[Federal Register Volume 90, Number 81 (Tuesday, April 29, 2025)]
[Notices]
[Pages 17765-17779]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-07344]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE772]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Lubec Harbor Project in Lubec,
Maine
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 Maine Department of Transportation (ME DOT) to incidentally harass
marine mammals during construction activities associated with the Lubec
Harbor project in Lubec, Maine.
DATES: This authorization is effective from April 10, 2025 through
April 9, 2026.
ADDRESSES: Electronic copies of the application and supporting
documents, as well as a list of the references cited in this document,
may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#authorizations-in-process. In case of problems accessing
these documents, please call the contact listed below.
FOR FURTHER INFORMATION CONTACT: Kelsey Potlock, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms used above are included in the relevant sections below
and can be found in section 3 of the MMPA (16 U.S.C. 1362) and NMFS
regulations at 50 CFR 216.103.
Summary of Request
On August 29, 2024, NMFS received a request from ME DOT for an IHA
to take marine mammals incidental to construction activities in Johnson
Bay in Lubec, Maine. Following NMFS' review of the application, ME DOT
submitted a revised version on December 19, 2024. The application was
deemed adequate and complete on December 20, 2024. ME DOT's request is
for take of six species of marine mammals, by Level B harassment and by
Level A harassment for 3 of those species. Neither ME DOT nor NMFS
expect serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate.
Description of the Specified Activity
Overview
The Maine Department of Transportation and the Town of Lubec are
planning to construct a boat launch and breakwater structure that would
extend into Johnson Bay from the northern coast of Lubec. The town was
once one of Maine's most active commercial fishing ports, consisting of
several large herring processing operations until the late 1970s. A
collapse of the herring fishery led to the closure of those processing
canneries; however, there is a rebound of the fishing industry in the
area due to lobster fishing, shellfish harvesting, and growth of salmon
farming. The project will address the lack of sheltered boat access and
safe launch locations. The breakwater is expected to provide a
sheltered area that mariners may launch behind and recover and moor
their vessels during periods of inclement weather. This project is
scheduled in order to provide a safer harbor for the mariners and
townspeople of Lubec. This construction project includes installation
of a falsework platform, a pile supported platform (PSP), and two
floating docks. The falsework platform will be installed using impact
and vibratory pile driving, while the PSP and floating docks will
require DTH (down the hole) drilling. ME DOT is requesting
authorization of take by Level B harassment for five marine mammal
species over an estimated 234 days of pile driving/drilling activities.
Table 1--Number and Types of Piles To Be Installed
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Vibratory DTH drilling Production
Project component Pile diameter and Number of Impact strikes duration per duration per rate (piles Days of
type piles per pile pile (minutes) pile (minutes) per day) installation
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Pile Supported Platform........... 36'' steel pipe pile 72 .............. .............. 780 0.5 144
Floating Docks.................... 24-30'' steel pipe 32 .............. .............. 780 0.5 64
pile.
[[Page 17766]]
Falsework Platform................ 14'' steel H pile... 65 150 30 .............. 5 13 Install
13 Removal
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Total......................... 169................. .............. .............. .............. .............. .............. 234
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A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (90 FR
11262, March 5, 2025). Since that time, no changes have been made to
the planned activities. Therefore, a detailed description is not
provided here. Please refer to that Federal Register notice for the
description of the specific activity.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to ME DOT was published
in the Federal Register on March 5, 2025 (90 FR 11262). That notice
described, in detail, ME DOT's activity, the marine mammal species that
may be affected by the activity, and the anticipated effects on marine
mammals. In that notice, we requested public input on the request for
authorization described therein, our analyses, the proposed
authorization, and any other aspect of the notice of proposed IHA, and
requested that interested persons submit relevant information,
suggestions, and comments. During the 30-day public comment period,
NMFS did not receive any public comments.
Changes From Proposed IHA to Final IHA
NMFS has corrected a typographical error related to the source
level values for 14-inch (35.56-centimeter) impact H piles. The
proposed IHA specified source levels of 183 dB sound exposure level
(SEL) and 170 dB root mean square (RMS) for this pile type. However,
these levels were erroneously transposed, and the source levels have
been corrected to 170 dB SEL and 183 dB RMS. The correction of these
values results in updated estimated harassment isopleths and associated
ensonified areas and, as a result, updated take numbers associated with
impact driving of 14-inch piles. Please see the Estimated Take of
Marine Mammals section for updated isopleth distances, areas, and take
numbers.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
Table 2 lists all species or stocks for which take is authorized
for this activity and summarizes information related to the population
or stock, including regulatory status under the MMPA and Endangered
Species Act (ESA) and potential biological removal (PBR), where known.
PBR is defined by the MMPA as the maximum number of animals, not
including natural mortalities, that may be removed from a marine mammal
stock while allowing that stock to reach or maintain its optimum
sustainable population (as described in NMFS' SARs). While no serious
injury or mortality is authorized here, PBR and annual serious injury
and mortality (M/SI) from anthropogenic sources are included here as
gross indicators of the status of the species or stocks and other
threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Atlantic SARs. All values presented in table 2 are the most
recent available at the time of publication (including from the draft
2024 SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.
Table 2--Species Likely Affected by the Specified Activities \1\
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ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
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Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals)
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Minke Whale......................... Balaenoptera Canadian Eastern -, -, N 21,968 (0.31, 17,002, 170 9.4
acutorostrata. Coastal. 2021).
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Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae
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Atlantic White-Sided Dolphin........ Lagenorhynchus acutus.. Western N Atlantic..... -, -, N 93,233 (0.71, 54,443, 544 28
2021).
Common Dolphin...................... Delphinus delphis...... Western N Atlantic..... -, -, N 93,100 (0.56, 59,897, 1,452 414
2021).
[[Page 17767]]
Family Phocoenidae (porpoises)
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Harbor Porpoise..................... Phocoena phocoena...... Gulf of Maine/Bay of -, -, N 85,765 (0.53, 56,420, 649 142
Fundy. 2021).
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Order Carnivora--Pinnipedia
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Family Phocidae (earless seals)
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Gray Seal........................... Halichoerus grypus..... Western N Atlantic..... -, -, N 394,311 (0.20, 12,052 4,491
376,621, 2021).
Harbor Seal......................... Phoca vitulina......... Western N Atlantic..... -, -, N 61,336 (0.08, 57,637, 1,729 339
2018).
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A detailed description of the species likely to be affected by the
Lubec Harbor 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 (90 FR
11262, March 5, 2025); 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'
website (https://www.fisheries.noaa.gov/find-species) for generalized
species accounts.
