[Federal Register Volume 82, Number 129 (Friday, July 7, 2017)]
[Notices]
[Pages 31579-31592]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-14261]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF250
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Seattle Multimodal Construction
Project in Washington State
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 we have issued an incidental harassment authorization (IHA) to
Washington State Department of Transportation (WSDOT) to take small
numbers of marine mammals, by harassment, incidental to Seattle
Multimodal Construction Project in Washington State.
DATES: This authorization is effective from August 1, 2017, through
July 31, 2018.
FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as the issued IHA, 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 to allow, upon request by U.S.
citizens who engage in a specified activity (other than commercial
fishing) within a specified area, the incidental, but not intentional,
taking of small numbers of marine mammals, provided that certain
findings are made and the necessary prescriptions are established.
The incidental taking of small numbers of marine mammals shall be
allowed if NMFS (through authority delegated by the Secretary) finds
that the total taking by the specified activity during the specified
time period will (i) have a negligible impact on the species or
stock(s) and (ii) not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant). Further, the permissible methods of taking, as well as the
other means of effecting the least practicable adverse impact on the
species or stock and its habitat (i.e., mitigation) must be prescribed.
Last, requirements pertaining to the monitoring and reporting of such
taking must be set forth.
Where there is the potential for serious injury or death, the
allowance of incidental taking requires promulgation of regulations
under MMPA section 101(a)(5)(A). Subsequently, a Letter (or Letters) of
Authorization may be issued as governed by the prescriptions
established in such regulations, provided that the level of taking will
be consistent with the findings made for the total taking allowable
under the specific regulations. Under MMPA section 101(a)(5)(D), NMFS
may authorize incidental taking by harassment only (i.e., no serious
injury
[[Page 31580]]
or mortality), for periods of not more than one year, pursuant to
requirements and conditions contained within an IHA. The promulgation
of regulations or issuance of IHAs (with their associated prescribed
mitigation, monitoring, and reporting) requires notice and opportunity
for public comment.
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.
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).
National Environmental Policy Act (NEPA)
Issuance of an MMPA 101(a)(5) authorization requires compliance
with the National Environmental Policy Act.
NMFS determined the issuance of the IHA is consistent with
categories of activities identified in CE B4 (issuance of incidental
harassment authorizations under section 101(a)(5)(A) and (D) of the
MMPA for which no serious injury or mortality is anticipated) of the
Companion Manual for NAO 216-6A and we have not identified any
extraordinary circumstances listed in Chapter 4 of the Companion Manual
for NAO 216-6A that would preclude this categorical exclusion.
Summary of Request
On July 28, 2016, WSDOT submitted a request to NMFS requesting an
IHA for the harassment of small numbers of 11 marine mammal species
incidental to construction associated with the Seattle Multimodal
Project at Colman Dock, Seattle, Washington, between August 1, 2017 and
July 31, 2018. NMFS initially determined the IHA application was
complete on September 1, 2016. However, WSDOT notified NMFS in November
2016 that the scope of its activities had changed. WSDOT stated that
instead of using vibratory hammers for the majority of in-water pile
driving and using impact hammer for proofing, it would be required to
use impact hammers to drive a large number of piles completely due to
sediment conditions at Colman Dock. On March 2, 2017, WSDOT submitted a
revised IHA application with updated project description. NMFS
determined that the revised IHA application was complete on March 3,
2017.
In the IHA issued to WSDOT, NMFS authorized the Level A and Level B
harassment of the following seven marine mammal species/stocks: Harbor
seal (Phoca vitulina), California sea lion (Zalophus californianus),
Steller sea lion (Eumetopias jubatus), killer whale (Orcinus orca),
gray whale (Eschrichtius robustus), harbor porpoise (Phocoena
phocoena), and Dall's porpoise (P. dalli).
Description of Specified Activities
Overview
WSDOT is proposing to preserve the Seattle Ferry Terminal at Colman
Dock. The project will reconfigure the dock while maintaining
approximately the same vehicle holding capacity as current conditions.
The reconfiguration would increase total permanent overwater coverage
(OWC) by about 5,400 square feet (ft\2\) (about 1.7 percent more than
existing overwater coverage at the site), due to the new walkway from
the King County Passenger Only Ferry (POF) facility to Alaskan Way and
new stairways and elevators from the POF to the upper level of the
terminal. The additional 5,400 ft\2\ will be mitigated by removing a
portion of Pier 48, a condemned timber structure.
The project will remove the northern timber trestle and replace a
portion of it with a new concrete trestle. The area from Marion Street
to the north edge of the property will not be rebuilt and will become,
after demolition, a new area of open water. A section of fill contained
behind a bulkhead underneath the northeast section of the dock will
also be removed.
WSDOT will construct a new steel and concrete trestle from Columbia
Street northward to Marion Street. Construction of the reconfigured
dock will narrow (reduce) the OWC along the shoreline (at the landward
edge) by 180 linear feet at the north end of the site, while 30 linear
feet of new trestle would be constructed along the shoreline at the
south end of the site. The net reduction of OWC in the nearshore zone
is 150 linear feet.
The purpose of the Seattle Multimodal Project at Colman Dock is to
preserve the transportation function of an aging, deteriorating and
seismically deficient facility to continue providing safe and reliable
service. The project will also address existing safety concerns related
to conflicts between vehicles and pedestrian traffic and operational
inefficiencies.
Details of the WSDOT's construction activities are provided in the
IHA application and in the Federal Register notice for the proposed IHA
(82 FR 15497; March 29, 2017).
Dates and Duration
Due to NMFS and the U.S. Fish and Wildlife Service (USFWS) in-water
work timing restrictions to protect Endangered Species Act (ESA) listed
salmonids, planned WSDOT in-water construction at this location is
limited each year to July 16 through February 15. For this project, in-
water construction is planned to take place between August 1, 2017 and
February 15, 2018.
The total worst-case time for pile installation and removal is
expected to be 83 working days (Table 1).
Vibratory driving of each of the 101 24-inch (in) steel
pile will take approximately 20 minutes, with a maximum of 16 piles
installed per day over 7 days.
Vibratory removal of 103 temporary 24-in diameter steel
piles will take approximately 20 minutes per pile, with maximum 16
piles removed per day over 8 days.
Impact driving (3,000 strikes per pile) of 14 30-in and
201 36-in diameter steel piles will take approximately 45 minutes per
pile, with maximum 8 piles per day for a total of 28 days.
Vibratory driving of 17 30- and 205 36-in diameter steel
piles will take 45 minutes per pile, with maximum 8 piles per day over
a total of 29 days.
Vibratory removal of 4-in timber piles will take
approximately 15 minutes per pile, with approximately 20 piles removed
per day for 11 days.
Table 1--Summary of In-Water Pile Driving Durations
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Time to
vibratory drive
Pile size per pile/ Duration
Method Pile type (inch) Pile number strikes to (days)
impact drive
per pile
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Vibratory removal............ Timber.......... 14 215 900 seconds.... 11
Vibratory removal............ Steel........... 24 103 1,200 seconds.. 8
[[Page 31581]]
Vibratory driving............ Steel........... 24 101 1,200 seconds.. 7
Vibratory driving............ Steel........... 30 17 1,200 seconds.. 3
Vibratory driving............ Steel........... 36 205 1,200 seconds.. 26
Impact driving............... Steel........... 30 14 3,000 strikes.. 2
Impact driving............... Steel........... 36 201 3,000 strikes.. 26
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Total.................... ................ .............. 856 ............... 83
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Specified Geographic Region
The proposed activities will occur at the Seattle Ferry Terminal at
Colman Dock, located in the City of Seattle, Washington (see Figure 1-2
of the IHA application).
Detailed Description of In-Water Pile Driving Associated With Seattle
Multimodal Project
The proposed project has two elements involving noise production
that may affect marine mammals: Vibratory hammer driving and removal,
and impact hammer driving.
