Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Gustavus Ferry Terminal Improvements Project, 40852-40870 [2016-14886]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 81, Number 121 (Thursday, June 23, 2016)]
[Notices]
[Pages 40852-40870]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-14886]



[[Page 40852]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE603


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Gustavus Ferry Terminal 
Improvements Project

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

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

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SUMMARY: NMFS has received a request from the Alaska Department of 
Transportation and Public Facilities (ADOT&PF) for authorization to 
take marine mammals incidental to reconstructing the existing Gustavus 
Ferry Terminal located in Gustavus, Alaska. The ADOT&PF requests that 
the incidental harassment authorization (IHA) be valid for one year 
from September 1, 2017 through August 31, 2018. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an authorization to the ADOT&PF to incidentally take, 
by harassment, small numbers of marine mammals for its ferry terminal 
improvements project in Gustavus, AK.

DATES: Comments and information must be received no later than July 25, 
2016.

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

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

SUPPLEMENTARY INFORMATION: 
    Availability: An electronic copy of ADOT&PF's application and 
supporting documents, as well as a list of the references cited in this 
document, may be obtained by visiting the Internet at: 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of 
problems accessing these documents, please call the contact listed 
above (see FOR FURTHER INFORMATION CONTACT).

National Environmental Policy Act

    NMFS is preparing an Environmental Assessment (EA) in accordance 
with National Environmental Policy Act (NEPA) and the regulations 
published by the Council on Environmental Quality and will consider 
comments submitted in response to this notice as part of that process. 
The draft EA will be posted at the foregoing Web site once it is 
finalized.

Background

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

Summary of Request

    On July 31, 2015, NMFS received an application from the ADOT&PF for 
the taking of marine mammals incidental to reconstructing the existing 
ferry terminal at Gustavus, Alaska, referred to as the Gustavus Ferry 
Terminal. On April 15, 2016, NMFS received a revised application. NMFS 
determined that the application was adequate and complete on April 20, 
2016. ADOT&PF proposes to conduct in-water work that may incidentally 
harass marine mammals (i.e., pile driving and removal). This IHA would 
be valid from September 1, 2017 through August 31, 2018.
    Proposed activities included as part of the Gustavus Ferry 
Improvements project with potential to affect marine mammals include 
vibratory pile driving and pile removal, as well as impact hammer pile 
driving.
    Species with the expected potential to be present during the 
project timeframe include harbor seal (Phoca viutlina), Steller sea 
lion (Eumetopias jubatus), harbor porpoise (Phocoena phocoena), Dall's 
porpoise (Phocoenoides dalli), killer whale (Orcinus orca), humpback 
whale (Megaptera novaeangliae), and minke whale (Balaenoptera 
acutorostra).

Description of the Specified Activity

Overview

    The purpose of the project is to improve the vehicle transfer span 
and dock such that damage during heavy storms is prevented, and to 
improve the safety of vehicle and pedestrian transfer operations. 
ADOT&PF requested an IHA for work that includes removal of the existing 
steel bridge float and restraint structure and replacing it with two 
steel/concrete bridge lift towers capable of elevating the relocated 
steel transfer bridge above the water when not in use. Each tower would 
be supported by four 30-inch steel piles.

Dates and Duration

    Pile installation and extraction associated with the Gustavus Ferry 
Terminal project will begin no sooner than September 1, 2017 and will 
be completed no later than August 31, 2018

[[Page 40853]]

(one year following IHA issuance). Project activities are proposed to 
occur during two time periods. The first period will occur in Fall of 
2017, with pile driving/removal and in-water work occurring during the 
period of September through November. The second period is scheduled 
for Spring of 2018, with pile driving/removal and in-water work 
occurring during the period of March through May.
    Pile driving/removal is estimated to occur for a total of about 114 
hours over the course of 16 to 50 days.

Specific Geographic Region

    The proposed activities will occur at the Gustavus Ferry Terminal 
located in Gustavus, Alaska on the Icy Passage water body in Southeast 
Alaska (See Figures 1 and 2 in the Application).

Detailed Description of Activities

    ADOT&PF plans to improve the ferry terminal in Gustavus, Alaska. 
ADOT&PF will remove the existing steel bridge float and restraint 
structure and replace it with two steel/concrete bridge lift towers 
capable of elevating the relocated steel transfer bridge above the 
water when not in use. Each tower would be supported by four 30-inch 
steel piles. The project would also expand the dock by approximately 
4,100 square feet, requiring 34 new 24-inch steel piles; construct a 
new steel six-pile (24-inch) bridge abutment; relocate the steel 
transfer bridge, vehicle apron, and aluminum pedestrian gangway; 
extract 16 steel piles; relocate the log float to the end of the 
existing float structure (requiring installation of three 12.75-inch 
steel piles); install a new harbor access float (assembled from a 
portion of the existing bridge float) and a steel six-pile (30-inch) 
float restraint structure; and provide access gangways and landing 
platforms for lift towers and an access catwalk to the existing 
breasting dolphins. Contractors on previous ADOT&PF dock projects have 
typically driven piles using the following equipment:
     Air Impact Hammers: Vulcan 512/Max Energy 60,000 foot-
pounds (ft-lbs); Vulcan 06/Max Energy 19,000 ft-lbs; ICE/Max Energy 
19,500 to 60,000 ft-lbs.
     Diesel Impact Hammer: Delmag D30/Max Energy 75,970 ft-lbs.
     Vibratory Hammers: ICE various models/7,930 to 13,000 
pounds static weight.
    Similar equipment may be used for the proposed project, though each 
contractor's equipment may vary.
    ADOT&PF anticipates driving one to three piles per day, which 
accounts for setting the pile in place, positioning the barge while 
working around existing dock and vessel traffic, splicing sections of 
pile, and driving the piles. Actual pile driving/removal time for 
nineteen 12.75-inch-, forty 24-inch-, and fourteen 30-inch-diameter 
steel piles would be approximately 57 hours of impact driving and 114 
hours of vibratory driving over the course of 16 to 50 days in 2017. 
(See Table 1.)

                                                                                 Table 1--Pile-Driving Schedule
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                                                                                                        Project components
                                 ---------------------------------------------------------------------------------------------------------------------------------------------------------------
           Description                                                                                                                           Piles installed/
                                    Dock extension    Bridge abutment      Lift towers       Access float        Log float       Pile removal       total piles    Installation/ Removal per day
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Number of Piles.................  34...............  6................  8................  6...............  3...............  16..............  57/73...........  3 piles/day (maximum).
Pile Size (Diameter)............  24-inch..........  24-inch..........  30-inch..........  30-inch.........  12.75-inch......  12.75-inch......
Total Strikes (Impact)..........  20,400...........  3,600............  4,800............  3,600...........  1,800...........  0...............  34,200..........  1,800 blows/day.
Total Impact Time...............  34 hrs...........  6 hrs............  8 hrs............  6 hrs...........  3 hrs...........  0...............  57 hrs..........  3 hrs/day.
Total Vibratory Time............  54 hrs...........  9 hrs............  13 hrs...........  9 hrs...........  5 hrs...........  24 hrs..........  114 hrs.........  6 hrs/day.
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Description of Marine Mammals in the Area of the Specified Activity

    Marine waters in Icy Passage support many species of marine 
mammals, including pinnipeds and cetaceans. There are nine marine 
mammal species documented in the waters of Icy Passage (Dahlheim et 
al., 2009; NMFS 2013; and personal communications with Janet Neilson, 
National Park Service (NPS); Tod Sebens, Cross Sound Express, LLC 
(CSE); and Stephen Vanderhoff, Spirit Walker Expeditions (SWE)). Two of 
the species are known to occur near the Gustavus Ferry terminal: The 
harbor seal and Steller sea lion. The remaining seven species may occur 
in Icy Passage but less frequently and farther from the ferry terminal: 
Harbor porpoise, Dall's porpoise, Pacific white-sided dolphin, killer 
whale, gray whale, humpback whale, and minke whale.
    Although listed on the NMFS MMPA mapper (NMFS 2014), gray whale 
sightings in Icy Strait are very rare and there have been only eight 
sightings since 1997 (Janet Neilson, NPS, personal communication). None 
of these sightings were in Icy Passage. Therefore, exposure of the gray 
whale to project impacts is considered unlikely and take is not 
requested for this species.
    The range of Pacific white-sided dolphin is also suggested to 
overlap with the project action area as portrayed on the NMFS MMPA 
mapper, but no sightings have been documented in the project vicinity 
(Janet Neilson, NPS, personal communication, Dahlheim et al., 2009). 
Therefore, exposure of the Pacific white-sided dolphin to project 
impacts is considered unlikely and take is not requested for this 
species. Table 2 presents the species most likely to occur in the area.

                                        Table 2--Marine Mammal Species Potentially Present in Region of Activity
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                                                                Stock abundance                                                   Frequency of occurence
            Common name                  Scientific name          estimate \1\            ESA status            MMPA status                 \2\
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Harbor seal........................  Phoca vitulina........  7,210................  Not listed...........  Not Strategic, non-    Likely.
                                                                                                            depleted.
Steller sea lion...................  Eumetopias jubatus....  49,497 (western        Endangered (western    Strategic, depleted..  Likely.
                                                              distinct population    Distinct Population
                                                              segment in Alaska)/    Segment).
                                                              60,131 (eastern
                                                              stock).
Dall's porpoise....................  Phocoenoides dalli....  Unknown..............  Not listed...........  Not Strategic, non-    Infrequent.
                                                                                                            depleted.
Harbor porpoise....................  Phocoena phocoena.....  11,146...............  Not listed...........  Strategic, non-        Likely.
                                                                                                            depleted.

[[Page 40854]]

 
Humpback whale.....................  Megaptera novaeangliae  10,252...............  Endangered...........  Strategic, depleted..  Infrequent.
Killer whale.......................  Orcinus orca..........  261 (Northern          Not listed...........  Strategic, non-        Infrequent.
                                                              resident)/587 (Gulf                           depleted.
                                                              of Alaska transient)/
                                                              243 (West Coast
                                                              transient).
Minke whale........................  Balaenoptera            Unknown..............  Not listed...........  Not Strategic/non-     Infrequent.
                                      acutorostra.                                                          depleted.
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\1\ NMFS marine mammal stock assessment reports at: https://www.nmfs.noaa.gov/pr/sars/species.htm.
\2\ Infrequent: Confirmed, but irregular sightings; Likely: Confirmed and regular sightings of the species in the area year-round.

