[Federal Register Volume 85, Number 245 (Monday, December 21, 2020)]
[Proposed Rules]
[Pages 83001-83026]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-27300]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 201207-0329]
RIN 0648-BJ90


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Navy Construction at Naval 
Station Norfolk in Norfolk, Virginia

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

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization to take marine mammals incidental to construction 
activities including marine structure maintenance, pile replacement, 
and select waterfront improvements at Naval Station Norfolk (NAVSTA 
Norfolk) over the course of five years (2021-2026). As required by the 
Marine Mammal Protection Act (MMPA), NMFS is proposing regulations to 
govern that take, and requests comments on the proposed regulations. 
NMFS will consider public comments prior to making any final decision 
on the issuance of the requested MMPA authorization and agency 
responses will be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than January 
20, 2021.

ADDRESSES: You may submit comments on this document, identified by 
NOAA-NMFS-2020-0154, by the following method:
     Electronic submission: Submit all electronic public 
comments via the Federal e-Rulemaking Portal. Go to 
www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2020-0154, click the 
``Comment Now!'' icon, complete the required fields, and enter or 
attach your comments.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address), confidential business information, 
or otherwise sensitive information submitted voluntarily by the sender 
will be publicly accessible. NMFS will accept anonymous comments (enter 
``N/A'' in the required fields if you wish to remain anonymous). 
Attachments to electronic comments will be accepted in Microsoft Word, 
Excel, or Adobe PDF file formats only.

FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Availability

    A copy of the Navy's application and any supporting documents, as 
well as a list of the references cited in this document, may be 
obtained online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-construction-naval-station-norfolk-norfolk-virginia. In case of problems accessing these documents, please call 
the contact listed above (see FOR FURTHER INFORMATION CONTACT).

Purpose and Need for Regulatory Action

    This proposed rule would establish a framework under the authority 
of the MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of 
take of marine mammals incidental to the Navy's construction activities 
including marine structure maintenance, pile replacement, and select 
waterfront improvements at NAVSTA Norfolk.
    We received an application from the Navy requesting five-year 
regulations and authorization to take multiple species of marine 
mammals. Take would occur by Level B harassment only incidental to 
impact and vibratory pile driving. Please see Background below for 
definitions of harassment.

Legal Authority for the Proposed Action

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs 
the Secretary of Commerce to allow, upon request, the incidental, but 
not intentional taking of small numbers of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region for up to five years 
if, after notice and public comment, the agency makes certain findings 
and issues regulations that set forth permissible methods of taking 
pursuant to that activity and other means of effecting the ``least 
practicable adverse impact'' on the affected species or stocks and 
their habitat (see the discussion below in the Proposed Mitigation 
section), as well as monitoring and reporting requirements. Section 
101(a)(5)(A) of the MMPA and

[[Page 83002]]

the implementing regulations at 50 CFR part 216, subpart I provide the 
legal basis for issuing this proposed rule containing five-year 
regulations, and for any subsequent letters of authorization (LOAs). As 
directed by this legal authority, this proposed rule contains 
mitigation, monitoring, and reporting requirements.

Summary of Major Provisions Within the Proposed Rule

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

Background

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

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the promulgation of 
regulations and subsequent issuance of an incidental take 
authorization) with respect to potential impacts on the human 
environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 of the Companion Manual for NOAA 
Administrative Order 216-6A, which do not individually or cumulatively 
have the potential for significant impacts on the quality of the human 
environment and for which we have not identified any extraordinary 
circumstances that would preclude this categorical exclusion. 
Accordingly, NMFS has preliminarily determined that the issuance of 
this proposed rule qualifies to be categorically excluded from further 
NEPA review.
    Information in the Navy's application and this document 
collectively provide the environmental information related to proposed 
issuance of these regulations and subsequent incidental take 
authorization for public review and comment. We will review all 
comments submitted in response to this document prior to concluding our 
NEPA process or making a final decision on the request for incidental 
take authorization.

Summary of Request

    In February 2020, NMFS received a request from the Navy for a 
proposed rule and LOA to take marine mammals incidental to construction 
activities including marine structure maintenance, pile replacement, 
and select waterfront improvements at NAVSTA Norfolk. NMFS reviewed the 
Navy's application, and the Navy provided an updated version addressing 
NMFS' questions and comments on May 22, 2020. The application was 
deemed adequate and complete and published for public review and 
comment on June 9, 2020 (85 FR 35267). We did not receive substantive 
comments on the NOR.
    The Navy requests authorization to take a small number of five 
species of marine mammals by Level B harassment only. Neither the Navy 
nor NMFS expects serious injury or mortality to result from this 
activity. The proposed regulations would be valid for five years (2021-
2026).

Description of Proposed Activity

Overview

    The Navy is proposing to conduct construction activities at NAVSTA 
Norfolk on the Naval Station, and at nearby facilities off of the lower 
Chesapeake Bay. The Navy's proposed activities include pile replacement 
at the Morale, Welfare and Recreation Marina, and installation of two 
new floating docks at the V-area. Both areas are located on the Naval 
Station. The Navy also proposes to conduct maintenance/repair 
activities at the Naval Station and neighboring Defense Fuel Supply 
Point Craney Island and Lambert's Point Deperming Station (see Figure 
1). The Navy has indicated specific projects where existing needs have 
been identified, as well as estimates for expected emergent or 
emergency repairs. The proposed project will include both vibratory 
pile driving and removal, and impact pile driving (hereafter, 
collectively referred to as ``pile driving'') over approximately 574 
days over five years.

Dates and Duration

    The proposed regulations would be valid for a period of five years 
(2021-2026). The specified activities may occur at any time during the 
five-year period of validity of the proposed regulations. The Navy 
expects pile driving across all sites to occur on approximately 574 
days over the five-year duration, with the greatest amount of work 
occurring during Year 1 (approximately 208 days). The Navy plans to 
conduct all work during daylight hours.

Specific Geographic Region

    NAVSTA Norfolk and the adjacent facilities where the Navy has 
proposed to conduct construction (Craney Island Fuel Depot and 
Lambert's Point Deperming Station) are located at the confluence of the 
Elizabeth River, James River, Nansemond River, LaFayette River, 
Willoughby Bay, and Chesapeake Bay (Figure 1).
    Human-generated sound is a significant contributor to the ambient 
acoustic environment surrounding NAVSTA Norfolk, as it is located in 
close proximity to shipping channels as well as several Port of 
Virginia facilities with frequent, noise-producing vessel traffic. 
NAVSTA Norfolk is located in close proximity to shipping channels as 
well as several Port of Virginia facilities that, altogether, have an 
annual average of 1,459 vessel calls (Port of Virginia,

[[Page 83003]]

2019). Other sources of human-generated underwater sound not specific 
to naval installations include sounds from echo sounders on commercial 
and recreational vessels, industrial ship noise, and noise from 
recreational boat engines. Additionally, on average, maintenance 
dredging of the Navigation Channel occurs every two years (USACE and 
Port of Virginia, 2018).
BILLING CODE 3510-22-P
[GRAPHIC] [TIFF OMITTED] TR21DE20.016

BILLING CODE 3510-22-C

Detailed Description of Specific Activity

    The Navy's existing waterfront inspection program identifies fender 
pile system deficiencies and prioritizes, designs, and conducts 
maintenance and repairs. The inspection program also addresses repairs 
(emergent projects) required due to unforeseen events such as weather 
and vessel incidents. Because construction details are unknown for all 
emergent projects, potential numbers of fender piles to be extracted 
and installed were estimated by Navy waterfront infrastructure 
engineers based on historic emergent

[[Page 83004]]

maintenance pile driving actions and scheduled/forecasted maintenance.
    The proposed action includes individual projects (where an existing 
need has been identified) and estimates for emergent or emergency 
repairs. The Navy proposes to conduct marine structure maintenance, 
pile replacement, and upgrades (MPU) activities over a five-year 
period. The Navy would also upgrade waterfront facilities at two areas.
Fender Pile Replacement: NAVSTA Norfolk Piers, Craney Island, and 
Lambert's Point
    All piles that the Navy plans to replace in the NAVSTA Norfolk 
Piers, Defense Fuel Supply Point (DFSP) Craney Island and Lambert's 
Point areas are fender piles. Fender piles (or guide piles) protect in-
water structures from direct contact with vessels and are not load-
bearing. In-water piles may be treated timber, pre-stressed concrete, 
high-density polyethylene (HDPE) plastic, or hollow core fiberglass. 
Existing timber fender piles would be replaced by either composite 
(HDPE or hollow core fiberglass) or timber fender piles (depending on 
availability of composite piles). Table 1 includes the number and types 
of fender piles to be removed and installed at each location during the 
five years of proposed MPU activities. Please see Figure 1-2 and Figure 
1-3 of the Navy's application for the detailed location of each pier. A 
full list of all pile replacement and removal in each year of the 
overall MPU project is provided in Appendix A of the Navy's 
application.

 Table 1--Fender Piles To Be Removed (12-inch [in] Timber Piles) and Installed (16-in Composite Piles) at NAVSTA Norfolk Piers, DFSP Craney Island, and
                                                                     Lambert's Point
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                 Location                             Pile type                2021            2022            2023            2024            2025
--------------------------------------------------------------------------------------------------------------------------------------------------------
NAVSTA Norfolk Piers......................  12-in Timber................             630             555             100             405             948
                                            16-in Composite.............             208             196               0             267             845
DFSP Craney Island........................  12-in Timber................             272               0               0               0               0
                                            16-in Composite.............             258               0               0               0               0
Lambert's Point Deperming Station.........  12-in Timber................              29               0               0               0               0
                                            16-in Composite.............              29               0               0               0               0
--------------------------------------------------------------------------------------------------------------------------------------------------------

Waterfront Improvements: Morale, Welfare, and Recreation (MWR) Marina 
and V-Area
    The MWR Marina features 200 deep-water slips, a boat ramp, and 
other recreational boating facilities (see Figure 1-2 of the Navy's 
application). Upgrades to the MWR Marina would consist of the 
replacement of timber load-bearing and guide piles with 24-by-24-in 
(61-by 61-cm) square pre-stressed concrete and composite or timber 
fender piles, respectively.
    The V-Area currently features a bulkhead, a breakwater, two 
floating piers, and a boat ramp (see Figure 1-2 of the Navy's 
application). Upgrades to this area would include the construction of 
two additional floating docks, for a total addition of approximately 
4,095 square feet (ft\2\) 380.4 square meters of dock space. These 
docks would be constructed using 24-by-24-in (61-by 61-cm) square pre-
stressed concrete for the load-bearing piles and composite or timber 
fender/guide piles.
    For the purposes of this assessment, the Navy assumed these 
upgrades would occur in Year 1, with maintenance replacements occurring 
thereafter. Concrete piles are anticipated to be fully impact driven. 
Composite piles are anticipated to be impact or vibratory driven 
depending on pile type--hollow core fiberglass piles may be impact or 
vibratory driven, while HDPE piles would be impact driven.
    The number of piles the Navy expects to remove and install are 
included in Table 2 and Table 3, respectively. The Navy does not plan 
to drive multiple piles concurrently.

          Table 2--Piles To Be Removed at MWR Marina and V-Area
------------------------------------------------------------------------
                                                             Number of
             Location                  Pile size/type        piles \1\
------------------------------------------------------------------------
MWR Marina........................  12-in timber........             100
                                    16-in composite.....              40
V-Area............................  16-in composite.....              40
------------------------------------------------------------------------
\1\ Includes piles for initial upgrade/construction as well as
  maintenance replacements over the five-year project span.


         Table 3--Piles To Be Installed at MWR Marina and V-Area
------------------------------------------------------------------------
                                                             Number of
             Location                  Pile size/type        piles \1\
------------------------------------------------------------------------
MWR Marina........................  24-by-24-in square                50
                                     concrete \2\.
                                    16-in composite \3\.              90
V-Area............................  24-by-24-in square                50
                                     concrete.
                                    16-in composite \3\.              90
------------------------------------------------------------------------
\1\ Includes piles for initial upgrade/construction as well as
  maintenance replacements over the five-year project span.
\2\ Concrete piles are anticipated to be fully impact driven.
\3\ The Navy may use timber piles if supply or funding issues prohibit
  the use of composite piles. However, as noted in Table 8, the sound
  source levels are expected to be the same for both pile types.