Details of pile driving activities are provided below:
The 14-in timber piles will be removed with a vibratory
hammer (Table 1).
The 24-in temporary piles will be installed and removed
with a vibratory hammer (no proofing) (Table 1).
Some of the permanent 30- and 36-in steel piles would be
installed with a vibratory hammer, and some would be installed with
impact hammer (Table 1).
Details of the in-water impact pile driving and vibratory pile
driving and removal activities are provided in the Federal Register
notice for the proposed IHA (82 FR 15497; March 29, 2017). No changes
are made since the proposed IHA was published.
Comments and Responses
A notice of NMFS' proposal to issue an IHA was published in the
Federal Register on March 29, 2017 (82 FR 15497). During the 30-day
public comment period, NMFS received a comment letter from the Marine
Mammal Commission (Commission). No other comments were received.
Specific comments and responses are provided below.
Comment 1: The Commission noted that several typographic and
analytical errors in the Federal Register notice for the proposed IHA.
These errors include: (1) Level B harassment for Steller sea lion and
Dall's porpoise should be 116 and 143, instead of 114 and 137,
respectively; (2) daily maximum number of observed harbor seal and
California sea lion in the project vicinity should be 13 and 47,
respectively. This would result the estimated Level A and Level B takes
of harbor seals to be 364 and 715, respectively; the estimated Level B
take of California sea lion to be 3,901; and (3) The most recent harbor
porpoise density of 0.69 animal/square kilometer (km\2\) from Jefferson
et al. (2016) should be used to calculate harbor porpoise takes.
Response: NMFS agrees with the Commission's assessment and made
corrections to these errors. Specifically, (1) The estimated Level B
takes of Steller sea lion and Dall's porpoise are corrected to 116 and
143, respectively; (2) Used corrected daily maximum number of observed
harbor seal and California sea lions to calculate estimated takes,
which resulted Level A and Level B takes of harbor seals to be 364 and
715 animals, respectively; and Level B take of California sea lion to
be 3,901 animals; and (3) The most recent harbor porpoise density of
0.69 animal/km\2\ from Jefferson et al. (2016) was used to correct
harbor porpoise takes, which result estimated 233 Level A and 2,056
Level B takes. All these corrections are included in this document in
the Estimated Takes section. The increased takes do not affect our
initial analysis of negligible impact determination and small number
conclusion as discussed later in this document.
Comment 2: The Commission states that it is concerned regarding
NMFS appropriateness of the manner in which Level A harassment zones
are estimated. The Commission points out that for impact driving of 30-
and 36-in piles using three hammers concurrently, the Level A
harassment zones for both low- and high-frequency cetaceans were
estimated to be much greater (1.85 and 2.84 km, respectively) than the
Level B harassment zone (1.20 km). The Commission recommends that NMFS
consult with both internal and external scientists and acousticians to
determine the relevant accumulation time that could result Level A
harassment based on associated permanent threshold shift (PTS) from
cumulative sound exposure levels (SELcum).
Response: NMFS understands the Commission's concern and is
continuing working to improve Level A harassment zone estimation based
on realistic noise propagation models and energy accumulation scheme.
At current, Level A harassment zones are based on exposure of
SELcum over a period of one working day's pile driving
duration or instantaneous peak sound pressure level (SPL), while Level
B harassment zones are based on instantaneous root-mean-squared SPL
that contains 90 percent of acoustic energy. The difference in the
metrics between SEL and SPL in assessing Level A and Level B
harassments is the notion that prolonged exposure of intense noise
could lead to PTS if the animal chooses to stay within the injury zone.
The process of impact assessments will continue to evolve as more
scientific data become available.
Description of Marine Mammals in the Area of Specified Activities
The marine mammal species under NMFS jurisdiction that have the
potential to occur in the proposed construction area include Pacific
harbor seal (Phoca vitulina), California sea lion (Zalophus
californianus), northern elephant seal (Mirounga angustirostris),
Steller sea lion (Eumetopias jubatus), killer whale (Orcinus orca),
long-beaked common dolphin (Delphis capensis), gray whale (Eschrichtius
robustus), humpback whale (Megaptera novaeangliae), minke whale
(Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), and
Dall's porpoise (P. dalli). A list of marine mammals that have the
potential to occur in the vicinity of the action and their legal status
under the MMPA and ESA are provided in Table 2. Among these species,
northern elephant seal, minke whale, and long-beaked common dolphin are
extralimital in the proposed project area. NMFS does not consider take
is likely to occur for these species. Therefore, these species are not
discussed further in this document.
[[Page 31582]]
Table 2--Marine Mammal Species Potentially Present in Region of Activity
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Species ESA status MMPA status Occurrence Abundance
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Harbor Seal...................... Not listed......... Non-depleted....... Frequent........... Unk
California Sea Lion.............. Not listed......... Non-depleted....... Frequent........... 296,750
Northern Elephant Seal........... Not listed......... Non-depleted....... Extralimital....... 179,000
Steller Sea Lion (eastern DPS)... Not listed......... Non-depleted....... Rare............... 71,256
Harbor Porpoise.................. Not listed......... Non-depleted....... Frequent........... 11,233
Dall's Porpoise.................. Not listed......... Non-depleted....... Occasional......... 25,750
Killer Whale (Southern Resident). Endangered......... Depleted........... Occasional......... 78
Killer Whale (West Coast Not listed......... Non-depleted....... Occasional......... 243
transient).
Long-beaked Common Dolphin....... Not listed......... Non-depleted....... Extralimital....... 101,305
Gray Whale....................... Not listed......... Non-depleted....... Occasional......... 20,990
Humpback Whale................... Endangered......... Depleted........... Rare............... 1,918
Minke Whale...................... Not listed......... Non-depleted....... Extralimital....... 636
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General information on the marine mammal species found in
Washington coastal waters can be found in Caretta et al. (2016), which
is available online at: http://www.nmfs.noaa.gov/pr/sars/pdf/pacific2015_final.pdf. Refer to that document for information on these
species. Specific information concerning these species in the vicinity
of the proposed action area is provided in detail in the WSDOT's IHA
application and in the Federal Register notice for the proposed IHA (82
FR 15497; March 29, 2017).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The ``Estimated Take'' section later in this document
will include a quantitative analysis of the number of individuals that
are expected to be taken by this activity. The ``Negligible Impact
Analyses and Determination'' section will consider the content of this
section, the ``Estimated Take by Incidental Harassment'' section, and
the ``Mitigation'' section, to draw conclusions regarding the likely
impacts of these activities on the reproductive success or survivorship
of individuals and how those impacts on individuals are likely to
impact marine mammal species or stocks.
When considering the influence of various kinds of sound on the
marine environment, it is necessary to understand that different kinds
of marine life are sensitive to different frequencies of sound. Based
on available behavioral data, audiograms derived using auditory evoked
potentials, anatomical modeling, and other data, NMFS (2016) designated
five ``marine mammal hearing groups'' for marine mammals and estimate
the lower and upper frequencies of hearing of the groups. The marine
mammal groups and the associated frequencies are indicated below
(though animals are less sensitive to sounds at the outer edge of their
functional range and most sensitive to sounds of frequencies within a
smaller range somewhere in the middle of their hearing range):
Low frequency cetaceans (13 species of mysticetes):
Functional hearing is estimated to occur between approximately 7 hertz
(Hz) and 35 kilohertz (kHz);
Mid-frequency cetaceans (32 species of dolphins, seven
species of larger toothed whales, and 19 species of beaked and
bottlenose whales): Functional hearing is estimated to occur between
approximately 150 Hz and 160 kHz;
High frequency cetaceans (eight species of true porpoises,
seven species of river dolphins, Kogia, the franciscana, and four
species of cephalorhynchids): Functional hearing is estimated to occur
between approximately 275 Hz and 160 kHz;
Phocid pinnipeds in Water: Functional hearing is estimated
to occur between approximately 50 Hz and 86 kHz; and
Otariid pinnipeds in Water: Functional hearing is
estimated to occur between approximately 60 Hz and 39 kHz.