    Although they are documented near the ferry terminal, harbor seal 
populations in Glacier Bay are declining (Janet Neilson, NPS, personal 
communication). It is estimated that less than 10 individuals are 
typically seen near the ferry dock during charter boat operations in 
the spring and summer (Tod Sebens, CSE, Stephen Vanderhoff, SWE, 
personal communication). Steller sea lions are common in the ferry 
terminal area during the charter fishing season (May to September) and 
are known to haul out on the public dock (Bruce Kruger, Alaska 
Department of Fish and Game (ADF&G), personal communication). The 
nearest natural Steller sea lion haulout sites are located on Black 
Rock on the south side of Pleasant Island and Carolus Point west of 
Point Gustavus (Mathews et al., 2011).
    There are confirmed sightings of Dall's porpoise, harbor porpoise, 
humpback whale, killer whale, and minke whale in Icy Passage (Janet 
Neilson, NPS, Tod Sebens, CSE, Stephen Vanderhoff, SWE, personal 
communication). However, sightings are less frequent in Icy Passage 
than in Icy Strait. Opportunistic sightings of marine mammals by NPS 
during humpback whale surveys and whale watching tour companies 
operating out of Gustavus (CSE and WSE operate 100 days of tours in the 
May to September season), provide the following estimates for each 
spring/summer season:
     Harbor porpoise are seen in Icy Passage on about 75+ 
percent of trips.
     Three to four minke whale sightings/season in Icy Strait. 
One or two in Icy Passage.
     Dall's porpoise have four to 12 sightings/season, mostly 
in Icy Strait.
     Killer whales have about 12 sightings/season in Icy Strait 
and one or two sightings a year in Icy Passage.
     Humpback whale sightings in Icy Passage are infrequent but 
on occasion they are seen between the ferry terminal and Pleasant 
Island (Stephen Vanderhoff, SWE, personal communication).
    By most measures, the populations of marine mammals that utilize 
Icy Strait are healthy and increasing. Populations of humpback whales 
using Glacier Bay and surrounding areas are increasing by 5.1 percent 
per year (Hendrix et al. 2012). Steller sea lions have increased in the 
Glacier Bay region by 8.2 percent per year from the 1970's to 2009, 
representing the highest rate of growth for this species in Alaska 
(Mathews et al. 2011). In addition, a Steller sea lion rookery and 
several haulouts have recently been established in the Glacier Bay 
region (Womble et al. 2009).
    In the species accounts provided here, we offer a brief 
introduction to the species and relevant stock that are likely to be 
taken as well as available information regarding population trends and 
threats, and describe any information regarding local occurrence.

Harbor Seal

    Harbor seals occurring in Icy Passage belong to the Glacier Bay/Icy 
Strait (GB/IS) harbor seal stock. The current statewide abundance 
estimate for this stock is 7,210 (Muto and Angliss 2015). The GB/IS 
harbor seals have been rapidly declining despite stable or slightly 
increasing trends in nearby populations (Womble and Gende 2013). A 
suite of recent studies suggest that (1) harbor seals in Glacier Bay 
are not significantly stressed due to nutritional constraints, (2) the 
clinical health and disease status of seals within Glacier Bay is not 
different than seals from other stable or increasing populations, and 
(3) disturbance by vessels does not appear to be a primary factor 
driving the decline. Long-term monitoring of harbor seals on glacial 
ice has occurred in Glacier Bay since the 1970s and has shown this area 
to support one of the largest breeding aggregations in Alaska. After a 
dramatic retreat of Muir Glacier, in the East Arm of Glacier Bay, 
between 1973 and 1986 (more than 7 kilometers) and the subsequent 
grounding and cessation of calving in 1993, floating glacial ice was 
greatly reduced as a haulout substrate for harbor seals and ultimately 
resulted in the abandonment of upper Muir Inlet by harbor seals.

Steller Sea Lion

    Steller sea lions occurring in Icy Passage could belong to either 
the western or eastern U.S. stock. The current total population 
estimate for the western stock in Alaska is estimated at 49,497 based 
on 2014 survey results (Muto and Angliss 2015). To get this estimate, 
pups were counted during the breeding season, and the number of births 
is estimated from the pup count. The western stock in Alaska shows a 
positive population trend estimate of 1.67 percent.
    The current total population estimate for the eastern stock of 
Steller sea lions is estimated at 60,131 based on counts made between 
2009 and 2014 (Muto and Angliss 2015). To get this estimate, pups were 
counted during the breeding season, and the number of births is 
estimated from the pup count. The best available information indicates 
the eastern stock of Steller sea lion increased at a rate of 4.18 
percent per year (90 percent confidence bounds of 3.71 to 4.62 percent 
per year) between 1979 and 2010 based on an analysis of pup counts in 
California, Oregon, British Columbia, and Southeast Alaska.

Dall's Porpoise

    There are no reliable abundance data for the Alaska stock of Dall's 
porpoise. Surveys for the Alaska stock of Dall's porpoise are greater 
than 21 years old (Allen and Angliss 2014). A population estimate from 
1987 to 1991 was 83,400. Since the abundance estimate is based on data 
older than eight years, NMFS does not consider the estimate to be valid 
and the minimum population number is also considered unknown.

[[Page 40855]]

Harbor Porpoise

    There are three harbor porpoise stocks in Alaska, including the 
Southeast Alaska stock, Gulf of Alaska stock, and the Bering Sea stock. 
Only the Southeast Alaska stock occurs in the project vicinity. Harbor 
porpoise numbers for the Southeast Alaska stock are estimated at 11,146 
animals (Allen and Angliss 2014). Abundance estimates for harbor 
porpoise occupying the inland waters of Southeast Alaska were 1,081 in 
2012. However, this number may be biased low due to survey methodology.

Humpback Whale

    The central North Pacific stock of humpback whales occurs in the 
project area. Estimates of this stock are determined by winter surveys 
in Hawaiian waters. Point estimates of abundance for Hawaii ranged from 
7,469 to 10,252; the estimate from the best model was 10,252 (Muto and 
Angliss 2015). Using the population estimate of 10,252, the minimum 
estimate for the central North Pacific humpback whale stock is 9,896 
(Muto and Angliss 2015).
    Since 1985, the NPS has been monitoring humpback whales in both 
Glacier Bay National Park and Icy Strait and has published annual 
reports (https://www.nps.gov/glba/naturescience/whale_acoustic_reports.htm). The NPS typically surveys Icy Strait, 
located south of Icy Passage, once a week between June 1 and August 31, 
with most survey effort focused in the area east of Point Gustavus and 
Pleasant Island. In 2013, 202 humpback whales were documented in Icy 
Strait during the NPS monitoring period; this was a 14 percent increase 
over the previous high count of 177 whales in 2012 (Neilson et al., 
2014). However, in 2014, a 39 percent decrease in abundance was 
observed, with only 124 whales documented in Icy Strait. The reasons 
for this decline in local abundance is not known, but NPS speculated 
that a magnitude 6.1 earthquake centered in Palma Bay that occurred on 
July 25, 2014, may have caused unfavorable environmental conditions in 
the Glacier Bay region. The earthquake and aftershocks caused one or 
more submarine landslides that increased turbidity in the region and 
may have decreased humpback whale foraging success over a period of 
several weeks in lower Glacier Bay and Icy Strait. In response, 
humpback whales may have shifted their distribution to other areas, 
such as Frederick Sound, seeking better foraging conditions (Neilson et 
al., 2015).
    Humpback whales are present in Southeast Alaska in all months of 
the year, but at substantially lower numbers in the fall and winter. At 
least 10 individuals were found to over-winter near Sitka, and NMFS 
researchers have documented one whale that over-wintered near Juneau. 
It is unknown how common over-wintering behavior is in most areas 
because there is minimal or no photographic identification effort in 
the winter in most parts of Southeast Alaska. Late fall and winter 
whale habitat in Southeast Alaska appears to correlate with areas that 
have over-wintering herring (lower Lynn Canal, Tenakee Inlet, Whale 
Bay, Ketchikan, Sitka Sound). In Glacier Bay and Icy Strait, the 
longest sighting interval recorded by NPS was over a span of 219 days, 
between April 17 and November 21, 2002, but overwintering in this 
region is expected to be low (Gabriele et al., 2015).

Killer Whale

    Killer whales occurring in Icy Passage could belong to one of three 
different stocks: Eastern North Pacific Northern residents stock 
(Northern residents); Gulf of Alaska, Aleutian Islands, and Bering Sea 
transient stock (Gulf of Alaska transients); or West Coast transient 
stock. The Northern resident stock is a transboundary stock, and 
includes killer whales that frequent British Columbia, Canada, and 
southeastern Alaska (Allen and Angliss 2014). Photo-identification 
studies since 1970 have catalogued every individual belonging to the 
Northern resident stock and in 2010 the population was composed of 
three clans representing a total of 261 whales.
    In recent years, a small number of the Gulf of Alaska transients 
(identified by genetics and association) have been seen in southeastern 
Alaska; previously only West Coast transients had been seen in the 
region (Allen and Angliss 2014). Therefore, the Gulf of Alaska 
transient stock occupies a range that includes southeastern Alaska. 
Photo-identification studies have identified 587 individual whales in 
this stock.
    The West Coast transient stock includes animals that occur in 
California, Oregon, Washington, British Columbia, and southeastern 
Alaska. Analysis of photographic data identifies 243 individual 
transient killer whales (Muto and Angliss 2015). The total number of 
transient killer whales reported above should be considered a minimum 
count for the West Coast transient stock.

 Minke Whale

    The Alaska stock of minke whales occurs in Icy Strait and Southeast 
Alaska. At this time, it is not possible to produce a reliable estimate 
of minimum abundance for this wide ranging stock. No estimates have 
been made for the number of minke whales in the entire North Pacific. 
Surveys of the Bering Sea, and from Kenai Fjords in the Gulf of Alaska 
to the central Aleutian Islands, estimate 1,003 and 1,233 animals, 
respectively (Allen and Angliss 2014).

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
stressors, (e.g., pile driving) and potential mitigation activities, 
associated with the improvements at Gustavus Ferry Terminal may impact 
marine mammals and their habitat. The Estimated Take by Incidental 
Harassment section later in this document will include an analysis of 
the number of individuals that are expected to be taken by this 
activity. The Negligible Impact Analysis section will include the 
analysis of how this specific activity will impact marine mammals and 
will consider 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 this activity on the 
reproductive success or survivorship of individuals and from that on 
the affected marine mammal populations or stocks. In the following 
discussion, we provide general background information on sound and 
marine mammal hearing before considering potential effects to marine 
mammals from sound produced by impact and vibratory pile driving.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks of a sound wave; lower frequency sounds have 
longer wavelengths than higher frequency sounds and attenuate 
(decrease) more rapidly in shallower water. Amplitude is the height of 
the sound pressure wave or the loudness of a sound and is typically 
measured using the decibel (dB) scale. A dB is the ratio between a 
measured pressure (with sound) and a reference pressure (sound at a 
constant pressure, established by

[[Page 40856]]

scientific standards). It is a logarithmic unit that accounts for large 
variations in amplitude; therefore, relatively small changes in dB 
ratings correspond to large changes in sound pressure. When referring 
to sound pressure levels (SPLs; the sound force per unit area), the 
reference intensity for sound in water is one micropascal ([mu]Pa). One 
pascal is the pressure resulting from a force of one newton exerted 
over an area of one square meter. The source level (SL) represents the 
sound level at a distance of 1 m from the source (referenced to 1 
[mu]Pa). The received level is the sound level at the listener's 
position. Note that all underwater sound levels in this document are 
referenced to a pressure of 1 [mu]Pa and all airborne sound levels in 
this document are referenced to a pressure of 20 [mu]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    When underwater objects vibrate or activity occurs, sound pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. The 
compressions and decompressions associated with sound waves are 
detected as changes in pressure by aquatic life and man-made sound 
receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions.
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times.
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz.
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise for frequencies between 20 
and 300 Hz. In general, the frequencies of anthropogenic sounds are 
below 1 kHz and, if higher frequency sound levels are created, they 
attenuate rapidly (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound. Representative levels of anthropogenic sound are 
displayed in Table 3.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.

