Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Waterfront Improvement Projects at Portsmouth Naval Shipyard, 56791-56815 [2017-25783]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 82, Number 229 (Thursday, November 30, 2017)]
[Notices]
[Pages 56791-56815]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-25783]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF611


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Waterfront Improvement Projects at 
Portsmouth Naval Shipyard

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS has received a request from the U.S. Department of the 
Navy (Navy) for authorization to take marine mammals incidental to 
continued construction activities as part of waterfront improvement 
projects at several Portsmouth Naval Shipyard (the Shipyard) berths in 
Kittery, Maine. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue an incidental 
harassment authorization (IHA) to incidentally take marine mammals 
during the specified activities. 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 January 
2, 2018.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to ITP.pauline@noaa.gov.
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm without change. All personal 
identifying information (e.g., name, address) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

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

SUPPLEMENTARY INFORMATION: 

Background

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

National Environmental Policy Act

    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 with respect to environmental 
consequences on the human environment.
    Accordingly, NMFS has preliminarily determined that the issuance of 
the proposed IHA qualifies to be categorically excluded from further 
NEPA review. This action is consistent with categories of activities 
identified in CE 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. We will 
review all comments submitted in response to this notice prior to 
concluding our NEPA process or making a final decision on the IHA 
request.

Summary of Request

    On July 14, 2017, NMFS received a request from the Navy for an IHA 
to take marine mammals incidental to impact driving, vibratory pile 
driving, vibratory pile extraction, and drilling associated with an 
ongoing waterfront improvement project at the Shipyard. The application 
was considered adequate and complete on August 25, 2017. The Navy's 
request is for take of harbor porpoise (Phocoena phocoena), gray seal 
(Halichoerus grypus), harbor seal (Phoca vitulina), and harp seal 
(Pagophilus groenlandicus) by Level A and Level B harassment 
(authorization of Level A harassment is not proposed for the harp 
seal). Neither the Navy nor NMFS expects serious injury or mortality to 
result from this activity and, therefore, an IHA is appropriate.
    This proposed IHA would cover the second year of a five-year 
project for which the Navy obtained a single prior IHA. The Navy 
intends to request take authorization for subsequent facets of the 
project. NMFS previously issued the first IHA to the Navy for this 
project

[[Page 56792]]

effective from January 1, 2017 through December 31, 2017. The larger 5-
year project involves restoring and modernizing infrastructure at the 
Shipyard. The Navy complied with all the requirements (e.g., 
mitigation, monitoring, and reporting) of the previous IHA and 
information regarding their monitoring results may be found in the 
Effects of the Specified Activity on Marine Mammals and their Habitat 
section.

Description of Proposed Activity

Overview

    The purpose of the proposed action is to modernize and maximize dry 
dock capabilities for performing current and future missions 
efficiently and with maximum flexibility. The need for the proposed 
action is to correct deficiencies associated with the pier structure at 
Berths 11, 12, and 13 and the Dry Dock 3 caisson and concrete seats to 
ensure that the Shipyard can continue to support its primary mission to 
service, maintain, and overhaul submarines. The proposed action covers 
the second year of activities (January 1, 2018 through December 31, 
2018) associated with the waterfront improvement projects at the 
Shipyard in Kittery, Maine. The project includes impact and vibratory 
pile driving, vibratory pile removal, and drilling. Construction 
activities may occur at any time during the calendar year.

Dates and Duration

    This authorization request covers in-water construction associated 
with the Year 2 activity as described above to occur from January 1, 
2018-December 31, 2018. No seasonal limitations would be imposed on the 
construction timeline in 2018. Based on construction and Shipyard 
schedules, the Navy anticipates that structural repairs initiated 
during 2017 at Berths 11A, 11B and 11C will continue into 2018. 
Therefore, the proposed IHA would cover the in-water activities 
estimated to occur in 2018 at Berths 11A, 11B and 11C. For reference 
the planned schedule of activity for 2018, Year 2, is included below in 
Table 1.

Table 1--Construction Timeframes for the Proposed Waterfront Improvement
                                Projects
------------------------------------------------------------------------
                                       Estimated           Estimated
             Project              construction start   construction end
------------------------------------------------------------------------
Berths 11, 12, and 13 Structural  January 2017......  October 2022.
 Repairs.
Phase 1.........................  January 2017......  June 2019.
In-Water Work--Phase 1 (Berth     April 2017........  December 2018.
 11).
Dry Dock 3 Caisson Replacement    February 2017.....  August 2018.
 (in progress).
In-Water Work--Phase 2 (Berths    To be determined    To be determined
 12 and 13).                       based on            based on
                                   availablity of      availablity of
                                   berths.             berths.
------------------------------------------------------------------------

    Pile driving, pile extraction, and drilling are scheduled to take 
place during the timeframe covered by the proposed IHA. Note that pile 
driving days are not necessarily consecutive. There will be a maximum 
of 100 days of pile driving and/or drilling during this period. 
However, there could be up to 16 overlapping days when concurrent 
driving/drilling would take place simultaneously for a total of 84 
driving days. The contractor could be working in more than one area of 
the berth at one time. Current schedule includes installation of king 
piles simultaneously with other construction activity including use of 
the vibratory hammer. A summary report will be issued for 2018 work 
with verified data of activity and days of duration of overlap.

Specific Geographic Region

    The Shipyard is located in the Piscataqua River in Kittery, Maine. 
The Piscataqua River originates at the boundary of Dover, New 
Hampshire, and Elliot, Maine. (See Figure 1-1 in application). The 
river flows in a southeasterly direction for 13 miles before entering 
Portsmouth Harbor and then emptying into the Atlantic Ocean. The lower 
Piscataqua River is part of the Great Bay Estuary system and varies in 
width and depth. Many large and small islands break up the straight-
line flow of the river as it continues toward the Atlantic Ocean. 
Seavey Island, the location of the Proposed Action, is located in the 
lower Piscataqua River approximately 547 yards from its southwest bank, 
219 yards from its north bank, and approximately 2.5 miles from the 
mouth of the river.
    Water depths in the project area range from 21 feet to 39 feet at 
Berths 11, 12, and 13. Water depths in the lower Piscataqua River near 
the project area range from 15 feet in the shallowest areas to 69 feet 
in the deepest areas. The river is approximately 3,300 feet wide near 
the project area, measured from the Kittery shoreline north of 
Wattlebury Island to the Portsmouth shoreline west of Peirce Island. 
The furthest direct line of sight from the project area would be 0.8 
mile to the southeast and 0.26 mile to the northwest.
    Benthic sediments and substrates in the project area were 
characterized during a benthic survey completed in May 2014 (CR 
Environmental, Inc. 2014). Surficial sediments were characterized using 
video transects and grab samples captured at five locations along 
Berths 11, 12, and 13. Sediment characteristics varied between the five 
locations. At the sample locations at both the north and south sides of 
the fitting-out pier (Berths 11 and 13), where the current was 
generally low energy, sediment consisted of soft mud, sand, pebbles, 
and old mussel shells. At the end of the pier (Berth 12), in an area of 
higher current flow, the substrate consisted of hard sand, pebbles/
cobbles, and small boulders (CR Environmental, Inc. 2014).
    Much of the shoreline in the project area has been characterized as 
hard shores (rocky intertidal). In general, rocky intertidal areas 
consist of bedrock that alternates between marine and terrestrial 
habitats, depending on the tide (Navy 2013). Rocky intertidal areas are 
characterized by ``bedrock, stones, or boulders that singly or in 
combination cover 75 percent or more of an area that is covered less 
than 30 percent by vegetation'' (Navy 2013).

Detailed Description of Specific Activity

    In-water work anticipated for Year 2 work is planned as follows and 
is summarized in Table 2 below. Work will continue from the 2017 
schedule with installation of the king pile template and support for 
excavation (SOE) system along Berth 11C and any remaining sections of 
Berth 11B and 11A. The end sheet wall sections (returns) will also be 
completed. The temporary SOE system with the H-pile is required due to 
site sediment conditions becoming potentially unstable. The Navy's 
contractor requested the use of alternative measures to provide a 
stable work area and protect worker safety. The SOE would be required 
to protect workers from underwater engulfment due to unstable sediments 
disturbed during

[[Page 56793]]

drilling and dredging activity. The SOE will maintain an excavation 
face of up to ten feet to protect divers who must be in the area during 
installation of the shutter panel system.
    It is anticipated that a significant amount of the temporary pile 
extraction work will be completed from behind the new shutter panel 
wall during low-water situations which is anticipated to reduce the 
noise generated from use of the vibratory hammer during extraction; 
however, work to be conducted from behind the new shutter panel wall 
has not been included in the calculations for this application as it 
was not feasible to determine exact amounts of activity which would be 
accomplished from behind the new shutter panel wall during low water 
conditions. During Year 2 activity, concurrent work utilizing a 
vibratory hammer during drilling operations is possible. This potential 
concurrent activity could occur during installation of the rock sockets 
for up to 16 days. The vibratory hammer may be working to install SOE 
sheets or H-pile as the drilling work is being conducted.
    The Navy plans to continue the project in 2018 with the 
installation of a king pile and concrete shutter panel bulkhead at 
Berth 11C. The bulkhead would extend from the western end of Berth 11B 
to the southern end of Berth 12. The in-water construction process 
would be the same as the process described below and utilized in 2017. 
See Figure 1-2 in the application depicting the layout of the berths at 
the Shipyard.
    The contractor will install templates for the king pile and work in 
increments along the berth from a jack-up barge. The contractor will 
set the template (including temporary piles and horizontal members), 
which may take approximately 1 day. The contractor would then drill the 
rock sockets, which is estimated to take about one day per socket. King 
piles would be regularly spaced along the berths and grouted into 
sockets drilled into the bedrock (i.e., ``rock-socketed'').
    The SOE system will then be installed within the current work area 
for the king pile (between king piles). The SOE system consists of an 
H-pile secured to a road plate. The H-pile will be placed utilizing the 
vibratory hammer to a depth sufficient to contain material, which could 
be dislodged during dredging activity, containing the activity to the 
permitted work area. The SOE system will not be utilized the full 
length of the berth. Soil borings and field conditions will determine 
need. The days and pile number for SOE installation are conservatively 
estimated from soil boring data obtained in 2017.
    The concrete shutter panels would then be installed in stacks 
between the king piles along most of the length of Berth 11C and 
remaining portions of 11A and 11B. Installation of the concrete shutter 
panels is not included in the noise analysis because no pile driving 
would be required.
    Along an approximately 16-foot section at the eastern end of Berth 
11A and an additional 101 feet between Berths 11A and 11B, the depth to 
bedrock is greater, thus allowing a conventional sheet-pile bulkhead to 
be constructed. The steel sheet-piles would be driven to bedrock using 
a vibratory hammer. Note that this work was originally slated to occur 
in Year 1 but has been re-scheduled to occur in Year 2.
    Sheet piles installed with a vibratory hammer also would be used to 
construct ``returns,'' which would be shorter bulkheads connecting the 
new bulkheads to the existing bulkhead under the pier. Installation of 
the sheeting with a vibratory hammer is estimated to take less than one 
hour per pair of sheets. The contractor would probably install two 
sheets at a time, and so the time required to install the sheeting (10 
pairs = 20 sheets) using vibratory hammers would only be about 8 hours 
per 10 pairs of sheets. The activities described in Table 2 reflect 
those estimated installation durations. Time requirements for all other 
pile types were estimated based on information compiled from ICF Jones 
and Stokes and Illingworth and Rodkin, Inc. (2012).
    Additional in-water work would be required to install steel H-type 
sister piles at the location of the inboard portal crane rail beam at 
Berth 11, including Berth 11C. The sister piles would provide 
additional support for the portal crane rail system and restore its 
load-bearing capacity. The sister piles would be driven into the 
bedrock below the pier, in water generally less than 10 feet deep, 
using an impact hammer. The timing of this work depends on operational 
schedules at the berths. The sister piles may be installed either 
before or after the bulkheads are constructed. Twenty-two (22) sister 
piles are (11C, 11A) planned for 2018. It is anticipated that this work 
will also be conducted behind the new shutter panel wall, providing for 
additional sound attenuation or completion of the work during low tide 
or ``out of water'' conditions.
    In summary, vibratory hammers will be used to install the 
following:
     15-inch timber piles used to reconstruct timber dolphins 
at the corners of Berth 11;
     25-inch steel sheet piles used for the bulkhead at Berth 
11;
     14-inch H-pile for SOE system (road plate system) initial 
installation; and
     25-inch sheet pile used for SOE in areas where the road 
plate system is not appropriate.
    Extracted piles would include:
     15-inch timber fender piles at Berth 11;
     15-inch timber piles making up the existing dolphins at 
the corner of Berth 11; and
     25-inch sheet pile and 14-inch H-pile road plate system 
for SOE.
    Piles that would be installed through impact driving include 14-
inch steel H-type piles used as sister piles at Berth 11. These piles 
must be fully installed with an impact hammer because the piles will 
not reach bearing depth or have the required load-bearing capacity if 
installed using vibratory methods only. The vibratory hammer will be 
used to set the pile with the impact hammer used to seat the pile for 
depth and assure load-bearing capacity. Estimated use of the impact 
hammer would be approximately four minutes per pile.
    Table 2 shows the anticipated work effort (e.g., days) and numbers 
planned for installation/extraction of each pile type while Table 3 
shows estimated hours for each type of pile driving an drilling 
activity.

