Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Columbia River Crossing Project, Washington and Oregon, 23548-23593 [2012-9086]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 77, Number 76 (Thursday, April 19, 2012)]
[Proposed Rules]
[Pages 23548-23593]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-9086]



[[Page 23547]]

Vol. 77

Thursday,

No. 76

April 19, 2012

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 217





 Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to Columbia River Crossing Project, Washington and Oregon; Proposed 
Rule

Federal Register / Vol. 77 , No. 76 / Thursday, April 19, 2012 / 
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 217

[Docket No. 110801455-2197-01]
RIN 0648-BB16


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Columbia River Crossing Project, Washington and Oregon

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS has received a request from the Department of 
Transportation's Federal Transit Authority (FTA) and Federal Highway 
Administration (FHWA), on behalf of the Columbia River Crossing project 
(CRC), for authorization to take marine mammals incidental to bridge 
construction and demolition activities at the Columbia River and North 
Portland Harbor, Washington and Oregon, over the course of 5 years from 
approximately July 2013 through June 2018. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is proposing regulations to govern 
that take and requests information, suggestions, and comments on these 
proposed regulations.

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

ADDRESSES: You may submit comments on this document, identified by 
110801455-2197-01, by any of the following methods:
     Electronic Submission: Submit all electronic public 
comments via the Federal e-Rulemaking Portal www.regulations.gov. To 
submit comments via the e-Rulemaking Portal, first click the Submit a 
Comment icon, then enter 110801455-2197-01 in the keyword search. 
Locate the document you wish to comment on from the resulting list and 
click on the Submit a Comment icon on the right of that line.
     Hand delivery or mailing of comments via paper or disc 
should be addressed to Tammy Adams, Acting Chief, Permits and 
Conservation Division, Office of Protected Resources, National Marine 
Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910.
    Comments regarding any aspect of the collection of information 
requirement contained in this proposed rule should be sent to NMFS via 
one of the means provided here and to the Office of Information and 
Regulatory Affairs, NEOB-10202, Office of Management and Budget, Attn: 
Desk Office, Washington, DC 20503, OIRA@omb.eop.gov.
    Instructions: Comments must be submitted by one of the above 
methods to ensure that the comments are received, documented, and 
considered by NMFS. Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered. All comments received are a part of the public 
record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address) submitted voluntarily by the sender 
will be publicly accessible. Do not submit confidential business 
information, or otherwise sensitive or protected information. NMFS will 
accept anonymous comments (enter N/A in the required fields if you wish 
to remain anonymous). Attachments to electronic comments will be 
accepted in Microsoft Word, Excel, or Adobe PDF file formats only.

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

SUPPLEMENTARY INFORMATION:

Availability

    A copy of CRC's application, and other supplemental documents, may 
be obtained by writing to the address specified above (see ADDRESSES), 
calling the contact listed above (see FOR FURTHER INFORMATION CONTACT), 
or visiting the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. A Draft Environmental Impact Statement (DEIS) on the 
Columbia River Crossing project, authored by the FTA and FHWA, is 
available for viewing at https://www.columbiarivercrossing.org/.

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined `negligible impact' in 50 CFR 216.103 
as ``* * * an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    Except with respect to certain activities not pertinent here, the 
MMPA defines `harassment' as: ``any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [``Level A harassment'']; or (ii) has 
the potential to disturb a marine mammal or marine mammal stock in the 
wild by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [``Level B harassment''].''

Summary of Request

    On November 22, 2010, NMFS received a complete application from CRC 
requesting authorization for take of three species of marine mammal 
incidental to construction and demolition activities in the Columbia 
River and North Portland Harbor, Washington and Oregon. CRC has 
requested regulations to be effective for the period of 5 years from 
approximately July 2013 through June 2018; portions of the project that 
may result in incidental take of marine mammals are anticipated to 
potentially last until March 2021. Marine mammals would be exposed to 
various operations, including pile driving and removal, demolition of 
existing structures, and the presence of construction-related vessels. 
Because the specified activities have the potential to take marine 
mammals present within the action area, CRC requests authorization to 
incidentally take, by Level B harassment only, Steller sea lions 
(Eumetopias jubatus), California sea lions (Zalophus californianus), 
and harbor seals (Phoca vitulina).

Description of the Specified Activity

    CRC is proposing a multimodal transportation project along a 5-mile 
section of the Interstate 5 (I-5) corridor connecting Vancouver, 
Washington, and Portland, Oregon. There are significant

[[Page 23549]]

congestion, safety, and mobility problems in the CRC project area. The 
existing northbound bridge was built in 1917, and the southbound bridge 
was added in 1958. These bridges have been classified as functionally 
obsolete because they do not meet current or future demands for 
interstate service, resulting in congestion-related delays. Assuming 
that no changes are made, the daily congestion period is projected to 
grow from the current 6 hours to 15 hours by 2030 (CRC, 2008). In 
addition, this section of I-5 has an accident rate more than double 
that of similar urban highways. Narrow lanes, short on-ramps, and non-
standard shoulders on the bridges contribute to accidents. When bridge 
lifts occur to allow passage of river traffic, all vehicular traffic is 
stopped, resulting in delays on connecting roadways and adding to 
unsafe driving conditions.
    Current public transit service between Vancouver and Portland is 
limited to bus service constrained by the limited capacity in the I-5 
corridor and is subject to the same congestion as other vehicles, which 
affects transit reliability and operations. Bicycle and pedestrian 
facilities are currently substandard in much of the project area.
    Seismic safety is also an important issue. Recent geotechnical 
studies have shown that the sandy soil under the mainstem Columbia 
River bridges would likely liquefy to a depth of 85 ft (26 m) during an 
earthquake greater than magnitude 8.0. This could cause irreparable 
damage to the bridges and potential loss of human life.
    To remedy these deficiencies, the CRC project proposes:
     Replacement of the existing Columbia River bridges with 
two new structures;
     Widening of the existing North Portland Harbor Bridge, and 
construction of three new structures across the harbor; and
     Demolition of existing Columbia River bridges.
    The new Columbia River crossing would carry traffic on two separate 
pier-supported bridges and would include a new light rail transit (LRT) 
line and improved bicycle/pedestrian facilities, using a stacked 
alignment that would reduce the number of in-water piers in the 
Columbia River by approximately one-third from alternative designs. CRC 
proposes six in-water pier complexes for a total of twelve piers for 
the Columbia River bridges.
    CRC proposes to widen the existing I-5 southbound bridge over North 
Portland Harbor, and would add three new bridges adjacent to the 
existing bridges. From east to west, these structures would carry:
     A three-lane northbound collector-distributor (CD) ramp 
carrying local traffic;
     Northbound and southbound I-5 on the widened existing 
bridge across the North Portland Harbor;
     Southbound CD ramps carrying local traffic; and
     LRT combined with a bicycle/pedestrian path.
    Each bridge would have four or five in-water bents, consisting of 
one to three drilled shafts. A bent is part of a bridge's substructure, 
composed of a rigid frame commonly made of reinforced concrete or steel 
that supports a vertical load and is placed transverse to the length of 
a structure. Bents are commonly used to support beams and girders. Each 
vertical member of a bent may be called a column, pier or pile. The 
horizontal member resting on top of the columns is a bent cap. The 
columns stand on top of some type of foundation or footer that is 
usually hidden below grade. A bent commonly has at least two or more 
vertical supports.
    The permanent in-water piers of both the Columbia River and North 
Portland Harbor crossings would be constructed using drilled shafts, 
rather than impact-driven piles. However, the project would require 
numerous temporary in-water structures to support equipment and 
materials during the course of construction, which may require the use 
of temporary impact-driven piles. These structures would include work 
platforms, work bridges, and tower cranes. Project construction would 
require the installation and removal of approximately 1,500 temporary 
steel piles.
    The existing Columbia River bridges would be demolished after the 
new Columbia River bridges have been constructed and after associated 
interchanges are operating. The existing Columbia River bridges would 
be demolished in two stages: (1) Superstructure demolition and (2) 
substructure demolition. In-water demolition would be accomplished 
either within cofferdams or with the use of diamond wire/wire saw. A 
full description of the activities proposed by CRC is described in the 
following sections.

Region of Activity

    The Region of Activity is located within the Lower Columbia River 
sub-basin. The Columbia River and its tributaries are the dominant 
aquatic system in the Pacific Northwest. The Columbia River originates 
on the west slope of the Rocky Mountains in Canada and flows 
approximately 1,200 mi (1,931 km) to the Pacific Ocean, draining an 
area of approximately 219,000 mi\2\ (567,207 km\2\) in Washington, 
Oregon, Idaho, Montana, Wyoming, Nevada, and Utah. Saltwater intrusion 
from the Pacific Ocean extends approximately 23 mi (37 km) upstream 
from the river mouth at Astoria, Oregon. Coastal tides influence the 
flow rate and river level up to Bonneville Dam at river mile (RM) 146 
(RKm 235) (USACE, 1989).
    The project area is highly altered by human disturbance, and 
urbanization extends to the shoreline. There has been extensive removal 
of streamside forests and wetlands. Riparian areas have been further 
degraded by construction of dikes and levees and the placement of 
stream bank armoring. For several decades, industrial, residential, and 
upstream agricultural sources have contributed to water quality 
degradation in the river. Additionally, existing levels of disturbance 
are high due to heavy commercial shipping traffic.
    The I-5 bridges are located at RM 106 (RKm 171) of the Columbia 
River. From north to south, the I-5 bridges cross the Columbia River 
from Vancouver, Washington, to Hayden Island in Portland, Oregon. From 
Hayden Island, a single I-5 bridge crosses North Portland Harbor to the 
mainland in Portland, Oregon. The North Portland Harbor is a large side 
channel of the Columbia River that flows between the southern bank of 
Hayden Island and the Oregon mainland. The channel branches off the 
Columbia River approximately 2 RM (3 RKm) upstream (east) of the 
existing bridge site, and flows approximately 5 RM (8 RKm) downstream 
(west) before rejoining the mainstem Columbia River (please see Figure 
2-2 of CRC's application). The Region of Activity has been defined as 
the area of the Columbia River and North Portland Harbor in which 
marine mammals may be directly impacted by sound generated by in-water 
construction activities, i.e., the area in which modeling indicates 
that underwater sound generated by the project would be greater than 
120 dB re: 1 [mu]Pa root mean square (rms; all underwater sound 
discussed in this document is referenced to 1 [mu]Pa).
    Due to the curvature of the river and islands present, underwater 
sound from pile installation would encounter land before it reaches 
modeled distances to the 120 dB disturbance threshold. Sound from pile 
installation could not extend beyond Sauvie Island, approximately 5.5 
RM (8.9 RKm) downstream, and Lady Island, 12.5 RM (20 RKm) upstream; 
thus, this distance

[[Page 23550]]

represents the extent of the Region of Activity downstream and upstream 
of CRC project construction activities. This distance encompasses the 
Columbia River from approximately RM 101 to 118 (RKm 163 to 190). 
Within North Portland Harbor, the maximum distance that underwater 
sound could extend would be 3.5 mi (5.6 km) downstream and 1.9 mi (3.1 
km) upstream of CRC project construction activities.

Dates of Activity

    CRC has requested regulations governing the incidental take of 
marine mammals for the 5-year period from July 2013 through June 2018. 
Construction activities for both the Columbia River and North Portland 
Harbor bridges are estimated to begin in July 2013. Construction 
activities for the Columbia River bridges are estimated to end in 2017, 
while construction activities for the North Portland Harbor bridges are 
estimated to end in 2016. Demolition of the existing Columbia River 
bridges is expected to occur for eighteen months, from approximately 
September 2019 until March 2021. However, some demolition could 
possibly occur during the proposed 5-year authorization period. Table 1 
provides an overview of the anticipated CRC project timeline and 
sequencing of project elements. Funding would be a significant factor 
in determining the overall sequencing and construction duration. 
Contractor schedules, weather, materials, and equipment could also 
influence construction duration. CRC would seek additional 
authorization under the MMPA for any in-water work continuing beyond 
the expiration of the proposed rule.
    The existing in-water work window for this portion of the Columbia 
River and North Portland Harbor, developed to reduce construction 
impacts to Endangered Species Act (ESA)-listed fish species, is 
November 1 through February 28. Because of the large amount of in-water 
work required, the CRC project would not be able to complete the in-
water work during this time period. Therefore, CRC has requested a 
variance to the in-water work window established by the Oregon and 
Washington Departments of Fish and Wildlife (ODFW and WDFW, 
respectively). Most in-water construction activities are proposed to 
occur year-round, although impact pile driving would occur only from 
September 15 to April 15. The rationale for CRC's proposed variance 
takes into account project hydroacoustic impacts in relation to run 
timing for ESA-listed fish species. The project's timing for impact 
pile driving overlaps with pinniped presence (primarily January through 
May) from approximately January through April 15.