As mentioned previously in this document, eight marine mammal
species (five cetacean and three pinniped species) are likely to occur
in the vicinity of the Seattle pile driving/removal area. Of the five
cetacean species, two belong to the low-frequency cetacean group (gray
and humpback whales), one is a mid-frequency cetacean (killer whale),
and two high-frequency cetacean (harbor and Dall's porpoises). One
species of pinniped is phocid (harbor seal), and two species of
pinniped are otariid (California and Steller sea lions). A species'
functional hearing group is a consideration when we analyze the effects
of exposure to sound on marine mammals.
The WSDOT's Seattle Colman ferry terminal construction work using
in-water pile driving and pile removal could adversely affect marine
mammal species and stocks by exposing them to elevated noise levels in
the vicinity of the activity area.
Exposure to high intensity sound for a sufficient duration may
result in auditory effects such as a noise-induced threshold shift--an
increase in the auditory threshold after exposure to noise (Finneran et
al., 2005). Factors that influence the amount of threshold shift
include the amplitude, duration, frequency content, temporal pattern,
and energy distribution of noise exposure. The magnitude of hearing
threshold shift normally decreases over time following cessation of the
noise exposure. The amount of threshold shift just after exposure is
the initial threshold shift. If the threshold shift eventually returns
to zero (i.e., the threshold returns to the pre-exposure value), it is
a temporary threshold shift (TTS) (Southall et al., 2007).
Threshold Shift (noise-induced loss of hearing)--When animals
exhibit reduced hearing sensitivity (i.e., sounds must be louder for an
animal to detect them) following exposure to an intense sound or sound
for long duration, it is referred to as a noise-induced threshold shift
(TS). An animal can experience TTS or permanent threshold shift (PTS).
TTS can last from minutes or hours to days (i.e., there is complete
recovery), can occur in specific frequency ranges (i.e., an animal
might only have a temporary loss of hearing sensitivity between the
frequencies of 1 and 10 kHz), and can be of varying amounts (for
example, an animal's hearing sensitivity might be reduced initially by
only 6 decibel (dB) or reduced by 30 dB). PTS is permanent, but some
recovery is possible. PTS can also occur in a specific frequency range
and amount as mentioned above for TTS.
For cetaceans, published data are limited to the captive bottlenose
[[Page 31583]]
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise
(Finneran et al., 2000, 2002, 2003, 2005, 2007, 2010a, 2010b; Finneran
and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 2009b;
Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et al.,
2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data are
limited to measurements of TTS in harbor seals, an elephant seal, and
California sea lions (Kastak et al., 1999, 2005; Kastelein et al.,
2012b).
Lucke et al. (2009) found a TS of a harbor porpoise after exposing
it to airgun noise with a received sound pressure level (SPL) at 200.2
dB (peak-to-peak) re: 1 micropascal ([mu]Pa), which corresponds to a
sound exposure level of 164.5 dB re: 1 [mu]Pa\2\ s after integrating
exposure. NMFS currently uses the root-mean-square (rms) of received
SPL at 180 dB and 190 dB re: 1 [mu]Pa as the threshold above which PTS
could occur for cetaceans and pinnipeds, respectively. Because the
airgun noise is a broadband impulse, one cannot directly determine the
equivalent of rms SPL from the reported peak-to-peak SPLs. However,
applying a conservative conversion factor of 16 dB for broadband
signals from seismic surveys (McCauley, et al., 2000) to correct for
the difference between peak-to-peak levels reported in Lucke et al.
(2009) and rms SPLs, the rms SPL for TTS would be approximately 184 dB
re: 1 [mu]Pa, and the received levels associated with PTS (Level A
harassment) would be higher. However, NMFS recognizes that TTS of
harbor porpoises is lower than other cetacean species empirically
tested (Finneran & Schlundt 2010; Finneran et al., 2002; Kastelein and
Jennings 2012).
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS, and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to serious
(similar to those discussed in auditory masking, below). For example, a
marine mammal may be able to readily compensate for a brief, relatively
small amount of TTS in a non-critical frequency range that occurs
during a time where ambient noise is lower and there are not as many
competing sounds present. Alternatively, a larger amount and longer
duration of TTS sustained during time when communication is critical
for successful mother/calf interactions could have more serious
impacts. Also, depending on the degree and frequency range, the effects
of PTS on an animal could range in severity, although it is considered
generally more serious because it is a permanent condition. Of note,
reduced hearing sensitivity as a simple function of aging has been
observed in marine mammals, as well as humans and other taxa (Southall
et al., 2007), so one can infer that strategies exist for coping with
this condition to some degree, though likely not without cost.
In addition, chronic exposure to excessive, though not high-
intensity, noise could cause masking at particular frequencies for
marine mammals that utilize sound for vital biological functions (Clark
et al., 2009). Acoustic masking is when other noises such as from human
sources interfere with animal detection of acoustic signals such as
communication calls, echolocation sounds, and environmental sounds
important to marine mammals. Therefore, under certain circumstances,
marine mammals whose acoustical sensors or environment are being
severely masked could also be impaired from maximizing their
performance fitness in survival and reproduction.
Masking occurs at the frequency band that the animals utilize.
Therefore, since noise generated from vibratory pile driving activity
is mostly concentrated at low frequency ranges, it may have less effect
on high frequency echolocation sounds by odontocetes (toothed whales).
However, lower frequency man-made noises are more likely to affect
detection of communication calls and other potentially important
natural sounds such as surf and prey noise. It may also affect
communication signals when they occur near the noise band and thus
reduce the communication space of animals (e.g., Clark et al., 2009)
and cause increased stress levels (e.g., Foote et al., 2004; Holt et
al., 2009).
Unlike TS, masking, which can occur over large temporal and spatial
scales, can potentially affect the species at population, community, or
even ecosystem levels, as well as individual levels. Masking affects
both senders and receivers of the signals and could have long-term
chronic effects on marine mammal species and populations. Recent
science suggests that low frequency ambient sound levels have increased
by as much as 20 dB (more than three times in terms of SPL) in the
world's ocean from pre-industrial periods, and most of these increases
are from distant shipping (Hildebrand 2009). For WSDOT's Seattle Colman
Ferry Terminal construction activities, noises from vibratory pile
driving and pile removal contribute to the elevated ambient noise
levels in the project area, thus increasing potential for or severity
of masking. Baseline ambient noise levels in the vicinity of project
area are high due to ongoing shipping, construction and other
activities in the Puget Sound.
Finally, marine mammals' exposure to certain sounds could lead to
behavioral disturbance (Richardson et al., 1995), such as: Changing
durations of surfacing and dives, number of blows per surfacing, or
moving direction and/or speed; reduced/increased vocal activities;
changing/cessation of certain behavioral activities (such as
socializing or feeding); visible startle response or aggressive
behavior (such as tail/fluke slapping or jaw clapping); avoidance of
areas where noise sources are located; and/or flight responses (e.g.,
pinnipeds flushing into water from haulouts or rookeries).
The onset of behavioral disturbance from anthropogenic noise
depends on both external factors (characteristics of noise sources and
their paths) and the receiving animals (hearing, motivation,
experience, demography) and is also difficult to predict (Southall et
al., 2007). Currently NMFS uses a received level of 160 dB re 1 [mu]Pa
(rms) to predict the onset of behavioral harassment from impulse noises
(such as impact pile driving), and 120 dB re 1 [mu]Pa (rms) for
continuous noises (such as vibratory pile driving). For the WSDOT's
Seattle Colman Ferry Terminal construction activities, both of these
noise levels are considered for effects analysis because WSDOT plans to
use both impact and vibratory pile driving, as well as vibratory pile
removal.