                          Table 3--Representative Sound Levels of Anthropogenic Sources
----------------------------------------------------------------------------------------------------------------
                                         Frequency
            Sound source                range (Hz)          Underwater sound level               Reference
----------------------------------------------------------------------------------------------------------------
Small vessels.......................       250-1,000  151 dB rms at 1 m.................  Richardson et al.,
                                                                                           1995.
Tug docking gravel barge............       200-1,000  149 dB rms at 100 m...............  Blackwell and Greene,
                                                                                           2002.
Vibratory driving of 72-in steel            10-1,500  180 dB rms at 10 m................  Reyff, 2007.
 pipe pile.
Impact driving of 36-in steel pipe          10-1,500  195 dB rms at 10 m................  Laughlin, 2007.
 pile.
Impact driving of 66-in cast-in-            10-1,500  195 dB rms at 10 m................  Reviewed in Hastings
 steel-shell (CISS) pile.                                                                  and Popper, 2005.
----------------------------------------------------------------------------------------------------------------

    High levels of vessel traffic are known to elevate background 
levels of noise in the marine environment. For example, continuous 
sounds for tugs pulling barges have been reported to range from 145 to 
166 dB re 1 [mu]Pa rms at 1 meter from the source (Miles et al., 1987; 
Richardson et al., 1995; Simmonds et al., 2004). Ambient underwater 
noise levels in Gustavus Ferry Terminal project area are both variable 
and relatively high, and are expected to

[[Page 40857]]

mask some sounds of pile installation and pile extraction.
    In-water construction activities associated with the project 
include impact and vibratory pile driving and removal. There are two 
general categories of sound types: Impulse and non-pulse (defined in 
the following). Vibratory pile driving is considered to be continuous 
or non-pulsed while impact pile driving is considered to be an impulse 
or pulsed sound type. The distinction between these two sound types is 
important because they have differing potential to cause physical 
effects, particularly with regard to hearing (e.g., Ward, 1997 in 
Southall et al., 2007). Please see Southall et al. (2007) for an in-
depth discussion of these concepts. Note that information related to 
impact hammers is included here for comparison.
    Pulsed sound sources (e.g., explosions, gunshots, sonic booms, 
impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) and 
occur either as isolated events or repeated in some succession. Pulsed 
sounds are all characterized by a relatively rapid rise from ambient 
pressure to a maximal pressure value followed by a rapid decay period 
that may include a period of diminishing, oscillating maximal and 
minimal pressures, and generally have an increased capacity to induce 
physical injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or non-continuous (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems (such as 
those used by the U.S. Navy). The duration of such sounds, as received 
at a distance, can be greatly extended in a highly reverberant 
environment.
    The likely or possible impacts of the proposed pile driving program 
at the Gustavus Ferry Terminal 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. 
Any impacts to marine mammals are expected to primarily be acoustic in 
nature. Acoustic stressors could include effects of heavy equipment 
operation and pile installation and pile removal at the Ferry Terminal.

Marine Mammal Hearing

    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms have been derived using 
auditory evoked potentials, anatomical modeling, and other data, 
Southall et al., (2007) designate ``functional hearing groups'' for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing of the groups. The functional groups and the 
associated frequencies are indicated below (though animals are less 
sensitive to sounds at the outer edge of their functional range and 
most sensitive to sounds of frequencies within a smaller range 
somewhere in the middle of their functional hearing range):
     Low-frequency cetaceans (mysticetes): Functional hearing 
is estimated to occur between approximately 7 Hz and 25 kHz (extended 
from 22 kHz; Watkins, 1986; Au et al., 2006; Lucifredi and Stein, 2007; 
Ketten and Mountain, 2009; Tubelli et al., 2012);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Functional hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; now considered to 
include two members of the genus Lagenorhynchus on the basis of recent 
echolocation data and genetic data [May-Collado and Agnarsson, 2006; 
Kyhn et al., 2009, 2010; Tougaard et al., 2010]): Functional hearing is 
estimated to occur between approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: Functional hearing is estimated to 
occur between approximately 75 Hz to 100 kHz for Phocidae (true seals) 
and between 100 Hz and 48 kHz for Otariidae (eared seals), with the 
greatest sensitivity between approximately 700 Hz and 20 kHz. The 
pinniped functional hearing group was modified from Southall et al., 
(2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth et al., 
2013).
    As mentioned previously in this document, seven marine mammal 
species (five cetacean and two pinniped) may occur in the project area. 
Of the seven species likely to occur in the proposed project area, two 
are classified as low frequency cetaceans (i.e., humpback whale, minke 
whale), one is classified as a mid-frequency cetacean (i.e., killer 
whale), and two are classified as high-frequency cetaceans (i.e., 
harbor porpoise, Dall's porpoise) (Southall et al., 2007). 
Additionally, harbor seals are classified as members of the phocid 
pinnipeds in water functional hearing group, while Steller sea lions 
are grouped under the Otariid pinnipeds in water functional hearing 
group. A species' functional hearing group is a consideration when we 
analyze the effects of exposure to sound on marine mammals.

Acoustic Impacts

    Potential Effects of Pile Driving Sound--The effects of sounds from 
pile driving might result in one or more of the following: Temporary or 
permanent hearing impairment; non-auditory physical or physiological 
effects; behavioral disturbance; and masking (Richardson et al., 1995; 
Gordon et al., 2004; Nowacek et al., 2007; Southall et al., 2007). The 
effects of pile driving on marine mammals are dependent on several 
factors, including: The size, type, and depth of the animal; the depth, 
intensity, and duration of the pile driving sound; the depth of the 
water column; the substrate of the habitat; the standoff distance 
between the pile and the animal; and the sound propagation properties 
of the environment. Impacts to marine mammals from pile driving 
activities are expected to result primarily from acoustic pathways. As 
such, the degree of effect is intrinsically related to the received 
level and duration of the sound exposure, which are in turn influenced 
by the distance between the animal and the source. The further away 
from the source, the less intense the exposure should be. The substrate 
and depth of the habitat affect the sound propagation properties of the 
environment. Shallow environments are typically more structurally 
complex, which leads to rapid sound attenuation. In addition, 
substrates that are soft (e.g., sand) would absorb or attenuate the 
sound more readily than hard substrates (e.g., rock) which may reflect 
the acoustic wave. Soft porous substrates would also likely require 
less time to drive the pile, and possibly less forceful equipment, 
which would ultimately decrease the intensity of the acoustic source.

[[Page 40858]]

    In the absence of mitigation, impacts to marine species would be 
expected to result from physiological and behavioral responses to both 
the type and strength of the acoustic signature (Viada et al., 2008). 
The type and severity of behavioral impacts are more difficult to 
define due to limited studies addressing the behavioral effects of 
impulse sounds on marine mammals. Potential effects from impulse sound 
sources can range in severity from effects such as behavioral 
disturbance or tactile perception to physical discomfort, slight injury 
of the internal organs and the auditory system, or mortality (Yelverton 
et al., 1973).
    Hearing Impairment and Other Physical Effects--Marine mammals 
exposed to high intensity sound repeatedly or for prolonged periods can 
experience hearing threshold shift (TS), which is the loss of hearing 
sensitivity at certain frequency ranges (Kastak et al., 1999; Schlundt 
et al., 2000; Finneran et al., 2002, 2005). TS can be permanent (PTS), 
in which case the loss of hearing sensitivity is not recoverable, or 
temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Marine mammals depend on 
acoustic cues for vital biological functions, (e.g., orientation, 
communication, finding prey, avoiding predators); thus, TTS may result 
in reduced fitness in survival and reproduction. However, this depends 
on the frequency and duration of TTS, as well as the biological context 
in which it occurs. TTS of limited duration, occurring in a frequency 
range that does not coincide with that used for recognition of 
important acoustic cues, would have little to no effect on an animal's 
fitness. Repeated sound exposure that leads to TTS could cause PTS. PTS 
constitutes injury, but TTS does not (Southall et al., 2007). The 
following subsections discuss in somewhat more detail the possibilities 
of TTS, PTS, and non-auditory physical effects.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises, and a sound 
must be stronger in order to be heard. In terrestrial mammals, TTS can 
last from minutes or hours to days (in cases of strong TTS). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
in both terrestrial and marine mammals recovers rapidly after exposure 
to the sound ends. Few data on sound levels and durations necessary to 
elicit mild TTS have been obtained for marine mammals, and none of the 
published data concern TTS elicited by exposure to multiple pulses of 
sound. Available data on TTS in marine mammals are summarized in 
Southall et al. (2007).
    Given the available data, the received level of a single pulse 
(with no frequency weighting) might need to be approximately 186 dB re 
1 [mu]Pa\2\-s (i.e., 186 dB sound exposure level (SEL) or approximately 
221-226 dB p-p (peak)) in order to produce brief, mild TTS. Exposure to 
several strong pulses that each have received levels near 190 dB rms 
(175-180 dB SEL) might result in cumulative exposure of approximately 
186 dB SEL and thus slight TTS in a small odontocete, assuming the TTS 
threshold is (to a first approximation) a function of the total 
received pulse energy.
    The above TTS information for odontocetes is derived from studies 
on the bottlenose dolphin (Tursiops truncatus) and beluga whale 
(Delphinapterus leucas). There is no published TTS information for 
other species of cetaceans. However, preliminary evidence from a harbor 
porpoise exposed to pulsed sound suggests that its TTS threshold may 
have been lower (Lucke et al., 2009). As summarized above, data that 
are now available imply that TTS is unlikely to occur unless 
odontocetes are exposed to pile driving pulses stronger than 180 dB re 
1 [mu]Pa (rms).
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, while in other cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985). There is no specific evidence that exposure to pulses of sound 
can cause PTS in any marine mammal. However, given the possibility that 
mammals close to a sound source can incur TTS, it is possible that some 
individuals might incur PTS. Single or occasional occurrences of mild 
TTS are not indicative of permanent auditory damage, but repeated or 
(in some cases) single exposures to a level well above that causing TTS 
onset might elicit PTS.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS, however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals, based on anatomical similarities. PTS might 
occur at a received sound level at least several dB above that inducing 
mild TTS if the animal were exposed to strong sound pulses with rapid 
rise time. Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS threshold for impulse sounds (such as pile 
driving pulses as received close to the source) is at least 6 dB higher 
than the TTS threshold on a peak-pressure basis and probably greater 
than 6 dB (Southall et al., 2007). On an SEL basis, Southall et al., 
(2007) estimated that received levels would need to exceed the TTS 
threshold by at least 15 dB for there to be risk of PTS. Thus, for 
cetaceans, Southall et al., (2007) estimate that the PTS threshold 
might be an M-weighted SEL (for the sequence of received pulses) of 
approximately 198 dB re 1 [mu]Pa\2\-s (15 dB higher than the TTS 
threshold for an impulse). Given the higher level of sound necessary to 
cause PTS as compared with TTS, it is considerably less likely that PTS 
could occur.
    Measured source levels from impact pile driving can be as high as 
214 dB rms. Although no marine mammals have been shown to experience 
TTS or PTS as a result of being exposed to pile driving activities, 
captive bottlenose dolphins and beluga whales exhibited changes in 
behavior when exposed to strong pulsed sounds (Finneran et al., 2000, 
2002, 2005). The animals tolerated high received levels of sound before 
exhibiting aversive behaviors. Experiments on a beluga whale showed 
that exposure to a single watergun impulse at a received level of 207 
kPa (30 psi) p-p, which is equivalent to 228 dB p-p, resulted in a 7 
and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. 
Thresholds returned to within 2 dB of the pre-exposure level within 
four minutes of the exposure (Finneran et al., 2002). Although the 
source level of pile driving from one hammer strike is expected to be 
much lower than the single watergun impulse cited here, animals being 
exposed for a prolonged period to repeated hammer strikes could receive 
more sound exposure in terms of SEL than from the single watergun 
impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the aforementioned 
experiment (Finneran et al., 2002). However, in order for marine 
mammals to experience TTS or PTS, the animals have to be close enough 
to be exposed to high intensity sound levels for a prolonged period of 
time. Based on the best scientific information available,

[[Page 40859]]

these SPLs are far below the thresholds that could cause TTS or the 
onset of PTS.
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. In general, little is known about 
the potential for pile driving to cause auditory impairment or other 
physical effects in marine mammals. Available data suggest that such 
effects, if they occur at all, would presumably be limited to short 
distances from the sound source and to activities that extend over a 
prolonged period. The available data do not allow identification of a 
specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. Marine mammals that show behavioral avoidance 
of pile driving, including some odontocetes and some pinnipeds, are 
especially unlikely to incur auditory impairment or non-auditory 
physical effects.

