[Federal Register Volume 83, Number 125 (Thursday, June 28, 2018)]
[Notices]
[Pages 30406-30420]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-13870]
[[Page 30406]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF870
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Service Pier Extension Project
on Naval Base Kitsap Bangor, Washington
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the United States Department of the Navy (Navy) to incidentally harass,
by Level A and Level B harassment, marine mammals during construction
activities associated with the Service Pier Extension (SPE) project at
Naval Base Kitsap Bangor, Washington.
DATES: This Authorization is effective from July 16, 2019 through July
15, 2020.
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: 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 August 9, 2017, NMFS received a request from the Navy for an IHA
to take marine mammals incidental to pile driving and removal
associated with planned construction of the SPE on Naval Base Kitsap
Bangor, Washington. The application was deemed adequate and complete by
NMFS on November 15, 2017.
The Navy's request is for take by Level B harassment of four marine
mammal species and Level A and Level B harassment of one species.
Neither the Navy nor NMFS expect serious injury or immortality to
result from this activity and, therefore, an IHA is appropriate.
Description of Planned Activity
Overview
The Navy is planning to extend the service pier to provide
additional berthing capacity and improve associated facilities for
existing homeported and visiting submarines at Naval Base Kitsap
Bangor. The project includes impact and vibratory pile driving and
vibratory pile removal. Sounds resulting from pile driving and removal
may result in the incidental take of marine mammals by Level A and
Level B harassment in the form of auditory injury or behavioral
harassment. Naval Base Kitsap Bangor is located on Hood Canal
approximately 20 miles (32 kilometers) west of Seattle, Washington. The
in-water construction period for the planned action will occur over 12
months. The issued IHA would be effective from July 16, 2019 through
July 15, 2020 and cover two in-water work windows. A detailed
description of the planned SPE project is provided in the Federal
Register notice for the proposed IHA (83 FR 10689; March 12, 2018).
Since that time, no changes have been made to the planned pile driving
and removal 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 the Navy was
published in the Federal Register on March 12, 2018 (83 FR 10689). That
notice described, in detail, the Navy's activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals. During the 30-day public comment period,
NMFS received comments from the Marine Mammal Commission, Whale and
Dolphin Conservation (WDC), and private citizens.
Comment: 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's 24-hour reset policy.
The Commission understands that NMFS has developed rounding criteria
and recommends that it be shared with the Commission.
Response: NMFS will share the rounding criteria with the Commission
following the completion of internal review and looks forward to
discussing the issue with them in the future.
Comment: 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 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.
[[Page 30407]]
Response: The 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. Importantly, 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.
Comment: The Commission supports NMFS's use of the updated
permanent threshold shift (PTS) thresholds and associated weighting
functions that are used to estimate the Level A harassment zones.
However, it 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, including stationary sound sources. The Commission does not
question the Level A harassment thresholds themselves, but rather the
manner in which the PTS SELcum thresholds are currently
implemented. The Level A and B harassment zones do not make sense
biologically or acoustically 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 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.
Comment: The Commission recommended that NMFS encourage the Navy to
reduce the sizes of its shutdown zones to ensure both that pinnipeds
are sufficiently protected from Level A harassment and that the
activities can be completed in an appropriate manner and within an
appropriate timeframe.
Response: NMFS consulted with the Navy who concurred that a
reduction in zone sizes were appropriate. Additional details may be
found in the Mitigation section of this notice.
Comment: The WDC recommended that lead observers should be familiar
with, or adequately trained on, the differences in appearance between
southern resident and transient killer whales and be able to
immediately report the presence of southern resident orcas should they
enter or approach Hood Canal.
Response: The Navy reports that qualified monitors would be
familiar with differences in appearance between resident and transient
killer whales.
Comment: The WDC recommended that the Navy install a hydroacoustic
system to detect the presence of marine mammals at or near the entrance
to Hood Canal, in order to monitor for southern resident killer whales,
which tend to be more vocally active than transient killer whales.
Response: NMFS does not believe that a hydroacoustic system is
necessary since southern resident killer whales have not occurred in
Hood Canal. Additionally, due to the use of Orca network, marine mammal
monitoring measures, and the high amount of attention that Southern
resident killer whale movements receive, NMFS is confident that the
Navy will be able to detect southern resident killer whale presence
near the Hood Canal Bridge.
Comment: A comment from the public stated that there is not enough
scientific data available on hearing impairment in marine mammals
resulting from the proposed activities to make any type of
determination. They also felt that there is a lack of scientific
understanding of the potential effects of the project on the species in
the surrounding area and that too many assumptions were made by NMFS in
the analysis.
Response: The Potential Impacts section of the notice of proposed
IHA (83 FR 10689; March 12, 2018) described numerous studies that have
examined the effects of underwater sound on marine mammal, as well as
those in the Technical Guidance that was directly used to assess noise-
induced hearing loss. While not all marine mammal species have been
subject to studies examining hearing and impacts of noise on hearing,
enough data has been collected to identify specific marine mammal
hearing groups as not all marine mammals have equal hearing
capabilities or susceptibility to noise-induced hearing loss. Current
hearing data (collected via direct behavioral and electrophysiological
measurements) and predictions (based on inner ear morphology, modeling,
behavior, vocalizations, or taxonomy) allow for individual species to
be placed in specific hearing groups and develop composite audiograms
for each hearing group. From composite audiograms, weighting functions
associated with each hearing group, along with data on noise-induced
hearing loss (i.e., acoustic thresholds), can be applied to predict the
exposures at which animals could suffer permanent hearing impairment.
NMFS uses the best available science to make determinations on the
potential impacts of underwater noise on marine mammals. When specific
data on a given topic or variable is not available, NMFS must make
assumptions in order to conduct an analysis. In many instances, such
assumptions are based on scenarios or conditions that existed at
locations where NMFS had previously issued incidental take
authorizations.
