Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Rehabilitation of Jetty A at the Mouth of the Columbia River, 43739-43760 [2015-18022]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 80, Number 141 (Thursday, July 23, 2015)]
[Notices]
[Pages 43739-43760]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-18022]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD978


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Rehabilitation of Jetty A at 
the Mouth of the Columbia River

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 request from the U.S. Army Corps of 
Engineers, Portland District (Corps) for authorization to take marine 
mammals incidental to the rehabilitation of jetty system at the mouth 
of the Columbia River (MCR): North Jetty, South Jetty, and Jetty A. The 
Corps is requesting an Incidental Harassment Authorization (IHA) for 
the first season of pile installation and removal at Jetty A only.

DATES: Comments and information must be received no later than August 
24, 2015.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Chief, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service. Physical comments should 
be sent to 1315 East-West Highway, Silver Spring, MD 20910 and 
electronic comments should be sent to ITP.Pauline@noaa.gov.
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted to the Internet at https://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm without 
change. All personal identifying information (e.g., name, address) 
voluntarily submitted by the commenter may be publicly accessible. Do 
not submit confidential business information or otherwise sensitive or 
protected information.

FOR FURTHER INFORMATION CONTACT: Robert Pauline, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION: 

Availability

    An electronic copy of the Corps' application and supporting 
documents, as well as a list of the references cited in this document, 
may be obtained by visiting the Internet at: https://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing 
these documents, please call the contact listed above.

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    An 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.''
    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

[[Page 43740]]

wild by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].

Summary of Request

    On February 13, 2015, NMFS received an application from the Corps 
for the taking of marine mammals incidental to the rehabilitation of 
Jetty A at the mouth of the Columbia River (MCR). On June 9, 2015 NMFS 
received a revised application. NMFS determined that the application 
was adequate and complete on June 12, 2015. The Corps proposes to 
conduct in-water work that may incidentally harass marine mammals 
(i.e., pile driving and removal). This IHA would be valid from May 1, 
2016 through April 30, 2017.
    The use of vibratory pile driving is expected to produce underwater 
sound at levels that have the potential to result in behavioral 
harassment of marine mammals. Species with the expected potential to be 
present during the project timeframe include killer whale (Orcinus 
orca), Steller sea lion (Eumatopius jubatus), gray whale (Eschrichtius 
robustus), harbor porpoise (Phocoena phocoena), California sea lion 
(Zalophus californianus), and harbor seal (Phoca vitulina richardii).

Description of the Specified Activity

Overview

    The Corps is seeking an IHA for the first year of pile installation 
and, possibly, removal work at Jetty A related to construction and 
maintenance of a barge offloading facility. The barge facility will be 
used for activities associated with the rehabilitation of Jetty A. The 
Corps is seeking this authorization by the end of August 2015 for 
contract bid schedule reasons. Because the work may extend beyond two 
seasons the Corps will request an LOA for any additional years of pile 
maintenance and removal at Jetty A. Jetty A is not a haul-out site for 
pinnipeds so pile installation and removal were the only activities 
identified as having the potential to adversely affect marine mammals 
at Jetty A.

Dates and Duration

    Work on the first year of pile installation may begin as early as 
May 2016 and would extend through September 2017. Work is anticipated 
for two seasons stone placement for head stabilization and trunk 
repairs starting in 2016. Because the work may extend to two seasons 
the Corps will be requesting an LOA for the second year of pile 
maintenance and removal at Jetty A.
    The scheduled program of repair and rehabilitation priorities are 
described in detail in Section 1 of the Corps' IHA application. The 
sequence and overall timing for remaining work requiring an IHA and 
future LOA at the three MCR jetties include:
    1. Jetty A Scheduled Repairs and Head Stabilization will require an 
IHA and future LOA for pile installation of an offloading facilities. 
Construction and stone placement will likely occur in 2016 and 2017. 
The Corps will request an LOA after the IHA expires to cover additional 
years of pile maintenance and removal.
    2. North Jetty Scheduled Repair and Head Stabilization will require 
an LOA in the future for pile installation and removal at offloading 
facility. Construction/placement is planned for 2016-2019.
    3. South Jetty Interim Repair and Head Determination will require 
an LOA for pile installation and removal at two barge offloading 
facilities. This work would be covered under a future LOA.
    The work season generally extends from April through October, with 
extensions, contractions, and additional work windows outside of the 
summer season varying by weather patterns. To avoid the presence of 
Southern resident killer whales, the Corps will prohibit pile 
installation for offloading facilities from October 1 until on or after 
May 1 since that is their primary feeding season when they may be 
present at the MCR plume. Installation would occur from May 1 to 
September 30 each year.

Specified Geographic Region

    This activity will take place at the three MCR jetties in Pacific 
County, Washington, and Clatsop County, Oregon. The scheduled program 
of repair and rehabilitation priorities are described and illustrated 
in Section 1 of the application.

Detailed Description of Activities

    Jetty A Scheduled Repair would occur as part of the Corps' Major 
Rehabilitation program for the jetties. Scheduled repairs would address 
the loss of cross-section, reduce future cross-section instability, and 
stabilize the head (terminus). Scheduled cross-section repairs are 
primarily above mean lower low water (MLLW), with a majority of stone 
placement not likely to extend below -5 feet MLLW. The jetty head 
(Southern-most end section) would be stabilized at approximately 
station (STA) 89+00 with large armoring stone placed on relic jetty 
stone that is mostly above MLLW. Stations (STA) indicate lineal 
distance along the jetty relative to a fixed reference point (0+00) 
located at the landward-most point on the jetty root (See Application 
Figure 2).
    Construction of an offloading facility will be necessary to 
transport materials to the Jetty A project site. This construction 
would require dredging and pile installation. There is a small chance 
that delivery and placement could occur exclusively via overland 
methods. If such were the case, the Corps would not have a need an IHA.
    Four offloading facilities will eventually be required for 
completion of entire project. However, only construction of the first 
facility would be covered under the proposed Authorization. 
Construction of all four offloading facilities combined will require up 
to 96 wood or steel piles and up to 373 sections of Z-piles, H-piles, 
and sheet pile to retain rock fill. A vibratory hammer will be used for 
pile installation due to the soft sediments (sand) in the project area 
and only untreated wood will be used, where applicable. No impact 
driving will be necessary under this Authorization. The piles will be 
located within 200 feet of the jetty structure. The presence of relic 
stone may require locating the piling further from the jetty so that 
use of this method is not precluded by the existing stone. The 
dolphins/Z- and H-piles would be composed of either untreated timber or 
steel piles installed to a depth of approximately 15 to 25 feet below 
grade in order to withstand the needs of off-loading barges and heavy 
construction equipment. Because vibratory hammers will be used in areas 
with velocities greater than 1.6 feet per second, the need for 
hydroacoustic attenuation is not an anticipated issue. Piling will be 
fitted with pointed caps to prevent perching by piscivorous birds to 
minimize opportunities for avian predation on listed species. Some of 
the pilings and offloading facilities will be removed at the end of the 
construction period.
    Pile installation is assumed to occur for about 10 hours a day, 
with a total of approximately 15 piles installed per day. Each 
offloading facility would have about \1/4\ of the total piles 
mentioned. As noted above, up to 96 piles could be installed, and up to 
373 sections of sheet pile to retain rock fill. This is a total of 469 
initial installation and 469 removal events, over the span of about 67 
days. In order to round the math, the NMFS has assumed 68 days, so that 
each of the four offloading facilities takes about 17 days total for 
installation and removal. This is likely to be the maximum number of 
days for pile

[[Page 43741]]

installation at Jetty A. The Corps is still determining whether or not 
to remove some or all of these offloading facilities once jetty 
rehabilitation work is completed. It is possible that portions of these 
facilities may not survive ocean conditions. Longer-term offloading 
facilities at South and North Jetties may need to be repaired if used 
more than one season. The Corps will also be conducting post-
construction pedestrian surveys along the jetties, and will have 
construction activities for about four seasons on the South Jetty.
    Note that only a portion of the activities described above will be 
covered under the IHA. Actions covered under the authorization would 
include installing a maximum of 24 piles for use as dolphins and a 
maximum of 93 sections of Z or H piles for retention of rock fill over 
17 days. The piles would be a maximum diameter of 24 inches and would 
only be installed by vibratory driving method. The possibility exists 
that smaller diameter piles may be used but for this analysis it is 
assumed that 24 inch piles will be driven.

Description of Marine Mammals in the Area of the Specified Activity

    Marine mammals known to occur in the Pacific Ocean offshore at the 
MCR include whales, orcas, dolphins, porpoises, sea lions, and harbor 
seals. Most cetacean species observed by Green and others (1992) 
occurred in Pacific slope or offshore waters (600 to 6,000 feet in 
depth). Harbor porpoises (Phocoena phocoena) and gray whales 
(Eschrichtius robustus) were prevalent in shelf waters less than 600 
feet in depth. Orcas are known to feed on Chinook salmon at the MCR, 
and humpback whales (Megaptera novaeangliae) may transit through the 
area offshore of the jetties. While humpbacks have been observed 
offshore they are unlikely to be found inside of the jetty system. The 
marine mammal species potentially present in the activity area are 
shown in Table 1.
    Pinniped species that occur in the vicinity of the jetties include 
Pacific harbor seals (Phoca vitulina richardsi), California sea lions 
(Zalophus californianus), and Steller sea lions (Eumetopias jubatus). 
Their use is primarily confined to the South Jetty. According to the 
Washington Department of Fish and Wildlife (WDFW) aerial survey counts 
from 2000-2014, there are no records for harbor seals, Steller sea 
lions or California sea lions using Jetty A (WDFW 2014).
    In the species accounts provided here, we offer a brief 
introduction to the species and relevant stock as well as available 
information regarding population trends and threats, and describe any 
information regarding local occurrence.

                     Table 1--Marine Mammal Species Potentially Present in the Project Area
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                                      Stock(s)
             Species                  abundance         ESA Status          MMPA* Status         Frequency of
                                    estimate \1\                                                occurrence \3\
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Killer Whale (Orcinus orca),                   85  Endangered.........  Depleted and         Infrequent/Rare.
 Eastern N. Pacific, Southern                                            Strategic.
 Resident Stock.
Killer Whale (Orcinus orca),                  243  ...................  Non-depleted.......  Rare.
 Eastern N. Pacific, West Coast
 Transient Stock.
Gray Whale (Eschrichtius             18,017 (173)  Delisted/Recovered   Non-depleted.......  Rare.
 robustus), Eastern North Pacific                   (1994).
 Stock, (Pacific Coast Feed
 Group).
Harbor Porpoise (Phocoena                  21,487  ...................  Non-depleted.......  Likely.
 phocoena), Northern Oregon/
 Washington Coast Stock.
Steller Sea Lion (Eumetopias        63,160-78,198  Delisted/Recovered   Depleted and         Likely.
 jubatus), Eastern U.S. Stock/                      (2013).              Strategic \2\.
 DPS**.
California Sea Lion (Zalophus             296,750  ...................  Non-depleted.......  Likely.
 californianus), U.S. Stock.
Harbor Seal (Phoca vitulina            24,732 \4\  ...................  Non-depleted.......  Seasonal.
 richardii), Oregon and
 Washington Stock.
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\1\ NOAA/NMFS 2014 marine mammal stock assessment reports at https://www.nmfs.noaa.gov/pr/sars/species.htm.
\2\ May be updated based on the recent delisting status.
\3\ Frequency defined here in the range of:
 Rare--Few confirmed sightings, or the distribution of the species is near enough to the area that the
  species could occur there.
 Infrequent--Confirmed, but irregular sightings.
 Likely--Confirmed and regular sightings of the species in the area year-round.
 Seasonal--Confirmed and regular sightings of the species in the area on a seasonal basis.
\4\ Data is 8 years old. No current abundance estimates exist.
*MMPA = Marine Mammal Protection Act.
**DPS = Distinct population segment.

