61432 Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 

anticipated nor will any be authorized 

in the proposed IHA. 

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 found that pile driving 

conducted by Bluewater during MDCF 

installation will result in the incidental 

take of small numbers of marine 

mammals, by Level B harassment only, 

and that the total taking from will have 

a negligible impact on the affected 

species or stocks. Therefore, issuance of 

an IHA to Bluewater was warranted. 

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) 

NMFS Protected Resources 

determined that, based on the 

implementation of the monitoring and 

mitigation plan developed by 

Bluewater, in consultation with NMFS, 

is not likely to adversely affect listed 

marine mammal species. NMFS 

Northeast Region provided concurrence 

with this determination on September 

14, 2010. 

National Environmental Policy Act 

(NEPA) 

On June 2, 2009, the BOEM issued an 

EA and associated Finding of No 

Significant Impact (FONSI) on the 

Issuance of Leases for Wind Resource 

Data Collection on the Outer 

Continental Shelf Offshore Delaware 

and New Jersey. The EA evaluates the 

impacts to the human environment, 

including those to marine mammals, 

from issuing seven leases in the Atlantic 

OCS for purposes of constructing, 

operating, and decommissioning a 

MDCF in each lease block. The MDCFs 

proposed by Bluewater are included in 

that analysis. BOEM concluded that the 

proposed action would not have a 

significant adverse impact on the 

human environment. Therefore, 

preparation of an EIS was not necessary. 

After independently reviewing BOEM’s 

EA, NMFS determined the EA 

adequately evaluated impacts to marine 

mammals anticipated from issuance of 

the IHA. Accordingly, NMFS adopted 

BOEM’s EA and issued a FONSI. 

Therefore, the preparation of another EA 

by NMFS for issuance of an IHA to 

Bluewater for the specified activity was 

not warranted. 

Dated: September 29, 2010. 

Helen M. Golde, 

Deputy Director, Office of Protected 

Resources, National Marine Fisheries Service. 

[FR Doc. 2010–24987 Filed 10–4–10; 8:45 am] 

BILLING CODE 3510–22–S 

DEPARTMENT OF COMMERCE 

National Oceanic and Atmospheric 

Administration 

RIN 0648–XY30 

Takes of Marine Mammals Incidental to 

Specified Activities; Construction of 

the Parsons Slough Sill Project 

AGENCY: National Marine Fisheries 

Service (NMFS), National Oceanic and 

Atmospheric Administration (NOAA), 

Commerce. 

ACTION: Notice; proposed incidental 

harassment authorization; request for 

comments. 

SUMMARY: NMFS has received an 

application from the NOAA Restoration 

Center, Southwest Region, for an 

Incidental Harassment Authorization 

(IHA) to take marine mammals, by 

harassment, incidental to the Parsons 

Slough Sill Project. Pursuant to the 

Marine Mammal Protection Act 

(MMPA), NMFS is requesting comments 

on its proposal to issue an IHA to the 

NOAA Restoration Center, Southwest 

Region, to take, by Level B Harassment 

only, small numbers of harbor seals 

(Phoca vitulina richardsi) during the 

specified activity. 

DATES: Comments and information must 

be received no later than November 4, 

2010. 

ADDRESSES: Comments on the 

application should be addressed to 

Michael Payne, Chief, Permits, 

Conservation and Education Division, 

Office of Protected Resources, National 

Marine Fisheries Service, 1315 EastWest Highway, Silver Spring, MD 

20910. The mailbox address for 

providing e-mail comments is PR1.0648- 

XY30@noaa.gov. NMFS is not 

responsible for e-mail comments sent to 

addresses other than the one provided 

here. Comments sent via e-mail, 

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: 

Brian D. Hopper or Candace Nachman, 

Office of Protected Resources, NMFS, 

(301) 713–2289, or Monica DeAngelis, 

NMFS Southwest Region, (562) 980– 

3232. 

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 

engage in a specified activity (other than 

commercial fishing) within a specified 

geographical region if certain findings 

are made and either regulations are 

issued or, if the taking is limited to 

harassment, a notice of a proposed 

authorization is provided to the public 

for review. 

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 U.S. can apply for 

an authorization to incidentally take 

small numbers of marine mammals by 

harassment. Section 101(a)(5)(D) 

establishes a 45-day time limit for 

NMFS review of an application 

followed by a 30-day public notice and 

comment period on any proposed 

authorization published in the Federal 

Register for the incidental harassment of 

marine mammals. Within 45 days of the 

mstockstill on DSKH9S0YB1PROD with NOTICES

Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 61433 

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 

NMFS received an application on 

August 5, 2010, from the NOAA 

Restoration Center, Southwest Region, 

for the taking, by harassment, of marine 

mammals incidental to the construction 

of a partially submerged tidal barrier 

(sill) across the mouth of the Parsons 

Slough Channel. Parsons Slough is 

located on the southeast side of the 

Elkhorn Slough Estuary, which is 

situated 90 miles (145 km) south of San 

Francisco and 20 miles (32 km) north of 

Monterey in Monterey County, 

California. The application was 

determined to be complete on August 

16, 2010. The sill structure would be 

constructed of steel sheet piles and 

would extend 270 ft (82.3 m) across the 

mouth of Parsons Slough. The sheet pile 

wall would be supported on two rows 

of seven end-bearing piles. All sheet 

pile and end-bearing piles would be 

driven starting with a vibratory hammer 

to set the sheets but may require an 

impact hammer to complete driving. 

Because pile driving has the potential to 

expose marine mammals to heightened 

levels of underwater and ambient noise, 

it may result in behavioral harassment 

to marine mammals located in the 

action area. An authorization under 

section 101(a)(5)(D) of the MMPA is 

required. The proposed action will 

result in the incidental take, by Level B 

harassment, of Pacific harbor seals 

(Phoca vitulina richarsi). The specified 

activities are also likely to result in the 

take by incidental harassment of 

southern sea otters (Enhydra lutirs). The 

U.S. Fish and Wildlife Service (USFWS) 

has management jurisdiction over 

southern sea otters. NOAA has applied 

for and received from USFWS a separate 

MMPA Section 101(a)(5)(D) 

authorization for incidental take of sea 

otters. The potential take of sea otters is 

not further addressed in this notice. 

Description of the Specified Activity 

The proposed sill structure would be 

located in the vicinity of the Union 

Pacific Railroad bride, milepost 103.27 

Coast Subdivision, which is located at 

the mouth of the Parsons Slough 

Complex. The bridge is a 165 ft (50.3 m) 

long concrete slab girder bridge that 

spans the Parsons Slough Channel. The 

overall goal of the proposed action is to 

reduce tidal scour within the Elkhorn 

Slough action area in general and the 

Parsons Slough study area in particular. 

