[Federal Register Volume 84, Number 137 (Wednesday, July 17, 2019)]
[Notices]
[Pages 34134-34163]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-15115]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG907


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Ferry Berth Improvements in Tongass 
Narrows, Alaska

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

ACTION: Notice; two proposed incidental harassment authorizations; 
request for comments on proposed authorizations and possible renewals.

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SUMMARY: NMFS has received a request from the Alaska Department of 
Transportation and Public Facilities (ADOT&PF) for authorization to 
take marine mammals incidental to two years of activity related to 
ferry berth improvements and construction in Tongass Narrows, near 
Ketchikan, AK. Pursuant to the Marine Mammal Protection Act (MMPA), 
NMFS is requesting comments on its proposal to issue two consecutive 
incidental harassment authorizations (IHAs) to incidentally take marine 
mammals during the specified activities. The marine construction 
associated with the proposed activities will occur during two distinct 
year-long phases, and incidental take associated with these phases 
would be authorized in separate, consecutive IHAs. NMFS is also 
requesting comments on a possible one-year renewal for each IHA that 
could be issued under certain circumstances and if all requirements are 
met, as described in Request for Public Comments at the end of this 
notice. NMFS will consider public comments prior to making any final 
decision on the issuance of the requested MMPA authorizations and 
agency responses will be summarized in the final notice of our 
decision.

DATES: Comments and information must be received no later than August 
16, 2019.

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

FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting

[[Page 34135]]

documents, as well as a list of the references cited in this document, 
may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In 
case of problems accessing these documents, please call the contact 
listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to as ``mitigation''); 
and requirements pertaining to the mitigation, monitoring and reporting 
of such takings are set forth.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (incidental harassment authorizations with 
no anticipated serious injury or mortality) of the Companion Manual for 
NOAA Administrative Order 216-6A, which do not individually or 
cumulatively have the potential for significant impacts on the quality 
of the human environment and for which we have not identified any 
extraordinary circumstances that would preclude this categorical 
exclusion. Accordingly, NMFS has preliminarily determined that the 
issuance of the two proposed IHAs qualifies to be categorically 
excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA requests.

Summary of Request

    On September 11, 2018, NMFS received a request from ADOT&PF for two 
consecutive IHAs to take marine mammals incidental to ferry berth 
improvements and construction in Tongass Narrows, near Ketchikan, 
Alaska. The application was deemed adequate and complete on March 20, 
2019. ADOT&PF's request is for take of a small number of eight species 
of marine mammals, by Level B harassment. Of those eight species, three 
(harbor seal (Phoca vitulina richardii), harbor porpoise (Phocoena 
phocoena), and Dall's porpoise (Phocoenoides dalli) may also be taken 
by Level A harassment. Neither ADOT&PF nor NMFS expects serious injury 
or mortality to result from this activity and, therefore, IHAs are 
appropriate. The proposed IHAs would each cover one year of the two 
year project.

Description of Proposed Activity

Overview

    The ADOT&PF plans to make improvements to existing ferry berths and 
construct new ferry berths on Gravina Island and Revilla Island in 
Tongass Narrows, near Ketchikan in southeast Alaska (Figure 1-1 of the 
application). These ferry facilities provide the only public access 
between the city of Ketchikan, AK on Revilla Island, and the Ketchikan 
International Airport on Gravina Island (see Figure 1-2 in 
application). The project's proposed activities that have the potential 
to take marine mammals, by Level A harassment and Level B harassment, 
include vibratory and impact pile driving, drilling operations for pile 
installation (rock socket and tension anchor drilling), and vibratory 
pile removal.
    Improvement and construction of facilities is important to provide 
reliable access to the airport and facilitate growth and development in 
the region. Some of the existing ferry facilities are aging and 
periodically out-of-service for repairs or maintenance, and this 
project will provide redundant ferry berths to increase reliability. 
Ketchikan is Alaska's fifth largest city, with a population of 
approximately 8,125, and numerous marine facilities including fishing 
infrastructure, cruise and ferry terminals, and shipyards.
    Planned construction includes the installation of new ferry 
facilities and the renovation of existing structures. The marine 
construction associated with the proposed activities will occur during 
two distinct year-long phases, and take associated with these phases 
would be authorized in separate, consecutive IHAs. Phase 1, which 
primarily includes both improvement of existing facilities and 
construction of new facilities on both islands, is planned to occur 
between March, 2020 to February, 2021, and Phase 2, which includes the 
improvement/refurbishing of existing facilities on both islands, is 
planned to occur from March, 2021, to February, 2022.
    Section 101(a)(5)(D) specifies that ``the Secretary shall authorize 
[incidental take by harassment] for periods of not more than 1 year.'' 
In this case, the ADOT&PF knows at this time that it will take two 
years to complete the entire project, knows which activities would be 
conducted in each of the two years, and has submitted the entire two-
year project to NMFS. NMFS has sufficient information to determine 
which species would be affected, the estimated amount and type of take 
that would result from the activities, and the estimated impacts to 
subsistence use from ADOT&PF's activities over each of the two years of 
the project. Thus NMFS is able to determine at this time whether the 
proposed activities meet all statutory requirements and can develop 
appropriate mitigation, monitoring, and reporting requirements for both 
years. It is therefore appropriate for NMFS to publish notice in the 
Federal Register, and seek public comment on, proposed IHAs for each of 
the two consecutive years of the project at this time.

Dates and Duration

    In-water construction of Phase 1 is scheduled to begin in March 
2020 and continue through February 2021. In-water construction of Phase 
2 is scheduled to begin in March 2021 and continue through February 
2022. Construction activities such as out-of-water work or in-water 
work that will not result in take may occur at multiple sites 
simultaneously; however, in-water pile installation/removal (including 
drilling) will not occur simultaneously at one or more component sites. 
Pile installation will occur intermittently over the work period, for 
durations of

[[Page 34136]]

minutes to hours at a time depending on weather, construction and 
mechanical delays, marine mammal shutdowns, and other potential delays 
and logistical constraints. There are 144 days of in-water construction 
planned for Phase 1 and 27 days planned for Phase 2.

Specific Geographic Region

    The proposed Tongass Narrows project is located within the City of 
Ketchikan, Alaska (see Figure 1 below). Improvements and new 
construction on Revilla Island will occur approximately 2.6 miles north 
of downtown Ketchikan. The new Revilla Island Airport Shuttle Ferry 
Berth will be constructed immediately adjacent to the existing Revilla 
Island Ferry Berth. Improvements and new construction on Gravina Island 
will all be adjacent to the Ketchikan International Airport, and the 
new Gravina Island Airport Shuttle Ferry Berth will be constructed 
immediately adjacent to the existing Gravina Island Ferry Berth. The 
new Gravina Island Heavy Freight Mooring Facility will be constructed 
in the same location as the existing barge offload facility.
    Tongass Narrows is an approximately 13-mile-long, north-south-
oriented marine channel situated between Revilla Island to the east and 
Gravina Island to the west. In the vicinity of the proposed project, 
Tongass Narrows is as little as 300 meters (984 feet) wide. Tongass 
Narrows is generally characterized by strong tidal currents and by 
steep bedrock or coarse gravel-cobble-boulder shoreline. Pile 
installation will occur in waters ranging in depth from less than 1 
meter (3.3 feet) nearshore to approximately 20 meters (66 feet), 
depending on the structure and location.
 BILLING CODE 4164-01-P

[[Page 34137]]

[GRAPHIC] [TIFF OMITTED] TN17JY19.000

 BILLING CODE 4164-01-C
    Ongoing vessel activities throughout Tongass Narrows, land-based 
industrial and commercial activities, and regular aircraft operations 
result in elevated in-air and underwater sound conditions in the 
project area that increase with proximity to the proposed project 
component sites. Sound levels likely vary seasonally, with elevated 
levels during summer when the tourism and fishing industries are at 
their peaks.

Detailed Description of Specific Activity

    As discussed earlier, this project is composed of two consecutive 
phases, with take of marine mammals from each phase proposed to be 
authorized through separate IHAs. When necessary, the description of 
activity is broken down by phase below, but information relevant to 
both phases is presented together. Proposed activities with potential 
to take marine mammals include the noise generated by drilling of rock 
sockets and tension anchors into bedrock for steel pipe piles, 
vibratory removal of steel pipe piles, vibratory installation of sheet 
piles, and vibratory and impact installation of steel pipe piles. Each 
phase of the project will include different activities that are 
described in detail in the following sections.
    Above-water work will consist of the installation of concrete or 
steel platform decking panels, transfer bridges, dock-mounted fenders, 
pedestrian walkways, gangways, and utility lines. Upland construction 
activities will consist of new terminal facilities, staging areas,

[[Page 34138]]

parking lot expansions, new roadways, retaining walls, stairways, and 
pedestrian walkways. No in-water noise is anticipated in association 
with above-water and upland construction activities and no take is 
expected to occur from in-air noise due to the lack of nearby pinniped 
haul-outs and the smaller in-air isopleths compared to isopleths from 
in-water activities.
Description of In-Water Activities (General to Both Phases)
    Four methods of pile installation are anticipated. These include 
vibratory and impact hammers, down-hole drilling of rock sockets, and 
installation of tension anchors at some locations. Most piles will be 
installed vertically (plumb), but some will be installed at an angle 
(battered). Tension anchors will be used to secure some piles to the 
bedrock to withstand uplift forces. Rock sockets will be drilled at 
other locations where overlying sediments are too shallow to adequately 
secure the bottom portion of the pile. Some piles will be seated in 
rock sockets as well as anchored with tension anchors. A vibratory 
hammer will be used to install 44 temporary template piles, no greater 
than 20 inches in diameter, to a depth of 25 feet or less. The total 
duration of vibratory installation and subsequent removal of temporary 
piles will be approximately 44 hours spread over multiple days as shown 
in Table 2, and will take place within the same days as permanent pile 
installation. Installation and removal of temporary piles is therefore 
not anticipated to add to the overall estimated 144 days of pile 
installation and removal for Phase 1 as shown in Table 1.
    The steel sheet piles for the bulkheads are of a Z-shape. Each pile 
is approximately 28 to 30 inches wide, and they interlock together to 
form a continuous wall. These sheet piles will be installed into the 
existing ground at elevations varying from +8 inches to +26 inches mean 
lower low water. Most of this work is expected to be done at lower 
tides so that in-water pile driving work is minimized. However, some 
installation work below the tidal elevations (in water) can be 
expected. The ground where the sheet piles will be installed is 
comprised of existing rubble mound slopes. Some excavation work will be 
needed to temporarily remove the large rocks prior to driving the sheet 
piles.
    Vibratory and Impact Pile-Driving Methods--Installation of steel 
piles through the sediment layer will be done using vibratory or impact 
methods. All piles will be advanced to refusal at bedrock. Where 
sediments are deep and rock socketing or anchoring is not required, the 
final approximately 10 feet of driving will be conducted using an 
impact hammer so that the structural capacity of the pile embedment can 
be verified. Where sediments are shallow, an impact hammer will be used 
to seat the piles into competent bedrock before rock drilling begins. 
The pile installation methods used will depend on sediment depth and 
conditions at each pile location. The sheet pile abutment bulkheads for 
the new Revilla and Gravina ferry berths will be installed using 
vibratory hammer methods. Vibratory and impact pile driving will occur 
during both Phase 1 and Phase 2 of the project (Table 1 and 3).
    In Table 1, it is estimated that some piles will require 50 strikes 
from the impact hammer and others will require 200 strikes. In general, 
projects on Gravina Island will require approximately 50 strikes and 
projects on Revillia Island will require approximately 200 strikes. 
These differences are based on sediment characteristics, depth to 
bedrock, and the planned need for further drilling once at bedrock.
    Vibratory Pile Removal--A total of 13 previously installed piles 
will be removed during Phase 2 of the project (Table 2), and no piles 
will be removed during Phase 1. When possible, existing piles will be 
extracted by directly lifting them with a crane. A vibratory hammer 
will be used if necessary to extract piles that cannot be directly 
lifted. Removal of each old pile is estimated to require no more than 
15 minutes of vibratory hammer use for the majority of the piles, but 
the removal of one 24-inch diameter pile may take up to 30 minutes.
    Rock Socket Drilling--Rock sockets are holes drilled into the 
bedrock to advance piles beyond the depth vibratory or impact driving 
methods are able to achieve in softer overlying sediments. The depth of 
the rock socket varies, but 10-15 feet is commonly required. Drilling 
of rock sockets through the bedrock may use both rotary and percussion 
drill mechanisms. Drilling breaks up the rock to allow removal of the 
fragments and insertion of the pile. Drill cuttings are expelled from 
the top of the pile using compressed air. The diameter of the drilled 
rock socket is slightly larger than the pile being driving, and the 
pile is therefore easily advanced in the rock as the hole is drilled. 
It is estimated that drilling rock sockets into the bedrock will take 
about 1-3 hours per pile. Rock sockets will be used in both Phase 1 and 
Phase 2 of the project (Table 1 and 3).
    Tension Anchors--Tension anchors are installed within piles that 
are drilled into the bedrock below the elevation of the pile tip, after 
the pile has been driven through the sediment layer to refusal. A 6- or 
8-inch diameter steel pipe casing is inserted inside the larger 
diameter production pile. A rock drill is inserted into the casing, and 
a 6- to 8-inch-diameter hole is drilled into bedrock with rotary and 
percussion drilling methods. The drilling work is contained within the 
smaller steel pile casing and the larger steel pipe pile. The typical 
depth of the drilled hole varies, but 20-30 feet is common. Rock 
fragments will be removed through the top of the casing with compressed 
air. A steel rod is then grouted into the drilled hole and affixed to 
the top of the pile. The purpose of a rock anchor is to secure the pile 
to the bedrock to withstand uplift forces. Tension anchors will be 
utilized during both Phase 1 and Phase 2 of the project, as shown in 
Table 1 and 3. Figure 1-3 in the IHA Application depicts a schematic of 
rock socket and tension anchor drilling techniques.
    Underwater noise from tension anchor construction is typically low. 
The bedrock is overlain with sediments, and will attenuate noise 
production from drilling and reduce noise propagation into the water 
column. Additionally, the casing used during drilling is inside the 
larger diameter pile, further reducing noise levels. Therefore, the 
effects of tension anchor drilling on marine mammals are not expected 
to rise to the level of take. As stated, take is highly unlikely and is 
not proposed to be authorized for tension anchor drilling activities, 
so its impacts are discussed minimally in this document.