                                                  Table 2--Year 2 (2018) Planned Construction Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                            Number     Number
         Activity/method                  Timing         Number of        Pile type        of piles   of piles      Overlap days          Production
                                                            days                          installed  extracted                            estimates
--------------------------------------------------------------------------------------------------------------------------------------------------------
Extract Timber Piles/Vibratory     January-December              3  15'' Timber Piles...  .........         18  ...................  Estimated 6 piles
 Hammer.                            2018.                                                                                             per day.

[[Page 56794]]

 
Install Casing & Drill Sockets/    January-December             56  36'' W-Section Steel         35  .........  ...................  Estimated less than
 Auger Drilling.                    2018.                                                                                             one pile completed
                                                                                                                                      per day. This
                                                                                                                                      includes setting
                                                                                                                                      the casing and
                                                                                                                                      rock socket
                                                                                                                                      drilling.
Install Sheet Pile (SKZ-20) SOE    January-December             12  24'' Sheet Piles            144  .........  9/during rock        Estimated 12 sheets
 Piles/Vibro.                       2018.                            Steel.                                      sockets.             per day.
Remove Sheet Pile (SKZ-20) SOE     January-December              6  24'' Sheet Piles      .........        144  4/during rock        Estimated 24 sheets
 Piles/Vibro.                       2018.                            Steel.                                      sockets.             per day.
Install Road Plate/H-Pile Support  January-December              3  14 inch H-Pile......         12  .........  2/during rock        Estimated 4 ea.
 of Excav. Vibro.                   2018.                                                                        sockets.             road plates per
                                                                                                                                      day.
Remove Road Plate/H-Pile Support   January-December              2  14 inch H-Pile......  .........         12  1/during rock        Estimated 8 ea.
 of Excav. Vibro.                   2018.                                                                        sockets.             Road plates per
                                                                                                                                      day.
Install Sheet Pile (AZ50) Sheet    January-December              6  24 inch Sheet Piles          74  .........  ...................  Estimated 13 sheets
 wall Bulkhead.                     2018.                            Steel.                                                           per day.
Install H-Pile (AZ50) Bulkhead     January-December              2  14inch H-Pile Steel.          4  .........  ...................  Estimated 2 piles
 Return @ West End of 11C-Vibro.    2018.                                                                                             per day.
Install Sheet Pile (AZ50)          January-December              1  24inch Sheet Piles            2  .........  ...................  Estimated 2 piles
 Bulkhead Return @ West End of      2018.                            Steel.                                                           per day.
 11C-Vibro.
Install Support/Sister Pile/Vibro  January-December      .........  14inch H-Pile Steel.         22  .........  ...................  Estimated 2.6 piles
 & Impact Hammer.                   2018.                                                                                             per day. The vibro
                                                                                                                                      would be used to
                                                                                                                                      stick the pile and
                                                                                                                                      the impact would
                                                                                                                                      drive the pile to
                                                                                                                                      refusal.*
                                                        ------------------------------------------------------------------------------------------------
    Totals.......................  ....................      Expected total work days           293        174  16.................
                                                            (including up to16 days of
                                                         concurrent activities) = 84-100
                                                                       days
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Depending on when these piles are driven in the tide cycle there is potential to install all 22 of the support piles in the dry which would further
  reduce the number of vibratory and impact hammer days. This pile quantity includes all the Support Pile in Berth 11C as well as 8 Support Pile
  remaining from Berth 11A.


                                          Table 3--Year 2 (2018) Hours Estimated for Each Pile Driving Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Driving type              Pile type                 Number of piles                          Days                              Hours
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact.................  14'' H-Pile (Sister     22 piles.........................  9................................  1.5.
                          Pile).
Vibratory..............  24'' and 36'' sheet     236 piles/sheet..................  27 install 8 remove..............  216 install 64 remove.
                          pile, 15'' timber
                          pile, 14'' H-pile.
Drilling...............  36'' Installation/Rock  35 casings.......................  56...............................  448.
                          Sockets.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The project schedule will include dredging operations. However, 
dredging operations are not expected to result in the take of any 
animals and will not be discussed further.
    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
    Five marine mammal species, including one cetacean and four 
pinnipeds, may inhabit or transit the waters near the Shipyard in the 
lower Piscataqua River during the specified activity. These include the 
harbor porpoise (Phocoena phocoena), gray seal (Halichoerus grypus), 
harbor seal (Phoca vitulina), hooded seal (Cystophora cristata), and 
harp seal (Pagophilus groenlandicus). None of the marine mammals that 
may be found in the Piscataqua River are listed under the Endangered 
Species Act (ESA). Table 3 lists the marine mammal species that could 
occur near the Shipyard and their estimated densities within the 
project area. As there are no specific density data for any of the 
species in the Piscataqua River, density data from the nearshore zone 
outside the mouth the Piscataqua River in the Atlantic Ocean have been 
used instead. Therefore, it can be assumed that the density estimates 
presented here for each species are conservative and higher than 
densities that would typically be expected in an industrialized, 
estuarine environment such as the lower Piscataqua River in the 
vicinity of the Shipyard.
    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical 
and behavioral descriptions) may be found on NMFS's Web site 
(www.nmfs.noaa.gov/pr/species/mammals/).
    Table 4 lists all species with expected potential for occurrence 
near the Shipyard and summarizes information related to the population 
or stock, including regulatory status under the MMPA and ESA and 
potential biological removal (PBR), where known.

[[Page 56795]]

For taxonomy, we follow Committee on Taxonomy (2017). PBR is defined by 
the MMPA as the maximum number of animals, not including natural 
mortalities, that may be removed from a marine mammal stock while 
allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS's SARs). While no mortality is 
anticipated or authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprise 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 Marine Mammal Stock 
Assessment--2016 (Hayes et al. 2017). All values presented in Table 4 
are the most recent available at the time of publication and are 
available in the 2016 SAR (Hayes et al. 2017) (available online at: 
www.nmfs.noaa.gov/pr/sars/draft.htm).

                                       Table 4--Marine Mammal Species Potentially Present in the Piscataqua River
                                                             in the Vicinity of the Shipyard
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    Stock abundance (CV,
                                                                                 ESA/MMPA status;     Nmin, most recent                        Annual  M/
           Common name                Scientific name            Stock           strategic  (Y/N)    abundance  survey)           PBR            SI \3\
                                                                                       \1\                   \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor Porpoise..................  Phocoena phocoena...  Gulf of Maine/Bay of  -;N                  79,883 (0.32;         706................        437
                                                          Fundy stock.                               61,415; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Seal........................  Halichoerus grypus..  Western North         -;N                  unknown 505,000       unknown............      4,959
                                                          Atlantic stock.                            (best estimate 2014
                                                                                                     Canadian population
                                                                                                     DFO 2014).
Harbor Seal......................  Phoca vitulina......  Western North         -;N                  75,834 (0.15;         2,006..............        389
                                                          Atlantic stock.                            66,884; 2012).
Hooded Seal 4....................  Cystophora cristata.  Western North         -;N                  592,100 (-;512,000,   unknown............      5,199
                                                          Atlantic stock.                            2005).
Harp Seal........................  Pagophilus            Western North         -;N                  7,100,000 (2012)....  unknown............    306,082
                                    groenlandicus.        Atlantic stock.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: www.nmfs.noaa.gov/pr/sars/. 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's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual 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\ Abundance estimates for these stocks are greater than eight years old and are, therefore, not considered current. PBR is considered undetermined for
  these stocks, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates
  and PBR values, as these represent the best available information for use in this document.
Note--Italicized species are not expected to be taken or proposed for authorization.

    As described below, all five species temporally and spatially co-
occur with the activity to the degree that take is reasonably likely to 
occur, and we are proposing to authorize it. However, the temporal and/
or spatial occurrence of hooded seals is such that take is not expected 
to occur, and they are not discussed further beyond the explanation 
provided here. While hooded seals have been recorded in the Piscataqua 
River, only two seals have been sighted near the shipyard with those 
observations occurring in 2009. We consider occurrence of the hooded 
seal in the Piscataqua River to be extralimital.

Harbor Porpoise

    The harbor porpoise is a member of the phocoenidae family. The Gulf 
of Maine/Bay of Fundy stock of the harbor porpoise is not listed under 
the ESA and is not considered strategic or depleted under the MMPA.
    Line-transect surveys have been conducted in the Gulf of Maine 
between 1991 and 2011. Based on the 2011 aerial surveys, the best 
abundance estimate for the Gulf of Maine/Bay of Fundy stock of harbor 
porpoise is 79,883 animals (CV = 0.32). The aerial surveys included 
central Virginia to the lower Bay of Fundy. The minimum population 
estimate is 61,415 animals (Hayes et al. 2017).
    Harbor porpoises are found commonly in coastal and offshore waters 
of both the Atlantic and Pacific Oceans. In the western North Atlantic, 
the species is found in both U.S. and Canadian waters. More 
specifically, the species can be found between West Greenland and Cape 
Hatteras, North Carolina (Hayes et al. 2017). Based on genetic 
analysis, it is assumed that harbor porpoises in the U.S. and Canadian 
waters are divided into four

[[Page 56796]]

populations, as follows: (1) Gulf of St. Lawrence; (2) Newfoundland; 
(3) Greenland; and (4) Gulf of Maine/Bay of Fundy.
    The Gulf of Maine/Bay of Fundy stock of the harbor porpoise is 
generally found over the Continental Shelf, ranging from the Gulf of 
Maine/Bay of Fundy region to North Carolina, in varying abundance and 
depending on the season (Waring et al. 2014). July through September 
are the primary months this species can be found concentrated in the 
Gulf of Maine and the southern Bay of Fundy area (Waring et al. 2014). 
During this time, harbor porpoises are generally found in less than 
approximately 150 m of water (Waring et al. 2014). During fall months 
(October through December) and spring months (April through June), this 
species is more dispersed throughout a larger region that ranges from 
Maine though New Jersey. During winter months (January through March), 
harbor porpoises are generally found in much lower densities between 
New York and Canada, as well as dispersed in more southerly locations 
between New Jersey and North Carolina (Waring et al., 2014; CeTAP 
1982). Harbor porpoises are known to occur in the Piscataqua River and 
are the most commonly observed cetacean species for the river.
    Harbor porpoises are considered high-frequency cetaceans. Hearing 
capabilities for harbor porpoises have been tested both behaviorally 
and with the auditory evoked potential technique. Based on an audiogram 
developed from behavioral methods, detection thresholds were estimated 
between 250 hertz (Hz) and 180 kilohertz (kHz). Within that, the range 
of best hearing was from 16 to 140 kHz, and maximum sensitivity was 
recorded at 100 to 140 kHz (Kastelein et al., 2002). Harbor porpoises 
are vocal animals, using echolocation for feeding and navigation and 
vocalizing for socialization (Southall et al., 2007).

