[Federal Register Volume 82, Number 203 (Monday, October 23, 2017)]
[Notices]
[Pages 48987-49001]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-22881]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF370
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Sand Point City Dock
Replacement Project in Sand Point, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the Alaska Department of Transportation and Public Facilities (ADOT&PF)
to incidentally harass, by Level A and Level B harassment, marine
mammals during construction activities associated with the Sand Point
City Dock Replacement Project in Sand Point, Alaska.
DATES: This Authorization is valid from August 1, 2018 through July 31,
2019.
FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected
Resources, NMFS, (301) 427-8401. 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 online at:
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of
problems accessing these documents, please call the contact listed
above.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce 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.
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal.
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: Any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild (Level A harassment); or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering (Level B harassment).
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment.
This action is consistent with categories of activities identified
in CE B4 of the Companion Manual for NOAA Administrative Order 216-6A,
which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has determined
that the issuance of the IHA qualifies to be categorically excluded
from further NEPA review and signed a Categorical Exclusion memo in
September 2017.
Summary of Request
On September 16, 2016, NMFS received an application from ADOT&PF
for the taking of marine mammals incidental to replacing the city dock
in Sand Point, Alaska. On April 11, 2017, ADOT&PF submitted a revised
application that NMFS determined was adequate and complete. ADOT&PF
proposed to conduct in-water activities that may incidentally take, by
Level A and Level B harassment, nine species of marine mammals.
Proposed activities included as part of the Sand Point City Dock
Replacement Project with potential to affect marine mammals include
impact hammer pile driving and vibratory pile driving and removal.
Neither ADOT&PF nor NMFS expect mortality to result from this activity
and, therefore, an IHA is appropriate.
Description of Specified Activities
Overview
We provided a description of the proposed action in our Federal
Register notice announcing the proposed authorization (82 FR 31400;
July 6, 2017; 31400-31402). Please refer to that
[[Page 48988]]
document; we provide only summary information here.
ADOT&PF plans to construct a new dock in Sand Point, Alaska. Impact
and vibratory driving of piles and vibratory pile removal is expected
to take place over a total of approximately 32 working days within a 5-
month window from August 1, 2018 through December 31, 2018. However,
due to the potential for unexpected delays, up to 40 working days may
be required. The new dock would be supported by approximately 52 round,
30-inch-diameter, 100-foot-long permanent steel pipe piles. Fender
piles installed at the dock face would consist of 8 round, 24-inch-
diameter, 80-foot-long permanent steel pipe piles. The single mooring
dolphin would consist of 3 round, 24-inch-diameter, 120-foot-long
permanent battered steel pipe piles. This equates to a total of 63
permanent piles. Up to 90 temporary piles would be installed and
removed during construction of the dock and would be either H-piles or
pipe piles with a diameter of less than 24 inches. Table 1 provides
detailed information regarding pile size and type as well as effort
required for installation and removal.
Table 1--Pile Details and Estimated Effort Required for Pile Installation
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Estimated Anticipated
Pile type Diameter Number of Maximum piles Hours per day minutes per days of effort
piles per day pile \1\
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Vibratory Installation or Removal
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Permanent support pile................. 30''........................... 52 4 3 45 13
Permanent dolphin pile................. 24''........................... 3 2 1 30 2
Permanent fender pile.................. 24''........................... 8 4 2 30 2
Installation, temporary support pile... <24'' or H-pile................ 90 6 1.5 15 15
Removal, temporary support pile........ <24'' or H-pile................ 90 6 1.5 15 15
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Impact Installation
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Permanent support pile................. 30''........................... 52 4 1.667 25 13
Permanent dolphin pile................. 24''........................... 3 2 0.33 10 2
Permanent fender pile.................. 24''........................... 8 4 0.20 3 2
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\1\ Vibratory and impact driving of each permanent pile will occur on the same day. Installation and removal of each temporary piles will occur on the
same day.
Dates and Duration
In-water pile driving and extraction activities are expected to
take place over a total of approximately 32 working days within a 5-
month window from August 1, 2018 through December 31, 2018. The issued
IHA will be valid for a period of one year in case there are delays.
Table 2 illustrates the anticipated number of days required for
installation and removal of various pile types. Pile driving and
removal may occur for up to 4.5 hours per day. Total driving time for
the planned project would consist of approximately 22 hours of impact
driving and 85 hours of vibratory driving and removal.
Table 2--Estimated Number of Days Required for Pile Installation and
Removal
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Number of
Activity piles Days required
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Support pile installation............... 52 13
Temporary pile installation and removal. 90 15
Dolphin pile installation............... 3 2
Fender pile installation................ 8 2
-------------------------------
Total Days.......................... .............. 32
-------------------------------
Total Days with 25% contingency..... .............. 40
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Specified Geographic Region
The Sand Point city dock is located in the city of Sand Point,
Alaska, on the northwest side of Popof Island, in the western Gulf of
Alaska. Sand Point is the largest community in the Shumagin Islands.
See Figure 1-1 and 1-2 in ADOT&PF's Application.
Comments and Responses
A notice of NMFS's proposal to issue an IHA to ADOT&PF was
published in the Federal Register on July 6, 2017 (82 FR 31400). That
notice described, in detail, ADOT&PF's activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals. During the 30-day public comment period,
NMFS received only one set of comments, from the Marine Mammal
Commission (Commission); the Commission's recommendations and our
responses are provided here, and the comments have been posted online
at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. Please
see the Commission's letter for background and rationale regarding the
recommendations, which are listed below.
Comment: The Commission expressed interest in NMFS's policy
associated with the rounding of numbers to derive take estimates.
Response: We thank the Commission for their interest in the matter.
Description of Marine Mammals in the Area of Specified Activities
We have reviewed the applicants' species information--which
summarizes available information regarding status and trends,
distribution
[[Page 48989]]
and habitat preferences, behavior and life history, and auditory
capabilities of the potentially affected species--for accuracy and
completeness and refer the reader to Sections 3 and 4 of the
application, as well as to NMFS's Stock Assessment Reports
(www.nmfs.noaa.gov/pr/sars/). A detailed description of the species
likely to be affected by the dock replacement project, including brief
introductions to the species and relevant stocks as well as available
information regarding population trends and threats, and information
regarding local occurrence, were provided in the Federal Register
notice for the proposed IHA (82 FR 31400; July 6, 2017; 31402-31408)
since that time, we are not aware of any changes in the status of these
species and stocks; therefore, detailed descriptions are not provided
here. Please refer to that Federal Register notice for these
descriptions. Please also refer to NMFS' Web site (www.nmfs.noaa.gov/pr/species/mammals/) for generalized species accounts.
Table 3 lists all species with expected potential for occurrence
near Sand Point and summarizes information related to the population or
stock, including potential biological removal (PBR), where known. For
taxonomy, we follow Committee on Taxonomy (2016). PBR, defined by the
MMPA as the maximum number of animals, not including natural
mortalities, that may be removed from a marine mammal stock while
allowing that stock to reach or maintain its optimum sustainable
population, is considered in concert with known sources of ongoing
anthropogenic mortality to assess the population-level effects of the
anticipated mortality from a specific project (as described in NMFS's
SARs). While no mortality is anticipated or authorized here, PBR and
annual serious injury and mortality are included here as gross
indicators of the status of the species and other threats. For status
of species, we provide information regarding U.S. regulatory status
under the MMPA and ESA. Marine mammal abundance estimates presented in
this document represent the total number of individuals that make up a
given stock or the total number estimated within a particular study
area. NMFS's stock abundance estimates for most species represent the
total estimate of individuals within the geographic area, if known,
that comprises that stock.
All values presented in Table 3 are the most recent available at
the time of publication and are available in the 2016 SARs (Muto et
al., 2016) online at: (www.nmfs.noaa.gov/pr/sars/draft.htm).
Table 3--Marine Mammal Species Potentially Present in the Project Area
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Stock abundance (CV,
Species Stock ESA/MMPA status; Nmin, most recent PBR \3\ Annual M/ Relative occurrence
strategic (Y/N) \1\ abundance survey) \2\ SI \4\ near Sand Point
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Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Phocoenidae (porpoises)
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Dall's porpoise.................... Alaska................ -; N 83,400 (0.097; n/a; Undet 38 Rare.
1993).
Harbor porpoise.................... Gulf of Alaska........ -; Y 25,987 (0.214; n/a; Undet 72 Common.
1998).
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Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae (dolphins)
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Killer whale....................... Eastern North Pacific -; N 2,347 (n/a; 2,347; 24 1 Uncommon.
