[Federal Register Volume 84, Number 146 (Tuesday, July 30, 2019)]
[Notices]
[Pages 36891-36904]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16155]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG737
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Confined Rock Blasting Near
Ketchikan, 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 Ketchikan to incidentally harass, by Level B and Level A
harassment only, marine mammals during underwater confined rock
blasting activities associated with a rock pinnacle removal project in
Ketchikan, Alaska.
DATES: This Authorization is effective from September 16, 2019 to
September 15, 2020.
FOR FURTHER INFORMATION CONTACT: Gray Redding, 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/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 may be provided to the public
for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable
[adverse] impact'' on the affected species or stocks and their habitat,
paying particular attention to rookeries, mating grounds, and areas of
similar significance, and on the availability of such species or stocks
for taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of such takings are set forth.
The definitions of all applicable MMPA statutory terms cited above
are included in the relevant sections below.
Summary of Request
On December 10, 2018, NMFS received a request from the City of
Ketchikan for an IHA to take marine mammals incidental to underwater
confined blasting and excavation in southeastern Alaska. The
application was deemed adequate and complete on February 7, 2019. City
of Ketchikan's request is for take of a small number of nine marine
mammal species by Level B harassment and three marine mammal species by
Level A harassment. Neither the City of Ketchikan nor NMFS expects
serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate.
Description of Specified Activity
Overview
The City of Ketchikan plans to conduct underwater confined blasting
of a rock pinnacle in the Tongass Narrows, southeastern Alaska. Removal
of the underwater pinnacle will expand the area of safe navigation
depths for cruise ships that presently visit Berths I and II. Removing
the pinnacle will provide a more reliable ingress and egress for ships
over a much wider range of wind and water level conditions. The project
is scheduled to occur from September 16, 2019 through April 30, 2020.
The blasting portion of the activities is expected to occur between
November 15, 2019 and March 15, 2020, but blasting is not restricted to
this time period, in order to allow appropriate flexibility for the
applicant to complete the project. The action has the potential to
affect waters in the Tongass Narrows and nearby Revillagigedo Channel,
approximately 3 miles to the south.
There will be up to 50 days of blasting (currently anticipating
between 25 and 50 total blasts) limited to at most, one blast per day.
A blast consists of a detonation of a series of sequential charges,
delayed from one another at an interval of 8 milliseconds (ms), with
the total blast typically lasting less than 1 second (one second = 1000
milliseconds). Each delayed charge in the blast will contain a maximum
of 75 total lbs (34 kg) of explosive. The timing of the blast must
assure that the maximum pounds per delay does not exceed 75 lbs. The
planned daily blast will consist of a grid of boreholes, each
containing a delayed charge (total number may vary but typically it
ranges between 30 to 60 holes), with the top section of the hole then
filled in with stone (this process is referred to as ``rock
stemming'').
Following blasting, the material freed by blasting will be dredged.
As discussed in the proposed Federal Register Notice, take is highly
unlikely and is not authorized for dredging activities.
A detailed description of the planned rock pinnacle removal project
is provided in the Federal Register notice for the proposed IHA (84 FR
11508; March 27, 2019). Since that time, no changes have been made to
the planned confined underwater blasting 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's proposal to issue and IHA to the City of
Ketchikan was
[[Page 36892]]
published in the Federal Register on March 27, 2019 (84 FR 11508). The
notice described, in detail, the City of Ketchikan'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 one comment from the Marine Mammal Commission
(Commission).
Comment 1: The Commission recommended that NMFS estimate and
ultimately authorize take by Level B harassment due to behavioral
harassment during all activities involving explosives, including single
detonation events, for this and all future IHAs. Additionally if NMFS
elects not to authorize these takes, it should in the Federal Register
Notices explain the basis for assuming no behavioral harassment occurs.
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 blasts conducted by the City
of Ketchikan are confined blasts with charge detonations separated by
microdelays, constituting a single detonation event per day with blasts
occurring for at most 50 days.
Comment 2: 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 (84 FR 11508, March 27,
2019) 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 Federal Register notices that consider renewals, requesting
input specifically on the possible renewal itself. NMFS appreciates the
streamlining achieved by the use of abbreviated Federal Register
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
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/marine-mammal-stock-assessments) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (https://www.fisheries.noaa.gov/find-species).
Table 1 lists all species with expected potential for occurrence in
waters near Ketchikan, Alaska and summarizes information related to the
population or stock, including regulatory status under the MMPA and ESA
and potential biological removal (PBR), where known. For taxonomy, we
follow Committee on Taxonomy (2018). PBR is defined by the MMPA as the
maximum number of animals, not including natural mortalities, that may
be removed from a marine mammal stock while allowing that stock to
reach or maintain its optimum sustainable population (as described in
NMFS's SARs). While no mortality is anticipated or authorized here, PBR
and annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Alaska SARs (e.g., Muto et al., 2018). All values presented
in Table 1 are the most recent available at the time of publication and
are available in the 2017 SARs (Muto et al., 2018) and draft 2018 SARs
(available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).
[[Page 36893]]
Table 1--Marine Mammals That Could Occur in the Planned Action Area
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Stock abundance Nbest,
ESA/MMPA status; (CV, Nmin, most recent Annual M/
Common name Scientific name MMPA Stock Strategic (Y/N) abundance survey) \2\ PBR SI \3\
\1\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
Gray Whale...................... Eschrichtius robustus.. Eastern North Pacific.. -, -, N 26,960 (0.05, 25,849, 801 138
2016).
Family Balaenidae:
Humpback whale.................. Megaptera novaeangliae. Central North Pacific.. E, D,Y 10,103 (0.3; 7,890; 83 25
2006).
Minke whale..................... Balaenoptera Alaska................. -, N N.A................... N.A. N.A.
acutorostrata.
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Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Killer whale.................... Orcinus orca........... Alaska Resident........ -, N 2,347 (N.A.; 2,347; 24 1
2012).
West Coast Transient... -, N 243 (N.A, 243, 2009).. 2.4 0
Northern Resident...... -, N 261 (N.A; 261; 2011).. 1.96 0
Gulf of Alaska -, N 587 (N.A; 587; 2012).. 5.87 1
Transient.
