[Federal Register Volume 83, Number 43 (Monday, March 5, 2018)]
[Notices]
[Pages 9287-9297]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-04381]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF582
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Bravo Wharf Recapitalization
Project, Year 2
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the Naval Facilities Engineering Command Southeast and Naval Facilities
Engineering Command Atlantic (the Navy) to incidentally harass, by
Level B harassment only, marine mammals during construction activities
associated with recapitalization of Bravo Wharf, Year 2, in Naval
Station Mayport (NSM), Jacksonville, Florida.
DATES: This Authorization is effective from March 13, 2018, to March
12, 2019.
FOR FURTHER INFORMATION CONTACT: Brianna Elliott, 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 www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing these
documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce (as delegated to NMFS) to allow, upon
request, the incidental, but not intentional, taking of small numbers
of marine mammals by U.S. citizens who engage in a specified activity
(other than commercial fishing) within a specified geographical region
if certain findings are made and either regulations are issued or, if
the taking is limited to harassment, a notice of a proposed
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 July 12, 2017, NMFS received a request from the Navy for an IHA
to take marine mammals incidental to pile driving in association with
the Bravo Wharf recapitalization project at NSM, FL. The Navy's request
is for take of bottlenose dolphins (Tursiops truncatus truncatus) by
only Level B harassment. Neither the Navy nor NMFS expect mortality to
result from this activity and, therefore, an IHA is appropriate.
NMFS previously issued IHAs to the Navy for similar work at Bravo
Wharf (81 FR 52637, 1 December 2016; revised IHA for this activity: 82
FR 11344, 13 March 2017) and Wharf C-2, also located within NSM (80 FR
55598, 8 September 2015; 78 FR 71566, 1 December 2013 and revised IHA
for this activity: 79 FR 27863, 1 September 2014). The Navy complied
with all the requirements (e.g., mitigation, monitoring, and reporting)
of previous IHAs at Bravo Wharf (revised IHA for this activity: 82 FR
11344, 13 March 2017) and at Wharf C-2 (80 FR 55598, 8 September 2015;
79 FR 27863, 1 September 2014) and information regarding their
monitoring results may be found at http://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
This IHA covers one year of a larger project for which the Navy
obtained a prior IHA at Bravo Wharf (81 FR 52637, 1 December 2016;
revised IHA for this activity: 82 FR 11344, 13 March 2017). The larger
project involves recapitalization of Bravo Wharf at three berths in NSM
spread across Phase I and Phase II, which involves installing 880
single sheet piles through the two phases and two years of
authorizations; this IHA authorizes the second year of construction at
Bravo Wharf.
Description of Proposed Activity
Bravo Wharf is a medium draft, general purpose berthing wharf that
was constructed in 1970 and lies at the western edge of the NSM turning
basin at the mouth of the St. Johns River and adjacent to the Atlantic
Ocean. Bravo Wharf is approximately 2,000 feet (ft) long, 125 ft wide,
and has a berthing depth of 50 ft mean lower low water. Bravo Wharf is
currently in poor condition, and therefore, the Navy requested an IHA
in order to conduct necessary repairs at the Wharf via vibratory pile
driving, and contingency impact driving if necessary.
This IHA covers one year of construction from March 13, 2018, to
March 12, 2019, during which the Navy plans a maximum of 40 days of
construction, including 30 days of vibratory pile driving and 10 days
of impact driving, to install 234 steel sheet piles. A detailed
description of the planned Bravo Wharf recapitalization project is
provided in the Federal Register notice for the proposed IHA (82 FR
55990; 27 November 2017). Since
[[Page 9288]]
that time, no changes have been made to the planned activities
reflected in the proposed IHA. 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
We published a notice of receipt of the Navy's application and
proposed IHA in the Federal Register on November 27, 2017 (82 FR
55990). We received one comment, a letter from the Marine Mammal
Commission (``the Commission''). The Commission concurred with NMFS's
preliminary findings to issue the proposed IHA, but had a comment
regarding NMFS's take estimation methodology.
Comment: The Commission wrote that NMFS's methodology for
estimating marine mammal takes incidental to this activity does not
account for NMFS's 24-hour reset policy when counting takes. The
Commission added that this is a policy issue rather than computational
error, and notes that NMFS has yet to share new criteria for rounding
marine mammal takes as NMFS did in this scenario. They recommended that
NMFS share this new methodology and policy with the Commission as soon
as possible.
Response: NMFS values the Commission's insight and diligence in
ensuring NMFS is operating with the best science and policy
information, which NMFS believes it is doing. NMFS has received similar
comments from the Commission in the past and has provided responses
(e.g., 82 FR 50628, 1 November 2017; 82 FR 458 11, 2 October 2017; 82
FR 10747, 15 February 2017). NMFS will share rounding criteria with the
Commission as soon as possible, and looks forward to engaging with the
Commission on this issue in the future.