Within the past 60 years, the proportion 

of salt marsh habitat and mudflat habitat 

within the Elkhorn Slough has reversed 

as a result of tidal erosion and 

inundation of interior marsh areas. 

Currently, there are approximately 800 

acres (3.2 km2) of salt marsh and tidal 

creeks within Elkhorn Slough, 1,600 

acres (6.5 km2) of mudflat, and 300 

acres (1.2 km2) of tidal channels. 

Modeling efforts predict that an 

additional 550 acres (2.2 km2) of salt 

marsh would be lost over the next 50 

years if tidal erosion in Elkhorn Slough 

is not addressed. Without intervention, 

excessive erosion would continue to 

widen tidal channels and convert salt 

marsh to mud flat. This would result in 

a significant loss of habitat function and 

a decrease in estuarine biodiversity. 

In order to reduce tidal scour, the 

NOAA Restoration Center, Southwest 

Region, proposes to construct a partially 

submerged tidal barrier (sill), similar to 

an underwater wall, across the mouth of 

Parsons Slough. The sill structure 

would prevent head cutting (i.e., erosion 

in a channel caused by an abrupt change 

in slope) in Elkhorn Slough from 

migrating upstream into Parsons Slough, 

would retain sediment that accretes 

within Parsons Slough, and would 

reduce the tidal prism of Parsons 

Slough. This reduction in tidal prism 

would reduce current velocities 

between Parsons Slough and the mouth 

of Elkhorn Slough, thereby reducing 

tidal scour. The proposed project, which 

is referred to as the Parsons Slough 

Project, would also include 

establishment of artificial reefs to 

support populations of Olympia oysters 

(Ostrea lurida) in the northeastern part 

of the Parsons Slough Complex. 

As mentioned earlier in this 

document, the sill structure would be 

constructed of steel sheet piles that 

would extend 270 ft (82.3 m) across the 

mouth of the Parsons Slough Channel. 

A 100 ft (30 m) wide lower area, located 

in the center of the structure, would 

allow water to flow between Parsons 

Slough and Elkhorn Slough. This 

portion of the structure would be 

submerged more than 99 percent of the 

time. The center of the lower part of the 

structure would include a notch 

approximately 25 ft (7.6 m) wide, with 

the top elevation of the sheet pile in this 

notch at an elevation of ¥5 ft (¥1.5 m). 

The notch would provide for the 

passage of water at all tide levels and 

would facilitate the movement of fish 

and wildlife into and out of Parsons 

Slough. The top elevation of the sheet 

pile in the remaining 75 ft (23 m) of the 

central section of the base structure 

would be ¥2 ft (¥0.6 m). The 

remaining portions of the sheet piles to 

the left and right of the center portion 

of the structure would have a top 

elevation of 9.6 ft (3 m). 

All in-channel construction activities 

would be constructed from barges, and 

no heavy equipment would enter the 

channels. Most of these construction 

activities are in-water (e.g., installation 

of end-bearing piles and sheet piles, 

placement of rockfill buttress). 

Installation of the sheet pile wall 

would be supported by two rows of 

seven end-bearing piles, as well as a 

single row of sheet pile located between 

the piles. The end-bearing piles would 

be driven through the soft soils to 

penetrate 10 ft (3 m) below the top of 

the dense sandy deposits that underlie 

the soft soils at an elevation of 

approximately ¥80 ft (¥24.4 m). 

Additionally, up to 45 temporary endbearing piles may be installed in the 

main channel of Elkhorn Slough at the 

Kirby Park staging site (approximately 2 

mi (3.2 km) from the project site) to 

facilitate barge docking and loading (if 

the temporary dock is constructed on 

pilings, rather than temporary rock-fill). 

These piles, if necessary, would be 

removed after construction when the 

floating dock is disassembled. Pile 

driving at the staging site is not 

expected to result in any harbor seal 

takes. Harbor seals usually occur just 

beyond the mouth of Elkhorn Slough in 

the Moss Landing harbor and in the 

Salinas River channel south of the Moss 

Landing Bridge, and the lower portion 

of Elkhorn Slough extending up to 

Parsons Slough and Rubis Creek. Harbor 

seals do not typically use the part of the 

estuary that leads up to Kirby Creek and 

the nearest occupied areas and haul-out 

locations (approximately 2 mi (3.2 km) 

to the south) are beyond the estimated 

distances to NMFS’ current threshold 

sound levels from pile driving proposed 

at the Kirby Park staging area (see Table 

3 and Table 4). 

A vibratory hammer would be used to 

start driving all sheet pile and endbearing piles, but an impact hammer 

may be required to complete driving. If 

an impact hammer is required during 

construction, cushioning blocks would 

be used to attenuate the sound. 

Vibratory hammers clamp onto the sheet 

pile, therefore, no cushioning blocks 

mstockstill on DSKH9S0YB1PROD with NOTICES

61434 Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 

would be used during vibratory pile 

driving. 

TABLE 1—TYPICAL NEAR-SOURCE (10M) UNDERWATER NOISE LEVELS

Type of pile Driving technique RMS level 

H-Pile ......................................................................................... Impact Hammer ........................................................................ 183 dB 

H-Pile ......................................................................................... Vibratory Hammer .................................................................... 155 dB 

Sheet Pile .................................................................................. Impact Hammer ........................................................................ 175 dB 

Sheet Pile .................................................................................. Vibratory Hammer .................................................................... 160 dB 

TABLE 2—AIRBORNE NOISE NEVEL (15 M) 

Type of pile Driving technique Lmax/rms level 

H-Pile ......................................................................................... Impact Hammer ........................................................................ 109 dBA 

H-Pile ......................................................................................... Vibratory Hammer .................................................................... 95 dBA 

Sheet Pile .................................................................................. Impact Hammer ........................................................................ 106 dBA 

Sheet Pile .................................................................................. Vibratory Hammer .................................................................... 97 dBA 

The applicant anticipates that 

construction would last 11 to 15 weeks 

beginning around November 1, 2010 

and ending in February 2011. In-water 

construction would primarily occur 

during slack tide. Actual pile driving 

time during this work window will 

depend on a number of factors, such as 

sediments, currents, presence of marine 

mammals, and equipment maintenance; 

however, the applicant anticipates that 

it will take approximately 20 days to 

install the end-bearing piles and sheet 

pile during the 11 to 15 weeks of 

construction. Construction activities at 

night are also anticipated during this 11 

to 15 week period but would not last for 

more than 5 hrs at a time (duration of 

a slack tide at night). 