Disturbance Reactions

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous changes in activities, and displacement. 
Behavioral responses to sound are highly variable and context-specific 
and reactions, if any, depend on species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day, and many other factors (Richardson et al., 1995; Wartzok 
et al., 2003; Southall et al., 2007).
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. Behavioral state may affect the type of response as well. For 
example, animals that are resting may show greater behavioral change in 
response to disturbing sound levels than animals that are highly 
motivated to remain in an area for feeding (Richardson et al., 1995; 
NRC, 2003; Wartzok et al., 2003).
    Controlled experiments with captive marine mammals showed 
pronounced behavioral reactions, including avoidance of loud sound 
sources (Ridgway et al., 1997; Finneran et al., 2003). Observed 
responses of wild marine mammals to loud pulsed sound sources 
(typically seismic guns or acoustic harassment devices, but also 
including pile driving) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds, 2002; Thorson and Reyff, 2006; see also Gordon et al., 2004; 
Wartzok et al., 2003; Nowacek et al., 2007). Responses to continuous 
sound, such as vibratory pile installation, have not been documented as 
well as responses to pulsed sounds.
    With both types of pile driving, it is likely that the onset of 
pile driving could result in temporary, short term changes in an 
animal's typical behavior and/or avoidance of the affected area. These 
behavioral changes may include (Richardson et al., 1995): Changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities; 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where sound sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haul-outs or rookeries). Pinnipeds 
may increase their haul-out time, possibly to avoid in-water 
disturbance (Thorson and Reyff, 2006).
    The biological significance of many of these behavioral 
disturbances is difficult to predict. However, the consequences of 
behavioral modification could be expected to be biologically 
significant if the change affects growth, survival, or reproduction. 
Significant behavioral modifications that could potentially lead to 
effects on growth, survival, or reproduction include:
     Changes in diving/surfacing patterns;
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic sound 
depends on both external factors (characteristics of sound sources and 
their paths) and the specific characteristics of the receiving animals 
(hearing, motivation, experience, demography) and is difficult to 
predict (Southall et al., 2007).
    Auditory Masking--Natural and artificial sounds can disrupt 
behavior by masking, or interfering with, a marine mammal's ability to 
hear other sounds. Masking occurs when the receipt of a sound is 
interfered with by another coincident sound at similar frequencies and 
at similar or higher levels. Chronic exposure to excessive, though not 
high-intensity, sound could cause masking at particular frequencies for 
marine mammals that utilize sound for vital biological functions. 
Masking can interfere with detection of acoustic signals such as 
communication calls, echolocation sounds, and environmental sounds 
important to marine mammals. It is important to distinguish TTS and 
PTS, which persist after the sound exposure, from masking, which occurs 
only during the sound exposure. Because masking (without resulting in 
TS) is not associated with abnormal physiological function, it is not 
considered a physiological effect, but rather a potential behavioral 
effect.
    Masking occurs at specific frequency bands, so understanding the 
frequencies that the animals utilize is important in determining any 
potential behavioral impacts. Because sound generated from in-water 
vibratory pile driving is mostly concentrated at low frequency ranges, 
it may have less effect on high frequency echolocation sounds made by 
porpoises. However, lower frequency man-made sounds are more likely to 
affect detection of communication calls and other potentially important 
natural sounds, such as surf and prey sound. It may also affect 
communication signals when they occur near the sound band and thus 
reduce the communication space of animals (e.g., Clark et al., 2009) 
and cause increased stress levels (e.g., Foote et al., 2004; Holt et 
al., 2009).
    Masking has the potential to impact species at the population or 
community levels as well as at individual levels. Masking affects both 
senders and receivers of the signals and can potentially in certain 
circumstances have long-term chronic effects on marine mammal species 
and populations. Recent research suggests that low frequency ambient 
sound levels have increased by as much as 20 dB (more than three times 
in terms of SPL) in the world's ocean from pre-industrial periods, and 
that most of these increases are from distant shipping (Hildebrand, 
2009). All anthropogenic sound sources, such as those from vessel 
traffic, pile driving, and dredging activities, contribute to the 
elevated ambient sound levels, thus intensifying masking.
    Vibratory pile driving may potentially mask acoustic signals 
important to marine mammal species. However, the short-term duration 
and limited affected

[[Page 40860]]

area would result in insignificant impacts from masking.
    Acoustic Effects, Airborne--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
that have the potential to cause behavioral harassment, depending on 
their distance from pile driving activities. Cetaceans are not expected 
to be exposed to airborne sounds that would result in harassment as 
defined under the MMPA.
    Airborne noise will primarily be an issue for pinnipeds that are 
swimming at the surface or hauled out near the project site within the 
range of noise levels elevated above the acoustic criteria in Table 4 
below. We recognize that pinnipeds in the water could be exposed to 
airborne sound that may result in behavioral harassment when looking 
with heads above water. Most likely, airborne sound would cause 
behavioral responses similar to those discussed above in relation to 
underwater sound. 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 as a result of exposure to underwater sound 
above the behavioral harassment thresholds, which are in all cases 
larger than those associated with airborne sound. Thus, the behavioral 
harassment of these animals is already accounted for in these estimates 
of potential take. Multiple incidents of exposure to sound above NMFS' 
thresholds for behavioral harassment are not believed to result in 
increased behavioral disturbance, in either nature or intensity of 
disturbance reaction. Therefore, we do not believe that authorization 
of incidental take resulting from airborne sound for pinnipeds is 
warranted, and airborne sound is not discussed further here.

Vessel Interaction

    Besides being susceptible to vessel strikes, cetacean and pinniped 
responses to vessels may result in behavioral changes, including: 
Greater variability in the dive, surfacing, and respiration patterns; 
changes in vocalizations; and changes in swimming speed or direction 
(NRC, 2003). There will be a temporary and localized increase in vessel 
traffic during construction.

Potential Effects on Marine Mammal Habitat

    The primary potential impacts to marine mammal habitat are 
associated with elevated sound levels produced by vibratory and impact 
pile driving and removal in the area. However, other potential impacts 
to the surrounding habitat from physical disturbance are also possible.
    Potential Pile Driving Effects on Prey--Construction activities 
would produce continuous (i.e., vibratory pile driving, down-hole 
drilling) sounds and pulsed (i.e., impact driving) sounds.
    Fish react to sounds that are especially strong and/or intermittent 
low-frequency sounds. Short duration, sharp sounds can cause overt or 
subtle changes in fish behavior and local distribution. Hastings and 
Popper (2005) identified several studies that suggest fish may relocate 
to avoid certain areas of sound energy. Additional studies have 
documented effects of pile driving on fish, although several are based 
on studies in support of large, multiyear bridge construction projects 
(e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Sound 
pulses at received levels of 160 dB may cause subtle changes in fish 
behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient 
strength have been known to cause injury to fish and fish mortality.
    The most likely impact to fish from pile driving activities at the 
project area would be temporary behavioral avoidance 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. In general, impacts to marine mammal prey 
species are expected to be minor and temporary due to the short 
timeframe for the project.
    Effects to Foraging Habitat--Pile installation may temporarily 
increase turbidity resulting from suspended sediments. Any increases 
would be temporary, localized, and minimal. ADOT&PF must comply with 
state water quality standards during these operations by limiting the 
extent of turbidity to the immediate project area. In general, 
turbidity associated with pile installation is localized to about a 25-
foot radius around the pile (Everitt et al., 1980). Cetaceans are not 
expected to be close enough to the project pile driving areas to 
experience effects of turbidity, and any pinnipeds will be transiting 
the area and could avoid localized areas of turbidity. Therefore, the 
impact from increased turbidity levels is expected to be discountable 
to marine mammals. Furthermore, pile driving and removal at the project 
site will not obstruct movements or migration of marine mammals.

Proposed Mitigation Measures

    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, 
their habitat. 50 CFR 216.104(a)(11). For the proposed project, ADOT&PF 
worked with NMFS and proposed the following mitigation measures to 
minimize the potential impacts to marine mammals in the project 
vicinity. The primary purposes of these mitigation measures are to 
minimize sound levels from the activities, and to shut down operations 
and monitor marine mammals within designated zones of influence 
corresponding to NMFS' current Level A and B harassment thresholds, 
which are depicted in Table 5 found later in the Estimated Take by 
Incidental Harassment section.
    In addition to the measures described later in this section, 
ADOT&PF would employ the following standard mitigation measures:
    (a) Conduct briefings between construction supervisors and crews, 
and marine mammal monitoring team, prior to the start of all pile 
driving activity, and when new personnel join the work, in order to 
explain responsibilities, communication procedures, marine mammal 
monitoring protocol, and operational procedures.
    (b) For in-water heavy machinery work other than pile driving 
(e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), 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)

[[Page 40861]]

positioning of the pile on the substrate via a crane (i.e., stabbing 
the pile).
    (c) To limit the amount of waterborne noise, a vibratory hammer 
will be used for initial driving, followed by an impact hammer to proof 
the pile to required load-bearing capacity.
    Establishment of Shutdown Zone--For all pile driving activities, 
ADOT&PF will establish a shutdown zone. Shutdown zones are intended to 
contain the area in which SPLs equal or exceed the 180/190 dB (rms) 
acoustic injury threshold, with the purpose being to define an area 
within which shutdown of activity would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area), 
thus preventing injury of marine mammals. Nominal radial distances for 
shutdown zones are shown in Table 5.
    Establishment of Disturbance Zone or Zone of Influence--Disturbance 
zones or zones of influence (ZOI) are the areas in which SPLs equal or 
exceed 160 dB rms for impact driving and 120 dB rms for vibratory 
driving. Disturbance zones provide utility for monitoring by 
establishing monitoring protocols for areas adjacent to the shutdown 
zones. Monitoring of disturbance zones enables observers to be aware of 
and communicate the presence of marine mammals in the project area but 
outside the shutdown zone and thus prepare for potential shutdowns of 
activity. However, the primary purpose of disturbance zone monitoring 
is for documenting incidents of Level B harassment; disturbance zone 
monitoring is discussed in greater detail later (see ``Proposed 
Monitoring and Reporting''). Nominal radial distances for disturbance 
zones are shown in Table 5. We discuss monitoring objectives and 
protocols in greater depth in ``Proposed Monitoring and Reporting.''
    Soft Start--The use of a soft-start procedure is 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. Soft-start techniques for impact 
pile driving will be conducted in accordance with the Anchorage Fish 
and Wildlife Field Office (AFWFO, 2012) Observer Protocols. For impact 
pile driving, contractors will be required to provide an initial set of 
strikes from the hammer at 40 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.

