[Federal Register Volume 83, Number 43 (Monday, March 5, 2018)]
[Proposed Rules]
[Pages 9366-9401]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-04148]



[[Page 9365]]

Vol. 83

Monday,

No. 43

March 5, 2018

Part II





 Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 218





 Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to U.S. Navy Marine Structure Maintenance and Pile Replacement in 
Washington; Proposed Rule

  Federal Register / Vol. 83 , No. 43 / Monday, March 5, 2018 / 
Proposed Rules  

[[Page 9366]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 218

[Docket No. 170919913-8186-01]
RIN 0648-BH27


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to U.S. Navy Marine Structure Maintenance and Pile 
Replacement in Washington

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 conducting 
construction activities related to marine structure maintenance and 
pile replacement at facilities in Washington, over the course of five 
years (2018-2023). As required by the Marine Mammal Protection Act 
(MMPA), NMFS is proposing regulations to govern that take, and requests 
comments on the proposed regulations. NMFS will consider public 
comments prior to making any final decision on the issuance of the 
requested MMPA authorization and agency responses will be summarized in 
the final notice of our decision.

DATES: Comments and information must be received no later than April 4, 
2018.

ADDRESSES: You may submit comments on this document, identified by 
NOAA-NMFS-2018-0032, by any of the following methods:
     Electronic submission: Submit all electronic public 
comments via the federal e-Rulemaking Portal. Go to 
www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2018-0032, click the 
``Comment Now!'' icon, complete the required fields, and enter or 
attach your comments.
     Mail: Submit written comments to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Silver 
Spring, MD 20910.
    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: Ben Laws, 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: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. 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 
related to marine structure maintenance and pile replacement at 
facilities in Washington.
    We received an application from the Navy requesting five-year 
regulations and authorization to take multiple species of marine 
mammals. Take would occur by Level A and Level B harassment incidental 
to impact and vibratory pile driving. Please see ``Background'' below 
for definitions of harassment.

Legal Authority for the Proposed Action

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs 
the Secretary of Commerce to allow, upon request, the incidental, but 
not intentional taking of small numbers of marine mammals by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified geographical region for up to five years 
if, after notice and public comment, the agency makes certain findings 
and issues regulations that set forth permissible methods of taking 
pursuant to that activity and other means of effecting the ``least 
practicable adverse impact'' on the affected species or stocks and 
their habitat (see the discussion below in the ``Proposed Mitigation'' 
section), as well as monitoring and reporting requirements. Section 
101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR 
part 216, subpart I provide the legal basis for issuing this proposed 
rule containing five-year regulations, and for any subsequent 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.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, or kill, or attempt to harass, hunt, capture, or kill any 
marine mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of

[[Page 9367]]

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 evaluate our proposed action (i.e., the promulgation of 
regulations and subsequent issuance of incidental take authorization) 
and alternatives 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 NAO 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 proposed action qualifies to be 
categorically excluded from further NEPA review.
    Information in the Navy's application and this notice 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 notice prior to concluding our NEPA process or making 
a final decision on the request for incidental take authorization.

Summary of Request

    On July 24, 2017, we received an adequate and complete request from 
the Navy requesting authorization for take of marine mammals incidental 
to construction activities related to marine structure maintenance and 
pile replacement at six Naval installations in Washington inland 
waters. On August 4, 2017 (82 FR 36359), we published a notice of 
receipt of the Navy's application in the Federal Register, requesting 
comments and information related to the request for thirty days. We 
received comments from Whale and Dolphin Conservation (WDC). The 
comments received from WDC were considered in development of this 
proposed rule and are available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
    The Navy proposes to conduct construction necessary for maintenance 
of existing in-water structures at the following facilities: Naval Base 
Kitsap (NBK) Bangor, NBK Bremerton, NBK Keyport, NBK Manchester, 
Zelatched Point, and Naval Station Everett (NS Everett). These repairs 
would include use of impact and vibratory pile driving, including 
installation and removal of steel, concrete, plastic, and timber piles. 
Hereafter (unless otherwise specified or detailed) we use the term 
``pile driving'' to refer to both pile installation and pile removal. 
The use of both vibratory and impact pile driving is expected to 
produce underwater sound at levels that have the potential to result in 
harassment of marine mammals.
    The Navy requests authorization to take individuals of 10 species 
by Level B harassment. Take by Level A harassment was requested only 
for the harbor seal. The proposed regulations would be valid for five 
years (2018-2023).

Description of the Specified Activity

Overview

    Maintaining existing wharfs and piers is vital to sustaining the 
Navy's mission and ensuring readiness. To ensure continuance of 
necessary missions at the six installations, the Navy must conduct 
annual maintenance and repair activities at existing marine waterfront 
structures, including removal and replacement of piles of various types 
and sizes. The Navy refers to this program as the Marine Structure 
Maintenance and Pile Replacement (MPR) program. Exact timing and amount 
of necessary in-water work is unknown, but the Navy estimates replacing 
up to 822 structurally unsound piles over the 5-year period, including 
individual actions currently planned and estimates for future marine 
structure repairs. Construction will include use of impact and 
vibratory pile driving, including removal and installation of steel, 
concrete, plastic, and timber piles. Aspects of construction activities 
other than pile driving are not anticipated to have the potential to 
result in incidental take of marine mammals because they are either 
above water or do not produce levels of underwater sound with likely 
potential to result in marine mammal disturbance.
    The Navy's waterfront inspection program prioritizes deficiencies 
in marine structures and plans those maintenance and repairs for design 
and construction. The Navy's proposed activities include individual 
projects (where an existing need has been identified and funds have 
been requested) and estimates for emergent or emergency repairs. The 
latter are also referred to as contingency repairs. Estimates of 
activity levels for contingency repairs are based on Navy surveys of 
existing structures, which provide assessments of structure condition 
and estimates of numbers of particular pile types that may require 
replacement (at an assumed 1:1 ratio) over the 5-year duration of these 
proposed regulations. Additional allowance is made for the likelihood 
that future waterfront inspections will reveal unexpected damage, or 
that damage caused by severe weather events and/or incidents caused by 
vessels will result in need for additional contingency repairs. This 
regional programmatic approach to MMPA compliance is expected to result 
in significantly increased efficiency for both the Navy and NMFS, while 
satisfying the requirements of the MMPA. The regulations proposed here 
(and any issued LOAs) would replace multiple project-specific 
incidental take authorization requests for actions that are small in 
scale, similar in nature, and located within a similar geographic area. 
The detailed discussion of planned or anticipated projects provided 
here and in the Navy's application allow for more comprehensive 
analysis, while providing a reduction in the time and effort necessary 
to obtain individual incidental take authorizations. LOAs could be 
issued for projects conducted at any of the six facilities if they fit 
within the structure of the programmatic analysis provided herein and 
are able to meet the requirements described in the regulations.
    The Navy would meet with NMFS on an annual basis prior to the start 
of in-water work windows to review upcoming projects, required 
monitoring plans, and the results of relevant projects conducted in the 
preceding in-water work window. The intent is to utilize lessons 
learned to better inform potential effects of future MPR activities and 
in any follow-up consultations.

Dates and Duration

    The proposed regulations would be valid for a period of five years 
(2018-2023). The specified activities may occur at any time during the 
five-year period of validity of the proposed regulations, subject to 
existing timing restrictions. These timing restrictions, or in-water 
work windows, are typically

[[Page 9368]]

designed to protect fish species listed under the Endangered Species 
Act (ESA). For NBK Bangor and Zelatched Point (located in Hood Canal), 
in-water work may occur from July 16 through January 15. At the 
remaining four facilities (located in Puget Sound), in-water work may 
occur from July 16 through February 15.
    For many projects the design details are not known; thus, it is not 
possible to state the number of pile driving days that will be 
required. Days of pile driving at each site were based on the estimated 
work days using a slow production rate, i.e., one pile removed per day 
and one pile installed per day for contingency pile driving and an 
average production rate of six piles per day for fender pile 
replacement. These conservative rates give the following estimates of 
total days at each facility over the 5-year duration: NBK Bangor, 119 
days; Zelatched Point, 20 days; NBK Bremerton, 168 days; NBK Keyport, 
20 days; NBK Manchester, 50 days; and NS Everett, 78 days. These totals 
include both extraction and installation of piles, and represent a 
conservative estimate of pile driving days at each facility. In a real 
construction situation, pile driving production rates would be 
maximized when possible and actual daily production rates may be 
higher, resulting in fewer actual pile driving days.

Specified Geographical Region

    The six installations are located within the inland waters of 
Washington State. Two facilities are located within Hood Canal, while 
the remainder are located within Puget Sound. Please see Figure 1-1 of 
the Navy's application for a regional map. For full details regarding 
the specified geographical region, please see section 2 of the Navy's 
application. The region is affected by high amounts of runoff from the 
Fraser River, which stimulates primary productivity, carrying nutrients 
northwards past Vancouver Island year-round. Puget Sound is one of the 
largest estuaries in the United States and is a place of great physical 
and ecological complexity and productivity. The average surface water 
temperature is 12.8 [deg]C in summer and 7.2 [deg]C in winter (Staubitz 
et al., 1997), but surface waters frequently exceed 20[deg]C in the 
summer and fall. With nearly six million people (doubled since the 
1960s), Puget Sound is also heavily influenced by human activity.
    NBK Bangor is located on the Hood Canal, a long, narrow, fjord-like 
basin of western Puget Sound. Please see Figure 1-2 of the Navy's 
application. Oriented northeast to southwest, the portion of the canal 
from Admiralty Inlet to a large bend, called the Great Bend, at 
Skokomish, Washington, is 84 kilometers (km) long. East of the Great 
Bend, the canal extends an additional 15 mi to Belfair. Throughout its 
108-km length, the width of the canal varies from 1.6 to 3.2 km and 
exhibits strong depth/elevation gradients. Hood Canal is characterized 
by relatively steep sides and irregular seafloor topography. In 
northern Hood Canal, water depths in the center of the waterway near 
Admiralty Inlet vary between 91 and 128 meters (m). As the canal 
extends southwestward toward the Olympic Mountain Range and Thorndyke 
Bay, water depth decreases to approximately 49 m over a moraine 
deposit. This deposit forms a sill across the canal in the vicinity of 
Thorndyke Bay, which limits seawater exchange with the rest of Puget 
Sound. The NBK Bangor waterfront occupies approximately 8 km of the 
shoreline within northern Hood Canal (1.7 percent of the entire Hood 
Canal coastline) and lies just south of the sill feature. Zelatched 
Point is located on the southwestern end of the Toandos Peninsula on 
Dabob Bay within Hood Canal. Please see Figure 1-6 of the Navy's 
application. It is approximately 6.4 km west of the NBK Bangor 
waterfront on the western facing portion of Toandos Peninsula. Dabob 
Bay is a 183-m deep fjord-like basin with a 101-m sill at its entrance. 
It runs north 19 km from its junction with Hood Canal. The width of the 
Dabob Bay is approximately 4.5 km at the Zelatched Point pier.
    NBK Bremerton is located on the north side of Sinclair Inlet in 
southern Puget Sound. Please see Figure 1-3 of the Navy's application. 
Sinclair Inlet is located off the main basin of Puget Sound and is 
about 6.9 long and 1.9 km wide. The inlet is connected to the main 
basin through Port Orchard Narrows and Rich Passage. Another relatively 
narrow waterway, Port Washington Narrows, connects Sinclair Inlet to 
Dyes Inlet. In-water structures, shoreline fill, and erosion protection 
at NBK Bremerton have resulted in a shoreline geometry and character 
that is quite different from undisturbed shorelines in Puget Sound. 
Bathymetry near existing piers and in turning basins immediately 
offshore has been altered by significant dredging to accommodate 
aircraft carriers and other Navy vessels. Water depths range from 12 to 
14 m, increasing to 14 to 15 m in dredged berthing areas. West of the 
project sites, further into the inlet, depths gradually decrease to 
less than 9 m.
    NBK Keyport is located on the eastern shore of the Kitsap 
Peninsula, approximately 24 km due west of Seattle and 16 km north of 
the city of Bremerton. Please see Figure 1-4 of the Navy's application. 
Keyport Pier is located along the shores of Liberty Bay, which flows 
into Port Orchard Bay and then through the narrow Agate Passage to the 
northeast and Port Orchard Narrows to the south. Liberty Bay and waters 
adjacent to Keyport are relatively shallow with water depths no greater 
than 30 m. Water depths increase from the northwest to south/southeast 
and are greatest in the southern portion of the Port Orchard Narrows.
    NBK Manchester is located on Orchard Point, approximately 6.4 km 
due east of Bremerton. Please see Figure 1-5 of the Navy's application. 
The installation is bounded by Clam Bay to the northwest, Rich Passage 
to the northeast, and Puget Sound to the east. NBK Manchester piers are 
located on the north side of Orchard Point and in a small embayment 
open on the south side of Orchard Point. In Clam Bay, the bathymetry is 
gently sloping with depths in the outer portions of the bay of 
approximately 5.5 m below mean lower low water (MLLW). Depths off 
Orchard Point drop off dramatically to 18 m below MLLW approximately 
150 m from shore and 90 m below MLLW 1.6 km offshore. Rich Passage is a 
shallow sill, less than 21 m deep.
    NS Everett is located in Port Gardner Bay in Puget Sound's Whidbey 
Basin. Please see Figure 1-7 of the Navy's application. To the west of 
the installation is the channelized mouth of the Snohomish River 
bounded by Jetty Island, which is composed of sediment from maintenance 
dredging and acts as a breakwater for the northwest area along the 
installation's waterfront. Jetty Island separates Port Gardner Bay and 
Possession Sound from the Snohomish River channel. The mouth of the 
Snohomish River channel is a historically industrialized area of highly 
modified shorelines and dredged waterways that forms a protected harbor 
within Port Gardner Bay. East of Jetty Island lies the Snohomish River 
estuary, consisting of a series of interconnected sloughs that flow 
through the lowlands east and north of the river's main channel. Water 
depths in Possession Sound range from about 9 m near the industrialized 
shoreline in Port Gardner to 180 m in mid-channel.

Detailed Description of Activities

    As described above, the Navy has requested incidental take 
regulations for its MPR program, which includes maintenance and repair 
activities at marine waterfront structures at six installations within 
Washington inland

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waters. In order to address identified deficiencies in existing marine 
structures at the six facilities, the Navy proposes to replace up to 
822 structurally unsound piles over the 5-year period using both impact 
and vibratory pile driving. Existing marine structures at the six 
facilities are identified in Table 1-2 of the Navy's application. The 
MPR program includes pile repair, extraction, and installation, all of 
which may be accomplished through a variety of methods. However, only 
pile extraction and installation using vibratory and impact pile 
drivers is expected to have the potential to result in incidental take 
of marine mammals. Pile repair methods include stubbing, wrapping, pile 
encapsulation, welding, or coating. These processes do not involve pile 
driving and are not expected to have the potential to result in 
elevated noise levels or incidental take of marine mammals. Pile 
removal may be accomplished via mechanical methods such as cutting/
chipping, clamshell removal, or direct pull. Water jetting may also be 
used to aid in pile installation. Noise levels produced through these 
activities are not expected to exceed baseline levels produced by other 
routine activities and operations at the six facilities, and any 
elevated noise levels produced through these activities are expected to 
be intermittent, of short duration, and with low peak values. 
Therefore, only vibratory and impact pile driving are carried forward 
for further analysis. To minimize underwater noise impacts on marine 
species, vibratory pile driving will be the primary method used to 
install new steel piles.
    Vibratory hammers, which can be used to either install or extract a 
pile, contain a system of counter-rotating eccentric weights powered by 
hydraulic motors, and are designed in such a way that horizontal 
vibrations cancel out, while vertical vibrations are transmitted into 
the pile. The pile driving machine is lifted and positioned over the 
pile by means of an excavator or crane, and is fastened to the pile by 
a clamp and/or bolts. The vibrations produced cause liquefaction of the 
substrate surrounding the pile, enabling the pile to be extracted or 
driven into the ground using the weight of the pile plus the hammer. 
Impact hammers use a rising and falling piston to repeatedly strike a 
pile and drive it into the ground. Impact or vibratory driving could 
occur on any work day within in-water work windows during the period of 
validity of these proposed regulations.
    Steel piles are typically vibratory-driven for their initial 
embedment depths or to refusal and finished with an impact hammer for 
proofing or until the pile meets structural requirements, as necessary. 
Proofing involves striking a driven pile with an impact hammer to 
verify that it provides the required load-bearing capacity, as 
indicated by the number of hammer blows per foot of pile advancement. 
Non-steel piles (concrete, timber, or plastic) are typically impact-
driven for their entire embedment depth, in part because non-steel 
piles are often displacement piles (as opposed to pipe piles) and 
require some impact to allow substrate penetration. Pile installation 
can typically take a minute or less to 60 minutes depending on pile 
type, pile size, and conditions (i.e., bedrock, loose soils, etc.) to 
reach the required tip elevation.
    The most effective and efficient method of pile installation and 
removal available would be implemented. The method fitting these 
criteria may vary based on specific project requirements and local 
conditions. Impact driving, while generally producing higher levels of 
sound, also minimizes the net amount of active driving time, thus 
reducing the amount of time during which marine mammals may be exposed 
to noise. Impact or vibratory pile driving could occur on any day, but 
would not occur simultaneously. Location-specific pile totals are given 
in Table 1 and described below. These totals assume a 1:1 replacement 
ratio; however, the actual number installed may result in a replacement 
ratio of less than 1:1. Please see Table A-1 of the Navy's application 
for additional detail regarding expectations for both planned work and 
possible contingency work.

  Table 1--Pile Types and Maximum Anticipated Number To Be Replaced at
                            Each Installation
------------------------------------------------------------------------
                                   Existing piles to   Anticipated piles
          Installation                be replaced       to be installed
------------------------------------------------------------------------
NBK Bangor......................  44 concrete; 75     119 steel or
                                   steel and/or        concrete.
                                   timber.
NBK Bremerton...................  75 steel and/or     100 steel (14-in
                                   timber; 460         diameter and
                                   timber.             sheet piles); 435
                                                       concrete.
NBK Keyport.....................  20 steel and/or     20 steel.
                                   concrete.
NBK Manchester..................  50 timber and/or    50 concrete,
                                   plastic.            timber, and/or
                                                       plastic.
Zelatched Point.................  20 timber.........  20 steel,
                                                       concrete, and/or
                                                       timber.
NS Everett......................  1 steel, 2          1 steel and 77
                                   concrete, and 75    concrete and/or
                                   timber.             timber.
------------------------------------------------------------------------

    Steel piles would be a maximum size of 36-inch (in) diameter except 
at NBK Bremerton where they would be 14-in diameter. Concrete piles 
will be a maximum of 24-in diameter and timber/plastic piles will be a 
maximum of 18-in diameter. For purposes of analysis, it is assumed that 
any unknown pile type would be steel, since this would give a worst-
case scenario in terms of noise levels produced. All concrete, timber, 
and plastic piles are assumed to be installed entirely by impact pile 
driver, and all steel piles are assumed to require some use of an 
impact driver. This is a conservative assumption, as all steel piles 
would be initially driven with a vibratory driver until they reach a 
point of refusal (where substrate conditions make use of a vibratory 
hammer ineffective) or engineering specifications require impact 
driving to verify load-bearing capacity. Therefore, some steel piles 
may not in fact require use of the impact driver during installation.
    At this time, of 822 piles expected to be installed as replacement 
piles, 121 have been identified as steel piles. These piles would be 
installed over the 5-year duration at NBK Bremerton, NBK Keyport, and 
NS Everett. In addition, another 139 piles that would be installed at 
NBK Bangor (119) and Zelatched Point (20) have not been identified as 
to pile type and could be steel, concrete, timber or plastic. For this 
analysis, it is assumed all 139 of these would be steel piles. 
Therefore, 260 piles are assumed to be steel, with 100 of these 14-in 
and the remainder assumed to be 36-in diameter. A total of 435 
replacement piles have been identified as concrete (NBK Bremerton). The 
remaining 127 replacement piles (NBK Manchester and NS Everett) could 
ultimately be concrete, timber, or plastic, but are assumed for 
purposes of analysis to be concrete, which is a more conservative noise 
scenario.