Comment: A private citizen comment noted NMFS fails to specify the
use of a hydraulic or an electrical hammer during pile driving, and
that the determination, or meaningful ``assumptions,'' of how
significantly marine mammals will be affected by frequency and
amplitude cannot be successful if the variation between the two
hammering techniques is not taken into account. NMFS also did not
define or have set criteria for the term problematic geotechnical
conditions.
Response: NMFS is unaware of any data indicating a difference in
frequency and/or amplitude between hydraulic and electric hammers
during pile
[[Page 30408]]
driving. Problematic geotechnical conditions refers to any situation in
which the use of a vibratory driver is insufficient to drive a pile to
its required depth.
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 1 lists all species with expected potential for occurrence in
Hood Canal and summarizes information related to the population or
stock, including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. An expected potential was
defined as species with any regular occurrence in Hood Canal since
1995. Note that while not observed on a consistent basis, west coast
transient killer whales have been recorded intermittently in Hood Canal
with the most recent sightings occurring in 2016 as described below.
They have also been recorded remaining in the area for extended
periods. As such, they have been listed as one of the species for which
authorized take has been requested. For taxonomy, we follow Committee
on Taxonomy (2017). PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS's SARs). While no
mortality is anticipated or authorized here, PBR and annual serious
injury and mortality from anthropogenic sources are included here as
gross indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
All managed stocks in this region are assessed in NMFS's U.S. Pacific
Marine Mammal SARs (Carretta et al., 2016) or Alaska Marine Mammal SARs
(Muto et al., 2016). All values presented in Table 1 are the most
recent available at the time of publication and are available in the
2016 SARs (Carretta et al., 2016, Muto et al., 2016) (available online
at: http://www.nmfs.noaa.gov/pr/sars/species.htm).
Table 1--Species Authorized for Take
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ESA/ MMPA status; Stock abundance (CV,
Species 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 Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae
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Killer whale........................ Orcinus orca........... West coast transient... -; N 243 (n/a; 243, 2009) 2.4 0
\4\.
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Family Phocoenidae (porpoises)
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Harbor porpoise..................... Phocoena phocoena Washington inland -; N 11,233 (0.37; 8,308; 66 >=7.2
vomerina. waters. 2015).
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and sea lions)
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California sea lion................. Zalophus californianus. U.S.................... -; N 296,750 (n/a; 153,337; 9,200 389
2011).
Steller sea lion.................... Eumetopias jubatus Eastern U.S............ -; N 41,638 (n/a; 41,638; 2,498 108
monteriensis. 2015).
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Family Phocidae (earless seals)
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Harbor seal......................... Phoca vitulina Hood Canal............. -; N 1,088 (0.15; unk; unk 0.2
richardii. 1999) \4\.
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ Abundance estimates for these stocks are greater than eight years old and are therefore not considered current. PBR is considered undetermined for
these stocks, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates,
as these represent the best available information for use in this document.
A detailed description of the of the species likely to be affected
by the SPE 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
10689; March 12, 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.
[[Page 30409]]
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from pile driving and removal
activities for the SPE 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 10689;
March 12, 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 during the SPE project. These
potential effects are discussed in detail in the Federal Register
notice for the proposed IHA (83 FR 10689; March 12, 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
authorization through this IHA, which informs both NMFS' 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 would primarily be by Level B harassment, as pile
driving has the potential to result in disruption of behavioral
patterns for individual marine mammals. There is also some potential
for auditory injury (Level A harassment) to result for the harbor seal,
due to larger predicted auditory injury zones and regular presence
around the waterfront area. Auditory injury is unlikely to occur for
mid-frequency cetaceans, high frequency cetaceans or otariid species
due to small predicted zones. The planned mitigation and monitoring
measures are expected to minimize the severity of such taking to the
extent practicable.
As described previously, no serious injury or 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 authorized take estimate.
Acoustic Thresholds
NMFS uses 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--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 affected 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) and above 160 dB re 1 [mu]Pa (rms) for non-
explosive impulsive (e.g., impact pile driving).
Level A harassment--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). The Navy's
planned activity includes the use of impulsive (impact pile driving)
and non-impulsive (vibratory pile driving and extraction) 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 Table 2. 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 30410]]
[GRAPHIC] [TIFF OMITTED] TN28JN18.000
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:
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 zone of influence (ZOI) or area exceeding
the noise criteria.
Source Levels
For the analyses that follow, the TL model described above was used
to calculate the expected noise propagation from pile driving, using an
appropriate representative source level from Table 3 to estimate the
area exceeding the noise criteria. The source levels were derived from
the Navy's document titled Proxy source sound levels and potential
bubble curtain attenuation for acoustic modeling of nearshore marine
pile driving at Navy installations in Puget Sound (Navy 2015). In that
document the Navy reviewed relevant data available for various types
and sizes of piles typically used for pile driving and recommend
[[Page 30411]]
proxy source values for Navy installations in Puget Sound. This
document may be found as Appendix B in the Navy's application.
Table 3--Underwater Noise Source Levels Modeled for Impact and Vibratory Pile Driving
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SEL (dB re 1
Pile type Installation method Pile diameter RMS (dB re 1 Peak (dB re 1 [mu]Pa \2\
[mu]Pa) [mu]Pa) sec)
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Timber................................... Vibratory.................. 15-18 in (38-45 cm)............. 155 \1\ N/A N/A
Concrete................................. Impact..................... 18 in (45 cm)................... 170 184 159
Steel.................................... Impact..................... 24 in (60 cm)................... 193 210 181
36 (90 cm)...................... 194 211 181
Vibratory.................. 24 (60 cm)...................... 161 N/A N/A
36 (90 cm)...................... 166 N/A N/A
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1. Navy opted to use conservative value of 155 dB for project
Key: cm = centimeter; dB re 1 [mu]Pa = decibels referenced at 1 micropascal; N/A = not applicable; RMS = root mean square; SEL = sound exposure level.