Description of Marine Mammals in the Area of Specified Activities
There are four marine mammal species which may inhabit or transit
through the waters nearby NSM at the mouth of the St. Johns River and
in nearby nearshore Atlantic waters. These include the bottlenose
dolphin (Tursiops truncatus truncatus), Atlantic spotted dolphin
(Stenella frontalis), North Atlantic right whale (Eubalaena glacialis),
and humpback whale (Megaptera novaeangliae). Multiple additional
cetacean species occur in south Atlantic waters but would not be
expected to occur in shallow nearshore waters of the action area. In
addition, the West Indian manatees may be found in the vicinity of NSM.
However, West Indian manatees are managed by the U.S. Fish and Wildlife
Service and are not considered further in this document.
Table 1 lists all species with expected potential for occurrence in
the vicinity of NSM and summarizes information related to the
population or stock, including regulatory status under the MMPA and ESA
and potential biological removal (PBR), where known. For taxonomy, we
follow Committee on Taxonomy (2017). Sections 3 and 4 of the Navy's
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/). Please also refer to the Navy's Marine Resource
Assessment for the Charleston/Jacksonville Operating Area, which
documents and describes the marine resources that occur in Navy
operating areas of the Southeast (DoN 2008). The document is publicly
available at www.navfac.navy.mil/products_and_services/ev/products_and_services/marine_resources/marine_resource_assessments.html
(accessed October 12, 2017). A detailed description of the species
likely to be affected by pile driving at Bravo Wharf, including brief
introductions to the species and relevant stocks as well as available
information regarding population trends and threats, and information
regarding local occurrence, were provided in the Federal Register
notice for the proposed IHA (82 FR 55990; 27 November 2017). Since that
time, NMFS published Draft Stock Assessment Reports with several new
abundances and information for several species occurring in the
vicinity of NSM (82 FR 60181; 19 December 2017); therefore, information
in Table 1 below reflects any new information in the draft SARs. Please
refer to the proposed Federal Register notice for descriptions of the
species below (82 FR 55990; 27 November 2017).
Table 1--Marine Mammals Potentially Present in the Vicinity of NSM
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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 Eschrichtiidae:
North Atlantic Right Whale...... Eubalaena glacialis.... Western North Atlantic. E/D; Y 458 (0; 455; n/a)..... 1.4 5.36
Humpback whale.................. Megaptera novaeangliae. Gulf of Maine.......... -; Y 335 (0; 239; 2011).... 3.7 8.5
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Atlantic Spotted Dolphin........ Stenella frontalis..... Western North Atlantic. -; N 44,715 (0.43; 31,610; 316 0
2011).
Common bottlenose dolphin....... Tursiops truncatus Jacksonville Estuarine -; Y 412 (0.06; unk; 1994- unk 1.2
truncatus. System. 97) \4\.
Common bottlenose dolphin....... Tursiops truncatus Western North Atlantic, -/D; Y 877 (0.49; 595; 2016). 6 0.46
truncatus. northern Florida
coastal.
Common bottlenose dolphin....... Tursiops truncatus Western North Atlantic, -; N 77,532 (0.40; 56,053; 561 39.4
truncatus. offshore. 2011). (0.29)
Common bottlenose dolphin....... Tursiops truncatus Western North Atlantic, -/D; Y 3,751 (0.60; 2,353; 23 0-14.3
truncatus. southern migratory 2016).
coastal.
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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.
[[Page 9289]]
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ This abundance estimate is considered an overestimate because it includes non- and seasonally-resident animals.
Note: Italicized species are not expected to be taken or proposed for authorization.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from vibratory and impact pile
driving at Bravo Wharf have the potential to result in behavioral
harassment of marine mammals in the vicinity of the action area and
temporary increases in underwater noise levels around the turning
basin. However, construction activity is not expected to cause serious
injury or mortality to marine mammals, nor will it permanently elevate
sound levels in the turning basin. Furthermore, the turning basin is an
industrialized, developed basin and is thus not known to be an
important foraging site or other habitat; therefore, any temporary
impacts to the turning basin and surrounding ensonified waters are not
expected to have significant or long-lasting impacts to marine mammals.
The Federal Register notice for the proposed IHA (82 FR 55990; 27
November 2017) included a discussion of the effects of anthropogenic
noise on marine mammals, and therefore, that information is not
repeated here; please refer to the Federal Register notice for that
information.
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through the IHA, which will inform both NMFS's consideration
of whether the number of takes is ``small'' 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 are by Level B harassment only, in the form of
disruption of behavioral patterns for individual marine mammals
resulting from exposure to vibratory and impact pile driving. Based on
the nature of the activity, Level A harassment is neither anticipated
nor authorized.
In order to estimate the potential incidents of take that may occur
incidental to the specified activity, we must first estimate the extent
of the sound field that may be produced by the activity and then
consider in combination with information about marine mammal density or
abundance in the project area. 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 authorized 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) (Table 2).
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). 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., seismic
airguns) or intermittent (e.g., scientific sonar) sources.
Recapitalization of Bravo Wharf 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) thresholds are
applicable.
Level A harassment for non-explosive sources--NMFS's 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)
(Table 2). The Navy's proposed recapitalization of Bravo Wharf includes
the use of impulsive (impact pile driving) and non-impulsive (vibratory
pile driving) sources.
These thresholds were developed by compiling and synthesizing the
best available science and soliciting input multiple times from both
the public and peer reviewers to inform the final product, and are
provided in the table 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.