Cetaceans

Killer Whale
    During construction of the project, it is possible that two killer 
whale stocks, the Eastern North Pacific Southern resident and Eastern 
North Pacific West Coast transient stocks could be in the nearshore 
vicinity of the MCR. However, based on the restrictions to the work 
window for pile installation, it is unlikely that either West Coast 
transient or Southern resident killer whales will be present in the 
area during the period of possible acoustic effects.
    Since the first complete census of this stock in 1974 when 71 
animals were identified, the number of Southern resident killer whales 
has fluctuated annually. Between 1974 and 1993 the Southern Resident 
stock increased approximately 35%, from 71 to 96 individuals (Ford et 
al. 1994), representing a net annual growth rate of 1.8% during those 
years. Following the peak census count of 99 animals in 1995, the 
population size has fluctuated and currently stands at 85 animals as of 
the 2013 census (Carretta et al. 2014).
    The Southern resident killer whale population consists of three 
pods, designated J, K, and L pods, that reside from late spring to fall 
in the inland waterways of Washington State and British Columbia (NMFS 
2008a). During winter, pods have moved into Pacific coastal waters and 
are known to travel as far south as central California. Winter and 
early spring movements and distribution are largely unknown for the 
population. Sightings of members of K and L pods in Oregon (L pod at 
Depoe

[[Page 43742]]

Bay in April 1999 and Yaquina Bay in March 2000, unidentified Southern 
residents at Depoe Bay in April 2000, and members of K and L pods off 
of the Columbia River) and in California (17 members of L pod and four 
members of K pod at Monterey Bay in 2000; L pod members at Monterey Bay 
in March 2003; L pod members near the Farallon Islands in February 2005 
and again off Pt. Reyes in January 2006) have considerably extended the 
Southern limit of their known range (NMFS 2008a). Sightings of Southern 
resident killer whales off the coast of Washington, Oregon, and 
California indicate that they are utilizing resources in the California 
Current ecosystem in contrast to other North Pacific resident pods that 
exclusively use resources in the Alaskan Gyre system (NMFS 2008a).
    During the 2011 Section 7 Endangered Species Act (ESA) 
consultation, NMFS indicated Southern resident killer whales are known 
to feed on migrating Chinook salmon in the Columbia River plume during 
the peak salmon runs in March through April. Anecdotal evidence 
indicates that orcas historically were somewhat frequent visitors in 
the vicinity of the estuary, but have been less common in current times 
(Wilson 2015). However, there is low likelihood of them being in close 
proximity to any of the pile installation locations, and there would be 
minimal overlap of their presence during the peak summer construction 
season. To further avoid any overlap with Southern resident killer 
whales use during pile installation, the Corps would limit the pile 
installation window to start on or after May 1 and end after September 
30 of each year to avoid peak adult salmon runs.
    Southern Resident killer whales were listed as endangered under the 
ESA in 2005 and consequently the stock is automatically considered as a 
``strategic'' stock under the MMPA. This stock was considered 
``depleted'' prior to its 2005 listing under the ESA.
    The West Coast transient stock ranges from Southeast Alaska to 
California. Preliminary analysis of photographic data resulted in the 
following minimum counts for `transient' killer whales belonging to the 
West Coast Transient Stock (NOAA 2013b). Over the time series from 1975 
to 2012, 521 individual transient killer whales have been identified. 
Of these, 217 are considered part of the poorly known ``outer coast'' 
subpopulation and 304 belong to the well-known ``inner coast'' 
population. However, of the 304, the number of whales currently alive 
is not certain. A recent mark-recapture estimate that does not include 
the ``outer coast'' subpopulation or whales from California for the 
west coast transient population resulted in an estimate of 243 in 2006. 
This estimate applies to the population of West Coast transient whales 
that occur in the inside waters of southeastern Alaska, British 
Columbia, and northern Washington. Given that the California transient 
numbers have not been updated since the publication of the catalogue in 
1997 the total number of transient killer whales reported above should 
be considered as a minimum count for the West Coast transient stock 
(NOAA 2014a)
    For this project, it is possible only the inner-coast species would 
be considered for potential exposure to acoustic effects. However, they 
are even less likely to be in the project area than Southern resident 
killer whales, especially outside of the peak salmon runs. The Corps is 
avoiding pile installation work during potential peak feeding 
timeframes in order to further reduce the potential for acoustic 
exposure. It is possible, however, that West Coast transients come in 
to feed on the pinniped population hauled out on the South Jetty.
    This stock of killer whales is not designated as ``depleted'' under 
the MMPA nor are they listed as ``threatened'' or ``endangered'' under 
the ESA. Furthermore, the West Coast transient stock of killer whales 
is also not classified as a strategic stock
Gray Whale
    During summer and fall, most gray whales in the Eastern North 
Pacific stock feed in the Chukchi, Beaufort and northwestern Bering 
Seas. An exception is the relatively small number of whales 
(approximately 200) that summer and feed along the Pacific coast 
between Kodiak Island, Alaska and northern California (Carretta et al. 
2014), also known as the ``Pacific Coast Feeding Group.'' The minimum 
population estimate for the Eastern North Pacific stock using the 2006/
2007 abundance estimate of 19,126 and its associated coefficient of 
variation (CV) of 0.071 is 18,017 animals. The minimum population 
estimate for Pacific Coast Feeding Group gray whales is calculated as 
the lower 20th percentile of the log-normal distribution of the 2010 
mark-recapture estimate, or 173 animals (Carretta et al. 2014). If gray 
whales were in the vicinity of MCR, the Pacific Coast Feeding Group 
would be the most likely visitor. Anecdotal evidence indicates they 
have been seen at MCR, but are not a common visitor, as they mostly 
remain in the vicinity of the offshore shelf-break (Griffith 2015).
    In 1994, the Eastern North Pacific stock of gray whales was removed 
from the Endangered Species List as it was no longer considered 
``endangered'' or ``threatened'' under the ESA. NMFS has not designated 
gray whales as ``depleted'' under the MMPA. The Eastern North Pacific 
gray whale stock is not classified as ``strategic.''
Harbor Porpoise
    The harbor porpoise inhabits temporal, subarctic, and arctic 
waters. In the eastern North Pacific, harbor porpoises range from Point 
Barrow, Alaska, to Point Conception, California. Harbor porpoise 
primarily frequent coastal waters and occur most frequently in waters 
less than 100 m deep (Hobbs and Waite 2010). They may occasionally be 
found in deeper offshore waters.
    Harbor porpoise are known to occur year-round in the inland 
transboundary waters of Washington and British Columbia, Canada and 
along the Oregon/Washington coast. Aerial survey data from coastal 
Oregon and Washington, collected during all seasons, suggest that 
harbor porpoise distribution varies by depth. Although distinct 
seasonal changes in abundance along the west coast have been noted, and 
attributed to possible shifts in distribution to deeper offshore waters 
during late winter seasonal movement patterns are not fully understood. 
Harbor porpoises are sighted regularly at the MCR (Griffith 2015, 
Carretta et al. 2014).
    According to the online database, Ocean Biogeographic Information 
System, Spatial Ecological Analysis of Megavertebrate Populations 
(Halpin 2009 at OBIS-SEAMAP 2015), West Coast populations have more 
restricted movements and do not migrate as much as East Coast 
populations. Most harbor porpoise groups are small, generally 
consisting of less than five or six individuals, though for feeding or 
migration they may aggregate into large, loose groups of 50 to several 
hundred animals. Behavior tends to be inconspicuous, compared to most 
dolphins, and they feed by seizing prey which consists of wide variety 
of fish and cephalopods ranging from benthic or demersal.
    The Northern Oregon/Washington coast stock of harbor porpoise 
inhabits the waters near the proposed project area. The population 
estimate for this stock is calculated at 21,847 with a minimum 
population estimate of 15,123. (Carretta et al., 2014)
    Harbor porpoise are not listed as ``depleted'' under the MMPA, 
listed as ``threatened'' or ``endangered'' under the

[[Page 43743]]

Endangered Species Act, or classified as ``strategic.''

Pinnipeds

Steller Sea Lion
    The Steller sea lion is a pinniped and the largest of the eared 
seals. Steller sea lion populations that primarily occur east of 
144[deg] W (Cape Suckling, Alaska) comprise the Eastern Distinct 
Population Segment (DPS), which was de-listed and removed from the list 
of Endangered Species List on November 4, 2013 (78 FR 66140). This 
stock is found in the vicinity of MCR. The population west of 144[deg] 
W longitude comprises the Western DPS, which is listed as endangered, 
based largely on over-fishing of the seal's food supply.
    The range of the Steller sea lion includes the North Pacific Ocean 
rim from California to northern Japan. Steller sea lions forage in 
nearshore and pelagic waters where they are opportunistic predators. 
They feed primarily on a wide variety of fishes and cephalopods. 
Steller sea lions use terrestrial haulout sites to rest and take 
refuge. They also gather on well-defined, traditionally used rookeries 
to pup and breed. These habitats are typically gravel, rocky, or sand 
beaches; ledges; or rocky reefs (Allen and Angliss, 2013).
    The MCR South Jetty is used by Steller sea lions for hauling out 
and is not designated critical habitat. Use occurs chiefly at the 
concrete block structure at the terminus, or head of the jetty, and at 
the emergent rubble mound comprised of the eroding jetty trunk near the 
terminus.
    Previous monthly averages between 1995 and 2004 for Steller sea 
lions hauled-out at the South Jetty head ranged from about 168 to 1,106 
animals. More recent data from ODFW from 2000-2014 reflects a lower 
frequency of surveys, and numbers ranged from zero animals to 606 
Steller sea lions (ODFW 2014). More frequent surveys by WDFW for the 
same time frame (2000-2014) put the monthly range at 177 to 1,663 
animals throughout the year. According to ODFW (2014), most counts of 
animals remain at or near the jetty tip.
    Steller sea lions are present, in varying abundances, all year as 
is shown in the Corps application. Abundance is typically lower as the 
summer progresses when adults are at the breeding rookeries. Steller 
sea lions are most abundant in the vicinity during the winter months 
and tend to disperse elsewhere to rookeries during breeding season 
between May and July. Abundance increases following the breeding 
season. However, this is not always true as evidenced by a flyover 
count of the South Jetty on May 23, 2007 where 1,146 Steller sea lions 
were observed on the concrete block structure and none on the rubble 
mound (ODFW 2007). Those counts represent a high-use day on the South 
Jetty. According to ODFW (2014), during the summer months it is not 
uncommon to have between 500-1,000 Steller sea lions present, the 
majority of which are immature males and females (no pups or pregnant 
females). All population age classes, and both males and females, use 
the South Jetty to haul out. Only non-breeding individuals are 
typically found on the jetty during May-July, and a greater percentage 
of juveniles are present. There is probably a lot of turnover in sea 
lion numbers using the jetty. That is, the 100 or so sea lions hauled 
out one week might not be the same individuals hauled out the following 
week. Recent ODFW and WDFW survey data continue to support these 
findings. The most recent estimate from 2007 put the populations 
between 63,160 and 78,198.(Allen and Angliss, 2013). The best available 
information indicates the eastern stock of Steller sea lion increased 
at a rate of 4.18% per year between 1979 and 2010 based on an analysis 
of pup counts in California, Oregon, British Columbia and Southeast 
Alaska (Allen and Angliss, 2013).
California Sea Lion
    California sea lions are found from the Southern tip of Baja 
California to southeast Alaska. They breed mainly on offshore islands 
from Southern California's Channel Islands south to Mexico. Non-
breeding males often roam north in spring foraging for food. Since the 
mid-1980s, increasing numbers of California sea lions have been 
documented feeding on fish along the Washington coast and--more 
recently--in the Columbia River as far upstream as Bonneville Dam, 145 
miles from the river mouth. The population size of the U.S. stock of 
California sea lions is estimated at 296,750 animals (Carretta et al. 
2014). As with Steller sea lions, according to ODFW (2014) most counts 
of California sea lions are also concentrated near the tip of the 
jetty, although sometimes haul out about halfway down the jetty. Survey 
information (2007 and 2014) from ODFW indicates that California sea 
lions are relatively less prevalent in the Pacific Northwest during 
June and July, though in the months just before and after their absence 
there can be several hundred using the South Jetty. More frequent WDFW 
surveys (2014) indicate greater numbers in the summer, and use remains 
concentrated to fall and winter months. Nearly all California sea lions 
in the Pacific Northwest are sub-adult and adult males (females and 
young generally stay in California). Again, there is probably a lot of 
turnover in sea lion numbers using the jetty. (ODFW 2014).
    California sea lions in the U.S. are not listed as ``endangered'' 
or ``threatened'' under the Endangered Species Act, listed as 
``depleted'' under the MMPA, or classified as ``strategic'' under the 
MMPA.
Harbor Seal
    Harbor seals range from Baja California, north along the western 
coasts of the U.S., British Columbia and southeast Alaska, west through 
the Gulf of Alaska, Prince William Sound, and the Aleutian Islands, and 
north in the Bering Sea to Cape Newenham and the Pribilof Islands. They 
haul out on rocks, reefs, beaches, and drifting glacial ice and feed in 
marine, estuarine, and occasionally fresh waters. Harbor seals 
generally are non-migratory, with local movements associated with 
tides, weather, season, food availability, and reproduction. Harbor 
seals do not make extensive pelagic migrations, though some long 
distance movement of tagged animals in Alaska (900 km) and along the 
U.S. west coast (up to 550 km) have been recorded. Harbor seals have 
also displayed strong fidelity to haulout sites (Carretta et al. 2014).
    The 1999 harbor seal population estimate for the Oregon/Washington 
Coast stock was about 24,732 animals. However, the data used was over 8 
years old and, therefore, there are no current abundance estimates. 
Harbor seals are not considered to be ``depleted'' under the MMPA or 
listed as ``threatened'' or ``endangered'' under the ESA. The Oregon/
Washington Coast stock of harbor seals is not classified as a 
``strategic'' stock (Carretta et al. 20140).
    Further information on the biology and local distribution of these 
species can be found in the Corps application available online at: 
https://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm and the 
NMFS Marine Mammal Stock Assessment Reports, which may be found at: 
https://www.nmfs.noaa.gov/pr/species/.