Gray Seal

    Gray seals, which are members of the ``true seal'' family 
(phocidae), are a coastal species that generally remains within the 
Continental Shelf region. The western North Atlantic stock of the gray 
seal is not categorized as strategic or depleted under the MMPA.
    Gray seals can be found on both sides of the North Atlantic. Within 
this area, the species is split into three primary populations: (1) 
Eastern Canada, (2) northwestern Europe, and (3) the Baltic Sea (Hayes 
et al. 2017). Gray seals within U.S. waters are considered the western 
North Atlantic stock and are expected to be part of the eastern 
Canadian population (Hayes et al. 2017) 2014). In general, this species 
can be found year-round in the coastal waters of the Gulf of Maine 
(Hayes et al. 2017). No known haul-out sites for gray seals are in the 
immediate vicinity of the project area. The closest known haul-out site 
for seals within the Piscataqua River is 1.5 miles downstream of the 
project area. Solitary seals could potentially haul out closer to the 
project area. In coastal Maine, gray seals are known to pup on Green 
Island and Sea Island and are year-round residents in southern Maine 
waters (Hayes et al. 2017). Gray seals are known to occur within the 
Piscataqua River but are not as commonly observed as harbor seals. 
During spring and summer months, gray seals are most commonly observed 
on offshore ledges off the central coast of Maine (Richardson et al. 
1995).
    Current estimates of the total western Atlantic gray seal 
population are not available; although estimates of portions of the 
stock are available for select time periods. The Canadian gray seal 
stock assessment (DFO 2014) reports gray seal pup production in 2014 
for the three Canadian aggregations (Gulf of St. Lawrence, Sable 
Island, and Nova Scotia) as 93,000 animals; these are projected using 
population models to total population levels of 505,000 animals.
    Gray seals, along with other members of the phocidae family, are 
capable of hearing in both air and water. In general, the estimated 
bandwidth for functional hearing for phocids in water is 50 Hz to 86 
kHz and in air is 75 Hz to 30 kHz (Southall et al. 2007). Hearing 
capabilities for gray seals both in water and in air have been tested 
behaviorally and with the auditory evoked potential technique (Southall 
et al. 2007).

Harbor Seal

    Harbor seals are members of the true seal family (Phocidae) and can 
be found in nearshore waters along both the North Atlantic and North 
Pacific coasts, generally at latitudes above 30[deg] N. (Burns 2009). 
In the western Atlantic Ocean, the harbor seal's range extends from the 
eastern Canadian Arctic to New York; however, they can be found as far 
south as the Carolinas (Hayes et al. 2017). In New England, the species 
can be found in coastal waters year-round (Hayes et al. 2017). Overall, 
there are five recognized subspecies of harbor seal, two of which occur 
in the Atlantic Ocean. The western Atlantic harbor seal (Phoca vitulina 
concolor) is the subspecies likely to occur in the 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. The western North Atlantic stock of harbor 
seal is not categorized as strategic or depleted under the MMPA.
    The best current abundance estimate of harbor seals is 75,834 (CV = 
0.15) which is from a 2012 survey (Waring et. al. 2015). The minimum 
population estimate is 66,884 based on corrected available counts along 
the Maine coast in 2012. In the Piscataqua River, harbor seals are the 
most abundant pinniped species.
    Harbor seals are capable of hearing in both air and water. In 
general, the estimated bandwidth for functional hearing for phocid 
(true seals) seals in water is 50 Hz to 86 kHz and in air is 75 Hz to 
30 kHz (Southall et al. 2007). Harbor seals hear nearly as well in air 
as underwater (Kastak and Schusterman 1998). Kastak and Schusterman 
(1998) reported airborne low-frequency (100 Hz) sound detection 
thresholds at 65.4 decibels (dB) re 20 micropascals ([mu]Pa) for harbor 
seals. In air, they hear frequencies from 0.25 kHz to 30 kHz and are 
most sensitive to frequencies from 6 to 16 kHz (Richardson et al. 1995; 
Terhune and Turnbull 1995; Wolski et al. 2003). Adult males also 
produce underwater sounds during the breeding season that typically 
range from 0.025 to 4 kHz at a duration range of 0.1 second to multiple 
seconds (Hanggi and Schusterman 1994). Hanggi and Schusteman (1994) 
found that there is individual variation in the dominant frequency 
range of sounds between different males, and Van Parijs et al. (2003) 
reported oceanic, regional, population, and site-specific variation 
that could be vocal dialects. In water, the species hears frequencies 
from 1 to 75 kHz (Southall 2007) and can detect sound levels as weak as 
60 to 85 dB re 1 [mu]Pa within that band. They are most sensitive at 
frequencies below 50 kHz; above 60 kHz, sensitivity rapidly decreases.

Harp Seal

    Harp seals are members of the true seal family and are classified 
into three stocks, which coincide with specific pupping sites on pack 
ice, as follows: (1) Eastern Canada, including the areas off the coast 
of Newfoundland and Labrador and the area near the Magdalen Islands in 
the Gulf of St. Lawrence; (2) the West Ice off eastern Greenland, and 
(3) the ice in the White Sea off the coast of Russia (Waring et al. 
2014). 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

[[Page 56797]]

increasing presence in the coastal waters between Maine and New Jersey 
(Waring et al. 2014). In the U.S., they are considered members of the 
western North Atlantic stock and generally occur in New England waters 
from January through May in the winter and spring (Waring et al. 2014). 
Harp seals are not listed under the ESA and the western North Atlantic 
stock is not considered strategic or depleted under the MMPA.
    Population abundance of harp seals in the western North Atlantic is 
derived from aerial surveys and mark-recapture (Waring et al. 2014). 
The most recent population estimate in the western North Atlantic was 
derived in 2012 from an aerial harp seal survey. The 2012 best 
population estimate for hooded seals is 7.1 million individuals (Waring 
et al. 2014). Currently, not enough data are available to determine 
what percentage of this estimate may represent the population within 
U.S. waters. Harp seals have been known to occur in the Piscataqua 
River; however, sightings are rare (Navy 2017).
    Hearing capabilities of this species have not been directly tested 
as they have for other species. However, as harp seals are within the 
phocidae family, the functional hearing limit of these species is 
expected to be similar to that of other phocid seals. In general, the 
estimated bandwidth for functional hearing for phocids in water is 50 
Hz to 86 kHz and in air is 75 Hz to 30 kHz (Southall et al. 2007). 
Pinnipeds in general are also known to produce a wide variety of low-
frequency social sounds, with varying hearing capabilities in air and 
in water (Southall et al. 2007).

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; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007) recommended that marine mammals be divided into functional 
hearing groups based on directly measured or estimated hearing ranges 
on the basis of available behavioral response data, audiograms derived 
using auditory evoked potential techniques, anatomical modeling, and 
other data. Note that no direct measurements of hearing ability have 
been successfully completed for mysticetes (i.e., low-frequency 
cetaceans). Subsequently, NMFS (2016) described generalized hearing 
ranges for these marine mammal hearing groups. Generalized hearing 
ranges were chosen based on the approximately 65 dB threshold from the 
normalized composite audiograms, with the exception for lower limits 
for low-frequency cetaceans where the lower bound was deemed to be 
biologically implausible and the lower bound from Southall et al. 
(2007) retained. The functional groups and the associated frequencies 
are indicated below (note that these frequency ranges correspond to the 
range for the composite group, with the entire range not necessarily 
reflecting the capabilities of every species within that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz, with best 
hearing estimated to be from 100 Hz to 8 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water: Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz, 
with best hearing between 1-50 kHz; and
     Pinnipeds in water: Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz, with best 
hearing between 2-48 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Four marine mammal species (one cetacean and three pinniped (phocid) 
species) have the reasonable potential to co-occur with the proposed 
survey activities. Please refer to Table 4. Of the cetacean species 
that may be present, harbor porpoises are classified are classified as 
high-frequency cetaceans, while the three seal species belong within 
the pinnipeds in water (Phocidae) hearing group.
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 by Incidental Harassment'' 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 Take by Incidental 
Harassment'' 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.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in Hz or cycles per second. Wavelength is the distance 
between two peaks of a sound wave; lower frequency sounds have longer 
wavelengths than higher frequency sounds and attenuate (decrease) more 
rapidly in shallower water. Amplitude is the height of the sound 
pressure wave or the `loudness' of a sound and is typically measured 
using the dB scale. A dB is the ratio between a measured pressure (with 
sound) and a reference pressure (sound at a constant pressure, 
established by scientific standards). It is a logarithmic unit that 
accounts for large variations in amplitude; therefore, relatively small 
changes in dB ratings correspond to large changes in sound pressure. 
When referring to sound pressure levels (SPLs; the sound force per unit 
area), sound is referenced in the context of underwater sound pressure 
to 1 [mu]Pa. One pascal is the pressure resulting from a force of one 
newton exerted over an area of one square meter. The source level (SL) 
represents the sound level at a distance of 1 m from the source 
(referenced to 1 [mu]Pa). The received level is the sound level at the 
listener's position. Note that all underwater sound levels in this 
document are referenced to a pressure of 1 [micro]Pa and all airborne 
sound levels in

[[Page 56798]]

this document are referenced to a pressure of 20 [micro]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. The 
compressions and decompressions associated with sound waves are 
detected as changes in pressure by aquatic life and man-made sound 
receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al.,1995), and the sound level of 
a region is defined by the total acoustical energy being generated by 
known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions;
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times;
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz; and
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise for frequencies between 20 
and 300 Hz. In general, the frequencies of anthropogenic sounds are 
below 1 kHz and, if higher frequency sound levels are created, they 
attenuate rapidly (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' 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, vibratory pile driving and vibratory pile 
extraction. The sounds produced by these activities fall into one of 
two general sound types: pulsed and non-pulsed (defined in the 
following paragraphs). 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). Please see Southall et al., (2007) for an in-
depth discussion of these concepts.
    Pulsed sound sources (e.g., explosions, gunshots, sonic booms, 
impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986; Harris, 1998, 1998; ISO, 2003) and occur either as 
isolated events or repeated in some succession. Pulsed sounds are all 
characterized by a relatively rapid rise from ambient pressure to a 
maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or non-continuous (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling, vibratory 
pile driving, and active sonar systems (such as those used by the U.S. 
Navy). The duration of such sounds, as received at a distance, can be 
greatly extended in a highly reverberant environment.
    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 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).

Acoustic Impacts

    Please refer to the information given previously (Description of 
Sound Sources) regarding sound, characteristics of sound types, and 
metrics used in this document.

[[Page 56799]]

Anthropogenic sounds cover a broad range of frequencies and sound 
levels and can have a range of highly variable impacts on marine life, 
from none or minor to potentially severe responses, depending on 
received levels, duration of exposure, behavioral context, and various 
other factors. The potential effects of underwater sound from active 
acoustic sources can potentially result in one or more of the 
following: Temporary or permanent hearing impairment, non-auditory 
physical or physiological effects, behavioral disturbance, stress, and 
masking (Richardson et al., 1995; Gordon et al., 2004; Nowacek et al., 
2007; Southall et al., 2007). The degree of effect is intrinsically 
related to the signal characteristics, received level, distance from 
the source, and duration of the sound exposure. In general, sudden, 
high level sounds can cause hearing loss, as can longer exposures to 
lower level sounds. Temporary or permanent loss of hearing will occur 
almost exclusively for noise within an animal's hearing range. In this 
section, we first describe specific manifestations of acoustic effects 
before providing discussion specific to the proposed construction 
activities in the next section.
    Permanent Threshold Shift--Marine mammals exposed to high-intensity 
sound, or to lower-intensity sound for prolonged periods, can 
experience hearing threshold shift (TS), which is the loss of hearing 
sensitivity at certain frequency ranges (Kastak et al., 1999; Schlundt 
et al., 2000; Finneran et al., 2002, 2005). TS can be permanent (PTS), 
in which case the loss of hearing sensitivity is not fully recoverable, 
or temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Repeated sound exposure that 
leads to TTS could cause PTS. In severe cases of PTS, there can be 
total or partial deafness, while in most cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter 
1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals--PTS data exists only for a single harbor seal 
(Kastak et al., 2008)--but are assumed to be similar to those in humans 
and other terrestrial mammals. PTS typically occurs at exposure levels 
at least several decibels above (a 40-dB threshold shift approximates 
PTS onset; e.g., Kryter et al., 1966; Miller 1974) that inducing mild 
TTS (a 6-dB threshold shift approximates TTS onset; e.g., Southall et 
al., 2007). Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS thresholds for impulse sounds (such as 
impact pile driving pulses as received close to the source) are at 
least six dB higher than the TTS threshold on a peak-pressure basis and 
PTS cumulative sound exposure level thresholds are 15 to 20 dB higher 
than TTS cumulative sound exposure level thresholds (Southall et al., 
2007).
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to sound (Kryter 1985). While 
experiencing TTS, the hearing threshold rises, and a sound must be at a 
higher level in order to be heard. In terrestrial and marine mammals, 
TTS can last from minutes or hours to days (in cases of strong TTS). In 
many cases, hearing sensitivity recovers rapidly after exposure to the 
sound ends.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that occurs during a time where ambient noise is lower and there 
are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)); and three species of pinnipeds (northern elephant 
seal (Mirounga angustirostris), harbor seal, and California sea lion 
(Zalophus californianus) exposed to a limited number of sound sources 
(i.e., mostly tones and octave-band noise) in laboratory settings 
(e.g., Finneran et al., 2002; Nachtigall et al., 2004; Kastak et al., 
2005; Lucke et al., 2009; Popov et al., 2011). In general, harbor seals 
(Kastak et al., 2005; Kastelein et al., 2012a) and harbor porpoises 
(Lucke et al., 2009; Kastelein et al., 2012b) have a lower TTS onset 
than other measured pinniped or cetacean species. Additionally, the 
existing marine mammal TTS data come from a limited number of 
individuals within these species. There are no data 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), and 
Finneran (2015).
    Behavioral Effects--Behavioral disturbance may include a variety of 
effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. 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). 
Please see Appendices B-C of Southall et al. (2007) for a review of 
studies involving marine mammal behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al.,

