Small Takes of Marine Mammals Incidental to Specified Activities; Pile Driving in Port Townsend Bay, WA, 39471-39485 [2012-16302]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 77, Number 128 (Tuesday, July 3, 2012)]
[Notices]
[Pages 39471-39485]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-16302]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XB041


Small Takes of Marine Mammals Incidental to Specified Activities; 
Pile Driving in Port Townsend Bay, WA

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 a complete and adequate application from the 
Washington State Department of Transportation/Ferries Division (WSF) 
for an Incidental Harassment Authorization (IHA) to take marine 
mammals, by harassment, incidental to pile driving during replacement 
of the Port Townsend Ferry Terminal Transfer Span. Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS proposes to issue an IHA to 
incidentally harass, by Level B harassment only, 11 species of marine 
mammals during the specified activity within a specific geographic area 
and requests comments on its proposal.

DATES: Comments and information must be received no later than August 
2, 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 20910-3225. The mailbox address 
for providing email comments is ITP.Hopper@noaa.gov. 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 https://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.
    An electronic 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: https://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, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who 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 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

    In August 2011, NMFS received an application from WSF, requesting 
an IHA for the take, by Level B harassment, of small numbers of harbor 
porpoises (Phocoena phocoena), Dall's porpoises (Phocoenoides dalli), 
Pacific white-sided dolphins (Lagenorhynchus obliquidens), killer 
whales (Orcinus orca), gray whales (Eschrichtius robustus), humpback 
whales (Megaptera novaeangliae), minke whales (Balaenoptera 
acutorostrata), Pacific harbor seals (Phoca vitulina richardii), 
California sea lions (Zalophus californianus), northern elephant seals 
(Mirounga angustirostris) and Steller sea lions (Eumatopius jubatus) 
incidental to pile driving activities conducted during the replacement 
of a transfer span at the Port Townsend ferry terminal, which is 
located inside Port Townsend Bay in northern Puget Sound (see Figure 1-
9 in the WSF IHA application). Upon receipt of additional information 
and a revised application (submitted October 2011), NMFS determined the 
application

[[Page 39472]]

complete and adequate on January 5, 2012.
    The applicant proposes to replace the current cable-lift transfer 
span at Slip 1 of the Port Townsend ferry terminal with a hydraulic 
lift H span (see Figure 1-3 in the WSF IHA application). The proposed 
project would include removal of the existing transfer span, lift 
towers, tower foundations, and a portion of the bridge seat and replace 
them with a new transfer span, bridge seat, and lift cylinder shafts. 
During the proposed project, up to 56 piles will be removed (40 timber 
and 16 steel), and require installation of up to 26 piles (16 steel, 8 
temporary H-piles, and 2 cylinder shaft casings). Because elevated 
sound levels from pile driving have the potential to result in marine 
mammal harassment, NMFS proposes to issue an IHA for take incidental to 
the specified activity.

Description of the Specified Activity

    The proposed project would replace an aging cable-lift transfer 
span with a new hydraulic lift span at the Port Townsend ferry terminal 
in northern Puget Sound, Washington. Transfer spans are moveable 
traffic bridges that connect ferries with the terminal dock, allowing 
the transfer span to be raised or lowered depending on the daily tide 
levels (see Figure 1-2 in WSF's IHA application). The new hydraulic 
lifts, or H-spans, would be operated vertically by two hydraulic 
cylinders located under the offshore ends of the transfer span. The 
proposed project would involve the removal of the existing transfer 
span, lift towers, tower foundations, and a portion of the bridge seat. 
Once the old structures are removed, they would be replaced with a new 
transfer span, bridge seat, and lift cylinder shafts (see Appendix A of 
the IHA application).
    To replace the aging transfer span, 40 timber piles and 16 steel 
piles (four 30-inch and four 24-inch wingwall steel piles, and eight 
temporary piles) will be removed using a vibratory hammer. The 
vibratory hammer will then be used to install up to 8 steel piles (five 
30-inch and up to three 24-inch), up to 8 temporary steel piles, up to 
8 piles for the new wingwall fender panels and reaction frames (up to 
four 24-inch and up to four 30-inch), and two 80-inch cylinder shafts 
that will house the hydraulic lifts. The use of an impact hammer will 
be limited to the ``proofing'' of five 30-inch piles and three 24-inch 
piles in order to drive them the last two feet into the substrate. A 
breakdown of pile types and associated activity are shown in Table 1.

                       Table 1--Summary of Total Pile Removal and Installation Activities
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                                                                       Total time to  remove/
                Activity                 Number of piles  (maximum)           install           Days to complete
----------------------------------------------------------------------------------------------------------------
Removal of timber piles................  40........................  10 hours.................                 2
Removal of steel wingwall piles........  16........................  4 hours..................                 4
Install steel piles....................  8 (5 30-inch and up to 3    2 hours 40 minutes.......                 3
                                          24-inch).
Install temporary piles................  8.........................  2 hours..................                 2
Install wingwall piles.................  8.........................  2 hours 40 minutes.......                 3
Install cylinder shaft casing..........  2 (80-inch)...............  40 minutes...............                 2
Proofing of steel piles................  8.........................  1 hour 20 minuntes.......                 2
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    Of the eight 24- and 30-inch steel piles, three 24-inch piles would 
be installed to support the platform for the new Hydraulic Power Unit 
(HPU) and five 30-inch piles would be installed for the new bridge 
seat. Up to eight temporary steel piles would be installed using a 
vibratory hammer to support a template for construction of the cylinder 
shafts. The vibratory hammer would then be used to install the two 80-
inch hollow steel cylinder shafts. The final eight 24- and 30-inch 
steel piles would be installed using a vibratory hammer for the new 
wingwall reaction frames and wingwall fender panels at the terminus of 
the transfer span.
    Although the exact duration of pile driving would vary depending on 
the installation procedures and geotechnical conditions, the applicant 
estimates that the 16 24-to 30-inch permanent piles would each require 
20 minutes of vibratory installation. Five 30-inch piles and up to 
three 24-inch piles would each require 10 minutes of impact driving or 
``proofing'' to verify capacity. The vibratory driving of eight 
temporary piles that support the template for the hydraulic cylinder 
shafts would each require 15 minutes to install because it would not be 
necessary to drive these piles as deep as the permanent piles. The two 
80-inch cylinder shaft casing would take approximately 20 minutes each 
to install using a vibratory hammer. All piles would be installed with 
an APE Model 400 (or equivalent) vibratory hammer; however, it will be 
necessary to proof the five 30-inch bridge seat piles and three 24-inch 
HPU support piles using an impact hammer. Proofing would require 10 
minutes of impact pile driving for each of these eight piles to verify 
load-bearing capcity. Sound attenuation devices, such as a bubble 
curtain, would be used during impact hammering. The wingwall temporary 
piles and the 80-inch cylinder shafts would be driven solely with a 
vibratory hammer.
    In addition to pile installation, a total of 56 piles would also be 
removed using vibratory extraction or a crane. These consist of the 16 
steel piles and 40 old timber piles. If a timber pile breaks below the 
mudline--something older timber piles are prone to do--pile stubs will 
be removed with a clamshell bucket, but noise associated with this 
activity is expected to be negligible. Once piles and fragments of 
piles are removed, they will be loaded onto a barge or container and 
disposed of at an approved offsite location. There could be barges in 
the water to support these pile removal activities; however, these 
would be concentrated in the direct vicinity of the ferry terminal. 
Because direct pull and clamshell pile removal, and use of barges do 
not release loud sounds into the environment, marine mammal harassment 
from these activities is not anticipated.

Region of Activity

    The proposed activity would occur at the Port Townsend ferry 
terminal located in northern Puget Sound inside Port Townsend Bay.

Dates and Duration of Activity

    The Washington Department of Fish and Wildlife's recommended in-
water work window for this area is July 16 through February 15. Timing 
restrictions such as this are used to avoid in-water work when ESA-
listed salmonid species are most likely to be present. Proposed pile 
installation and removal activities are scheduled to occur between 
December 2012 and February 15, 2013, in agreement with the state's 
recommendation. The on-site

[[Page 39473]]

work will last approximately 16 weeks with actual pile removal and 
driving activities taking place approximately 25 percent of that time 
(approximately 4 weeks).

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 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.
    Data from other Washington State Ferries projects were used for the 
noise analysis of vibratory removal of 12-inch timber piles as well as 
the vibratory removal and driving of 30-inch and 24-inch hollow steel 
piles (Laughlin, 2005; Laughlin, 2010; Laughlin, 2011). Due to the lack 
of information related to the vibratory driving of 80-inch hollow steel 
cylinder shafts, noise levels recorded for a project using similar 
equipment in Richmond, California were used to estimate sound levels 
(CalTrans, 2007). For impact pile driving, WSF relied on measurements 
for steel piles at other Puget Sound ferry terminal locations 
(Laughlin, 2005). Sound levels for impact and vibratory pile driving 
are shown in Table 2. Ambient underwater sound levels in the vicinity 
of Port Townsend were measured in April 2010 (Stockham et al., 2010). 
These data show that local background levels are below 120 dB (50th 
percentile between 100 and 104 dB), at least during April; therefore, 
the Level B harassment threshold for continuous sound sources (120 dB) 
was not adjusted for this location. WSF conducted a site specific 
vibratory test pile project in coordination with NMFS at the Port 
Townsend Ferry Terminal to determine the distances at which vibratory 
pile removal or driving attenuate down to the 120 dB threshold (i.e., 
the threshold level used to measure Level B harassment for continuous 
sounds). The site specific test allowed physical factors in Port 
Townsend Bay that can influence sound attenuation rates to be taken 
into account, such as absorption in seawater, absorption in the sub-
bottom, scattering from inhomogeneities (lack of uniformity) in the 
water column and from surface and bottom roughness and water depth 
(bathymetry). During the test, two hollow steel piles, one 36-inch and 
one 30-inch, were driven and removed using a vibratory hammer. An array 
of hydrophones measured in-water noise during the test project. 
Vibratory driving of the 36-inch steel pile generated 159 to 177 dB rms 
at 10 m, and vibratory driving of the 30-inch steel pile generated 164 
to 174 dB rms at 10 m. Vibratory removal of the 30-inch steel pile 
generated 171 dB rms at 10 m. Based on these results, the sound 
generated from vibratory installation and removal of 30-inch piles may 
take up to 4.2 miles (6.8 km) to attenuate to below 120 dB. Because of 
the project area's location on a river bend and across from Hayden 
Island, sound transmission will be stopped by land masses much earlier 
in certain directions. In-air sound from pile driving also has the 
potential to affect marine mammals. However, in-air sound is not a 
concern here because there are no pinniped haul-out sites near the 
project area.

