[Federal Register Volume 77, Number 50 (Wednesday, March 14, 2012)]
[Notices]
[Pages 15045-15052]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-6196]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XA916
Takes of Marine Mammals Incidental to Specified Activities; Pile
Placement for ORPC Maine's Cobscook Bay Tidal Energy Pilot Project
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 Marine Mammal Protection Act (MMPA)
implementing regulations, notification is hereby given that NMFS has
issued an Incidental Harassment Authorization (IHA) to Ocean Renewable
Power Company Maine, LLC (ORPC), allowing the take of small numbers of
marine mammals, by Level B harassment only, incidental to pile driving
in Cobscook Bay, Maine.
DATES: Effective March 12, 2012, through March 11, 2013.
ADDRESSES: A copy of the IHA, the application, and the Environmental
Assessment may be obtained by writing to Tammy Adams, Acting Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service, 1315 East-West Highway, Silver
Spring, MD 20910 or by telephoning the contact listed here (see FOR
FURTHER INFORMATION CONTACT), or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. Documents
cited in this notice may be viewed, by appointment, during regular
business hours, at the aforementioned address.
FOR FURTHER INFORMATION CONTACT: Michelle Magliocca, Office of
Protected Resources, NMFS, (301) 427-8401.
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, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who
[[Page 15046]]
engage in a specified activity (other than commercial fishing) within a
specific 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.
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.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which U.S. citizens can apply for an authorization to incidentally
take small numbers of marine mammals by harassment. Section
101(a)(5)(D) further established a 45-day time limit for NMFS' review
of an application, followed by a 30-day public notice and comment
period on any proposed authorizations for the incidental harassment of
marine mammals. Within 45 days of the close of the comment period, NMFS
must either issue or deny the authorization.
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 November 2, 2011, NMFS received an application from ORPC
requesting an IHA for the take, by Level B harassment, of small numbers
of harbor seal (Phoca vitulina), gray seal (Halichoerus grypus), harbor
porpoise (Phocoena phocoena), and Atlantic white-sided dolphin
(Lagenorhynchus acutus) incidental to pile driving activities in
Cobscook Bay, Maine. In accordance with the MMPA and implementing
regulations, NMFS issued a notice in the Federal Register on January
19, 2012 (77 FR 2701), requesting comments from the public on the
proposed IHA.
Description of the Specified Activity
A complete description of the specified activity may be found in
NMFS' proposed IHA notice (77 FR 2701, January 19, 2012) and a summary
is provided here. ORPC plans to install foundational piles to support
an underwater tidal turbine unit as part of the first phase of a long-
term project. The turbine unit is approximately 30 meters (m) (98 feet
(ft)) long, 5 m (17 ft) high, and 5 m (17 ft) wide and is attached to a
bottom support frame, which holds the unit in place about 4.5 m (15 ft)
above the sea floor. The turbine unit weighs about 69,000 pounds (lbs)
and is coupled with the bottom support frame to comprise what is called
a single-device TidGen\TM\ Power System. At the interface with the
seabed, the bottom support frame requires a site-specific design based
on the environmental conditions at the deployment area. The foundation
design for the single-device TidGen\TM\ Power System is a pile bent
arrangement consisting of 10 steel pipe piles. Each foundation pile
will have a 76-centimeter (cm) (30 inch (in)) diameter and a 1-cm
(half-inch) wall thickness and will rest on bedrock. Piles will vary in
length from 15-18 m (50-60 ft) due to bottom sediment depth, but each
pile will be driven to the top of bedrock and will protrude 3-5 m (10-
15 ft) above the seafloor.
A total of 11 piles (10 for the foundation and one for mounting
environmental monitoring equipment) will be driven from a moored barge
for the first phase. Piles will be placed about six m (20 ft) apart in
two rows of five and the rows will be separated by about 15 m (50 ft).
Geotechnical data shows that the TidGen\TM\ device will be located in
an area with up to 12 m (40 ft) of marine clay and some thin layers of
glacial till overlaying bedrock. Based on this data and extensive soil
studies in the area, piles are expected to sink fairly deep into the
mud line under their own weight. Piles will be driven the remaining
depth using vibratory and impact pile driving procedures from barge-
based pile driving equipment. A pile for mounting environmental
monitoring equipment will also be installed with the same pile driving
equipment. The monitoring pile will be two m (six ft) in diameter, or
consist of an array of three piles not greater than 76 cm (30 in) in
diameter. The monitoring pile will protrude about six m (20 ft) above
the seafloor.