                                    Table 1--Proposed Timing of In-Water Work
                               [CR = Columbia River; NPH = North Portland Harbor]
----------------------------------------------------------------------------------------------------------------
               Activity                      Description           Activity duration              Timing
----------------------------------------------------------------------------------------------------------------
1. Install small-diameter piles (less  Small-diameter piles     45 min/day (impact       Only within approved
 than or equal to 48 in (1.2 m)) with   would be used in the     hammer operation) with   extended in-water work
 impact methods \1\.                    construction of          up to 7.5 min/week of    window of September 15
                                        temporary work bridges/  unattenuated driving     through April 15 each
                                        platforms, tower         in CR and 5 min/week     year.
                                        cranes, and support      of unattenuated
                                        platforms.               driving in NPH.
                                                                138 days in CR, 134
                                                                 days in NPH.
2. Install small-diameter piles with   Small-diameter piles     Length of work day is    Year-round provided
 non-impact methods.                    would be used in the     subject to local sound   work does not violate
                                        construction of          ordinances, however      water quality
                                        temporary work bridges/  could be up to 24        standards.\2\
                                        platforms, barge         hours/day.
                                        moorings, tower         138 days in CR, 134
                                        cranes, and oscillator   days in NPH.
                                        support platforms.
3. Extract small-diameter piles (not   Removal of small-        Length of work day is    Year-round provided
 including cofferdams).                 diameter piles would     subject to local sound   work does not violate
                                        be done using            ordinances, however      water quality
                                        vibratory equipment or   could be up to 24        standards.
                                        direct pull.             hours/day.
4. Install/remove cofferdam for        Used to construct piers  Cofferdams could be in   Year-round provided
 construction of Columbia River         nearest to shore in      place for a maximum of   work does not violate
 bridges.                               the Columbia River       250 work days each.      water quality
                                        (Pier complexes 2 and    Installation and         standards.
                                        7). Steel sheet pile     dewatering of each
                                        sections to be           cofferdam would not
                                        installed by non-        take more than 65 work
                                        impact means to form a   days; cofferdam
                                        cofferdam. Sheet pile    removal would not take
                                        removal can be direct    more than 25 work
                                        pull or use a            days. Length of work
                                        vibratory hammer.        day is subject to
                                                                 local sound ordinances.
5a. Install large-diameter drilled     Used to construct piers  CR: 110-120 days/pier    Year-round provided
 shaft casings (greater than or equal   and bents not            complex.                 work does not violate
 to 72 in (1.8 m)) using vibratory      immediately adjacent    NPH: approximately 8      water quality
 hammer, rotator, or oscillator         to shore in the          days/shaft..             standards.
 outside of a cofferdam.                Columbia River and
                                        North Portland Harbor.
5b. Install large-diameter drilled     Used to construct piers  CR pier complexes 2 and  Year-round provided
 shaft casings using vibratory          and bents nearest to     7: approximately 84      work does not violate
 hammer, rotator, or oscillator         shore in the Columbia    days each.               water quality
 inside of a water- or sand-filled      River and North         NPH: approximately 8      standards.
 cofferdam.                             Portland Harbor.         days/shaft..
6. Clean out shafts and place          Applies to all piers     CR: 110-120 days/pier    Year-round provided
 reinforcing and concrete inside        and shafts. All          complex.                 work does not violate
 steel casings.                         activities/materials    NPH: approximately 8      water quality
                                        would be contained       days/shaft..             standards.
                                        within the casings and
                                        have no contact with
                                        the water.

[[Page 23551]]

 
7a. Perform placement of               Possible construction    Estimate 95 work days    Year-round. For pier
 reinforcement and concrete for a       method for shaft cap     per pier.                caps nearest shore:
 cast-in-place pile cap.                at pier complexes 2                               year-round if work
                                        and 7. All activities                             occurs within a de-
                                        and materials would be                            watered cofferdam.
                                        contained within forms
                                        and would have no
                                        contact with the
                                        water. The bottom of
                                        the pier caps may sit
                                        below the mud line.
7b. Place a prefabricated pile cap,    At CR pier complexes 3-  100 work days per pier.  For deep water piers:
 form, pile template, or similar        6. Potentially at pier                            year-round provided
 element into the water.                complexes 2 and 7.                                work does not violate
                                        Assume contact with                               water quality
                                        the water surface, but                            standards. For piers
                                        not with the riverbed.                            nearest shore: year-
                                                                                          round if work occurs
                                                                                          within a de-watered
                                                                                          cofferdam.
8. Install and remove cofferdam for    Steel sheet pile         Approximately 370 days.  Year-round provided
 demolition of existing Columbia        sections would be       Installation: 10 work     work does not violate
 River bridges.                         installed with a         days per pier,           water quality
                                        vibratory hammer or      Demolition: 20 work      standards.
                                        pushed in, to form a     days per pier,
                                        cofferdam. Sheet pile    Removal: 10 work days
                                        removal can be direct    per pier..
                                        pull or with a
                                        vibratory hammer. More
                                        than one cofferdam is
                                        to be in use at a time.
9a. Perform wire saw/diamond wire      Used throughout for      Pier cutting and         Year-round provided
 cutting outside of a cofferdam at or   demolition of existing   removal to take          work does not violate
 below the water surface.               bridges to cut           approximately 7 work     water quality
                                        concrete piers into      days per pier.           standards.
                                        manageable pieces.
                                        These pieces would
                                        then be loaded onto
                                        barges and transported
                                        off site.
9b. Perform wire saw/diamond wire      Used for demolition of   Pier cutting and         Year-round provided
 cutting or a hydraulic breaker         the existing Columbia    removal to take          work does not violate
 inside of a cofferdam.                 River bridges. Used in   approximately 7 work     water quality
                                        water to cut concrete    days per pier.           standards.
                                        piers into manageable
                                        pieces. Cofferdam
                                        would not be dewatered.
10. Remove material from river bed...  Old pier/bent            Less than 7 work days    No variance requested.
                                        foundations or riprap    during the published     November 1 to February
                                        from North Portland      standard in-water work   28.
                                        Crossing would be        window per pier.
                                        removed if obstructing
                                        construction. Would
                                        use bucket dredge.
10a. Spot remove debris and riprap     Guided removal (likely   Up to 2 hrs/day. Less    Year-round provided
 from river bed.                        underwater diver         than 7 work days.        work does not violate
                                        assisted) of specific                             water quality
                                        pieces of debris or                               standards.
                                        large riprap only in
                                        the location where the
                                        shaft would be
                                        drilled. In North
                                        Portland Harbor only.
                                        Would use bucket
                                        dredge.
----------------------------------------------------------------------------------------------------------------
Note: Proposed timing is contingent upon obtaining an in-water work variance from all relevant regulatory
  agencies.
\1\ To reduce number of impact pile strikes, temporary piles that are load-bearing would be vibrated to refusal,
  then driven and proofed with an impact hammer to confirm load-bearing capacity.
\2\ In the event water quality monitoring determines that work exceeds water quality standards, all in-water
  work would be suspended until corrective measures can be implemented.

Description of the Activity--Columbia River Bridges

    The project would construct two new bridges across the Columbia 
River downstream (to the west) of the existing interstate bridges. Each 
of the structures would range from approximately 91 to 136 ft (28-41 m) 
wide, with a gap of approximately 15 ft (5 m) between them. The over-
water length of each new mainstem bridge would be approximately 2,700 
ft (823 m).
    The Columbia River bridges would consist of six in-water pier 
complexes of two piers each, for a total of twelve in-water piers. 
Piers 3-6 would each have separate structures for the northbound and 
southbound bridges. Each pier would consist of up to nine 10-ft-
diameter (3 m) drilled shafts topped by a shaft cap (see Figure 1-4 of 
CRC's application for illustration). Pier complexes 2 through 7 are in-
water, beginning on the Oregon side. Pier complex 1 would be on land in 
Oregon, while pier complex 8 would be on land in Washington. Portions 
of pier complex 7 occur in shallow water (less than 20 ft [6 m] deep). 
The basic configuration of these bridges, the span lengths, and the 
layout of the bridges relative to the Columbia River shoreline and 
navigation channels are illustrated in Figure 1-2 of CRC's application.
    The proposed Columbia River mainstem crossing design uses dual 
stacked bridge structures, which reduces the number of in-water piers 
in the Columbia River by approximately one-third compared with 
alternative designs, and greatly reduces both the temporary 
construction impacts and the permanent effects of in-water piers. The 
western structure would carry southbound I-5 traffic on the top deck,

[[Page 23552]]

with LRT on the lower deck. The eastern structure would carry 
northbound I-5 traffic on the top deck, with bicycle/pedestrian traffic 
on the lower deck.
    At each pier complex, sequencing would occur as listed below. 
Details of each activity are presented in following sections.
     Install temporary cofferdam (applies to pier complexes 2 
and 7 only).
     Install temporary piles to moor barges and to support 
temporary work platforms (at pier complexes 3 through 6) and work 
bridges (at pier complexes 2 and 7).
     Install drilled shafts for each pier complex.
     Remove work platform or work bridge and associated piles.
     Install shaft caps at the water level.
     Remove cofferdam (applies to pier complexes 2 and 7 only).
     Erect tower crane.
     Construct columns on the shaft caps.
     Build bridge superstructure spanning the columns.
     Remove tower crane.
     Connect superstructure spans with mid-span closures.
     Remove barge moorings.
    A construction sequence was developed for building the new Columbia 
River bridges and demolishing the existing structures (see Figure 1-5 
of CRC's application). Once a construction contract is awarded, the 
contractor may sequence the construction in a way that may not conform 
exactly to the proposed schedule but that best utilizes the materials, 
equipment, and personnel available to perform the work. However, the 
amount of in-water work that can be conducted at any one time is 
limited, and is based on three factors:
    1. The amount of equipment available to build the project would 
likely be limited. Based on equipment availability, the CRC engineering 
team estimates that only two drilled shaft operations could occur at 
any time.
    2. The physical space the equipment requires at each pier would be 
substantial. The estimated sizes of the work platforms/bridges and 
associated barges are shown in Appendix A of CRC's application. This is 
a conceptual design developed by the CRC project team to provide a 
maximum area of impact. The actual work platforms would be designed by 
the contractor; therefore, actual sizes would be determined at a later 
date. The overlap of work platforms/bridges and barge space limits the 
amount and type of equipment that can operate at a pier complex at one 
time.
    3. The U.S. Coast Guard has required that one navigation channel be 
open at all times during construction, to the extent feasible.
    All the activities listed above may occur at more than one pier 
complex at a time. Please see Appendix A of CRC's application for 
conceptual diagrams of the construction sequence.
    Temporary Structures--Pier complexes 2 and 7 would each require one 
temporary cofferdam. Cofferdams would consist of interlocking sections 
of sheet piles to be installed with a vibratory hammer or with press-in 
methods. Cofferdams would be removed using a vibratory hammer or direct 
pull.
    Additionally, the project would include numerous temporary in-water 
structures to support equipment and materials during the course of 
construction. These structures would include work platforms, work 
bridges, and tower cranes. They would be designed by the contractor 
after a contract is awarded, but prior to construction.
    Work platforms, which would surround the future location of each 
shaft cap, would be constructed at pier complexes 3 through 6. A 
conceptual design of a temporary in-water work platform may be found in 
CRC's application (Figure 11 of Appendix A). Work bridges would be 
installed at pier complexes 2 and 7 so that equipment can access these 
pier complexes directly from land. Temporary work bridges would be 
placed only on the landward side of these pier complexes. The bottom of 
the temporary work platforms and bridges would be a few feet above the 
water surface. The decks of the temporary work structures would be 
constructed of large, untreated wood beams to accommodate large 
equipment, such as 250-ton cranes. After drilled shafts and shaft caps 
have been constructed, the temporary work platforms and their support 
piles would be removed.
    After work platforms/bridges are removed at a given pier complex, 
one tower crane would be constructed between each pair of adjacent 
piers that makes up the pier complex. The crane would construct the 
bridge columns and the superstructure. Following construction of the 
columns and superstructure, the tower cranes and their support piles 
would be removed.
    Steel pipe piles would be used to support the temporary support 
structures. In addition, four temporary piles could surround each of 
the drilled shafts. Due to the heavy equipment and stresses placed on 
the support structures, all of these temporary piles would need to be 
load-bearing. Load-bearing piles would be installed using a vibratory 
hammer and then proofed with an impact hammer to ensure that they meet 
project specifications demonstrating load-bearing capacity. The number 
and size of temporary piles for these structures is listed in Table 2.