[[Page 9370]]

    NBK Bangor is the Pacific homeport for the Navy's TRIDENT submarine 
fleet with the mission to support and maintain a TRIDENT submarine 
squadron and other ships home-ported or moored at the installation and 
to maintain and operate administrative and personnel support facilities 
including security, berthing, messing, and recreational services. NBK 
Bangor is the only naval installation on the west coast with the 
specialized infrastructure able to support the TRIDENT program. The 
specialized infrastructure includes buildings, utilities, and systems 
used to support missile production shops, missile maintenance, missile 
component storage, and missile handling cranes, in addition to 
providing security and operational port facilities.
    Pile-supported structures at the NBK Bangor waterfront include: 
Carderock Pier, Service Pier, Keyport-Bangor (K/B) Dock, Delta Pier, 
Marginal Wharf, Explosives Handling Wharf #1 (EHW-1), and the Magnetic 
Silencing Facility (see Figure 1-2 of the Navy's application). Over the 
5-year duration, up to 44 piles are anticipated to be replaced at EHW-1 
and up to 75 piles could be installed at any of the structures for 
emergent projects.
    Zelatched Point supports test and evaluation operations conducted 
by the Naval Undersea Warfare Center Keyport within Dabob Bay, and 
contains a single pier historically used for mooring small craft and 
float planes during Navy range operations in Dabob Bay (see Figure 1-6 
of the Navy's application). Two dolphins are located at the outboard 
end of the facility, each consisting of three timber piles. Up to 20 
piles of any type are anticipated for emergent/emergency repairs during 
the course of the 5-year duration.
    Puget Sound Naval Shipyard and Intermediate Maintenance Facility is 
the major tenant command of NBK Bremerton. NBK Bremerton contains 
multiple dry docks, piers, and wharfs and is capable of overhauling and 
repairing, constructing, deactivating, and dry-docking all types and 
sizes of ships. It also serves as the homeport for a nuclear aircraft 
carrier and other Navy vessels.
    There are 13 pile-supported structures located at NBK Bremerton 
(see Figure 1-3 of the Navy's application). Two pile repair and 
replacement projects are planned for Piers 4 and 5. The project at Pier 
4 would involve replacing missing or broken timber fender piles with 80 
steel fender piles. Steel piles would be up to 14-in diameter and 
installed with a vibratory driver and only impact driven if they cannot 
be advanced to tip elevation using a vibratory driver. Prior projects 
at Piers 4 and 5 indicate steel piles will be able to be vibratory 
driven. However, some impact driving may be necessary. The project at 
Pier 5 would replace an existing primarily timber fendering system, 
with 360 concrete piles ranging in size up to 24-in diameter. All 
concrete piles are anticipated to be impact driven. Work on Piers 5, 6, 
7, Mooring A, and Dry Dock 5 will involve replacement of up to 20 
timber piles with 20 sheet steel piles. In addition, 75 concrete piles 
are anticipated for emergent/emergency repairs over the 5-year 
duration. Naval Undersea Warfare Center Keyport is the major tenant 
command at NBK Keyport and is the Navy's premier provider of cold-water 
testing and evaluation for undersea warfare systems. In this capacity, 
NBK Keyport provides depot maintenance and repair, in-service 
engineering, and fleet industrial support for torpedoes and other 
undersea warfare systems including mobile mines, unmanned underwater 
vehicles, and countermeasures.
    There is one pier, Keyport Pier, in the northern portion of the NBK 
Keyport installation (see Figure 1-4 of the Navy's application). There 
are no planned pile repair and replacement projects at NBK Keyport; 
however, up to 20 piles are anticipated for emergent/emergency repairs 
or replacement at the Keyport Pier during the course of the 5-year 
duration.
    NBK Manchester provides bulk fuel and lubricant support to area 
Navy afloat and shore activities. The primary pile-supported structures 
at NBK Manchester are the fuel pier and the finger pier with a barge 
mooring platform and a small boat float (see Figure 1-5 of the Navy's 
application). There are no planned projects at NBK Manchester. A 
contingency estimate of 50 concrete, timber, or plastic piles for 
emergent/emergency repairs at the fuel pier or finger pier is proposed 
for the 5-year duration.
    NS Everett provides homeport ship berthing, industrial support, and 
a Navy administrative center. Pile-supported structures at NS Everett 
include Piers A, B, C, D, and E; North Wharf and South Wharf; a 
recreational marina; and the small boat launch (see Figure 1-7 of the 
Navy's application). Additionally, there are fender piles along the 
waterfront areas. Repairs to the North Wharf could require replacement 
of up to two concrete piles. Additionally, contingency planning 
estimated up to 75 concrete or timber piles and one steel pile could be 
repaired or replaced over the 5-year duration.

Description of Marine Mammals in the Area of the Specified Activity

    We have reviewed the Navy's species descriptions--which summarize 
available information regarding status and trends, distribution and 
habitat preferences, behavior and life history, and auditory 
capabilities of the potentially affected species--for accuracy and 
completeness and refer the reader to Sections 3 and 4 of the Navy's 
application, instead of reprinting the information here. Additional 
information regarding population trends and threats may be found in 
NMFS's Stock Assessment Reports (SAR; 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 (www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence in 
the specified geographical region where the Navy proposes to conduct 
the specified activities and summarizes information related to the 
population or stock, including regulatory status under the MMPA and ESA 
and potential biological removal (PBR), where known. For taxonomy, we 
follow Committee on Taxonomy (2017). PBR, 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, is considered in 
concert with known sources of ongoing anthropogenic mortality (as 
described in NMFS's SARs).
    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. All managed stocks in the specified geographical 
regions are assessed in either NMFS's U.S. Alaska SARs or U.S. Pacific 
SARs. All values presented in Table 2 are the most recent available at 
the time of writing and are available in the draft 2017 SARs (available 
online at: www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).
    Ten species (with 13 managed stocks) are considered to have the 
potential to

[[Page 9371]]

co-occur with Navy activities. There are several species or stocks that 
occur in Washington inland waters, but which are not expected to occur 
in the vicinity of the six Naval installations. These species may occur 
in waters of the Strait of Juan de Fuca or in more northerly waters in 
the vicinity of the San Juan Islands and areas north to the Canadian 
border, and include the Pacific white-sided dolphin (Lagenorhynchus 
obliquidens) and the northern resident stock of killer whales. In 
addition, the sea otter is found in coastal waters, with the northern 
(or eastern) sea otter (Enhydra lutris kenyoni) found in Washington. 
However, sea otters are managed by the U.S. Fish and Wildlife Service 
and are not considered further in this document.
    Two populations of gray whales are recognized, eastern and western 
North Pacific (ENP and WNP). WNP whales are known to feed in the 
Okhotsk Sea and off of Kamchatka before migrating south to poorly known 
wintering grounds, possibly in the South China Sea. The two populations 
have historically been considered geographically isolated from each 
other; however, data from satellite-tracked whales indicate that there 
is some overlap between the stocks. Two WNP whales were tracked from 
Russian foraging areas along the Pacific rim to Baja California (Mate 
et al., 2011), and, in one case where the satellite tag remained 
attached to the whale for a longer period, a WNP whale was tracked from 
Russia to Mexico and back again (IWC, 2012). Between 22-24 WNP whales 
are known to have occurred in the eastern Pacific through comparisons 
of ENP and WNP photo-identification catalogs (IWC, 2012; Weller et al., 
2011; Burdin et al., 2011). Urban et al. (2013) compared catalogs of 
photo-identified individuals from Mexico with photographs of whales off 
Russia and reported a total of 21 matches. Therefore, a portion of the 
WNP population is assumed to migrate, at least in some years, to the 
eastern Pacific during the winter breeding season.
    However, there is no indication that WNP whales occur in waters of 
Hood Canal or southern Puget Sound, and it is extremely unlikely that a 
gray whale in close proximity to Navy construction activity would be 
one of the few WNP whales that have been documented in the eastern 
Pacific. The likelihood that a WNP whale would be present in the 
vicinity of Navy construction activities is insignificant and 
discountable, and WNP gray whales are omitted from further analysis.
---------------------------------------------------------------------------

    \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 at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments. CV is coefficient of variation; 
Nmin is the minimum estimate of stock abundance. In some 
cases, CV is not applicable. For two stocks of killer whales, the 
abundance values represent direct counts of individually 
identifiable animals; therefore there is only a single abundance 
estimate with no associated CV. For certain stocks of pinnipeds, 
abundance estimates are based upon observations of animals (often 
pups) ashore multiplied by some correction factor derived from 
knowledge of the species' (or similar species') life history to 
arrive at a best abundance estimate; therefore, there is no 
associated CV. In these cases, the minimum abundance may represent 
actual counts of all animals ashore.
    \3\ These values, found in NMFS' SARs, represent annual levels 
of human-caused mortality plus serious injury from all sources 
combined (e.g., commercial fisheries, subsistence hunting, ship 
strike). Annual M/SI often cannot be determined precisely and is in 
some cases presented as a minimum value. All M/SI values are as 
presented in the draft 2017 SARs.
    \4\ Transient and resident killer whales are considered unnamed 
subspecies (Committee on Taxonomy, 2017).
    \5\ The abundance estimate for this stock includes only animals 
from the ``inner coast'' population occurring in inside waters of 
southeastern Alaska, British Columbia, and Washington--excluding 
animals from the ``outer coast'' subpopulation, including animals 
from California--and therefore should be considered a minimum count. 
For comparison, the previous abundance estimate for this stock, 
including counts of animals from California that are now considered 
outdated, was 354.
    \6\ Abundance estimates for these stocks are not considered 
current. PBR is therefore considered undetermined for these stocks, 
as there is no current minimum abundance estimate for use in 
calculation. We nevertheless present the most recent abundance 
estimates, as these represent the best available information for use 
in this document.
    \7\ This stock is known to spend a portion of time outside the 
U.S. EEZ. Therefore, the PBR presented here is the allocation for 
U.S. waters only and is a portion of the total. The total PBR for 
humpback whales is 22 (one half allocation for U.S. waters). Annual 
M/SI presented for these species is for U.S. waters only.

                               Table 2--Marine Mammals Potentially Present in the Vicinity of Navy Construction Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock  abundance (CV,
             Common name                  Scientific name               Stock             Strategic (Y/N)     N min, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray whale......................  Eschrichtius robustus..  Eastern North Pacific..  -; N                20,990 (0.05; 20,125;         624        132
                                                                                                             2011).
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera novaeangliae   California/Oregon/       E/D; Y              1,918 (0.03; 1,876;        \7\ 11      >=9.2
                                       kuzira.                  Washington (CA/OR/WA).                       2014).
    Minke whale.....................  Balaenoptera             CA/OR/WA...............  -; N                636 (0.72; 369; 2014).        3.5      >=1.3
                                       acutorostrata scammoni.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale....................  Orcinus orca \4\.......  West Coast Transient     -; N                243 (n/a; 2009).......        2.4          0
                                                                \5\.
                                                               Eastern North Pacific    E/D; Y              83 (n/a; 2016)........       0.14          0
                                                                Southern Resident.
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena        Washington Inland        -; N                11,233 (0.37; 8,308;           66      >=7.2
                                       vomerina.                Waters.                                      2015).

[[Page 9372]]

 
    Dall's porpoise.................  Phocoenoides dalli       CA/OR/WA...............  -; N                25,750 (0.45; 17,954;         172        0.3
                                       dalli.                                                                2014).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
California sea lion.................  Zalophus californianus.  United States..........  -; N                296,750 (n/a; 153,337;      9,200        389
                                                                                                             2011).
Steller sea lion....................  Eumetopias jubatus       Eastern U.S............  D; Y                41,638 (n/a; 2015)....      2,498        108
                                       monteriensis.
Family Phocidae (earless seals):
Harbor seal.........................  Phoca vitulina           Washington Northern      -; N                11,036 (0.15; 7,213;       Undet.        9.8
                                       richardii.               Inland Waters.\6\                            1999).
                                                               Southern Puget Sound     -; N                1,568 (0.15; 1,025;        Undet.        3.4
                                                                \6\.                                         1999).
                                                               Hood Canal \6\.........  -; N                1,088 (0.15; 711;          Undet.        0.2
                                                                                                             1999).
Northern elephant seal..............  Mirounga angustirostris  California Breeding....  -; N                179,000 (n/a; 81,368;       4,882        8.8
                                                                                                             2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------

Gray Whale

    Gray whales are observed in Washington inland waters in all months 
of the year, with peak numbers from March through June (Calambokidis et 
al., 2010). Most whales sighted are part of a small regularly occurring 
group of 6 to 10 whales that use mudflats in the Whidbey Island and 
Camano Island area as a springtime feeding area (Calambokidis et al., 
2010). Observed feeding areas are located in Saratoga Passage between 
Whidbey and Camano Islands including Crescent Harbor, and in Port Susan 
Bay located between Camano Island and the mainland north of Everett. 
Gray whales that are not identified with the regularly occurring 
feeding group are occasionally sighted in Puget Sound. These whales are 
not associated with feeding areas and are often emaciated (WDFW, 2012). 
There are typically from 2 to 10 stranded gray whales per year in 
Washington (Cascadia Research, 2012).
    In the waterways near NBK Bremerton and Keyport (Rich Passage/
Sinclair Inlet/Dyes Inlet/Agate Passage), 11 opportunistic sightings of 
gray whales were reported to Orca Network (a public marine mammal 
sightings database) between 2003 and 2012. One stranding occurred at 
NBK Bremerton in 2013. Gray whales have been sighted in Hood Canal 
south of the Hood Canal Bridge on six occasions since 1999, including a 
stranded whale. The most recent report was in 2010.
    Gray whales are expected to occur in the waters surrounding all of 
the installations considered here other than those in Hood Canal (i.e., 
NBK Bangor and Zelatched Point), due to rarity of occurrence. Gray 
whales are expected to occur primarily from March through June when in-
water construction will not occur. Therefore, although some exposure to 
individual gray whales could occur at four facilities, project timing 
will help to minimize potential exposures.

Humpback Whale

    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 distinct population 
segments (DPS) with different listing statuses (81 FR 62259; September 
8, 2016) pursuant to the ESA. The DPSs that occur in U.S. waters do not 
necessarily equate to the existing stocks designated under the MMPA and 
shown in Table 2. Because MMPA stocks cannot be portioned, i.e., parts 
managed as ESA-listed while other parts managed as not ESA-listed, 
until such time as the MMPA stock delineations are reviewed in light of 
the DPS designations, NMFS considers the existing humpback whale stocks 
under the MMPA to be endangered and depleted for MMPA management 
purposes (e.g., selection of a recovery factor, stock status).
    Within U.S. west coast waters, three current DPSs may occur: The 
Hawaii DPS (not listed), Mexico DPS (threatened), and Central America 
DPS (endangered). According to Wade et al. (2016), the probability that 
whales encountered in Washington waters are from a given DPS are as 
follows: Hawaii, 52.9% (CV = 0.15); Mexico, 41.9% (0.14); Central 
America, 5.2% (0.91).
    Most humpback whale sightings reported since 2003 were in the main 
basin of Puget Sound with numerous sightings in the waters between 
Point No Point and Whidbey Island, Possession Sound, and southern Puget 
Sound in the vicinity of Point Defiance. Some of the reported sightings 
were in the vicinity of NS Everett and NBK Manchester. A few sightings 
of possible humpback whales were reported by Orca Network in the waters 
near NBK Bremerton and Keyport (Rich Passage to Agate Passage area 
including Sinclair and Dyes Inlet) between 2003 and 2015. Humpback 
whales were sighted in the vicinity of Manette Bridge in Bremerton in 
2016 and 2017, and a carcass was found under a dock at NBK Bremerton in 
2016 (Cascadia Research, 2016).
    In Hood Canal, single humpback whales were observed for several 
weeks in 2012 and 2015. One sighting was reported in 2016. Review of 
the 2012 sightings information indicated they were of one individual. 
Prior to the 2012 sightings, there were no confirmed reports of 
humpback whales entering Hood Canal. The number of humpback whales 
potentially present near any of the six installations is expected to be 
very low in any month.

Minke Whale

    Sightings of minke whales in Puget Sound are infrequent, with 
approximately 14 opportunistic sightings recorded between 2005 and 
2012, from March through October. No sightings were reported in the 
vicinity of NBK Bremerton and Keyport (Rich Passage through the Agate 
Passage including Sinclair Inlet and Dyes Inlet) or in Hood Canal. The 
number of minke whales potentially present near any of the six 
installations is expected to be very low in any month and even lower in 
winter months.

[[Page 9373]]

Killer Whale (Transient)

    Groups of transient killer whales were observed for lengthy periods 
in Hood Canal in 2003 (59 days) and 2005 (172 days) (London, 2006), but 
were not observed again until 2016, when they were seen on a handful of 
days between March and May (including in Dabob Bay). Transient killer 
whales have been seen infrequently near NBK Bremerton, including in 
Dyes Inlet and Sinclair Inlet (e.g., sightings in 2010, 2013, and 
2015). Sightings in the vicinity of NBK Keyport have also been 
infrequent, and no records were found for Rich Passage in the vicinity 
of NBK Manchester. Transient killer whales have been observed in 
Possession Sound near NS Everett.
    West Coast transient killer whales most often travel in small pods 
averaging four individuals (Baird and Dill, 1996); however, the most 
commonly observed group size in Puget Sound (waters east of Admiralty 
Inlet, including Hood Canal, through South Puget Sound and north to 
Skagit Bay) from 2004 to 2010 was 6 whales (Houghton et al., 2015).

Killer Whales (Resident)

    Critical habitat for southern resident killer whales, designated 
pursuant to the ESA, includes three specific areas: (1) Summer core 
area in Haro Strait and waters around the San Juan Islands; (2) Puget 
Sound; and (3) Strait of Juan de Fuca (71 FR 69054; November 29, 2006). 
The primary constituent elements essential for conservation of the 
habitat are: (1) Water quality to support growth and development; (2) 
Prey species of sufficient quantity, quality, and availability to 
support individual growth, reproduction, and development, as well as 
overall population growth; and (3) Passage conditions to allow for 
migration, resting, and foraging. However, the six naval installations 
are specifically excluded from the critical habitat designation. A 
revision to the critical habitat designation is currently under 
consideration (80 FR 9682; February 24, 2015).
    Southern resident killer whales are expected to occur occasionally 
in the waters surrounding all of the installations except those in Hood 
Canal, where they have not been reported since 1995 (NMFS, 2006). 
Southern resident killer whales are rare near NBK Bremerton and 
Keyport, with the last confirmed sighting in Dyes Inlet in 1997. 
Southern residents have been observed in Saratoga Passage and 
Possession Sound near NS Everett.
    The stock contains three pods (J, K, and L pods), with pod sizes 
ranging from approximately 20 (in J pod) to 40 (in L pod) individuals. 
Group sizes encountered can be smaller or larger if pods temporarily 
separate or join together. Therefore, some exposure to groups of up to 
20 individuals or more could occur over the 5-year duration.

Harbor Porpoise

    Sightings in Hood Canal have increased in recent years, and an 
average of six harbor porpoises were sighted per day in deeper waters 
during line transect vessel surveys conducted in 2011 near NBK Bangor 
and Dabob Bay (HDR, 2012). Mean group size of harbor porpoises for each 
survey season in the 2013-2016 aerial surveys was 1.7 (Smultea et al., 
2017). Site-specific information is not available for NBK Bremerton, 
Keyport, or Manchester, but harbor porpoises have been seen 
infrequently at NS Everett.

Dall's Porpoise

    Dall's porpoise are known to occur in Puget Sound, and have been 
sighted as far south as Carr Inlet in southern Puget Sound and as far 
north as Saratoga Passage, north of NS Everett (Nysewander et al., 
2005; WDFW, 2008). Dall's porpoise could also occasionally occur in 
Hood Canal. with the last observation in deeper water near NBK Bangor 
in 2008 (Tannenbaum et al., 2009). However, Dall's porpoise were not 
observed during vessel line-transect surveys and other monitoring 
efforts completed in Hood Canal (including Dabob Bay) in 2011 (HDR, 
2012). Dall's porpoises have not been documented in the Rich Passage to 
Agate Passage area in the vicinity of NBK Bremerton or Keyport, but 
have been observed in Possession Sound near NS Everett (primarily 
during winter) (Nysewander et al., 2005; WDFW, 2008). Dall's porpoises 
could be present in waters in the vicinity of any of the installations 
considered here, and are considered more likely to occur during winter 
months than summer months in groups of up to 25 individuals.
    The Navy conducts surveys at installations with known pinniped 
haul-outs, which are located at NBK Bangor, NBK Bremerton, NBK 
Manchester, and NS Everett (see Figures 4-2, 4-3, 4-4, and 4-5 of the 
Navy's application). More detail regarding these surveys may be found 
in Appendix C of the Navy's application.