[[Page 83005]]

    In extracting piles, the Navy would primarily use a vibratory 
hammer. In cases where removal with a vibratory hammer is not possible 
because piles break or are damaged, a clamshell may be used; a 
clamshell is a hinged steel apparatus that operates similar to a set of 
steel jaws, which grasps the pile as the attached crane pulls upward on 
the pile. Lastly, depending on site conditions, piles may be removed by 
wrapping the piles with a cable or chain and pulling them directly from 
the sediment with a crane. In some cases, depending on access and 
location, piles may be cut at or below the mud-line.

                    Table 4--Estimated Number of Pile Driving Days Each Year (574 Days Total)
----------------------------------------------------------------------------------------------------------------
                                       2021            2022            2023            2024            2025
----------------------------------------------------------------------------------------------------------------
Pile Driving Days...............             208              84              18              76             188
----------------------------------------------------------------------------------------------------------------

    In addition to pile driving, the Navy also plans to conduct pile 
repair, demolition of deck portions, wetwall repair, recoating of piles 
and mooring fittings, installation of a passive cathodic protection 
system, repair or replacement of pile caps, concrete spalling repairs, 
mooring foundation and substructure repair, repair or replacement of 
structural and non-structural components, rewrapping/replacement of 
steel cable straps on dolphins, and construction access and project 
staging.
    Pile Repair--Several methods of pile repair may be used, including 
stubbing, wrapping, pile encapsulation, and welding. Pile stubbing is a 
process in which an existing, damaged length of timber pile above the 
ground line is removed and replaced with a new length of timber pile. 
All of the above repair activities would either occur over water or 
involve only minor in-water work, not including pile driving. We do not 
expect these activities to harass marine mammals and do not discuss 
them further.
    Demolition of Deck Portions--A wire saw or other equipment would be 
used to cut timber or concrete decks that are damaged or need 
replacement into sections. Sections would be removed with a crane. 
Debris would be captured using debris curtains/sheeting and removed 
from the project area. Deck pieces would be hauled to a barge and then 
to an upland disposal site. Large concrete deck areas requiring repair 
would be cast-in-place with formwork, and repairs of smaller areas 
would be performed using hand trowels. We do not expect these 
activities to harass marine mammals and do not discuss them further.
    Wetwall Repair--A wetwall is an above-water, reinforced concrete 
encasement for a sanitary sewer lift station pump. Repairs would occur 
by removing failed and delaminated concrete. The reinforced steel 
substructure would then be repaired and new concrete applied, either 
using cast-in-place methods or hand trowels. We do not expect wetwall 
repair to harass marine mammals and do not discuss it further.
    Recoat Piles and Mooring Fittings--The Navy is proposing to clean 
and recoat some piles and mooring fittings. All coatings would be 
applied to dry surfaces and limited to areas above mean sea level (6.5 
ft mean lower low water). We do not expect these activities to harass 
marine mammals and do not discuss them further.
    Passive Cathodic Protection System--The Navy is proposing to 
install a passive cathodic protection system which is a metallic rod 
(anode) attached to a metal object to protect it from corrosion. We do 
not expect installation of the system to harass marine mammals and do 
not discuss it further.
    Repair or Replacement of Pile Caps--The Navy is proposing to repair 
and/or replace pile caps. Replacement concrete pile caps may be cast-
in-place, and the framework may be located below mean higher high 
water. However, we do not expect repair or replacement of pile caps to 
harass marine mammals, and we do not discuss it further.
    Concrete Spalling Repairs--Concrete spalling occurs when concrete 
becomes chipped, scaled or flaked. Repair of spalled concrete involves 
removal of damaged sections and installation of new concrete. We do not 
expect concrete spalling repairs to harass marine mammals and do not 
discuss it further.
    Mooring Foundation and Substructure Repair--Repairs may involve 
removal and replacement of concrete mooring foundations and concrete 
substructure on piers, wharfs, and quay walls. Work may include 
preservation of rebar and injection of epoxy, as required. We do not 
expect mooring foundation and substructure repair to harass marine 
mammals and do not discuss it further.
    Repair or Replacement of Components--Structural and non-structural 
components of waterfront structures would be repaired or replaced as 
required. Replacement of components would involve removal of existing 
components and installation of new components. Components may include, 
but are not limited to the following:
     Timber wave breaks;
     cross bracing members;
     fender components, including but not limited to camels, 
chocks, and whalers;
     hand rails;
     splash guards;
     safety ladders;
     electrical conduit and wiring;
     light poles;
     guide pile systems for floats (used to secure a floating 
dock or barge to a pile but allow the floating dock or barge to move up 
and down with tidal changes); and
     brows (small, movable, bridge-like structures used to 
board or leave a vessel) or gangways.
    We do not expect repair or replacement of these components to 
harass marine mammals and they are not discussed further.
    Rewrap/Replace Steel Cable Straps on Dolphins--The Navy is 
proposing to rewrap and/or replace steel cable straps that hold dolphin 
pile groupings together. We do not expect these activities to harass 
marine mammals and do not discuss them further.
    Construction Access and Project Staging--Barges would be used as 
platforms for conducting in-water work activities and to haul materials 
and equipment to and from work sites. Barges would be moored with spuds 
or anchors. Other than barges, no staging sites have been identified. 
If staging areas for equipment and materials are identified at a future 
date, they would occur in currently developed lots or managed fields.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the Navy's application summarize available 
information regarding status and trends, distribution and habitat 
preferences,

[[Page 83006]]

and behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 5 lists all species or stocks for which take is expected and 
proposed for authorization, and summarizes information related to the 
population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. For taxonomy, we follow Committee on Taxonomy (2020). PBR 
is defined by the MMPA as the maximum number of animals, not including 
natural mortalities, that may be removed from a marine mammal stock 
while allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS's SARs). While no mortality is 
anticipated or authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Atlantic and Gulf of Mexico SARs (e.g., Hayes et al. 2020). 
All values presented in Table 5 are the most recent available at the 
time of publication and are available in the 2019 SARs (Hayes et al. 
2020).

                                          Table 5--Marine Mammal Species Likely To Occur Near the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      ESA/MMPA status;   Stock abundance (CV,
            Common name                  Scientific name              Stock           Strategic (Y/N)     Nmin, most recent       PBR       Annual M/SI
                                                                                            \1\         abundance survey) \2\                   \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
    Humpback whale.................  Megaptera novaeangliae  Gulf of Maine.........  -,-; N             1,396 (0; 1,380; see          22           12.15
                                                                                                         SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin.............  Tursiops truncatus....  Western North Atlantic  -,-; Y             6,639 (0.41; 4,759;           48        6.1-13.2
                                                              (WNA) Coastal,                             2011).
                                                              Northern Migratory.
                                                             WNA Coastal, Southern   -,-; Y             3,751 (0.06; 2,353;           23          0-14.3
                                                              Migratory.                                 2011).
                                                             Northern North          -,-; Y             823 (0.06; 782; 2013)        7.8        0.8-18.2
                                                              Carolina Estuarine
                                                              System (NNCES).
Family Phocoenidae (porpoises):
    Harbor porpoise................  Phocoena phocoena.....  Gulf of Maine/Bay of    -, -; N            95,543 (0.31; 74,034;        851             217
                                                              Fundy.                                     see SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Harbor seal....................  Phoca vitulina........  WNA...................  -; N               75,834 (0.15; 66,884,      2,006             350
                                                                                                         see SAR).
    Gray seal......................  Halichoerus grypus....  WNA...................  -; N               27,131 (0.19, 23,158,      1,359           5,410
                                                                                                         see SAR).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. 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 Mortality/Serious Injury (M/SI) often cannot be determined precisely and is in some cases presented as a
  minimum value or range. A CV associated with estimated mortality due to commercial fisheries is presented in some cases.

    As indicated above, all five species (with seven managed stocks) in 
Table 5 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur, and we have proposed 
authorizing take. While North Atlantic right whales (Eubalaena 
glacialis), minke whales (Balaenoptera acutorostrata acutorostrata), 
and fin whales (Balaenoptera physalus) have been documented in the 
area, the temporal and/or spatial occurrence of these whales is such 
that take is not expected to occur, and they are not discussed further 
beyond the explanation provided here.
    Based on sighting data and passive acoustic studies, the North 
Atlantic right whale could occur off Virginia year-round (DoN 2009; 
Salisbury et al. 2016). They have also been reported seasonally off 
Virginia during migrations in the spring, fall, and winter (CeTAP 1981, 
1982; Niemeyer et al. 2008; Kahn et al. 2009; McLellan 2011b, 2013; 
Mallette et al. 2016a, 2016b, 2017, 2018a; Palka et al. 2017; Cotter 
2019). Right whales are known to frequent the coastal waters of the 
mouth of the Chesapeake Bay (Knowlton et al. 2002) and the area is a 
seasonal management area (November 1-April 30) mandating reduced ship 
speeds out to

[[Page 83007]]

approximately 20 nautical miles (37 kilometers [km]) for the species; 
however, the project area is further inside the Bay.
    North Atlantic right whales have stranded in Virginia, one each in 
2001, 2002, 2004, 2005: Three during winter (February and March) and 
one in summer (September) (Costidis et al. 2017, 2019). In January 
2018, a dead, entangled North Atlantic right whale was observed 
floating over 60 miles (96.6 km) offshore of Virginia Beach (Costidis 
et al. 2019). All North Atlantic right whale strandings in Virginia 
waters have occurred on ocean-facing beaches along Virginia Beach and 
the barrier islands seaward of the lower Delmarva Peninsula (Costidis 
et al. 2017). Due to the low occurrence of North Atlantic right whales 
in the project area, NMFS is not proposing to authorize take of this 
species.
    Fin whales have been sighted off Virginia (Cetacean and Turtle 
Assessment Program (CeTAP) 1981, 1982; Swingle et al. 1993; DoN 2009; 
Hyrenbach et al. 2012; Barco 2013; Mallette et al. 2016a, b; Aschettino 
et al. 2018; Engelhaupt et al. 2017, 2018; Cotter 2019), and in the 
Chesapeake Bay (Bailey 1948; CeTAP 1981, 1982; Morgan et al. 2002; 
Barco 2013; Aschettino et al. 2018); however, they are not likely to 
occur in the project area. Sightings have been documented around the 
Chesapeake Bay Bridge Tunnel (CBBT) during the winter months (CeTAP 
1981, 1982; Barco 2013; Aschettino et al. 2018).
    Eleven fin whale strandings have occurred off Virginia from 1988 to 
2016 mostly during the winter months of February and March, followed by 
a few in the spring and summer months (Costidis et al. 2017). Six of 
the strandings occurred in the Chesapeake Bay (three on eastern shore; 
three on western shore) with the remaining five occurring on the 
Atlantic coast (Costidis et al. 2017. Documented strandings near the 
project area have occurred: February 2012, a dead fin whale washed 
ashore on Oceanview Beach in Norfolk (Swingle et al. 2013); December 
2017, a live fin whale stranded on a shoal in Newport News and died at 
the site (Swingle et al. 2018); February 2014, a dead fin whale 
stranded on a sand bar in Pocomoke Sound near Great Fox Island, 
Accomack (Swingle et al. 2015); and, March 2007, a dead fin whale near 
Craney Island, in the Elizabeth River, in Norfolk (Barco 2013). Only 
stranded fin whales have been documented in the project area; no free-
swimming fin whales have been observed. Due to the low occurrence of 
fin whales in the project area, NMFS is not proposing to authorize take 
of this species.
    Minke whales have been sighted off Virginia (CeTAP 1981, 1982; 
Hyrenbach et al. 2012; Barco 2013; Mallette et al. 2016a, b; McLellan 
2017; Engelhaupt et al. 2017, 2018; Cotter 2019), near the CBBT 
(Aschettino et al. 2018), but sightings in the project area are from 
strandings (Jensen and Silber 2004; Barco 2013; DoN 2009). In August 
1994, a ship strike incident involved a minke whale in Hampton Roads 
(Jensen and Silber 2004; Barco 2013). It was reported that the animal 
was struck offshore and was carried inshore on the bow of a ship (DoN 
2009). Twelve strandings of minke whales have occurred in Virginia 
waters from 1988 to 2016 (Costidis et al. 2017). There have been six 
minke whale stranding from 2017 through 2020 in Virginia waters. 
Because all known minke whale occurrences in the project area are due 
to strandings, NMFS is not proposing to authorize take of this species.