Phase 1 Project Components

    Each of the four permanent project components in Phase 1 will 
include installation of steel pipe piles that are 18, 24, or 30 inches 
in diameter. Temporary piles installed and removed during Phase 1 to 
support templates for permanent piles will be a maximum of 20 inches in 
diameter. Two of the components (Revilla and Gravina New Ferry Berths) 
will require the installation of steel sheet piles that will comprise 
the bulkhead abutments and are 27.6 or 30.3 inches in width. These 
sheet piles will be installed using vibratory driving at elevations 
varying from +8 inches to +26 inches mean lower low-water. Most of this 
work is expected to be done at lower tides so that in-water pile 
driving work is minimized. However, some installation work below the 
tidal elevations (in

[[Page 34139]]

water) can be expected. The ground where the sheet piles will be 
installed is comprised of existing rubble mound slopes. Some excavation 
work will be needed to temporarily remove the large rocks prior to 
driving the sheet piles.
    The estimated installation and removal rates for Phase 1 are 1.5 
permanent pipe piles per day, 10 permanent sheet piles per day, and 4 
to 6 temporary piles per day. Different types of piles may be installed 
or removed within a day.
    Project components are briefly described below and Table 1 shows 
the number and size of piles broken down by the individual components 
of Phase 1. For additional information on how these piles will be 
configured, and what structures they will make up, please refer to the 
IHA Application.
    Revilla New Ferry Berth and Upland Improvements--The new Revilla 
Island airport shuttle ferry berth will be constructed immediately 
adjacent to the existing Revilla Island Ferry Berth (Figure 1-2 in IHA 
Application). It is the only Phase 1 component that will occur on 
Revilla Island.
    New Gravina Island Shuttle Ferry Berth/Related Terminal 
Improvements--The new Gravina Island airport shuttle ferry berth will 
be constructed immediately adjacent to the existing Gravina Island 
Ferry Berth (Figure 1-2 in IHA Application).
    Gravina Airport Ferry Layup Facility--Improvements to the Gravina 
Island Ferry layup dock facility will occur in the same location as the 
existing layup dock facility (Figure 1-2 in IHA Application). The 
current layup dock is in disrepair and needs to be replaced.
    Gravina Freight Facility--The new Gravina Island heavy freight 
mooring facility will be constructed in the same location as the 
existing barge offload facility (Figure 1-2 in IHA Application). This 
facility will provide improved access to Gravina Island for highway 
loads that cannot be accommodated by the shuttle ferry. Five breasting 
dolphins and one mooring dolphin will be constructed to support barge 
docking and will include pedestrian walkways for access by personnel. 
In addition, two new pile-supported mooring line structures will be 
constructed above the high tide line.

                                Table 1--Pile Details and Estimated Effort Required for Pile Installation During Phase 1
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         Project component                                                                Average
-----------------------------------                                          Average      drilling                  Average
                                                  Number of    Number of    vibratory     duration      Impact      duration     Average
                                     Number of       rock       tension      duration     for rock   strikes per   (minutes)    piles per      Days of
             Pile type                 piles       sockets      anchors      per pile   sockets per      pile       per pile   day (range)  installation
                                                                            (minutes)       pile                      for
                                                                                         (minutes)                 vibratory
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Revilla New Ferry Berth and Upland
 Improvements:
    24'' Pile Diameter............           65            0           35           30          N/A          200           30    1.5 (1-3)            43
    30'' Pile Diameter............           18            0           14           30          N/A          200           30    1.5 (1-3)            12
    AZ 14-770 Sheet Pile..........           55          N/A          N/A           15          N/A          N/A           15     6 (6-12)             9
New Gravina Island Shuttle Ferry
 Berth/Related Terminal
 Improvements:
    24'' Pile Diameter............           66           52           25           15          120           50           15    1.5 (1-3)            44
    30'' Pile Diameter............            8            4            4           15          180           50           15    1.5 (1-3)             5
    AZ 19-700 Sheet Pile..........           80          N/A          N/A           15          N/A          N/A           15     6 (6-12)            12
Gravina Airport Ferry Layup
 Facility:
    18'' Pile Diameter............            3            0            0           15          N/A           50           15    1.5 (1-3)             2
    30'' Pile Diameter............           12           12           10           15          180           50           15    1.5 (1-3)             8
Gravina Freight Facility:
    20'' Pile Diameter............            6            0            6           15          N/A           50           15    1.5 (1-3)             4
    24'' Pile Diameter............            3            3            3  ...........          120           50           15    1.5 (1-3)             2
    30'' Pile Diameter............            4            2            4           15          180           50           15    1.5 (1-3)             3
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
        Phase 1 Total.............          320           73           91  ...........  ...........  ...........  ...........  ...........           144
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                                                 Table 2--Numbers of Temporary Piles To Be Installed and Removed for Each Project During Phase 1
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                                                                Average vibratory          Average vibratory
       Project component         Number of temporary piles    duration per pile for      duration per pile for       Days of installation         Days of removal             Piles per day
                                                              installation (minutes)       removal (minutes)
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Revilla New Ferry Berth and      12.......................  15.......................  15.......................  2 to 3...................  2 to 3...................  4 to 6.
 Upland Improvements.
New Gravina Island Shuttle       12.......................  15.......................  15.......................  2 to 3...................  2 to 3...................  4 to 6.
 Ferry Berth/Related Terminal
 Improvements.
Gravina Airport Ferry Layup      8........................  15.......................  15.......................  1 to 2...................  0.75 to 2................  4 to 6.
 Facility.
Gravina Freight Facility.......  12.......................  15.......................  15.......................  2 to 3...................  2 to 3...................  4 to 6.
                                ----------------------------------------------------------------------------------------------------------------------------------------------------------------
    Total......................  44.......................  660 (11 hours)...........  660 (11 hours)...........  7-11.....................  7-11.....................  ........................
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[[Page 34140]]

Phase 2 Project Components

    The two project components in Phase 2 will include installation of 
steel pipe piles that are 16, 20, 24 and 30 inches in diameter as shown 
in Table 3. Methods for vibratory and impact installation of temporary 
and permanent piles, drilling of rock sockets, and installation of 
tension anchors will be consistent with those described above. The 
estimated installation and removal rate for Phase 2 is 1.5 pipe piles 
per day.
    One 24-inch-diameter pile will be installed at the existing Revilla 
ferry berth. Fifteen 24-inch diameter piles and eight 30-inch-diameter 
piles will be installed at the existing Gravina ferry berth. A total of 
10 piles will be removed to accommodate upgrades to the existing 
Revilla Island and Gravina Island ferry berths. One 24-inch pile will 
be removed from the floating fender dolphin at the existing Revilla 
ferry berth. The nine 16-inch-diameter piles that support the three 
existing dolphins at the Gravina ferry berth will also be removed. It 
is anticipated that, when possible, existing piles will be extracted by 
directly lifting them with a crane. A vibratory hammer will be used if 
necessary to extract piles that cannot be directly lifted. Installation 
of sheet piles and tension anchor drilling is not planned during Phase 
2.
    Revilla Refurbish Existing Ferry Berth Facility--Improvements to 
the existing Revilla Island Ferry Berth will include the following: (1) 
Replace the transfer bridge, (2) replace rubber fender elements and 
fender panels, (3) replace one 24-inch pile on the floating fender 
dolphin, and (4) replace the bridge float with a concrete or steel 
float of the same dimensions. Construction of the transfer bridge, 
bridge float, and fender elements will occur above water. The only in-
water work will be pile installation and removal associated with 
construction of the dolphins. No temporary piles will be installed or 
removed during this component of the project.
    Gravina Refurbish Existing Ferry Berth Facility--Improvements to 
the existing Gravina Island Ferry Berth will include the following: (1) 
Replace the transfer bridge, (2) remove the catwalk and dolphins, (3) 
replace the bridge float with a concrete or steel float of the same 
dimensions, (4) construct a floating fender dolphin, and (5) construct 
four new breasting dolphins. Construction of the transfer bridge, 
catwalk, and bridge float will occur above water. The only in-water 
work will be pile installation and removal associated with construction 
of the dolphins. A vibratory hammer will be used to install and remove 
12 temporary template piles, no greater than 20 inches in diameter, to 
a depth of 25 feet or less (Table 4). The total duration of vibratory 
installation and subsequent removal of temporary piles will be 
approximately 6 hours spread over multiple days, and will take place 
within the same days as permanent pile installation. Installation and 
removal of temporary piles is therefore not anticipated to add to the 
overall estimated 27 days of pile installation and removal for Phase 2.

                          Table 3--Pile Details and Estimated Effort Required for Pile Installation and Removal During Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
         Project component                                                                Average
-----------------------------------                                          Average      drilling
                                                  Number of    Number of    vibratory     duration      Impact     Estimated     Average       Days of
                                     Number of       rock       tension      duration     for rock   strikes per     total      piles per   installation
             Pile type                 piles       sockets      anchors      per pile   sockets per      pile      number of   day (range)   and removal
                                                                            (minutes)       pile                     hours
                                                                                         (minutes)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Revilla Refurbish Existing Ferry
 Berth Facility:
    24'' Pile Diameter............            1  ...........  ...........           30  ...........           50            1            1             1
    24'' Pile Diameter (Removal)..            1  ...........  ...........           30  ...........          N/A            1            1             1
Gravina Refurbish Existing Ferry
 Berth Facility:
    24'' Pile Diameter............           15            0  ...........           15  ...........           50           11    1.5 (1-3)            10
    30'' Pile Diameter............            8            3           12           15          180           50            6    1.5 (1-3)             7
    16'' Pile Diameter (Removal)..           12  ...........  ...........           15  ...........  ...........            2    1.5 (1-3)             8
                                   ---------------------------------------------------------------------------------------------------------------------
        Phase 2 Total.............      24 (+13            3  ...........  ...........  ...........  ...........  ...........  ...........            27
                                       Removal)
--------------------------------------------------------------------------------------------------------------------------------------------------------


                 Table 4--Number of Temporary Piles To Be Installed and Removed for Each Project Component and Structure During Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Average         Average
                                                                             vibratory       vibratory
                                                             Number of     duration per    duration per       Days of         Days of
                    Project component                        temporary       pile for        pile for      installation       removal      Piles per day
                                                               piles       installation       removal
                                                                             (minutes)       (minutes)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Revilla Refurbish Existing Ferry Berth Facility.........               0               0               0               0               0               0
Gravina Refurbish Existing Ferry Berth Facility.........              12              15              15          2 to 3          2 to 3          4 to 6
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................              12   180 (3 hours)   180 (3 hours)          2 to 3          2 to 3  ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats

[[Page 34141]]

may be found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 5 lists all species with expected potential for occurrence in 
waters near Ketchikan, Alaska 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 (2016). PBR is defined by the MMPA as the 
maximum number of animals, not including natural mortalities, that may 
be removed from a marine mammal stock while allowing that stock to 
reach or maintain its optimum sustainable population (as described in 
NMFS's SARs). While no mortality is anticipated or authorized here, PBR 
and annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Alaska SARs (e.g., Muto et al., 2018) except for gray 
whale, which could occur in the proposed project area and is assessed 
in the U.S. Pacific SARs (Carretta et al. 2018). All values presented 
in Table 3 are the most recent available at the time of publication and 
are available in the 2017 SARs (Muto et al., 2018, Carretta et al. 
2018) and draft 2018 SARs (available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                          Table 5--Marine Mammals That Could Occur in the Proposed Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Stock abundance Nbest,
                                                                                        ESA/ MMPA  status;      (CV, Nmin,  most               Annual  M/
             Common name                  Scientific name             MMPA stock          strategic  (Y/N)     recent  abundance       PBR       SI \3\
                                                                                                \1\               survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray Whale......................  Eschrichtius robustus..  Eastern North Pacific..  -, -, N             26,960 (0.05, 25,849,         801        138
                                                                                                             2016).
Family Balaenidae:
    Humpback whale..................  Megaptera novaeangliae.  Central North Pacific..  E, D, Y             10,103 (0.3; 7,890;            83         25
                                                                                                             2006).
    Minke whale.....................  Balaenoptera             Alaska.................  -, N                N.A...................       N.A.       N.A.
                                       acutorostrata.
    Fin whale.......................  Balaenoptera physalus..  Northeast Pacific......  E, D, Y             N.A...................        5.1        0.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Alaska Resident........  -, N                2,347 (N.A.; 2,347;            24          1
                                                                                                             2012).
                                                               West Coast Transient...  -, N                243 (N.A, 243, 2009)..        2.4          0
  2                                                            Northern Resident......  -, N                261 (N.A.; 261, 2011..       1.96          0
    Pacific white-sided dolphin.....  Lagenorhynchus           North Pacific..........  -,-; N              26,880 (N.A.; N.A.;          N.A.          0
                                       obliquidens.                                                          1990).
Family Phocoenidae:
    Harbor porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -, Y                975 (0.10; 896; 2012).       8.95         34
    Dall's porpoise.................  Phocoenoides dalli.....  Alaska.................  -, N                83400 (0.097, N.A.,          N.A.         38
                                                                                                             1993).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Eastern U.S............  -,-, N              41,638 (N.A.; 41,638;       2,498        108
                                                                                                             2015).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina           Clarence Strait........  -, N                31,634 (N.A.; 29,093;       1,222         41
                                       richardii.                                                            2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\-Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\-NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N.A.).
\3\-These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.

    All species that could potentially occur in the proposed project 
areas are included in Table 5. However, the spatial occurrence of gray 
whale and fin whale is such that take is not expected to occur, and 
they are not discussed further beyond the explanation provided here. 
Gray whales have not been reported by any local experts or recorded in 
monitoring reports and it would be extremely unlikely for a gray whale 
to enter Tongass Narrows or the small portions of Revillagigedo Channel 
this project will impact. Similarly for fin whale, sightings have not 
been reported and it would be unlikely for a fin whale to enter the 
project area as they are generally associated with deeper, more 
offshore waters.

Steller Sea Lion

    Steller sea lions were listed as threatened range-wide under the 
ESA on November 26, 1990 (55 FR 49204). Steller sea lions were 
subsequently partitioned into the western and eastern Distinct 
Population Segments (DPSs; western and eastern stocks) in 1997 (62 FR 
24345). The eastern DPS remained classified as threatened until it was

[[Page 34142]]

