[Federal Register Volume 84, Number 57 (Monday, March 25, 2019)]
[Notices]
[Pages 11066-11079]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-05668]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG506
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to In-Water Demolition and
Construction Activities Associated With a Harbor Improvement Project in
Statter Harbor, 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 City of Juneau to incidentally harass, by Level A and Level B
harassment, marine mammals during construction activities associated
with harbor improvements at Statter Harbor in Auke Bay, Alaska
DATES: This authorization is effective from October 1, 2019 to
September 30, 2020.
FOR FURTHER INFORMATION CONTACT: Sara Young, Office of Protected
Resources, NMFS, (301) 427-8401. 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/
[[Page 11067]]
marine-mammal-protection/incidental-take-authorizations-construction-
activities. In case of problems accessing these documents, please call
the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization was provided to the public for
review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other means of effecting the least practicable adverse
impact on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth.
The NDAA (Pub. L. 108-136) removed the ``small numbers'' and
``specified geographical region'' limitations indicated above and
amended the definition of ``harassment'' as it applies to a ``military
readiness activity.'' The definitions of all applicable MMPA statutory
terms cited above are included in the relevant sections below.
Summary of Request
On February 12, 2018, NMFS received a request from the City of
Juneau for an IHA to take marine mammals incidental to harbor
improvement projects in Statter Harbor, Alaska. The original
application covered three years of potential work and was revised to
one year of work on March 9, 2018. A series of exchanges regarding
acoustic analyses continued until a meeting was held on June 21, 2018.
An additional revision was received on August 8, 2018. The application
was deemed adequate and complete on September 18, 2018. The City of
Juneau's request is for take of a small number of harbor seal, harbor
porpoise, humpback whale, and Steller sea lion by Level B harassment
and Level A harassment. Neither the City of Juneau nor NMFS expects
serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate.
Description of Activity
The harbor improvements described in the application include
demolition and disposal of the existing boat launch ramp and timber
haulout pier, dredging of the planned harbor basin with offshore
disposal, excavation of bedrock within the basin by blasting from a
temporary fill pad, and construction of a mechanically stabilized earth
wall. In our notice of proposed IHA, we stated work was expected to
begin in April. Due to administrative delays and other permitting
needs, we were notified by the City of Juneau that work is now expected
to occur between October 1, 2019 and September 30, 2020. The expected
allocation of days for each activity is as follows: Two to ten days of
vibratory pile removal, 30-45 days of dredging and dredge disposal, 15
days of in-water fill placement and removal, and two days of blasting.
To be conservative, 12-hour work days were used to analyze construction
noise. The daily construction window for blasting and dredging will
begin no sooner than 30 minutes after sunrise to allow for initial
marine mammal monitoring to take place and will end 30 minutes before
sunset to allow for post-activity monitoring.
The activities will occur at Statter Harbor in Auke Bay, Alaska
which is in the southeast portion of the state. See Figures 1 and 4 in
the application for detailed maps of the project area. Statter Harbor
is located at the most northeasterly point of Auke Bay.
A detailed description of the planned harbor improvements project
is provided in the Federal Register notice for the proposed IHA (83 FR
52394; October 17, 2018). 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
detailed description of the specified activity.
Comments and Responses
A notice of NMFS's proposal to issue an IHA to the City of Juneau
was published in the Federal Register on October 17, 2018 (83 FR
52394). That notice described, in detail, the City'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 comments from the Marine Mammal Commission. For
full details of the comments, please see the Commission's letter, which
is available online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#active-authorizations. The comments and our response are
provided below.
Comment: The Commission recommends that NMFS estimate and
ultimately authorize takes of marine mammals by Level B harassment
during all activities involving explosives, including single detonation
events, for this and all future IHAs.
Response: NMFS believes that the best scientific evidence available
indicates that it is appropriate to use a behavioral onset threshold
for multiple detonations and to consider detonations with microdelays
between them as a single detonation. The two blasts conducted by
Statter Harbor are confined blasts with charge detonations separated by
microdelays, constituting a single detonation event per day with blasts
occurring for a total of two days.
Comment: The Commission recommends that NMFS require the City of
Juneau to conduct hydroacoustic monitoring of blasting activity and
provide data from the first blast event to NMFS for review prior to the
second blasting event. The Commission also states that NMFS should
adjust Level A and B harassment zones if necessary prior to the second
blasting event.
Response: NMFS disagrees with the Commission that hydroacoustic
monitoring of the two blasts conducted at Statter Harbor should be
required. The blasts are considered single detonation events with only
two total blasts proposed, occurring on two separate days. It is still
unknown how close together the two blasting days would occur, and is
likely not enough time to analyze data and develop a hydroacoustic
monitoring report, submit to NMFS for review, and make adjustments
accordingly. Additionally, the City plans to conduct blasting as
quickly and efficiently as possible so as not to overlap with the
beginning of harbor seal pupping season, as harbor seals are resident
in the area. Therefore, this requirement may result in more severe
impacts to local harbor seals through delay of the second blast.
[[Page 11068]]
Comment: The Commission states that if NMFS believes that
authorization for taking marine mammals incidental to vessel transit by
tug is not warranted, that NMFS should find that authorization for take
of marine mammals incidental to dredging is also not warranted.
Furthermore, the Commission recommends that NMFS determine which
activities warrant incidental take authorizations under the MMPA and
apply that approach consistently for all actions.
Response: NMFS makes determinations on whether take should be
authorized for specific activities on a case by case basis while
factoring in project-specific considerations. While NMFS does not
generally think noise generated from dredging is likely to result in
take, the dredging that is planned for this action occurs directly in
an area known to be habitat for a resident harbor seal population and
will occur for an extended period. This project constitutes a grouping
of activities in a small geographic area, where marine mammals are
known to be resident, and the presence of these activities could
disrupt their behavioral patterns. While we do not think that dredging
by itself is likely to result in take, the combination of factors
presented in this specific circumstance, in conjunction with other
activities in a confined harbor area that is consistently inhabited by
harbor seals, leads us to conclude that dredging presents the potential
to harass marine mammals.