[[Page 9290]]
Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift
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PTS onset thresholds
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
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Low-Frequency (LF) Cetaceans........... Lpk,flat: 219 dB; LE,LF,24h: LE,LF,24h: 199 dB.
183 dB.
Mid-Frequency (MF) Cetaceans........... Lpk,flat: 230 dB; LE,MF,24h: LE,MF,24h: 198 dB.
185 dB.
High-Frequency (HF) Cetaceans.......... Lpk,flat: 202 dB; LE,HF,24h: LE,HF,24h: 173 dB.
155 dB.
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* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]Pa2s. In this Table, thresholds are abbreviated to reflect American National
Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds.
Distance to Sound Thresholds
Underwater Sound Propagation Formula--Pile driving generates
underwater noise that can potentially result in disturbance to marine
mammals in the project area. Transmission loss (TL) is the decrease in
acoustic intensity as an acoustic pressure wave propagates out from a
source. TL parameters vary with frequency, temperature, sea conditions,
current, source and receiver depth, water depth, water chemistry, and
bottom composition and topography. The general formula for underwater
TL is:
TL = B * log10 (R1/R2),
Where:
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6 dB reduction in sound level for each doubling of
distance from the source (20 * log[range]). Cylindrical spreading
occurs in an environment in which sound propagation is bounded by the
water surface and sea bottom, resulting in a reduction of 3 dB in sound
level for each doubling of distance from the source (10*log[range]). A
practical spreading value of fifteen is often used under conditions,
such as at the NSM turning basin, where water increases with depth as
the receiver moves away from the shoreline, resulting in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions. Practical spreading loss (4.5 dB
reduction in sound level for each doubling of distance) is assumed
here.
Underwater Sound--The intensity of pile driving sounds is greatly
influenced by factors such as the type of piles, hammers, and the
physical environment in which the activity takes place. A number of
studies, primarily on the west coast, have measured sound produced
during underwater pile driving projects. However, these data are
largely for impact driving of steel pipe piles and concrete piles as
well as vibratory driving of steel pipe piles. Vibratory driving of
steel sheet piles was monitored during the first year of construction
at the nearby Wharf C-2 at Naval Station Mayport during 2015.
Measurements were conducted from a small boat in the turning basin and
from the construction barge itself. Average SPLs for steel sheet piles
ranged from 135 to 158 dB (DoN 2015) and SPLs for a 10-second period of
driving averaged 156 dB re 1[mu]Pa rms (DoN, 2017a). No impact driving
was measured at this location; therefore, proxy levels for impact
driving have been calculated from other available source levels.
In order to determine reasonable SPLs and their associated effects
on marine mammals that are likely to result from impact pile driving at
NSM, we considered existing measurements from similar physical
environments (sandy sediments and water depths greater than 15 ft) for
driving of steel sheet piles (all measured at 10 m; e.g., Laughlin,
2005a, 2005b; Illingworth and Rodkin, 2010, 2012, 2013; CalTrans 2012;
CalTrans 2015). Proxy source values based on similarity to the physical
environment at NSM and measurement location in the mid-water column
were selected for acoustic modeling: 156 dB for vibratory driving (DoN
2017a) and 190 dB for impact driving (CalTrans 2015). All calculated
distances to and the total area encompassed by the marine mammal sound
thresholds are provided in Table 3.
Table 3--Distance to Relevant Underwater Sound Tresholds and Areas of Ensonification
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Pile type Method Threshold Distance (m) Area (km2)
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Steel sheet piles................ Vibratory.......... MF Level A (injury): 198 0.1
dB SELcum.
Level B (behavior): 120 2,512 1.3550776
dB re 1[mu]Pa rms.
Impact (contingency MF Level A (injury): 185 1.7
only). dB SELcum.
Level B (behavior): 160 1,000 0.5313217
dB re 1[mu]Pa rms.
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\1\ Sound pressure levels used for calculations are 156 dB rms and 190 dB rms for vibratory and impact driving,
respectively.
\2\ Level B areas of ensonification were calculated using the practical spreading loss model described above.
[[Page 9291]]
\3\ Level A areas of ensonfication were calculated using NOAA's Acoustic Criteria Spreadsheet (see Appendix D of
the Navy's application). To calculate the distance to Level A injury for vibratory driving, the Navy assumed a
source level of 156 dB rms at 10 m, a transmission loss of 15logR, 20 minutes of activity within a 24-hour
period, a weighting factor adjustment (WFA) of 2.5, and transmission loss of 15logR. To calculate Level A
injury for impact driving, the Navy assumed a SL of 190 dB rms at 10 m, a 100 msec pulse duration, 1 pile
driven per day with 20 strikes, a WFA of 2.0, and transmission loss of 15logR.
The Mayport turning basin does not represent open water, or free
field, conditions. Therefore, sounds would attenuate as per the
confines of the basin, and may only reach the full estimated distances
to the harassment thresholds via the narrow, east-facing entrance
channel. Distances shown in Table 3 are estimated for free-field
conditions, but areas are calculated per the actual conditions of the
action area. See Figures 6-1 and 6-2 of the Navy's application for a
depiction of areas in which each underwater sound threshold is
predicted to occur at the project area due to pile driving.