Mitigation Conclusions

    We have carefully evaluated ADOT&PF's proposed mitigation measures 
and considered their effectiveness in past implementation to determine 
whether they are likely to effect the least practicable impact on the 
affected marine mammal species and stocks and their habitat. Our 
evaluation of potential measures included consideration of the 
following factors in relation to one another: (1) The manner in which, 
and the degree to which, the successful implementation of the measure 
is expected to minimize adverse impacts to marine mammals, (2) the 
proven or likely efficacy of the specific measure to minimize adverse 
impacts as planned; and (3) the practicability of the measure for 
applicant implementation.
    Any mitigation measure(s) we prescribe should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    (2) A reduction in the number (total number or number at 
biologically important time or location) of individual marine mammals 
exposed to stimuli expected to result in incidental take (this goal may 
contribute to 1 above).
    (3) A reduction in the number (total number or number at 
biologically important time or location) of times any individual marine 
mammal would be exposed to stimuli expected to result in incidental 
take (this goal may contribute to 1 above).
    (4) A reduction in the intensity of exposure to stimuli expected to 
result in incidental take (this goal may contribute to 1 above).
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying particular attention to the prey base, blockage or 
limitation of passage to or from biologically important areas, 
permanent destruction of habitat, or temporary disturbance of habitat 
during a biologically important time.
    (6) For monitoring directly related to mitigation, an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of ADOT&PF's proposed measures, including 
information from monitoring of implementation of mitigation measures 
very similar to those described here under previous IHAs from other 
marine construction projects, we have determined that the proposed 
mitigation measures provide the means of effecting the least 
practicable impact on marine mammal 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 
incidental take authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present in the proposed action area. ADOT&PF submitted a marine mammal 
monitoring plan as part of the IHA application. It can be found in 
Appendix B of the Application. The plan may be modified or supplemented 
based on comments or new information received from the public during 
the public comment period.
    Any monitoring requirement we prescribe should improve our 
understanding of one or more of the following:
     Occurrence of marine mammal species in action area 
(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 responses to acute stressors, or impacts of 
chronic exposures (behavioral or physiological).
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of an individual; or (2) Population, 
species, or stock.
     Effects on marine mammal habitat and resultant impacts to 
marine mammals.
     Mitigation and monitoring effectiveness.

[[Page 40862]]

Proposed Monitoring Measures

    Monitoring Protocols--Monitoring will be conducted by qualified 
marine mammal observers (MMO), who are trained biologists, with the 
following minimum qualifications:
    (a) 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 spotting 
scopes and binoculars may be necessary to correctly identify the 
target.
    (b) Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience).
    (c) Experience or training in the field identification of marine 
mammals (cetaceans and pinnipeds).
    (d) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations.
    (e) Writing skills sufficient to prepare a report of observations 
that would include such information as the number and type of marine 
mammals observed; the behavior of marine mammals in the project area 
during construction; dates and times when observations were conducted; 
dates and times when in-water construction activities were conducted; 
dates and times when marine mammals were present at or within the 
defined disturbance or injury zones; dates and times when in-water 
construction activities were suspended to avoid injury from 
construction noise; etc.
    (f) 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.
    In order to effectively monitor the pile driving monitoring zones, 
the MMO will be positioned at the best practical vantage point. The 
monitoring position may vary based on pile driving activities and the 
locations of the piles and driving equipment. These may include the 
catwalk at the ferry terminal, the contractor barge, or another 
location deemed to be more advantageous. The monitoring location will 
be identified with the following characteristics: 1. Unobstructed view 
of pile being driven; 2. Unobstructed view of all water within a 1.9 km 
(vibratory driving) and 1.6 km (impact driving) radius of each pile; 3. 
Clear view of pile-driving operator or construction foreman in the 
event of radio failure; and 4. Safe distance from pile driving 
activities in the construction area.
    A single MMO will be situated on the Ferry Terminal to monitor the 
appropriate injury and behavioral disturbance zones during all pile 
driving activities. Because the action area for vibratory driving 
disturbance extends for 1.9 kilometers from the Gustavus Ferry Terminal 
into Icy Strait/Passage, it would be difficult to monitor this area 
effectively with only terminal-based MMOs. Due to potentially severe 
and highly unpredictable weather conditions, ADOT&PF has concluded that 
the use of Pleasant Island-based, mainland-based, or vessel-based MMOs 
would be infeasible and, in many circumstances, unsafe. However, when 
possible, ADOT&PF will augment land-based monitoring with information 
from boats in Icy Strait/Passage. Specifically, the MMO will coordinate 
with the NPS and whale-watching charters for recent observations of 
marine mammals within Icy Strait/Passage. This will help inform the MMO 
of marine mammals in the area. NPS and whale-watching charters could 
also inform monitoring personnel of any marine mammals seen approaching 
the disturbance zone. The MMO will conduct telephone checks with NPS 
and whale-watching charters to monitor the locations of humpback whales 
and Steller sea lions, which are listed under the Endangered Species 
Act, within Icy Strait/Passage. Checks will begin three days before 
pile-driving operations to ascertain the location and movements of 
these listed species in relation to the disturbance zones. Once 
construction has begun, checks will be made in the evening after the 
completion of pile driving activities, in preparation of the next day's 
monitoring. Use of the organizations identified above to augment 
monitoring efforts will depend on their observation schedules and 
locations within the Glacier Bay region. It is expected that these 
organizations will only be active in May and September during the pile-
driving season.
    The following additional measures apply to visual monitoring:
     Monitoring will begin 30 minutes prior to pile driving. 
This will ensure that all marine mammals in the monitoring zone are 
documented and that no marine mammals are present in the injury zone;
     If a marine mammal comes within or approaches the shutdown 
zone, such operations shall cease. Pile driving will only commence once 
observers have declared the shutdown zone clear of marine mammals. 
Their behavior will be monitored and documented. The shutdown zone may 
only be declared clear, and pile driving started, when the entire 
shutdown zone is visible (i.e., when not obscured by dark, rain, fog, 
etc.);
     When a marine mammal is observed, its location will be 
determined using a rangefinder to verify distance and a GPS or compass 
to verify heading;
     If any cetaceans or pinnipeds are observed approaching 
injury zones, impact pile-driving activities will be immediately 
halted. The MMO will immediately radio to alert the contractor and 
raise a red flag, requiring an immediate ``all-stop.'' Impact pile-
driving activities will resume when the animal is no longer proximal to 
the injury zone or 30 minutes have passed without re-sighting the 
animal near the zone. The observer will continue to monitor the animal 
until it has left the larger disturbance zones;
     The MMOs will record any cetacean or pinniped present in 
the disturbance zone;
     MMOs will record all harbor seals present in the in-air 
disturbance zone. This applies to animals that are hauled out and those 
that have surfaced while swimming;
     At the end of the pile-driving day, post-construction 
monitoring will be conducted for 30 minutes beyond the cessation of 
pile driving;
     If any cetaceans or pinnipeds are observed approaching the 
10-meter exclusion zone, heavy equipment activities will be immediately 
halted. The observer will immediately radio to alert the contractor and 
raise a red flag, requiring an immediate ``all-stop.'' Observers will 
continue to monitor the animal after it has left the injury zone, if 
visible;
     If any marine mammal species are encountered during 
activities that are not listed in Table 1 for authorized taking and are 
likely to be exposed to SPLs greater than or equal to 160 dB re 1 
[mu]Pa (rms) for impact driving and 120 dB re 1 [mu]Pa (rms), then the 
Holder of this Authorization must stop pile driving activities and 
report observations to NMFS' Office of Protected Resources;
     If waters exceed a sea-state which restricts the 
observers' ability to make observations within the marine mammal 
shutdown zone (e.g., excessive wind or fog), pile installation will 
cease. Pile driving will not be initiated until the entire shutdown 
zone is visible;
     Work would occur only during daylight hours, when visual 
monitoring of marine mammals can be conducted; and
     Pile driving in September or May will end by approximately 
5:00 p.m. local time to avoid the late afternoon period when most 
fishing charters return to the public dock adjacent to the Ferry 
Terminal. This is also the time of

[[Page 40863]]

day when most sea lions are attracted to the Ferry Terminal, due to 
fish processing activities; therefore, shutting down construction 
operations at this time will help to avoid take of sea lions.

Data Collection

    Observers are required to use approved data forms. Among other 
pieces of information, ADOT&PF will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the ADOT&PF will attempt 
to distinguish between the number of individual animals taken and the 
number of incidents of take. At a minimum, the following information 
will be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    ADOT&PF will notify NMFS prior to the initiation of the pile 
driving activities and will provide NMFS with a draft monitoring report 
within 90 days of the conclusion of the proposed construction work. 
This report will detail the monitoring protocol, summarize the data 
recorded during monitoring, and estimate the number of marine mammals 
that may have been harassed. If no comments are received from NMFS 
within 30 days of submission of the draft final report, the draft final 
report will constitute the final report. If comments are received, a 
final report must be submitted within 30 days after receipt of 
comments.

Estimated Take by Incidental Harassment

    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].''
    All anticipated takes would be by Level B harassment resulting from 
vibratory and impact pile driving and involving temporary changes in 
behavior. The proposed mitigation and monitoring measures are expected 
to minimize the possibility of injurious or lethal takes such that take 
by Level A harassment, serious injury, or mortality is considered 
discountable. However, it is unlikely that injurious or lethal takes 
would occur even in the absence of the planned mitigation and 
monitoring measures.
    Given the many uncertainties in predicting the quantity and types 
of impacts of sound on marine mammals, it is common practice to 
estimate how many animals are likely to be present within a particular 
distance of a given activity, or exposed to a particular level of 
sound.
    ADOT&PF has requested authorization for the incidental taking of 
small numbers of marine mammals near the Gustavus Ferry Terminal that 
may result from impact pile driving, vibratory pile driving and 
vibratory pile removal. In order to estimate the potential incidents of 
take that may occur incidental to the specified activity, we must first 
estimate the extent of the sound field that may be produced by the 
activity and then consider in combination with information about marine 
mammal density or abundance in the project area. We first provide 
information on applicable sound thresholds for determining effects to 
marine mammals before describing the information used in estimating the 
sound fields, the available marine mammal density or abundance 
information, and the method of estimating potential incidences of take.

Sound Thresholds

    We use the generic sound exposure thresholds shown in Table 4 to 
determine when an activity that produces underwater sound might result 
in impacts to a marine mammal such that a take by harassment might 
occur.

             Table 4--Underwater Injury and Disturbance Threshold Decibel Levels for Marine Mammals
----------------------------------------------------------------------------------------------------------------
              Criterion                     Criterion definition                      Threshold *
----------------------------------------------------------------------------------------------------------------
Level A harassment...................  PTS (injury) conservatively    190 dB rms for pinnipeds.
                                        based on TTS **.              180 dB rms for cetaceans.
Level B harassment...................  Behavioral disruption for      160 dB rms.
                                        impulse noise (e.g., impact
                                        pile driving).
Level B harassment...................  Behavioral disruption for non- 120 dB rms.
                                        pulse noise (e.g., vibratory
                                        pile driving, drilling).
----------------------------------------------------------------------------------------------------------------
* All decibel levels referenced to 1 [mu]Pa. Note all thresholds are based off root mean square (rms) levels.
** PTS=Permanent Threshold Shift; TTS=Temporary Threshold Shift.

Distance to Sound Thresholds

    The sound field in the project area is the existing ambient noise 
plus additional construction noise from the proposed project. The 
primary components of the project expected to affect marine mammals are 
the sounds generated by impact pile driving, vibratory pile driving, 
and vibratory pile removal.
    In order to calculate the Level A and Level B sound thresholds, 
ADOT&PF used acoustic monitoring data for this project that had been 
collected at the Kake Ferry Terminal, located approximately 115 miles 
south of the project area (MacGillvray et al., 2015; Appendix A). 
ADOT&PF provided a comprehensive analysis describing how the Kake Ferry 
Terminal data provides a more accurate representation of underwater 
noise than the California-based dataset that NMFS usually recommends.
    The Gustavus Ferry Terminal improvement project proposes to use

[[Page 40864]]

24- and 30-inch-diameter steel piles for most project support 
components. According to data collected from the Kake Ferry Terminal 
(MacGillvray et al., 2015; Appendix A) and WSDOT (Laughlin 2010; WSDOT 
2014), piles of this size generate similar levels of waterborne noise. 
The sound levels selected to calculate impact zones are as follows:

 Waterborne noise: 193.2 dB rms for impact driving and 154.3 dB 
rms for vibratory driving
    The formula below is used to calculate underwater sound 
propagation. Transmission loss (TL) is the decrease in acoustic 
intensity as an acoustic pressure wave propagates out from a source. TL 
parameters vary with frequency, temperature, sea conditions, current, 
source and receiver depth, water depth, water chemistry, and bottom 
composition and topography. The general formula for underwater TL is:

TL = B * log 10 (R 1/R 2)

Where:

TL = transmission loss in dB
B = wave mode coefficient; for practical spreading equals 15
R 1 = the distance of the modeled SPL from the driven 
pile, and
R 2 = the distance from the driven pile of the initial 
measurement.