Comment: The Commission recommends that NMFS refrain from
implementing its proposed renewal process and instead use abbreviated
Federal Register notices and reference existing documents to streamline
the IHA process. If NMFS adopts the proposed renewal process, the
Commission recommends that NMFS provide the Commission and the public a
legal analysis supporting its conclusion that the process is consistent
with section 101(a)(5)(D) of the MMPA.
Response: The notice of the proposed IHA (83 FR 52394; October 17,
2018) expressly notifies the public that under certain, limited
conditions an applicant could seek a renewal IHA for an additional
year. The notice describes the conditions under which such a renewal
request could be considered and expressly seeks public comment in the
event such a renewal is sought. Additional reference to this
solicitation of public comment has recently been added at the beginning
of the FR notices that consider renewals, requesting input specifically
on the possible renewal itself. NMFS appreciates the streamlining
achieved by the use of abbreviated FR notices and intends to continue
using them for proposed IHAs that include minor changes from previously
issued IHAs, but which do not satisfy the renewal requirements.
However, we believe our method for issuing renewals meets statutory
requirements and maximizes efficiency. However, importantly, such
renewals will be limited to circumstances where: The activities are
identical or nearly identical to those analyzed in the proposed IHA;
monitoring does not indicate impacts that were not previously analyzed
and authorized; and, the mitigation and monitoring requirements remain
the same, all of which allow the public to comment on the
appropriateness and effects of a renewal at the same time the public
provides comments on the initial IHA. NMFS has, however, modified the
language for future proposed IHAs to clarify that all IHAs, including
renewal IHAs, are valid for no more than one year and that the agency
will consider only one renewal for a project at this time. In addition,
notice of issuance or denial of a renewal IHA will be published in the
Federal Register, as they are for all IHAs. The option for issuing
renewal IHAs has been in NMFS' incidental take regulations since 1996.
We will provide any additional information to the Commission and
consider posting a description of the renewal process on our website
before any renewal is issued utilizing this process.
Description of Marine Mammals in the Area of Specified Activities
Seven species of marine mammal have been documented in southeast
Alaska waters in the vicinity of Statter Harbor. These species are:
Harbor seal, harbor porpoise, Dall's porpoise, killer whale, humpback
whale, minke whale, and Steller sea lion. Of these species, only three
are known to occur in Statter Harbor: Harbor seal, Steller sea lion,
and humpback whale.
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history, of the potentially affected species.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SAR; https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports) and more general information about
these species (e.g., physical and behavioral descriptions) may be found
on NMFS's website (https://www.fisheries.noaa.gov/find-species).
Table 1 lists all species with expected potential for occurrence in
Statter Harbor and summarizes information related to the population or
stock, including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. For taxonomy, we follow
Committee on Taxonomy (2017). PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS's
SARs). While no mortality is anticipated or authorized here, PBR and
annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Alaska Region Draft 2018 SAR (Muto et al, 2018). All values
presented in Table 1 are the most recent available at the time of
publication and are available in the Draft 2018 SAR (Muto et al, 2018).
[[Page 11069]]
Table 1--Species With the Potential to Occur in Statter Harbor
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ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera noveangliae.. Central North Pacific.. E, D,Y 10,103 (0.3, 7,891, 83 26
2006).
Minke whale..................... Balaenoptera Alaska................. -;N N/A................... Und 0
acutorostrata.
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Killer whale.................... Orcinus orca........... Northern Resident...... -;N 261 (N/A, 261, 2011).. 1.96 0
Killer whale.................... Orcinus orca........... Gulf of Alaska -;N 587 (N/A, 587, 2012).. 5.87 1
transient.
Killer whale.................... Orcinus orca........... West Coast Transient... -;N 243 (N/A, 243, 2009).. 2.4 0
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Southeast Alaska....... -; Y 975 (0.14, 872, 2012). 8.7 34
Dall's porpoise................. Phocoenoides dalli..... Alaska................. -;N 83,400 (0.097, N/A, Und 38
1991).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Western DPS............ E/D; Y 54,267 (N/A; 54,267, 326 252
2017).
Steller sea lion................ Eumetopias jubatus..... Eastern DPS............ T/D; Y 41,638 (N/A, 41,638, 2498 108
2015).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... Lynn Canal............. -; N 9,478 (N/A, 8,605, 155 50
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\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.
Note--Italicized species are not expected to be present and take is not authorized.
All species that could potentially occur in the action areas are
included in Table 1. It is unlikely the species italicized above in
Table 1 are likely to venture far enough into the harbor to enter the
acoustic isopleths where we expect take to occur. The spatial
occurrence of minke whale and Dall's porpoise is such that take is not
expected to occur, and they are not discussed further beyond the
explanation provided here. While these species have been sighted in
southeast Alaska more broadly, these sightings have been recorded for
areas closer to the ocean. Auke Bay is separated from the Pacific by
multiple barrier islands and Statter Harbor is located in the most
inland section of the bay, making the occurrence of species
infrequently sighted farther seaward even less likely. Killer whales
are not known to occur frequently in Auke Bay, although they have been
sighted infrequently, with no obvious temporal pattern to the
sightings. While it is possible killer whales could enter Auke Bay
during work, it is unlikely they would continue as far inland as
Statter Harbor. If killer whales did venture into Statter Harbor to a
distance where acoustic exposure would be a concern, they would be
easily identifiable to observers stationed in the harbor for mitigation
and monitoring purposes and a shutdown would be ordered. Therefore,
take of killer whales from these activities is unlikely to occur and
they are not considered further in this document. The work in Statter
Harbor is in a very sheltered and inland harbor with a consistent
sightings record of the three species considered further: Steller sea
lion, humpback whale, and harbor seal. Harbor porpoise, while
infrequently sighted near Statter Harbor, are considered further as
their fast swim speeds and small size make detection to implement
mitigation measures difficult.