delisted in November 2013. The current minimum abundance estimate for 
the eastern DPS of Steller sea lions is 41,638 individuals (Muto et al. 
2018). The western DPS (those individuals west of 144[deg] W longitude 
or Cape Suckling, Alaska) was upgraded to endangered status following 
separation of the DPSs, and it remains endangered today. There is 
regular movement of both DPSs across this 144[deg] W longitude boundary 
(Jemison et al., 2013), however, due to the distance from this DPS 
boundary, it is likely that only eastern DPS Steller sea lions are 
present in the project area. Therefore, animals potentially affected by 
the project are assumed to be part of the eastern DPS. Sea lions from 
the western DPS, which is listed as endangered under the Endangered 
Species Act (ESA), are not likely to be affected by the proposed 
activity and are not discussed further.
    The nearest known Steller sea lion haulout is located approximately 
17 miles west/northwest of Ketchikan on Grindall Island (Figure 4-1 in 
application). Summer counts of adult and juvenile sea lions at this 
haulout since 2000 have averaged approximately 191 individuals, with a 
range from 6 in 2009 to 378 in 2008. Only two winter surveys of this 
haulout have occurred. In March 1993, a total of 239 individuals were 
recorded, and in December 1994, a total of 211 individuals were 
recorded. No sea lion pups have been observed at this haulout during 
surveys. Although this is a limited sample, it suggests that abundance 
may be consistent year-round at the Grindall Island haulout.
    No systematic studies of sea lion abundance or distribution have 
occurred in Tongass Narrows. Anecdotal reports suggest that Steller sea 
lions may be found in Tongass Narrows year-round, with an increase in 
abundance from March to early May during the herring spawning season, 
and another increase in late summer associated with salmon runs. 
Overall sea lion presence in Tongass Narrows tends to be lower in 
summer than in winter (FHWA 2017). During summer, Steller sea lions may 
aggregate outside the project area, at rookery and haulout sites. 
Monitoring during construction of the Ketchikan Ferry Terminal in 
summer (July 16 through August 17, 2016) did not record any Steller sea 
lions (ADOT&PF 2015).
    Marine mammal monitoring was conducted during construction of the 
Icy Strait Point Cruise Ship Terminal in Hoonah, Alaska, between June 
1, 2015, and January 25, 2016. This site is approximately 387 km (240 
miles) Northwest of Tongass Narrows, but still in Southeast Alaska and 
a useful prior project for comparison. These data from Icy Strait Point 
support similar estimates described above and are an example of how 
abundance can fluctuate throughout the season. Steller sea lions were 
observed on 47 of the 135 days of monitoring. Although sea lions were 
observed during all times of the year, observations peaked between late 
August and mid-October (Berger ABAM 2016).
    Sea lions are known to transit through Tongass Narrows while 
pursuing prey. Steller sea lions are known to follow fishing vessels, 
and may congregate in small numbers at seafood processing facilities 
and hatcheries or at the mouths of rivers and creeks containing 
hatcheries, where large numbers of salmon congregate in late summer. 
Three seafood processing facilities are located east of the proposed 
berth location on Revilla Island, and two salmon hatcheries operated by 
the Alaska Department of Fish & Game (ADF&G) are located east of the 
project area. Steller sea lions may aggregate near the mouth of 
Ketchikan Creek, where a hatchery upstream supports a summer salmon 
run. The Creek mouth is more than 4 kilometers (2.5 miles) from both 
ferry berth sites, and is positioned behind the cruise ship terminal 
and within the small boat harbor. In addition to these locations, 
anecdotal information from a local kayaking company suggests that there 
are Steller sea lions present at Gravina Point, near the southwest 
entrance to Tongass Narrows.
Harbor Seals
    Harbor seals range from Baja California north along the west coasts 
of Washington, Oregon, California, British Columbia, and Southeast 
Alaska; west through the Gulf of Alaska, Prince William Sound, and the 
Aleutian Islands; and north in the Bering Sea to Cape Newenham and the 
Pribilof Islands. Harbor seals are not listed as endangered or 
threatened under the ESA. In 2010, harbor seals in Alaska were 
partitioned into 12 separate stocks based largely on genetic structure 
(Allen and Angliss 2010). Harbor seals in Tongass Narrows are 
recognized as part of the Clarence Strait stock, which is increasing in 
population size (Muto et al. 2018). They haul out on rocks, reefs, 
beaches, and drifting glacial ice, and feed in marine, estuarine, and 
occasionally fresh waters. Harbor seals are generally non-migratory, 
with local movements associated with such factors as tides, weather, 
season, food availability, and reproduction (Muto, 2017a).
    No systematic studies of harbor seal abundance or distribution have 
occurred in Tongass Narrows. Aerial surveys conducted in August 2011 
did not record any harbor seal haulouts in Tongass Narrows, but several 
haulouts were located on the outer shores of Gravina Island (London et 
al. 2015). There are no known large harbor seal haulouts in Tongass 
Narrows. Harbor seals have been observed hauled out on docks in 
Ketchikan Harbor.
    Anecdotal observations indicate that harbor seals are common in 
Tongass Narrows, although no data exist to quantify abundance. Two 
salmon hatcheries operated by ADF&G are located east of the project 
area. Like Steller sea lions, harbor seals may aggregate near the mouth 
of Ketchikan Creek when salmon are running in summer. The creek mouth 
is more than 4 kilometers (2.5 miles) from the project component sites, 
and is positioned behind both the cruise ship terminal and within the 
small boat harbor.
Harbor Porpoise
    In the eastern North Pacific Ocean, the harbor porpoise ranges from 
Point Barrow, along the Alaska coast, and down the west coast of North 
America to Point Conception, California. Harbor porpoises are not 
listed as endangered or threatened under the ESA. In Alaska, harbor 
porpoises are currently divided into three stocks, based primarily on 
geography: The Bering Sea stock, the Southeast Alaska stock, and the 
Gulf of Alaska stock. The Southeast Alaska stock ranges from Cape 
Suckling to the Canadian border (Muto et al. 2018). Only the Southeast 
Alaska stock is considered in this proposed IHA because the other 
stocks occur outside the geographic area under consideration. Harbor 
porpoises frequent primarily coastal waters in Southeast Alaska 
(Dahlheim et al. 2009) and occur most frequently in waters less than 
100 meters (328 feet) deep (Hobbs and Waite 2010).
    Abundance data for harbor porpoises in Southeast Alaska were 
collected during 18 seasonal surveys spanning 22 years, from 1991 to 
2012 (Dahlheim et al. 2015). The project area and Tongass Narrows fall 
within the Clarence Strait to Ketchikan region, as identified by this 
study for the survey effort.
    Studies of harbor porpoises reported no evidence of seasonal 
changes in distribution for the inland waters of Southeast Alaska 
(Dahlheim et al. 2009). Their small overall size, lack of a visible 
blow, low dorsal fins and overall low profile, and short surfacing time 
make them difficult to spot (Dahlheim et al. 2015), likely reducing 
identification and

[[Page 34143]]

reporting of this species, and these estimates therefore may be low.
    Harbor porpoises were observed on 19 days during 135 days of 
monitoring in Hoonah, Alaska, primarily between June and September 
(Berger ABAM 2016). Icy Strait was identified as an area with 
relatively high densities of harbor porpoises in the Dahlheim et al. 
(2015) study, and the Ketchikan area densities are expected to be much 
lower. This is supported by anecdotal estimates of harbor porpoise 
abundance.
    Anecdotal reports (see IHA Application) specific to Tongass Narrows 
indicate that harbor porpoises are rarely observed in the project area, 
and actual sightings are less common than those suggested by Dahlheim 
et al. (2015). Harbor porpoises prefer shallower waters (Dahlheim et 
al. 2015) and generally are not attracted to areas with elevated levels 
of vessel activity and noise such as Tongass Narrows. Harbor porpoises 
are expected to be present in the project area only a few times per 
year.
Dall's Porpoise
    Dall's porpoises are found throughout the North Pacific, from 
southern Japan to southern California north to the Bering Sea. Dall's 
porpoises are not listed as endangered or threatened under the ESA. All 
Dall's porpoises in Alaska are members of the Alaska stock, and those 
off California, Oregon, and Washington are part of a separate stock. 
This species can be found in offshore, inshore, and nearshore habitat.
    No systematic studies of Dall's porpoise abundance or distribution 
have occurred in Tongass Narrows; however, surveys for cetaceans 
throughout Southeast Alaska were conducted between 1991 and 2007 
(Dahlheim et al. 2009). The species is generally found in waters in 
excess of 600 feet (183 meters) deep (Dahlheim et al. 2009, Jefferson 
2009), which do not occur in Tongass Narrows. Jefferson et al. (2019) 
presents historical survey data showing few sightings in the Ketchikan 
area, and based on these occurrence patterns, concludes that Dall's 
porpoise rarely come into narrow waterways, like Tongass Narrows. The 
mean group size in Southeast Alaska is estimated at approximately three 
individuals (Dahlheim et al. 2009, Jefferson 2019), although Freitag 
(2017, as cited in 83 FR 37473) suggested group sizes near Ketchikan 
range from 10 to 15 individuals. Although two individuals were observed 
near Hoonah during monitoring of the Icy Strait Point cruise ship 
terminal, both were in deeper offshore waters (Berger ABAM 2016) 
dissimilar to habitat found in the project area.
    Anecdotal reports suggest that Dall's porpoises are found northwest 
of Ketchikan near the Guard Islands, where waters are deeper, as well 
as in deeper waters to the southeast of Tongass Narrows. Should Dall's 
porpoises occur in the project area, they would likely be present in 
March or April, given past observations in the region. Despite 
generalized water depth preferences, Dall's porpoises may occur in 
shallower waters. This species has a tendency to bow-ride with vessels 
and may occur in the project area incidentally a few times per year.
Pacific White-Sided Dolphin
    Pacific white-sided dolphins are a pelagic species inhabiting 
temperate waters of the North Pacific Ocean and along the coasts of 
California, Oregon, Washington, and Alaska (Muto et al. 2018). Despite 
their distribution mostly in deep, offshore waters, they may also be 
found over the continental shelf and near shore waters, including 
inland waters of Southeast Alaska (Ferrero and Walker 1996). Pacific 
white-sided dolphins are not listed as endangered or threatened under 
the ESA. They are managed as two distinct stocks: The California/
Oregon/Washington stock, and the North Pacific stock (north of 45[deg] 
N, including Alaska).
    Scientific studies and data are lacking relative to the presence or 
abundance of Pacific white-sided dolphins in or near Tongass Narrows. 
Although they generally prefer deeper and more-offshore waters, 
anecdotal reports suggest that Pacific white-sided dolphins have 
previously been observed in Tongass Narrows, although they have not 
been observed entering Tongass Narrows or nearby inter-island waterways 
in 15-20 years.
    Pacific white-sided dolphins are rare in the inside passageways of 
Southeast Alaska. Most observations occur off the outer coast or in 
inland waterways near entrances to the open ocean. According to Muto 
(2018), aerial surveys in 1997 sighted one group of 164 Pacific white-
sided dolphins in Dixon entrance to the south of Tongass Narrows. 
Surveys in April and May from 1991 to 1993 identified Pacific white-
sided dolphins in Revillagigedo Channel, Behm Canal, and Clarence 
Strait (Dahlheim and Towell 1994). These areas are contiguous with the 
open ocean waters of Dixon Entrance. This observational data, combined 
with anecdotal information, indicates there is a rare, however, slight 
potential for Pacific white-sided dolphins to occur in the project 
area.
Killer Whale
    Killer whales have been observed in all the world's oceans, but the 
highest densities occur in colder and more productive waters found at 
high latitudes (NMFS 2016a). Killer whales occur along the entire 
Alaska coast, in British Columbia and Washington inland waterways, and 
along the outer coasts of Washington, Oregon, and California (NMFS 
2016a).
    Based on data regarding association patterns, acoustics, movements, 
and genetic differences, eight killer whale stocks are now recognized 
within the Pacific U.S. Exclusive Economic Zone. This proposed IHA 
considers only the Eastern North Pacific Alaska Resident stock (Alaska 
Resident stock), Eastern North Pacific Northern Resident stock 
(Northern Resident stock), and West Coast Transient stock, because all 
other stocks occur outside the geographic area under consideration 
(Muto et al. 2018). Killer whales that have the potential to occur in 
Alaska are not listed as endangered or threatened under the ESA. 
Therefore, the ESA-listed southern resident killer whale would not be 
affected by the proposed activity.
    Surveys between 1991 and 2007 encountered resident killer whales 
during all seasons throughout Southeast Alaska. Both residents and 
transients were common in a variety of habitats and all major 
waterways, including protected bays and inlets. There does not appear 
to be strong seasonal variation in abundance or distribution of killer 
whales, but there was substantial variability between years during this 
study (Dahlheim et al. 2009).
    No systematic studies of killer whales have been conducted in or 
around Tongass Narrows. Killer whales were observed infrequently (11 of 
135 days) during monitoring in Hoonah, and most were recorded in 
deeper, offshore waters (Berger ABAM 2016). Anecdotal reports suggest 
that large pods of killer whales (as many as 80 individuals, but 
generally between 25 and 40 individuals) are not uncommon in May, June, 
and July when the king salmon are running. During the rest of the year, 
killer whales occur irregularly in pods of 6 to 12 or more individuals. 
Large pods would be indicative of the Alaska resident population, which 
travels and hunts in large social groups.
    Although killer whales may occur in large numbers, they generally 
form large pods and would incur fewer work stoppages than their numbers 
suggest. Killer whales tend to transit through Tongass Narrows, and do 
not linger in the project area. Killer whales are observed on average 
about once every 2

[[Page 34144]]

weeks in Tongass Narrows, and abundance increases between May and July. 
A previous incidental take authorization in the Ketchikan area (83 FR 
37473) has estimated that one group of killer whales is present in 
Tongass Narrows once a month.
    Transient killer whales are often found in long-term stable social 
units (pods) of 1 to 16 whales. Average pod sizes in Southeast Alaska 
were 6.0 in spring, 5.0 in summer, and 3.9 in fall. Pod sizes of 
transient whales are generally smaller than those of resident social 
groups. Resident killer whales occur in larger pods, ranging from 7 to 
70 whales that are seen in association with one another more than 50 
percent of the time (Dahlheim et al. 2009; NMFS 2016b). In Southeast 
Alaska, resident killer whale mean pod size was approximately 21.5 in 
spring, 32.3 in summer, and 19.3 in fall (Dahlheim et al. 2009).
Humpback Whale
    Humpback whales worldwide were designated as ``endangered'' under 
the Endangered Species Conservation Act in 1970, and were listed under 
the ESA at its inception in 1973. However, on 08 September 2016, NMFS 
published a final decision that changed the status of humpback whales 
under the ESA (81 FR 62259), effective 11 October 2016. The decision 
recognized the existence of 14 DPSs based on distinct breeding areas in 
tropical and temperate waters. Five of the 14 DPSs were classified 
under the ESA (4 endangered and 1 threatened), while the other 9 DPSs 
were delisted. Humpback whales found in the project area are 
predominantly members of the Hawaii DPS, which is not listed under the 
ESA. However, based on a comprehensive photo-identification study, 
members of the Mexico DPS, which is listed as threatened, are known to 
occur in Southeast Alaska. Members of different DPSs are known to 
intermix on feeding grounds; therefore, all waters off the coast of 
Alaska should be considered to have ESA-listed humpback whales. 
Approximately 6.1 percent of all humpback whales in Southeast Alaska 
and northern British Columbia are members of the Mexico DPS, while all 
others are members of the Hawaii DPS (Wade et al. 2016).
    The DPSs of humpback whales that were identified through the ESA 
listing process do not necessarily equate to the existing MMPA stocks. 
The stock delineations of humpback whales under the MMPA are currently 
under review. Until this review is complete, NMFS considers humpback 
whales in Southeast Alaska to be part of the Central North Pacific 
stock, with a status of endangered under the ESA and designations of 
strategic and depleted under the MMPA (Muto et al. 2018).
    Humpback whales are found throughout Southeast Alaska in a variety 
of marine environments, including open-ocean, near-shore waters, and 
areas with strong tidal currents (Dahlheim et al. 2009). Most humpback 
whales are migratory and spend winters in the breeding grounds off 
either Hawaii or Mexico. Humpback whales generally arrive in Southeast 
Alaska in March and return to their wintering grounds in November. Some 
humpback whales depart late or arrive early to feeding grounds, and 
therefore the species occurs in Southeast Alaska year-round (Straley 
1990). Across the region, there have been no recent estimates of 
humpback whale density.
    No systematic studies have documented humpback whale abundance near 
Ketchikan. Anecdotal information (See Section 3 of IHA Application) 
suggests that this species is present in low numbers year-round in 
Tongass Narrows, with the highest abundance during summer and fall. 
Anecdotal reports suggest that humpback whales are seen only once or 
twice per month, while more recently it has been suggested that the 
occurrence is more regular, such as once per week on average, and more 
seasonal. Humpbacks observed in Tongass Narrows are generally alone or 
in groups of one to three individuals. In August 2017, a group of six 
individuals was observed passing through Tongass Narrows several times 
per day, for several days in a row. Local residents reported that such 
high abundance is common in August and September. NMFS reported that 
airport ferry personnel, in 2018, observed a lone humpback whale in the 
area every few days for several months and a group of two humpback 
whales every other week (NMFS 2019).
    A total of 226 humpback whales were recorded as takes during 135 
days of monitoring in Hoonah, Alaska (Berger ABAM 2016). During Hoonah 
monitoring, as many as 18 whales were observed in a single day, but the 
90th percentile of individuals per day was approximately 7. Humpback 
whales were observed on 84 of the 135 days and were most often seen as 
lone individuals, or in small groups. An average of 2 individuals was 
recorded as take each day of the construction program. Abundance of 
humpback whales did not appear to change substantially with time; 
however, there was a noticeable increase in activity during September 
and October (Berger ABAM 2016). Hoonah is approximately 240 miles north 
of Ketchikan near an area of known humpback concentrations, so these 
data do not directly support anticipated levels of abundance in 
Ketchikan as recently reported by interviewed locals (See Section 3 of 
IHA Application).
    In the Biological Opinion provided to the US Army Corp of Engineers 
(USACE) for this ADOT&PF project, NMFS assumed the occurrence of 
humpback whales in the project area to be one (1) group of two (2) 
humpback whales within the Level B harassment zone twice each week. 
This assumption was also used to estimate take for this proposed IHA. 
The assumption was based on differences in abundance throughout the 
year, recent observations of larger groups of whales present during 
summer, and a higher than average frequency of occurrence in recent 
months (NMFS 2019).
    Southeast Alaska is considered a biologically important area for 
feeding humpback whales between March and May (Ellison et al. 2012). 
Most humpback whales migrate to other regions during the winter to 
breed, but rare events of over-wintering humpbacks have been noted, 
(Straley 1990). It is thought that those humpbacks that remain in 
Southeast Alaska do so in response to the availability of winter 
schools of fish prey (Straley 1990).
Minke Whale
    The population status of minke whales is considered stable 
throughout most of their range. Historically, commercial whaling 
reduced the population size of this species, but given their small 
size, they were never a primary target of whaling and did not 
experience the severe population declines as did larger cetaceans. 
Minke whales are not listed as endangered or threatened under the ESA. 
Minke whales are found throughout the northern hemisphere in polar, 
temperate, and tropical waters. There is a dwarf form of minke whale 
found in the southern hemisphere, and the subspecies of Antarctic minke 
whales is found around the continent of Antarctica.
    The International Whaling Commission has identified three stocks in 
the North Pacific: One near the Sea of Japan, a second in the rest of 
the western Pacific (west of 180[deg]W), and a third, less concentrated 
stock, found throughout the eastern Pacific. NOAA further splits this 
third stock between Alaska whales and resident whales of California, 
Oregon, and Washington (Muto et al. 2018). Minke whales are found in 
all Alaska waters. There are no