Pacific white-sided dolphin..... Lagenorhynchus North Pacific.......... -,-; N 26,880 (N.A.; N.A.; N.A. 0
obliquidens. 1990).
Family Phocoenidae:
Harbor porpoise................. Phocoena phocoena...... Southeast Alaska....... -, Y 975 (0.10; 896; 2012). 8.95 34
Dall's porpoise................. Phocoenoides dalli..... Alaska................. -, N 83400 (0.097, N.A., N.A. 38
1993).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Eastern U.S............ -,-, N 41,638 (N.A.; 41,638; 2,498 108
2015).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina Clarence Strait........ -, N 31,634 (N.A.; 29,093; 1,222 41
richardii. 2011).
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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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N.A.).
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
All species that could potentially occur in the planned action
areas are included in Table 1. As described below, all 9 species (with
12 managed stocks) temporally and spatially co-occur with the activity
to the degree that take is reasonably likely to occur, and we have
authorized it. In addition, the northern sea otter (Enhydra lutris) may
be found in waters near Ketchikan, Alaska. However, northern sea otters
are managed by the U.S. Fish and Wildlife Service and are not
considered further in this document.
A detailed description of the of the species likely to be affected
by the City of Ketchikan's 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 (84 FR 11508; March 27, 2019); 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 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. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 2.
[[Page 36894]]
Table 2--Marine Mammal Hearing Groups
[NMFS, 2018]
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Hearing group Generalized hearing range *
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Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Nine marine mammal species (seven cetacean and two pinniped (one
otariid and one phocid) species) have the reasonable potential to co-
occur with the planned blasting activities. Please refer to Table 1. Of
the cetacean species that may be present, three are classified as low-
frequency cetaceans (i.e., all mysticete species), two are classified
as mid-frequency cetaceans (i.e., all delphinid and ziphiid species and
the sperm whale), and two are classified as high-frequency cetaceans
(i.e., harbor porpoise and Kogia spp.).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from confined underwater blasting
activities for the Ketchikan pinnacle removal project have the
potential to result in temporary threshold shifts (TTS) (Level B
harassment) and a small degree of permanent threshold shifts (PTS)
(Level A harassment) of marine mammals in the vicinity of the action
area. The Federal Register notice for the proposed IHA (84 FR 11508;
March 27, 2019) 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 (84 FR 11508; March
27, 2019) for that information.
The main impact to marine mammal habitat associated with the
Ketchikan pinnacle removal project would be temporarily elevated sound
levels and the associated direct effects on marine mammals. The project
would not result in permanent impacts to habitats used directly by
marine mammals, such as haulout sites, because the underwater pinnacle
to be removed is not prime foraging habitat. The project may have
potential minor impacts to food sources such as forage fish and smaller
marine mammals (transient killer whale prey), and permanent but minor
impacts to the seafloor due to dredging and blasting as part of the
pinnacle removal project. These potential effects are discussed in
detail in the Federal Register notice for the proposed IHA (84 FR
11508; March 27, 2019), 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.
After public comment and review of the proposed authorization, the
following items have changed in the final authorization.
(1) Estimated group sizes, which were the basis for take estimates
in this project, were increased for some species, including Pacific
white sided dolphin, killer whale, minke whale, and gray whale. Changes
to group size were made to more conservatively account for the
variability possible in group size, and these changes are outlined for
each species in the ``Marine Mammal Occurrence'' section below.
(2) The expected frequency of occurrence for minke whales was
increased based on behavioral information suggested by the Commission.
The details of this increase are discussed in the ``Marine Mammal
Occurrence'' section below.
(3) These changes in group size and occurrence resulting in changes
to the estimated take for these species. These changes are discussed in
the ``Take Calculation and Estimation'' section below.
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 (via
TTS), as use of the explosive source (i.e., blasting) for a very short
period each day has the potential to result in TTS for individual
marine mammals. There is also some potential for auditory injury and
slight tissue damage (Level A harassment) to result, primarily for
mysticetes, porpoise, and phocids because predicted auditory injury
zones are larger than for mid-frequency cetaceans and otariids. The
planned mitigation and monitoring measures are expected to minimize the
severity of such taking to the extent practicable. The primary relevant
mitigation measure is avoiding blasting when any marine mammal is
observed in the PTS zone. While this measure should avoid all take by
Level A harassment, NMFS is authorizing takes by Level A harassment to
account for the possibility that marine mammals escape observation in
the PTS zone. Additionally, while the zones for slight lung injury are
large enough that a marine mammal could occur within the zone (42
meters), the mitigation and monitoring measures, such as avoiding
blasting when marine mammals are observed in PTS zone, are expected to
minimize the potential for such taking to the extent practicable.
Therefore the potential for non-auditory physical
[[Page 36895]]
injury is considered discountable, and all takes by Level A harassment
are expected to occur due to PTS.
As described previously, no mortality is anticipated or authorized
for this activity. Below we describe how the take is estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will incur some degree of 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 incur TTS
(equated to Level B harassment) or PTS (equated to Level A harassment)
of some degree. 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. TTS
is possible and Table 3 lists TTS onset thresholds.
Level A harassment--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 Ketchikan's planned activity includes the use of an impulsive
source, blasting.
These thresholds are provided in Table 3 below. Table 3 also
provides threshold for tissue damage and mortality. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2016 Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 3--Explosive Acoustic and Pressure Thresholds for Marine Mammals
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Level B harassment Level A harassment Serious injury
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Group Behavioral Mortality
(multiple TTS PTS Gastro- intestinal Lung
detonations) tract
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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:............ where:
M = mass of the M = mass of the
animals in kg. animals in kg.
D = depth of D = depth of
animal in m. animal in m.
Mid-freq cetacean.............. 165 dB SEL........ 170 dB SEL of 224 185 dB SEL or 230
dB SPLpk. dB SPLpk.
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.
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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.