A detailed description of the species likely to be affected by the
Statter 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 (83 FR 52394; October 17, 2018); 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.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms
[[Page 11070]]
derived using auditory evoked potential techniques, anatomical
modeling, and other data. Note that no direct measurements of hearing
ability have been successfully completed for mysticetes (i.e., low-
frequency cetaceans). Subsequently, NMFS (2018) described generalized
hearing ranges for these marine mammal hearing groups. Generalized
hearing ranges were chosen based on the approximately 65 decibels (dB)
threshold from the normalized composite audiograms, with the exception
for lower limits for low-frequency cetaceans where the lower bound was
deemed to be biologically implausible and the lower bound from Southall
et al. (2007) retained. The functional groups and the associated
frequencies are indicated below (note that these frequency ranges
correspond to the range for the composite group, with the entire range
not necessarily reflecting the capabilities of every species within
that group):
Low-frequency cetaceans (mysticetes): Generalized hearing
is estimated to occur between approximately 7 hertz (Hz) and 35
kilohertz (kHz);
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Generalized hearing is estimated to occur
between approximately 150 Hz and 160 kHz;
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, on the basis of recent echolocation data
and genetic data): Generalized hearing is estimated to occur between
approximately 275 Hz and 160 kHz.
Pinnipeds in water; Phocidae (true seals): Generalized
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
Pinnipeds in water; Otariidae (eared seals): Generalized
hearing is estimated to occur between 60 Hz and 39 kHz.
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Four marine mammal species (two cetacean and two pinniped (one otariid
and one phocid) species) have the reasonable potential to co-occur with
the construction activities. Please refer to Table 1. Of the cetacean
species that may be present, humpback whales are classified as low-
frequency cetaceans, and harbor porpoise are classified as high-
frequency cetaceans.
Potential Effects of Specified Activities on Marine Mammals and their
Habitat
The effects of underwater noise from blasting, vibratory pile
removal, and dredging activities for the Statter Harbor project have
the potential to result in behavioral harassment of marine mammals in
the vicinity of the action area. The Federal Register notice for the
proposed IHA (83 FR 52394; October 17, 2018) included a discussion of
the effects of anthropogenic noise on marine mammals, therefore that
information is not repeated here; please refer to the Federal Register
notice for that information.
Anticipated Effects on Habitat
The main impact associated with the Statter Harbor improvement
project will be temporarily elevated sound levels and the associated
direct effects on marine mammals. The project will not result in
permanent impacts to habitats used directly by marine mammals, such as
haulout sites, but may have potential short-term impacts to food
sources such as forage fish, etc, and minor impacts to the immediate
substrate during installation and removal of piles and blasting during
the project. These potential effects are discussed in detail in the
Federal Register notice for the proposed IHA (53 FR 5394; October 17,
2018), 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 this IHA, which will inform both NMFS' consideration
of ``small numbers'' and the negligible impact determination.
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 will primarily be by Level B harassment, as use of
the explosives, vibratory pile removal, and dredging has 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 from blasting, primarily for high frequency
species and phocids because predicted auditory injury zones are larger
than for low-frequency species and otariids. The mitigation and
monitoring measures are expected to minimize the severity of such
taking to the extent practicable. While the zones for slight lung
injury are large enough that a marine mammal could occur within the
zone (45 meters), the mitigation and monitoring measures, such as
delaying blasting as long as possible until animals are no longer
within the PTS zone, are expected to minimize the potential for such
taking to the extent practicable, such that the potential for non-
auditory physical injury is considered discountable.
As described previously, no mortality is anticipated or authorized
for this activity. Of the activities for which take is requested, only
blasting has the potential to result in mortality. When the isopleths
within which mortality could occur were calculated, the zones were
sufficiently small that the risk of mortality is considered
discountable. Below we describe how the take is estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (2) the area or volume of water
that will be ensonified above these levels in a day; (3) the density or
occurrence of marine mammals within these ensonified areas; and, (4)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the take estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B
[[Page 11071]]
harassment) or to incur permanent threshold shift (PTS) of some degree
(equated to Level A harassment). Thresholds have also been developed to
identify the pressure levels above which animals may incur different
types of tissue damage from exposure to pressure waves from explosive
detonation.
Level B Harassment for non-explosive sources--Though significantly
driven by received level, the onset of behavioral disturbance from
anthropogenic noise exposure is also informed to varying degrees by
other factors related to the source (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. This threshold is not applied to single
detonations as the sound is instantaneous in nature such that a
behavioral harassment is not expected to result, although temporary
threshold shift (TTS) may occur. A single detonation is not considered
as being able to result in a disruption of behavioral patterns because
the instantaneous sound is not likely to result in anything more
prolonged than a brief startle response. NMFS predicts that marine
mammals are likely to be behaviorally harassed in a manner we consider
Level B harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 micro pascal ([mu]Pa) root mean square
(rms) for continuous (e.g., vibratory pile-driving, drilling) and above
160 dB re 1 [mu]Pa (rms) for intermittent (e.g., impact pile driving)
sources.
The City of Juneau's activity includes the use of continuous sounds
(vibratory pile removal, dredging) and therefore the 120 dB re 1 [mu]Pa
(rms) threshold for behavioral harassment is applicable. While the
activity also includes impulsive sounds (blasting), the 160 dB re 1
[mu]Pa (rms) threshold for behavioral harassment is not applicable, as
behavioral harassment is not expected from single detonation events,
although TTS is possible.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual
criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). The City of Juneau's activity includes
the use non-impulsive (dredging, vibratory pile removal) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2018 Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift
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PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
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Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
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* 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]Pa2s. 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.