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
stressors, (e.g. pile driving,) and potential mitigation activities, 
associated with the rehabilitation of Jetty A at MCR may impact marine 
mammals and their

[[Page 43744]]

habitat. The Estimated Take by Incidental Harassment section later in 
this document will include an analysis of the number of individuals 
that are expected to be taken by this activity. The Negligible Impact 
Analysis section will include the analysis of how this specific 
activity will impact marine mammals and will consider the content of 
this section, the Estimated Take by Incidental Harassment section, and 
the Proposed Mitigation section to draw conclusions regarding the 
likely impacts of this activity on the reproductive success or 
survivorship of individuals and from that on the affected marine mammal 
populations or stocks. In the following discussion, we provide general 
background information on sound and marine mammal hearing before 
considering potential effects to marine mammals from sound produced by 
vibratory pile driving.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks of a sound wave; lower frequency sounds have 
longer wavelengths than higher frequency sounds and attenuate 
(decrease) more rapidly in shallower water. Amplitude is the height of 
the sound pressure wave or the `loudness' of a sound and is typically 
measured using the decibel (dB) scale. A dB is the ratio between a 
measured pressure (with sound) and a reference pressure (sound at a 
constant pressure, established by scientific standards). It is a 
logarithmic unit that accounts for large variations in amplitude; 
therefore, relatively small changes in dB ratings correspond to large 
changes in sound pressure. When referring to sound pressure levels 
(SPLs; the sound force per unit area), sound is referenced in the 
context of underwater sound pressure to 1 microPascal ([mu]Pa). One 
pascal is the pressure resulting from a force of one newton exerted 
over an area of one square meter. The source level (SL) represents the 
sound level at a distance of 1 m from the source (referenced to 1 
[mu]Pa). The received level is the sound level at the listener's 
position. Note that all underwater sound levels in this document are 
referenced to a pressure of 1 [mu]Pa and all airborne sound levels in 
this document are referenced to a pressure of 20 [mu]Pa.
    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, 1983). 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 than by peak pressures.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. The 
compressions and decompressions associated with sound waves are 
detected as changes in pressure by aquatic life and man-made sound 
receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions.
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times.
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz.
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise for frequencies between 20 
and 300 Hz. In general, the frequencies of anthropogenic sounds are 
below 1 kHz and, if higher frequency sound levels are created, they 
attenuate rapidly (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound. Representative levels of anthropogenic sound are 
displayed in Table 2.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.

[[Page 43745]]



                                              Table 2--Representative Sound Levels of Anthropogenic Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Frequency
               Sound source                  range (Hz)       Underwater  sound level                               Reference
--------------------------------------------------------------------------------------------------------------------------------------------------------
Small vessels............................       250-1,000  151 dB rms at 1 m...........  Richardson et al., 1995.
Tug docking gravel barge.................       200-1,000  149 dB rms at 100 m.........  Blackwell and Greene, 2002.
Vibratory driving of 72-in steel pipe            10-1,500  180 dB rms at 10 m..........  Reyff, 2007.
 pile.
Impact driving of 36-in steel pipe pile..        10-1,500  195 dB rms at 10 m..........  Laughlin, 2007.
Impact driving of 66-in cast-in- steel-          10-1,500  195 dB rms at 10 m..........  Reviewed in Hastings and Popper, 2005.
 shell (CISS) pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In-water construction activities associated with the project 
include vibratory pile driving and removal. There are two general 
categories of sound types: Impulse and non-pulse (defined in the 
following). Vibratory pile driving is considered to be continuous or 
non-pulsed while impact pile driving is considered to be an impulse or 
pulsed sound type. The distinction between these two sound types is 
important because they have differing potential to cause physical 
effects, particularly with regard to hearing (e.g., Ward, 1997 in 
Southall et al., 2007). Please see Southall et al., (2007) for an in-
depth discussion of these concepts. Note that information related to 
impact hammers is included here for comparison. The Corps does not 
intend to employ the use of impact hammers as part of this proposed 
project. Pulsed sound sources (e.g., explosions, gunshots, sonic booms, 
impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) and 
occur either as isolated events or repeated in some succession. Pulsed 
sounds are all characterized by a relatively rapid rise from ambient 
pressure to a maximal pressure value followed by a rapid decay period 
that may include a period of diminishing, oscillating maximal and 
minimal pressures, and generally have an increased capacity to induce 
physical injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or non-continuous (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems (such as 
those used by the U.S. Navy). The duration of such sounds, as received 
at a distance, can be greatly extended in a highly reverberant 
environment.
    The likely or possible impacts of the proposed pile driving program 
in the MCR area on marine mammals could involve both non-acoustic and 
acoustic stressors. Potential non-acoustic stressors could result from 
the physical presence of the equipment and personnel. Any impacts to 
marine mammals are expected to primarily be acoustic in nature. 
Acoustic stressors could include effects of heavy equipment operation, 
dredging and disposal actions, and pile installation at Jetty A.

Marine Mammal Hearing

    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 have been derived using 
auditory evoked potentials, 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 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 
30 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 (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz;
     Phocid pinnipeds in Water: functional hearing is estimated 
to occur between approximately 75 Hz and 75 kHz; and
     Otariid pinnipeds in Water: functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, nine marine mammal 
species (seven cetacean and two pinniped) may occur in the project 
area. Of the three cetacean species likely to occur in the proposed 
project area, one is classified as low-frequency cetaceans (i.e., 
minke), one is classified as a mid-frequency cetacean (i.e., killer 
whale), and one is classified as a high-frequency cetaceans (i.e., 
harbor porpoise) (Southall et al., 2007). Additionally, harbor seals 
are classified as members of the phocid pinnipeds in water functional 
hearing group while Stellar sea lions and California sea lions are 
grouped under the Otariid pinnipeds in water functional hearing group. 
A species' functional hearing group is a consideration when we analyze 
the effects of exposure to sound on marine mammals.

Acoustic Impacts

    Potential Effects of Pile Driving Sound--The effects of sounds from 
pile driving might 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

[[Page 43746]]

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 
impulse sounds on marine mammals. Potential effects from impulse sound 
sources can range in severity from effects such as behavioral 
disturbance or tactile perception to physical discomfort, slight injury 
of the internal organs and the auditory system, or mortality (Yelverton 
et al., 1973).
    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. 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 
constitutes injury, but TTS does not (Southall et al., 2007). The 
following subsections discuss in somewhat more detail the possibilities 
of TTS, PTS, and non-auditory physical effects.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter, 
1985). While experiencing TTS, the hearing threshold rises, and a sound 
must be stronger in order to be heard. In terrestrial mammals, TTS can 
last from minutes or hours to days (in cases of strong TTS). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
in both terrestrial and marine mammals 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, and none of the 
published data concern TTS elicited by exposure to multiple pulses of 
sound. Available data on TTS in marine mammals are summarized in 
Southall et al. (2007).
    Given the available data, the received level of a single pulse 
(with no frequency weighting) might need to be approximately 186 dB re 
1 [mu]Pa\2\-s (i.e., 186 dB sound exposure level [SEL] or approximately 
221-226 dB p-p [peak]) in order to produce brief, mild TTS. Exposure to 
several strong pulses that each have received levels near 190 dB rms 
(175-180 dB SEL) might result in cumulative exposure of approximately 
186 dB SEL and thus slight TTS in a small odontocete, assuming the TTS 
threshold is (to a first approximation) a function of the total 
received pulse energy.
    The above TTS information for odontocetes is derived from studies 
on the bottlenose dolphin (Tursiops truncatus) and beluga whale 
(Delphinapterus leucas). There is no published TTS information for 
other species of cetaceans. However, preliminary evidence from a harbor 
porpoise exposed to pulsed sound suggests that its TTS threshold may 
have been lower (Lucke et al., 2009). As summarized above, data that 
are now available imply that TTS is unlikely to occur unless 
odontocetes are exposed to pile driving pulses stronger than 180 dB re 
1 [mu]Pa rms.
    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 a sound source can incur TTS, it is possible that some 
individuals 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, based on anatomical similarities. 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.
    Measured source levels from impact pile driving can be as high as 
214 dB rms. 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, 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

[[Page 43747]]

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.
    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 unlikely to incur auditory impairment or non-auditory 
physical effects.

Disturbance Reactions

    Disturbance includes a variety of effects, including subtle changes 
in behavior, more conspicuous changes in activities, and displacement. 
Behavioral responses to sound are highly variable and context-specific 
and reactions, if any, depend on species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day, and many other factors (Richardson et al., 1995; Wartzok 
et al., 2003; Southall et al., 2007).
    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). 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).
    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; Thorson and Reyff, 2006; see also Gordon et al., 2004; 
Wartzok et al., 2003; 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 (Thorson and Reyff, 2006).
    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 cause 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 anthropogenic, 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 only during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    Masking occurs at the frequency band which the animals utilize so 
the frequency range of the potentially masking sound is important in 
determining any potential behavioral impacts. Because sound generated 
from in-water vibratory 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).