                    Table 2--Summary of Steel Pipe Piles and Temporary Structures Required for Construction of Columbia River Bridges
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                 Total
       Structure              Number            Pile diameter           Pile length       Piles per structure  number of     Duration present in water
                                                                                                                 piles              (days-each)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Work platforms/bridges.  6...............  18-24 in (0.5-0.6 m)..  70-90 ft (21-27 m)...  100................        600  260-315.
                                           42-48 in (1.1-1.2 m)..  120 ft (37 m)........  32.................        192  ..............................
Tower cranes...........  6...............  42-48 in..............  120 ft...............  8..................         48  150-275.
Barge moorings.........  N/A.............  18-24 in..............  70-90 ft.............  Varies.............         80  120/mooring.
Barges (cumulative, at   Up to 12........  N/A...................  N/A..................  N/A................        N/A  Varies.
 a single time).
                        --------------------------------------------------------------------------------------------------------------------------------
    Total..............  Varies..........  ......................  .....................  ...................        920  ..............................
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 23553]]

    Barges would be used as platforms to conduct work activities and to 
haul materials and equipment to and from the work site. Barges would be 
moored to non-load-bearing steel pipe piles and adjacent to temporary 
work structures. Several types and sizes of barges would be used for 
bridge construction. The type and size of a barge would depend on how 
the barge is used. No more than twelve barges are estimated to be 
moored or active in the Columbia River at any one time throughout the 
construction period. Barges would be moored around each pier complex. 
Approximately eighty mooring piles would be installed over the life of 
the project, each in place for approximately 120 work days. Mooring 
piles would be vibrated into the sediment until refusal. Vibratory 
installation would take between 5-30 minutes per pile.
    The number of temporary platforms or bridges in the Columbia River 
at one time would vary between zero and three during construction. Up 
to four work platforms and two work bridges would be required to 
install drilled shafts and construct shaft caps. Each work platform/
bridge would require 22 to 25 work days to install. Each work platform/
bridge would be in place for approximately 260 to 315 work days. Each 
tower crane would require approximately two work days to drive support 
piles and an additional thirteen work days to construct the platform. 
Each tower crane would be in place for approximately 150 to 275 work 
days.
    Load-bearing piles (used for work platforms/bridges and tower 
cranes) would be vibrated to refusal (approximately 5-30 minutes per 
pile), then driven and proofed with an impact hammer to confirm load-
bearing capacity. An average of six temporary piles would be installed 
per day using vibratory installation to set the piles, and up to two 
impact drivers to proof them. Rates of installation would be determined 
by the type of installation equipment, substrate, and required load-
bearing capacity of each pile. Temporary piles would be installed and 
removed throughout the construction process. No more than two impact 
pile drivers would operate at one time. Use of two impact pile drivers 
would primarily occur within a single pier complex.
    In general, temporary piles would extend only into the alluvium to 
an approximate depth of 70 to 120 ft (21-37 m). Standard pipe lengths 
are 80 to 90 ft (24-27 m), so some piles may need to be spliced to 
achieve these depths.
    Estimated pile installation specifications are provided in Table 3. 
The number of pile strikes was estimated by Washington Department of 
Transportation (WSDOT) geotechnical and CRC project engineers, based on 
information from past projects and knowledge of site sediment 
conditions. The actual number of pile strikes would vary depending on 
the type of hammer, the hammer energy used, and substrate composition. 
The strike interval of 1.5 seconds (forty strikes per minute) is also 
estimated from past projects and is based on use of a diesel hammer. 
This estimate is within the typical range of 35-52 strikes per minute 
for diesel hammers (HammerSteel, 2009). As shown in Table 3, for any 
one 12-hour daily pile driving period, less than 1 hour of pile driving 
would occur. Please see Table 8 for a summary of time required for 
vibratory driving.

                         Table 3--Pile Strike Summary for Construction in Columbia River
----------------------------------------------------------------------------------------------------------------
                                                                                                 Hours of pile
                                                                                Estimated      driving per 12-hr
              Pile Size                Estimated piles   Estimated strikes   maximum strikes       daily pile
                                      installed per day       per pile           per day         driving  work
                                                                                                    period*
----------------------------------------------------------------------------------------------------------------
18-24 in (0.5-0.6 m)................                  2                300                600               0.25
42-48 in (1.1-1.2 m)................                  4                300              1,200               0.50
                                     ---------------------------------------------------------------------------
    Total...........................                  6                N/A              1,800               0.75
----------------------------------------------------------------------------------------------------------------
* This scenario assumes just one pile being driven at a time. During construction, up to two piles may be driven
  at the same time in the Columbia River. If this were to occur, the strike numbers would stay the same, but the
  actual driving time would decrease.

    A sound attenuation device (i.e., bubble curtain) would be used 
during all impact pile driving, with the exception of periods when the 
device would be turned off to measure its effectiveness, in accordance 
with the hydroacoustic monitoring plan. A period of up to 7.5 min per 
week of pile driving without the use of an attenuation device has been 
allocated in analyses of project impacts, to allow for this study of 
mitigation effectiveness, as well as for instances when the device 
might fail. If the attenuation device fails, pile driving activities 
would shut down as soon as practicable and resolution of the problem 
would occur; however, some amount of unattenuated driving may occur 
before shut-down can safely occur. By incorporating this time into the 
analysis, the project may still proceed in the event of an equipment 
failure without exceeding analyzed thresholds. With the exception of 
hydroacoustic monitoring, intentional impact pile driving without a 
sound attenuation device is not proposed nor would it be authorized. In 
addition, to limit hydroacoustic impacts to marine mammals, there would 
be, at minimum, a consecutive 12-hour period without impact pile 
driving for every 24-hour day.
    Permanent Structures--In-water drilled shaft construction is 
accomplished by installing large diameter steel casing to a specified 
depth (up to -270 ft (-82 m) North American Vertical Datum of 1988) to 
the top of the competent geological layer, which is the Troutdale 
Formation in the project area. The top layer of river substrate is 
composed of loose to very dense alluvium (primarily sand and some 
fines), beneath which is approximately 20 ft (6 m) of dense gravel, 
underlain by the Troutdale Formation.
    A vibratory hammer, oscillator, or rotator would be used to advance 
a casing. If casings are installed by a vibratory hammer, installation 
is estimated to be 1 work day per casing. If casings need to be welded 
together, 1 work day is estimated for the weld. No more than two 
casings are estimated per shaft. Soil would be removed from inside the 
casing and transferred onto a barge as the casing is advanced, and the 
soil would be deposited at an approved upland site. Drilling would 
continue below the casing approximately 30 ft (9 m) into the Troutdale 
Formation to a specified tip elevation. After excavating soil from 
inside the casing, reinforcing steel would be installed into the shaft 
and then the shaft would be filled with concrete.
    During construction of the drilled shafts, uncured concrete would 
be poured into water-filled steel casings, creating a mix of concrete 
and water. As

[[Page 23554]]

the concrete is poured into the casing, it would displace this highly 
alkaline mixture. The project would implement best management practices 
(BMPs) to contain the mixture and ensure that it does not enter any 
surface water body. Once contained, the water would be treated to meet 
state water quality standards and either released to a wastewater 
treatment facility or discharged to a surface water body. The steel 
casing may or may not be removed, depending on the installation method. 
Figures 1-6 through 1-9 of CRC's application depict typical drilled 
shaft operations and equipment.
    The total duration of the permanent shaft installation could vary 
considerably depending on the type of installation equipment used, the 
quantity of available installation equipment, and actual soil 
conditions. Installation of each drilled shaft is estimated to take 
approximately 10 days. With the limited in-water work window for impact 
pile driving and construction phasing constraints, the total duration 
of drilled shaft installation would be approximately thirty months. For 
each of the in-water pier complexes (Piers 2-7), six to nine shafts 
would be drilled. For piers 3-6, which would support separate 
northbound and southbound bridges, this means a minimum of 48 drilled 
shafts. For piers 2 and 7, which would support a unified structure, 
there would be a minimum of twelve drilled shafts. At minimum, there 
would be an overall total of 72 drilled shafts.
    Precast shaft caps would be placed on top of the drilled shafts. 
Installation of the shaft caps would require cranes, work barges, and 
material barges. Columns would be constructed of cast-in-place 
reinforced concrete or precast concrete. Column construction is 
estimated to take 120 days for each pier complex. Construction of 
columns would require cranes, work barges, and material barges in the 
river year-round. The superstructure would be constructed of structural 
steel, cast-in-place concrete, or precast concrete. Precast elements 
would be fabricated at a casting yard.

Description of the Activity--North Portland Harbor Bridges

    The existing North Portland Harbor bridge would be upgraded to meet 
current seismic standards. The seismic retrofit activities would 
consist solely of minor modifications to the bent caps and girders that 
would not require in-water work. In addition, four new bridge 
structures would be constructed across North Portland Harbor. The 
bridges, illustrated in Figure 1-12 of CRC's application are, from west 
to east: the LRT/pedestrian/bicycle bridge, I-5 southbound off-ramp, I-
5 southbound on-ramp, existing mainline, and I-5 northbound on-ramp.
    The existing North Portland Harbor bridge was constructed in the 
early 1980s of prestressed concrete girders and reinforced concrete 
bents. The bents are supported by driven steel pilings. Two previous 
bridges, constructed in 1917 and 1958, were built at the same location 
as the current bridge, but may not have been fully removed during 
subsequent replacement efforts. These bridges had reinforced concrete 
bents supported on timber piles. Some of this material may still be 
present, but this would not be confirmed until construction begins. 
Some removal of previous bridge elements is anticipated prior to 
installation of the new bridge shafts. Removal of remnant bridge 
elements would be with a clamshell dredge. The five new or improved 
bridges over the North Portland Harbor would range from approximately 
900-1,000 ft (274-305 m) over water, and would range from 40-150 ft 
(12-46 m) in width. Bridge widths would vary due to merging of lanes on 
some structures.
    Construction is expected to be sequential, beginning with either of 
the most nearshore bents of a given bridge and proceeding to the 
adjacent bent. The actual sequencing would be determined by the 
contractor once a construction contract is awarded. No more than three 
of the five bridges are likely to have in-water work occurring 
simultaneously. For the bents closest to shore, construction would 
occur from work bridges. At the other in-water bents, as described for 
Columbia River bridges, construction would likely occur from barges and 
support platforms. General construction activities to build the bents 
and superstructure are similar to those for the Columbia River bridges, 
except that shaft caps would not be used and bridge decks would be 
placed on girders instead of balanced cantilevers. General sequencing 
of the construction of a single bridge appears below. Some of these 
activities may occur simultaneously at separate bents.
     Construct support platforms and work bridges using 
vibratory and impact pile drivers.
     Vibrate temporary piles for barge moorings.
     Extract large pieces of debris as needed to allow casings 
to advance.
     Install drilled shafts at each bent.
     Construct columns on the drilled shafts.
     Construct a bent cap or crossbeam on top of the columns at 
a bent location.
     Erect bridge girders on the bent caps or crossbeams.
     Place the bridge deck on the girders.
     Remove temporary work bridges, support platforms, and 
supporting piles.
    Temporary Structures--At the bents closest to shore, up to nine 
temporary work bridges would be constructed to support equipment for 
drilled shafts. In addition, at each of the 31 bent locations, one 
support platform would be constructed, each consisting of four load-
bearing piles. The bridges and support platforms would be designed by 
the contractor after a contract is awarded, but prior to construction. 
The number and size of piles for temporary in-water work structures are 
listed in Table 4.

                       Table 4--Approximate Number of Steel Pipe Piles Required for Construction of North Portland Harbor Bridges
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   Total
            Structure                      Number            Pile diameter         Pile length       Piles per   number of    Duration present in water
                                                                                                     structure     piles             (days-each)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Work bridges.....................  9....................  18-24 in (0.5-0.6    70-120 ft (21-37 m)           25        225  20-42.
                                                           m).
Support platforms................  31...................  36-48 in (0.9-1.2    120 ft.............            4        124  10-34.
                                                           m).
Barge moorings...................  N/A..................  36-48 in...........  120 ft.............          N/A        216  30/mooring.
Barges (cumulative, at a single    Up to 9..............  N/A................  N/A................          N/A        N/A  10-34.
 time).
                                  ----------------------------------------------------------------------------------------------------------------------
    Total........................  Varies...............  ...................  ...................  ...........        565  ............................
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 23555]]

    As with the mainstem Columbia River bridges, temporary piles would 
be required to support in-water work bridges or to moor barges during 
construction of the North Portland Harbor bridges. Unlike the Columbia 
River bridges, cofferdams are not necessary. Piles used for the 
temporary work bridges and the support platforms must be load bearing. 
They would first be vibrated to refusal, and then proofed with an 
impact hammer to confirm load-bearing capacity. An average of three 
load-bearing piles would be installed per day using vibratory 
installation to set the piles, with one impact driver to proof. Rates 
of installation would be determined by the type of installation 
equipment, substrate, and required load-bearing capacity of each pile.
    Temporary mooring piles would be installed and removed throughout 
the construction process. Installation of these mooring piles could 
occur year-round and at any time during sufficient visibility. These 
piles would be installed using vibratory methods only. In general, 
temporary piles would extend only into the alluvium to an estimated 
depth of 70 to 120 ft (21-37 m). Standard pipe lengths are 80 to 90 ft 
(24-27 m), so some piles may need to be welded to achieve the lengths 
required to drive them to these depths. Estimated pile installation 
specifications are provided in Table 5. Estimates of required number of 
strikes per pile and total strikes are the same as for the Columbia 
River. However, only one impact driver at a time would be used. Impact 
pile driving is proposed to occur only during a modified in-water work 
period from approximately September 15 to April 15. No impact pile 
driving would occur outside of the approved dates.
    As discussed for Columbia River, a sound attenuation device (i.e., 
bubble curtain) would be used during all impact pile driving, with the 
exception of periods when the device would be turned off to measure its 
effectiveness, in accordance with the hydroacoustic monitoring plan. A 
period of up to 5 minutes per week of pile driving without the use of 
an attenuation device has been allocated in analyses of project impacts 
for North Portland Harbor, to allow for this study of mitigation 
effectiveness, as well as for instances when the device might fail. If 
the attenuation device fails, pile driving activities would shut down 
as soon as practicable and resolution of the problem would occur; 
however, some amount of unattenuated driving may occur before shut-down 
can safely occur. By incorporating this time into the analysis, the 
project may still proceed in the event of an equipment failure without 
exceeding analyzed thresholds. With the exception of hydroacoustic 
monitoring, intentional impact pile driving without a sound attenuation 
device is not proposed nor would it be authorized. In addition, to 
limit hydroacoustic impacts to marine mammals, there would be, at 
minimum, a consecutive 12-hour period without impact pile driving for 
every 24-hour day. Please see Table 8 for a summary of time required 
for vibratory driving.