Explosive sources--Based on the best available science, NMFS uses
the acoustic and pressure thresholds indicated in Table 3 to predict
the onset of behavioral harassment, PTS, tissue damage, and mortality.
Table 3--Explosive Acoustic and Pressure Thresholds for Marine Mammals
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level B harassment Level A harassment Serious injury
----------------------------------------------------------------------------------------------------
Group Behavioral Mortality
(multiple TTS PTS Gastro- Lung
detonations) intestinal tract
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-freq cetacean............... 163 dB SEL......... 168 dB SEL or 213 183 dB SEL or 219 237 dB SPL...... 39.1M\1/3\ (1+[D/ 91.4M\1/3\ (1+[D/
dB SPLpk. dB SPLpk. 10.081])\1/2\ Pa- 10.081])\1/2\ Pa-
sec sec
where: M = mass of where: M = mass of
the animals in kg. the animals in kg
D = depth of D = depth of
animal in m. animal in m
[[Page 11072]]
High-freq cetacean.............. 135 dB SEL......... 140 dB SEL or 196 155 dB SEL or 202
dB SPLpk. dB SPLpk.
Phocidae........................ 165 dB SEL......... 170 dB SEL or 212 185 dB SEL or 218
dB SPLpk. dB SPLpk.
Otariidae....................... 183 dB SEL......... 188 dB SEL or 226 203 dB SEL or 232
dBpk. dB SPLpk.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
Vibratory removal--The closest known measurements of vibratory pile
removal similar to this project are from the Kake Ferry Terminal
project for vibratory extraction of an 18-inch (in) steel pile. The
extraction of 18-in steel pipe pile using a vibratory hammer resulted
in underwater noise levels reaching 156.2 dB rms at 7 meters (m) (Denes
et al. 2016). The pile diameters for this project are smaller, thus the
use of noise levels associated with the pile extraction at Kake may be
somewhat conservative. For timber pile removal, the Seattle Pier 62/63
sound source verification report contains an appendix with source
measurements at different distances for 63 individual pile removals
(WSDOT, 2015). When the data are normalized to 10 m, the median source
level is 152 dB rms at 10 m.
Dredging--For dredging, sound source data was used from bucket
dredging operations in Cook Inlet, Alaska (Dickerson et al. 2001).
Dredging in that project consisted of six distinct events, including
the bucket striking the channel bottom, bucket digging, winch in/out as
the bucket is lowered/raised, dumping of the material on the barge and
emptying the barge at the disposal site. Although the waveform of the
bucket strike has a high peak sound pressure with rapid rise time and
rapid decay (characteristics typical of an impulsive sound source), the
duration of the source signal was longer than what is often considered
for an impulsive sound source, about 50 seconds, which is the
approximate duration of one continuous noise signal from the dredging
equipment. The events following the initial waveform impulse were of
longer duration and were non-impulsive in form and therefore dredging
was analyzed as a continuous source. Dickerson et al. (2001) took 104
SPLrms measurements for the first five distinct phases of the dredging
cycle and averaged them, including the impulse in the waveform of the
dredge making contact with the substrate. These averages were distance
corrected to determine an average SPL of 150.5 dB rms at 1 m for the
bucket dredging process, with an assumed maximum duration of up to 50
seconds, of non-impulsive, continuous noise.
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, NMFS developed a User Spreadsheet that includes
tools to help predict a simple isopleth that can be used in conjunction
with marine mammal density or occurrence to help predict takes. We note
that because of some of the assumptions included in the methods used
for these tools, we anticipate that isopleths produced are typically
going to be overestimates of some degree, which may result in some
degree of overestimate of Level A harassment take. However, these tools
offer the best way to predict appropriate isopleths when more
sophisticated 3D modeling methods are not available, and NMFS continues
to develop ways to quantitatively refine these tools, and will
qualitatively address the output where appropriate. For stationary
sources, the NMFS User Spreadsheet predicts the closest distance at
which, if a marine mammal remained at that distance the whole duration
of the activity, it will not incur PTS. Inputs used in the User
Spreadsheet, and the resulting isopleths are reported below.
Table 4--NMFS User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
Timber removal Steel removal Dredging
--------------------------------------------------------
Spreadsheet tab used A: Stationary:
A.1: Vibratory A.1: Vibratory Non-impulsive,
pile driving pile driving continuous
----------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL)................................. 152 156.2 150.5
Weighting Factor Adjustment (kHz)...................... 2.5 2.5 2
a) Activity Duration (h) within 24-h period............ ................. ................. 11
Propagation (xLogR).................................... 15 15 15
Distance of source level measurement (m) +............. 10 7 1
# of piles/shots in a 24 h period...................... 16 4 .................
Duration to drive (remove) a single pile (min)......... 20 20 .................
----------------------------------------------------------------------------------------------------------------
When using the inputs from Table 4, the outputs generated are
summarized below in Table 5.
[[Page 11073]]
Table 5--NMFS User Spreadsheet Generated Outputs
[User spreadsheet output]
----------------------------------------------------------------------------------------------------------------
PTS Isopleth (meters)
---------------------------------------------------------------------------
Source type Low-frequency High-frequency
cetaceans cetaceans Phocid pinnipeds Otariid pinnipeds
----------------------------------------------------------------------------------------------------------------
Timber removal...................... 5.2 7.7 3.2 0.2
Steel Removal....................... 2.8 4.1 1.7 0.1
Dredging............................ 0.7 0.6 0.4 0.0
----------------------------------------------------------------------------------------------------------------
Level B Behavioral Harassment Isopleth (meters)
----------------------------------------------------------------------------------------------------------------
Timber removal...................... 1359.36
Steel removal....................... 1813.14
Dredging............................ 107.98
----------------------------------------------------------------------------------------------------------------
* Impulsive sounds have a dual metric threshold (SELcum and PK). Metric producing the largest isopleth should be
used.