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\1\ Information on the classification of marine mammal species
can be found on the web page for The Society for Marine Mammalogy's
Committee on Taxonomy (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of
variation; Nmin is the minimum estimate of stock
abundance.
\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
(mortality/serious injury) 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.
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Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Subsequently, NMFS (2024) updated
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the ~65 decibel (dB)
threshold from composite audiograms, previous analyses in NMFS (2018),
and/or data from Southall et al. (2007) and Southall et al. (2019).
Marine mammal hearing groups and their associated hearing ranges are
provided in table 3.
Table 3--Marine Mammal Hearing Groups
[NMFS 2024]
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Hearing group Generalized hearing range *
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Underwater
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Low-frequency (LF) cetaceans (baleen 7 Hz to 36 kHz.
whales).
High-frequency (HF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales, bottlenose
whales).
Very High-frequency (VHF) cetaceans (true 200 Hz to 165 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid,Lagenorhynchus cruciger &
L. australis).
Phocid pinnipeds (PW) (underwater) (true 40 Hz to 90 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 68 kHz.
lions and fur seals).
------------------------------------------------------------------------
In-Air
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Phocid pinnipeds (PA) (true seals)......... 42 Hz to 52 kHz.
Otariid pinnipeds (OA) (sea lions and fur 90 Hz to 40 kHz.
seals).
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* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges may not be as broad. Generalized hearing range
chosen based on ~65 dB threshold from composite audiogram, previous
analysis in NMFS 2018, and/or data from Southall et al. 2007; Southall
et al. 2019. Additionally, animals are able to detect very loud sounds
above and below that ``generalized'' hearing range
[[Page 17768]]
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2024) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from ME DOT's construction
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of
proposed IHA (90 FR 11262, March 5, 2025) included a discussion of the
effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from ME DOT's construction on marine
mammals and their habitat. That information and analysis is referenced
in this final IHA determination and is not repeated here; please refer
to the notice of proposed IHA (90 FR 11262, March 5, 2025).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
for authorization through the IHA, which will inform NMFS'
consideration of ``small numbers,'' the negligible impact
determinations, and impacts on subsistence uses. Harassment is the only
type of take expected to result from these activities. Except with
respect to certain activities not pertinent here, section 3(18) of the
MMPA defines ``harassment'' as any act of pursuit, torment, or
annoyance, which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild (Level A harassment); or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as
certain construction activities (i.e., pile driving and DTH drilling)
have the potential to result in disruption of behavioral patterns for
individual marine mammals. There is also some potential for auditory
injury (Level A harassment) to result, primarily for very high
frequency cetacean species and phocids because predicted auditory
injury zones are larger than for low-frequency and high-frequency
cetacean species. Auditory injury is unlikely to occur for low
frequency and high frequency cetacean species. The mitigation and
monitoring measures are expected to minimize the severity of the taking
to the extent practicable.
As described previously, no serious injury or mortality is
anticipated for this activity. Below we describe how the take numbers
are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic criteria above which NMFS believes the best
available science indicates marine mammals will likely be behaviorally
harassed or incur some degree of auditory injury; (2) the area or
volume of water that will be ensonified above these levels in a day;
(3) the density or occurrence of marine mammals within these ensonified
areas; and, (4) the number of days of activities. We note that while
these factors can contribute to a basic calculation to provide an
initial prediction of takes, additional information that can
qualitatively inform take estimates is also sometimes available (e.g.,
previous monitoring results or average group size). Below, we describe
the factors considered here in more detail and present the take
estimates.
Acoustic Criteria
NMFS recommends the use of acoustic criteria that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur auditory injury (AUD INJ) of some
degree (equated to Level A harassment). We note that the criteria for
AUD INJ, as well as the names of two hearing groups, have been recently
updated (NMFS 2024) as discussed below in the Level A harassment
section.
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 re 1 [mu]Pa) for continuous (e.g., vibratory pile driving,
drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-explosive
impulsive (e.g., seismic airguns) or intermittent (e.g., scientific
sonar) sources. Generally speaking, Level B harassment take estimates
based on these behavioral harassment thresholds are expected to include
any likely takes by TTS as, in most cases, the likelihood of TTS occurs
at distances from the source less than those at which behavioral
harassment is likely. TTS of a sufficient degree can manifest as
behavioral harassment, as reduced hearing sensitivity and the potential
reduced opportunities to detect important signals (conspecific
communication, predators, prey) may result in changes in behavior
patterns that would not otherwise occur.
ME DOT's activity includes the use of continuous (vibratory pile
driving and removal and DTH drilling) and impulsive (impact pile
driving and DTH drilling), and therefore the RMS SPL thresholds of 120
and 160 dB re 1 [mu]Pa are applicable.
Level A harassment--NMFS' 2024 Updated Technical Guidance for
Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing
(Version 3.0) (Technical Guidance, 2024) identifies dual criteria to
assess auditory injury (Level A harassment) to five different
underwater marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). ME DOT's activity includes the use of
impulsive (impact pile driving and DTH drilling) and non-impulsive
(vibratory pile driving and removal) sources.
The 2024 Updated Technical Guidance criteria include both updated
thresholds and updated weighting functions for each hearing group. The
thresholds are provided in the table below. The references, analysis,
and methodology used in the development of the criteria are described
in NMFS' 2024 Updated Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools.
[[Page 17769]]
Table 4--Thresholds Identifying the Onset of Auditory Injury
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AUD INJ onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
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Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 222 dB; Cell 2: LE,LF,24h: 197 dB.
LE,LF,24h: 183 dB.
High-Frequency (HF) Cetaceans.......... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,HF,24h: 201 dB.
LE,HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans.... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,VHF,24h: 181 dB.
LE,VHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 223 dB; Cell 8: LE,PW,24h: 195 dB.
LE,PW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 230 dB; Cell 10: LE,OW,24h: 199 dB.
LE,OW,24h: 185 dB.
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* Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for
calculating AUD INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure
level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-
impulsive sources.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [mu]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1 [mu]Pa\2\s. In this table, criteria are abbreviated to be
more reflective of International Organization for Standardization (ISO) standards (ISO 2017; ISO 2020). The
subscript ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within
the generalized hearing range of marine mammals underwater (i.e., 7 Hz to 165 kHz). The subscript associated
with cumulative sound exposure level criteria indicates the designated marine mammal auditory weighting
function (LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is
24 hours. The weighted cumulative sound exposure level criteria 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 criteria will be exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Marine
mammals are expected to be affected via sound generated by the primary
components of the project (i.e., pile driving and removal and DTH
drilling). The maximum (underwater) area ensonified above the
thresholds for behavioral harassment referenced above is approximately
29 km\2\ (7,166.06 acres) for the total area, and 11 km\2\ (2,718.16
acres) in US waters.
