[Federal Register Volume 83, Number 146 (Monday, July 30, 2018)]
[Notices]
[Pages 36522-36538]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-16204]
[[Page 36522]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XG107
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Parallel Thimble Shoal Tunnel
Project in Virginia Beach, Virginia
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
Chesapeake Tunnel Joint Venture (CTJV) to incidentally take, by Level A
and/or Level B harassment, four species of marine mammals during the
Parallel Thimble Shoal Tunnel Project (PTST) in Virginia Beach,
Virginia.
DATES: This Authorization is effective from August 1, 2018, through
July 31, 2019.
FOR FURTHER INFORMATION CONTACT: Rob Pauline, 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
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 United States citizens who engage in a specified
activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed authorization is provided to the public for review.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an
impact resulting from the specified activity that cannot be reasonably
expected to, and is not reasonably likely to, adversely affect the
species or stock through effects on annual rates of recruitment or
survival.
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal.
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild (Level A harassment); or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering (Level B harassment).
Summary of Request
On January 11, 2018, NMFS received a request from the CTJV for an
IHA to take marine mammals incidental to pile driving at the Chesapeake
Bay Bridge and Tunnel (CBBT) near Virginia Beach, Virginia. CTJV's
request is for take of small numbers of harbor seal (Phoca vitulina),
gray seal (Halichoerus grypus), bottlenose dolphin (Tursiops spp.),
harbor porpoise (Phocoena phocoena), and humpback whale (Megaptera
novaeangliae) by Level A and Level B harassment. Neither the CTJV nor
NMFS expect serious injury or mortality to result from this activity
and, therefore, an IHA is appropriate.
NMFS has issued an IHA to CTJV authorizing the take of five species
by Level A and Level B harassment. Pile driving and removal will take
up to 202 days. The IHA is effective from August 1, 2018 through July
31, 2019.
Description of Planned Activity
The PTST project consists of the construction of a two-lane
parallel tunnel to the west of the existing Thimble Shoal Tunnel,
connecting Portal Island Nos. 1 and 2 (Figure 1 in application). Upon
completion, the new tunnel will carry two lanes of southbound traffic
and the existing tunnel will remain in operation and carry two lanes of
northbound traffic. The PTST project will address existing constraints
to regional mobility based on current traffic volume along the
Chesapeake Bay Bridge-Tunnel (CBBT) facility; improve safety by
minimizing one lane, two-way traffic in the tunnel; improve the ability
to conduct necessary maintenance with minimal impact to traffic flow;
and ensure a reliable southwest hurricane evacuation route for
residents of the eastern shore and/or a northern evacuation route for
residents of the eastern shore, Norfolk, and Virginia Beach. The CBBT
is a 23 mile fixed link crossing the mouth of the Chesapeake Bay which
connects Northampton County on the Delmarva Peninsula with Virginia
Beach, which is part of the Hampton Roads metropolitan area.
The new parallel tunnel will be bored under the Thimble Shoal
Channel. The 6,525 linear feet (ft) of new tunnel will be constructed
with a top of tunnel depth/elevation of 100 ft below Mean Low Water
(MLW) within the width of the 1,000-ft-wide navigation channel. Impact
pile driving will be used to install steel piles and vibratory pile
driving will be utilized to install sheet piles. This issued IHA would
cover one year of a larger project for which will run through 2022. The
larger project, which does not employ pile driving and does not require
additional IHAs, involves tunnel excavation with a tunnel boring
machine and construction of a roadway within the tunnel. The type and
numbers of piles to be installed, as well as those that will be removed
during the effective period are summarized in Table 1.
Table 1--Anticipated Pile Installation Schedule
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Number of
Pile location Pile function Pile type piles (upland/ Anticipated
In-water) installation date
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Portal Island Nos. 1 and 2....... Mooring dolphins 36-inch diameter 30 15 July to 15
(in-water). hollow steel. August 2018.
[[Page 36523]]
West of Portal Island No. 1...... Berm construction 36-inch diameter 80 15 July 2018
trestle (in-water). hollow steel. through 1 January
2019.
West of Portal Island No. 2...... Berm construction 36-inch diameter 80 15 July 2018
trestle (in-water). hollow steel. through 1 January
2019.
Portal Island No. 1.............. Temporary docks 36-inch diameter 50 1 May 2018 through
(upland). hollow steel. 30 June 2018.
Portal Island No. 1.............. Temporary docks (in- 36-inch diameter 82 15 July 2018 to 30
water). hollow steel. August 2018.
Portal Island No. 2 (above MHW).. Temporary roadway 36-inch diameter 12 1 May to 31 May
trestle (upland). hollow steel. 2018.
Portal Island No. 1 (above MHW).. Excavated TBM 28 and 18-inch 1,110 1 May 2018 to 30
material steel sheet. September 2018.
containment
holding (muck) bin
(upland).
Portal Island Nos. 1 and 2 (above Settlement 28-inch steel sheet 2,554 1 August 2018 to 30
and below MHW). mitigation and March 2019.
flowable fill
containment.
Portal Island Nos. 1 and 2 (above Portal excavation.. Steel sheet........ 1,401 1 June 2018 to 30
MHW). September 2018, 1
January to 30
March 2019.
Portal Island Nos. 1 and 2 (above Excavation Support. Steel sheet........ 240 1 April 2018 to 30
MHW). August 2019 to 1
January 2019 to 30
March 2019.
Total (above and below water) ................... ................... 5,305 Sheet ...................
Piles 334
Round Piles
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CTJV will install up to 272 in-water 36-in steel pipe piles by
impact driving and 1,936 in-water sheet piles by vibratory installation
and expects activities to take up to 202 days. These actions could
produce underwater sound at levels that could result in the injury or
behavioral harassment of marine mammal species. A detailed description
of CTJV's planned project is provided in the Federal Register notice
for the proposed IHA (83 FR 18777; April 30, 2018). Since that time,
the project start date has been delayed by approximately one month. No
additional changes have been made to the planned project 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 an IHA to CTJV was published
in the Federal Register on April 30, 2018 (83 FR 18777). That notice
described, in detail, CTJV's activity, the marine mammal species that
may be affected by the activity, the anticipated effects on marine
mammals and their habitat, proposed amount and manner of take, and
proposed mitigation, monitoring and reporting measures. During the 30-
day public comment period, NMFS received one comment letter from the
Marine Mammal Commission (Commission); the Commission's recommendations
and our responses are provided here, and the comments have been posted
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
Comment 1: The Commission recommended that NMFS review more
thoroughly both the applications prior to deeming them complete and its
notices prior to submitting them for publication in the Federal
Register and that NMFS better evaluate the proposed exclusion/shut-down
zones that are to be implemented for each proposed incidental take
authorization. Further, the Commission references several specific
minor errors that were in the proposed notice (for example, incorrect
numbers in Tables).
Response: NMFS thanks the Commission for its recommendation. NMFS
makes every effort to read the notices thoroughly prior to publication
and will continue this effort to publish the best possible product for
public comment. NMFS will be diligent when considering the
appropriateness of proposed exclusion and shutdown zones for future
IHAs. Further, NMFS has corrected the errors the Commission noted.
Comment 2: The Commission noted that NMFS used the lower reported
source level for estimating the various Level A and B harassment zones
during vibratory pile driving, which resulted in underestimating the
Level A and B harassment zones, associated ensonified areas, and number
of takes of bottlenose dolphins.
Response: Note that in the Federal Register notice of proposed IHA
(83 FR 18777; April 30, 2018) a source value of 154 dB RMS SPL was
applied for vibratory installation of 28-inch sheet. NMFS used a higher
source level of 155 dB RMS SPL in this notice. The vibratory source
levels based on root-mean-square sound pressure levels (SPLrms) and
sound exposure levels metrics were not the same value according to
NAVFAC 2017 which was cited as the reference for these values.
Furthermore, the source levels based on 1-sec averages (155 dB RMS SPL)
and 10-sec averages (154 dB RMS SPL) were not identical when they
should be represented by the same value. When a difference is reported,
it likely is due to the operator averaging decibels rather than taking
the linear average of the pressures/intensities and then converting to
dB. Therefore, the higher source level (155 dB RMS SPL) has been
adopted in this notice.