                                                       Table 2--Distances to Harassment Thresholds
                                                                   [Vibratory hammer]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                   Sound levels (rms)
         Pile type and size                 Hammer type       ------------------------------------------------------------------------------------------
                                                                   190 dB          180 dB          160 dB                        120 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Timber (removal)....................  Vibratory..............             n/a             n/a             n/a  2.2 km (1.4 miles).
24-inch steel (removal).............  Vibratory..............             n/a             n/a             n/a  4 km (2.4 miles).
24-inch steel (install).............  Vibratory..............             n/a             n/a             n/a  6.3 km (3.9 miles).
30-inch steel (removal).............  Vibratory..............             n/a             n/a             n/a  18.5 km (15.6 miles).
30-inch steel (install).............  Vibratory..............             n/a             n/a             n/a  39.8 km (24.7 miles).
80-inch steel (install).............  Vibratory..............             n/a             n/a             n/a  50 km (31 miles).
--------------------------------------------------------------------------------------------------------------------------------------------------------


                         Table 3--Distances to Harassment Thresholds Without Mitigation
                                                 [Impact hammer]
----------------------------------------------------------------------------------------------------------------
                                                                          Sound levels (rms)
       Pile type and size            Hammer type    ------------------------------------------------------------
                                                            190 dB              180 dB              160 dB
----------------------------------------------------------------------------------------------------------------
30-inch steel..................  Impact............  5 m................  22 m..............  465 m.
----------------------------------------------------------------------------------------------------------------

Description of Marine Mammals in the Area of the Specified Activity

    Due to Port Townsend's location on the boundary between two inland 
water regions, 11 marine mammal species may occur at some time of year 
in the vicinity of the ferry terminal: Harbor porpoise, Dall's 
porpoise, Pacific white-sided dolphin, killer whale, gray whale, 
humpback whale, minke whale, Pacific harbor seal, California sea lion, 
northern elephant seal, and Steller sea lion.

[[Page 39474]]

Harbor Porpoise

    Harbor porpoise on the west coast are divided into two stocks: (1) 
The Washington Inland Waters Stock; and (2) the Oregon/Washington Coast 
Stock (Carretta et al., 2007b). Neither stock is listed as 
``endangered'' or ``threatened'' under the ESA or as ``depleted'' under 
the MMPA. The Washington Inland Waters Stock occurs in waters east of 
Cape Flattery (Strait of Juan de Fuca, San Juan Island Region, and 
Puget Sound) and has a mean abundance estimate of 10,682 (J. Laake, 
unpubl. data as cited in Carretta et al., 2007b). Abundance estimates 
of harbor porpoise for the Strait of Juan de Fuca and the San Juan 
Islands in 1991 were approximately 3,300 animals (Calambokidis et al., 
1993). Harbor porpoise were once considered common in southern Puget 
Sound (Scheffer and Slipp, 1948); however, there has been a significant 
decline in sightings within southern Puget Sound since the 1940s 
(Everitt et al., 1980, Calambokidis et al., 1985, 1992, Carretta et 
al., 2007b). They are found in coastal and inland waters of the eastern 
North Pacific Ocean from Point Barrow, Alaska, south to Point 
Conception, California (Gaskin, 1984). Although harbor porpoises have 
been spotted in deep water, they tend to remain in shallower shelf 
waters (<150 meters) where they are most often observed in small groups 
of 1 to 8 animals (Baird, 2003). Harbor porpoises are high-frequency 
cetaceans with an estimated auditory bandwidth of 200 Hz to 180 kHz 
(Southall et al., 2007) with a maximum sensitivity between 16 and 140 
kHz (73 FR 41318).

Dall's Porpoise

    Dall's porpoise occur in the North Pacific Ocean and is divided 
into two stocks: (1) California, Oregon, and Washington; and (2) Alaska 
(Carretta et al., 2007). Neither stock is listed as ``endangered'' or 
``threatened'' under the ESA or as ``depleted'' under the MMPA. The 
California, Oregon, and Washington stock mean abundance estimate of 
Dall's porpoises is 57,549 (Barlow, 2003; Forney, 2007). In 1994, 
Calambokidis and Baird (1994) estimated the Juan de Fuca population at 
3,015 animals and the San Juan Island population at about 133 animals. 
More recently, the segment of the population within Washington's inland 
waters was last assessed by aerial surveys in 1996 and estimated that 
900 animals annually inhabit Washington's inland waters (Calambokidis 
et al., 1997). During a ship line-transect survey conducted in 2005, 
Dall's porpoise was the most abundant cetacean species off the Oregon 
and Washington coast (Forney, 2007). Dall's porpoise are migratory and 
appear to have predictable seasonal movements associated with changes 
in oceanographic conditions (Green et al., 1992, 1993). This species is 
commonly found in shelf, slope, and offshore waters (Carretta et al., 
2007). Like harbor porpoises, Dall's porpoises are high-frequency 
cetaceans with an estimated auditory bandwidth of 200 Hz to 180 kHz 
(Southall et al., 2007).

Pacific White-Sided Dolphin

    Pacific white-sided dolphins are divided into northern and southern 
stocks comprising two discrete, non-contiguous areas: (1) Waters off 
California, Oregon, and Washington; and (2) Alaskan waters (Carretta et 
al., 2007). Neither stock is listed as ``endangered'' or ``threatened'' 
under the ESA or as ``depleted'' under the MMPA. The California, 
Oregon, and Washington stock mean abundance estimate is 25,233 Pacific 
white-sided dolphins (Forney, 2007). Surveys in Oregon and Washington 
coastal waters resulted in an estimated abundance of 7,645 animals 
(Forney, 2007). Fine-scale surveys in Olympic Coast slope waters and 
the Olympic Coast National Marine Sanctuary resulted in an estimated 
abundance of 1,196 and 1,432 animals, respectively (Forney, 2007), but 
there are no population estimates for Washington's inland waters. 
Aerial surveys conducted by Washington Department of Fish and Wildlife 
between 1992 and 2008 only reported a single group of three Pacific 
white-sided dolphins in the Strait of Juan de Fuca. Pacific white-sided 
dolphins are occasionally reported in the northernmost part of the 
Strait of Georgia and in western Strait of Juan de Fuca, but are 
generally only rarely seen in Puget Sound (Calambokidis and Baird, 
1994). Pacific white-sided dolphins have been documented primarily in 
deep, offshore areas (Green et al., 1992, 1993; Calambokidis et al., 
2004). Pacific white-sided dolphins are mid-frequency cetaceans with an 
estimated auditory bandwidth of 150 Hz to 160 kHz (Southall et al., 
2007).

Killer Whale

    Two distinct forms, or ecotypes, of killer whales--``residents'' 
and ``transients''--are found in the greater Puget Sound. These two 
ecotypes are different populations of killer whales that vary in 
morphology, ecology, behavior, and genetics. Although the range of 
transient and resident killer whales overlaps, the two ecotypes do not 
interact or interbreed with one another. Killer whales of both ecotypes 
are mid-frequency cetaceans (Southall et al., 2007) with an estimated 
auditory bandwidth of 50 Hz to 100 kHz and peak sensitivity around 15 
kHz (73 FR 41318, July 18, 2008).
    The ``resident'' population that could occur in the proposed 
project area is the Southern Resident killer whale (SRKW). This 
population contains three pods (or stable family-related groups)--J 
pod, K pod, and L pod--and is considered a stock under the MMPA. The 
Southern Resident killer whale population is currently estimated at 
about 86 whales (Center for Whale Research, 2011). In 2005, NMFS listed 
this population as endangered under the ESA (70 FR 69903, November 18, 
2005). This population is also listed as depleted under the MMPA. Their 
range during the spring, summer, and fall includes the inland waterways 
of Puget Sound, Strait of Juan de Fuca, and Southern Georgia Strait. 
Their occurrence in the coastal waters off Oregon, Washington, 
Vancouver Island, and more recently off the coast of central California 
in the south and off the Queen Charlotte Islands to the north has been 
documented. Little is known about the winter movements and range of the 
Southern Resident stock. Resident killer whales feed exclusively on 
fish such as salmon (Calambokidis and Baird, 1994).
    Southern resident killer whale presence is possible but unlikely in 
the proposed project area. Based on the sighting records kept by The 
Whale Museum in Friday Harbor, between 1990 and 2005 an average of 1.75 
killer whale group sightings were annually reported in the quadrant 
that includes Port Townsend. Most sightings (primarily J Pod) occurred 
between September and December, and March; therefore, encountering 
killer whales during the project work window is very low, although 
encountering a single group is possible.
    Transient killer whales occur throughout the eastern North Pacific, 
primarily in coastal waters. Individual transient killer whales have 
been documented as traveling great distances, reflecting a large home 
range. Pod structure is small (e.g., fewer than 10 whales) and dynamic 
in nature. Transient killer whales feed exclusively on other marine 
mammals such as dolphins, sea lions, and seals.
    The transient killer whale population that could occur in the 
proposed project area is the West Coast transient stock. This stock of 
killer whale is not designated as ``depleted'' under the MMPA nor is it 
listed under the ESA. It is a trans-boundary stock, which includes 
killer whales from British Columbia. In the proposed activity area,

[[Page 39475]]

small groups of one to five individuals are sighted intermittently 
throughout the year. Within inland water, transient killer whales may 
frequent areas near seal rookeries when pups are weaned (Baird and 
Dill, 1995).
    Preliminary analysis of photographic data results in a minimum of 
314 killer whales belonging to the West Coast transient stock (Angliss 
and Allen, 2009). This number is also considered the minimum population 
estimate of the population since no correction factor is available to 
provide a best estimate of the population. At present, reliable data on 
trends in population abundance for the West Coast transient stock of 
killer whales are unavailable (Angliss and Allen, 2009).