Blasting--While the NMFS Technical Guidance (2016) and associated
User Spreadsheet include tools for predicting threshold shift isopleths
for multiple detonations, the Marine Mammal Commission noted in
response to a previous proposed IHA (83 FR 52394, October 17, 2018)
that the User Spreadsheet contained some errors in methodology for
single detonations. Following a method generated through consultation
with the Marine Mammal Commission, NMFS computed cumulative sound
exposure impact zones from the blasting information provided by the
City of Ketchikan. Peak source levels of the confined blasts were
calculated based on Hempet et al. (2007), using a distance of 4 feet
and a weight of 75 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 maximum number of charges is 60. 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 four feet, the accumulation of acoustic energy is added
sequentially, assuming the transmission loss follows cylindrical
spreading within the matrix of charges. The 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 with a least 4 ft
by 4 ft spacing, the received SELs from different charges to a given
point will vary depending on the distance of the charges from the
receiver. As stated in the ``Detailed Description of Specific
Activity,'' the actual spacing between charges will be determined based
on how the rock responds to the blasting. Modeling was carried out
using 4 ft spacing as this closest potential spacing results in the
most conservative (highest) source values and largest resulting impact
zones. Without specific information regarding the layout of the
[[Page 36896]]
charges, the modeling assumes a grid of 7 by 8 charges with an
additional four charges located in 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 (Urick 1983), 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 Ketchikan ocean temperatures recorded from November through
March (National Centers for Environmental Information, 2018) and
salinity data presented in Vanderhoof and Carls (2012). Transmission
loss was calculated using the sonar equation:
TL = SELtotal(m)-SELthreshold
where SELthreshold is the Level A harassment and Level B
harassment (TTS) 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. While this
spreading coefficient would normally indicate an assumption of
spherical spreading, in this instance, the higher coefficient is
actually used to account for acoustic energy loss from the sediment
into the water column. The outputs from this model are summarized in
Table 4 below. For the dual criteria of SELcum and SPLpk shown in Table
4, distances in bold are the larger of the two isopleths, and were used
in further analysis. Because the blast is composed of multiple charges
arranged in a grid, these distances are measured from any individual
charge, meaning that measurement begins at the outermost charges. For
additional information on these calculations please refer to the
``Ketchikan Detonation Modeling Concept'' document which can be found
at the following address: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
Table 4--Model Results of Impact Zones for Blasting in Meters (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Slight lung
Marine mammal hearing group Mortality * injury * GI Tract PTS: SELcum PTS: SPLpk TTS: SELcum TTS: SPLpk
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low frequency cetacean.................. 6 12 24 ** 430 188 2350 375
Mid frequency cetacean.................. 14 31 24 90 53 430 106
High frequency cetacean................. 18 42 24 1420 1328 5000 2650
Otariid................................. 12 28 24 30 ** 42 150 84
Phocid.................................. 16 37 24 210 211 1120 420
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Estimates for Mortality and Slight lung injury are based on body size of each individual species, so multiple estimates exist for some marine mammal
hearing groups. The value entered into the table is the most conservative (largest isopleth) calculated for that group.
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. Expected marine mammal presence is determined by past
observations and general abundance near the Ketchikan waterfront during
the construction window. The take requests for this IHA were estimated
using local marine mammal data sets (e.g., National Marine Mammal
Laboratory databases; Dahlheim et al., 2009) and observations from
local Ketchikan charter operators and residents. A recent IHA and
associated application for nearby construction (83 FR 37473, August 1,
2018) was also reviewed to identify marine mammal group size and
potential frequency of occurrence within the project vicinity.
Harbor Seals
Low numbers of harbor seals are a common observation around the
Ketchikan waterfront, and likely utilize other, less developed
nearshore habitats within and adjacent to the Level B harassment zone.
Harbor seals can occur in the project area year-round with an estimated
maximum group size of three animals (83 FR 37473, August 1, 2018,
Solstice 2018), and up to three groups of three animals occurring daily
in the Level B harassment (TTS) zone (1,120 meters). Additionally,
harbor seals could occasionally be found in the Level A harassment
(PTS) zone.
Steller Sea Lions
Known Steller sea lion haulouts are well outside of the pinnacle
blasting Level B harassment zone. However, Steller sea lions are
residents of the wider vicinity and could be present within the Level B
harassment zone on any given day of construction. Steller sea lion
observations in the project area typically include groups composed of
up to 10 animals (83 FR 37473, August 1, 2018, Solstice 2018), with one
group potentially present each day.
Harbor Porpoise
Based on observations of local boat charter captains and watershed
stewards, harbor porpoise are infrequently encountered in the Tongass
Narrows, and more frequently in the nearby larger inlets and Clarence
Strait. Therefore, they could potentially transit through both the
Level B harassment zone and Level A harassment zone during a blasting
event. They could occupy the Ketchikan waterfront and be exposed to the
Level A harassment zone during transit between preferred habitats.
Harbor porpoises observed in the project vicinity typically occur in
groups of one to five animals with an estimated maximum group size of
eight animals (83 FR 37473, August 1, 2018, Solstice 2018). For our
impact analysis, we are considering a group to consist of five animals,
a value on the high end of the typical group size. The frequency of
harbor porpoise occurrence in the project vicinity is estimated to be
one group passing through the area per month (83 FR 37473, August 1,
2018, Solstice 2018), but, for our analysis, we conservatively consider
a group of five animals could be present every five days (approximately
once per week).
Humpback Whales
Based on observations of local boat charter captains and watershed
stewards, humpback whales regularly utilize the surrounding waters and
are occasionally observed near Ketchikan, most often on a seasonal
basis. Most observations occur during the summer with sporadic
occurrences during other periods. The typical humpback whale group size
in the project vicinity is
[[Page 36897]]
between one and two animals observed at a frequency of up to three
times per month (83 FR 37473, August 1, 2018, Solstice 2018), but
conservatively, a group of two whales could be present every third day.
Killer Whales
Killer whales could occur within the action area year-round.
Typical pod sizes observed within the project vicinity range from 1 to
10 animals and the frequency of killer whales passing through the
action area is estimated to be once per month (83 FR 37473, August 1,
2018, Solstice 2018). In the Federal Register Notice announcing the
proposed IHA, NMFS assumed a group of five whales will be present every
fifth day (approximately once per week). However, in order to more
conservatively account for the reported range of group sizes, the
expected group size was increased to 7 killer whales expected to be
present each week, which is the still in the reported range of 1 to 10
animals. Note that groups could be larger, but we expect that the
overall number of authorized takes is sufficient to account for this
possibility given the conservative assumption that a pod would be
present once per week.