Description of Marine Mammals in the 

Area of the Specified Activity 

Two species of marine mammals may 

be affected by the proposed action: 

Pacific harbor seals and southern sea 

otters (Enhydra lutirs). However, 

southern sea otters are managed by the 

U.S. Fish and Wildlife Service and will 

not be considered further in this 

proposed IHA notice. 

Pacific Harbor Seals 

Harbor seals are the most widely 

distributed pinniped species, occurring 

on both sides of the northern Pacific and 

Atlantic Oceans (NMFS, 2005). The 

Pacific harbor seal ranges from Baja 

Mexico to the Aleutian Islands and 

occurs along the entire length of the 

California coast. In 2005, harbor seal 

populations in California were 

estimated at 34,233 and have been 

growing at an estimated rate of 3.5 

percent from 1982 to 1995 (NMFS, 

2005). Harbor seals are not listed as 

depleted under the MMPA or threatened 

or endangered under the Endangered 

Species Act (ESA). 

The harbor seal breeding season lasts 

from March through June each year, 

with peak births occurring between 

April and May. Females give birth to 

one pup each year and mate again 

shortly after weaning. Harbor seals are 

not territorial on land but they do 

maintain spacing between individuals 

in haul outs. 

Harbor seals feed on fish, crustaceans, 

and some cephalopods. Foraging occurs 

in shallow littoral waters, and common 

prey items include flounder, sole, hake, 

codfish, sculpin, anchovy, and herring. 

Harbor seals are typically solitary while 

foraging, although small groups have 

been observed. 

Harbor seals are rarely found in 

pelagic waters and typically stay within 

the tidal and intertidal zones. On land, 

harbor seals haul out on rocky outcrops, 

mudflats, sandbars, and sandy beaches 

with unrestricted access to water and 

with minimal human presence. Harbor 

seals are non-migratory, but will make 

short to moderate distance journeys for 

feeding and breeding, including 

venturing into estuaries and rivers 

(CDFG, 2005). 

Harbor seals use Elkhorn Slough for 

hauling out, resting, socializing, 

foraging, molting, and reproduction. 

Within the Parsons Slough Complex, 

there are an estimated 100 harbor seals 

using the area on a daily basis (Maldini 

et al., 2009). In Parsons Slough, harbor 

seals use exposed mudflats to haul-out 

during low tide. During high tide, 

harbor seals are absent from Parsons 

Slough (Maldini et al., 2009). There are 

five main haul-out areas within the 

Parsons Slough Complex, two of which 

are located east and west of the Union 

Pacific Railroad bridge, respectively 

(Maldini et al., 2009). Consistent with 

harbor seal behavior, abundance on the 

mudflats is highest during the day and 

drops after sunset. Harbor seal activity 

at night is unknown, but researchers 

speculate that the animals leave Parsons 

Slough at night to forage in the main 

channel or Monterey Bay (Maldini et al., 

2009). Maldini et al. (2009) found that 

exit times peaked at 5 pm and 

continued to be high until 8 pm with 

another smaller peak occurring around 

10 pm. Additional information on the 

Pacific harbor seal can be found in the 

NMFS Stock Assessment Report (SAR). 

The 2009 Pacific SAR is available at 

http://www.nmfs.noaa.gov/pr/pdfs/sars/ 

po2009.pdf. 

Potential Effects of the Specified 

Activity on Marine Mammals 

Sound is a physical phenomenon 

consisting of minute vibrations that 

travel through a medium, such as air or 

water. Sound levels are compared to a 

reference sound pressure to identify the 

medium. For air and water, these 

reference pressures are ‘‘re 20 microPa’’ 

and ‘‘re 1 microPa,’’ respectively. Sound 

is generally characterized by several 

variables, including frequency and 

sound level. 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. However, it should be 

noted that humans perceive a 10 dB 

increase in sound level as only a 

doubling of sound loudness, and a 10 

dB decrease in sound level as a halving 

of sound loudness. 

mstockstill on DSKH9S0YB1PROD with NOTICES

Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 61435 

Marine mammals use sound for vital 

life functions, and introducing sound 

into their environment could disrupt 

those behaviors. Sound (hearing and 

vocalization) serves four main functions 

for marine mammals. These functions 

include: (1) Providing information about 

their environment; (2) communication; 

(3) enabling remote detection of prey; 

and (4) enabling detection of predators. 

Noise from pile driving may affect 

marine mammals at a level which could 

cause Level B behavioral harassment by 

disturbing important behavioral patterns 

of Pacific harbor seals. The distances at 

which these sounds may be audible 

depend on the source levels, ambient 

noise levels, and sensitivity of the 

receptor (Richardson et al., 1995). 

Mitigation measures (see Proposed 

Mitigation section later in this 

document) and the low source level of 

vibratory pile driving (the main method 

used to install sheet pile and endbearing piles in this proposed project) 

are expected to prevent marine 

mammals from being exposed to 

injurious levels of sound. 

Pinnipeds produce a wide range of 

social signals, most occurring at 

relatively low frequencies (Southall et 

al., 2007), suggesting hearing is keenest 

at these frequencies. Pinnipeds 

communicate acoustically both on land 

and in the water, suggesting that they 

possess amphibious hearing and have 

different hearing capabilities dependent 

upon the media (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 in water than in air. 

In-water, pinnipeds can hear 

frequencies from 75 Hz to 75 kHz. In air, 

the lower limit remains at 75 Hz, but the 

highest audible frequencies are only 

around 30 kHz (Southall et al., 2007). 

Hearing Impairment 

Temporary or permanent hearing 

impairment is possible when marine 

mammals are exposed to very loud 

sounds. Hearing impairment is 

measured in two forms: Temporary 

threshold shift (TTS) and permanent 

threshold shift (PTS). Relationships 

between TTS and PTS have not been 

studied in marine mammals, but are 

assumed to be similar to those in 

humans and terrestrial mammals. There 

is no empirical data for onset of PTS in 

any marine mammal, therefore, PTSonset must be estimated from TTS-onset 

measurements and from the rate of TTS 

growth with increasing exposure levels 

above those eliciting TTS-onset. NMFS 

presumes PTS to be likely if the 

threshold is reduced by ≥ 40 dB (i.e., 40 

dB of TTS). Due to proposed mitigation 

measures and the fact that source levels 

of the impact and vibratory hammers are 

below the 190 dB injury threshold used 

by NMFS for pinniped species, NMFS 

does not expect that harbor seals will be 

exposed to levels that could elicit PTS; 

therefore, it will not be discussed 

further. 

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 (in cases of 

strong TTS) days. For sound exposures 

at or somewhat above the TTS-onset 

threshold, hearing sensitivity recovers 

rapidly after exposure to the noise ends. 