Steller Sea Lion

    Steller sea lions have been seasonally documented during shore-
based surveys at NBK Bangor in Hood Canal since 2008, with up to 13 
individuals observed hauled out on submarines at Delta Pier. Steller 
sea lions begin arriving at NBK Bangor in September and depart by the 
end of May.
    Shore-based surveys at NBK Bremerton have not detected Steller sea 
lions since the surveys were initiated in 2010. A Steller sea lion was 
sighted on the floating security barrier in 2012 and others were 
detected during aerial surveys conducted by the Washington Department 
of Fish and Wildlife (WDFW) in 2013 (Jeffries, 2013).
    Steller sea lions haul out on floating platforms in Clam Bay 
approximately 800 m offshore from the Manchester Fuel Depot's finger 
pier, approximately 13 km from NBK Bremerton. The Navy conducted 
surveys of sea lions on the floats from 2012 through 2016; Steller sea 
lions were seen in all surveyed months except for June, July, and 
August with as many as 42 individuals present in November 2014. Aerial 
surveys were conducted by WDFW from March-April 2013, July-August 2013, 
November 2013, and February 2014. These surveys detected Steller sea 
lions on the floating platforms during all survey months except July 
and August, with up to 37 individuals present on one survey in November 
2013.
    No haul-outs are known in the vicinity of NBK Keyport or Zelatched 
Point; therefore, no shore-based surveys have been conducted at these 
installations. No opportunistic sightings have been reported at these 
installations. The nearest Steller sea lion haul-outs to NBK Keyport 
are navigation buoys that can support at most two individuals, located 
over 15 km away in Puget Sound. Therefore, Steller sea lions are not 
expected to frequent waters off this installation. The only Steller sea 
lion haul-out in Hood Canal is at NBK Bangor, as described above, which 
is over 14 km from Zelatched Point.
    Shore-based surveys conducted from July 2012 through June 2014 at 
NS Everett did not detect Steller sea lions. However, occasional 
observations have been reported from the port security barrier (PSB). 
Other than these detections on the installation's PSBs, the nearest 
known Steller sea lion haul-out is 22.5 km away; therefore, Steller sea 
lions are not expected to occur in waters off this installation.

California Sea Lion

    California sea lion haul-outs occur at NBK Bangor, NBK Bremerton, 
and NS Everett. California sea lions are typically present most of the 
year except for mid-June through July in Washington inland waters, with 
peak abundance numbers between October and May (NMFS, 1997; Jeffries et 
al., 2000). During summer months and associated breeding

[[Page 9374]]

periods, the inland waters would not be considered a high-use area by 
California sea lions, as they would be returning to rookeries in 
California waters. However, as described below, surveys at Bangor 
indicate that a few individuals are present through mid-June and have 
arrived as early as August with at least one individual remaining in 
July 2014. Surveys at NS Everett from 2012 to 2016 indicate a few 
individuals may remain year-round.
    California sea lions have been documented during shore-based 
surveys at NBK Bangor in Hood Canal since 2008 in all survey months, 
with as many as 122 individuals observed at one time (November 2013) 
hauled out on submarines at Delta Pier and on PSB floats.
    California sea lions have been documented during shore- and boat-
based surveys at NBK Bremerton since 2010, with as many as 315 
individuals hauled out at one time (November 2015) on PSB floats.
    California sea lions haul out on floating platforms in Clam Bay 
approximately 800 m offshore from the Manchester Fuel Depot's finger 
pier, approximately 13 km from NBK Bremerton. The Navy conducted 
surveys of sea lions on the floats incidental to other surveys from 
2012 through 2016. California sea lions were seen in every survey month 
except July and August, with as many as 130 individuals present in one 
survey in October 2014. Aerial surveys were conducted by WDFW from 
March-April 2013, July-August 2013, November 2013, and February 2014. 
These surveys detected California sea lions on the floating platforms 
during all survey months except July, with up to 54 individuals present 
on one survey in November 2013.
    California sea lions have been documented during shore-based 
surveys at NS Everett from 2012 to 2016 in all survey months, with as 
many as 215 individuals hauled out at one time (April 2016) on PSB 
floats.
    No shore-based surveys have been conducted at NBK Keyport or 
Zelatched Point and no opportunistic sightings have been reported at 
these installations. No haul-outs are known in the vicinity of these 
installations. The nearest California sea lion haul-outs to NBK Keyport 
are navigation buoys that can support at most two individuals, located 
over 15 km away in Puget Sound. Therefore, California sea lions are not 
expected to frequent waters off this installation. The only California 
sea lion haul-out in Hood Canal is at NBK Bangor, as described above, 
which is over 14 km from Zelatched Point.
    California sea lions are expected to be exposed to noise from 
project activities at NBK Bangor, Bremerton, Manchester, and NS Everett 
because haul-outs are at these installations or nearby. Exposure is 
estimated to occur primarily from August through the end of the in-
water work window in mid-January or early March.

Harbor Seal

    Harbor seals in Washington inland waters have been divided into 
three stocks: Hood Canal, Northern Inland Waters, and Southern Puget 
Sound. The range of the northern inland waters stock includes Puget 
Sound north of the Tacoma Narrows Bridge, the San Juan Islands, and the 
Strait of Juan de Fuca, while the southern Puget Sound stock range 
includes waters south of the Tacoma Narrows Bridge. Therefore, animals 
present at NBK Bremerton, NBK Keyport, NBK Manchester, and NS Everett 
are most likely to be from the northern inland waters stock, while 
those present at NBK Bangor and Zelatched Point are expected to be from 
the Hood Canal stock.
    Harbor seals are expected to occur year-round at all installations, 
with the greatest numbers expected at installations with nearby haul-
out sites. In Hood Canal, known haul-outs occur on the west side of 
Hood Canal at the mouth of the Dosewallips River and on the western and 
northern shorelines in Dabob Bay located approximately 13 and 3.7 km 
away from NBK Bangor and Zelatched Point, respectively. Site-specific 
surveys have not been conducted at Zelatched Point because no haul-outs 
are documented in this part of Dabob Bay. Vessel-based surveys 
conducted from 2007 to 2010 at NBK Bangor observed harbor seals in 
every month of surveys (Agness and Tannenbaum, 2009; Tannenbaum et al., 
2009, 2011). Harbor seals were routinely seen during marine mammal 
monitoring for two construction projects (HDR, 2012; Hart Crowser, 
2013, 2014, 2015). Small numbers of harbor seals have been documented 
hauling out opportunistically at NBK Bangor (e.g., on the PSB floats, 
wave screen at Carderock Pier, buoys, barges, marine vessels, and logs) 
and on man-made floating structures near K/B Dock and Delta Pier. 
Surveys conducted in August and September 2016 recorded as many as 28 
harbor seals hauled out under Marginal Wharf or swimming in adjacent 
waters. On two occasions, four to six individuals were observed hauled 
out near Delta Pier. Known harbor seal births include one on the 
Carderock wave screen in August 2011 and at least one on a small 
floating dock in fall 2013, and afterbirth reported on a float at 
Magnetic Silencing Facility. In addition, harbor seal pupping has 
occurred on a section of the Service Pier since approximately 2001. 
Harbor seal mother and pup sets were observed in 2014 hauled out on the 
Carderock wave screen and swimming in nearby waters, and swimming in 
the vicinity of Delta Pier.
    At NS Everett, Navy surveys conducted regularly from 2012 to 2016 
have documented up to 491 harbor seals hauling out adjacent to the 
installation on log rafts in Notch Basin in the East Waterway. Harbor 
seals occupy the waters and haul-out sites near NS Everett year-round. 
Based on the survey data, the number of individuals peaks from August 
to October, with an average maximum number of 343 seals in October. The 
log rafts are privately owned and their location can vary within the 
East Waterway, which ranges from approximately 200-300 m wide. Only 
harbor seals on logs rafts that are within sight distance from NS 
Everett are counted, and if visible, numbers on floats outside the 
Notch Basin are noted, but not counted. Therefore, Navy counts of 
harbor seals hauled out do not necessarily represent the number of 
hauled out seals in the East Waterway. Pupping is documented on the log 
rafts; however, no pup counts have been conducted.
    No haul-outs have been identified at NBK Bremerton, Keyport, or 
Manchester. The nearest documented haul-outs to NBK Bremerton are 
across Sinclair Inlet, approximately 1.1 km away. The nearest 
documented haul-out to NBK Keyport is in Liberty Bay at the Poulsbo 
Marina approximately 3.2 km from the Keyport Pier. The nearest 
documented haul-out to NBK Manchester is Blakely Rocks approximately 
5.6 km away on the east side of Bainbridge Island. All haul-outs listed 
here near the three installations are estimated to have less than 100 
individuals.

Northern Elephant Seal

    No haul-outs occur in Puget Sound with the exception of individual 
elephant seals occasionally hauling out for two to four weeks to molt, 
usually during the spring and summer and typically on sandy beaches 
(Calambokidis and Baird, 1994). These animals are usually yearlings or 
subadults and their haul-out locations are unpredictable. One male 
subadult elephant seal was observed hauled out to molt at Manchester 
Fuel Depot in 2004. Although regular haul-outs occur in the Strait of 
Juan de Fuca, the

[[Page 9375]]

occurrence of elephant seals in Puget Sound is unpredictable and rare.

Unusual Mortality Events (UME)

    A UME is defined under the MMPA as ``a stranding that is 
unexpected; involves a significant die-off of any marine mammal 
population; and demands immediate response.'' The only currently 
ongoing UME investigation involves California sea lions along the west 
coast. Beginning in January 2013, elevated strandings of California sea 
lion pups were observed in southern California, with live sea lion 
strandings nearly three times higher than the historical average. 
Findings to date indicate that a likely contributor to the large number 
of stranded, malnourished pups was a change in the availability of sea 
lion prey for nursing mothers, especially sardines. The causes and 
mechanisms of this remain under investigation (www.nmfs.noaa.gov/pr/health/mmume/californiasealions2013.htm; accessed November 24, 2017).

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with an exception 
for lower limits for low-frequency cetaceans where the result was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz;
     Pinnipeds in water; Phocidae (true seals): Functional 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
     Pinnipeds in water; Otariidae (eared seals): Functional 
hearing is estimated to occur between 60 Hz and 39 kHz for Otariidae.
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Ten marine mammal species (six cetacean and four pinniped (two otariid 
and two phocid) species) have the potential to co-occur with Navy 
construction activities. Please refer to Table 2. Of the six cetacean 
species that may be present, three are classified as low-frequency 
cetaceans (i.e., all mysticete species), one is classified as a mid-
frequency cetacean (i.e., killer whales), and two are classified as 
high-frequency cetaceans (i.e., porpoises).

Potential Effects of the Specified Activity 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 and 
the material it references, 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 to impact marine mammal species or stocks. In the following 
discussion, we provide general background information on sound before 
considering potential effects to marine mammals from sound produced by 
pile driving.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see, e.g., Au and Hastings (2008); Richardson et al. (1995); 
Urick (1983).
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks or corresponding points of a sound wave 
(length of one cycle). Higher frequency sounds have shorter wavelengths 
than lower frequency sounds, and typically attenuate (decrease) more 
rapidly, except in certain cases in shallower water. Amplitude is the 
height of the sound pressure wave or the ``loudness'' of a sound and is 
typically described using the relative unit of the decibel (dB). A 
sound pressure level (SPL) in dB is described as the ratio between a 
measured pressure and a reference pressure (for underwater sound, this 
is 1 microPascal ([mu]Pa)), and is a logarithmic unit that accounts for 
large variations in amplitude; therefore, a relatively small change in 
dB corresponds to large changes in sound pressure. The source level 
(SL) represents the SPL referenced at a distance of 1 m from the source 
(referenced to 1 [mu]Pa), while the received level is the SPL at the 
listener's position (referenced to 1 [mu]Pa).
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral

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effects, in part because behavioral effects, which often result from 
auditory cues, may be better expressed through averaged units than by 
peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy in a stated frequency band over a stated 
time interval or event, and considers both intensity and duration of 
exposure. The per-pulse SEL is calculated over the time window 
containing the entire pulse (i.e., 100 percent of the acoustic energy). 
SEL is a cumulative metric; it can be accumulated over a single pulse, 
or calculated over periods containing multiple pulses. Cumulative SEL 
represents the total energy accumulated by a receiver over a defined 
time window or during an event. Peak sound pressure (also referred to 
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source, and is represented in the same units as the rms sound pressure.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams or may radiate in all directions 
(omnidirectional sources), as is the case for sound produced by the 
pile driving activity considered here. The compressions and 
decompressions associated with sound waves are detected as changes in 
pressure by aquatic life and man-made sound receptors such as 
hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The sound level of a region 
is defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
hertz (Hz) and 50 kilohertz (kHz) (Mitson, 1995). In general, ambient 
sound levels tend to increase with increasing wind speed and wave 
height. Precipitation can become an important component of total sound 
at frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times. Marine mammals can contribute significantly to ambient sound 
levels, as can some fish and snapping shrimp. The frequency band for 
biological contributions is from approximately 12 Hz to over 100 kHz. 
Sources of ambient sound related to human activity include 
transportation (surface vessels), dredging and construction, oil and 
gas drilling and production, geophysical surveys, sonar, and 
explosions. Vessel noise typically dominates the total ambient sound 
for frequencies between 20 and 300 Hz. In general, the frequencies of 
anthropogenic sounds are below 1 kHz and, if higher frequency sound 
levels are created, they attenuate rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human 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 decibels (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.
    Underwater ambient sound in Puget Sound is comprised of sounds 
produced by a number of natural and anthropogenic sources and varies 
both geographically and temporally. Human-generated sound is a 
significant contributor to the ambient acoustic environment at the 
installations considered here. The underwater acoustic environment at 
each installation will vary depending on the amount of anthropogenic 
activity, weather conditions, and tidal currents. In high-use 
installations, such as NBK Bremerton, anthropogenic noise may dominate 
the ambient soundscape. In areas with less anthropogenic activity 
(e.g., Zelatched Point), ambient sound is likely to be dominated by 
sound from natural sources. Under normal weather and traffic 
conditions, average ambient sound at all installations is assumed to be 
below 120 dB rms. More detail regarding specific installations is 
available in section 2.3.1.5 of the Navy's application. Details of 
source types are described in the following text.
    Sounds are often considered to fall into one of two general types: 
Pulsed and non-pulsed (defined in the following). The distinction 
between these two sound types is important because they have differing 
potential to cause physical effects, particularly with regard to 
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see 
Southall et al. (2007) for an in-depth discussion of these concepts. 
The distinction between these two sound types is not always obvious, as 
certain signals share properties of both pulsed and non-pulsed sounds. 
A signal near a source could be categorized as a pulse, but due to 
propagation effects as it moves farther from the source, the signal 
duration becomes longer (e.g., Greene and Richardson, 1988).
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.
    The impulsive sound generated by impact hammers is characterized by 
rapid rise times and high peak levels. Vibratory hammers produce non-
impulsive, continuous noise at levels significantly lower than those 
produced by impact hammers. Rise time is slower,

[[Page 9377]]

reducing the probability and severity of injury, and sound energy is 
distributed over a greater amount of time (e.g., Nedwell and Edwards, 
2002; Carlson et al., 2005).

Acoustic Effects

    We previously provided general background information on marine 
mammal hearing (see ``Description of Marine Mammals in the Area of the 
Specified Activity''). Here, we discuss the potential effects of sound 
on marine mammals.
    Potential Effects of Underwater Sound--Note that, in the following 
discussion, we refer in many cases to a review article concerning 
studies of noise-induced hearing loss conducted from 1996-2015 (i.e., 
Finneran, 2015). For study-specific citations, please see that work. 
Anthropogenic sounds cover a broad range of frequencies and sound 
levels and can have a range of highly variable impacts on marine life, 
from none or minor to potentially severe responses, depending on 
received levels, duration of exposure, behavioral context, and various 
other factors. The potential effects of underwater sound from active 
acoustic sources can potentially result in one or more of the 
following: Temporary or permanent hearing impairment, non-auditory 
physical or physiological effects, behavioral disturbance, stress, and 
masking (Richardson et al., 1995; Gordon et al., 2004; Nowacek et al., 
2007; Southall et al., 2007; G[ouml]tz et al., 2009). The degree of 
effect is intrinsically related to the signal characteristics, received 
level, distance from the source, and duration of the sound exposure. In 
general, sudden, high level sounds can cause hearing loss, as can 
longer exposures to lower level sounds. Temporary or permanent loss of 
hearing will occur almost exclusively for noise within an animal's 
hearing range. We first describe specific manifestations of acoustic 
effects before providing discussion specific to pile driving.
    Richardson et al. (1995) described zones of increasing intensity of 
effect that might be expected to occur, in relation to distance from a 
source and assuming that the signal is within an animal's hearing 
range. First is the area within which the acoustic signal would be 
audible (potentially perceived) to the animal but not strong enough to 
elicit any overt behavioral or physiological response. The next zone 
corresponds with the area where the signal is audible to the animal and 
of sufficient intensity to elicit behavioral or physiological 
responsiveness. Third is a zone within which, for signals of high 
intensity, the received level is sufficient to potentially cause 
discomfort or tissue damage to auditory or other systems. Overlaying 
these zones to a certain extent is the area within which masking (i.e., 
when a sound interferes with or masks the ability of an animal to 
detect a signal of interest that is above the absolute hearing 
threshold) may occur; the masking zone may be highly variable in size.
    We describe the more severe effects (i.e., certain non-auditory 
physical or physiological effects) only briefly as we do not expect 
that there is a reasonable likelihood that pile driving may result in 
such effects (see below for further discussion). Potential effects from 
impulsive sound sources can range in severity from effects such as 
behavioral disturbance or tactile perception to physical discomfort, 
slight injury of the internal organs and the auditory system, or 
mortality (Yelverton et al., 1973). Non-auditory physiological effects 
or injuries that theoretically might occur in marine mammals exposed to 
high level underwater sound or as a secondary effect of extreme 
behavioral reactions (e.g., change in dive profile as a result of an 
avoidance reaction) caused by exposure to sound include neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007; Zimmer and 
Tyack, 2007; Tal et al., 2015). The construction activities considered 
here do not involve the use of devices such as explosives or mid-
frequency tactical sonar that are associated with these types of 
effects.
    Threshold Shift--Marine mammals exposed to high-intensity sound, or 
to lower-intensity sound for prolonged periods, can experience hearing 
threshold shift (TS), which is the loss of hearing sensitivity at 
certain frequency ranges (Finneran, 2015). TS can be permanent (PTS), 
in which case the loss of hearing sensitivity is not fully recoverable, 
or temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Repeated sound exposure that 
leads to TTS could cause PTS. In severe cases of PTS, there can be 
total or partial deafness, while in most cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans, but such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. PTS typically occurs at exposure levels at least 
several decibels above (a 40-dB threshold shift approximates PTS onset; 
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB 
threshold shift approximates TTS onset; e.g., Southall et al. 2007). 
Based on data from terrestrial mammals, a precautionary assumption is 
that the PTS thresholds for impulse sounds (such as impact pile driving 
pulses as received close to the source) are at least 6 dB higher than 
the TTS threshold on a peak-pressure basis and PTS cumulative sound 
exposure level thresholds are 15 to 20 dB higher than TTS cumulative 
sound exposure level thresholds (Southall et al., 2007). Given the 
higher level of sound or longer exposure duration necessary to cause 
PTS as compared with TTS, it is considerably less likely that PTS could 
occur.
    TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. Few data 
on sound levels and durations necessary to elicit mild TTS have been 
obtained for marine mammals.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that occurs during a time where ambient noise is lower and there 
are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for

[[Page 9378]]

successful mother/calf interactions could have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and three species of pinnipeds (northern elephant 
seal, harbor seal, and California sea lion) 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. There 
are no data available on noise-induced hearing loss for mysticetes. For 
summaries of data on TTS in marine mammals or for further discussion of 
TTS onset thresholds, please see Southall et al. (2007), Finneran and 
Jenkins (2012), Finneran (2015), and NMFS (2016).
    Behavioral Effects--Behavioral disturbance may include a variety of 
effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. Behavioral responses to sound are highly 
variable and context-specific and any reactions depend on numerous 
intrinsic and extrinsic factors (e.g., species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day), as well as the interplay between factors (e.g., 
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007; 
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not 
only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al., 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). 
Please see Appendices B-C of Southall et al. (2007) for a review of 
studies involving marine mammal behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al., 2009). The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. As noted, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with 
captive marine mammals have showed pronounced behavioral reactions, 
including avoidance of loud sound sources (Ridgway et al., 1997; 
Finneran et al., 2003). Observed responses of wild marine mammals to 
loud pulsed sound sources (typically airguns or acoustic harassment 
devices) have been varied but often consist of avoidance behavior or 
other behavioral changes suggesting discomfort (Morton and Symonds, 
2002; see also Richardson et al., 1995; Nowacek et al., 2007). However, 
many delphinids approach low-frequency airgun source vessels with no 
apparent discomfort or obvious behavioral change (e.g., Barkaszi et 
al., 2012), indicating the importance of frequency output in relation 
to the species' hearing sensitivity.
    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). However, there are broad categories of potential response, which 
we describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely and may consist of 
increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive (e.g., Frankel 
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et 
al.; 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior 
may reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at the time of the exposure and the 
type and magnitude of the response.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001,