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.
Marine Mammal Densities
For all species, the best scientific information available was
considered for use in the marine mammal take assessment calculations.
All densities for marine mammals with the possibility of occurring in
the project area were calculated from the Navy's Marine Species Density
Database and Technical Report (DoN 2017b). Density for bottlenose
dolphins is derived from site-specific surveys conducted by the Navy
(see Appendix C of the Navy's application for more information); it is
not currently possible to identify observed individuals to stock. This
survey effort consists of 24 half-day observation periods covering
mornings and afternoons during four seasons (December 10-13, 2012,
March 4-7, 2013, June 3-6, 2013, and September 9-12, 2013). During each
observation period, two observers (a primary observer at an elevated
observation point and a secondary observer at ground level) monitored
for the presence of marine mammals in the turning basin (0.712 km\2\)
and an additional grid east of the basin entrance. Observers tracked
marine mammal movements and behavior within the observation area, with
observations recorded for five-minute intervals every half-hour.
Morning sessions typically ran from 7 to 11:30 and afternoon sessions
from 1 to 5:30.
Most observations of bottlenose dolphins were of individuals or
pairs, although larger groups were occasionally observed (median number
of dolphins observed ranged from 1-3.5 across seasons). Densities were
calculated using observational data from the primary observer
supplemented with data from the secondary observer for grids not
visible by the primary observer. Season-specific density was then
adjusted by applying a correction factor for observer error (i.e.,
perception bias). The seasonal densities range from 1.98603 (winter) to
4.15366 (summer) dolphins/km\2\. We conservatively use the largest
density value to assess take, as the Navy does not have specific
information about when in-water work may occur during the period of
validity.
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
incidents 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;
There will be 30 total days of vibratory driving and 10
days of contingency of impact pile driving;
Exposures to sound levels at or above the relevant
thresholds equate to take, as defined by the MMPA.
The estimation of marine mammal takes typically uses the following
calculation:
Exposure estimate (rounded to the nearest whole number) = n * ZOI *
total activity days
Where:
n = density estimate used for each species/season
ZOI = sound threshold ZOI area; the area encompassed by all
locations where the SPLs equal or exceed the threshold being
evaluated
The ZOI impact area is estimated using the relevant distances in
Table 3, taking into consideration the possible affected area with
attenuation due to the constraints of the basin. Because the basin
restricts sound from propagating outward, with the exception of the
east-facing entrance channel, the radial distances to thresholds are
not generally reached.
There are a number of reasons why estimates of potential incidents
of take may be conservative, assuming that available density or
abundance estimates and estimated ZOI areas are accurate. We assume, in
the absence of information supporting a more refined conclusion, that
the output of the calculation represents the number of individuals that
may be taken by the specified activity. In fact, in the context of
stationary activities such as pile driving and in areas where resident
animals may be present, this number more realistically represents the
number of incidents of take that may accrue to a smaller number of
individuals. While pile driving can occur any day throughout the in-
water work window, and the analysis is conducted on a per day basis,
only a fraction of that time (typically a matter of hours on any given
day) is actually spent pile driving. The potential effectiveness of
mitigation measures in reducing the number of takes is typically not
quantified in the take estimation process. For these reasons, these
take estimates may be conservative.
The quantitative exercise described above indicates that no
incidents of Level A harassment would be expected, independent of the
implementation of required mitigation measures. See Table 4 for total
estimated incidents of take.
Table 4--Calculations for Incidental Take Estimation
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n (animals/ Authorized
Species km\2\) Activity ZOI takes \1\
----------------------------------------------------------------------------------------------------------------
Phase II (40 days)
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Bottlenose dolphin \2\................ 4.15366 Vibratory driving (30 1.350776 169
days).
Bottlenose dolphin \2\................ 4.15366 Contingency impact 0.5313217 22
driving (10 days).
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[[Page 9292]]
Total exposures................... .............. ........................ .............. 191
----------------------------------------------------------------------------------------------------------------
\1\ The product of n * ZOI * total activity days (rounded to the nearest whole number) is used to estimate the
number of takes.
\2\ It is impossible to estimate from available information which stock these takes may accrue to.
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.
Measurements from similar pile driving events were coupled with
practical spreading loss to estimate zones of influence (ZOI; see
Estimated Take); these values were used to develop mitigation measures
for pile driving activities at NSM. The ZOIs effectively represent the
mitigation zone that would be established around each pile to prevent
Level A harassment to marine mammals, while providing estimates of the
areas within which Level B harassment might occur. In addition to the
specific measures described later in this section, the Navy would
conduct briefings between construction supervisors and crews, marine
mammal monitoring team, and Navy staff prior to the start of all pile
driving activity, and when new personnel join the work, in order to
explain responsibilities, communication procedures, marine mammal
monitoring protocol, and operational procedures.