Few data on sound levels and durations 

necessary to elicit mild TTS have been 

obtained for marine mammals. Southall 

et al. (2007) considers a 6 dB TTS (i.e., 

baseline thresholds are elevated by 6 

dB) sufficient to be recognized as an 

unequivocal deviation and thus a 

sufficient definition of TTS-onset. 

Because it is non-injurious, NMFS 

considers TTS to be 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. 

Sound exposures that elicit TTS in 

pinnipeds underwater have been 

measured in harbor seals, California sea 

lions, and northern elephant seals from 

broadband or octaveband (OBN) nonpulse noise ranging from approximately 

12 minutes to several hours (Kastak and 

Schusterman, 1996; Finneran et al., 

2003; Kastak et al., 1999; Kastak et al., 

2005). Collectively, Kastak et al. (2005) 

analyzed these data to indicate that in 

the harbor seal a TTS of ca. 6 dB 

occurred with 25 minute exposure to 2.5 

kHz OBN with sound pressure level 

(SPL) of 152 dB re 1 microPa (as 

summarized in Southall et al., 2007). 

Underwater TTS experiments involving 

exposure to pulse noise are limited to a 

single study. Finneran et al. (2003) 

found no measurable TTS when two 

California sea lions were exposed to 

sounds up to 183 dB re 1 microPa (peakto-peak). 

Behavioral Impacts 

The source of underwater noise 

during construction would be pile 

driving to install the end-bearing piles 

and sheet pile tidal barrier. There are 

limited data available on the effects of 

non-pulse noise on pinnipeds in-water; 

however, field and captive studies to 

date collectively suggest that pinnipeds 

do not strongly react to exposure 

between 90–140 dB re 1 microPa. Jacobs 

and Terhune (2002) observed wild 

harbor seal reactions to acoustic 

harassment devices (AHDs) around nine 

sites. Seals came within 144.4 ft (44 m) 

of the active AHD and failed to 

demonstrate any behavioral response 

when received SPLs were estimated at 

120–130 dB re 1 microPa. In a captive 

study, a group of seals were collectively 

subjected to non-pulse sounds (e.g., 

vibratory pile driving) at 8–16 kHz 

(Kastelein, 2006). Exposures between 

80–107 dB re 1 microPa did not induce 

strong behavioral responses; however, a 

single observation at 100–110 dB re 1 

microPa indicated an avoidance 

response at this level. The group 

returned to baseline conditions 

following exposure (i.e., no long term 

impact). Southall et al. (2007) notes 

contextual differences between these 

two studies, noting that the captive 

animals were not reinforced with food 

for remaining in the noise fields, 

whereas free-ranging subjects may have 

been more tolerant of exposures because 

of motivation to return to a safe location 

or approach enclosures holding prey 

items. Southall et al. (2007) reviewed 

relevant data from studies involving 

pinnipeds exposed to pulse noise (e.g., 

impact pile driving) and concluded that 

exposures of 150 to 180 dB re 1 microPa 

generally have limited potential to 

induce avoidance behavior. 

Seals exposed to sound levels that 

exceed the Level B harassment 

threshold (120 dB for non-pulse; 160 dB 

for pulse) may exhibit temporary avoid 

behavior around the Union Pacific 

Railroad bridge, which may affect 

movement of seals under the bridge or 

inhibit them from resting at haul-out 

sites near the bridge. The estimated 11– 

15 weeks required for construction may 

result in the temporary abandonment of 

haul-out sites near the bridge and 

within Parsons Slough. Although harbor 

seals may temporarily abandon haul out 

sites, there are an abundance of other 

haul-out sites in the area. Additionally, 

the required mitigation measures restrict 

construction to the non-breeding season 

to avoid impacts to potentially sensitive 

mother-pup pairs. In general, ambient 

noise levels in the area are low; 

however, animals in the vicinity of the 

project site have been exposed to 

various types and levels of 

anthropogenic noise—from recreational 

boating, to the 15–20 trains that pass 

daily over the Union Pacific Railroad 

bridge. Harbor seals have also been 

exposed to in-water construction 

activities at the site and animals are 

likely tolerant or habituated to 

mstockstill on DSKH9S0YB1PROD with NOTICES

61436 Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 

anthropogenic disturbance, including 

pile driving. For example, in October 

2002, the Union Pacific Railroad 

replaced the existing wooden pile trestle 

bridge spanning the Parsons Slough 

Channel with a 165 ft (50.3 m) slab 

girder bridge. Biological monitors 

reported that harbor seals were present 

during construction and came and went 

from the site without any visible signs 

of stress or undue harassment (MACTEC 

Engineering and Consulting, 2003). 

Based on these studies and 

monitoring reports, NMFS has 

preliminarily determined that harbor 

seals exposed to sound levels exceeding 

the Level B harassment threshold (120 

dB for non-pulse; 160 dB for pulse) may 

exhibit temporary avoidance behavior. 

The most likely impact to harbor seals 

from the sheet pile and end-bearing pile 

installation would be temporary 

disruption of resting patterns because 

individual harbor seals may abandon 

haul out sites and leave the area during 

construction activities. However, the 

scheduling of construction activities 

during the non-breeding season will 

avoid more severe effects such as 

reduced pup survival due to motherpup separation and interrupted suckling 

bouts. Temporary hearing loss is 

unlikely for those harbor seals that enter 

into the zone of Level B harassment 

because source levels from vibratory 

pile driving are not loud enough to 

induce TTS. Furthermore, the short 

duration of impact pile driving and 

close proximity to the source necessary 

to induce TTS makes it unlikely that 

harbor seals would be exposed to source 

levels loud enough to induce TTS. 

Permanent hearing loss or other harm is 

not anticipated due to monitoring and 

mitigation efforts (described below) and 

the low source levels of pile driving 

hammers to be used in this proposed 

project; however, even without 

mitigation measures, it is unlikely that 

harbor seals would experience Level A 

harassment, serious injury or mortality 

because of the close proximity to the 

source necessary to induce these types 

of impacts and the avoidance behavior 

expected of harbor seals during pile 

driving activities. 

Anticipated Effects on Habitat 

The proposed action requires the 

placement of about 2,000 yd3 (1,529 m3) 

of fill (rock and sheet pile), which 

would result in the permanent loss of 

approximately 0.75 acres (3,035 m2) of 

subtidal habitat within the project 

footprint. The expected extent of direct 

habitat loss is equivalent to 

approximately 2.3 percent of the 

subtidal habitat area (32.9 acres (0.13 

km2)) present within Parsons Slough, 

and a fraction of the subtidal habitat 

within Elkhorn Slough (1,400 acres (5.7 

km2)). Although the proposed action 

would permanently alter habitat within 

the project footprint, harbor seals haulout in many locations throughout the 

estuary, and the proposed action is not 

expected to have any habitat-related 

effects that could cause significant or 

long-term consequences for individual 

harbor seals or their population. 