The project includes vibratory pile installation and removal,
impact pile driving, and DTH drilling. Source levels for these
activities are based on reviews of measurements of the same or similar
types and dimensions of piles available in the literature and proxies
from similar, previous projects. Source levels for each pile size and
activity are presented in table 5. Source levels for vibratory
installation and removal of piles of the same diameter are assumed to
be the same.
Table 5--Proxy Sound Source Levels for Pile Installation Activity
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Source levels (re
Installation Distance to 1[mu]Pa)
Project component Pile type method Proxy Reference measurement --------------------------
(m) Peak SEL RMS
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PSP............................ 36'' Diameter DTH Drilling \2\.. 25'' to 42'' Piles NMFS 2022b, Denes 10 194 164 174
Steel Pipe Piles. \3\. et al., 2019;
Floating Docks................. 24-30'' Diameter Reyff and
Steel Pipe Heyvaert, 2019;
Piles.\1\. Reyff, 2020.
Falsework Platform............. 14'' Diameter Vibratory Pile 14'' steel H pile. Caltrans 2015; 10 ....... ....... 150
Steel H Piles. Driving. NMFS 2022a. ............ ....... ....... .......
Impact Pile 10 200 170 183
Driving.
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\1\ For the purpose of this IHA, it is assumed that a 30-inch (76.2-centimeter) pile would be used to install the floating docks.
\2\ DTH drilling is considered an impulsive sound source for Level A harassment calculations, and a non-impulsive source for Level B harassment
calculations.
\3\ As a conservative measure, the same proxy measurements were used for both the PSP and the floating docks due to their pile design and installation
method similarities.
NMFS recommends treating DTH systems as both impulsive and
continuous, non-impulsive sound source types simultaneously. Thus,
impulsive thresholds are used to evaluate Level A harassment, and
continuous thresholds are used to evaluate Level B harassment. With
regards to DTH mono-hammers, NMFS recommends proxy levels for Level A
harassment based on available data regarding DTH systems of similar
sized piles and holes (Denes et al., 2019; Reyff and Heyvaert, 2019;
Reyff, 2020) (table 1 and table 6 includes number of piles and
duration; table 5 includes sound pressure and sound exposure levels for
each pile type).
ME DOT will use bubble curtains for all PSP and floating dock
construction which will use DTH drilling. We assume here that use of
the bubble curtain would result in a reduction of 5 dB from the assumed
SPL (rms) and SPL (peak) source levels for these pile sizes, and reduce
the applied source levels accordingly. 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 x Log10 (R1/R2),
where:
TL = transmission loss in dB;
B = transmission loss coefficient;
R1 = the distance of the modeled SPL from the driven pile; and
R2 = the distance from the driven pile of the initial measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading
[[Page 17770]]
occurs in a perfectly unobstructed (free-field) environment not limited
by depth or water surface, resulting in a 6-dB reduction in sound level
for each doubling of distance from the source (20*log [range]).
Cylindrical spreading occurs in an environment in which sound
propagation is bounded by the water surface and sea bottom, resulting
in a reduction of 3 dB in sound level for each doubling of distance
from the source (10*log [range]). A practical spreading value of 15 is
often used under conditions, such as the project site, where water
increases with depth as the receiver moves away from the shoreline,
resulting in an expected propagation environment that would lie between
spherical and cylindrical spreading loss conditions. Practical
spreading loss is assumed here.
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles, hammers, and the physical
environment in which the activity takes place. In order to calculate
the distances to the Level A harassment and the Level B harassment
sound thresholds for the methods and piles being used in this project,
the applicant and NMFS used acoustic monitoring data from other
locations to develop proxy source levels for the various pile types,
sizes and methods. The project includes vibratory and impact pile
installation of steel H piles and vibratory removal of steel H piles
and DTH drilling of 36-inch steel pipe piles and 24 to 30-inch steel
pipe piles. NMFS consulted multiple sources to determine valid proxy
source levels for the construction planned. This is the best available
data for pile source levels, and source levels for each pile size and
driving method are presented in table 5.
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the 2024 Updated Technical Guidance that
can be used to relatively simply predict an isopleth distance for use
in conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources such as pile driving, the optional User Spreadsheet
tool predicts the distance at which, if a marine mammal remained at
that distance for the duration of the activity, it would be expected to
incur AUD INJ. Inputs used in the optional User Spreadsheet tool, and
the resulting estimated isopleths, are reported below (table 6).
Table 6--User Spreadsheet Inputs for Calculating Level A and B Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Weighting
Pile size and installation Spreadsheet tab factor Number of Number of Activity
method used adjustment strikes per piles per day duration
(kHz) pile (minutes)
----------------------------------------------------------------------------------------------------------------
14'' H Pile Vibratory A.1 Vibratory 2.5 N/A 5 30
Installation. pile driving.
14'' H Pile Vibratory Removal. A.1 Vibratory 2.5 N/A 5 30
pile driving.
14'' H Pile Impact E.1 Impact pile 2 150 5 N/A
Installation. driving.
24''-30'' Steel Pipe Piles DTH E.2 DTH Drilling 2 \1\ 15 0.5 780
Drilling.
36'' Steel Pipe Piles DTH E.2 DTH Drilling 2 \1\ 15 0.5 780
Drilling.
----------------------------------------------------------------------------------------------------------------
\1\ For DTH drilling, column 4 represents number of strikes per second.
Table 7--Calculated Level A and Level B Harassment Isopleths
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment (m) Level B
Broadband ------------------------------------------------ harassment
noise (m)
Project component Pile type Installation method Sound signal attenuation LF HF VHF PW ------------
\b\ Cetaceans Cetaceans Cetaceans Pinnipeds All marine
mammals
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PSP & Floating Docks \a\............. 24-30'' Diameter Steel DTH Drilling............ Non-Impulsive & 5 (dB) 1,243.6 158.7 1,924.5 1,104.8 18,478.5
Pipe Piles. Impulsive. (1,817.0) (6,335.9)
Falsework Platform................... 14'' Diameter Steel H Vibratory Pile Driving Non-Impulsive........... 0 (dB> 3.1 1.2 2.6 4.0 1,000
Piles. and Removal.
Impact Pile Driving..... Impulsive............... 0 (dB) 111.7 14.2 172.8 99.2 341.5
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The isopleths for PSP & floating dock piles for Level A harassment (VHF cetaceans) and Level B harassment (all marine mammals) extend into Canadian waters. Isopleths in parentheses
represent the truncated radii within US waters only.
\b\ A NAS (noise attenuation system) will be deployed during all phases of PSP/floating dock pile installation. No NAS is planned during falsework platform installation and removal.