[[Page 34145]]

population estimates for minke whales in Alaska. Surveys in Southeast 
Alaska have consistently identified individuals throughout inland 
waters in low numbers (Dahlheim et al. 2009).
    Minke whales in Southeast Alaska are part of the Alaska stock (Muto 
et al. 2018). Dedicated surveys for cetaceans in Southeast Alaska found 
that minke whales were scattered throughout inland waters from Glacier 
Bay and Icy Strait to Clarence Strait, with small concentrations near 
the entrance of Glacier Bay (Dahlheim et al. 2009). All sightings were 
of single minke whales, except for a single sighting of multiple minke 
whales. Surveys took place in spring, summer, and fall, and minke 
whales were present in low numbers in all seasons and years. None of 
the interviews with local experts conducted by ADOT&PF reported winter 
sightings of minke whales in Southeast Alaska. Minke whales are 
expected to occur in Tongass Narrows no more than once per year.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups which 
were later adopted by Southall et al (2019) with slight changes to the 
naming convention of each hearing group. Generalized hearing ranges 
were chosen based on the approximately 65 decibel (dB) threshold from 
the normalized composite audiograms, with the exception for lower 
limits for low-frequency cetaceans where the lower bound was deemed to 
be biologically implausible and the lower bound from Southall et al. 
(2007) retained. Marine mammal hearing groups and their associated 
hearing ranges are provided in Table 6.

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

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Eight marine mammal species (six cetacean and two pinniped (one otariid 
and one phocid) species) have the reasonable potential to co-occur with 
the proposed survey activities. Please refer to Table 6. Of the 
cetacean species that may be present, two are classified as low-
frequency cetaceans (i.e., all mysticete species), two are classified 
as mid-frequency cetaceans (i.e., all delphinid and ziphiid species and 
the sperm whale), and two are classified as high-frequency cetaceans 
(i.e., harbor porpoise and Kogia spp.).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

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

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a

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result of the dependence on a large number of varying factors, ambient 
sound levels can be expected to vary widely over both coarse and fine 
spatial and temporal scales. Sound levels at a given frequency and 
location can vary by 10-20 dB from day to day (Richardson et al. 1995). 
The result is that, depending on the source type and its intensity, 
sound from the specified activity may be a negligible addition to the 
local environment or could form a distinctive signal that may affect 
marine mammals.
    In-water construction activities associated with the project would 
include impact pile driving, vibratory pile driving and removal, and 
drilling. The sounds produced by these activities fall into one of two 
general sound types: Impulsive and non-impulsive. Impulsive sounds 
(e.g., explosions, gunshots, sonic booms, impact pile driving) are 
typically transient, brief (less than 1 second), broadband, and consist 
of high peak sound pressure with rapid rise time and rapid decay (ANSI 
1986; NIOSH 1998; ANSI 2005; NMFS 2018). Non-impulsive sounds (e.g. 
aircraft, machinery operations such as drilling or dredging, vibratory 
pile driving, and active sonar systems) can be broadband, narrowband or 
tonal, brief or prolonged (continuous or intermittent), and typically 
do not have the high peak sound pressure with rapid rise/decay time 
that impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward 1997 in Southall et al. 2007).
    Two types of pile hammers would be used on this project: Impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels, a potentially injurious combination (Hastings and Popper 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak SPLs may be 
180 dB or greater, but are generally 10 to 20 dB lower than SPLs 
generated during impact pile driving of the same-sized pile (Oestman et 
al. 2009). Rise time is slower, reducing the probability and severity 
of injury, and sound energy is distributed over a greater amount of 
time (Nedwell and Edwards 2002; Carlson et al. 2005).
    Drilling of rock sockets would be conducted using a down-hole drill 
inserted through the hollow steel piles. A down-hole drill is a drill 
bit that drills through the bedrock using both rotary and percussion 
(impact) mechanisms that function at the bottom of the hole. This 
breaks up rock to allow removal of debris and insertion of the pile. 
The head extends so that the drilling takes place below the pile. The 
sounds produced by the down-the-hole drilling method are considered 
continuous as the noise from the drilling component is dominant. In 
addition, this method likely increases sound attenuation because the 
noise is primarily contained within the steel pile and below ground 
rather than impact hammer driving methods which occur at the top of the 
pile and introduce sound into the water column to a greater degree.
    The likely or possible impacts of ADOT&PF's proposed activity on 
marine mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of the equipment and personnel; however, any impacts to marine 
mammals are expected to primarily be acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during pile 
installation and removal and drilling.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal and down-hole drilling is the 
primary means by which marine mammals may be harassed from ADOT&PF's 
specified activity. In general, animals exposed to natural or 
anthropogenic sound may experience physical and psychological effects, 
ranging in magnitude from none to severe (Southall et al. 2007, 2019). 
In general, exposure to pile driving and drilling noise has the 
potential to result in auditory threshold shifts and behavioral 
reactions (e.g., avoidance, temporary cessation of foraging and 
vocalizing, changes in dive behavior). Exposure to anthropogenic noise 
can also lead to non-observable physiological responses such an 
increase in stress hormones. Additional noise in a marine mammal's 
habitat can mask acoustic cues used by marine mammals to carry out 
daily functions such as communication and predator and prey detection. 
The effects of pile driving and drilling noise on marine mammals are 
dependent on several factors, including, but not limited to, sound type 
(e.g., impulsive vs. non-impulsive), the species, age and sex class 
(e.g., adult male vs. mom with calf), duration of exposure, the 
distance between the pile and the animal, received levels, behavior at 
time of exposure, and previous history with exposure (Wartzok et al. 
2004; Southall et al. 2007). Here we discuss physical auditory effects 
(threshold shifts) followed by behavioral effects and potential impacts 
on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al. 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960; 
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al. 
2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al. 2008), there are no empirical data measuring PTS in 
marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS

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2018). Based on data from cetacean TTS measurements (see Southall et 
al. 2007), a TTS of 6 dB is considered the minimum threshold shift 
clearly larger than any day-to-day or session-to-session variation in a 
subject's normal hearing ability (Schlundt et al. 2000; Finneran et al. 
2000, 2002). As described in Finneran (2015), marine mammal studies 
have shown the amount of TTS increases with cumulative sound exposure 
level (SELcum) in an accelerating fashion: At low exposures with lower 
SELcum, the amount of TTS is typically small and the growth curves have 
shallow slopes. At exposures with higher SELcum, the growth curves 
become steeper and approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al. 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and five species of pinnipeds exposed to a limited 
number of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (Finneran 2015). TTS was not observed in trained 
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to 
impulsive noise at levels matching previous predictions of TTS onset 
(Reichmuth et al. 2016). In general, harbor seals and harbor porpoises 
have a lower TTS onset than other measured pinniped or cetacean species 
(Finneran 2015). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species. No data are 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), Finneran (2015), and Table 5 in NMFS (2018).
    Installing piles requires a combination of impact pile driving, 
vibratory pile driving, and down-hole drilling. For the project, these 
activities would not occur at the same time and there would likely be 
pauses in activities producing the sound during each day. Given these 
pauses and that many marine mammals are likely moving through the 
project area and not remaining for extended periods of time, the 
potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal and drilling also has the potential to behaviorally disturb 
marine mammals. Available studies show wide variation in response to 
underwater sound; therefore, it is difficult to predict specifically 
how any given sound in a particular instance might affect marine 
mammals perceiving the signal. If a marine mammal does react briefly to 
an underwater sound by changing its behavior or moving a small 
distance, the impacts of the change are unlikely to be significant to 
the individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a prolonged period, impacts on individuals and populations 
could be significant (e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 
2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are 
highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al. 1995; Wartzok et al. 2003; Southall et al. 
2007; Weilgart 2007; Archer et al. 2010). Behavioral reactions can vary 
not only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al. 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). In 
general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B-C of Southall et al. 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al. 
2001; Nowacek et al. 2004; Madsen et al. 2006; Yazvenko et al. 2007). A 
determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    In 2016, ADOT&PF documented observations of marine mammals during 
construction activities (i.e., pile driving and down-hole drilling) at 
the Kodiak Ferry Dock (ABR 2016) in the Gulf of Alaska. In the marine 
mammal monitoring report for that project, 1,281 Steller sea lions were 
observed within the Level B harassment zone during pile driving or 
drilling (i.e., documented as take by Level B harassment). Of these, 19 
individuals demonstrated an alert behavior, 7 were fleeing, and 19 swam 
away from the project site. All other animals (98 percent) were engaged 
in activities such as milling, foraging, or fighting and did not change 
their behavior. In addition, two sea lions approached within 20 meters 
of active vibratory pile driving activities. Three harbor seals were 
observed within the disturbance zone during pile driving activities; 
none of them displayed disturbance behaviors. Fifteen killer

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whales and three harbor porpoise were also observed within the Level B 
harassment zone during pile driving. The killer whales were travelling 
or milling while all harbor porpoises were travelling. No signs of 
disturbance were noted for either of these species. Given the 
similarities in activities and habitat and the fact the same species 
are involved, we expect similar behavioral responses of marine mammals 
to the specified activity. That is, disturbance, if any, is likely to 
be temporary and localized (e.g., small area movements). Monitoring 
reports from other recent pile driving and down-hole drilling projects 
in Alaska have observed similar behaviors (for example, the Biorka 
Island Dock Replacement Project https://www.fisheries.noaa.gov/action/incidental-take-authorization-faa-biorka-island-dock-replacement-project-sitka-ak).
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al. 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g. on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal and down-hole drilling that have the potential to cause 
behavioral harassment, depending on their distance from pile driving 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, these animals would previously have 
been `taken' because of exposure to underwater sound above the 
behavioral harassment thresholds, which are in all cases larger than 
those associated with airborne sound. Thus, the behavioral harassment 
of these animals is already accounted for in these estimates of 
potential take. 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.

Marine Mammal Habitat Effects

    The proposed activities at the project area would not result in 
permanent negative impacts to habitats used directly by marine mammals, 
but may have potential short-term impacts to food sources such as 
forage fish and may affect acoustic habitat (see masking discussion 
above). There are no known foraging hotspots or other ocean bottom 
structure of significant biological importance to marine mammals 
present in the marine waters of the project area during the 
construction window, but there are times of increased foraging during 
periods of forage fish and salmonid spawning. ADOT&PF construction 
activities in Tongass Narrows could have localized, temporary impacts 
on marine mammal habitat and their prey by increasing in-water sound 
pressure levels and slightly decreasing water quality. Increased noise 
levels may affect acoustic habitat (see masking discussion above) and 
adversely affect marine mammal prey in the vicinity of the project area 
(see discussion below). During impact pile driving, elevated levels of 
underwater noise would ensonify a portion of Tongass Narrows and nearby 
waters where both fish and mammals occur and could affect foraging 
success.
    Construction activities are of short duration and would likely have 
temporary impacts on marine mammal habitat through increases in 
underwater noise. These sounds would not be detectable at the nearest 
known Steller sea lion haulouts (Figure 4-1 in IHA application), and 
there are no known harbor seal haulouts in Tongass Narrows.
    The area likely impacted by the project includes much of Tongass 
Narrows, but overall this area is relatively small compared to the 
available habitat in the surrounding area including Revillagigedo 
Channel, Behm Canal, and Clarence Strait. Pile installation/removal and 
drilling may temporarily increase turbidity resulting from suspended 
sediments. Any increases would be temporary, localized, and minimal. In 
general, turbidity associated with pile installation is localized to 
about a 25-foot radius around the pile (Everitt et al. 1980). Cetaceans 
are not expected to be close enough to the project pile driving areas 
to experience effects of turbidity, and pinnipeds could avoid localized 
areas of turbidity. Therefore, the impact from increased turbidity 
levels is expected to minimal for marine mammals. Furthermore, pile 
driving and removal at the project site would not obstruct movements or 
migration of marine mammals.
    In-water Construction Effects on Potential Prey -- Construction 
activities would produce continuous (i.e., vibratory pile driving and 
down-hole drilling) and intermittent (i.e. impact driving) sounds. Fish 
react to sounds that are especially strong and/or intermittent low-
frequency sounds. Short duration, sharp sounds can cause overt or 
subtle changes in fish behavior and local distribution. Hastings and 
Popper (2005) identified several studies that suggest fish may relocate 
to avoid certain areas of sound energy. Additional studies have 
documented effects of pile driving on fish, although several are based 
on studies in support of large, multiyear bridge construction projects 
(e.g., Scholik and Yan 2001, 2002; Popper and Hastings 2009). Sound 
pulses at received levels of 160 dB may cause subtle changes in fish 
behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al. 1992; Skalski et al. 1992). SPLs of sufficient strength 
have been known to cause injury to fish and fish mortality.