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2005, 2006; Gailey et al., 2007; Gailey et al., 2016).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from airgun surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996). The result of a flight response could range from 
brief, temporary exertion and displacement from the area where the 
signal provokes flight to, in extreme cases, marine mammal strandings 
(Evans and England, 2001). However, it should be noted that response to 
a perceived predator does not necessarily invoke flight (Ford and 
Reeves, 2008), and whether individuals are solitary or in groups may 
influence the response.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    Stress Responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle, 1950; 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000; 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found 
that noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that

[[Page 9380]]

some of these would be classified as ``distress.'' In addition, any 
animal experiencing TTS would likely also experience stress responses 
(NRC, 2003).
    Auditory Masking--Sound can disrupt behavior through masking, or 
interfering with, an animal's ability to detect, recognize, or 
discriminate between acoustic signals of interest (e.g., those used for 
intraspecific communication and social interactions, prey detection, 
predator avoidance, navigation) (Richardson et al., 1995; Erbe et al., 
2016). Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher intensity, and may occur whether the sound is natural (e.g., 
snapping shrimp, wind, waves, precipitation) or anthropogenic (e.g., 
shipping, sonar, seismic exploration) in origin. The ability of a noise 
source to mask biologically important sounds depends on the 
characteristics of both the noise source and the signal of interest 
(e.g., signal-to-noise ratio, temporal variability, direction), in 
relation to each other and to an animal's hearing abilities (e.g., 
sensitivity, frequency range, critical ratios, frequency 
discrimination, directional discrimination, age or TTS hearing loss), 
and existing ambient noise and propagation conditions.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore, 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand, 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.
    Potential Effects of Navy Activity--As described previously (see 
``Description of Active Acoustic Sound Sources''), the Navy proposes to 
conduct pile driving, including impact and vibratory driving. The 
effects of pile driving on marine mammals are dependent on several 
factors, including the size, type, and depth of the animal; the depth, 
intensity, and duration of the pile driving sound; the depth of the 
water column; the substrate of the habitat; the standoff distance 
between the pile and the animal; and the sound propagation properties 
of the environment. With both types of pile driving, it is likely that 
the onset of pile driving could result in temporary, short term changes 
in an animal's typical behavioral patterns and/or avoidance of the 
affected area. These behavioral changes may include (Richardson et al., 
1995): 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; and/or flight responses.
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, or reproduction. Significant 
behavioral modifications that could lead to effects on growth, 
survival, or reproduction, such as drastic changes in diving/surfacing 
patterns or significant habitat abandonment are extremely unlikely in 
this area (i.e., shallow waters in modified industrial areas).
    The onset of behavioral disturbance from anthropogenic sound 
depends on both external factors (characteristics of sound sources and 
their paths) and the specific characteristics of the receiving animals 
(hearing, motivation, experience, demography) and is difficult to 
predict (Southall et al., 2007).
    Whether impact or vibratory driving, sound sources would be active 
for relatively short durations, with relation to potential for masking. 
The frequencies output by pile driving activity are lower than those 
used by most species expected to be regularly present for communication 
or foraging. We expect insignificant impacts from masking, and any 
masking event that could possibly rise to Level B harassment under the 
MMPA would occur concurrently within the zones of behavioral harassment 
already estimated for vibratory and impact pile driving, and which have 
already been taken into account in the exposure analysis.

Anticipated Effects on Marine Mammal Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals, but may have potential short-
term impacts to food sources such as forage fish. The proposed 
activities could also affect acoustic habitat (see masking discussion 
above), but meaningful impacts are unlikely. There are no known 
foraging hotspots, or other ocean bottom structures of significant 
biological importance to marine mammals present in the marine waters in 
the vicinity of the project areas. Therefore, the main impact issue 
associated with the proposed activity would be temporarily elevated 
sound levels and the associated direct effects on marine mammals, as 
discussed previously in this preamble. The most likely impact to marine 
mammal habitat occurs from pile driving effects on likely marine mammal

[[Page 9381]]

prey (i.e., fish) near the six installations. Impacts to the immediate 
substrate during installation and removal of piles are anticipated, but 
these would be limited to minor, temporary suspension of sediments, 
which could impact water quality and visibility for a short amount of 
time, but which would not be expected to have any effects on individual 
marine mammals. Impacts to substrate are therefore not discussed 
further.
    Effects to Prey--Sound may affect marine mammals through impacts on 
the abundance, behavior, or distribution of prey species (e.g., 
crustaceans, cephalopods, fish, zooplankton). Marine mammal prey varies 
by species, season, and location and, for some, is not well documented. 
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). More commonly, though, the impacts of noise on fish are 
temporary.
    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. In general, impacts to marine mammal prey 
species are expected to be minor and temporary due to the expected 
short daily duration of individual pile driving events and the 
relatively small areas being affected. It is also not expected that the 
industrial environment of the Naval installations provides important 
fish habitat or harbors significant amounts of forage fish.
    The area likely impacted by the activities is relatively small 
compared to the available habitat in inland waters in the region. 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 
Navy 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. Effects to habitat will not be 
discussed further in this document.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization, which will inform both NMFS's consideration 
of whether the number of takes is ``small'' and the negligible impact 
determination.
    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).
    Take of marine mammals incidental to Navy construction activities 
could occur as a result of Level A or Level B harassment. Below we 
describe how the potential take is estimated.

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 exhibit behavioral disruptions (equated 
to Level B harassment) or to incur PTS of some degree (equated to Level 
A harassment).
    Level B Harassment--Although available data are consistent with the 
basic concept that louder sounds evoke more significant behavioral 
responses than softer sounds, defining sound levels that disrupt 
behavioral patterns is difficult because responses depend on the 
context in which the animal receives the sound, including an animal's 
behavioral mode when it hears sounds (e.g., feeding, resting, or 
migrating), prior experience, and biological factors (e.g., age and 
sex). Some species, such as beaked whales, are known to be more highly 
sensitive to certain anthropogenic sounds than other species. Other 
contextual factors, such as signal characteristics, distance from the 
source, and signal to noise ratio, may also help determine response to 
a given received level of sound. Therefore, levels at which responses 
occur are not necessarily consistent and can be difficult to predict 
(Southall et al., 2007; Ellison et al., 2012; Bain and Williams, 2006).
    However, based on the practical need to use a relatively simple 
threshold based on available information that is both predictable and 
measurable for most activities, NMFS has historically used a 
generalized acoustic threshold

[[Page 9382]]

based on received level to estimate the onset of Level B harassment. 
These thresholds are 160 dB rms (impulsive sources) and 120 dB rms 
(continuous sources).
    Level A Harassment--NMFS's Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (NMFS, 2016) 
identifies dual criteria to assess the potential for auditory injury 
(Level A harassment) to occur for different marine mammal groups (based 
on hearing sensitivity) as a result of exposure to noise. The technical 
guidance identifies the received levels, or thresholds, above which 
individual marine mammals are predicted to experience changes in their 
hearing sensitivity for all underwater anthropogenic sound sources, and 
reflects the best available science on the potential for noise to 
affect auditory sensitivity by:
     Dividing sound sources into two groups (i.e., impulsive 
and non-impulsive) based on their potential to affect hearing 
sensitivity;
     Choosing metrics that best address the impacts of noise on 
hearing sensitivity, i.e., peak sound pressure level (peak SPL) 
(reflects the physical properties of impulsive sound sources to affect 
hearing sensitivity) and cumulative sound exposure level (cSEL) 
(accounts for not only level of exposure but also duration of 
exposure); and
     Dividing marine mammals into hearing groups and developing 
auditory weighting functions based on the science supporting that not 
all marine mammals hear and use sound in the same manner.
    The premise of the dual criteria approach is that, while there is 
no definitive answer to the question of which acoustic metric is most 
appropriate for assessing the potential for injury, both the received 
level and duration of received signals are important to an 
understanding of the potential for auditory injury. Therefore, peak SPL 
is used to define a pressure criterion above which auditory injury is 
predicted to occur, regardless of exposure duration (i.e., any single 
exposure at or above this level is considered to cause auditory 
injury), and cSEL is used to account for the total energy received over 
the duration of sound exposure (i.e., both received level and duration 
of exposure) (Southall et al., 2007; NMFS, 2016). As a general 
principle, whichever criterion is exceeded first (i.e., results in the 
largest isopleth) would be used as the effective injury criterion 
(i.e., the more precautionary of the criteria). Note that cSEL acoustic 
threshold levels incorporate marine mammal auditory weighting 
functions, while peak pressure thresholds do not (i.e., flat or 
unweighted). Weighting functions for each hearing group (e.g., low-, 
mid-, and high-frequency cetaceans) are described in NMFS (2016).
    NMFS (2016) recommends 24 hours as a maximum accumulation period 
relative to cSEL thresholds. These thresholds were developed by 
compiling and synthesizing the best available science, and are provided 
in Table 3 below. The references, analysis, and methodology used in the 
development of the thresholds are described in NMFS (2016), which is 
available online at: www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

                                 Table 3--Exposure Criteria for Auditory Injury
----------------------------------------------------------------------------------------------------------------
                                                                                     Cumulative sound exposure
                                                                                             level \2\
                          Hearing group                           Peak  pressure -------------------------------
                                                                     \1\ (dB)        Impulsive     Non-impulsive
                                                                                       (dB)            (dB)
----------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans.........................................             219             183             199
Mid-frequency cetaceans.........................................             230             185             198
High-frequency cetaceans........................................             202             155             173
Phocid pinnipeds................................................             218             185             201
Otariid pinnipeds...............................................             232             203             219
----------------------------------------------------------------------------------------------------------------
\1\ Referenced to 1 [mu]Pa; unweighted within generalized hearing range.
\2\ Referenced to 1 [mu]Pa\2\-s; weighted according to appropriate auditory weighting function.

Zones of Ensonification

    Sound Propagation--Transmission loss (TL) is the decrease in 
acoustic intensity as an acoustic pressure wave propagates out from a 
source. TL parameters vary with frequency, temperature, sea conditions, 
current, source and receiver depth, water depth, water chemistry, and 
bottom composition and topography. The general formula for underwater 
TL is:

    TL = B * log10(R1/R2)

Where:

B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20 * log(range)). Cylindrical spreading 
occurs in an environment in which sound propagation is bounded by the 
water surface and sea bottom, resulting in a reduction of 3 dB in sound 
level for each doubling of distance from the source (10 * log(range)). 
As is common practice in coastal waters, here we assume practical 
spreading loss (4.5 dB reduction in sound level for each doubling of 
distance). Practical spreading is a compromise that is often used under 
conditions where water depth increases as the receiver moves away from 
the shoreline, resulting in an expected propagation environment that 
would lie between spherical and cylindrical spreading loss conditions.
    Sound Source Levels--The intensity of pile driving sounds is 
greatly influenced by factors such as the type of piles, hammers, and 
the physical environment in which the activity takes place. There are 
source level measurements available for certain pile types and sizes 
from the specific environment of several of the installations 
considered here (i.e., NBK Bangor and NBK Bremerton), but not from all. 
Numerous studies have examined sound pressure levels (SPLs)

[[Page 9383]]

recorded from underwater pile driving projects in California (e.g., 
Caltrans, 2015) and elsewhere in Washington. In order to determine 
reasonable SPLs and their associated effects on marine mammals that are 
likely to result from pile driving at the six installations, studies 
with similar properties to the specified activity were evaluated. Full 
details are available in Appendix B of the Navy's application, which 
evaluates available data sources for each pile size and type in order 
to develop reasonable proxy values.

                                         Table 4--Assumed Source Levels
----------------------------------------------------------------------------------------------------------------
                                                                                 SPL (peak) 1 2
           Method                   Type         Size  (in)     SPL (rms) \1\                        SEL 1 3
----------------------------------------------------------------------------------------------------------------
Impact......................  Plastic........              13  156............  Not available..  Not available.
                              Timber.........           12/14  170............  Not available..  Not available.
                              Concrete.......              18  170............  184............  159.
                                                           24  178............  189............  166.
                              Steel pipe.....           12/13  177............  192............  167.
                                                           14  184............  200............  174.
                                                           24  193............  210............  181.
                                                           30  195............  216............  186.
                                                           36  194 (Bangor)...  211............  181 (Bangor).
                                                               192 (others)...                   184 (others).
Vibratory...................  Timber.........              12  153............  n/a............  n/a.
                                                        13/14  155............  n/a............  n/a.
                              Steel pipe.....           13/14  155............  n/a............  n/a.
                                                        16/24  161............  n/a............  n/a.
                                                        30/36  166 (Bangor)...  n/a............  n/a.
                                                               167 (others)...
                              Steel sheet....             n/a  163............  n/a............  n/a.
----------------------------------------------------------------------------------------------------------------
\1\ Source levels presented at standard distance of 10 m from the driven pile. Peak source levels are not
  typically evaluated for vibratory pile driving, as they are lower than the relevant thresholds for auditory
  injury. SEL source levels for vibratory driving are equivalent to SPL (rms) source levels.

    Acoustic measurements were conducted during impact driving of 24- 
and 36-in steel piles in 2011 at NBK Bangor (Navy, 2012). However, for 
the 24-in piles only seven strikes from a single pile were measured, 
and the reported values are lower than those from other projects 
reviewed. Therefore, these data were not considered in the selection of 
the most appropriate proxy value. For 36-in piles, the reported values 
from this study are directly used in evaluating similar pile driving at 
NBK Bangor. For 24-in piles, data from projects conducted by the 
Washington State Department of Transportation (WSDOT) at Bainbridge 
Island and Friday Harbor, as well as data from several projects 
conducted in California and Oregon were considered. The two Washington 
projects were used in developing the proxy value, as these locations 
were considered to be representative of substrate conditions likely 
encountered in other locations in Puget Sound (WSDOT, 2005a, 2005b). 
For 30-in piles, data from projects conducted by WSDOT at three 
locations--Bainbridge Island, Friday Harbor, and Vashon Island (WSDOT, 
2005b, 2008, 2010b; Jasco, 2005)--as well as from one project in 
California were considered. The three Washington projects were again 
used in developing the proxy value, for the same reasons. For impact 
driving of 36-in piles, data from the Navy project at NBK Bangor (Navy, 
2012), from two WSDOT projects (at Mukilteo and Anacortes) (WSDOT, 
2007a, 2007b), and from one project in California were considered. The 
three projects conducted in Washington inland waters were used in 
developing the proxy value. Values for impact driving of small diameter 
steel pipe piles were taken from the summary value tables provided by 
Caltrans (2015) (see Table I.2-1 in that publication). No values are 
provided for 13-in steel piles; therefore, we assume that source levels 
for 12-in piles would apply to 13-in piles. While values for both 12-in 
and 14-in piles are provided, we believe that the 12-in values are more 
appropriate as the water depth for these measurements is closer to what 
would be encountered at the Navy project sites. No SEL source level is 
provided; therefore, we assume that the SEL source level is 10 dB less 
than the SPL (rms) source level. This is a conservative assumption, as 
the average difference between SPL (rms) and SEL source levels given in 
the Caltrans (2015) summary table is 11.5 dB.
    The 2011 Navy study described above provided data from measurements 
of vibratory driving of 36-in steel piles (Navy, 2012), while a 
separate 2011 project at NBK Bangor provided measurements from 
vibratory driving of 30-in piles (Miner, 2012). These projects together 
provide directly applicable data for use in evaluating vibratory 
driving of 30- and 36-in steel piles at NBK Bangor. For vibratory 
driving of 30- and 36-in steel piles at other locations, data from a 
variety of additional studies from other locations in Washington 
(Coupeville, Edmonds, Vashon Island, Port Townsend, and Anacortes) 
(WSDOT 2010c, 2010d, 2010e, 2011b, 2012) were considered and, with the 
two Navy studies, used in developing a proxy value for 30- and 36-in 
piles. The same 2011 NBK Bangor study provided limited data for 
vibratory driving of 24-in piles, while the separate 2012 NBK Bangor 
provided data from vibratory driving of 16-in piles. These were 
considered together with a WSDOT study from Friday Harbor (WSDOT, 
2010a) and with data from a project at the Trinidad Bay in Humboldt 
County, CA (Caltrans, 2015) to develop a generally applicable proxy 
value for 16- and 24-in piles. The proxy source level for vibratory 
driving of 13-in steel piles is taken from a study at the Mad River 
Slough in Arcata, CA, and is assumed to be applicable to 14-in piles as 
well (Caltrans, 2015). Caltrans (2015) also provides a summary value of 
155 dB rms for vibratory driving of 12-in steel piles. For vibratory 
driving of sheet piles, data from multiple projects conducted in 
Oakland, CA (Berth 23, Berth 30, and Berth 35/37 at Port of Oakland; 
Caltrans, 2015) were considered in developing an appropriate proxy 
value. Values for vibratory installation are conservatively assumed to 
apply to vibratory extraction of same-sized piles.

[[Page 9384]]

    Acoustic measurements were conducted during impact driving of 24-in 
concrete piles in 2015 at NBK Bremerton (Navy, 2016). These 
measurements provide a proxy value for use during impact driving of 24-
in concrete piles at all facilities. For impact driving of smaller 
concrete piles, data from three projects conducted at Concord, CA and 
Berkeley, CA and involving impact driving of 16- and 18-in piles 
(Caltrans, 2015) were evaluated and used in developing a proxy value.
    Relatively few data are available for timber and plastic piles. The 
proxy value for impact driving of plastic piles is from a project 
conducted in Solano County, CA (Illingworth and Rodkin, 2008). For 
impact driving of timber piles, data from one study in Alameda, CA, 
provides the proxy source level (Caltrans, 2015). However, we assume 
that the assumed source level for impact driving of 14-in steel piles 
is a suitable proxy for impact driving of larger diameter timber piles 
(18-in). For vibratory extraction of timber piles, the Navy considered 
measured values from NBK Bremerton (Navy, 2016) as well as data from a 
WSDOT project at Port Townsend involving removal of 12-in timber piles 
(WSDOT, 2011a). Source levels for vibratory driving of 13/14-in timber 
piles is assumed as a reasonable proxy for vibratory removal of timber 
and plastic piles up to 18-in diameter.
    The Navy proposes to use bubble curtains when impact driving steel 
piles of 24-in diameter and greater, except at NBK Bremerton and NBK 
Keyport (see Proposed Mitigation for further discussion). For the 
reasons described in the next paragraph, we assume here that use of the 
bubble curtain would result in a reduction of 8 dB from the assumed SPL 
(rms) and SPL (peak) source levels for these pile sizes, and reduce the 
applied source levels accordingly. For determining distances to the 
cumulative SEL injury thresholds, auditory weighting functions were 
applied to the attenuated one-second SEL spectra for steel pipe piles 
(see Appendix E of the Navy's application).
    During the 2011 study at NBK Bangor, the Navy conducted comparative 
measurements of source levels when impact driving steel piles with and 
without a bubble curtain. Across all piles (36- and 48-in) and all 
metrics (rms, peak, SEL), the weighted average effective attenuation 
was 9 dB. The Navy also reviewed unconfined bubble curtain attenuation 
rates from available reports from projects in Washington, California, 
and Oregon that impact drove steel pipe piles of up to 48-in diameter. 
These results are summarized in Table 3-2 of Appendix A in the Navy's 
application. Of the studies reviewed, significant variability in 
attenuation occurred; however, an average of at least 8 dB of peak SPL 
attenuation was achieved on ten of the twelve projects. Some of the 
lower attenuation levels reported were attributed to failures in 
setting up or operating the bubble curtain system (e.g., bottom ring 
not seated on the substrate, poor airflow). While proper set-up and 
operation of the system is critical, and variability in performance 
should be expected, we believe that in the circumstances evaluated here 
an effective attenuation performance of 8 dB is a reasonable 
assumption.
    Level A Harassment--In order to assess the potential for injury on 
the basis of the cumulative SEL metric, one must estimate the total 
strikes per day (impact driving) or the total driving duration per day 
(vibratory driving). To provide a general estimate of pile driving 
daily durations/strikes, the Navy reviewed information from past 
projects (Table 5). Navy geotechnical and engineering staff used data 
from a large wharf construction project at NBK Bangor to estimate pile 
driving time and strikes needed to install steel piles using impact 
hammers. Vibratory installation was estimated to take a median time of 
10 minutes per pile with 45 minutes estimated as a maximum.
    For steel piles that are ``proofed,'' a median of approximately 600 
strikes per pile was estimated. However, not all projects will require 
proofing every pile. Some projects will require only a subset of piles 
be proofed and some projects, such as those installing fender piles, 
may not require any proofing because the structure is not load-bearing. 
Other piles may encounter difficult substrate and need to be advanced 
further with an impact driver. For piles that cannot be advanced with a 
vibratory driver, less than approximately 1,300 strikes was 
conservatively estimated to complete installation. Based on these 
estimates, no more than 4,000 strikes are estimated to occur on any one 
day. This estimate would account for approximately six steel piles 
installed with a median time of 14 minutes per pile (~1.5 hours of 
drive time) or three steel piles needing extended driving. Estimates of 
concrete pile impact driving durations are based on data for the 
installation of fender piles at NBK Bremerton. For purposes of 
analysis, impact pile driving of concrete piles is estimated to take a 
maximum of 4 hours or an average of 1.5 hours in a day.
    Actual driving duration at any of the project sites will vary due 
to substrate conditions and the type and energy of impact hammers. For 
example, during a past project at NBK Bangor (where most of the steel 
pile work will occur), four piles were installed with a vibratory 
driver and impact proofed in 61 minutes total (vibratory and impact 
driving) with an average of 172 strikes/pile. Additionally, some of the 
anticipated pile driving is contingent on emergent needs or emergencies 
that could potentially never occur. Therefore, estimates of marine 
mammal exposure based on the maximum strike numbers would be too 
conservative for this programmatic analysis of all potential project 
sites. Table 5 presents an estimate of average strikes per day; average 
strikes per day and average daily duration values are used in the 
exposure analyses. For vibratory driving of piles less than 16-in, a 
daily duration of 0.5 hours was assumed; for vibratory driving of 
larger piles a daily duration of 2.25 hours was assumed.