Gray Whale

    Gray whales migrate within 5 to 43 km of the Washington cast during 
their annual north/south migrations (Green et al., 1995). Small numbers 
of gray whales have been observed in Northern Puget Sound between the 
months of September and January, with peak numbers reported from March 
through May (J. Calambokidis pers. comm. 2007). The North Pacific gray 
whale stock is divided into two distinct geographically isolated 
stocks: Eastern and western (Rice et al., 1984; Angliss and Outlaw, 
2007). Individuals in the Pacific Northwest are part of the Eastern 
North Pacific stock. Population surveys estimate that the Eastern North 
Pacific stock is at or just below its carrying capacity (~26,000 
individuals) (Rugh et al., 1999; Calambokidis et al., 1994; Angliss and 
Outlaw, 2007). Abundance estimates calculated for the area between 
Oregon and southern Vancouver Island, including the San Juan Islands 
and Puget Sound, suggest there were 137 to 153 individual gray whales 
from 2001 through 2003 (Calambokidis et al., 2004). In 1994, the 
Eastern North Pacific stock of gray whales was removed from listing 
under the ESA and are no longer considered depleted under the MMPA 
(Angliss and Outlaw, 2007).

Humpback Whale

    Few humpback whales have been seen in Puget Sound, but more 
frequent sightings occur in the Strait of Juan de Fuca and near the San 
Juan Islands. These whales are members of the Eastern North Pacific 
stock, which is one of three distinct stocks of humpback whale 
recognized in the North Pacific. Recent estimates of the Eastern North 
Pacific stock indicate that the population is between 1,100 and 1,300 
individuals (Caretta et al., 2007; Calambokidis et al., 2008). 
Abundance estimates for Washington and southern British Columbia are 
less than 500 (Calambokidis et al., 2008). Humpback whales are listed 
as endangered under the ESA and the Eastern North Pacific stock is 
listed as depleted and strategic under the MMPA.

Minke Whale

    Worldwide, minke whales are one of the most abundant whales 
(Calambokidis and Baird, 1994). The northern minke whale is separated 
into two distinct subspecies: The Northern Pacific and the Northern 
Atlantic. Within U.S. waters, the North Pacific stock is divided into 
three separate stocks for management purposes: (1) The Alaskan stock; 
(2) the California/Oregon/Washington stock; and (3) the Hawaiian stock 
(NMFS, 2008). Minke whales within the inland Washington waters of Puget 
Sound and the San Juan Islands are part of the California/Oregon/
Washington stock (Dorsey et al., 1990; Carretta et al., 2007). The 
total population size for the entire North Pacific population is 
unknown (Calambokidis and Baird, 1994; Carretta et al., 2007). Some 
estimates indicate as many as 9,000 individuals in the North Pacific 
(Wade, 1976; Green et al., 1992), but this number is uncertain 
(Calambokidis and Baird, 1994). The number of minke whales in the 
California/Oregon/Washington stock is estimated between 500 and 1,015 
individuals (Barlow, 2003; Carretta et al., 2007; NMFS, 2008). Minke 
whales are not listed under the ESA nor considered depleted under the 
MMPA.
    Minke whales are reported in Washington inland waters year-round, 
although few are reported in the winter (Calambokidis and Baird, 1994). 
Minke whales are more common in the San Juan Islands and Strait of Juan 
de Fuca (especially around several of the banks in both the central and 
eastern Strait), but are relatively rare in Puget Sound. Infrequent 
observations occur in Puget Sound south of Admiralty Inlet (Orca 
Network, 2011). There have been no reported sightings of minke whales 
in Puget Sound in the months of December and January. Although the 
likelihood of encountering a minke whale is remote, based on the 
sighting records, it is possible that minke whales could occur in Port 
Townsend during the proposed work window.
    Like other baleen whales, gray whales, humpback whales, and minke 
whales are low-frequency cetaceans. Although no direct measurements of 
auditory capacity have been conducted for these large whales, hearing 
sensitivity has been estimated by Southall et al. (2007) from various 
studies or observations of behavioral responses, vocalization 
frequencies used most, body size, ambient noise levels, and cochlear 
morphometry (Southall et al., 2007). A generalized auditory bandwidth 
of 7 Hz to 22 kHz has been estimated for all baleen whales, including 
gray whales, humpback whales, and minke whales (Southall et al., 2007).

Pacific Harbor Seals

    Pacific harbor seals reside in coastal and estuarine waters off 
Baja, California, north to British Columbia, west through the Gulf of 
Alaska, and in the Bering Sea. Harbor seals in Puget Sound are part of 
the Oregon/Washington coastal stock. The most recent NMFS stock 
assessment report estimated this stock to be at least 22,380 
individuals and the population is likely at carrying capacity and no 
longer increasing (NMFS, 2007). The Oregon/Washington stock is not 
listed under the Endangered Species Act (ESA) nor considered depleted 
under the MMPA.
    Harbor seals are the most numerous marine mammal within the 
proposed action area. Harbor seals are non-migratory with local 
movements associated with such factors as tides, weather, season, food 
availability, and reproduction (Scheffer and Slipp, 1944; Fisher, 1952; 
Bigg, 1969, 1981). They are not known to make extensive pelagic 
migrations, although some long distance movement of tagged animals in 
Alaska (174 km) and along the U.S. west coast (up to 550 km) have been 
recorded (Pitcher and McAllister, 1981; Brown and Mate, 1983; Herder, 
1983).
    Harbor seals haul out on rocks, reefs, beaches, and drifting 
glacial ice and feed in marine, estuarine, and occasionally fresh 
waters. Harbor seals display strong fidelity for haulout sites (Pitcher 
and Calkins, 1979; Pitcher and McAllister, 1981). Within the region of 
activity, there are numerous harbor seal haulout sites located on 
intertidal rocks, reefs, and islands. Nearest known haulout sites to 
the ferry terminals and number of haulout sites within 5 miles of 
terminals are listed in Table 3-2 of the application.
    Group sizes range from small numbers of animals on intertidal rocks 
to several thousand animals found seasonally in coastal estuaries. 
Numerous haulouts in the region of activity have between 100 and 500 
individuals, while others have 100 or less (Jeffries et al., 2000) (see 
Figure 3-1 in the application).
    Pinniped hearing is measured for two mediums, air and water. In 
water hearing ranges from 1-180 kHz with peak sensitivity around 32kHz. 
In air, hearing capabilities are greatly reduced

[[Page 39476]]

to 1-22kHz with peak sensitivity at 12kHz. This in-air hearing range is 
comparable to human hearing (0.02 to 20 kHz). Harbor seals have the 
potential to be affected by in-air and in-water noise associated with 
construction activities.

California Sea Lions

    California sea lions reside throughout the Eastern North Pacific 
Ocean in shallow coastal and estuarine waters, ranging from Central 
Mexico to British Columbia, Canada. Their primary breeding range 
extends from Central Mexico to the Channel Islands in Southern 
California. The U.S. stock abundance is estimated at 238,000 sea lions 
(NMFS, 2007). This stock is approaching carrying capacity and is 
reaching ``optimum sustainable population'' limits, as defined by the 
MMPA. California sea lions are not listed under the ESA nor considered 
depleted under the MMPA. It is estimated that approximately 1,000 
California sea lions occur in Puget Sound (P. Gearin pers. comm. 2008).
    In Washington, California sea lions use haul-out sites within all 
inland water regions (Jeffries et al., 2000). The nearest California 
sea lion haul-out to the action area is a channel buoy (used by less 
than 10 animals) located off Bush Point 12.9 km southeast of the ferry 
terminal. The nearest large (100-500 animals) haul-out is located 42 km 
to the southeast at the Everett Harbor log boom. California sea lions 
may also be seen resting in the water (rafting) together in Puget Sound 
(Jeffries et al., 2000).