[[Page 43748]]

    Masking has the potential to impact species at the population or 
community 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.
    Vibratory pile driving is relatively short-term, with rapid 
oscillations occurring for 10 to 30 minutes per installed pile. 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 would result in insignificant impacts from masking. Any 
masking event that could possibly rise to Level B harassment under the 
MMPA would occur concurrently within the zones of behavioral harassment 
already estimated for vibratory pile driving, and which have already 
been taken into account in the exposure analysis.
    Acoustic Effects, Airborne--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 pinnipeds 
either hauled-out or looking with heads above water in the project 
area. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out 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. 
However, since there are no haulout areas in the immediate vicinity of 
Jetty A, pinnipeds are unlikely to be disturbed by airborne acoustics 
associated with pile driving activities. Therefore, such impacts to 
will not be considered as part of the analysis

Vessel Interaction

    Besides being susceptible to vessel strikes, cetacean and pinniped 
responses to vessels may result in behavioral changes, including 
greater variability in the dive, surfacing, and respiration patterns; 
changes in vocalizations; and changes in swimming speed or direction 
(NRC 2003). There will be a temporary and localized increase in vessel 
traffic during construction. A maximum of three work barges will be 
present at any time during the in-water and over water work. The barges 
will be located near each other where construction is occurring

Potential Effects on Marine Mammal Habitat

    The primary potential impacts to marine mammal habitat are 
associated with elevated sound levels produced by vibratory and impact 
pile driving and removal in the area. However, other potential impacts 
to the surrounding habitat from physical disturbance are also possible.
    Potential Pile Driving Effects on Prey--Construction activities 
would produce continuous (i.e., vibratory pile driving) sounds. Fish 
react to sounds that are especially strong and/or intermittent low-
frequency sounds. Short duration, sharp sounds can cause overt or 
subtle changes in fish behavior and local distribution. Hastings and 
Popper (2005) identified several studies that suggest fish may relocate 
to avoid certain areas of sound energy. Additional studies have 
documented effects of pile driving on fish, although several are based 
on studies in support of large, multiyear bridge construction projects 
(e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Sound 
pulses at received levels of 160 dB may cause subtle changes in fish 
behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient 
strength have been known to cause injury to fish and fish mortality. 
The most likely impact to fish from pile driving activities at the 
project area would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Additionally, NMFS 2011 Biological Opinion 
indicated that no adverse effects were anticipated for critical habitat 
of prey species for marine mammals. In general, impacts to marine 
mammal prey species are expected to be minor and temporary due to the 
short timeframe for the project.
    Effects to Foraging Habitat--Pile installation may temporarily 
increase turbidity resulting from suspended sediments. Any increases 
would be temporary, localized, and minimal. The Corps must comply with 
state water quality standards during these operations by limiting the 
extent of turbidity to the immediate project area. In general, 
turbidity associated with pile installation is localized to about a 25-
foot radius around the pile (Everitt et al. 1980). Cetaceans are not 
expected to be close enough to the project pile driving areas to 
experience effects of turbidity, and any pinnipeds will be transiting 
the terminal area and could avoid localized areas of turbidity. 
Therefore, the impact from increased turbidity levels is expected to be 
discountable to marine mammals. Furthermore, pile driving and removal 
at the project site will not obstruct movements or migration of marine 
mammals.
    Natural tidal currents and flow patterns in MCR waters routinely 
disturb sediments. High volume tidal events can result in hydraulic 
forces that re-suspend benthic sediments, temporarily elevating 
turbidity locally. Any temporary increase in turbidity as a result of 
the proposed action is not anticipated to measurably exceed levels 
caused by these normal, natural periods.

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 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.
    For the proposed project, the Corps worked with NMFS and proposed 
the following mitigation measures to minimize the potential impacts to 
marine mammals in the project vicinity. The primary purposes of these 
mitigation measures are to minimize sound levels from the activities, 
and to monitor marine mammals within designated zones of influence 
corresponding to NMFS' current Level A and B harassment thresholds 
which are depicted in Table 3 found later in the Estimated Take by 
Incidental Harassment section.

[[Page 43749]]

    The Corps committed to the use of vibratory hammers for pile 
installation and will implement a soft-start procedure. In order to 
avoid exposure of Southern resident killer whales (Orcinus orca) the 
Corps also is limiting the installation window to on or after May 1 and 
will avoid installation or removal after September 30
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving and removal activities. In addition, observers 
shall record all incidents of marine mammal occurrence, regardless of 
distance from activity, and shall document any behavioral reactions in 
concert with distance from piles being driven. Observations made 
outside the shutdown zone will not result in shutdown; that pile 
segment would be completed without cessation, unless the animal 
approaches or enters the shutdown zone, at which point all pile driving 
activities would be halted. Monitoring will take place from 15 minutes 
prior to initiation through thirty minutes post-completion of pile 
driving activities. Pile driving activities include the time to remove 
a single pile or series of piles, as long as the time elapsed between 
uses of the pile driving equipment is no more than thirty minutes. 
Please see Section 13 of the Application for details on the marine 
mammal monitoring plan developed by the Corps with NMFS' cooperation.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. These vantage 
points include Jett A or the barge. Qualified observers are trained 
biologists, with the following minimum qualifications:
    (a) Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    (b) Advanced education in biological science or related field 
(undergraduate degree or higher required);
    (c) Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience);
    (d) Experience or training in the field identification of marine 
mammals, including the identification of behaviors;
    (e) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (f) Writing skills sufficient to prepare a report of observations 
including but not limited to the number and species of marine mammals 
observed; dates and times when in-water construction activities were 
conducted; dates and times when in-water construction activities were 
suspended to avoid potential incidental injury from construction sound 
of marine mammals observed within a defined shutdown zone; and marine 
mammal behavior; and
    (g) Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    (2) Prior to the start of pile driving activity, the shutdown zone 
will be monitored for 15 minutes to ensure that it is clear of marine 
mammals. Pile driving will only commence once observers have declared 
the shutdown zone clear of marine mammals; animals will be allowed to 
remain in the shutdown zone (i.e., must leave of their own volition) 
and their behavior will be monitored and documented. The shutdown zone 
may only be declared clear, and pile driving started, when the entire 
shutdown zone is visible (i.e., when not obscured by dark, rain, fog, 
etc.). In addition, if such conditions should arise during impact pile 
driving that is already underway, the activity would be halted.
    If a marine mammal approaches or enters the shutdown zone during 
the course of pile driving operations, activity will be halted and 
delayed until either the animal has voluntarily left and been visually 
confirmed beyond the shutdown zone or 15 minutes have passed without 
re-detection of the animal. Monitoring will be conducted throughout the 
time required to drive a pile.
    Soft Start--The use of a soft start procedure is believed to 
provide additional protection to marine mammals by warning or providing 
a chance to leave the area prior to the hammer operating at full 
capacity, and typically involves a requirement to initiate sound from 
the hammer at reduced energy followed by a waiting period. This 
procedure is repeated two additional times. It is difficult to specify 
the reduction in energy for any given hammer because of variation 
across drivers. The project will utilize soft start techniques for all 
vibratory pile driving. We require the Corps to initiate sound from 
vibratory hammers for fifteen seconds at reduced energy followed by a 
thirty-second waiting period, with the procedure repeated two 
additional times. Soft start will be required at the beginning of each 
day's pile driving work and at any time following a cessation of pile 
driving of 20 minutes or longer.
    In addition to the measures described later in this section, the 
Corps would employ the following standard mitigation measures:
    (a) Conduct briefings between construction supervisors and crews, 
marine mammal monitoring team, and Corps staff prior to the start of 
all pile driving activity, and when new personnel join the work, in 
order to explain responsibilities, communication procedures, marine 
mammal monitoring protocol, and operational procedures.
    (b) For in-water heavy machinery work other than pile driving 
(using, e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), if a marine 
mammal comes within 10 m, operations shall cease and vessels shall 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions. This type of work could include the following 
activities: (1) Movement of the barge to the pile location or (2) 
positioning of the pile on the substrate via a crane (i.e., stabbing 
the pile).

Monitoring and Shutdown for Pile Driving

    The following measures would apply to the Corps' mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--For all pile driving activities, the Corps will 
establish a shutdown zone. Shutdown zones are intended to contain the 
area in which SPLs equal or exceed the 180/190 dB rms acoustic injury 
criteria, with the purpose being to define an area within which 
shutdown of activity would occur upon sighting of a marine mammal (or 
in anticipation of an animal entering the defined area), thus 
preventing injury of marine mammals. The estimated shutdown zone for 
Level A injury to cetaceans would be 1 meter. The Corps, however, would 
implement a minimum shutdown zone of 10 m radius for all marine mammals 
around all vibratory pile driving and removal activities. These 
precautionary measures are intended to further reduce the unlikely 
possibility of injury from direct physical interaction with 
construction operations.
    Disturbance Zone--Disturbance zones are the areas in which sound 
pressure levels (SPLs) equal or exceed 120 dB rms (for continuous 
sound) for pile

[[Page 43750]]

driving installation and removal. Disturbance zones provide utility for 
monitoring conducted for mitigation purposes (i.e., shutdown zone 
monitoring) by establishing monitoring protocols for areas adjacent to 
the shutdown zones. Monitoring of disturbance zones enables observers 
to be aware of and communicate the presence of marine mammals in the 
project area but outside the shutdown zone and thus prepare for 
potential shutdowns of activity. However, the primary purpose of 
disturbance zone monitoring is for documenting incidents of Level B 
harassment; disturbance zone monitoring is discussed in greater detail 
later (see ``Proposed Monitoring and Reporting''). Nominal radial 
distances for disturbance zones are shown in Table 4 later in this 
notice. The shutdown zone for Level B injury wound extend 7,356 meters 
from the sound source. Given the size of the disturbance zone for 
vibratory pile driving, it is impossible to guarantee that all animals 
would be observed or to make comprehensive observations of fine-scale 
behavioral reactions to sound. We discuss monitoring objectives and 
protocols in greater depth in ``Proposed Monitoring and Reporting.''
    In order to document observed incidents of harassment, monitors 
record all marine mammal observations, regardless of location. The 
observer's location, as well as the location of the pile being driven, 
is known from a GPS. The location of the animal is estimated as a 
distance from the observer, which is then compared to the location from 
the pile and the estimated zone of influence (ZOI) for relevant 
activities (i.e., pile installation and removal). This information may 
then be used to extrapolate observed takes to reach an approximate 
understanding of actual total takes.
    Time Restrictions--Work would occur only during daylight hours, 
when visual monitoring of marine mammals can be conducted. In order 
minimize impact to Southern resident killer whales, in-water work will 
not be conducted during their primary feeding season extending from 
October 1 until on or after May 1. Installation could occur from May 1 
through September 30 each year.

Mitigation Conclusions

    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 affecting the least 
practicable impact on the affected marine mammal species and stocks and 
their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
     The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals
     The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned
     The practicability of the measure for applicant 
implementation,
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of pile driving, or other activities expected to result in the 
take of marine mammals (this goal may contribute to 1, above, or to 
reducing harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of pile driving, or other activities expected to 
result in the take of marine mammals (this goal may contribute to 1, 
above, or to reducing harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of pile driving, or other activities expected to result in the 
take of marine mammals (this goal may contribute to a, above, or to 
reducing the severity of harassment takes only).
    5. Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    6. For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means of 
effecting the least practicable impact 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 ITA 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 
incidental take authorizations (ITAs) must include the suggested means 
of accomplishing the necessary monitoring and reporting that will 
result in increased knowledge of the species and of the level of taking 
or impacts on populations of marine mammals that are expected to be 
present in the proposed action area.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    1. An increase in the probability of detecting marine mammals, both 
within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    2. An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of pile driving that we associate with 
specific adverse effects, such as behavioral harassment, TTS, or PTS;
    3. An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how anticipated adverse 
effects on individuals (in different ways and to varying degrees) may 
impact the population, species, or stock (specifically through effects 
on annual rates of recruitment or survival) through any of the 
following methods:
    [ssquf] Behavioral observations in the presence of stimuli compared 
to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
    [ssquf] Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
    [ssquf] Distribution and/or abundance comparisons in times or areas 
with concentrated stimuli versus times or areas without stimuli;
    4. An increased knowledge of the affected species; and

[[Page 43751]]

    5. An increase in our understanding of the effectiveness of certain 
mitigation and monitoring measures.
    The Corps submitted a marine mammal monitoring plan as part of the 
IHA application for this project, which can be found at 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. The plan may 
be modified or supplemented based on comments or new information 
received from the public during the public comment period.