[[Page 34149]]

    The most likely impact to fish from pile driving and drilling 
activities at the project area would be temporary behavioral avoidance 
of the area. The duration of fish avoidance of this area after pile 
driving stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. 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 in 
Revillagigedo Channel, Behm Canal, and Clarence Strait. Additionally, 
the City of Ketchikan within Tongass Narrows has a busy industrial 
water front, and human impact lessens the value of the area as foraging 
habitat. There are times of known seasonal marine mammal foraging in 
Tongass Narrows around fish processing/hatchery infrastructure or when 
fish are congregating, but the impacted areas of Tongass Narrows are a 
small portion of the total foraging habitat available in the region. In 
general, impacts to marine mammal prey species are expected to be minor 
and temporary due to the short timeframe of the project.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect eulachon, herring, and juvenile 
salmonid outmigratory routes in the project area. Salmon and forage 
fish, like eulachon and herring, form a significant prey base for 
Steller sea lions and are major components of the diet of many other 
marine mammal species that occur in the project area. Increased 
turbidity is expected to occur only in the immediate vicinity of 
construction activities and to dissipate quickly with tidal cycles. 
Given the limited area affected and high tidal dilution rates any 
effects on fish are expected to be minor.
    Additionally, the presence of transient killer whales means some 
marine mammal species are also possible prey (harbor seals, harbor 
porpoises). ADOT&PF's pile driving, pile removal, and drilling are 
expected to result in limited instances of take by Level B and Level A 
harassment on these smaller marine mammals. That, as well as the fact 
that ADOT&PF is impacting a small portion of the total available marine 
mammal habitat means that there will be minimal impact on these marine 
mammals as prey.
    In summary, given the short daily duration of sound associated with 
individual pile driving and drilling events and the small area being 
affected relative to available nearby habitat, pile driving and 
drilling activities associated with the proposed action are not likely 
to have a permanent, adverse effect on any fish habitat, or populations 
of fish species or other prey. Thus, we conclude that impacts of the 
specified activity are not likely to have more than short-term adverse 
effects on any prey habitat or populations of prey species. Further, 
any impacts to marine mammal habitat are not expected to result in 
significant or long-term consequences for individual marine mammals, or 
to contribute to adverse impacts on their populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through these IHAs, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the sources (i.e., impact/vibratory pile driving and drilling) has 
the potential to result in disruption of behavioral patterns for 
individual marine mammals and some small amount of TTS. There is also 
some potential for auditory injury (Level A harassment) to result, 
primarily for mysticetes, high frequency species and phocids because 
predicted auditory injury zones are larger than for mid-frequency 
species and otariids. Auditory injury is unlikely to occur for, mid-
frequency species and otariids. The proposed mitigation and monitoring 
measures are expected to minimize the severity of such taking to the 
extent practicable, and result in no take by Level A harassment for 
mysticetes.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Due to the lack of marine 
marine mammal density, NMFS relied local occurrence data and average 
group size to estimate take. Below, we describe the factors considered 
here in more detail and present the proposed take estimates.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) (microPascal root mean 
square) for continuous (e.g., vibratory pile-driving, drilling) and 
above 160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., 
seismic airguns) or intermittent (e.g., scientific sonar) sources. 
Typically, and especially in cases where PTS is predicted, NMFS 
anticipates that some number of individuals may incur TTS. However, it 
is not necessary to separately quantify those takes, as it is very 
unlikely that an individual marine mammal would be exposed at the 
levels and duration necessary to incur TTS without also being exposed 
to the levels

[[Page 34150]]

associated with behavioral harassment and, therefore, we expect any 
potential TTS takes to be captured by the estimated takes by behavioral 
harassment.
    Both phases of ADOT&PF's proposed activity includes the use of 
continuous (vibratory pile driving/removal and drilling) and impulsive 
(impact pile driving) sources, and therefore both the 120 and 160 dB re 
1 [mu]Pa (rms) thresholds are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (NMFS, 2018) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
Both phases of ADOT&PF's proposed activity includes the use of 
impulsive (impact pile driving) and non-impulsive (vibratory pile 
driving/removal and drilling) sources.
    These thresholds are provided in Table 7 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 7--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS Onset acoustic thresholds \*\ (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4:LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving, vibratory pile removal, and drilling).
    Vibratory hammers produce constant sound when operating, and 
produce vibrations that liquefy the sediment surrounding the pile, 
allowing it to penetrate to the required seating depth. An impact 
hammer would then generally be used to place the pile at its intended 
depth. The actual durations of each installation method vary depending 
on the type and size of the pile. An impact hammer is a steel device 
that works like a piston, producing a series of independent strikes to 
drive the pile. Impact hammering typically generates the loudest noise 
associated with pile installation.
    In order to calculate distances to the Level A harassment and Level 
B harassment sound thresholds for piles of various sizes being used in 
this project, NMFS used acoustic monitoring data from other locations 
to develop source levels (see Table 6). Note that piles of differing 
sizes have different sound source levels (SSLs).
    Empirical data from recent ADOT&PF sound source verification (SSV) 
studies at Ketchikan were used to estimate sound source levels for 
vibratory and impact driving of 30-inch steel pipe piles and Kodiak for 
drilling (Denes et al. 2016). Data from Ketchikan was used because of 
its proximity to this proposed project in Tongass Narrows and Kodiak 
drilling data was used as a proxy here because of its relative 
proximity. However, the use of data from Alaska sites was not 
appropriate in all instances. Details are described below.
    The source level for rock socket drilling was derived from the 
above mentioned ADOT&PF SSV study at Kodiak, Alaska. The reported 
median source value for drilling was determined to be 166.2 dB rms for 
all pile types (Denes et al. 2016, Table 72).
    For vibratory driving of 24-inch steel piles, data from a Navy pile 
driving project in the Puget Sound, WA was reviewed (Navy, 2015). From 
this review, ADOT&PF determined the Navy's suggested source value of 
161 dB rms was an appropriate proxy source value, and NMFS concurs. 
Because the source value of smaller piles of the same general type 
(steel in this case) are not expected to exceed a larger pile, the same 
161 dB rms source value was used for 18-inch and 16-inch steel piles. 
This assumption conforms with source values presented in Navy (2015) 
for a project using 16-inch steel piles at Naval Base Kitsap in Bangor, 
WA.
    For vibratory driving of both 27.6-inch and 30.3-inch sheet piles, 
ADOT&PF used a source level of 160 dB rms. These source levels were 
reported in Caltrans (2015) summary tables for 24-inch steel sheet 
piles, and NMFS concurs that this value was an acceptable proxy.
    Finally, ADOT&PF used source values of 177 dB SEL and 190 dB rms 
for impact driving of 24-inch and 18-inch steel piles. These values 
were determined based on summary values presented in Caltrans (2015) 
for impact driving of 24-inch steel piles. NMFS concurs that the same 
source value was

[[Page 34151]]

an acceptable proxy for impact driving of 18-inch steel piles.

    Table 8--Estimates of Mean Underwater Sound Levels Generated During Vibratory and Impact Pile Installation, Drilling, and Vibratory Pile Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Method and pile type                    Sound source level at 10 meters
-----------------------------------------------------------------------------------------                        Literature source
        Vibratory hammer                                  dB rms
--------------------------------------------------------------------------------------------------------------------------------------------------------
30-inch steel piles.............  162...................................................  Denes et al. 2016, Table 72.
24-inch steel piles.............  161...................................................  Navy 2015.
20-inch steel piles.............  161...................................................  Navy 2015.
18-inch steel piles.............  161...................................................  Navy 2015.
16-inch steel piles.............  161...................................................  Navy 2015.
27.6-inch sheet pile............  160...................................................  Caltrans 2015.
30.3-inch sheet pile............  160...................................................  Caltrans 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------


 
      Drilling rock sockets                               dB rms
--------------------------------------------------------------------------------------------------------------------------------------------------------
All pile diameters..............  166.2.................................................  Denes et al. 2016, Table 72.
--------------------------------------------------------------------------------------------------------------------------------------------------------


 
             Impact hammer                  dB rms        dB SEL        dB peak
--------------------------------------------------------------------------------------------------------------------------------------------------------
30-inch steel piles....................          195           181           209   Denes et al. 2016, Table 72.
24-inch steel piles....................          190           177           203   Caltrans 2015.
18-inch steel piles....................          190           177           203   Caltrans 2015.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: It is assumed that noise levels during pile installation and removal are similar. Use of an impact hammer will be limited to 5-10 minutes per
  pile, if necessary. It is assumed that drilling produces the same SSL regardless of down-hole diameter. SEL = sound exposure level; dB peak = peak
  sound level; rms = root mean square.

Level B Harassment Zones

    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

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    The recommended TL coefficient for most nearshore environments is 
the, practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for ADOT&PFs proposed activity.
    Using the practical spreading model, ADOT&PF determined underwater 
noise would fall below the behavioral effects threshold of 120 dB rms 
for marine mammals at a maximum radial distance of 12,023 m for rock 
socket drilling. This distance determines the maximum Level B 
harassment zone for the project. Other activities, including vibratory 
and impact pile driving, will have smaller Level B harassment zones. 
All Level B harassment isopleths are reported in Table 9 below and 
visualized in Figure 6-3 (Phase 1) and Figure 6-7 (Phase 2) in the IHA 
Application. It should be noted that based on the geography of Tongass 
Narrows and the surrounding islands, sound will not reach the full 
distance of the Level B harassment isopleth in all directions. 
Generally, due to interaction with land, only a thin slice of the 
possible area is ensonified to the full distance of the Level B 
harassment isopleth.

                 Table 9--Calculated Distances to Level B Harassment Isopleths and Ensonified Areas During Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Isopleth-                       Isopleth-                       Isopleth-
                        Pile size                           impact  (m)   Impact (km\2\)  vibratory  (m)     Vibratory     drilling  (m)     Drilling
                                                             (160 dB)                        (120 dB)         (km\2\)        (120 dB)         (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Phase 1 Revilla side:
    24-inch piles.......................................           1,000        0.780348           5,412        3.224297  ..............  ..............
    30-inch piles.......................................           2,154        1.504843           6,310        3.584237  ..............  ..............
    Sheet pile..........................................  ..............  ..............           4,642        2.856483  ..............  ..............
Phase 1 Gravina side:
    18-inch.............................................           1,000        1.297393           5,412        9.361061  ..............  ..............
    24-inch piles.......................................           1,000        1.297393           5,412        9.361061          12,023       23.618314
    30-inch piles.......................................           2,154        3.077801           6,310        11.11939          12,023       23.618314
    Sheet pile..........................................  ..............  ..............           4,642        7.712967  ..............  ..............
Phase 2 Revilla side:
    24-inch.............................................           1,000        0.780348           5,412        3.187212  ..............  ..............
Phase 2 Gravina side:
    16-inch.............................................  ..............  ..............           5,412         8.03168  ..............  ..............
    24-inch piles.......................................           1,000        1.297393           5,412         8.03168  ..............  ..............

[[Page 34152]]

 
    30-inch piles.......................................           2,154        3.077801           6,310        9.472484          12,023       23.618314
--------------------------------------------------------------------------------------------------------------------------------------------------------

Level A Harassment Zones

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of take by Level A harassment. However, these tools offer 
the best way to predict appropriate isopleths when more sophisticated 
3D modeling methods are not available, and NMFS continues to develop 
ways to quantitatively refine these tools, and will qualitatively 
address the output where appropriate. For stationary sources such as 
impact/vibratory pile driving or drilling, NMFS User Spreadsheet 
predicts the closest distance at which, if a marine mammal remained at 
that distance the whole duration of the activity, it would not incur 
PTS. Inputs used in the User Spreadsheet, and the resulting isopleths 
are reported below (Table 10).
    Level A harassment thresholds for impulsive sound sources (impact 
pile driving) are defined for both SELcum and Peak SPL with the 
threshold that results in the largest modeled isopleth for each marine 
mammal hearing group used to establish the Level A harassment isopleth. 
In this project, Level A harassment isopleths based on SELcum were 
always larger than those based on Peak SPL. It should be noted that 
there is a duration component when calculating the Level A harassment 
isopleth based on SELcum, and this duration depends on the number of 
piles that will be driven in a day and strikes per pile. For some 
activities, ADOT&PF has proposed to drive variable numbers of piles per 
day throughout the project (See ``Piles Installed or Removed per day'' 
in Table 9), and determine at the beginning of each pile driving day, 
how many piles will be driven that day. Here, this flexibility has been 
accounted for by modeling multiple durations for the activity, and 
determining the relevant isopleths.

[[Page 34153]]



                                                                           Table 10--Parameters of Pile Driving and Drilling Activity Used in User Spreadsheet
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
         Equipment type             Vibratory pile      Vibratory pile      Vibratory pile      Vibratory pile      Vibratory pile      Vibratory pile    Impact pile driver  Impact pile driver  Impact pile driver      Rock socket
---------------------------------       removal             driver              driver              driver              driver              driver          (30-inch steel      (24-inch steel      (18-inch steel         drilling
                                 --------------------  (installation of    (installation of    (installation of    (installation of    (installation of         piles)              piles)              piles)       -------------------
                                                         sheet piles)        30-inch steel       24-inch steel       24-inch steel       18-inch steel   ------------------------------------------------------------
                                                     --------------------       piles)              piles)              piles)              piles)
      Spreadsheet tab used          Non-impulsive,                       --------------------------------------------------------------------------------   Impulsive, non-     Impulsive, non-     Impulsive, non-     Non-impulsive,
                                      continuous        Non-impulsive,      Non-impulsive,      Non-impulsive,      Non-impulsive,      Non-impulsive,        continuous          continuous          continuous          continuous
                                                          continuous          continuous          continuous          continuous          continuous
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level....................  161 SPL...........  160 SPL...........  162 SPL...........  161 SPL...........  161 SPL...........  161 SPL...........  181 SEL...........  177 SEL...........  177 SEL...........  166.2 SPL.
Weighting Factor Adjustment       2.5...............  2.5...............  2.5...............  2.5...............  2.5...............  2.5...............  2.................  2.................  2.................  2.
 (kHz).
(a) Activity duration (hours)     (a) 2.5, 5 * 30     (a) 2.5 (15 mins *  (a) 1.5, 3 * 30     (a) 1.5, 3 * 30     (a) 1.5, 3 * 30     (a) 1.5, 3 * 30     (b) 200 or 50 (c)   (b) 200 or 50 (c)   (b) 50 (c) 1 to 3.  (a) 9 or 6.*
 within 24 hours.                  mins.               10).                mins.               mins.               mins.               mins.               1 to 3.             1 to 3.
(b) Number of strikes per pile..
(c) Number of piles per day.....
Propagation (xLogR).............  15................  15................  15................  15................  15................  15................  15................  15................  15................  15.
Distance of source level          10................  10................  10................  10................  10................  10................  10................  10................  10................  10.
 measurement (meters) +.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Duration estimates for rock socket drilling are based on assumption of drilling 3 rock sockets per day. 9 hours would be the estimated duration for drilling related to 30 inch piles, and 6 hours would be the duration for drilling
  related to 24 and 18 inch piles.
** For specifics of what number of strikes and number of piles will be used in a given situation, please refer to Table 1 and Table 3.


[[Page 34154]]


                           Table 11--Calculated Distances to Level A Harassment Isopleths During Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  Level A harassment isopleth distance  (meters)
                                                                               Piles    ----------------------------------------------------------------
            Activity                Pile diameter(s)   Minutes per pile or   installed                 Cetaceans                        Pinnipeds
                                                         strikes per pile    or removed ----------------------------------------------------------------
                                                                              per day         LF           MF           HF           PW           OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation..........  30-inch............  30 Minutes.........            3           11           <1           15            6           <1
                                  24-inch, 20-inch,    15-30 Minutes......            3            9           <1           13            5           <1
                                   18-inch.
                                  27.6-inch sheet      15 Minutes.........           10           11            1           16            7           <1
                                   pile, 30.3-inch
                                   sheet pile.
Vibratory Removal...............  24-inch............  30 Minutes.........            5           13            1           19            8           <1
                                  16-inch............
Drilling Rock Sockets...........  30-inch............  180 Minutes........            3           66            4           58           36            3
                                  24-inch, 18-inch...  120 Minutes........            3           51            3           45           27            2
Impact Installation.............  30-inch............  50 Strikes.........            3          208            8          247          111            9
                                                       50 Strikes.........            2          159            6          189           85            7
                                                       50 Strikes.........            1          100            4          119           54            4
                                                       200 Strikes........            3          523           19          623          280           21
                                                       200 Strikes........            2          399           15          476          214           16
                                                       200 Strikes........            1          252            9          300          135           10
Impact Installation.............  24-inch............  50 Strikes.........            3          113            4          134           61            5
                                                       50 Strikes.........            2           86            3          102           46            4
                                                       50 Strikes.........            1           54            2           65           29            3
                                                       200 Strikes........            3          283           11          337          152           11
                                                       200 Strikes........            2          216            8          258          116            9
                                                       200 Strikes........            1          136            5          162           73            6
Impact Installation.............  18-inch............  50 Strikes.........            3          113            4          134           61            5
                                                       50 Strikes.........            2           86            3          102           46            4
                                                       50 Strikes.........            1           54            2           65           29            3
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: A 10-meter shutdown zone will be implemented for all species and activity types to prevent direct injury of marine mammals.