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be biologically significant if the change affects
growth, survival, and/or reproduction, which depends on the severity,
duration, and context of the effects.
Potential Effects on Marine Mammal Habitat
The primary potential impacts to marine mammal habitat are
associated with elevated sound levels produced by pile driving and
removal associated with marine mammal prey species. However, other
potential impacts to the surrounding habitat from physical disturbance
are also possible. These potential effects are discussed below.
SPLs from impact pile driving have the potential to injure or kill
fish in the
[[Page 31584]]
immediate area. These few isolated fish mortality events are not
anticipated to have a substantial effect on prey species population or
their availability as a food resource for marine mammals.
Studies also suggest that larger fish are generally less
susceptible to death or injury than small fish. Moreover, elongated
forms that are round in cross section are less at risk than deep-bodied
forms. Orientation of fish relative to the shock wave may also affect
the extent of injury. Open water pelagic fish (e.g., mackerel) seem to
be less affected than reef fishes. The results of most studies are
dependent upon specific biological, environmental, explosive, and data
recording factors.
The huge variation in fish populations, including numbers, species,
sizes, and orientation and range from the detonation point, makes it
very difficult to accurately predict mortalities at any specific site
of detonation. Most fish species experience a large number of natural
mortalities, especially during early life-stages, and any small level
of mortality caused by the WSDOT's impact pile driving will likely be
insignificant to the population as a whole.
For non-impulsive sound such as that of vibratory pile driving,
experiments have shown that fish can sense both the strength and
direction of sound (Hawkins 1981). Primary factors determining whether
a fish can sense a sound signal, and potentially react to it, are the
frequency of the signal and the strength of the signal in relation to
the natural background noise level.
The level of sound at which a fish will react or alter its behavior
is usually well above the detection level. Fish have been found to
react to sounds when the sound level increased to about 20 dB above the
detection level of 120 dB (Ona 1988); however, the response threshold
can depend on the time of year and the fish's physiological condition
(Engas et al., 1993).
During construction activity at Colman Dock, only a small fraction
of the available habitat would be ensonified at any given time.
Disturbance to fish species would be short-term and fish would return
to their pre-disturbance behavior once the pile driving activity
ceases. Thus, the proposed construction would have little, if any,
impact on the abilities of marine mammals to feed in the area where
construction work is planned.
Finally, the time of the proposed construction activity would avoid
the spawning season of the ESA-listed salmonid species between March
and July.
Short-term turbidity is a water quality effect of most in-water
work, including pile driving.
Cetaceans are not expected to be close enough to the Colman
terminal to experience turbidity, and any pinnipeds will be transiting
the terminal area and could avoid localized areas of turbidity.
Therefore, the impact from increased turbidity levels is expected to be
discountable to marine mammals.
For these reasons, WSDOT's proposed Seattle Multimodal construction
at Colman Dock is not expected to have adverse effects to marine mammal
habitat in the area.
Estimated Take
This section includes an estimate of the number of incidental
``takes'' likely to occur pursuant to this IHA, which will inform both
NMFS' consideration of whether the number of takes is ``small'' and the
negligible impact determination.
Harassment is the only means of take expected to result from these
activities. 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).
As described previously in the section Potential Effects of
Specified Activities on Marine Mammals and their Habitat, no incidental
take is anticipated to result from effects on prey species or as a
result of turbidity. Level B Harassment is expected to occur as
discussed below and is authorized in the numbers identified below.
As described below, a small number of takes by Level A Harassment
are authorized, as the calculation show that Level A takes could occur.
The death of a marine mammal is also a type of incidental take.
However, as described previously, no mortality is anticipated or
authorized to result from this activity.
Basis for Takes
Take estimates are based on average marine mammal density in the
project area multiplied by the area size of ensonified zones within
which received noise levels exceed certain thresholds (i.e., Level A
and/or Level B harassment) from specific activities, then multiplied by
the total number of days such activities would occur. Certain
adjustments were made for marine mammals whose local abundance are
known through long-term monitoring efforts. Therefore, their local
abundance data are used for take calculation instead of general animal
density (see below).
Basis for Threshold Calculation
As discussed above, in-water pile removal and pile driving
(vibratory and impact) generate loud noises that could potentially
harass marine mammals in the vicinity of WSDOT's proposed Seattle
Multimodal Project at Colman Dock.
Under the NMFS' Technical Guidance for Assessing the Effects of
Anthropogenic Sound on Marine Mammal Hearing (Guidance), dual criteria
are used to assess marine mammal auditory injury (Level A harassment)
as a result of noise exposure (NMFS 2016). The dual criteria under the
Guidance provide onset thresholds in instantaneous peak SPLs
(Lpk) as well as 24-hr cumulative sound exposure levels
(SELcum or LE) that could cause PTS to marine
mammals of different hearing groups. The peak SPL is the highest
positive value of the noise field, log transformed to dB in reference
to 1 [mu]Pa.
[GRAPHIC] [TIFF OMITTED] TN07JY17.000
where p(t) is acoustic pressure in pascal or micropascal, and
pref is reference acoustic pressure equal to 1 [mu]Pa.
The cumulative SEL is the total sound exposure over the entire
duration of a given day's pile driving activity, specifically, pile
driving occurring within a 24-hr period.
[[Page 31585]]
[GRAPHIC] [TIFF OMITTED] TN07JY17.001
where p(t) is acoustic pressure in pascal or micropascal,
pref is reference acoustic pressure equals to 1 [mu]Pa,
t1 marks the beginning of the time, and t2 the
end of time.
For onset of Level B harassment, NMFS continues to use the root-
mean-square (rms) sound pressure level (SPLrms) at 120 dB re
1 [mu]Pa and 160 dB re 1 [mu]Pa as the received levels from non-impulse
(vibratory pile driving and removal) and impulse sources (impact pile
driving) underwater, respectively. The SPLrms for pulses
(such as those from impact pile driving) should contain 90 percent of
the pulse energy, and is calculated by
[GRAPHIC] [TIFF OMITTED] TN07JY17.002
where p(t) is acoustic pressure in pascal or micropascal,
pref is reference acoustic pressure equals to 1 [mu]Pa,
t1 marks the beginning of the time, and t2 the
end of time. In the case of an impulse noise, t1 marks the
time of 5 percent of the total energy window, and t2 the
time of 95 percent of the total energy window.
Table 3 summarizes the current NMFS marine mammal take criteria.
Table 3--Current Acoustic Exposure Criteria for Non-Explosive Sound Underwater
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds Behavioral thresholds
Hearing group -------------------------------------------------------------------------------
Impulsive Non-impulsive Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.... Lpk,flat: 219 dB.. LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans.... Lpk,flat: 230 dB.. LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans... Lpk,flat: 202 dB.. LE,HF,24h: 173 dB. Lrms,flat: 160 dB. Lrms,flat: 120 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW)........... Lpk,flat: 218 dB.. LE,PW,24h: 201 dB.
(Underwater).................... LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW).......... Lpk,flat: 232 dB.. LE,OW,24h: 219 dB.
(Underwater).................... LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
a reference value of 1[mu]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.
Sound Levels and Acoustic Modeling for the Proposed Construction
Activity
Source Levels
The project includes vibratory removal of 14-in timber piles,
vibratory driving and removal of 24-in steel piles, vibratory driving
of 30- and 36-in steel piles, and impact pile driving of 30- and 36-in
steel piles. In February of 2016, WSDOT conducted a test pile project
at Colman Dock in order to gather data to select the appropriate piles
for the project. The test pile project measured impact pile driving of
24- and 36-in steel piles. The measured results from the project are
used here to provide source levels for the prediction of isopleths
ensonified over thresholds for the Seattle project. The results show
that the SPLrms for impact pile driving of 36-in steel pile
is 189 dB re 1 [micro]Pa at 14 m from the pile (WSDOT 2016b). This
value is also used for impact driving of the 30-in steel piles, which
is a precautionary approach.
