[Federal Register Volume 77, Number 12 (Thursday, January 19, 2012)]
[Notices]
[Pages 2701-2708]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-991]


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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; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS has received an application from Ocean Renewable Power 
Company Maine, LLC (ORPC) for an Incidental Harassment Authorization 
(IHA) to take marine mammals, by harassment, incidental to pile driving 
in Cobscook Bay, Maine. Pursuant to the Marine Mammal Protection Act 
(MMPA), NMFS is proposing to issue an IHA to incidentally harass, by 
Level B harassment, four species of marine mammals during the specified 
activity within a specific geographic region and is requesting comments 
on its proposal.

DATES: Comments and information must be received no later than February 
21, 2012.

ADDRESSES: Comments on the application and this proposal should be 
addressed to Michael Payne, Chief, Permits and Conservation Division, 
Office of Protected Resources, National Marine Fisheries Service, 1315 
East-West Highway, Silver Spring, MD 20910. The mailbox address for 
providing email comments is [email protected]. NMFS is not 
responsible for email comments sent to addresses other than the one 
provided here. Comments sent via email, including all attachments, must 
not exceed a 10-megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information 
(for example, name, address, etc.) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    A copy of the application containing a list of the references used 
in this document may be obtained by writing to the address specified 
above, telephoning the contact listed below (see FOR FURTHER 
INFORMATION CONTACT), or visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited in this 
notice may also 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 United States citizens who 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 citizens of the United States can

[[Page 2702]]

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. Upon receipt of additional information and a 
revised application, NMFS determined the application complete and 
adequate on January 7, 2011.
    ORPC plans to build, deploy, monitor, and test a single-device 
tidal turbine as the first phase of a long-term project with the 
ultimate goal of generating and delivering electricity to an on-shore 
location in Lubec, Maine and connecting to the Bangor Hydro Electric 
Company power grid. The long-term project would be carried out in two 
separate phases over an expected 8-year pilot license term. Because 
elevated sound levels from pile driving during the first phase of the 
project have the potential to result in marine mammal harassment, NMFS 
is proposing to issue an IHA for take incidental to pile driving 
activities.

Description of the Specified Activity

    ORPC proposes to install foundational piles to support an 
underwater tidal turbine unit. The turbine unit is approximately 98 
feet (ft) long, 17 ft high, and 17 ft wide and is attached to a bottom 
support frame, which holds the unit in place about 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 TidGenTM 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 TidGenTM Power System is a pile 
bent arrangement consisting of ten steel pipe piles. Each foundation 
pile would have a 30-inch (in) diameter and a half-inch wall thickness 
and would rest on bedrock. Piles would vary in length from 15-18 m (50-
60 ft) due to bottom sediment depth, but each pile would be driven to 
the top of bedrock and would 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) would be driven from a moored barge 
for the first phase. Piles would be placed about six m (20 ft) apart in 
two rows of five and the rows would be separated by about 15 m (50 ft). 
Geotechnical data shows that the TidGenTM device would be 
located in an area with up to 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 would 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 would also be installed with the same pile driving 
equipment. The monitoring pile would be two m (six ft) in diameter, or 
an array of three piles not greater than 30 in in diameter. The 
monitoring pile would protrude about six m (20 ft) above the seafloor. 
The two-m diameter pile would sit about two m below the mud line while 
the array of smaller diameter piles would be driven to bedrock.
    ORPC would 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 would be 
used, with maximum rated impact energy of 21,533 ft-lb. ORPC expects 
that the need for an impact hammer would be minimal and for very short 
durations. To lessen the amount and intensity of sound propagation, 
ORPC would evaluate the use of wooden sound absorption cushions and/or 
bubble curtains.