ORPC plans to use an H&M model H-1700 vibratory hammer to drive
piles to the extent possible. If additional energy is required to reach
bedrock, a Berminghammer model B-3505 diesel impact hammer may be used,
with maximum rated impact energy of 21,533 ft-lb. ORPC expects that the
need for an impact hammer will be minimal and for very short durations.
To lessen the amount and intensity of sound propagation, ORPC is
evaluating the use of wooden sound absorption cushions and/or bubble
curtains.
Date and Duration of Proposed Activity
ORPC plans to begin pile driving in mid-March, 2012. Pile driving
with a vibratory hammer may take up to three minutes per pile and pile
driving with an impact hammer may take up to five minutes per pile. Due
to strong currents during ebb and flood tides, pile driving will only
occur during slack tides. ORPC expects that only one pile will be
driven per tide cycle for a total of 7-12 days of pile driving during
daylight hours only. NMFS Northeast Region recommends that in-water
construction involving pile driving be conducted between November 8 and
April 9 to avoid impacts to fisheries resources. However, ORPC may be
able to conduct pile driving activities after April 9 if they can
demonstrate that noise levels caused by the impact hammer are below
NMFS guidelines. Although pile driving is only expected to last 7-12
days, NMFS issued the IHA for a 1-year period to allow for permitting
and weather delays. Pile driving will only occur in weather that
provides adequate visibility for marine mammal monitoring activities.
Region of Proposed Activity
The activity will occur in Cobscook Bay, in between Lubec and
Eastport, Maine. Piles and other deployment materials will be
transported by barge from a staging area at the Eastport Boat School or
other local access point. Cobscook Bay has extremely strong tidal
currents and notably high tides, creating an extensive intertidal
habitat for marine and coastal species. Water depth at the proposed
project location is 26 m (85 ft) at mean lower low water. The Bay is
considered a relatively intact marine system, as the area has not
experienced much industrialization.
Sound Propagation
For background, sound is a mechanical disturbance consisting of
minute vibrations that travel through a medium, such as air or water,
and is generally characterized by several variables. Frequency
describes the
[[Page 15047]]
sound's pitch and is measured in hertz (Hz) or kilohertz (kHz), while
sound level describes the sound's loudness and is measured in decibels
(dB). Sound level increases or decreases exponentially with each dB of
change. For example, 10 dB yields a sound level 10 times more intense
than 1 dB, while a 20 dB level equates to 100 times more intense, and a
30 dB level is 1,000 times more intense. Sound levels are compared to a
reference sound pressure (micro-Pascal) to identify the medium. For air
and water, these reference pressures are ``re: 20 [mu]Pa'' and ``re: 1
[mu]Pa,'' respectively. Root mean square (RMS) is the quadratic mean
sound pressure over the duration of an impulse. RMS is calculated by
squaring all of the sound amplitudes, averaging the squares, and then
taking the square root of the average (Urick, 1975). RMS accounts for
both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper, 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units rather than by peak pressures.
Source levels for the vibratory and impact hammer are expected to
be 175 dB and 190 dB, respectively. Assuming a practical spreading loss
of 15 log R, OPRC estimates that the 180-dB (Level A harassment)
isopleth for the impact hammer could be as far as 100 m (328 ft). The
120-dB (Level B harassment for continuous sound sources) isopleth for
the vibratory hammer could be as far as 4,600 m (2.5 mi).
Comments and Responses
A notice of receipt and request for public comment on the
application and proposed authorization was published on January 19,
2012 (77 FR 2701). During the 30-day public comment period, NMFS only
received comments from the Marine Mammal Commission (Commission).
Comment 1: The Commission recommends that NMFS defer issuance of
the IHA until NMFS evaluates the potential effects of construction,
installation, and subsequent operation of the tidal turbine.
Furthermore, the Commission recommends that NMFS then use that
information as a basis for (1) determining the potential for marine
mammal injury or mortality, (2) designing mitigation and monitoring
measures to minimize injury and mortality caused by direct
interactions, and (3) determining whether the anticipated takes are
expected to have negligible impacts on marine mammal species and
stocks.