Source level of vibratory pile driving of 36-in steel piles is
based on test pile driving at Port Townsend in 2010 (Laughlin 2011).
Recordings of vibratory pile driving were made at a distance of 10 m
from the pile. The results show that the SPLrms for
vibratory pile driving of 36-in steel pile was 177 dB re 1 [micro]Pa
(WSDOT 2016a).
Up to three pile installation crews may be active during the day
within the project footprint. Each crew will use one vibratory and one
impact hammer, and it is possible that more than 1 hammer, up to 3
impact and/or vibratory hammers, could be conducted concurrently for
driving the 24-, 30-, and 36-in piles. Overlapping noise fields created
by multiple hammer use are handled differently for impact and vibratory
hammers. When more than one impact hammer is being used close
[[Page 31586]]
enough to another impact hammer, the cumulative acoustic energy is
accounted for by including all hammer strikes. When more than one
vibratory hammer is being used close enough to another vibratory hammer
to create overlapping noise fields, additional sound levels are added
to account for the overlap, creating a larger zone of influence (ZOI).
A simplified nomogram method (Kinsler et al., 2000) is proposed to
account for the addition of noise source levels for multiple vibratory
hammers, as shown in Table 4. Using this method, the source levels of
24-, 30-, and 36-in piles during vibratory pile driving are adjusted to
182 dB re 1 [micro]Pa (at 10 m).
Table 4--Multiple Sound Level Addition
------------------------------------------------------------------------
Add the
following to
When two sound levels differ by the higher
level (dB)
------------------------------------------------------------------------
0-1 dB.................................................. 3
2-3 dB.................................................. 2
4-9 dB.................................................. 1
>10 dB.................................................. 0
------------------------------------------------------------------------
For vibratory pile removal, vibratory pile driving data were used
as proxies because we conservatively consider noises from pile removal
would be the same as those from pile driving.
The source level of vibratory removal of 14-in timber piles were
based on measurements conducted at the Port Townsend Ferry Terminal
during vibratory removal of a 12-in timber pile by WSDOT (Laughlin
2011). The recorded source level is 152 dB re 1 [micro]Pa at 16 m from
the pile. In the absence of spectral data for timber pile vibratory
driving, the weighting factor adjustment (WFA) recommended by NMFS
acoustic guidance (NMFS 2016) was used to determine these zones.
These source levels are used to compute the Level A ensonified
zones and to estimate the Level B harassment zones. For Level A
harassment zones, zones calculated using cumulative SEL are all larger
than those calculated using SPLpeak, therefore, only zones
based on cumulative SEL for Level A harassment are used.
Estimating Injury Zones
Calculation and modeling of applicable ensonified zones are based
on source measurements of comparable types and sizes of piles driven by
different methods (impact vs. vibratory hammers) either during the
Colman test pile driving or at a different location within the Puget
Sound. As mentioned earlier, isopleths for injury zones are based on
cumulative SEL (LE) criteria.
For peak SPL (Lpk), distances to marine mammal injury
thresholds were calculated using a simple geometric spreading model
using a transmission loss coefficient of 15:
[GRAPHIC] [TIFF OMITTED] TN07JY17.003
where SLMeasure is the measured source level in dB re 1 [micro]Pa, EL
is the specific received level of threshold, DMeasure is the distance
(m) from the source where measurements were taken, and R is the
distance (radius) of the isopleth to the source in meters.
For cumulative SEL (LE), distances to marine mammal exposure
thresholds were computed using spectral modeling that incorporates
frequency specific absorption. First, representative pile driving
sounds recorded during test pile driving with impact and vibratory
hammers were used to generate power spectral densities (PSDs), which
describe the distribution of power into frequency components composing
that sound, in 1-Hz bins. Parserval's theorem, which states that the
sum of the square of a function is equal to the sum of the square of
its transform, was applied to ensure that all energies within a strike
(for impact pile driving) or a given period of time (for vibratory pile
driving) were captured through the fast Fourier transform, an algorithm
that converts the signal from its original domain (in this case, time
series) to a representation in frequency domain. For impact pile
driving, broadband PSDs were generated from SPLrms time
series of a total of 270 strikes with a time window that contains 90
percent of pulse energy. For vibratory pile driving, broadband PSDs
were generated from a series of continuous 1-second SEL. Broadband PSDs
were then adjusted based on weighting functions of marine mammal
hearing groups (Finneran 2016) by using the weighting function as a
band-pass filter. For impact pile driving, cumulative exposures (Esum)
were computed by multiplying the single rms pressure squared by rms
pulse duration for the specific strike, then by the number of strikes
(provided in Table 1) required to drive one pile, then by the number of
piles to be driven in a given day, as shown in the equation below:
[GRAPHIC] [TIFF OMITTED] TN07JY17.004
where prms,i is the rms pressure, [tau] is the rms pulse duration for
the specific strike, Ns is the anticipated number of strikes (provided
in Table 1) needed to install one pile, and N is the number of total
piles to be installed.
For vibratory pile driving, cumulative exposures were computed by
summing 1-second noise exposure by the duration needed to drive on pile
(provided in Table 1), then by the number of piles to be driven in a
given day, as shown in the equation below:
[GRAPHIC] [TIFF OMITTED] TN07JY17.005
[[Page 31587]]
where E1s is the 1-second noise exposure, and [Delta]t is
the duration (provided in Table 1) need to install 1 pile by vibratory
piling.
Frequency-specific transmission losses, TL(f), were then computed
using practical spreading along with frequency-specific absorption
coefficients that were computed with nominal seawater properties (i.e.,
salinity = 35 psu, pH = 8.0) at 15[deg]C at the surface by
[GRAPHIC] [TIFF OMITTED] TN07JY17.006
where a(f) is dB/km, and R is the distance (radius) of the specific
isopleth to the source in meters. For broadband sources such as those
from pile driving, the transmission loss is the summation of the
frequency-specific results.
Approach to Estimate Behavioral Zones
As mentioned earlier, isopleths to Level B behavioral zones are
based on root-mean-square SPL (SPLrms) that are specific for
impulse (impact pile driving) and non-impulse (vibratory pile driving)
sources. Distances to marine mammal behavior thresholds were calculated
using a simple geometric spreading equation as shown in Equation (4).
For Level B harassment zones from vibratory pile driving of 30-in
and 36-in piles, the ensonified zones are calculated based on practical
spreading of back-calculated source level of 36-in pile driving
adjusted for 3 hammers operating concurrently by adding 5 dB. The
results show that the 120 dB re 1 [micro]Pa isopleth is at 13.6 km. For
Level B harassment zone from vibratory pile driving of 24-in and 36-in
piles, WSDOT conducted site measurements during Seattle test pile
driving project using 24-in and 36-in steel piles. The results show
that underwater noise cannot be detected at a distance of 5 km (3 mi)
and 6.88 km (4.3 mi) for the 24-in and 36-in steel piles, respectively.
Since this measurement was based on pile driving using 1 hammer, the
Level B harassment zone for 24- and 36-in steel pile is adjusted by
factoring in a 5 dB difference (see above) using the following
equation, based on the inverse law of acoustic propagation (i.e., dB
difference in transmission loss is the inverse of distance difference
in logarithm):
[GRAPHIC] [TIFF OMITTED] TN07JY17.007
where dBdifference is the 5 dB difference, R3-hammer is the
distance from the pile where piling noise is no longer audible, and
R1-hammer is the measured distance from the pile where
piling noise is no longer audible, which is 5 km for the 24-in steel
pile and 6.88 km for the 36-in steel pile.