Humpback Whale

    Humpback whales are distributed worldwide in all major oceans and 
most seas. Most humpback whale sightings are in nearshore and 
continental shelf waters; however, humpback whales frequently travel 
through deep oceanic waters during migration (Calambokidis et al. 2001; 
Clapham, P.J. and Mattila, D.K., 1990). Prior to 2016, humpback whales 
were listed under the ESA as an endangered species worldwide. Following 
a 2015 global status review (Bettridge et al. 2015), NMFS established 
14 DPSs with different listing statuses (81 FR 62259; September 8, 
2016) pursuant to the ESA. Humpback whales in the project area are 
expected to be from the West Indies DPS, which consists of the whales 
whose breeding range includes the Atlantic margin of the Antilles from 
Cuba to northern Venezuela, and whose feeding range primarily includes 
the Gulf of Maine, eastern Canada, and western Greenland, was delisted. 
Bettridge et al. (2003) estimated the size of the West Indies DPS at 
12,312 (95% CI 8,688-15,954) whales in 2004-05, which is consistent 
with previous population estimates of approximately 10,000-11,000 
whales (Stevick et al. 2003; Smith et al. 1999) and the increasing 
trend for the West Indies DPS (Bettridge et al. 2015).
    Although humpback whales are migratory between feeding areas and 
calving areas, individual variability in the timing of migrations may 
result in the presence of individuals in high-latitude areas throughout 
the year (Straley, 1990). Records of humpback whales off the U.S. mid-
Atlantic coast (New Jersey to North Carolina) from January through 
March suggest these waters may represent a supplemental winter feeding 
ground used by juvenile and mature humpback whales of U.S. and Canadian 
North Atlantic stocks (LaBrecque et al. 2015).
    Humpback whales are most likely to occur near the mouth of the 
Chesapeake Bay and coastal waters of Virginia Beach between January and 
March; however, they could be found in the area year-round, based on 
shipboard sighting and stranding data (Barco and Swingle, 2014; 
Aschettino et al. 2015; 2016; 2017; 2018). Photo-identification data 
support the repeated use of the mid-Atlantic region by individual 
humpback whales. Results of the vessel surveys show site fidelity in 
the survey area for some individuals and a high level of occurrence 
within shipping channels--an important high-use area by both the Navy 
and commercial traffic (Aschettino et al. 2015; 2016; 2017; 2018). 
Nearshore surveys conducted in early 2015 reported 61 individual 
humpback whale sightings, and 135 individual humpback whale sightings 
in late 2015 through May 2016 (Aschettino et al. 2016). Subsequent 
surveys confirmed the occurrence of humpback whales in the nearshore 
survey area: 248 individuals were detected in 2016-2017 surveys 
(Aschettino et al. 2017), 32 individuals were detected in 2017-2018 
surveys (Aschettino et al. 2018), and 80 individuals were detected in 
2019 surveys (Aschettino et al. 2019). Sightings in the Hampton Roads 
area in the vicinity of NAVSTA Norfolk were reported in nearshore 
surveys and through tracking of satellite-tagged whales in 2016, 2017 
and 2019. The numbers of whales detected, most of which were juveniles, 
reflect the varying level of survey effort and changes in survey 
objectives from year to year, and do not indicate abundance trends over 
time.

Bottlenose Dolphin

    Along the U.S. East Coast and northern Gulf of Mexico, the 
bottlenose dolphin stock structure is well studied. There are currently 
53 management stocks identified by NMFS in the western North Atlantic 
and Gulf of Mexico, including oceanic, coastal, and estuarine stocks 
(Hayes et al. 2017; Waring et al. 2015, 2016).
    There are two morphologically and genetically distinct bottlenose 
dolphin morphotypes (distinguished by physical differences) described 
as coastal and offshore forms (Duffield et al. 1983; Duffield, 1986). 
The offshore form is larger in total length and skull length,

[[Page 83008]]

and has wider nasal bones than the coastal form. Both inhabit waters in 
the western North Atlantic Ocean and Gulf of Mexico (Curry and Smith, 
1997; Hersh and Duffield, 1990; Mead and Potter, 1995) along the U.S. 
Atlantic coast. The coastal morphotype of bottlenose dolphin is 
continuously distributed along the Atlantic coast south of Long Island, 
New York, around the Florida peninsula, and along the Gulf of Mexico 
coast. This type typically occurs in waters less than 25 meters deep 
(Waring et al. 2015). The range of the offshore bottlenose dolphin 
includes waters beyond the continental slope (Kenney R.D., 1990), and 
offshore bottlenose dolphins may move between the Gulf of Mexico and 
the Atlantic (Wells et al. 1999).
    Two coastal stocks are likely to be present in the MPU project 
area: Western North Atlantic Northern Migratory Coastal stock and 
Western North Atlantic Southern Migratory Coastal stock. Additionally, 
the Northern North Carolina Estuarine System stock may occur in the 
project area.
    Bottlenose dolphins are the most abundant marine mammal along the 
Virginia coast and within the Chesapeake Bay, typically traveling in 
groups of 2 to 15 individuals, but occasionally in groups of over 100 
individuals (Engelhaupt et al. 2014; 2015; 2016). Bottlenose dolphins 
of the Western North Atlantic Northern Migratory Coastal stock winter 
along the coast of North Carolina and migrate as far north as Long 
Island, New York, in the summer. They are rarely found north of North 
Carolina in the winter (NMFS, 2018a). The Western North Atlantic 
Southern Migratory Coastal stock occurs in waters of southern North 
Carolina from October to December, moving south during winter months 
and north to North Carolina during spring months. During July and 
August, the Western North Atlantic Southern Migratory Coastal stock is 
presumed to occupy coastal waters north of Cape Lookout, North 
Carolina, to the eastern shore of Virginia (NMFS, 2018a). It is 
possible that these animals also occur inside the Chesapeake Bay and in 
nearshore coastal waters. The North Carolina Estuarine System stock 
dolphins may also occur in the Chesapeake Bay during July and August 
(NMFS, 2018a).
    Vessel surveys conducted along coastal and offshore transects from 
NAVSTA Norfolk to Virginia Beach in most months from August 2012 to 
August 2015 reported bottlenose dolphins throughout the survey area, 
including the vicinity of NAVSTA Norfolk (Engelhaupt et al. 2014; 2015; 
2016). The final results from this project confirmed earlier findings 
that bottlenose dolphins are common in the study area, with highest 
densities in the coastal waters in summer and fall months. However, 
bottlenose dolphins do not completely leave this area during colder 
months, with approximately 200-300 individuals still present in winter 
and spring months (Engelhaupt et al. 2016).

Harbor Porpoise

    Harbor porpoises inhabit cool temperate-to-subpolar waters, often 
where prey aggregations are concentrated (Watts and Gaskin, 1985). 
Thus, they are frequently found in shallow waters, most often near 
shore, but they sometimes move into deeper offshore waters. Harbor 
porpoises are rarely found in waters warmer than 63 degrees Fahrenheit 
(17 degrees Celsius) (Read 1999) and closely follow the movements of 
their primary prey, Atlantic herring (Gaskin 1992).
    In the western North Atlantic, harbor porpoise range from 
Cumberland Sound on the east coast of Baffin Island, southeast along 
the eastern coast of Labrador to Newfoundland and the Gulf of St. 
Lawrence, then southwest to about 34 degrees North on the coast of 
North Carolina (Waring et al. 2016). During winter (January to March), 
intermediate densities of harbor porpoises can be found in waters off 
New Jersey to North Carolina, and lower densities are found in waters 
off New York to New Brunswick, Canada (Waring et al. 2016). Harbor 
porpoises sighted off the mid-Atlantic during winter include porpoises 
from other western North Atlantic populations (Rosel et al. 1999). 
There does not appear to be a temporally coordinated migration or a 
specific migratory route to and from the Bay of Fundy region (Waring et 
al. 2016). During fall (October to December) and spring (April to 
June), harbor porpoises are widely dispersed from New Jersey to Maine, 
with lower densities farther north and south (LaBrecque et al. 2015).
    Based on stranding reports, passive acoustic recorders, and 
shipboard surveys, harbor porpoise occur in coastal waters primarily in 
winter and spring months, but there is little information on their 
presence in the Chesapeake Bay. They do not appear to be abundant in 
the NAVSTA Norfolk area in most years, but this is confounded by wide 
variations in stranding occurrences over the past decade.

Harbor Seal

    The Western North Atlantic stock of harbor seals occurs in the MPU 
project area. Harbor seal distribution along the U.S. Atlantic coast 
has shifted in recent years, with an increased number of seals reported 
from southern New England to the mid-Atlantic region (DiGiovanni et al. 
2011; Hayes et al. 2017; Kenney R. D. 2019; Waring et al. 2016). 
Regular sightings of seals in Virginia have become a common occurrence 
in winter and early spring (Costidis et al. 2019). Winter haulout sites 
for harbor seals have been documented in the Chesapeake Bay at the 
CBBT, on the Virginia Eastern Shore, and near Oregon Inlet, North 
Carolina (Waring et al. 2016; Rees et al. 2016; Jones et al. 2018).
    Harbor seals regularly haul out on rocks around the portal islands 
of the CBBT and on mud flats on the nearby southern tip of the Eastern 
Shore from December through April (Rees et al. 2016; Jones et al. 
2018). Seals captured in 2018 on the Eastern Shore and tagged with 
satellite-tracked tags that lasted from 2 to 5 months spent at least 60 
days in Virginia waters before departing the area. All tagged seals 
returned regularly to the capture site while in Virginia waters, but 
individuals utilized offshore and Chesapeake Bay waters to different 
extents (Ampela et al. 2019). The area that was utilized most heavily 
was near the Eastern Shore capture site, but some seals ranged into the 
Chesapeake Bay.

Gray Seal

    The Western North Atlantic stock of gray seal occurs in the project 
area. The western North Atlantic stock is centered in Canadian waters, 
including the Gulf of St. Lawrence and the Atlantic coasts of Nova 
Scotia, Newfoundland, and Labrador, Canada, and the northeast U.S. 
continental shelf (Hayes et al. 2017). Gray seals range south into the 
northeastern United States, with strandings and sightings as far south 
as North Carolina (Hammill et al. 1998; Waring et al. 2004). Gray seal 
distribution along the U.S. Atlantic coast has shifted in recent years, 
with an increased number of seals reported in southern New England 
(DiGiovanni et al. 2011; Kenney R.D., 2019; Waring et al. 2016). Recent 
sightings included a gray seal in the lower Chesapeake Bay during the 
winter of 2014 to 2015 (Rees et al. 2016). Along the coast of the 
United States, gray seals are known to pup at three or more colonies in 
Massachusetts and Maine.
    Gray seals are uncommon in Virginia and in the Chesapeake Bay. Only 
15 gray seal strandings were documented

[[Page 83009]]

in Virginia from 1988 through 2013 (Barco and Swingle, 2014). They are 
rarely found resting on the rocks around the portal islands of the CBBT 
from December through April alongside harbor seals. Seal observation 
surveys conducted at the CBBT recorded one gray seal in each of the 
2014/2015 and 2015/2016 seasons while no gray seals were reported 
during the 2016/2017 and 2017/2018 seasons (Rees et al. 2016, Jones et 
al. 2018). Sightings have been reported off Virginia and near the 
project area during the winter and spring (Barco 2013; Rees et al. 
2016; Jones et al. 2018; Ampela et al. 2019).

Unusual Mortality Events

    An unusual mortality event (UME) is defined under Section 410(6) of 
the MMPA as a stranding that is unexpected; involves a significant die-
off of any marine mammal population; and demands immediate response. 
Currently, ongoing UME investigations are underway for pinnipeds along 
the Northeast coast, and humpback whales along the Atlantic coast.
Northeast Pinniped UME
    Since July 2018, elevated numbers of harbor seal and gray seal 
mortalities have occurred across Maine, New Hampshire and 
Massachusetts. This event has been declared an UME. Additionally, seals 
showing clinical signs have been stranding as far south as Virginia, 
although not in elevated numbers; therefore, the UME investigation now 
encompasses all seal strandings from Maine to Virginia. Lastly, while 
take is not proposed for these species in this proposed rule, ice seals 
(harp and hooded seals) have also started stranding with clinical 
signs, again not in elevated numbers, and those two seal species have 
also been added to the UME investigation. Additional information is 
available at https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along.
Atlantic Humpback Whale UME
    Since January 2016, elevated humpback whale mortalities have 
occurred along the Atlantic coast from Maine through Florida. This 
event has been declared an UME. A portion of the whales have shown 
evidence of pre-mortem vessel strike; however, this finding is not 
consistent across all whales examined, and additional research is 
needed. Additional information is available at https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2020-humpback-whale-unusual-mortality-event-along-atlantic-coast.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et al. 
1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 6.