Date and Duration of Proposed Activity

    ORPC plans to begin pile driving on March 1, 2012. Pile driving 
with a vibratory hammer would take up to 3 minutes per pile and pile 
driving with an impact hammer would take up to 5 minutes per pile. Due 
to strong currents during ebb and flood tides, pile driving would occur 
during slack tides only. ORPC expects that only one pile would be 
driven per slack tide period, for a total of 7-12 days of pile driving 
during daylight hours only. Pile driving could occur for up to 90 
minutes per slack tide, with the potential for two slack tide pile 
driving sessions per day. NMFS Northeast Regional Office 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 would issue the IHA for a 1-year 
period to allow for permitting and weather delays. Pile driving would 
only occur in weather that provides adequate visibility for marine 
mammal monitoring activities.

Region of Proposed Activity

    The proposed activity would occur in Cobscook Bay, in between Lubec 
and Eastport, Maine. Piles and other deployment materials would 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

    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 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

[[Page 2703]]

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) isopleth for the 
impact hammer could be as far as 100 m (328 ft). Based on similar 
estimates, the 160-dB (Level B) isopleth for the impact hammer could be 
about 1,800 m (5,906 ft) The 120-dB (Level B for continuous sound 
sources) isopleth for the vibratory hammer could be as far as 4,600 m 
(2.5 mi).

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 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 2). 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 not likely to occur in Cobscook Bay and 
are generally associated with open ocean habitats and offshore 
locations. NMFS has concluded that the specified activity will not 
impact these five species and they are not discussed further.

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                                                             Harbor and grey                     Atlantic white-
                  Month                    Hours of effort        seal         Harbor 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
                                         -----------------------------------------------------------------------
    Total...............................             1,008                57                47                 2
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Harbor Seals

    Harbor seals are typically found in temperate coastal habitats and 
use rocks, reefs, beaches, and drifting glacial ice as haul outs and 
pupping sites. On the east coast, they range from the Canadian Arctic 
to southern New England, New York, and occasionally the Carolinas. 
There are an estimated 91,000 harbor seals in the western North 
Atlantic stock and the population is increasing. Harbor seals are not 
listed under the Endangered Species Act (ESA) nor considered depleted 
under the MMPA. More information, including stock assessment reports, 
can be found at: http://www.nmfs.noaa.gov/pr/species/mammals/pinnipeds/harborseal.htm. The only species-specific data for Cobscook Bay is from 
ORPC's 2007-2010 marine mammal observations.

Gray Seals

    Gray seals reside in coastal waters and also inhabit islands, 
sandbars, ice shelves, and icebergs. The western North Atlantic stock 
ranges from eastern Canada to the northeastern United States. Current 
population numbers for the western North Atlantic stocks are unknown, 
but are estimated at over 250,000 animals. Most recent population 
estimates show increases in abundance in Canada and the United States, 
although the population in the Gulf of St. Lawrence appears to be 
declining. Gray seals pup at two established colonies off the coast of 
Maine: Green Island and Seal Island. Both colonies are tens of miles 
away from the proposed project site. Gray seals are not listed under 
the ESA nor considered depleted under the MMPA. More information, 
including stock assessment reports, can be found at http://ww.nmfs.noaa.gov/pr/sepcies/mammals/pinnipeds/grayseal.htm. The only 
species-specific data for Cobscook Bay is from ORPC's 2007-2010 marine 
mammal observations.
    Pinnipeds produce a wide range of social signals, most occurring at 
relatively low frequencies (Southall et al., 2007), suggesting that 
hearing is keenest at these frequencies. Pinnipeds communicate 
acoustically both on land and underwater, but have different hearing 
capabilities dependent upon the medium (air or water). Based on 
numerous studies, as summarized in Southall et al. (2007), pinnipeds 
are more sensitive to a broader range of sound frequencies underwater 
than in air. Underwater, pinnipeds can hear frequencies from 75 Hz to 
75 kHz. In air, pinnipeds can hear frequencies from 75 Hz to 30 kHz 
(Southall et al., 2007).