Dall's Porpoise
Based on local observations and regional studies, Dall's porpoise
are infrequently encountered in small numbers in the waters surrounding
Ketchikan. This body of evidence is supported by Jefferson et al.'s
(2019) presentation of historical survey data showing very few
sightings in the Ketchikan area and conclusion that Dall's porpoise
generally are rare in narrow waterways, like the Tongass Narrows.
Tongass Narrows is not a preferred habitat, so if they are present,
they would most likely be traveling between areas of preferred forage,
which are not within the blasting work window. However, they could
still potentially transit through the Level B or Level A harassment
zone infrequently during blasting. Typical Dall's porpoise group sizes
in the project vicinity range from 10 to 15 animals observed roughly
once per month (83 FR 37473, August 1, 2018, Solstice 2018). In this
project, NMFS assumes a group of 10 Dall's porpoises could be present
every 10th day, or approximately every other week.
Minke Whale
Based on observations of local marine mammal specialists, the
possibility of minke whales occurring in the Tongass Narrows is rare.
Minke whales are generally observed individually or in groups of up to
three animals. This, along with scientific survey data showing that
this species has not been documented within the vicinity, indicates
that there is little risk of exposure to blasting. However, the
accessible habitat in the Revillagigedo Channel leaves the potential
that minke whale could enter the action area. In the Federal Register
Notice announcing the proposed IHA, NFMS assumed that a group of two
whales may be present every tenth day, or approximately every other
week. The Commission commented that minke whales tend be seen
individually, not as members of groups. Additionally, the expected
frequency of occurrence was conservatively increased from two whales
every other week, to two whales each week, based on potentially
increasing observations in Southeast Alaska. Therefore, in the final
authorization is based on an expected occurrence of two individual
whales being present every fifth day, or approximately every week.
Gray Whale
No gray whales were observed during surveys of the inland waters of
southeast Alaska conducted between 1991 and 2007 (Dahlheim et al.,
2009). It is possible that a migrating whale may venture up Nichols
Passage and enter the underwater Level B harassment zone. In the
Federal Register Notice announcing the proposed IHA, NMFS estimated
that one whale may be present every tenth day, or approximately every
two weeks. The Commission commented that gray whales tend to be
observed in groups, of generally around two whales. Therefore, in the
final authorization, NMFS estimates that a group of two gray whales
will be present every tenth day, or approximately every two weeks.
Pacific White-Sided Dolphin
Dolphins are regularly seen within Clarence Strait but have been
reported to prefer larger channel areas near open ocean. Their presence
within the Tongass Narrows has not been reported. They are not expected
to enter the Tongass Narrows toward their relatively small injury zone,
so no take by Level A harassment is requested. Pacific white-sided
dolphin group sizes generally range from between 20 and 164 animals.
For the purposes of this assessment, within the proposed IHA, we
assumed one group of 20 dolphins may be present within the Level B
harassment zone every tenth day, or about every other week. However,
NMFS has conservatively increased the expected group size to 30
dolphins, which is still within the reported group size range for the
species.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate. Incidental take is
estimated for each species by considering the likelihood of a marine
mammal being present within the Level A or B harassment zone during a
blasting event. Expected marine mammal presence is determined by past
observations and general abundance near the Ketchikan waterfront during
the construction window, as described above. The calculation for marine
mammal exposures is estimated by the following two equations:
Level B harassment estimate = N (number of animals) x number of days
animals are expected within Level B harassment zones for blasting.
Level A harassment estimate = N (number of animals) x number of days
animals are expected to occur within the Level A harassment zone
without being observed by PSOs.
For many species, the equation may also include a term to factor in the
frequency a group is expected to be seen, which is explained within the
paragraphs for that species.
Harbor Seals
We conservatively estimate that three groups of three harbor seals
could be present within the Level B harassment zone on each day of
construction and two additional harbor seals could be present within
the Level A harassment zone on each day of construction. Because take
estimates are based on anecdotal occurrences, including these
additional individual harbor seals that could occur in the Level A
harassment zone is another conservative assumption. Potential airborne
disturbance would be accounted for by the Level B harassment zone,
which covers a wider distance. Using these estimates the following
number of harbor seals are estimated to be present through the
construction period.
Level B harassment: Three groups of animals x three animals per group x
50 blasting days = 450
Level A harassment: Two animals x 50 days of blasting = 100
Steller Sea Lions
We conservatively estimate that a group of 10 sea lions could be
present within the Level B harassment zone on any given day of
blasting. No exposure within the blasting Level A harassment
[[Page 36898]]
zone is expected based on the small size of this zone and behavior of
the species in context of the planned mitigation. The Level A
harassment zones can be effectively monitored during the marine mammal
monitoring program and prevent take by Level A harassment. Using these
estimates the following number of Steller sea lions are estimated to be
present in the Level B harassment zone:
Level B harassment: 10 animals daily over 50 blasting days = 500
No take by Level A harassment was requested or is authorized
because the small Level A harassment zone can be effectively observed.
Harbor Porpoise
We conservatively estimate and assume that a group of five harbor
porpoise could be sighted in the Level B harassment zone every 5th day,
or approximately once per week. Additionally, while the City of
Ketchikan does not anticipate take by Level A harassment to occur, the
cryptic nature of harbor porpoises and large Level A harassment
isopleth mean the species could be in the Level A harassment zone
without prior observation. Therefore, one additional group of 5 animals
could be present in the Level A harassment zone every second week or
10th day, a conservative assumption because this group is in addition
to those anticipated in the Level B harassment zone.
Level B harassment: Five animals x 50 days of work divided by 5
(frequency of occurrence) = 50
Level A harassment: Five animals x 50 days of work divided by 10
(frequency of occurrence) = 25
Humpback Whale
Based on occurrence information in the area, we conservatively
estimate that a group of two humpback whales will be sighted within the
Level B harassment zone every third day. The City is requesting
authorization for 33 takes by Level B harassment of humpback whales. Of
this number, we estimate 31 humpback whales will belong to the unlisted
Hawaii DPS while three will belong to the ESA listed Mexico DPS based
on the estimated occurrence of these DPSs (Wade et al., 2016). It
should be noted that these estimates sum to 34, because take estimates
were rounded up to avoid fractional takes of individuals in the DPSs.