For vibratory pile driving distances to the PTS thresholds, the TL
model described above incorporated the auditory weighting functions for
each hearing group using a single frequency as described in the NMFS
Optional Spreadsheet (NMFS, 2016b). When NMFS' Technical Guidance
(2016) was published, in recognition of the fact that ensonified area/
volume could be more technically challenging to predict because of the
duration component in the new thresholds, 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 may 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. NMFS continues to develop ways to quantitatively refine
these tools, and will qualitatively address the output where
appropriate. For stationary sources, including pile driving, NMFS User
Spreadsheet predicts the closest distance at which a marine mammal, if
it remained beyond that distance the whole duration of the activity,
would not incur PTS.
For impact pile driving distances to the cumulative PTS thresholds
for 36-inch (90 cm) and 24-inch (60 cm) steel and concrete pile, the TL
model described above incorporated frequency weighting adjustments by
applying the auditory weighting function over the entire 1-second SEL
spectral data sets from impact pile driving. The Navy believes, and
NMFS concurs, that this methodology provides a closer estimate than
applying the weighting function at a single frequency as suggested in
the NMFS Spreadsheet. The NMFS Spreadsheet is considered to be a
conservative method that typically results in higher estimates of the
PTS onset distance from the pile driving activity. The Navy analysis
focused on the data provided from the Naval Kitsap Bangor Test Pile
Program (steel piles) and the Puget Sound Naval Shipyard Intermediate
Maintenance Facility Pier 6 Fender Pile Replacement Project (concrete
piles) (Grebner et al., 2016). This analysis is described in more
detail in the Appendix in the application.
An unconfined bubble curtain will be used during impact driving of
steel piles, since the project is located in an area without high
currents. While bubble curtain performance is variable, data from the
Bangor Naval Base Test Pile Program indicated an average peak SPL
reduction of 8 dB to 10 dB at 10 meters was achieved for impact driving
of 36- and 48-inch steel pipes (Navy 2015). However, for the SPE
project, a reduction of 8 dB was utilized as shown in Table 4.
Table 4--Inputs for Determining Distances to Cumulative PTS Thresholds
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36'' Steel impact 24'' Steel impact 18'' Concrete impact 24'' Steel vibratory 36'' Steel vibratory Timber
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INPUTS
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Spreadsheet Tab Used............ (E.1-2) Impact pile driving (E.1-2) Impact pile driving (E.1-2) Impact pile (A.1) Vibratory pile (A.1) Vibratory pile (A.1) Vibratory pile
driving. driving. driving. driving.
Source Level (Single Strike/shot 173 dB (assumes 8 dB 173 dB (assumes 8 dB 159 dB...................
SEL). attenuation) *. attenuation) *.
Source Level (RMS SPL).......... ........................... ........................... ......................... 161 dB................. 166 dB................. 155
Weighting Factor Adjustment Weighting override (Grebner Weighting override (Grebner Weighting override 2.5.................... 2.5.................... 2.5
(kHz) **. et al. 2016). et al. 2016). (Grebner et al. 2016).
Number of strikes per day....... 1600....................... 1600....................... 1600.....................
Number of piles per day within 2.......................... 1.......................... 3........................
24-h period.
Duration of sound Production ........................... ........................... ......................... 300.................... 300.................... 300
(minutes).
Propagation (xLogR)............. 15......................... 15......................... 15....................... 15..................... 15..................... 15
[[Page 30412]]
Distance of source level 10......................... 10......................... 10....................... 10..................... 10..................... 10
measurement (meters).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* 8 dB reduction from use of unconfined bubble curtain during steel pipe impact driving.
** For impact driving, the TL model described above incorporated frequency weighting adjustments by applying the auditory weighting function over the entire 1-second SEL spectral data sets.
Table 5--Calculated Radial Distances (meters) to Underwater Marine Mammal Impact Pile Driving Noise Thresholds-
SELCUM Isopleths 1
----------------------------------------------------------------------------------------------------------------
Level A isopleths--impact driving 2
---------------------------------------------------------------
Source type High-
Mid-frequency frequency Phocid Otariid
cetaceans cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
18-in concrete 3................................ 2 74 19 1
24-in steel 4................................... 5 253 34 2
36-in steel 4................................... 14 740 217 12
----------------------------------------------------------------------------------------------------------------
Notes:
1 Calculations based on SELCUM threshold criteria shown in Table 4.
Calculated values were rounded up the nearest meter.
2 Representative spectra were used to calculate the distances to the injury (PTS onset) thresholds for each
functional hearing group for 24-inch and 36-inchsteel pile and 24-inch (60 cm) concrete pile. Distances for 18-
inch (45 cm) concrete piles assumed to be the same as 24-inch (60 cm) concrete piles.
3 No bubble curtain planned for concrete pile.
4 Bubble curtain will be used for 24-inch (60 cm) and 36-inch (90 cm) steel piles, and calculations include 8 dB
attenuation
Table 6--Calculated Radial Distances (meters) to Level A Underwater Marine Mammal Vibratory Pile Driving Noise
Isopleths
----------------------------------------------------------------------------------------------------------------
Level A isopleths--vibratory driving 1
---------------------------------------------------------------
Source type High-
Mid-frequency frequency Phocid Otariid
cetaceans cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
15-18-in timber................................. <1 12 5 <1
24-in steel..................................... 2 30 12 1
36-in steel..................................... 4 64 26 1.8
----------------------------------------------------------------------------------------------------------------
Notes:
1 Distances to the injury (PTS onset) thresholds calculated using National Marine Fisheries Service calculator
with default Weighting Factor Adjustment of 2.5 (NMFS, 2016b).
Calculated values were rounded up the nearest meter.
Tables 5 and 6 show the radial distances to impact and vibratory
Level A isopleths. Based on the dual criteria provided in the NMFS
Spreadsheet, the cumulative SEL was selected over peak threshold to
calculate injury thresholds because the ensonified distances were
larger.
Using the same source level and transmission loss inputs discussed
above the Level B isopleths were calculated for impact and vibratory
driving (Table 7). Note that these attenuation distances are based on
sound characteristics in open water. The actual attenuation distances
are constrained by numerous land features and islands; these actual
distances are reflected in the ensonified areas given below.