Long-term operation of the proposed 

sill is expected to result in the 

conversion of approximately 11 acres 

(0.04 km2) of intertidal mudflat habitat 

to subtidal habitat. The conversion of 

intertidal habitat to subtidal habitat will 

have no adverse effect and possibly a 

long-term beneficial effect on harbor 

seals by improving ecological function 

of the slough, such as higher species 

diversity, more species abundance, 

larger fish, and better habitat. Moreover, 

decrease of mudflat by up to 11 acres 

(0.04 km2) would not cause significant 

or long-term consequences for 

individual harbor seals or their 

population because harbor seals 

typically use a very small percentage of 

the potential haul-out sites that 

currently exist throughout the slough 

complex. Therefore, the proposed 

activity is not expected to have any 

habitat-related effects that could cause 

significant or long-term consequences 

for individual harbor seals or their 

population. 

It is unlikely that the sill structure 

itself, when completed, will result in 

long-term adverse effects on harbor seal 

movements through the slough because 

the sill structure allows for continued 

access to Parsons Slough by aquatic 

species, including harbor seals. A 25 ft 

(7.6 m) long section of the sill will be 

completely underwater with a minimum 

of 5 ft (1.5 m) of water above it at all 

times. On either side of this 25 ft (7.6 

m) section will be two 37 ft (11.3 m) 

sections that will be under 2 ft (.6 m) of 

water. The remaining 170 ft (51.8 m) of 

the sill structure will be above water. 

With respect to increased velocities, the 

current velocity of water flowing under 

the bridge is 5.6 ft (1.7 m) per second 

during ebbing tides and 4.9 ft (1.5 m) 

per second during flood tides (Moffat 

and Nichol, 2008). When completed, the 

sill structure will increase current 

velocities in the vicinity of the 

structure. The greatest turbulence would 

be during spring tides near low tide. For 

example, the applicant’s modeling 

results indicate that peak velocities at 

the sill during spring ebb tide would not 

exceed 10.7 ft (3.3 m) per second, which 

is much slower than the average wave 

velocities in Monterey Bay that harbor 

seals easily navigate on a daily basis. At 

¥5 ft (¥1.5 m) elevation, where 

velocities are anticipated to be higher, 

velocities on an ebb tide would be less 

than 5.6 ft (1.7 m) per second 

approximately 90 percent of the time; 

velocities would never exceed about 4.5 

ft (1.4 m) per second on a flood tide. 

The sill structure would not alter 

velocities during slack tide; therefore, 

conditions at optimal movement times 

would not change from the baseline 

conditions. During times of high 

velocity, the seals may avoid crossing 

the sill structure. The exception to this 

may be inexperienced mothers with 

young pups that could get swept into 

Parsons Slough. This would not injure 

pups, but it may result in pups staying 

in Parsons Slough longer than they 

would otherwise. Therefore, the 

proposed activity is not expected to 

have any habitat-related effects that 

could cause significant or long-term 

consequences for individual harbor 

seals or their population. 

Harbor seals and forage fish may 

occupy the same habitat and harbor seal 

distributions within the estuary reflect 

foraging locations to some extent. Noise 

from pile driving would result in 

degradation of in-water habitat; 

however, this impact would be short 

term and site-specific, and habitat 

conditions would return to their predisturbance state shortly after the 

cessation of in-water construction 

activities. In addition, research by 

Oxman (1995) and Harvey et al. (1995) 

comparing catch rates from trawls 

conducted in the Slough to species 

detected in seal scat found that seals 

primarily feed between Seal Bend and 

the oceanic nearshore shelf in Monterey 

Bay. Oxman (1995) also radio-tagged 

seals and found that they all spend their 

nights diving within 0.5 to 7 km of 

shore, most (88 percent) 1.25 km south 

of the Slough entrance, with the others 

(12 percent) either 4 km north at the 

Pajaro Rivermouth, or 7.25 km north at 

Sunset Beach, Santa Cruz. Therefore, 

because any habitat disturbance caused 

by pile driving will be short-term and 

site specific, and in light of the fact that 

harbor seals may conduct most foraging 

in the nearshore oceanic and not at the 

project site, NMFS does not expect the 

proposed action to have habitat-related 

effects on either forage fish populations 

or harbor seal foraging success that 

could cause long-term consequences for 

individual harbor seals or their 

population. 

Proposed Mitigation 

In order to issue an incidental take 

authorization (ITA) under Section 

101(a)(5)(D) of the MMPA, NMFS 

mustset forth the permissible methods 

mstockstill on DSKH9S0YB1PROD with NOTICES

Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 61437 

of taking pursuant to such activity, and 

other means of effecting the least 

practicable impact on such species or 

stock and its habitat, paying particular 

attention to rookeries, mating grounds, 

and areas of similar significance, and on 

the availability of such species or stock 

for taking for certain subsistence uses 

(where relevant). 

The applicant has proposed 

mitigation measures in their application 

for reducing impacts to environmental 

resources. For example, installing endbearing piles and sheet pile with a 

vibratory hammer instead of an impact 

hammer will introduce less sound into 

the marine environment and prevent 

marine mammals from being exposed to 

injurious levels of sound. Some of the 

following proposed mitigation measures 

that follow were developed by the 

NOAA Restoration Center, Southwest 

Region and accepted by NMFS while 

others were developed in discussions 

between the applicant and NMFS’ 

Office of Protected Resources. These 

proposed mitigation measures are 

designed to eliminate the potential for 

injury and reduce Level B harassment of 

marine mammals. 

Establishment of Safety Zones and Shut 

Down Requirements 

Vibratory pile driving does not result 

in source levels that are at or above 

NMFS’ harassment threshold for Level 

A harassment; therefore, shut down 

zones would not be required for 

vibratory pile driving. For impact pile 

driving, the isolpleth for the Level A 

harassment threshold (190 dB re 1 

microPa rms) is modeled to be within 10 

ft (3 m) of end-bearing piles driven with 

a impact hammer and 5 ft (1.5 m) of 

sheet piles driven with an impact 

hammer; The NOAA Restoration Center, 

Southwest Region, and NMFS, however, 

have proposed to delay impact pile 

driving if a harbor seal comes within 33 

ft (10 m) of the pile being driven, which 

further reduces the risk of Level A 

harassment. In addition, if an impact 

hammer is required during construction, 

cushioning blocks would be used to 

help attenuate the sound. 