Level B: Two animals x 50 days of work divided by 3 (frequency of
occurrence) = 33
No take by Level A harassment was requested or is authorized
because these large whales can be effectively monitored and work can be
shutdown when they are present.
Killer Whale
Based on information presented above (Marine Mammal Occurrence),
including the change in group size which has occurred since proposed
IHA, we conservatively estimate that a group of seven whales may be
sighted within the Level B harassment zone once every fifth day, or
about once per week. Using this number, the following number of killer
whales are estimated to be present within the Level B harassment zone:
Level B: Seven animals x 50 days of work divided by 5 (frequency of
occurrence) = 70.
This number of expected takes has been increased from 50 killer whales
in the proposed IHA to 70 in the final authorization.
No take by Level A harassment was requested or is authorized
because the relatively small Level A harassment zone can be effectively
monitored to prevent take by Level A harassment.
Dall's Porpoise
Based on information presented above (Marine Mammal Occurrence) we
conservatively estimate and assume that a group of 10 Dall's porpoise
could be sighted within the Level B harassment zone every tenth day, or
about every other week. Additionally, while the City of Ketchikan does
not anticipate take by Level A harassment to occur, the large Level A
isopleth mean the species could be in the Level A harassment zone
without prior observation. Therefore, one additional group of 10
animals could be present in the Level A harassment zone every month,
which is a conservative assumption because this group is in addition to
those anticipated in the Level B harassment zone.
Using this assumption, the following number of Dall's porpoise are
estimated to be present in the Level B harassment zone:
Level B harassment: 10 animals x 50 days of work divided by 10
(frequency of occurrence) = 50
Level A harassment: 10 animals x 50 days of work divided by 20
(frequency of occurrence) = 25; because this is a fraction of group,
this number is rounded up to 30 to represent 3 full groups of Dall's
porpoise
Minke Whale
Based on information presented above (Marine Mammal Occurrence) we
conservatively estimate that two minke whales may be sighted within the
Level B harassment zone every fifth day, or about once every week. The
frequency of occurrence has been increased from every tenth day, as
stated in the proposed IHA, to every fifth day here.
Level B harassment: Two individual animals x 50 days work divided by 5
(frequency of occurrence) = 20.
The expected rate of occurrence has been increased, resulting in a
final authorization of 20 minke whales, compared to 10 in the proposed
IHA.
No take by Level A harassment was requested or is authorized
because the City of Ketchikan can effectively monitor for these whales
and shutdown if are present in the Level A harassment zone.
Gray Whale
Based on information presented above (Marine Mammal Occurrence) we
conservatively estimate that a group of two whales may be sighted
within the Level B harassment zone every tenth day, or about every 2
weeks. This group size has been increased from one individual gray
whale as shown in the proposed IHA.
Level B harassment: two animal x 50 days work divided by 10 (frequency
of occurrence) = 10.
The final authorized take of gray whales has increased from 5 to 10
individuals due to the change in group size.
No take by Level A harassment was requested or is authorized
because the City of Ketchikan can effectively monitor for these whales
and shutdown if are present in the Level A harassment zone.
Pacific White-Sided Dolphin
Based on the assumption that Pacific white-sided dolphins are not
expected to enter Tongass Narrows, despite their regular occurrence in
the Clarence Strait, we estimate that one group of 30 dolphins may be
sighted within the Level B harassment zone every tenth day, or about
every other week. As explained above in ``Marine Mammal Occurrence,''
the group size has been increased from 20 to 30 dolphins in the final
authorization.
Level B harassment: 30 animals x 50 days of work divided by 10
(frequency of occurrence) = 150.
The final authorized take of gray whales has increased from 100, in
the proposed IHA, to 150 individuals due to the change in group size.
No take by Level A harassment was requested or is authorized
because the relatively small Level A harassment zone can be effectively
monitored in
[[Page 36899]]
order to avoid take by Level A harassment.
Table 5--Authorized Take Estimates as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
Percent of
Species Stock (NEST) Level A Level B stock
----------------------------------------------------------------------------------------------------------------
Humpback Whale........................ Hawaii DPS (11,398) \a\. 0 \a\ 31 0.34
Mexico DPS (3,264) \a\.. 2
Minke Whale........................... Alaska (N/A)............ 0 20 N/A
Gray Whale............................ Eastern North Pacific 0 10 0.04
(26,960).
Killer Whale.......................... Alaska Resident (2,347). 0 70 2.98
Northern Resident (261). .............. .............. 26.82
West Coast Transient 28.81
(243).
Gulf of Alaska Transient \c\ 11.93
(587).
Pacific White-Sided Dolphin........... North Pacific (26,880).. 0 150 0.56
Dall's Porpoise....................... Alaska (83,400)......... 30 50 0.10
Harbor Porpoise....................... Southeast Alaska (975) 25 50 7.69
\b\.
Harbor Seal........................... Clarence Strait (31,634) 100 450 1.74
Steller Sea Lion...................... Eastern U.S (41,638).... 0 500 1.20
----------------------------------------------------------------------------------------------------------------
\a\ Total estimated stock size for Central North Pacific humpback whales is 10,103. Under the MMPA humpback
whales are considered a single stock (Central North Pacific); however, we have divided them here to account
for DPSs listed under the ESA. Based on calculations in Wade et al. (2016), 93.9 percent of the humpback
whales in Southeast Alaska are expected to be from the Hawaii DPS and 6.1 percent are expected to be from the
Mexico DPS.
\b\ In the SAR for harbor porpoise (NMFS 2017), NMFS identified population estimates and PBR for porpoises
within inland Southeast Alaska waters (these abundance estimates have not been corrected for g(0); therefore,
they are likely conservative)
\c\ These percentages assume all 50 takes come from each individual stock, thus the percentage are likely
inflated as multiple stocks are realistically impacted.
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.