Blasting--In our proposed IHA, historic data from an analog project
were analyzed to create a conservative attenuation model for
anticipated pressure levels from confined blasting in drilled shafts in
underwater bedrock. Sound pressure data from the analog project were
analyzed to compare source pressure levels to received impulse levels
(Alaska Seismic, 2018). These models were used to predict distances to
the peak level and impulse thresholds. Cumulative source levels from
the analog project were used in conjunction with the NMFS 2018 updated
User Spreadsheet Tool for predicting threshold shift isopleths for
multiple detonations, after being corrected to a 1-m reference source
level. The median of 10 measurements, consisting of detonations ranging
from 19 to 78 individual holes for the detonation, resulted in a source
level of 227.98 dB single shot SEL.
However, during the public comment period, the Marine Mammal
Commission noted some errors in the User Spreadsheet methodology for
single detonations. Following consultation with the Commission, NMFS
computed cumulative sound exposure impact zones from the blasting
information by the City of Juneau. Peak source levels of the confined
blasts were calculated based on Hempet et al. (2007), using a distance
of eight feet and a weight of 95 pounds for a single charge. The total
charge weight is defined as the product of the single charge weight and
the number of charges. In this case, the number of charges is 75.
Explosive energy was then computed from peak pressure of the single
maximum charge, using the pressure and time relationship of a shock
wave (Urick 1983). Due to time and spatial separation of each single
charge by a distance of eight feet, the accumulation of acoustic energy
is added sequentially, assuming the transmission loss follows
cylindrical spreading within the matrix of charges. The sound exposure
level (SEL) from each charge at its source can then be calculated,
followed by the received SEL from each charge. Since the charges will
be deployed in a grid of 8 ft by 8 ft apart, thus the received SELs
from different charges to a given point will vary depending on the
distance of the charges from the receiver. Without specific information
regarding the layout of the charges, the modeling assumes a grid of 8
by 9 charges with an additional three charges located in three
peripheral locations. Among the various total SELs calculated, the
largest value, SELtotal(max) is selected to calculate the impact range.
Using the pressure versus time relationship above, the frequency
spectrum of the explosion can be computed by taking the Fourier
transform of the pressure (Weston, 1960). Frequency specific
transmission loss of acoustic energy due to absorption is computed
using the absorption coefficient, [alpha] (dB/km), summarized by
Fran[ccedil]ois and Garrison (1982a, b). Seawater properties for
computing sound speed and absorption coefficient were based on NMFS
Alaska Fisheries Science Center report of mean measurements in Auke Bay
(Sturdevant and Landingham, 1993). Transmission loss was calculated
using the sonar equation:
TL = SELtotal(m)-SELthreshold
where SELthreshold is the Level A harassment threshold. The
distances, R, where such transmission loss is achieved were computed
numerically by combining both geometric transmission loss, and
transmission loss due to frequency-specific absorption. A spreading
coefficient of 20 is assumed to account for acoustic energy loss from
the sediment into the water column. The outputs from this model are
summarized in Table 6 below, and replace those values given for
blasting previously in Table 5 of our Federal Register Notice of
Proposed IHA.
Table 6--Model Results of Impact Zones for Blasting in Meters
[m]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Slight lung
Species Mortality injury GI tract PTS: SELcum PTS: SPLpk TTS: SELcum TTS: SPLpk
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low frequency ceteacean................. 3.9975 9.3445 26.0142 380 206.64 2120 412.3
High frequency cetacean................. 20.5573 48.0546 26.0142 1340 1462.9 4910 2918.8
Otariid................................. 13.9502 32.6100 26.0142 20 * 46.261 * 140 92.302
[[Page 11074]]
Phocid.................................. 18.3762 42.9561 26.0142 180 231.85 1000 462.61
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For the dual criteria of SELcum and SPLpk, distances in bold are more predominant and were used in our analysis. The PTS and TTS distances for Steller
sea lions resulting from the model seemed uncharacteristically small when compared to the other thresholds resulting from the model and were doubled
to 93 m and 280 m respectively for take estimation, mitigation, and monitoring.
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations. Reliable densities are not available for Statter Harbor
or the Auke Bay area. Generalized densities for the North Pacific are
not applicable given the high variability in occurrence and density at
specific inlets and harbors. Therefore, the applicant consulted
opportunistic sightings data from oceanographic surveys in Auke Bay and
sightings from Auke Bay Marine Station observation pier for Statter
Harbor to arrive at a number of animals expected to occur within the
harbor per day. For humpback whales, it is assumed that a maximum of
two animals per day are likely to occur in the harbor. For Steller sea
lions, the potential maximum daily occurrence of animals is 121
individuals within the harbor. For harbor seals, the maximum daily
occurrence of animals is 52 individuals.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
Because reliable densities are not available, the applicant
requests take based on the above mentioned maximum number of animals
that may occur in the harbor per day multiplied by the number of days
of the activity. The applicant varied these calculations based on
certain factors.
Humpback whale--Based on the size of the harassment zone for
dredging, in combination with the Mitigation outlined below, the
applicant does not expect humpback whales to approach the dredging
vessel and therefore is not requesting take of humpback whales from
dredging. Because of the nature of blasting, there is no behavioral
threshold associated with the activity, but TTS, which is a form of
Level B harassment take, may occur. With a maximum take of two animals
per day, multiplied by a maximum of 10 days of pile removal and two
days of blasting (TTS), the applicant requests authorization of 24
Level B harassment takes of humpback whale.