Construction Timing 

Pile driving is anticipated to occur 

during an 11 to 15 week period 

beginning around November 1, 2010 

and ending in February 2011. This work 

window was selected to coincide with 

the non-pupping season for harbor seals 

and avoid haul-out site abandonment 

during pupping season that may result 

in reduced pup survival due to mother/ 

pup separation and interrupted suckling 

bouts. The work window also coincides 

with the U.S. Fish and Wildlife 

Department’s required construction 

work window to avoid the peak 

pupping period for sea otters (75 FR 

42121, July 20, 2010). In addition, inwater construction activities such as 

pile driving will be conducted during 

high tide when haul-out sites are 

inaccessible, and harbor seals are largely 

absent from Parsons Slough (Maldini et 

al., 2009). 

Limited Use of Impact Hammer 

All piles would be installed using a 

vibratory pile driver unless sufficient 

depth cannot be reached, at which point 

an impact hammer may be used. If an 

impact hammer is required, cushioning 

blocks would be used as an attenuation 

device to reduce hydroacoustic sound 

levels and avoid the potential for injury. 

These actions would also serve to 

reduce impacts to harbor seals. 

Mitigation Monitoring 

Monitoring during construction of the 

sill would occur from an observation 

post adjacent to the Union Pacific 

railroad bridge as well as from a zodiac. 

Monitoring would be conducted by 

qualified, NMFS approved protected 

species observers (PSOs). On a daily 

basis, construction monitoring would 

begin 30 minutes prior to the initiation 

of construction activities and continue 

until 30 minutes after construction 

activities have ceased for the day. The 

PSO would maintain a log that 

documents numbers of marine 

mammals present before, during, and at 

the end of daily construction activities. 

In addition, the PSO would record basic 

weather conditions (ambient 

temperature, tidal activity, 

precipitation, wind, horizontal 

visibility, etc.), as well as marine 

mammal behavior. 

The PSO would have the authority to 

cease construction if a harbor seal is 

detected within or approaching the 

safety zone or if an animal appears 

injured. Within 30 days of the 

completion of the sill construction, a 

report would be completed and 

submitted to NMFS that would include 

a summary of the daily log maintained 

by the PSO during construction. In 

addition, the report would include an 

assessment of the number of harbor 

seals that may have been harassed as a 

result of pile driving activities, based on 

direct observation of harbor seals 

observed in the area. 

Soft Start to Pile Driving Activities 

A ‘‘soft start’’ technique would be used 

at the beginning of each pile installation 

to allow any harbor seals that may be in 

the immediate area to leave before the 

activity reaches its full energy. The soft 

start requires contractors to initiate pile 

driving with a vibratory hammer for 15 

seconds at reduced energy followed by 

a 1-minute waiting period. This 

procedure would be repeated two 

additional times. Due to the short 

duration of impact pile driving 

(typically lasting between 1 and 10 

minutes), the traditional ramp-up 

requirement does not apply because it 

would actually increase the duration of 

noise emitted into the environment, and 

monitoring should effectively detect 

harbor seals within or near the proposed 

impact pile driving shut down zone. If 

any harbor seals are sighted within or 

approaching the 33 ft (10 m) shut down 

zone prior to pile driving, the 

construction contractor will delay piledriving until the animal has moved 

outside and is on a path away from the 

safety zone or after 15 minutes have 

elapsed since the last sighting. 

NMFS has carefully evaluated the 

applicant’s proposed mitigation 

measures. NMFS accepted some of the 

applicant’s proposed measures, such as 

the seasonal timing of construction, 

suggested additional mitigation 

measures like the establishment of a 33 

ft (10 m) safety zone and hydroacoutic 

monitoring to measure sound pressure 

levels from pile driving, and considered 

a range of other measures in the context 

of ensuring that NMFS prescribes the 

means of effecting the least practicable 

impact on the affected marine mammal 

species and stocks and their habitat. Our 

evaluation of potential measures 

included consideration of the following 

factors in relation to one another: (1) 

The manner in which, and the degree to 

which, the successful implementation of 

the measure is expected to minimize 

adverse impacts to marine mammals; (2) 

the proven or likely efficacy of the 

specific measure to minimize adverse 

impacts as planned; and (3) the 

practicability of the measure for 

applicant implementation, including 

consideration of personal safety, and 

practicality of implementation. 

Based on our evaluation of the 

applicant’s proposed measures, as well 

as other measures developed by NMFS 

in cooperation with the applicant, 

NMFS has preliminarily determined 

that the proposed mitigation measures 

provide the means of effecting the least 

practicable impact on marine mammal 

species or stocks and their habitat, 

paying particular attention to rookeries, 

mating grounds, and areas of similar 

significance. 

Proposed Monitoring and Reporting 

In order to issue an ITA for an 

activity, Section 101(a)(5)(D) of the 

MMPA states that NMFS must, where 

mstockstill on DSKH9S0YB1PROD with NOTICES

61438 Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 

applicable, 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 

ITAs must include the suggested means 

of accomplishing the necessary 

monitoring and reporting that will result 

in increased knowledge of the species 

and of the level of taking or impacts on 

populations of marine mammals that are 

expected to be present in the proposed 

action area. 

Monitoring during construction of the 

sill would occur from an observation 

post adjacent to the Union Pacific 

railroad bridge as well as from a zodiac. 

Monitoring would be conducted by 

qualified, NMFS approved PSOs. On a 

daily basis, construction monitoring 

would begin 30 minutes prior to the 

initiation of construction activities and 

continue until 30 minutes after 

construction activities have ceased for 

the day. The PSO would maintain a log 

that documents numbers of marine 

mammals present before, during, and at 

the end of daily construction activities. 

In addition, the PSO would record basic 

weather conditions (ambient 

temperature, tidal activity, 

precipitation, wind, horizontal 

visibility, etc.), as well as marine 

mammal behavior. 

The PSO would have the authority to 

cease construction if a harbor seal is 

detected within or approaching the 

safety zone or if an animal appears 

injured. Within 30 days of the 

completion of the sill construction, a 

report would be completed and 

submitted to NMFS that would include 

a summary of the daily log maintained 

by the PSO during construction. In 

addition, the report would include an 

assessment of the number of harbor 

seals that may have been harassed as a 

result of pile driving activities, based on 

direct observation of harbor seals 

observed in the area. 

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 stock in the wild by causing 

disruption of behavioral patterns, 

including but not limited to, migration, 

breathing, nursing, breeding, feeding, or 

shelter [Level B harassment]. 

Based on the NOAA Restoration 

Center, Southwest Region’s 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 harbor seals within the 

action area. Harbor seals may avoid the 

area or halt any behaviors (e.g., resting) 

when exposed to anthropogenic noise. 

Due to the abundance of suitable resting 

habitat available in the greater Elkhorn 

Slough estuary, the short-term 

displacement of resting harbor seals is 

not expected to affect the overall fitness 

of any individual animal. 