Northern Elephant Seals

    Northern elephant seals present in the proposed action area are 
considered part of the California breeding stock, which is considered 
an isolated population from the Mexican stock (Carretta et al., 2007a). 
Northern elephant seals are not listed as ``endangered'' or 
``threatened'' under the ESA nor as ``depleted'' under the MMPA. By 
2001, the California breeding stock was estimated at 101,000 
individuals based on pup counts (Carretta et al., 2007a; Carretta et 
al., 2002) Pup estimates in California indicate that the population of 
northern elephant seals in 2005 was 124,000 (Carretta et al., 2007b). 
Based on current trends and pup counts in California, the population of 
northern elephant seals appears to be stable (Carretta et al., 2007b). 
Current estimates indicate that the minimum population would be 74,193 
or twice the current pup count (Carretta et al., 2005). Abundance 
estimates for inland Washington waters are not available due to the 
infrequency of sightings and the low numbers encountered incidentally 
(Calambokidis pers. comm. 2008). Rough estimates suggest less than 100 
individuals (Jeffries pers. comm. 2008a).
    Inland Washington waters primarily in the Strait of Juan de Fuca 
are used by elephant seals to feed, haulout, and pup. Small numbers of 
juveniles haul out throughout this area for periods of over a month to 
molt (Calambokidis and Baird, 1994). Rat Island across the bay from the 
Port Townsend ferry terminal is occasionally used by juvenile elephant 
seals (Jeffries pers. comm. 2008a).
    Haulout areas are not as predictable as for the other species of 
pinnipeds found there. In recent years pups have been seen at beaches 
at Destruction, Protection, and Smith/Minor Islands in the Strait of 
Juan de Fuca (Jeffries et al., 2000). WDFW has identified seven haulout 
sites in inland Washington waters. There are regular haulout sites at 
Smith and Minor Islands, Dungeness Spit, Protection Island, and Race 
Rocks in the Strait of Juan de Fuca (Jeffries pers. comm. 2008a; Figure 
3-3 in the application). Typically these sites have only two to ten 
adult males and females, but pupping has been reported at all of these 
sites of the past ten years (Jeffries pers. comm. 2008a).

Steller Sea Lions

    Steller sea lions reside along the North Pacific Rim from northern 
Japan to California, with centers of abundance and distribution in the 
Gulf of Alaska and Aleutian Islands, respectively. Steller sea lions in 
Puget Sound are part of the eastern distinct population segment, which 
is listed as threatened under the ESA, but currently the subject of a 
proposed rule to delist (77 FR 23209, April 18, 2012), and designated 
as depleted under the MMPA. Based on pup counts conducted between 2002 
and 2005, the eastern stock of Steller sea lions is estimated to be 
between 48,519 and 54,989 individuals. The estimate for Washington, 
including the outer coast, is 651 individuals (non-pups only) (Pitcher 
et al., 2007).
    For Washington inland waters, Steller sea lion abundances vary 
seasonally with a minimum estimate of 1,000 to 2,000 individuals 
present or passing through the Strait of Juan de Fuca in fall and 
winter months (S. Jeffries pers. comm. 2008). However, the number of 
haul-out sites has increased in recent years and includes most 
navigation buoys in Admiralty Inlet, and the Craven Rock haul-out site 
east of Marrowstone Island, approximately 7 km southeast of the ferry 
terminal. There are no Steller sea lion rookeries in Washington.
    All pinniped species 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).

Potential Effects on Marine Mammals

    Impact and vibratory pile driving are the construction activities 
associated with the proposed action with the potential to take marine 
mammals. Elevated in-water sound levels from pile driving in the 
proposed project area may temporarily impact marine mammal behavior. 
However, elevated in-air sound levels are not expected to affect marine 
mammals because the nearest pinniped haul-out is approximately 3 km 
away.

Marine Mammals and Sound

    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 
also 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. Exposure to sound can affect marine mammal hearing or cause 
changes in behavior. When considering the influence of various kinds of 
sound on the marine environment, it is necessary to understand that 
different kinds of marine life are sensitive to different frequencies 
of sound. Based on available behavioral data, audiograms derived using 
auditory evoked potential techniques, anatomical modeling, and other 
data, Southall et al. (2007) designate functional hearing groups for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing of the groups. The functional groups and the 
associated frequencies are indicated below (though animals are less 
sensitive to sounds at the outer edge of their functional range and 
most sensitive to sounds of frequencies within a smaller range 
somewhere in

[[Page 39477]]

the middle of their functional hearing range):
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
22 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High frequency cetaceans (six species of true porpoises, 
four species of river dolphins, two members of the genus Kogia, and 
four dolphin species of the genus Cephalorhynchus): Functional hearing 
is estimated to occur between approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: Functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
    As mentioned previously in this document, four pinniped and seven 
cetacean species may occur in the proposed project area during the 
project timeframe. Harbor porpoise and Dall's porpoise are classified 
as high frequency cetaceans (Southall et al., 2007). Pacific white-
sided dolphin and killer whale are classified as mid frequency 
cetaceans (Southall et al., 2007). Gray whale, humpback whale, and 
minke whale are classified as low frequency cetaceans (Southall et al., 
2007).

Potential Effects of Pile Driving Sound

    The effects of sounds from pile driving might generally result in 
one or more of the following: Temporary or permanent hearing 
impairment, non-auditory physical or physiological effects, behavioral 
disturbance, and masking (Richardson et al., 1995; Gordon et al., 2004; 
Nowacek et al., 2007; Southall et al., 2007). The effects of pile 
driving on marine mammals are dependent on several factors, including 
the size, type, and depth of the animal; the depth, intensity, and 
duration of the pile driving sound; the depth of the water column; the 
substrate of the habitat; the standoff distance between the pile and 
the animal; and the sound propagation properties of the environment. 
Impacts to marine mammals from pile driving activities are expected to 
result primarily from acoustic pathways. As such, the degree of effect 
is intrinsically related to the received level and duration of the 
sound exposure, which are in turn influenced by the distance between 
the animal and the source. The further away from the source, the less 
intense the exposure should be. The substrate and depth of the habitat 
affect the sound propagation properties of the environment. Shallow 
environments are typically more structurally complex, which leads to 
rapid sound attenuation. In addition, substrates that are soft (e.g., 
sand) would absorb or attenuate the sound more readily than hard 
substrates (e.g., rock) which may reflect the acoustic wave. Soft 
porous substrates would also likely require less time to drive the 
pile, and possibly less forceful equipment, which would ultimately 
decrease the intensity of the acoustic source.
    In the absence of mitigation, impacts to marine species would be 
expected to result from physiological and behavioral responses to both 
the type and strength of the acoustic signature (Viada et al., 2008). 
The type and severity of behavioral impacts are more difficult to 
define due to limited studies addressing the behavioral effects of 
sound on marine mammals. Potential effects from impulsive sound sources 
can range in severity, ranging from effects such as behavioral 
disturbance, tactile perception, physical discomfort, slight injury of 
the internal organs and the auditory system, to mortality (Yelverton et 
al., 1973; O'Keefe and Young, 1984; DoN, 2001b).

Hearing Impairment and Other Physical Effects

    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift (TS), which is 
the loss of hearing sensitivity at certain frequency ranges (Kastak et 
al., 1999; Schlundt et al., 2000; Finneran et al., 2002, 2005). TS can 
be permanent (PTS), in which case the loss of hearing sensitivity is 
not recoverable, or temporary (TTS), in which case the animal's hearing 
threshold would recover over time (Southall et al., 2007). Marine 
mammals depend on acoustic cues for vital biological functions, (e.g., 
orientation, communication, finding prey, avoiding predators); thus, 
TTS may result in reduced fitness in survival and reproduction, either 
permanently or temporarily. However, this depends on the frequency and 
duration of TTS, as well as the biological context in which it occurs. 
TTS of limited duration, occurring in a frequency range that does not 
coincide with that used for recognition of important acoustic cues, 
would have little to no effect on an animal's fitness. Repeated sound 
exposure that leads to TTS could cause PTS. PTS, in the unlikely event 
that it occurred, would constitute injury, but TTS is not considered 
injury (Southall et al., 2007). It is unlikely that the project would 
result in any cases of temporary or especially permanent hearing 
impairment or any significant non-auditory physical or physiological 
effects for reasons discussed later in this document. Some behavioral 
disturbance is expected, but it is likely that this would be localized 
and short-term because of the short project duration.
    Several aspects of the planned monitoring and mitigation measures 
for this project (see the ``Proposed Mitigation'' and ``Proposed 
Monitoring and Reporting'' sections later in this document) are 
designed to detect marine mammals occurring near the pile driving to 
avoid exposing them to sound pulses that might, in theory, cause 
hearing impairment. In addition, many cetaceans are likely to show some 
avoidance of the area where received levels of pile driving sound are 
high enough that hearing impairment could potentially occur. In those 
cases, the avoidance responses of the animals themselves would reduce 
or (most likely) avoid any possibility of hearing impairment. Non-
auditory physical effects may also occur in marine mammals exposed to 
strong underwater pulsed sound. It is especially unlikely that any 
effects of these types would occur during the present project given the 
brief duration of exposure for any given individual and the planned 
monitoring and mitigation measures. The following subsections discuss 
in somewhat more detail the possibilities of TTS, PTS, and non-auditory 
physical effects.