[[Page 56800]]

2009). The opposite process is sensitization, when an unpleasant 
experience leads to subsequent responses, often in the form of 
avoidance, at a lower level of exposure. As noted, behavioral state may 
affect the type of response. For example, animals that are resting may 
show greater behavioral change in response to disturbing sound levels 
than animals that are highly motivated to remain in an area for feeding 
(Richardson et al., 1995; NRC, 2003; Wartzok et al., 2003). Controlled 
experiments with captive marine mammals have showed pronounced 
behavioral reactions, including avoidance of loud sound sources 
(Ridgway et al., 1997; Finneran et al., 2003). Observed responses of 
wild marine mammals to loud pulsed sound sources (typically seismic 
airguns or acoustic harassment devices) have been varied but often 
consist of avoidance behavior or other behavioral changes suggesting 
discomfort (Morton and Symonds, 2002; see also Richardson et al., 1995; 
Nowacek et al., 2007).
    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, 
2003). However, there are broad categories of potential response, which 
we describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely, and may consist of 
increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive (e.g., Frankel 
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et 
al.; 2004; Goldbogen et al., 2013a,b). Variations in dive behavior may 
reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at the time of the exposure and the 
type and magnitude of the response.
    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.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005b, 2006; Gailey et 
al., 2007).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007b). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from seismic surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996). The result of a flight response could range from 
brief, temporary exertion and displacement from the area where the 
signal provokes flight to, in extreme cases, marine mammal strandings 
(Evans and England 2001). However, it should be noted that response to 
a perceived predator does not necessarily invoke flight (Ford and 
Reeves 2008), and whether individuals are solitary or in groups may 
influence the response.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In 
addition, chronic disturbance can cause population declines through 
reduction

[[Page 56801]]

of fitness (e.g., decline in body condition) and subsequent reduction 
in reproductive success, survival, or both (e.g., Harrington and 
Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    Stress Responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral 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 state of 
distress 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 would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC 2003).
    Auditory 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., 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.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007b; Di Iorio and Clark 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the

[[Page 56802]]

population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand, 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.
    Non-Auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. In general, little is known about 
the potential for pile driving to cause auditory impairment or other 
physical effects in marine mammals. Available data suggest that such 
effects, if they occur at all, would presumably be limited to short 
distances from the sound source, where SLs are much higher, and to 
activities that extend over a prolonged period. The available data do 
not allow identification of a specific exposure level above which non-
auditory effects can be expected (Southall et al., 2007) or any 
meaningful quantitative predictions of the numbers (if any) of marine 
mammals that might be affected in those ways. However, the proposed 
activities do not involve the use of devices such as explosives or mid-
frequency active sonar that are associated with these types of effects. 
Therefore, non-auditory physiological impacts to marine mammals are 
considered unlikely.

Underwater Acoustic Effects From the Proposed Activities

    Potential Effects of Pile Driving and Drilling Sound--The effects 
of sounds from pile driving might include one or more of the following: 
temporary or permanent hearing impairment, non-auditory physical or 
physiological effects, and behavioral disturbance (Richardson et al., 
1995; Gordon et al., 2003; Nowacek et al., 2007; Southall et al., 
2007). The effects of pile driving on marine mammals are dependent on 
several factors, including the type and depth of the animal; the pile 
size and type, and the intensity and duration of the pile driving 
sound; the substrate; the standoff distance between the pile and the 
animal; and the sound propagation properties of the environment. 
Impacts to marine mammals from pile driving activities are expected to 
result primarily from acoustic pathways. As such, the degree of effect 
is intrinsically related to the frequency, received level, and duration 
of the sound exposure, which are in turn influenced by the distance 
between the animal and the source. The further away from the source, 
the less intense the exposure should be. The substrate and depth of the 
habitat affect the sound propagation properties of the environment. In 
addition, substrates that are soft (e.g., sand) would absorb or 
attenuate the sound more readily than hard substrates (e.g., rock) 
which may reflect the acoustic wave. Soft porous substrates would also 
likely require less time to drive the pile, and possibly less forceful 
equipment, which would ultimately decrease the intensity of the 
acoustic source.
    Hearing Impairment and Other Physical Effects-- Marine mammals 
exposed to high intensity sound repeatedly or for prolonged periods can 
experience hearing threshold shifts. PTS constitutes injury, but TTS 
does not (Southall et al., 2007). Based on the best scientific 
information available, the SPLs for the proposed construction 
activities may exceed the thresholds that could cause TTS or the onset 
of PTS based on NMFS' new acoustic guidance (NMFS, 2016).
    Disturbance Reactions--Responses to continuous sound, such as 
vibratory pile installation, have not been documented as well as 
responses to pulsed sounds. With both types of pile driving, it is 
likely that the onset of pile driving could result in temporary, short 
term changes in an animal's typical behavior and/or avoidance of the 
affected area. Specific behavioral changes that may result from this 
proposed project include changing durations of surfacing and dives, 
moving direction and/or speed; 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); 
and avoidance of areas where sound sources are located. If a marine 
mammal responds to a stimulus by changing its behavior (e.g., through 
relatively minor changes in locomotion direction/speed or vocalization 
behavior), the response may or may not constitute taking at the 
individual level, and is unlikely to affect the stock or the species as 
a whole. However, if a sound source displaces marine mammals from an 
important feeding or breeding area for a prolonged period, potential 
impacts on the stock or species could potentially be significant if 
growth, survival and reproduction are affected (e.g., Lusseau and 
Bejder, 2007; Weilgart, 2007). Note that the significance of many of 
these behavioral disturbances is difficult to predict, especially if 
the detected disturbances appear minor.
    Auditory Masking--Natural and artificial sounds can disrupt 
behavior by masking. Given that the energy distribution of pile driving 
covers a broad frequency spectrum, sound from these sources would 
likely be within the audible range of marine mammals present in the 
project area. Impact pile driving activity is relatively short-term, 
and mostly for proofing, with rapid pulses occurring for only a few 
minutes per pile. The probability for impact pile driving resulting 
from this proposed action masking acoustic signals important to the 
behavior and survival of marine mammal species is low. Vibratory pile 
driving is also relatively short-term. It is possible that vibratory 
pile driving resulting from this proposed action may mask acoustic 
signals important to the behavior and survival of marine mammal 
species, but the short-term duration and limited affected area would 
result in insignificant impacts from masking. Any masking event that 
could possibly rise to Level B harassment under the MMPA would occur 
concurrently within the zones of behavioral harassment already 
estimated for vibratory and impact pile driving, and which have already 
been taken into account in the exposure analysis.
    Airborne Acoustic Effects From the Proposed Activities--Pinnipeds 
that occur near the project site could be exposed to airborne sounds 
associated with pile driving that have the potential to cause 
behavioral harassment, depending on their distance from pile driving 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise will primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with heads above water. 
Most likely, airborne sound would cause behavioral responses similar to 
those discussed above in relation to underwater sound. However, these 
animals would previously have been ``taken'' as a result of exposure to 
underwater sound above the behavioral harassment thresholds, which are 
in all cases larger than those associated with airborne sound. Thus, 
the behavioral

[[Page 56803]]

harassment of these animals is already accounted for in these estimates 
of potential take. Multiple instances of exposure to sound above NMFS' 
thresholds for behavioral harassment are not believed to result in 
increased behavioral disturbance, in either nature or intensity of 
disturbance reaction. Therefore, we do not believe that authorization 
of incidental take resulting from airborne sound for pinnipeds is 
warranted, and airborne sound is not discussed further here.
    Potential Pile Driving Effects on Prey--Construction activities 
would produce continuous (i.e., vibratory pile driving) sounds and 
pulsed (i.e., impact driving) sounds. Fish react to sounds that are 
especially strong and/or intermittent low-frequency sounds. Short 
duration, sharp sounds can cause overt or subtle changes in fish 
behavior and local distribution. 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). Sound pulses at received levels 
of 160 dB may cause subtle changes in fish behavior. SPLs of 180 dB may 
cause noticeable changes in behavior (Pearson et al., 1992; Skalski et 
al., 1992). SPLs of sufficient strength have been known to cause injury 
to fish and fish mortality.
    The most likely impact to fish from pile driving activities at the 
project area would be temporary behavioral avoidance. The duration of 
fish avoidance of this area after pile driving stops is unknown, but a 
rapid return to normal recruitment, distribution and behavior is 
anticipated. In general, impacts to marine mammal prey species from the 
proposed project are expected to be minor and temporary due to the 
relatively short timeframe of between 84 and 100 days of pile driving, 
pile extraction and drilling.
    Effects to Foraging Habitat--Pile installation may temporarily 
impact foraging habitat by increasing turbidity resulting from 
suspended sediments. Any increases would be temporary, localized, and 
minimal. The Navy must comply with state water quality standards during 
these operations by limiting the extent of turbidity to the immediate 
project area. In general, turbidity associated with pile installation 
is localized to about a 25-foot radius around the pile (Everitt et al. 
1980). Cetaceans are not expected to be close enough to the project 
pile driving areas to experience effects of turbidity, and any 
pinnipeds will be transiting the area and could avoid localized areas 
of turbidity. Therefore, the impact from increased turbidity levels is 
expected to be discountable to marine mammals. Furthermore, pile 
driving and removal at the project site will not obstruct movements or 
migration of marine mammals.
    In summary, given the relatively short and intermittent nature of 
sound associated with individual pile driving and drilling events and 
the relatively small area that would be affected, pile driving 
activities associated with the proposed action are not likely to have a 
permanent, adverse effect on any fish habitat, or populations of fish 
species. Thus, any impacts to marine mammal habitat are not expected to 
cause significant or long-term consequences for individual marine 
mammals or their populations.
    Previous Monitoring Report--The Navy submitted a preliminary 
monitoring report covering the period between April 18, 2017 and 
October 27, 2017. During this period piles were installed using 
vibratory hammer, the impact hammer, and drilling. Work was conducted 
over 73 days. Drilling has accounted for 98.8% of the total noise-
generating time spent on installation/extraction activities at the 
Shipyard; vibratory activity occurred during 1% of the total time; and 
impact driving took place <1% of the total time. During this time, 
observers noted 142 occurrences of marine mammals within designated 
zones, with all but one occurring within the Level B harassment zone as 
shown in Table 13.

                                         Table 13--Summary of 2017 Takes
----------------------------------------------------------------------------------------------------------------
                                      Harbor
                                     porpoise       Harbor seal      Gray seal       Harp seal      Hooded seal
----------------------------------------------------------------------------------------------------------------
                                         Takes through October 28, 2018
----------------------------------------------------------------------------------------------------------------
Level A.........................               0               1               0               0               0
Level B.........................               3             120              18               0               0
----------------------------------------------------------------------------------------------------------------

Estimated Take
    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, 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 primarily be by Level B harassment, as 
impact and vibratory pile driving as well as drilling have the 
potential to result in disruption of behavioral patterns for individual 
marine mammals. There is also some potential for auditory injury (Level 
A harassment) due to large predicted auditory injury zones. The 
proposed mitigation and monitoring measures are expected to minimize 
the severity of such taking to the extent practicable.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed or incur 
some degree of permanent hearing impairment; (2) the area or volume of 
water that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and, (4) and the number of days of activities. Below, we describe these 
components in more detail and present the proposed take estimate.