Comment 3: The Commission noted that NMFS used incorrect
assumptions for estimating the various Level A and B harassment zones
when multiple hammers are used.
Response: NMFS used a source value of 186 dB RMS SPL to estimate
the extent of the Level A harassment zone during simultaneous impact
driving of two piles. NMFS incorrectly added 3 dB to the source levels
after employing the rules for decibal addition as described in WSDOT
2017. However, the rules of decibal addition do not apply to
simultaneous impact driving scenarios since hammer strikes will not be
synchronized. Therefore, NMFS has reverted to using the original proxy
source level of 183 dB when estimating the extent of the Level A
harassment zone during simultaneous impact
[[Page 36524]]
driving of two piles with bubble curtains.
Comment 4: The Commission commented that NMFS did not not account
for the possibility that the proposed in-water activities would not be
finished by March 31 which is the deadline established by CTJV.
Therefore, the numbers of harbor seal Level A and B harassment takes is
underestimated.
Response: Even with the delay in project schedule, CTJV is
confident that in-water activities will be concluded by March 31, 2019.
To minimize the risk that the number of harbor seal takes may be
exceeded, for this notice NMFS used the maximum haul-out count from on-
site surveys (40) multiplied by the number of days of proposed
activities (202) to estimate the number of harbor seal takes. In the
Federal Register notice of proposed IHA (83 FR 18777; April 30, 2018),
NMFS had multiplied monthly sighting rates by months of activities with
an end date of March 31.
Comment 5: The Commission noted NMFS used inconsistent assumptions
regarding estimating Level A harassment takes. NMFS assumed that 40
percent of the total number of harbor porpoise takes would equate to
total Level A harassment takes based on the large size of the Level A
harassment zones. However, NMFS did not make this assumption when
estimated Level A jarassment take of harbor and gray seals.
Response: In this notice, NMFS has assumed that Level A harassment
takes of harbor seals and gray seals represent 40 percent of total
takes for each species.
Comment 6: The Commission noted that NMFS was requiring two
protected species observers (PSOs) only during simultaneous pile
driving. The Commission felt that two PSOs should be employed during
all pile driving activities.
Response: NMFS had proposed that only a single PSO would be
required during non-simultaneous pile driving. The PSO would be
stationed on the portal island where non-simultaneous pile driving was
underway. However, given the large sizes of the monitoring zones, NMFS
will require two PSO's during all pile driving operations to ensure
adequate visual coverage of the monitoring zones.
Comment 7: The Commission felt that the proposed 50-m exclusion
zone for phocids was unnecessarily large for vibratory pile driving
which could put CTJV in a situation in which it is implementing
numerous unnecessary delays or shut downs for pinnipeds.
Response: NMFS agrees with this assessment and has reduced the size
of the exclusion zone for phocids from 50 m to 15 m during vibratory
pile driving.
Comment 8: The Commission feels there are some shortcomings that
need to be addressed regarding the methodology for determining the
extent of the Level A harassment zones based on the associated PTS
cumulative sound exposure level (SELcum) thresholds for the
various types of sound sources. Specifically, the Commission believes
that the Level A and B harassment zones do not make sense biologically
or acoustically in the context of one another (when the Level A
harassment zone is larger than the Level B harassment zone) due to
NMFS's unrealistic assumption that the animals remain stationary
throughout the entire day of the activity. The Commission believes that
it would be prudent for NMFS to consult with scientists and
acousticians to determine the appropriate accumulation time that action
proponents should use to determine the extent of the Level A harassment
zones based on the associated PTS SELcum thresholds in such
situations.
Response: During the 2016 Technical Guidance's recent review, in
accordance with E.O. 13795, NMFS received comments from multiple
Federal agencies, including the Commission, recommending the
establishment of a working group to investigate more realistic means of
approximating the accumulation period associated with sound exposure
beyond the default 24-h accumulation period. Based on these comments,
NMFS will be convening a working group to re-evaluate implementation of
the default 24-h accumulation period and investigate means for deriving
more realistic accumulation periods. Nonetheless, although NMFS Level A
harassment zones include conservative assumptions and may overestimate
the likelihood of injury somewhat, the take estimates are appropriate
given the available information and support a robust negligible impact
analysis and support the small numbers finding.
Comment 9: The Commission noted that NMFS has been inconsistently
applying presumed source level reductions when bubble curtains are used
during impact pile driving. The Commission recommended that NMFS
refrain from using a source level reduction factor for sound
attenuation device implementation (i.e., bubble curtains) during impact
pile driving for all relevant incidental take authorizations. If and
when NMFS determines the appropriate accumulation time associated with
its SELcum thresholds, it could consider using a source level reduction
to estimate the ranges to Level A harassment. NMFS should then review
the related literature on bubble curtain efficacy in concert with
estimated ranges to the SELcum thresholds based on the
revised accumulation time to determine what, if any, source level
reduction would be appropriate. The Commission further recommended that
NMFS refrain from using a source level reduction factor for sound
attenuation device implementation during impact pile driving for all
relevant incidental take authorizations and that source levels should
not be reduced when determining the range to Level B harassment.
Response: NMFS believes it reasonable to use a source level
reduction factor for sound attenuation device implementation during
impact pile driving. NMFS understands that previous study results have
been inconsistent and that noise level reductions measured at different
received ranges may vary, given that both Level A and Level B
estimation using geometric modeling is based on noise levels measured
at near-source distances (~10 m). NMFS is working on guidance to
increase consistency in the application of source level deductions from
bubble curtain use, but in the meanwhile continues to evaluate
proposals on a case by case basis. In this case we used a 10-dB
reduction factor based on data from Caltrans 2015. We understand that
there are other reported reduction levels that also could have been
selected. However, we were unable to identify studies of bubble curtain
efficacy that would have been any more applicable to the CTJV project
than Caltrans 2015.
The Commission is opposed to the use of noise reduction factors
during impact driving as well as application of reductions to Level B
harassment. The Commission feels that bubble curtains have not
consistently achieved reduced sound levels in the far field because
sound resonates through the ground into the far field. Bubble curtains
are not designed to, nor can they, attenuate ground-borne sound. While
NMFS agrees that some energy is transmitted through the ground into the
farfield, it is also likely that most of the energy is transmitted
through the water column. Given that most studies of bubble curtain
effectiveness have demonstrated at least some decrease in energy
transmitted through the water column, NMFS will continue to permit
appropriate source level reductions during impact driving for both
Level A
[[Page 36525]]
and Level B harassment. Furthermore, if there are no reductions
permitted when using bubble curtains, applicants would have less
incentive to employ them at all. Without bubble curtains, more energy
will likely be transmitted into both the near field and far field,
potentially increasing the risk of animal's exposure to sound at Level
A and Level B harassment levels.
Comment 10: The Commission commented that the method NMFS used to
estimate the numbers of takes during the proposed activities, which
summed fractions of takes for each species across project days, does
not account for and negates the intent of NMFS' 24-hour reset policy.
The Commission also recommends that NMFS develop and share guidance on
this issue.
Response: NMFS has shared our internal guidance on rounding and the
consideration of qualitative factors in take estimation with the
Commission and further, as noted, disagrees with the assertion that the
method described is at odds with what the Commission terms NMFS' ``24-
hour reset policy.''
Comment 11: The Commission requested clarification of certain
issues associated with NMFS's notice that one-year renewals could be
issued in certain limited circumstances and expressed concern that the
renewal process, as proposed, would bypass the public notice and
comment requirements. The Commission recommended that instead of
bypassing comment, NMFS utilize abbreviated Federal Register notices,
as have been used recently to solicit comment on actions that meet the
renewal criteria. The Commission also suggested that NMFS should
discuss the possibility of renewals through a more general route, such
as a rulemaking, instead of notice in a specific authorization. The
Commission further recommended that if NMFS did not pursue a more
general route, that the agency provide the Commission and the public
with a legal analysis supporting our conclusion that this process is
consistent with the requirements of section 101(a)(5)(D) of the MMPA.