Visual Marine Mammal Observation

    The Corps will collect sighting data and behavioral responses to 
construction for marine mammal species observed in the region of 
activity during the period of activity. All observers will be trained 
in marine mammal identification and behaviors and are required to have 
no other construction-related tasks while conducting monitoring. The 
Corps will monitor the shutdown zone and disturbance zone before, 
during, and after pile driving, with at least one located at a best 
practicable vantage point, such as on the Jetty A or the barge. Based 
on our requirements, the Marine Mammal Monitoring Plan would implement 
the following procedures for pile driving:
     Individuals meeting the minimum qualifications identified 
in the applicant's monitoring plan, Section 13 of the application, 
Level A and Level B harassment zones during impact during vibratory 
pile driving.
     The area within the Level B harassment threshold for 
impact driving (shown in Figure 19 of the application) will be 
monitored by the field monitor stationed either on Jetty A or a pile 
driving rig. Any marine mammal documented within the Level B harassment 
zone during impact driving would constitute a Level B take 
(harassment), and will be recorded and reported as such.
     During vibratory pile driving, a shutdown zone will be 
established to include all areas where the underwater SPLs are 
anticipated to equal or exceed the Level A (injury) criteria for marine 
mammals (180 dB isopleth for cetaceans; 190 dB isopleth for pinnipeds). 
Pile installation will not commence or will be suspended temporarily if 
any marine mammals are observed within or approaching the area. The 
shutdown zone will always be a minimum of 10 meters (33 feet) to 
prevent injury from physical interaction of marine mammals with 
construction equipment
     The individuals will scan the waters within each 
monitoring zone activity using binoculars (Vector 10X42 or equivalent), 
spotting scopes (Swarovski 20-60 zoom or equivalent), and visual 
observation.
     Use a hand-held or boat-mounted GPS device or rangefinder 
to verify the required monitoring distance from the project site.
     If waters exceed a sea-state which restricts the 
observers' ability to make observations within the marine mammal 
shutdown zone (e.g. excessive wind or fog), pile installation will 
cease. Pile driving will not be initiated until the entire shutdown 
zone is visible.
     Conduct pile driving only during daylight hours from 
sunrise to sunset when it is possible to visually monitor marine 
mammals.
     The waters will be scanned 15 minutes prior to commencing 
pile driving at the beginning of each day, and prior to commencing pile 
driving after any stoppage of 15 minutes or greater. If marine mammals 
enter or are observed within the designated marine mammal shutdown zone 
during or 15 minutes prior to pile driving, the monitors will notify 
the on-site construction manager to not begin until the animal has 
moved outside the designated radius.
     The waters will continue to be scanned for at least 30 
minutes after pile driving has completed each day, and after each 
stoppage of 20 minutes or greater.

Data Collection

    We require that observers use approved data forms. Among other 
pieces of information, the Corps will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the Corps will attempt to 
distinguish between the number of individual animals taken and the 
number of incidents of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.

Proposed Reporting Measures

    The Corps would provide NMFS with a draft monitoring report within 
90 days of the conclusion of the proposed construction work. This 
report will detail the monitoring protocol, summarize the data recorded 
during monitoring, and estimate the number of marine mammals that may 
have been harassed. If no comments are received from NMFS within 30 
days, the draft final report will constitute the final report. If 
comments are received, a final report must be submitted within 30 days 
after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury (Level A harassment), serious injury or 
mortality (e.g., ship-strike, gear interaction, and/or entanglement), 
the Corps would immediately cease the specified activities and 
immediately report the incident to Jolie Harrison 
(Jolie.Harrison@NOAA.gov), Chief of the Permits and Conservation 
Division, Office of Protected Resources, NMFS, and Brent Norberg 
(Brent.Norberg@noaa.gov), the West Coast Regional Stranding 
Coordinator. The report would include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with the Corps to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA

[[Page 43752]]

compliance. The Corps would not be able to resume their activities 
until notified by NMFS via letter, email, or telephone.
    In the event that the Corps discovers an injured or dead marine 
mammal, and the lead MMO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
the Corps would immediately report the incident to Jolie Harrison 
(Jolie.Harrison@NOAA.gov), Chief of the Permits and Conservation 
Division, Office of Protected Resources, NMFS, and Brent Norberg 
(Brent.Norberg@noaa.gov), the West Coast Regional Stranding Coordinator 
.
    The report would include the same information identified in the 
paragraph above. Activities would be able to continue while NMFS 
reviews the circumstances of the incident. NMFS would work with the 
Corps to determine whether modifications in the activities are 
appropriate.
    In the event that the Corps discovers an injured or dead marine 
mammal, and the lead MMO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the Corps would report the 
incident to Jolie Harrison (Jolie.Harrison@NOAA.gov), Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS West Coast Stranding Hotline and/or by 
email to Brent Norberg (Brent.Norberg@noaa.gov), the West Coast 
Regional Stranding Coordinator, within 24 hours of the discovery. The 
Corps would provide photographs or video footage (if available) or 
other documentation of the stranded animal sighting to NMFS and the 
Marine Mammal Stranding Network.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, 
section 3(18) of the MMPA defines ``harassment'' as: ``. . . any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild [Level A harassment]; 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering [Level B harassment].''
    All anticipated takes would be by Level B harassment resulting from 
vibratory pile driving and removal and may result in temporary changes 
in behavior. Injurious or lethal takes are not expected due to the 
expected source levels and sound source characteristics associated with 
the activity, and the proposed mitigation and monitoring measures are 
expected to further minimize the possibility of such take.
    If a marine mammal responds to a stimulus by changing its behavior 
(e.g., through relatively minor changes in locomotion direction/speed 
or vocalization behavior), the response may or may not constitute 
taking at the individual level, and is unlikely to affect the stock or 
the species as a whole. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on animals or on the stock or species could potentially 
be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007). Given 
the many uncertainties in predicting the quantity and types of impacts 
of sound on marine mammals, it is common practice to estimate how many 
animals are likely to be present within a particular distance of a 
given activity, or exposed to a particular level of sound.
    Upland work can generate airborne sound and create visual 
disturbance that could potentially result in disturbance to marine 
mammals (specifically, pinnipeds) that are hauled out or at the water's 
surface with heads above the water. However, because there are no 
regular haul-outs in the vicinity of Jetty A, we believe that incidents 
of incidental take resulting from airborne sound or visual disturbance 
are unlikely.
    The Corps requested authorization for the incidental taking of 
small numbers of killer whale, Gray whale, harbor porpoise, Steller sea 
lion, California sea lion, and harbor seal near the MCR project area 
that may result from vibratory pile driving and removal during 
construction activities associated with the rehabilitation of Jetty A 
at the MCR.
    In order to estimate the potential incidents of take that may occur 
incidental to the specified activity, we must first estimate the extent 
of the sound field that may be produced by the activity and then 
consider in combination with information about marine mammal density or 
abundance in the project area. We first provide information on 
applicable sound thresholds for determining effects to marine mammals 
before describing the information used in estimating the sound fields, 
the available marine mammal density or abundance information, and the 
method of estimating potential incidences of take.

Sound Thresholds

    We use generic sound exposure thresholds to determine when an 
activity that produces sound might result in impacts to a marine mammal 
such that a take by harassment might occur. To date, no studies have 
been conducted that explicitly examine impacts to marine mammals from 
pile driving sounds or from which empirical sound thresholds have been 
established. These thresholds (Table 3) are used to estimate when 
harassment may occur (i.e., when an animal is exposed to levels equal 
to or exceeding the relevant criterion) in specific contexts; however, 
useful contextual information that may inform our assessment of effects 
is typically lacking and we consider these thresholds as step 
functions. NMFS is working to revise these acoustic guidelines; for 
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

             Table 3--Underwater Injury and Disturbance Threshold Decibel Levels for Marine Mammals
----------------------------------------------------------------------------------------------------------------
            Criterion                       Criterion definition                        Threshold *
----------------------------------------------------------------------------------------------------------------
Level A harassment...............  PTS (injury) conservatively based on   190 dB RMS for pinnipeds
                                    TTS **.                               180 dB RMS for cetaceans
Level B harassment...............  Behavioral disruption for impulse      160 dB RMS
                                    noise (e.g., impact pile driving).
Level B harassment...............  Behavioral disruption for non-pulse    120 dB RMS
                                    noise (e.g., vibratory pile driving,
                                    drilling).
----------------------------------------------------------------------------------------------------------------
* All decibel levels referenced to 1 micropascal (re: 1 [mu]Pa). Note all thresholds are based off root mean
  square (RMS) levels
** PTS=Permanent Threshold Shift; TTS=Temporary Threshold Shift.


[[Page 43753]]

Distance to Sound Thresholds

    Underwater Sound Propagation Formula--Pile driving generates 
underwater noise that can potentially result in disturbance to marine 
mammals in the project area. Transmission loss (TL) is the decrease in 
acoustic intensity as an acoustic pressure wave propagates out from a 
source. TL parameters vary with frequency, temperature, sea conditions, 
current, source and receiver depth, water depth, water chemistry, and 
bottom composition and topography. The general formula for underwater 
TL is:

TL = B * log 10 (R 1/R 2), where
TL = transmission loss in dB
R 1= the distance of the modeled SPL from the driven 
pile, and
R 2= the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]). A 
practical spreading value of fifteen is often used under conditions 
where water increases with depth as the receiver moves away from the 
shoreline, resulting in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions. 
Practical spreading loss (4.5 dB reduction in sound level for each 
doubling of distance) is assumed here.
    The Corps does not have information or modeling results related to 
pile installation activities. However, some features of the proposed 
action are similar to those recently proposed by the Navy, WSDOT, and 
other entities which were issued IHA/LOAs. For these reasons, NMFS 
considered some of the results from previous, representative monitoring 
efforts. Though the MCR navigation channel is a major commercial 
thoroughfare, there are no ports or piers in the immediate proximity of 
the jetties, as the seas are too dangerous. The location and setting of 
the MCR jetties is far more dynamic than a naval pier setting in the 
Puget Sound, the substrate is mostly sand, and the natural background 
noise is likely to be much higher with the large, breaking wave sets, 
dynamic currents, and high winds. The Corps project is also in the 
immediate proximity of the open ocean, with less opportunity for sound 
attenuation by land.
    NMFS considered representative results from underwater monitoring 
for concrete, steel, and wood piles that were installed via both impact 
and vibratory hammers in water depths from 5 to 15 meters (Illingworth 
and Rodkin 2007, WSDOT 2011 cited in Naval Base Kitsap 2014, Navy 2014, 
and NMFS 2011b). Transmission loss and propagation estimates are 
affected by the size and depth of the piles, the type of hammer and 
installation method, frequency, temperature, sea conditions, currents, 
source and receiver depth, water depth, water chemistry, and bottom 
composition and topography. NMFS reviewed several documents that 
included relevant monitoring results for radial distances and proxy 
sound levels encompassed by underwater pile driving noise. These 
distances for impact driving and vibratory driving for 24-in steel 
piles were summarized previously in Table 15 and Table 16 in the 
Application.
    Since no site-specific, in-water noise attenuation data is 
available, the practical spreading model described and used by NMFS was 
used to determine transmission loss and the distances at which impact 
and vibratory pile driving or removal source levels are expected to 
attenuate down to the pertinent acoustic thresholds. The underwater 
practical spreading model is provided below:

R2 = R1 * 10- ((dBat R1- 
dBacoustic threshold)/15)
where:
R1 = distance of a known or measured sound level.
R2 = estimated distance required for sound to attenuate 
to a prescribed acoustic threshold.

    NMFS used representative sound levels from different studies to 
determine appropriate proxy sound levels and to model estimated 
distances until pertinent thresholds (R1 and dB at 
R1). Studies which met the following parameters were 
considered: Pile materials comprised of wood, concrete, and steel pipe 
piles; pile sizes 24- up to 30-inches diameter, and pile driver type of 
either vibratory and impact hammers. These types and sizes of piles 
were considered in order to evaluate a representative range of sound 
levels that may result from the Proposed Action. In some cases since 
there was little or no data specific to 24-inch piles, NMFS analyzed 
30-inch piles as the next larger pile size with available data. The 
Corps will include a maximum pile size of 24-inches as a constraint in 
its construction contracts, though it will consult with NMFS regarding 
the originally proposed size.
    Results of the practical spreading model provided the distance of 
the radii that were used to establish a ZOI or area affected by the 
noise criteria. At the MCR, the channel is about 3 miles across between 
the South and North Jetty. These jetties, as well as Jetty A, could 
attenuate noise, but the flanking sides on two of the jetties are open 
ocean, and Jetty A is slightly further interior in the estuary. Clatsop 
Spit, Cape Disappointment, Hammond Point, as well as the Sand Islands, 
are also land features that would attenuate noise. Therefore, as a 
conservative estimate, the NMFS is using (and showing on ZOI maps) the 
maximum distance and area but has indicated jetty attenuation in the 
ZOI area maps (See Figure 19 in the Application).
    NMFS selected proxy values for impact installation methods and 
calculated distances to acoustic thresholds for comparison and 
contextual purposes. As note previously, the Corps is not proposing 
impact installation. NMFS ultimately relied most heavily on the proxy 
values developed by the Navy (2014).
    For impact installation, NMFS used 193 rms dB re 1 [micro]Pa rms at 
a distance of 10 meters, which is comprised of the range of average rms 
of n-weighted piles used to determine the recommended proxy source SPLs 
at 10m as determined by Navy (2014). The Tongue Point data (182 db re 1 
[micro]Pa rms at a distance of 10 meters for 24-in steel piles (Navy 
2014) is likely applicable to this MCR jetty project because it is of 
similar sandy rather than gravely substrate; and it is within the same 
geographical and hydraulic context, though it is likely more sheltered 
than conditions at the jetties. Therefore, 193 rms dB re 1 [micro]Pa 
rms is an extremely conservative proxy estimate for impact 
installation, as sandy substrate and the hydraulic context at the MCR 
project area would further reduce spreading distance. Note that impact 
driving is not being proposed by the Corps.
    For vibratory installation, NMFS proposes 163 dB re 1 [mu]Pa rms. 
The proxy value of 163 dB re 1 [mu]Pa rms is greater than the 24-inch 
pipe pile proxy and equal to the sheet pile values proposed by Navy 
(2014) at 161 dB re 1 [micro]Pa rms and 163 dB re 1 [micro]Pa rms, 
respectively, and is also higher than the Friday Harbor Ferry sample 
(162 dB re

[[Page 43754]]

1 [micro]Pa rms) (Navy 2014 and Laughlin 2010a cited in Washington 
State Ferries 2013, respectively). NMFS also proposes 163 dB re 1 
[micro]Pa rms to reflect sheet pile installation, which registered 
higher than the pipe pile levels in the proxy study. Given the 
comparative differences between the substrate and context used in the 
Navy study relative to the MCR, 163 dB re 1 [micro]Pa rms is a very 
conservative evaluation level. Results are listed in Table 4.