Harbor Porpoises

    Harbor porpoises reside in northern temperate and subarctic coastal 
and offshore waters. They are commonly found in bays, estuaries, 
harbors, and fjords less than 200 m (650 ft) deep. In the western North 
Atlantic, harbor porpoises range from west Greenland to

[[Page 2704]]

Cape Hatteras, North Carolina. Harbor porpoises in United States waters 
are divided into 10 stocks, based on genetics, movement patterns, and 
management. Any harbor porpoises encountered during the proposed 
project would be part of the Gulf of Maine-Bay of Fundy stock, which 
has an estimated abundance of 89,054 animals. Population trends for all 
U.S. stocks of harbor porpoises are currently unknown. Gulf of Maine-
Bay of Fundy harbor porpoises are not listed under the ESA nor 
considered depleted under the MMPA. More information, including stock 
assessment reports, can be found at: http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/harborporpoise.htm. The only species-specific 
data for Cobscook Bay is from ORPC's 2007-2010 marine mammal 
observations.
    Cetaceans are divided into three functional hearing groups: low-
frequency, mid-frequency, and high-frequency. Harbor porpoises are 
considered high-frequency cetaceans and the estimated auditory 
bandwidth (lower to upper frequency hearing cut-off) for this group 
ranges from 200 Hz to 180 kHz.

Atlantic White-Sided Dolphins

    Atlantic white-sided dolphins are only found in temperate waters of 
the North Atlantic Ocean and typically reside along the continental 
shelf and slope. They range from Greenland to North Carolina and 
exhibit seasonal movements between inshore northern waters and southern 
offshore waters. The western North Atlantic stock has an estimated 
63,000 animals, but there is insufficient information to determine 
population trends. Atlantic white-sided dolphins are not listed under 
the ESA nor considered depleted under the MMPA. More information, 
including stock assessment reports, can be found at: http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/whitesideddolphin_atlantic.htm. The only species-specific data for Cobscook Bay is from 
ORPC's 2007-2010 marine mammal observations.
    Atlantic white-sided dolphins, like harbor porpoises, are 
considered mid-frequency cetaceans and their estimated auditory 
bandwidth ranges from 150 Hz to 160 kHz.

Potential Effects on Marine Mammals

    Elevated in-water sound levels from pile driving in the proposed 
project area may temporarily impact marine mammal behavior. Elevated 
in-air sound levels are not a concern because the nearest significant 
pinniped haul-out is more than six nautical miles (NM) away. 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 either as temporary threshold shift (TTS) or permanent 
threshold shift (PTS). There are no empirical data for at what received 
level PTS occurs in marine mammals; therefore, it must be estimated 
from at what received levels the onset of TTS occurs and 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 
received sound levels associated with PTS.

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 subbottom 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 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. 
Southall et al. (2007) summarizes underwater pinniped data from Kastak 
et al. (2005), indicating that a tested harbor seal showed a TTS of 
around 6 dB when exposed to a nonpulse noise at sound pressure level 
152 dB re: 1 [mu]Pa for 25 minutes. Some studies suggest that harbor 
porpoises may be more sensitive to sound than other odontocetes (Lucket 
et al., 2009; Kastelein et al., 2011). However, while TTS onset may 
occur in harbor porpoises at lower received levels (when compared to 
other odontocetes), NMFS' 160-dB threshold criteria are based on the 
onset of behavioral harassment, not the onset of TTS. There is no 
information on TTS for Atlantic white-sided dolphins or gray seals 
specifically; published data on the onset of TTS are limited to the 
captive bottlenose dolphin and beluga (Finneran et al., 2000, 2002b, 
2005a; Schlundt et al., 2000; Nachtigall et al., 2003, 2004).

Behavioral Disturbance

    Behavioral responses to sound are highly variable and context-
specific. An 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

[[Page 2705]]

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). In order to estimate 
the number of takes by Level B harassment, as defined by the MMPA, it 
is common practice to estimate how many mammals would be present within 
a particular distance of activities and/or exposed to a particular 
level of sound. Additional analyses that include a consideration of the 
context of the exposures and other factors are then employed to 
determine what subset of the takes would likely affect a marine mammal 
in some biologically-important manner.