                  Table 6--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
        Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans   7 Hz to 35 kHz
 (baleen whales).
Mid-frequency (MF) cetaceans   150 Hz to 160 kHz
 (dolphins, toothed whales,
 beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans  275 Hz to 160 kHz
 (true porpoises, Kogia,
 river dolphins,
 cephalorhynchid,
 Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW)          50 Hz to 86 kHz
 (underwater) (true seals).
Otariid pinnipeds (OW)         60 Hz to 39 kHz
 (underwater) (sea lions and
 fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al. 2006; Kastelein et al. 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Five marine mammal species (three cetacean and two phocid pinniped 
species) have the reasonable potential to co-occur with the proposed 
construction activities. Please refer to Table 5. Of the cetacean 
species that may be present, one is classified as a low-frequency 
cetacean (i.e., humpback whale) one is classified as a mid-frequency 
cetacean (i.e., bottlenose dolphin), and one is classified as a high-
frequency cetacean (i.e., harbor porpoise).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The Negligible Impact Analysis 
and Determination section considers the content of this section, the 
Estimated Take section, and the Proposed Mitigation section, to draw 
conclusions regarding the likely impacts of these activities on the 
reproductive success or survivorship of individuals and how those 
impacts on individuals are likely

[[Page 83010]]

to impact marine mammal species or stocks.
    Acoustic effects on marine mammals during the specified activity 
can occur from vibratory and impact pile driving. The effects of 
underwater noise from the Navy's proposed activities have the potential 
to result in Level A and Level B harassment of marine mammals in the 
action area.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' 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 
removal. The sounds produced by these activities fall into one of two 
general sound types: Impulsive and non-impulsive. Impulsive sounds 
(e.g., explosions, gunshots, sonic booms, impact pile driving) are 
typically transient, brief (less than 1 second), broadband, and consist 
of high peak sound pressure with rapid rise time and rapid decay (ANSI 
1986; NIOSH 1998; ANSI 2005; NMFS 2018a). Non-impulsive sounds (e.g. 
aircraft, machinery operations such as drilling or dredging, vibratory 
pile driving, and active sonar systems) can be broadband, narrowband or 
tonal, brief or prolonged (continuous or intermittent), and typically 
do not have the high peak sound pressure with raid rise/decay time that 
impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018a). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward 1997 in Southall et al. 2007).
    Two types of pile hammers would be used on this project: Impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels, a potentially injurious combination (Hastings and Popper 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak sound 
pressure levels (SPLs) may be 180 dB or greater, but are generally 10 
to 20 dB lower than SPLs generated during impact pile driving of the 
same-sized pile (Oestman et al. 2009). Rise time is slower, reducing 
the probability and severity of injury, and sound energy is distributed 
over a greater amount of time (Nedwell and Edwards 2002; Carlson et al. 
2005).
    The likely or possible impacts of the Navy's proposed activity on 
marine mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of the equipment and personnel; however, any impacts to marine 
mammals are expected to primarily be acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during pile 
driving.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving is the primary means by which marine 
mammals may be harassed from the Navy's specified activity. In general, 
animals exposed to natural or anthropogenic sound may experience 
physical and psychological effects, ranging in magnitude from none to 
severe (Southall et al. 2007). In general, exposure to pile driving 
noise has the potential to result in auditory threshold shifts and 
behavioral reactions (e.g., avoidance, temporary cessation of foraging 
and vocalizing, changes in dive behavior). Exposure to anthropogenic 
noise can also lead to non-observable physiological responses such an 
increase in stress hormones. Additional noise in a marine mammal's 
habitat can mask acoustic cues used by marine mammals to carry out 
daily functions such as communication and predator and prey detection. 
The effects of pile driving noise on marine mammals are dependent on 
several factors, including, but not limited to, sound type (e.g., 
impulsive vs. non-impulsive), the species, age and sex class (e.g., 
adult male vs. mom with calf), duration of exposure, the distance 
between the pile and the animal, received levels, behavior at time of 
exposure, and previous history with exposure (Wartzok et al. 2004; 
Southall et al. 2007). Here we discuss physical auditory effects 
(threshold shifts) followed by behavioral effects and potential impacts 
on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how an animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al. 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960; 
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al. 
2008). PTS levels for

[[Page 83011]]

marine mammals are estimates, as with the exception of a single study 
unintentionally inducing PTS in a harbor seal (Kastak et al. 2008), 
there are no empirical data measuring PTS in marine mammals largely due 
to the fact that, for various ethical reasons, experiments involving 
anthropogenic noise exposure at levels inducing PTS are not typically 
pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--TTS is a temporary, reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range above a previously established 
reference level (NMFS 2018). Based on data from cetacean TTS 
measurements (see Southall et al. 2007), a TTS of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability 
(Schlundt et al. 2000; Finneran et al. 2000, 2002). As described in 
Finneran (2015), marine mammal studies have shown the amount of TTS 
increases with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, the amount of 
TTS is typically small and the growth curves have shallow slopes. At 
exposures with higher SELcum, the growth curves become steeper and 
approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during a time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al. 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor 
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis)) 
and five species of pinnipeds exposed to a limited number of sound 
sources (i.e., mostly tones and octave-band noise) in laboratory 
settings (Finneran 2015). TTS was not observed in trained spotted 
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive 
noise at levels matching previous predictions of TTS onset (Reichmuth 
et al. 2016). In general, harbor seals and harbor porpoises have a 
lower TTS onset than other measured pinniped or cetacean species 
(Finneran 2015). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species. No data are 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), Finneran (2015), and Table 5 in NMFS (2018). Installing piles 
requires a combination of impact pile driving and vibratory pile 
driving. For this project, these activities would not occur at the same 
time and there would be pauses in activities producing the sound during 
each day. Given these pauses and that many marine mammals are likely 
moving through the ensonified area and not remaining for extended 
periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
Available studies show wide variation in response to underwater sound; 
therefore, it is difficult to predict specifically how any given sound 
in a particular instance might affect marine mammals perceiving the 
signal. If a marine mammal does react briefly to an underwater sound by 
changing its behavior or moving a small distance, the impacts of the 
change are unlikely to be significant to the individual, let alone the 
stock or population. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on individuals and populations could be significant 
(e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are 
highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al. 1995; Wartzok et al. 2003; Southall et al. 
2007; Weilgart 2007; Archer et al. 2010). Behavioral reactions can vary 
not only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al. 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). In 
general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B-C of Southall et al. 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al. 
2001; Nowacek et al. 2004; Madsen et al. 2006; Yazvenko et al. 2007). A 
determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral 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

[[Page 83012]]

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), however 
distress is an unlikely result of this project based on observations of 
marine mammals during previous, similar projects in the area.
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al. 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked.
    Airborne Acoustic Effects--Although pinnipeds are known to haul-out 
regularly on man-made objects in the vicinity of some of the potential 
project sites, we believe that incidents of take resulting solely from 
airborne sound are unlikely. There is a possibility that an animal 
could surface in-water, but with head out, within the area in which 
airborne sound exceeds relevant thresholds and thereby be exposed to 
levels of airborne sound that we associate with harassment, but any 
such occurrence would likely be accounted for in our estimation of 
incidental take from underwater sound. Therefore, authorization of 
incidental take resulting from airborne sound for pinnipeds is not 
warranted, and airborne sound is not discussed further here. Cetaceans 
are not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.

Marine Mammal Habitat Effects

    The Navy's construction activities could have localized, temporary 
impacts on marine mammal habitat by increasing in-water sound pressure 
levels and slightly decreasing water quality. Construction activities 
are of short duration and would likely have temporary impacts on marine 
mammal habitat through increases in underwater sound. Increased noise 
levels may affect acoustic habitat (see masking discussion above) and 
adversely affect marine mammal prey in the vicinity of the project area 
(see discussion below). During impact and vibratory pile driving, 
elevated levels of underwater noise would ensonify the project area 
where both fish and mammals may occur and could affect foraging 
success. Additionally, marine mammals may avoid the area during 
construction, however, displacement due to noise is expected to be 
temporary and is not expected to result in long-term effects to the 
individuals or populations.
    A temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles are 
installed (and removed in the case of the temporary piles). The 
sediments on the sea floor will be disturbed during pile driving; 
however, suspension will be brief and localized and is unlikely to 
measurably affect marine mammals or their prey in the area. In general, 
turbidity associated with pile installation is localized to about a 25-
ft (7.6-meter) radius around the pile (Everitt et al. 1980). Cetaceans 
are not expected to be close enough to the pile driving areas to 
experience effects of turbidity, and any pinnipeds could avoid 
localized areas of turbidity. Therefore, we expect the impact from 
increased turbidity levels to be discountable to marine mammals and do 
not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals except for the actual 
footprint of the project. The total seafloor area affected by pile 
installation and removal is a very small area compared to the vast 
foraging area available to marine mammals in the project area and lower 
Chesapeake Bay.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is

[[Page 83013]]

also possible. The duration of fish avoidance of this area after pile 
driving stops is unknown, but we anticipate a rapid return to normal 
recruitment, distribution and behavior. Any behavioral avoidance by 
fish of the disturbed area would still leave large areas of fish and 
marine mammal foraging habitat in the nearby vicinity in the project 
area and lower Chesapeake Bay.

Effects on Potential Prey

    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., fish). Marine mammal 
prey varies by species, season, and location. Here, we describe studies 
regarding the effects of noise on known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick et al. 1999; Fay, 2009). 
Depending on their hearing anatomy and peripheral sensory structures, 
which vary among species, fishes hear sounds using pressure and 
particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al. 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 
2009). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al. 1992; Skalski et al. 1992; 
Santulli et al. 1999; Paxton et al. 2017). However, some studies have 
shown no or slight reaction to impulse sounds (e.g., Pena et al. 2013; 
Wardle et al. 2001; Jorgenson and Gyselman, 2009; Cott et al. 2012).
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours 
for one species. Impacts would be most severe when the individual fish 
is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al. 2012b; Casper et al. 2013).
    The most likely impact to fish from pile driving activities at the 
project areas would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of an area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated.
    The area impacted by the project is relatively small compared to 
the available habitat in the remainder of the project area and the 
lower Chesapeake Bay, and there are no areas of particular importance 
that would be impacted by this project. Any behavioral avoidance by 
fish of the disturbed area would still leave significantly large areas 
of fish and marine mammal foraging habitat in the nearby vicinity. As 
described in the preceding, the potential for the Navy's construction 
to affect the availability of prey to marine mammals or to meaningfully 
impact the quality of physical or acoustic habitat is considered to be 
insignificant.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would be by Level B harassment only, in the form 
of disruption of behavioral patterns and potential TTS for individual 
marine mammals resulting from exposure to pile driving and removal. 
Based on the nature of the activity and the anticipated effectiveness 
of the mitigation measures (i.e., shutdown zones) discussed in detail 
below in Proposed Mitigation section, Level A harassment is neither 
anticipated nor proposed to be authorized.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
the number of days of activities. We note that while these factors can 
contribute to a basic calculation to provide an initial prediction of 
takes, additional information that can qualitatively inform take 
estimates is also sometimes available (e.g., previous monitoring 
results or average group size). Below, we describe the factors 
considered here in more detail and present the proposed take estimate.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment 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

[[Page 83014]]

can be difficult to predict (Southall et al. 2007, Ellison et al. 
2012). 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) (microPascal, root mean square) for continuous 
(e.g., vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa 
(rms) for non-explosive impulsive (e.g., seismic airguns) or 
intermittent (e.g., scientific sonar) sources.
    The Navy's construction includes the use of continuous (vibratory 
pile driving) and impulsive (impact pile driving) sources, and 
therefore the 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 (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). The Navy's proposed construction includes 
the use of impulsive (impact pile driving) and non-impulsive (vibratory 
pile driving) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 7--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds \*\ (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 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 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving and 
vibratory pile driving). The largest calculated Level B harassment zone 
extends 7.2 km (4.5 mi) from the source (though truncated by land in 
some directions), with an area of 4.7 km\2\ (1.8 mi\2\), as calculated 
using geographic information system (GIS) data as determined by the 
transmission loss modeling.