Table 7--Level B Impact and Vibratory Pile Driving Exposure Distances
and Ensonified Areas
------------------------------------------------------------------------
Attenuation
Pile type distance Area *
------------------------------------------------------------------------
Impact (160 dB)
------------------------------------------------------------------------
18-in concrete.................... 46 m 6.64 m\2\.
------------------------------------------------------------------------
24-in steel....................... 464 m 0.62 km\2\.
36-in steel....................... 541 m 0.78 km\2\.
Vibratory (120 dB)
------------------------------------------------------------------------
15-18-in timber................... 2.2 km 6.8 km\2\.
------------------------------------------------------------------------
[[Page 30413]]
24-in steel....................... 5.4 km 26.1 km\2\.
36-in steel....................... 11.7 km 49.6 km\2\.
------------------------------------------------------------------------
* Areas were adjusted wherever land masses are encountered prior to
reaching the full extent of the radius around the driven pile.
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.
Transient killer whales are rare in Hood Canal and there are few
data to describe transient killer whale abundance within Hood Canal.
There have been anecdotal accounts of the whales in Hood Canal for
decades. There was a report from one day in April 2016 and eight days
in May 2016 of whales in Dabob Bay in Hood Canal (Orca Network, 2016).
It is not known if these sightings were all of the same group of
transient killer whales. However, the temporally discontinuous data
suggest a high degree of variability in the habitat use and localized
relative abundances of transient killer whales in Hood Canal. Given
that whales were observed on eight days, in May 2016, NMFS will assume
that whales could be observed on up to 8 days during the SPE project.
The most commonly observed group size in Puget Sound from 2004 to 2010
was 6 whales (Navy 2017).
Harbor porpoises may be present in Puget Sound year-round typically
in groups of one to five individuals and are regularly detected in Hood
Canal. Aerial surveys conducted throughout 2013 to 2015 in Puget Sound
indicated density in Puget Sound was 0.91 individuals/km\2\) (95%
CI=0.72-1.10, all seasons pooled) and density in Hood Canal was 0.47/
km\2\ (95% CI=0.29-0.75, all seasons pooled) (Jefferson et al., 2016).
However, after reviewing the most recent data the Navy has estimated
that harbor porpoise density in Hood Canal is 0.44 animals/km\2\
(Smultea et al., 2017). Mean group size of harbor porpoises in Puget
Sound in the 2013-2015 surveys was 1.7 in Hood Canal.
Steller sea lions are routinely seen hauled out on submarines at
Naval Base Kitsap. The Navy relied on monitoring data from 2012 to 2016
to determine the average of the maximum count of hauled out Steller sea
lions for each month in the in-water work window (Appendix A). The
average of the monthly maximum counts during the in-water work window
was 3.14.
California sea lions can occur at Naval Base Kitsap Bangor in any
month, although numbers are low from June through August (Appendix A in
the application).
California sea lions peak abundance occurs between October and May
(NMFS, 1997; Jeffries et al., 2000) but animals can occur at Naval Base
Kitsap Bangor in any month. The Navy relied on monitoring data from
2012 to 2016 to determine the average of the maximum count of hauled
out California sea lions for each month (Appendix A). The Navy
determined abundance of California sea lions based on the average
monthly maximum counts during the in-water work window (Appendix A),
respectively, for an average maximum count of 48.85 animals.
Boat-based surveys and monitoring indicate that harbor seals
regularly swim in the waters at Naval Base Kitsap Bangor (Appendix A in
Application). Hauled-out adults, mother/pup pairs, and neonates have
been documented occasionally, but quantitative data are limited.
Incidental surveys in August and September 2016 recorded as many as 28
harbor seals hauled out under Marginal Wharf or swimming in adjacent
waters. Additional animals were likely present at other locations
during the same time of the surveys. To be conservative, the Navy
estimated that an additional 7 animals were present based on typical
sightings at the other piers at Bangor. Therefore, the Navy and NMFS
assume that up to 35 seals could occur near the SPE project area on any
given day.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
To quantitatively assess exposure of marine mammals to noise levels
from pile driving over the NMFS threshold guidance, one of three
methods was used depending on the species spatial and temporal
occurrence. For species with rare or infrequent occurrence during the
in-water work window, the likelihood of occurrence was reviewed based
on the information in Chapter 3 of the application and the potential
maximum duration of work days and total work days. Only one species was
in this category, transient killer whale, and it had the potential to
linger for multiple days based on historical information. The
calculation was:
(1) Exposure estimate = Probable abundance during construction x
Probable duration
Where:
Probable abundance = maximum expected group size
Probable duration = probable duration of animal(s) presence at
construction sites during in-water work window
For species that regularly occur in Puget Sound, but for which
local abundance data are not available, marine mammal density estimates
were used when available to determine the number of animals potentially
exposed in a ZOI on any one day of pile driving or extraction. Only
harbor porpoise was in this category.
The equation for this species with only a density estimate and no
site-specific abundance was:
(2) Exposure estimate = N x ZOI x maximum days of pile driving
Where:
N = density estimate used for each species
ZOI = Zone of Influence; the area where noise exceeds the noise
threshold value
For species with site-specific surveys available, exposures were
estimated by:
(3) Exposure estimate = Abundance x maximum days of pile driving
Where:
Abundance = average monthly maximum over the time period when pile
driving will occur for sea lions, and estimated total abundance for
harbor seals
All three pinniped species were in this category. Average monthly
maximum counts of Steller sea lions and California sea lions (see
Appendix A for abundance data of these species) were averaged over the
in-water work window. The maximum number of animals observed during the
month(s) with the highest number of animals present on a survey day was
used in the analysis. For harbor seals, an abundance estimate for the
Bangor waterfront was used.
The following assumptions were used to calculate potential
exposures to impact and vibratory pile driving noise for each
threshold.
For formulas (2) and (3), each species will be assumed to
be present in
[[Page 30414]]
the project area each day during construction. The timeframe for
takings would be one potential take (Level B harassment exposure) per
individual, per 24 hours.