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. Southall et al. (2007) conclude that the results 
of these studies do not clearly indicate at what received levels marine 
mammals are likely to be disturbed by these types of sources. 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. The disparity in results was 
likely due to contextual variation and the differences between the 
results in the field and laboratory data (animals typically responded 
at lower levels in the field).
    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. Jacobs and Terhune (2002) observed 
wild harbor seal reactions to high-frequency acoustic harassment 
devices around nine sites. Seals came within 44 m of the active 
acoustic harassment devices and failed to demonstrate any behavioral 
response when received SPLs were estimated at 120-130 dB. In a captive 
study (Kastelein, 2006), scientists subjected a group of seals to non-
pulse sounds between 8 and 16 kHz. Exposures between 80 and 107 dB did 
not induce strong behavioral responses; however, a single observation 
from 100 to 110 dB indicated an avoidance response. The seals returned 
to baseline conditions shortly following exposure. Southall et al. 
(2007) notes contextual differences between these two studies; the 
captive animals were not reinforced with food for remaining in the 
noise fields, whereas free-ranging animals may have been more tolerant 
of exposures because of motivation to return to a safe location or 
approach enclosures holding prey items.

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).
    No impacts to marine mammal reproduction are anticipated because 
there are no known pinniped rookeries within the proposed project area 
and Cobscook Bay is not a known breeding ground for cetaceans. 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 the proposed project. Disturbance in the water 
column would be limited to the area of each pile. Turbidity resulting 
from pile driving activity would be limited because pile driving would 
only occur at slack tide and the seafloor geology in the proposed 
action area is predominantly gravel and cobbles. 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 would 
be about 113 ft\2\ during pile placement, including disturbance from 
pile driving equipment. 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.

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable adverse 
impact on such species or stock and its habitat, paying particular 
attention to rookeries, mating

[[Page 2706]]

grounds, and areas of similar significance, and on the availability of 
such species or stock for taking for certain subsistence uses.
    ORPC proposed the following mitigation measures to minimize adverse 
impacts to marine mammals:

Sound Attenuation Device

    When using a diesel impact hammer to ``proof'' piles, ORPC would 
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.

Exclusion Zone

    The purpose of the proposed exclusion zone is to prevent Level A 
harassment (injury) of any marine mammal species. During all in-water 
impact pile driving, ORPC would establish a preliminary marine mammal 
exclusion zone around each pile to avoid exposure to sounds at or above 
180 dB. The preliminary exclusion zone would 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. The buffer 
zone would be established to account for the initial lack of in-water 
acoustic measurements. Once hydroacoustic monitoring is conducted, the 
exclusion zone may be adjusted upward accordingly to ensure that marine 
mammals are not exposed to Level A harassment sound pressure levels. 
The exclusion zone would be monitored continuously during impact pile 
driving to ensure that no marine mammals enter the area. Protected 
species observers (PSOs) would be stationed on two observer boats, one 
152 m (500 ft) upstream and one 500 ft downstream of the installation 
site. One observer on each vessel would survey the exclusion zone, 
while the second observer would conduct behavioral monitoring outwards 
to a distance of 1 nm. Several floats anchored at 152 m (500 ft) and 
305 m (1,000 ft) would 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 would 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 would notify 
the on-site project lead (or other authorized individual) who would 
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 would 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 would 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 would be repeated two additional times before full energy may 
be achieved. For impact hammering, contractors would 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 would be conducted 
any time hammering ceases for more than 30 minutes.