                                                          Table 8--Project Sound Source Levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
            Pile size and type                   Installation  method            RMS SPL        Peak SPL           SEL                  Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Square Concrete....................  Impact..........................             176             189             163  Illingworth and Rodkin,
                                                                                                                              2017.
16-in Composite..........................  Impact..........................             165             177             157  Caltrans, 2015.\1\
                                           Vibratory.......................             158  ..............  ..............  Illingworth and Rodkin,
                                                                                                                              2017.
12-in Timber.............................  Vibratory.......................         \2\ 158  ..............  ..............  Illingworth and Rodkin,
                                                                                                                              2017.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ These source levels are from a 12-inch timber pile (Table 2-2, page 2-16).
\2\ NMFS typically recommends a proxy source level of 152dB RMS SPL for installation and removal of 12-in timber piles; however, the Navy's application
  included specialized modeling (described below) using 158dB RMS SPL. Given that modeling and that 158dB RMS SPL is a more conservative source level,
  NMFS concurred with the use of 158dB RMS SPL as the proxy source level for 12-in timber piles.

    The Navy contracted the University of Washington, Applied Physics 
Laboratory (APL) to conduct site-specific acoustic transmission loss 
modeling for the project. The APL's full report is included in Appendix 
B of the Navy's application. NMFS independently reviewed and concurred 
with the modeling in the report, and has adopted the resulting 
isopleths for the project, as included in Table 9.

[[Page 83015]]



                                                    Table 9--Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Level A harassment isopleth  (m)                     Level B
                                                                         ----------------------------------------------------------------   harassment
                   Site                          Pile size and type                                                                        isopleth  (m)
                                                                            LF cetacean     MF cetacean     HF cetacean       Phocid            \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pier 3....................................  16-in Composite.............              18                       <10m                                   27
Pier 12...................................  16-in Composite.............              18                                                              24
MWR Marina................................  24-in Concrete..............              52                                                              59
                                            16-in Composite.............              11                                                              18
V-Area....................................  24-in Concrete..............              42                                                              47
                                            16-in Composite.............              11                                                              17
Craney Island.............................  16-in Composite.............              16                                                              21
Lambert's Point...........................  16-in Composite.............              19                                                              28
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pier 3....................................  16-in Composite/12-in Timber                               <10m                                        5,615
Pier 12...................................  ............................                                                                           4,159
MWR Marina................................  ............................                                                                             469
V-Area....................................  ............................                                                                             382
Craney Island.............................  ............................                                                                           3,001
Lambert's Point...........................  ............................                                                                           7,161
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Please refer to Tables 6-5 and 6-6 in the Navy's application for the areas of the Level B harassment zones.

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. We describe how the information provided above is brought 
together to produce a quantitative take estimate.
Humpback Whale
    Humpback whales occur in the mouth of the Chesapeake Bay and 
nearshore waters of Virginia during winter and spring months. Most 
detections during shipboard surveys were of one or two juveniles per 
sighting. Although two individuals were detected in the vicinity of MPU 
project activities, there is no evidence that they linger for multiple 
days. Because no density estimates are available for the species in 
this area, the Navy estimated one take for every 60 days of pile 
driving. However, given the potential group size of two, as indicated 
by the sightings referenced above, NMFS has estimated that two humpback 
whales may be taken by Level B harassment for every 60 days of pile 
driving. Therefore, given the number of project days expected in each 
year (Table 4), NMFS is proposing to authorize a total of 24 takes by 
Level B harassment of humpback whale over the five-year authorization, 
with no more than eight takes by Level B harassment in one year.
    The largest Level A harassment zone for low-frequency cetaceans 
extends approximately 52 m from the source during impact pile driving 
of 24-in concrete piles at the MWR Marina (Table 9). For most 
activities, the Level A harassment zone is less than 20 m. The Navy is 
planning to implement a 50-m shutdown zone for humpback whales during 
impact pile driving of 24-in concrete piles, and shutdown zones that 
include the entire Level A harassment isopleth for all activities, as 
indicated in Table 15. Therefore, the Navy did not request, and NMFS 
does not propose to authorize Level A harassment take of humpback 
whale.
Bottlenose Dolphin
    The expected number of bottlenose dolphins in the project area was 
estimated using inshore seasonal densities provided in Engelhaupt et 
al. (2016) from vessel line-transect surveys near NAVSTA Norfolk and 
adjacent areas near Virginia Beach, Virginia, from August 2012 through 
August 2015 (Engelhaupt et al. 2016). To calculate Level B harassment 
takes of bottlenose dolphin, NMFS used the Chesapeake Bay density of 
1.38 dolphins/km\2\ (Engelhaupt et al. 2016). This density includes 
sightings inshore of the Chesapeake Bay from NAVSTA Norfolk west to the 
Thimble Shoals Bridge, and is the most representative density for the 
project area. NMFS conservatively multiplied the density of 1.38 
dolphins/km\2\ by the largest Level B harassment zone for each project 
location (Table 11) and then by the proportional number of estimated 
pile driving days at each location for each year (Table 10). For 
example, to calculate Level B harassment takes associated with work at 
Pier 3 in 2021, NMFS multiplied the density (1.38 dolphins/km\2\) by 
largest Level B harassment zone for Pier 3 (10.3 km\2\) by the 
proportional number of pile driving days at Pier 3 in 2021 (24.6) for a 
total of 350 Level B harassment takes at Pier 3 in 2021. Therefore, 
NMFS proposes to authorize 7,566 takes by Level B harassment of 
bottlenose dolphin across all five years, with no more than 2,742 in 
one year.

                    Table 10--Estimated Number of Pile Driving Days at Each Project Location
----------------------------------------------------------------------------------------------------------------
                                         Estimated           Proportional number of pile driving days \3\
                                         number of   -----------------------------------------------------------
            Location \1\               pile driving
                                        days  (all       2021        2022        2023        2024        2025
                                         seasons)
----------------------------------------------------------------------------------------------------------------
Pier 3..............................              68        24.6        10.0         2.1         9.0        22.3
Pier 12.............................             352       127.6        51.5        11.0        46.6       115.3
MWR Marina..........................              52        18.8         7.6         1.6         6.9        17.0
V-Area..............................              44        15.9         6.4         1.4         5.8        14.4
Craney Island.......................              52        18.8         7.6         1.6         6.9        17.0
Lambert's Point.....................               8         2.9         1.2         0.3         1.1         2.6

[[Page 83016]]

 
Estimated Total Pile Driving Days            \2\ 574         208          84          18          76         188
 per Year...........................
                                     ---------------------------------------------------------------------------
  Percentage of Total Pile Driving    ..............          36          15           3          13          33
   Days.............................
----------------------------------------------------------------------------------------------------------------
\1\ While the Navy plans to conduct work at additional locations not listed here, these locations are assumed to
  be representative of the overall project site (ex: all pile driving lumped together at Lambert's Point
  Deperming Station), as noted in Appendix A of the Navy's application. Pile driving at these additional
  locations is included in the total number of pile driving days assumed here.
\2\ NMFS recognizes that due to rounding, the sum of the estimated number of work days at each location is 576,
  not 574. However, as mentioned previously, the Navy expects construction to last 574 days across all five
  years.
\3\ The number of pile driving days indicated per year at each location is intended to inform our assessment of
  both the total and maximum annual taking allowable under the rule. NMFS does not expect that the Navy will
  conduct exactly the fractional number of days of pile driving indicated for each year in each location.


                                   Table 11--Annual Level B Harassment Takes of Bottlenose Dolphin by Project Location
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Largest  Level                       Level B harassment takes \1\
                            Location                               B  harassment -----------------------------------------------------------------------
                                                                   zone  (km\2\)     2021        2022        2023        2024        2025        Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pier 3..........................................................            10.3       350.2       141.4        30.3       128.0       316.6       966.6
Pier 12.........................................................            13.1     2,305.9       931.2       199.6       842.5     2,084.2     6,363.5
MWR Marina......................................................             0.2         5.2         2.1         0.5         1.9         4.7        14.4
V-Area..........................................................             0.2         4.4         1.8         0.4         1.6         4.0        12.1
Craney Island...................................................             2.2        57.2        23.1         5.0        20.9        51.7       157.9
Lambert's Point.................................................             4.7        18.8         7.6         1.6         6.9        17.0        51.9
                                                                 ---------------------------------------------------------------------------------------
  Total Level B Harassment Takes per Year.......................  ..............       2,742       1,107         237       1,002       2,478       7,566
                                                                 ---------------------------------------------------------------------------------------
      Annual Takes as Percentage of Five-Year Total.............  ..............        36.2        14.6         3.1        13.2        32.8  ..........
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note actual calculations were not rounded at each step as they are shown in Table 10 and Table 11.

    The Level A harassment zones for mid-frequency cetaceans extend 
less than 10 m from the source during all activities (Table 9). Given 
the small size of the Level A harassment zones, we do not expect Level 
A harassment take of bottlenose dolphins. Additionally, the Navy is 
planning to implement a 10 m shutdown zone for bottlenose dolphins 
during all pile driving and other in-water activities (Table 15), which 
includes the entire Level A harassment zone for all pile driving 
activities. Therefore, the Navy did not request, and NMFS does not 
propose to authorize Level A harassment take of bottlenose dolphin.
Harbor Porpoise
    Harbor porpoises are known to occur in the coastal waters near 
Virginia Beach (Hayes et al. 2019). Density data for this species 
within the project vicinity do not exist or were not calculated because 
sample sizes were too small to produce reliable estimates of density. 
Harbor porpoise sighting data collected by the U.S. Navy near NAVSTA 
Norfolk and Virginia Beach from 2012 to 2015 (Engelhaupt et al. 2014; 
2015; 2016) did not produce enough sightings to calculate densities. 
One group of two harbor porpoises was seen during spring 2015 
(Engelhaupt et al. 2016). Elsewhere in their range, harbor porpoises 
typically occur in groups of two to three individuals (Carretta et al. 
2001; Smultea et al. 2017).
    Because there are no density estimates for the species in the MPU 
project area, the Navy conservatively estimated two takes of harbor 
porpoise by Level B harassment per 60 pile driving days (Table 4), 
resulting in 20 takes by Level B harassment across the five year rule, 
and no more than 7 takes by Level B harassment in one year (Table 13). 
NMFS concurs with this estimate and proposes to authorize 20 takes by 
Level B harassment of harbor porpoise.
    The Level A harassment zones for high-frequency cetaceans extend 
less than 10 m from the source during all activities (Table 9). Given 
the small size of the Level A harassment zones, we do not expect take 
by Level A harassment of harbor porpoise. Additionally, the Navy is 
planning to implement a 10 m shutdown zone for during pile driving and 
other in-water activities (Table 15). Therefore, the Navy did not 
request, and NMFS does not propose to authorize take by Level A 
harassment of harbor porpoise.
Harbor Seal
    The expected number of harbor seals in the project area was 
estimated using systematic, land- and vessel-based survey data for in-
water and hauled-out seals collected by the U.S. Navy at the CBBT rock 
armor and portal islands from 2014 through 2019 (Jones et al. 2020). 
The average daily seal count from the 2014 through 2019 field seasons 
ranged from 8 to 23, with an average of 13.6 harbor seals across all 
the field seasons (Table 12) (rounded up to 14 seals).

[[Page 83017]]



                          Table 12--Harbor Seal Counts at Chesapeake Bay Bridge Tunnel
----------------------------------------------------------------------------------------------------------------
                                                   ``In season''    Total  seal   Average  daily     Max daily
                  Field season                      survey days        count        seal  count     seal count
----------------------------------------------------------------------------------------------------------------
2014-2015.......................................              11             113              10              33
2015-2016.......................................              14             187              13              39
2016-2017.......................................              22             308              14              40
2017-2018.......................................              15             340              23              45
2018-2019.......................................              10              82               8              17
Average.........................................  ..............  ..............            13.6            34.8
----------------------------------------------------------------------------------------------------------------
Source: Jones et al. 2020.