Response: The proposed process of issuing a renewal IHA does not
bypass the public notice and comment requirements of the MMPA. The
notice of the proposed IHA 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 FR notices that consider renewals. 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 proposed method for issuing
renewals meets statutory requirements and maximizes efficiency. Note
that such renewals would be limited to 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
would consider only one renewal for a project at this time. In
addition, notice of issuance or denial of a renewal IHA would be
published in the Federal Register, as are all IHAs. Last, NMFS will
publish on our website a description of the renewal process before any
renewal is issued utilizing the new 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; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical
and behavioral descriptions) may be found on NMFS's website
(www.nmfs.noaa.gov/pr/species/mammals/).
Table 2 lists all species with expected potential for occurrence
near the PTST project location 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 (2016). 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 United States waters. All managed stocks in this region are
assessed in NMFS's United States Atlantic and Gulf of Mexico Marine
Mammal Stock Assessments (Hayes et al., 2017a,b). All values presented
in Table 2 are the most recent available at the time of publication and
are available in the 2016 Stock Assessment Report (Hayes et al., 2017a)
and draft 2017 stock assessment report (Hayes et al. 2017b) (available
online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).
Table 2--Marine Mammal Species Likely To Occur Near the Project Area
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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 Balaenidae:
North Atlantic Right whale...... Eubalaena glacialis.... Western North Atlantic E/D; Y 458 (0; 455; 2017).... 1.4 36
(WNA).
[[Page 36526]]
Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeangliae. Gulf of Maine.......... -; N 335 (0.42; 239; 2012). 3.7 8.5
Fin whale....................... Balaenoptera physalus.. WNA.................... E/D; Y 1,618 (0.33; 1,234; 2.5 2.65
2011).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Bottlenose dolphin.............. Tursiops spp........... WNA Coastal, Northern D; Y 11,548 (0.36; 8,620; 86 1.0-7.5
Migratory. 2010-11).
WNA Coastal, Southern D; Y 9,173 (0.46; 6,326; 63 0-12
Migratory. 2010-11).
Northern North Carolina D; S 823 (0.06; 782; 2013). 7.8 1.0-16.7
Estuarine System.
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Gulf of Maine/Bay of -; N 79,833 (0.32; 61,415; 706 307
Fundy. 2011). (0.16)
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Order Carnivora--Superfamily Pinnipedia
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Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... WNA.................... -; N 75,834 (0.1; 66,884, 2,006 368
2012).
Gray seal....................... Halichoerus grypus..... WNA.................... -; N 27,131 (.1, 25,908, 1,554 5,207
2016).
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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.
\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.
Note: Italicized species are not expected to be taken or authorized for take.
All species that could potentially occur in the planned project
areas are included in Table 2. However, the occurrence of endangered
North Atlantic right whales and endangered fin whales is such that take
is not expected to occur, and they are not discussed further beyond the
explanation provided here. Between 1998 and 2013, there were no reports
of North Atlantic right whale strandings within the Chesapeake Bay and
only four reported standings along the coast of Virginia. During this
same period, only six fin whale strandings were recorded within the
Chesapeake Bay (Barco and Swingle 2014). In 2016, there were no reports
of fin whale strandings (Barco et al., 2017). Due to the low occurrence
of North Atlantic right whales and fin whales, NMFS is not authorizing
take of these species.
A detailed description of the of the species likely to be affected
by the planned 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 18777; April 30, 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 (www.nmfs.noaa.gov/pr/species/mammals/) for
generalized species accounts.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from pile driving and removal
activities for the planned 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 18777;
April 30, 2018) included a discussion of the effects of anthropogenic
noise on marine mammals. The project would 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 and minor impacts to the immediate substrate during
installation and removal of piles. These potential effects are
discussed in detail in the Federal Register notice for the proposed IHA
(83 FR 18777; April 30, 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 informs 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 would be by Level B harassment, in the form of
disruption of behavioral patterns for individual
[[Page 36527]]
marine mammals resulting from exposure to acoustic sources including
impact and vibratory pile driving equipment. There is also potential
for auditory injury (Level A harassment) to result, due to larger
predicted auditory injury zones. The mitigation and monitoring measures
are expected to minimize the severity of such taking to the extent
practicable.
As described previously, no mortality is anticipated or authorized
for this activity. Below we describe how the take is estimated.
Described in the most basic way, 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. Below, we describe these
components 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 harassment) or to incur PTS
of some degree (equated to Level A harassment).
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., 2011). 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. 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 [mu]Pa (rms) for continuous (e.g.,
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms)
for non-explosive impulsive (e.g., impact pile driving, seismic
airguns) or intermittent (e.g., scientific sonar) sources.
CTJV's planned activity includes the use of continuous (vibratory
pile driving) and impulsive (impact pile driving) sources, and
therefore the 120 and 160 dB re 1 [mu]Pa (rms) are applicable.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Technical Guidance, 2016) 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).
CTJV's tunnel project includes the use of impulsive (impact hammer) and
non-impulsive (vibratory hammer) sources.
These thresholds are provided in Table 3 below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS 2016 Technical Guidance, which may be accessed at:
http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 Cell 2: LE,LF,24h: 199 dB.
dB;LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 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.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds.
Pile driving will generate underwater noise that potentially could
result in disturbance to marine mammals swimming by the project area.
Transmission loss (TL) underwater is the decrease in acoustic intensity
as an acoustic pressure wave propagates out from a source until the
source becomes indistinguishable from ambient sound. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. A standard sound propagation model, the Practical
Spreading Loss model, was used to estimate the range from pile driving
activity to various expected SPLs at potential project structures. This
model follows a geometric propagation loss based on the distance from
the driven pile, resulting in a 4.5 dB reduction in level for each
doubling of distance from the source. In this model, the SPL at some
distance away from the source (e.g., driven pile) is governed by a
measured source level, minus the TL of the energy as it dissipates with
distance. The TL equation is:
[[Page 36528]]
TL = 15log10(R1/R2)
Where:
TL is the transmission loss in dB,
R1 is the distance of the modeled SPL from the driven
pile, and
R2 is the distance from the driven pile of the initial
measurement.
The degree to which underwater noise propagates away from a noise
source is dependent on a variety of factors, most notably by the water
bathymetry and presence or absence of reflective or absorptive
conditions including the sea surface and sediment type. The TL model
described above was used to calculate the expected noise propagation
from both impact and vibratory pile driving, using representative
source levels to estimate the harassment zone or area exceeding
specified noise criteria.
Sound source levels from the PTST project site were not available.
Therefore, literature values published for projects similar to the PTST
project were used to estimate the amount of sound (RMS SPL) that could
potentially be produced. The PTST Project will use round, 36-inch-
diameter, hollow steel piles and 28-inch wide sheet piles. Data
reported in the Compendium of Pile Driving Sound Data (Caltrans 2015)
for similar piles size and types are shown in Table 4. The use of an
encased bubble curtain is expected to reduce sound levels by 10
decibels (dB) (NAVFAC 2014, ICF Jones and Stokes 2009). Using data from
previous projects (Caltrans 2015) and the amount of sound reduction
expected from each of the sound mitigation methods, we estimated the
peak noise level (SPLpeak), the root mean squared sound pressure level
(RMS SPL), and the single strike sound exposure level (sSEL) for each
pile driving scenario of the PTST project (Table 4).
Table 4--The Sound Levels (dB Peak, dB RMS, and dB Ssel) Expected To Be Generated by Each Hammer Type/Mitigation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated
Estimated single
Estimated cumulative Estimated strike
Type of pile Hammer type peak noise sound pressure sound Relevant piles at the Pile function
level (dB exposure level (dB exposure PTST project
peak) level (dB RMS) level (dB
cSEL) sSEL)
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-inch Steel Pipe............... Impact \a\.......... 210 NA 193 183 Battered............. Mooring dolphins.
36-inch Steel Pipe............... Impact with Bubble 200 NA 183 173 Plumb................ Mooring dolphins and
Curtain \b\. Temporary Pier.
24-inch AZ Sheet................. Vibratory \c\....... 182 NA 155 155 Sheet................ Containment
Structure.
36-inch Steel Pipe and 36-inch Impact w/Bubble 200 NA 183 183 Plumb................ Mooring Dolphins,
Steel Pipe. Curtain at PI 1 and Temporary Pier.
PI 2.