The result show that when using 3 vibratory hammers concurrently,
the distance from the pile to where pile noise is no longer audible is
11 km for the 24-in steel pile and 14.8 km for the 36-in steel pile.
Since the landmass intercepts the water at 13.6 km, this distance is
used as the Level B harassment distance for the 36-in steel pile.
A summary of the measured and modeled harassment zones is provided
in Table 5.
Table 5--Distances to Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Injury zone (m)
Pile type, size & pile driving method -------------------------------------------------------------------------------- Behavior zone
LF cetacean MF cetacean HF cetacean Phocid Otariid (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory 14'' timber................................... 8 0.7 11.9 4.9 0.3 2,175
Vibratory 24'' steel.................................... 255 65 1,365 115 10 11,000
Vibratory 30'' & 36'' steel............................. 285 65 1,455 125 10 13,600
Impact 30'' & 36'' steel................................ 1,845 75 2,835 465 35 1,200
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated Takes From Proposed Construction Activity
Incidental take is estimated for each species by estimating the
likelihood of a marine mammal being present within a Level A or Level B
harassment zone during active pile driving or removal. The Level A
calculation includes a duration component, along with an assumption
(which can lead to overestimates in some cases) that animals within the
zone stay in that area for the whole duration of the pile driving
activity within a day. For all marine mammal species except harbor
seals and California sea lions, estimated takes are calculated based on
ensonified area for a specific pile driving activity multiplied by the
marine mammal density in the action area, multiplied by the number of
pile driving (or removal) days. Marine mammal density data for all
animals except harbor porpoise are from the U.S. Navy Marine Species
Density Database (Navy 2015). Harbor porpoise density is based on a
recent study by Jefferson et al. (2016) for the Seattle area near the
Colman Dock. Harbor seal and California sea lion takes are based on
observations near Seattle, since these data provide the best
information on distribution and presence of these species that are
often associated with nearby haulouts (see below). A summary of marine
mammal density, days and Level A and Level B harassment areas from
different pile driving and removal activities is provided in Table 6.
[[Page 31588]]
Table 6--Summary of Marine Mammal Density, Days and Level A and Level B Ensonified Areas From Different Pile Driving and Removal Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Density (km- Vibratory 14- Vibratory 24- Vibratory 30- Vibratory 36- Impact 30-in Impact 36-in
Species 2) in timber in steel in steel in steel steel steel
--------------------------------------------------------------------------------------------------------------------------------------------------------
Days .............. 11 15 3 26 2 26
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A Areas (m\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific harbor seal..................... 1.219000 50 41,548 49,087 49,087 394,075 394,075
California sea lion..................... 0.12660 0.126 314 314 314 3,849 3,849
Steller sea lion........................ 0.036800 0.126 314 314 314 3,849 3,849
Killer whale, transient................. 0.002373 50 13,273 13,273 13,273 17,672 17,672
Killer whale, Southern Resident......... 0.020240 50 13,273 13,273 13,273 17,672 17,672
Gray whale.............................. 0.000510 154 153,311 189,384 189,384 4,129,836 4,129,836
Humpback whale.......................... 0.00070 154 153,311 189,384 189,384 4,129,836 4,129,836
Harbor porpoise......................... 0.156000 13,273 2,547,906 2,678,940 2,678,940 8,190,639 8,190,639
Dall's porpoise......................... 0.047976 13,273 2,547,906 2,678,940 2,678,940 8,190,639 8,190,639
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level B Areas (m\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific harbor seal..................... 1.219000 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
California sea lion..................... 0.12660 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Steller sea lion........................ 0.036800 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Killer whale, transient................. 0.020240 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Killer whale, Southern Resident......... 0.002373 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Gray whale.............................. 0.000510 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Humpback whale.......................... 0.00070 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Harbor porpoise......................... 0.69 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
Dall's porpoise......................... 0.047976 5,419,792 58,338,838 74,290,934 74,290,934 1,926,124 1,926,124
--------------------------------------------------------------------------------------------------------------------------------------------------------
The Level A take total was further adjusted by subtracting animals
expected to occur within the exclusion zone, where pile driving
activities are suspended when an animal is observed in or approaching
the zone (see Mitigation section). Further, the number of Level B takes
was adjusted to exclude those already counted for Level A takes.
The harbor seal take estimate is based on local seal abundance
information off the Seattle area from WSDOT's Seattle Colman test pile
project in 2016. Marine mammal visual monitoring during the 10-day
period of the project indicates that a maximum of 13 harbor seals were
observed in the general area of the Colman Dock project (WSDOT 2012).
Based on a total of 83 pile-driving days for the WSDOT Seattle Colman
Dock project, it is estimated that up to 1,079 harbor seals could be
exposed to noise levels associated with ``take.'' Since 28 days would
involve impact pile driving of 30-in and 36-in steel piles with Level A
zones beyond shutdown zones (465 m vs 160 m shutdown zone), we consider
that 364 harbor seals exposed during these 28 days would experience
Level A harassment.
The California sea lion take estimate is based on local sea lion
abundance information from the Seattle's Elliott Bay Sea Wall Project
(City of Seattle 2014). Marine mammal visual monitoring during the Sea
Wall Project indicates that up to 47 sea lions were observed in the
general area of the Colman Dock project at any given time (City of
Seattle 2014). Based on a total of 83 pile driving days for the WSDOT
Seattle Colman Dock project, it is estimated that up to 3,901
California sea lions could be exposed to noise levels associated with
``take''. Since the Level A zones of otariids are all very small (<35m,
Table 5), we do not consider it likely that any sea lions would be
taken by Level A harassment. Therefore, all California sea lion takes
estimated here are expected to be taken by Level B harassment.
A summary of estimated marine mammal takes is listed in Table 7.
Table 7--Estimated Numbers of Marine Mammals That May Be Exposed to Received Noise Levels That Cause Level A or
Level B Harassment
----------------------------------------------------------------------------------------------------------------
Estimated Estimated Estimated
Species Level A take Level B take total take Abundance Percentage
----------------------------------------------------------------------------------------------------------------
Pacific harbor seal............. 364 715 1,079 11,036 9.77
California sea lion............. 0 3,901 3,901 296,750 1.31
Steller sea lion................ 0 116 116 71,562 0.16
Killer whale, transient......... 0 7 7 243 3
Killer whale, Southern Resident. 0 0 0 78 0
Gray whale...................... 1 15 16 20,990 0.08
Humpback whale.................. 0 0 0 1,918 0
Harbor porpoise................. 233 2,056 2,289 11,233 20.37
Dall's porpoise................. 16 137 153 25,750 0.59
----------------------------------------------------------------------------------------------------------------
[[Page 31589]]
Mitigation
Under section 101(a)(5)(D) of the MMPA, NMFS shall prescribe the
``permissible methods of taking by harassment 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 subsistence
uses.''
To ensure that the ``least practicable adverse impact'' will be
achieved, NMFS evaluates mitigation measures in consideration of the
following factors in relation to one another: 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, their habitat, and their availability for subsistence uses
(latter where relevant); the proven or likely efficacy of the measures;
and the practicability of the measures for applicant implementation.
For WSDOT's proposed Seattle Multimodal Project at Colman Dock,
WSDOT worked with NMFS and prescribed the following mitigation measures
to minimize the potential impacts to marine mammals in the project
vicinity. The primary purposes of these mitigation measures are to
minimize sound levels from the activities, to monitor marine mammals
within designated ZOIs and exclusion zones corresponding to NMFS'
current Level B and Level A harassment thresholds and, to implement
shut-down measures for certain marine mammal species when they are
detected approaching the exclusion zones or actual take numbers are
approaching the authorized take numbers.
Time Restriction
Work would occur only during daylight hours, when visual monitoring
of marine mammals can be conducted. In addition, all in-water
construction will be limited to the period between August 1, 2017, and
February 15, 2018.