Table 8--The Calculated ZOIs for each Project Component and Installation and Removal Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment ZOI (km\2\) Level B
------------------------------------------------ harassment
Broadband ZOI
Project component Pile type Installation method noise (km\2\)
attenuation LF HF VHF PW ------------
\b\ Cetaceans Cetaceans Cetaceans Pinnipeds All marine
mammals
--------------------------------------------------------------------------------------------------------------------------------------------------------
PSP & Floating Docks \a\......... 36'' Diameter Steel DTH Drilling....... 5 dB 2.633 0.079 4.485 2.167 29.336
Pipe Piles. (4.480) (11.330)
24-30'' Diameter
Steel Pipe Piles.
[[Page 17771]]
Falsework Platform............... 14'' Diameter Steel Vibratory Pile 0 dB 0.00003 0.000005 0.000021 0.00005 1.833
H Piles. Driving and
Removal.
Impact Pile Driving 39.197 0.634 93.807 30.915 351.81
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The ZOIs for PSP & floating dock piles for Level A VHF cetaceans and Level B harassment all marine mammals both extend into Canadian waters. ZOIs in
parentheses represent the truncated zones within US waters only.
\b\ A NAS will be deployed during all phases of PSP/floating dock pile installation. No NAS is planned during falsework platform installation and
removal.
Marine Mammal Occurrence
In this section we provide information about the occurrence of
marine mammals, including density and other relevant information which
will inform the take calculations. Density estimates, scientific
literature, local information, and monitoring data from the previous
nearby Eastport Breakwater Project (Maine DOT 2015 & 2017) were used to
inform take calculations. Density estimates were calculated using the
2023 density models from the Duke University Marine Geospatial
Ecological Laboratory (Roberts et al., 2016, 2023). The density models
have 5 x 5 km spatial resolution cells with monthly density values for
each cell. At the mouth of the Quoddy Narrows Inlet, ME are three
density cells which represent the nearest density data to the project
location. The maximum monthly density data from these three cells were
used to determine density estimates for all cetacean species with
regular or common presence in the area, i.e., Atlantic white-sided
dolphin, minke whale, common dolphin, and harbor porpoise (table 9).
Local and recent monitoring data are available for harbor and gray
seals near the project area. For seals, sighting records from nearby
monitoring surveys are preferred because the data represent reliable
detections of local species and may provide more detail and context to
each sighting than what can be inferred from model results. Two nearby
monitoring reports have been reviewed, and each contain sufficient
detection data to calculate exposure estimates for this project (ME DOT
2015, 2017) (table 10 and table 11). Both monitoring reports contain
PSO (protected species observer) detections during breakwater
construction at Eastport, Maine, located in Washington County, in
Cobscook Bay and situated approximately 4.83 km (3 mi) from the Lubec
Safe Harbor Project Area.
Table 9--Maximum Estimated Densities (animals/km\2\) used for Exposure Estimation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monthly densities (animals/km\2\)
Species -----------------------------------------------------------------------------------------------------------------------
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke whale..................... 0.0001 0.0001 0.0002 0.002 0.005 0.009 0.008 0.007 0.004 0.003 0.0001 0.0001
Harbor seal \a\................. 0.128 0.162 0.120 0.134 0.228 0.855 1.268 1.037 0.669 0.473 0.043 0.063
Gray seal \a\................... 0.058 0.074 0.055 0.061 0.104 0.389 0.577 0.472 0.304 0.215 0.019 0.029
Harbor porpoise................. 0.073 0.102 0.099 0.116 0.101 1.661 2.951 3.205 2.531 1.966 1.743 0.050
Atlantic white-sided dolphin.... 0.021 0.017 0.013 0.017 0.032 0.049 0.038 0.025 0.037 0.054 0.033 0.033
Common dolphin.................. 0.005 0.001 0.001 0.001 0.003 0.005 0.008 0.014 0.015 0.017 0.019 0.016
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source: Roberts et al., 2016, 2023.
Note: Blue cells with bold values indicate the highest monthly density for each species.
\a\ Density was adjusted by their relative abundance.
Table 10--Individuals Observed per Month at Eastport, Maine Breakwater
Project 2015-2016 Season
------------------------------------------------------------------------
Month Number of seals observed
------------------------------------------------------------------------
July 2015.................................. 190
August 2015................................ 133
September 2015............................. 139
November 2015.............................. 170
December 2015.............................. 20
January 2016............................... 42
February 2016.............................. 13
March 2016................................. 27
April 2016................................. 22
May 2016................................... 3
June 2016.................................. 11
Total...................................... 916
------------------------------------------------------------------------
Table 11--Individuals Observed per Month at Eastport, Maine Breakwater
Project 2017 Season
------------------------------------------------------------------------
Month (2017) Number of seals observed
------------------------------------------------------------------------
January.................................... 0
February................................... 3
[[Page 17772]]
March...................................... 14
April...................................... 12
May........................................ 15
Total...................................... 44
------------------------------------------------------------------------
Take Estimation
Here we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and is authorized.
ME DOT estimated the take of marine mammals for the Lubec Safe
Harbor Project using two different methods. Take for cetaceans was
calculated using the 2023 density models from Duke University Marine
Geospatial Ecological Laboratory (Roberts et al., 2016, 2023). Take for
seals was calculated based on monitoring data from two construction
seasons of the nearby Eastport Breakwater Project in Eastport, Maine
which is about 5 km away from Lubec.
As previously noted, NMFS cannot authorize incidental take under
the MMPA that may occur within the territorial seas of foreign nations
(from 0-12 nmi (nautical miles) (22.2 km) from shore), as the MMPA does
not apply in those waters. However, NMFS has still calculated the
estimated level of incidental take in the entire activity area
(including Canadian territorial waters) as part of the analysis
supporting our determination under the MMPA that the activity will have
a negligible impact on the affected species. The total estimated take
in U.S. and Canadian waters is presented in table 14 (see Negligible
Impact Analysis and Determination).
Take calculations for cetaceans used the maximum monthly density
and equation 1 below. Take calculations for gray and harbor seals used
monitoring data recorded from two construction seasons at the Eastport
Breakwater Project and equation 2 below.
(1) Estimated Take = maximum monthly density (table 9) x ZOI for the
specific pile-related activity (table 8) x total number of days of
specific pile-related activity (table 1)
(2) Estimated Take = average daily number of observed individuals per
month (table 12) x total number of days of specific pile-related
activity per month (table 13)
Minke Whale
A total of 28 minke whales were observed during the Eastport
Breakwater Project, and there is a small potential for them to overlap
with the Lubec Project area. Use of the information and equation
described above results in an estimated total of 98 minke whale takes,
by Level B harassment only. However, NMFS authorizes only the take of
minke whales estimated to occur in US waters (65).