[[Page 56804]]

Acoustic Thresholds

    NMFS recommends acoustic thresholds that identify the received 
level of underwater sound above which exposed marine mammals would be 
reasonably expected to be behaviorally harassed (equated to Level B 
harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2011). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous non-
impulsive (e.g. vibratory pile-driving, drilling) and above 160 dB re 1 
[mu]Pa (rms) for non-explosive impulsive (e.g., impact pile driving, 
seismic airguns) or intermittent (e.g., scientific sonar) sources.
    The Navy's proposed activity includes the use of continuous 
(vibratory pile driving, drilling) and impulsive (impact pile driving) 
sources, and therefore the 120 and 160 dB re 1 [mu]Pa (rms) are 
applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Technical Guidance, 2016) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
The Navy's proposed activity includes the use of impulsive (impact pile 
driving) and non-impulsive (vibratory pile driving, drilling) sources.
    These thresholds are provided in Table 5. The references, analysis, 
and methodology used in the development of the thresholds are described 
in NMFS 2016 Technical Guidance, which may be accessed at: https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

                     Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
                                                (Received level)
----------------------------------------------------------------------------------------------------------------
                                                             PTS onset acoustic thresholds *
             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: 218 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 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1 [mu]Pa2s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds.
    Pile driving generates underwater noise that can potentially result 
in disturbance to marine mammals in the project area. 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 * log10(R1/R2),

Where:
R1 = the distance of the modeled SPL from the driven pile, and
R2 = 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]). Although 
cylindrical spreading loss was applied to driving of 14-inch H-piles in 
the previous IHA, in an effort to maintain consistency NMFS utilized 
practical spreading loss (4.5 dB reduction in sound level for each 
doubling of distance) for all driving and drilling activities for this 
proposed IHA. A practical spreading value of 15 is often used under 
conditions, such as at the Shipyard dock, where water increases with 
depth as the receiver moves away from the shoreline, resulting in an 
expected propagation environment that

[[Page 56805]]

would lie between spherical and cylindrical spreading loss conditions.
    Underwater Sound--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. A number of 
studies have measured sound produced during underwater pile driving 
projects. These data are largely for impact driving of steel pipe piles 
and concrete piles as well as vibratory driving of steel pipe piles.
Source Levels
    Source levels were collected for the four types of piles that would 
be installed and two pile-driving methods proposed for the project:
    1. 14-inch steel H-type piles--Used as sister piles and for SOE 
system installation; installed/extracted via vibratory hammer and 
seated as needed with impact hammer.
    2. 15-inch timber piles--Used for re-installation of dolphins at 
Berths 11, 12, and 13 and extracted via vibratory hammer.
    3. 25-inch steel sheet piles--Used for the bulkhead at Berth 11 and 
for SOE installed/extracted via vibratory hammer.
    Reference source levels for the project were determined using data 
for piles of similar sizes, the same pile-driving method as that 
proposed for the project, and at similar water depths. While the pile 
sizes and water depths chosen as proxies do not exactly match those for 
the project, they are the closest matches available, and it is assumed 
that the source levels shown in Table 6, 7 and 8 are the most 
representative for each pile type and associated pile-driving method.
    The intensity of pile driving or sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. Reference source levels 
for the proposed project were determined using data for piles of 
similar sizes, the same pile driving method as that proposed for the 
project, and at similar water depths. While the pile sizes and water 
depths chosen as proxies do not exactly match those for the project, 
they are the closest matches available, and it is assumed that the 
source levels shown in Table 6, 7, and 8 are the most representative 
for each pile type and associated pile driving method.
    The Navy analyzed source level values associated with a number of 
projects involving impact driving of steel H-piles to approximate 
environmental conditions and driving parameters at the Shipyard 
(Caltrans 2015). Data from pertinent projects were used to obtain 
average SEL and rms values for H pile impact installation. To be sure 
all values were relevant to the site, the Navy eliminated all piles in 
waters greater than 5 m, as well as all readings measured at ranges 
greater than 10 m. The Navy used all H piles for which the diameter was 
not specified as well as the 14 to 15-inch H piles, converted the dB 
measurements to a linear scale before averaging, and re-converted the 
average measurements to the appropriate dB units. Piles driven at this 
project site will be driven in 0-11 feet of water (0-3.4 m). During low 
tide, piles will essentially be driven in the dry. This varies 
drastically from other Navy projects on the east coast, such as at the 
Naval Submarine Base New London, where 14-inch H piles will be driven 
in water depths of 25 feet (7.62 m). Results are shown in Table 6.

              Table 6--Source Levels for In-Water Impact Hammer 14-Inch Steel H-Type (Sister) Piles
----------------------------------------------------------------------------------------------------------------
                                                                Distance
               Pile size and type                Water depth    measured       Peak      RMS  (dB)    SEL  (dB)
                                                      (m)         (m)
----------------------------------------------------------------------------------------------------------------
15-inch steel H pile...........................          2-3           10          187          164          154
15-inch steel H pile...........................          2-3           10          180          165          155
15-inch steel H pile...........................          2-3           10          194          177          170
Unspecified steel H pile.......................        0.5-2           10          172          160          147
14-inch steel H pile...........................          1-5           10          205          184          174
14-inch steel H pile...........................          1-5           10          206          182          172
14-inch steel H pile...........................          1-5           10          206          184          174
14-inch steel H pile...........................          1-5           10          210          190          180
14-inch steel H pile...........................          1-5           10          212          192          182
14-inch steel H pile...........................          1-5           10          210          189          179
14-inch steel H pile...........................          1-5           10          212          190          180
14-inch steel H pile...........................          1-5           10          205          190          180
14-inch steel H pile...........................          1-5           10          207          187          177
Unspecified steel H pile.......................        0-0.9           10  ...........          151          142
Unspecified steel H pile.......................        0-0.9           10  ...........          154          144
Unspecified steel H pile.......................        0-0.9           10  ...........          170          159
Unspecified steel H pile.......................        0-0.9           10  ...........          147          136
Unspecified steel H pile.......................        0-0.9           10  ...........          147          136
Unspecified steel H pile.......................        0-0.9           10  ...........          150          143
Unspecified steel H pile.......................        0-0.9           10  ...........          153          142
Unspecified steel H pile.......................        0-0.9           10  ...........          151          142
Unspecified steel H pile.......................        0-0.9           10  ...........          156          146
Unspecified steel H pile.......................        0-0.9           10  ...........          172          162
Unspecified steel H pile.......................        0-0.9           10  ...........          161          150
Unspecified steel H pile.......................        0-0.9           10  ...........          155          145
Unspecified steel H pile.......................        0-0.9           10  ...........          163          152
Unspecified steel H pile.......................        0-0.9           10  ...........          178          145
Unspecified steel H pile.......................        0-0.9           10  ...........          165          154
Averages.......................................  ...........  ...........        200.4        181.4        171.3
----------------------------------------------------------------------------------------------------------------
Source: Caltrans 2015.


[[Page 56806]]

    While the average rms value is 181.4, the Navy rounded up to 182 dB 
rms to be conservative.
    Table 7 shows the source levels that were utilized to calculate 
isopleths for vibratory driving of 24-inch steel sheet piles, and 15-
inch timber piles. An average value of 163 dB rms was used for 24-inch 
AZ steel sheet and 150 dB rms for 15-inch timber pile. For Year 1 work 
at the Shipyard Berth 11 the contractor has obtained initial acoustic 
readings associated with vibratory driving of 14'' H-Pile of 148 dB rms 
at 10 m. Additional details are found in Appendix A in the application. 
NMFS will use 148 dB as the source level since it is site-specific and 
more conservative than the 145 dB value depicted in WSDOT 2012.

                 Table 7--Source Levels for In-Water Vibratory Hammer 24-Inch Steel Sheet Piles,
                                            and 15-Inch Timber Piles
----------------------------------------------------------------------------------------------------------------
                                              Distance
   Pile size and pile type     Water depth    measured    Peak (dB)     RMS (dB)     SEL (dB)       Location
                                    (m)         (m)
----------------------------------------------------------------------------------------------------------------
24-inch AZ Steel Sheet \1\...           15           10          177          163          162  Berth 23, Port
                                                                                                 of Oakland, CA.
24-inch AZ Steel Sheet \1\...           15           10          175          162          162  Berth 30, Port
                                                                                                 of Oakland, CA.
24-inch AZ Steel Sheet \1\...           15           10          177          163          163  Berth 35/37,
                                                                                                 Port of
                                                                                                 Oakland, CA.
24-inch AZ Steel Sheet--                15           10          175          160          160  CA (Specific
 Typical \1\.                                                                                    location
                                                                                                 unknown).
24-inch AZ Steel Sheet--                15           10          182          165          165  CA (Specific
 Loudest \1\.                                                                                    location
                                                                                                 unknown).
24-inch AZ Steel Sheet                  15           10          178          163          163  CA (Specific
 (Average) \1\.                                                                                  location
                                                                                                 unknown).
15-inch Timber Pile \2\......           10           16          164          150  ...........  WSF Port
                                                                                                 Townsend Ferry
                                                                                                 Terminal, WA.
14-inch H-type Pile \3\......            6           10          155          148          145  CA (Specific
                                                                                                 location
                                                                                                 unknown).
----------------------------------------------------------------------------------------------------------------
Source:
\1\ ICF Jones & Stokes and Illingsworth & Rodkin 2012.
\2\ WSDOT 2010.
\3\ WSDOT 2012.

    Using the data presented in Table 6 and Table 7, underwater sound 
levels were estimated using the practical spreading model to determine 
over what distance the thresholds would be exceeded.
    Drilling is considered a continuous, non-impulsive noise source, 
similar to vibratory pile driving. Very little information is available 
regarding source levels of in-water drilling activities associated with 
nearshore pile installation such as that proposed for the Berths 11, 
12, and 13 structural repairs project. Dazey et al. (2012) attempted to 
characterize the source levels of several marine pile-drilling 
activities. One such activity was auger drilling (including 
installation and removal of the associated steel casing). Auger 
drilling will be employed as part of the Shipyard Project. The average 
sound pressure levels re 1 [mu]Pa rms were displayed for casing 
installation, auger drilling (inside the casing), and casing removal. 
For the purposes of this plan, it is assumed that the casing 
installation and removal activities would be conducted in a manner 
similar to that described in Dazey et al, (2012), primarily via 
oscillation. These average source levels are reported in Table 8.

              Table 8--Average Source Levels for Auger Drilling Activities During Pile Installation
----------------------------------------------------------------------------------------------------------------
                                          Water depth      Distance
           Drilling activity                  (m)        measured  (m)     RMS (dB)             Location
----------------------------------------------------------------------------------------------------------------
Casing Installation...................             1-5               1             157  Bechers Bay Santa Rosa
                                                                                         Island, CA.
Auger Drilling........................             1-5               1             151  Bechers Bay Santa Rosa
                                                                                         Island, CA.
Casing Removal........................             1-5               1             152  Bechers Bay Santa Rosa
                                                                                         Island, CA.
Average Drilling Activity.............             1-5               1             154  ........................
----------------------------------------------------------------------------------------------------------------
Source: Dazey et al., 2012.
Note: All source levels are referenced to 1 microPascal (re 1 [micro]Pa).

    IHA applications for other construction projects have reported 
that, due to a lack of information regarding pile drilling source 
levels, it is generally assumed that pile drilling would produce less 
in-water noise than both impact and vibratory pile driving. Based on 
the general lack of information about these activities and the 
assumption that in-water noise from pile drilling would be less than 
either impact or vibratory pile driving, it is assumed that the source 
levels presented in Table 7 are the most applicable for acoustic impact 
analysis at Berths 11, 12, and 13. For the purposes of this proposed 
IHA, however, we will conservatively assume that drilling has identical 
source levels to vibratory driving when calculating zones of influence. 
This includes instances where drilling is underway in the absence of 
any concurrent driving.
    During the proposed Year 2 activity, concurrent work utilizing a 
vibratory hammer during drilling operations is possible. This potential 
concurrent activity could occur during installation of the rock sockets 
for approximately 16 days. The vibratory hammer may be working to 
install SOE sheets or H-Pile as the drilling work is being conducted. 
Under concurrent driving conditions, the Navy will use the larger of 
the two source level values to calculate size of entire ensonified 
area. Since the vibratory source level is greater than the level 
associated with drilling, it will be utilized.
    With limited source level data available for vibratory pile 
extraction of 24-inch steel sheet piles, NMFS used the same values for 
both vibratory installation and extraction assuming that the two 
activities would produce similar source levels if water depth, pile 
size, and equipment remain constant.
    When NMFS Technical Guidance (2016) was published, in recognition 
of the fact that ensonified area/volume could be more technically 
challenging to predict because of the duration component in the new 
thresholds, an User Spreadsheet was developed that includes tools to 
help predict a simple

[[Page 56807]]

isopleth that can be used in conjunction with marine mammal density or 
occurrence to help predict takes. We note that because of some of the 
assumptions included in the methods used for these tools, we anticipate 
that isopleths produced are typically going to be overestimates of some 
degree, which will result in some degree of overestimate of Level A 
take. However, these tools offer the best way to predict appropriate 
isopleths when more sophisticated 3D modeling methods are not 
available, and NMFS continues to develop ways to quantitatively refine 
these tools, and will qualitatively address the output where 
appropriate. For stationary sources pile driving, NMFS User Spreadsheet 
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 and the resulting isopleths 
are reported below in Table 9 and Table 10.