[[Page 9385]]



                              Table 5--Estimated Daily Strikes and Driving Duration
----------------------------------------------------------------------------------------------------------------
                                                                           Estimated duration
                                        Installation  ----------------------------------------------------------
         Pile type and method           rate per day       Average
                                                         strikes/day             Average daily duration
----------------------------------------------------------------------------------------------------------------
14-in steel; impact..................         No data     \1\ <<1,000  No data.
24- to 30-in steel; impact...........             1-6           1,000  4.5 minutes to 1.5 hours.
18- to 24-in concrete; impact........            1-11       \2\ 4,000  3 minutes to 4 hours.
13-in steel; vibratory...............            2-17             n/a  0-31 minutes. \3\
24- to 30-in steel; vibratory........             1-6             n/a  10 minutes to 4.5 hours. \4\
----------------------------------------------------------------------------------------------------------------
\1\ All 14-in piles are expected to be vibratory driven for full embedment depth. In the event that conditions
  requiring impact driving are encountered, very few strikes are expected to be necessary.
\2\ Estimate based on data from 272 piles installed at NBK Bremerton.
\3\ Estimate based on data from 70 piles installed at NBK Bremerton.
\4\ Estimate based on data from 809 piles installed at NBK Bangor. Maximum assumes six piles advanced at a rate
  of 45 minutes per pile.

    Delineation of potential injury zones on the basis of the peak 
pressure metric was performed using the SPL(peak) values provided in 
Table 4 above. As described previously, source levels for peak pressure 
are unweighted within the generalized hearing range, while SEL source 
levels are weighted according to the appropriate auditory weighting 
function. Delineation of potential injury zones on the basis of the 
cumulative SEL metric for vibratory driving was performed using a 
single-frequency weighting factor adjustment (WFA) of 2.5 kHz, as 
recommended by the NMFS User Spreadsheet, described in Appendix D of 
NMFS's Technical Guidance (NMFS, 2016). In order to assist in simple 
application of the auditory weighting functions, NMFS recommends WFAs 
for use with specific types of activities that produce broadband or 
narrowband noise. WFAs consider marine mammal auditory weighting 
functions by focusing on a single frequency. This will typically result 
in higher predicted exposures for broadband sounds, since only one 
frequency is being considered, compared to exposures associated with 
the ability to fully incorporate the Technical Guidance's weighting 
functions.
    Because use of the WFA typically results in an overestimate of zone 
size, the Navy took an alternative approach to delineating potential 
injury zones for impact driving of 24- and 36-in steel piles and 24-in 
concrete piles. Note that, because data is not available for all pile 
sizes and types, we conservatively assume the following in using the 
available data for 24- and 36-in steel piles and 24-in concrete piles: 
(1) Injury zones for impact driving 14-in piles are equivalent to the 
zones for 24-in piles with no bubble curtain; (2) injury zones for 
impact driving plastic and timber piles and for 18-in concrete piles 
are equivalent to the zones for 24-in concrete piles; and (3) injury 
zones for impact driving 30-in steel piles are equivalent to the zones 
calculated for 36-in piles (both with and without bubble curtain).
    This approach, described in detail in Appendix E of the Navy's 
application, incorporated frequency weighting adjustments by applying 
the auditory weighting function over the entire one-second SEL spectral 
data sets from impact pile driving. If this information for a 
particular pile size was not available, the next highest source level 
was used to produce a conservative estimate of areas above threshold 
values. Sound level measurements from construction activities during 
the 2011 Test Pile Program at NBK Bangor were used for evaluation of 
impact-driven steel piles, and sound level measurements from 
construction activities during the 2015 Intermediate Maintenance 
Facility Pier 6 Fender Pile Replacement Project at NBK Bremerton were 
used for evaluation of impact-driven concrete piles.
    In consideration of the assumptions relating to propagation, sound 
source levels, and the methodology applied by the Navy towards 
incorporating frequency weighting adjustments for delineation of 
cumulative SEL injury zones for impact driving of steel and concrete 
piles, notional radial distances to relevant thresholds were calculated 
(Table 6). However, these distances are sometimes constrained by 
topography. Actual notional ensonified zones at each facility are shown 
in Tables 6-1 to 6-6b of the Navy's application. These zones are 
modeled on the basis of a notional pile located at the seaward end of a 
given structure in order to provide a conservative estimate of 
ensonified area.

                                                Table 6--Calculated Distances to Level A Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       PW                OW                LF                MF                HF
                 Pile                           Driver         -----------------------------------------------------------------------------------------
                                                                   pk      cSEL      pk      cSEL      pk      cSEL      pk      cSEL      pk      cSEL
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in concrete \1\...................  Impact.................        0       34        0        2        0      216        0        3        1      136
24-in steel \2\......................  Impact; BC.............        1       25        0      1.4        1      136        0        3       10      185
24-in steel \2\......................  Impact; no BC..........        3       86        0        5        3      159        0        6       34      342
36-in steel \2\......................  Impact; BC.............        1      158        0        9        1      736        0       10       12      541
36-in steel \2\......................  Impact; no BC..........        3      736        0       46        3    2,512        1       63       40    2,512
12- to 14-in timber \3\..............  Vibratory..............      n/a        1      n/a       <1      n/a        2      n/a       <1      n/a        3
16- and 24-in steel \4\..............  Vibratory..............      n/a        7      n/a        1      n/a       12      n/a        1      n/a       17
30- and 36-in steel (Bangor) \4\.....  Vibratory..............      n/a       15      n/a       11      n/a       25      n/a        2      n/a       37
30- and 36-in steel (others) \4\.....  Vibratory..............      n/a       18      n/a        1      n/a       30      n/a        3      n/a       43
Sheet steel \4\......................  Vibratory..............      n/a       10      n/a        1      n/a       16      n/a        1      n/a       24
--------------------------------------------------------------------------------------------------------------------------------------------------------
PW=Phocid; OW=Otariid; LF=low frequency; MF=mid frequency; HF=high frequency; pk=peak pressure; cSEL=cumulative SEL; BC=bubble curtain.
\1\ Assumes 4,000 strikes per day.
\2\ Assumes 1,000 strikes per day. Bubble curtain will be used for 24-, 30-, and 36-in steel piles except at NBK Bremerton and NBK Keyport. Steel piles
  will not be installed at NBK Manchester.
\3\ Assumes 30 minute daily driving duration.
\4\ Assumes 2.25 hour daily driving duration.


[[Page 9386]]

    Airborne Noise--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.
    Certain locations where pinnipeds may haul-out may be within an 
airborne noise harassment zone. We generally recognize that pinnipeds 
occurring within an estimated airborne harassment zone, whether in the 
water or hauled out, could be exposed to airborne sound that may result 
in behavioral harassment. However, any animal exposed to airborne sound 
above the behavioral harassment threshold is likely to also be exposed 
to underwater sound above relevant thresholds (which are typically in 
all cases larger zones than those associated with airborne sound). 
Thus, the behavioral harassment of these animals is already accounted 
for in these estimates of potential take. Multiple incidents of 
exposure to sound above NMFS's thresholds for behavioral harassment are 
not believed to result in increased behavioral disturbance, in either 
nature or intensity of disturbance reaction. Therefore, we do not 
believe that authorization of incidental take resulting from airborne 
sound for pinnipeds is warranted, and airborne sound is not discussed 
further here. Further information regarding anticipated airborne noise 
from pile driving may be found in section 6.8 of the Navy's 
application.
    Summary--Here, we summarize facility-specific information about 
piles to be removed and installed. In general, it is likely that pile 
removals may be accomplished via a combination of methods (e.g., 
vibratory driver, cut at mudline, direct pull). However, for purposes 
of analysis we assume that all removals would be via vibratory driver. 
In addition, we assume that installation of all steel piles larger than 
14-in would require use of both impact and vibratory drivers, although 
it is likely that some of these piles would be installed solely via use 
of the vibratory driver. All concrete, timber, and plastic piles would 
be installed solely via impact driver. Steel sheet piles and steel pipe 
piles of 14-in diameter and smaller would be installed solely via 
vibratory driver. All piles removed are assumed to be replaced at a 1:1 
ratio, although it is likely that a lesser number of replacement piles 
would be required. For full details, please see Appendix A of the 
Navy's application.
     NBK Bangor: The Navy anticipates ongoing maintenance work 
at the older Explosives Handling Wharf (EHW-1), including removal and 
replacement of up to 44 piles. Replacement of up to 75 piles is 
anticipated for contingency repairs at any existing structure. Piles to 
be removed would be steel, timber, and/or concrete, and replacement 
piles would be steel and/or concrete. As a conservative scenario, all 
piles are assumed to be 36-in steel for purposes of analysis.
     Zelatched Point: Replacement of up to 20 piles is 
anticipated for contingency repairs. Piles to be removed would be 12-in 
timber piles, while replacement piles could be steel, timber, and/or 
concrete. As a conservative scenario, all replacement piles are assumed 
to be 36-in steel for purposes of analysis.
     NBK Bremerton: The Navy anticipates ongoing maintenance 
work at multiple existing structures. At Pier 5, 360 timber fender 
piles would be removed and replaced with concrete piles. Timber piles 
are assumed to be 14-in diameter, and concrete piles are assumed to be 
24-in. At Pier 4, 80 timber fender piles would be replaced with steel 
piles--timber and steel piles are assumed to be 14-in diameter. 
Anticipated repairs to other piers would require removal of up to 20 
timber piles, followed by installation of steel sheet piles. 
Replacement of up to 75 piles is anticipated for contingency repairs at 
any existing structure. Piles to be removed would be steel and/or 
timber, and replacement piles would be 24-in concrete. The largest 
estimated Level B ZOI results from vibratory driving of sheet piles, 
which is expected to occur for only twenty of the estimated total of 
168 activity days. The Navy has elected to assume this largest 
estimated ZOI for all 168 activity days as a conservative scenario.
     NBK Keyport: Replacement of up to 20 piles is anticipated 
for contingency repairs. Piles to be removed would be steel and/or 
concrete (up to 18-in), while replacement piles would be steel. As a 
conservative scenario, all replacement piles are assumed to be 36-in 
steel for purposes of analysis.
     NBK Manchester: Replacement of up to 50 piles is 
anticipated for contingency repairs. Piles to be removed would be 
timber and/or plastic (up to 18-in), while replacement piles could be 
timber, plastic, and/or concrete. As a conservative scenario, all 
replacement piles are assumed to be 24-in concrete for purposes of 
analysis.
     NS Everett: The Navy anticipates minor repairs at the 
North Wharf, requiring replacement of two concrete piles (assumed to be 
24-in). Replacement of up to 76 piles is anticipated for contingency 
repairs. Piles to be removed would include one steel pile and 75 timber 
piles. The one steel pile would be replaced by a 36-in steel pile, 
while the timber piles could be replaced by concrete and/or timber 
piles. As a conservative scenario, these replacement piles are assumed 
to be 24-in concrete for purposes of analysis.
    Behavioral harassment zones and associated areas of ensonification 
are identified in Table 7 below. Although not all zones are applied to 
the exposure analysis, these may be effected as part of the required 
monitoring. Ensonified areas vary based on topography in the vicinity 
of the facility and are provided for each relevant facility.

           Table 7--Radial Distances to Relevant Behavioral Isopleths and Associated Ensonified Areas
----------------------------------------------------------------------------------------------------------------
                                    Impact (160-dB                         Vibratory (120-
        Pile size and type             rms) \1\      Ensonified area \2\       dB) \3\      Ensonified area \2\
----------------------------------------------------------------------------------------------------------------
Plastic (13-in)...................               5  0.001................             n/a  n/a.
Timber (12-in)....................              46  0.01.................             1.6  3.8 (Manchester
                                                                                            Finger Pier); 4.6
                                                                                            (Manchester Fuel
                                                                                            Pier).
Timber (13/14-in) \4\.............              46  0.01.................             2.2  6.8 (Bremerton); 5.9
                                                                                            (Manchester Finger
                                                                                            Pier); 7.8
                                                                                            (Manchester Fuel
                                                                                            Pier); \6\ 9.4
                                                                                            (Everett)
Concrete (24-in) \4\..............             159  0.08.................             n/a  n/a.
Steel (14-in).....................             398  0.5 (Bremerton)......             2.2  6.8 (Bremerton).

[[Page 9387]]

 
Steel (24-in; BC).................             464  0.54 (Bangor)........             n/a  n/a.
                                                    0.48 (Zelatched
                                                     Point).
Steel (24-in; no BC) \5\..........           1,585  2.09 (Keyport).......             5.4  26.8 (Bangor); 4.9
                                                                                            (Keyport); 37.9
                                                                                            (Zelatched Point).
Steel (30-in; BC).................             631  0.91 (Bangor); 0.85               n/a  n/a.
                                                     (Zelatched Point);
                                                     1.2 (Everett).
Steel (30-in; no BC)..............           2,154  1.94 (Keyport).......   Same as 36-in  Same as 36-in.
Steel (36-in; BC).................   541 (Bangor);  0.7 (Bangor); 0.36                n/a  n/a.
                                      398 (others)   (Zelatched Point);
                                                     0.5 (Everett).
Steel (36-in; no BC)..............           1,359  0.42 (Keyport).......  11.7 (Bangor);  4.9 (Keyport); 75.24
                                                                            13.6 (others)   (Zelatched Point);
                                                                                            117.8 (Everett);
                                                                                            40.9 (Bangor).
Sheet steel.......................             n/a  n/a..................             7.4  15.0 (Bremerton).
----------------------------------------------------------------------------------------------------------------
BC=bubble curtain.
\1\ Radial distance to threshold in meters.
\2\ Ensonified area in square kilometers.
\3\ Radial distance to threshold in kilometers.
\4\ Zones for impact driving of 18-in concrete piles are equivalent to those for impact driving of timber piles.
  Zones for vibratory removal of up to 18-in diameter plastic/timber piles are assumed to be equivalent to those
  for 13/14-in timber piles.
\5\ Zones for vibratory driving of 16-in steel piles assumed equivalent to those for 24-in steel piles.
\6\ Worst-case values for vibratory extraction of timber/plastic piles at NBK Manchester, where piles to be
  removed are a maximum 18-in diameter.

Marine Mammal Occurrence

    Available information regarding marine mammal occurrence in the 
vicinity of the six installations includes density information 
aggregated in the Navy's Marine Mammal Species Density Database (NMSDD; 
Navy, 2015) or site-specific survey information from particular 
installations (e.g., local pinniped counts). More recent density 
estimates for harbor porpoise are available in Smultea et al. (2017). 
The latter of these is described in Appendix C of the Navy's 
application. First, for each installation we describe anticipated 
frequency of occurrence and the information deemed most appropriate for 
the exposure estimates. For all facilities, large whales (humpback 
whale, minke whale, and gray whale), killer whales (transient and 
resident), and the elephant seal are considered as occurring only 
rarely and unpredictably, on the basis of past sighting records. For 
these species, average group size is considered in concert with 
expected frequency of occurrence to develop the most realistic exposure 
estimate. Although certain species are not expected to occur at all at 
some facilities--for example, resident killer whales are not expected 
to occur in Hood Canal--the Navy has developed an overall take estimate 
and request for these species that would apply to activities occurring 
over the 5-year duration at all six installations.
     NBK Bangor: In addition to the species described above, 
the Dall's porpoise is considered as a rare, unpredictably occurring 
species. A density-based analysis is used for the harbor porpoise, 
while data from site-specific abundance surveys is used for the 
California sea lion, Steller sea lion, and harbor seal.
     Zelatched Point: In addition to the species described 
above, the Dall's porpoise is considered as a rare, unpredictably 
occurring species. A density-based analysis is used for the harbor 
porpoise, California sea lion, Steller sea lion, and harbor seal.
     NBK Bremerton: A density-based analysis is used for the 
harbor porpoise, Dall's porpoise, and Steller sea lion, while data from 
site-specific abundance surveys is used for the California sea lion and 
harbor seal.
     NBK Keyport: A density-based analysis is used for the 
harbor porpoise, Dall's porpoise, California sea lion, Steller sea 
lion, and harbor seal.
     NBK Manchester: A density-based analysis is used for the 
harbor porpoise, Dall's porpoise, and harbor seal, while data from 
site-specific abundance surveys is used for the California sea lion and 
Steller sea lion.
     NS Everett: A density-based analysis is used for the 
harbor porpoise, Dall's porpoise, and Steller sea lion, while data from 
site-specific abundance surveys is used for the California sea lion and 
harbor seal.

                    Table 8--Marine Mammal Densities
------------------------------------------------------------------------
                                                         Density (June-
             Species                     Region            February)
------------------------------------------------------------------------
Harbor porpoise.................  Hood Canal (Bangor,               0.44
                                   Zelatched Point).
                                  East Whidbey                      0.75
                                   (Everett).
                                  Bainbridge                        0.53
                                   (Bremerton,
                                   Keyport).
                                  Vashon (Manchester)               0.25
Dall's porpoise.................  Puget Sound........              0.039
Steller sea lion................  Puget Sound........             0.0368
                                  Dabob Bay..........             0.0251
California sea lion.............  Puget Sound........             0.1266
                                  Dabob Bay..........              0.279
Harbor seal.....................  Everett............             2.2062
                                  Keyport/Manchester.              1.219

[[Page 9388]]

 
                                  Dabob Bay..........              9.918
------------------------------------------------------------------------
Sources: Navy, 2015; Smultea et al., 2017 (harbor porpoise).