    NMFS typically recommends a default practical spreading loss of 15 
dB per tenfold increase in distance. ADOT&PF analyzed the available 
underwater acoustic data utilizing the practical spreading loss model.
    The practical spreading loss model estimates small injury zones for 
whales (76 m) and pinnipeds (16 m) for pulsed sound generated by piles 
driven by an impact pile driver within the project area. The 
disturbance zone for impact pile driving is larger, at approximately 
1.6 km from the driven pile for all marine mammals. The disturbance 
zone for continuous noise generated by a vibratory hammer is similar, 
predicted to extend for 1.9 km from the pile to an ambient background 
level of 120 dB. For airborne sound, the Level B disturbance threshold 
is calculated at 163 m for harbor seals and 51 m for other pinnipeds 
during impact driving and 36 m for harbor seals during vibratory 
driving. The selected sound level of 97 dB for vibratory driving is 
below the 100 dB disturbance threshold for other pinnipeds, so there is 
no disturbance zone for other pinniped species.

                                     Table 5--Impact Zones of Marine Mammals
----------------------------------------------------------------------------------------------------------------
                                                          Distance to criterion (meters)
                                 -------------------------------------------------------------------------------
                                                                 Waterborne noise
        Pile driver type         -------------------------------------------------------------------------------
                                     Marine mammal                                             Continuous noise
                                   disturbance  (160    Cetacean injury     Pinniped injury    disturbance  (120
                                      dB)/Level B      (180 dB)/Level A    (190 dB)/Level A       dB)/Level B
----------------------------------------------------------------------------------------------------------------
Impact..........................               1,634                  76                  16  ..................
Vibratory.......................  ..................  ..................  ..................               1,935
----------------------------------------------------------------------------------------------------------------

    Note that the actual area ensonified by pile driving activities is 
significantly constrained by local topography relative to the total 
threshold radius. The actual ensonified area was determined using a 
straight line-of-sight projection from the anticipated pile driving 
locations. Distances to the underwater sound isopleths for Level B and 
Level A are illustrated respectively in Figure 2 and Figure 3 in the 
Application.
    The method used for calculating potential exposures to impact and 
vibratory pile driving noise for each threshold uses local marine 
mammal data sets and data from IHA estimates on similar projects with 
similar actions. All estimates are conservative and include the 
following assumptions:
     All pilings installed at each site would have an 
underwater noise disturbance equal to the piling that causes the 
greatest noise disturbance (i.e., the piling furthest from shore) 
installed with the method that has the largest ZOI. The largest 
underwater disturbance ZOI would be produced by vibratory driving steel 
and timber piles. The ZOIs for each threshold are not spherical and are 
truncated by land masses on either side of the channel which would 
dissipate sound pressure waves; and
     Exposures were based on estimated work days. Between 16 
and 50 work days of pile driving and removal will be required for the 
proposed project. NMFS will assume that a full 50 days are required to 
complete pile driving and removal activities.
    The calculation for marine mammal exposures, except for Dall's 
porpoise and killer whales, was estimated using the following:

Exposure estimate = N (number of animals exposed above disturbance 
threshold) x no. of days of pile driving/removal activity.

    The methods for the calculation of exposures for Dall's porpoise 
and killer whales is described under those respective species below.

Harbor Seal

    There are no documented haulout sites for harbor seals in the 
vicinity of the project. The nearest haulouts, rookeries, and pupping 
grounds occur in Glacier Bay over 20 miles from the ferry terminal. 
However, occasionally an individual will haul out on rocks on the north 
side of Pleasant Island (Stephen Vanderhoff, SWE, personal 
communication). A recent study of post-breeding harbor seal migrations 
from Glacier Bay demonstrates that some harbor seals traveled 
extensively beyond the boundaries of Glacier Bay during the post-
breeding season (Womble and Gende 2013). Strong fidelity of individuals 
for haulout sites during the breeding season was documented in this 
study as well.
    Harbor seals have declined dramatically in Glacier Bay region over 
the past few decades which may be a reason why there are few 
observations at the Gustavus Ferry Terminal. Sightings of harbor seals 
around the ferry terminal used to be more common (Stephen Vanderhoff, 
SWE, personal communication). NPS has documented one harbor seal 
observation near the terminal. It is estimated that less than 10 
individuals are seen near the ferry dock during charter boat operations 
from mid- to late-May through September (Tod Sebens, CSE, Stephen 
Vanderhoff, SWE, Bruce Kruger, ADF&G, personal communication). Harbor 
seals are also documented in Icy Passage in the winter and early spring 
(Womble and Gende 2013).
    For this analysis, we take a conservative estimate and assume that 
four harbor seals could be present on any day of pile driving 
regardless of when the pile driving is conducted (Spring and Fall 
2017). Two seals would

[[Page 40865]]

be subject would be exposed to underwater noise. Therefore, it is 
estimated that the following number of harbor seals may be present in 
the disturbance zone:
     Underwater exposure estimate: 4 animals x 50 days of pile 
activity = 200.
    NMFS proposes authorization for 200 Level B acoustical harassment 
takes of harbor seals. It is likely that one or more animals will be 
taken on repeated or subsequent days. Therefore, the number of 
individual animals taken will likely be less than 200.

Steller Sea lion

    There are numerous Steller sea lion haulouts in Icy Strait but none 
occurring in Icy Passage (Mathews et al., 2011; Tod Sebens, CSE, 
Stephen Vanderhoff, SWE, Janet Neilson, NPS, personal communication). 
The nearest Steller sea lion haulout sites are located on Black Rock on 
the south side of Pleasant Island and Point Carolus west across the 
strait from Point Gustavus (Mathews et al., 2011). Both haulouts are 
over 16 km from the Gustavus ferry terminal.
    Steller sea lions are common in the ferry terminal area during the 
charter fishing season (May to September) and are known to haul out on 
the public dock (Tod Sebens, CSE, Stephen Vanderhoff, SWE, Janet 
Neilson, NPS, personal communication Bruce Kruger, ADF&G, personal 
communication). During the charter fishing season, Steller sea lions 
begin arriving at the ferry terminal as early as 2:00 p.m. local time, 
reaching maximum abundance when the charter boats return at 
approximately 5:00 p.m. local time. The sea lions forage on the 
carcasses of the sport fish catch and then vacate the area. For the 
sake of our analysis we propose at least 10 animals will be present 
every day during charter fishing season. Outside of the charter fishing 
season, it is assumed that two Steller sea lions may transit in front 
of the ferry terminal to and from foraging grounds.
    For the purpose of our analysis we conservatively estimate that two 
Steller sea lions will transit within the disturbance zones each day 
during the months of October and November of 2017 as well as March and 
April of 2018. We estimate, conservatively, that up to 10 individuals 
may be present each day in the months of September 2017 and May 2018 
during the charter fishing season.
    We also assume that 33 total combined days of pile driving/removal 
will occur in October and November, 2017 as well as in March and April, 
2018. Seventeen combined driving days will occur in September, 2017 and 
May, 2018. Using these estimates we calculate the following number of 
Steller sea lions may be present in the disturbance zone:

 October 2017, November 2017, March 2018 and April 2018 
underwater exposure estimate: 2 animals x 33 days of pile activity = 66
 September 2017 and May 2018 underwater exposure estimate: 10 
animals x 17 days of pile activity = 170

    The underwater take estimate for March through November is 236 
animals. NMFS proposes authorization for 236 Level B acoustical 
harassment takes of Steller sea lions. Note that a small number of 
Steller sea lions (up to five) may have become habituated to human 
activity and, therefore, it is highly likely that there will be 
numerous repeated takes of these same animals. (Kruger, ADF&G, personal 
communication).

Dall's Porpoise

    Dall's porpoise are documented in Icy Strait but not Icy Passage. 
Dahlheim et al., (2009) found Dall's porpoise throughout Southeast 
Alaska, with concentrations of animals consistently found in Icy 
Strait, Lynn Canal, Stephens Passage, upper Chatham Strait, Frederick 
Sound, and Clarence Strait. It is estimated that there are anywhere 
from four to 12 sightings of Dall's porpoise in Icy Strait per season 
during the May through September whale watching charter months (Tod 
Sebens, CSE, Stephen Vanderhoff, SWE, personal communication). NPS 
documented seven sightings in Icy Strait since 1993 in September, 
October, November, April, and May. Six of the seven sightings are of 
pods with less than 10 individuals. The mean group size of Dall's 
porpoise in Southeast Alaska is estimated at three individuals 
(Dahlheim et al., 2009).
    Based on observations of local marine mammal specialists, Dall's 
porpoise are uncommon in Icy Passage. However, they do occur in Icy 
Strait and could potentially transit through the disturbance zone. For 
this analysis, we take the maximum number of 12 sightings per season 
between May and September, which equates to 2.4 sightings per month. 
Using this number it is estimated that the following number of Dall's 
porpoise may be present in the disturbance zone:

 Underwater exposure estimate: 2.4 group sightings/month x 3 
animals/group x 6 months of pile activity = 43.2
NMFS proposes authorizing the Level B take of 43 Dall's porpoise.

Harbor Porpoise

    Harbor porpoise are common in Icy Strait. Concentrations of harbor 
porpoise were consistently found in varying habitats surrounding 
Zarembo Island and Wrangell Island, and throughout the Glacier Bay and 
Icy Strait regions (Dahlheim et al., 2009). These concentrations 
persisted throughout the three seasons sampled. Dahlheim (2015) 
indicated that 332 resident harbor porpoises occur in the Icy Strait 
area, though the population has been declining across Southeast Alaska 
since the early 1990's (Dahlheim et al., 2012). During a 2014 survey, 
Barlow et al. (in press) observed 462 harbor porpoises in the Glacier 
Bay and Icy Strait area during a three-month summer survey period. It 
is estimated that harbor porpoise are observed on at least 75 percent 
of whale watch excursions (75 of 100 days) during the May through 
September months (Tod Sebens, CSE, Stephen Vanderhoff, SWE, personal 
communication). While NPS documented numerous sightings in Icy Strait 
since 1993 in September, October, November, April, and May, none were 
observed in Icy Passage. The mean group size of harbor porpoise in 
Southeast Alaska is estimated at two individuals (Dahlheim et al., 
2009).
    Harbor porpoise could potentially transit through the disturbance 
zone during pile driving activity. For this analysis we take a 
conservative estimate and assume that four harbor porpoise (two pods of 
two per day) could be present on any of the 50 days of pile driving. 
Using this number it is estimated that the following number of harbor 
porpoise may be present in the disturbance zone:
    Underwater exposure estimate:

 4 animals x 50 days of pile activity = 200

    NMFS is proposing authorization for 200 Level B acoustical 
harassment takes of harbor porpoise.