Alaska Resident. 2012).
Eastern North Pacific -; N 587 (n/a; 587; 2012). 5.9 1 Uncommon.
Gulf of AK, Aleutian
Islands, and Bering
Sea Transient.
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Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Balaenopteridae
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Humpback whale..................... Central North Pacific. n/a/D; \5\ Y 10,103 (0.300; 7,890; 83 24 Uncommon.
2006).
Western North Pacific. n/a/D; \5\ Y 1,107 (0.300; 865; 3 2.6 Uncommon.
2006).
Fin whale.......................... Northeast Pacific..... E/D; Y 1,368 (n/a, 1,036; 2.1 0.6 Rare.
2010).
Minke whale........................ Alaska................ -; N ..................... ......... 0 Rare.
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Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Eschrichtiidae
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Gray whale......................... Eastern North Pacific. -; N 20,990 (0.05; 20,125; 624 132 Rare.
2011).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and sea lions)
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Steller sea lion................... wDPS.................. E/D; S 50,983 (n/a; 50,983; 306 236 Very common.
2015).
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Family Phocidae (earless seals)
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Harbor seal........................ (Cook Inlet/Shelikof -; N 27,386 (n/a; 25,651, 770 234 Occasional.
Strait. 2011).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks of
pinnipeds, abundance estimates are based upon observations of animals (often pups) ashore multiplied by some correction factor derived from knowledge
of the specie's (or similar species') life history to arrive at a best abundance estimate; therefore, there is no associated CV. In these cases, the
minimum abundance may represent actual counts of all animals ashore.
[[Page 48990]]
\3\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP).
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ The newly defined DPSs do not currently align with the stocks defined under the MMPA. On September 8, 2016, NMFS published a final decision which
changed the status of humpback whales under the ESA (81 FR 62259). The decision recognized the existence of 14 DPSs based on distinct breeding areas
in tropical and temperate waters. Five of the 14 DPSs were classified under the ESA (4 endangered and 1 threatened), while the other 9 DPSs were
delisted. Humpback whales found in the Shumagin Islands are predominantly members of the Hawaii DPS, which are not listed under the ESA. However,
based on a comprehensive photo-identification study, members of both the Western North Pacific DPS (ESA-listed as endangered) and Mexico DPS (ESA-
listed as threatened) are known to occur in the Gulf of Alaska and Aleutian Islands.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from construction activities for
the project have the potential to result in injury and behavioral
harassment of marine mammals in the vicinity of the project area. The
Federal Register notice for the proposed IHA (82 FR 31400; July 6,
2017; 31408-31409) included a discussion of the potential effects of
anthropogenic noise on marine mammals. The main impact associated with
the ADOT&PF project would be temporarily elevated sound levels and the
associated direct effects on marine mammals. The project would not
result in permanent impacts to habitats used directly by marine mammals
but may have potential short-term impacts to food sources such as
forage fish, and minor impacts to the immediate substrate resulting in
a temporary, localized increase in turbidity. These potential effects
are discussed in detail in the Federal Register notice for the proposed
IHA (82 FR 31400; July 6, 2017; 31410-31414), therefore that
information is not repeated here; please refer to that Federal Register
notice for that information.
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through the IHA, which informed both NMFS' consideration of
whether the number of takes is ``small'' and the negligible impact
determination.
Harassment is the only means of take expected to result from these
activities. 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). Level A and Level B harassment is
expected to occur and is authorized in the numbers identified below.
Take has been authorized by Level B harassment in the form of
behavioral disturbance for harbor porpoise, Dall's porpoise, killer
whale, humpback whale, fin whale, gray whale, minke whale, Steller sea
lion, and harbor seal near the project area that may result from impact
and vibratory pile driving activities. Level A harassment in the form
of PTS resulting from impact driving has also been authorized for small
numbers of harbor porpoise, humpback whale, and harbor seal.
Take estimates are generally based on average marine mammal density
in the project area multiplied by the area size of ensonified zones
within which received noise levels exceed certain thresholds (i.e.,
Level A and/or Level B harassment) from specific activities, then
multiplied by the total number of days such activities would occur. If
density information is not available, local observational data were
used instead.
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 the sound field 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 incidents of take.
Sound Thresholds
We use the following generic sound exposure thresholds (Table 4) to
determine when an activity that produces sound might result in impacts
to a marine mammal such that a take by behavioral harassment (Level B)
might occur.
Table 4--Underwater Level B Threshold Decibel Levels for Marine Mammals
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Criterion Criterion definition Threshold \1\
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Level B harassment.......... Behavioral 160 dB RMS.
disruption for
impulse noise
(e.g., impact pile
driving).
Level B harassment.......... Behavioral 120 dB RMS.
disruption for non-
pulse noise (e.g.,
vibratory pile
driving, drilling).
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\1\ All decibel levels referenced to 1 micropascal (re: 1 [mu]Pa). Note
all thresholds are based off root mean square (RMS) levels.
We use NMFS' acoustic criteria (NMFS 2016a, 81 FR 51694; August 4,
2016), which establishes sound exposure thresholds to determine when an
activity that produces sound might result in impacts to a marine mammal
such that a take by auditory injury, i.e., PTS, (Level A harassment)
might occur. The specific methodology is presented in Appendix D of the
Technical Guidance for Assessing the Effects of Anthropogenic Sound on
Marine Mammal Hearing (Guidance), available at http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm and the accompanying User
Spreadsheet. The Guidance provides updated PTS onset thresholds using
the cumulative SEL (SELcum) metric, which incorporates
marine mammal auditory weighting functions, to identify the received
levels, or acoustic thresholds, at which individual marine mammals are
predicted to experience changes in their hearing sensitivity for acute,
incidental exposure to all underwater anthropogenic sound sources. The
Guidance (Appendix D) and its companion User Spreadsheet provide
alternative methodology for incorporating these more complex thresholds
and associated weighting functions.
The User Spreadsheet accounts for effective hearing ranges using
Weighting Factor Adjustments (WFAs), and
[[Page 48991]]
ADOT&PF's application uses the recommended values for vibratory and
impact driving therein. The acoustic thresholds are presented using
dual metrics of SELcum and peak sound level (PK) as shown in
Table 5. In the case of the duel metric acoustic thresholds
(Lpk and LE) for impulsive sound, the larger of
the two isopleths for calculating PTS onset is used. The method uses
estimates of sound exposure level and duration of the activity to
calculate the threshold distances at which a marine mammal exposed to
those values would experience PTS. Differences in hearing abilities
among marine mammals are accounted for by use of weighting factor
adjustments for the five functional hearing groups (NMFS 2016). Note
that for all planned pile driving activities at Sand Point, the User
Spreadsheet indicated that the Level A isopleths generated using the
SELcum were the largest.
Table 5--Summary of PTS Onset Acoustic Thresholds
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PTS onset acoustic thresholds \1\ (received level)
Hearing group --------------------------------------------------------------------------
Impulsive Non-impulsive
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Low-Frequency (LF) Cetaceans......... Cell 1: Lpk,flat: 219 Cell 2: LE,LF,24h: 199 dB.
dB; LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans......... Cell 3: Lpk,flat: 230 Cell 4: LE,MF,24h: 198 dB.
dB; LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans........ Cell 5: Lpk,flat: 202 Cell 6: LE,HF,24h: 173 dB.
dB; LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)... Cell 7: Lpk,flat: 218 Cell 8: LE,PW,24h: 201 dB.
dB; LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).. Cell 9: Lpk,flat: 232 Cell 10: LE,OW,24h: 219 dB.
dB; LE,OW,24h: 203 dB.
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\1\ Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Distance to Sound Thresholds
The sound field in the project area is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected via sound generated by the
primary components of the project (i.e., impact pile driving, vibratory
pile driving, and vibratory pile removal). Vibratory hammers produce
constant sound when operating, and produce vibrations that liquefy the
sediment surrounding the pile, allowing it to penetrate to the required
seating depth. An impact hammer would then generally be used to place
the pile at its intended depth. The actual durations of each
installation method vary depending on the type and size of the pile. An
impact hammer is a steel device that works like a piston, producing a
series of independent strikes to drive the pile. Impact hammering
typically generates the loudest noise associated with pile
installation. Factors that could potentially minimize the potential
impacts of pile installation associated with the project include:
The relatively shallow waters in the project area (Taylor
et al., 2008);
Land forms around Sand Point that would block the noise
from spreading; and
Vessel traffic and other commercial and industrial
activities in the project area that contribute to elevated background
noise levels.