                     Table 5--Pile Strike Summary for Construction in North Portland Harbor
----------------------------------------------------------------------------------------------------------------
                                                                                                 Hours of pile
                                      Estimated piles   Estimated strikes      Estimated       driving per 12-hr
             Pile size               installed per day       per pile       maximum strikes   daily pile driving
                                                                                per day           work period
----------------------------------------------------------------------------------------------------------------
18-24 in (0.5-0.6 m)...............                  3                300                900               0.375
36-48 in (0.9-1.2 m)...............                  3                300                900               0.375
                                    ----------------------------------------------------------------------------
    Total..........................                  6                N/A              1,800               0.75
----------------------------------------------------------------------------------------------------------------

    Barges would be used as platforms for conducting work activities 
and to haul materials and equipment to and from the work site. Barges 
would be moored with steel pipe piles adjacent to temporary work 
bridges or bents. Several types and sizes of barges would be used 
according to specific function. No more than nine barges are estimated 
to be present in North Portland Harbor at any one time during the 
construction period.
    Following installation of the drilled shafts, the temporary work 
structures and their support piles would be removed through vibratory 
methods. Other temporary piles would be installed to moor barges 
adjacent to the new bents. These non-load bearing piles would be 
installed through vibratory methods only. The installation of steel 
pipe piles would occur throughout the construction period. Steel piles 
would be installed and removed during the multi-year construction of 
the temporary support structures. Although the project would use over 
500 piles in the North Portland Harbor, only 100 to 200 piles are 
estimated to be in the water at any one time.
    Debris Removal--Debris from previous structures, including 
foundations from the 1917 and 1953 bridges, may be present in North 
Portland Harbor at some locations where drilled shafts would be 
installed. This debris is likely to consist of large rock or old 
concrete. Because casings cannot advance through this type of material, 
it must be removed. Removal would consist of capturing the debris in a 
clamshell bucket. Capture of sediment would be limited. Debris would be 
placed in an upland location, and disposed of at a landfill if 
appropriate. Debris removal activities would be limited to the 
designated in-water work window of November 1 through February 28. 
Removal activities would take no more than 10 days over the course of 
construction.
    Before debris removal begins, divers would pinpoint the location of 
the material. Debris removal would only occur in the precise locations 
where material overlaps with the footprint of the new shafts, greatly 
minimizing the areal extent of the activity. The amount of material in 
this location is unknown; however, assuming a worst-case scenario (that 
the area of the material is the same as the footprint of the drilled 
shafts), the project would remove debris in no more than 31 locations 
over an area of roughly 2,433 ft\2\ (226 m\2\). No more than 90 yd\3\ 
(69 m\3\) of material would be removed. If any items are found during 
excavation that contain potential contaminants (e.g., buried drums, car 
bodies containing petroleum products), activities to control and clean 
up contaminants would be implemented in accordance with the project's 
approved Spill Prevention, Control, and Countermeasures (SPCC) plan.
    Permanent Structures--In-water drilled shaft construction for the 
North Portland Harbor would occur as described for the Columbia River 
bridges. Installation of each drilled shaft is estimated to take 
approximately 10 days. However, the total duration of this activity 
could vary considerably depending on the type of equipment

[[Page 23556]]

used, the quantity of available equipment, and on-site soil conditions. 
The total duration of drilled shaft installation would be approximately 
eighteen months. A maximum of 31 shafts would be installed for the 
North Portland Harbor bridges. Each bridge would have four to seven 
spans, each a maximum of 255 ft (78 m) long. Each new bridge would have 
three to five in-water bents, consisting of one to three 10-ft diameter 
(3 m) drilled shafts. Unlike the Columbia River piers, shafts would not 
be topped by a shaft cap. Current designs place all of the bents in 
shallow water (less than 20 ft (6 m) deep).
    Columns would be constructed of cast-in-place reinforced concrete. 
Construction of cast-in-place columns would require cranes, work 
barges, and material barges continuously throughout this period. The 
superstructure would consist of girders and a deck. Girders would be 
constructed of structural steel, cast-in-place concrete, or precast 
concrete. Precast girders may be fabricated at a casting yard. A cast-
in-place concrete deck would be placed on the girders.

Description of the Activity--Columbia River Bridge Demolition

    The existing Columbia River bridges would be demolished after the 
new Columbia River bridges have been constructed and after associated 
interchanges are operating. The existing Columbia River bridges would 
be demolished in two stages: (1) Superstructure demolition and (2) 
substructure demolition.
    Demolition of the superstructure would begin with removal of the 
counterweights. The lift span would be locked into place and the 
counterweights would be cut into pieces and transferred off-site via 
truck or barge. Next, the lift towers would be cut into manageable 
pieces and loaded onto barges by a crane. Prior to removal of the 
trusses, the deck would be removed by cutting it into manageable 
pieces; these pieces would be transported by barge or truck or by using 
a breaker, in which case debris would be caught on a barge or other 
containment system below the work area. After demolition of the 
concrete deck, trusses would be lifted off of their bearings and onto 
barges and transferred to a shoreline dismantling site.
    The existing Columbia River bridge structures comprise eleven pairs 
of steel through-truss spans with reinforced concrete decks, including 
one pair of movable spans over the primary navigation channel and one 
pair of 531-ft long (162 m) span trusses. The remaining nine pairs of 
trusses range from 265 to 275 ft (81-84 m) in length. In addition to 
the trusses, there are reinforced concrete approach spans (over land) 
on either end of the bridges.
    Nine sets of the eleven existing Columbia River bridge piers are 
below the ordinary high water (OHW) level and are supported on a total 
of approximately 1,800 driven timber piles. Demolition methods are not 
finalized; however, the final design would consider factors such as 
pier depth, safety, phasing constraints, and impacts to aquatic 
species. Demolition of the concrete piers and timber piling foundations 
would be accomplished using one of two methods:
    1. After removal of the trusses, a cofferdam would be installed at 
each of the nine in-water bridge piers to contain demolition 
activities. Cofferdams would not be dewatered. The piers would be 
broken up and removed from within the cofferdam. Timber piles that pose 
a navigation hazard would then be extracted or cut off below the mud 
line.
    2. A diamond wire/wire saw would be used to cut the piers into 
manageable chunks that would be transported offsite. Cofferdams would 
not be used. Timber piles would then be extracted or cut off below the 
mud line. With either method, the pieces of the piers would be removed 
via barge.
    Although maintenance personnel regularly inspect the existing 
bridge, the timber piles located underneath the existing piers are 
inaccessible and have not been inspected. Therefore, it is unknown 
whether these timber piles have been treated with creosote, but given 
their age and intended purpose, it is assumed that they have been so 
treated. Only piles that could pose a navigation hazard would be 
removed or cut off below the mud line. These piles include those that 
are present in the proposed navigation channels and any that extend 
above the surface of the river bed. Piles would be removed (using a 
vibratory extractor, direct pull, or clam shell dredge) or cut off 
below the mud line using an underwater saw. The exact number of piles 
to be removed is unknown.
    A conceptual demolition sequence was determined based on the amount 
of equipment likely available to build the project and the physical 
space the equipment requires at each pier. The sequence is provided in 
Appendix A, Figures 12-16 of CRC's application. The actual construction 
sequence would be determined by the contractor once a construction 
contract is awarded. Demolition would occur after the new Columbia 
River replacement bridges are built. Demolition activities would take 
approximately eighteen months, from approximately September 2019 until 
March 2021. However, some demolition activities could occur during the 
period of this proposed rule.
    Temporary Structures--Temporary cofferdams would be required to 
isolate work activities and temporary piles would be installed to 
anchor work and material barges during demolition of the spans and in-
water piers. If the diamond wire/wire saw is not used, a temporary 
cofferdam consisting of interlocking sections of sheet piles would be 
used to isolate demolition activities at each of the nine in-water 
piers. Sheet piles for cofferdams would be installed with a vibratory 
hammer or a press-in method. Up to three cofferdams would be in place 
at any given time. Sheet piles would be removed using a vibratory 
hammer or direct pull.
    Barges would be used as platforms to perform the demolition and to 
haul materials and equipment to and from the work site. Several types 
and sizes of barges are anticipated to be used for bridge demolition. 
The type and size of each barge would depend on how the barge is used. 
Up to six stationary or moving barges are expected to be present at any 
one time during bridge demolition. Over 300 steel pipe piles would be 
used to anchor and support the work and material barges necessary for 
demolition. Table 6 summarizes temporary pile use during bridge 
demolition. All temporary piles would be installed using a vibratory 
hammer or push-in method. They would be extracted using vibratory 
methods or direct pull. Piles would be installed and removed 
continuously throughout the demolition process.

[[Page 23557]]



                                        Table 6--Summary of Barges and Temporary Piles Used in Bridge Demolition
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Barges per                                           Duration in water
                       Application                             Locations           location       Piles per barge      Total piles       (days/location)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Span removal.............................................                  9                4-6                  4                160                 30
Pier demolition..........................................                  9                  4                  4                144                 30
                                                          ----------------------------------------------------------------------------------------------
    Total................................................  .................  .................                304  .................  .................
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Equipment required for bridge demolition includes barge-mounted 
cranes/hammers or hydraulic rams. Vibratory hammers would be used to 
install and remove sheet piles for cofferdams and pipe piles for barge 
moorings. New permanent piles would not be required for demolition of 
the Columbia River bridges.

Method of Incidental Taking

    Vibratory and impact pile installation and removal, and steel 
casing installation, may result in behavioral disturbance, constituting 
Level B harassment. Project construction would require the installation 
and removal of approximately 1,500 temporary steel piles. In addition 
to pile and casing installation, behavioral disturbance could also be 
caused by increased activity and vessel traffic, airborne sound from 
the equipment and human work activity, as well as underwater sound from 
debris removal, vessels, and physical disturbance.
    Table 7 summarizes the extent, timing, and duration of impact pile 
driving. Impact pile driving is expected to take place only within a 
31-week in-water work window, ranging from September 15 to April 15 
over the bridge construction period. There would be a total of about 
138 days of impact pile driving in the Columbia River and about 134 
days of impact pile driving in North Portland Harbor for the entire 
project from the start of bridge construction in 2013 to its 
anticipated completion in 2017 (approximately 4.25 years for both 
Columbia River and North Portland Harbor Bridges). Impact pile driving 
in the mainstem Columbia River would occur at more than one pier 
complex on about 1-2 days total during the course of the approximately 
4-year construction period. Impact pile driving would be restricted to 
approximately 45 minutes per 12-hour work day. A sound attenuation 
device would generally be used for all impact pile driving, with the 
exception of weekly testing of the attenuation device, requiring that 
some impact hammering occur with the device turned off in order to 
compare produced sound with that produced while the device is on. This 
would occur for a maximum of 7.5 minutes per week. Each work day would 
include a period of at least 12 consecutive hours with no impact pile 
driving in order to minimize disturbance to aquatic animals. Impact 
pile driving would only occur during daylight hours. Airborne sound 
effects from impact pile driving would occur on the same schedule as 
described in Table 7.

                                     Table 7--Summary of Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
                                           Columbia River                         North Portland Harbor
          Pile size          -----------------------------------------------------------------------------------
                                      Duration               Days               Duration               Days
----------------------------------------------------------------------------------------------------------------
18-24 in (without             7.5 min/week............              38  2.5-5 min/week..........              18
 attenuation device).
18-24 in (with attenuation    45 min/day..............             138  45 min/day..............              72
 device).
36-48 in (without             7.5 min/week............              38  2.5-5 min/week..........              31
 attenuation device).
36-48 in (with attenuation    45 min/day..............             138  45 min/day..............              62
 device).
----------------------------------------------------------------------------------------------------------------

    Table 8 summarizes the extent, timing, and duration of vibratory 
installation of pipe pile and sheet pile. Vibratory installation of 
pipe pile is likely to occur throughout the entire 5-year duration of 
the proposed regulations period during construction of all new in-water 
piers or bents and for installation of mooring piles. Vibratory 
installation of sheet pile would only occur in the Columbia River 
during construction of the new Columbia River bridges and demolition of 
the existing Columbia River bridges. This activity would occur 
intermittently throughout the construction and demolition period. 
Vibratory activity is not restricted to an in-water work window, and 
therefore may take place during any time of the year. If steel casings 
for drilled shafts are vibrated into place, the CRC project design team 
estimates that installation of the 10-ft-diameter casings would take 
approximately 90 days in the Columbia River and 31 days in North 
Portland Harbor.