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. Additionally, we describe how the occurrence information 
is brought together to produce a quantitative take estimate for each 
phase. Table 12 and 13 below show take from Phase 1 and Phase 2, 
respectively, as a percentage of population for each of the species.
Steller Sea Lion
    Steller sea lion abundance in the Tongass Narrows area is not well 
known. No systematic studies of Steller sea lions have been conducted 
in or near the Tongass Narrows area. Steller sea lions are known to 
occur year-round and local residents report observing Steller sea lions 
about once or twice per week (based on communication outlined in 
Section 3 of the IHA application). Abundance appears to increase during 
herring runs (March to May) and salmon runs (July to September). Group 
sizes are generally 6 to 10 individuals (Freitag 2017 as cited in 83 FR 
37473) but have been reported to reach 80 animals (HDR 2003). Tongass 
Narrows represents an area of high anthropogenic activity that sea 
lions would normally avoid, but at least three seafood processing 
plants and two fish hatcheries may be attractants to these 
opportunistic scavengers and predators. Sea lions are generally 
unafraid of humans when food sources are available. For these reasons, 
we conservatively estimate that one group of 10 Steller sea lions may 
be present in the project area each day, but this occurrence rate may 
as much as double (20 Steller sea lions per day) during periods of 
increased abundance associated with the herring and salmon runs (March 
to May and July to September).
    Take Estimation for Phase 1: During Phase 1, we anticipate that one 
large group (10 individuals) may be present in the Level B harassment 
zone once per day. However, as discussed above, we anticipate that 
exposure may be as much as twice this rate during March, April, May, 
July, August, and September, due to the increased presence of prey. 
Therefore, we anticipate that two large groups (20 individuals) may be 
present in the Level B harassment zone each day during these months 
(approximately half of Phase 1). Therefore, we estimate a total of 
2,160 potential takes of Steller sea lions by Level B harassment (i.e., 
1 group of 10 sea lions per day x 72 days [or half of Phase 1] + 2 
groups of 10 sea lions per day x 72 days = 2,160 sea lions) (Table 12).
    Take by Level A harassment is not expected for Steller sea lions in 
Phase 1, because of the small Level A harassment zones for otarrids 
(Table 11) and the expected effectiveness of the proposed monitoring 
and mitigation measures discussed below.
    Take Estimation for Phase 2: During Phase 2, we anticipate Steller 
sea lions would be exposed at the same rate as during Phase 1. Phase 2 
construction is planned to occur in the months of April, May and June. 
Therefore, we expect that one large group (10 individuals) may be 
present in the Level B harassment zone once per day for 9 days in June, 
with an increase to 2 large groups per day when fish runs occur for 9 
days each month in April and May. Therefore, we estimate a total of 450 
potential takes of Steller sea lions by Level B harassment (i.e., 1 
group of 10 sea lions per day x 9 days in June + 2 groups of 10 sea 
lions per day x 9 days per month in both April and May = 450 sea lions) 
(Table 13).
    Take by Level A harassment is not expected for Steller sea lions in 
Phase 2, because of the small Level A harassment zones for otarrids 
(Table 11) and the expected effectiveness of the proposed monitoring 
and mitigation measures discussed below.
Harbor Seal
    Harbor seal densities in the Tongass Narrows area are not well 
known. No systematic studies of harbor seals have been conducted in or 
near Tongass Narrows. They are known to occur year-round with little 
seasonal variation in abundance (Freitag 2017 as cited in 83 FR 37473) 
and local experts estimate that there are about 1 to 3 harbor seals in 
Tongass Narrows every day, in addition to those that congregate near

[[Page 34155]]

the seafood processing plants and fish hatcheries. Based on this 
knowledge, the expected maximum group size in Tongass Narrows is three 
individuals. Harbor seals are known to be curious and may approach 
novel activity. For these reasons we conservatively estimate that up to 
two groups of 3 harbor seals per group could be exposed to project-
related underwater noise each day. Additionally, a smaller number of 
harbor seals could occasionally be present in the Level A harassment 
(PTS) zone and exposed to sound levels for a duration expected to 
result in take by Level A harassment. To account for these uncommon 
instances, ADOT&PF assumed and NMFS agrees that the equivalent of six 
groups of three individuals may be exposed in the Level A harassment 
zone during the whole of Phase 1, and the equivalent of three groups of 
three individuals may be exposed during the whole of Phase 2. Because 
of the nature of take by Level A harassment (small zone size, factoring 
in duration of exposure) and possibility for a marine mammal group to 
be spread over a relatively large area compared to the Level A 
harassment zone, take by Level A harassment will likely not occur to an 
entire group at once. Despite being expected to occur on an individual 
basis, these group size estimates still serve as the basis for take 
estimation for harbor seals.
    Take Estimation for Phase 1: During Phase 1, we anticipate that two 
groups of 3 individuals could be present in the Level B harassment zone 
once per day for a total of 864 takes of harbor seals by Level B 
harassment (i.e., 6 individuals per day x 144 days = 864 seals) (Table 
12).
    During Phase 1, it is possible, but unlikely, that harbor seals may 
be exposed to sound levels in the Level A harassment zone for a 
duration expected to result in take. Therefore, NMFS is proposing take 
by Level A harassment for the equivalent of six groups (18 individuals) 
during Phase 1.
    Take Estimation for Phase 2: During Phase 2, we anticipate that two 
groups of 3 individuals could be present in the Level B harassment zone 
once per day for a total of 162 takes of harbor seals by Level B 
harassment (i.e., 6 individuals per day x 27 days = 162 seals) (Table 
11).
    During Phase 2, we anticipate that the equivalent of three groups 
of 3 individuals may be present in the Level A harassment zone without 
detection. Therefore, NMFS is proposing take by Level A harassment of 9 
harbor seals during Phase 2.
Harbor Porpoise
    Harbor porpoises are non-migratory; therefore, our occurrence 
estimates are not dependent on season. Freitag (2017 as cited in 83 FR 
37473) observed harbor porpoises in Tongass Narrows zero to one time 
per month. Harbor porpoises observed in the project vicinity typically 
occur in groups of one to five animals with an estimated maximum group 
size of eight animals (83 FR 37473, August 1, 2018, Solstice 2018). For 
our impact analysis, we are considering a group to consist of five 
animals, a value on the high end of the typical group size. Based on 
Freitag (2017), and supported by the reports of knowledgeable locals as 
described in the application, it is estimated that one group of harbor 
porpoises could enter Tongass Narrows and potentially be exposed to 
project related noise each month. Additionally harbor porpoises may 
rarely enter the applicable Level A harassment zone and be exposed to 
sound levels for a duration expected to result in take by Level A 
harassment, necessitating the proposed authorization of take by Level A 
harassment.
    Take Estimation for Phase 1: During Phase 1, we estimate that two 
groups of harbor porpoises could be present in the Level B harassment 
zone each month for a total of 120 takes of harbor porpoises by Level B 
harassment (i.e., 2 groups of 5 per month x 12 months = 120 harbor 
porpoises) (Table 12).
    During Phase 1, we anticipate that 5 individuals (the equivalent of 
one group) may enter the Level A harassment zone undetected, and be 
exposed to sound levels for a duration expected to result in take by 
Level A harassment, approximately once during every 4 months of 
construction, for a total of 15 potential takes by Level A harassment.
    Take Estimation for Phase 2: During Phase 2, we estimate that two 
groups of harbor porpoises may be present in the Level B harassment 
zone each month for a total of 30 individuals takes by Level B 
harassment (i.e., 2 groups of 5 per month x 3 months = 30 harbor 
porpoises) (Table 13).
    During Phase 2, we anticipate that the equivalent of two groups of 
5 individuals may enter the Level A harassment zone undetected, and be 
exposed to sound levels for a duration expected to result in take by 
Level A harassment, during the 3 months of construction, for a total of 
10 potential takes by Level A harassment.
Dall's Porpoise
    Dall's porpoises are expected to only occur in the project area a 
few times per year. Their relative rarity is supported by Jefferson et 
al.'s (2019) presentation of historical survey data showing very few 
sightings in the Ketchikan area and conclusion that Dall's porpoise 
generally are rare in narrow waterways, like the Tongass Narrows. This 
species is non-migratory; therefore, our occurrence estimates are not 
dependent on season. We anticipate that one large Dall's porpoise pod 
(15 individuals) (Freitag 2017, as cited in 83 FR37473) may be present 
in the project area each month during construction. Additionally Dall's 
porpoises may rarely be present in the applicable Level A harassment 
zone and be exposed to sound levels for a duration expected to result 
in take by Level A harassment. To account for this rare circumstance, 
ADOT&PF assumes and NMFS concurs that the equivalent of one group of 15 
individuals may be exposed to sound levels in the Level A harassment 
zone for a duration expected to result in take during the whole of 
Phase 1, and one group of 15 individuals may be present during the 
whole of Phase 2.
    Take Estimation for Phase 1: During Phase 1, we estimate that 180 
Dall's porpoises could be present in the Level B harassment zone (i.e., 
15 individuals per month x 12 months of construction = 180 total 
potential takes by Level B harassment) (Table 12).
    During Phase 1, we anticipate that the equivalent of one group of 
15 individuals may be exposed to sound levels in the Level A harassment 
zone for a duration expected to result in take, resulting in take by 
Level A harassment of 15 individual Dall's porpoises.
    Take Estimation for Phase 2: During Phase 2, we estimate that 45 
Dall's porpoises could be present in the Level B harassment zone (i.e., 
15 individuals per month x 3 months of construction = 45 takes by Level 
B harassment) (Table 13).
    During Phase 2, we anticipate that the equivalent of one group of 
15 individuals may be exposed to sound levels in the Level A harassment 
zone for a duration expected to result in take, resulting in take by 
Level A harassment of 15 individual Dall's porpoises.
Pacific White-Sided Dolphin
    Pacific white-sided dolphins do not generally occur in the shallow, 
inland waterways of Southeast Alaska. There are no records of this 
species occurring in Tongass Narrows, and it is uncommon for 
individuals to occur in the proposed project area. However, historical 
sightings in nearby areas (Dahlheim and Towell 1994; Muto et al. 2018) 
and recent fluctuations in

[[Page 34156]]

distribution and abundance mean it is possible the species could be 
present.
    To account for the possibility that this species may be present in 
the project area, we conservatively predict that one large group (50 
individuals) of Pacific white-sided dolphins may experience take by 
Level B harassment during each phase of the proposed activity.
    Take Estimation for Phase 1: 50 takes by Level B harassment (Table 
12).
    Take by Level A harassment is not expected for Pacific white-sided 
dolphins in Phase 1, because of the small Level A harassment zones for 
mid-frequency cetaceans (Table 9) and the expected effectiveness of the 
proposed monitoring and mitigation measures discussed below.
    Take Estimation for Phase 2: 50 takes by Level B harassment (Table 
13).
    Take by Level A harassment is not expected for Pacific white-sided 
dolphins in Phase 2, because of the small Level A harassment zones for 
mid-frequency cetaceans (Table 9) and the expected effectiveness of the 
proposed monitoring and mitigation measures discussed below.
Killer Whale
    Killer whales are observed in Tongass Narrows irregularly with 
peaks in abundance between May and July. A previous incidental take 
authorization in the Ketchikan area estimated killer whale occurrence 
in Tongass Narrows at one pod per month (Freitag 2017 as cited in 83 FR 
37473). We estimate that one pod of 12 individuals may be present and 
exposed to project-related underwater noise every month except between 
May and July, when two pods of 12 individuals may be present and 
exposed.
    Take Estimation for Phase 1: During Phase 1, we predict that a 
total of 180 killer whales may be present in the Level B harassment 
zone (i.e., (12 exposures per month x 9 months) + (24 exposures per 
month x 3 months) = 180 takes of killer whales by Level B harassment) 
(Table 12).
    Take by Level A harassment is not expected for killer whales in 
Phase 1, because of the small Level A harassment zones for mid-
frequency cetaceans (Table 11) and the expected effectiveness of the 
proposed monitoring and mitigation measures discussed below.
    Take Estimation for Phase 2: During Phase 2, we anticipate that 
construction would occur in April, May and June. Therefore, a total of 
96 killer whales may be present in the Level B harassment zone (i.e., 
12 exposures per month x 1 month (April) + 24 exposures per month x 2 
months (May, June) = 60 takes of killer whales by Level B harassment) 
(Table 13).
    Take by Level A harassment is not expected for killer whales in 
Phase 2, because of the small Level A harassment zones for mid-
frequency cetaceans (Table 11) and the expected effectiveness of the 
proposed monitoring and mitigation measures discussed below.
Humpback Whale
    As discussed in ``Description of Marine Mammals in the Area of 
Specified Activities,'' locals have observed humpback whales about once 
per week, on average, in Tongass Narrows but there is evidence to 
suggest occurrence may be higher during some periods of the year. In 
the Biological Opinion provided to USACE for this ADOT&PF project, NMFS 
determined, based on the observations of local experts, that across the 
whole year, approximately one group of two individuals would be present 
in Tongass Narrows during ADOT&PF activity two times every seven days 
during pile driving, pile removal, and drilling activities.
    Take Estimation for Phase 1: Based on the estimated occurrence rate 
of 2 groups of 2 individuals every 7 days and an anticipated timeframe 
of Phase 1 pile driving to occur over the course of 144 days (Table 1), 
an estimated total of 82 humpback whales are expected to be present in 
the Level B harassment zone during project activity. Of these 82 takes, 
based on the estimated proportion of humpback whales in Southeast 
Alaska that belong to the ESA-listed Mexico DPS, 6.1 percent (Wade et 
al., 2016), there would be an estimated 5 takes by Level B harassment 
of Mexico DPS humpback whales. This estimated take of the Mexico DPS 
concurs with the assessment presented in Biological Opinion (Table 12).
    Take by Level A harassment is not expected for humpback whales in 
Phase 1, because of the expected effectiveness of the proposed 
monitoring and mitigation measures and detecting and avoiding take by 
Level A harassment via shutdowns of pile installation equipment.
    Take Estimation for Phase 2: Based on the estimated occurrence rate 
of 2 groups of 2 individuals every 7 days and an anticipated timeframe 
of Phase 2 pile driving to occur over the course of 27 days (Table 3), 
an estimated total of 16 humpback whales were initially expected to be 
present in the Level B harassment zone during project activity. At the 
ADOT&PF's request, and based on the analysis in the Biological Opinion, 
this take estimate for Phase 2 has been increased to 17 takes by Level 
B harassment. The difference in calculations is the result of a slight 
difference in rounding between the Biological Opinion and the method 
presented here. This increase in estimated take is a conservative 
change. Based on the estimated proportion of humpback whales in 
Southeast Alaska that belong to the ESA-listed Mexico DPS, 6.1 percent 
(Wade et al., 2016), there would be an estimated 1 take by Level B 
harassment of Mexico DPS humpback whales. This estimate concurs with 
the assessment presented in the Biological Opinion (Table 13).
    Take by Level A harassment is not expected for humpback whales in 
Phase 2, because of the expected effectiveness of the proposed 
monitoring and mitigation measures and detecting and avoiding take by 
Level A harassment via shutdowns of pile installation equipment.
Minke Whales
    Minke whales may be present in Tongass Narrows year-round. Their 
abundance throughout Southeast Alaska is very low, and anecdotal 
reports have not included minke whales near the project area. However, 
minke whales are distributed throughout a wide variety of habitats and 
could occur near the project area. Minke whales are generally sighted 
as individuals (Dahlheim et al. 2009). Based on Freitag (2017 as cited 
in 83 FR 37473) it is estimated that three individual minke whales may 
occur near or within Tongass Narrows every 4 months.
    Take Estimation for Phase 1: Based on the estimated occurrence rate 
of three individuals every four months, we predict that 9 minke whales 
(i.e., 3 individuals over a 4 month time period and 12 months of work = 
9 individuals in 12 months) may be present in the Level B harassment 
zone during the 12 month duration of Phase 1, resulting in 9 takes of 
minke whales by Level B harassment (Table 12).
    Take by Level A harassment is not expected for minke whales in 
Phase 1, because of the expected effectiveness of the proposed 
monitoring and mitigation measures at detecting and avoiding take by 
Level A harassment via shutdowns of pile installation equipment. 
Additionally, minke whales are expected to be rare in the project area 
so they will likely not occur in the Level A harassment zone.
    Take Estimation for Phase 2: Based on the estimated occurrence rate 
of three individuals every 4 months, we conservatively predict that 3 
minke whales may be present in the Level B harassment zone during the 3 
month

