigation measures described herein, and, if
sound produced by project activities is sufficiently disturbing,
animals are likely to simply avoid the area while the activity is
occurring, particularly as the project is located on a waterfront with
vessel traffic from both Navy and non-Navy activities.
The project is also not expected to have significant adverse
effects on any marine mammal habitat. The project activities will not
modify existing marine mammal habitat since the project will occur
within the same footprint as existing marine infrastructure. Impacts to
the immediate substrate during installation and removal of piles are
anticipated, but these would be limited to minor, temporary suspension
of sediments, which could impact water quality and visibility for a
short amount of time, but which would not be expected to have any
effects on individual marine mammals. The nearshore and intertidal
habitat where the project will occur is an area of consistent vessel
traffic from Navy and non-Navy vessels, and some local individuals
would likely be somewhat habituated to the level of activity in the
area, further reducing the likelihood of more severe impacts. The
closest pinniped haulout, The Sisters, is used by harbor seals and is
less than a mile from the project area; however, for the reasons
described immediately above (including the nature of expected responses
and the duration of the project), impacts to reproduction or survival
of individuals is not anticipated, much less effects on the species or
stock. There are no other biologically important areas for marine
mammals near the project area.
In addition, impacts to marine mammal prey species are expected to
be minor and temporary. Overall, the area impacted by the project is
very small compared to the available habitat in Narragansett Bay. The
most likely impact to prey will be temporary behavioral avoidance of
the immediate area. During pile driving activities, it is expected that
some fish and marine mammals would temporarily leave the area of
disturbance, 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.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
[ssquf] No mortality is anticipated or authorized;
[ssquf] No Level A harassment is anticipated or authorized for
Atlantic white-sided dolphins, Short-beaked common dolphins, and hooded
seals;
[ssquf] Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior;
[ssquf] The required mitigation measures (i.e., shutdown zones) are
expected to be effective in reducing the effects of the specified
activity;
[ssquf] Minimal impacts to marine mammal habitat/prey are expected;
[ssquf] The action area is located within an active marine
waterfront area, and
[ssquf] There are no known biologically important areas in the
vicinity of the project, with the exception of one harbor seal haulout
(The Sisters)--however, as described above, exposure to the work
conducted in the vicinity of the haulout is not expected to impact the
reproduction or survival of any individual seals.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal 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 sections 101(a)(5)(A) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers, so, in practice, where estimated numbers are
available, 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. When the predicted number of individuals to
be taken is fewer than one third of the species or stock abundance, the
take is considered to be of small numbers. Additionally, other
qualitative factors may be considered in the analysis, such as the
temporal or spatial scale of the activities.
Take of five of the marine mammal stocks authorized will comprise
at most approximately 2 percent or less of the stock abundance (Table
18). There are no official stock abundance for harp seals or hooded
seals; however, we believe for the abundance information that is
available for Canada (N = 7+million for harp seals and N = 593,500 for
hooded seals) combined with the fact they are highly migratory species
and would be rare in the project area, the estimated takes are likely
very small percentages of the stock abundance. The number of animals
authorized to be taken from these stocks would be considered small
relative to the relevant stock's abundances even if each estimated take
occurred to a new individual, which is an unlikely scenario.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals will be taken relative to the population size
of the affected species or stocks.
Unmitigable Adverse Impact 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 construction activities would contain an adaptive management
component. The reporting requirements associated with this rule are
designed to provide NMFS with monitoring data from completed projects
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
[[Page 56881]]
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.
Endangered Species Act
Section 7(a)(2) of the ESA (16 U.S.C. 1531 et seq.) requires that
each Federal agency ensure that any action it authorizes, funds, or
carries out is not likely to jeopardize the continued existence of any
endangered or threatened species or result in the destruction or
adverse modification of designated critical habitat. To ensure ESA
compliance for the issuance of incidental take authorizations, NMFS
consults internally whenever we propose to authorize take for
endangered or threatened species.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Request for Information
NMFS requests interested persons to submit comments, information,
and suggestions concerning the Navy request and the proposed
regulations (see ADDRESSES). All comments will be reviewed and
evaluated as we prepare a final rule and make final determinations on
whether to issue the requested authorization. This proposed rule and
referenced documents provide all environmental information relating to
our proposed action for public review.