Sound would likely dissipate relatively rapidly in the shallow
waters over soft seafloors in the project area. Additionally, portions
of Popof Island and Unga Island would block much of the noise from
propagating to its full extent through the marine environment.
In order to calculate distances to the Level A and Level B sound
thresholds for piles of various sizes being used in this project, NMFS
used acoustic monitoring data from other locations. Note that piles of
differing sizes have different sound source levels.
Empirical data from recent ADOT&PF sound source verification (SSV)
studies at Kake, Ketchikan, and Auke Bay, were used to estimate sound
source levels (SSLs) for vibratory and impact installation of 30-inch
steel pipe piles (MacGillivray et al., 2016, Warner and Austin 2016b,
Denes et al., 2016a, respectively). Construction sites in Alaska were
generally assumed to best represent the environmental conditions found
in Sand Point and represent the nearest available source level data for
30-inch steel piles. Similarities among the sites include island chains
and groups of islands adjacent to continental landmasses; deeply
incised marine channels and fjords; local water depths of 20-40 meters;
Gulf of Alaska marine water influences; and numerous freshwater inputs.
However, the use of data from Alaska sites was not appropriate in all
instances. Details are described below.
To derive source levels for vibratory driving of 30-in piles, NMFS
used summary data from Auke Bay and Ketchikan as described in a
comprehensive summary report by Denes et al., (2016b). During the two
studies, three 30-inch steel piles were installed at each location via
both impact and vibratory driving. For each pile, the mean recorded SPL
in dB re 1 [mu]Pa was reported for the locations monitoring hydrophones
(Denes et al., 2016; Warner and Austin 2016b). The vibratory data were
then derived to a 10-meter standard distance. The average of the mean
source levels from both Auke Bay and Ketchikan locations was then
calculated for each measurement (rms and peak SPL, as well as sound
exposure level [SEL]) (Denes et al., 2016b). ADOT&PF also considered
data from a study in Kake (MacGillivray et al., 2016). However,
conditions at Kake include an organic mud substrate which would likely
absorb sound and decrease source level values for vibratory driving.
NMFS believes that these conditions resulted in anomalous source level
measurements for vibratory pile driving that would not be expected at
locations with dissimilar substrates. NMFS will continue to evaluate
use of these data on a case-specific basis, however, for these reasons
vibratory data from that study was not included in this analysis.
Results are shown in Table 6.
[[Page 48992]]
For vibratory driving of 24-inch steel dolphin and fender piles,
data from three projects (two projects in Washington and one in
California) were reviewed. The Washington marine projects at the
Washington State Ferries Friday Harbor Terminal (WSDOT, 2010) and Naval
Base Kitsap, Bangor waterfront (Navy 2012), only measured one pile
each, but reported similar sound levels of 162 dB RMS and 159 dB RMS
(range 157 dB to 160 dB), respectively. Because only two piles were
measured in Washington, the California project was also included in the
analysis. The California project was located in a coastal bay and
reported a ``typical'' value of 160 dB RMS with a range 158 to 178 dB
RMS for two piles where vibratory levels were measured. Caltrans
summarized the project's RMS level as 170 dB RMS, although most levels
observed were nominally 160 dB. Although the data set is limited to
these projects, close agreement of the levels (average project values
from 159 to 162 dB at 10 meters) resulted in NMFS selecting a source
level of 161 dB RMS. Note that a fourth project at NBK, Bangor drove
16-inch hollow steel piles, with measured levels similar to those for
the 24-inch piles. Therefore, NMFS elected to use the same 161 dB RMS
as a source level for vibratory driving of 18-inch steel piles. NMFS
believes it appropriate to use source levels from the next largest pile
size when data are lacking for specific pile sizes, as is the case with
the18-inch piles under consideration.
ADOT&PF suggested a source level of 142 dB RMS for vibratory
driving of steel H-piles. However, NMFS found this data to be
inconsistent with other reported values and opted to use a value of 150
dB which was derived from summary data pertaining to vibratory driving
of 12-inch H piles (Caltrans 2015).
In the application, ADOT&PF derived source levels for impact
driving of 30-inch steel piles by averaging the individual mean values
associated with impact driving of the same size and type from Auke Bay,
Kake, and Ketchikan (Denes et al., 2016a; MacGillivray et al., 2016;
Warner and Austin 2016b; Denes et al., 2016b). Impact driving values at
Kake did not seem to be influenced by substrate conditions in the way
vibratory driving measurements are believed to have been and,
therefore, Kake data was included. The average of the mean source
levels from these three sites was then calculated for each metric (rms,
SEL, and peak). Results are shown in Table 6.
For the 24-inch impact pile driving, NMFS used data from a Navy
(2015) study of proxy sound source values for use at Puget Sound
military installations. The Navy study recommended a value of 193 dB
RMS which was derived from data generated by impact driving of 24-inch
steel piles at the Bainbridge Island Ferry Terminal Preservation
Project and the Friday Harbor Restoration Ferry Terminal Project. NMFS
found this estimated source level to be appropriate.
Table 6--Estimates of Mean Underwater Sound Levels (Decibels) Generated During Vibratory and Impact Pile
Installation and Vibratory Pile Removal
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Method and pile type Sound level at 10 meters Literature source
-------------------------------------------------------------------------
Vibratory hammer dB re 1 [mu]Pa rms
----------------------------------------------------------------------------------------------------------------
30-inch steel piles.................... 165.6 Derived from Denes et al. 2016a
(Auke); Warner and Austin 2016b
(Ketchikan).
----------------------------------------------------------------------------------------------------------------
24-inch steel piles.................... 161 WSDOT 2010; Caltrans 2012; Navy 2012.
----------------------------------------------------------------------------------------------------------------
18-inch steel piles.................... 161 WSDOT 2010; Caltrans 2012; Navy 2012.
----------------------------------------------------------------------------------------------------------------
Steel H-piles.......................... 150 Caltrans 2015.
----------------------------------------------------------------------------------------------------------------
Impact hammer dB rms dB SEL dB peak
----------------------------------------------------------------------------------------------------------------
30-inch steel piles.................... 193.6 179.3 207.1 Derived from Denes et al. 2016a;
Warner and Austin 2016b, MacGillivray
et al., 2016.
----------------------------------------------------------------------------------------------------------------
24-inch steel piles.................... 193 181 210 Navy 2015.
----------------------------------------------------------------------------------------------------------------
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 * log10 (R1/R2)
Where:
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven
pile, and
R2 = the distance from the driven pile of the initial
measurement.
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.
Pulse duration from the SSV studies described above are unknown.
All necessary parameters were available for the SELcum
(cumulative Single Strike Equivalent) method for calculating isopleths.
Therefore, this method was selected. To account for potential
variations in daily productivity during impact installation, isopleths
were calculated for different numbers of piles that could be installed
each day (Table 7). Should the contractor expect to install fewer piles
in a day than the maximum anticipated, a smaller Level A shutdown zone
would be employed to monitor take.
To derive Level A harassment isopleths associated with the impact
driving of 30-inch piles, ADOT&PF utilized a single strike SEL of 179.3
dB and assumed 1000 strikes per pile for 1 to 4 piles per day. For 24-
inch dolphin piles, ADOT&PF used a single strike SEL of 181 dB and
assumed 400 strikes at a rate of 1 or 2 piles per day. For 24-inch
fender piles, ADOT&PF used the same single strike SEL of 181 dB and
assumed 120 strikes per pile and 1 to 4 pile installations per day. To
calculate Level A harassment isopleths associated
[[Page 48993]]
with the vibratory driving of 30-inch piles, ADOT&PF utilized a source
level (RMS SPL) of 165.6 dB and assumed 3 hours of driving per day. For
24-inch dolphin and fender piles, ADOT&PF used a source level of 161 dB
and assumed up to 2 hours of driving per day. For installation and/or
removal of piles less than 24-inches in diameter, ADOT&PF assumed use
of 18-inch piles and used the same source level of 161 dB for up to 3
hours per day. If H-piles are used, a source level of 150 dB was
utilized. Practical spreading was used in all instances. Results are
shown in Table 7. Isopleths for Level B harassment associated with
impact (160 dB) and vibratory harassment (120 dB) were also calculated
and are included in Table 7.