Between the proposed IHA and this Federal Register notice
announcing the final IHA, NMFS has made changes to required mitigation
measures. NMFS increased the post-blast monitoring from 30 minutes to 1
hour to help ensure that all effects from the blast can be effectively
monitored. NMFS also added timing restrictions related to sunrise and
sunset to ensure that blasting was conducted during daylight and
required monitoring could be completed. NMFS also increased to time
between a marine mammal observation in the shutdown zone and when the
shutdown zone can be considered cleared to 30 minutes, from 15 minutes,
to help ensure that take by Level A harassment is minimized.
Shutdown Zone for In-Water Heavy Machinery Work
For in-water heavy machinery work (using, e.g., standard barges,
tug boats, barge-mounted excavators, or equipment used to place or
remove material), a minimum 10 meter shutdown zone shall be
implemented. If a marine mammal comes within 10 meters of such
operations, operations shall cease (safely) and vessels shall reduce
speed to the minimum level required to maintain steerage and safe
working conditions. This type of work could include (but is not limited
to) the following activities: (1) Movement of blasting barge; (2)
drilling of boreholes; (3) dredging of rubble; and (4) transport of
dredge material. An operation that requires completion due to safety
reasons (e.g. material actively being handled by excavator/clamshell),
that singular operation will be allowed to be completed. The monitoring
of this 10 m shutdown zone can be conducted by construction personal as
they perform their other duties.
Additional Shutdown Zones and Monitoring Zones
For blasting, the Level B harassment zone will be monitored for a
minimum of 30 minutes prior to the planned blast, and continue for 1
hour (60 minutes) after the blast. If a marine mammal with authorized
take remaining is sighted within this monitoring zone, blasting can
occur and take will be tallied against the authorized number of takes
by Level B harassment. Data will be recorded on the location, behavior,
and disposition of the mammal as long as the mammal is within this
monitoring zone.
The City of Ketchikan will establish a shutdown zone for a marine
mammal species that is greater than its corresponding Level A
harassment zone,
[[Page 36900]]
as measured from any charge in the blasting grid. If any cetaceans or
pinnipeds are observed within the shutdown zone, the blasting
contractor would be notified and no blast would be allowed to occur
until the animals are observed voluntarily leaving the shutdown zone or
30 minutes have passed without re-sighting the animal in the shutdown
zone, or up until 1 hour before sunset. When weather conditions prevent
accurate sighting of marine mammals, blasting activities will not occur
until conditions in the shutdown zone return to acceptable levels and
the entire Level A zone can be monitored and cleared.
Table 6--Blasting Shutdown and Monitoring Zones
------------------------------------------------------------------------
Shutdown Monitoring
Marine mammal hearing group zone (m) zone (m)
------------------------------------------------------------------------
Low frequency cetacean.......................... *1,000 2,500
Mid frequency cetacean.......................... 100 500
High frequency cetacean......................... 1,500 5,000
Otariid......................................... *100 200
Phocid.......................................... 250 1,500
------------------------------------------------------------------------
Note: These distances are measured from the outermost points of the grid
of charges that make up a blast.
* The City of Ketchikan expressed an opinion that the PTS distances for
Otariids and LF cetaceans presented in Table 4 seemed
uncharacteristically small when compared to the other thresholds
resulting from the model. The PTS zones were therefore doubled to 84 m
for Otariids and 860 m for LF cetaceans for purposes of mitigation and
monitoring, resulting in the Shutdown Zones presented here.
If blasting is delayed due to marine mammal presence, PSO's will
continue monitoring for marine mammals during the delay. If blasting is
delayed for a reason other than marine mammal presence, and this delay
will be greater than 30 minutes, marine mammal monitoring does not need
to occur during the delay. However, if monitoring is halted, a new
period of the 30 minute pre-blast monitoring must occur before the
rescheduled blast.
Timing and Daylight Restrictions
In-water blasting work is expected to occur from November 15, 2019,
to March 15, 2020, but will be limited to September 16, 2019, to April
30, 2020. Pinnacle blasting will be conducted during daylight hours
(sunrise to sunset) to help ensure that marine mammal observers have
acceptable conditions to survey the shutdown and monitoring zones. To
ensure that blasting does occur between daylight hours, and required
pre- and post-blast monitoring can be conducted, blasting must be
planned to occur at least 30 minutes after sunrise and 1 hour before
sunset. Non-blasting activities, including but not limited to dredging
and borehole drilling can occur outside of daylight hours, but the 10-
meter general shutdown zone must be maintained.
Non-Authorized Take Prohibited
If a marine mammal is observed within the monitoring zone and that
species is either not authorized for take or its authorized takes are
met, blasting must not occur. Blasting must be delayed until the animal
has been confirmed to have left the area or an observation time period
of 15 minutes has elapsed without seeing the marine mammal in the
monitoring zone.
Blasting BMPs
The City of Ketchikan will use industry BMPs to reduce the
potential adverse impacts on protected species from in-water noise and
overpressure. These include the use of multiple small boreholes,
confinement of the blast (rock stemming), use of planned sequential
delays, and all measures designed to help direct blast energy into the
rock rather than the water column. Additional BMPs to minimize impact
on marine mammals and other species include adherence to a winter in-
water work window, accurate drilling, shot duration, and limiting the
blasts to a maximum of one per day. The project will adhere to all
Federal and state blasting regulations, which includes the development
and adherence to blasting plans, monitoring, and reporting.
Based on our evaluation of the applicant's mitigation measures, as
well as other measures considered by NMFS, 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
proposed 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.
Since the proposed IHA, there have been some changes to the
monitoring and reporting measures. NMFS has added a requirement to
conduct acoustic and pressure monitoring for a ``production'' blast in
addition to the test blast, to ensure blasting isopleths in this IHA
are correct. NMFS has also further specified what measurements and
information the results of this blast monitoring should include to
ensure the results are informative. Additionally, NMFS has added a
requirement to notify the Alaska Regional Office and Alaska Stranding
Network prior to, and following blasting in order to conform with
previous blasting authorizations.