The pile type, size, and installation method that produce
the largest ZOI were used to estimate exposure of marine mammals to
noise impacts. Vibratory installation of 36-inch (90 cm) steel piles
created the largest ZOI, so the exposure analysis calculates marine
mammal exposures based on 36-inch steel piles for the 125 days when
steel piles would be installed. For the estimated 35 days when concrete
fender piles would be installed, impact driving was the only
installation method and only 18-inch piles were proposed, so the
exposure analysis calculated marine mammal exposures based on impact
driving 18-inch concrete piles.
All pilings will have an underwater noise disturbance
distance equal to the pile that causes the greatest noise disturbance
(i.e., the piling farthest from shore) installed with the method that
has the largest ZOI. If vibratory pile driving would occur, the largest
ZOI will be produced by vibratory driving. In this case, the ZOI for an
impact hammer will be encompassed by the larger ZOI from the vibratory
driver. Vibratory driving was assumed to occur on all 125 days of steel
pile driving, but not the 35 days of concrete fender pile installation.
Days of pile driving were conservatively based on a
relatively slow daily production rate, but actual daily production
rates may be higher, resulting in fewer actual pile driving days. The
pile driving days are used solely to assess the number of days during
which pile driving could occur if production was delayed due to
equipment failure, safety, etc. In a real construction situation, pile
driving production rates would be maximized when possible.
Transient Killer Whale
Using the first calculation described in the above section,
exposures to underwater pile driving were calculated using the average
group size times the 8 days transient killer whales would be
anticipated in the Hood Canal during pile driving activities. The Navy
assumed that the average pod size was six individuals.
Using this rationale, 48 potential Level B exposures of transient
killer whales from vibratory pile driving are estimated (six animals
times 8 days of exposure). Based on this analysis, the Navy requested
and NMFS has authorized 48 Level B incidental takes for behavioral
harassment. Concrete and steel ZOIs from impact driving will be fully
monitorable (maximum distances to behavioral thresholds of 46 m and 541
m, respectively, and maximum distance to injury thresholds is 14 m), so
no killer whale behavioral or injury takes are expected from impact
driving.
Harbor Porpoise
Applying formula (2) to the animal density (0.44 animals/km\2\),
the largest ZOI for Level B exposure (49.6 km\2\) and the estimated
days of steel pile driving (125), the Navy requested and NMFS has
authorized 2,728 Level B incidental takes of harbor porpoises. The 49.6
km\2\ ZOI excludes the area behind the PSB because harbor porpoise have
never been observed within the barrier. Harbor porpoise can be visually
detected to a distance of about 200 m by experienced observers in
conditions up to Beaufort 2 (Navy 2017). Therefore, the concrete ZOIs
will be fully monitorable (maximum distance of 46 m), so no takes were
calculated for the estimated 35 days of concrete fender pile
installation.
Steller Sea Lion
Formula (3) as described in the previous section was used with
site-specific abundance data to calculate potential exposures of
Steller sea lions during steel pile driving for the SPE project.
Animals could be exposed when traveling, resting, and foraging. Because
a Level A injury shut-down zone will be implemented, Level A harassment
is not expected to occur.
The Navy conservatively assumes that any Steller sea lion that
hauls out at Bangor could swim into the behavioral harassment zone each
day during pile driving because this zone extends across Hood Canal and
up to 11.7 km from the driven pile. The Navy estimated 3.14 animals
could be exposed to harassment per day. These values provide a worst
case assumption that on all 125 days of pile driving, all animals would
be in the water each day during pile driving. Applying formula (3) to
this abundance and the 125 steel pile driving days, the Navy requested
and NMFS authorized the take of up to 393 Steller sea lions. If project
work occurs during months when Steller sea lions are less likely to be
present, actual exposures would be less. Additionally, if daily pile
driving duration is short, exposure would be expected to be less
because some animals would remain hauled out for the duration of pile
driving. With a shutdown zone of 15 meters, Level B take is also
anticipated to occur during 35 days of concrete fender pile
installation. NMFS assumed that 3.14 animals would be exposed per day
in the small Level B zone associated with impact driving of concrete
piles resulting in 110 takes. Any exposure of Steller sea lions to pile
driving noise will be minimized to short-term behavioral harassment.
Therefore, NMFS has authorized the Level B take of 503 Steller sea
lions.
California Sea Lion
Formula (3) was used with site-specific abundance data to calculate
potential exposures of California sea lions during pile driving for the
SPE project. Because a Level A injury shut-down zone will be
implemented, no exposure to Level A noise levels will occur at any
location. Based on site-specific data regarding the average maximum
counts, the Navy assumes that 48.85 exposures per day could occur over
125 planned steel pile driving days resulting in 6,106 exposures. With
a shutdown zone of 15 meters, Level B take is also anticipated to occur
during 35 days of concrete fender pile installation. NMFS assumed that
48.85 animals would be exposed per day in the small Level B zone
associated with impact driving of concrete piles resulting in 1,710
takes. Any exposure of Steller sea lions to pile driving noise will be
minimized to short-term behavioral harassment. Therefore, NMFS has
authorized 7,816 Level B takes.
Harbor Seal
The Navy calculated up to 35 harbor seals may be present per day
during summer and early fall months. Exposure of harbor seals to pile
driving noise will be primarily in the form of short-term behavioral
harassment (Level B) during steel and concrete pile driving. Formula
(3) was used with site-specific abundance data to calculate potential
exposures of harbor seals due to pile driving for the SPE.
The Navy assumes that any harbor seal that hauls out at Bangor
could swim into the behavioral harassment zone each day during impact
pile driving. The largest ZOI for behavioral disturbance (Level B)
would be 11.7 km for vibratory driving and extraction of 36-inch steel
piles. Applying formula (3) to the abundance of this species (35
individuals) and the 125 pile driving days, results in 4,375 takes
Level B takes. With a shutdown zone of 35 meters Level B take is also
anticipated to occur during 35 days of concrete fender pile
installation. NMFS assumed that 35 animals would be exposed per day in
the small Level B zone associated with impact driving of concrete piles
resulting in 1,225 takes.