Table 7--Pile Installation and Removal Activities and Calculated Distances to Level A and Level B Harassment Isopleths \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated duration Level A harassment zone (meters) (based on new Level B harassment
-------------------------------------------- technical guidance) zone (meters) \2\
---------------------------------------------------------------------
Activity Days of Cetaceans Pinnipeds
Hours per day effort -------------------------------------------------- Cetaceans and
LF MF HF PW OW pinnipeds (120 dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation 30''........... 3 13 28.8 2.6 42.6 17.5 1.2 10,970 (10,964)
Vibratory Installation 24'' Dolphin... 2 2 6.8 0.6 10.1 4.2 0.3 5,420 (5,412)
Vibratory Installation 24'' Fender.... 2 2 10.8 1 16 6.6 0.5 ..................
Vibratory Installation and/or removal 3 15 14.2 1.3 21 8.6 0.6 ..................
<24'' (18'').
Vibratory Installation and/or removal 3 15 2.6 0.2 3.9 1.6 0.1 1,000
< 24'' (H-piles).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cetaceans Pinnipeds
Activity Piles Strikes Days of -------------------------------------------------- Cetaceans and
per day per pile effort LF MF HF PW OW pinnipeds (160 dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Installation 30''............................ 4 1,000 13 1,426 51 1,699 763 56 1,740 (1,738)
3 ........ 18 1,177 42 1,402 630 46 ..................
2 ........ 26 898 32 1,070 481 35 ..................
1 ........ 52 566 20 674 303 22 ..................
Impact Installation 24'' Dolphin.................... 2 400 2 633 23 754 339 25 1,590 (1,585)
1 ........ 3 399 14 475 213 16 ..................
Impact Installation 24'' Fender..................... 4 120 2 450 16 537 241 18 ..................
3 ........ 3 372 13 443 199 15 ..................
2 ........ 4 284 10 338 152 11 ..................
1 ........ 8 179 6 213 96 7 ..................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ To account for potential variations in daily productivity during impact installation, isopleths were calculated for different numbers of piles that
could be installed each day (Therefore, should the contractor expect to install fewer piles in a day than the maximum anticipated, a smaller Level A
shutdown zone would be required to avoid take.)
\2\ Mitigation zones have been rounded up to the nearest 10 m. Number in parenthesis is distance used in calculation of take estimates.
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. The corresponding areas of the Level A and Level B
ensonified zones for impact driving and vibratory installation/removal
are shown in Table 8.
Table 8--Calculated Areas (km\2\) Ensonified Within Level A and Level B Harassment Thresholds in Excess of 100-Meter Distance During Pile Installation
and Removal Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated duration Level A harassment zone (km\2\) (based on new Level B harassment
-------------------------------------------- technical guidance) zone (km\2\)
-------------------------------------------------- (based on
Cetaceans Pinnipeds practical
Activity -------------------------------------------------- spreading loss
Hours per day Days of model)
effort -------------------
LF MF HF PW OW Cetaceans and
pinnipeds (120 dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation 30''........... 3 13 NA NA NA NA NA 24.42
Vibratory Installation 24'' Dolphin... 2 2 NA NA NA NA NA 17.19
Vibratory Installation 24'' Fender.... 2 2 NA NA NA NA NA ..................
Vibratory Installation and/or removal 3 15 NA NA NA NA NA ..................
<24'' (18'').
Vibratory Installation and/or removal 3 15 NA NA NA NA NA 1.47
< 24'' (H-piles).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cetaceans Pinnipeds
Activity Piles Strikes Days of -------------------------------------------------- Cetaceans and
per day per pile effort LF MF HF PW OW pinnipeds (160 dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Installation 30''............................ 4 1,000 13 2.84 NA 3.91 0.91 NA 4.08
[[Page 48994]]
3 ........ 18 1.98 NA 2.75 0.66 NA ..................
2 ........ 26 1.21 NA 1.66 0.41 NA ..................
1 ........ 52 0.55 NA 0.74 0.18 NA ..................
Impact Installation 24'' Dolphin.................... 2 400 2 0.67 NA 0.89 0.22 NA 3.45
1 ........ 3 0.29 NA 0.40 0.09 NA ..................
Impact Installation 24'' Fender..................... 4 120 2 0.36 NA 0.50 0.11 NA ..................
3 ........ 3 0.26 NA 0.35 0.08 NA ..................
2 ........ 4 0.16 NA 0.22 0.04 NA ..................
1 ........ 8 0.06 NA 0.09 0.02 NA ..................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Potential exposures to impact and vibratory pile driving noise for
each threshold were estimated using local marine mammal density
datasets where available and local observational data.
Dall's Porpoise
There currently is no information on the presence or abundance of
Dall's porpoises in the Shumagin Islands. No sightings of Dall's
porpoises have been documented in Humboldt Harbor and they are not
expected to occur there (HDR 2017). However, individuals may occur in
the deeper waters north of Popof Island or in Popof Strait, west of the
Sand Point Airport. These porpoises have been sighted infrequently on
research cruises heading in and out of Sand Point in deeper local
waters (Speckman, Pers. Comm.). Dall's porpoise are non-migratory;
therefore, exposure estimates are not dependent on season. Exposure of
Dall's porpoise to noise from impact hammer pile installation is
unlikely, as they are not expected to occur within the 1,738 meter
Level B harassment zone. Similarly, we do not anticipate Dall's
porpoise would be exposed to noise in excess of the Level A harassment
threshold, which would be located at a maximum distance of 1,699
meters. It is possible, however, that they would occur in the larger
Level B zone associated with vibratory driving of 30-inch (up to 10,970
meters) and 24-inch piles (up to 5,420 meters). Over the course of 40
days in which vibratory driving will be employed, NMFS conservatively
anticipates no more than one observation of a Dall's porpoise pod in
these Level B vibratory harassment zones. With an average pod size of
3.7 (Wade et al., 2003), NMFS has authorized take of four Dall's
porpoises during the pile driving activities. No Level A take is
authorized for Dall's porpoises.
Harbor Porpoise
There are no reports of harbor porpoises or harbor porpoise
densities in the Shumagin Islands. It is reasonable to assume that they
would occur in the vicinity of Popof and Unga Islands given that they
are common in the Gulf of Alaska and their preferred habitat consists
of coastal waters of 100 meters or less (Hobbs and Waite 2010). Based
on the known range of the Gulf of Alaska stock, only six sightings of
singles or pairs during 110 days of monitoring of the Kodiak Ferry
Terminal and Dock Improvements project, and occasional sightings during
monitoring of projects at other locations on Kodiak Island, it is
assumed that harbor porpoises could be present on an intermittent
basis.
Harbor porpoises are non-migratory; therefore, exposure estimates
are not dependent on season. NMFS conservatively estimates harbor
porpoise could be exposed to construction-related in-water noise on two
out of every three construction days. Harbor porpoises in this area
have a mean group size of 1.82 (Watwood and Buonantony, 2012).
Therefore, NMFS authorizes the take of 49 harbor porpoises as shown
below.
Sighting every 0.667 days * 40 days of exposure * 1.82 group size =
49 (48.55 rounded up).
During impact installation of piles, the Level A harassment
isopleth for harbor porpoises extends up to 1,699 meters when a maximum
of four 30-inch piles are installed on the same day. Given that harbor
porpoises prefer near-shore waters, we anticipate that it is possible
for up to one-third of the harbor porpoise sighting to occur in a Level
A harassment zone. Therefore, of the 49 authorized takes, 16 will occur
within a Level A harassment isopleth and 33 will occur within a Level B
harassment isopleth.
Killer Whale
Line transect surveys conducted in the Shumagin Islands between
2001 and 2003 did not record any resident killer whales, but did record
a relatively high abundance of transient killer whales (Zerbini et al.,
2007). The same study estimated a density of approximately 0.002 killer
whales per square kilometer (km\2\) in the Shumagin Islands (Zerbini et
al., 2007). The population trend of the transient stock of killer
whales in Alaska has remained stable since the 1980s (Muto et al.,
2016a). Anecdotal observations indicate that killer whales are not
often seen in the vicinity of Sand Point, including Popof Strait (HDR
2017). Killer whales are expected to be uncommon in the project area
and are not expected to enter into Humboldt Harbor. However, NMFS used
the density estimate of 0.002 per km\2\ to determine the number of
killer whales potentially observed within the project area. Given the
low probability of occurrence within the project area, using the
available density estimates as an indication of exposure is a
conservative approach to estimate potential killer whale exposure to
pile driving noise. Vibratory installation of 30-inch piles will occur
on 13 days while vibratory installation of 24-inch dolphin piles, 24-
inch fender piles, and temporary 18-inch or h-piles will occur on a
total of 19 days. NMFS assumed that 18-inch piles would be installed
instead of h-piles and that 18-inch piles have the same source level
and isopleth as 24-in piles. NMFS also added a 25 percent contingency
factor to account for unanticipated delays. Therefore, there would be
up to 16.25 days of vibratory installation of 30-inch piles and 23.75
days of 24-inch piles. At a density of 0.002 whales/km\2\, NMFS
anticipates approximately 0.79 killer whales (i.e., 0.002 whales/km\2\
* 24.42 km\2\ 30-inch vibratory harassment zone * 16.25 days) would be
exposed to Level B harassment associated with 30-inch vibratory driving
while 0.82 killer whales (i.e., 0.002 whales/km\2\ * 17.19 km\2\ 24-
inch vibratory harassment zone * 23.75 days) would be exposed to Level
B harassment from 24-inch vibratory driving over 40 days. Over the 40
day construction period, 2 killer whales (1.61 rounded up) would be
exposed to Level B harassment.