Monitoring and Shutdown for Pile Driving
Shutdown Zone--For all pile driving activities, the Navy will
establish a shutdown zone intended to contain the area in which SPLs
equal or exceed the acoustic injury criteria for mid-frequency hearing
specialists (e.g., bottlenose dolphins) at 198 dB SELcum for
vibratory driving and 185 dB SELcum for impact driving. The
purpose of a shutdown zone is to define an area within which shutdown
of activity would occur upon sighting of a marine mammal (or in
anticipation of an animal entering the defined area), thus preventing
injury of marine mammals (as described previously under Potential
Effects of the Specified Activity on Marine Mammals, serious injury or
death are unlikely outcomes even in the absence of mitigation
measures). Modeled radial distances for shutdown zones are shown in
Table 3. However, a minimum shutdown zone of 15 m (which is larger than
the maximum predicted injury zone) will be established during all pile
driving activities, regardless of the estimated zone. Vibratory pile
driving activities are not predicted to produce sound exceeding 198 dB
SELcum threshold, but these precautionary measures are
intended to prevent the already unlikely possibility of physical
interaction with construction equipment and to further reduce any
possibility of acoustic injury.
Disturbance Zone--Disturbance zones are the areas in which SPLs
equal or exceed 160 and 120 dB rms (for impulse and continuous sound,
respectively). Disturbance zones provide utility for monitoring
conducted for mitigation purposes (i.e., shutdown zone monitoring) by
establishing monitoring protocols for areas adjacent to the shutdown
zones. Monitoring of disturbance zones enables observers to be aware of
and communicate the presence of marine mammals in the project area but
outside the shutdown zone and thus prepare for potential shutdowns of
activity. However, the primary purpose of disturbance zone monitoring
is for documenting incidents of Level B harassment; disturbance zone
monitoring is discussed in greater detail later (see Monitoring and
Reporting). Nominal radial distances for disturbance zones are shown in
Table 3. Given the size of the disturbance zone for vibratory pile
driving, it is impossible to guarantee that all animals would be
observed or to make comprehensive observations of fine-scale behavioral
reactions to sound, and only a portion of the zone (e.g., what may be
reasonably observed by visual observers stationed within the turning
basin) would be observed.
In order to document observed incidents of harassment, monitors
record all marine mammal observations, regardless of location. The
observer's location, as well as the location of the pile being driven,
is known from a GPS. The location of the animal is estimated as a
distance from the observer, which is then compared to the location from
the pile. It may then be estimated whether the animal was exposed to
sound levels constituting incidental harassment on the basis of
predicted distances to relevant thresholds in post-processing of
observational and acoustic data, and a precise accounting of observed
incidences of harassment created. This information may then be used to
extrapolate observed takes to reach an approximate understanding of
actual total takes.
Monitoring Protocols--Monitoring would be conducted before, during,
and after pile driving activities. In addition, observers shall record
all incidents of marine mammal occurrence within the
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ZOI and shall document any behavioral reactions in concert with
distance from piles being driven. Observations made outside the
shutdown zone will not result in shutdown; that pile segment would be
completed without cessation, unless the animal approaches or enters the
shutdown zone, at which point all pile driving activities would be
halted. Monitoring will take place from 15 minutes prior to initiation
through 30 minutes post-completion of pile driving activities. 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. Please see the
Monitoring Plan (www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), developed by the Navy in agreement with NMFS, for
full details of the monitoring protocols.
The following additional measures apply to visual monitoring:
(1) Marine mammal observer (MMO) requirements for this construction
action are as follows:
(a) The Navy will use two MMOs during all construction activity.
(b) At least one observer must have prior experience working as an
observer.
(c) Other observers may substitute education (undergraduate degree
in biological science or related field) or training for experience.
(d) Where a team of three or more observers are required, one
observer should be designated as lead observer or monitoring
coordinator. The lead observer must have prior experience working as an
observer.
(2) Qualified MMOs are trained biologists, and need the following
additional minimum qualifications:
(a) Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
(b) Ability to conduct field observations and collect data
according to assigned protocols
(c) Experience or training in the field identification of marine
mammals, including the identification of behaviors;
(d) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
(e) Writing skills sufficient to prepare a report of observations
including but not limited to the number and species of marine mammals
observed; dates and times when in-water construction activities were
conducted; dates and times when in-water construction activities were
suspended to avoid potential incidental injury from construction sound
of marine mammals observed within a defined shutdown zone; and marine
mammal behavior; and
(f) 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.
(2) Prior to the start of pile driving activity, the shutdown zone
will be monitored for fifteen minutes to ensure that it is clear of
marine mammals. Pile driving will only commence once observers have
declared the shutdown zone clear of marine mammals; animals will be
allowed to remain in the shutdown zone (i.e., must leave of their own
volition) and their behavior will be monitored and documented. The
shutdown zone may only be declared clear, and pile driving started,
when the entire shutdown zone is visible (i.e., when not obscured by
dark, rain, fog, etc.). In addition, if such conditions should arise
during impact pile driving that is already underway, the activity would
be halted.
(3) If a marine mammal approaches or enters the shutdown zone
during the course of pile driving operations, activity will be halted
and delayed until either the animal has voluntarily left and been
visually confirmed beyond the shutdown zone or 15 minutes (30 minutes
in the case of a large whale) have passed without re-detection of the
animal. Should any marine mammal not authorized for Level B harassment
in this IHA enter the ensonified area, pile driving will cease until
the animal(s) leaves the area and will resume after the observer has
determined through re-sighting or by waiting 15 minutes that the animal
moved outside the ensonified area. Monitoring will be conducted
throughout the time required to drive a pile.