Classification
Pursuant to the procedures established to implement Executive Order
12866, the Office of Management and Budget has determined that this
proposed rule is not significant.
Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA),
the Chief Counsel for Regulation of the Department of Commerce has
certified to the Chief Counsel for Advocacy of the Small Business
Administration that this proposed rule, if adopted, would not have a
significant economic impact on a substantial number of small entities.
The 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.
List of Subjects in 50 CFR Part 217
Administrative practice and procedure, Alaska, Endangered and
threatened species, Exports, Fish, Imports, Indians, Labeling, Marine
mammals, Oil and gas exploration, Penalties, Reporting and
recordkeeping requirements, Seafood, Transportation, Wildlife.
Dated: September 28, 2021.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For reasons set forth in the preamble, 50 CFR part 217 is proposed
to be amended as follows:
PART 217--REGULATIONS GOVERNING THE TAKE OF MARINE MAMMALS
INCIDENTAL TO SPECIFIED ACTIVITIES
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 R to part 217 to read as follows:
Subpart R--Taking and Importing Marine Mammals Incidental to U.S. Navy
Construction at Naval Station Newport in Newport, Rhode Island
Sec.
217.70 Specified activity and geographical region.
217.71 Effective dates.
217.72 Permissible methods of taking.
217.73 Prohibitions.
217.74 Mitigation requirements.
217.75 Requirements for monitoring and reporting.
217.76 Letters of Authorization.
217.77 Renewals and modifications of Letters of Authorization.
217.78-217.79 [Reserved]
Subpart R--Taking and Importing Marine Mammals Incidental to U.S.
Navy Construction at Naval Station Newport in Newport, Rhode Island
Sec. 217.70 Specified activity and 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 areas
outlined in paragraph (b) of this section and that occurs incidental to
construction activities including for bulkhead replacement and repairs
at Naval Station (NAVSTA) Newport, Rhode Island.
(b) The taking of marine mammals by the Navy may be authorized in a
Letter of Authorization (LOA) only if it occurs at NAVSTA Newport,
Rhode Island.
Sec. 217.71 Effective dates.
Regulations in this subpart are effective from [EFFECTIVE DATE OF
THE FINAL RULE] to [DATE 5 YEARS AFTER EFFECTIVE DATE OF THE FINAL
RULE].
Sec. 217.72 Permissible methods of taking.
Under an LOA issued pursuant to Sec. Sec. 216.106 of this chapter
and 217.76, the Holder of the LOA (hereinafter ``Navy'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 217.70 (b) by harassment associated with
construction activities, provided the activity is in compliance with
all terms, conditions, and requirements of the regulations in this
subpart and the applicable LOA.
Sec. 217.73 Prohibitions.
(a) Except for the takings contemplated in Sec. 217.72 and
authorized by a LOA issued under Sec. Sec. 216.106 of this chapter and
217.76, it is unlawful for any person to do any of the following in
connection with the activities described in Sec. 217.70:
(1) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or a LOA issued under Sec. Sec. 216.106
of this chapter and 217.76;
(2) Take any marine mammal not specified in such LOA;
(3) Take any marine mammal specified in such LOA in any manner
other than as specified;
(4) Take a marine mammal specified in such LOA if NMFS determines
such taking results in more than a negligible impact on the species or
stocks of such marine mammal; or
(5) Take a marine mammal specified in such LOA if NMFS determines
such taking results in an unmitigable adverse impact on the species or
stock of such marine mammal for taking for subsistence uses.