Response: NMFS disagrees that issuance of the IHA should be
deferred. ORPC requested authorization for incidental takings subject
to a specified activity (i.e., pile driving). NMFS has not received an
IHA request for incidental takings subject to further construction,
installation, or subsequent operation of the tidal turbine. However,
NMFS did analyze the cumulative effects of ongoing and future Cobscook
Bay activities in an Environmental Assessment (EA), which included the
eventual operation of ORPC's tidal turbine. The environmental effects
of ORPC's long-term project were also analyzed in an EA prepared by the
Federal Energy Regulatory Commission and the Department of Energy (FERC
and DOE, 2012). In summary, an assortment of mitigation and monitoring
measures are expected to minimize impacts to marine species and the
surrounding environment. To date, information on currently operating
tidal turbines does not suggest the need for an incidental take
authorization. However, if ORPC determines that there is a potential
for further marine mammal harassment, they may choose to apply for
another authorization.
Comment 2: If an IHA is issued, the Commission recommends that NMFS
authorize the taking of harbor seals and gray seals by both in-water
and in-air harassment. If authorization does not include both in-water
and in-air harassment, the Commission recommends that NMFS require ORPC
to shutdown pile driving activities whenever a seal is observed within
the in-air Level B harassment zone.
Response: As explained in the notice of proposed IHA (77 FR 2701,
January 19, 2012), elevated in-air sound levels are not a concern
because the nearest significant haul-out is more than six nautical
miles (nmi) away. ORPC has not observed any pinnipeds hauled out within
the proposed project area during their 3 years of conducting visual
observations in Cobscook Bay. Any pinniped observed swimming or diving
within 152 m (500 ft) of the pile driving location would be considered
to be taken by elevated underwater sounds from pile driving; therefore,
there is no additional need to shutdown any time a pinniped is within
the in-air Level B harassment zone.
Comment 3: The Commission recommends that NMFS require ORPC to
monitor the presence and behavior of marine mammals for 30 minutes
before, during, and 30 minutes after all impact and vibratory pile
driving activities.
Response: As detailed in the notice of proposed IHA (77 FR 2701,
January 19, 2012) and the mitigation and monitoring sections of this
notice, ORPC is required to monitor the exclusion zone for 30 minutes
before, during, and 30 minutes after all impact pile driving. ORPC is
also required to monitor the larger Level B harassment zone on at least
three days of vibratory pile driving. NMFS believes that this amount of
monitoring is sufficient to prevent the injury or mortality of marine
mammals and to document behavioral responses of marine mammals to pile
driving.
Comment 4: The Commission recommends that NMFS require ORPC to
record distances to observed marine mammals and document their behavior
within the entirety of the Level B harassment zone for vibratory pile
driving.
Response: As detailed in the notice of proposed IHA (77 FR 2701,
January 19, 2012) and the mitigation and monitoring sections of this
notice, ORPC is required to monitor the Level B harassment zone on at
least three days of vibratory pile driving to validate take estimates
and evaluate the behavioral impacts pile driving has on marine mammals
out to the Level B harassment isopleth. Protected species observers
will record species, behaviors, and responses to pile driving within
this area.
Comment 5: The Commission recommends that NMFS require ORPC to
monitor before, during, and after all soft-starts of vibratory and
impact pile driving activities to gather the data needed to determine
the effectiveness of this technique as a mitigation measure.
Response: NMFS disagrees that ORPC needs to monitor for marine
mammals before, during, and after all soft-starts. Protected species
observers will be on-site and monitoring for marine mammals at least 30
minutes before, during, and 30 minutes after all impact driving
(including during soft-starts) and on at least three days of vibratory
pile driving. NMFS believes that monitoring for all impact driving and
on at least three days of vibratory pile driving will allow for
adequate interpretation of how marine mammals are behaving in response
to pile driving, including during soft-starts.
Description of Marine Mammals in the Area of the Specified Activity
Marine mammals with known presence in this region of Cobscook Bay
are the harbor seal, grey seal, harbor porpoise, and Atlantic white-
sided dolphin. ORPC has been conducting incidental visual observations
of marine mammals in Cobscook Bay since 2007, for a total effort of 252
4-hr
[[Page 15048]]
observational periods over 222 days. During this time, marine mammal
observers have recorded 57 seals, 47 harbor porpoises, and two Atlantic
white-sided dolphins (Table 1). No observations of any whale species
have been made in Cobscook Bay by ORPC since monitoring began in 2007.
In addition, a review of available databases does not indicate any
recorded whale sightings in Cobscook Bay. Other species that may
possibly occur in the vicinity of the proposed activity include North
Atlantic right whale (Eubalaena glacialis), humpback whale (Megaptera
novaengliae), fin whale (Balaenoptera borealis), minke whale
(Balaenoptera acutorostrata), and sei whale (Balaenoptera borealis).