 Table 4. Calculated Area Encompassed Within Zone of Influence at MCR Jetties for Underwater Marine Mammal Sound
                                              Thresholds at Jetty A
----------------------------------------------------------------------------------------------------------------
                                                                                                 Area excluding
                                                                                                  land & jetty
                Jetty                       Underwater threshold          Distance--m (ft)       masses--km\2\
                                                                                                    (mi\2\)
----------------------------------------------------------------------------------------------------------------
Jetty A: ~ Station 78+50, River Side.  Impact driving, pinniped       16 (52.5)..............    <0.001 (0.0003)
                                        injury (190 dB)*.
                                       Impact driving, cetacean       74 (242.8).............       0.01 (0.004)
                                        injury (180 dB)*.
                                       Impact driving, disturbance    1,585 (5,200.1, or ~1          3.38 (1.31)
                                        (160 dB)*.                     mile).
                                       Vibratory driving, pinniped    0......................                  0
                                        injury (190 dB).
                                       Vibratory driving, cetacean    1 (3.3)................          <0.000003
                                        injury (180 dB).                                              (0.000001)
                                       Vibratory driving,             7,356 (4.6 miles)......       23.63 (9.12)
                                        disturbance (120 dB).
----------------------------------------------------------------------------------------------------------------

    Note that the actual area insonified by pile driving activities is 
significantly constrained by local topography relative to the total 
threshold radius. The actual insonified area was determined using a 
straight line-of-sight projection from the anticipated pile driving 
locations. This area is depicted in Table 4 and represented in the 
Application submitted by the Corps in Figure 19 of the Application.
    The method used for calculating potential exposures to impact and 
vibratory pile driving noise for each threshold was estimated using 
local marine mammal data sets, the Biological Opinion, best 
professional judgment from state and federal agencies, and data from 
IHA estimates on similar projects with similar actions. All estimates 
are conservative and include the following assumptions:
     During construction, each species could be present in the 
project area each day. The potential for a take is based on a 24-hour 
period. The model assumes that there can be one potential take (Level B 
harassment exposure) per individual per 24-hours.
     All pilings installed at each site would have an 
underwater noise disturbance equal to the piling that causes the 
greatest noise disturbance (i.e., the piling furthest from shore) 
installed with the method that has the largest ZOI. The largest 
underwater disturbance ZOI would be produced by vibratory driving steel 
piles. The ZOIs for each threshold are not spherical and are truncated 
by land masses which would dissipate sound pressure waves.
     Exposures were based on estimated work days. Numbers of 
days were based on an average production rate of 15 pilings per day for 
a total of 68 pile installation days. This means construction at each 
jetty offloading facility would occur over an approximate span of ~ 17 
days.
     In absence of site specific underwater acoustic 
propagation modeling, the practical spreading loss model was used to 
determine the ZOI.

Killer Whale

    Southern resident killer whales have been observed offshore near 
the study area and ZOI, but the Corps does not have fine-scale details 
on frequency of use. However, as noted in Section 3, members of K and L 
pods were sighted off the Oregon Coast in 1999 and 2000 and whales move 
as far north as Canada down to California, passing the MCR. While 
killer whales do occur in the Columbia River plume, where fresh water 
from the river intermixes with salt water from the ocean, they are 
rarely seen in the interior of the Columbia River Jetty system. The 
insonified area associated with the proposed action at Jetty A does not 
extend out into the open ocean where killer whales are likely to be 
found. Furthermore, the Corps has limited its pile installation window 
in order to avoid peak salmon runs and any overlap with the presence of 
Southern residents. To ensure no Level B acoustical harassment occurs, 
the Corps will restrict pile installation from October 1 until on or 
after May 1 of each season. However, this restriction was enacted 
primarily for construction work at the North and South jetties, where 
the insonified zone will radiate out towards the open ocean. As such 
NMFS is not anticipating any acoustic exposure to Southern residents. 
Also note that in the 2011 Biological Opinion, NMFS issued a not likely 
to adversely affect determination. Therefore, NMFS has determined that 
authorization of take for Southern residents is not warranted.
    Western Transient killer whales may be traversing offshore over a 
greater duration of time than the feeding resident. They are rarely 
observed inside of the jetty system. The Southwest Fisheries Science 
Center (SWFSC) stratum model under the Marine Animal Monitor Model 
provides an estimated density of 0.00070853 animals per km \2\ for 
summer killer whales for areas near MCR, which may provide a surrogate 
proxy value for assuming possible densities near the jetties (Barlow et 
al. 2009, Halpin et al. 2009 at OBIS-SEAMAP). Given anecdotal evidence 
(Griffith 2015) and sightings recorded on the OBIS network from surveys 
done in 2005 (Halpin et al. 2009, OBIS-SEAMAP 2015), this density may 
be appropriate for the MCR vicinity.
    The following formula was used to calculate exposure using

Exposure Estimate = (0.000708DensityEstimate * 
23.63ZOI Jetty A * 17days) = 0.28 killer whale 
exposures
Where:
NDensityEstimate = Represents estimated density of 
species within the 4.6-mile radius encompassing the ZOI at Jetty A; 
using the density model suggested by NOAA (2015), this equates to 
0.000708 animals per km \2\ (Barlow et al. 2009).
Days = Total days of pile installation or removal activity (~17 
days)

    Given the low density and rare occurrence of transient killer 
whales in the ZOI, exposure of feeding or transient killer whales to 
Level B acoustical harassment from pile driving is unlikely to occur. 
However, NMFS proposes to authorize take of small number due to the 
remote chance that transient orcas remain in the vicinity to feed on 
pinnipeds that frequent the haulouts at the South Jetty.

[[Page 43755]]

    NMFS proposes to authorize the take of 8 transients because 
solitary killer whales are rarely observed, and transient whales travel 
in pods of 2-15 members. NMFS has assumed a pod size of 8.

Gray Whale

    Based on anecdotal information and sightings between 2006 and 2011 
(Halpin et al. 2009 at OBIS SEAMAP 2015), gray whales may be in the 
proximity of the proposed action area and exposed to underwater 
acoustic disturbances. However, no data exists that is specific to 
presence and numbers in the MCR vicinity and gray whale density 
estimates were not available on the SERDP or OBIS-SEAMAP web model 
sites. Anecdotal evidence also indicates gray whales have been seen at 
MCR, but are not a common visitor, as they mostly remain in the 
vicinity of the further offshore shelf-break (Griffith 2015). According 
to NOAA's Cetacean Mapping classification of the MCR vicinity 
pertaining to gray whale use, its Biologically Important Area 
categorization is indicated as a migration corridor (https://cetsound.noaa.gov/biologically-important-area-map). As primarily bottom 
feeders, gray whales are the most coastal of all great whales; they 
primarily feed in shallow continental shelf waters and live much of 
their lives within a few tens of kilometers of shore (Barlow et. al. 
2009 on OBIS-SEAMAP 2015).
    A relatively small number of whales (approximately 200) summer and 
feed along the Pacific coast between Kodiak Island, Alaska and northern 
California (Darling 1984, Gosho et al. 2011, Calambokidis et al. 2012 
cited in NOAA 2014c).
    The Pacific Coast Feeding Group or northbound summer migrants would 
be the most likely gray whales to be in the vicinity of MCR. Since no 
information pertaining to gray whale densities could be identified, 
NMFS elected to apply proxy data for estimating densities. As a proxy, 
data pertinent to humpback whales (0.0039 animals per km\2\) was 
selected because both are baleen species found near the MCR vicinity 
for the same purposes (as a migration route or temporary feeding zone). 
However, the number of estimated exposures at Jetty A was increased to 
account for the fact that gray whales are more likely to be in the 
nearshore environment than humpback whales. This increase was proposed 
strictly as a conservative assumption to acknowledge the distinct 
preference gray whales may have over humpbacks for nearshore feeding.
    The following formula was used to calculate exposure:

Exposure Estimate = (0.0039DensityEstimate * 
23.63ZOI Jetty A * 17days) + 1 = 1.56 gray 
whale exposures

    Migrating gray whales often travel in groups of 2, although larger 
pods do occur. For gray whales, NMFS is proposing 4 Level B authorized 
takes.

Harbor Porpoise

    Harbor porpoises are known to occupy shallow, coastal waters and, 
therefore, are likely to be found in the vicinity of the MCR. They are 
known to occur within the proposed project area, however, density data 
for this region is unavailable (Griffith 2015).
    The SWFSC stratum model under the Marine Animal Monitor Model 
provides an estimated density per km\2\ of year-round porpoises for 
areas near northern California, which may provide a surrogate proxy 
value for assuming possible densities near the jetties. Though not in 
the project vicinity, the range of 3.642 animals/km \2\ (Barlow et al. 
2009, Halpin et al. 2009) is a relatively high density compared to 
values moving even further south along the model boundaries, for which 
the northern-most extent ends in California. Given anecdotal evidence 
(Griffith 2015) and sightings recorded on the OBIS network from surveys 
done between 1989 and 2005, (Halpin et al. 2009, OBIS-SEAMAP 2015), 
this higher density may be appropriate for the MCR vicinity, or may be 
conservative.
    The formula previously described was used to arrive at a take 
estimate for harbor porpoise.

Exposure Estimate = (3.642DensityEstimate * 
23.63ZOI Jetty A * 17days) = 1,464.

    Based on the density model suggested by NOAA (2015), the Corps has 
provided a very conservative maximum estimate of 1,4640 harbor porpoise 
disturbance exposures over the 17 days of operation. However, this 
number of potential exposures does not accurately reflect the actual 
number of animals that would potentially be taken for the MCR jetty 
project. Rather, it is more likely that the same pod may be exposed 
more than once during the 17-day operating window. The highest 
estimated number of animals exposed on any single day based on the 
modeled proxy density (Barlow et al. 2009 at SERDP) and the jetty with 
the greatest ZOI is 193 animals (from South Jetty Channel). While the 
number of pods in the vicinity of the MCR is unknown, the size of the 
pods is usually assumed to be significantly smaller than 193 animals. 
According to OBIS-SEAMAP (2015 and Halpin et al. 2009), the normal 
range of group size generally consists of less than five or six 
individuals, though aggregations into large, loose groups of 50 to 
several hundred animals could occur for feeding or migration. Because 
the ZOI only extends for a maximum of 4.6 miles, it may also be assumed 
that due to competition and territorial circumstances only a limited 
number of pods would be feeding in the ZOI at any particular time. If 
the modeled density calculations are assumed, then this means anywhere 
from 32 small pods to 2 large, 100-animal pods might be feeding during 
every day of pile installation. Given these values seem an unrealistic 
representation of use and pod densities within any one of the ZOIs, 
NMFS is proposing an alternative calculation.
    NMFS conservatively assumed that a single, large feeding pod of 50 
animals forms within the ZOI for Jetty A on each day of pile 
installation. Though this is likely much higher than actual use by 
multiple pods in the vicinity, it more realistically represents a 
worst-case scenario for the number of animals that could potentially be 
affected by the proposed work. This calculation also assumes that it is 
a new pod of individuals would be affected on each installation day, 
which is also unlikely given pod residency. NMFS is proposing this 
higher number in acknowledgement of the SERDP density estimates 
originally proposed by NOAA (2015). Therefore, Corps has provided an 
extreme estimate of disturbance exposures over the duration of the 
entire project, and is requesting Level B take for 850 animals.