                                               Table 9--Table Input for Level A Isopleth PTS Calculations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                               25'' steel sheet
       User spreadsheet input          14'' steel H impact      14'' steel vibro       15'' timber vibro            vibro                 Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...............  (E.1) Impact pile       (A) Non-Impulsive,      (A) Non-Impulsive,     (A) Non-Impulsive,     (A) Non-Impulsive,
                                      driving.                Stationary,             Stationary,            Stationary,            Stationary,
                                                              Continuous.             Continuous.            Continuous.            Continuous.
Source Level (Single Strike/shot     171 SEL...............  148 rms...............  150 rms..............  163..................  154 rms.
 SEL).
Weighting Factor Adjustment (kHz)..  2.....................  2.5...................  2.5..................  2.5..................  2.5.
Number of strikes per pile.........  160...................  NA....................  NA...................  NA...................  NA.
Activity duration within 24-h        4 piles...............  4 hours...............  4 hours..............  4 hours..............  8 hours.
 period OR number of piles per day.
Propagation (xLogR)................  15LogR................  15LogR................  15LogR...............  15LogR...............  15LogR.
Distance of source level             10....................  10....................  16...................  10...................  10.
 measurement (meters)+.
--------------------------------------------------------------------------------------------------------------------------------------------------------


  Table 10--User Spreadsheet Output for Level A Isopleth and Ensonified
                          Area PTS Calculations
------------------------------------------------------------------------
                                              PTS Isopleth
                               -----------------------------------------
          Source type             High-frequency
                                    cetaceans         Phocid pinnipeds
------------------------------------------------------------------------
14'' Steel H Impact...........  140 m............  63 m.
14'' Steel Vibro..............  3.5 m............  1.4 m.
15'' Timber Vibro.............  7.5 m............  1.9 m.
25'' Steel Sheet Vibro........  34.6 m...........  14.2 m.
Drilling (8 hours/day) within   54.9 m...........  22.6 m.
 Shutdown Zone * utilizing 163
 dB rms value.
------------------------------------------------------------------------
                          Daily Ensonified Area
------------------------------------------------------------------------
14'' Steel H Impact...........  0.0615 km\2\.....  0.0125 km\2\.
14'' Steel H Vibro............  38.46 m\2\.......  6.15 m\2\.
15'' Timber Vibro.............  179.9 m\2\.......  11.33 m\2\.
25'' Steel Sheet Vibro........  0.0038 km\2\.....  0.00062 km\2\.
Drilling (8 hours/day) within   0.0095 km\2\.....  0.0016 km\2\.
 Shutdown Zone * utilizing 163
 dB rms value.
------------------------------------------------------------------------
* While 154 dB rms is shown for drilling activity source level, take
  estimates and calculation of the ensonified area have been based on
  163 dB rms (vibratory drilling) as these activities may run
  concurrently.

    Using the same source level and transmission loss inputs discussed 
in the Level A isopleths section above, the Level B distance was 
calculated for both impact and vibratory driving (Table 11). The 
attenuation distance for impact hammer use associated with the 
installation of the sister pile/support pile with a source level of 182 
dB rms resulted in an isopleth of 293 meters (m). The attenuation 
distance for vibratory hammer use with a source level of 163 dB rms 
resulted in an isopleth of 7.35 kilometers (km). The Level B area 
associated with the 120-dB isopleth for vibratory driving and which is 
used in the take calculations is 0.9445 square kilometers (km\2\). Note 
that these attenuation distances are based on sound characteristics in 
open water. The project area is located in a river surrounded by 
topographic features. Therefore, the actual attenuation distances are 
constrained by numerous land features and islands.

              Table 11--Pile-Driving Sound Exposure Distances (In-Water) Level B Zone of Influence
----------------------------------------------------------------------------------------------------------------
                                    Behavioral thresholds
         Drilling activity            for cetaceans and      Propagation model       Attenuation distance to
                                          pinnipeds                                         threshold
----------------------------------------------------------------------------------------------------------------
Vibratory Hammer..................  120 dB rms...........  Practical Spreading   7.35 km (4.57 mi).
                                                            Loss.
Impact Hammer (rms)...............  160 dB rms...........  Practical Spreading   293 m (961 ft).
                                                            Loss.
----------------------------------------------------------------------------------------------------------------


[[Page 56808]]

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. For all species, the best scientific information 
available was considered for use in the marine mammal take assessment 
calculations. Density information was taken from the Navy Marine Mammal 
Density Database as shown in Table 12. (Craine 2015; Krause 2015). 
These data are generally used for broad-scale offshore activities; 
however, due to a lack of any other data within the general project 
area, these data are presented as the best available data for the 
Piscataqua River.

          Table 12--Marine Mammal Species Potentially Present in the Piscataqua River Near the Shipyard
----------------------------------------------------------------------------------------------------------------
                                                                        Approximate density in the vicinity  of
                                     Relative                          the project area  (individuals per km\2\)
            Species               occurrence in       Season(s) of                        \1\
                                 Piscataqua River      occurrence    -------------------------------------------
                                                                        Winter     Spring     Summer      Fall
----------------------------------------------------------------------------------------------------------------
Harbor Porpoise Gulf of Maine/  Occasional use...  Spring to Fall        1.2122     1.1705     0.7903     0.9125
 Bay of Fundy stock.                                (April to
                                                    December).\2\
Gray Seal Western North         Common...........  Year-round.......     0.2202     0.2202     0.2202     0.2202
 Atlantic stock.
Harbor Seal Western North       Common...........  Year-round.......     0.1998     0.1998     0.1998     0.1998
 Atlantic stock.
Harp Seal Western North         Rare.............  Winter to Spring      0.0125     0.0125     0.0125     0.0125
 Atlantic stock.                                    (January-May).
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ Density data are taken from the Navy Marine Species Density Database (Crain 2015; Krause 2015).
\2\ Densities shown for all seasons, even when species are unlikely to occur in the river.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    The following assumptions are made when estimating potential 
incidences of take:
     All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
     An individual can only be taken once during a 24-h period;
     While up to 16 days of concurrent driving/drilling could 
occur, NMFS will conservatively assume that there are zero (0) days 
resulting in a total of 100 pile driving/drilling days; and
     Exposures to sound levels at or above the relevant 
thresholds equate to take, as defined by the MMPA.
    In this case, the estimation of marine mammal takes uses the 
following calculation:

Exposure estimate = n * ZOI * days of total activity

Where:

n = density estimate used for each species/season.
ZOI = sound threshold ZOI area; the area encompassed by all 
locations where the SPLs equal or exceed the threshold being 
evaluated.

    The ZOI impact area is estimated using the relevant distances in 
Table 10 and Table 11, assuming that sound radiates from a central 
point in the water column at project site and taking into consideration 
the possible affected area due to topographical constraints of the 
action area (i.e., radial distances to thresholds are not always 
reached) as shown in Figure 6-1 in the application.
    There are a several reasons why estimates of potential incidents of 
take may be conservative, assuming that available density and estimated 
ZOI areas are accurate. We assume, in the absence of information 
supporting a more refined conclusion, that the output of the 
calculation represents the number of individuals that may be taken by 
the specified activity. In fact, in the context of stationary 
activities such as pile driving and in areas where resident animals may 
be present, this number more realistically represents the number of 
incidents of take that may accrue to a smaller number of individuals. 
While pile driving can occur any day throughout the period of validity, 
and the analysis is conducted on a per day basis, only a fraction of 
that time (typically a matter of hours on any given day) is actually 
spent pile driving. The potential effectiveness of mitigation measures 
in reducing the number of takes is typically not quantified in the take 
estimation process. For these reasons, these take estimates may be 
conservative.

Harbor Porpoise

    Harbor porpoises may be present in the project area year-round. 
Based on density data from the Navy Marine Species Density Database, 
their presence is highest in winter and spring, decreases in summer, 
and slightly increases in fall. However, in general, porpoises are 
known to occasionally occur in the river. Average density for the 
predicted seasons of occurrence was used to determine abundance of 
animals that could be present in the area for exposure, using the 
equation abundance = n * ZOI. Estimated abundance estimate for harbor 
porpoises was 0.96 animals generated from the equation (0.9445 km\2\ 
Level B ensonified area *1.02 animals/km\2\). The number of Level B 
harbor porpoise exposures within the ZOIs is (100 days * 0.96 animals/
day) is 96. Therefore, NMFS proposed 96 Level B takes of harbor 
porpoise.
    The injury zone for harbor porpoise was calculated to extend to a 
radius of 140 m from impact driven piles and a maximum of 55 m from 
vibratory or drilling activity. A 75-m shutdown zone is proposed (see 
``Proposed Mitigation''); therefore, the area between the 75 m and 140 
m isopleths is where Level A take may occur during impact hammer use. 
The area of the 75 m shutdown zone was subtracted from the full Level A 
injury zone to obtain the Level A take zone, 0.0132 km\2\. The density 
of harbor porpoises is estimated at 1.02 harbor porpoises/km\2\. Using 
the density of harbor porpoises potentially present (1.02 animal/km\2\) 
and the area of the Level A take zone, less than one (0.1218 mammals) 
harbor porpoise a day was estimated to be exposed to injury over the 
nine days of impact pile driving. Therefore, we assume that one harbor 
porpoise could be exposed to injurious noise levels during impact pile 
driving.

Harbor Seal

    Harbor seals may be present year-round in the project vicinity, 
with constant densities throughout the year. Based on local anecdotal 
data, harbor seals are the most common pinniped in the Piscataqua River 
near the Shipyard. Average density for the predicted seasons of 
occurrence was used to determine abundance of animals that could be 
present in the area for exposure, using the equation abundance = n * 
ZOI. Abundance for harbor seals were 0.19/day. (Average year-round 
density = 0.1998). Therefore, Level B harbor seal exposures within the 
ZOI is (100 days * 0.19 animals/day) would be up to 19 Level B 
exposures of harbor

[[Page 56809]]

seals within the ZOI. As described above in the gray seal section, 
however, the modeling of estimated takes may be underestimated. The 
data from the preliminary monitoring report indicated 120 Level B 
exposures of harbor seals over 73 work days resulting in 1.64 takes per 
day (120 takes/73 days). Therefore, NMFS is proposing to authorize 164 
Level B harbor seal takes (1.64 takes/day * 100 days).
    The injury zone for harbor seals was calculated to extend a radius 
of 63 m from impact driven piles and 14m for vibratory hammer use. The 
injury zone for drilling activity is estimated at 23 m. The Level A 
injury zone is within the shutdown zone, therefore no injurious takes 
of harbor seals are estimated to occur. However, as stated above for 
the gray seal take request, this may be an underestimate. The Navy has 
requested four Level A takes of harbor seal to coincide with the same 
number of Level A takes requested in Year 1. Preliminary monitoring 
report results support authorization of Level A take as one harbor seal 
was detected within 50 m of drilling activity. Therefore, NMFS is 
conservatively proposing four Level A takes of harbor seals so that 
operations will not have to be suspended due to exceeding authorized 
Level A takes.

Gray Seal

    Gray seals are less common in the Piscataqua River than the harbor 
seal. Average density for the predicted seasons of occurrence was used 
to determine abundance of animals that could be present in the area for 
exposure, using the equation abundance = n * ZOI. The estimated 
abundance for gray seals is 0.21/day (average year-round density = 
0.2202). Therefore, the number of Level B gray seal exposures within 
the ZOI is (100 days * 0.21 animals/day) resulting in up to 21 Level B 
exposures of gray seals within the ZOI.
    However, current monitoring data indicate that this could be an 
underestimate. While there could be 21 Level B and 0 Level A takes for 
gray seal during construction activity monitoring of the zones, 
observations of gray seals have shown 18 Level B exposures over 73 days 
of activity through October 27, 2017. This comes out to 0.246 exposures 
per day (18/73 = 0.246). Therefore, the Navy has requested and NMFS is 
proposing to authorize 25 gray seal takes (0.246 takes/day * 100 days) 
under the proposed IHA.
    The injury zone for gray seals was calculated to extend to a radius 
of 63m for impact driven piles and 14m for vibratory hammer use. 
Drilling activity is estimated at 23m from the activity. The injury 
zone for impact, vibratory and drilling activity remains within the 
shutdown zone of 75m for impact hammer use and 55 m for vibratory 
driving and drilling (see ``Proposed Mitigation''). These zones were 
utilized during Year 1. Based on these calculations and continued 
implementation of the shutdown zones, no injurious takes of gray seals 
are estimated to occur. The Navy, however, requests authorization of 
two Level A takes of gray seal to coincide with the same number of 
Level A takes requested in Year 1. This is partially supported by data 
collected in the preliminary Year 1 IHA monitoring report in which 
observers recorded one gray seal within 50 m of drilling activity. 
Because animals were observed within the shutdown zone during Year 1, 
NMFS is conservatively proposing authorization of two Level A gray seal 
takes, so that operations will not have to be suspended if animals 
unexpectedly occur in the Level A zones.