However, these five species are generally associated with open ocean
habitats and occur in more offshore locations. NMFS has concluded that
the specified activity will not impact these five species and they are
not discussed further. Information on the harbor seal, grey seal,
harbor porpoise, and Atlantic white-sided dolphin was provided in the
January 19, 2012 Federal Register notice (77 FR 2701).
Table 1--Marine Mammal Observations in the Proposed Project Vicinity Between December 2007, and December 2010
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Hours of Harbor and Harbor Atlantic white-
Month effort grey seal porpoise sided dolphin
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January......................................... 16 0 0 0
February........................................ 36 0 1 0
March........................................... 56 1 0 0
April........................................... 160 4 3 0
May............................................. 56 1 3 0
June............................................ 84 8 1 0
July............................................ 84 4 10 0
August.......................................... 120 16 24 2
September....................................... 100 9 5 0
October......................................... 96 8 0 0
November........................................ 72 4 0 0
December........................................ 104 2 0 0
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Total....................................... 1,008 57 47 2
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Potential Effects on Marine Mammals
Elevated in-water sound levels from pile driving in the project
area may temporarily impact marine mammal behavior. A detailed
description of potential impacts to marine mammals can be found in
NMFS' January 19, 2012 Federal Register notice (77 FR 2701) and is
summarized here.
Marine mammals are continually exposed to many sources of sound.
For example, lightning, rain, sub-sea earthquakes, and animals are
natural sound sources throughout the marine environment. Marine mammals
produce sounds in various contexts and use sound for various biological
functions including, but not limited to, (1) social interactions; (2)
foraging; (3) orientation; and (4) predator detection. Interference
with producing or receiving these sounds may result in adverse impacts.
Audible distance or received levels will depend on the sound source,
ambient noise, and the sensitivity of the receptor (Richardson et al.,
1995). Marine mammal reactions to sound may depend on sound frequency,
ambient sound, what the animal is doing, and the animal's distance from
the sound source (Southall et al., 2007).
Hearing Impairment
Marine mammals may experience temporary or permanent hearing
impairment when exposed to loud sounds. Hearing impairment is
classified by temporary threshold shift (TTS) and permanent threshold
shift (PTS). There are no empirical data for when PTS first occurs in
marine mammals; therefore, it must be estimated from when TTS first
occurs and from the rate of TTS growth with increasing exposure levels.
PTS is likely if the animal's hearing threshold is reduced by >= 40 dB
of TTS. PTS is considered auditory injury (Southall et al., 2007) and
occurs in a specific frequency range and amount. Irreparable damage to
the inner or outer cochlear hair cells may cause PTS; however, other
mechanisms are also involved, such as exceeding the elastic limits of
certain tissues and membranes in the middle and inner ears and
resultant changes in the chemical composition of the inner ear fluids
(Southall et al., 2007). Due to proposed mitigation measures and source
levels in the proposed project area, NMFS does not expect marine
mammals to be exposed to PTS levels.
Temporary Threshold Shift (TTS)
TTS is the mildest form of hearing impairment that can occur during
exposure to a loud sound (Kryter, 1985). While experiencing TTS, the
hearing threshold rises and a sound must be louder in order to be
heard. TTS can last from minutes or hours to days, but is recoverable.
TTS also occurs in specific frequency ranges; therefore, an animal
might experience a temporary loss of hearing sensitivity only between
the frequencies of 1 and 10 kHz, for example. The amount of change in
hearing sensitivity is also variable and could be reduced by 6 dB or 30
dB, for example. Recent literature highlights the inherent complexity
of predicting TTS onset in marine mammals, as well as the importance of
considering exposure duration when assessing potential impacts (Mooney
et al., 2009a, 2009b; Kastak et al., 2007). Generally, with sound
exposures of equal energy, quieter sounds (lower SPL) of longer
duration were found to induce TTS onset more than louder sounds (higher
SPL) of shorter duration (more similar to subbotom profilers). For
sound exposures at or somewhat above the TTS-onset threshold, hearing
sensitivity recovers rapidly after exposure to the sound ends. Southall
et al. (2007) considers a 6 dB TTS (i.e., baseline thresholds are
elevated by 6 dB) to be a sufficient definition of TTS-onset. NMFS
considers TTS as Level B harassment that is mediated by physiological
effects on the auditory system; however, NMFS does not consider onset
TTS to be the lowest level at which Level B harassment may occur.