[[Page 30415]]
The largest ZOI for Level A injury will be 217 m for impact driving
(with bubble curtain) of 36-inch steel piles. A monitors' ability to
observe the entire 217 m injury zone may be difficult because
construction barges and the current Service Pier structure and
associated mooring floats and vessels will interfere with a monitors'
ability to observe the entire injury zone. Some individuals could
enter, and remain in, the injury zone undetected by monitors, resulting
in potential PTS. It is assumed that one of the 35 individuals present
on the Bangor waterfront would enter, and remain in, the injury zone
without being detected by marine mammal monitors each day during steel
impact driving. Therefore, with 125 steel pile driving days and one
individual per day being exposed to Level A noise levels, 125 Level A
takes of harbor seals are authorized by NMFS. With a shutdown zone of
35 meters Level B take is also anticipated to occur during 35 days of
concrete fender pile installation. NMFS assumed that 35 animals would
be exposed per day in the small Level B zone associated with impact
driving of concrete piles resulting in an additional 1,225 Level B
takes. Therefore, NMFS has authorized 5,600 Level B takes
It should be noted that Level A takes of harbor seals would likely
be multiple exposures of the same individuals, rather than single
exposures of unique individuals. This request overestimates the likely
Level A exposures because: (1) Seals are unlikely to remain in the
Level A zone underwater long enough to accumulate sufficient exposure
to noise resulting in PTS, and (2) the estimate assumes that new seals
are in the Level A ZOI every day during pile driving. No Level A takes
are requested for vibratory pile driving because the maximum harbor
seal injury zone is 26 m and is within a practicable shutdown distance.
It is important to note that the estimate of potential Level A
harassment of harbor seals is expected to be an overestimate, since the
planned project is not expected to occur near Marginal Wharf--the
location where most harbor seal activity occurs.
Table 8 provides a summary of authorized Level A and Level B takes
as well as the percentage of a stock or population authorized for take.
Table 8--Authorized Take and Percentage of Stock or Population
----------------------------------------------------------------------------------------------------------------
Authorized take
Species -------------------------------- % population
Level A Level B
----------------------------------------------------------------------------------------------------------------
Killer whale.................................................... 0 48 19.7
Harbor porpoise................................................. 0 2,728 24.3
Steller sea lion................................................ 0 503 1.2
California sea lion............................................. 0 7,816 2.6
Harbor seal..................................................... 125 5,600 n/a
----------------------------------------------------------------------------------------------------------------
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable impact on
such species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of such species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned) the likelihood of effective implementation (probability
implemented as planned) and;
(2) the practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
In addition to the 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.
Use of Vibratory Installation--The Navy will employ vibratory
installation to the greatest extent possible when driving steel piles
to minimize high sound pressure levels associated with impact pile
driving. Impact driving of steel piles will only occur when required by
geotechnical conditions or to ``proof'' load-bearing piles driven by
vibratory methods.
Timing Restrictions--To minimize the number of fish exposed to
underwater noise and other construction disturbance, in-water work will
occur during the in-water work window previously described when ESA-
listed salmonids are least likely to be present (USACE, 2015), July 16-
January 15.
All in-water construction activities will occur during daylight
hours (sunrise to sunset) except from July 16 to September 15, when
impact pile driving will only occur starting 2 hours after sunrise and
ending 2 hours before sunset, to protect foraging marbled murrelets
during the nesting season (April 15-September 23). Sunrise and sunset
are to be determined based on National Oceanic and Atmospheric
Administration data, which can be found at http://www.srrb.noaa.gov/highlights/sunrise/sunrise.html.
Use of Bubble Curtain--A bubble curtain will be employed during
impact installation or proofing of steel piles where water depths are
greater than 0.67 m (2 ft). A noise attenuation device is not required
during vibratory pile driving. If a bubble curtain or similar measure
is used, it will distribute air bubbles around 100 percent of the
piling
[[Page 30416]]
perimeter for the full depth of the water column. Any other attenuation
measure must provide 100 percent coverage in the water column for the
full depth of the pile. The lowest bubble ring shall be in contact with
the mudline for the full circumference of the ring. 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.
A performance test of the bubble curtain shall be conducted prior
to initial use for impact pile driving. The performance test shall
confirm the calculated pressures and flow rates at each manifold ring.
The contractor shall also train personnel in the proper balancing of
air flow to the bubblers. The contractor shall submit an inspection/
performance report to the Navy for approval within 72 hours following
the performance test. Corrections to the noise attenuation device to
meet the performance stands shall occur prior to use for 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 30 second waiting period,
then two subsequent reduced energy strike sets. (The reduced energy of
an individual hammer cannot be quantified because it varies by
individual drivers. Also, the number of strikes will vary at reduced
energy because raising the hammer at less than full power and then
releasing it results in the hammer ``bouncing'' as it strikes the pile,
resulting in multiple ``strikes.'')
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.
Establishment of Shutdown Zones and Disturbance Zones--For all
impact and vibratory pile driving of steel piles, shutdown and
disturbance zones will be established and monitored. The Navy will
focus observations within 1,000 m for all species during these
activities but will record all observations. During impact driving of
concrete piles the Navy will focus on monitoring within 100 m but will
record all observations. The Navy will monitor and record marine mammal
observations within zones and extrapolate these values across the
entirety of the Level B zone as part of the final monitoring report. To
the extent possible, the Navy will record and report on any marine
mammal occurrences, including behavioral disturbances, beyond 1,000 m
for steel pile installation and 100 m for concrete pile installation.
The shutdown zones are based on the distances from the source
predicted for each threshold level. Although different functional
hearing groups of cetaceans and pinnipeds were evaluated, the threshold
levels used to develop the disturbance zones were selected to be
conservative for cetaceans (and therefore at the lowest levels); as
such, the disturbance zones for cetaceans were based on the high
frequency threshold (harbor porpoise). The shutdown zones are based on
the maximum calculated Level A radius for pinnipeds and cetaceans
during installation of 36-inch steel and concrete piles with impact
techniques, as well as during vibratory pile installation and removal.