Steller sea lion--For the final IHA it is still estimated that a
maximum of 121 Steller sea lions may occur in outer Statter Harbor
within one day. A maximum take of 121 animals per day for 10 days of
pile removal is 1,210 Steller sea lions. Given the size of the Level B
harassment zone for dredging (108 m), it is possible Steller sea lions
may approach the source vessel. However, given the small size of the
zone, the applicant reduced the number of animals expected to be
sighted daily within the Level B harassment isopleth to be 10 animals
per day for 45 days of dredging. This is reduced from the 60 sea lions
per day that were estimated to occur within the dredging isopleth in
the proposed IHA. However, because animals would not be expected to
occur so close to the source every day, we assume that takes would
occur on only half of dredging days, resulting in 225 estimated
exposures of Steller sea lions from dredging. This second reduction in
dredging takes was incorporated based on input from the Marine Mammal
Commission during the public comment period suggesting that Steller sea
lions are infrequently seen in the inner harbor. For blasting, the size
of the TTS zone (280 m) increased from the distance estimated in the
proposed IHA (57 m). Given the size of the revised zones for blasting
and the location of the blasting close to shore and harbor structures,
it is expected that a maximum of 106 Steller sea lions could occur
within the inner harbor where the blasts will occur. Therefore, it is
assumed that 106 sea lions may occur within the zone for two days of
blasting, resulting in a potential Level B harassment take (TTS only)
of 212 Steller sea lions. No more than 15 Steller sea lions are assumed
to be within range of the PTS blasting isopleth (46.3 m, which has been
conservatively doubled to 93 m), resulting in a total of 30 potential
Level A harassment takes of Steller sea lion from blasting. While it is
conservative to assume this many Steller sea lions may occur close to
the blast source, they are regularly seen in the area and the
explosives need to be detonated within a certain number of hours after
being planted. It is possible that Steller sea lions could approach the
source and the detonation could no longer be delayed, exposing Steller
sea lions to sound levels that may induce PTS. This adds to a total of
1,447 Level B takes and 30 Level A takes of Steller sea lion.
Harbor seal--The largest known group size to occur in Statter
Harbor is 52 individuals, which is the maximum number of takes per day
used here. For 10 days of pile removal, using an assumed rate of 52
individuals per day, the potential take of harbor seals is 520. For 45
days of dredging, the estimated daily take was reduced by half due to
the small size of the zone (26 individuals), resulting in an estimate
of 1,170 takes. For blasting, the size of the Level A harassment
isopleth increased from 71 m to 232 m. Therefore, we assume an
increased abundance of harbor seals potentially present within the
Level A harassment zone, i.e., all 52 assumed resident seals may occur
within the Level A harassment zone during blasts on each of the two
days of blasting for a total of 104 takes by Level A harassment.
However, as these are the only harbor seals that could occur in the
harbor, no additional seals are added as Level B harassment (TTS)
exposures from blasting. Summed together, this would result in 1,690
Level B takes and 104 Level A takes of harbor seal.
Harbor porpoise--Very little is known about likelihood of
occurrence of harbor porpoise in Statter Harbor but they are rarely
observed in the area and we assume that may occur, while their cryptic
nature makes it difficult to mitigate all potential for take. If it is
assumed one pair could occur per day for 10 days of pile removal, this
would result in potential take of 20 harbor porpoise. For 45 days of
dredging, the estimated daily take was reduced by half due to the small
size of the zone, which would result in take of 44 estimated takes of
harbor porpoise. For two days of blasting, it is assumed three pairs of
harbor porpoise (6 individuals) may occur each day in the TTS zone, for
12 total TTS takes, and two pairs on each day may appear in the PTS
zone, resulting in eight Level A harassment takes of harbor porpoise.
This is an
[[Page 11075]]
increase from the estimated take number provided in the proposed IHA,
reflecting the increase in zone size for blasting.
The total number of takes authorized are summarized in Table 7
below.
Table 7--Takes Authorized
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Level B Total Level A
Takes from Takes from TTS takes from PTS takes from harassment harassment
pile removal dredging blasting blasting takes takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.......................................... 20 0 4 0 24 0
Steller sea lion........................................ 1,210 225 12 30 1,447 30
Harbor seal............................................. 520 1,170 0 104 1,690 104
Harbor porpoise......................................... 20 44 12 8 76 8
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (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 such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned) the likelihood of effective implementation (probability
implemented as planned); and
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
In addition to the measures described later in this section, the
City of Juneau will employ the following standard mitigation measures:
Conduct a briefing between construction supervisors and
crews and the marine mammal monitoring team prior to the start of
construction, and when new personnel join the work, to explain
responsibilities, communication procedures, marine mammal monitoring
protocol, and operational procedures;
For in-water and over-water heavy machinery work, if a
marine mammal comes within 10 m, operations must cease and vessels must
reduce speed to the minimum level required to maintain steerage and
safe working conditions. This 10 m shutdown encompasses the Level A
harassment zone for pile removal and dredging and therefore this
requirement is not listed separately;
Work may only occur during daylight hours, when visual
monitoring of marine mammals can be conducted;
For those marine mammals for which Level B harassment take
has not been requested, pile removal and dredging will shut down
immediately when the animals are sighted approaching the monitoring
zones; and
If take reaches the authorized limit for an authorized
species, activity for which take is authorized will be stopped as these
species approach the monitoring zones to avoid additional take of them.
The following measures will apply to the City of Juneau's
mitigation requirements:
Establishment of Monitoring Zones for Level B--The City of Juneau
will establish Level B monitoring zones or zones of influence (ZOI)
which are areas where SPLs are equal to or exceed the 120 dB rms
threshold during vibratory removal and dredging. Similar harassment
monitoring zones will be established for the TTS isopleths associated
with each functional hearing group for blasting activities. Monitoring
zones provide utility for observing by establishing monitoring
protocols for areas adjacent to the shutdown zones. Monitoring zones
enable observers to be aware of and communicate the presence of marine
mammals in the project area outside the shutdown zone and thus prepare
for a potential cease of activity should the animal enter the shutdown
zone. The Level B monitoring zones are depicted in Table 8.