Use of Noise Attenuation Devices
To reduce impact on marine mammals, WSDOT shall use a marine pile
driving energy attenuator (i.e., air bubble curtain system), or other
equally effective sound attenuation method (e.g., dewatered cofferdam)
for all impact pile driving.
Establishing and Monitoring Level A, Level B Harassment Zones, and
Exclusion Zones
Before the commencement of in-water construction activities, which
include impact pile driving and vibratory pile driving and pile
removal, WSDOT shall establish Level A harassment zones where received
underwater SPLs or SELcum could cause PTS (see above).
WSDOT shall also establish Level B harassment zones where received
underwater SPLs are higher than 160 dBrms and 120
dBrms re 1 [mu]Pa for impulse noise sources (impact pile
driving) and non-impulses noise sources (vibratory pile driving and
pile removal), respectively.
WSDOT shall establish a maximum 160-m Level A exclusion zone for
all marine mammals. For Level A harassment zones that are smaller than
160 m from the source, WSDOT shall establish exclusion zones that
correspond to the estimated Level A harassment distances, but shall not
be less than 10 m.
A summary of exclusion zones is provided in Tables 8a and 8b.
Table 8a--Exclusion Zones for Various Pile Driving Activities and Marine Mammal Hearing Groups (for Non-ESA-
Listed Species)
----------------------------------------------------------------------------------------------------------------
Exclusion zone (m)
Pile type, size & pile driving -------------------------------------------------------------------------------
method LF cetacean MF cetacean HF cetacean Phocid Otariid
----------------------------------------------------------------------------------------------------------------
14'' timber pile, vibratory..... 10 10 12 10 10
24'' steel pile, vibratory...... 255 65 160 115 10
30'' & 36'' steel pile, 285 65 160 125 10
vibratory......................
30'' & 36'' steel pile, impact.. 500 75 160 160 35
----------------------------------------------------------------------------------------------------------------
Table 8b--Exclusion Zones for Various Pile Driving Activities and ESA-
Listed Marine Mammal Species
------------------------------------------------------------------------
Exclusion zone (m)
-------------------------------
Pile type, size & pile driving method Southern
Humpback whale resident
killer whale
------------------------------------------------------------------------
14'' timber pile, vibratory............. 2,175 2,175
24'' steel pile, vibratory.............. 11,000 11,000
30'' & 36'' steel pile, vibratory....... 13,600 13,600
30'' & 36'' steel pile, impact.......... 1,845 1,200
------------------------------------------------------------------------
NMFS-approved protected species observers (PSO) shall conduct an
initial survey of the exclusion zones to ensure that no marine mammals
are seen within the zones before impact pile driving of a pile segment
begins. If marine mammals are found within the exclusion zone, pile
driving of the segment will be delayed until they move out of the area.
If a marine mammal is seen above water and then dives below, the
contractor will wait 30 minutes. If no marine mammals are seen by the
observer in that time it can be assumed that the animal has moved
beyond the exclusion zone.
If pile driving of a segment ceases for 30 minutes or more and a
marine mammal is sighted within the designated exclusion zone prior to
commencement of pile driving, the observer(s) must notify the pile
driving operator (or other authorized individual) immediately and
continue to monitor the exclusion zone. Operations may not resume until
the marine mammal has exited the exclusion zone or 30 minutes have
elapsed since the last sighting.
[[Page 31590]]
Soft Start
A ``soft-start'' technique is intended to allow marine mammals to
vacate the area before the impact pile driver reaches full power.
Whenever there has been downtime of 30 minutes or more without impact
pile driving, the contractor will initiate the driving with ramp-up
procedures described below.
Soft start for impact hammers requires contractors to provide an
initial set of three strikes from the impact hammer at 40 percent
energy, followed by a 1-minute waiting period, then two subsequent
three-strike sets. Each day, WSDOT will use the soft-start technique at
the beginning of impact pile driving, or if pile driving has ceased for
more than 30 minutes.
Shutdown Measures
WSDOT shall implement shutdown measures if a marine mammal is
detected within an exclusion zone or is about to enter an exclusion
zone listed in Tables 8a and 8b.
WSDOT shall also implement shutdown measures if southern resident
killer whales or humpback whales are sighted within the vicinity of the
project area and are approaching the Level B harassment zone (ZOI)
during in-water construction activities.
If a killer whale approaches the ZOI during pile driving or
removal, and it is unknown whether it is a Southern Resident killer
whale or a transient killer whale, it shall be assumed to be a Southern
Resident killer whale and WSDOT shall implement the shutdown measure.
If a Southern Resident killer whale, an unidentified killer whale,
or a humpback whale enters the ZOI undetected, in-water pile driving or
pile removal shall be suspended until the whale exits the ZOI to avoid
further Level B harassment.
Further, WSDOT shall implement shutdown measures if the number of
authorized takes for any particular species reaches the limit under the
IHA and if such marine mammals are sighted within the vicinity of the
project area and are approaching the Level B harassment zone during in-
water construction activities.
Coordination With Local Marine Mammal Research Network
Prior to the start of pile driving for the day, the Orca Network
and/or Center for Whale Research will be contacted by WSDOT to find out
the location of the nearest marine mammal sightings. The Orca Sightings
Network consists of a list of over 600 (and growing) residents,
scientists, and government agency personnel in the U.S. and Canada.
Sightings are called or emailed into the Orca Network and immediately
distributed to other sighting networks including: The NMFS Northwest
Fisheries Science Center, the Center for Whale Research, Cascadia
Research, the Whale Museum Hotline and the British Columbia Sightings
Network.
Sightings information collected by the Orca Network includes
detection by hydrophone. The SeaSound Remote Sensing Network is a
system of interconnected hydrophones installed in the marine
environment of Haro Strait (west side of San Juan Island) to study orca
communication, in-water noise, bottom fish ecology and local climatic
conditions. A hydrophone at the Port Townsend Marine Science Center
measures average in-water sound levels and automatically detects
unusual sounds. These passive acoustic devices allow researchers to
hear when different marine mammals come into the region. This acoustic
network, combined with the volunteer (incidental) visual sighting
network allows researchers to document presence and location of various
marine mammal species.
With this level of coordination in the region of activity, WSDOT
will be able to get real-time information on the presence or absence of
whales before starting any pile driving.
Based on our evaluation of the mitigation measures described above,
NMFS has determined that the prescribed mitigation measures provide the
means effecting the least practicable adverse impact on the affected
species or stocks and their habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) of
the MMPA states that NMFS must set forth, requirements pertaining to
the monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
proposed action area. Effective reporting is critical to both
compliance and 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
action area (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.
Monitoring Measures
WSDOT shall employ NMFS-approved PSOs to conduct marine mammal
monitoring for its Seattle Multimodal Project. The PSOs will observe
and collect data on marine mammals in and around the project area for
30 minutes before, during, and for 30 minutes after all pile removal
and pile installation work. NMFS-approved PSOs shall meet the following
requirements:
1. Independent observers (i.e., not construction personnel) are
required;
2. At least one observer must have prior experience working as an
observer;
3. Other observers may substitute education (undergraduate degree
in biological science or related field) or training for experience;
4. 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
5. NMFS will require submission and approval of observer CVs.
Monitoring of marine mammals around the construction site shall be
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conducted using high-quality binoculars (e.g., Zeiss, 10 x 42 power).
Due to the different sizes of ZOIs from different pile sizes, several
different ZOIs and different monitoring protocols corresponding to a
specific pile size will be established.
During 14-in timber pile removal, two land-based PSOs will
monitor the exclusion zones and Level B harassment zone.
During impact pile driving of 30-in and 36-in steel piles,
4 land-based PSOs will monitor the Level A and Level B harassment
zones.
During vibratory pile driving of 24-in, 30-in, and 36-in
steel piles, 5 land-based PSOs and two vessel-based PSOs on ferries
will monitor the Level A and Level B harassment zones.