    The Navy expects, and NMFS concurs, that harbor seals are likely to 
be present from November to April. NMFS calculated take by Level B 
harassment by multiplying 14 seals by the number of pile driving days 
expected in each year if fewer than 183 project days (half of the year) 
were expected. To account for seasonal occurrence (November to April), 
NMFS calculated take based on 183 project days for years which have 
more than 183 expected project days (2021, 2025). Therefore, NMFS 
proposes to authorize 7,616 takes by Level B harassment of harbor seals 
across the five-year duration of this rule, with no more than 2,562 
takes by Level B harassment in one year (Table 13).
    The Level A harassment zones for phocids extend less than 10 m from 
the source during all activities (Table 9). Given the small size of the 
Level A harassment zones, we do not expect take by Level A harassment 
of harbor seal. Additionally, the Navy is planning to implement a 10 m 
shutdown zone for during pile driving and other in-water activities 
(Table 15), which includes the entire Level A harassment zone for all 
pile driving activities. Therefore, the Navy did not request, and NMFS 
does not propose to authorize take by Level A harassment of harbor 
seal.
Gray Seal
    Very little information is available about the occurrence of gray 
seals in the Chesapeake Bay and coastal waters. Although the population 
of the United States may be increasing, there are only a few records at 
known haulout sites in Virginia used by harbor seals, strandings are 
rare, and they have not been reported in shipboard surveys. Assuming 
that they may utilize the Chesapeake Bay waters, the Navy 
conservatively estimates that one gray seal may be exposed to noise 
levels above the Level B harassment threshold for every 60 days of 
vibratory pile driving during the six month period when they are most 
likely to be present. NMFS concurs, and calculated take based on the 
number of project days for years which have fewer than 183 project days 
(half of the year). To account for the expected seasonal presence of 
gray seals, NMFS calculated take based on 183 project days for years 
which have more than 183 expected project days (2021, 2025). Therefore, 
NMFS is proposing to authorize nine takes by Level B harassment of gray 
seals over the five-year duration of the rule, with no more than three 
takes by Level B harassment in one year (Table 13).
    The Level A harassment zones for phocids extend less than 10 m from 
the source during all activities (Table 9). Given the small size of the 
Level A harassment zones and the low occurrence of gray seals in the 
project area, we do not expect Level A harassment take of gray seal. 
Additionally, the Navy is planning to implement a 10 m shutdown zone 
for during pile driving and other in-water activities (Table 15), which 
includes the entire Level A harassment zone for all pile driving 
activities. Therefore, the Navy did not request, and NMFS does not 
propose to authorize take by Level A harassment of gray seal.

                                               Table 13--Estimated Take By Level B harassment, by Species
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         Species                               2021            2022            2023            2024            2025            Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale..........................................               6               4               2               4               8              24
Bottlenose dolphin......................................           2,742           1,107             237           1,002           2,478           7,566
Harbor porpoise.........................................               7               3               1               3               6              20
Harbor seal.............................................           2,562           1,176             252           1,064           2,562           7,616
Gray seal...............................................               3               1               1               1               3               9
--------------------------------------------------------------------------------------------------------------------------------------------------------


     Table 14--Estimated Take by Level B Harassment (Greatest Annual Take Expected), by Species and Stock in
                                          Comparison to Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                                                      Level B
                Species                           Stock                Stock        harassment      Percent  of
                                                                     abundance         take            stock
----------------------------------------------------------------------------------------------------------------
Humpback Whale........................  Gulf of Maine...........      \b\ 12,312               8             0.6
Bottlenose Dolphin....................  WNA Coastal, Northern              6,639           1,353            20.4
                                         Migratory \a\.
WNA Coastal, Southern Migratory \a\...  3,751...................           1,353            36.1
NNCES \a\.............................  823.....................              36             4.4
Harbor Porpoise.......................  Gulf of Maine/Bay of              95,543               7           0.007
                                         Fundy.
Harbor Seal...........................  Western North Atlantic..          75,834           2,562             3.4
Gray Seal.............................  Western North Atlantic..      \d\ 27,131               3            0.01
----------------------------------------------------------------------------------------------------------------
\a\ Take estimates are weighted based on calculated percentages of population for each distinct stock, assuming
  animals present would follow same probability of presence in the project area. Please see the Small Numbers
  section for additional information.
\b\ West Indies DPS.
\c\ Assumes multiple repeated takes of same individuals from small portion of each stock as well as repeated
  takes of Chesapeake Bay resident population (size unknown). Please see the Small Numbers section for
  additional information.
\d\ This stock abundance estimate includes only the U.S. portion of this stock. The actual stock abundance,
  including the Canadian portion of the population, is estimated to be approximately 451,431 animals.


[[Page 83018]]

Proposed Mitigation

    Under section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
permissible methods of taking pursuant to the activity, and other means 
of effecting the least practicable impact on the species or stock and 
its habitat, paying particular attention to rookeries, mating grounds, 
and areas of similar significance, and on the availability of the 
species or stock for taking for certain subsistence uses (latter not 
applicable for this action). NMFS regulations require applicants for 
incidental take authorizations to include information about the 
availability and feasibility (economic and technological) of equipment, 
methods, and manner of conducting the activity or other means of 
effecting the least practicable adverse impact upon the affected 
species or stocks and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, 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, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    In addition to the measures described later in this section, the 
Navy will employ the following mitigation measures:
     For in-water heavy machinery work other than pile driving, 
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;
     The Navy will conduct briefings between construction 
supervisors and crews and the marine mammal monitoring team prior to 
the start of all pile driving activity and when new personnel join the 
work, to explain responsibilities, communication procedures, marine 
mammal monitoring protocol, and operational procedures;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal will shut 
down immediately if such species are observed within or entering the 
Level B harassment zone; and
     If take reaches the authorized limit for an authorized 
species, pile installation/removal will shut down immediately if these 
species approach the Level B harassment zone to avoid additional take.
    The following mitigation measures apply to the Navy's in-water 
construction activities.
    Establishment of Shutdown Zones--The Navy will establish shutdown 
zones for all pile driving and removal activities. The purpose of a 
shutdown zone is generally to define an area within which shutdown of 
the activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
will vary based on the activity type and marine mammal hearing group 
(Table 15).
    Protected Species Observers (PSOs)--The placement of PSOs during 
all pile driving and removal activities (described in the Proposed 
Monitoring and Reporting section) will ensure that the entire shutdown 
zone is visible during pile driving and removal. Should environmental 
conditions deteriorate such that marine mammals within the entire 
shutdown zone would not be visible (e.g., fog, heavy rain), pile 
driving and removal must be delayed until the PSO is confident marine 
mammals within the shutdown zone could be detected.
    Monitoring for Level B Harassment--The Navy will monitor the Level 
B harassment zones (areas where SPLs are equal to or exceed the 160 dB 
rms threshold for impact driving and the 120 dB rms threshold during 
vibratory pile driving) to the extent practicable, and the Level A 
harassment zones. The Navy will monitor at least a portion of the Level 
B harassment zone on all pile driving days. Monitoring zones provide 
utility for observing by establishing monitoring protocols for areas 
adjacent to the shutdown zones. Monitoring zones enable observers to be 
aware of and communicate the presence of marine mammals in the project 
area outside the shutdown zone and thus prepare for a potential 
cessation of activity should the animal enter the shutdown zone.
    Pre-activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal of 
30 minutes or longer occurs, PSOs will observe the shutdown and 
monitoring zones for a period of 30 minutes. The shutdown zone will be 
considered cleared when a marine mammal has not been observed within 
the zone for that 30-minute period. If a marine mammal is observed 
within the shutdown zone, a soft-start cannot proceed until the animal 
has left the zone or has not been observed for 15 minutes. When a 
marine mammal for which Level B harassment take is authorized is 
present in the Level B harassment zone, activities may begin and Level 
B harassment take will be recorded. If the entire Level B harassment 
zone is not visible at the start of construction, pile driving 
activities can begin. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones will commence. A 
determination that the shutdown zone is clear must be made during a 
period of good visibility (i.e., the entire shutdown zone and 
surrounding waters must be visible to the naked eye).
    Soft Start--Soft-start procedures are believed to provide 
additional protection to marine mammals by providing warning and/or 
giving marine mammals a chance to leave the area prior to the hammer 
operating at full capacity. For impact pile driving, contractors will 
be required to provide an initial set of three strikes from the hammer 
at reduced energy, followed by a 30-second waiting period. This 
procedure will be conducted three times before impact pile driving 
begins. Soft start will be implemented at the start of each day's 
impact pile driving and at any time following cessation of impact pile 
driving for a period of 30 minutes or longer.
    The Navy does not plan to use a pile driving energy attenuator 
during construction.

[[Page 83019]]



                          Table 15--Shutdown Zones During Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
                                                                           Shutdown Zone
             Site                 Pile size and  ---------------------------------------------------------------
                                      type          LF cetacean     MF cetacean     HF cetacean       Phocid
----------------------------------------------------------------------------------------------------------------
Pier 3........................  16-in Composite.              20                        10m
Pier 12.......................  16-in Composite.              20
MWR Marina....................  24-in Concrete..              50
                                16-in Composite.              20
V-Area........................  24-in Concrete..              50
                                16-in Composite.              20
Craney Island.................  16-in Composite.              20
Lambert's Point...............  16-in Composite.              20
----------------------------------------------------------------------------------------------------------------
Pier 3........................  16-in Composite/                                10m
                                 12-in Timber.
Pier 12.
MWR Marina.
V-Area.
Craney Island.
Lambert's Point.
----------------------------------------------------------------------------------------------------------------

    Based on our evaluation of the Navy's proposed measures, as well as 
other measures considered by NMFS, 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 LOA for an activity, section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. NMFS' MMPA implementing 
regulations further describe the information that an applicant should 
provide when requesting an authorization (50 CFR 216.104 (a)(13)), 
including the means of accomplishing the necessary monitoring and 
reporting that will result in increased knowledge of the species and 
the level of taking or impacts on populations of marine mammals.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
    The Navy will submit a Marine Mammal Monitoring Plan to NMFS for 
approval in advance of the start of construction.

Visual Monitoring

    Marine mammal monitoring during pile driving and removal must be 
conducted by PSOs meeting NMFS' standards and in a manner consistent 
with the following:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
     At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     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, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
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.
    At least two PSOs will monitor all pile driving activities. 
Depending on available resources, and depending on the size of the zone 
associated with the activity, additional PSOs may be utilized as 
necessary. PSOs will be placed at the best vantage point(s) practicable 
to monitor for marine mammals and implement shutdown/delay procedures. 
(See Figure 13-1 of the Navy's application for example representative 
monitoring locations.)
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile driving activities. In addition, observers shall 
record all incidents of marine mammal occurrence, regardless

[[Page 83020]]

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.

Acoustic Monitoring

    The Navy intends to conduct a sound source verification (SSV) study 
for all pile types other than concrete and timber piles and will follow 
accepted methodological standards to achieve their objectives. The Navy 
will submit an acoustic monitoring plan to NMFS for approval prior to 
the start of construction.

Reporting

    The Navy would submit a draft report to NMFS within 45 workdays of 
the completion of required monitoring for each MPU project. The report 
will detail the monitoring protocol and summarize the data recorded 
during monitoring. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring.
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method (i.e., impact or vibratory).
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance (if less 
than the harassment zone distance).
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting.
     Age and sex class, if possible, of all marine mammals 
observed.
     PSO locations during marine mammal monitoring.
     Distances and bearings of each marine mammal observed to 
the pile being driven or removed for each sighting (if pile driving or 
removal was occurring at time of sighting).
     Description of any marine mammal behavior patterns during 
observation, including direction of travel and estimated time spent 
within the Level A and Level B harassment zones while the source was 
active.
     Number of marine mammals detected within the harassment 
zones, by species.
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any.
     Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals.
    If no comments are received from NMFS within 30 days, the draft 
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 event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Navy shall report the 
incident to the Office of Protected Resources (OPR) (301-427-8401), 
NMFS and to the Greater Atlantic Region New England/Mid-Atlantic 
Regional Stranding Coordinator as soon as feasible. If the death or 
injury was clearly caused by the specified activity, the Navy must 
immediately cease the specified activities until NMFS is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the authorization. The Navy must not resume their activities until 
notified by NMFS.
    The report must include the following information:
    i. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    ii. Species identification (if known) or description of the 
animal(s) involved;
    iii. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    iv. Observed behaviors of the animal(s), if alive;
    v. If available, photographs or video footage of the animal(s); and
    vi. General circumstances under which the animal was discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, this introductory discussion of our analyses 
applies to all of the species listed in Table 5, given that many of the 
anticipated effects of this project on different marine mammal stocks 
are expected to be relatively similar in nature. Where there are 
meaningful differences between species or stocks in anticipated 
individual responses to activities, impact of expected take on the 
population due to differences in population status, or impacts on 
habitat, they are described independently in the analysis below.
    Pile driving activities associated with the project, as outlined 
previously, have the potential to disturb or displace marine mammals. 
Specifically, the specified activities may result in take, in the form 
of Level B harassment from underwater sounds generated by pile driving. 
Potential takes could occur if marine mammals are present in zones 
ensonified above the thresholds for Level B harassment, identified 
above, while activities are underway.
    No serious injury or mortality would be expected even in the 
absence of the proposed mitigation measures. For all species other than 
humpback whale, no Level A harassment is anticipated given the nature 
of the activities. For humpback whale, no Level A harassment is 
anticipated due to the proposed mitigation measures, which we expect 
the Navy will be able to effectively implement given the small Level A 
harassment zone sizes and high visibility of humpback whales.