Harp Seal

    Harp seals may be present in the project vicinity during the winter 
and spring, from January through February. In general, harp seals are 
much rarer than the harbor seal and gray seal in the Piscataqua River. 
These animals are conservatively assumed to be present within the 
underwater Level B ZOI during each day of in-water pile driving. 
Average density for the predicted seasons of occurrence was used to 
determine abundance of animals that could be present in the area for 
exposure, using the equation abundance = n * ZOI. Abundance for harp 
seals was 0.014/day (average year-round density = 0.0125). The number 
of Level B harp seal exposures within the ZOI is (100 days * 0.0125 
animals/day) resulting in approximately 1 Level B exposure. Therefore, 
NMFS is proposing to authorize Level B take of 1 harp seal.
    The injury zone for harp seals was calculated to extend a radius of 
63m from impact driven piles and 14m for vibratory hammer use. Drilling 
activity is estimated at 23 m from the activity. These isopleths are 
within the shutdown zones and NMFS. Therefore, no Level A take is 
proposed as shown in Table 14.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned); and
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost and impact on 
operations.

Mitigation for Marine Mammals and Their Habitat

    The mitigation strategies described below are similar to those 
required and implemented under the first IHA associated with this 
project. In addition to the measures described later in this section, 
the Navy would conduct briefings between construction supervisors and 
crews, marine mammal monitoring team, and Navy staff prior to the start 
of all pile driving activity, and when new personnel join the work, in 
order to explain responsibilities, communication procedures, marine 
mammal monitoring protocol, and operational procedures.
    The following measures would apply to the Navy's mitigation through 
shutdown and disturbance zones:
    Time Restrictions--Pile driving/removal (vibratory as well as 
impact) will only be conducted during daylight hours so that marine 
mammals can be adequately monitored to determine if mitigation measures 
are to be implemented.

[[Page 56810]]

    Establishment of Shutdown Zone--During pile driving and removal, 
shutdown zones shall be established to prevent injury to marine mammals 
as determined under acoustic injury thresholds. During all pile driving 
and removal activities, regardless of predicted sound pressure levels 
(SPLs), the entire shutdown zone will be monitored to prevent injury to 
marine mammals from their physical interaction with construction 
equipment during in-water activities. The shutdown zone during impact 
driving will extend to 75 m for all authorized species. The shutdown 
during vibratory driving and drilling will extend to 55 m for all 
authorized species. Pile driving and removal operations will cease if a 
marine mammal approaches the shutdown zone. Pile driving and removal 
operations will restart once the marine mammal is visibly seen leaving 
the zone or after 15 minutes have passed with no sightings.
    Establishment of Level A Harassment Zone--The Level A harassment 
zone is an area where animals may be exposed to sound levels that could 
result in PTS injury. The primary purpose of the Level A zone is 
monitoring for documenting incidents of Level A harassment. The Level A 
zones will extend from the 75 m shutdown zone out to 140 m for harbor 
porpoises. Animals observed in the Level A harassment zone will be 
recorded as potential Level A takes.
    Establishment of Disturbance/Level B Harassment Zone--During pile 
driving and removal, the Level B zone shall include areas where the 
underwater SPLs are anticipated to equal or exceed the Level B 
harassment criteria for marine mammals (160 dB rms isopleths for impact 
pile driving, 120 dB rms isopleth for vibratory pile-driving and 
drilling). The Level B zone will extend out to 293 m for impact driving 
and 7.35 km during vibratory driving and drilling and will include all 
waters in the sight line of the driving or drilling operation not 
constrained by land.
    Shutdown Zone During Other In-Water Construction or Demolition 
Activities--During all in-water construction or demolition activities 
having the potential to affect marine mammals, in order to prevent 
injury from physical interaction with construction equipment, a 
shutdown zone 10 m will be implemented to ensure marine mammals are not 
present within this zone. These activities could include, but are not 
limited to: (1) The movement of a barge to the construction site, or 
(2) the removal of a pile from the water column/substrate via a crane 
(i.e., a ``dead pull'').
    Soft Start for Impact Pile Driving--The use of a soft-start 
procedure is believed to provide additional protection to marine 
mammals by providing a warning and/or giving marine mammals a chance to 
leave the area prior to the hammer operating at full capacity. The 
project will use soft-start techniques recommended by NMFS for impact 
pile driving. Soft start must be conducted at beginning of day's 
activity and at any time impact pile driving has ceased for more than 
30 minutes. If an impact hammer is used, contractors are required to 
provide an initial set of three strikes from the impact hammer at 40 
percent energy, followed by a 1-minute waiting period, then two 
subsequent 3-strike sets.
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving activities. In addition, observers shall record 
all incidents of marine mammal occurrence, regardless of distance from 
activity, and shall document any behavioral reactions in concert with 
distance from piles being driven. Observations made outside the 
shutdown zone will not result in shutdown; that pile segment would be 
completed without cessation, unless the animal approaches or enters the 
shutdown zone, at which point all pile driving activities would be 
halted. Monitoring will take place from 15 minutes prior to initiation 
through 30 minutes post-completion of pile driving activities. Pile 
driving activities include the time to remove a single pile or series 
of piles, as long as the time elapsed between uses of the pile driving 
equipment is no more than 30 minutes.
    Monitoring will be conducted within the Level A harassment shutdown 
zone during all pile-driving operations and the Level B harassment 
buffer zone during two-thirds of pile-driving days. If a marine mammal 
is observed approaching a Level A zone, operations will be shut down. 
If an animal is seen entering the Level B harassment zone, an exposure 
would be recorded and behaviors documented. The Navy will extrapolate 
data collected during monitoring days and calculate total takes for all 
pile-driving days.
    Prior to the start of pile driving activity, the shutdown zone will 
be monitored for 15 minutes to ensure that it is clear of marine 
mammals. Pile driving will only commence once observers have declared 
the shutdown zone clear of marine mammals; animals will be allowed to 
remain in the shutdown zone (i.e., must leave of their own volition) 
and their behavior will be monitored and documented. The shutdown zone 
may only be declared clear, and pile driving started, when the entire 
shutdown zone is visible (i.e., when not obscured by dark, rain, fog, 
etc.). In addition, if such conditions should arise during impact pile 
driving that is already underway, the activity would be halted.
    If a marine mammal approaches or enters the shutdown zone during 
the course of pile driving operations, activity will be halted and 
delayed until either the animal has voluntarily left and been visually 
confirmed beyond the shutdown zone or 15 minutes have passed. 
Monitoring will be conducted throughout the time required to drive a 
pile and for 30 minutes following the conclusion of pile driving.
    Based on our evaluation of the applicant's proposed measures NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable 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 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);

[[Page 56811]]

     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Observers shall record all incidents of marine mammal occurrence, 
regardless of distance from activity, and shall document any behavioral 
reactions in concert with distance from piles being driven or removed. 
Pile driving activities include the time to install or remove a single 
pile or series of piles, as long as the time elapsed between uses of 
the pile driving equipment is no more than 30 minutes.
    Marine mammal monitoring will include the following:
    A minimum of two marine mammal observers (MMOs) will be on location 
during two-thirds of all pile driving/removal days. They will be placed 
at the best vantage point(s) practicable to monitor for marine mammals 
and implement shutdown/delay procedures when applicable by calling for 
the shutdown to equipment operators. The observer will be trained on 
the observation zones, potential species, how to observe, and how to 
fill out the data sheets by the Navy Natural Resources Manager prior to 
any pile-driving activities. The supervisory observer will be a trained 
biologist; additional observers will be trained by that supervisor as 
needed.
    Shutdown zones must be monitored at all times. When MMOs are not 
available during one-third of pile driving/removal days, project 
contractors/workers will be responsible for monitoring shutdown zones 
and will call for shutdown as appropriate. The following additional 
measures apply to visual monitoring during the \2/3\ of days on which 
MMOs are present:
     Independent observers (i.e., not construction personnel) 
are required;
     At least one observer must have prior experience working 
as an observer;
     Other observers (that do not have prior experience) may 
substitute education (undergraduate degree in biological science or 
related field) or training for experience;
     NMFS will require submission and approval of observer 
resumes.
    Qualified observers are trained biologists with the following 
minimum qualifications:
     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;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     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 and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior; and
     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.
    Monitoring will be conducted within the Level A harassment and 
shutdown zone during all pile-driving operations and the Level B 
harassment buffer zone during two-thirds of pile-driving days. 
Monitoring will take place from 15 minutes prior to initiation through 
30-minutes post-completion of pile-driving/removal activities.
     During pile removal or installation the observers will 
monitor the shutdown zones to record take when marine mammals enter the 
relevant Level B harassment zones based on type of construction 
activity.
     Prior to the start of pile-driving/removal activity, the 
shutdown and safety zones will be monitored for 15 minutes to ensure 
that they are clear of marine mammals. Pile driving will only commence 
once observers have declared the shutdown zone clear of marine mammals; 
if present, animals will be allowed to remain in the ZOI and their 
behavior will be monitored and documented.
     In the unlikely event of conditions that prevent the 
visual detection of marine mammals, such as heavy fog, activities with 
the potential to result in Level A or Level B harassment will not be 
initiated. Impact pile driving would be curtailed, but vibratory pile 
driving or extraction would be allowed to continue if such conditions 
arise after the activity has begun.
    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities or 60 days prior to the issuance of any subsequent IHA for 
this project, whichever comes first. It will include an overall 
description of work completed, a narrative regarding marine mammal 
sightings, and associated marine mammal observation data sheets. 
Specifically, the report must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as serious injury or mortality, the Navy will 
immediately cease the specified activities and report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the Northeast/Greater Atlantic Regional Stranding 
Coordinator. The report would include the following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the

[[Page 56812]]

circumstances of the prohibited take. NMFS would work with the Navy to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. The Navy would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that the Navy discovers an injured or dead marine 
mammal, and the lead MMO determines that the cause of the injury or 
death is unknown and the death is relatively recent (e.g., in less than 
a moderate state of decomposition as described in the next paragraph), 
the Navy would immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
and the Northeast/Greater Atlantic Regional Stranding Coordinator. The 
report would include the same information identified in the paragraph 
above. Activities would be able to continue while NMFS reviews the 
circumstances of the incident. NMFS would work with the Navy to 
determine whether modifications in the activities are appropriate.
    In the event that the Navy discovers an injured or dead marine 
mammal and the lead MMO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the Navy would report the incident 
to the Chief of the Permits and Conservation Division, Office of 
Protected Resources, NMFS, and the Northeast/Greater Atlantic Regional 
Stranding Coordinator within 24 hours of the discovery. The Navy would 
provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Network.