Current NMFS practice regarding inwater exposure of marine mammals to 

anthropogenic noise is that in order to 

avoid the potential for injury of marine 

mammals (e.g., PTS), pinnipeds should 

not be exposed to impulsive sounds of 

190 dB rms or above. 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 harassment (Level B) is 

considered to have occurred when 

marine mammals are exposed to sounds 

at or above 160 dB rms for impulse 

sounds (e.g., impact pile driving) and 

120 dB rms for non-pulse noise (e.g., 

vibratory pile driving), but below the 

thresholds mentioned above. These 

levels are considered to be 

precautionary. 

Current NMFS practice regarding inair exposure of pinnipeds to noise 

generated from human activity is that 

the onset of Level B harassment for 

harbor seals is 90 dB rms re 20 microPa. 

In-air noise calculations from using an 

impact pile driver predict that noise 

levels will reach 90 dB rms re 20 

microPa within 600 ft (183 m) for endbearing piles and 450 ft (137 m) for 

sheet piles. For installation using a 

vibratory hammer, noise levels will 

reach 90 dB rms within 100 ft (30 m) of 

the end-bearing pile and 120 ft (36.6 m) 

for sheet pile. Harbor seals are known to 

haul-out on the mudflats 200 ft (61 m) 

east of the work site and 680 ft (207 m) 

west of the work site, therefore, in-air 

noise may contribute to harassment for 

the proposed action. 

Estimated distances to NMFS’ current 

threshold sound levels from pile driving 

during the Parsons Slough Sill Project 

are presented in Table 3. These 

estimates are based on the worst case 

scenario of driving the H-piles and sheet 

piles but would be carried over for all 

pile driving. Note that despite short 

distances to the Level A harassment 

isolpleth, the NOAA Restoration Center, 

Southwest Region, has proposed to 

implement a 10 m safety zone until 

empirical pile driving measurements 

can be made and distances to this 

threshold isopleths can be verified. 

TABLE 3—UNDERWATER DISTANCES TO NMFS HARASSMENT THRESHOLD LEVELS DURING PILE DRIVING

[dB re: 1μPa rms] 

Pile type Hammer type 

Sound levels (rms) 

190 dB 160 dB 120 dB 

H–Piles .............................. Impact ............................... 3 m (10 ft) ......................... 227 m (745 ft) ................... n/a 

H–Piles .............................. Vibratory ............................ 0 ........................................ n/a ..................................... 1,140 m (3,740 ft) 

Sheet Pile .......................... Impact ............................... 1.5 m (5 ft) ........................ 75 m (245 ft) ..................... n/a 

Sheet Pile .......................... Vibratory ............................ 0 ........................................ n/a ..................................... 2,256 m (7,400 ft) 

mstockstill on DSKH9S0YB1PROD with NOTICES

Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 61439 

TABLE 4—AIRBORNE DISTANCES TO

NMFS HARASSMENT THRESHOLD

LEVELS DURING PILE DRIVING

[dB re: 20μPa rms] 

Pile type Hammer type 

Sound level 

(rms) 

90 dB 

H–Piles ......... Impact ........... 600 m 

H–Piles ......... Vibratory ....... 100 m 

Sheet Pile ..... Impact ........... 450 m 

Sheet Pile ..... Vibratory ....... 120 m 

It is difficult to estimate the number 

of harbor seals that could be affected by 

the installation of end-bearing piles and 

sheet pile because the animals only 

venture in the project areas to haul-out 

during the day when the tide is low. Inwater construction will occur near 

several haul-out sites and, although the 

construction activities are planned to 

take place during slack tide (some of 

which will be on either side of high 

tide, when harbor seals are less likely to 

be present), there may still be animals 

exposed to sound from pile driving even 

if the number of individual harbor seals 

expected to be encountered is very low. 

These individuals would mostly likely 

be adult males and females as well as 

juveniles. The NOAA Restoration 

Center, Southwest Region requests, and 

NMFS proposes, authorization to take 

2,000 individual harbor seals incidental 

to pile driving activities over the course 

of the proposed action (November 1, 

2010 through February 28, 2011). This 

is a estimate based on the average 

number of harbor seals that occupy 

Parsons Slough during the day (100) 

multiplied by the total number of days 

the applicant expects pile driving 

activities to occur (20 days). NMFS 

considers this to be an over-estimate for 

the following reasons: (1) As mentioned 

above, haul-out sites are inaccessible to 

harbor seals during high tide and NMFS 

would not expect harbor seals to be 

affected by pile driving activities during 

the days/times when pile driving and 

high tide events co-occur; (2) harbor 

seals are likely absent from Parsons 

Slough at night when they are likely 

foraging in Monterey Bay and will not 

be exposed to sound generated during 

pile driving that is proposed to take 

place in the evening hours (no more 

than 5 hrs at a time); and, (3) based on 

previous survey effort conducted in 

Parsons Slough, harbor seals would 

move out of the disturbance area when 

construction activities are initiated and 

move west (downstream) towards Seal 

Bend until the end of construction. 

Negligible Impact and Small Numbers 

Analysis and Preliminary 

Determination 

The regulations implementing the 

MMPA found at 50 CFR 216.103 define 

‘‘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 

variety of factors, including but not 

limited to: (1) The number of 

anticipated mortalities (none of which 

would be authorized here); (2) the 

number and nature of anticipated 

injuries (none of which would be 

authorized here); and (3) the number, 

nature, and duration of Level B 

harassment, and the context in which 

the takes occur (e.g., will the takes occur 

in an area or time of significance for 

harbor seals, are takes occurring to a 

small, localized population?). 

As described above, harbor seals 

would not be exposed to activities or 

sound levels which would result in 

injury (e.g., PTS), serious injury, or 

mortality. Takes will be limited to Level 

B behavioral harassment. Pile driving 

would take place in the relatively 

shallow estuarine waters of Elkhorn 

Slough and affect harbor seals that 

belong to a stock that occurs throughout 

California. Although two harbor seal 

haul-outs are located within 300–400 ft 

of the action area (waters around the 

Union Pacific Railroad bridge), the 

Parsons Slough Complex is not 

considered to be an important habitat 

for harbor seals compared to other sites 

in the area (e.g. Seal Bend). NMFS has 

preliminarily determined that no 

injuries or mortalities are anticipated to 

occur as a result of the proposed action, 

and none are proposed to be authorized. 

In addition, harbor seals in the area are 

not expected to incur hearing 

impairment (i.e., TTS or PTS) or nonauditory physiological effects. Although 

it is possible for some individual harbor 

seals to be exposed to sounds from pile 

driving activities more than once, the 

extent of these multi-exposures are 

expected to be limited by the constant 

movement of harbor seals in and out of 

Elkhorn Slough and the timing of inwater construction to coincide with 

periods when the animals are less likely 

to be present. 