Visual Monitoring
Monitoring by NMFS-approved protected species observers (PSOs) will
begin 30 minutes prior to a planned blast and extend through 30 minutes
after the blast. This will ensure that all marine mammals in the
monitoring zone are documented and that no
[[Page 36901]]
marine mammals are present within the shutdown zone. No PSOs will be
required during other activities associated with pinnacle removal
including, but not limited to, bore-hole drilling and dredging. Hauled
out marine mammals within the shutdown and monitoring zones will be
tallied and monitored closely. PSOs will be stationed at the best
vantage points possible for monitoring the monitoring zone (see Figure
3 and 4 of the IHA application); however, should the entire zone not be
visible, take will be extrapolated daily, based on anticipated marine
mammal occurrence and documented observations within the portion of the
monitoring zone observed.
During blasting, there will be two land-based PSOs and one PSO on
the barge used for blasting operations, with no duties other than
monitoring. Establishing a monitoring station on the barge will provide
the observer with an unobstructed view of the injury zones during
blasting and direct communication with the operator.
Land based PSOs will be positioned at the best practical vantage
points based on blasting activities and the locations of equipment. The
land-based observers will be positioned with a clear view of the
remaining of the injury zone and will monitor the shutdown zones and
monitoring zones with binoculars and a spotting scope. The land-based
observers will communicate via radio to the lead monitor positioned on
the barge. Specific locations of the observers will be based on
blasting activities and the locations of equipment. Shore-based
observers will be stationed along the outer margins of the largest
shutdown zone.
The monitoring position of the observers will be identified with
the following characteristics:
1. Unobstructed view of blasting area;
2. Unobstructed view of all water within the shutdown zone;
3. Clear view of operator or construction foreman in the event of
radio failure (lead biologist); and
4. Safe distance from activities in the construction area.
Monitoring of blasting 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;
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 vitae (CVs) for
approval by NMFS Permits and Conservation Division.
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
blasting 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.
Blast Monitoring
The City of Ketchikan will perform a minimum of one test blast to
confirm underwater overpressure values. The City of Ketchikan will
conduct underwater monitoring of both this test blast and at least one
full scale ``production'' blast. During blast monitoring, overpressure
will be measured during all blasting monitoring with pressure
transducers and hydrophones at pre-determined locations. This work will
be performed by an experienced contractor with process documents,
results, and the blast reports all being approved by a blasting
consultant. For monitoring of these blasts, the City of Ketchikan will
be required to record the following information:
Hydrophone equipment and methods: Recording device,
sampling rate, distance of recording devices from the blast where
recordings were made; depth of recording devices;
Number of charges and the weight of each charge detonated
during the blast;
Spectra and/or waveform of blasts of blasts including
power spectral density reported as dB re 1 [micro]Pa2/Hz; and
Mean, median, and maximum sound levels (dB re: 1[micro]Pa)
of SPLrms, SELcum, single-shot SEL, and SPLpeak.
Reporting
At least 24 hours (+/- 4 hours) prior to blasting, the City of
Ketchikan 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 (+/- 4 hours) after blasting that blasting actually occurred.
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of blasting 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.
Additionally, the City of Ketchikan will submit the report and
results of their test blast to NMFS prior to beginning production
blasting. This report will include the information outlined in Test
Blast Monitoring.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner
[[Page 36902]]
prohibited by the IHA (if issued), such as a serious injury or
mortality, The City of Ketchikan would immediately cease the specified
activities and report the incident to the Office of Protected
Resources, NMFS, and the Alaska Regional Stranding Coordinator. The
report would include the following information:
Description of the incident;
Environmental conditions (e.g., Beaufort sea state,
visibility);
Description of all marine mammal observations in the 24
hours preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS would work with the City of
Ketchikan to determine what is necessary to minimize the likelihood of
further prohibited take and ensure MMPA compliance. The City of
Ketchikan would not be able to resume their activities until notified
by NMFS via letter, email, or telephone.
In the event that the City of Ketchikan 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 Ketchikan would immediately report the incident
to the Office of Protected Resources, NMFS (301-427-8401), and the
Alaska Regional Stranding Coordinator (877-925-7773). The report would
include the same information identified in the paragraph above.
Activities would be able to continue while NMFS reviews the
circumstances of the incident. NMFS would work with the City of
Ketchikan to determine whether modifications in the activities are
appropriate.
In the event that the City of Ketchikan 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 Ketchikan would 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
Ketchikan would 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).
To avoid repetition, our analysis applies to all species listed in
Table 5, given that NMFS expects the anticipated effects of the planned
blasting to be similar in nature. Where there are meaningful
differences between species or stocks, or groups of species, in
anticipated individual responses to activities, impact of expected take
on the population due to differences in population status, or impacts
on habitat, NMFS has identified species-specific factors to inform the
analysis.
NMFS does not anticipate that serious injury or mortality would
occur as a result of the City of Ketchikan's planned blasting. In the
absence of mitigation including shutdown zones, these impacts are
possible, but at very short distances from the blasts (Table 4). NMFS
feels that the mitigation measures stated in ``Mitigation,'' include
adequate shutdown zones, marine mammal monitoring, and blasting BMPs
sufficient to prevent serious injury or mortality. Thus, no serious
injury or morality authorized. As discussed in the Potential Effects
section, non-auditory physical effects are not expected to occur.
The authorized number of takes by both Level A harassment and Level
B harassment is given in Table 5. Take by Level A harassment is only
authorized for harbor seals, harbor porpoises, and Dall's porpoises. As
stated in ``Mitigation'' the City of Ketchikan will establish shutdown
zones, greater than Level A harassment zones for blasting, and a
blanket 10 m shutdown zone will be implemented for all other in-water
use of heavy machinery. The authorization of take by Level A harassment
is meant to account for the slight possibility that these species
escape observation by the PSOs within the Level A harassment zone. Any
take by Level A harassment is expected to arise from a small degree of
PTS, because the isopleths related to PTS are consistently larger than
those associated with slight lung and GI tract injury (Table 4).
Blasting is only planned to occur on a maximum of 50 days, with
just one blast per day, from November 15, 2019, to March 15, 2020.
Because only one blast is authorized per day, and this activity would
only generate noise for approximately one second, no behavioral
response that could rise to the level of take is expected to occur.
Therefore, all takes by Level B harassment are expected to arise from
TTS, but we expect only a small degree of TTS, which is fully
recoverable and not considered injury.