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, occurs in specific 
frequency ranges (e.g., an animal might only have a temporary loss of 
hearing sensitivity between the frequencies of 1 and 10 kHz), and can 
occur to varying degrees (e.g., an animal's hearing sensitivity might 
be reduced by 6 dB or by 30 dB). For sound exposures at or somewhat 
above the TTS-onset threshold, hearing sensitivity recovers rapidly 
after exposure to the sound 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

[[Page 39478]]

considers TTS as Level B harassment that is mediated by physiological 
effects on the auditory system; however, NMFS does not consider onset 
TTS to be the lowest level at which Level B harassment may occur. 
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 non-pulse noise at SPL 152 dB re: 1 
[micro]Pa for 25 minutes. In contrast, a tested sea lion exhibited TTS-
onset at 174 dB re: 1 [micro]Pa under the same conditions as the harbor 
seal. Data from a single study on underwater pulses found no signs of 
TTS-onset in sea lions at exposures up to 183 dB re: 1 [micro]Pa (peak-
to-peak) (Finneran et al., 2003).
    Vibratory pile driving emits low-frequency broadband noise, which 
may be detectable by marine mammals within the proposed project area. 
There are limited data available on the effects of non-pulse noise (for 
example, vibratory pile driving) 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. While most of 
the pile driving at the proposed project site would be vibratory, an 
impact hammer (pulse noise) may be used to complete installation of 
seven piles (five 30-inch and two 24-inch). Vibratory and impact pile 
driving may result in anticipated hydroacoustic levels between 159 and 
195 dB rms at 10 m (unattenuated). Southall et al. (2007) reviewed 
relevant data from studies involving pinnipeds exposed to pulse noise 
and concluded that exposures to 150 to 180 dB generally have limited 
potential to induce avoidance behavior.
    The proposed action includes vibratory removal of 12-inch timber 
piles, vibratory removal and driving of 30-inch and 24-inch hollow 
steel piles, and vibratory installation of 72-inch hollow steel 
cylindrical shafts. Based on previous in-water measurements at the Port 
Townsend ferry terminal, removal of the 12-inch timber piles generated 
149 to 152 dB rms, with an overall average rms value of 150 dB, at 16 
m. In-water measurements conducted during another test pile project at 
the Port Townsend ferry terminal indicated that vibratory pile removal 
of a 30-inch steel pile generated 171 dB rms at 10 m, and vibratory 
pile driving of a 30-inch steel pile generated 170 dB rms at 10 m with 
the highest measured sound of 174 dB rms at 10 m (Laughlin, 2010). 
Based on in-water measurements at the WSF Friday Harbor ferry terminal, 
vibratory pile driving of 24-inch steel piles generated 162 dB rms at 
10 m (Laughlin, 2005). Vibratory pile removal data for 24-inch steel 
piles is not available, so a reduction of 3 dB rms will be assumed, 
which is the same reduction as the 30-inch vibratory removal at Port 
Townsend. The average value of 174 dB rms from a Washington State 
Department of Transportation monitoring project of vibratory 
installation of a 36-inch steel pipe pile at Port Townsend was used in 
the noise analysis for vibratory pile installation (WSDOT, 2010). There 
is also a lack of information available for the 80-inch cylinders. The 
closest in-water measurement available were for 72-inch cylinders from 
the California Pile Driving Compendium (Caltrans, 2007), which 
generated 180 dB rms at 5 m and equals 175.5 dB rms at 10 m (Laughlin, 
2011). The Caltrans report is considered to be the best available data 
for estimating the sound source levels for installing 80-inch cylinders 
with a vibratory hammer; therefore, this source level will be applied.

Permanent Threshold Shift

    When PTS occurs, there is physical damage to the sound receptors in 
the ear. In severe cases, there can be total or partial deafness, while 
in other cases the animal has an impaired ability to hear sounds in 
specific frequency ranges (Kryter, 1985). There is no specific evidence 
that exposure to pulses of sound can cause PTS in any marine mammal. 
However, given the possibility that mammals close to pile driving 
activity might incur TTS, there has been further speculation about the 
possibility that some individuals occurring very close to pile driving 
might incur PTS. Single or occasional occurrences of mild TTS are not 
indicative of permanent auditory damage, but repeated or (in some 
cases) single exposures to a level well above that causing TTS onset 
might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals. PTS might occur at a received sound level at 
least several decibels above that inducing mild TTS if the animal were 
exposed to strong sound pulses with rapid rise time. Based on data from 
terrestrial mammals, a precautionary assumption is that the PTS 
threshold for impulse sounds (such as pile driving pulses as received 
close to the source) is at least 6 dB higher than the TTS threshold on 
a peak-pressure basis and probably greater than 6 dB (Southall et al., 
2007). On an SEL basis, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB for 
there to be risk of PTS. Thus, for cetaceans, Southall et al. (2007) 
estimate that the PTS threshold might be an M-weighted SEL (for the 
sequence of received pulses) of approximately 198 dB re 1 [mu]Pa\2\-s 
(15 dB higher than the TTS threshold for an impulse). Given the higher 
level of sound necessary to cause PTS as compared with TTS, it is 
considerably less likely that PTS could occur.

Non-Auditory Physiological Effects

    Non-auditory physiological effects or injuries that theoretically 
might occur in marine mammals exposed to strong underwater sound 
include stress, neurological effects, bubble formation, resonance 
effects, and other types of organ or tissue damage (Cox et al., 2006; 
Southall et al., 2007). Studies examining such effects are limited. In 
general, little is known about the potential for pile driving to cause 
auditory impairment or other physical effects in marine mammals. 
Available data suggest that such effects, if they occur at all, would 
presumably be limited to short distances from the sound source and to 
activities that extend over a prolonged period. The available data do 
not allow identification of a specific exposure level above which non-
auditory effects can be expected (Southall et al., 2007) or any 
meaningful quantitative predictions of the numbers (if any) of marine 
mammals that might be affected in those ways. Marine mammals that show 
behavioral avoidance of pile driving, including some odontocetes and 
some pinnipeds, are especially

[[Page 39479]]

unlikely to incur auditory impairment or non-auditory physical effects.
    Measured source levels from impact pile driving can be as high as 
214 dB re 1 [mu]Pa at 1 m (3.3 ft). Although no marine mammals have 
been shown to experience TTS or PTS as a result of being exposed to 
pile driving activities, captive bottlenose dolphins and beluga whales 
exhibited changes in behavior when exposed to strong pulsed sounds 
(Finneran et al., 2000, 2002, 2005). The animals tolerated high 
received levels of sound before exhibiting aversive behaviors. 
Experiments on a beluga whale showed that exposure to a single watergun 
impulse at a received level of 207 kPa (30 psi) p-p, which is 
equivalent to 228 dB p-p re 1 [mu]Pa, resulted in a 7 and 6 dB TTS in 
the beluga whale at 0.4 and 30 kHz, respectively. Thresholds returned 
to within 2 dB of the pre-exposure level within four minutes of the 
exposure (Finneran et al., 2002). Although the source level of pile 
driving from one hammer strike is expected to be much lower than the 
single watergun impulse cited here, animals being exposed for a 
prolonged period to repeated hammer strikes could receive more sound 
exposure in terms of SEL than from the single watergun impulse 
(estimated at 188 dB re 1 [mu]Pa\2\-s) in the aforementioned experiment 
(Finneran et al., 2002). However, in order for marine mammals to 
experience TTS or PTS, the animals have to be close enough to be 
exposed to high intensity sound levels for a prolonged period of time. 
Based on the best scientific information available, these SPLs are far 
below the thresholds that could cause TTS or the onset of PTS.

Disturbance Reactions

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous changes in activities, and displacement. 
Reactions to sound, if any, depend on species, state of maturity, 
experience, current activity, reproductive state, time of day, and many 
other factors (Richardson et al., 1995; Wartzok et al., 2004; Southall 
et al., 2007; Weilgart, 2007). Behavioral responses to sound are highly 
variable and context-specific. For each potential behavioral change, 
the magnitude of the change ultimately determines the severity of the 
response. A number of factors may influence an animal's response to 
sound, including its previous experience, its auditory sensitivity, its 
biological and social status (including age and sex), and its 
behavioral state and activity at the time of exposure.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003/04). Animals are most likely to habituate 
to sounds that are predictable and unvarying. The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. Behavioral state may affect the type of response as well. For 
example, animals that are resting may show greater behavioral change in 
response to disturbing sound levels than animals that are highly 
motivated to remain in an area for feeding (Richardson et al., 1995; 
NRC, 2003; Wartzok et al., 2003/04).
    Controlled experiments with captive marine mammals showed 
pronounced behavioral reactions, including avoidance of loud sound 
sources (Ridgway et al., 1997; Finneran et al., 2003). Observed 
responses of wild marine mammals to loud pulsed sound sources 
(typically seismic guns or acoustic harassment devices, but also 
including pile driving) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds, 2002; Caltrans, 2001, 2006; see also Gordon et al., 2004; 
Wartzok et al., 2003/04; Nowacek et al., 2007). Responses to continuous 
sound, such as vibratory pile installation, have not been documented as 
well as responses to pulsed sounds.
    With both types of pile driving, it is likely that the onset of 
pile driving could result in temporary, short term changes in an 
animal's typical behavior and/or avoidance of the affected area. These 
behavioral changes may include (Richardson et al., 1995): Changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities; 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where sound sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haul-outs or rookeries). Pinnipeds 
may increase their haul-out time, possibly to avoid in-water 
disturbance (Caltrans, 2001, 2006). Since pile driving typically occurs 
for short periods of time, and because marine mammals present at the 
ferry terminal are likely acclimated to a loud environment and heavy 
urban and industrial usage of the area, it is unlikely to result in 
permanent displacement. Any potential impacts from pile driving 
activities could be experienced by individual marine mammals, but would 
not be likely to cause population level impacts, or affect the long-
term fitness of the species.
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, or reproduction. Significant 
behavioral modifications that could potentially lead to effects on 
growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those thought to be causing beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic sound 
depends on both external factors (characteristics of sound sources and 
their paths) and the specific characteristics of the receiving animals 
(hearing, motivation, experience, demography) and is difficult to 
predict (Southall et al., 2007).