36-inch Steel Pipe and 24-inch AZ Impact w/Bubble 200 NA 183 183 Plumb and Sheet...... Mooring Dolphins,
Sheet Pile. Curtain at PI 1 and Containment
Vibratory at PI 2. Structure.
36-inch Steel Pipe and 24-inch AZ Vibratory at PI 1 200 NA 183 183 Plumb and Sheet...... Mooring Dolphins and
Sheet Pile. and Impact w/Bubble Containment
Curtain at PI 2. Structure.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Examples from Caltrans 2015. These examples were the loudest provided in the Caltrans 2015 compendium for 36-inch-diameter hollow steel piles and in
the Proxy Source Sound Levels and Potential Bubble Curtain Attenuation for Acoustic Modeling of nearshore marine Pile Driving at Navy Installations in
Puget Sound (NAVFAC 2014).
\b\ Estimates of sound produced from impact that use sound mitigation measures were developed by subtracting 10 dB for an encased bubble curtain (ICF
Jones and Stokes 2009, NAVFAC 2014). A 10-dB reduction in sound for this sound mitigation method is the minimum that may be expected and, therefore,
represents a conservative estimate in sound reduction.
\c\ Example from NAVFAC 2017. Average 1-second and 10-second Broadband RMS SPL (dB re 1 [micro]Pa) for Vibratory Pile-Driving normalized to 10 meters at
JEB Little Creek.
When NMFS's 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, we 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 will result in some degree of
overestimate of Level A 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, NMFS's User
Spreadsheet predicts the closest distance at which, if a marine mammal
remained at that distance the whole duration of the activity, it would
not incur PTS. Inputs used in the User Spreadsheet, and the resulting
isopleths are reported below.
The Impact Pile Driving (Stationary Source: Impulsive,
Intermittent) (Sheet E.1) spreadsheet provided by NOAA Fisheries
requires inputs for assorted variables which are shown in Table 4. RMS
SPL's for simultaneous pile driving were determined using the rules for
decibel addition (WSDOT 2017). The expected number of steel piles
driven during a 24-hour period would be a maximum of eight for plumb
piles and three for battered piles for each portal island. Practical
spreading was assumed (15logR) and a pulse duration of 0.1 seconds
utilized. The distance from the source where the literature based RMS
SPL was 10 meters while the number of strikes per pile was 1,000. Model
outputs delineating PTS isopleths are provided in Table 6 assuming
impact installation of three battered round steel piles per day and
eight plumb round steel piles per day as well as vibratory installation
of up to eight sheets per day over eight hours.
The Optional User Spreadsheet for vibratory pile driving (non-
impulsive, stationary, continuous) (Sheet A) requires inputs for the
sound pressure level of the source (dB RMS SPL), the expected activity
duration in hours during per 24-hour period, the propagation of the
sound and the distance from the source at which the sound pressure
level was measured. Calculations also assumed that the expected
activity level duration would be eight hours per Portal Island per 24-
hour period. Practical spreading was assumed and the measured distance
from the sound source was 10 meters.
The inputs from Table 5 determined isopleths where PTS from
underwater sound during impact and vibratory driving as shown in Table
6. Note that
[[Page 36529]]
in the Federal Register notice of proposed IHA (83 FR 18777; April 30,
2018) a source value of 154 dB RMS SPL was used for vibratory
installation of 28-inch sheet piles and a value of 186 dB RMS SPL was
used for simultaneous impact installation of 36-inch steel piles
employing bubble curtains. NMFS opted to use a higher source level of
155 dB RMS SPL. Since the vibratory source levels based on root-mean-
square sound pressure levels (SPLrms) and sound exposure levels metrics
were not the same value in NAVFAC 2017, neither were the source levels
based on 1-sec and 10-sec averages. These metrics should be represented
by the same value. When a difference is reported, it likely is due to
the operator averaging decibels rather than taking the linear average
of the pressures/intensities and then converting to dB. Therefore, the
higher source level has been adopted in this notice.
A source value of 186 dB RMS SPL was used to estimate the extents
of the Level A harassment zone during simultaneous impact driving of
two piles. NMFS incorrectly added 3 dB to the impact driving source
levels rather than assuming the proxy source level (186 vs. 183 dB).
NMFS has reverted to using a proxy source level of 183 dB re 1
[micro]Pa when estimating the extent of the Level A harassment zone
during simultaneous impact driving of two piles with bubble curtains.
These revisions have been included in Table 4 and Table 5. Table 6
shows user spreadsheet outputs of the radial distance from piles driven
from Portal Island 1 and Portal Island 2 to PTS isopleths.
Table 5--User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
E.1: Impact pile E.1: Impact pile E.1: Impact pile
driving A: Stationary driving driving
Spreadsheet tab used (stationary source: non- (stationary (stationary
source: impulsive, impulsive, source: impulsive, source: impulsive,
intermittent) continuous intermittent) intermittent)
----------------------------------------------------------------------------------------------------------------
Pile Type and Hammer Type....... 36-in steel impact 28-in sheet 36-in steel impact 36-in steel impact
(battered pile). vibratory. w/bubble curtain w/bubble curtain
at P1 and P2 at P1 (plumb
(plumb piles). pile) and sheet
pile vibratory at
P2.
Source Level (RMS SPL).......... 193............... 155............... 183............... 183.
Weighting Factor Adjustment 2................. 2.5............... 2................. 2.
(kHz).
Number of strikes in 1 h OR 1,000............. NA................ 1,000............. 1,000.
number of strikes per pile.
Activity Duration (h) within 24- 3 steel piles..... 8 hours/8 sheets.. 8 steel piles per 8 steel piles.
h period OR number of piles per portal island (16
day. total).
Propagation (xLogR)............. 15................ 15................ 15................ 15.
Distance of source level 10................ 10................ 10................ 10.
measurement (meters).
Pulse Duration (seconds)........ 0.1............... NA................ 0.1............... 0.1.
----------------------------------------------------------------------------------------------------------------
Table 6--Radial Distance (Meters) From Pile Driven From Portal Island 1 (PI 1) and Portal Island 2 (PI 2) to PTS Isopleths *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-frequency Mid-frequency High-frequency Phocid pinnipeds
cetaceans cetaceans cetaceans ------------------------ Applicable piles in
Hammer type ------------------------------------------------------------------------ the PTST project
Island 1 Island 2 Island 1 Island 2 Island 1 Island 2 Island 1 Island 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact (battered) at PI 1 OR PI 2. 2,077.2 2,077.2 73.9 73.9 2,474.3 2,474.3 1,111.6 1,111.6 Battered Piles for
Mooring Dolphins.
Vibratory......................... 10.9 10.9 1.0 1.0 16.1 16.1 6.6 6.6 Sheet Piles for
Containment.
Impact w/Bubble Curtain (plumb) 1,366.1 1,366.1 48.6 48.6 1,627.2 1,627.2 731.1 731.1 Plumb Piles for
simultaneous at PI 1 and PI 2. temporary pier.
Impact w/Bubble Curtain (plumb) 860.6 10.9 30.6 1.0 1,025.1 16.1 460.5 6.6 Plumb Piles for
simultaneous at PI 1 and Temporary Pier and
Vibratory at PI 2. Mooring Dolphins;
Sheet Pile for
Containment.
Vibratory at PI 1 and Impact w/ 10.9 860.6 1.0 30.6 16.18 1,025.1 6.6 460.5 Plumb Piles for
Bubble Curtain (plumb) at PI 2 temporary pier and
Simultaneous. Mooring Dolphins;
Sheet Pile for
Containment.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Distances based on up to 3 battered round steel piles per day, 8 plumb round steel piles per day, and up to 8 sheets per day over 8 hours.
Table 7 shows the radial distance to Level B isopleths and Table 8
shows the areas of ensonified Level B zones associated with each of the
planned driving scenarios.
Table 7--Radial Distance (Meters) From Driven Pile(s) to Level B Isopleths 1 for Cetaceans and Pinnipeds
----------------------------------------------------------------------------------------------------------------
Radial distance (m)
Hammer type driving scenario -------------------------------- Applicable piles in the PTST
Island 1 Island 2 project
----------------------------------------------------------------------------------------------------------------
Impact (battered)............................. 1,584.9 1,584.9 Battered Piles for Mooring
Dolphins.