(4) Monitoring of the shutdown zone will continue for 30 minutes
following completion of construction activity.
(5) If a species for which authorization has not been granted
(i.e., North Atlantic right whales, Atlantic spotted dolphins, and
humpback whales) or for which authorization has been granted but meets
take limits approaches or enters the Level B harassment zone,
construction activity must cease and the Navy shall contact the Office
of Protected Resources, NMFS.
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. This
procedure is repeated two additional times. It is difficult to specify
the reduction in energy for any given hammer because of variation
across drivers and, for impact hammers, the actual number of strikes at
reduced energy will vary because operating the hammer at less than full
power results in ``bouncing'' of the hammer as it strikes the pile,
resulting in multiple ``strikes.'' For impact driving, we require an
initial set of three strikes from the impact hammer at reduced energy,
followed by a 30-second waiting period, then two subsequent three
strike sets. Soft start will be required at the beginning of each day's
impact pile driving work and at any time following a cessation of
impact pile driving of thirty minutes or longer.
Based on our evaluation of the applicant's proposed measures, NMFS
has determined that the mitigation measures provide the means effecting
the least practicable impact on the affected species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
action area. Effective reporting is critical both to compliance as well
as ensuring that the most value is obtained from the required
monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or
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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.
The Navy's proposed monitoring and reporting is also described in
their Marine Mammal Monitoring Plan, on the internet at
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Visual Marine Mammal Observations
The Navy will collect sighting data and behavioral responses to
construction for marine mammal species observed in the region of
activity during the period of activity. All marine mammal observers
(MMOs) will be trained in marine mammal identification and behaviors
and are required to have no other construction-related tasks while
conducting monitoring. The Navy will monitor the shutdown zone and
disturbance zone before, during, and after pile driving, with observers
located at the best practicable vantage points. Based on our
requirements, the Navy would implement the following procedures for
pile driving:
The two MMOs would be located at the best vantage point(s)
in order to properly see the entire shutdown zone and as much of the
disturbance zone as possible;
During all observation periods, observers will use
binoculars and the naked eye to search continuously for marine mammals;
If the shutdown zones are obscured by fog or poor lighting
conditions, pile driving at that location will not be initiated until
that zone is visible. Should such conditions arise while impact driving
is underway, the activity would be halted; and
The shutdown and disturbance zones around the pile will be
monitored for the presence of marine mammals before, during, and after
any pile driving or removal activity.
In the event that Navy discovers an injured or dead marine
mammal, and the lead observer 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, scavenger damage), the Navy shall report the incident to
the Office of Protected Resources, NMFS, and the Southeast Fisheries
Science Center Stranding Coordinator, NMFS, within 24 hours of the
discovery. Navy shall provide photographs or video footage or other
documentation of the stranded animal sighting to NMFS. The Navy can
continue its operations under such a case.
Likewise, if the Navy discovers an injured or dead marine
mammal, and the lead observer 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), the Navy shall immediately
report the incident to the Office of Protected Resources, NMFS, and the
Southeast Fisheries Science Center Stranding Coordinator, NMFS.
Individuals implementing the monitoring protocol will assess its
effectiveness using an adaptive approach. The monitoring biologists
will use their best professional judgment throughout implementation and
seek improvements to these methods when deemed appropriate. Any
modifications to protocol will be coordinated between NMFS and the
Navy.
Data Collection
We require that observers use approved data forms. Among other
pieces of information, the Navy will record detailed information about
any implementation of shutdowns, including the distance of animals to
the pile and description of specific actions that ensued and resulting
behavior of the animal, if any. In addition, the Navy will attempt to
distinguish between the number of individual animals taken and the
number of incidences of take. We require that, at a minimum, the
following information be collected on the sighting forms:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
Weather parameters (e.g., percent cover, visibility);
Water conditions (e.g., sea state, tide state);
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any observable marine mammal behavior
patterns, including bearing and direction of travel, and if possible,
the correlation to SPLs;
Duration of marine mammals within the shutdown area;
Distance from pile driving activities to marine mammals
and distance from the marine mammals to the observation point;
Description of implementation of mitigation measures
(e.g., shutdown or delay);
Locations of all marine mammal observations; and
Other human activity in the area.
Reporting
A draft report would be submitted to NMFS within 90 days of the
completion of marine mammal monitoring, or sixty days prior to the
requested date of issuance of any future IHA for projects at the same
location, whichever comes first. The report will include marine mammal
observations pre-activity, during-activity, and post-activity during
pile driving days, and will also provide descriptions of any behavioral
responses to construction activities by marine mammals and a complete
description of all mitigation shutdowns and the results of those
actions and an extrapolated total take estimate based on the number of
marine mammals observed during the course of construction. A final
report must be submitted within thirty days following resolution of
comments on the draft report.