Behavioral Effects
Behavioral responses to sound are highly variable and context-
specific. An
[[Page 15049]]
animal's perception of and response to (in both nature and magnitude)
an acoustic event can be influenced by prior experience, perceived
proximity, bearing of the sound, familiarity of the sound, etc.
(Southall et al., 2007). If a marine mammal does react briefly to an
underwater sound by changing its behavior or moving a small distance,
the impacts of the change are unlikely to be significant to the
individual, let alone the stock or populations. However, if a sound
source displaces marine mammals from an important feeding or breeding
area for a prolonged period, impacts on individuals and populations
could be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007).
Based on the limited amount of pile driving and use of vibratory pile
driving, any impacts to marine mammal behavior from ORPC's pile driving
operations are expected to be temporary. Any disturbance to marine
mammals is likely to be in the form of temporary avoidance or
alteration of opportunistic foraging behavior near the pile driving
location.
Non-pulse Sounds
The studies that address responses of mid-frequency cetaceans (such
as Atlantic white-sided dolphins) to non-pulse sounds (like vibratory
pile driving) include data gathered both in the field and the
laboratory and related to several different sound sources (of varying
similarity to chirps) including: pingers, drilling playbacks, ship and
ice-breaking noise, vessel noise, acoustic harassment devices (AHDs),
acoustic deterrent devices (ADDs), mid-frequency active sonar, and non-
pulse bands and tones. While none of these studies are specific to
Atlantic white-sided dolphins, they include species with similar
auditory bandwidths. Southall et al. (2007) were unable to come to a
clear conclusion regarding the results of these studies. In some cases
animals in the field showed significant responses to received levels
between 90 and 120 dB, while in other cases these responses were not
seen in the 120 to 150 dB range. This disparity is likely due to
contextual variables beyond received level and species differences.
The studies that address responses of high-frequency cetaceans
(such as the harbor porpoise) to non-pulse sounds include data gathered
both in the field and the laboratory and related to several different
sound sources (of varying similarity to chirps), including: pingers,
AHDs, and various laboratory non-pulse sounds. All of these data were
collected from harbor porpoises. Southall et al. (2007) concluded that
the existing data indicate that harbor porpoises are likely sensitive
to a wide range of anthropogenic sounds at low received levels (around
90 to 120 dB), at least for initial exposures. All recorded exposures
above 140 dB induced profound and sustained avoidance behavior in wild
harbor porpoises (Southall et al., 2007). Rapid habituation was noted
in some but not all studies.
There are limited data available on the behavioral effects of non-
pulse noise on pinnipeds while underwater; however, field and captive
studies to date collectively suggest that pinnipeds do not react
strongly to exposures between 90 and 140 dB re: 1 [mu]Pa; no data exist
from exposures at higher levels.
Impulse Sounds
Southall et al. (2007) also addressed behavioral responses of
marine mammals to impulse sounds (like impact pile driving). The
studies that address the responses of mid-frequency cetaceans to
impulse sounds include data gathered both in the field and the
laboratory and related to several different sound sources (of varying
similarity to boomers), including: small explosives, airgun arrays,
pulse sequences, and natural and artificial pulses. The data show no
clear indication of increasing probability and severity of response
with increasing received level. Behavioral responses seem to vary
depending on species and stimuli. Data on behavioral responses of high-
frequency cetaceans to multiple pulses is not available. Although
individual elements of some non-pulse sources (such as pingers) could
be considered pulses, it is believed that some mammalian auditory
systems perceive them as non-pulse sounds (Southall et al., 2007).
The studies that address the responses of pinnipeds in water to
impulse sounds include data gathered in the field and related to
several different sources, including: small explosives, impact pile
driving, and airgun arrays. Quantitative data on reactions of pinnipeds
to impulse sounds is limited, but a general finding is that exposures
in the 150 to 180 dB range generally have limited potential to induce
avoidance behavior (Southall et al., 2007).
As discussed below, impacts to marine mammal reproduction are not
anticipated because there are no known pinniped rookeries within the
proposed project area and Cobscook Bay is not a known breeding ground
for cetaceans. Marine mammals may avoid the area around the hammer,
thereby reducing their exposure to elevated sound levels. NMFS expects
any impacts to marine mammal behavior to be temporary, Level B
harassment (for example, avoidance or alteration of behavior). ORPC
conservatively assumes 12 pile driving days may occur over the validity
of the IHA. Marine mammal injury or mortality is not likely, as the 180
dB isopleth (NMFS' Level A harassment threshold for cetaceans) for the
impact hammer is expected to be no more than a 100-m (328 ft) radius.