                                   Table 8--Summary of Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
                                           Columbia River                         North Portland Harbor
          Pile type          -----------------------------------------------------------------------------------
                                      Duration               Days               Duration               Days
----------------------------------------------------------------------------------------------------------------
Pipe pile...................  Up to 5 hours/day.......     1,470-1,620  Up to 5 hours/day.......             334
Sheet pile..................  Up to 24 hours/day......              99  N/A.....................             N/A
Steel casings...............  ........................              90  ........................              31
----------------------------------------------------------------------------------------------------------------

    Debris removal is not certain to occur, but is included to present 
the fullest disclosure of potential effects. It is possible that debris 
removal would occur in North Portland harbor at the location of each of 
the new piers where

[[Page 23558]]

there is anecdotal evidence that riprap occurs within the pier 
footprints. The exact quantity of this material is unknown, but as a 
worst-case scenario this activity would remove approximately 90 yd\3\ 
(69 m\3\) of material over an area of approximately 2,433 ft\2\ (226 
m\2\) from all piers combined. Debris removal would produce sound 
through use of a bucket dredge, for up to 12 hours per day for a 
maximum of 7 days during the November 1-February 28 in-water work 
window each year.

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 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, which is why the lower 
frequency sound associated with the proposed activities would attenuate 
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 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.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1975). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units 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.
    The underwater acoustic environment consists of ambient sound, 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The ambient underwater sound 
level of a region is defined by the total acoustical energy being 
generated by known and unknown sources, including sounds from both 
natural and anthropogenic 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). 
Known sound levels and frequency ranges associated with anthropogenic 
sources similar to those that would be used for this project are 
summarized in Table 9. Details of each of the sources are described in 
the following text.

                          Table 9--Representative Sound Levels of Anthropogenic Sources
----------------------------------------------------------------------------------------------------------------
                                          Frequency range     Underwater sound level
              Sound source                      (Hz)             (dB re 1 [mu]Pa)              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 (328   Blackwell and Greene,
                                                             ft).                       2002.
Vibratory driving of 72-in (1.8 m)                10-1,500  180 dB rms at 10 m (33     Caltrans, 2007.
 steel pipe pile.                                            ft).
Impact driving of 36-in (0.9 m) steel             10-1,500  195 dB rms at 10 m.......  WSDOT, 2007.
 pipe pile.
Impact driving of 66-in (1.7 m) CISS             100-1,500  195 dB rms at 10 m.......  Reviewed in Hastings and
 \1\ piles.                                                                             Popper, 2005.
----------------------------------------------------------------------------------------------------------------
\1\ CISS = cast-in-steel-shell.

    The CRC project would produce underwater sound through installation 
of piles for temporary in-water work platforms and temporary barge 
moorings, and vibratory installation of steel casings for drilled 
shafts. Piles would be installed by using impact and/or vibratory 
hammers, or by press-in techniques that do not produce notable 
underwater sound.
    Several types of impact hammers are commonly used to install in-
water piles: air-driven, steam-driven, diesel-driven, and hydraulic. 
Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. Sound generated by impact 
hammers is characterized by rapid rise times and high peak levels, a 
potentially injurious combination (Hastings and Popper, 2005). Table 10 
summarizes observed underwater sound levels generated by driving 
various types and sizes of piles. Sound generated by impact pile 
driving is highly variable, based on site-specific conditions such as 
substrate, water depth, and current. Sound levels may also vary based 
on the size of the pile, the type of pile, and the energy of the 
hammer.

   Table 10--Summary of Observed Underwater Sound Levels Generated by
                           Impact Pile Driving
------------------------------------------------------------------------
      Pile size, in (m)          Driver type      dB Peak       dB rms
------------------------------------------------------------------------
12 (0.3).....................  Impact.........          208          191

[[Page 23559]]

 
14 (0.4).....................  Impact.........      \1\ 195      \1\ 180
16 (0.4).....................  Impact.........      \2\ 200      \2\ 187
24 (0.6).....................  Impact.........          212          189
30 (0.8).....................  Impact.........          212          195
36 (0.9).....................  Impact.........          214          201
60 (1.5).....................  Impact.........          210          195
66 (1.7).....................  Impact.........          210          195
96 (2.4).....................  Impact.........          220          205
126 (3.2)....................  Impact.........      \3\ 213      \3\ 202
150 (3.8)....................  Impact.........      \4\ 200      \4\ 185
12...........................  Vibratory......          171          155
24 (sheet), typical..........  Vibratory......          175          160
24 (sheet), loudest..........  Vibratory......          182          165
36 (typical).................  Vibratory......          180          170
36 (loudest).................  Vibratory......          185          175
72 (typical) (1.8)...........  Vibratory......          183          170
72 (loudest).................  Vibratory......          195         180
------------------------------------------------------------------------
Source: Caltrans, 2009
Note: Sound levels measured at a distance of 10 m except where indicated
  by the following footnotes: \1\ 30 m; \2\ 9 m; \3\ 11 m; \4\ 100 m.

    Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce much less sound than impact hammers. Peak SPLs may be 180 dB or 
greater, but are generally 10 to 20 dB lower than SPLs generated during 
impact pile driving of the same-sized pile (Caltrans, 2009). Rise time 
is slower, reducing the probability and severity of injury (USFWS, 
2009), and sound energy is distributed over a greater amount of time 
(Nedwell and Edwards, 2002; Carlson et al., 2001).
    Vibratory hammers cannot be used in all circumstances. In some 
substrates, the capacity of a vibratory hammer may be insufficient to 
drive the pile to load-bearing capacity or depth (Caltrans, 2009). 
Additionally, some vibrated piles must be `proofed' (i.e., struck with 
an impact hammer) for several seconds to several minutes in order to 
verify the load-bearing capacity of the pile (WSDOT, 2008).
    Table 10 outlines typical sound levels produced by installation of 
various types of pile using a vibratory pile driver. Note that peak 
sound levels range from 171 to 195 dB, whereas peak sound levels 
generated by impact pile driving range from 195 to 220 dB.
    Impact and vibratory pile driving are the primary in-water 
construction activities associated with the project. The sounds 
produced by these activities fall into one of two sound types: pulsed 
and non-pulsed (defined in next paragraph). Impact pile driving 
produces pulsed sounds, while vibratory pile driving produces non-
pulsed sounds. The distinction between these two general 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.
    Pulsed sounds (e.g., explosions, gunshots, sonic booms, seismic 
pile driving pulses, and impact pile driving) are brief, broadband, 
atonal transients (ANSI, 1986; Harris, 1998) 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 decay period that may include a 
period of diminishing, oscillating maximal and minimal pressures. 
Pulsed sounds generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds (which may be intermittent or continuous) can be 
tonal, broadband, or both. Some of these non-pulse sounds can be 
transient signals of short duration but without the essential 
properties of pulses (e.g., rapid rise time). Examples of non-pulse 
sounds include those produced by vessels, aircraft, machinery 
operations such as drilling or dredging, vibratory pile driving, and 
active sonar systems. The duration of such sounds, as received at a 
distance, can be greatly extended in a highly reverberant environment.

Sound Attenuation Devices

    Sound levels can be greatly reduced during impact pile driving 
using sound attenuation devices. There are several types of sound 
attenuation devices including bubble curtains, cofferdams, and 
isolation casings. Three types of attenuation devices are described 
here.
    Bubble curtains create a column of air bubbles rising around a pile 
from the substrate to the water surface. The air bubbles absorb and 
scatter sound waves emanating from the pile, thereby reducing the sound 
energy. Bubble curtains may be confined or unconfined. An unconfined 
bubble curtain may consist of a ring seated on the substrate and 
emitting air bubbles from the bottom. An unconfined bubble curtain may 
also consist of a stacked system, that is, a series of multiple rings 
placed at the bottom and at various elevations around the pile. Stacked 
systems may be more effective than non-stacked systems in areas with 
high current and deep water (Caltrans, 2009).
    A confined bubble curtain contains the air bubbles within a 
flexible or rigid sleeve made from plastic, cloth, or pipe. Confined 
bubble curtains generally offer higher attenuation levels than 
unconfined curtains because they may physically block sound waves and 
they prevent air bubbles from migrating away from the pile. For this 
reason, the confined bubble curtain is commonly used in areas with high 
current velocity (Caltrans, 2009). In Oregon, confined bubble curtains 
are typically required where current velocity is 0.6 m/s or greater 
(NMFS, 2008a).
    Cofferdams are often used during construction for isolating the in-
water work area, but may also be used as a sound attenuation device. 
Dewatered cofferdams may provide the highest levels of sound reduction 
of any attenuation device; however, they do not eliminate underwater 
sound because sound can be transmitted through the substrate (Caltrans, 
2009). Cofferdams that are not dewatered provide very limited reduction 
in sound levels.

[[Page 23560]]

    An isolation casing is a hollow pipe that surrounds the pile, 
isolating it from the in-water work area. The casing is dewatered 
before pile driving. This device provides levels of sound attenuation 
similar to that of bubble curtains; however, attenuation rates are not 
as great as those achieved by cofferdams because the dewatered area 
between the pile and the water column is generally much smaller 
(Caltrans, 2009).
    Both environmental conditions and the characteristics of the sound 
attenuation device may influence the effectiveness of the device. 
According to Caltrans (2009):
     In general, confined bubble curtains attain better sound 
attenuation levels in areas of high current than unconfined bubble 
curtains. If an unconfined device is used, high current velocity may 
sweep bubbles away from the pile, resulting in reduced levels of sound 
attenuation.
     Softer substrates may allow for a better seal for the 
device, preventing leakage of air bubbles and escape of sound waves. 
This increases the effectiveness of the device. Softer substrates also 
provide additional attenuation of sound traveling through the 
substrate.
     Flat bottom topography provides a better seal, enhancing 
effectiveness of the sound attenuation device, whereas sloped or 
undulating terrain reduces or eliminates its effectiveness.
     Air bubbles must be close to the pile; otherwise, sound 
may propagate into the water, reducing the effectiveness of the device.
     Harder substrates may transmit ground-borne sound and 
propagate it into the water column.
    The literature presents a wide array of observed attenuation 
results (see, e.g., WSF, 2009; WSDOT, 2008; USFWS, 2009; Caltrans, 
2009). The variability in attenuation levels is due to variation in 
design, as well as differences in site conditions and difficulty in 
properly installing and operating in-water attenuation devices. WSDOT 
personnel have observed that, on average, unconfined bubble curtains 
typically achieve 9 dB of attenuation while confined bubble curtains 
achieve 12 dB. Caltrans (2009) offers the following generalizations:
     For steel or concrete pile 24 in (0.6 m) in diameter or 
less, bubble curtains would generally reduce sound levels by 5 dB.
     For steel pile measuring 24 to 48 in (0.6-1.2 m), bubble 
curtains may reduce sound levels by about 10 dB.
     For piles greater than 48 in diameter, bubble curtains may 
reduce sound levels by about 20 dB.
     As a general rule, reductions of greater than 10 dB cannot 
be reliably predicted.

Sound Thresholds

    Since 1997, NMFS has used generic sound exposure thresholds to 
determine when an activity in the ocean that produces sound might 
result in impacts to a marine mammal such that a take by harassment or 
injury might occur (NMFS, 2005b). To date, no studies have been 
conducted that examine impacts to marine mammals from pile driving 
sounds from which empirical sound thresholds have been established. 
Current NMFS practice regarding exposure of marine mammals to high 
level sounds is that cetaceans and pinnipeds exposed to impulsive 
sounds of 180 and 190 dB rms or above, respectively, are considered to 
have been taken by Level A (i.e., injurious) harassment. Behavioral 
harassment (Level B) is considered to have occurred when marine mammals 
are exposed to sounds at or above 160 dB rms for impulse sounds (e.g., 
impact pile driving) and 120 dB rms for non-pulsed sound (e.g., 
vibratory pile driving), but below injurious thresholds. For airborne 
sound, pinniped disturbance from haul-outs has been documented at 100 
dB (unweighted) for pinnipeds in general, and at 90 dB (unweighted) for 
harbor seals. NMFS uses these levels as guidelines to estimate when 
harassment may occur.