Exposure Estimates

    To quantitatively assess exposure of marine mammals to noise from 
pile driving activities, the Navy proposed three methods, to be used 
depending on the species' spatial and temporal occurrence. For species 
with rare or infrequent occurrence at a given installation during the 
in-water work window, the likelihood of interaction was reviewed on the 
basis of past records of occurrence (described in Description of Marine 
Mammals in the Area of the Specified Activity) and the potential 
maximum duration of work days at each installation, as well as total 
work days for all installations. Occurrence of the species in this 
category (i.e., large whales, killer whales, elephant seal (all 
installations), and Dall's porpoise (Hood Canal)) would not be 
anticipated to extend for multiple days. For the large whales and 
killer whales, the duration of occurrence was set to two days, expected 
to be roughly equivalent to one transit in the vicinity of a project 
site. The calculation for species with rare or infrequent occurrence 
is:

Exposure estimate = expected group size x probable duration

    For species that occur regularly but for which site-specific 
abundance information is not available, density estimates (Table 8) 
were used to determine the number of animals potentially exposed on any 
one day of pile driving or extraction. The calculation for density-
based analysis of species with regular occurrence is:

Exposure estimate = N (density) x ZOI (area) x maximum days of pile 
driving

    For remaining species, site-specific abundance information (i.e., 
average monthly maximum over the time period when pile driving will 
occur) was used:

Exposure estimate = Abundance x maximum days of pile driving

    Large Whales--For each species of large whale (i.e., humpback 
whale, minke whale, and gray whale), we assume rare and infrequent 
occurrence at all installations. For all three species, if observed, 
they typically occur singly or in pairs. Therefore, for all three 
species, we assume that a pair of whales may occur in the vicinity of 
an installation for a total of two days. We do not expect that this 
would happen multiple times, and cannot predict where such an 
occurrence may happen, so propose to authorize a total of four takes of 
each species in total for the 5-year duration (across all 
installations).
    It is important to note that the Navy proposes to implement a 
shutdown of pile driving activity if any large whale is observed within 
any defined harassment zone (see Proposed Mitigation). Therefore, the 
proposed take authorization is intended to provide insurance against 
the event that whales occur within Level B harassment zones that cannot 
be fully observed by monitors. As a result of this proposed mitigation, 
we do not believe that Level A harassment is a likely outcome upon 
occurrence of any large whale. While the calculated Level A harassment 
zone is as large as 2.5 km for impact driving of 36-in steel piles 
without a bubble curtain (ranging from 136-736 m for other impact 
driving scenarios), this requires that a whale be present at that range 
for the full assumed duration of 1,000 pile strikes (expected to 
require 1.5 hours). Given the Navy's commitment to shut down upon 
observation of a large whale, and the likelihood that the presence of a 
large whale in the vicinity of any Navy installation would be known due 
to reporting via Orca Network, we do not expect that any whale would be 
present within a Level A harassment zone for sufficient duration to 
actually experience PTS.
    Killer Whales--For killer whales, the proposed take authorization 
is derived via the same thought process described above for large 
whales. For transient killer whales, we assume an average group size of 
six whales occurring for a period of two days. The resulting total 
proposed take authorization of 12 would also account for the low 
probability that a larger group occurred once. For resident killer 
whales, we assume an average group size of 20 whales occurring for two 
days. This is equivalent to the expected pod size for J pod, which is 
most likely to occur in the vicinity of Navy installations, but would 
also account for the unlikely occurrence of L pod (with a size of 
approximately 40 whales) once in the vicinity of any Navy installation.
    Similar to large whales, the Navy proposes to implement shutdown of 
pile driving activity at any time that any killer whale is observed 
within any calculated harassment zone. We expect this to minimize the 
extent and duration of any behavioral harassment. Given the small size 
of calculated Level A harassment zones--maximum of 63 m for the worst-
case scenario of impact-driven 36-in steel piles with no bubble 
curtain, other scenarios range from 1-10 m--we do not anticipate any 
potential for Level A harassment of killer whales.
    Dall's Porpoise--Using the density given in Table 8, the largest 
appropriate ZOI for each of the four installations in Puget Sound, and 
the number of days associated with each of these installations (as 
indicated in harbor porpoise section below), the total estimated 
exposure of Dall's porpoises above Level B harassment thresholds is 
146. Dall's porpoises are not expected to occur in Hood Canal. Dall's 
porpoises are not expected to occur frequently in the vicinity of Navy 
installations and have not been reported in recent years. This total 
proposed take authorization (146) is applied to all installations over 
the 5-year duration.
    The Navy proposes to implement shutdown of pile driving activity at 
any time if a Dall's porpoise is observed in any harassment zone. 
Therefore, the take estimate is precautionary in accounting for 
potential occurrence in areas that cannot be visually observed or in 
the event that porpoises appear within behavioral harassment zones 
before shutdown can be implemented. As was described for large whales, 
as a result of this proposed mitigation, we do not believe that Level A 
harassment is a likely outcome. While the calculated Level A harassment 
zone is as large as 2.5 km for impact driving of 36-in steel piles 
without a bubble curtain (ranging from 136-541 m for other impact 
driving scenarios), this requires that a porpoise be present at that 
range for the full assumed duration of 1,000 pile strikes (expected to 
require 1.5 hours). Given the Navy's commitment to shut down upon 
observation of a porpoise, and the likelihood that a porpoise would 
engage in aversive behavior prior to experiencing PTS, we do not expect 
that any porpoise would be present within a Level A harassment zone for

[[Page 9389]]

sufficient duration to actually experience PTS.
    Harbor Porpoise--Level B exposure estimates for harbor porpoise 
were calculated for each installation using the appropriate density 
given in Table 8, the largest appropriate ZOI for each installation, 
and the appropriate number of days.
     NBK Bangor: Using the Hood Canal sub-region density, 119 
days of pile driving, and the largest ZOI calculated for pile driving 
at this location (40.9 km\2\ for vibratory installation of 30- or 36-in 
steel piles) produces an estimate of 2,142 incidents of Level B 
exposure for harbor porpoise.
     Zelatched Point: Using the Hood Canal sub-region density, 
20 days of pile driving, and the largest ZOI calculated for pile 
driving at this location (75.24 km\2\ for vibratory installation of 30- 
or 36-in steel piles) produces an estimate of 662 incidents of Level B 
exposure for harbor porpoise.
     NBK Bremerton: Using the Bainbridge sub-region density, 
168 days of pile driving, and the largest ZOI calculated for pile 
driving at this location (15 km\2\ for vibratory installation of sheet 
steel piles) produces an estimate of 1,336 incidents of Level B 
exposure for harbor porpoise.
     NBK Keyport: Using the Bainbridge sub-region density, 20 
days of pile driving, and the largest ZOI calculated for pile driving 
at this location (4.9 km\2\ for vibratory installation of 30- or 36-in 
steel piles) produces an estimate of 52 incidents of Level B exposure 
for harbor porpoise.
     NBK Manchester: Using the Vashon sub-region density, 50 
days of pile driving, and the largest ZOI calculated for vibratory 
removal of timber piles (7.8 km\2\ for vibratory extraction of timber 
piles) produces an estimate of 98 incidents of Level B exposure for 
harbor porpoise.
     NS Everett: Using the East Whidbey sub-region density, 78 
days of pile driving, and the largest ZOI calculated for vibratory 
extraction of timber piles (9.4 km\2\) produces an estimate of 552 
incidents of Level B exposure for harbor porpoise. Although some 
vibratory installation is anticipated for a single steel pile, we 
anticipate this would occur for only a brief period. Therefore, use of 
the assumed zone for vibratory extraction of timber piles is 
appropriate in accounting for reasonably expected marine mammal 
exposure at this location.
    The Navy proposes to implement shutdown of pile driving activity at 
any time if a harbor porpoise is observed in any harassment zone. 
Therefore, the take estimate is precautionary in accounting for 
potential occurrence in areas that cannot be visually observed or in 
the event that porpoises appear within behavioral harassment zones 
before shutdown can be implemented. As was described for large whales, 
as a result of this proposed mitigation, we do not believe that Level A 
harassment is a likely outcome. While the calculated Level A harassment 
zone is as large as 2.5 km for impact driving of 36-in steel piles 
without a bubble curtain (ranging from 136-541 m for other impact 
driving scenarios), this requires that a porpoise be present at that 
range for the full assumed duration of 1,000 pile strikes (expected to 
require 1.5 hours). Given the Navy's commitment to shut down upon 
observation of a porpoise, and the likelihood that a porpoise would 
engage in aversive behavior prior to experiencing PTS, we do not expect 
that any porpoise would be present within a Level A harassment zone for 
sufficient duration to actually experience PTS.
    Steller Sea Lion--Level B exposure estimates for Steller sea lions 
were calculated for each installation using the appropriate density 
given in Table 8 or site-specific abundance, the largest appropriate 
ZOI for each installation, and the appropriate number of days. Please 
see Appendix C of the Navy's application for details of site-specific 
abundance information.
     NBK Bangor: Steller sea lions are routinely seen hauled 
out from mid-September through May, with a maximum daily haul-out count 
of 13 individuals in November 2014. Because the daily average number of 
Steller sea lions hauled out at Bangor has increased since 2013 
compared to prior years, the Navy relied on 2013-2016 monitoring data 
to determine the average of the maximum count of hauled out Steller sea 
lions for each month in the in-water work window. The average of the 
monthly maximum counts during the in-water work window provides an 
estimate of three sea lions present per day. Using this value for 119 
days results in an estimate of 357 incidents of Level B exposure.
     Zelatched Point: Using the Dabob Bay density value, 20 
days of pile driving, and the largest ZOI calculated for pile driving 
at this location (75.24 km\2\ for vibratory installation of 30- or 36-
in steel piles) produces an estimate of 38 incidents of Level B 
exposure for Steller sea lions.
     NBK Bremerton: Using the Puget Sound density value, 168 
days of pile driving, and the largest ZOI calculated for pile driving 
at this location (15 km\2\ for vibratory installation of sheet steel 
piles) produces an estimate of 93 incidents of Level B exposure for 
Steller sea lions.
     NBK Keyport: Using the Puget Sound density value, 20 days 
of pile driving, and the largest ZOI calculated for pile driving at 
this location (4.9 km\2\ for vibratory installation of 30- or 36-in 
steel piles) produces an estimate of four incidents of Level B exposure 
for Steller sea lions.
     NBK Manchester: Sea lions haul out on floats approximately 
800 m offshore. Based on shore-based observations conducted 
intermittently in 2012-2013 and more frequently in 2014-2016, in 
addition to aerial surveys conducted by WDFW in selected months in 
2013-2014, the Navy estimates that 10 Steller sea lions may be present 
on any given day. Using this average value for 50 days results in an 
estimate of 500 incidents of Level B exposure.
     NS Everett: Using the Puget Sound density value, 78 days 
of pile driving, and the largest ZOI calculated for this location (9.4 
km\2\) produces an estimate of 27 incidents of Level B exposure for 
harbor porpoise.
    Given the small size of calculated Level A harassment zones--
maximum of 43 m for the worst-case scenario of impact-driven 36-in 
steel piles with no bubble curtain, other scenarios range from 1-11 m--
we do not anticipate any potential for Level A harassment of Steller 
sea lions.
    California Sea Lions--Level B exposure estimates for California sea 
lions were calculated for each installation using the appropriate 
density given in Table 8 or site-specific abundance, the largest 
appropriate ZOI for each installation, and the appropriate number of 
days. Please see Appendix C of the Navy's application for details of 
site-specific abundance information.
     NBK Bangor: California sea lions are routinely seen hauled 
out in all months other than July. Because the daily average number of 
California sea lions hauled out at Bangor has increased since 2013 
compared to prior years, the Navy relied on 2013-2016 monitoring data 
to determine the average of the maximum count of hauled out California 
sea lions for each month in the in-water work window. The average of 
the monthly maximum counts during the in-water work window provides an 
estimate of 49 sea lions per day. Using this value for 119 days results 
in an estimate of 5,831 incidents of Level B exposure.
     Zelatched Point: Using the Dabob Bay density value, 20 
days of pile driving, and the largest ZOI calculated for pile driving 
at this location (75.24 km\2\ for vibratory installation of 30- or

[[Page 9390]]

36-in steel piles) produces an estimate of 420 incidents of Level B 
exposure for California sea lions.
     NBK Bremerton: California sea lions are routinely seen 
hauled out on floats at NBK Bremerton. Survey data from 2012-2016 
indicate as many as 144 animals hauled out each day during this time 
period, with the majority of animals observed August through May and 
the greatest numbers observed in November. The average of the monthly 
maximum counts during the in-water work window provides an estimate of 
69 sea lions per day. Using this value for 168 days results in an 
estimate of 11,592 incidents of Level B exposure.
     NBK Keyport: Using the Puget Sound density value, 20 days 
of pile driving, and the largest ZOI calculated for pile driving at 
this location (4.9 km\2\ for vibratory installation of 30- or 36-in 
steel piles) produces an estimate of 12 incidents of Level B exposure 
for California sea lions.
     NBK Manchester: Sea lions haul out on floats approximately 
800 m offshore. Based on shore-based observations conducted 
intermittently in 2012-2013 and more frequently in 2014-2016, in 
addition to aerial surveys conducted by WDFW in selected months in 
2013-2014, the Navy estimates that 43 California sea lions may be 
present on any given day. Using this average value for 50 days results 
in a Level B exposure estimate of 2,150 incidents of Level B exposure.
     NS Everett: California sea lions are routinely seen hauled 
out on floats at NS Everett. Survey data from 2012-2016 indicate as 
many as 130 animals hauled out each day during this time period, with 
the majority of animals observed July through February and the greatest 
numbers observed in November. The average of the monthly maximum counts 
during the in-water work window provides an estimate of 67 sea lions 
per day. Using this value for 78 days results in an estimate of 5,148 
incidents of Level B exposure.
    Given the small size of calculated Level A harassment zones--
maximum of 43 m for the worst-case scenario of impact-driven 36-in 
steel piles with no bubble curtain, other scenarios range from 1-11 m--
we do not anticipate any potential for Level A harassment of California 
sea lions.
    Harbor Seal--Harbor seals are expected to occur year-round at all 
installations, with the greatest numbers expected at installations with 
nearby haul-out sites. Level B exposure estimates for harbor seals were 
calculated for each installation using the appropriate density given in 
Table 8 or site-specific abundance, the largest appropriate ZOI for 
each installation, and the appropriate number of days. Please see 
Appendix C of the Navy's application for details of site-specific 
abundance information.
    Harbor seals are expected to be the most abundant marine mammal at 
all installations, often occurring in and around existing in-water 
structures in a way that may restrict observers' ability to adequately 
observe seals and subsequently implement shutdowns. In addition, the 
calculated Level A harassment zones are significantly larger than those 
for sea lions, which may also be abundant at various installations at 
certain times of year. For harbor seals, the largest calculated Level A 
harassment zone is 736 m (compared with a maximum zone of 43 m for sea 
lions), calculated for the worst-case scenario of impact-driven 36-in 
steel piles without use of the bubble curtain. Other scenarios range 
from 25-158 m. Therefore, we assume that some Level A harassment is 
likely to occur for harbor seals and provide installation-specific 
estimates below.
     NBK Bangor: The closest major haul-outs to NBK Bangor that 
are regularly used by harbor seals are located approximately 13.2 km 
away. However, a small haul-out occurs under Marginal Wharf and small 
numbers of harbor seals are known to routinely haul out around the 
Carderock pier. Boat-based surveys and monitoring indicate that harbor 
seals regularly swim in the waters at NBK Bangor. Surveys conducted in 
August and September 2016 recorded as many as 28 harbor seals hauled 
out per day under Marginal Wharf or swimming in adjacent waters. 
Assuming a few other individuals may be present elsewhere on the Bangor 
waterfront, the Navy estimates that 35 harbor seals may be present per 
day near the installation during summer and early fall, which are 
expected to be months with greatest abundance of seals. Using this 
value for 119 days results in an estimate of 4,165 incidents of Level B 
exposure.
    Considering the largest Level A harassment zone expected to 
typically occur at NBK Bangor (158 m), and assuming as a precaution 
that one seal per day could remain within the calculated zone for a 
sufficient period to accumulate enough energy to result in PTS, we 
propose to authorize 119 incidents of take by Level A harassment. It is 
important to note that the estimate of potential Level A harassment for 
NBK Bangor is expected to be an overestimate, as planned projects are 
not expected to occur near Marginal Wharf--the location where most 
harbor seal activity occurs.
     Zelatched Point: Using the Dabob Bay density value, 20 
days of pile driving, and the largest ZOI calculated for pile driving 
at this location (75.24 km\2\ for vibratory installation of 30- or 36-
in steel piles) produces an estimate of 14,925 incidents of Level B 
exposure for harbor seals. The largest calculated Level A harassment 
zone at Zelatched Point would be 158 m. However, because harbor seals 
are not known to haul-out or congregate in the vicinity of in-water 
structures, as is the case at NBK Bangor, we do not anticipate that 
Level A harassment will occur at Zelatched Point and do not propose to 
authorize such take.
     NBK Bremerton: Harbor seals do not typically haul out at 
NBK Bremerton, but are commonly present in the nearby vicinity within 
Sinclair Inlet. Marine mammal surveys conducted nearby during the 
construction of the Manette Bridge (WSDOT, 2011, 2012) indicate that 
approximately 11 animals may be present per day. Using this value for 
168 days results in an estimate of 1,848 incidents of Level B exposure. 
The largest Level A harassment zone at NBK Bremerton would be 86 m and, 
given the lack of regular presence of harbor seals in close proximity 
to existing in-water structures, we do not anticipate that Level A 
harassment will occur at NBK Bremerton and do not propose to authorize 
such take.
     NBK Keyport: No harbor seal haul-outs have been identified 
at this installation. Using the Puget Sound density value, 20 days of 
pile driving, and the largest ZOI calculated for pile driving at this 
location (4.9 km\2\ for vibratory installation of 30- or 36-in steel 
piles) produces an estimate of 119 incidents of Level B exposure for 
harbor seals. Given the lack of haul-outs and of regular harbor seal 
presence at this installation, we do not anticipate that Level A 
harassment will occur at NBK Keyport and do not propose to authorize 
such take.
     NBK Manchester: No harbor seal haul-outs have been 
identified at this installation. Using the appropriate density value, 
50 days of pile driving, and the largest ZOI calculated for vibratory 
extraction of timber piles (7.8 km\2\) produces an estimate of 477 
incidents of Level B exposure for harbor seals. Given the lack of haul-
outs and of regular harbor seal presence at this installation, we do 
not anticipate that Level A harassment will occur at NBK Manchester and 
do not propose to authorize such take.
     NS Everett: Harbor seals haul out year-round on log rafts 
adjacent to NS Everett. Surveys from 2012-2016 indicate as many as 491 
animals hauled

[[Page 9391]]

out each day during the in-water work period from July through January 
with the maximum number observed in September and October. The average 
of the monthly maximum counts during the in-water work window provides 
an estimate of 212 seals per day. Using this value for 78 days results 
in an estimate of 16,536 incidents of Level B exposure.
    The largest Level A harassment zone calculated for NS Everett (158 
m) would occur for only one day during impact driving of the single 36-
in steel pile. During the remainder of pile driving at this 
installation, the largest Level A zone would be 34 m (impact driving of 
24-in concrete piles). Given the abundant seal population at this site, 
we assume that some portion of the seal population may be present and 
unobserved within these zones for a sufficient period to accumulate 
enough energy to result in PTS. For the larger zone, the Navy assumes 
that five percent of animals present (11) may occur within the Level A 
zone for such a duration, while for the smaller zone associated with 
concrete piles, the Navy assumes that one percent (2) of the population 
may occur within the zone for such a duration. Therefore, we propose to 
authorize 165 incidents of take by Level A harassment (i.e., two seals 
on each of the 77 concrete pile driving days in addition to 11 seals on 
the one day on which a steel pile would be installed).
    Northern Elephant Seal--Northern elephant seals are considered rare 
visitors to Puget Sound. However, solitary juvenile elephant seals have 
been known to sporadically haul out to molt in Puget Sound during 
spring and summer months. Because there are occasional sightings in 
Puget Sound, the Navy reasons that exposure of up to one seal to noise 
above Level B harassment thresholds could occur for a two-day duration. 
This event could occur at any installation over the 5-year duration.
    The total proposed take authorization for all species and 
installations is summarized in Table 9 below. No authorization of take 
by Level A harassment is proposed for authorization, except a total of 
286 such incidents for harbor seals (anticipated to occur at NBK Bangor 
and NS Everett only).

                                               Table 9--Proposed Take Authorization by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Zelatched                                                           Percent
                            Species                                Bangor     Point    Bremerton   Keyport   Manchester   Everett     Total       \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.................................................                   Applies across all installations                          4        0.2
                                                                -------------------------------------------------------------------
Minke whale....................................................                   Applies across all installations                          4       0.02
                                                                -------------------------------------------------------------------
Gray whale.....................................................                   Applies across all installations                          4        0.6
                                                                -------------------------------------------------------------------
Killer whale (transient).......................................                   Applies across all installations                         12        4.9
                                                                -------------------------------------------------------------------
Killer whale (resident)........................................                   Applies across all installations                         40       48.2
                                                                -------------------------------------------------------------------
Dall's porpoise................................................                   Applies across all installations                        146        0.6
                                                                -------------------------------------------------------------------
Harbor porpoise................................................      2,142        662      1,336         52          98        552      4,842       43.1
Steller sea lion...............................................        357         38         93          4         500         27      1,019        2.4
California sea lion............................................      5,831        420     11,592         12       2,150      5,148     25,153        8.5
Harbor seal....................................................      4,680     14,925      1,848        119         477     16,536     38,585        n/a
                                                                -------------------------------------------------------------------
Elephant seal..................................................                   Applies across all installations                          2      0.001
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Please see Small Numbers Analysis for more details about these percentages.

Proposed Mitigation

    Under Section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
permissible methods of taking pursuant to such activity, and other 
means of effecting the least practicable adverse impact on such species 
or stock and its habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of such species or stock for taking for certain 
subsistence uses (``least practicable adverse impact''). NMFS does not 
have a regulatory definition for ``least practicable adverse impact.'' 
However, NMFS's implementing regulations require applicants for 
incidental take authorizations to include information about the 
availability and feasibility (economic and technological) of equipment, 
methods, and manner of conducting such activity or other means of 
effecting the least practicable adverse impact upon the affected 
species or stocks and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, we carefully consider two primary factors:
    (1) The manner in which, and the degree to which, implementation of 
the measure(s) is expected to reduce impacts to marine mammal species 
or stocks, their habitat, and their availability for subsistence uses. 
This analysis will consider such things as the nature of the potential 
adverse impact (such as likelihood, scope, and range), the likelihood 
that the measure will be effective if implemented, and the likelihood 
of successful implementation.
    (2) The practicability of the measure for applicant implementation. 
Practicability of implementation may consider such things as cost, 
impact on operations, personnel safety, and practicality of 
implementation.
    The mitigation strategies described below largely follow those 
required and successfully implemented under previous incidental take 
authorizations issued in association with similar construction 
activities. Measurements from similar pile driving events were coupled 
with practical spreading loss and other relevant information to 
estimate zones of influence (ZOI; see ``Estimated Take''); these ZOI 
values were used to develop mitigation measures for pile driving 
activities at the six installations. Background discussion related to 
underwater sound concepts and terminology is provided in the section on 
``Description of Sound Sources,'' earlier in this preamble. The ZOIs 
were used to inform the mitigation zones that would be established to 
prevent Level A harassment and to minimize Level B harassment for all 
cetacean species, while providing estimates of the areas within which 
Level B harassment might occur.