Pinnipeds--Stellar Sea Lion, California Sea Lion and Harbor Seal

    There are haulout sites on the South Jetty used by pinnipeds, 
especially Steller sea lions. It is likely that pinnipeds that use the 
haulout area in would be exposed to 120 dB threshold acoustic threshold 
during pile driving activities. The number of exposures would vary 
based on weather conditions, season, and daily fluctuations in 
abundance. Based on a survey by the Washington Department of Fish & 
Wildlife (WDFW) the number of affected Steller sea lions could be 
between 200-800 animals per month; California sea lion numbers could 
range from 1 to 500 per month and the number of harbor seals could be 
as low as 1 to as high as 57 per month. Exposure and take estimates 
below are based on past pinniped data from WDFW (2000-2014 data), which 
had a more robust monthly sampling frequency relative to ODFW counts. 
The

[[Page 43756]]

exception to this was for harbor seal counts, for which ODFW (also 
2000-2014 data) had more sampling data in certain months. Therefore, 
ODFW harbor seal data was used for the months of May and July. Exposure 
estimates are much higher than take estimates. This is because unlike 
the exposure estimate which assumes all new individuals, the take 
estimate request assumes that some of the same individuals will remain 
in the area and be exposed multiple times during the short 17-day 
installation period to complete and remove each offloading facility 
(for a total of about 68 days). NMFS examined the estimated monthly 
average number of animals from 2000-2014 hauled on South Jetty during 
May and June, which are the most likely months for pile installation as 
is shown in Table 5. NMFS assumed that 50% of the three species may be 
in the water at any given time during pile installation. This is based 
on the best professional judgment of a ODFW biologist, who stated: 
``Assuming another 50% in the water above what is hauled out is 
probably on the high end, but it's probably best to be conservative 
(i.e., have more takes authorized than actually incurred). It's 
probably more like 10-20% but it's highly variable and dependent on a 
lot of unpredictable factors like weather conditions, recent 
disturbance events, etc.'' (ODFW 2015). There are no anticipated 
airborne exposures since the main haul out sites are not in close 
proximity to Jetty A. Note that the formula used by NMFS is different 
than that employed by the Corps in their application as NMFS is only 
analyzing potential impacts associated with Jetty A.
    To reiterate, these exposure estimates assume a new individual is 
exposed every day throughout each acoustic disturbance, for the entire 
duration of the project.

Exposure EstimateStellar = (Nest(May+June) * 
50% * 17underwater/piles days) = 12,750 Steller sea lions
Exposure EstimateCalifornia = (Nest(May+June) 
* 50% * 17underwater/piles days) = 2,788 CA sea lions
Exposure EstimateHarbor = (Nest(May+June) * 
50% * 17underwater/piles days)= 493 Harbor porpoises

where:

Nest = Estimated monthly average number of species hauled 
out at South Jetty based on WDFW data.
Duration = total days of pile installation or removal activity for 
underwater thresholds (68);
Density = the estimated percentage of individuals in the respective 
ZOI: underwater assumed to be 50% of WDFW haul-out average during 2 
most likely months of pile installation (May or June);

  Table 5--Estimated Sound Exposures Events Experienced by Pinnipeds During Pile Installation at All MCR Jetties and Construction/Survey Seasons at the
                                                                       South Jetty
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Steller sea lion               California sea lion                 Harbor seal
                                                         -----------------------------------------------------------------------------------------------
                          Month                            Avg \1\  Underwater (# at 50%   Avg \1\  Underwater (# at 50%   Avg 1 2  Underwater (# at 50%
                                                              #           Density)            #           Density)            #           Density)
--------------------------------------------------------------------------------------------------------------------------------------------------------
April...................................................       587  ....................        99  ....................  ........  ....................
May.....................................................       824                   412       125                    63         0                     0
June....................................................       676                   338       202                   101        57                    29
July....................................................       358  ....................         1  ....................        10  ....................
August..................................................       324  ....................       115  ....................         1  ....................
September...............................................       209  ....................       249  ....................  ........  ....................
October.................................................       384  ....................       508  ....................  ........  ....................
Preliminary Number of Individuals \3\...................  ........                   750  ........                   164  ........                    29
Total Exposures (over Duration \4\: 17 days.............  ........                12,750  ........                 2,788  ........                   493
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ WDFW monthly average from 2000-2014.
\2\ ODFW monthly averages for May and July 2000-2014 data due to additional available sampling data.
\3\ Conservatively assumes each exposure is to new individual, all individuals are new arrivals each month, and no individual is exposed more than one
  time.
\4\ Assumed 17 pile installation/removal days.

    Note that NMFS is using data from the South Jetty since data exists 
for this pinniped population data exists for haulouts near this 
location. This represents a worst-case scenario since Jetty A is likely 
to have fewer pinniped exposures. Therefore, South Jetty will serve as 
a proxy for Jetty A as part of this analysis.
    However, requesting take based on exposure calculations using the 
above density/duration would inaccurately suggest that the proposed 
action would take a disproportionally large number of pinnipeds on the 
West Coast. It also assumes that each exposure is affecting a new 
animal, when the reality is a single animal is likely to be exposed to 
underwater disturbance more than one time.
    NMFS is proposing the following take estimate and assumptions which 
should provide more realistic take estimates. NMFS will assume pile 
installation occurs only in either May or June, which is the most 
likely construction scenario. Further, it is assumed that the number of 
animals taken by underwater acoustic disturbance is represented by the 
highest average number of animals present during the installation month 
(May or June), and that all animals are exposed to the underwater 
disturbance. Therefore, for Steller sea lions, 824 animals will 
represent the seasonal take; for California sea lions, seasonal take 
will be 202 animals; and for harbor seals seasonal take will be 57 
animals. NMFS will assume one installation season of 17 days and that 
in-water work on Jetty A take would take only a single season. It is 
also assumed that every animal observed during a season would count as 
a take. Using these assumptions, the take calculations are estimated in 
Table 6 and result in 824 Stellar sea lion, 202 California sea lion and 
57 harbor seal takes.

[[Page 43757]]



  Table 6--Estimated Sound Exposures Events Experienced by Pinnipeds during Pile Installation at the South Jetty during and Construction/Survey Seasons
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Steller sea lion               California sea lion                 Harbor seal
                                                         -----------------------------------------------------------------------------------------------
                          Month                            Avg \1\  Underwater \3\ (# at   Avg \1\    Underwater (# at     Avg 1 2    Underwater (# at
                                                              #        100% exposure)         #        100% exposure)         #        100% exposure)
--------------------------------------------------------------------------------------------------------------------------------------------------------
April...................................................       587  ....................        99  ....................  ........  ....................
May.....................................................       824                   824       125                   125         0                     0
June....................................................       676                   676       202                   202        57                    57
July....................................................       358  ....................         1  ....................        10  ....................
August..................................................       324  ....................       115  ....................         1  ....................
September...............................................       209  ....................       249  ....................  ........  ....................
October.................................................       384  ....................       508  ....................  ........  ....................
Preliminary Number of Individuals per season (~17 days)   ........                   824  ........                   202  ........                    57
 \4\....................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ WDFW monthly average for daily populations counts from 2000-2014.
\2\ ODFW monthly averages for May and July 2000-2014 data) for daily population count due to additional available sampling data.
\3\ Conservatively assumes each exposure is to new individual, all individuals are new arrivals each month, and no individual is exposed more than one
  time.
\4\ Assumed 17 pile installation/removal days.

Analysis and Preliminary Determinations

Negligible Impact

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes, 
alone, is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, effects on habitat, and the status 
of the species.
    To avoid repetition, the discussion of our analyses applies to all 
the species listed in Table 6, given that the anticipated effects of 
this pile driving project on marine mammals are expected to be 
relatively similar in nature. There is no information about the size, 
status, or structure of any species or stock that would lead to a 
different analysis for this activity, else species-specific factors 
would be identified and analyzed.
    Pile driving activities associated with the rehabilitation of Jetty 
A at the mouth of the Columbia River, as outlined previously, have the 
potential to disturb or displace marine mammals. Specifically, the 
specified activities may result in take, in the form of Level B 
harassment (behavioral disturbance) only, from underwater sounds 
generated from pile driving. Potential takes could occur if individuals 
of these species are present in the insonified zone when pile driving 
is happening.
    No injury, serious injury, or mortality is anticipated given the 
nature of the activity and measures designed to minimize the 
possibility of injury to marine mammals. The potential for these 
outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Specifically, 
vibratory hammers will be the only method of installation utilized. No 
impact driving is planned. Vibratory driving does not have significant 
potential to cause injury to marine mammals due to the relatively low 
source levels produced (site-specific acoustic monitoring data show no 
source level measurements above 180 dB rms) and the lack of potentially 
injurious source characteristics. The likelihood that marine mammal 
detection ability by trained observers is high under the environmental 
conditions described for the rehabilitation of Jetty A at MCR further 
enables the implementation of shutdowns to avoid injury, serious 
injury, or mortality.
    The Corps' proposed activities are localized and of short duration. 
The entire project area is limited to the Jetty A area and its 
immediate surroundings. Actions covered under the Authorization would 
include installing a maximum of 24 piles for use as dolphins and a 
maximum of 93 sections of Z or H piles for retention of rock fill over 
17 days. The piles would be a maximum diameter of 24 inches and would 
only be installed by vibratory driving method. The possibility exists 
that smaller diameter piles may be used but for this analysis it is 
assumed that 24 inch piles will be driven.
    These localized and short-term noise exposures may cause brief 
startle reactions or short-term behavioral modification by the animals. 
These reactions and behavioral changes are expected to subside quickly 
when the exposures cease. Moreover, the proposed mitigation and 
monitoring measures are expected to reduce potential exposures and 
behavioral modifications even further. Additionally, no important 
feeding and/or reproductive areas for marine mammals are known to be 
near the proposed action area. Therefore, the take resulting from the 
proposed project is not reasonably expected to and is not reasonably 
likely to adversely affect the marine mammal species or stocks through 
effects on annual rates of recruitment or survival.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat, as analyzed in detail in 
the ``Anticipated Effects on Marine Mammal Habitat'' section. The 
project activities would not modify existing marine mammal habitat. The 
activities may cause some fish to leave the area of disturbance, thus 
temporarily impacting marine mammals' foraging opportunities in a 
limited portion of the foraging range; but, because of the short 
duration of the activities and the relatively small area of the habitat 
that may be affected, the impacts to marine mammal habitat are not 
expected to cause significant or long-term negative consequences.