Distance to Sound Thresholds

    The extent of project-generated sound both in and over water was 
calculated for the locations where pile driving would occur in the 
Columbia River and North Portland Harbor. The extent of underwater 
sound was modeled for several pile driving scenarios:
     For two sizes of pile: 18- to 24-in (0.5-0.6 m) pile and 
36- to 48-in (0.9-1.2 m) pile.
     For single impact pile drivers operating both with and 
without an attenuation device. Use of an attenuation device was assumed 
to decrease initial SPLs by 10 dB (see discussion previously in this 
document).
     For vibratory driving of pipe pile and sheet pile.
    Underwater Sound--Models may be used to estimate the distances and 
areas within which sound is likely to exceed certain threshold levels. 
Please note that the results of such modeling are described here to 
provide a frame of reference for the reader. Actual distances and areas 
within which sound is likely to exceed certain threshold levels are 
known from collection of site-specific hydroacoustic monitoring data 
(see `Test Pile Project', later in this document).
    In the absence of site-specific data, the practical spreading loss 
model may be used for determining the extent of sound from a source 
(Davidson, 2004; Thomsen et al., 2006). The model assumes a logarithmic 
coefficient of 15, which equates to sound energy decreasing by 4.5 dB 
with each doubling of distance from the source. To calculate the loss 
of sound energy from one distance to another, the following formula is 
used:

Transmission Loss (dB) = 15 log(D1/D0)

D1 is the distance from the source for which SPLs need to be 
known, and D0 is the distance from the source for which SPLs 
are known (typically 10 m from the pile). This model also solves for 
the distance at which sound attenuates to various decibel levels (e.g., 
a threshold or background level). The following equation solves for 
distance:

D1 = D0 x 10(TL/15)

where TL stands for transmission loss (the difference in decibel levels 
between D0 and D1). For example, using the 
distance to an injury threshold (D1), the area of effect is 
calculated as the area of a circle, [pi]r2, where r (radius) 
is the distance to the threshold or background. If a landform or other 
shadowing element interrupts the spread of sound within the threshold 
distance, then the area of effect truncates at the location of the 
shadowing element.
    Sound levels are highly dependent on environmental site conditions. 
Therefore, published hydroacoustic monitoring data for projects with 
similar site conditions as the CRC project were considered. WSDOT and 
the California Department of Transportation (Caltrans) have compiled 
hydroacoustic monitoring data from in-water impact pile driving. No 
projects with hydroacoustic monitoring data and similar site conditions 
were identified in the Columbia River.
    A review of WSDOT and Caltrans projects containing in-water pile 
driving found projects in California had the most similar substrates 
and depths; however, only one project used 48-in pile, the largest size 
in the CRC project. This work occurred in the Russian River, which was 
only 15 m wide and 0.6 m deep at the project location. Therefore, the 
results are not applicable to the CRC project. Instead, data from 
projects that drove 36-in pile were used, using the highest sound 
levels

[[Page 23561]]

encountered as proxy values for 48-in pile.
    Maximum measured sound levels from 36-in steel pile installation 
were 201 dB rms (WSDOT, 2008), as shown in Table 10. Site conditions 
for this project, in Puget Sound, are somewhat comparable to the 
Columbia River, as both are large, with similar depths. The maximum 
source level from the next largest pile size, 60-in (1.5-m) pile, was 
195 dB rms at 10 m. As such, the use of data from the 36-in pile 
measurements provides a more conservative estimate. The CRC project 
would also drive 18- to 24-in diameter steel pile. Conservatively, the 
highest recorded value of 189 dB rms for this range of pile sizes was 
used (see Table 10).
    No studies were available that measured site-specific initial sound 
levels generated by vibratory pile driving in the Region of Activity. 
However, Table 10 outlines a range of typical sound levels produced by 
vibratory pile driving as measured by Caltrans during hydroacoustic 
monitoring of several construction projects (Caltrans, 2009). A worst-
case scenario of installing 48-in steel pipe pile (the largest pile 
size to be used on the CRC project) at the loudest measured SPLs was 
considered, however, as there were no data for 48-in pile, it was 
assumed that sound levels for 48-in pile would be intermediate between 
those levels generated by 36-in pile and 72-in (1.8-m) pile. Typical 
values for both 36- and 72-in pile were 170 dB, while the loudest 
values were 175 dB for 36-in pile and 180 dB for 72-in pile. Thus, 175 
dB was considered an appropriate value for initial SPLs for vibratory 
driving of pipe pile. The project may also install sheet pile, in the 
Columbia River only. In general, installation of sheet pile produces 
lower SPLs than pipe pile. Using data presented in Table 10, an initial 
SPL of approximately 160 dB rms at a distance of 15 m was assumed. 
Table 11 shows the calculated distances required for underwater sound 
to attenuate to relevant thresholds, as per the practical spreading 
model (please see Figures B-1 to B-6 of CRC's application for graphical 
depictions of threshold distances discussed here).

                               Table 11--Calculated Distances to Sound Thresholds
----------------------------------------------------------------------------------------------------------------
                                                                                    Distance to     Distance to
                                                                                     threshold       threshold
                   Threshold                                Pile size                (without          (with
                                                                                    attenuation     attenuation
                                                                                   device)  (m)    device)*  (m)
----------------------------------------------------------------------------------------------------------------
Injury: 190 dB rms............................  18-24 in........................               9               2
Harassment: 160 dB rms........................  18-24 in........................             858             185
Injury: 190 dB rms............................  36-48 in........................              54              12
Harassment: 160 dB rms........................  36-48 in........................           5,412           1,166
Harassment: 120 dB rms........................  36-72 in........................          23,208             n/a
Harassment: 120 dB rms........................  24-in sheet pile................           6,962             n/a
----------------------------------------------------------------------------------------------------------------
* 10 dB reduction in SPLs assumed from use of attenuation device.

    Landforms in the Columbia River and North Portland Harbor would 
block underwater sound well before it reaches certain calculated 
distances. Table 12 shows actual site-specific values for the maximum 
distance within which sound is likely to exceed a given threshold level 
until contact with landforms. Categories not listed in Table 12 would 
remain the same as shown in Table 11.

                                 Table 12--Actual Distances to Sound Thresholds
----------------------------------------------------------------------------------------------------------------
                                                                                                    Downstream
             Threshold                      Pile size             Location*        Upstream  (m)        (m)
----------------------------------------------------------------------------------------------------------------
Harassment: 160 dB rms.............  36-48 in (without       NPH                           3,058           5,412
                                      attenuation).
Harassment: 120 dB rms.............  36-72 in..............  CR                           20,166           8,851
Harassment: 120 dB rms.............  36-72 in..............  NPH                           3,058           5,632
----------------------------------------------------------------------------------------------------------------
* NPH = North Portland Harbor; CR = Columbia River.

    Airborne Sound--For calculating the levels and extent of project-
generated airborne sound, a point sound source and hard-site conditions 
were assumed because pile drivers would be stationary, and work would 
largely occur over open water and adjacent to an urbanized landscape. 
Thus, calculations assumed that pile driving sound would attenuate at a 
rate of 6 dB per doubling distance, based on a spherical spreading 
model. The following formula was used to determine the distances at 
which pile-driving sound attenuates to the 90 dB rms and 100 dB rms 
(re: 20 [micro]Pa; all airborne SPLs discussed here are referenced to 
20 [micro]Pa) airborne disturbance thresholds:

D1 = D0 * 10 
((initial SPL-airborne disturbance threshold)/[alpha])

where D1 is the distance from the pile at which sound 
attenuates to the threshold value, D0 is the distance 
from the pile at which the initial SPLs were measured, and [alpha] 
is the variable for soft-site or hard-site conditions. These 
calculations used [alpha] = 20 for hard-site conditions.
    The estimate of initial sound level is based on the results of 
monitoring performed by WSDOT during pile driving at Friday Harbor 
Ferry Terminal (Laughlin, 2005b). The results showed airborne rms sound 
levels of 112 dB taken at 160 ft (49 m) from the source during impact 
pile driving. This project drove 24-in steel pipe pile, which is only 
half the size of the largest pile proposed for use in the CRC project. 
However, airborne sound levels are independent of the size of the pile 
(CRC, 2010), and therefore the sound levels encountered at Friday 
Harbor are applicable to the CRC project.
    The model used 112 dB rms at 160 ft from the source as the initial 
sound level for a single pile driver. Because multiple pile drivers 
would not strike

[[Page 23562]]

piles synchronously, operation of multiple pile drivers would not 
generate sound louder than that of a single pile driver. Therefore, 
initial sound levels for multiple pile drivers were assumed to be the 
same as for a single pile driver. The CRC project is not likely to use 
an airborne sound-attenuation device. Sound generated by impact pile 
driving in the Columbia River and North Portland Harbor is likely to 
exceed the 100 dB rms airborne disturbance threshold within 195 m of 
the source and is likely to exceed the 90 dB rms airborne disturbance 
threshold within 650 m of the source.
    Debris Removal--Debris removal may occur in North Portland Harbor 
at the location of each of the new piers where there is anecdotal 
evidence that riprap occurs within the pier footprints. Debris removal 
in the North Portland Harbor, if it occurs, is likely to create sound 
at or above the 120-dB disturbance threshold for continuous sound in 
underwater portions of the Region of Activity.
    Few studies have been conducted on sound emissions produced by 
underwater debris removal. A review of the literature indicates that 
underwater debris removal would produce sound in the range of 135 dB to 
147 dB at 10 m (Dickerson et al., 2001; OSPAR, 2009; Thomsen et al., 
2009).
    Underwater debris removal is not expected to generate significant 
airborne sound. The air-water interface creates a substantial sound 
barrier and reduces the intensity of underwater sound waves by a factor 
of more than 1,000 when they cross the water surface. The above-water 
environment is, thus, virtually insulated from the effects of 
underwater sound (Hildebrand, 2005). Therefore, underwater debris 
removal is not expected to measurably increase ambient airborne sound. 
Underwater sound from debris removal would likely attenuate to the 120-
dB underwater disturbance threshold for continuous sound within 631 m 
of the source. This activity would occur for only 7 days, during the 
in-water work window.

Test Pile Project

    In February 2011, CRC conducted a test pile project in order to 
acquire geotechnical and sound propagation data to assess site-specific 
characteristics and verify the modeling results discussed in the 
preceding section, and to assess mitigation measures related to pile 
installation activities planned for the CRC project. Please see CRC's 
Test Pile Hydroacoustic Monitoring Report for detailed analysis 
(SUPPLEMENTARY INFORMATION).
    Engineering objectives included the following:
     Determine strike numbers necessary to install piles to 
reach load-bearing capacity with an impact hammer;
     Identify suitable equipment and materials and verify 
production rates for pile installation;
     Determine the feasibility of vibratory installation 
methods; and
     Validate geotechnical and engineering calculations.
    Environmental objectives included the following:
     Determine the underwater sound levels resulting from 
vibratory installation of temporary piles in the predominant substrate 
types found at typical mid-channel depths at the project site;
     Determine the underwater sound levels resulting from 
impact installation of temporary piles in the predominant substrate 
types found at typical mid-channel depths at the project site;
     Determine the effectiveness of two sound attenuation 
strategies (unconfined and confined bubble curtains) during impact pile 
driving;
     Determine the transmission loss of pile installation sound 
for both impact and vibratory installation;
     Determine the extent of construction sound impacts in-air 
for impact pile driving; and
     Determine the extent of turbidity plumes resulting from 
vibratory and impact pile installation and extraction, and from 
unconfined and confined bubble curtain operation.
    Test pile operations consisted of impact driving or vibratory 
driving at six pile locations using 24- and 48-in piles. A confined or 
unconfined bubble curtain was tested during each pile installation. 
Background sound level monitoring was successfully conducted between 
January 27 and February 3, 2011. The background sound level at fifty 
percent cumulative distribution function (CDF) on the Washington 
(north) side of the river was found to be 110 dB, while the background 
level at fifty percent CDF on the Oregon (south) side of the river was 
slightly higher at 117 dB.
    Hydroacoustic monitoring was successfully conducted during test 
pile construction activities February 11-21, 2011. Rms pressure levels 
associated with vibratory driving varied widely pile to pile; 
subsurface driving conditions are the likely cause of this variability. 
For impact driving, average sound levels were derived for both 24-in 
and 48-in piles. Impact driving on 48-in piles was, on average, 10 dB 
louder than driving on 24-in piles.
    Measured sound levels for both vibratory driving and impact driving 
were similar to those expected as outlined previously in this document. 
For vibratory driving, the maximum observed sound level was 181 dB, 
only slightly louder than the anticipated maximum sound level (180 dB). 
For impact driving, observed unattenuated rms sound levels for 24-in 
piles were 191 dB, slightly louder than anticipated (189 dB). 
Unattenuated rms sound levels for 48-in piles (201 dB) were as 
anticipated. The average rms pressure level for vibratory pile 
extraction was 173 dB, and did not appear to vary with pile size. The 
173 dB observed for extraction was slightly less than the 176 dB 
average observed during pile installation. The variance of the pressure 
levels was also less, with extraction values ranging from 167-176 dB 
while installation values ranged from 157-181 dB.
    Open curtain attenuation methods reduced the sound levels for 48-in 
piles 11 dB on average, and 9 dB on average for 24-in piles. Confined 
curtain attenuation methods reduced the sound levels for 48-in piles 13 
dB on average, and 8.5 dB on average for 24-in piles. Open bubble 
curtain attenuation was similar to confined curtain attenuation at 10 m 
downstream; however, the effectiveness of the open bubble curtain 
appeared to be significantly less upstream when compared to downstream, 
likely due to the effect of current on the open bubble curtain. The 
observed effectiveness of both open and confined bubble curtains at 
attenuating peak amplitudes (8-13 dB) was approximately as anticipated 
(10 dB).
    Transmission loss was analyzed for both vibratory driving and 
impact driving. Transmission loss for vibratory driving was in line 
with the practical spreading model, as anticipated. However, this 
analysis is based on results from only one pile; for two of the piles, 
the signal could not be distinguished from background noise at 200 m, 
while for a third pile, the signal could not be distinguished from 
background noise at 800 m. Thus, transmission loss could not be 
calculated for those piles, although energy from those piles clearly 
showed rapid attenuation. Transmission loss for impact driving was in 
line with the practical spreading model at the 200-m range, but 
steadily increased toward spherical spreading with increasing range, 
resulting in greater than anticipated transmission loss.
    The data for transmission loss associated with vibratory driving 
suggest that the majority of the energy occurs in frequencies below 
1,000 Hz,