[[Page 9392]]

    During installation of steel piles, the Navy would use vibratory 
driving to the maximum extent practicable. In addition to the specific 
measures described later in this section, the Navy would conduct 
briefings for construction supervisors and crews, the marine mammal 
monitoring team, and Navy staff prior to the start of all pile driving 
activity, and when new personnel join the work, in order to explain 
responsibilities, communication procedures, the marine mammal 
monitoring protocol, and operational procedures. Other mitigation 
requirements committed to by the Navy but not relating to marine 
mammals (e.g., construction best management practices) are described in 
section 11 of the Navy's application.

Timing

    As described previously, the Navy would adhere to in-water work 
windows designed for the protection of fish. These timing windows would 
also benefit marine mammals by limiting the annual duration of 
construction activities. At NBK Bangor and Zelatched Point, the Navy 
would adhere to a July 16 through January 15 window, while at the 
remaining facilities this window is extended to February 15.
    On a daily basis, in-water construction activities will occur only 
during daylight hours (sunrise to sunset) except from July 16 to 
September 15 when impact pile driving will only occur starting two 
hours after sunrise and ending two hours before sunset in order to 
protect marbled murrelets (Brachyramphus marmoratus) during the nesting 
season.

Monitoring and Shutdown for Pile Driving

    The following measures would apply to the Navy's mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--The purpose of a shutdown zone is to define an area 
within which shutdown of activity would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area), 
thus preventing some undesirable outcome, such as auditory injury or 
behavioral disturbance of sensitive species (serious injury or death 
are unlikely outcomes even in the absence of mitigation measures). For 
all pile driving activities, the Navy would establish a minimum 
shutdown zone with a radial distance of 10 m. This minimum zone is 
intended to prevent the already unlikely possibility of physical 
interaction with construction equipment and to establish a 
precautionary minimum zone with regard to acoustic effects.
    Using NMFS's user spreadsheet, an optional companion spreadsheet 
associated with the alternative implementation methodology provided in 
Appendix D of NMFS's acoustic guidance (NMFS, 2016), pile type, size, 
and pile driving methodology-specific zones within which auditory 
injury (i.e., Level A harassment) could occur were calculated. For 
larger steel piles and concrete piles, an alternative methodology 
(described in greater detail in ``Estimated Take'' and in Appendix E of 
the Navy's application) was used. The user spreadsheet is publicly 
available online at www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. In 
using the spreadsheet, practical spreading loss was used in addition to 
information regarding assumed number of pile strikes per day (for 
impact pile driving) and daily duration of pile driving (for vibratory 
pile driving). Relevant information was provided in Tables 3-5 and 
calculated zones were provided in Table 6.
    In many cases, especially for vibratory driving, the minimum 
shutdown zone of 10 m is expected to contain the area in which auditory 
injury could occur. In all circumstances where the predicted Level A 
harassment zone exceeds the minimum zone, the Navy proposes to 
implement a shutdown zone equal to the predicted Level A harassment 
zone (see Table 6). In all cases, predicted injury zones are calculated 
on the basis of cumulative sound exposure, as peak pressure source 
levels produce smaller predicted zones. In addition, the Navy proposes 
to implement shutdown upon observation of any cetacean within a 
calculated Level B harassment zone (see Table 7).
    Injury zone predictions generated using the optional user 
spreadsheet are precautionary due to a number of simplifying 
assumptions. For example, the spreadsheet tool assumes that marine 
mammals remain stationary during the activity and does not account for 
potential recovery between intermittent sounds. In addition, the tool 
incorporates the acoustic guidance's weighting functions through use of 
a single-frequency weighting factor adjustment intended to represent 
the signal's 95 percent frequency contour percentile (i.e., upper 
frequency below which 95 percent of total cumulative energy is 
contained; Charif et al., 2010). This will typically result in higher 
predicted exposures for broadband sounds, since only one frequency is 
being considered, compared to exposures associated with the ability to 
fully incorporate the guidance's weighting functions. Note that the 
caveats related to WFA do not apply to the alternative method used by 
the Navy and applied to impact driving of 24- and 36-in steel piles and 
24-in concrete piles.
    Disturbance Zone--Disturbance zones are the areas in which sound 
pressure levels equal or exceed 160 and 120 dB rms (for impact and 
vibratory pile driving, respectively). Disturbance zones provide 
utility for monitoring conducted for mitigation purposes (i.e., 
shutdown zone monitoring) by establishing monitoring protocols for 
areas adjacent to the shutdown zones and, as noted above, the 
disturbance zones act as de facto shutdown zones for cetaceans. 
Monitoring of disturbance zones enables observers to be aware of and 
communicate the presence of marine mammals in the project area but 
outside the shutdown zone, and thus prepare for potential shutdowns of 
activity. For cetaceans, the Navy would implement shutdowns upon 
observation of any cetacean within a disturbance zone (while 
acknowledging that some disturbance zones are too large to practicably 
monitor)--these would also be recorded as incidents of harassment. For 
pinnipeds, the primary purpose of disturbance zone monitoring is for 
documenting incidents of Level B harassment; disturbance zone 
monitoring is discussed in greater detail later (see ``Proposed 
Monitoring and Reporting''). Nominal radial distances for disturbance 
zones are shown in Table 7.
    In order to document observed incidents of harassment, monitors 
record all marine mammal observations, regardless of location. The 
observer's location and the location of the pile being driven are 
known, and the location of the animal may be estimated as a distance 
from the observer and then compared to the location from the pile. It 
may then be estimated whether the animal was exposed to sound levels 
constituting incidental harassment on the basis of predicted distances 
to relevant thresholds in post-processing of observational data, and a 
precise accounting of observed incidents of harassment created. This 
information may then be used to extrapolate observed takes to reach an 
approximate understanding of actual total takes, in cases where the 
entire zone was not monitored.
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving activities. In addition, observers will record 
all incidents of marine mammal occurrence, regardless of distance from 
activity, and monitors will document any behavioral reactions in 
concert with distance from piles being driven. Observations made

[[Page 9393]]

outside the shutdown zone will not result in shutdown; that pile 
segment will be completed without cessation, unless the animal 
approaches or enters the shutdown zone, at which point all pile driving 
activities would be halted. Monitoring will take place from 15 minutes 
prior to initiation through 30 minutes post-completion of pile driving 
activities. Pile driving activities include the time to 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.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified, trained protected 
species observers, who will be placed at the best vantage point(s) 
practicable (i.e., from a small boat, construction barges, on shore, or 
any other suitable location) to monitor for marine mammals and 
implement shutdown/delay procedures when applicable by calling for the 
shutdown to the hammer operator. Observers would have no other 
construction-related tasks while conducting monitoring. Observers 
should have the following minimum qualifications:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
     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 document observations 
including, but not limited to: The number and species of marine mammals 
observed; dates and times when in-water construction activities were 
conducted; dates and times when in-water construction activities were 
suspended to avoid potential incidental injury of marine mammals from 
construction noise within a defined shutdown zone; and marine mammal 
behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Observer teams employed by the Navy in satisfaction of the 
mitigation and monitoring requirements described herein must meet the 
following additional requirements:
     Independent observers (i.e., not construction personnel) 
are required.
     At least one observer must have prior experience working 
as an observer.
     Other observers may substitute education (degree in 
biological science or related field) or training for experience.
     Where a team of three or more observers are required, one 
observer should be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer.
     We will require submission and approval of observer CVs.
    (2) Prior to the start of pile driving activity, the shutdown zone 
will be monitored for 15 minutes to ensure that it is clear of marine 
mammals. Pile driving will only commence once observers have declared 
the shutdown zone clear of marine mammals; animals will be allowed to 
remain in the shutdown zone (i.e., must leave of their own volition), 
and their behavior will be monitored and documented. The shutdown zone 
may only be declared clear, and pile driving started, when the entire 
shutdown zone is visible (i.e., when not obscured by dark, rain, fog, 
etc.). In addition, if such conditions should arise during impact pile 
driving that is already underway, the activity would be halted.
    (3) If a marine mammal approaches or enters the shutdown zone 
during the course of pile driving operations, activity will be halted 
and delayed until either the animal has voluntarily left and been 
visually confirmed beyond the shutdown zone or fifteen minutes have 
passed without re-detection of the animal. Monitoring will be conducted 
throughout the time required to drive a pile and for thirty minutes 
following the conclusion of pile driving.

Soft Start

    The use of a soft start procedure is believed to provide additional 
protection to marine mammals by warning marine mammals or providing 
them with a chance to leave the area prior to the hammer operating at 
full capacity, and typically involves a requirement to initiate sound 
from the hammer at reduced energy followed by a waiting period. This 
procedure is repeated two additional times. It is difficult to specify 
the reduction in energy for any given hammer because of variation 
across drivers and, for impact hammers, the actual number of strikes at 
reduced energy will vary because operating the hammer at less than full 
power results in ``bouncing'' of the hammer as it strikes the pile, 
resulting in multiple ``strikes.'' The Navy will utilize soft start 
techniques for impact pile driving. We require an initial set of three 
strikes from the impact hammer at reduced energy, followed by a 30-
second waiting period, then 2 subsequent 3-strike sets. Soft start will 
be required at the beginning of each day's impact pile driving work and 
at any time following a cessation of impact pile driving of thirty 
minutes or longer; the requirement to implement soft start for impact 
driving is independent of whether vibratory driving has occurred within 
the prior 30 minutes.

Bubble Curtain

    Sound levels can be greatly reduced during impact pile driving 
using sound attenuation devices, including bubble curtains, which 
create a column of air bubbles rising around a pile from the substrate 
to the water surface. The air bubbles absorb and scatter sound waves 
emanating from the pile, thereby reducing the sound energy. Bubble 
curtains may be confined or unconfined. Cushion blocks are also 
commonly used by construction contractors in order to protect equipment 
and the driven pile; use of cushion blocks typically reduces emitted 
sound pressure levels to some extent.
    The literature presents a wide array of observed attenuation 
results for bubble curtains (see Appendix B of the Navy's application). 
The variability in attenuation levels is due to variation in design, as 
well as differences in site conditions and difficulty in properly 
installing and operating in-water attenuation devices. As a general 
rule, reductions of greater than 10 dB cannot be reliably predicted. 
Prior monitoring by the Navy during a project at NBK Bangor reported a 
range of measured values for realized attenuation mostly within 6 to 12 
dB, but with an overall average of 9 dB in effective attenuation 
(Illingworth and Rodkin, 2012).
    The Navy would use a bubble curtain during impact driving of all 
steel piles greater than 14-in diameter in water depths greater than 2 
ft (0.67 m), except at NBK Bremerton and Keyport. Bubble curtains are 
not proposed for use during impact driving of smaller steel piles or 
other pile types due to the relatively low source levels, as the 
requirement to deploy the curtain system at each driven pile results in 
a significantly lower production rate. Where a bubble curtain is used, 
the contractor would be required to turn it on prior to the soft start 
in order to flush fish from the area closest to the driven pile.
    Bubble curtains cannot be used at NBK Bremerton and Keyport due to 
the

[[Page 9394]]

risk of disturbing contaminated sediments at these sites. Sediment 
contamination within Sinclair Inlet, including the project areas at NBK 
Bremerton, includes a variety of metals and organic chemicals 
originating from human sources. The marine sediments have been affected 
by past shipyard operations, leaching from creosote-treated piles, and 
other activities in Sinclair Inlet. Sediments at the project sites and 
adjacent to the piers at Bremerton have a pollution control plan for 
various metals, polycyclic aromatic hydrocarbons, polychlorinated 
biphenyls, and other semivolatile organic compounds (SVOC), and active 
cleanup is occurring pursuant to the terms of an agreement developed 
under the Comprehensive Environmental Response, Compensation, and 
Liability Act (CERCLA) in cooperation with the U.S. Environmental 
Protection Agency and the Washington Department of Ecology. The 
sediment at and near Keyport in Liberty Bay also has a pollution 
control plan, for multiple heavy metals, polychlorinated aromatic 
hydrocarbons, phthalates, and various other SVOCs.
    To avoid loss of attenuation from design and implementation errors, 
the Navy will require specific bubble curtain design specifications, 
including testing requirements for air pressure and flow at each 
manifold ring prior to initial impact hammer use, and a requirement for 
placement on the substrate. The bubble curtain must distribute air 
bubbles around 100 percent of the piling perimeter for the full depth 
of the water column. The lowest bubble ring shall be in contact with 
the mudline for the full circumference of the ring, and the weights 
attached to the bottom ring shall ensure 100 percent mudline contact. 
No parts of the ring or other objects shall prevent full mudline 
contact. The contractor shall also train personnel in the proper 
balancing of air flow to the bubblers, and must submit an inspection/
performance report to the Navy for approval within 72 hours following 
the performance test. Corrections to the noise attenuation device to 
meet the performance standards shall occur prior to use for impact 
driving.
    We have carefully evaluated the Navy's proposed mitigation measures 
and considered a range of other measures in the context of ensuring 
that we prescribed the means of effecting the least practicable adverse 
impact on the affected marine mammal species and stocks and their 
habitat. Based on our evaluation of these measures, we have 
preliminarily determined that the proposed mitigation measures provide 
the means of effecting the least practicable adverse impact on marine 
mammal species or stocks and their habitat, paying particular attention 
to rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for subsistence uses.

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 the authorized taking. NMFS's 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 significant interactions with marine mammal 
species in action area (e.g., animals that came close to the vessel, 
contacted the gear, or are otherwise rare or displaying unusual 
behavior).
     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 important physical components of marine 
mammal habitat).
     Mitigation and monitoring effectiveness.

Coordination and Plan Development

    An installation-specific marine mammal monitoring plan for each 
year's anticipated work will be developed by the Navy and presented in 
March of each year for approval by NMFS prior to the start of 
construction. Final monitoring plans will be prepared and submitted to 
NMFS within 30 days following receipt of comments on the draft plans 
from NMFS. Please see Appendix D of the Navy's application for a marine 
mammal monitoring plan template. During each in-water work period 
covered by an LOA, the Navy would update NMFS every two months on the 
progress of ongoing projects (September 15, November 15, and January 
15).

Visual Marine Mammal Observations

    The Navy will collect sighting data and behavioral responses to 
pile driving activity for marine mammal species observed in the region 
of activity during the period of activity. The number and location of 
required observers would be determined specific to each installation on 
an annual basis, depending on the nature of work anticipated (including 
the size of zones to be monitored). All observers will be trained in 
marine mammal identification and behaviors and are required to have no 
other construction-related tasks while conducting monitoring. The Navy 
would monitor all shutdown zones at all times, and would monitor 
disturbance zones to the extent practicable (some zones are too large 
to fully observe (Table 7)). The Navy would conduct monitoring before, 
during, and after pile driving, with observers located at the best 
practicable vantage points.
    As described in ``Proposed Mitigation'' and based on our 
requirements, the Navy would implement the following procedures for 
pile driving:
     Marine mammal observers would be located at the best 
vantage point(s) in order to properly see the entire shutdown zone and 
as much of the disturbance zone as possible.
     During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals.
     If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving at that location will not be initiated until 
that zone is visible. Should such conditions arise while impact driving 
is underway, the activity would be halted.
     The shutdown zone around the pile would be monitored for 
the presence of marine mammals before, during, and

[[Page 9395]]

after all pile driving activity, while disturbance zone monitoring 
would be implemented according to the schedule proposed here.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. Monitoring biologists will 
use their best professional judgment throughout implementation and seek 
improvements to these methods when deemed appropriate. Any 
modifications to the protocol will be coordinated between NMFS and the 
Navy.

Data Collection

    We require that observers use standardized data forms. Among other 
pieces of information, the Navy will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and a description of specific actions that ensued and 
resulting behavior of the animal, if any. We require that, at a 
minimum, the following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., wind speed, percent cloud cover, 
visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Description of implementation of mitigation measures 
(e.g., shutdown or delay).
     Locations of all marine mammal observations; and
     Other human activity in the area.
    The Navy will note in behavioral observations, to the extent 
practicable, if an animal has remained in the area during construction 
activities. Therefore, it may be possible to identify if the same 
animal or different individuals are being exposed.

Acoustic Monitoring

    The Navy will conduct hydroacoustic monitoring for a subset of 
impact-driven steel piles for projects including more than three piles 
where a bubble curtain is used. The USFWS has imposed requirements 
relating to impact driving of steel piles, including restrictions on 
unattenuated driving of such piles, as a result of concern regarding 
impacts to the ESA-listed marbled murrelet. If USFWS allows the Navy to 
conduct minimal driving of steel piles without the use of the bubble 
curtain, baseline sound measurements of steel pile driving will occur 
prior to the implementation of noise attenuation to evaluate the 
performance of the device. Impact pile driving without noise 
attenuation would be limited to the number of piles necessary to obtain 
an adequate sample size for each project.

Marine Mammal Surveys

    Subject to funding availability, the Navy would continue pinniped 
haul-out survey counts at specific installations. Biologists conduct 
counts of seals and sea lions at NBK Bremerton, Bangor, Manchester, and 
NS Everett. Counts are conducted several times per month, depending on 
the installation. All animals are identified to species where possible. 
This information aids in determination of seasonal use of each site and 
trends in the number of animals.

Reporting

    A draft report would be submitted to NMFS within 90 days of the 
completion of monitoring for each installation's in-water work window. 
The report will include marine mammal observations pre-activity, 
during-activity, and post-activity during pile driving days, and will 
also provide descriptions of any behavioral responses to construction 
activities by marine mammals and a complete description of all 
mitigation shutdowns and the results of those actions and an 
extrapolated total take estimate based on the number of marine mammals 
observed during the course of construction. A final report must be 
submitted within 30 days following resolution of comments on the draft 
report. The Navy would also submit a comprehensive annual summary 
report covering all activities conducted under the incidental take 
regulations.