However, killer whales generally travel in pods, or groups of
individuals. The average pod size for transient killer whales is four
individuals (Zerbini et
[[Page 48995]]
al., 2007) and 5-50 for resident killer whales (Heise et al., 2003). A
monitoring report associated with issuance of an IHA for Kodiak Ferry
Terminal and Dock Improvements Project recorded four killer whale pod
observations during 110 days of monitoring with the largest pod size
consisting of seven individuals. NMFS will, therefore, assume that
there will be sightings of two pods with an average group size of seven
over the course of the 40-day construction period resulting in 14
authorized Level B killer whale takes. These killer whales would likely
be transients, but could also be residents, so take is authorized for
both stocks. No Level A take is authorized for killer whales since the
injury zone is smaller than the 100 meter shutdown zone.
Humpback Whale
Surveys from 2001 to 2004 estimated humpback whale abundance in the
Shumagin Islands at between 410 and 593 individuals during the summer
feeding season (July-August; Witteveen et al., 2004; Zerbini et al.,
2006). Annual vessel-based, photo-identification surveys in the
Shumagin Islands from 1999 to 2015 identified 654 unique individual
humpback whales between June and September (Witteveen and Wynne 2016).
Humpback whale abundance in the Shumagin Islands increased 6 percent
per year between 1987 and 2003 (Zerbini et al., 2006). Between 2001 and
2003, summer line transect surveys in the Shumagin Islands estimated
the humpback whale density at 0.02 whales per km\2\ (Zerbini et al.,
2006). Given an approximate population increase of 6 percent each year
since the early 2000's (Muto et al., 2016b), we conservatively estimate
the current density of humpback whales as about 0.04 whale per km\2\
(0.02 whale/km\2\ * (6% increase/year * 13 years)).
Exposure of humpback whales to Level A and Level B harassment noise
levels is possible in August and, to a lesser extent, in September.
Exposure is unlikely between October and December because humpback
whale abundance is low during late fall and winter. Humpback whales,
when present, are unlikely to enter Humboldt Harbor or approach the
City of Sand Point, but would instead transit through Popof Strait or
feed in the deeper waters off the airport, between Popof and Unga
islands (HDR 2017). Harassment from pile installation is possible in
waters between Popof and Unga islands, including Popof Strait. Because
we do not know exactly when construction might occur, we will use the
updated summer density estimate (and our only density estimate) of 0.04
whales/km\2\ to estimate exposure.
At a density of 0.04 whales/km\2\, NMFS anticipates approximately
15.87 humpback whales (i.e., 0.04 whales/km\2\ * 24.42 km\2\ 30-inch
vibratory harassment zone * 16.25 days) would be exposed to harassment
on days when 30-inch vibratory driving would occur. Additionally, 16.33
whales (i.e., 0.04 whales/km\2\ * 17.19 km\2\ 24-inch vibratory
harassment zone * 23.75 days) would be exposed to harassment on days in
which 24-inch piles are driven for a total of 32 (32.2 rounded down)
whale takes over 40 days.
A subset of the 32 humpback whales potentially exposed to
harassment noise levels may enter the Level A harassment zone, which
extends 1,426 meters assuming an optimal productivity of driving four
30-inch piles per day; 633 meters when driving two 24-inch dolphins;
and 450 meters when driving four 24-inch fenders. NMFS has again added
a 25 percent contingency and will assume 16.25 days of 30-inch impact
pile driving, 2.5 days of 24-inch dolphin installation and 2.5 days of
24-inch fender installation. Note that when estimating Level A take,
NMFS conservatively defaulted to the Level A isopleth and corresponding
area associated with maximum number of piles that can be driven each
day for each pile size. We anticipate approximately 1.84 humpback
whales (e.g., 0.04 whales/km\2\ * 2.84 km\2\ Level A harassment zone *
16.25 days) would be exposed to Level A harassment during 30-inch
impact pile driving; approximately 0.07 humpback whales (e.g., 0.04
whales/km\2\ * 0.67 km\2\ Level A harassment zone * 2.5 days) would be
exposed to Level A harassment during 24-inch dolphin installation; and
approximately 0.04 humpback whales (e.g., 0.04 whales/km\2\ * 0.36
km\2\ Level A harassment zone * 2.5 days) would be exposed to Level A
harassment during 24-inch fender installation. Therefore, a total of 2
(1.95 rounded up) humpback whales could be exposed to Level A
harassment. Therefore, NMFS is authorizing 30 Level B and 2 Level A
humpback whale takes.
Humpback whales found in the Shumagin Islands are predominantly
members of the Hawaii DPS, which are not listed under the ESA. However,
based on a comprehensive photo-identification study, members of both
the Western North Pacific DPS (ESA-listed as endangered) and Mexico DPS
(ESA-listed as threatened) are known to occur in the Gulf of Alaska and
Aleutian Islands. Members of different DPSs are known to intermix on
feeding grounds; therefore, all waters off the coast of Alaska should
be considered to have ESA-listed humpback whales. According to Wade et
al. (2016), the probability of encountering a humpback whale from the
Western North Pacific DPS in the Gulf of Alaska is 0.5 percent (CV
[coefficient of variation]=0.001). The probability of encountering a
humpback whale from the Mexico DPS is 10.5 percent (CV=0.16). The
remaining 89 percent (CV=0.01) of individuals in the Gulf of Alaska are
likely members of the Hawaii DPS (Wade et al., 2016). Therefore, it is
estimated that 28 humpback whales would be from the Hawaii DPS, three
humpback whales would be from the threatened Mexico DPS, and 1 humpback
whale would be from the endangered Western North Pacific DPS. Given the
small number of anticipated Level A takes, NMFS will assume that both
authorized Level A takes represent members of the Hawaii DPS.
Fin Whale
Vessel-based line-transect surveys of coastal waters between
Resurrection Bay and the central Aleutian Islands were completed in
July and August from 2001 to 2003 (Zerbini et al., 2006). Large
concentrations of fin whales were found in the Semidi Islands, located
midway between the Shumagin Islands and Kodiak Island just south of the
Alaska Peninsula. The abundance of fin whales in the Shumagin Islands
ranged from a low estimate of 604 in 2003 to a high estimate of 1,113
in 2002. The estimated density of fin whales in the Shumagin Islands
was 0.007 whales per km\2\ and this is the density estimate assumed for
the project area. Fin whale density in the Shumagin Islands at other
times of the year is unknown, and they are uncommon in Humboldt Harbor
or Popof Strait (HDR 2017). At a density of 0.007 whales/km\2\, NMFS
anticipates approximately 2.77 fin whales (i.e., 0.007 whales/km\2\ *
24.42 km\2\ 30-inch vibratory harassment zone * 16.25 days) would be
exposed to Level B harassment on days when 30-inch vibratory driving
would occur. Additionally, 2.86 whales (i.e., 0.007 whales/km\2\ *
17.19 km\2\ 24-inch vibratory harassment zone * 23.75 days) would be
exposed to Level B harassment on days in which 24-inch piles are driven
for a total of 6 (5.63 rounded up) Level B takes of fin whales over 40
days. Therefore, NMFS is authorizing 6 Level B fin whale takes. Fin
whales are typically found in deep, offshore waters so no Level A take
is authorized for this species.