[[Page 83021]]

    The Navy's proposed pile driving activities and associated impacts 
will occur within a limited portion of the confluence of the Chesapeake 
Bay area. Localized noise exposures produced by project activities may 
cause short-term behavioral modifications in affected cetaceans and 
pinnipeds. However, as described previously, the mitigation and 
monitoring measures are expected to further reduce the likelihood of 
injury as well as reduce behavioral disturbances.
    Effects on individuals that are taken by Level B harassment, 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). Individual animals, even if taken multiple times, will most 
likely move away from the sound source and be temporarily displaced 
from the areas of pile driving, although even this reaction has been 
observed primarily only in association with impact pile driving. The 
pile driving activities analyzed here are similar to, or less impactful 
than, numerous other construction activities conducted along both 
Atlantic and Pacific coasts, which have taken place with no known long-
term adverse consequences from behavioral harassment. Furthermore, many 
projects similar to this one are also believed to result in multiple 
takes of individual animals without any documented long-term adverse 
effects. Level B harassment will be minimized through use of mitigation 
measures described herein and, if sound produced by project activities 
is sufficiently disturbing, animals are likely to simply avoid the area 
while the activity is occurring, particularly as the project is located 
on a busy waterfront with high amounts of vessel traffic.
    As previously described, UMEs have been declared for Northeast 
pinnipeds (including harbor seal and gray seal) and Atlantic humpback 
whales. However, we do not expect takes proposed for authorization in 
this action to exacerbate or compound upon these ongoing UMEs. As noted 
previously, no injury, serious injury, or mortality is expect or 
proposed for authorization, and Level B harassment takes of humpback 
whale, harbor seal and gray seal will be reduced to the level of least 
practicable adverse impact through the incorporation of the proposed 
mitigation measures. For the WNA stock of gray seal, the estimated 
stock abundance is 451,431 animals, including the Canadian portion of 
the stock (estimated 27,131 animals in the U.S. portion of the stock). 
Given that only 1 to 3 takes by Level B harassment are proposed for 
this stock annually, we do not expect this proposed authorization to 
exacerbate or compound upon the ongoing UME.
    With regard to humpback whales, the UME does not yet provide cause 
for concern regarding population-level impacts. Despite the UME, the 
relevant population of humpback whales (the West Indies breeding 
population, or distinct population segment (DPS)) remains healthy. 
Prior to 2016, humpback whales were listed under the ESA as an 
endangered species worldwide. Following a 2015 global status review 
(Bettridge et al. 2015), NMFS established 14 DPSs with different 
listing statuses (81 FR 62259; September 8, 2016) pursuant to the ESA. 
The West Indies DPS, which consists of the whales whose breeding range 
includes the Atlantic margin of the Antilles from Cuba to northern 
Venezuela, and whose feeding range primarily includes the Gulf of 
Maine, eastern Canada, and western Greenland, was delisted. The status 
review identified harmful algal blooms, vessel collisions, and fishing 
gear entanglements as relevant threats for this DPS, but noted that all 
other threats are considered likely to have no or minor impact on 
population size or the growth rate of this DPS (Bettridge et al. 2015). 
As described in Bettridge et al. (2015), the West Indies DPS has a 
substantial population size (i.e., 12,312 (95% CI 8,688-15,954) whales 
in 2004-05 (Bettridge et al. 2003)), and appears to be experiencing 
consistent growth. Further, NMFS is proposing to authorize no more than 
eight takes by Level B harassment annually of humpback whale.
    For the WNA stock of harbor seals, the estimated abundance is 
75,834 individuals. The estimated M/SI for this stock (350) is well 
below the PBR (2,006). As such, the proposed Level B harassment takes 
of harbor seal are not expected to exacerbate or compound upon the 
ongoing UMEs.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
will not modify existing marine mammal habitat for a significant amount 
of time. The 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 short duration of the activities and the relatively small area 
of the habitat that may be affected (with no known particular 
importance to marine mammals), the impacts to marine mammal habitat are 
not expected to cause significant or long-term negative consequences.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     No Level A harassment is anticipated or authorized;
     The intensity of anticipated takes by Level B harassment 
is relatively low for all stocks;
     The number of anticipated takes is very low for humpback 
whale, harbor porpoise, and gray seal;
     The specified activity and associated ensonifed areas are 
very small relative to the overall habitat ranges of all species and do 
not include habitat areas of special significance (Biologically 
Important Areas or ESA-designated critical habitat);
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and
     The presumed efficacy of the 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 sections 101(a)(5)(A) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. When the predicted number of individuals to 
be taken is fewer than one third of the species or stock abundance, the 
take is considered to be of small numbers. Additionally, other 
qualitative factors may be considered in the analysis, such

[[Page 83022]]

as the temporal or spatial scale of the activities.
    The authorized instances of take of humpback whale, harbor 
porpoise, harbor seal, and gray seal comprises less than one-third of 
the best available stock abundance (Table 14). The number of animals 
authorized to be taken from these stocks would be considered small 
relative to the relevant stock's abundances even if each estimated 
taking occurred to a new individual, which is an unlikely scenario.
    Three bottlenose dolphin stocks could occur in the project area: 
WNA Coastal Northern Migratory, WNA Coastal Southern Migratory, and 
NNCES stocks. Therefore, the estimated takes of bottlenose dolphin by 
Level B harassment would likely be portioned among these stocks. Based 
on the stocks' respective occurrence in the area, NMFS estimated that 
there would be 100 takes from the NNCES stock over the five-year period 
(no more than 36 in one year), with the remaining takes evenly split 
between the northern and southern migratory coastal stocks. Based on 
consideration of various factors described below, we have determined 
the numbers of individuals taken would likely comprise less than one-
third of the best available population abundance estimate of either 
coastal migratory stock.
    Both the WNA Coastal Northern Migratory and WNA Coastal Southern 
Migratory stocks have expansive ranges and they are the only dolphin 
stocks thought to make broad-scale, seasonal migrations in coastal 
waters of the western North Atlantic. Given the large ranges associated 
with these stocks it is unlikely that large segments of either stock 
would approach the project area and enter into the Chesapeake Bay. The 
majority of both stocks are likely to be found widely dispersed across 
their respective habitat ranges and unlikely to be concentrated in or 
near the Chesapeake Bay.
    Furthermore, the Chesapeake Bay and nearby offshore waters 
represent the boundaries of the ranges of each of the two coastal 
stocks during migration. The WNA Coastal Northern Migratory stock 
occurs during warm water months from coastal Virginia, including the 
Chesapeake Bay and Long Island, New York. The stock migrates south in 
late summer and fall. During cold-water months, dolphins may occur in 
coastal waters from Cape Lookout, North Carolina, to the North 
Carolina/Virginia. During January-March, the WNA Coastal Southern 
Migratory stock appears to move as far south as northern Florida. From 
April to June, the stock moves back north to North Carolina. During the 
warm water months of July-August, the stock is presumed to occupy 
coastal waters north of Cape Lookout, North Carolina, to Assateague, 
Virginia, including the Chesapeake Bay. There is likely some overlap 
between the northern and southern migratory stocks during spring and 
fall migrations, but the extent of overlap is unknown.
    The Chesapeake Bay and waters offshore of its mouth are located on 
the periphery of the migratory ranges of both coastal stocks (although 
during different seasons). Additionally, each of the migratory coastal 
stocks are likely to be located in the vicinity of the Chesapeake Bay 
for relatively short timeframes. Given the limited number of animals 
from each migratory coastal stock likely to be found at the seasonal 
migratory boundaries of their respective ranges, in combination with 
the short time periods (~two months) animals might remain at these 
boundaries, it is reasonable to assume that takes are likely to occur 
to only a small portion of either of the migratory coastal stocks.
    Both migratory coastal stocks likely overlap with the NNCES stock 
at various times during their seasonal migrations. The NNCES stock is 
defined as animals that primarily occupy waters of the Pamlico Sound 
estuarine system (which also includes Core, Roanoke, and Albemarle 
sounds, and the Neuse River) during warm water months (July-August). 
Animals from this stock also use coastal waters (<=1 km from shore) of 
North Carolina from Beaufort north to Virginia Beach, Virginia, 
including the lower Chesapeake Bay. Comparison of dolphin photo-
identification data confirmed that limited numbers of individual 
dolphins observed in Roanoke Sound have also been sighted in the 
Chesapeake Bay (Young, 2018). Like the migratory coastal dolphin 
stocks, the NNCES stock covers a large range. The spatial extent of 
most small and resident bottlenose dolphin populations is on the order 
of 500 km\2\, while the NNCES stock occupies over 8,000 km\2\ 
(LeBrecque et al. 2015). Given this large range, it is again unlikely 
that a preponderance of animals from the NNCES stock would depart the 
North Carolina estuarine system and travel to the northern extent of 
the stock's range. However, recent evidence suggests that there is 
likely a small resident community of NNCES dolphins of indeterminate 
size that inhabits the Chesapeake Bay year-round (E. Patterson, NMFS, 
pers. comm.).
    Many of the dolphin observations in the Chesapeake Bay are likely 
repeated sightings of the same individuals. The Potomac-Chesapeake 
Dolphin Project has observed over 1,200 unique animals since 
observations began in 2015. Re-sightings of the same individual can be 
highly variable. Some dolphins are observed once per year, while others 
are highly regular with greater than 10 sightings per year (J. Mann, 
Potomac-Chesapeake Dolphin Project, pers. comm.). Similarly, using 
available photo-identification data, Engelhaupt et al. (2016) 
determined that specific individuals were often observed in close 
proximity to their original sighting locations and were observed 
multiple times in the same season or same year. Ninety-one percent of 
re-sighted individuals (100 of 110) in the study area were recorded 
less than 30 km from the initial sighting location. Multiple sightings 
of the same individual would considerably reduce the number of 
individual animals that are taken by Level B harassment. Furthermore, 
the existence of a resident dolphin population in the Bay would 
increase the percentage of dolphin takes that are actually re-sightings 
of the same individuals.
    In summary and as described above, the following factors primarily 
support our determination regarding the incidental take of small 
numbers of the affected stocks of bottlenose dolphin:
     Potential bottlenose dolphin takes in the project area are 
likely to be allocated among three distinct stocks;
     Bottlenose dolphin stocks in the project area have 
extensive ranges and it would be unlikely to find a high percentage of 
any one stock concentrated in a relatively small area such as the 
project area or the Chesapeake Bay;
     The Chesapeake Bay represents the migratory boundary for 
each of the specified dolphin stocks and it would be unlikely to find a 
high percentage of any stock concentrated at such boundaries; and
     Many of the takes would likely be repeats of the same 
animals and likely from a resident population of the Chesapeake Bay.
    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

[[Page 83023]]

stocks would not have an unmitigable adverse impact on the availability 
of such species or stocks for taking for subsistence purposes.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
Navy maintenance construction activities would contain an adaptive 
management component.
    The reporting requirements associated with this proposed rule are 
designed to provide NMFS with monitoring data from completed projects 
to allow consideration of whether any changes are appropriate. The use 
of adaptive management allows NMFS to consider new information from 
different sources to determine (with input from the Navy regarding 
practicability) on an annual or biennial basis if mitigation or 
monitoring measures should be modified (including additions or 
deletions). Mitigation measures could be modified if new data suggests 
that such modifications would have a reasonable likelihood of reducing 
adverse effects to marine mammals and if the measures are practicable.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring reports, as required by MMPA authorizations; (2) 
results from general marine mammal and sound research; and (3) any 
information which reveals that marine mammals may have been taken in a 
manner, extent, or number not authorized by these regulations or 
subsequent LOAs.