The largest Level A harassment zone for minke whales extends 1,244
m (table 7). ME DOT is required to implement shutdown zones for low-
frequency cetaceans that exceed the Level A harassment isopleth for all
activities. Therefore, when considered in context of the expected low
occurrence of minke whales in the area, implementation of the shutdown
zones is expected to eliminate the potential for take by Level A
harassment of minke whales. Therefore, no take by Level A harassment is
authorized for minke whales.
Atlantic White-Sided Dolphin
No Atlantic white-sided dolphins were observed during the Eastport
Breakwater Project, and there is a small potential for them to overlap
with the Lubec Project area. Use of the information and equation
described above results in an estimated total of 581 Atlantic white-
sided dolphin takes by Level B harassment only. However, NMFS
authorizes only the take of Atlantic white-sided dolphins estimated to
occur in US waters (379).
The largest Level A harassment zone for Atlantic white-sided
dolphins extends 159 m from the noise source (table 7). ME DOT is
required to implement shutdown zones for high-frequency cetaceans that
exceed the Level A harassment isopleth for all activities. Therefore,
when considered in context of the expected rare occurrence of Atlantic
white-sided dolphins in the area, implementation of the shutdown zones
is expected to eliminate the potential for take by Level A harassment
of Atlantic white-sided dolphins. Therefore, no take by Level A
harassment authorized for Atlantic white-sided dolphins.
Common Dolphin
No common dolphins were observed during the Eastport Breakwater
Project, and there is a small potential for them to overlap with the
Lubec Project area. Use of the information and equation described above
results in an estimated total of 204 common dolphin takes by Level B
harassment. However, NMFS authorizes only the take of common dolphins
estimated to occur in US waters (133).
The largest Level A harassment zone for common dolphins extends 159
m from the noise source (table 7). ME DOT is required to implement
shutdown zones for high-frequency cetaceans that exceed the Level A
harassment isopleth for all activities. Therefore, when considered in
context of the expected rare occurrence of common dolphins in the area,
implementation of the shutdown zones is expected to eliminate the
potential for take by Level A harassment of common dolphins. Therefore,
no take by Level A harassment is authorized for common dolphins.
Harbor Porpoise
A total of 76 harbor porpoises were observed during the Eastport
Breakwater Project, and they are expected to occur within the Lubec
Project area. Use of the information and equation described above
results in an estimated total of 32,238 harbor porpoise takes by Level
B harassment. However, NMFS authorizes only the take of harbor
porpoises estimated to occur in US waters (20,131).
To estimate expected take by Level A harassment for species with
larger Level A harassment zones and which are expected to occur more
frequently (i.e., harbor porpoise and seals), while accounting for
implementation of shutdown zones (table 15), exposures within the
estimated Level A harassment zones but outside the shutdown zones
(where the Level A harassment zones are larger than the shutdown zones)
were calculated. Proportions of the total Level A harassment areas that
are outside of the shutdown zones are applied to the total Level A
harassment estimates to calculate the expected instances of take by
Level A harassment that are authorized. Where the estimated Level A
harassment zones extend into Canadian waters, the associated estimates
of take by Level A harassment
[[Page 17773]]
are adjusted as described above for Level B harassment to ensure that
only takes expected to occur within U.S. waters are authorized. Use of
the information and equation described above results in an estimated
total of 6,080 harbor porpoise takes by Level A harassment. However,
NMFS authorizes only the take of harbor porpoises estimated to occur in
US waters (6,031).
Gray Seal
A total of 916 seals were observed during the 2015-2016 Eastport
Breakwater Project 2015-2016 season. Seal data were combined as
observers had difficulty differentiating in the field between harbor
and gray seals. There is potential for gray seals to overlap with the
Lubec Project area. Use of the information and equation described above
results in an estimated total of 268 gray seal takes. However, NMFS
authorizes only the take of gray seals estimated to occur in US waters
(132), with 92 (228 including Canadian waters) by Level B harassment
and 40 by Level A harassment. Instances of Level A harassment versus
Level B harassment was proportioned out by the number of days per
activity and proportion of Level A and B harassment zone size. The
number of days of DTH reflects 88.9% of activity while vibratory and
impact pile driving represent 5.5% each. Once take was proportioned out
into each activity it was further proportioned based on the size of the
Level A and Level B harassment zone. DTH has about 10.5% of its Level A
harassment zone within the Level B harassment zone, while due to
shutdown procedures and zone size vibratory driving will only cause
potential take by Level B harassment and impact driving will only cause
potential take by Level A harassment.
Harbor Seal
A total of 916 seals were observed during the 2015-2016 Eastport
Breakwater Project 2015-2016 season, seal data were combined as
observers had difficulty differentiating in the field between harbor
and gray seals. However, there were 44 harbor seals observed during the
2017 construction season of the Eastport Project. There is potential
for harbor seals to overlap with the Lubec Project area. Use of the
information and equation described above results in an estimated total
of 548 harbor seal takes. However, NMFS authorizes only the take of
gray seals estimated to occur in US waters (301), with 220 (548
including Canadian waters) by Level B harassment and 81 by Level A
harassment. Take by Level A versus Level B harassment was proportioned
out by the number of days per activity and proportion of Level A and B
harassment zone size. The number of days of DTH reflects 88.9% of
activity while vibratory and impact pile driving represent 5.5% each.
Once take was proportioned out into each activity it was further
proportioned based on the size of the Level A and Level B harassment
zone. DTH has about 10.5% of its Level A harassment zone within the
Level B harassment zone, while due to shutdown procedures and zone size
vibratory driving will only cause potential take by Level B harassment
and impact driving will only cause potential take by Level A
harassment.
Table 12--Average Daily Observed Individual Animals Detected per Month
at Eastport, Maine Breakwater Project
------------------------------------------------------------------------
Species detected at Eastport, Maine
Observation month -------------------------------------
Harbor seal Gray seal
------------------------------------------------------------------------
January........................... 0.96 0.88
February.......................... 0.84 0.68
March............................. 0.82 0.37
April............................. 0.88 0.34
May............................... 0.85 0.16
June.............................. 0.42 0.19
July.............................. 6.53 2.97
August............................ 5.08 2.31
September......................... 5.31 2.42
October........................... 5.02 2.28
November.......................... 6.87 3.13
December.......................... 1.15 0.52
------------------------------------------------------------------------
* Source Maine DOT.