[[Page 48996]]
Minke Whale
There are no population estimates for minke whales in Alaska;
however, nearshore aerial surveys of the western Gulf of Alaska took
place between 2001 and 2003. These surveys estimated the minke whale
population in that area at approximately 1,233 individuals (Zerbini et
al., 2006). Conservatively, minke whales could be exposed to
construction-related noise levels year round. Surveys indicate a
density of 0.001 minke whales per km\2\ south of the Alaska Peninsula
(including the Shumagin Islands). At a density of 0.001 whales/km\2\,
NMFS anticipates approximately 0.40 minke whales (i.e., 0.001 whales/
km\2\ * 24.42 km\2\ 30-inch vibratory harassment zone * 16.25 days)
would be exposed to Level B harassment on days when 30-inch vibratory
driving would occur. Additionally, 0.41 whales (i.e., 0.001 whales/
km\2\ * 17.19 km\2\ 24-inch vibratory harassment zone * 23.75 days)
would be exposed to Level B harassment on days in which 24-inch piles
are driven for a total of 1 (0.81 rounded up) level B take of minke
whales over 40 construction days. With a pod size of two or three (NMFS
2015), NMFS authorizes the take of three minke whales during the 40-day
construction period. No Level A take is authorized due to low abundance
near the project area.
Gray Whale
Gray whales could potentially migrate through the area between
March through May and November through January. Gray whale presence
near Sand Point and in Humboldt Harbor is rare and unlikely to occur
during the construction period. As such, exposure of gray whales to
noise from impact hammer pile installation is unlikely, as they are not
expected to occur within the 1,426 meter harassment zone. Harassment
from vibratory pile installation is possible in the deeper water north
of Popof Strait. Because there are no density estimates for the area
and the rarity of gray whales within the project area, NMFS
conservatively estimates that gray whales will not be observed more
than one time during the construction period. Multiplying the one
potential observation by the average pod size of 2.4 (Rugh et al.,
2005), NMFS authorizes the take of two gray whales by Level B
harassment level over the course of the construction period. No Level A
take is authorized for gray whales.
Steller Sea Lion
The number of unique individuals used to calculate take was based
on information reported by the nearby seafood processing facility. It
is estimated that about 12 unique individual sea lions likely occur in
Humboldt Harbor each day during the pollock fishing seasons (HDR 2017).
It is assumed that Steller sea lions may be present every day, and that
take will include multiple harassments of the same individual(s) both
within and among days. It is also assumed that 12 unique individual sea
lions occur in Humboldt Harbor each day and could potentially be
exposed to Level B harassment over 40 days of construction. Given that
the project area is located within the aquatic zones (i.e., designated
critical habitat) of two designated major haulouts (Sea Lion Rocks and
The Whaleback), sea lions could commonly enter into the Level B
ensonified zone outside of the Humboldt Harbor. As such, it assumed
that an additional 12 animals per day may occur in the Level B
harassment zone outside of Humboldt Harbor. Total exposures is
calculated using the following equation:
24 sea lions per day * 40 days of exposure = 960 potential exposures
Therefore, we authorize the Level B take of 960 Steller sea lions.
No Level A take is anticipated as the Level A isopleths are smaller
than the 100 meter shutdown zone.
Harbor Seal
Anecdotal observations indicate that harbor seals are uncommon in
Humboldt Harbor proper (HDR 2017). However, they are expected to occur
occasionally in the project area. The Kodiak Ferry Terminal and Dock
Improvements Project on Kodiak Island recorded 13 single sightings of
harbor seals during 110 days of monitoring. Although the harbor seal
stock is different at Kodiak (South Kodiak stock) and the project sites
are somewhat dissimilar, NMFS used this information to conservatively
estimate that one harbor seal could be present near Sand Point on any
given day. An aerial haulout survey in 2011 estimated that 15 harbor
seals occupy the survey unit along the south coast of Popof Island
(London et al., 2015) and anecdotal observations indicate that harbor
seals are known to occur intermittently near the airport (HDR 2017).
NMFS conservatively estimates that one animal per day will be observed
near the harbor while another animal will occur near the airport or
elsewhere within an ensonified zone. Therefore, NMFS estimates that up
to two harbor seals may be taken each day during the 40-day pile
installation period for a total of 80 authorized takes.
During impact installation of 30-inch piles, the Level A harassment
isopleth for harbor seals extends out to a maximum distance of 763
meters on days when four piles are driven; out to 339 meters when two
24-inch dolphins are installed on the same day; and out to 241 meters
when four fenders are installed on a single day. Harbor seals often act
curious toward on-shore activities and are known to approach humans,
lifting their heads from the water to look around. Given that harbor
seals are likely to be found in the near-shore environment, we are
authorizing limited Level A take since the impact pile driving injury
zones can extend well beyond the 100 meter shutdown zone. We anticipate
that up to one-third of harbor seal takes would be by Level A
harassment resulting in 27 authorized Level A and 53 authorized Level B
takes of harbor seals.
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
and their habitat (50 CFR 216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully balance two primary factors: (1) The manner in which, and the
degree to which, the successful implementation of the measure(s) is
expected to reduce impacts to marine mammals, marine mammal species or
stocks, and their habitat which considers the nature of the potential
adverse impact being mitigated (likelihood, scope, range), as well as
the likelihood that the measure will be effective if implemented; and
the likelihood of effective implementation,
[[Page 48997]]
and; (2) the practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
In addition to the measures described later in this section,
ADOT&PF will 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, and;
(b) For in-water heavy machinery work other than pile driving
(e.g., standard barges, tug boats), if a marine mammal comes within 10
m, operations shall cease and vessels shall reduce speed to the minimum
level required to maintain steerage and safe working conditions. This
type of work could include the following activities: (1) Movement of
the barge to the pile location; or (2) positioning of the pile on the
substrate via a crane (i.e., stabbing the pile).
(c) Work will only occur during daylight hours, when visual
monitoring of marine mammals can be conducted.
The following measures would apply to ADOT&PFs mitigation
requirements:
Establishment of Shutdown Zone--For all pile driving activities,
ADOT&PF will establish a shutdown zone. The purpose of a shutdown zone
is generally to define an area within which shutdown of activity would
occur upon sighting of a marine mammal (or in anticipation of an animal
entering the defined area). In this case, shutdown zones are intended
to contain areas in which SPLs equal or exceed acoustic injury criteria
for some authorized species, based on NMFS' new acoustic technical
guidance published in the Federal Register on August 4, 2016 (81 FR
51693). The shutdown zones vary for specific species. A conservative
shutdown zone of 100 meters will be monitored during all pile driving
activities to prevent Level A exposure to most species. During
vibratory installation of piles of all sizes and impact installation of
24-inch piles, piles under 24 inches, and H-piles, a 100-meter shutdown
zone would prevent Level A take to marine mammals. A 100-meter shutdown
zone would also be sufficient to prevent Level A take of mid-frequency
cetaceans and otariid pinnipeds (i.e., Steller sea lions) during impact
installation of 30-inch and 24-inch piles. Note that Level A take is
not authorized for the low-frequency species of fin whale, gray whale
and minke whale, mid-frequency killer whale and high-frequency Dall's
porpoise since estimated take numbers are low. In the unlikely
occurrence that animals of these species are observed approaching their
respective Level A zones, pile driving operations will shut down. If an
animal for which take is authorized is unexpectedly sighted within the
100-meter shutdown zone during impact or vibratory driving, operations
shall immediately cease. The animal will be counted as a Level B take
assuming it is outside of the Level A take zone as delineated in Table
7.
Establishment of Level A Take Zone--ADOT&PF will establish Level A
take zones which are areas beyond the shutdown zones where animals may
be exposed to sound levels that could result in PTS. During impact
installation of 30-inch and 24-inch piles, a 100-meter shutdown zone
would not be sufficient to prevent Level A take of low-frequency
cetaceans (i.e., humpback whales), high-frequency cetaceans (i.e.,
harbor porpoises), or phocid pinnipeds (i.e., harbor seals). For this
reason, Level A take for small numbers of humpback whales, harbor
porpoises, and harbor seals is authorized.
To account for potential variations in daily productivity during
impact installation, isopleths were calculated for different numbers of
piles that could be installed each day. Therefore, should the
contractor expect to install fewer piles in a day than the maximum
anticipated, a smaller Level A shutdown zone reflecting the number of
piles driven would be required to avoid take. Furthermore, if the first
pile is driven and no marine mammals have been observed within the
radius of corresponding Level A zone, then the Level A radius for the
next pile shall be decreased to next largest Level A radius. This
pattern shall continue unless an animal is observed within the most
recent shutdown zone radius, at which that specific shutdown radius
shall remain in effect for the rest of the workday. Additionally, if
piles of different sizes are installed in a single day, the size of the
monitored Level A zone for all installed piles will default to the
isopleth corresponding to the largest pile being driven that day. Level
A zones will be rounded up to the nearest 10 m and are depicted in
Table 9.