Proposed 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 would 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 to assess the efficiency of the sound attenuation 
devices. ORPC would 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 would 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 
would survey inwards toward the pile driving site and the second 
observer would conduct behavioral monitoring outwards to a distance of 
1 nm during all impact pile driving. In addition, PSOs would be 
stationed at the Level B harassment isopleth 4,600 m (2.5 mi) during at 
least three events of vibratory pile driving to conduct behavioral 
monitoring. Additional PSOs would 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.
    Protected species observers would 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 would 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 zone. Protected species 
observers would be required to submit a report to NMFS within 90 days 
of completion of pile driving. The report would 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 
(if issued), such as an injury (Level A harassment), serious injury, or 
mortality, ORPC would immediately cease the specified activities and 
immediately report the incident to the Chief of the Permits and

[[Page 2707]]

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;
     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 would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would 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 would immediately report the incident to the 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 would 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 would report the incident to 
the 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 would 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].
    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 (Table 3). The 152-m (500-ft) distance to the exclusion 
zone provides protected species observers plenty of time and adequate 
visibility to prevent marine mammals from entering the area during 
impact pile driving. This would prevent marine mammals from being 
exposed to sound levels that reach the Level A harassment threshold.
    The estimated number of marine mammals potentially taken is based 
on ORPC's marine mammal monitoring observations between 2007 and 2010. 
NMFS is unaware of any other species-specific data for Cobscook Bay. 
Based on marine mammal sightings during that period, and the estimated 
number of pile driving days, ORPC requested authorization for the 
incidental take of four harbor and grey seals and two harbor porpoises. 
Based on further consultation with NMFS and further evaluation of 
ORPC's monitoring records between 2007 and 2010, NMFS is proposing to 
authorize the take of 72 total seals (because they cannot always be 
identified to the species-level), 72 harbor porpoises, and 12 Atlantic 
white-sided dolphins. The increase in proposed take is based on the 
maximum group size of animals observed during ORPC's marine mammal 
observations (i.e., six seals, five to six harbor porpoises, and one 
Atlantic white-sided dolphin) multiplied by the maximum expected number 
of pile driving days (i.e., 12). NMFS recognizes that ORPC's 2007-2010 
marine mammal observations may not have accounted for every animal in 
the area; however, NMFS believes that the above take estimates are 
extremely conservative considering the short duration of proposed pile 
driving and indicate the maximum number of animals expected to occur 
within the largest Level B harassment isopleth 4,600 m (2.5 mi).

Negligible Impact and Small Numbers Analysis and Determination

    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.'' 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 would not be exposed to 
activities or sound levels which would result in injury (PTS), serious 
injury, or mortality. Pile driving would occur in relatively shallow 
coastal waters of Cobscook Bay. The proposed project area is not 
considered significant habitat for marine mammals. The closest regular 
pinniped haul out is more than six NM away, which is well outside the

[[Page 2708]]

project area's largest harassment zone. Pinnipeds may occasionally haul 
out in areas closer to the proposed project, but not with any 
regularity. Marine mammals approaching the action area would likely be 
traveling or opportunistically foraging. The amount of take NMFS 
proposes to authorize, 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 adversely impacted by pile 
driving noise. However, some marine mammals are expected to avoid the 
area when pile driving is occurring, thereby reducing exposure and 
impacts, and mitigation will further ensure that injury is unlikely to 
occur (although it would not be expected even in the absence of 
mitigation given the source levels, density of animals in the area, and 
short duration of the activities). Pile driving activities are expected 
to occur for about 7-12 days total (up to 180 minutes per day). 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 the area or temporarily alter their behavior at time of exposure.
    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 mitigation and monitoring 
measures, NMFS preliminarily determines that ORPC's proposed 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, no effects to listed species 
are expected and 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 is preparing an Environmental 
Assessment (EA) to consider the environmental impacts of issuance of a 
one-year IHA. Upon completion, this EA will be available on the NMFS 
Web site listed in the beginning of this document (see ADDRESSES).

    Dated: January 13, 2012.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2012-991 Filed 1-18-12; 8:45 am]
BILLING CODE 3510-22-P