Vibratory..................................... 2,154.4 2,154.4 Sheet Piles for Containment.
Impact w/Bubble Curtain (plumb) at PI 1 and PI 341.5 341.5 Plumb Piles for temporary pier.
2 simultaneous.
[[Page 36530]]
Impact w/Bubble Curtain (plumb) at PI 1 and 341.5 2,154.4 Plumb Piles for Temporary Pier
Vibratory at PI 2 simultaneous. and Mooring Dolphins; Sheet
Pile for Containment.
Vibratory at PI 1 and Impact w/Bubble Curtain 2,154.4 341.5 Plumb Piles for temporary pier
(plumb) at PI 2 simultaneous. and Mooring Dolphins; Sheet
Pile for Containment.
----------------------------------------------------------------------------------------------------------------
\1\ Level B harassment thresholds--160 dB for impact driving/120 dB for vibratory driving.
Table 8--Level B Areas (km2) for All Pile Driving Scenarios Planned for
Use During PTST Project
------------------------------------------------------------------------
Zone size
Scenario (km\2\)
------------------------------------------------------------------------
Impact Simultaneous Plumb............................... 0.88
Impact Battered......................................... 8.27
Vibratory Sheet......................................... \1\ 16.49
Simultaneous Vibratory Sheet and Impact Plumb........... 16.49
------------------------------------------------------------------------
\1\ Level B ensonified area at Portal Island 1 = 16.37 km2 and at Portal
Island 2 = 16.49 km2. For the purposes of this IHA, NMFS will
conservatively assume that the ensonified area at both Portal Islands
= 16.49 km2.
To calculate level B disturbance zones for airborne noise from pile
driving, the spherical spreading loss equation (20LogR) was used to
determine the Level B zones. The airborne noise threshold for
behavioral harassment for all pinnipeds, except harbor seals, is 100 dB
RMS re 20 [micro]Pa (unweighted) and for harbor seals is 90 dB RMS re
20 [micro]Pa (unweighted).
Literature estimates were used to estimate the amount of in-air
sound produced from driving a pile above the MHW line (Laughlin
2010a,b). Hollow steel piles that were 30 inches in diameter were used
as a close proxy to the 36-inch-diameter hollow steel piles that will
be driven at the PTST project. AZ 24-inch sheet pile was used as a
proxy for the sheet pile to be driven during the PTST Project (Table
9). Using the spherical spreading loss model with these estimates,
Level B isopleths were estimated as shown below in Table 9. Note that
the take estimates for pinnipeds were based on surveys which included
counts of hauled out animals. Therefore, to avoid double counting,
airborne exposures are not evaluated further for purposes of estimating
take under the issued IHA. During any upland pile driving before
issuance of the IHA, however, shutdown will occur whenever pinnipeds
enter into the Level B zones as depicted below to avoid unauthorized
take.
Table 9--Radial Distance (Meters) from Pile Driven Above MHW to Level B Sound Thresholds for Harbor Seals and
Gray Seals
----------------------------------------------------------------------------------------------------------------
Level A Level B harassment zone (m)
Source Sound level harassment -------------------------------
zone (m) Harbor seals Gray seals
----------------------------------------------------------------------------------------------------------------
Impact Hammer 36- inch Pile........... 110 dBL5SEQ at 15m\a\... N/A 150 47
Vibratory Hammer Assumed equivalent to 92 dBL5SEQ at 15m....... N/A 19 6
24-in sheet.
----------------------------------------------------------------------------------------------------------------
\a\Laughlin 2010a,b as cited in City of Unalaska 2016 IHA for Unalaska Marine Center.
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.
Humpback whales are relatively rare in the Chesapeake Bay but may
be found within or near the Chesapeake Bay at any time of the year.
Between 1998 and 2014, 11 humpback whale strandings were reported
within the Chesapeake Bay (Barco and Swingle 2014). Strandings occurred
in all seasons, but were most common in the spring. There is no
existing density data for this species within or near the Chesapeake
Bay. Populations in the mid-Atlantic have been estimated for humpback
whales off the coast of New Jersey with a density of 0.00013 per square
kilometer (Whitt et al., 2015). A similar density may be expected off
the coast of Virginia.
Bottlenose dolphins are abundant along the Virginia coast and
within the Chesapeake Bay and can be seen seen annually in Virginia
from May through October. Approximately 65 strandings are reported each
year (Barco and Swingle 2014). Stranded bottlenose dolphins have been
recorded as far north as the Potomac River in the Chesapeake Bay
(Blaylock 1985). A 2016 Navy report on the occurrence, distribution,
and density of marine mammals near Naval Station Norfolk and Virginia
Beach, Virginia provides seasonal densities of bottlenose dolphins for
inshore areas in the vicinity of the project area (Engelhaupt et al.,
2016) (Table 10).
There is little data on the occurrence of harbor porpoises in the
Chesapeake Bay. Harbor porpoises are the second most common marine
mammal to strand in Virginia waters with 58 reported strandings between
2007 through 2016. Unlike bottlenose dolphins, harbor porpoises are
found in Virginia in the cooler months, primarily late winter and early
spring, and they strand primarily on ocean facing beaches (Barco et
al., 2017). Given the lack of abundance data, NMFS assumed that a
limited number of harbor porpoises (2) would be taken during each month
of planned construction in order to generate a take estimate for this
species.
Harbor seals are the most common seal in Virginia (Barco and
Swingle 2014). They can be seen resting on the rocks around the portal
islands of the CBBT from December through April. They are unlikely to
occur in the project area in the summer and early fall.
[[Page 36531]]
Survey data for in-water and hauled out harbor seals was collected by
the United States Navy at the CBBT portal islands from 2014 through
2016 (Rees et al., 2016) (Table 12). Surveys reported 112 harbor seals
in the 2014/2015 season, 185 harbor seals during the 2015/2016 season,
and 307 during the 2016/2017 season. (Rees et al., 2016; Rees et al.
2017).
Gray seals are uncommon in Virginia and the Chesapeake Bay with
only 15 gray seal strandings documented in Virginia from 1988-2013
(Barco and Swingle 2014). They are rarely found resting on the rocks
around the portal islands of the CBBT from December through April
alongside harbor seals. Observation surveys conducted by the Navy at
the CBBT portal islands recorded one gray seal in the 2014/2015, two
gray seals in 2015/2016, and two gray seals in 2016/2017 seasons (Rees
et al., 2016; Rees et al. 2017).
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
The following assumptions are made when estimating potential
incidences of take:
All marine mammal individuals potentially available are
assumed to be present within the relevant area, and thus incidentally
taken;
An individual can only be taken once during a 24-h period;
Exposures to sound levels at or above the relevant
thresholds equate to take, as defined by the MMPA.
Humpback Whale
As noted previously, humpback whales are rare in the Chesapeake
Bay, although they do occur. Density off of the coast of New Jersey,
and presumably Virginia and Maryland, is extremely low (0.00013
animals/km\2\). Because density is extremely low, CTJV has requested
and NMFS is authorizing one Level B take every two months for the
duration of in-water pile driving activities. Pile driving activities
are expected to occur over a 10-month period. Therefore, a total of 5
Level B takes of humpback whales is authorized by NMFS.
Bottlenose Dolphin
Total number of takes for bottlenose dolphin were calculated using
the seasonal density described above (individuals/km\2\/day) of animals
within the inshore study area at the mouth of the Chesapeake Bay
(Englehaupt et al., 2016). Project specific dolphin densities were
calculated within the respective Level B harassment zone and season.
Densities were then used to calculate the seasonal takes based on the
number and type of pile driving days per season. For example, the
density of dolphins in summer months is assumed to be 3.55 dolphins/
km\2\ * 0.88 km\2\ (harassment zone for Simultaneous Plumb Pile driving
as shown in Table 8) = 3.12 dolphins/km\2\ per day in summer as shown
in Table 11. This density was then multiplied by number of simultaneous
plumb pile driving days to provide takes for that season (e.g. 3.12
dolphins/km\2\ * 24 days = 74.88 estimated summer exposures from
simultaneous plumb pile driving). The sum of the anticipated number of
seasonal takes resulted in 4,740 estimated exposures as shown in Table
10 split among three stocks. There is insufficient information to
apportion the takes precisely to the three stocks present in the area.