ORPC proposes to continuously monitor a 152-m (500-ft) area around the
sound source and cease all pile driving if a marine mammal is observed
nearing or within this 152-m (500-ft) isopleth.
Anticipated Effects on Habitat
No permanent detrimental impacts to marine mammal habitat are
expected to result from pile driving. Pile driving (resulting in
temporary ensonification) may impact prey species and marine mammals by
causing avoidance or abandonment of the area; however these impacts are
expected to be local and temporary. The benthic impact of the
foundation for this phase of the proposed project will be about 10 m\2\
(113 ft\2\) during pile placement. While the foundation frame will take
up a limited amount of space on the seafloor, there are no expected
adverse impacts to marine mammal habitat.
Mitigation Measures
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 adverse
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. There are no subsistence hunting
grounds within the action area and since the activity will not result
in marine mammal mortality, the availability of marine mammals for
subsistence uses will not be impacted. ORPC will implement the
following mitigation measures to minimize adverse impacts to marine
mammals:
Sound Attenuation Device
When using a diesel impact hammer to ``proof'' piles, ORPC will use
wooden sound absorption cushions and/or a bubble curtain to reduce
hydroacoustic sound levels and avoid the potential for marine mammal
injury. Based on previous studies, sound attenuation devices are
expected to reduce sound levels by at least 5 dB.
[[Page 15050]]
Exclusion Zone
The purpose of the proposed exclusion zone is to prevent Level A
harassment (injury) of any marine mammal species. Current NMFS practice
regarding exposure of marine mammals to anthropogenic sound is that in
order to avoid the potential for injury (PTS), cetaceans and pinnipeds
should not be exposed to impulsive sounds of 180 and 190 dB or above,
respectively. These levels are considered precautionary as it is likely
that more intense sounds would be required before injury would actually
occur (Southall et al., 2007). During all in-water impact pile driving,
ORPC will establish a preliminary marine mammal exclusion zone around
each pile to avoid exposure to sounds at or above 180 dB. The
preliminary exclusion zone will have a radius of 152 m (500 ft). This
encompasses the initial estimate of the 180 dB isopleth, where injury
could occur, plus a 52-m (171-ft) buffer zone. Once hydroacoustic
monitoring is conducted, the exclusion and buffer zone may be adjusted
accordingly so that marine mammals are not exposed to Level A
harassment sound pressure levels. The exclusion zone will be monitored
continuously during impact pile driving to ensure that no marine
mammals enter the area. Protected species observers (PSOs) will be
stationed on two observer boats, one 152 m (500 ft) upstream and one
152 m (500 ft) downstream of the installation site. One observer on
each vessel will survey the exclusion zone, while the second observer
will conduct behavioral monitoring outwards to a distance of 1 nmi.
Several floats anchored at 152 m (500 ft) and 305 m (1,000 ft) will be
located around the installation site to help identify when marine
mammals are entering or within the exclusion zone. An exclusion zone
for vibratory pile driving or installation of concrete piles is
unnecessary as source levels will not exceed the Level A harassment
threshold.
Pile Driving Shut Down and Delay Procedures
If a PSO sees a marine mammal within or approaching the exclusion
zone prior to start of impact pile driving, the observer will notify
the on-site project lead (or other authorized individual) who will then
be required to delay pile driving until the marine mammal has moved 305
m (1,000 ft) from the sound source or if the animal has not been
resighted within 30 minutes. If a marine mammal is sighted within or on
a path toward the 152-m (500-ft) exclusion zone during pile driving,
pile driving will cease until that animal has moved 305 m (1,000 ft)
and is on a path away from the exclusion zone or 30 minutes has lapsed
since the last sighting.
Soft-start Procedures
A ``soft-start'' technique will be used at the beginning of each
pile installation to allow any marine mammal that may be in the
immediate area to leave before the pile hammer reaches full energy. For
vibratory pile driving, the soft-start procedure requires contractors
to initiate noise from the vibratory hammer for 15 seconds at 40-60
percent reduced energy followed by a 1-minute waiting period. The
procedure will be repeated two additional times before full energy may
be achieved. For impact hammering, contractors will be required 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. Soft-start procedures will be conducted
any time hammering ceases for more than 30 minutes.
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 IHAs
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.