Auditory Masking

    Natural and artificial sounds can disrupt behavior by masking, or 
interfering with, a marine mammal's ability to hear other sounds. 
Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular frequencies for 
marine mammals that utilize sound for vital biological functions. 
Masking can interfere with detection of acoustic signals such as 
communication calls, echolocation sounds, and environmental sounds 
important to marine mammals. Therefore, under certain circumstances, 
marine mammals whose acoustical sensors or environment are being 
severely masked could also be impaired from maximizing their 
performance fitness in survival and reproduction. If the coincident 
(masking) sound were man-made, it could be potentially harassing if it 
disrupted hearing-related behavior. It is important to distinguish TTS 
and PTS, which persist after the sound exposure, from masking, which 
occurs during the sound exposure. Because masking (without resulting in 
TS) is not

[[Page 39480]]

associated with abnormal physiological function, it is not considered a 
physiological effect, but rather a potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. Because sound 
generated from in-water pile driving is mostly concentrated at low 
frequency ranges, it may have less effect on high frequency 
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls 
and other potentially important natural sounds such as surf and prey 
sound. It may also affect communication signals when they occur near 
the sound band and thus reduce the communication space of animals 
(e.g., Clark et al., 2009) and cause increased stress levels (e.g., 
Foote et al., 2004; Holt et al., 2009).
    Masking has the potential to impact species at population, 
community, or even ecosystem levels, as well as at individual levels. 
Masking affects both senders and receivers of the signals and can 
potentially have long-term chronic effects on marine mammal species and 
populations. Recent research suggests that low frequency ambient sound 
levels have increased by as much as 20 dB (more than three times in 
terms of SPL) in the world's ocean from pre-industrial periods, and 
that most of these increases are from distant shipping (Hildebrand, 
2009). All anthropogenic sound sources, such as those from vessel 
traffic, pile driving, and dredging activities, contribute to the 
elevated ambient sound levels, thus intensifying masking. However, the 
sum of sound from the proposed activities is confined in an area of 
inland waters that is bounded by landmass; therefore, the sound 
generated is not expected to contribute to increased ocean ambient 
sound. The most intense underwater sounds in the proposed action are 
those produced by impact pile driving, although the proposed activity 
involves the striking of only relatively small diameter piles, meaning 
that source levels would be much lower than are typically produced by 
impact pile driving. Given that the energy distribution of pile driving 
covers a broad frequency spectrum, sound from these sources would 
likely be within the audible range of animals in the vicinity. Impact 
pile driving activity is relatively short-term, with rapid pulses 
occurring for short periods of time. The probability for impact pile 
driving resulting from this proposed action masking acoustic signals 
important to the behavior and survival of marine mammal species is 
likely to be negligible. Vibratory pile driving is also relatively 
short-term, producing sound from rapid oscillations. It is possible 
that vibratory pile driving resulting from this proposed action may 
mask acoustic signals important to the behavior and survival of marine 
mammal species, but the short-term duration and limited affected area, 
coupled with high levels of ambient noise in the action area, would 
result in a negligible impact from masking.

Airborne Sound Effects

    Marine mammals that occur in the project area could be exposed to 
airborne sounds associated with pile driving that have the potential to 
cause harassment, depending on their distance from pile driving 
activities. Airborne pile driving sound would have less impact on 
cetaceans than pinnipeds because sound from atmospheric sources does 
not transmit well underwater (Richardson et al., 1995); thus, airborne 
sound would only be an issue for hauled-out pinnipeds in the project 
area or those pinnipeds in the water but with their heads above water. 
Given the busy and loud environment within which the proposed 
activities would occur and the distance to the nearest pinniped haul-
out site, it is unlikely that airborne sound from pile driving would 
cause behavioral responses similar to those discussed above in relation 
to underwater sound. However, anthropogenic sound could potentially 
cause pinnipeds to exhibit changes in their normal behavior, such as 
reduction in vocalizations, or cause them to temporarily abandon their 
habitat and move further from the source. Studies by Blackwell et al. 
(2004) and Moulton et al. (2005) indicate a tolerance or lack of 
response to unweighted airborne sounds as high as 112 dB peak and 96 dB 
rms.
    Based on the available information, NMFS expects any impacts to 
marine mammal behavior to be temporary, Level B harassment, for two 
reasons: First, animals may avoid the area around the hammer, thereby 
reducing their exposure to elevated sound levels; and second, pile 
removal and driving does not occur continuously throughout the day. 
Depending on the size of the pile, the vibratory hammer would operate 
for about 15-20 minutes per pile and the impact hammer would operate 
for about 10 minutes per pile. The applicant anticipates about 6 days 
of pile removal and approximately 9 total hours of pile driving 
activity, averaging about two hours of active pile driving for each 
construction day. Disturbance to marine mammal behavior may be in the 
form of temporary avoidance of the pile driving location. In addition, 
because a vibratory hammer would be used for the majority of pile 
removal and installation, and the distance to the Level A harassment 
isopleth for the impact hammer is 22 m for cetaceans (180 dB) and 5 m 
for pinnipeds (190 dB), marine mammal injury or mortality is not 
likely. Impact pile driving would cease if a marine mammal (including 
pinnipeds) is observed nearing or within the 180 dB isopleth. For these 
reasons, NMFS expects any changes to marine mammal behavior to be 
temporary, site-specific, and has preliminarily determined will result 
in a negligible impact to affected species and stocks.

Anticipated Effects on Habitat

    WSF has run the state ferry system since the 1950s. Since acquiring 
control of the most used ferry system in the world, WSF has developed 
and routinely uses the best guidance available (e.g., best management 
practices (BMPs) and mitigation measures) to avoid and minimize (to the 
greatest extent possible) impacts to the environment, ESA species, 
designated critical habitats, and species protected under the MMPA. To 
protect habitat, WSF must adhere to the measures outlined in the 
Implementing Agreement (IA) with the Washington State Department of 
Ecology (Ecology)/WSDOT dated February 13, 1998 (to be superseded by 
any agreement that is more current that the 1998 IA). Precautionary 
measures such as using bubble curtains to protect salmonids from 
injurious noise levels, protecting eelgrass beds, preparation and 
implementation of a Spill Prevention, Control, and Countermeasures 
(SPCC) plan, compliance with appropriate water quality standards, 
ensuring no leakage of petroleum products, fresh cement, lime or 
concrete, chemicals, or other toxic or deleterious materials into 
terminal waters, proper disposal of wash water resulting from washdown 
of equipment or work areas, and minimizing and confining use of 
equipment to defined corridors where beach access is required will aid 
in minimizing direct and indirect impacts to marine mammal habitat. 
More information on habitat related protection measures can be found in 
WSF's application.
    Marine mammals in the action area primarily feed on salmonids and 
other fishes present in Puget Sound. Use of a bubble curtain will 
prevent injurious level sounds from entering into the aquatic 
environment. Popper et al. (2006) recommend a dual criterion of 208 dB 
(peak) and 187 dB re: 1 microPa\2\-s as interim guidance to

[[Page 39481]]

protect fish from physical injury and mortality for a single pile 
driving impact. During a test pile study at the Mukilteo ferry 
terminal, none of the single strike SEL values calculated on the 
absolute peak pile strike exceeded the proposed threshold of 187 dB SEL 
and none of the calculated cumulative SEL values exceeded the benchmark 
of 220 dB SEL based on the total number of pile strikes for each 
individual pile and total pile strikes for the entire day (Laughlin, 
2007). Mitigation measures also reduce noise pollution released into 
marine mammal habitat. In addition, pile driving is not occurring 
continuously and at each site would occur for only 2 hours per day for 
a maximum of 11 days. Based on the intermittent nature of pile driving, 
limited pile driving days/hours, and mitigation measures employed by 
WSF, NMFS has preliminarily determined that pile driving for ferry 
terminal repair and maintenance will not adversely impact marine mammal 
habitat.
    Installation and removal of piles will result in short-term, site-
specific increase in turbidity. In general, turbidity is the amount of 
particulate matter suspended in the water. High levels of turbidity can 
reduce the amount of light reaching lower depth, which can inhibit the 
growth of aquatic plants, and affect the ability of fish gills to 
absorb dissolved oxygen. Cetaceans are not expected to be close enough 
to the ferry terminal to experience turbidity and any pinnipeds that 
use the area as a transit corridor could detect in-water activities 
that create turbidity and avoid the area. Removal of the 40 creosote-
treated wood piles will result in the temporary re-suspension of 
sediment containing contaminants often associated with creosote, such 
as polycyclic aromatic hydrocarbons (PAHs) that cause cancers and 
mutations. However, the actual removal of the wood piles from the 
marine environment has long-term benefits due to improvements in water 
and sediment quality.
    In conclusion, the impacts on marine mammal habitat from the 
proposed project are likely to be in the form of underwater noise, 
temporary increase in turbidity levels, and changes in prey species 
distribution. The impact of habitat loss during construction due to 
noise or water quality (turbidity) is expected to be minimal. Marine 
mammals that utilize habitat in the vicinity of the ferry terminal are 
primarily transiting through the area; however, a harbor seal haul-out 
site is located 3 km away. Any impacts to prey species during 
construction will be short-term and localized. Given the large numbers 
of fish and other prey species in Puget Sound, the short-term and 
localized effects on fish species, the mitigation measures employed, 
and the BMPs designed to protect salmonids, the proposed project is not 
expected to have measurable effects on the distribution or abundance of 
marine mammal prey species.

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

Temporal Restrictions

    The Washington Department of Fish and Wildlife recommends an in-
water work window of July 16 through February 15, annually. This work 
window was designed to avoid in-water work when ESA-listed salmonids 
are most likely to be present, but may also be beneficial to marine 
mammals that prey on salmon. Actual construction activities are planned 
to take place from December 2012 through February 15, which would 
ensure these activities do not coincide with salmonid use of the action 
area.

Use of Noise Attenuation During Pile Driving With Impact Hammer

    To the extent possible, a vibratory hammer would be used to drive 
all piles. It is anticipated that an impact hammer will be necessary to 
``proof'' five 30-inch hollow steel piles. During impact pile driving, 
a bubble curtain will be used as an attenuation device to reduce 
hydroacoustic sound levels and avoid the potential for injury. In the 
event that hydroacoustic monitoring during in-water construction 
activities involving impact pile driving indicates that the proper 
attenuation is not being achieved, the proposed harassment and 
exclusion zones (described next) will be modified to account for the 
reduced attenuation.