As previously mentioned Pacific 

harbor seals are not listed as depleted 

under the MMPA or threatened or 

endangered under the Endangered 

Species Act (ESA). Although 

populations of Pacific harbor seals were 

greatly depleted by the end of the 19th 

century due to commercial hunting, the 

population has increased dramatically 

during the last half of the 20th century 

and appears to be stabilizing at what 

may be their carrying capacity (Caretta 

et al., 2009). The amount of take the 

NOAA Restoration Center, Southwest 

Region, has requested, and NMFS 

proposes to authorize is considered 

small (less than 6 percent) relative to the 

estimated population of 34,233 Pacific 

harbor seals. 

Pacific harbor seals may be 

temporarily impacted by pile driving 

noise. However, these animals are 

expected to avoid the area, thereby 

reducing exposure and impacts. In 

addition, although the sill project is 

expected to take 11 to 15 weeks to 

complete, the installation of end-bearing 

piles and sheet pile would only occur 

for approximately 20 days. Further, the 

Union Pacific Railroad bridge that is 

located in the vicinity of the project site 

has approximately 15–20 trains passing 

over it each day and harbor seals haulout on the mud flats located on either 

side of the bridge. As mentioned earlier, 

during a previous project at this site 

involving pile driving, harbor seals were 

observed to be present during 

construction and reportedly entered and 

exited the area without any visible signs 

of stress or undue harassment (MACTEC 

Engineering and Consulting 2003). 

Therefore, animals are likely tolerant or 

habituated to anthropogenic 

disturbance, including pile driving. 

Finally, breeding and pupping occur 

outside of the proposed work window; 

therefore, no disruption to reproductive 

behavior is anticipated. There is no 

anticipated effect on annual rates of 

recruitment or survival of the affect 

harbor seal population. 

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 the 

Parsons Slough sill project will result in 

the incidental take of small numbers of 

marine mammals, by Level B 

harassment only, and that the total 

taking from the Parsons Slough project 

will have a negligible impact on the 

affected species or stocks. 

Impact on Availability of Affected 

Species or Stock for Taking for 

Subsistence Uses 

There are no relevant subsistence uses 

of marine mammals implicated by this 

action. 

mstockstill on DSKH9S0YB1PROD with NOTICES

61440 Federal Register / Vol. 75, No. 192 / Tuesday, October 5, 2010 / Notices 

Endangered Species Act (ESA) 

No ESA-listed species under NMFS’ 

jurisdiction are expected to be affected 

by these activities. Therefore, NMFS has 

determined that a section 7 consultation 

for issuance of the proposed IHA under 

the ESA is not required. 

National Environmental Policy Act 

(NEPA) 

Pursuant to NEPA, the general 

impacts associated with the design and 

construction phases of the proposed 

action are described in the CommunityBased Restoration Program (CRP) 

Programmatic Environmental 

Assessment (PEA) and the 

Supplemental Programmatic 

Environmental Assessment (SPEA), 

which were prepared by the NOAA 

Restoration Center, Southwest Region. 

The NOAA Restoration Center, 

Southwest Region, will complete a 

Targeted Supplemental Environmental 

Assessment (TSEA) to include all 

project-specific impacts not described in 

the CRP PEA/SPEA. If it is adequate, 

NMFS will consider adopting it. If not, 

NMFS would prepare an independent 

EA. A copy of NOAA’s EA can be 

obtained by going to the NMFS Web site 

listed in the beginning of this document. 

This analysis will be completed prior to 

the issuance or denial of this proposed 

IHA. The public is invited to provide 

comments on the potential effects to 

marine mammals disclosed in this 

notice as well as NOAA’s EA. NMFS 

will consider public comments as it 

completes its NEPA analysis and 

decides whether or not to prepare a 

Finding of No Significant Impact should 

NMFS decide to issue a final IHA. 

Proposed Authorization 

As a result of these preliminary 

determinations, NMFS proposes to 

authorize the take of marine mammals 

incidental to the Parsons Slough project, 

provided the previously mentioned 

mitigation, monitoring, and reporting 

requirements are incorporated. 

Dated: September 29, 2010. 

Helen M. Golde, 

Deputy Director, Office of Protected 

Resources, National Marine Fisheries Service. 

[FR Doc. 2010–24986 Filed 10–4–10; 8:45 am] 

BILLING CODE 3510–22–P 

CONSUMER PRODUCT SAFETY 

COMMISSION 

Sunshine Act Meetings 

TIME AND DATE: Wednesday, October 6, 

2010; 10 a.m.–11 a.m. 

PLACE: Hearing Room 420, Bethesda 

Towers, 4330 East West Highway, 

Bethesda, Maryland. 

STATUS: Closed to the Public. 

Matter To Be Considered 

Compliance Status Report 

The Commission staff will brief the 

Commission on the status of compliance 

matters. For a recorded message 

containing the latest agenda 

information, call (301) 504–7948. 

FOR MORE INFORMATION CONTACT: Todd 

A. Stevenson, Office of the Secretary, 

U.S. Consumer Product Safety 

Commission, 4330 East West Highway, 

Bethesda, MD 20814, (301) 504–7923. 

Dated: September 29, 2010. 

Todd A. Stevenson, 

Secretary. 

[FR Doc. 2010–25174 Filed 10–1–10; 4:15 pm] 

BILLING CODE 6355–01–P 

DEPARTMENT OF DEFENSE 

Office of the Secretary 

[Transmittal Nos. 10–47, 10–48, and 10–51] 

36(b)(1) Arms Sales Notifications 

AGENCY: Defense Security Cooperation 

Agency, DoD. 

ACTION: Notice. 

SUMMARY: The Department of Defense is 

publishing the unclassified text of three 

section 36(b)(1) arms sales notifications 

to fulfill the requirements of section 155 

of Public Law 104–164, dated 21 July 

1996. 

FOR FURTHER INFORMATION CONTACT: Ms. 

B. English, DSCA/DBO/CFM, (703) 601– 

3740. 

SUPPLEMENTARY INFORMATION: The 

following are copies of letters to the 

Speaker of the House of Representatives, 

Transmittals 10–20, 10–23, and 10–42 

with associated attachments. 

Dated: September 29, 2010. 

Mitchell S. Bryman, 

Alternate OSD Federal Register Liaison 

Officer, Department of Defense. 

Transmittal No. 10–47 

The following is a copy of a letter to 

the Speaker of the House of 

Representatives, Transmittal 10–47 with 

attached transmittal and policy 

justification. 

BILLING CODE 5001–06–P 

mstockstill on DSKH9S0YB1PROD with NOTICES