Hydroacoustic monitoring will be performed at the initial
installation of each pile driving method to ensure that the harassment
isopleths are not extending past the calculated distances described in
this notice and the proposed IHA (77 FR 2701, January 19, 2012) and to
assess the efficiency of the sound attenuation devices. ORPC will
designate two biologically-trained, on-site PSOs, approved in advance
by NMFS, to monitor the exclusion zone (preliminarily set at 152 m [500
ft]) for marine mammals 30 minutes before, during, and 30 minutes after
all impact pile driving activities and call for shut down if any marine
mammal is observed within or approaching the exclusion zone. These PSOs
will be positioned on two vessels, one anchored upstream and one
anchored downstream at 152 m (500 ft) on the edge of the exclusion
zone. One observer on each vessel will survey inwards toward the pile
driving site and the second observer will conduct behavioral monitoring
outwards to a distance of 1 nmi during all impact pile driving.
Additional PSOs will be stationed at the Level B harassment isopleth
(preliminarily set at 4,600 m [2.5 mi]) on at least three days of
vibratory pile driving to validate take estimates and evaluate the
behavioral impacts pile driving has on marine mammals out to the Level
B harassment isopleth.
PSOs will be provided with the equipment necessary to effectively
monitor for marine mammals (for example, high-quality binoculars,
compass, and range-finder as well as a digital SLR camera with
telephoto lens and video capability) in order to determine if animals
have entered into the exclusion zone or Level B harassment isopleth and
to record species, behaviors, and responses to pile driving. If
hydroacoustic monitoring indicates that threshold isopleths are greater
than originally calculated, ORPC will contact NMFS within 48 hours and
make the necessary adjustments. Likewise, if threshold isopleths are
actually less than originally calculated, downward adjustments may be
made to the exclusion and buffer zone. PSOs will submit a report to
NMFS within 90 days of completion of pile driving. The report will
include data from marine mammal sightings (such as date, time,
location, species, group size, and behavior), any observed reactions to
construction, distance to operating pile hammer, and construction
activities occurring at time of sighting and environmental data for the
period (wind speed and direction, Beaufort sea state, cloud cover, and
visibility).
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA,
such as an injury (Level A harassment), serious injury, or mortality,
ORPC will immediately cease the specified activities and immediately
report the incident to the Acting Chief of the Permits and Conservation
Division, Office of Protected Resources, NMFS, at 301-427-8401 and/or
by email to [email protected] and [email protected] and
the Northeast Regional Stranding Coordinator ([email protected]).
The report must include the following information:
Time, date, and location (latitude/longitude) of the
incident;
Name and type of vessel involved;
Vessel's speed during and leading up to the incident;
Description of the incident;
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Status of all sound source use in the 24 hrs preceding the
incident;
Water depth;
Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
Description of all marine mammal observations in the 24
hrs preceding the incident;
Species identification or description of the animal(s)
involved;
Fate of the animal(s); and
Photographs or video footage of the animal(s) (if
equipment is available).
Activities will not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS will work with ORPC to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. ORPC may not resume their
activities until notified by NMFS via letter, email, or telephone.
In the event that ORPC discovers an injured or dead marine mammal,
and the lead PSO determines that the cause of the injury or death is
unknown and the death is relatively recent (i.e., in less than a
moderate state of decomposition as described in the next paragraph),
ORPC will immediately report the incident to the Acting Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
at 301-427-8401, and/or by email to [email protected] and
[email protected] and the Northeast Regional Stranding
Coordinator at 978-281-9300 ([email protected]). The report must
include the same information identified in the paragraph above.
Activities may continue while NMFS reviews the circumstances of the
incident. NMFS will work with ORPC to determine whether modifications
in the activities are appropriate.
In the event that ORPC discovers an injured or dead marine mammal,
and the lead PSO determines that the injury or death is not associated
with or related to the activities authorized in the IHA (e.g.,
previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), ORPC will report the incident to
the Acting Chief of the Permits and Conservation Division, Office of
Protected Resources, NMFS, at 301-427-8401, and/or by email to
[email protected] and [email protected] and the NMFS
Northeast Stranding Hotline (866-755-6622) and/or by email to the
Northeast Regional Stranding Coordinator ([email protected]),
within 24 hrs of the discovery. ORPC will provide photographs or video
footage (if available) or other documentation of the stranded animal
sighting to NMFS and the Marine Mammal Stranding Network. Activities
may continue while NMFS reviews the circumstances of the incident.
Estimated Take by Incidental Harassment
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].