[[Page 34157]]

duration of Phase 2, resulting in 3 takes of minke whales by Level B 
harassment (Table 13).
    Take by Level A harassment is not expected for minke whales in 
Phase 2, because of the expected effectiveness of the proposed 
monitoring and mitigation measures and detecting and avoiding take by 
Level A harassment via shutdowns of pile installation equipment. 
Additionally, minke whales are expected to be rare in the project area 
so they will likely not occur in the Level A harassment zone.

                                    Table 12--Proposed Take Estimates as a Percentage of Stock Abundance for Phase 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Estimated       Estimated         Total
                                                                             number of       number of       estimated                     Instances of
                  Species                             DPS/stock            exposures to    exposures to      exposures         Stock          take as
                                                                              Level B         Level A      (Level A and      abundance     percentage of
                                                                            harassment      harassment       Level B)                       population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion..........................  Eastern DPS.................           2,160               0           2,160          41,638             5.2
Harbor seal...............................  Clarence Strait.............             846              18             864          31,634             2.7
Harbor porpoise...........................  Southeast Alaska............             105              15             120          11,146             1.1
Dall's porpoise...........................  Alaska......................             165              15             180          83,400             0.2
Pacific white-sided dolphin...............  North Pacific...............              50               0              50          26,880             0.2
Killer whale..............................  West Coast transient........             180               0             180           2,347           a 7.7
                                            Alaska resident.............                                                             261          a 69.0
                                            Northern Resident...........                                                             243          a 74.1
Humpback whale............................  Hawaii DPS..................              77               0              77          11,398           b 0.7
                                            Mexico DPS..................               5               0               5           3,264           b 0.2
Minke whale...............................  Alaska......................               9               0               9         Unknown             N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: DPS = distinct population segment.
a These percentages assume all takes come from the same killer whale stock, thus the percentage should be adjusted down if multiple stocks are actually
  affected.
b Assumes that 6.1 percent of humpback whales exposed are members of the Mexico DPS (Wade et al. 2016).


                                    Table 13--Proposed Take Estimates as a Percentage of Stock Abundance for Phase 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Estimated       Estimated         Total
                                                                             number of       number of       estimated                     Instances of
                  Species                             DPS/stock            exposures to    exposures to      exposures         Stock          take as
                                                                              Level B         Level A      (Level A and      abundance     percentage of
                                                                            harassment      harassment       Level B)                       population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion..........................  Eastern DPS.................             450               0             450          41,638             1.1
Harbor seal...............................  Clarence Strait.............             162               9             171          31,634             0.5
Harbor porpoise...........................  Southeast Alaska............              30              10              40          11,146             0.4
Dall's porpoise...........................  Alaska......................              45              15              60          83,400            <0.1
Pacific white-sided dolphin...............  North Pacific...............              50               0              50          26,880             0.2
Killer whale..............................  West Coast transient........                                                           2,347           a 4.1
                                            Alaska resident.............              96               0              96             261          a 36.8
                                            Northern Resident...........                                                             243          a 39.5
Humpback whale............................  Hawaii DPS..................              16               0              16          11,398           b 0.1
                                            Mexico DPS..................               1               0               1           3,264          b <0.1
Minke whale...............................  Alaska......................               6               0               6         Unknown             N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: DPS = distinct population segment.
a These percentages assume all takes come from the same killer whale stock, thus the percentage should be adjusted down if multiple stocks are actually
  impacted.
b Assumes that 6.1 percent of humpback whales exposed are members of the Mexico DPS (Wade et al. 2016).

Proposed Mitigation

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

[[Page 34158]]

effectiveness of the military readiness activity.
    In addition to the measures described later in this section, 
ADOT&PF must employ the following standard mitigation measures:
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water heavy machinery work other than pile driving/
removal and drilling (e.g., standard barges, tug boats), if a marine 
mammal comes within 10 m, operations shall cease and vessels shall 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions. This type of work could include the following 
activities: (1) Movement of the barge to the pile location; or (2) 
positioning of the pile on the substrate via a crane (i.e., stabbing 
the pile);
     Work may only occur during daylight hours, when visual 
monitoring of marine mammals can be conducted;
     For any marine mammal species for which take by Level B 
harassment has not been requested or authorized, in-water pile 
installation/removal and drilling will shut down immediately when the 
animals are sighted;
     If take by Level B harassment reaches the authorized limit 
for an authorized species, pile installation will be stopped as these 
species approach the Level B harassment zone to avoid additional take 
of them.
    The following mitigation measures would apply to ADOT&PF's in-water 
construction activities:
    Establishment of Shutdown Zone for Level A Harassment--For all pile 
driving/removal and drilling activities, ADOT&PF will establish a 
shutdown zone. The purpose of a shutdown zone is generally 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). Shutdown zones will vary based on the activity type, marine 
mammal hearing group, and in the case of impact pile driving, 
additional details about the activity including the expected number of 
pile strikes required, size of the pile, and number of piles to be 
driving during that day (See Table 10). Here, shutdown zones are larger 
than the calculated Level A harassment isopleth shown in Table 11. The 
largest shutdown zones are generally for low frequency and high 
frequency cetaceans as shown in Table 14. The placement of Protected 
Species Observers (PSOs) during all pile driving, pile removal and 
drilling activities (described in detail in the Proposed Monitoring and 
Reporting Section) will ensure that the entire shutdown zone is visible 
during pile installation.

                                                            Table 14--Proposed Shutdown Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Piles                                 Shutdown distances (m)
                                                        Minutes per pile or   installed or       Level B    --------------------------------------------
            Activity               Pile size (inches)    strikes per pile      removed per     harassment
                                                                                   day        isopleth (m)      LF       MF       HF       PW       OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation..........  30.................  30 min..............               3           6,310                       50
                                  24, 18.............  30 min..............               3           5,420
                                  27.6 sheet pile,     15 min..............              10           4,650
                                   30.3 sheet pile.
Vibratory Removal...............  24, 16.............  30 min..............               5           5,420
--------------------------------------------------------------------------------------------------------------------------------------------------------
Drilling Rock Sockets...........  30.................  180 min.............               3          12,030       70       50       60         50
                                                                                                                     ------------------
                                  24, 18.............  120 min.............               3                       60         50
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Installation.............  30.................  50 strikes..........               3           2,160      250       50      250      150       50
                                                                                          2                      200               200      100
                                                                                          1                      100               150      100
                                                       200 strikes.........               3                      550               650      300
                                                                                          2                      400               500      250
                                                                                          1                      300               300      150
                                                                                            ----------------
                                  24.................  50 strikes..........               3           1,000      150               150      100
                                                                                          2                      100               150       50
                                                                                          1                      100               100       50
                                                       200 strikes.........               3                      300               350      200
                                                                                          2                      250               300      150
                                                                                          1                      150               200      100
                                  18.................  50 strikes..........               3                      150               150      100
                                                                                          2                      100               150       50
                                                                                          1                      100               100       50
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Establishment of Monitoring Zones for Level B Harassment--ADOT&PF 
will establish monitoring zones, based on the Level B harassment zones 
which are areas where SPLs are equal to or exceed the 160 dB rms 
threshold for impact driving and the 120 dB rms threshold during 
vibratory driving, removal and drilling. Monitoring zones provide 
utility for observing by establishing monitoring protocols for areas 
adjacent to the shutdown zones. Monitoring zones enable observers to be 
aware of and communicate the presence of marine mammals in the project 
area outside the shutdown zone and thus prepare for a potential cease 
of activity should the animal enter the shutdown zone. The isopleths 
for the Level B harassment zones are depicted in Table 9. As shown, the 
largest Level B harassment zone for both Phase 1 and Phase 2 extends to 
a radius of 12,023 meters in at least one direction up or down Tongass 
Narrows (Figure 6-3 and 6-7 in IHA Application), making it 
impracticable for the PSOs to consistently view the entire harassment 
area. Due to this, takes by Level B harassment will be recorded and 
extrapolated based upon the number of observed takes and the percentage 
of the Level B harassment zone that was not visible.
    In order to observe as much of the monitoring zone as possible, one 
PSO will be centrally located near the worksite where pile 
installation/removal is occurring that day, and

[[Page 34159]]

primarily tasked with observing the shutdown zones. Other PSOs will 
begin at the central worksite and travel along the Tongass Narrows 
until they have reached the edges of the monitoring zone, based on the 
Level B harassment zone. These PSOs will then monitor the edges of the 
monitoring zone and as much as possible of the rest of the monitoring 
zone, allowing awareness of animals entering the Level B harassment 
zone. If waters exceed a sea state that restricts the MMO's ability to 
make observations within the Level A harassment zones (e.g., excessive 
wind or fog), pile installation and removal must cease. Pile driving 
must not be re-initiated until the entire relevant Level A harassment 
zones are visible.
    Soft Start--The use of a soft-start procedure are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
will be required to provide an initial set of strikes from the hammer 
at reduced percent energy, each strike followed by no less than a 30-
second waiting period. This procedure will be conducted a total of 
three times before impact pile driving begins. Soft Start is not 
required during vibratory pile driving and removal activities. If a 
marine mammal is present within the Level A harassment zone, soft start 
will be delayed until the animal leaves the Level A harassment zone. 
Soft start will begin only after the MMO has determined, through 
sighting, that the animal has moved outside the Level A harassment 
zone. If a marine mammal is present in the Level B harassment zone, 
soft start may begin and a Level B take will be recorded. Soft start up 
may occur when these species are in the Level B harassment zone, 
whether they enter the Level B zone from the Level A zone or from 
outside the Project area.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving of 30 
minutes or longer occurs, the observer will observe the shutdown and 
monitoring zones for a period of 30 minutes. The shutdown zone will be 
cleared when a marine mammal has not been observed within the zone for 
that 30-minute period. If a marine mammal is observed within the 
shutdown zone, a soft-start cannot proceed until the animal has left 
the zone or has not been observed for 15 minutes. If the Level B 
harassment zone has been observed for 30 minutes and marine mammals are 
not present within the zone, soft start procedures can commence and 
work can continue even if visibility becomes impaired within the Level 
B harassment zone. When a marine mammal permitted for take by Level B 
harassment is present in the Level B harassment zone, piling activities 
may begin and take by Level B will be recorded. As stated above, if the 
entire Level B harassment zone is not visible at the start of 
construction, piling or drilling activities can begin. If work ceases 
for more than 30 minutes, the pre-activity monitoring of both the Level 
B harassment and shutdown zone will commence.
    Based on our evaluation of the applicant's proposed measures NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means of effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed project area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal and drilling activities. In 
addition, observers shall record all incidents of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions in concert with distance from piles being 
driven or removed. Pile driving activities include the time to install 
or remove a single pile or series of piles, as long as the time elapsed 
between uses of the pile driving equipment is no more than thirty 
minutes.
    There will be at least two PSOs monitoring at all specified times. 
PSOs will not perform duties for more than 12 hours in a 24-hour 
period. PSOs would be land-based observers, positioned at the best 
practical vantage points. Suitable observation points are available 
from the Tongass Highway (Revillia Island) and Gravina Airport Access 
Road (Gravina Island). The positions may vary based on construction 
activity and location of piles or equipment. One PSO, generally the 
lead, will be stationed centrally near the work site. This individual 
will be able to monitor all Level A harassment zones under normal 
circumstances. Depending on the activity (vibratory driving/removal, 
drilling, or impact driving), additional PSOs will be stationed along 
the road system, as described above in ``Proposed Mitigation.'' With 
this configuration, PSOs can have a full view of the Level A harassment 
zone and awareness of as much of the Level B harassment zone as 
possible. This monitoring will provide information on marine mammal 
occurrence within Tongass Narrows and how these marine mammals are 
impacted by pile installation and removal.
    As part of monitoring, PSOs would scan the waters using binoculars, 
and/or spotting scopes, and would use a

[[Page 34160]]

handheld GPS or range-finder device to verify the distance to each 
sighting from the project site. All PSOs would be trained in marine 
mammal identification and behaviors and are required to have no other 
project-related tasks while conducting monitoring. In addition, 
monitoring will be conducted by qualified observers, who will be placed 
at the best vantage point(s) practicable to monitor for marine mammals 
and implement shutdown/delay procedures when applicable by calling for 
the shutdown to the hammer operator. Qualified observers are trained 
and/or experienced professionals, with the following minimum 
qualifications:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target.
     Independent observers (i.e., not construction personnel).
     Observers must have their CVs/resumes submitted to and 
approved by NMFS
     Advanced education in biological science or related field 
(i.e., undergraduate degree or higher). Observers may substitute 
education or training for experience.
     Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience).
     At least one observer must have prior experience working 
as an observer.
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors.
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations.
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior.
     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.

Preliminary Reporting

    NMFS is proposing to issue two distinct and consecutive IHAs within 
this action. In recognition of the value of marine mammal monitoring in 
understanding the impacts of ADOT&PF's activity, NMFS is requiring that 
ADOT&PF submit a preliminary marine mammal monitoring report for Phase 
1 of the project (2020 through 2021) at least 4 months prior to the 
effective date of the second IHA and initiation of Phase 2. This 
preliminary report must contain all items that would be included in the 
draft final report, listed below under ``Reporting''. This will allow 
NMFS to assess the impact of the proposed action relative to the 
analysis presented here, and modify the IHA for Phase 2 if the 
preliminary monitoring report shows unforeseen impacts on marine 
mammals in the area. If needed, NMFS will publish a Federal Register 
Notice for a proposed amended IHA, describing any changes but 
referencing the original IHA for Phase 2, and include an opportunity 
for the public to comment on the amended authorization.