Hydroacoustic Monitoring

    The Navy will continue to implement its in situ acoustic monitoring 
efforts in 2018. During Year 2, the Navy will verify acoustic 
monitoring at the source (33 feet) and, where the potential for Level A 
harassment exists, at a second representative monitoring location at an 
intermediate distance between the cetacean and pinniped shutdown zones. 
A draft hydroacoustic monitoring plan will be submitted to NMFS for 
approval. A final report will be submitted to NMFS within 30 days of 
completing the verification monitoring. Results from the 2017 
Hydroacoustic Monitoring Report may be found in Appendix A of the 
application.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Pile driving, pile extraction and drilling activities associated 
with the Navy project as outlined previously have the potential to 
injure, disturb or displace marine mammals. Specifically, the specified 
activities may result in Level B harassment (behavioral disturbance) 
for all species authorized for take from underwater sound generated 
during pile driving. Level A harassment in the form of PTS may also 
occur to limited numbers of three marine mammal species. Potential 
takes could occur if individuals of these species are present in the 
ensonified zone when pile driving and removal occurs.
    No serious injury or mortality is anticipated given the nature of 
the activities and measures designed to minimize the possibility of 
injury to marine mammals. The potential for these outcomes is minimized 
through the construction method and the implementation of the planned 
mitigation measures. Specifically, vibratory driving and drilling will 
be the primary methods of installation (impact driving will occur for 
only 1.5 hours over 84-100 days). During impact driving, implementation 
of soft start and shutdown zones significantly reduces any possibility 
of injury. Given sufficient ``notice'' through use of soft start (for 
impact driving), marine mammals are expected to move away from a sound 
source that is annoying prior to it becoming potentially injurious. 
Conditions at the Shipyard offer MMOs clear views of the shutdown 
zones, enabling a high rate of success in implementation of shutdowns 
to avoid injury.
    The Navy's planned activities are highly localized. A small portion 
of the Piscataqua River may be affected which is only a subset of the 
ranges of species for which take is authorized. The project is not 
expected to have significant adverse effects on marine mammal habitat. 
No important feeding and/or reproductive areas for marine mammals are 
known to be near the project area. Project-related activities may cause 
some fish to leave the area of disturbance, thus temporarily impacting 
marine mammals' foraging opportunities in a limited portion of the 
foraging range, but because of the relatively small area of the habitat 
range utilized by each species that may be affected, the impacts to 
marine mammal habitat are not expected to cause significant or long-
term negative consequences.
    Exposures to elevated sound levels produced during pile driving 
activities may cause behavioral responses by an animal, but they are 
expected to be mild and temporary. Effects on individuals that are 
taken by Level B harassment, 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; Lerma, 2014). Most likely, individuals 
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. These reactions and behavioral changes are expected to subside 
quickly when the exposures cease. The pile driving activities analyzed 
here are similar to, or less impactful than, numerous construction 
activities conducted in other similar locations, which have taken place 
with no reported injuries or mortality to marine mammals, and no known 
long-term adverse consequences

[[Page 56813]]

from behavioral harassment. Repeated exposures of individuals to levels 
of sound that may cause Level B harassment are unlikely to result in 
permanent hearing impairment or to significantly disrupt foraging 
behavior. Level B harassment will be reduced through use of mitigation 
measures described herein.
    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:
     No mortality or serious injury is anticipated or 
authorized;
     The area of potential impacts is highly localized;
     No adverse impacts to marine mammal habitat;
     The absence of any significant habitat within the project 
area, including rookeries, or known areas or features of special 
significance for foraging or reproduction;
     Anticipated incidences of Level A harassment would be in 
the form of a small degree of PTS to a limited number of animals;
     Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior;
     Very few individuals are likely to be affected by project 
activities (<0.01 percent of population for all authorized species); 
and
     The anticipated efficacy of the required mitigation 
measures in reducing the effects of the specified activity.
    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 Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and 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. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.

  Table 14--Estimated Number of Exposures and Percentage of Stocks That May Be Subjected to Level A and Level B
                                                   Harassment
----------------------------------------------------------------------------------------------------------------
                                                                     Proposed authorized take
                             Species                             --------------------------------  % Population
                                                                      Level B         Level A
----------------------------------------------------------------------------------------------------------------
Harbor porpoise.................................................              96               1           <0.01
Gray Seal.......................................................              25               2           <0.01
Harbor Seal.....................................................             164               4           <0.01
Harp Seal.......................................................               1               0           <0.01
----------------------------------------------------------------------------------------------------------------

    Table 14 illustrates the number of animals that could be exposed to 
Level A and Level B harassment from work associated with the waterfront 
improvement project. The analysis provided indicates that authorized 
takes account for <0.01 percent of the populations of the stocks that 
could be affected. These are small numbers of marine mammals relative 
to the sizes of the affected species and population stocks under 
consideration.
    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.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure 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.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that consultation under section 7 of the ESA is not 
required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the Navy for conducting in-water construction 
activities at the Portsmouth Naval Shipyard in Kittery, Maine from 
January 1, 2018 through December 31, 2018 provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. This section contains a draft of the IHA itself. The 
wording contained in this section is proposed for inclusion in the IHA 
(if issued).
    1. This Incidental Harassment Authorization (IHA) is valid from 
January 1, 2018 through December 31, 2018. This IHA is valid only for 
pile driving, extraction, and drilling activities associated with the 
waterfront improvements project at the Shipyard.
    2. General Conditions.
    (a) A copy of this IHA must be in the possession of the Navy, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are the harbor porpoise 
(Phocoena phocoena), gray seal (Halichoerus grypus), harbor seal (Phoca 
vitulina), and harp seal (Pagophilus groenlandicus).
    (c) The taking, by Level A and Level B harassment, is limited to 
the species listed in condition 2(b). See Table 14 for numbers of Level 
A and Level B take authorized.
    (d) The take of any other species not listed in condition 2(b) of 
marine mammal is prohibited and may result in

[[Page 56814]]

the modification, suspension, or revocation of this IHA.
    (e) The Navy shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, acoustical 
monitoring team prior to the start of all pile driving activities, and 
when new personnel join the work, in order to explain responsibilities, 
communication procedures, marine mammal monitoring protocol, and 
operational procedures.
    3. Mitigation Measures.
    The holder of this Authorization is required to implement the 
following mitigation measures.
    (a) Time Restriction: For all in-water pile driving activities, the 
Navy shall operate only during daylight hours.
    (b) Pile driving shall only take place when the shutdown and Level 
A zones are visible and can be adequately monitored. If conditions 
(e.g., fog) prevent the visual detection of marine mammals, activities 
with the potential to result in Level A harassment (i.e., impact 
driving) shall not be initiated. If such conditions arise after the 
activity has begun, impact pile driving shall be halted but vibratory 
pile driving or extraction is allowed to continue.
    (c) Establishment of Shutdown Zones.
    (i) The shutdown zone during impact driving shall extend to 75 m 
for all authorized species. The shutdown during vibratory driving or 
drilling shall extend to 55 m for all authorized species.
    (ii) If a marine mammal comes within or approaches the shutdown 
zone, pile driving operations shall cease.
    (iii) Pile driving and removal operations shall restart once the 
marine mammal is visibly seen leaving the zone or after 15 minutes have 
passed with no sightings.
    (iii) For in-water heavy machinery work other than pile driving 
(using, e.g., standard barges, tug boats), if a marine mammal comes 
within 10 m, operations shall cease and vessels shall reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions.
    (iv) Shutdown shall occur if a species for which authorization has 
not been granted or for which the authorized numbers of takes have been 
met approaches or is observed within the Level B harassment zone. The 
Navy shall then contact NMFS within 24 hours.
    (d) Establishment of Level A and B Harassment Zones.
    (i) The Level A take zones shall extend from the 75 m shutdown zone 
out to 140 m for harbor porpoises during all impact pile driving 
activities.
    (ii) The Level B take zones shall extend from the 55 m shutdown 
zone out to 293 m during impact driving activities and from 55 m out to 
7.35 km during vibratory driving activities.
    (e) Use of Soft-Start for Impact Pile Driving.
    (i) The project shall utilize soft start techniques for impact pile 
driving. The Navy shall conduct an initial set of three strikes from 
the impact hammer at 40 percent energy, followed by a 1-minute waiting 
period, then two subsequent three strike sets. Soft start shall be 
required for any impact driving, including at the beginning of the day, 
and at any time following a cessation of impact pile driving of 30 
minutes or longer.
    4. Monitoring.
    The holder of this Authorization is required to conduct visual 
marine mammal monitoring and acoustic monitoring during pile driving 
activities.
    (a) Visual Marine Mammal Observation--The Navy shall collect 
sighting data and behavioral responses to pile driving for marine 
mammal species observed in the region of activity during the period of 
activity. Visual monitoring shall include the following:
    (i) A minimum of two marine mammal observers (MMOs) shall be in 
place during two-thirds of pile driving days.
    (ii) Shutdown zones shall be monitored at all times. When MMOs are 
not on-site during one-third of pile driving/removal days, project 
contractors/workers shall be responsible for monitoring shutdown zones 
and shall call for shutdown as appropriate.
    (iii) Monitoring shall take place from 15 minutes prior to 
initiation of pile driving activity through 30 minutes post-completion 
of pile driving activity.
    (iv) MMOs shall be placed at the best vantage point(s) practicable 
to monitor for marine mammals during two-thirds of all pile driving 
days.
    (b) The following additional measures apply to visual monitoring 
during two-thirds of all pile driving days:
    (i) Independent observers (i.e., not construction personnel) are 
required;
    (ii) At least one observer must have prior experience working as an 
observer;
    (iii) Other observers (that do not have prior experience) may 
substitute education (undergraduate degree in biological science or 
related field) or training for experience;
    (iv) NMFS shall require submission and approval of observer 
resumes.
    (v) 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;
    (vi) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (vii) 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 and times when in-water construction activities were 
suspended to avoid potential incidental injury from construction sound 
of marine mammals observed within a defined shutdown zone; and marine 
mammal behavior; and
    (viii) 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.
    (c) Hydroacoustic Monitoring.
    (i) During Year 2, the Navy shall verify acoustic monitoring at the 
source (33 feet) and, where the potential for Level A harassment 
exists, at a second representative monitoring location at an 
intermediate distance between the cetacean and pinniped shutdown zones.
    (ii) A draft hydroacoustic monitoring plan shall be submitted to 
NMFS for approval.
    (iii) A final report shall be submitted to NMFS within 30 days of 
completing the verification monitoring.
    5. Reporting.
    (a) A draft marine mammal monitoring report shall be submitted to 
NMFS within 90 days after the completion of pile driving and removal 
activities or 60 days prior to the issuance of any subsequent IHA for 
this project, whichever comes first. The report shall include an 
overall description of work completed, a narrative regarding marine 
mammal sightings, and associated marine mammal observation data sheets. 
Specifically, the report shall include.
    (i) Date and time that monitored activity begins or ends;
    (ii) Construction activities occurring during each observation 
period;
    (iii) Weather parameters (e.g., percent cover, visibility);
    (iv) Water conditions (e.g., sea state, tide state);
    (v) Species, numbers, and, if possible, sex and age class of marine 
mammals;
    (vi) Description of any observable marine mammal behavior patterns, 
including bearing and direction of travel and distance from pile 
driving activity;
    (vii) Distance from pile driving activities to marine mammals and

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distance from the marine mammals to the observation point;
    (viii) Locations of all marine mammal observations; and
    (ix) Other human activity in the area.
    (b) Reporting injured or dead marine mammals:
    (i) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA, 
such as serious injury, or mortality, the Navy shall immediately cease 
the specified activities and report the incident to the Office of 
Protected Resources, NMFS, and the Northeast/Greater Atlantic Regional 
Stranding Coordinator, NMFS. The report must include the following 
information:
    (1) Time and date of the incident;
    (2) Description of the incident;
    (3) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (4) Description of all marine mammal observations and active sound 
source use in the 24 hours preceding the incident;
    (5) Species identification or description of the animal(s) 
involved;
    (6) Fate of the animal(s); and
    (7) Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with the Navy to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The Navy may not 
resume their activities until notified by NMFS.
    (ii) In the event that the Navy discovers an injured or dead marine 
mammal, and the lead observer determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition), the Navy shall immediately 
report the incident to the Office of Protected Resources, NMFS, and the 
Northeast/Greater Atlantic Regional Stranding Coordinator, NMFS.
    The report must include the same information identified in 5(b)(i) 
of this IHA. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS shall work with the Navy to 
determine whether additional mitigation measures or modifications to 
the activities are appropriate.
    (iii) In the event that the Navy discovers an injured or dead 
marine mammal, and the lead observer determines that the injury or 
death is not associated with or related to the activities authorized in 
the IHA (e.g., previously wounded animal, carcass with moderate to 
advanced decomposition, or scavenger damage), the Navy shall report the 
incident to the Office of Protected Resources, NMFS, and the Northeast/
Greater Atlantic Regional Stranding Coordinator, NMFS, within 24 hours 
of the discovery. The Navy shall provide photographs or video footage 
or other documentation of the stranded animal sighting to NMFS.
    6. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    We request comment on our analyses, the draft authorization, and 
any other aspect of this Notice of Proposed IHA for proposed Waterfront 
Improvement Projects at Portsmouth Naval Shipyard. Please include with 
your comments any supporting data or literature citations to help 
inform our final decision on the request for MMPA authorization.

    Dated: November 24, 2017.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2017-25783 Filed 11-29-17; 8:45 am]
 BILLING CODE 3510-22-P