Humpback Whale

    From May to September, humpback whales congregate and forage in 
nearby Glacier Bay and in Icy Strait. Since 1985, the NPS has been 
monitoring humpback whales in both Glacier Bay National Park and Icy 
Strait and publishing annual reports (https://www.nps.gov/glba/naturescience/whale_acoustic_reports.htm). The NPS typically surveys 
Icy Strait, located south of Icy Passage, once a week between June 1 
and August 31, with most survey effort focused in the area east of 
Point Gustavus and Pleasant Island (Figure 3). Several Icy Strait 
surveys included waters around

[[Page 40866]]

Pleasant Island, the closest island to the Gustavus Ferry Terminal. 
Because the NPS is most interested in whales within Glacier Bay and 
areas where vessel management is a concern, their monitoring data do 
not represent a true distribution of whales. Their survey locations are 
also dependent on where the whales are actually distributed (Neilson et 
al., 2014).
    In 2013, 237 humpback whales were documented in Icy Strait during 
the NPS monitoring period; this was a 14 percent increase over the 
previous high count of 177 whales in 2012 (Neilson et al., 2014). In 
2014, a 39 percent decrease in area abundance was observed (124 
whales), which may have been caused by increased turbidity resulting 
from seismic generated marine landslides (Neilson et al., 2015). The 
majority of whales observed in Icy Strait in 2013 and 2014 were 
recorded in the area between the mouth of Glacier Bay and Point 
Adolphus; there were no whales observed between Pleasant Island and the 
Gustavus Ferry Terminal (the waterbody known as Icy Passage). While 
this does not mean that no whales were present between the island and 
ferry terminal at any time, it does suggest that the number of 
individual whales present in Icy Passage is relatively low and 
occurrence is infrequent. In other years, a number of humpback whales 
have been observed to the south and west of Pleasant Island (Neilson et 
al., 2014; Figures 4 through 6). The lack of whale observations between 
Pleasant Island and the ferry terminal likely reflects the fact that 
Icy Passage is relatively shallow and muddy; for this reason NPS does 
not consider it a whale ``hot spot'' (C. Gabriele, NPS, personal 
communication).
    Based on these observations humpback whales appear to be common in 
Icy Strait and are occasionally seen in Icy Passage. However, NPS 
believes that whale abundance decreases substantially in September 
through November and March through April, but has limited data for 
these periods. For this analysis, we take a conservative estimate and 
assume that two humpback whales could be present in the disturbance 
zone on any day of the 50 days of pile driving. Using this number it is 
estimated that the following number of humpback whales may be present 
in the disturbance zone:
    Underwater exposure estimate:

 2 animals x 50 days of pile activity = 100

NMFS is proposing authorization for 100 Level B acoustical harassment 
takes of humpback whales.

Killer whale

    Based on observations of local marine mammal specialists, the 
probability of killer whales occurring in Icy Passage is low. However, 
they do occur in Icy Strait and could potentially transit through the 
disturbance zone in Icy Passage. Since there is no density information 
available for killer whales in this area, we assumed a pod size of 27 
for resident and six for transient killer whales, based on an average 
of group sizes observed during surveys in Spring and Fall in Southeast 
Alaska between 1991 and 2007 (Dalheim et al., 2008). We also assumed 
that a pod of resident (27) or transient (6) killer whales may occur in 
the Level B disturbance zone twice during the course of the project. 
Therefore, to account for the potential for two resident (54 total) and 
two transient pods (12 total) to occur in the disturbance zone during 
the course of the project, ADOT&PF is requesting authorization for 66 
Level B acoustical harassment takes of killer whales.

Minke Whale

    Based on observations of local marine mammal specialists, the 
probability of minke whales occurring in Icy Passage is low. However, 
they have been documented in Icy Strait and could potentially transit 
through the disturbance zone. For this analysis, we take a conservative 
estimate and assume that one minke whale could be present on any one 
day during the 50 days of pile driving. Using this number it is 
estimated that the following number of minke whales may be present in 
the disturbance zone:
    Underwater exposure estimate:

 1 animal x 50 days of pile activity = 50

    NMFS is therefore proposing authorization for 50 Level B acoustical 
harassment takes of minke whales.

Analyses and Preliminary Determinations

Negligible Impact Analysis

    Negligible impact is ``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 Level B harassment 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 behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, effects on habitat, and the status 
of the species.
    To avoid repetition, the discussion of our analyses applies to all 
the species listed in Table 1. There is little information about the 
nature of severity of the impacts or the size, status, or structure of 
any species or stock that would lead to a different analysis for this 
activity.
    Pile driving and pile extraction activities associated with the 
Gustavus Ferry Terminal improvements project, as outlined previously, 
have the potential to disturb or displace marine mammals. Specifically, 
the specified activities may result in Level B harassment (behavioral 
disturbance) for all species authorized for take, from underwater sound 
generated from pile driving and removal. Potential takes could occur if 
individuals of these species are present in the ensonified zone when 
pile driving or drilling is under way.
    The takes from Level B harassment will be due to potential 
behavioral disturbance and potential TTS. Serious injury or death is 
unlikely for all authorized species and injury is unlikely for these 
species, as ADOT&PF will enact several required mitigation measures. 
Soft start techniques will be employed during pile driving operations 
to allow marine mammals to vacate the area prior to commencement of 
full power driving. ADOT&PF will establish and monitor shutdown zones 
for authorized species, which will prevent injury to these species. 
ADOT&PF will also record all occurrences of marine mammals and any 
behavior or behavioral reactions observed, any observed incidents of 
behavioral harassment, and any required shutdowns, and will submit a 
report upon completion of the project. We have determined that the 
required mitigation measures are sufficient to reduce the effects of 
the specified activities to the level of effecting the least 
practicable adverse impact upon the affected species, as required by 
the MMPA.
    The ADOT&PF's proposed activities are localized and of short 
duration. The entire project area is limited to the Gustavus Ferry 
Terminal area and its immediate surroundings. Specifically,

[[Page 40867]]

the use of impact driving will be limited to an estimated maximum of 57 
hours over the course of 16 to 50 days of construction. Total vibratory 
pile driving time is estimated at 114 hours over the same period. While 
impact driving does have the potential to cause injury to marine 
mammals, mitigation in the form of shutdown zones should eliminate 
exposure to Level A thresholds. Vibratory driving does not have 
significant potential to cause injury to marine mammals due to the 
relatively low source levels produced and the lack of potentially 
injurious source characteristics. Additionally, no important feeding 
and/or reproductive areas for marine mammals are known to be within the 
ensonified area during the construction time frame.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
would not modify existing marine mammal habitat. The activities may 
cause some fish to leave the area of disturbance, thus temporarily 
impacting marine mammals' foraging opportunities in a limited portion 
of the foraging range; but, because of the short duration of the 
activities and the relatively small area of the habitat that may be 
affected, the impacts to marine mammal habitat are not expected to 
cause significant or long-term negative consequences.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff, 
2006; Lerma, 2014). Most likely, individuals will simply move away from 
the sound source and be temporarily displaced from the areas of pile 
driving, although even this reaction has been observed primarily only 
in association with impact pile driving. In response to vibratory 
driving, pinnipeds (which may become somewhat habituated to human 
activity in industrial or urban waterways) have been observed to orient 
towards and sometimes move towards the sound. The pile extraction and 
driving activities analyzed here are similar to, or less impactful 
than, numerous construction activities conducted in other similar 
locations, which have taken place with no reported serious injuries or 
mortality to marine mammals, and no known long-term adverse 
consequences from behavioral harassment. Repeated exposures of 
individuals to levels of sound that may cause Level B harassment are 
unlikely to result in hearing impairment or to significantly disrupt 
foraging behavior. Thus, even repeated Level B harassment of some small 
subset of the overall stock is unlikely to result in any significant 
realized decrease in fitness for the affected individuals, and thus 
would not result in any adverse impact to the stock as a whole.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of serious injury or mortality 
to authorized species may reasonably be considered discountable; (2) 
the anticipated incidents of Level B harassment consist of, at worst, 
temporary modifications in behavior and; (3) the presumed efficacy of 
the planned mitigation measures in reducing the effects of the 
specified activity to the level of effecting the least practicable 
adverse impact upon the affected species. In combination, we believe 
that these factors, as well as the available body of evidence from 
other similar activities, demonstrate that the potential effects of the 
specified activity will have only short-term effects on individuals. 
The specified activity is not expected to impact rates of recruitment 
or survival and will therefore not result in population-level impacts.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the planned monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
ADOT&PF's Gustavus Ferry terminal improvement project will have a 
negligible impact on the affected marine mammal species or stocks.

    Table 6--Estimated Number of Exposures and Percentage of Stocks That May Be Subject to Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                            Proposed
                Species                    authorized        Stock(s) abundance       Percentage of total stock
                                              takes               estimate
----------------------------------------------------------------------------------------------------------------
Harbor Seal............................             200  7,210.....................  2.8.
Steller Sea Lion.......................             236  49,497 (western stock in    0.48.
                                                          AK).                       0.39.
                                                         60,131 (eastern stock)....
Dall's Porpoise........................              43  Unknown...................  Unknown.
Harbor Porpoise........................             200  11,146....................  1.7.
Humpback Whale.........................             100  10,252....................  0.98.
Killer whale...........................              66  261 (Northern resident)...  25.3.
                                                         587 (Gulf of Alaska         11.2.
                                                          transient).
                                                         243 (West Coast transient)  27.1.
Minke Whale............................              50  Unknown...................  Unknown.
----------------------------------------------------------------------------------------------------------------

Small Numbers Analysis

    Table 6 demonstrates the number of animals that could be exposed to 
received noise levels that could cause Level B behavioral harassment 
for the proposed work at the Gustavus Ferry Terminal project. The 
analyses provided above represents between 0.39-27.1 percent of the 
populations of these stocks that could be affected by harassment, 
except for Minke whales and Dall's porpoise, since their population 
numbers are unknown. While the proposed West Coast transient and 
Northern resident killer whale takes and percentages of stock affected 
appears high (27.1 percent and 25.3 percent), in reality only 66 
transient killer whale individuals are not likely to be harassed. 
Instead, it is more likely that there will be multiple takes of a 
smaller number of individuals. Both the West coast transient stock and 
the Northern Resident stock range from southeastern Alaska, through 
British Columbia, and into northern Washington. It is unlikely that 
such a large portion of either stock with ranges of this size would be 
concentrated in and around Icy Passage.
    Furthermore, though there is not a current abundance estimate, the 
proposed take of 43 Dall's porpoise and

[[Page 40868]]

50 Minke whale are also considered small numbers. Population data on 
these species is dated. Surveys conducted between 1987 and 1991 put the 
population of the Alaska stock of Dall's porpoise at between 83,400 and 
417,000 (Allen and Angliss, 2012). As such, the 14 proposed authorized 
takes represent <0.01 percent of the population. A visual survey for 
cetaceans was conducted in the central-eastern Bering Sea in July-
August 1999, and in the southeastern Bering Sea in 2000. Results of the 
surveys in 1999 and 2000 provide provisional abundance estimates of 810 
and 1,003 minke whales in the central-eastern and southeastern Bering 
Sea, respectively (Moore et al., 2002). Additionally, line-transect 
surveys were conducted in shelf and nearshore waters in 2001-2003 from 
the Kenai Fjords in the Gulf of Alaska to the central Aleutian Islands. 
Minke whale abundance was estimated to be 1,233 for this area (Zerbini 
et al., 2006). However, these estimates cannot be used as an estimate 
of the entire Alaska stock of minke whales because only a portion of 
the stock's range was surveyed. (Allen and Anglis 2012). Clearly, 50 
authorized takes should be considered a small number, as it constitutes 
only 6.1 percent of the smallest abundance estimate generated during 
the surveys just described and each of these surveys represented only a 
portion of the minke whale range.
    Note that the numbers of animals authorized to be taken for all 
species, with the exception of resident killer whales, would be 
considered small relative to the relevant stocks or populations even if 
each estimated taking occurred to a new individual--an extremely 
unlikely scenario.
    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 mitigation and monitoring 
measures, which are expected to reduce the number of marine mammals 
potentially affected by the proposed action, NMFS finds that small 
numbers of marine mammals will be taken relative to the populations of 
the affected species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Use

    The proposed Gustavus Ferry Terminal Improvements project will 
occur near but not overlap the subsistence area used by the villages of 
Hoonah and Angoon (Wolfe et al., 2013). Harbor seals and Steller sea 
lions are available for subsistence harvest in this area (Wolfe et al., 
2013). There are no harvest quotas for other non-listed marine mammals 
found there. The Alaska Department of Fish and Game (Wolfe et al., 
2013) has regularly conducted surveys of harbor seal and Steller sea 
lion subsistence harvest in Alaska. Since proposed work at the Gustavus 
Ferry Terminal will only cause temporary, nonlethal disturbance of 
marine mammals, we anticipate no impacts to subsistence harvest of 
marine mammals in the region.