Based on the application and subsequent analysis, the impact of the
described pile driving activities, in conjunction with the required
mitigation and monitoring measures, may result in, at most, short-term
modification of behavior by small numbers of marine mammals within the
action area. Marine mammals may avoid the area or temporarily alter
their behavior at time of exposure. Current NMFS practice regarding
exposure of marine mammals to anthropogenic noise is that in order to
avoid the potential for injury (PTS), cetaceans and pinnipeds should
not be exposed to impulsive sounds of 180 and 190 dB or above,
respectively. This level is considered precautionary as it is likely
that more intense sounds would be required before injury would actually
occur (Southall et al., 2007). Potential for behavioral Level B
harassment is considered to have occurred when marine mammals are
exposed to sounds at or above 160 dB for impulse sounds (such as impact
pile driving) and 120 dB for non-pulse noise (such as vibratory pile
driving). These levels are also considered precautionary.
Distances to NMFS' harassment thresholds were calculated based on
the expected sound levels at each source and the expected attenuation
rate of sound (see 77 FR 2701, January 19, 2012). The 100-m (328-ft)
distance to the Level A harassment threshold provides protected species
observers plenty of time and adequate visibility to prevent marine
mammals from entering the area during impact pile driving. This will
prevent marine mammals from being exposed to sound levels that reach
the Level A harassment threshold.
Based on ORPC's marine mammal monitoring records and the maximum
number of pile driving days, NMFS authorized the take by Level B
harassment of 72 total seals (because they cannot always be identified
to the species-level), 72 harbor porpoises, and two Atlantic white-
sided dolphins. These numbers are extremely conservative and indicate
the maximum number of animals expected to occur within the largest
Level B harassment isopleth 4,600 m (2.5 mi). For more detailed
information on how these numbers were calculated, see the notice of
proposed IHA (77 FR 2701, January 19, 2012).
Negligible Impact and Small Numbers 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.'' In making a negligible impact determination, NMFS considers
a number of factors which include, but are not limited to, the number
of anticipated injuries or mortalities (none of which would be
authorized here), number, nature, intensity, and duration of Level B
harassment, and the context in which takes occur.
As described above, marine mammals will not be exposed to
activities or sound levels which could result in injury (PTS), serious
injury, or mortality. Pile driving will occur in relatively shallow
coastal waters of Cobscook Bay. The project area is not considered
significant habitat for marine mammals. The closest significant
pinniped haul out is more than six nmi away, which is well outside the
project area's largest harassment zone. Marine mammals approaching the
action area will likely be traveling or opportunistically foraging. The
amount of take NMFS authorized, is considered small (less than one
percent) relative to the estimated populations of 91,000 harbor seals,
250,000 gray seals, 89,054 harbor porpoises, and 63,000 Atlantic white-
sided dolphins. Marine mammals may be temporarily impacted by pile
driving noise. However, marine mammals are expected to avoid the area,
thereby reducing exposure and impacts, and mitigation will prevent
injury. Pile driving activities are expected to occur for about 7-12
days total. There is no anticipated effect on annual rates of
recruitment or survival of affected marine mammals. Based on the
application and subsequent analysis, the impact of the described pile
driving operations may result in, at most, short-term modification of
behavior by small numbers of marine mammals within the action area.
Marine mammals may avoid
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the area or temporarily alter their behavior at time of exposure.
Based on the analysis contained in this notice, the proposed IHA
notice (77 FR 2701, January 19, 2012), and the IHA application, and
taking into consideration the implementation of the mitigation and
monitoring measures, NMFS has determined that ORPC's pile driving
activities will result in the incidental take of small numbers of
marine mammals, by Level B harassment only, and that the total taking
will have a negligible impact on the affected species or stocks.
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no relevant subsistence uses of marine mammals implicated
by this action.
Endangered Species Act (ESA)
No marine mammal species listed under the ESA are anticipated to
occur within the action area. Therefore, section 7 consultation under
the ESA is not required.
National Environmental Policy Act (NEPA)
In compliance with the National Environmental Policy Act of 1969
(42 U.S.C. 4321 et seq.), as implemented by the regulations published
by the Council on Environmental Quality (40 CFR parts 1500-1508), and
NOAA Administrative Order 216-6, NMFS prepared an Environmental
Assessment (EA) to consider the environmental impacts of issuance of a
1-year IHA and made a finding of no significant impact FONSI. The EA
and FONSI are available on the NMFS Web site listed in the beginning of
this document (see ADDRESSES).
Dated: March 8, 2012.
Helen M. Golde,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2012-6196 Filed 3-13-12; 8:45 am]
BILLING CODE 3510-22-P