(b) [Reserved]
Sec. 217.74 Mitigation requirements.
(a) When conducting the activities identified in Sec. 217.71(a),
the mitigation measures contained in any LOA issued under Sec. Sec.
216.106 of this chapter and 217.76 must be implemented. These
mitigation measures must include but are not limited to:
(1) A copy of any issued LOA must be in the possession of the Navy,
its designees, and work crew personnel operating under the authority of
the issued LOA.
[[Page 56882]]
(2) The Navy will follow mitigation procedures as described in this
section. In general, if poor environmental conditions restrict full
visibility of the shutdown zone, pile driving activities would be
delayed.
(3) The Navy will ensure that construction supervisors and crews,
the monitoring team, and relevant Navy staff are trained prior to the
start of construction activity subject to this rule, so that
responsibilities, communication procedures, monitoring protocols, and
operational procedures are clearly understood. New personnel joining
during the project will be trained prior to commencing work.
(4) The Navy will avoid direct physical interaction with marine
mammals during construction activity. If a marine mammal comes within
10 m of such activity, operations will cease and vessels will reduce
speed to the minimum level required to maintain steerage and safe
working conditions, as necessary, to avoid direct physical interaction.
(5) For all pile driving activity, the Navy must implement shutdown
zones with radial distances as identified in a LOA issued under
Sec. Sec. 216.106 of this chapter and 217.76. If a marine mammal comes
within or approaches the shutdown zone, such operations must cease.
(6) The Navy will use soft start techniques when impact pile
driving. Soft start requires contractors to provide an initial set of
three strikes from the hammer at reduced energy, followed by a 30-
second waiting period. Then two subsequent reduced-energy strike sets
would occur. A soft start will be implemented at the start of each
day's impact pile driving and at any time following cessation of impact
pile driving for a period of 30 minutes or longer. Soft start is not
required during vibratory pile driving activities.
(7) The Navy must deploy protected species observers (observers) as
indicated in its Marine Mammal Monitoring Plan approved by NMFS.
(8) For all pile driving activities, a minimum of two protected
species observers (observers) must be stationed at the best vantage
points practicable to monitor for marine mammals and implement
shutdown/delay procedures. However, additional monitors will be added
if warranted by site conditions and/or the level of marine mammal
activity in the area. Any activity that would result in threshold
exceedance at or more than 1,000 m would require a minimum of three
PSOs to effectively monitor the entire region of influence (the full
extent of potential underwater noise impact (Level A and Level B
calculated harassment zones)).
(9) Monitoring must take place from 30 minutes prior to initiation
of pile driving activity (i.e., pre-start clearance monitoring) through
30 minutes post-completion of pile driving activity. Pre-activity
monitoring must be conducted for 30 minutes to ensure that the shutdown
zone is clear of marine mammals, and pile driving 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 must be allowed to remain in the
shutdown zone (i.e., must leave of their own volition) and their
behavior must be monitored and documented. If a marine mammal is
observed within the shutdown zone, a soft-start cannot proceed until
the animal has left the zone or has not been observed for 15 minutes.
Monitoring must occur throughout the time required to drive a pile. If
work ceases for more than 30 minutes, the pre-activity monitoring of
the shutdown zones must commence. 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).
(10) If a marine mammal approaches or enters the shutdown zone, all
pile driving activities at that location must be halted. If pile
driving is halted or delayed due to the presence of a marine mammal,
the activity may not commence or resume until either the animal has
voluntarily left and been visually confirmed beyond the shutdown zone
or fifteen minutes have passed without re-detection of the animal.
(11) Pile driving activity must be halted upon observation of
either a species entering or within the harassment zone, for which
incidental take is not authorized, or a species for which incidental
take has been authorized but the authorized number of takes has been
met.
(12) Should environmental conditions deteriorate such that marine
mammals within the entire shutdown zone would not be visible (e.g.,
fog, heavy rain), the Navy must delay pile driving and pile removal
until observers are confident marine mammals within the shutdown zone
could be detected.