[[Page 23563]]

with energy levels gradually falling off at higher frequencies (CRC, 
2011). For vibratory installation in this study, driving of two piles 
produced energy that could not be distinguished from background by 200 
m, while the signal from a third could not be detected at the 800 m 
station. The signal was distinguishable from background sound levels at 
approximately 800 m for only one of the piles, indicating that distance 
to the threshold would likely be less than the modeling results 
predicted. However, background sound levels during pile driving were 
higher than those measured previously. It is possible that increased 
background levels resulted from sound associated with the project, 
instrumentation, or some other source. Nevertheless, data indicate that 
transmission loss for vibratory driving is approximately in conformance 
with practical spreading loss. Piles were generally installed or 
extracted during the test pile study in less than 5 minutes (ranging 
from less than 1 minute to less than 10 minutes, for all but one 
outlier).
    Measured, site-specific values were either substantially similar to 
assumed values or, in the case of transmission loss or realized 
attenuation from use of bubble curtains in certain circumstances, the 
assumed values described previously in this document were more 
conservative than the actual values. As such, those values remain valid 
but likely represent a significantly more conservative scenario than 
would realistically occur. Actual distances to be monitored for 
potential injury or harassment of pinnipeds would be based on the 
results of in-situ hydroacoustic monitoring, where relevant, and are 
discussed in greater detail in `Proposed Mitigation', later in this 
document.

Comments and Responses

    On December 15, 2010, NMFS published a notice of receipt of an 
application for a Letter of Authorization (LOA) in the Federal Register 
(75 FR 78228) and requested comments and information from the public 
for 30 days. NMFS did not receive any substantive comments.

Description of Marine Mammals in the Area of the Specified Activity

    Marine mammal species that have been observed within the Region of 
Activity consist of the harbor seal, California sea lion, and Steller 
sea lion. Pinnipeds follow prey species into freshwater up to, 
primarily, the Bonneville Dam (RM 145, RKm 233) in the Columbia River, 
but also to Willamette Falls in the Willamette River (RM 26, RKm 42). 
The Willamette River enters the Columbia River approximately 5 mi (8 
km) downstream of the CRC project area and is within the Region of 
Activity. Harbor seals rarely, but occasionally, transit the Region of 
Activity. The eastern population of the Steller sea lion is listed as 
threatened under the ESA and as depleted and strategic under the MMPA. 
Neither the California sea lion nor the harbor seal is listed under the 
ESA, nor are they considered depleted or strategic under the MMPA.
    The sea lions use this portion of the river primarily for 
transiting to and from Bonneville Dam, which concentrates adult 
salmonids and sturgeon returning to natal streams, providing for 
increased foraging efficiency. The U.S. Army Corps of Engineers (USACE) 
has conducted surface observations to evaluate the seasonal presence, 
abundance, and predation activities of pinnipeds in the Bonneville Dam 
tailrace each year since 2002. This monitoring program was initiated in 
response to concerns over the potential impact of pinniped predation on 
adult salmonids passing Bonneville Dam in the spring. An active sea 
lion hazing, trapping, and permanent removal program was in place below 
the dam from 2008 through 2010. Much of the information presented in 
this application is based on research conducted as part of the 
Bonneville Dam sea lion program.
    Pinnipeds remain in upstream locations for a couple of days or 
longer, feeding heavily on salmon, steelhead, and sturgeon (NOAA 2008), 
although the occurrence of harbor seals near Bonneville Dam is much 
lower than sea lions (Stansell et al., 2009). Sea lions congregate at 
Bonneville Dam during the peaks of salmon return, from March through 
May each year, and a few California sea lions have been observed 
feeding on salmonids in the area below Willamette Falls during the 
spring adult fish migration (NOAA, 2008).
    There are no pinniped haul-out sites in the Region of Activity. The 
nearest haul-out sites, shared by harbor seals and California sea 
lions, are near the Cowlitz River/Carroll Slough confluence with the 
Columbia River, approximately 45 mi (72 km) downriver from the Region 
of Activity (Jeffries et al., 2000). The nearest known haul-out for 
Steller sea lions is a rock formation (Phoca Rock) near RM 132 (RKm 
212) approximately 8 mi (13 km) downstream of Bonneville Dam and 26 mi 
(42 km) upstream from the Region of Activity. Steller sea lions are 
also known to haul out on the south jetty at the mouth of the Columbia 
River, near Astoria, Oregon. There are no pinniped rookeries located in 
or near the Region of Activity.

Harbor Seal

    Species Description--Harbor seals, which are members of the Phocid 
family (true seals), inhabit coastal and estuarine waters and shoreline 
areas from Baja California, Mexico to western Alaska. For management 
purposes, differences in mean pupping date (i.e., birthing) (Temte, 
1986), movement patterns (Jeffries, 1985; Brown, 1988), pollutant loads 
(Calambokidis et al., 1985) and fishery interactions have led to the 
recognition of three separate harbor seal stocks along the west coast 
of the continental U.S. (Boveng, 1988). The three distinct stocks are: 
(1) Inland waters of Washington (including Hood Canal, Puget Sound, and 
the Strait of Juan de Fuca out to Cape Flattery), (2) outer coast of 
Oregon and Washington, and (3) California (Carretta et al. 2007b). The 
seals in the Region of Activity are from the outer coast of Oregon and 
Washington stock.
    The average weight for adult seals is about 180 lb (82 kg) and 
males are typically slightly larger than females. Male harbor seals 
weigh up to 245 lb (111 kg) and measure approximately 5 ft (1.5 m) in 
length. The basic color of harbor seals' coat is gray and mottled but 
highly variable, from dark with light color rings or spots to light 
with dark markings (NMFS, 2008c).
    Status--In 1999, the population of the Oregon/Washington coastal 
stock of harbor seals was estimated at 24,732 animals (Carretta et al., 
2007a). Although this abundance estimate represents the best scientific 
information available, per NMFS stock assessment policy it is not 
considered current because it is more than 8 years old. This harbor 
seal stock includes coastal estuaries (Columbia River) and bays 
(Willapa Bay and Grays Harbor). Both the Washington and Oregon portions 
of this stock are believed to have reached carrying capacity and the 
stock is within its optimum sustainable population level (Jeffries et 
al., 2003; Brown et al., 2005). Because there is no current estimate of 
minimum abundance, potential biological removal (PBR) cannot be 
calculated for this stock. However, the level of human-caused mortality 
and serious injury is less than ten percent of the previous PBR of 
1,343 harbor seals per year (Carretta et al., 2007), and human-caused 
mortality is considered to be small relative to the stock size. 
Therefore, the Oregon and Washington outer coast stock of harbor seals 
are not classified as a strategic stock under the MMPA.

[[Page 23564]]

    Behavior and Ecology--Harbor seals are non-migratory with local 
movements associated with such factors as tides, weather, season, food 
availability, and reproduction (Scheffer and Slipp, 1944; Fisher, 1952; 
Bigg, 1969, 1981). They are not known to make extensive pelagic 
migrations, although some long distance movement of tagged animals in 
Alaska (174 km), and along the U.S. west coast (up to 550 km), have 
been recorded (Pitcher and McAllister, 1981; Brown and Mate, 1983; 
Herder, 1986). Harbor seals are coastal species, rarely found more than 
12 mi (20 km) from shore, and frequently occupy bays, estuaries, and 
inlets (Baird, 2001). Individual seals have been observed several miles 
upstream in coastal rivers. Ideal harbor seal habitat includes haul-out 
sites, shelter during the breeding periods, and sufficient food 
(Bjorge, 2002).
    Harbor seals haul out on rocks, reefs, beaches, and ice and feed in 
marine, estuarine, and occasionally fresh waters. Harbor seals display 
strong fidelity for haul-out sites (Pitcher and Calkins, 1979; Pitcher 
and McAllister, 1981), although human disturbance can affect haul-out 
choice (Harris et al., 2003). Group sizes range from small numbers of 
animals on intertidal rocks to several thousand animals found 
seasonally in coastal estuaries. The harbor seal is the most commonly 
observed and widely distributed pinniped found in Oregon and Washington 
(Jeffries et al., 2000; ODFW, 2010). Harbor seals use hundreds of sites 
to rest or haul out along the coast and inland waters of Oregon and 
Washington, including tidal sand bars and mudflats in estuaries, 
intertidal rocks and reefs, beaches, log booms, docks, and floats in 
all marine areas of the two states. Numerous harbor seal haul-out sites 
are found on intertidal mudflats and sand bars from the mouth of the 
lower Columbia River to Carroll Slough at the confluence of the Cowlitz 
and Columbia Rivers.
    Harbor seals mate at sea and females give birth during the spring 
and summer, although the pupping season varies by latitude. Pupping 
seasons vary by geographic region with pups born in coastal estuaries 
(Columbia River, Willapa Bay, and Grays Harbor) from mid-April through 
June and in other areas along the Olympic Peninsula and Puget Sound 
from May through September (WDFW, 2000). Suckling harbor seal pups 
spend as much as forty percent of their time in the water (Bowen et 
al., 1999).
    They can be found throughout the year at the mouth of the Columbia 
River. Peak harbor seal abundances in the Columbia River occur during 
the winter and spring when a number of upriver haul-out sites are used. 
Peak abundances and upriver movements in the winter and spring months 
are correlated with spawning runs of eulachon (Thaleichthys pacificus) 
smelt and out-migration of salmonid smolts. Harbor seals are 
infrequently observed at Bonneville Dam or in the Region of Activity. 
In 2009 and again in 2010, two harbor seals were observed at the dam 
(Stansell et al., 2009; Stansell and Gibbons, 2010), and observations 
of harbor seals at Bonneville Dam have ranged from one to three per 
year from 2002 to 2010.
    Within the Region of Activity, there are no known harbor seal haul-
out sites. The nearest known haul-out sites to the Region of Activity 
are located at Carroll Slough at the confluence of the Cowlitz and 
Columbia Rivers approximately 45 mi (72 km) downriver of the Region of 
Activity. The low number of observations of harbor seals at Bonneville 
Dam over the years, combined with the fact that no pupping or haul-out 
locations are within or upstream from the Region of Activity, suggest 
that very few harbor seals transit through the Region of Activity 
(Stansell et al., 2010).
    Acoustics--In air, harbor seal males produce a variety of low-
frequency (less than 4 kHz) vocalizations, including snorts, grunts, 
and growls. Male harbor seals produce communication sounds in the 
frequency range of 100-1,000 Hz (Richardson et al., 1995). Pups make 
individually unique calls for mother recognition that contain multiple 
harmonics with main energy below 0.35 kHz (Bigg, 1981; Thomson and 
Richardson, 1995). Harbor seals hear nearly as well in air as 
underwater and have lower thresholds than California sea lions (Kastak 
and Schusterman, 1998). Kastak and Schusterman (1998) reported airborne 
low frequency (100 Hz) sound detection thresholds at 65 dB for harbor 
seals. In air, they hear frequencies from 0.25-30 kHz and are most 
sensitive from 6-16 kHz (Richardson, 1995; Terhune and Turnbull, 1995; 
Wolski et al., 2003).
    Adult males also produce underwater sounds during the breeding 
season that typically range from 0.25-4 kHz (duration range: 0.1 s to 
multiple seconds; Hanggi and Schusterman 1994). Hanggi and Schusterman 
(1994) found that there is individual variation in the dominant 
frequency range of sounds between different males, and Van Parijs et 
al. (2003) reported oceanic, regional, population, and site-specific 
variation that could be vocal dialects. In water, they hear frequencies 
from 1-75 kHz (Southall et al., 2007) and can detect sound levels as 
weak as 60-85 dB within that band. They are most sensitive at 
frequencies below 50 kHz; above 60 kHz sensitivity rapidly decreases.