Given that members of the NNCES stock are thought to occur in or near
the Bay in very small numbers, and only during July and August, we will
conservatively assume that no more than 100 of the takes will be from
this stock. Most animals from this stock spend the summer months in
Pamlico Sound and the range of species extends as far south as
Beaufort, NC. In colder months, animals are thought to go no farther
north than Pamlico Sound. Since members of the southern migratory
coastal and northern migratory coastal stocks are known to occur in or
near the Bay in greater numbers, we will conservatively assume that no
more than half of the remaining animals (2,320) will accrue to either
of these stocks. The largest level B zone for mid-frequency cetaceans
occurs during vibratory driving and extends out 2,154.4 meters. The
largest Level A isopleth is 73.9 meters and would occur during
installation of three battered piles on a single day. NMFS proposes a
shutdown zone that extends 200 m, so no Level A take is authorized.
Table 10--Summary of Information Used To Calculate Bottlenose Dolphin Exposures
----------------------------------------------------------------------------------------------------------------
Density Estimated Total number
Season (individuals number of pile of requested
per km\2\) driving days takes
----------------------------------------------------------------------------------------------------------------
Summer 2018..................................................... 3.55 45 866.37
Fall 2018....................................................... 3.88 77 2745.94
Winter 2019..................................................... 0.63 70 962.62
Spring 2019..................................................... 1.00 10 194.9
-----------------------------------------------
Total....................................................... .............. .............. 4,740
----------------------------------------------------------------------------------------------------------------
Table 11--Seasonal Daily Take by Driving Scenario (Seasonal Density * Scenario Zone Size) and Estimated Number of Driving Days per Season
--------------------------------------------------------------------------------------------------------------------------------------------------------
Simultaneous
Impact Impact batter Vibratory sheet vibratory sheet
Season simultaneous daily take (days/ daily take (days/ and impact plumb Number of pile
plumb daily take season) season) daily take (days/ driving days
(days/season) season)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Summer........................................................ 3.12 (24) 29.35 (15) 58.54 (6) 58.54 (0) 45
Fall.......................................................... 3.41 (36) 32.10 (0) 63.98 (41) 63.98 (0) 77
Winter........................................................ 0.55 (12) 5.21 (0) 10.39 (34) 10.39 (24) 70
Spring........................................................ 0.88 (0) 8.27 (0) 16.49 (9) 16.49 (1) 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 36532]]
Harbor Porpoise
Little is known about the abundance of harbor porpoises in the
Chesapeake Bay. A recent survey of the Maryland Wind Energy Area found
that porpoises occur frequently offshore January to May (Wingfield et
al., 2017). This finding reflects the pattern of winter and spring
strandings in the mid-Atlantic. NMFS will assume that there is a
porpoise sighting once during every two months of operations. That
would equate to five sightings over ten months. Assuming an average
group size of two results in a total estimated take of 10 porpoises.
Harbor porpoises are members of the high-frequency hearing group which
would have Level A isopleths as large of 2,474 meters during impact
installation of three battered piles per day. Given the relatively
large Level A zones during impact driving, NMFS will assume that 40
precent of porpoises are taken by Level A harassment. Therefore, NMFS
authorizes the take of 4 porpoises by Level A take and 6 porpoises by
Level B take.
Harbor Seal
The number of harbor seals expected to be present in the PTST
project area was estimated using survey data for in-water and hauled
out seals collected by the United States Navy at the portal islands in
2016 and 2017 (Rees et al., 2017). The survey data revealed a maximum
of 40 animals observed per day. The maximum number of seals per day
(40) was multiplied by the total number of driving days (202) resulting
in an estimated 8,080 harbor seal takes. The largest level B zone would
occur during vibratory driving and extends out 2,154.4 meters from the
sound source. The largest Level A isopleth is 1,111.6 meters which
would occur during impact installation of three battered piles. The
smallest Level A zone during impact driving is 6.6 meters meters which
would occur when a single steel pile is impact driven at the same time
that vibratory driving of sheet piles is occurring. NMFS authorized a
shutdown zone for harbor seals of 15 meters since seals are common in
the project area and are known to approach the shoreline. A larger
shutdown zone would likely result in multiple shutdowns and impede the
project schedule. NMFS will assume that 40 percent of the exposed seals
will occur within the Level A zone specified for a given scenario.
Therefore, NMFS authorizes the Level A take of 3,232 and Level B take
of 4,848 harbor seals.
Gray Seals
The number of gray seals potentially exposed to Level B harassment
in the project area was calculated using survey data recording gray
seal observations was collected by the U.S. Navy at the portal islands
from 2014 through 2016 (Rees et al., 2016). Potential gray seal
exposures were calculated as the number of potential seals per pile
driving day (8 hours) multiplied by the number of pile driving days per
month. The anticipated numbers of monthly exposures as shown in Table
13 were summed. Therefore, NMFS has authorized the take of 67 gray
seals by Level B harassment. The Level A isopleths for gray seals are
identical to those for harbor seals. With a shutdown zone of 15 meters,
NMFS recommended the Level A take of 40 percent of gray seals.
Therefore, NMFS authorizes the Level A take of 27 and Level B take of
40 gray seals.
Table 13--Calculation for the Number of Gray Seal Exposures
----------------------------------------------------------------------------------------------------------------
Total pile
driving days
Estimated per month Gray seal
Month seals per work (includes takes
day upland
driving)
----------------------------------------------------------------------------------------------------------------
June 2018....................................................... Seals not expected to be present.
July 2018....................................................... Seals not expected to be present.
August 2018..................................................... Seals not expected to be present.
September 2018.................................................. Seals not expected to be present.
October 2018.................................................... Seals not expected to be present.
-----------------------------------------------
November 2018................................................... 0 27 0
December 2018................................................... 0 24 0
January 2019.................................................... 0 42 0
February 2019................................................... 1.6 42 67
March 2019...................................................... 0 11 0
----------------------------------------------------------------------------------------------------------------
Table 14 provides a summary of authorized Level B takes as well as
the percentage of a stock or population authorized for take.
Table 14--Authorized Take and Percentage of Stock or Population
----------------------------------------------------------------------------------------------------------------
Authorized Authorized Percent
Species Stock Level A takes Level B takes population
----------------------------------------------------------------------------------------------------------------
Humpback whale........................ Gulf of Maine........... .............. 5 1.5
Bottlenose dolphin.................... WNA Coastal, Northern .............. 2,320 20.1
Migratory.
WNA Coastal, Southern .............. 2,320 25.2
Migratory.
NNCES................... .............. 100 12.1
Harbor porpoise....................... Gulf of Maine/Bay of 4 6 <0.01
Fundy.
Harbor seal........................... Western North Atlantic.. 3,232 4,848 10.6
Gray seal............................. Western North Atlantic.. 27 40 0.25
----------------------------------------------------------------------------------------------------------------
[[Page 36533]]
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.
The following mitigation measures are contained in the IHA:
Pile Driving Delay/Shutdown Zone--For in-water heavy
machinery work (using, e.g., standard barges, tug boats, barge-mounted
excavators, or clamshell equipment used to place or remove material), a
minimum 10 meters shutdown zone shall be implemented. If a marine
mammal comes within 10 meters of such operations, operations shall
cease and vessels shall reduce speed to the minimum level required to
maintain steerage and safe working conditions. This type of work could
include (but is not limited to) the following activities: (1) Vibratory
pile driving; (2) movement of the barge to the pile location; (3)
positioning of the pile on the substrate via a crane (i.e., stabbing
the pile); or (4) removal of the pile from the water column/substrate
via a crane (i.e., deadpull).
Non-authorized Take Prohibited--If a species for which
authorization has not been granted (e.g., North Atlantic right whale,
fin whale) or a species for which authorization has been granted but
the authorized takes are met, is observed approaching or within the
Level B Isopleth, pile driving and removal activities must shut down
immediately using delay and shut-down procedures. Activities must not
resume until the animal has been confirmed to have left the area or an
observation time period of 15 minutes has elapsed.