(13) Monitoring must be conducted by trained observers, who must
have no other assigned tasks during monitoring periods. Trained
observers must be placed at the best vantage point(s) practicable to
monitor for marine mammals and implement shutdown or delay procedures
when applicable through communication with the equipment operator. The
Navy must adhere to the following additional observer qualifications:
(i) Independent observers are required;
(ii) At least one observer must have prior experience working as an
observer;
(iii) Other observers may substitute education (degree in
biological science or related field) or training for experience;
(iv) Where a team of three or more observers are required, one
observer must be designated as lead observer or monitoring coordinator.
The lead observer must have prior experience working as an observer;
and
(v) PSOs must be approved by NMFS prior to beginning any activity
subject to this proposed rule.
(b) [Reserved]
Sec. 217.75 Requirements for monitoring and reporting.
(a) The Navy must submit a Marine Mammal Monitoring Plan to NMFS
for approval in advance of construction.
(b) The Navy must deploy observers as indicated in its approved
Marine Mammal Monitoring Plan.
(c) Observers must be trained in marine mammal identification and
behaviors. Observers must have no other construction-related tasks
while conducting monitoring.
(d) For all pile driving activities, a minimum of two observers
must be stationed at the active pile driving site or in reasonable
proximity in order to monitor the shutdown zone.
(e) The Navy must monitor the Level B harassment zones (areas where
SPLs are equal to or exceed the 160 dB rms threshold for impact driving
and the 120 dB rms threshold during vibratory pile driving) to the
extent practicable and the shutdown zones. For those activities with
larger Level A (PTS onset) harassment zones, the shutdown zone would be
limited to 150 m from the point of noise generation to ensure adequate
monitoring for each bulkhead section and the remaining area would be
considered part of the disturbance zone. The Navy must monitor the
disturbance zone, which is the Level B harassment zone and, where
present, the Level A harassment zone (PTS onset) beyond 150 m from the
point of noise generation. The Navy must monitor at least a portion of
the Level B harassment zone on all pile driving days.
(f) The Navy must conduct hydroacoustic data collection (sound
source verification and propagation loss) in accordance with a
hydroacoustic monitoring plan that
[[Page 56883]]
must be approved by NMFS in advance of construction.
(g) The Navy must submit a draft monitoring report to NMFS within
90 work days of the completion of required monitoring for each portion
of the project as well as a comprehensive summary report at the end of
the project. The report will detail the monitoring protocol and
summarize the data recorded during monitoring. Final annual reports
(each portion of the project and comprehensive) must be prepared and
submitted within 30 days following resolution of any NMFS comments on
the draft report. If no comments are received from NMFS within 30 days
of receipt of the draft report, the report must be considered final. If
comments are received, a final report addressing NMFS comments must be
submitted within 30 days after receipt of comments. The reports must
contain the informational elements described at minimum below (and be
included in the Marine Mammal Monitoring Plan), including:
(1) Dates and times (begin and end) of all marine mammal
monitoring;
(2) Construction activities occurring during each daily observation
period, including how many and what type of piles were driven or
removed and by what method (i.e., impact or vibratory) and the total
duration of driving time for each pile (vibratory driving) and number
of strikes for each pile (impact driving);
(3) Environmental conditions during monitoring periods (at
beginning and end of observer shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance (if less
than the harassment zone distance);
(4) Upon observation of a marine mammal, the following information
should be collected:
(i) Observer who sighted the animal and observer location and
activity at time of sighting;
(ii) Time of sighting;
(iii) Identification of the animal (e.g., genus/species, lowest
possible taxonomic level, or unidentified), observer confidence in
identification, and the composition of the group if there is a mix of
species;
(iv) Distances and bearings of each marine mammal observed in
relation to the pile being driven for each sighting (if pile driving
was occurring at time of sighting);
(v) Estimated number of animals (min/max/best);
(vi) Estimated number of animals by cohort (adults, juveniles,
neonates, group composition etc.);
(vii) Animal's closest point of approach and estimated time spent
within the harassment zone; and
(viii) Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses to the activity (e.g., no response
or changes in behavioral state such as ceasing feeding, changing
direction, flushing, or breaching);
(5) Detailed information about any implementation of any mitigation
(e.g., shutdowns and delays), a description of specific actions that
ensued, and resulting changes in the behavior of the animal, if any;
and
(6) All observer datasheets and/or raw sightings data.