Table 8--Shutdown and Monitoring Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monitoring zones Shutdown zones
-------------------------------------------------------------------------------------
Source High frequency Low frequency
cetacean ceteacean Phocid Otariid All species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Removal--Steel.......................................... 1,820 m 1,820 m 1,820 m 1,820 m 10 m.
Vibratory Removal--Timber......................................... 1,360 m 1,360 m 1,360 m 1,360 m 10 m.
Dredging.......................................................... 110 m 110 m 110 m 110 m 10 m.
Blasting (PTS).................................................... 1,465 m 380 m 235 m 95 m N/A.
Blasting (TTS).................................................... 4,910 m 2,120 m 1,000 m 280 m N/A.
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 11076]]
As shown, the largest Level B harassment zone is greater than 4,000
m, making it unlikely that PSOs will be able to view the entire
harassment area. Due to this, Level B harassment exposures will be
recorded and extrapolated based upon the number of observed take and
the percentage of the Level B harassment zone that was not visible.
Pre-Activity Monitoring--Prior to the start of daily in-water
activity, or whenever a break in activity of 30 minutes or longer
occurs, the observer will observe the shutdown and monitoring zones for
a period of 30 minutes. The shutdown zone will be cleared when a marine
mammal has not been observed within the zone for that 30-minute period.
If a marine mammal is observed within the shutdown zone, activity
cannot proceed until the animal has left the zone or has not been
observed for 15 minutes. If the Level B harassment zone has been
observed for 30 minutes and non-permitted species are not present
within the zone, activity can commence in good visibility conditions.
Work can continue even if visibility becomes impaired within the
monitoring zone. When a marine mammal permitted for Level B harassment
take is present in the monitoring zone, activities may begin and Level
B harassment take will be recorded. As stated above, if the entire
monitoring zone is not visible at the start of construction, activity
can begin. If work ceases for more than 30 minutes, the pre-activity
monitoring of both the monitoring zone and shutdown zone will commence.
Charges for blasting will not be laid if marine mammals are within
the shutdown zone or appear likely to enter the shutdown zone. However,
once charges are placed, they cannot be safely left undetonated for
more than 24 hours. For blasting, the TTS zone will be monitored for a
minimum of 30 minutes prior to detonating the blasts. If a marine
mammal is sighted within the TTS zone, blasting will be delayed until
the zone is clear of marine mammals for 30 minutes. This will continue
as long as practicable within the constraints of the blasting design
but not beyond sunset on the same day as the charges cannot lay dormant
for more than 24 hours, which may force the detonation of the blast in
the presence of marine mammals. Charges will be laid as early as
possible in the morning and stemming procedures will be used to fill
the blasting holes to potentially reduce the noise from the blasts.
Blasting will only be planned to occur in good visibility conditions,
and at least 30 minutes after sunrise and at least one hour prior to
sunset. The TTS zone will also be monitored for one hour post-blasting.
Based on our evaluation of the applicant's measures, NMFS has
determined that the mitigation measures provide the means 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 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 both to compliance as well
as ensuring that the most value is obtained from the required
monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Visual Monitoring
Monitoring will be conducted 30 minutes before, during, and 30
minutes after construction activities. In addition, observers must
record all incidents of marine mammal occurrence, regardless of
distance from activity, and must document any behavioral reactions in
concert with distance from construction activities.
Protected Species Observers (PSO) will be land-based observers. For
dredging, pile removal, and blasting, one, two, and four PSOs will be
required, respectively. Observers will be stationed at locations that
provide adequate visual coverage for shutdown and monitoring zones.
Potential observation locations are depicted in Figures 2 and 3 of the
applicant's Marine Mammal Mitigation and Monitoring Plan. A minimum of
one observer will be placed at a vantage point providing total coverage
of the monitoring zones and for observation zones larger than 500 m, at
least one other additional observer will be placed at the outermost
float or other similar vantage point in order to observe the extend
observation zone. During blasting, pre-blast monitoring, and post-blast
monitoring, four observers will be on duty. Optimal observation
locations will be selected based on visibility and the type of work
occurring. All PSOs will be trained in marine mammal identification and
behaviors and are required to have no other project-related tasks while
conducting monitoring. In addition, monitoring will be conducted by
qualified observers, who will be placed at the best vantage point(s)
practicable to monitor for marine mammals and implement shutdown/delay
procedures when applicable by calling for the shutdown to the hammer
operator. Monitoring of construction activities must be conducted by
qualified PSOs (see below), who must have no other assigned tasks
during monitoring periods. The applicant must adhere to the following
conditions when selecting observers:
Independent PSOs must be used (i.e., not construction
personnel);
At least one PSO must have prior experience working as a
marine mammal observer during construction activities;
Other PSOs may substitute education (degree in biological
science or related field) or training for experience;
[[Page 11077]]
Where a team of three or more PSOs are required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience working as a marine mammal observer
during construction; and
The applicant must submit PSO curriculum vitaes for
approval by NMFS.
The applicant must ensure that observers 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.
At least 24 hours prior to blasting, the City will notify the
Office of Protected Resources, NMFS Alaska Regional Office, and the
Alaska Regional Stranding Coordinator that blasting is planned to
occur, as well as notify these parties within 24 hours after blasting
that blasting actually occurred.
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of construction activities. It will
include an overall description of work completed, a narrative regarding
marine mammal sightings, and associated PSO data sheets. Specifically,
the report must include:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
Weather parameters (e.g., percent cover, visibility);
Water conditions (e.g., sea state, tide state);
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any observable marine mammal behavior
patterns, including bearing and direction of travel and distance from
construction activity;
Distance from construction 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.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as a serious injury or mortality, The City of Juneau
will immediately cease the specified activities and report the incident
to the Office of Protected Resources, NMFS Alaska Regional Office, and
the Alaska Regional Stranding Coordinator. The report will include the
following information:
Description of the incident;
Environmental conditions (e.g., Beaufort sea state,
visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities will not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS will work with The City of
Juneau to determine what is necessary to minimize the likelihood of
further prohibited take and ensure MMPA compliance. The City of Juneau
will not be able to resume their activities until notified by NMFS via
letter, email, or telephone.