Establishment of an Exclusion Zone

    During impact pile driving, WSF would establish a marine mammal 
exclusion zone of 22m around each pile to avoid exposure to sounds at 
or above 180 dB. The 190 dB (pinniped) injury isopleth is contained 
within the 22m exclusion zone. The exclusion zone would be monitored 
during all impact pile driving to ensure that no marine mammals enter 
the 22m radius. The purpose of this area is to prevent Level A 
harassment (injury) of any marine mammal species. An exclusion zone for 
vibratory pile driving is unnecessary to prevent Level A harassment, as 
source levels would not exceed the Level A harassment threshold.

Pile Driving Shut Down and Delay Procedures

    Monitoring will be initiated 30 minutes prior to the commencement 
of pile driving activities. If a protected species observer sees a 
marine mammal within or approaching the exclusion zone prior to start 
of impact pile driving, the observer would notify the on-site 
construction manager (or other authorized individual), who would then 
be required to delay pile driving until the marine mammal has moved 
outside of the exclusion zone or if the animal has not been resighted 
within 15 minutes. If a marine mammal is sighted within or on a path 
toward the exclusion zone during pile driving, pile driving would cease 
until that animal has cleared and is on a path away from the exclusion 
zone or 15 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.
    Each pile will take approximately 20 minutes to install, followed 
by 20 minutes of monitoring for the presence of marine mammals. Marine 
mammal monitoring will also be required for 30 minutes before 
installing subsequent piles. During pile driving activities, these time 
periods will overlap; therefore, if the driving of a new pile begins 
before the 50-minute (or less) total observation periods is complete,

[[Page 39482]]

and no marine mammals are observed within the exclusion zone, a soft-
start will not be required. However, if the total 50-minute observation 
period has lapsed before beginning the next pile, a soft-start will be 
required.

In-Water Pile Driving Weather Delays

    Should environmental conditions (e.g., fog, high sea state, poor 
lighting) obscure the harassment zone, pile driving will be suspended 
until visibility returns.
    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and considered a range of other measures in the context of 
ensuring that NMFS prescribes the means of effecting the least 
practicable adverse 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 personnel safety, and practicality of implementation.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means of effecting the least practicable adverse impacts on 
marine mammals 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 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.
    WSF has developed a monitoring plan that includes monitoring the 
harassment and exclusion zones during pile driving and collecting 
sighting data for each marine mammal species observed during in-water 
construction activities. To implement this plan, qualified marine 
mammals observers will be on-site at all times during pile removal and 
installation. WSF must designate at least one biologically-trained, on-
site individual, approved in advance by NMFS, to monitor the area for 
marine mammals 30 minutes before, during, and 20 minutes after all 
impact pile driving activities and call for shut down if any marine 
mammal is observed within or approaching the designated exclusion zone 
(preliminarily set at 22m). In addition, at least two NMFS-approved 
protected species observers would conduct behavioral monitoring at 
least two days per week to estimate take and evaluate the behavioral 
impacts pile driving has on marine mammals out to the Level B 
harassment isopleths. Note that for impact hammering, this distance is 
about 465 m. For vibratory hammering, this estimated distance is about 
6.8 km. Protected species observers would be provided with the 
equipment necessary to effectively monitor for marine mammals (for 
example, high-quality binoculars, spotting scopes, compass, and range-
finder) 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.
    WSF also plans to conduct acoustic monitoring during vibratory pile 
installation of 24-inch and 80-inch steel piles. Acoustic monitoring 
during timber pile removal and installation and removal of 30-inch 
steel piles will not be conducted because data from these activities 
was collected in 2010 during the Port Townsend test pile driving 
project (Laughlin, 2010; Stockham et al., 2010) and during a 2010 
dolphin replacement project in Port Townsend.
    Protected species observers would be required to submit a report to 
NMFS within 120 days of expiration of the IHA or completion of pile 
driving, whichever comes first. The report would include data from 
marine mammal sightings (such as species, group size, and behavior), 
any observed reactions to construction, distance to operating pile 
hammer, and construction activities occurring at time of sighting.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].
    Based on the application and subsequent analysis, the impact of the 
described pile driving 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.
    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 harassment (Level B) 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), but below the 
aforementioned thresholds. These levels are also considered 
precautionary.
    Based on empirical measurements taken by WSDOT and Caltrans (which 
are presented in the Description of Specified Activities section 
above), estimated distances to NMFS' current threshold sound levels 
from pile driving during the proposed construction activities are 
presented in Table 4. The 22 m distance to the Level A harassment 
threshold provides protected species observers a reasonably sized area 
to monitor during impact pile driving. Monitoring this zone would 
prevent marine mammals from being exposed to sound levels that reach 
the Level A harassment threshold.

[[Page 39483]]



                         Table 4--Distances to NMFS' Marine Mammal Harassment Thresholds
                                              [Without attenuation]
----------------------------------------------------------------------------------------------------------------
                                                               Level B harassment (160   Level B harassment (120
                                      Level A (190/180 dB)               dB)                       dB)
----------------------------------------------------------------------------------------------------------------
Impact hammering.................  22 m.....................  465 m...................  n/a
Vibratory hammering..............  n/a......................  n/a.....................  6.8 km
----------------------------------------------------------------------------------------------------------------

    For each of the 11 marine mammal species that may occur within the 
proposed action area, incidental take was determined by estimating the 
likelihood of a marine mammal being present with the Zone of Influence 
(ZOI) during pile driving activities (Table 5). Typically, incidental 
take is estimated by multiplying the area of the ZOI by the local 
animal density. This provides an estimate of the number of animals that 
might occupy the ZOI at any time; however, there are no density 
estimates for marine mammal populations in Puget Sound. Therefore, the 
take requests were estimated using local marine mammal data sets (e.g., 
Orca Network, state and federal agencies), opinions from state and 
federal agencies, and incidental observations from WSF biologists. 
Expected marine mammal presence was determined by past observation and 
general abundance near the Port Townsend ferry terminal during the 
construction work window. Distances to the applicable NMFS thresholds 
for Level A and Level B harassment take for each type of pile 
(vibratory and impact) were presented in Section 1.6.6 in the IHA 
application. These distances were used to calculate the various ZOIs or 
area ensonified by sounds at or greater than threshold. For example, 
for the Level A threshold, the estimated distance to the 180 dB 
isopleth was 22 m for impact pile driving, which equates to a 1,520 
square meter ZOI. The distance to the 160 dB isopleths during impact 
pile driving was estimated at 465 m, which equates to a 0.45 square km 
(only half the area is water). The distance to the 120 dB threshold for 
vibratory pile driving was estimated at 6.8 km, which equates to a ZOI 
of approximately 42 square km in water. Both of these areas will be 
monitored during construction to report actual marine mammal takes by 
Level B harassment.

Table 5--Population Abundance Estimates, Total Proposed Take, and the Percentage of the Population or Stock That
 May Be Exposed to Sounds Resulting in Level B Harassment During the Proposed Ferry Terminal Replacement Project
----------------------------------------------------------------------------------------------------------------
                                                                                                 Percentage of
                        Species                              Abundance        Proposed take      population or
                                                                              authorization          stock
----------------------------------------------------------------------------------------------------------------
Gray Whale.............................................             20,000                  2               0.01
Humpback Whale.........................................              1,100                  2               0.18
Minke Whale............................................              1,000                  2                0.2
Killer Whale...........................................            \1\ 314                 30            \1\ 9.5
                                                                    \2\ 86  .................             \2\ 35
Harbor Porpoise........................................             10,682                 50                0.5
Dall's Porpoise........................................             57,000                  9               0.02
Pacific White-sided Dolphin............................             25,233                 10               0.04
Harbor Seal............................................             14,612                 45                0.3
California Sea Lion....................................        3,000-5,000                 18            0.6-.36
Northern Elephant Seal.................................            101,000                  5              0.005
Steller Sea Lion.......................................        1,000-2,000                 35           3.5-1.75
----------------------------------------------------------------------------------------------------------------
\1\ (Transient).
\2\ (Southern Resident).

    Airborne noises can affect pinnipeds, especially resting seals 
hauled out on rocks or sand spits. The airborne 90 dB Level B threshold 
for hauled out harbor seals was estimated at 81 m, and the airborne 100 
dB Level B threshold for other pinnipeds was estimated at 17 m. No 
haulout sites are within the disturbance threshold distances; the 
nearest harbor seal haulout is approximately 3 km from the ferry 
terminal. In addition, the airborne noise harassment ZOI is smaller 
than both the impact and vibratory hammer underwater noise harassment 
ZOIs, and therefore is encompassed in the underwater noise take 
estimates.
    Surveys conducted during the fall/winter of 2009/2010 by biologists 
contracted by the Snohomish Public Utility District recorded about 10 
harbor seals per day (Tollit et al., 2010). The applicant estimates 
that the total number of pile driving and removal hours would not 
exceed 21.5 hours, or about 3 eight-hour work days; therefore, the 
estimated number of seals that could be harassed would be 30. For 
conservative purposes, based on their predilection for embayments like 
Port Townsend Bay, WSF requests authorization to harass 45 harbor 
seals. The survey conducted by Tollit et al. (2010) also recorded 
sightings of California sea lions passing Admiralty Head (located 
directly across Admiralty Inlet from Port Townsend) and reported six 
animals over the course of 88 days between October 2009 and February 
2010. Similarly, the Washington Department of Fish and Wildlife 
recorded eight California sea lions in Admiralty Inlet during vessel-
based surveys in Puget Sound between 1992 and 2004. Based on the 
results from these surveys, WSF estimates that up to six California sea 
lions could enter the 160 dB harassment zone per day, or a total of 18 
during the 3 eight-hour work days that would involve in-water pile 
installation and removal activities.