Prior Monitoring
As required, the Navy submitted a monitoring report for the first
year of construction at Bravo Wharf in advance of sixty days prior to
the requested date of issuance for this IHA. They met all mitigation,
monitoring, and reporting protocols. Sixty takes occurred by Level B
harassment to bottlenose dolphins--the only species for which take was
authorized--and takes were below the 111 authorized number of takes for
this particular stage (Phase II) of construction. Additionally, the
Navy met all monitoring requirements for similar construction activity
at nearby Wharf C-2 in NSM (80 FR 55598, 8 September 2015; 78 FR 71566,
1 December 2013 and revised IHA for this activity: 79 FR 27863, 1
September 2014). During the course of both IHAs at Wharf C-2, the Navy
did not exceed authorized take levels. The first IHA (covering the
period of May 26 to August 17, 2015) authorized incidental take of 365
bottlenose dolphins and 95
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Atlantic spotted dolphins by Level B harassment. Observers documented
272 bottlenose dolphins based on derived correction factors, and no
Atlantic spotted dolphins were observed (DoN 2015b). As mentioned in
the Estimated Take section, the Navy also monitored underwater
acoustics during vibratory installation of king piles and steel sheet
piles during the period of this IHA at NSM; the sound pressure level
average ranged from 135 to 158 dB and averaged 21 seconds to install a
sheet pile (DoN 2015b). Collection of underwater sound and production
of a subsequent report was not required under the respective IHA, and
is thus not discussed below for the second IHA at Wharf C-2.
An IHA for the second year of construction at Wharf C-2 (covering a
period from September 8, 2015 to September 7, 2016) authorized
incidental take of 304 total bottlenose dolphins. After applying
correction factors to derive a total number of estimated takes,
estimated Level B takes were calculated to be 128 bottlenose dolphins
(DoN 2016).
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).
Pile driving activities associated with the wharf construction
project, as outlined previously, have the potential to disturb or
displace marine mammals. Specifically, the specified activities may
result in take, in the form of Level B harassment (behavioral
disturbance) only, from underwater sounds generated from pile driving.
Potential takes could occur if individuals of these species are present
in the ensonified zone when pile driving is happening.
No injury, serious injury, or mortality is anticipated given the
nature of the activities and measures designed to minimize the
possibility of injury to marine mammals. The potential for these
outcomes is minimized through the construction method and the
implementation of the planned mitigation measures. Specifically,
vibratory hammers will be the primary method of installation (impact
driving is included only as a contingency). Vibratory pile driving does
have the potential to cause injury to marine mammals, but sound
pressure levels in this activity (156 dB rms) do not exceed the
threshold for injury in mid-frequency cetaceans. Impact pile driving
produces short, sharp pulses with higher peak levels and much sharper
rise time to reach those peaks. If impact driving is necessary,
implementation of soft start and shutdown zones 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 that is annoying prior to it becoming
potentially injurious. Environmental conditions in the confined and
protected Mayport turning basin mean that marine mammal detection
ability by trained observers is high, enabling a high rate of success
in implementation of shutdowns to avoid injury.
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; HDR Inc. 2012). 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. The pile driving
activities analyzed here are similar to, or less impactful than,
numerous other construction activities conducted in San Francisco Bay
and in the Puget Sound region, which have taken place with no reported
injuries or mortality to marine mammals, and no known long-term adverse
consequences from behavioral harassment. These activities are also
nearly identical to the pile driving activities that took place at
Wharf C-2 at NSM, which also reported zero injuries or mortality to
marine mammals and no known long-term adverse consequences from
behavioral harassment. Repeated exposures of individuals to levels of
sound that may cause Level B harassment are unlikely to result in
hearing impairment or to significantly disrupt foraging behavior. Thus,
even repeated Level B harassment of some small subset of the overall
stock is unlikely to result in any significant realized decrease in
viability for the affected individuals, and thus would not result in
any adverse impact to the stock as a whole. Level B harassment will be
reduced to the level of least practicable impact through use of
mitigation measures described herein and, if sound produced by project
activities is sufficiently disturbing, animals are likely to simply
avoid the turning basin while the activity is occurring.
The turning basin is not considered important habitat for marine
mammals, as it is a man-made, semi-enclosed basin with frequent
industrial activity and regular maintenance dredging. The surrounding
waters may be an important foraging habitat for the dolphins, but the
small area of ensonification does not extend outside of the turning
basin and into this foraging habitat (see Figure 6-1 in the Navy's
application). Therefore, behavioral disturbances that could result from
anthropogenic sound associated with these activities are expected to
affect only a relatively small number of individual marine mammals that
may venture near the turning basin, although those effects could be
recurring over the life of the project if the same individuals remain
in the project vicinity. In summary and as described above, the
following factors primarily support our preliminary determination that
the impacts resulting from this activity are not expected to adversely
affect the species or stock through effects on annual rates of
recruitment or survival:
No mortality or injury is anticipated or authorized;
Behavioral disturbance is possible, but the significance
to the affected stocks is expected to be minimal due to:
[cir] No more than 40 days of pile driving during the authorized
year;
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[cir] The time required to drive each pile is brief, with no more
than 60 seconds per pile via vibratory driving and no more than 10
minutes per pile via impact driving;
[cir] Mitigation (e.g. shut-downs and soft start) would reduce
acoustic impacts to species in the area of activities;
The absence of any significant habitat within the project
area, including known areas or features of special significance for
foraging or reproduction; Noise associated with pile driving will
ensonify relatively small areas, the majority of which are within the
industrialized turning basin.