Table 13--Monthly Construction Schedule for the Safe Harbor Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of piles installed per month Number of
--------------------------------------- piles removed
per month Days of
Year Month Floating Falsework ---------------- activity per
PSP piles dock piles piles Falsework month
piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
2025.......................................... March............................ 6 ........... 5 5 14
April............................ 6 ........... 5 5 14
May.............................. 6 ........... 5 5 14
June............................. 6 ........... 5 5 14
July............................. 6 ........... 5 5 14
August........................... 6 ........... 5 5 14
September........................ 6 ........... 5 5 14
October.......................... 6 ........... 5 5 14
November......................... 6 ........... 5 5 14
December......................... 6 8 5 5 30
2026.......................................... January.......................... 6 8 5 5 30
February......................... 6 8 5 5 30
[[Page 17774]]
March............................ ........... 8 5 5 18
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Piles............................... ................................. 72 32 65 65 234
---------------------------------------------------------------------------------------------------------
Total Days................................ ................................. 144 64 13 13 234
--------------------------------------------------------------------------------------------------------------------------------------------------------
The total take estimates that are authorized for each species for
the Lubec Harbor Project can be found below in table 14.
Table 14--Estimated and Authorized Take by Level A and Level B Harassment by Species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total take--US Take
Stock Level A Level B waters percentage of
Common name Stock abundance harassment \a\ harassment \a\ authorized stock in US
only \a\ waters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke Whale............................... Canadian Eastern Coast....... 21,968 0 65 (98) 65 (98) <1
Atlantic White-Sided Dolphin.............. Western North Atlantic....... 31,506 0 379 (581) 379 (581) 1.2
Common Dolphin............................ Western North Atlantic....... 93,100 0 133 (204) 133 (204) <1
Harbor Porpoise........................... Gulf of Maine/Bay of Fundy... 85,765 6,031 (6,080) 20,131 (32,238) 26,162 (38,318) 30.5
Harbor Seal............................... Western North Atlantic....... 61,336 81 220 (467) 301 (548) <1
Gray Seal................................. Western North Atlantic....... 394,311 40 92 (228) 132 (268) <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The parenthetical number represents the total number of takes including those estimated to occur in Canadian waters.
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, and impact on
operations.
Mitigation for Marine Mammals and Their Habitat
Implementation of Shutdown Zones--For all pile driving/removal
activities, ME DOT would implement shutdowns within designated zones.
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).
Implementation of shutdowns would be used to avoid or minimize
incidental Level A harassment takes from vibratory, impact pile driving
and removal, and DTH drilling (table 15). For all vibratory pile
driving/removal activities, a minimum 10-m shutdown zone would be
established for marine mammals as outlined in ME DOT's IHA application.
Shutdown zones for impact pile driving and DTH drilling are based on
the Level A harassment zones and monitoring feasibility and therefore
vary by marine mammal hearing group (table 15). The shutdown zones for
DTH drilling for low frequency and high frequency cetaceans were
rounded up from the estimated Level A harassment zone for each
particular activity. The largest Level A harassment zone for low
frequency cetaceans from DTH is 1,244 m, and a shutdown zone of 1,245 m
is required, given the expected ability to detect those species at that
distance. The largest Level A harassment zone from DTH for high
frequency cetaceans is 159 m, and a shutdown zone of 160 m is required,
given the expected ability to detect those species at that distance.
The same methodology was used for impact pile driving for low
frequency, high frequency, very high frequency cetaceans, and
pinnipeds. The largest Level A harassment zone for low frequency
cetaceans is 112 m, so a shutdown zone of 115 m is required, given the
expected ability to detect those species at that distance. The largest
Level A harassment zone for high frequency cetaceans for impact pile
driving is 14 m, so a shutdown zone of 15 m is required, given the
expected ability to detect those species at that
[[Page 17775]]
distance. The largest Level A harassment zone for very high frequency
cetaceans is 173 m, so a shutdown zone of 175 m is required, given the
expected ability to detect those species at that distance. The largest
Level A harassment zone for pinnipeds is 99 m, so a shutdown zone of
100 m is required, given the expected ability to detect those species
at that distance. The Level A harassment zones for DTH drilling for
very high frequency cetaceans and phocids are considered too large to
effectively monitor (Table 7). Therefor a shutdown zone of 500m is
required, as we consider that distance to be the largest reasonable
zone a PSO can monitor for more cryptic species like harbor porpoises
and seals in this circumstance. The placement of PSOs during all pile
driving activities (described in detail in the Monitoring and Reporting
section) would ensure the full extent of shutdown zones are visible to
PSOs.
Table 15--Shutdown and Clearance Zones (m) for Each Project Component
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown & clearance distances
---------------------------------------------------
Project component Pile installation activity Bubble curtain used LF HF VHF PW
cetaceans cetaceans cetaceans pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
PSP..................................... DTH Drilling............... Yes.......................... 1,245 160 \a\ 500 \a\ 500
Floating Docks..........................
Falsework Platform...................... Vibratory Setting & Removal No........................... 10 10 10 10
Impact Hammer.............. No........................... 115 15 175 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Mitigation ranges were selected based on the acoustic isopleth results, plus an added buffer of rounding up to the nearest 5 m for PSO clarity.
\a\ It is NMFS' recommendation for this Project that a 500-m maximum shutdown and clearance zone be assumed for VHF cetaceans and pinnipeds for
monitoring feasibility.
Monitoring for Level A and Level B harassment--ME DOT has
identified monitoring zones correlated with the Level B harassment
zones. Monitoring zones provide utility for observing by establishing
monitoring protocols for areas adjacent to the shutdown zones.
Monitoring zones enable observers to be aware of and communicate the
presence of marine mammals in the project area outside the shutdown
zone and thus prepare for a potential cessation of activity should the
animal enter the shutdown zone. PSOs would monitor the entire visible
area to maintain the best sense of where animals are moving relative to
the zone boundaries defined in table 15. A minimum of two PSOs will be
required to be on duty at all times during pile activity. ME DOT will
send a Marine Mammal Monitoring Plan 90 days prior to the project's
starting date with specific PSO locations.
Bubble Curtain--A bubble curtain would be used for all DTH drilling
activities for construction of the PSP and floating dock. Bubble
curtains will not be used for installation or removal of the piles for
the falsework platform. Bubble curtains will be used to achieve a
broadband noise attenuation which will effectively minimize the extent
of the SELcum isopleths and reduce the sizes of the overall ZOIs. It is
anticipated that a 5-dB broadband attenuation level will consistently
be achieved; therefore, all exposure estimates and the resulting take
request account for all stages of structural pile installation
activities associated with this project and are based on 5 dB
attenuation (not including falsework pile installation and removal).