If the sound source verification (SSV) measurements show
that Level B harassment distance for the vibratory pile driving of 24-
in, 30-in, and 36-in steel piles is less than 10 km, monitoring efforts
listed above can be reduced to 4 land-based PSOs and one vessel-based
PSO on a ferry.
If the sound source verification (SSV) measurements show
that Level B harassment distance for the vibratory pile driving of 24-
in, 30-in, and 36-in steel piles is less than 10 km, 4 land-based PSOs
and one vessel-based PSO on a ferry will monitor the Level A and level
B harassment zones.
Locations of the land-based PSOs and routes of monitoring vessels
are shown in WSDOT's Marine Mammal Monitoring Plan, which is available
online at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
To verify the required monitoring distance, the exclusion zones and
ZOIs will be determined by using a range finder or hand-held global
positioning system device.
In addition, WSDOT shall conduct SSV measurements when conduction
vibratory pile driving of 24-in, 30-in, and 36-in steel piles using
more than one hammer.
Reporting Measures
WSDOT will be required to submit a draft monitoring report within
90 days after completion of the construction work or the expiration of
the IHA, whichever comes earlier. This report would detail the
monitoring protocol, summarize the data recorded during monitoring, and
estimate the number of marine mammals that may have been harassed. NMFS
would have an opportunity to provide comments on the report, and if
NMFS has comments, WSDOT would address the comments and submit a final
report to NMFS within 30 days after receiving NMFS' comments.
In addition, NMFS would require WSDOT to notify NMFS' Office of
Protected Resources and NMFS' West Coast Stranding Coordinator within
48 hours of sighting an injured or dead marine mammal in the
construction site. WSDOT shall provide NMFS and the Stranding Network
with the species or description of the animal(s), the condition of the
animal(s) (including carcass condition, if the animal is dead),
location, time of first discovery, observed behaviors (if alive), and
photo or video (if available).
In the event that WSDOT finds an injured or dead marine mammal that
is not in the construction area, WSDOT would report the same
information as listed above to NMFS within 48 hours of sighting.
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 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, etc.), as well as effects on habitat, the status of the
affected stocks, and the likely effectiveness of the mitigation.
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 these analyses
via their impacts on the environmental baseline (e.g., as reflected in
the regulatory status of the species, population size and growth rate
where known, ongoing sources of human-caused mortality, or ambient
noise levels).
To avoid repetition, this introductory discussion of our analyses
applies to all the species listed in Table 7, given that the
anticipated effects of WSDOT's Seattle Multimodal Project at Colman
Dock activities involving pile driving and pile removal on marine
mammals are expected to be relatively similar in nature. There is no
information about the nature or severity of the impacts, or the size,
status, or structure of any species or stock that would lead to a
different analysis by species for this activity, or else species-
specific factors would be identified and analyzed.
Although a few marine mammal species (364 harbor seals, 1 gray
whale, 233 harbor porpoises, and 16 Dall's porpoise) are estimated to
experience Level A harassment in the form of PTS if they stay within
the Level A harassment zone during the entire pile driving for the day,
the degree of injury is expected to be mild and is not likely to affect
the reproduction or survival of the individual animals. It is expected
that, if hearing impairments occurs, most likely the affected animal
would lose a few dB in its hearing sensitivity, which in most cases is
not likely to affect its survival and recruitment. Hearing impairment
that occur for these individual animals would be limited to the
dominant frequency of the noise sources, i.e., in the low-frequency
region below 2 kHz. Therefore, the degree of PTS is not likely to
affect the echolocation performance of the two porpoise species, which
use frequencies mostly above 100 kHz. Nevertheless, for all marine
mammal species, it is known that in general animals avoid areas where
sound levels could cause hearing impairment. Therefore, it is not
likely that an animal would stay in an area with intense noise that
could cause severe levels of hearing damage. In addition, even if an
animal receives a TTS, the TTS would be a one-time event from the
exposure, making it unlikely that the TTS would evolve into PTS.
Furthermore, Level A take estimates are based on the assumption that
the animals are randomly distributed in the project area and would not
avoid intense noise levels that could cause TTS or PTS. In reality,
animals tend to avoid areas where noise levels are high (Richardson et
al. 1995).
For these species and the rest of the three marine mammal species,
takes that are anticipated and authorized are expected to be limited to
short-term Level B harassment (behavioral and TTS). Marine mammals
present in the vicinity of the action area and taken by Level B
harassment would most likely show overt brief disturbance (startle
reaction) and avoidance of the area from elevated noise levels during
pile driving and pile removal and the implosion noise. A few marine
mammals could experience TTS if they occur within the Level B TTS ZOI.
However, as discussed earlier in this document, TTS is a
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temporary loss of hearing sensitivity when exposed to loud sound, and
the hearing threshold is expected to recover completely within minutes
to hours. Therefore, it is not considered an injury.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat, as analyzed in detail in
the ``Anticipated Effects on Marine Mammal Habitat'' section. There is
no ESA designated critical area in the vicinity of the Seattle
Multimodal Project at Colman Dock area. The project activities would
not permanently modify existing marine mammal habitat. The activities
may kill some fish and cause other fish to leave the area temporarily,
thus impacting marine mammals' foraging opportunities in a limited
portion of the foraging range. However, because of the short duration
of the activities and the relatively small area of the habitat that may
be affected, the impacts to marine mammal habitat are not expected to
cause significant or long-term negative consequences. Therefore, given
the consideration of potential impacts to marine mammal prey species
and their physical environment, WSDOT's proposed construction activity
at Colman Dock would not adversely affect marine mammal habitat.
Injury--only 4 species of marine mammals would experience
Level A affects in the form of mild PTS, which is expected to be of
small degree.
Behavioral disturbance--seven species/stocks of marine
mammals would experience behavioral disturbance and TTS from the
WSDOT's Seattle Colman Dock project. However, as discussed earlier, the
area to be affected is small and the duration of the project is short.
Therefore, the overall impacts are expected to be insignificant.
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 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, NMFS compares the number of
individuals anticipated to be taken to the most appropriate estimation
of the relevant species or stock size in our determination of whether
an authorization would be limited to small numbers of marine mammals.
The takes represent less than 21 percent of all populations or
stocks with known abundance potentially impacted (see Table 7 in this
document). These take estimates represent the percentage of each
species or stock that could be taken by both Level A and Level B
harassments. In general, the numbers of marine mammals estimated to be
taken are small proportions of the total populations of the affected
species or stocks.
Based on the analysis contained herein of the proposed activity
(including the precribed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS finds that small numbers of
each species or stock will be taken relative to the population size of
the affected species or stocks.
Unmitigable Adverse Impact Subsistence 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.
Endangered Species Act (ESA)
Issuance of an MMPA authorization requires compliance with the ESA
for any species that are listed or proposed as threatened or
endangered.
The MMPA California-Oregon-Washington stock of humpback whale and
the Southern Resident stock of killer whale are the only marine mammal
species listed under the ESA that could occur in the vicinity of
WSDOT's proposed construction projects. Two DPSs of humpback whales,
the Mexico DPS and the Central America DPS, are listed as threatened
and endangered under the ESA, respectively. NMFS worked with WSDOT to
implement shutdown measures in the IHA that would avoid takes of both
SR killer whale and humpback whales. Therefore, NMFS determined that no
ESA-listed marine mammal species would be affected as a result of
WSDOT's Seattle Colman Dock construction project.
Authorization
As a result of these determinations, NMFS has issued an IHA to the
Washington State Department of Transportation for conducting ferry
terminal construction at Colman Dock in Seattle Washington, provided
the previously described mitigation, monitoring, and reporting
requirements are incorporated.
Dated: July 3, 2017.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2017-14261 Filed 7-6-17; 8:45 am]
BILLING CODE 3510-22-P