(h) The Navy must report the hydroacoustic data collected as
required by a LOA issued under Sec. Sec. 216.106 of this chapter and
217.76.
(i) In the event that personnel involved in the construction
activities discover an injured or dead marine mammal, the Navy must
report the incident to NMFS Office of Protected Resources (OPR), and to
the Greater Atlantic Region New England/Mid-Atlantic Stranding
Coordinator, as soon as feasible. If the death or injury was clearly
caused by the specified activity, the Navy must immediately cease the
specified activities until NMFS OPR is able to review the circumstances
of the incident and determine what, if any, additional measures are
appropriate to ensure compliance with the terms of this rule and the
LOA issued under Sec. Sec. 216.106 of this chapter and 217.76. The
Navy will not resume their activities until notified by NMFS. The
report must include the following information:
(1) Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
(2) Species identification (if known) or description of the
animal(s) involved;
(3) Condition of the animal(s) (including carcass condition if the
animal is dead);
(4) Observed behaviors of the animal(s), if alive;
(5) If available, photographs or video footage of the animal(s);
and
(6) General circumstances under which the animal was discovered.
Sec. 217.76 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to these
regulations, the Navy must apply for and obtain an LOA.
(b) An LOA, unless suspended or revoked, may be effective for a
period of time not to exceed the expiration date of these regulations.
(c) If an LOA expires prior to the expiration date of these
regulations, the Navy may apply for and obtain a renewal of the LOA.
(d) In the event of projected changes to the activity or to
mitigation and monitoring measures required by an LOA, the Navy must
apply for and obtain a modification of the LOA as described in Sec.
217.77.
(e) The LOA will set forth the following information:
(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact (i.e.,
mitigation) on the species, its habitat, and on the availability of the
species for subsistence uses; and
(3) Requirements for monitoring and reporting.
(f) Issuance of the LOA will be based on a determination that the
level of taking will be consistent with the findings made for the total
taking allowable under these regulations.
(g) Notice of issuance or denial of an LOA will be published in the
Federal Register within 30 days of a determination.
Sec. 217.77 Renewals and modifications of Letters of Authorization.
(a) An LOA issued under Sec. Sec. 216.106 of this chapter and
217.76 for the activity identified in Sec. 217.70(a) may 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; and
(2) NMFS determines that the mitigation, monitoring, and reporting
measures required by the previous LOA 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 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) A LOA issued under Sec. Sec. 216.106 of this chapter and
217.76 for the activity identified in Sec. 217.70 (a) may be
[[Page 56884]]
modified by NMFS under the following circumstances:
(1) NMFS may modify (including augment) the existing mitigation,
monitoring, or reporting measures (after consulting with Navy regarding
the practicability of the modifications) 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 a LOA:
(A) Results from Navy's monitoring from previous years;
(B) Results from other marine mammal and/or sound research or
studies; and
(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; and
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, NMFS
will publish a notice of proposed LOA in the Federal Register and
solicit public comment;
(2) 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 a LOA issued pursuant to Sec. Sec. 216.106 of
this chapter and 217.76, a LOA may be modified without prior notice or
opportunity for public comment. Notification would be published in the
Federal Register within 30 days of the action.
Sec. Sec. 217.78--217.79 [Reserved]
[FR Doc. 2021-21426 Filed 10-12-21; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on October 13, 2021.
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