Table 9--Level A Zone Isopleths During Impact Driving\1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Isopleths (m)
Piles -------------------------------------------------------------------------------
Activity installed per LF (Humpback HF (Harbor PW (Harbor
day whales) MF porpoises) seals) OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Installation 30''................................ 4 1,430 (1,426) 60 (51) 1,700 (1,699) 770 (763) 60 (56)
3 1,180 (1,177) 50 (42) 1,410 (1,402) 630 (630) 50 (46)
2 900 (898) 40 (32) 1,070 (1,070) 490 (481) 40 (35)
1 570 (566) 20 (20) 680 (674) 310 (303) 30 (22)
Impact Installation 24'' Dolphin........................ 2 640 (633) 30 (23) 760 (754) 340 (339) 30 (25)
1 400 (399) 20 (14) 480 (475) 220 (213) 20 (16)
Impact Installation 24'' Fender......................... 4 450 (450) 20 (16) 540 (537) 250 (241) 20 (18)
3 380 (372) 20 (20) 450 (443) 200 (199) 20 (15)
2 290 (284) 10 (10) 340 (338) 160 (152) 20 (11)
1 180 (179) 10 (6) 220 (213) 100 (96) 10 (7)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Mitigation zones have been rounded up to the nearest 10 m. Number in parenthesis is distance used in calculation of take estimates where applicable.
Establishment of Disturbance Zones--ADOT&PF will establish Level B
disturbance zones or zones of influence (ZOI) which are areas where
SPLs equal or exceed 160 dB rms for impact driving and 120 dB rms
during vibratory
[[Page 48998]]
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 and
outside the shutdown zone and thus prepare for potential shutdowns of
activity. The Level B zone isopleths will be rounded up to the nearest
10 m and are depicted in Table 10.
Table 10--Level B Zone Isopleths During Impact and Vibratory Driving
------------------------------------------------------------------------
Level B
Activity Harassment
Zone (meters)
------------------------------------------------------------------------
Vibratory Installation 30''............................. 10,970
Vibratory Installation 24'' Dolphin..................... 5,420
Vibratory Installation 24'' Fender...................... 5,420
Vibratory Installation and/or removal <24'' (18'' piles) 5,420
Vibratory Installation and/or removal <24'' (H-piles)... 1,000
Impact Installation 30''................................ 1,740
Impact Installation 24'' Dolphin........................ 1,590
Impact Installation 24'' Fender......................... 1,590
------------------------------------------------------------------------
\1\ Mitigation zones have been rounded up to the nearest 10 m. Number in
parenthesis is distance used in calculation of take estimates where
applicable.
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. 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. Soft Start is not required during
vibratory pile driving and removal activities.
Pre-Activity Monitoring--Prior to the start of daily in-water
construction activity, or whenever a break in pile driving of 30
minutes or longer occurs, the observer will observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone will be
cleared when a marine mammal has not been observed within zone for that
30-minute period. If a marine mammal is observed within the shutdown
zone, a soft-start cannot proceed until the animal has left the zone or
has not been observed for 30 minutes for medium and large-sized
odontocetes and mysticetes and 15 minutes for small cetaceans and
pinnipeds. If the Level B harassment zone has been observed for 30
minutes and non-permitted species are not present within the zone, soft
start procedures can commence and work can continue even if visibility
becomes impaired within the Level B zone. If the Level B zone is not
visible while work continues, exposures will be recorded at the
estimated exposure rate for each permitted species. If work ceases for
more than 30 minutes, the pre-activity monitoring of both zones must
recommence.
Based on our evaluation of the applicant's proposed measures, as
well as other measures considered by NMFS, NMFS has determined that the
planned mitigation measures provide the means effecting the least
practicable adverse impact on the affected species or stocks and their
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104 (a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
action area. Effective reporting is critical to compliance as well as
ensuring that the most value is obtained from the required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the
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 marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
Mitigation and monitoring effectiveness.
Visual Marine Mammal Observation
Monitoring will be conducted by qualified marine mammal observers
(MMOs), who are trained biologists, with the following minimum
qualifications:
Independent observers (i.e., not construction personnel)
are required;
At least one observer must have prior experience working
as an observer;
Other observers may substitute education (undergraduate
degree in biological science or related field) or training for
experience;
Ability to conduct field observations and collect data
according to assigned protocols;
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates and times when in-water construction
activities were suspended to avoid potential incidental injury from
construction sound of marine mammals observed within a defined shutdown
zone; and marine mammal behavior;
Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary; and
NMFS will require submission and approval of observer CVs.
In order to effectively monitor the pile driving monitoring zones,
two MMOs will be positioned at the best practical vantage point(s). The
monitoring position may vary based on pile driving activities and the
locations of the piles
[[Page 48999]]
and driving equipment. The monitoring location(s) will be identified
with the following characteristics: (1) Unobstructed view of pile being
driven; (2) Unobstructed view of all water within the Level A (if
applicable) and Level B harassment zones for pile being driven,
although it is understood that monitoring may be impaired at longer
distances; and (3) Safe distance from pile driving activities in the
construction area. If necessary, observations may occur from two
locations simultaneously. Potential observation locations include the
existing City Dock, the airport, the fish processing facility, or the
quarry hillside located south of the project site.
Observers will be on site and actively observing the shutdown and
disturbance zones during all pile driving and extraction activities.
Observers will use their naked eye with the aid of binoculars, big-eye
binoculars or spotting scope to search continuously for marine mammals
during all pile driving and extraction activities.
The following additional measures apply to visual monitoring:
If waters exceed a sea-state which restricts the
observers' ability to make observations within 100 m of the pile
driving activity (e.g., excessive wind or fog), pile installation and
removal will cease. Pile driving will not be initiated until the entire
shutdown zone is visible;
If a marine mammal authorized for Level A take is present
within the Level A harassment zone, a Level A take would be recorded.
If Level A take reaches the authorized limit, then pile installation
would be stopped as these species approach the Level A harassment area
to avoid additional take of these species;
If a marine mammal authorized for Level B take is present
in the Level B harassment zone, pile driving activities or soft-start
may begin and a Level B take would be recorded. Pile driving activities
may occur when these species are in the Level B harassment zone,
whether they entered the Level B zone from the Level A zone (if
relevant), shutdown zone or from outside the project area. If Level B
take reaches the authorized limit, then pile installation would be
stopped as these species approach to avoid additional take of these
species;
If any marine mammal species for which take is not
authorized or if a species for which authorization has been granted but
the number of authorized takes has been met enters or approaches the
ZOI all activities shall be shut down until the animal is seen leaving
the ZOI or it has not been seen in the shutdown zone for 30 minutes for
medium and large-sized odontocetes and mysticetes and 15 minutes for
small cetaceans and pinnipeds;
If any marine mammal species not authorized for take are
encountered during activities and are likely to be exposed to Level B
harassment, then ADOT&PF must stop pile driving activities and report
observations to NMFS' Office of Protected Resources;
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;
The MMOs will record any authorized cetacean or pinniped
present in the relevant injury zone. The Level A zones are shown in
Table 9;
The MMOs will record any authorized cetacean or pinniped
present in the relevant disturbance zone. The Level B zones are shown
in Table 10;
Ongoing in-water pile installation may be continued during
periods when conditions such as high sea state, rain, glare, or other
conditions prevent effective marine mammal monitoring of the entire
Level B harassment zone. MMOs would continue to monitor the visible
portion of the Level B harassment zone throughout the duration of
driving activities; and
At the end of the pile driving day, post-construction
monitoring shall be conducted for 30 minutes beyond the cessation of
pile driving.
Data Collection
Observers are required to use data forms approved by NMFS. 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;
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;
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 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, including the total number extrapolated from observed
animals across the entirety of relevant monitoring zones. 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.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as ``an impact resulting from
the specified activity that cannot be reasonably expected to, and is
not reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival'' (50 CFR 216.103).
A negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes, alone, is not
enough information on which to base an impact determination. In
addition to considering the authorized number of marine mammals that
might be ``taken'' through harassment, NMFS considers other factors,
such as the likely nature of any responses (e.g., intensity, duration),
the context of any responses (e.g., critical reproductive time or
location, migration, etc.), as well as effects on habitat, the status
of the affected stocks, and the likely effectiveness of the mitigation.
Consistent with the 1989 preamble for NMFS's implementing regulations
(54 FR 40338; September 29, 1989), the impacts from other past and
ongoing anthropogenic activities are
[[Page 49000]]
incorporated into these analyses via their impacts on the environmental
baseline (e.g., as reflected in the regulatory status of the species,
population size and growth rate where known, ongoing sources of human-
caused mortality, or ambient noise levels).