[[Page 39484]]

These surveys did not, however, report any sightings of northern 
elephant seals in Admiralty Inlet. Wintering elephant seals haul out on 
Protection Island, which is 12 km to the west of Port Townsend, and 
Smith and Minor Islands 24 km to the north, but may forage as far south 
as Admiralty Inlet. Therefore, it is possible that elephant seals could 
enter Port Townsend Bay during the proposed activity at the ferry 
terminal, and WSF believes that a couple northern elephant seals could 
be exposed to sound from pile driving and removal activities each day, 
especially since they are capable of spending prolonged periods below 
the water where they cannot be detected. Based on these considerations, 
WSF requests a total of 5 northern elephant seal takes by Level B 
harassment during for the three eight-hour work days that involve pile 
driving and removal. Among pinnipeds, Steller sea lions are relatively 
common in Admiralty Inlet during the winter as they move between the 
Strait of Juan de Fuca and Puget Sound; hauling out at Craven Rock east 
of Marrowstone Island, or on channel buoys. The survey conducted by 
Tollit et al. (2010) recorded nearly 800 Steller sea lions over 88 
days, or about 9 Steller sea lions per day. Considering that pile 
driving activities are expected to take about three work days to 
complete, WSF estimates that 27 Steller sea lions could be exposed to 
sound resulting in Level B harassment. However, for conservative 
purposes, WSF requests authorization for 35 Steller sea lion takes by 
Level B harassment to account for variations in Steller sea lion 
distribution.
    Take estimates for cetaceans also relied on recent survey data 
because density estimates for the inland waters of Washington are not 
available. Harbor porpoises are frequently observed in Admiralty Inlet, 
Tollit et al. (2010) recorded over 1,500 harbor porpoises during 88 
survey days between October 2009 and February 2010, or approximately 17 
per day. WSF estimates that 21.5 hours of pile driving equates to about 
three work days, and approximately 50 harbor porpoises may be exposed 
to sound levels resulting in Level B harassment during this period. The 
survey by Tollit et al. (2010) did not positively identify any Dall's 
porpoises, and their preference for deeper waters and spatial 
distribution in Puget Sound make it unlikely that Dall's porpoises 
transiting through Admiralty Inlet would regularly enter the shallow 
waters of Port Townsend Bay; however, it is possible for Dall's 
porpoises to approach close enough to the proposed pile-driving 
activity to be exposed to sound resulting in Level B harassment. 
Therefore, based on an average winter group size of three animals 
(PSAMP data), WSF estimates that three Dall's porpoise may enter the 
Level B harassment zone three times during pile driving activities, and 
request a total of nine Dall's porpoise takes by Level B harassment. 
The inland distribution of Pacific white-sided dolphins is largely 
limited to the Strait of Juan de Fuca and Haro Strait on the west side 
of the San Juan Islands. Because these dolphins appear confined to the 
deeper channels of the inland waters of Washington State, they may 
occur in Admiralty Inlet, but are unlikely to enter the shallower 
waters of Port Townsend Bay. In addition, these animals move to warmer 
waters in the fall and winter and may be entirely absent from the area 
during the proposed ferry terminal replacement project. Without better 
evidence on the reports of Pacific white-sided dolphins sighted in 
Admiralty Inlet during the winter or on the likelihood of these 
dolphins occurring in the vicinity of the ferry terminal, WSF requests 
10 takes of Pacific white-sided dolphins by Level B harassment, which 
is based on their average group size exposed to one day of pile driving 
activity. Similar to Pacific white-sided dolphins, killer whales are 
not expected to be present near Port Townsend during the proposed fall/
winter activity period. Transient killer whale rarely occur in Puget 
Sound, and Southern Resident killer whales spend much of the winter in 
the vicinity of the Fraser River; however, based on the unpredictable 
nature of transient movements and past records of Southern Resident 
sightings, it is possible that a pod of killer whales could pass 
through Admiralty Inlet and be within the Level B harassment zone. For 
example, Tollit et al. (2010) did report three sightings of Southern 
Resident killer whales passing Admiralty Head in October 2009, and one 
group of transients passed by in December 2009 (neither group entered 
Port Townsend Bay). Therefore, WSF requests 30 killer whale takes by 
Level B harassment, which equates to one group of three transients plus 
the 27 animals that comprise J pod--the Southern Resident pod most 
likely to occur in Puget Sound during the proposed activity period.
    The IHA application also request takes of three species of baleen 
whale--gray whale, humpback whale, and minke whale. Gray whales 
generally enter the inland waters of Washington from March through May 
and sightings during the fall and winter are infrequent. However, 
because gray whales that enter Puget Sound tend to localize around 
Admiralty Inlet and Possession Sound, the possibility of a gray whale 
occurring in the vicinity of Port Townsend Bay during the proposed pile 
driving activity cannot be discounted. Therefore, based on the average 
gray whale group size, WSF requests two gray whale takes by Level B 
harassment. Humpback whales are also occasionally observed in Puget 
Sound, but most sightings occur during the summer months and nearly all 
recent winter and fall sightings have been confined to the vicinity of 
the San Juan Islands. Although humpback whales are not expected in the 
vicinity of Port Townsend Bay during the proposed action, the 
possibility of a sighting cannot be fully discounted. Based on the 
average group size, WSF requests two humpback whale takes by Level B 
harassment. Minke whales are also very rare in Puget Sound during the 
winter; however, of the few reported sightings in Puget Sound, most 
have occurred in the vicinity of Admiralty Inlet. Given the rarity of 
these animals in winter, WSF only anticipates that minke whales would 
make an occasional transit, if any, of Admiralty Inlet during the 
proposed activity with the remote possibility of one or two whales 
entering Port Townsend Bay. Therefore, based on these considerations, 
WSF requests two minke whale takes by Level B harassment.
    To summarize, WSF requests takes of 45 harbor seals, 18 California 
sea lions, 5 northern elephant seals, 35 Steller sea lions, 50 harbor 
porpoises, 9 Dall's porpoises, 10 Pacific white-sided dolphins, 30 
killer whales, 2 gray whales, 2 humpback whales, and 2 minke whales. 
These numbers do not take the proposed mitigation measures into 
consideration, and are likely overestimates representing the maximum 
number of animals expected to occur within the Level B harassment 
isopleth. The actual number of animals that may be harassed is likely 
to be less.

Negligible Impact and Small Numbers Analysis and Preliminary 
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

[[Page 39485]]

include, but are not limited to, 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.
    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 shallow coastal waters of Port Townsend Bay. The 
action area (waters around the ferry terminal) is not considered 
significant feeding or reproductive habitat for pinnipeds. The closest 
haul-out is 3 km away, which is outside the project area's largest 
harassment zone for airborne noise. Any marine mammals--most likely 
pinnipeds--approaching the action area would likely be traveling or 
opportunistically foraging. The amount of take WSF requested for each 
species, and NMFS proposes to authorize, is considered small (less than 
five percent) relative to the estimated populations or stocks of 14,612 
Pacific harbor seals, 238,000 California sea lions, 101,000 northern 
elephant seals, 48,500 Steller sea lions, 10,632 harbor porpoises, 
57,000 Dall's porpoises, 25,233 Pacific white-sided dolphins, 20,000 
gray whales, 1,100 humpback whales, and 1,000 minke whales. The request 
of up to 30 takes of killer whales by Level B harassment represents a 
larger percentage of the local killer whale population; this number was 
estimated because Southern Resident killer whales travel in large 
groups. Although killer whales are unlikely to occur in the vicinity of 
the ferry terminal during pile driving, if they were to appear, it may 
be as a full group or pod, which necessitates the need for a larger 
number of takes requested. Marine mammals may be temporarily impacted 
by pile driving noise. However, marine mammals are expected to avoid 
the area to some degree, thereby potentially reducing exposure and 
impacts. Pile driving activities are expected to occur for 
approximately 4 weeks. Although marine mammal prey species may be 
affected by pile driving activities, any impacts would be short in 
duration and limited to the immediate vicinity of the ferry terminal. 
NMFS expect that any fish that exhibit behavioral responses (i.e., 
avoidance) while in-water construction activities occur would resume 
normal behavior following the cessation of the activity. Furthermore, 
Puget Sound is a highly populated and industrialized area, so animals 
are likely tolerant or habituated to anthropogenic disturbance, 
including low level vibratory pile driving operations, and noise from 
other anthropogenic sources (such as vessels) may mask construction 
related sounds. There are no known areas within Port Townsend Bay where 
any of these species concentrate specifically for breeding or feeding. 
Based on all the information considered, there is no anticipated effect 
on annual rates of recruitment or survival of affected marine mammals.
    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 proposed pile removal 
and installation would result in the incidental take of small numbers 
of marine mammals, by Level B harassment only, and that the total 
taking would 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)

    The Southern Resident killer whale is listed as endangered under 
the ESA and the eastern stock of Steller sea lion is listed as 
threatened. Both species may occur within the action area. NMFS is in 
the process of consulting internally on the issuance of an IHA under 
section 101(a)(5)(A) of the MMPA for the takes of Southern Resident 
killer whales and Steller sea lions incidental to the proposed 
activity. ESA consultation will be concluded prior to a determination 
on the issuance of a final IHA.

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 direct, indirect, and cumulative 
effects to marine mammals and other applicable environmental resources 
resulting from issuance of a one-year IHA and the potential issuance of 
additional authorizations for incidental harassment for the ongoing 
project. Upon completion, this EA will be available on the NMFS Web 
site listed in the beginning of this document.

    Dated: June 27, 2012.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-16302 Filed 7-2-12; 8:45 am]
BILLING CODE 3510-22-P