The bubble curtain must distribute air bubbles around 100 percent of
the piling circumference for the full depth of the water column. The
lowest bubble ring must be in contact with the substrate for the full
circumference of the ring, and the weights attached to the bottom ring
shall ensure 100 percent substrate contact. No parts of the ring or
other objects shall prevent full substrate contact. Air flow to the
bubblers must be balanced around the circumference of the pile.
Pre-Activity Monitoring--Prior to the start of daily in-water
construction activity, or whenever a break in pile driving/removal of
30 minutes or longer occurs, PSOs would observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone would be
considered cleared when a marine mammal has not been observed within
the zone for that 30-minute period. If a marine mammal is observed
within the shutdown zone, a soft-start cannot proceed until the animal
has left the zone or has not been observed for 15 minutes. If the
monitoring zone has been observed for 30 minutes and marine mammals are
not present within the zone, soft-start procedures can commence and
work can continue. Pre-start clearance monitoring must be conducted
during periods of visibility sufficient for the lead PSO to determine
that the shutdown zones, indicated in table 15, are clear of marine
mammals. When a marine mammal for which take by Level B harassment is
authorized is present in the Level B harassment zone, activities may
begin. If work ceases for more than 30 minutes, the pre-activity
monitoring of both the monitoring zone and shutdown zone would
commence.
Soft Start--The use of a soft start procedure is believed to
provide additional protection to marine mammals by warning marine
mammals or providing them with a chance to leave the area prior to the
hammer operating at full capacity. ME DOT will utilize soft start
techniques for impact pile driving. We require an initial set of three
strikes from the impact hammer at reduced energy, followed by a 30-
second waiting period, then two subsequent three-strike sets. Soft
start will be required at the beginning of each day's impact pile
driving work and at any time following a cessation of impact pile
driving of 30 minutes or longer; the requirement to implement soft
start for impact driving is independent of whether vibratory driving
has occurred within the prior 30 minutes. Soft start is not required
during vibratory pile driving activities. Based on our evaluation of
the applicant's measures, NMFS has determined that the mitigation
measures provide the means of effecting the least practicable impact on
the affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
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
[[Page 17776]]
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 while conducting the activities. Effective
reporting is critical both to compliance as well as ensuring that the
most value is obtained from the required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; 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); and,
Mitigation and monitoring effectiveness.
Visual Monitoring--Marine mammal monitoring during pile driving
activities would be conducted by PSOs meeting NMFS' standards and in a
manner consistent with the following:
PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods;
At least one PSO would have prior experience performing
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization;
Other PSOs may substitute education (degree in biological
science or related field) or training for experience; and
Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator would be designated. The lead
observer would be required to have prior experience working as a marine
mammal observer during construction.
PSOs must be approved by NMFS prior to beginning any
activities subject to this IHA.
PSOs should have the following additional qualifications:
Ability to conduct field observations and collect data
according to assigned protocols;
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
Monitoring will be conducted 30 minutes before, during, and 30
minutes after pile driving/removal activities. In addition, observers
shall record all incidents of marine mammal occurrence, regardless of
distance from activity, and shall document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving/
removal activities include the time to install or remove a single pile
or series of piles, as long as the time elapsed between uses of the
pile driving equipment is no more than 30 minutes.
A minimum of two PSOs would be on duty during all in-water
construction activities. Locations from which PSOs would be able to
monitor from will be determined by ME DOT 90 days prior to the start of
construction in their NMFS-approved Marine Mammal Monitoring Plan.
PSOs would scan the waters using binoculars or spotting scopes and
would use a handheld range-finder device to verify the distance to each
sighting from the project site. PSOs would be placed at the best
vantage point(s) practicable to monitor for marine mammals and
implement shutdown/delay procedures when applicable by calling for the
shutdown to the hammer operator via a radio.
Reporting--A draft marine mammal monitoring report would be
submitted to NMFS within 90 days after the completion of pile driving
and removal activities. It would include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report must include:
Dates and times (begin and end) of all marine mammal
monitoring.
Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact driving) and for each pile or
total number of strikes for each pile (impact driving).
PSO locations during marine mammal monitoring.
Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
Upon observation of a marine mammal, the following
information: Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting; time of sighting; identification of the
animal(s) (e.g., genus/species, lowest possible taxonomic level, or
unidentified), PSO confidence in identification, and the composition of
the group if there is a mix of species; distance and bearing of each
marine mammal observed relative to the pile being driven for each
sighting (if pile driving was occurring at time of sighting); estimated
number of animals (min/max/best estimate); estimated number of animals
by cohort (adults, juveniles, neonates, group composition, etc.);
animal's closest point of approach and estimated time spent within the
harassment zone; description of any marine mammal behavioral
observations (e.g., observed behaviors such as feeding or traveling),
including an assessment of behavioral responses thought to have
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching);
Number of marine mammals detected within the harassment
zones, by species; and,
Detailed information about any implementation of any
mitigation
[[Page 17777]]
triggered (e.g., shutdowns and delays), a description of specific
actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
final report would constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Dead or Injured Marine Mammals--In the event that
personnel involved in the construction activities discover an injured
or dead marine mammal, the Holder must report the incident to the
Office of Protected Resources (OPR), NMFS
([email protected] and [email protected]), and to
the Greater Atlantic Marine Mammal Stranding Network as soon as
feasible. If the death or injury was clearly caused by the specified
activity, the Holder must immediately cease the activities until NMFS
OPR is able to review the circumstances of the incident and determine
what, if any, additional measures are appropriate to ensure compliance
with the terms of this IHA. The Holder must not resume their activities
until notified by NMFS. The report must include the following
information:
Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
Species identification (if known) or description of the
animal(s) involved;
Condition of the animal(s) (including carcass condition if
the animal is dead);
Observed behaviors of the animal(s), if alive;
If available, photographs or video footage of the
animal(s); and
General circumstances under which the animal was
discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the 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 majority of our analysis applies to all
the species listed in table 2, given that many of the anticipated
effects of this project on different marine mammal stocks are expected
to be relatively similar in nature. Where there are meaningful
differences between species or stocks, or groups of species, in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, they are described independently in the analysis below.
Pile driving, removal, and DTH drilling activities associated with
the project as outlined previously, have the potential to disturb or
displace marine mammals. Specifically, the specified activities may
result in take, in the form of Level A harassment and Level B
harassment from underwater sounds generated from pile driving, removal,
and DTH drilling. Potential takes could occur if individuals of these
species are present in zones ensonified above the thresholds for Level
A or Level B harassment identified above when these activities are
underway.
Take by Level A and Level B harassment would be due to potential
behavioral disturbance, TTS, and PTS. No serious injury or mortality is
authorized given the nature of the activity and measures designed to
minimize the possibility of injury to marine mammals. Take by Level A
harassment is only anticipated for harbor porpoises, harbor seals, and
gray seals. The potential for harassment is minimized through the
construction method (i.e. vibratory methods to the extent practical)
and the implementation of the mitigation measures (see the Mitigation
section).