Use of Impact Installation--During pile installation of
hollow steel piles, an impact hammer rather than a vibratory hammer
will be used to reduce the duration of pile driving decrease the ZOI
for marine mammals.
Cushion Blocks--Use of cushion blocks will be required
during impact installation. Cushion blocks reduce source levels and, by
association, received levels, although exact decreases in sound levels
are unknown.
Use of Bubble Curtain--An encased bubble curtain will be
used for impact installation of plumb round piles at water depths
greater than 3 m (10 ft). Bubble curtains will not function effectively
in shallower depths. shall employ a bubble curtain during impact pile
driving of steel piles. CTJV shall implement the following performance
standards: (1) The bubble curtain must distribute air bubbles around
100 percent of the piling perimeter for the full depth of the water
column; (2) the lowest bubble ring shall be in contact with the mudline
for the full circumference of the ring, and the weights attached to the
bottom ring shall ensure 100 percent mudline contact. No parts of the
ring or other objects shall prevent full mudline contact; and (3) CTJV
will require that construction contractors train personnel in the
proper balancing of air flow to the bubblers, and shall require that
construction contractors submit an inspection/performance report for
approval by the CTJV within 72 hours following the performance test.
Corrections to the attenuation device to meet the performance standards
shall occur prior to impact driving.
Soft-Start--The use of a soft start procedure is believed
to provide additional protection to marine mammals by warning or
providing a chance to leave the area prior to the hammer operating at
full capacity, and typically involves a requirement to initiate sound
from the hammer at reduced energy followed by a waiting period. A soft-
start procedure will be used for impact pile driving at the beginning
of each day's in-water pile driving or any time impact pile driving has
ceased for more than 30 minutes. The CTJV will start the bubble curtain
prior to the initiation of impact pile driving. The contractor will
provide an initial set of strikes from the impact hammer at reduced
energy, followed by a 30-second waiting period, then two subsequent
sets.
Establishment of Additional Shutdown Zones and Monitoring
Zones--For all impact and vibratory pile driving shutdown and
monitoring zones will be established and monitored.
CTJV will establish a shutdown zone of 200 meters for
common dolphins and harbor porpoises and 15 meters for harbor and gray
seals. The shutdown zones for humpback whales are depicted in Table 16.
For all impact and vibratory pile driving shutdown and
monitoring zones will be established and monitored. Level B zones are
shown in Table 15.
Table 15--Radial Distance (Meters) From Pile Driven to Level B Isopleths
for Cetaceans and Pinnipeds
------------------------------------------------------------------------
Radial distance (m)
Hammer type driving scenario -------------------------------
Island 1 Island 2
------------------------------------------------------------------------
Impact (battered)....................... 1,585 1,585
Vibratory............................... 2,155 2,155
Impact w/Bubble Curtain (plumb) at PI 1 345 345
and PI 2 simultaneous..................
Impact w/Bubble Curtain (plumb) at PI 1 345 2,155
and Vibratory at PI 2 simultaneous.....
[[Page 36534]]
Vibratory at PI 1 and Impact w/Bubble 2,155 345
Curtain (plumb) at PI 2 simultaneous...
------------------------------------------------------------------------
The Level A zones will depend on the number of piles
driven and the presence of marine mammals per 24-hour period. Up to 3
battered piles or 8 plumb steel piles will be driven per 24-hour period
using the following adaptive monitoring approach. Monitoring will begin
each day using the three-pile Level A zone for battered piles (or
eight-pile zone for plumb piles). If after the first pile is driven, no
marine mammals have been observed in the Level A zone, then the Level A
zone will reduce to the two-pile zone. If no marine mammals are
observed within the two-pile shutdown zone during the driving of the
second pile, then the Level A zone will reduce to the one-pile zone.
However, if a mammal is observed approaching or entering the three-pile
Level A zone during the driving of the first pile, then the three-pile
Level A zone will be monitored for the remainder of pile driving
activities for that day. Likewise, if a marine mammal is observed
within the two-pile but not the three-pile Level A zone, then the two-
pile Level A zone will be monitored for the remainder of pile driving
activities for that day. The same protocol will be followed for
installation of up to 8 plumb piles per day.
The Level A isopleths for all authorized species are shown in Table
16. Isopeths associated with low-frequency cetaceans will signify
shutdown zones for humpback whales.
Table 16--Radial Distance (Meters) From Driven Pile to PTS Zones for Cetaceans and Phocid Pinnipeds for
Scenarios Involving Impact Hammer
----------------------------------------------------------------------------------------------------------------
Simultaneous
Impact hammer Driving--
with bubble Vibratory hammer
Class of marine mammals Piles per day Impact hammer curtain and impact
(battered pile) simultaneous hammer with
(plumb pile) ** bubble curtain
(plumb pile)
----------------------------------------------------------------------------------------------------------------
Low-Frequency Cetaceans *............... 8 N/A 1,366 860.6
7 N.A 1,249.1 787.3
6 N/A 1,127.7 710.4
5 N/A 998.6 629.1
4 N/A 860.6 542.1
3 2,077.2 710.4 447.5
2 1,585.2 542.1 341.5
1 998.6 341.5 215.1
Mid-Frequency Cetaceans................. 8 N/A 48 30.6
7 N/A 44.4 28.0
6 N/A 40.1 25.3
5 N/A 35.5 22.4
4 N/A 30.6 19.3
3 73.9 25.3 15.9
2 56.4 19.3 12.1
1 35.5 12.1 7.7
High Frequency Cetaceans................ 8 N/A 1,627 1,025.1
7 N/A 1,488.6 937.8
6 N/A 1,343.3 846.2
5 N/A 1,189.5 749.4
4 N/A 1,025.1 645.8
3 2,474.3 846.2 533.1
2 1,888.3 645.8 406.8
1 1,189.5 406.8 256.3
Phocid Pinnipeds........................ 8 N/A 731 460.5
7 N/A 68.8 412.3
6 N/A 603.5 380.2
5 N/A 534.4 336.7
4 N/A 460.5 290.1
3 1,111.6 380.2 239.5
2 848.3 290.1 182.8
1 534.4 182.8 115.1
----------------------------------------------------------------------------------------------------------------
* These isopleths serve as shutdown zones for all large whales, including humpback and fin whales.
** Assumes 1 pile installed at each island per day ranging from maximum of 16 piles to minimum of 2 piles.
[[Page 36535]]
Based on our evaluation of the applicant's suggested 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
planned 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).
Mitigation and monitoring effectiveness.
Visual Monitoring
The following visual monitoring measures are contained in the IHA:
Pre-activity monitoring shall take place from 30 minutes
prior to initiation of pile driving activity and post-activity
monitoring shall continue through 30 minutes post-completion of pile
driving activity. Pile driving may commence at the end of the 30-minute
pre-activity monitoring period, provided observers have determined that
the shutdown zone is clear of marine mammals, which includes delaying
start of pile driving activities if a marine mammal is sighted in the
zone.
If a marine mammal approaches or enters the shutdown zone
during activities or pre-activity monitoring, all pile driving
activities at that location shall be halted or delayed, respectively.
If pile driving is halted or delayed due to the presence of a marine
mammal, the activity may not resume or commence until either the animal
has voluntarily left and been visually confirmed beyond the shutdown
zone and 15 minutes have passed without re-detection of the animal.
Pile driving activities include the time to install or remove a single
pile or series of piles, as long as the time elapsed between uses of
the pile driving equipment is no more than thirty minutes.
Monitoring distances, in accordance with the identified
shutdown zones, Level A zones and Level B zones, will be determined by
using a range finder, scope, hand-held global positioning system (GPS)
device or landmarks with known distances from the monitoring positions.
A minimum of two PSOs will be required during all pile
driving activities. Monitoring locations shall be based on land both at
Portal Island No. 1 and Portal Island No. 2 during simultaneous driving
or on the Portal Island with active driving during non-simultaneous
driving.
Monitoring will be continuous unless the contractor takes
a break longer than 2 hours from active pile and sheet pile driving, in
which case, monitoring will be required 30 minutes prior to restarting
pile installation.
If marine mammals are observed, their location within the
zones, and their reaction (if any) to pile activities will be
documented.