In the event that The City of Juneau discovers an injured or dead
marine mammal, and the lead PSO determines that the cause of the injury
or death is unknown and the death is relatively recent (e.g., in less
than a moderate state of decomposition as described in the next
paragraph), the City of Juneau will immediately report the incident to
the Office of Protected Resources, NMFS, and the Alaska Regional
Stranding Coordinator. The report will include the same information
identified in the paragraph above. Activities will be able to continue
while NMFS reviews the circumstances of the incident. NMFS will work
with the City of Juneau to determine whether modifications in the
activities are appropriate.
In the event that the City of Juneau discovers an injured or dead
marine mammal and the lead PSO determines that the injury or death is
not associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), the City of Juneau will report the
incident to the Office of Protected Resources, NMFS, and the NMFS
Alaska Stranding Hotline and/or by email to the Alaska Regional
Stranding Coordinator, within 24 hours of the discovery. The City of
Juneau will provide photographs, video footage (if available), or other
documentation of the stranded animal sighting to NMFS and the Marine
Mammal Stranding Coordinator.
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 responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
As stated in the mitigation section, shutdown zones equal to or
exceeding Level A isopleths shown in Table 8 for all activities other
than blasting will be implemented. Serious injury or mortality is not
anticipated nor
[[Page 11078]]
authorized. Behavioral responses of marine mammals to pile removal and
dredging, if any, are expected to be mild and temporary due to the
short term duration of the noise produced by the source as well as the
relatively low source levels when compared with ambient levels in an
area with high levels of anthropogenic activity. Given the short
duration of noise-generating activities per day and that pile removal
and dredging would occur for 55 days, any harassment would be
temporary. The blasting will only occur across two days, with one blast
scheduled on each day. In addition, the project includes generally low
level sound sources, such as dredging and removal of piles much smaller
than those frequently used in other construction projects. In addition,
for all species except humpbacks, there are no known biologically
important areas near the project zone that would be impacted by the
construction activities. The region of Statter Harbor where the project
will take place is located in a developed harbor area with regular
marine vessel traffic. Although there is a resident harbor seal
population, the area of construction is not known to be of important
biological significance such as used for breeding or foraging. 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 the species or stock through effects on
annual rates of recruitment or survival:
No mortality is anticipated or authorized;
There are no known biologically important areas within the
project area;
The City of Juneau will implement mitigation measures such
as shut down zones for all in-water and over-water activities;
Monitoring reports from similar work in Alaska have
documented little to no effect on individuals of the same species
impacted by the specified activities;
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 above, only small numbers of incidental take may be
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. Additionally, other qualitative
factors may be considered in the analysis, such as the temporal or
spatial scale of the activities.
Table 9 below shows take as a percent of population for each of the
species listed above.
Table 9--Summary of Authorized Instances of Level A and Level B Harassment
----------------------------------------------------------------------------------------------------------------
Number of Number of
Species DPS/stock Level B takes Level A takes Stock Percent of
by stock by stock abundance population \1\
----------------------------------------------------------------------------------------------------------------
Steller sea lion.............. Eastern DPS..... 1,418 29 41,638 3.48
Western DPS..... 29 1 53,303 0.06
Harbor seal................... Lynn Canal...... 1,690 104 9,478 18.93
Harbor porpoise............... Southeast Alaska 76 8 975 8.62
Humpback whale................ Central North 24 0 10,103 0.24
Pacific Stock.
----------------------------------------------------------------------------------------------------------------
Table 9 presents the number of animals that could be exposed to
received noise levels that may result in Level A or Level B take for
the construction at Statter Harbor. Our analysis shows that less than
one third of the best available population estimate of each affected
stock could be taken. 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 harbor seals and 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.
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 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 project is not
known to occur in an important subsistence hunting area. It is a
developed area with regular marine vessel traffic and the project is
one year of a multi-year harbor improvement effort that is already
underway. The work at this harbor has been publicized and public input
has been solicited on the overall improvement.
Based on the description of the specified activity, the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the mitigation and monitoring
measures, NMFS has determined that there will not be an unmitigable
adverse impact on subsistence uses from the City of Juneau's
activities.
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 IHA)
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 will preclude this
categorical exclusion. Accordingly, NMFS has determined that the
issuance
[[Page 11079]]
of the IHA qualifies to be categorically excluded from further NEPA
review.
Endangered Species Act (ESA)
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally, in this case with the NMFS Alaska Regional
Office, whenever we propose to authorize take for endangered or
threatened species.
There are two marine mammal species (western DPS Steller sea lion;
Mexico DPS humpback whale) with confirmed occurrence in the project
area that are listed as endangered under the ESA. The NMFS Alaska
Regional Office issued a Biological Opinion on February 22, 2019 under
section 7 of the ESA, on the issuance of an IHA to the City of Juneau
under section 101(a)(5)(D) of the MMPA by the NMFS Office of Protected
Resources. The Biological Opinion concluded that the action is not
likely to jeopardize the continued existence of western DPS Steller sea
lions or the Mexico DPS of humpback whales, and is not likely to
destroy or adversely modify western DPS Steller sea lion critical
habitat.
Authorization
NMFS has issued an IHA to the City of Juneau for the potential
harassment of small numbers of four marine mammal species incidental to
the Statter Harbor improvements project in Auke Bay, Alaska, provided
the previously mentioned mitigation, monitoring and reporting.
Dated: March 20, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2019-05668 Filed 3-22-19; 8:45 am]
BILLING CODE 3510-22-P