Behavioral responses of marine mammals to pile driving, removal,
and drilling at the project site, if any, are expected to be mild and
temporary. Marine mammals within the Level B harassment zone may not
show any visual cues that they are disturbed by activities or could
become alert, avoid the area, leave the area, or display other mild
responses that are not observable such as changes in vocalization
patterns. However, given the project schedule and appropriate
mitigation, any harassment would be temporary.
In addition to the expected effects resulting from Level B
harassment, we anticipate that harbor porpoises, harbor seals, and gray
seals may sustain some limited Level A harassment in the form of PTS.
However, any PTS is expected to be of a small degree (i.e., minor
degradation of hearing capabilities within regions of hearing that
align most completely with the energy produced by pile driving (below 2
kHz)) because animals would need to be exposed to higher levels and/or
longer duration than are expected to occur here in order to incur any
more than a small degree of PTS. If hearing impairment occurs, it is
most likely that the affected animal would lose a few decibels in its
hearing sensitivity, which in most cases is not likely to meaningfully
affect its ability to forage and communicate with conspecifics, as it
would be minor and not in the region of greatest hearing sensitivity.
Additionally, and as noted previously, some subset of the
individuals that are behaviorally harassed could also simultaneously
incur some small degree of TTS for a short duration of time. Because of
the small degree anticipated, though, any PTS or TTS potentially
incurred here would not be expected to adversely impact individual
fitness, let alone annual rates of recruitment or survival.
The pile driving activities are also not expected to have
significant adverse effects on these affected marine mammals' habitats.
The activities may cause some fish to leave the area of disturbance,
thus temporarily impacting marine mammals' foraging opportunities in a
limited portion of the foraging range; but, because of the short
duration of the activities and the relatively small area of the habitat
that may be affected (with no known particular importance to marine
mammals), the impacts to marine mammal habitat are not expected to
cause significant or long-term negative consequences.
[[Page 17778]]
In combination, we believe that these factors, as well as the
available body of evidence from other similar activities, demonstrate
that the specified activities will have only minor, short-term effects
on individuals that will not have any bearing on those individuals'
fitness. Thus the specified activities are not expected to impact rates
of recruitment or survival and will therefore have a negligible impact
on those species or stocks.
As described above, we authorize only the takes estimated to occur
in United States waters (table 14); however, for the purposes of our
negligible impact analysis and determination, we consider the total
number of takes that are anticipated to occur as a result of the entire
project (including the portion of the Level B harassment zone that
extends into Canadian waters) (table 14).
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
No serious injury or mortality is anticipated or
authorized;
The anticipated incidents of Level B harassment consist
of, at worst, temporary modifications in behavior;
The potential impacts of Level A harassment on harbor
porpoises, harbor seals, and gray seals are not anticipated to increase
individual impacts to a point where any population-level impacts might
be expected;
The absence of any significant habitat within the
industrialized project areas, including known areas or features of
special significance for foraging or reproduction; and
The presumed efficacy of the mitigation measures in
reducing the effects of the specified activity to the level of least
practicable adverse impact.
Effects on species that serve as prey for marine mammals
from the activities are expected to be short-term and, therefore, any
associated impacts on marine mammal feeding are not expected to result
in significant or long-term consequences for individuals, or to accrue
to adverse impacts on their populations from either project;
The ensonified areas from the project are very small
relative to the overall habitat ranges of all species and stocks, and
will not cause more than minor impacts.
There are no ESA-designated critical habitat, Biologically
Important Areas, or any other areas of known biological importance near
the project site.
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 monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is less than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
Table 16--Total Estimated Take, Including Canadian Territorial Waters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Take
Common name Stock Stock Level A Level B Total take percentage of
abundance harassment harassment stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke Whale............................... Canadian Eastern Coast...... 21,968 0 98 98 <1
Atlantic-White Sided Dolphin.............. Western North Atlantic...... 31,506 0 581 581 1.8
Common Dolphin............................ Western North Atlantic...... 93,100 0 204 204 <1
Harbor Porpoise........................... Gulf of Maine/Bay of Fundy.. 85,765 6,080 32,238 38,318 44.7
Harbor Seal............................... Western North Atlantic...... 61,336 81 467 548 <1
Gray Seal................................. Western North Atlantic...... 394,311 40 228 268 <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 16 demonstrates the number of animals that NMFS anticipates
could be taken by Level A and Level B harassment for the project. Our
analysis shows that, other than harbor porpoise, less than 2 percent of
each affected stock could be taken by harassment. The numbers of
animals authorized to be taken for these stocks would be considered
small relative to the relevant stock's abundances, even if each
estimated taking occurred to a new individual, which is an unlikely
scenario. For harbor porpoise, the number is higher. However, because
the project is located in a single, localized area (Lubec, ME) relative
to the range of the affected stock of harbor porpoise, it is likely
that the number of takes authorized for harbor porpoise would represent
repeated takes of a significantly smaller number of individuals. In
summer, harbor porpoise are most likely to range from the northern Gulf
of Maine through the southern Bay of Fundy and around the southern tip
of Nova Scotia. This more concentrated range is itself a very large
area relative to the area affected by this project, and in the spring
and fall porpoise are likely to be dispersed over an even broader range
from North Carolina to New Brunswick. On this basis, NMFS finds that
the number of individuals likely to be taken for harbor porpoise is
likely to be of no more than small numbers.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals would
be taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or
[[Page 17779]]
stocks would not have an unmitigable adverse impact on the availability
of such species or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.)
requires that each Federal agency insure that any action it authorizes,
funds, or carries out is not likely to jeopardize the continued
existence of any endangered or threatened species or result in the
destruction or adverse modification of designated critical habitat. To
ensure ESA compliance for the issuance of IHAs, NMFS consults
internally whenever we authorize take for endangered or threatened
species.
No incidental take of ESA-listed species authorized or expected to
result from this activity. Therefore, NMFS has determined that formal
consultation under section 7 of the ESA is not required for this
action.
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 action (i.e., the issuance of an IHA) and
alternatives with respect to potential impacts on the human
environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NAO 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has determined that the
issuance of the IHA qualifies to be categorically excluded from further
NEPA review.
Authorization
NMFS has issued an IHA to ME DOT for the potential harassment of
small numbers of 6 marine mammal species incidental to the Lubec Harbor
project in Lubec, Maine, that includes the previously explained
mitigation, monitoring and reporting requirements.
Dated: April 23, 2025.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2025-07344 Filed 4-28-25; 8:45 am]
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