If weather or sea conditions restrict the observer's
ability to observe, or become unsafe, pile installation will be
suspended until conditions allow for monitoring to resume.
For in-water pile driving, under conditions of fog or poor
visibility that might obscure the presence of a marine mammal within
the shutdown zone, the pile in progress will be completed and then pile
driving suspended until visibility conditions improve.
Monitoring of pile driving shall be conducted by qualified
PSOs (see below), who shall have no other assigned tasks during
monitoring periods. CVTJV shall adhere to the following conditions when
selecting observers:
(1) Independent PSOs shall be used (i.e., not construction
personnel).
(2) At least one PSO must have prior experience working as a marine
mammal observer during construction activities.
(3) Other PSOs may substitute education (degree in biological
science or related field) or training for experience.
(4) CTJV shall submit PSO CVs for approval by NMFS.
CTJV will ensure that observers have the following
additional qualifications:
(1) Ability to conduct field observations and collect data
according to assigned protocols.
(2) Experience or training in the field identification of marine
mammals, including the identification of behaviors.
(3) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations.
(4) 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.
(5) 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.
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated marine
mammal observation data sheets. Specifically, the report must include:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
[[Page 36536]]
Deviation from initial proposal in pile numbers, pile
types, average driving times, etc.;
Weather parameters (e.g., percent cover, visibility); and
Water conditions (e.g., sea state, tide state).
For each marine mammal sighting:
(1) Species, numbers, and, if possible, sex and age class of marine
mammals;
(2) Description of any observable marine mammal behavior patterns,
including bearing and direction of travel and distance from pile
driving activity;
(3) Location and distance from pile driving activities to marine
mammals and distance from the marine mammals to the observation point;
(4) Estimated amount of time that the animals remained in the Level
A Level B zone;
Description of implementation of mitigation measures
within each monitoring period (e.g., shutdown or delay); and
Other human activity in the area.
A summary of the following:
(1) Total number of individuals of each species detected within the
Level A and Level B Zone, and estimated as taken if correction factor
is applied.
(2) Daily average number of individuals of each species
(differentiated by month as appropriate) detected within the Level A
and Level B Zone, and estimated as taken, if correction factor is
applied.
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 an injury, serious injury or mortality, CTJV would
immediately cease the specified activities and report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources, NMFS, and the NMFS Greater Atlantic Region New England/Mid-
Atlantic 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 CTJV to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. CTJV would not be able to
resume their activities until notified by NMFS via letter, email, or
telephone.
In the event that CTJV 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),
CTJV would immediately report the incident to the Chief of the Permits
and Conservation Division, Office of Protected Resources, NMFS, and the
NMFS Greater Atlantic Region New England/Mid-Atlantic Regional
Stranding Coordinator. 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 CTJV to determine whether modifications in the activities are
appropriate.
In the event that CTJV 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), CTJV would report the incident to
the Chief of the Permits and Conservation Division, Office of Protected
Resources, NMFS, and the NMFS Greater Atlantic Region New England/Mid-
Atlantic Regional Stranding Coordinator, within 24 hours of the
discovery. CTJV would provide photographs or video footage (if
available) or other documentation of the stranded animal sighting to
NMFS and the Marine Mammal Stranding Network.
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).
CTJV's planned pile driving activities are highly localized. Only a
relatively small portion of the Chesapeake Bay may be affected. The
project is not expected to have significant adverse effects on marine
mammal habitat. No important feeding and/or reproductive areas for
marine mammals are known to be near the project area. Project-related
activities may cause some fish to leave the area of disturbance, thus
temporarily impacting marine mammals' foraging opportunities in a
limited portion of their foraging range, but because of the relatively
small impacted area of the habitat range utilized by each species that
may be affected, the impacts to marine mammal habitat are not expected
to cause significant or long-term negative consequences.
A limited number of animals could experience Level A harassment in
the form of PTS if they remain within the Level A harassment zone
during certain impact driving scenarios. The sizes of the Level A zones
are dependent on the number of steel piles driven in a 24-hour period.
Up to 8 steel plumb piles or 3 steel battered piles could be driven in
a single day, which would result in a relatively large Level A zones.
(If fewer piles are driven per day then the Level A zones would be
smaller). However, an animal would have to be within the Level A zones
during the driving of all 8 plumb or 3 battered piles. This is
unlikely, as marine mammals tend to move away from sound sources.
Furthermore, the degree of injury is expected to be mild and is not
likely to affect the reproduction or survival of the individual
animals. It is expected that, if hearing impairments occurs, most
likely the affected animal
[[Page 36537]]
would lose a few dB in its hearing sensitivity, which in most cases is
not likely to affect its survival and recruitment.
Exposures to elevated sound levels produced during pile driving
activities may cause behavioral responses by an animal, but they are
expected to be mild and temporary. Effects on individuals that are
taken by Level B harassment, on the basis of reports in the literature
as well as monitoring from other similar activities, will likely be
limited to reactions such as increased swimming speeds, increased
surfacing time, or decreased foraging (if such activity were occurring)
(e.g., Thorson and Reyff, 2006; Lerma, 2014). Most likely, individuals
will simply move away from the sound source and be temporarily
displaced from the areas of pile driving, although even this reaction
has been observed primarily only in association with impact pile
driving. These reactions and behavioral changes are expected to subside
quickly when the exposures cease. The pile driving activities analyzed
here are similar to, or less impactful than, numerous construction
activities conducted in numerous other locations on the east coast,
which have taken place with no reported injuries or mortality to marine
mammals, and no known long-term adverse consequences from behavioral
harassment. Repeated exposures of individuals to levels of sound that
may cause Level B harassment are unlikely to result in permanent
hearing impairment or to significantly disrupt foraging behavior.
Furthermore, Level B harassment will be reduced through use of
mitigation measures described herein.
CTJV will employ noise attenuating devices (i.e., bubble curtains,
pile caps) during impact driving of plumb steel piles. During impact
driving of both plumb and battered piles, implementation of soft start
procedures and monitoring of established shutdown zones will be
required, significantly reduces any possibility of injury. Given
sufficient notice through use of soft start (for impact driving),
marine mammals are expected to move away from a sound source. PSOs will
be stationed on a portal island whenever pile driving operations are
underway at that island. The portal island locations provide a
relatively clear view of the shutdown zones as well as monitoring
zones. These factors will limit exposure of animals to noise levels
that could result in injury.
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;
The area of potential impacts is highly localized;
No adverse impacts to marine mammal habitat;
The absence of any significant habitat within the project
area, including rookeries, or known areas or features of special
significance for foraging or reproduction;
Anticipated incidents of Level A harassment would likely
be mild;
Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior; and
The anticipated efficacy of the required mitigation
measures in reducing the effects of the specified activity.
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 section 101(a)(5)(D) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers and so, in practice, 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.
NMFS has determined that the estimated Level B take of humpback
whale is 1.5 percent of the Gulf of Maine stock; take of harbor seals
is 10.6 percent of the Western North Atlantic stock; take of gray seals
is 0.25 percent of the Western North Atlantic stock; and take of harbor
porpoise is <0.01 percent of the Gulf of Maine/Bay of Fundy stock.
Total estimated take of bottlenose dolphins is 4,740. NMFS assumes 100
takes accruing to the NNCES stock and no more than half (2,300) of the
remaining takes accruing to either of two migratory coastal stocks.
This stock division represents 12.1 percent of the NCCES stock, 20.1
percent of the Western North Atlantic northern migratory coastal stock
and 25.2 percent of the Western North Atlantic southern migratory
coastal stock. Additionally, some number of the anticipated takes are
likely to be repeat sightings of the same individual, lowering the
number of individuals taken.
Based on the analysis contained herein of the planned activity
(including the proposed 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. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
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.
[[Page 36538]]
No incidental take of ESA-listed species is authorized or expected
to result from this activity. Therefore, NMFS has determined that
formal consultation under section 7 of the ESA is not required for this
action.
Authorization
NMFS has issued an IHA to CTJV for conducting pile driving and
removal activities as part of the PTST project between August 1, 2018
through July 31, 2019, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated.
Dated: July 25, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2018-16204 Filed 7-27-18; 8:45 am]
BILLING CODE 3510-22-P