These actions serve to protect marine mammals, allow for practical
implementation of the Navy's marine mammal monitoring plan and reduce
the risk of a take. The shutdown zone during any non-pile driving
activity will always be a minimum of 10 m (33 ft) to prevent injury
from physical interaction of marine mammals with construction
equipment. Note that in the notice of proposed IHA (83 FR 10689: March
12, 2018), the Navy had requested and NMFS proposed larger shutdown
zones than those authorized as depicted below. The shutdown zones were
reduced to more closely align with the Level A isopleths shown in
Tables 5 and 6. Reducing zone size should minimize shutdown occurrences
caused by entry of animals into Level A zones. Excessive shutdowns
caused by the originally proposed zones could negatively affect SPE
project schedule without decreasing the risk of auditory injury to
marine mammals.
During all pile driving, the shutdown, Level A, and Level B zones
as shown in Tables 9, 10, and 11 will be monitored out to the greatest
extent possible with a focus on monitoring within 1,000 m for steel
pile and 100 m for concrete pile installation.
For steel pile impact pile driving, monitors would initiate
shutdown when harbor seals approach or enter the zone. However, because
of the size of the zone and the inherent difficulty in monitoring
harbor seals, a highly mobile species, it may not be practical, which
is why Level A take is requested.
The isopleths delineating shutdown, Level A, and Level B zones
during impact driving of all steel piles are shown in Table 10. Note
that the Level A isopleth is larger than the Level B isopleth for
harbor porpoises.
Table 9--Shutdown, Level A, and Level B Isopleths During Impact Driving of Steel Piles
----------------------------------------------------------------------------------------------------------------
Level B Level A
Marine mammal group isopleth isopleth Shutdown zone
(meters) (meters) (meters)
----------------------------------------------------------------------------------------------------------------
Cetaceans....................................................... 541 740 750
Harbor Seal..................................................... 541 217 220
Sea Lions....................................................... 541 12 15
----------------------------------------------------------------------------------------------------------------
The isopleths for the shutdown, Level A, and Level B zones during
vibratory driving of all steel piles are shown in Table 11.
Table 10--Shutdown, Level A, Level B Isopleths During Vibratory Driving of Steel Piles
----------------------------------------------------------------------------------------------------------------
Level B Level A
Marine mammal group isopleth isopleth Shutdown zone
(meters) (meters) (meters)
----------------------------------------------------------------------------------------------------------------
Cetaceans....................................................... 11,700 64 100
Harbor Seal..................................................... 11,700 26 30
[[Page 30417]]
Sea Lions....................................................... 11,700 12 15
----------------------------------------------------------------------------------------------------------------
The shutdown, Level A, and Level B isopleths for implementation
during impact driving of concrete piles are shown in Table 11. Given
that the shutdown zone for all authorized species is larger than the
Level A and Level B isopleths there should be no take recorded during
concrete pile driving.
Table 11--Shutdown, Level A, and Level B Isopleths During Impact Driving of Concrete Piles
----------------------------------------------------------------------------------------------------------------
Level B Level A
Marine mammal group isopleth isopleth Shutdown zone
(meters) (meters) (meters)
----------------------------------------------------------------------------------------------------------------
Cetaceans....................................................... 46 74 100
Harbor Seal..................................................... 46 19 35
Sea Lions....................................................... 46 1 15
----------------------------------------------------------------------------------------------------------------
Note that the radii of the disturbance zones may be adjusted if in-
situ acoustic monitoring is conducted by the Navy to establish actual
distances to the thresholds for a specific pile type and installation
method. However, any planned acoustical monitoring plan must be pre-
approved by NMFS. The results of any acoustic monitoring plan must be
reviewed and approved by NMFS before the radii of any disturbance zones
may be revised.
The mitigation measures described above should reduce marine
mammals' potential exposure to underwater noise levels which could
result in injury or behavioral harassment. Based on our evaluation of
the applicant's planned measures, as well as other measures considered
by NMFS, NMFS has determined that the planned 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); and
Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring will include the following requirements.
Marine Mammal Observers (MMOs) will be positioned at the best
practicable vantage points, taking into consideration security, safety,
and space limitations. During pile driving, one MMO will be stationed
in a vessel, and at least four will be stationed on the pier, along the
shore, or on the pile driving barge to maximize observation coverage.
Each MMO location will have a minimum of one dedicated MMO (not
including boat operators). There will be be 3-5 MMOs working depending
on the location, site accessibility and line of sight for adequate
coverage. Additional standards required for visual monitoring include:
(a) Independent observers (i.e., not construction personal) are
required;
(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; and
Monitoring will be conducted by qualified observers, who will
monitor for marine mammals and implement shutdown/delay procedures when
applicable by calling for the shutdown to the hammer operator.
Qualified observers are trained biologists, with the following 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;
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(b) Advanced education in biological science or related field
(undergraduate degree or higher required);
(c) Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience);
(d) Experience or training in the field identification of marine
mammals, including the identification of behaviors;
(e) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
(f) 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
(g) 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.
MMOs will survey the disturbance zone 15 minutes prior to
initiation of pile driving through 30 minutes after completion of pile
driving to ensure there are no marine mammals present. A determination
that the shutdown zone is clear must be made during a period of good
visibility (i.e., the entire shutdown zone and surrounding waters must
be visible to the naked eye). Marine Mammal Observation Record forms
(Appendix A of the application) will be used to document observations.
Survey boats engaged in marine mammal monitoring will maintain speeds
equal to or less than 10 knots.
MMOs will use binoculars and the naked eye to search continuously
for marine mammals and will have a means to communicate with each other
to discuss relevant marine mammal information (e.g., animal sighted but
submerged with direction of last sighting). MMOs will have the ability
to correctly measure or estimate the animals distance to the pile
driving equipment such that records of any takes are accurate relevant
to the pile size and type.