Endangered Species Act (ESA)

    There are two marine mammal species that are listed as endangered 
under the ESA with confirmed or possible occurrence in the study area: 
humpback whale and Steller sea lion (Western DPS). NMFS' Permits and 
Conservation Division has initiated consultation with NMFS' Protected 
Resources Division under section 7 of the ESA on the issuance of an IHA 
to ADOT&PF under section 101(a)(5)(D) of the MMPA for this activity. 
Consultation will be concluded prior to a determination on the issuance 
of an IHA.

National Environmental Policy Act (NEPA)

    NMFS is preparing an EA in accordance with the NEPA and will 
consider comments submitted in response to this notice as part of that 
process. The draft EA will be posted at https://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm once it is finalized.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to ADOT&PF for reconstructing the existing Gustavus Ferry 
Terminal located in Gustavus, Alaska, Alaska, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. The proposed IHA language is provided next.
    1. This Incidental Harassment Authorization (IHA) is valid from 
September 1, 2017 through August 31, 2018.
    2. This Authorization is valid only for in-water construction work 
associated with the reconstruction of the existing Gustavus Ferry 
Terminal located in Gustavus, Alaska.
    3. General Conditions.
    (a) A copy of this IHA must be in the possession of the Alaska 
Department of Transportation & Public Facilities (ADOT&PF), its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are harbor seal (Phoca 
vitulina), Steller sea lion (Eumatopius jubatus), Dall's porpoise 
(Phocoenoides dalli), harbor porpoise (Phocoena phocoena), humpback 
whale (Megaptera novaeangliae), killer whale (Orcinus orca), and minke 
whale (Balaenoptera acutorostrata).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b).
    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 3(b) of the 
Authorization or any taking of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    4. Mitigation Measures.
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) Time Restriction: For all in-water pile driving activities, 
ADOT&PF shall operate only during daylight hours when visual monitoring 
of marine mammals can be conducted;
    (b) To limit the amount of waterborne noise, a vibratory hammer 
will be used for initial driving, followed by an impact hammer to proof 
the pile to required load-bearing capacity;
    (c) Establishment of Level B Harassment Zones of Influence (ZOIs):
    (i) Before the commencement of in-water pile driving activities, 
ADOT&PF shall establish Level B behavioral harassment ZOIs where 
received underwater sound pressure levels (SPLs) are higher than 160 dB 
(rms) and 120 dB (rms) re 1 [micro]Pa for impulse noise sources (impact 
pile driving) and non-pulse sources (vibratory hammer), respectively; 
and
    (ii) The ZOIs delineate where Level B harassment would occur. For 
impact driving, the area within the Level B harassment threshold is 
between approximately 76 m and 1.6 km. For vibratory driving, the level 
B harassment area is between 10 m and 1.9 km.
    (d) Establishment of shutdown zone--Implement a minimum shutdown 
zone around the pile of 76 m radius during impact pile driving and 10 m 
during vibratory driving activities. If a marine mammal comes within or 
approaches the shutdown zone, such operations shall cease.
    (e) Use of Soft-start:
    (i) The project will utilize soft start techniques for impact pile 
driving. Contractors shall be required to provide an initial set of 
three strikes from the impact hammer at 40 percent reduced energy, 
followed by a thirty-second

[[Page 40869]]

waiting period, then two subsequent three strike sets. Soft start will 
be required at the beginning of each day's pile driving work and at any 
time following a cessation of pile driving of thirty minutes or longer 
(specific to either vibratory or impact driving); and
    (ii) Whenever there has been downtime of 20 minutes or more without 
vibratory or impact driving, the contractor will initiate the driving 
with soft-start procedures described above.
    (f) Standard mitigation measures:
    (i)(e) ADOT&PF shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, and staff prior 
to the start of all in-water pile driving, and when new personnel join 
the work, in order to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures; and
    (ii) For in-water heavy machinery work other than pile driving 
(using, e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), 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.
    5. Monitoring and Reporting.
    The holder of this Authorization is required to report all 
monitoring conducted under the IHA within 90 calendar days of the 
completion of the marine mammal monitoring. This report shall detail 
the monitoring protocol, summarize the data recorded during monitoring, 
and estimate the number of marine mammals that may have been harassed. 
If no comments are received from NMFS within 30 days of submission of 
the draft final report, the draft final report will constitute the 
final report. If comments are received, a final report must be 
submitted within 30 days after receipt of comments:
    (a) Marine Mammal Observers (MMOs) must have the following 
qualifications:
    (i) 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 spotting 
scopes and binoculars may be necessary to correctly identify the 
target;
    (ii) Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience);
    (iii) Experience or training in the field identification of marine 
mammals (cetaceans and pinnipeds);
    (iv) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (v) Writing skills sufficient to prepare a report of observations 
that would include such information as the number and type of marine 
mammals observed; the behavior of marine mammals in the project area 
during construction; dates and times when observations were conducted; 
dates and times when in-water construction activities were conducted; 
dates and times when marine mammals were present at or within the 
defined disturbance or injury zones; dates and times when in-water 
construction activities were suspended to avoid injury from 
construction noise; etc; and
    (vi) 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.
    (b) Visual Marine Mammal Monitoring and Observation:
    (i) During impact pile driving, one MMO shall monitor the 1.6-
kilometer disturbance zone from the Gustavus Ferry Terminal. The 
smaller injury zone of 76 meters for whales and 16 meters for pinnipeds 
will also be monitored by a MMO during impact pile driving. During 
vibratory driving, one MMO shall monitor the 1.9 km disturbance zone 
from the Gustavus Ferry Terminal;
    (ii) At the beginning of each day, the observer shall determine 
their vantage positions using a handheld GPS unit. If a MMO changes 
position throughout the day, each new position will also be determined 
using a hand-held GPS unit;
    (iii) Monitoring shall begin 30 minutes prior to impact pile 
driving;
    (iv) If all marine mammals in the disturbance zone have been 
documented and no marine mammals are in the injury zone, the 
coordinator shall instruct the contractor to initiate the soft-start 
procedure for any impact pile driving;
    (v) When a marine mammal is observed, its location shall be 
determined using a rangefinder to verify distance and a GPS or compass 
to verify heading;
    (vi) If marine mammals listed in 3(b) are observed nearing their 
respective injury zones, pile-driving activities shall be immediately 
shut down. Operations shall continue after the animal has been spotted 
out of the zone or 30 minutes have passed without re-sighting the 
animal in the zones;
    (vii) The MMO shall record all cetaceans and pinnipeds present in 
the disturbance zones;
    (ix) The observer will use their naked eye with the aid of 
binoculars and a spotting scope to search continuously for marine 
mammals;
    (x) During the in-water operation of heavy machinery (e.g., barge 
movements), a 10-meter shutdown zone for all marine mammals will be 
implemented;
    (xi) At the end of the pile-driving day, post-construction 
monitoring will be conducted for 30 minutes beyond the cessation of 
pile driving; and
    (xii) If waters exceed a sea-state which restricts the MMO's 
ability to make observations within the marine mammal shutdown zone 
(e.g. excessive wind or fog), pile installation will cease. Pile 
driving will not be initiated until the entire shutdown zone is 
visible.
    (c) During pile driving, one MMO shall be positioned at the best 
practical vantage point. The monitoring position will be on the ferry 
terminal, but may vary based on pile driving activities and the 
locations of the piles and driving equipment. The monitoring location 
will be identified with the following characteristics:
    (i) Unobstructed view of pile being driven;
    (ii) Unobstructed view of all water within a 1.6 km (impact 
driving) or 1.9 km (vibratory driving) radius of each pile;
    (iii) Clear view of pile-driving operator or construction foreman 
in the event of radio failure; and
    (iv) Safe distance from pile-driving activities in the construction 
area.
    (d) When possible, ADOT&PF shall augment land-based monitoring with 
information from boats in Icy Strait/Passage by coordinating with the 
NPS and whale-watching charters. The MMO shall conduct telephone checks 
with NPS and whale-watching charters to monitor the locations of 
humpback whales and Steller sea lions within Icy Strait/Passage.
    (e) Data Collection:
    Observers are required to use approved data forms. Among other 
pieces of information, ADOT&PF will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, ADOT&PF will attempt to 
distinguish between the number of individual animals taken and the 
number of incidents of take. At a minimum, the following information 
shall be recorded on the sighting forms:
    1. Date and time that monitored activity begins or ends;
    2. Construction activities occurring during each observation 
period;

[[Page 40870]]

    3. Weather parameters (e.g., percent cover, visibility);
    4. Water conditions (e.g., sea state, tide state);
    5. Species, numbers, and, if possible, sex and age class of marine 
mammals;
    6. Description of any observable marine mammal behavior patterns, 
including bearing and direction of travel and distance from pile 
driving activity;
    7. Distance from pile driving activities to marine mammals and 
distance from the marine mammals to the observation point;
    8. Locations of all marine mammal observations; and
    9. Other human activity in the area.
    (f) Reporting Measures:
    (i) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA, 
such as an injury (Level A harassment), serious injury or mortality 
(e.g., ship-strike, gear interaction, and/or entanglement), ADOT&PF 
would immediately cease the specified activities and immediately report 
the incident to the Chief of the Permits and Conservation Division, 
Office of Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinators. The report would include the following information:
    1. Time, date, and location (latitude/longitude) of the incident;
    2. Name and type of vessel involved;
    3. Vessel's speed during and leading up to the incident;
    4. Description of the incident;
    5. Status of all sound source use in the 24 hours preceding the 
incident;
    6. Water depth;
    7. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    8. Description of all marine mammal observations in the 24 hours 
preceding the incident;
    9. Species identification or description of the animal(s) involved;
    10. Fate of the animal(s); and
    11. Photographs or video footage of the animal(s) (if equipment is 
available);
    (ii) 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;
    (iii) In the event that ADOT&PF discovers an injured or dead marine 
mammal, and the lead MMO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., 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 Coordinators. 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;
    (iv) In the event that ADOT&PF discovers an injured or dead marine 
mammal, and the lead MMO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), ADOT&PF would 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 Coordinators, within 24 hours 
of the discovery. ADOT&PF would provide photographs or video footage 
(if available) or other documentation of the stranded animal sighting 
to NMFS and the Marine Mammal Stranding Network.
    6. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    NMFS requests comment on our analysis, the draft authorization, and 
any other aspect of the Notice of Proposed IHA for ADOT&PF's 
reconstruction of the existing Gustavus Ferry Terminal located in 
Gustavus, Alaska. Please include with your comments any supporting data 
or literature citations to help inform our final decision on ADOT&PF's 
request for an MMPA authorization.

    Dated: June 20, 2016.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2016-14886 Filed 6-22-16; 8:45 am]
 BILLING CODE 3510-22-P