Although the removal of the rock pinnacle would result in the
permanent alteration of habitat available for marine mammals and their
prey, the affected area would be discountable. Overall, the area
impacted by the project is very small compared to the available habitat
around Ketchikan. The pinnacle is adjacent to an active marine
commercial and industrial area, and is regularly disturbed by human
activities. In addition, for all species except humpbacks, there are no
known biologically important areas (BIA) near the project zone that
would be impacted by the blasting activities. For humpback whales,
Southeast Alaska is a seasonally important BIA from spring through late
fall (Ferguson et al., 2015), however, Tongass Narrows is not an
important portion of this habitat due to development and human
presence. Additionally, the work window is not expected to overlap with
periods of peak foraging, and the action area
[[Page 36903]]
represents a small portion of available habitat. While impacts from
blasting to fish can be severe, blasting will occur for a relatively
short period of 50 days, meaning the duration of impact should also be
short. Any impacts on prey that would occur during that period would
have at most short-terms effects on foraging of individual marine
mammals, and likely no effect on the populations of marine mammals as a
whole. Therefore, indirect effects on marine mammal prey during the
construction are not expected to be substantial, and these
insubstantial effects would therefore be unlikely to cause substantial
effects on marine mammals at the individual or population level.
In summary and as described above, the following factors primarily
support our 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 serious injury or mortality is anticipated or
authorized;
Blasting would not occur during fish runs, avoiding
impacts during peak foraging periods;
Only a very small portion of marine mammal habitat would
be temporarily impacted;
The City of Ketchikan would implement mitigation measures
including shut down zones for all blasting and other in-water activity
to minimize the potential for take by Level A harassment and the
severity if it does occur; and
TTS that will occur is expected to be of a small degree
and is recoverable.
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 planned
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 5, in the Take Calculation and Estimation section, presents
the number of animals that could be exposed to received noise levels
that may result in take by Level A harassment or Level B harassment for
the planned blasting by the City of Ketchikan. Our analysis shows that
at most, approximately 29 percent of the best population estimates of
each affected stock could be taken, but for most species and stocks,
the percentage is below 2 percent. There was one stock, minke whale,
where the lack of an accepted stock abundance value prevented us from
calculating an expected percentage of the population that would be
affected. The most relevant estimate of partial stock abundance is
1,233 minke whales for a portion of the Gulf of Alaska (Zerbini et al.,
2006). Given 20 authorized takes by Level B harassment for the stock,
comparison to the best estimate of stock abundance shows less than 2
percent of the stock is expected to be impacted. Therefore, the numbers
of animals authorized to be taken for all species, including minke
whale, would be considered small relative to the relevant stocks or
populations even if each estimated taking occurred to a new
individual--an unlikely scenario for pinnipeds, but a possibility for
other marine mammals based on their described transit through Tongass
Narrows. 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 planned 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
In order to issue an IHA, NMFS must find that the specified
activity will not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
That is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid hunting areas; (ii) Directly
displacing subsistence users; or (iii) Placing physical barriers
between the marine mammals and the subsistence hunters; and (2) That
cannot be sufficiently mitigated by other measures to increase the
availability of marine mammals to allow subsistence needs to be met.
In August of 2018, the City of Ketchikan and its representatives
attempted to contact the Alaska Harbor Seal Commission and contacted
the Alaska Sea Otter and Steller Sea Lion Commission and the Ketchikan
Indian Commission to inform them about the project and gather comment.
Neither of the organizations that were successfully contacted expressed
concern about the project.
In 2012, the community of Ketchikan had an estimated subsistence
take of 22 harbor seals and 0 Steller sea lions (Wolf et al., 2013).
Hunting usually occurs in October and November (Alaska Department of
Fish and Game (ADF&G) 2009), but there are also records of relatively
high harvest in May (Wolfe et al., 2013). All project activities will
take place within the industrial area of Tongass Narrows immediately
adjacent to Ketchikan where subsistence activities do not generally
occur. The project will not have an adverse impact on the availability
of marine mammals for subsistence use at locations farther away, where
these activities are expected to take place. Some minor, short-term
harassment of the harbor seals could occur, but this is not likely to
have any measureable effect on subsistence harvest activities in the
region. Additionally, blasting associated with the project is expected
to occur from November 15 to March 15. This means that blasting, and
the associated harassment of marine mammals will only overlap with a
small portion of the expected period of subsistence harvest. Based on
the spatial separation and partial temporal separation of blasting
activities and subsistence harvest, no changes to availability of
subsistence resources are expected to result from the City of
Ketchikan's planned activities.
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 City of Ketchikan's planned
activities.
[[Page 36904]]
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (incidental harassment authorizations with
no anticipated serious injury or mortality) of the Companion Manual for
NOAA Administrative Order 216-6A, which do not individually or
cumulatively have the potential for significant impacts on the quality
of the human environment and for which we have not identified any
extraordinary circumstances that would preclude this categorical
exclusion. Accordingly, NMFS has determined that the issuance 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 Office of Protected Resources consults internally, in this case
with the NMFS Alaska Regional Office, whenever we propose to authorize
take for endangered or threatened species.
There is one marine mammal species (Mexico DPS humpback whale) with
confirmed occurrence in the project area that is listed as endangered
under the ESA. The NMFS Alaska Regional Office Protected Resources
Division issued a Biological Opinion on July 16, 2019 under section 7
of the ESA, on the issuance of an IHA to the City of Ketchikan under
section 101(a)(5)(D) of the MMPA by the NMFS Permits and Conservation
Division. The Biological Opinion concluded that the proposed action is
not likely to jeopardize the continued existence of Mexico DPS humpback
whale, and is not likely to destroy or adversely modify critical
habitat because none exists.
Authorization
NMFS has issued an IHA to the City of Ketchikan for the potential
harassment of small numbers of nine marine mammal species incidental to
the rock pinnacle removal project in Tongass Narrows, near Ketchikan,
Alaska, provided the previously mentioned mitigation, monitoring and
reporting are incorporated.
Dated: July 25, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2019-16155 Filed 7-29-19; 8:45 am]
BILLING CODE 3510-22-P