Endangered Species Act

    Section 7(a)(2) of the ESA (16 U.S.C. 1531 et seq.) requires that 
each Federal agency 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. To ensure ESA 
compliance for the issuance of incidental take authorizations, NMFS 
consults internally whenever we propose to authorize take for 
endangered or threatened species.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Request for Information

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

Classification

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

List of Subjects in 50 CFR Part 218

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

    Dated: December 8, 2020.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, 50 CFR part 218 is proposed 
to be amended as follows:

PART 218--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 218 continues to read as follows:

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

0
2. Add subpart A to part 218 to read as follows:

Subpart A--Taking and Importing Marine Mammals Incidental to U.S. 
Navy Construction at Naval Station Norfolk in Norfolk, Virginia

Sec.
218.1 Specified activity and geographical region.
218.2 Effective dates.
218.3 Permissible methods of taking.
218.4 Prohibitions.
218.5 Mitigation requirements.
218.6 Requirements for monitoring and reporting.
218.7 Letters of Authorization.
218.8 Renewals and modifications of Letters of Authorization.
218.9 [Reserved]

Subpart A--Taking and Importing Marine Mammals Incidental to U.S. 
Navy Construction at Naval Station Norfolk in Norfolk, Virginia


Sec.  218.1   Specified activity and geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy (Navy) 
and those persons it authorizes or funds to conduct activities on its 
behalf for the taking of marine mammals that occurs in the areas 
outlined in paragraph (b) of this section and that occurs incidental to 
construction activities including marine structure maintenance, pile 
replacement, and select waterfront improvements at Naval Station 
(NAVSTA) Norfolk.
    (b) The taking of marine mammals by the Navy may be authorized in a 
Letter of Authorization (LOA) only if it occurs at NAVSTA Norfolk and 
adjacent Navy facilities.


Sec.  218.2   Effective dates.

    Regulations in this subpart are effective from [EFFECTIVE DATE OF 
THE FINAL RULE] to [DATE 5 YEARS AFTER EFFECTIVE DATE OF THE FINAL 
RULE].


Sec.  218.3   Permissible methods of taking.

    Under an LOA issued pursuant to Sec.  216.106 of this chapter and 
Sec.  218.7, the Holder of the LOA (hereinafter ``Navy'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  218.1(b) by Level B harassment associated with 
construction activities, provided the

[[Page 83024]]

activity is in compliance with all terms, conditions, and requirements 
of the regulations in this subpart and the applicable LOA.


Sec.  218.4   Prohibitions.

    (a) Except for the takings contemplated in Sec.  218.3 and 
authorized by a LOA issued under Sec.  216.106 of this chapter and 
Sec.  218.7, it is unlawful for any person to do any of the following 
in connection with the activities described in Sec.  218.1 may:
    (1) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec.  216.106 of 
this chapter and Sec.  218.7;
    (2) Take any marine mammal not specified in such LOA;
    (3) Take any marine mammal specified in such LOA in any manner 
other than as specified;
    (4) Take a marine mammal specified in such LOA if NMFS determines 
such taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (5) Take a marine mammal specified in such LOA if NMFS determines 
such taking results in an unmitigable adverse impact on the species or 
stock of such marine mammal for taking for subsistence uses.
    (b) [Reserved]


Sec.  218.5   Mitigation requirements.

    (a) When conducting the activities identified in Sec.  218.20(a), 
the mitigation measures contained in any LOA issued under Sec.  216.106 
of this chapter and Sec.  218.7 must be implemented. These mitigation 
measures shall include but are not limited to:
    (1) A copy of any issued LOA must be in the possession of the Navy, 
its designees, and work crew personnel operating under the authority of 
the issued LOA.
    (2) The Navy shall conduct briefings for construction supervisors 
and crews, the 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, the marine 
mammal monitoring protocol, and operational procedures.
    (3) For in-water heavy machinery work other than pile driving, if a 
marine mammal comes within 10 m, the Navy shall cease operations and 
reduce vessel speed to the minimum level required to maintain steerage 
and safe working conditions.
    (4) For all pile driving activity, the Navy shall implement a 
minimum shutdown zone of a 10 m radius around the pile. If a marine 
mammal comes within or approaches the shutdown zone, such operations 
shall cease.
    (5) For all pile driving activity, the Navy shall implement 
shutdown zones with radial distances as identified in a LOA issued 
under Sec.  216.106 of this chapter and Sec.  218.7. If a marine mammal 
comes within or approaches the shutdown zone, such operations shall 
cease.
    (6) The Navy shall deploy protected species observers (observers) 
as indicated in its Marine Mammal Monitoring Plan approved by NMFS.
    (7) For all pile driving activities, a minimum of two observers 
shall be stationed at the best vantage points practicable to monitor 
for marine mammals and implement shutdown/delay procedures.
    (8) Monitoring shall take place from 30 minutes prior to initiation 
of pile driving activity through 30 minutes post-completion of pile 
driving activity. Pre-activity monitoring shall be conducted for 30 
minutes to ensure that the shutdown zone is clear of marine mammals, 
and pile driving may commence when observers have declared the shutdown 
zone clear of marine mammals. In the event of a delay or shutdown of 
activity resulting from marine mammals in the shutdown zone, animals 
shall be allowed to remain in the shutdown zone (i.e., must leave of 
their own volition) and their behavior shall be monitored and 
documented. If a marine mammal is observed within the shutdown zone, a 
soft-start cannot proceed until the animal has left the zone or has not 
been observed for 15 minutes. Monitoring shall occur throughout the 
time required to drive a pile. If work ceases for more than 30 minutes, 
the pre-activity monitoring of the shutdown zones must commence. A 
determination that the shutdown zone is clear must be made during a 
period of good visibility (i.e., the entire shutdown zone and 
surrounding waters must be visible to the naked eye).
    (9) If a marine mammal approaches or enters the shutdown zone, all 
pile driving activities at that location shall be halted. If pile 
driving is halted or delayed due to the presence of a marine mammal, 
the activity may not commence or resume until either the animal has 
voluntarily left and been visually confirmed beyond the shutdown zone 
or fifteen minutes have passed without re-detection of the animal.
    (10) Pile driving activity must be halted upon observation of 
either a species for which incidental take is not authorized or a 
species for which incidental take has been authorized but the 
authorized number of takes has been met, entering or within the 
harassment zone.
    (11) Should environmental conditions deteriorate such that marine 
mammals within the entire shutdown zone would not be visible (e.g., 
fog, heavy rain), the Navy shall delay pile driving and removal until 
observers are confident marine mammals within the shutdown zone could 
be detected.
    (12) Monitoring shall be conducted by trained observers, who shall 
have no other assigned tasks during monitoring periods. Trained 
observers shall be placed at the best vantage point(s) practicable to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable through communication with the equipment operator. The 
Navy shall adhere to the following additional observer qualifications:
    (i) Independent observers are required.
    (ii) At least one observer must have prior experience working as an 
observer.
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience.
    (iv) Where a team of three or more observers are required, one 
observer shall be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer.
    (v) Personnel who are engaged in construction activities may not 
serve as observers.
    (13) The Navy shall use soft start techniques for impact pile 
driving. Soft start for impact drivers requires the Navy and those 
persons it authorizes or funds to provide an initial set of three 
strikes at reduced energy, followed by a 30-second waiting period, then 
two subsequent reduced energy three-strike sets. Soft start shall be 
implemented at the start of each day's impact pile driving and at any 
time following cessation of impact pile driving for a period of thirty 
minutes or longer.
    (b) [Reserved]


Sec.  218.6   Requirements for monitoring and reporting.

    (a) The Navy shall submit a Marine Mammal Monitoring Plan to NMFS 
for approval in advance of construction.
    (b) The Navy shall deploy observers as indicated in its approved 
Marine Mammal Monitoring Plan.
    (c) Observers shall be trained in marine mammal identification and 
behaviors. Observers shall have no other construction-related tasks 
while conducting monitoring.
    (d) For all pile driving activities, a minimum of two observers 
shall be

[[Page 83025]]

stationed at the active pile driving site or in reasonable proximity in 
order to monitor the shutdown zone.
    (e) The Navy shall monitor the Level B harassment zones (areas 
where SPLs are equal to or exceed the 160 dB rms threshold for impact 
driving and the 120 dB rms threshold during vibratory pile driving) to 
the extent practicable and the shutdown zones. The Navy shall monitor 
at least a portion of the Level B harassment zone on all pile driving 
days.
    (f) The Navy shall conduct hydroacoustic data collection (sound 
source verification and propagation loss) in accordance with a 
hydroacoustic monitoring plan that must be approved by NMFS in advance 
of construction.
    (g) The Navy shall submit a draft monitoring report to NMFS within 
45 work days of the completion of required monitoring for each marine 
structure maintenance, pile replacement, and upgrades project. The 
report must detail the monitoring protocol and summarize the data 
recorded during monitoring. If no comments are received from NMFS 
within 30 days, the draft 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. Specifically, the 
report must include:
    (1) Dates and times (begin and end) of all marine mammal 
monitoring.
    (2) Construction activities occurring during each daily observation 
period, including how many and what type of piles were driven or 
removed and by what method (i.e., impact or vibratory).
    (3) Environmental conditions during monitoring periods (at 
beginning and end of observer shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance (if less 
than the harassment zone distance).
    (4) The number of marine mammals observed, by species, relative to 
the pile location and if pile driving or removal was occurring at time 
of sighting.
    (5) Age and sex class, if possible, of all marine mammals observed.
    (6) Observer locations during marine mammal monitoring.
    (7) Distances and bearings of each marine mammal observed to the 
pile being driven or removed for each sighting (if pile driving or 
removal was occurring at time of sighting).
    (8) Description of any marine mammal behavior patterns during 
observation, including direction of travel and estimated time spent 
within the Level A and Level B harassment zones while the source was 
active.
    (9) Number of marine mammals detected within the harassment zones, 
by species.
    (10) Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any.
    (11) Description of attempts to distinguish between the number of 
individual animals taken and the number of incidences of take, such as 
ability to track groups or individuals.
    (h) The Navy shall report the hydroacoustic data collected as 
required by a LOA issued under Sec.  216.106 of this chapter and Sec.  
218.7.
    (i) In the event that personnel involved in the construction 
activities discover an injured or dead marine mammal, the Navy shall 
report the incident to the Office of Protected Resources (OPR) (301-
427-8401), NMFS and to the Greater Atlantic Region New England/Mid-
Atlantic Regional Stranding Coordinator as soon as feasible. If the 
death or injury was clearly caused by the specified activity, the Navy 
must immediately cease the specified activities until NMFS is able to 
review the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the authorization. The Navy must not resume their activities until 
notified by NMFS.
    (1) The report must include the following information:
    (i) Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    (ii) Species identification (if known) or description of the 
animal(s) involved;
    (iii) Condition of the animal(s) (including carcass condition if 
the animal is dead);
    (iv) Observed behaviors of the animal(s), if alive;
    (v) If available, photographs or video footage of the animal(s); 
and
    (vi) General circumstances under which the animal was discovered.
    (2) [Reserved]


Sec.  218.7   Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, the Navy must apply for and obtain an LOA.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed the expiration date of these regulations.
    (c) If an LOA expires prior to the expiration date of these 
regulations, the Navy may apply for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by an LOA, the Navy must 
apply for and obtain a modification of the LOA as described in Sec.  
218.8.
    (e) The LOA shall set forth the following information:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and on the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (f) Issuance of the LOA shall be based on a determination that the 
level of taking will be consistent with the findings made for the total 
taking allowable under these regulations.
    (g) Notice of issuance or denial of an LOA shall be published in 
the Federal Register within 30 days of a determination.


Sec.  218.8   Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec.  216.106 of this chapter and Sec.  
218.7 for the activity identified in Sec.  218.1(a) shall be renewed or 
modified upon request by the applicant, provided that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for these regulations, and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under these regulations were 
implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting that do not change the findings made for the regulations or 
result in no more than a minor change in the total estimated number of 
takes (or distribution by species or years), NMFS may publish a notice 
of proposed LOA in the Federal Register, including the associated 
analysis of the change, and solicit public comment before issuing the 
LOA.
    (c) An LOA issued under Sec.  216.106 of this chapter and Sec.  
218.7 for the activity identified in Sec.  218.1(a) may be modified by 
NMFS under the following circumstances:
    (1) NMFS may modify (including augment) the existing mitigation,

[[Page 83026]]

monitoring, or reporting measures (after consulting with Navy regarding 
the practicability of the modifications) if doing so creates a 
reasonable likelihood of more effectively accomplishing the goals of 
the mitigation and monitoring set forth in the preamble for these 
regulations.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in a LOA:
    (A) Results from Navy's monitoring from previous years.
    (B) Results from other marine mammal and/or sound research or 
studies.
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent or number not authorized by these regulations or 
subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) If NMFS determines that an emergency exists that poses a 
significant risk to the well-being of the species or stocks of marine 
mammals specified in a LOA issued pursuant to Sec.  216.106 of this 
chapter and Sec.  218.7, a LOA may be modified without prior notice or 
opportunity for public comment. Notice would be published in the 
Federal Register within 30 days of the action.


Sec.  218.9  [Reserved]

[FR Doc. 2020-27300 Filed 12-18-20; 8:45 am]
BILLING CODE 3510-22-P