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
proposed 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.
Of the 191 incidents of behavioral harassment proposed to be
authorized for bottlenose dolphins, we have no information allowing us
to parse the predicted incidents amongst the four stocks that may occur
in the project area. Therefore, we assessed the total number of
predicted incidents of take against the best abundance estimate for
each stock, as though the total would occur for the stock in question.
For two of the bottlenose dolphin stocks--Western North Atlantic
Southern Migratory Coastal and Western North Atlantic Northern Florida
coastal stock--the total predicted number of incidents of take
authorized would be considered small at 5.09 percent and 21.78 percent,
respectively. This estimate assumes that estimated take occurs to a new
individual, which is an extremely unlikely scenario and therefore a
conservative estimate, as there is likely to be some overlap in both
bottlenose dolphin stocks and individuals from day to day. Likelihood
of actual take to the latter Northern Florida coastal stock is
relatively low, and this estimate assumes all takes would occur to this
one stock. In the western North Atlantic, the Northern Florida Coastal
Stock is present in coastal Atlantic waters from the Georgia/Florida
border south to 29.4[deg] N. (Waring et al., 2014), a span of more than
90 miles. There is no obvious boundary defining the offshore extent of
this stock. They occur in waters less than 20 m deep; however, they may
also occur in lower densities over the continental shelf (waters
between 20 m and 100 m depth) and overlap spatially with the offshore
morphotype (Waring et al., 2014).
For the other stock, the Jacksonville Estuarine System stock, if
all takes occurred to this one stock, this could take 46.36 percent of
the stock (n=412). It is, however, highly unlikely that all takes would
occur to this one stock due to their distribution relative to Bravo
Wharf and social patterns within stock range. JES bottlenose dolphins
range from Cumberland Sound at the Georgia-Florida border south to
approximately Jacksonville Beach, FL, an area consisting of coastline
and complex estuarine habitat of riverines and tidal marshes. Three
behaviorally different communities exist within the JES stock: in
estuarine waters north of St. Johns River (termed the Northern area),
estuarine waters south of St. Johns River to Jacksonville Beach (the
Southern area), and the coastal area (Caldwell 2001). Caldwell (2001)
found that dolphins in the northern area exhibit year-round site
fidelity and are the most isolated of the three communities. They are
also not known to socialize with dolphins in the Southern area, which
show summer site fidelity but traverse in and out of the Jacksonville
area each year (Caldwell 2001). Dolphins in the coastal area are much
more mobile, exhibit fluid social patterns, and show no long-term site
fidelity. Furthermore, genetic analysis also supports differentiation
from JES dolphins between the Northern and Southern areas (Caldwell
2011). Although members of both groups have been observed outside their
preferred areas, it is likely that the majority of JES dolphins would
not occur within waters ensonified by project activities. In summary,
JES dolphins largely comprise two predominant groups and exhibit strong
site fidelity to those areas, which does not significantly overlap with
the larger ZOI, which is almost entirely confined within NSM.
Furthermore, assessing potential impacts to individuals or stocks
based on take estimates alone, in the absence of further context (e.g.
quality of surrounding habitat, site fidelity, etc.), has limitations.
It is common practice to estimate how many animals are likely to be
present within a particular distance of a given activity, or exposed to
a particular level of sound, given the many uncertainties in predicting
the quantity and types of impacts of sound on marine mammals. In
practice, depending on the amount of information available to
characterize daily and seasonal movement and distribution of affected
marine mammals, it can be difficult to distinguish between the number
of individuals harassed and the instances of harassment and, when
duration of the activity is considered, it can result in a take
estimate that overestimates the number of individuals harassed. In
particular, for stationary activities, it is more likely that some
smaller number of individuals may accrue a number of incidences of
harassment per individual than for each incidence to accrue to a new
individual, especially if those individuals display some degree of
residency or site fidelity and the impetus to use the site (e.g.,
because of foraging opportunities) is stronger than the deterrence
presented by the harassing activity. Given stock distribution, site
fidelity, social patterns, the small likelihood that all takes would
occur to new individuals within this stock, and that fact that NSM does
not include any particularly unique habitat to aggregate dolphins, the
majority of JES dolphins are not expected to occur within ensonified
waters of project activities. Therefore, proposed takes are not
expected to exceed small numbers relative to stock abundance.
Based on the analysis contained herein of the proposed 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
[[Page 9297]]
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 CE B4 of the Companion Manual for NOAA Administrative Order 216-6A,
which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS determined that
the issuance of this Authorization was 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.
No incidental take of ESA-listed species is authorized or expected
to result from this activity. Therefore, NMFS has determined that
consultation under Section 7 of the ESA is not required for this
action.
Authorization
NMFS has issued an IHA to the Navy for the harassment of small
numbers of bottlenose dolphins incidental to the Bravo Wharf
recapitalization project in NSM, Jacksonville, FL, provided the
previously mentioned mitigation, monitoring, and reporting
requirements.
Dated: February 27, 2018.
Donna Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2018-04381 Filed 3-2-18; 8:45 am]
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