[[Page 43758]]

    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff, 
2006; Lerma, 2014). Most likely, individuals will simply move away from 
the sound source and be temporarily displaced from the areas of pile 
driving, although even this reaction has been observed primarily only 
in association with impact pile driving. In response to vibratory 
driving, pinnipeds (which may become somewhat habituated to human 
activity in industrial or urban waterways) have been observed to orient 
towards and sometimes move towards the sound. The pile driving 
activities analyzed here are similar to, or less impactful than, 
numerous construction activities conducted in other similar locations, 
which have taken place with no reported injuries or mortality to marine 
mammals, and no known long-term adverse consequences from behavioral 
harassment. Repeated exposures of individuals to levels of sound that 
may cause Level B harassment are unlikely to result in hearing 
impairment or to significantly disrupt foraging behavior. Thus, even 
repeated Level B harassment of some small subset of the overall stock 
is unlikely to result in any significant realized decrease in fitness 
for the affected individuals, and thus would not result in any adverse 
impact to the stock as a whole. Level B harassment will be reduced to 
the level of least practicable impact through use of mitigation 
measures described herein and, if sound produced by project activities 
is sufficiently disturbing, animals are likely to simply avoid the 
project area while the activity is occurring.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of injury, serious injury, or 
mortality may reasonably be considered discountable; (2) the 
anticipated incidents of Level B harassment consist of, at worst, 
temporary modifications in behavior and; (3) the presumed efficacy of 
the proposed mitigation measures in reducing the effects of the 
specified activity to the level of least practicable impact. In 
combination, we believe that these factors, as well as the available 
body of evidence from other similar activities, demonstrate that the 
potential effects of the specified activity will have only short-term 
effects on individuals. The specified activity is not expected to 
impact rates of recruitment or survival and will therefore not result 
in population-level impacts.
    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 proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the Corps' rehabilitation of Jetty A at MCR will have 
a negligible impact on the affected marine mammal species or stocks.

Small Numbers Analysis

    Table 7 demonstrates the number of animals that could be exposed to 
received noise levels that could cause Level B behavioral harassment 
for the proposed work associated with the rehabilitation of Jetty A at 
MCR. The analyses provided above represents between <0.01%--3.9% of the 
populations of these stocks that could be affected by Level B 
behavioral harassment. The numbers of animals authorized to be taken 
for all species would be considered small relative to the relevant 
stocks or populations even if each estimated taking occurred to a new 
individual--an extremely unlikely scenario. For pinnipeds occurring in 
the vicinity of Jetty A, there will almost certainly be some overlap in 
individuals present day-to-day, and these takes are likely to occur 
only within some small portion of the overall regional stock.

             Table 7--Estimated Numbers of Marine Mammals That May Be Exposed to Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                         Total proposed                          Percentage  of
                       Species                          authorized takes        Abundance         total stock
----------------------------------------------------------------------------------------------------------------
Killer whale (Western transient stock)..............                     8                243                3.2
Gray whale (Eastern North Pacific Stock)............                     4             18,017              <0.01
Harbor porpoise.....................................                   850             21,487                3.9
Steller sea lion....................................                   824      63,160-78,198            1.3-1.0
California sea lion.................................                   202            296,750               0.01
Harbor seal.........................................                    57             24,732                0.2
----------------------------------------------------------------------------------------------------------------

    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, which are expected to reduce the number of marine mammals 
potentially affected by the proposed action, NMFS preliminarily finds 
that small numbers of marine mammals will be taken relative to the 
populations of 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. Therefore, NMFS has determined that the total taking of 
affected species or stocks would not have an unmitigable adverse impact 
on the availability of such species or stocks for taking for 
subsistence purposes.

Endangered Species Act (ESA)

    There are two marine mammal species that are listed as endangered 
under the ESA with confirmed or possible occurrence in the study area: 
humpback whale and Southern resident killer whale. For the purposes of 
this IHA, NMFS determined that take of Southern resident killer whales 
was highly unlikely given the rare occurrence of these animals in the 
project area. A similar conclusion was reached for humpback whales. On 
March 18, 2011, NMFS signed a Biological Opinion concluding that the 
proposed action is not likely to jeopardize the continued existence of 
humpback whales and may affect, but is not likely to adversely affect 
Southern resident killer whales.

National Environmental Policy Act (NEPA)

    The Corps issued the Final Environmental Assessment Columbia River 
at the Mouth, Oregon and Washington Rehabilitation of the Jetty System 
at the Mouth of the Columbia River and Finding of No Significant Impact 
in 2011. The environmental assessment (EA) and finding of no 
significant interest (FONSI) were

[[Page 43759]]

revised in 2012 with a FONSI being signed on July 26, 2012. NMFS will 
seek to re-affirm the findings of the 2012 FONSI.

Proposed Incidental Harassment Authorization

    As a result of these preliminary determinations, we propose to 
issue an IHA to the USACE the rehabilitation of Jetty A of the Columbia 
River Jetty System provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. The proposed 
IHA language is provided next.
    1. This Incidental Harassment Authorization (IHA) is valid from May 
1, 2016 through April 30, 2017.
    2. This Authorization is valid only for in-water construction work 
associated with the rehabilitation of Jetty A at MCR.
    3. General Conditions
    (a) A copy of this IHA must be in the possession of the Corps, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking include killer whale (Orcinus 
orca), Steller sea lion (Eumatopius jubatus), gray whale (Eschrichtius 
robustus), harbor porpoise (Phocoena phocoena), California sea lion 
(Zalophus californianus), and harbor seal (Phoca vitulina richardii)
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b).
    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 3(b) of the 
Authorization or any taking of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    (e) The Corps shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, and staff prior 
to the start of all in-water pile driving, and when new personnel join 
the work, in order to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures.
    4. Mitigation Measures
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) Time Restriction: For all in-water pile driving activities, the 
Corps shall operate only during daylight hours when visual monitoring 
of marine mammals can be conducted.
    (b) Establishment of Level B Harassment (ZOI)
    (i) Before the commencement of in-water pile driving activities, 
The Corps shall establish Level B behavioral harassment ZOI where 
received underwater sound pressure levels (SPLs) are higher then 120 dB 
(rms) re 1 [micro]Pa for and non-pulse sources (vibratory hammer). The 
ZOI delineates where Level B harassment would occur. For vibratory 
driving, the level B harassment area is between 10 m and 7.3 km.
    (c) The Corps is authorized to utilize only vibratory driving under 
this IHA.
    (d) Establishment of shutdown zone
    (i) Implement a minimum shutdown zone of 10 m during vibratory 
driving activities. If a marine mammal comes within or approaches the 
shutdown zone, such operations shall cease.
    (e) Use of Soft-start
    (i) The project will utilize soft start techniques for vibratory 
pile driving. We require the Corps to initiate sound from vibratory 
hammers for fifteen seconds at reduced energy followed by a thirty-
second waiting period, with the procedure repeated two additional 
times. Soft start will be required at the beginning of each day's pile 
driving work and at any time following a cessation of pile driving of 
thirty minutes or longer.
    (ii) Whenever there has been downtime of 20 minutes or more without 
vibratory driving, the contractor will initiate the driving with soft-
start procedures described above.
    (f) Standard mitigation measures
    (i) Conduct briefings between construction supervisors and crews, 
marine mammal monitoring team, and Corps staff prior to the start of 
all pile driving activity, and when new personnel join the work, in 
order to explain responsibilities, communication procedures, marine 
mammal monitoring protocol, and operational procedures.
    (ii) For in-water heavy machinery work other than pile driving 
(e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), if a marine 
mammal comes within 10 meters, operations shall cease and vessels shall 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions. This type of work could include the following 
activities: (1) movement of the barge to the pile location or (2) 
positioning of the pile on the substrate via a crane (i.e., stabbing 
the pile).
    (g) The Corps shall establish monitoring locations as described 
below.
    5. Monitoring and Reporting
    The holder of this Authorization is required to report all 
monitoring conducted under the IHA within 90 calendar days of the 
completion of the marine mammal monitoring
    (a) Visual Marine Mammal Monitoring and Observation
    (i) At least one individual meeting the minimum qualifications 
identified in Section 13 of the application by the Corps will monitor 
the exclusion and Level B harassment zones during vibratory pile 
driving.
    (ii) During pile driving, the area within 10 meters of pile driving 
activity will be monitored and maintained as marine mammal buffer area 
in which pile installation will not commence or will be suspended 
temporarily if any marine mammals are observed within or approaching 
the area of potential disturbance. This area will be monitored by one 
qualified field monitor stationed either on the jetty pile or pile 
driving rig.
    (iii) The area within the Level B harassment threshold for pile 
driving will be monitored by one observer stationed to provide adequate 
view of the harassment zone, such as Jetty A or the barge. Marine 
mammal presence within this Level B harassment zone, if any, will be 
monitored. Pile driving activity will not be stopped if marine mammals 
are found to be present. Any marine mammal documented within the Level 
B harassment zone during impact driving would constitute a Level B take 
(harassment), and will be recorded and reported as such.
    (iv) The individuals will scan the waters within each monitoring 
zone activity using binoculars (Vector 10X42 or equivalent), spotting 
scopes (Swarovski 20-60 zoom or equivalent), and visual observation .
    (v) If waters exceed a sea-state which restricts the observers' 
ability to make observations within the marine mammal buffer zone (the 
100 meter radius) (e.g. excessive wind or fog), impact pile 
installation will cease until conditions allow the resumption of 
monitoring.
    (vi) The waters will be scanned 15 minutes prior to commencing pile 
driving at the beginning of each day, and prior to commencing pile 
driving after any stoppage of 20 minutes or greater. If marine mammals 
enter or are observed within the designated marine mammal buffer zone 
(the 10m radius) during or 15 minutes prior to impact pile driving, the 
monitors will notify the on-site construction manager to not begin 
until the animal has moved outside the designated radius.
    (vii) The waters will continue to be scanned for at least 30 
minutes after pile driving has completed each day, and after each 
stoppage of 20 minutes or greater.
    (b) Data Collection

[[Page 43760]]

    (i) Observers are required to use approved data forms. Among other 
pieces of information, the Corps will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the Corps will attempt to 
distinguish between the number of individual animals taken and the 
number of incidents of take. At a minimum, the following information be 
collected on the sighting forms:
    1. Date and time that monitored activity begins or ends;
    2. Construction activities occurring during each observation 
period;
    3. Weather parameters (e.g., percent cover, visibility);
    4. Water conditions (e.g., sea state, tide state);
    5. Species, numbers, and, if possible, sex and age class of marine 
mammals;
    6. Description of any observable marine mammal behavior patterns, 
including bearing and direction of travel and distance from pile 
driving activity;
    7. Distance from pile driving activities to marine mammals and 
distance from the marine mammals to the observation point;
    8. Locations of all marine mammal observations; and
    9. Other human activity in the area.
    (c) Reporting Measures
    (i) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA, 
such as an injury (Level A harassment), serious injury or mortality 
(e.g., ship-strike, gear interaction, and/or entanglement), the Corps 
would immediately cease the specified activities and immediately report 
the incident to the Chief of the Permits and Conservation Division, 
Office of Protected Resources, NMFS, and the West Coast Regional 
Stranding Coordinators. The report would include the following 
information:
    1. Time, date, and location (latitude/longitude) of the incident;
    2. Name and type of vessel involved;
    3. Vessel's speed during and leading up to the incident;
    4. Description of the incident;
    5. Status of all sound source use in the 24 hours preceding the 
incident;
    6. Water depth;
    7. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    8. Description of all marine mammal observations in the 24 hours 
preceding the incident;
    9. Species identification or description of the animal(s) involved;
    10. Fate of the animal(s); and
    11. Photographs or video footage of the animal(s) (if equipment is 
available).
    (ii) Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with the Corps to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. The Corps would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    (iii) In the event that the Corps discovers an injured or dead 
marine mammal, and the lead MMO determines that the cause of the injury 
or death is unknown and the death is relatively recent (i.e., in less 
than a moderate state of decomposition as described in the next 
paragraph), the Corps would immediately report the incident to the 
Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS West Coast Stranding Hotline and/or by 
email to the West Coast Regional Stranding Coordinators. The report 
would include the same information identified in the paragraph above. 
Activities would be able to continue while NMFS reviews the 
circumstances of the incident. NMFS would work with the Corps to 
determine whether modifications in the activities are appropriate.
    (iv) In the event that the Corps discovers an injured or dead 
marine mammal, and the lead MMO determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the Corps would report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the NMFS West Coast Stranding Hotline 
and/or by email to the West Coast Regional Stranding Coordinators, 
within 24 hours of the discovery. The Corps would provide photographs 
or video footage (if available) or other documentation of the stranded 
animal sighting to NMFS and the Marine Mammal Stranding Network.
    6. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    NMFS requests comment on our analysis, the draft authorization, and 
any other aspect of the Notice of Proposed IHA for the Corps' 
rehabilitation of Jetty A at MCR. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on the Corps' request for an MMPA authorization.

    Dated: July 17, 2015.
Perry Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2015-18022 Filed 7-22-15; 8:45 am]
 BILLING CODE 3510-22-P