To avoid repetition, the discussion of our analyses applies to all
the species listed in Table 3. 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 extraction activities associated with the Sand
Point City Dock Replacement Project, as outlined previously, have the
potential to injure, disturb or displace marine mammals. Specifically,
Level A harassment (injury) in the form of PTS may occur to a limited
numbers of three marine mammal species while a total of nine species
could experience Level B harassment (behavioral disturbance). Potential
takes could occur if individuals of these species are present in Level
A or Level B ensonified zones when pile driving or removal is under
way.
No mortality is anticipated to result from this activity. Limited
take of three species of marine mammal by Level A harassment (injury)
is authorized due to potential auditory injury (PTS) that cannot
reasonably be prevented through mitigation. The marine mammals
authorized for Level A take (27 harbor seals, 16 harbor porpoises, and
2 humpback whales) are estimated to experience PTS if they remain
within the outer limits of a Level A harassment zone during the entire
time that impact pile driving would occur during a single day. Marine
mammal species, however, are known to avoid areas where noise levels
are high (Richardson et al.,1995). Animals would likely move away from
the sound source and exit the Level A zone. Because of the proximity to
the source in which the animals would have to approach, and the longer
time in which they would need to remain in a farther proximity from the
sound source within a Level A zone, we believe the likelihood of marine
mammals experiencing PTS is low but acknowledge it could occur.
Although NMFS is authorizing limited take by PTS, the anticipated takes
reflect the onset of PTS, which would be relatively mild, rather than
severe PTS which would be expected to have more impact on an animal's
overall fitness.
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 driving and
extraction activities analyzed here are similar to, or less impactful
than, numerous construction activities conducted in similar locations
in Alaska, 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 would
not result in any adverse impact to the stock as a whole.
ADOT&PF's planned activities are localized and of relatively short
duration. The entire project area is limited to the Sand Point dock
area and its immediate surroundings. Specifically, the use of impact
driving will be limited to approximately 22 hours over the course of up
to 40 days of construction. Total vibratory pile driving time is
estimated at approximately 85 hours over the same period. While impact
driving does have the potential to cause injury to marine mammals,
mitigation in the form of a 100 m shutdown zone should limit exposure
to potentially injurious sound.
The project is not expected to have significant adverse effects on
marine mammal habitat. No important marine mammal reproductive areas,
such as rookeries, are known to exist within the ensonified areas. The
project is located within the aquatic zones (i.e., designated critical
habitat) of two major Steller sea lion haul outs, and the Level B
underwater harassment zone associated with the planned project overlaps
with a third. The closest major haulout is approximately 27 km distant.
The project activities are limited in time and would not modify
existing marine mammal habitat. EFH near the project area has been
designated for a number of species. While the activities may cause some
fish to leave the area of disturbance, temporarily impacting marine
mammals' foraging opportunities, this would encompass a relatively
small area of habitat leaving large areas of existing fish and marine
mammal foraging habitat unaffected. As such, the impacts to marine
mammal habitat are not expected to cause significant or long-term
negative consequences.
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 likelihood that PTS could occur in a limited number of animals is
low, but acknowledged; (3) the anticipated incidences of Level B
harassment consist of, at worst, temporary modifications in behavior or
potential temporary threshold shift (TTS); (4) the limited temporal and
spatial impacts on marine mammals or their habitat; (5) the absence of
any major haul outs or rookeries near the project area; and (6) the
presumed efficacy of the planned mitigation measures in reducing the
effects of the specified activity to the level of effecting the least
practicable 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 Sand Point City Dock Replacement Project will have a
negligible impact on all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Section 101(a)(5)(D) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers and so, in practice, NMFS compares the number of
individuals taken to the most
[[Page 49001]]
appropriate estimation of the relevant species or stock size in our
determination of whether an authorization is limited to small numbers
of marine mammals.
Table 11 presents the number of animals that could be exposed to
received noise levels that could cause Level A and Level B harassment
for the planned work at the Sand Point Dock Replacement Project. Our
analysis shows that between <0.01 percent and 2.89 percent of the
populations of affected stocks could be taken by harassment. Therefore,
the numbers of animals authorized to be taken for all species 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. For pinnipeds, especially Steller sea lions,
occurring in the vicinity of the project site, there will almost
certainly be some overlap in individuals present day-to-day, and these
takes are likely to occur only within some small portion of the overall
regional stock. Table 11. Summary of the estimated numbers of marine
mammals potentially exposed to Level A and Level B harassment noise
levels.
Table 11--Summary of the Estimated Numbers of Marine Mammals Potentially Exposed to Level A and Level B
Harassment Noise Levels
----------------------------------------------------------------------------------------------------------------
Estimated Estimated
number of number of
individuals individuals
potentially potentially DPS/Stock abundance Percent of population
Species (DPS/stock) exposed to the exposed to the (DPS/Stock) exposed to Level A or
Level A Level B Level B thresholds
harassment harassment
threshold threshold
----------------------------------------------------------------------------------------------------------------
Steller sea lion.................. 0 960 50,983............... 1.88.
(wDPS)............................
Harbor seal (Cook Inlet/Shelikof 27 53 27,386............... 0.29.
Strait).
Harbor porpoise (Gulf of Alaska).. 16 33 31,046............... 0.16.
Dall's porpoise (Alaska).......... 0 4 83,400............... <0.01.
Killer whale (Gulf of Alaska, 0 14 587 (transient)...... 2.38 (transient).
Aleutian Islands, and Bering Sea 2,347 (resident)..... 0.6 (resident)
transient or Alaska resident).
Humpback whale \1\ (Central North 2 30 10,103 (Central NP).. 0.32.
Pacific/Western North Pacific). 1,107 (Western NP)... 2.89.
Fin whale (Northeast Pacific)..... 0 6 1,368 \2\............ 0.44.
Gray whale (Eastern North Pacific) 0 2 20,990............... <0.01.
Minke whale (Alaska).............. 0 3 2,020 \3\............ <0.01.
Total......................... 45 1,105 N/A.................. N/A.
----------------------------------------------------------------------------------------------------------------
\1\ The Hawaii DPS is estimated to account for approximately 89 percent of all humpback whales in the Gulf of
Alaska, whereas the Mexico and Western North Pacific DPSs account for approximately 10.5% and 0.5%,
respectively (Wade et al., 2016; NMFS 2016). Therefore, an estimated 28 animals from Hawaii DPS; 3 from Mexico
DPS: and 1 from Western North Pacific DPS.
\2\ Based on 2010 survey of animals north and west of Kenai Peninsula in U.S. waters and is likely an
underestimate (Muto et al., 2016b).
\3\ Based on 2010 survey on Eastern Bering Sea shelf. Considered provisional and not representative of abundance
of entire stock (Muto et al., 2016a).
N/A: Not Applicable.
Based on the analysis contained herein of the planned activity
(including mitigation and monitoring measures) and the anticipated take
of marine mammals, NMFS finds that small numbers of marine mammals will
be taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. The planned project
is not known to occur in a subsistence hunting area. It is a developed
area with regular marine vessel traffic. Additionally, ADOT&PF has
spoken with local officials about concerns regarding impacts to
subsistence uses and none were expressed. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Endangered Species Act (ESA)
Issuance of an MMPA authorization requires compliance with the ESA.
There are four DPSs of three marine mammal species that are listed
under the ESA with confirmed or possible occurrence in the study area:
The WNP DPS and Mexico DPS of humpback whale; the western DPS of
Steller sea lion; and fin whale. The NMFS Alaska Regional Office (AKR)
Protected Resources Division issued a Biological Opinion in September
2017 under section 7 of the ESA, on the issuance of an IHA to ADOT&PF
under section 101(a)(5)(D) of the MMPA by the NMFS Permits and
Conservation Division. The biological opinion concluded that while the
issuance of the authorization may adversely affect members of these
listed species it is not likely to jeopardize the continued existence
of any listed marine mammal species or destroy or modify any critical
habitat.
Authorization
NMFS has issued an IHA to ADOT&PF for the potential harassment of
small numbers of nine marine mammal species incidental to the Sand
Point City Dock Replacement Project in Sand Point, Alaska, provided the
previously mentioned mitigation, monitoring and reporting.
Dated: October 17, 2017.
Catherine Marzin,
Acting Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2017-22881 Filed 10-20-17; 8:45 am]
BILLING CODE 3510-22-P