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'' by mortality, serious injury, and Level A or Level B 
harassment, we consider other factors, such as the likely nature of any 
behavioral responses (e.g., intensity, duration), the context of any 
such responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of 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, and 
specific consideration of take by M/SI previously authorized for other 
NMFS research activities).
    Pile driving activities associated with the maintenance projects, 
as described 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 (behavioral disturbance) only 
(for all species other than the harbor seal) from underwater sounds 
generated from pile driving. Potential takes could occur if individual 
marine mammals are present in the ensonified zone when pile driving is 
happening.
    No serious injury or mortality would be expected even in the 
absence of the proposed mitigation measures. For all species other than 
the harbor seal, no Level A harassment is anticipated given the nature 
of the activities, i.e., much of the anticipated activity would involve 
vibratory driving and/or installation of small-diameter, non-steel 
piles, and measures designed to minimize the possibility of injury. The 
potential for injury is small for cetaceans and sea lions, and is 
expected to be essentially eliminated through implementation of the 
planned mitigation measures--use of the bubble curtain for larger steel 
piles at most installations, soft start (for impact driving), and 
shutdown zones. Impact driving, as compared with vibratory driving, has 
source characteristics (short, sharp pulses with higher peak levels and 
much sharper rise time to reach those peaks) that are potentially 
injurious or more likely to produce severe behavioral reactions. Given 
sufficient notice through use of soft start, marine mammals are 
expected

[[Page 9396]]

to move away from a sound source that is annoying prior to its becoming 
potentially injurious or resulting in more severe behavioral reactions. 
Environmental conditions in inland waters are expected to generally be 
good, with calm sea states, and we expect conditions would allow a high 
marine mammal detection capability, enabling a high rate of success in 
implementation of shutdowns to avoid injury.
    As described previously, there are multiple species that should be 
considered rare in the proposed project areas and for which we propose 
to authorize only nominal and precautionary take of a single group for 
a minimal period of time (two days). Therefore, we do not expect 
meaningful impacts to these species (i.e., humpback whale, gray whale, 
minke whale, transient and resident killer whales, and northern 
elephant seal) and preliminarily find that the total marine mammal take 
from each of the specified activities will have a negligible impact on 
these marine mammal species.
    For remaining species, we discuss the likely effects of the 
specified activities in greater detail. 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; HDR, Inc., 2012; Lerma, 2014). Most 
likely, individuals will simply move away from the sound source and be 
temporarily displaced from the areas of pile driving, although even 
this reaction has been observed primarily only in association with 
impact pile driving. The pile driving activities analyzed here are 
similar to, or less impactful than, numerous other construction 
activities conducted in San Francisco Bay and in the Puget Sound 
region, which have taken place with no known long-term adverse 
consequences from behavioral harassment.
    The Navy has conducted multi-year activities potentially affecting 
marine mammals, and typically involving greater levels of activity than 
is contemplated here in various locations such as San Diego Bay and 
some of the installations considered herein (NBK Bangor and NBK 
Bremerton). Reporting from these activities has similarly reported no 
apparently consequential behavioral reactions or long-term effects on 
marine mammal populations (Lerma, 2014; Navy, 2016). Repeated exposures 
of individuals to relatively low levels of sound outside of preferred 
habitat areas are unlikely to significantly disrupt critical behaviors. 
Thus, even repeated Level B harassment of some small subset of the 
overall stock is unlikely to result in any significant realized 
decrease in viability for the affected individuals, and thus would not 
result in any adverse impact to the stock as a whole. Level B 
harassment will be reduced to the level of least practicable adverse 
impact 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. While vibratory driving associated with some project 
components may produce sound at distances of many kilometers from the 
pile driving site, thus intruding on higher-quality habitat, the 
project sites themselves and the majority of sound fields produced by 
the specified activities are within industrialized areas. Therefore, we 
expect that animals annoyed by project sound would simply avoid the 
area and use more-preferred habitats.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that harbor seals may sustain some limited 
Level A harassment in the form of auditory injury at two locations (NBK 
Bangor and NS Everett), assuming they remain within a given distance of 
the pile driving activity for the full number of pile strikes. However, 
seals in these locations that experience PTS would likely only receive 
slight PTS, i.e. minor degradation of hearing capabilities within 
regions of hearing that align most completely with the energy produced 
by pile driving, i.e. the low-frequency region below 2 kHz, not severe 
hearing impairment or impairment in the regions of greatest hearing 
sensitivity. If hearing impairment occurs, it is most likely that the 
affected animal would lose a few decibels in its hearing sensitivity, 
which in most cases is not likely to meaningfully affect its ability to 
forage and communicate with conspecifics. As described above, we expect 
that marine mammals would be likely to move away from a sound source 
that represents an aversive stimulus, especially at levels that would 
be expected to result in PTS, given sufficient notice through use of 
soft start.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of serious injury or mortality 
may reasonably be considered discountable; (2) as a result of the 
nature of the activity in concert with the planned mitigation 
requirements, injury is not anticipated for any species other than the 
harbor seal; (3) the anticipated incidents of Level B harassment 
consist of, at worst, temporary modifications in behavior; (4) the 
additional impact of PTS of a slight degree to few individual harbor 
seals at two locations is not anticipated to increase individual 
impacts to a point where any population-level impacts might be 
expected; (5) the absence of any significant habitat within the 
industrialized project areas, including known areas or features of 
special significance for foraging or reproduction; and (6) the presumed 
efficacy of the proposed mitigation measures in reducing the effects of 
the specified activity to the level of least practicable adverse 
impact.
    In addition, although affected humpback whales may be from DPSs 
that are listed under the ESA, and southern resident killer whales are 
depleted under the MMPA as well as listed as endangered under the ESA, 
it is unlikely that minor noise effects in a small, localized area of 
sub-optimal habitat would have any effect on the stocks' ability to 
recover. In combination, we believe that these factors, as well as the 
available body of evidence from other similar activities, demonstrate 
that the potential effects of the specified activities will have only 
minor, short-term effects on individuals. The specified activities are 
not expected to impact rates of recruitment or survival and will 
therefore not result in population-level impacts.
    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, we preliminarily find that the total marine mammal 
take from the Navy's maintenance construction activities will have a 
negligible impact on the affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(A) of the MMPA for specified 
activities. The MMPA does not define small numbers and so, in practice, 
where estimated numbers are available, NMFS compares the number of 
individuals taken to the most appropriate estimation of abundance of 
the relevant species or stock in our determination of whether an 
authorization is limited to small numbers of marine mammals. 
Additionally, other qualitative factors may be considered in the 
analysis, such

[[Page 9397]]

as the temporal or spatial scale of the activities.
    Please see Table 9 for information relating to this small numbers 
analysis. We propose to authorize incidental take of 12 marine mammal 
stocks. The total amount of taking proposed for authorization is less 
than one percent for five of these, less than five percent for an 
additional two stocks, and less than ten percent for another stock, all 
of which we consider relatively small percentages and we preliminarily 
find are small numbers of marine mammals relative to the estimated 
overall population abundances for those stocks.
    For the southern resident killer whale (in addition to the humpback 
whale, gray whale, minke whale, transient killer whale, and northern 
elephant seal), we propose to authorize take resulting from a brief 
exposure of one group of the stock. We believe that a single incident 
of take of one group of any of these species represents take of small 
numbers for that species.
    For the two affected stocks of harbor seal (Hood Canal and Northern 
Inland Waters), no valid abundance estimate is available. The most 
recent abundance estimates for harbor seals in Washington inland waters 
are from 1999, and it is generally believed that harbor seal 
populations have increased significantly during the intervening years 
(e.g., Mapes, 2013). However, we anticipate that takes estimated to 
occur for harbor seals are likely to occur only within some portion of 
the relevant populations, rather than to animals from the stock as a 
whole. For example, takes anticipated to occur at NBK Bangor or at NS 
Everett would be expected to accrue to the same individual seals that 
routinely occur on haul-outs at these locations, rather than occurring 
to new seals on each construction day. Similarly, at Zelatched Point in 
Hood Canal many known haul-outs are at locations elsewhere in Hood 
Canal and, although a density estimate rather than haul-out count is 
used to inform the exposure estimate for Zelatched Point, we expect 
that exposed individuals would comprise some limited portion of the 
overall stock abundance. In summary, harbor seals taken as a result of 
the specified activities at each of the six installations are expected 
to comprise only a limited portion of individuals comprising the 
overall relevant stock abundance. Therefore, we preliminarily find that 
small numbers of marine mammals will be taken relative to the 
population size of both the Hood Canal and Northern Inland Waters 
stocks of harbor seal.
    The estimated taking for harbor porpoise comprises greater than 
one-third of the best available stock abundance. However, due to the 
nature of the specified activity--construction activities occurring at 
six specific locations, rather than a mobile activity occurring 
throughout the stock range--the available information shows that only a 
portion of the stock would likely be impacted. Recent aerial surveys 
(2013-2016) that inform the current abundance estimate for harbor 
porpoise involved effort broken down by region and subregion. According 
to the data available as a result of these surveys, the vast majority 
of harbor porpoise abundance occurs in the ``northern waters'' region, 
including the San Juan Islands and Strait of Juan de Fuca, where no 
Navy construction activity is proposed to occur. The six installations 
considered here occur within the Hood Canal, North Puget Sound, and 
South Puget Sound regions, which contain approximately 24 percent of 
stock-wide harbor porpoise abundance (Jefferson et al., 2016). 
Therefore, we assume that affected individuals would most likely be 
from the 24 percent of the stock expected to occur in these regions. 
This figure itself may be an overestimate, as Navy facilities are 
located within only three of seven subregions within the North and 
South Puget Sound regions (i.e., East Whidbey, Bainbridge, and Vashon). 
However, at this finer scale, it is possible that harbor porpoise 
individuals transit across subregions. In consideration of this 
conservative scenario, i.e., that 24 percent of the stock abundance is 
taken, we preliminarily find that small numbers of marine mammals will 
be taken relative to the population size of the Washington inland 
waters stock of harbor porpoise.
    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 
sizes of the affected species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    There are no relevant subsistence uses of marine mammals implicated 
by these actions. Therefore, we have determined that the total taking 
of affected species or stocks would not have an unmitigable adverse 
impact on the availability of such species or stocks for taking for 
subsistence purposes.

Adaptive Management

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

Endangered Species Act (ESA)

    The southern resident killer whale, as well as multiple DPSs of 
humpback whale, are listed under the ESA (see Table 3). The proposed 
authorization of incidental take pursuant to the Navy's specified 
activity would not affect any designated critical habitat. OPR has 
initiated consultation with NMFS's West Coast Regional Office under 
section 7 of the ESA on the promulgation of five-year regulations and 
the subsequent issuance of LOAs to the Navy under section 101(a)(5)(A) 
of the MMPA. This consultation will be concluded prior to issuing any 
final rule.

Request for Information

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

Classification

    Pursuant to the procedures established to implement Executive

[[Page 9398]]

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: February 23, 2018.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.
    For reasons set forth in the preamble, 50 CFR part 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.

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

Subpart C--Taking Marine Mammals Incidental to U.S. Navy Marine 
Structure Maintenance and Pile Replacement in Washington

Sec.
218.20 Specified activity and specified geographical region.
218.21 Effective dates.
218.22 Permissible methods of taking.
218.23 Prohibitions.
218.24 Mitigation requirements.
218.25 Requirements for monitoring and reporting.
218.26 Letters of Authorization.
218.27 Renewals and modifications of Letters of Authorization.
218.28 [Reserved]
218.29 [Reserved]


Sec.  218.20   Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the U.S. Navy (Navy) 
and those persons it authorizes or funds to conduct activities on its 
behalf for the taking of marine mammals that occurs in the areas 
outlined in paragraph (b) of this section and that occurs incidental to 
maintenance construction activities.
    (b) The taking of marine mammals by the Navy may be authorized in a 
Letter of Authorization (LOA) only if it occurs within Washington 
inland waters in the vicinity of one of the following six naval 
installations: Naval Base Kitsap Bangor, Zelatched Point, Naval Base 
Kitsap Bremerton, Naval Base Kitsap Keyport, Naval Base Kitsap 
Manchester, and Naval Station Everett.


Sec.  218.21   Effective dates.

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


Sec.  218.22   Permissible methods of taking.

    Under LOAs issued pursuant to Sec.  216.106 of this chapter and 
Sec.  218.26, the Holder of the LOA (hereinafter ``Navy'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  218.20(b) by Level A or Level B harassment 
associated with maintenance construction activities, provided the 
activity is in compliance with all terms, conditions, and requirements 
of the regulations in this subpart and the appropriate LOA.


Sec.  218.23   Prohibitions.

    Notwithstanding takings contemplated in Sec.  218.22 and authorized 
by a LOA issued under Sec.  216.106 of this chapter and Sec.  218.26, 
no person in connection with the activities described in Sec.  218.20 
may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec.  216.106 of 
this chapter and Sec.  218.26;
    (b) Take any marine mammal not specified in such LOAs;
    (c) Take any marine mammal specified in such LOAs in any manner 
other than as specified;
    (d) Take a marine mammal specified in such LOAs if NMFS determines 
such taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (e) Take a marine mammal specified in such LOAs if NMFS determines 
such taking results in an unmitigable adverse impact on the species or 
stock of such marine mammal for taking for subsistence uses.


Sec.  218.24   Mitigation requirements.

    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.  218.26 must be implemented. These mitigation 
measures shall include but are not limited to:
    (a) General conditions:
    (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.
    (b) Shutdown zones:
    (1) 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.
    (2) For all pile driving activity, the Navy shall implement 
shutdown zones with radial distances as identified in any LOA issued 
under Sec.  216.106 of this chapter and Sec.  218.26. If a marine 
mammal comes within or approaches the shutdown zone, such operations 
shall cease.
    (3) For all pile driving activity, the Navy shall designate 
monitoring zones with radial distances as identified in any LOA issued 
under Sec.  216.106 of this chapter and Sec.  218.26. Anticipated 
observable zones within the designated monitoring zones shall be 
identified in annual Marine Mammal Monitoring Plans, subject to 
approval by NMFS. If

[[Page 9399]]

any cetacean is observed outside the shutdown zone identified pursuant 
to Sec.  218.24(b)(1)-(2) of this subpart, but within the designated 
monitoring zone, such operations shall cease.
    (c) Shutdown protocols:
    (1) The Navy shall deploy marine mammal observers as indicated in 
annual Marine Mammal Monitoring Plans, which shall be subject to 
approval by NMFS, and as described in Sec.  218.25.
    (2) For all pile driving activities, a minimum of one observer 
shall be stationed at the active pile driving rig or in reasonable 
proximity in order to monitor the shutdown zone.
    (3) Monitoring shall take place from 15 minutes prior to initiation 
of pile driving activity through 30 minutes post-completion of pile 
driving activity. Pre-activity monitoring shall be conducted for 15 
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. Monitoring shall occur throughout the time required to 
drive a pile. A determination that the shutdown zone is clear must be 
made during a period of good visibility (i.e., the entire shutdown zone 
and surrounding waters must be visible to the naked eye).
    (4) 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.
    (5) Monitoring shall be conducted by trained observers, who shall 
have no other assigned tasks during monitoring periods. Trained 
observers shall be placed at the best vantage point(s) practicable to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable through communication with the equipment operator. The 
Navy shall adhere to the following additional observer qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required.
    (ii) At least one observer must have prior experience working as an 
observer.
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience.
    (iv) Where a team of three or more observers are required, one 
observer shall be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer.
    (v) The Navy shall submit observer CVs for approval by NMFS.
    (d) The Navy shall use soft start techniques for impact pile 
driving. Soft start for impact drivers requires contractors to provide 
an initial set of three strikes at reduced energy, followed by a 
thirty-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.
    (e) The Navy shall employ a bubble curtain (or other sound 
attenuation device with proven typical performance of at least 8 
decibels effective attenuation) during impact pile driving of steel 
piles greater than 14 inches diameter in water depths greater than 2 
feet, except at Naval Base Kitsap Bremerton and Naval Base Kitsap 
Keyport. In addition, the Navy shall implement the following 
performance standards:
    (1) The bubble curtain must distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column.
    (2) The lowest bubble ring shall be in contact with the mudline for 
the full circumference of the ring, and the weights attached to the 
bottom ring shall ensure 100 percent mudline contact. No parts of the 
ring or other objects shall prevent full mudline contact.
    (3) The Navy shall require that construction contractors train 
personnel in the proper balancing of air flow to the bubblers, and 
shall require that construction contractors submit an inspection/
performance report for approval by the Navy within 72 hours following 
the performance test. Corrections to the attenuation device to meet the 
performance standards shall occur prior to impact driving.


Sec.  218.25   Requirements for monitoring and reporting.

    (a) Not later than March 1 of each year, the Navy shall develop and 
submit for NMFS's approval an installation-specific Marine Mammal 
Monitoring Plan for each year's anticipated work. Final monitoring 
plans shall be prepared and submitted to NMFS within 30 days following 
receipt of comments on the draft plans from NMFS.
    (b) During each in-water work period, the Navy shall update NMFS 
every two months on the progress of ongoing projects.
    (c) Trained observers shall receive a general environmental 
awareness briefing conducted by Navy staff. At minimum, training shall 
include identification of marine mammals that may occur in the project 
vicinity and relevant mitigation and monitoring requirements. All 
observers shall have no other construction-related tasks while 
conducting monitoring.
    (d) For shutdown zone monitoring, the Navy shall report on 
implementation of shutdown or delay procedures, including whether the 
procedures were not implemented and why (when relevant).
    (e) The Navy shall deploy additional observers to monitor 
disturbance zones according to the minimum requirements defined in 
annual Marine Mammal Monitoring Plans, subject to approval by NMFS. 
These observers shall collect sighting data and behavioral responses to 
pile driving for marine mammal species observed in the region of 
activity during the period of activity, and shall communicate with the 
shutdown zone observer as appropriate with regard to the presence of 
marine mammals. All observers shall be trained in identification and 
reporting of marine mammal behaviors.
    (f) Reporting:
    (1) Annual reporting:
    (i) Navy shall submit an annual summary report to NMFS not later 
than 90 days following the end of construction during each in-water 
work period. Navy shall provide a final report within 30 days following 
resolution of comments on the draft report.
    (ii) These reports shall contain, at minimum, the following:
    (A) Date and time that monitored activity begins or ends;
    (B) Construction activities occurring during each observation 
period;
    (C) Weather parameters (e.g., wind speed, percent cloud cover, 
visibility);
    (D) Water conditions (e.g., sea state, tide state);
    (E) Species, numbers, and, if possible, sex and age class of marine 
mammals;
    (F) Description of any observable marine mammal behavior patterns, 
including bearing and direction of travel and distance from pile 
driving activity;
    (G) Distance from pile driving activities to marine mammals and 
distance from the marine mammals to the observation point;

[[Page 9400]]

    (H) Description of implementation of mitigation measures (e.g., 
shutdown or delay);
    (I) Locations of all marine mammal observations; and
    (J) Other human activity in the area.
    (2) Navy shall submit a comprehensive summary report to NMFS not 
later than ninety days following the conclusion of marine mammal 
monitoring efforts described in this subpart.
    (g) Reporting of injured or dead marine mammals:
    (1) In the unanticipated event that the activity defined in Sec.  
218.20 clearly causes the take of a marine mammal in a prohibited 
manner, Navy shall immediately cease such activity and report the 
incident to the Office of Protected Resources (OPR), NMFS, and to the 
West Coast Regional Stranding Coordinator, NMFS. Activities shall not 
resume until NMFS is able to review the circumstances of the prohibited 
take. NMFS will work with Navy to determine what measures are necessary 
to minimize the likelihood of further prohibited take and ensure MMPA 
compliance. Navy may not resume their activities until notified by 
NMFS. The report must include the following information:
    (i) Time, date, and location (latitude/longitude) of the incident;
    (ii) Description of the incident;
    (iii) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, visibility);
    (iv) Description of all marine mammal observations in the 24 hours 
preceding the incident;
    (v) Species identification or description of the animal(s) 
involved;
    (vi) Fate of the animal(s); and
    (vii) Photographs or video footage of the animal(s). Photographs 
may be taken once the animal has been moved from the waterfront area.
    (2) In the event that Navy discovers an injured or dead marine 
mammal and determines that the cause of the injury or death is unknown 
and the death is relatively recent (e.g., in less than a moderate state 
of decomposition), Navy shall immediately report the incident to OPR 
and the West Coast Regional Stranding Coordinator, NMFS. The report 
must include the information identified in paragraph (g)(1) of this 
section. Activities may continue while NMFS reviews the circumstances 
of the incident. NMFS will work with Navy to determine whether 
additional mitigation measures or modifications to the activities are 
appropriate.
    (3) In the event that Navy discovers an injured or dead marine 
mammal and determines that the injury or death is not associated with 
or related to the activities defined in Sec.  218.20 (e.g., previously 
wounded animal, carcass with moderate to advanced decomposition, 
scavenger damage), Navy shall report the incident to OPR and the West 
Coast Regional Stranding Coordinator, NMFS, within 24 hours of the 
discovery. Navy shall provide photographs or video footage or other 
documentation of the stranded animal sighting to NMFS. Photographs may 
be taken once the animal has been moved from the waterfront area.


Sec.  218.26   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.  
218.27.
    (e) The LOA shall set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, 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 thirty days of a determination.


Sec.  218.27   Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec.  216.106 of this chapter and Sec.  
218.26 for the activity identified in Sec.  218.20(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 (excluding changes 
made pursuant to the adaptive management provision in paragraph (c)(1) 
of this section), and
    (2) NMFS determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA 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 (excluding changes made pursuant to the adaptive management 
provision in paragraph (c)(1) of this section) that do not change the 
findings made for the regulations or result in no more than a minor 
change in the total estimated number of takes (or distribution by 
species or years), NMFS may publish a notice of proposed LOA in the 
Federal Register, including the associated analysis of the change, and 
solicit public comment before issuing the LOA.
    (c) An LOA issued under Sec.  216.106 of this chapter and Sec.  
218.26 for the activity identified in Sec.  218.20(a) may be modified 
by NMFS under the following circumstances:
    (1) Adaptive Management--NMFS may modify (including augment) the 
existing mitigation, monitoring, or reporting measures (after 
consulting with the 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 an LOA:
    (A) Results from the Navy's monitoring from the previous year(s).
    (B) Results from other marine mammal and/or sound research or 
studies.
    (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.

[[Page 9401]]

    (2) Emergencies--If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in LOAs issued pursuant to Sec.  216.106 of 
this chapter and Sec.  218.26, an LOA may be modified without prior 
notice or opportunity for public comment. Notice would be published in 
the Federal Register within thirty days of the action.


Sec.  218.28   [Reserved]


Sec.  218.29   [Reserved]

[FR Doc. 2018-04148 Filed 3-2-18; 8:45 am]
 BILLING CODE 3510-22-P