Reporting

    Separate draft marine mammal monitoring reports must be submitted 
to NMFS within 90 days after the completion of both Phase 1 and Phase 2 
pile driving, pile removal, and drilling activities. These reports will 
include an overall description of work completed, a narrative regarding 
marine mammal sightings, and associated PSO data sheets. Specifically, 
the reports must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations;
     An estimate of total take based on proportion of the 
monitoring zone that was observed; and
     Other human activity in the area.
    If no comments are received from NMFS within 30 days, that phase's 
draft final report will constitute the final report. If comments are 
received, a final report for the given phase addressing NMFS comments 
must be submitted within 30 days after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHAs 
(if issued), such as an injury, serious injury or mortality, ADOT&PF 
would immediately cease the specified activities and report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinator. The report would include the following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with ADOT&PF to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. ADOT&PF would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that ADOT&PF discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (e.g., in less than 
a moderate state of decomposition as described in the next paragraph), 
ADOT&PF would immediately report the incident to the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
and the NMFS Alaska Stranding Hotline and/or by email to the Alaska 
Regional Stranding Coordinator. The report would include the same 
information identified in the paragraph above. Activities would be able 
to continue while NMFS reviews the circumstances of the incident. NMFS 
would work with ADOT&PF to determine whether modifications in the 
activities are appropriate.
    In the event that ADOT&PF discovers an injured or dead marine 
mammal and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in these IHAs 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), ADOT&PF would report the incident 
to the Chief of the Permits and

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Conservation Division, Office of Protected Resources, NMFS, and the 
NMFS Alaska Stranding Hotline and/or by email to the Alaska Regional 
Stranding Coordinator, within 24 hours of the discovery. ADOT&PF would 
provide photographs, video footage (if available), or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Network.

Negligible Impact Analyses and Determinations

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, our analysis applies to all species listed in 
Tables 12 and 13, given that NMFS expects the anticipated effects of 
the proposed pile driving/removal and drilling to be similar in nature. 
Where there are meaningful differences between species or stocks, or 
groups of species, in anticipated individual responses to activities, 
impact of expected take on the population due to differences in 
population status, or impacts on habitat, NMFS has identified species-
specific factors to inform the analysis. Additionally, the proposed 
activity for both Phase 1 and Phase 2 is similar in nature, so the 
impacts are expected to be similar and are analyzed as such, unless 
otherwise noted.
    NMFS does not anticipate that serious injury or mortality would 
occur as a result of ADOT&PF's proposed activity. As stated in the 
proposed mitigation section, shutdown zones that equal or exceed Level 
A harassment isopleths shown in Table 11 will be implemented. Take by 
Level A harassment is proposed for authorization for some species 
(harbor seals, harbor porpoises, and Dall's porpoises) to account for 
the slight possibility that these species escape observation by the 
PSOs within the Level A harassment zone. Further, any take by Level A 
harassment is expected to arise from, at most, a small degree of PTS 
because animals would need to be exposed to higher levels and/or longer 
duration than are expected to occur here in order to incur any more 
than a small degree of PTS. Additionally, as noted previously, some 
subset of the individuals that are behaviorally harassed could also 
simultaneously incur some small degree of TTS for a short duration of 
time. Because of the small degree anticipated, though, any PTS or TTS 
potentially incurred here would not be expected to adversely impact 
individual fitness.
    Behavioral responses of marine mammals to pile driving, pile 
removal, and drilling at the proposed sites in Tongass Narrows are 
expected to be mild, short term, and temporary. Marine mammals within 
the Level B harassment zone may not show any visual cues they are 
disturbed by activities (as noted during modification to the Kodiak 
Ferry Dock (ABR 2016) See ``Acoustic Impacts'' above) or they could 
become alert, avoid the area, leave the area, or display other mild 
responses that are not observable such as changes in vocalization 
patterns. Given the short duration of noise-generating activities per 
day and that pile driving, removal, and drilling would occur for only a 
portion of the project's two years on nonconsecutive days (144 days in 
Phase 1, or 27 days in Phase 2), any harassment during both phases 
would be temporary. Additionally, many of the species present in 
Tongass Narrows would only be present temporarily based on seasonal 
patterns or during transit between other habitats. These temporarily 
present species would be exposed to even smaller periods of noise-
generating activity, further decreasing the impacts.
    In addition, for all species except humpbacks, there are no known 
Biologically Important Areas (BIAs) near the project zone that would be 
impacted by ADOT&PF's proposed activities. For humpback whales, the 
whole of Southeast Alaska is a seasonally important BIA from spring 
through late fall (Ferguson et al., 2015), however, Tongass Narrows is 
not an important portion of this habitat due to development and human 
presence. Additionally, Tongass Narrows is a small passageway and 
represents a very small portion of the total available habitat. There 
is no ESA-designated critical habitat for humpback whales.
    More generally, there are no known calving or rookery grounds 
within the project area, but anecdotal evidence from local experts 
shows that marine mammals are more prevalent in Tongass Narrows during 
spring and summer associated with feeding on aggregations of fish, 
meaning the area may play a role in foraging. Because ADOT&PF's 
activities, especially in Phase 1, could occur at any time of year, 
takes may occur at any time of the year, including these times of 
feeding. However, the project area represents a small portion of 
available foraging habitat and the actual duration of noise-producing 
activities each day is short, meaning impacts on marine mammal feeding 
for all species, including humpback whale, should be minimal.
    Any impacts on marine mammal prey that would occur during ADOT&PF's 
proposed activity would have at most short-terms effects on foraging of 
individual marine mammals, and likely no effect on the populations of 
marine mammals as a whole. Therefore, indirect effects on marine mammal 
prey during the construction are not expected to be substantial, and 
these insubstantial effects would therefore be unlikely to cause 
substantial effects on marine mammals at the individual or population 
level.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity, for both Phase 1 and Phase 2, are not expected to 
adversely affect the species or stocks through effects on annual rates 
of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized.
     ADOT&PF would implement mitigation measures including 
soft-starts for impact pile driving and shutdown zones that exceed 
Level A harassment zones for most authorized species, which will help 
to ensure that take by Level A harassment is at most a small degree of 
PTS.
     The only known BIA is across a broad area of southeast 
Alaska for humpback whales, and the project area is a very small 
portion of that BIA. No

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other known areas of particular biological importance to any of the 
affected stocks are impacted by the activity.
     The project area represents a very small portion of the 
available foraging area for all marine mammal species and anticipated 
habitat impacts are minor.
    Phase 1--Based on the analysis contained herein of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the proposed 
monitoring and mitigation measures, NMFS preliminarily finds that the 
total marine mammal take from ADOT&PF's proposed Phase 1 activities 
will have a negligible impact on all affected marine mammal species or 
stocks.
    Phase 2--Based on the analysis contained herein of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the proposed 
monitoring and mitigation measures, NMFS preliminarily finds that the 
total marine mammal take from ADOT&PF's proposed Phase 2 activities 
will have a negligible impact on all affected marine mammal species or 
stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals that may 
be taken to the most appropriate estimation of abundance of the 
relevant species or stock in our determination of whether an 
authorization is limited to small numbers of marine mammals. 
Additionally, other qualitative factors may be considered in the 
analysis, such as the temporal or spatial scale of the activities.
    Table 12 and 13, in the Marine Mammal Occurrence and Take 
Calculation and Estimation section, present the number of animals that 
could be exposed to received noise levels that may result in take by 
Level A harassment or Level B harassment for both Phase 1 and Phase 2 
of ADOT&PF's proposed activities. Our analysis of ADOT&PF's planned 
Phase 1 activity shows that for all but the two stocks of killer whale 
mentioned above, approximately 8 percent or less of the best population 
estimates of each affected stock could be taken. Similar analysis of 
Phase 2 showed similar results, with all but the two mentioned killer 
whale stocks, expected to have less than 5 percent or less of their 
stock experience take.
    There are two stocks, Northern Resident killer whales and West 
Coast Transient killer whales, for which the estimated instances of 
take, in both Phase 1 and Phase 2 of the ADOT&PF's planned project, 
appear high when compared to the stock abundance (Table 12 and 13). 
However, when other qualitative factors are used to inform an 
assessment of the likely number of individual marine mammals taken, the 
resulting numbers are appropriately considered small. Initial analysis 
of the West Coast Transient stock shows that in Phase 1, when instances 
of take (not individuals taken) are compared to the stock abundance, 
74.1 percent of the stock is expected to experience take, and in Phase 
2, approximately 39.5 percent of the stock is expected to experience 
take. For the Northern Resident stock, the initial analysis shows that 
when instances of take (not individuals taken) are compared to the 
stock abundance, approximately 69 percent of the stock is expected to 
experience take in Phase 1, and 36.8 of the stock is expected to 
experience take in Phase 2. While these numbers appear high, the 
extensive ranges of both stocks compared to ADOT&PF's project area mean 
that realistically there will be multiple takes of a smaller number of 
individuals from these stocks, resulting in no more than a third of the 
individuals of any of these stocks being taken. The Northern Resident 
stock's range stretches from Washington State into southeast Alaska and 
the stock is frequently observed along British Columbia, Canada (Muto 
et al., 2018). The West Coast transient stock occurs in California, 
Oregon, Washington, British Columbia, and southeastern Alaska. In both 
cases, ADOT&PF is only impacting a small portion of the total range, 
and this impact is intermittent. Further, the above percentages are 
based on analyzing the entire estimated take of killer whales as if it 
would occur to each stock.
    Realistically, the take will be spread in some way among the stocks 
expected to be in the area (i.e., 100 percent of the take cannot occur 
to each of the three stocks), further reducing the percentage of takes 
anticipated to come from any single stock. As a result, it is likely 
that fewer than one third of both the Northern Resident and West Coast 
Transient killer whale stocks would be taken in each phase of the 
project.
    For both Phase 1 and Phase 2, there was one stock, minke whale, 
where the lack of an accepted stock abundance value prevented us from 
calculating an expected percentage of the population that would be 
affected. The most relevant estimate of partial stock abundance is 
1,233 minke whales for a portion of the Gulf of Alaska (Zerbini et al., 
2006). Given the proposed 9 authorized takes by Level B harassment for 
the stock in Phase 1, comparison to the best estimate of stock 
abundance shows less than 1 percent of the stock is expected to be 
impacted. A similar analysis of the Phase 2, with 6 takes of minke 
whale by Level B harassment proposed for authorization, comparison to 
the best estimate of stock abundance show less then 1 percent of the 
stock is expected to be impacted. Additionally, the range of the Alaska 
stock of minke whales is extensive, stretching from the Canadian 
Pacific coast to the Chukchi Sea, and ADOT&PF's project area impacts a 
small portion of this range. Therefore, the numbers of minke whales 
authorized to be taken would be considered small relative to estimated 
survey abundance even if each estimated taking occurred to a new 
individual.
    Phase 1--Based on the analysis contained herein of the proposed 
activity (including the proposed mitigation and monitoring measures) 
and the anticipated take of marine mammals for Phase 1 of ADOT&PF's 
activity, NMFS preliminarily finds that small numbers of marine mammals 
will be taken relative to the population size of the affected species 
or stocks in Phase 1 of the project.
    Phase 2--Based on the analysis contained herein of the proposed 
activity (including the proposed mitigation and monitoring measures) 
and the anticipated take of marine mammals for Phase 2 of ADOT&PF's 
activity, NMFS preliminarily finds that small numbers of marine mammals 
will be taken relative to the population size of the affected species 
or stocks in Phase 2 of the project.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine

[[Page 34163]]

mammals and the subsistence hunters; and (2) That cannot be 
sufficiently mitigated by other measures to increase the availability 
of marine mammals to allow subsistence needs to be met.
    Harbor seals are the marine mammal species most regularly harvested 
for subsistence by households in Ketchikan and Saxman (A community a 
few miles south of Ketchikan, on the Tongass Narrows). Eighty harbor 
seals were harvested by Ketchikan residents in 2007, which ranked 
fourth among all communities in Alaska that year for harvest of harbor 
seals. Thirteen harbor seals were harvested by Saxman residents in 
2007. In 2008, two Steller sea lions were harvested by Ketchikan-based 
subsistence hunters, but this is the only record of sea lion harvest by 
residents of either Ketchikan or Saxman. In 2012, the community of 
Ketchikan had an estimated subsistence take of 22 harbor seals and 0 
Steller sea lion (Wolf et al., 2013). This is the most recent data 
available. Hunting usually occurs in October and November (ADF&G 2009), 
but there are also records of relatively high harvest in May (Wolfe et 
al., 2013). The ADF&G has not recorded harvest of cetaceans from either 
community (ADF&G 2018). All project activities will take place within 
the industrial area of Tongass Narrows immediately adjacent to 
Ketchikan where subsistence activities do not generally occur. The 
project will not have an adverse impact on the availability of marine 
mammals for subsistence use at locations farther away, where these 
construction activities are expected to take place. Some minor, short-
term harassment of the harbor seals could occur, but this is not likely 
to have any measureable effect on subsistence harvest activities in the 
region.
    Phase 1--Based on the description and location of the specified 
activity, and the proposed mitigation and monitoring measures, NMFS has 
preliminarily determined that there will not be an unmitigable adverse 
impact on subsistence uses from Phase 1 of ADOT&PF's proposed 
activities.
    Phase 2--Based on the description and location of the specified 
activity, and the proposed mitigation and monitoring measures, NMFS has 
preliminarily determined that there will not be an unmitigable adverse 
impact on subsistence uses from Phase 2 of ADOT&PF's proposed 
activities.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS Office of Protected Resources consults internally, in this case 
with NMFS Alaska Regional Office, whenever we propose to authorize take 
for endangered or threatened species.
    NMFS is proposing to authorize take of the Central North Pacific 
stock of humpback whales, of which a portion belong to the Mexico DPS 
humpback whales, which are listed under the ESA. During the USACE 
permitting process for the Tongass Narrows Project, the effects of this 
proposed Federal action were analyzed in NMFS' 2019 Endangered Species 
Act (ESA) Section 7(a)(2) Biological Opinion for Construction of the 
Tongass Narrows Project (Gravina Access), however, this biological 
opinion did not analyze the issuance of IHAs. Therefore, the NMFS 
Permit and Conservation Division has requested initiation of Section 7 
consultation with the NMFS Alaska Regional Office for the issuance of 
these IHAs. NMFS will conclude the ESA consultation prior to reaching a 
determination regarding the proposed issuance of the authorizations.

Proposed Authorizations

    As a result of these preliminary determinations, NMFS proposes to 
issue two distinct and consecutive IHAs to ADOT&PF for conducting ferry 
berth improvements and construction in Tongass Narrows, Alaska in 2020 
through 2021 (Phase 1) and 2021 through 2022 (Phase 2), provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. Drafts of the proposed IHAs can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed in-
water construction project. We also request at this time comment on the 
potential renewal of this proposed IHA as described in the paragraph 
below. Please include with your comments any supporting data or 
literature citations to help inform decisions on the request for this 
IHA or a subsequent Renewal.
    On a case-by-case basis, NMFS may issue a one-year IHA renewal with 
an additional 15 days for public comments when (1) another year of 
identical or nearly identical activities as described in the Specified 
Activities section of this notice is planned or (2) the activities as 
described in the Specified Activities section of this notice would not 
be completed by the time the IHA expires and a second IHA would allow 
for completion of the activities beyond that described in the Dates and 
Duration section of this notice, provided all of the following 
conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA.
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal are identical to the activities analyzed under the 
initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: July 11, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-15115 Filed 7-16-19; 8:45 am]
BILLING CODE 3510-22-P