Shutdown shall occur if a species for which authorization has not
been granted or for which the authorized numbers of takes have been
met. The Navy shall then contact NMFS within 24 hours.
If marine mammal(s) are present within or approaching a shutdown
zone prior to pile driving, the start of these activities will be
delayed until the animal(s) have left the zone voluntarily and have
been visually confirmed beyond the shutdown zone, or 15 minutes has
elapsed without re-detection of the animal.
If animal is observed within or entering the Level B zone during
pile driving, a take would be recorded, behaviors documented. However,
that pile segment would be completed without cessation, unless the
animal approaches or enters the shutdown Zone, at which point all pile
driving activities will be halted. The MMOs shall immediately radio to
alert the monitoring coordinator/construction contractor. This action
will require an immediate ``all-stop'' on pile operations. Once a
shutdown has been initiated, pile driving will be delayed until the
animal has voluntarily left the Shutdown Zone and has been visually
confirmed beyond the Shutdown Zone, or 15 minutes have passed without
re-detection of the animal (i.e., the zone is deemed clear of marine
mammals).
All marine mammals observed within the disturbance zones during
pile driving activities will be recorded by MMOs. These animals will be
documented as Level A or Level B takes as appropriate. Additionally,
all shutdowns shall be recorded. For vibratory driving activities, this
data will be extrapolated across the full extent of the Level B
ensonified zone (i.e. 11.7 km radii) to provide total estimated take
numbers.
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
information as described in the Marine Mammal Monitoring Report
(Appendix D of the application).
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: (1) 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; (2) an
injured or dead animal is discovered and cause of death is known; or
(3) an injured or dead animal is discovered and cause of death is not
related to the authorized activities, the Navy will follow the
protocols described in the Section 3 of Marine Mammal Monitoring Report
(Appendix D of the application). Additionally, the Navy will report any
pinniped hauled out at unusual sites (e.g., in work boats) to the local
stranding network and to NMFS, and follow any procedures or measures
stipulated by the 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).
Pile driving and extraction associated with the Navy SPE project as
outlined previously have the potential to injure, disturb or displace
marine mammals. Specifically, the specified activities may result in
Level B harassment (behavioral disturbance) for five marine mammal
species authorized for take from underwater sound generated during pile
driving operations. Level A harassment in the form of PTS may also
occur to limited numbers of one species. Level A harassment was
conservatively authorized for harbor seals since seals
[[Page 30419]]
can occur in high numbers near the project area, can be difficult to
spot, and MMO's ability to observe the entire 217 m injury zone may be
slightly impaired because of construction barges and vessels. Potential
takes could occur if marine mammals are present in the Level A or Level
B ensonified zones when pile driving and removal occurs.
No 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 injury is minimized through
the construction method and the implementation of the planned
mitigation measures. Specifically, vibratory driving will be the
primary method of installation. This driving method decreases the
potential for injury due to relatively low source levels and lack of
potentially injurious source characteristics. Only piles that cannot be
driven to their desired depths using the vibratory hammer will be
impact driven for the remainder of their required driving depth. Noise
attenuating devices (i.e., bubble curtain) will be used during impact
hammer operations for steel piles. During impact driving,
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. Given the number of MMOs that will be employed,
observers should have a relatively clear view of the shutdown zones,
although under limited circumstances the presence of barges and vessels
may impair observation of small portions of shutdown zones. This will
enable a high rate of success in implementation of shutdowns to avoid
injury.
The Navy's planned activities are highly localized. Only a
relatively small portion of Hood Canal 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. Impacts to salmonid and
forage fish populations, including ESA-listed species, will be
minimized by adhering to the designated in-water work period. 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 the foraging range, but because
of the relatively small 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.
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 other similar locations including Hood Canal,
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. Level
B harassment will be reduced through use of mitigation measures
described herein.
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 stocks through
effects on annual rates of recruitment or survival:
No mortality or serious injury is anticipated or
authorized;
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 incidences of Level A harassment would be in
the form of a small degree of PTS to a limited number of animals from
one species;
Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior;
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 planned monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
the planned activity will have a negligible impact on all affected
marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under 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.
Table 8 depicts the number of animals that could be exposed to
Level A and Level B harassment from work associated with the SPE
project. With the exception of harbor seals, the analysis provided
indicates that authorized takes account for no more than 24.3 percent
of the populations of the stocks that could be affected. These are
small numbers of marine mammals relative to the sizes of the affected
species and population stocks under consideration.
For the affected stock of harbor seals, no valid abundance estimate
is available. The most recent abundance estimates for harbor seals in
Washington inland waters are from 1999, and it is generally believed
that harbor seal populations have increased significantly during the
intervening years (e.g., Mapes, 2013). However, we anticipate that
takes estimated to occur for harbor seals are likely to occur only
within some portion of the relevant populations, rather than to animals
from the stock as a whole. For example, takes anticipated to occur at
NBK Bangor would be expected to accrue to the same individual seals
that routinely occur on haulouts at these locations, rather than
occurring to new seals on each construction day. In summary, harbor
seals taken as a result of the specified
[[Page 30420]]
activities are expected to comprise only a limited portion of
individuals comprising the overall relevant stock abundance. Therefore,
we find that small numbers of marine mammals will be taken relative to
the population size of the Hood Canal stock of harbor seal.
Based on the analysis contained herein of the planned activity
(including the planned 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 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 has determined
that the issuance of the IHA qualifies to be categorically excluded
from further NEPA review and signed a Categorical Exclusion memo in
June 2018.
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 planned for
authorization 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 the Navy for the potential harassment of
small numbers of five marine mammal species incidental to the Service
Pier Extension project at Naval Base Kitsap Bangor provided the
previously mentioned mitigation, monitoring and reporting requirements
are incorporated.
Dated: June 22, 2018.
Elaine T. Saiz,
Acting Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2018-13870 Filed 6-27-18; 8:45 am]
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