California Sea Lions

    Species Description--California sea lions are members of the 
Otariid family (eared seals). The species, Zalophus californianus, 
includes three subspecies: Z. c. wollebaeki (in the Galapagos Islands), 
Z. c. japonicus (in Japan, but now thought to be extinct), and Z. c. 
californianus (found from southern Mexico to southwestern Canada; 
referred to here as the California sea lion) (Carretta et al., 2007). 
The breeding areas of the California sea lion are on islands located in 
southern California, western Baja California, and the Gulf of 
California (Carretta et al., 2007). These three geographic regions are 
used to separate this subspecies into three stocks: (1) The U.S. stock 
begins at the U.S./Mexico border and extends northward into Canada, (2) 
the Western Baja California stock extends from the U.S./Mexico border 
to the southern tip of the Baja California peninsula, and (3) the Gulf 
of California stock which includes the Gulf of California from the 
southern tip of the Baja California peninsula and across to the 
mainland and extends to southern Mexico (Lowry et al., 1992).
    The California sea lion is sexually dimorphic. Males may reach 
1,000 lb (454 kg) and 8 ft (2.4 m) in length; females grow to 300 lb 
(136 kg) and 6 ft (1.8 m) in length. Their color ranges from chocolate 
brown in males to a lighter, golden brown in females. At around 5 years 
of age, males develop a bony bump on top of the skull called a sagittal 
crest. The crest is visible in the dog-like profile of male sea lion 
heads, and hair around the crest gets lighter with age.
    Status--The U.S. stock of California sea lions is estimated at 
238,000 and the minimum population size of this stock is 141,842 
individuals (Carretta et al., 2007). These numbers are from counts 
during the 2001 breeding season of animals that were ashore at the four 
major rookeries in southern California and at haul-out sites north to 
the Oregon/California border. Sea lions that were at-sea or hauled-out 
at other locations were not counted (Carretta et al., 2007). The stock 
has likely reached its carrying capacity and, even though current total 
human-caused mortality is unknown (due a lack of observer coverage in 
the California set gillnet fishery that historically has been the 
largest source of human-caused mortalities), California sea lions are 
not considered a strategic stock under the

[[Page 23565]]

MMPA because total human-caused mortality is still likely to be less 
than the PBR.
    Behavior and Ecology--During the summer, California sea lions breed 
on islands from the Gulf of California to the Channel Islands and 
seldom travel more than about 31 mi (50 km) from the islands (Bonnell 
et al., 1983). The primary rookeries are located in the California 
Channel Islands (Le Boeuf and Bonnell, 1980; Bonnell and Dailey, 1993). 
Their distribution shifts to the northwest in fall and to the southeast 
during winter and spring, probably in response to changes in prey 
availability (Bonnell and Ford, 1987).
    The non-breeding distribution extends from Baja California north to 
Alaska for males, and encompasses the waters of California and Baja 
California for females (Reeves et al., 2008; Maniscalco et al., 2004). 
In the non-breeding season, an estimated 3,000 to 5,000 adult and sub-
adult males migrate northward along the coast to central and northern 
California, Oregon, Washington, and Vancouver Island from September to 
May (Jeffries et al., 2000) and return south the following spring 
(Mate, 1975; Bonnell et al., 1983). During migration, they are 
occasionally sighted hundreds of miles offshore (Jefferson et al., 
1993). Females and juveniles tend to stay closer to the rookeries 
(Bonnell et al., 1983).
    California sea lions do not breed in Oregon. Though a few young 
animals may remain in Oregon during summer months, most return south 
for the breeding season (ODFW, 2010). Male California sea lions are 
commonly seen in Oregon from September through May. During this time 
period California sea lions can be found in many bays, estuaries and on 
offshore sites along the coast, often hauled-out in the same locations 
as Steller sea lions. Some pass through Oregon to feed along coastal 
waters to the north during fall and winter months (ODFW, 2010).
    California sea lions feed on a wide variety of prey, including many 
species of fish and squid (Everitt et al., 1981; Roffe and Mate, 1984; 
Antonelis et al., 1990; Lowry et al., 1991). In some locations where 
salmon runs exist, California sea lions also feed on returning adult 
and out-migrating juvenile salmonids (London, 2006). Sexual maturity 
occurs at around 4-5 years of age for California sea lions (Heath, 
2002). California sea lions are gregarious during the breeding season 
and social on land during other times.
    California sea lions are known to occur in several areas of the 
Columbia River during much of the year, except the summer breeding 
months of June through August. Approximately 1,000 California sea lions 
have been observed at haul-out sites at the mouth of the Columbia 
River, while approximately 100 individuals have been observed in past 
years at the Bonneville Dam between January and May prior to returning 
to their breeding rookeries in California at the end of May (Stansell, 
2010). The nearest known haul-out sites to the Region of Activity are 
near the Cowlitz River/Carroll Slough confluence with the Columbia 
River, approximately 45 mi (72 km) downriver of the Region of Activity 
(Jeffries et al., 2000).
    The USACE's intensive sea lion monitoring program began as a result 
of the 2000 Federal Columbia River Power System (FCRPS) biological 
opinion, which required an evaluation of pinniped predation in the 
tailrace of Bonneville Dam. The objective of the study was to determine 
the timing and duration of pinniped predation activity, estimate the 
number of fish caught, record the number of pinnipeds present, identify 
and track individual California sea lions, and evaluate various 
pinniped deterrents used at the dam (Tackley et al., 2008a). The study 
period for monitoring was January 1 through May 31, beginning in 2002. 
During the study period, pinniped observations began after consistent 
sightings of at least one animal occurred. Tackley et al. (2008a) note 
that sightings began earlier each year from 2002 to 2004. Although some 
sightings were reported earlier in the season, full-time observations 
began March 21 in 2002, March 3 in 2003, and February 24 in 2004 
(Tackley et al., 2008a). In 2005 observations began in April, but in 
2006 through 2010 observations began in January or early February 
(Tackley et al., 2008a, 2008b; Stansell et al., 2009; Stansell and 
Gibbons, 2010). In 2009, 54 California sea lions were observed at 
Bonneville Dam, the fewest since 2002 (Stansell et al., 2009). However, 
in 2010, 89 California sea lion individuals were observed at Bonneville 
Dam (Stansell et al., 2010). In addition, up to four California sea 
lions have been observed at Bonneville Dam during the September-January 
period in recent years (CRC, 2010).
    Up to eight California sea lions have been observed in recent years 
feeding on salmonids in the Willamette River below Willamette Falls 
(NOAA, 2008). The earliest known report of California sea lions at 
Willamette Falls was in 1975, when two sea lions were reported taking 
salmon and hindering fish passage at the fish ladder. Other than the 
1975 sighting, there were no reports of sea lions at Willamette Falls 
until the late 1980s when personnel at the fish ladder reported 
California sea lion sightings below the falls. California sea lions 
were sighted sporadically near the falls until 1995 when they began 
occurring almost daily from February through late May (Scordino, 2010).
    California sea lion arrival and departure dates at Bonneville Dam 
are compiled in Table 13 from the reports listed in the preceding 
paragraph. If arrival and departure dates were not available, the 
timing of surface observations within the January through May study 
period were recorded. Because regular observations in the study period 
generally began as California sea lions were observed below Bonneville 
Dam, and sometimes reports stated that observations stopped as sea lion 
numbers dropped, the observation dates only give a general idea of 
first arrival and departure. Because tracking data indicate that sea 
lions travel at fast rates between hydrophone locations above and below 
the CRC project area, dates of first arrival at Bonneville Dam and 
departure from the dam are assumed to coincide closely with potential 
passage timing through the CRC project area.

                                   Table 13--Arrival and Departure Dates for California Sea Lions Below Bonneville Dam
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                 2008
                                                                    2002     2003     2004        2005         2006     2007     \3\      2009     2010
--------------------------------------------------------------------------------------------------------------------------------------------------------
Arrival.........................................................   \1\ 3-   \1\ 3-   \1\ 2-   \1\ 4-11/1-21     2-09     1-08   \1\ 1-   \1\ 1-   \1\ 1-
                                                                       21       03       24                                         11       14       08
Departure.......................................................   \1\ 5-   \1\ 6-   \1\ 5-   \1\ 5-31/6-10     6-02   \2\ 5-   \1\ 5-   \4\ 5-     6-04
                                                                       24       02       30                                26       31       19
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Dates are dates observations were taken and not when sea lions were first seen. In 2005 through 2007, observations were made intermittently until
  sea lions were seen consistently (Tackley et al., 2008a). In 2005, surface observations were made from April 11 through May 31. However, the first
  California sea lion arrived January 21 and departed on June 10 (Tackley et al., 2008a).
\2\ A single sighting was made on November 7 (Tackley et al., 2008a).
\3\ Three California sea lions were observed between September and December 2008. These observations were opportunistic and outside the regular
  observation period of January through May (Stansell et al., 2009).

[[Page 23566]]

 
\4\ Observations ended because few sea lions were present. One California sea lion was in the Bonneville Dam forebay through at least August 11
  (Stansell et al., 2009).

    Based on the information presented in Table 13, California sea 
lions have generally been observed at Bonneville Dam between early 
January and early June, although beginning in 2008, a few individuals 
have been noted at the dam as early as September and as late as August. 
Therefore, the majority of California sea lions are expected to pass 
the project site beginning in early January through early June. 
Stansell and Gibbons (2010) and Stansell et al. (2009) show that 
California sea lion abundance below Bonneville Dam peaks in April, when 
it drops through about the end of May. In 2010, California sea lions 
stayed below the dam until almost mid-June, which was late historically 
and enters into the time they normally depart for southern breeding 
grounds. Wright et al. (2010) reported a median start date for the 
southbound migration from the Columbia River to the breeding grounds of 
May 20 (range: May 7 to May 27; n = 8 sea lions).
    The highest number of California sea lions observed in the 
Bonneville Dam tailrace over the last 9 years was 104 in 2003 (Stansell 
et al., 2010). However, Tackley et al. (2008a) noted that numbers of 
sea lions estimated from early study years were likely underestimated, 
because the observers' ability to uniquely identify individuals 
increased over the years. In addition, the high number of 104 
individuals present below the dam in 2003 occurred prior to hazing 
(2005) or permanent removal (2008) activities began. The high for the 
2008 through 2010 time period is a minimum of 89 individuals in a year 
(Stansell et al., 2010).
    The Pacific States Marine Fisheries Commission (PSMFC) leads a 
tagging and tracking program for California sea lions, observing that 
the transit time for California sea lions between Astoria and 
Bonneville Dam is 30-36 hours upstream, and 15 hours downstream (CRC, 
2010). ODFW studied the migration of male California sea lions during 
the nonbreeding season by satellite tracking 26 sea lions captured in 
the lower Columbia River over the course of three non-breeding seasons 
between November and May in 2003-04, 2004-05, and 2006-07.
    Fourteen of the sea lions had previously been observed in the 
Columbia River (`river type') and twelve animals were `unknown' types. 
Wright et al. (2010) found there was considerable within and between 
individual variation in spatial and temporal movements, which 
presumably reflected variation in foraging behavior. Many sea lions 
repeatedly alternated between several haul-out sites throughout the 
non-breeding season.
    Twenty of the 26 satellite-tagged sea lions remained within the 
waters of Oregon and Washington during the time they were monitored; 
the remainder made forays north to British Columbia or south to 
California. All fourteen of the previously known `river' sea lions were 
later documented upriver (either by tracking or direct observation); 
none of the twelve `unknown' animals were detected upriver. Southward 
departure dates from the Columbia River ranged from May 7 to June 17. 
Travel time to the breeding grounds ranged from 12 to 21 days. Only one 
animal was tracked back to the Columbia River; it returned on August 18 
after a 21-day trip from San Miguel Island (Wright et al., 2010). 
Movement of sea lions to the base of Bonneville Dam to forage on 
salmonids was documented in only a fraction of the sea lions tracked, 
which suggested that the problem of pinniped predation on Columbia 
River salmonid stocks should be addressed primarily at upriver sites 
such as Bonneville Dam rather than in the estuary where sea lions of 
many behavioral types co-occur (Wright et al., 2010).
    Acoustics--On land, California sea lions make incessant, raucous 
barking sounds; these have most of their energy at less than 2 kHz 
(Schusterman et al., 1967). Males vary both the number and rhythm of 
their barks depending on the social context; the barks appear to 
control the movements and other behavior patterns of nearby 
conspecifics (Schusterman, 1977). Females produce barks, squeals, 
belches, and growls in the frequency range of 0.25-5 kHz, while pups 
make bleating sounds at 0.25-6 kHz. California sea lions produce two 
types of underwater sounds: Clicks (or short-duration sound pulses) and 
barks (Schusterman et al., 1966, 1967; Schusterman and Baillet, 1969). 
All of these underwater sounds have most of their energy below 4 kHz 
(Schusterman et al., 1967).
    The range of maximal hearing sensitivity for California sea lions 
underwater is between 1-28 kHz (Schusterman et al., 1972). Functional 
underwater high frequency hearing limits are between 35-40 kHz, with 
peak sensitivities from 15-30 kHz (Schusterman et al., 1972). The 
California sea lion shows relatively poor hearing at frequencies below 
1 kHz (Kastak and Schusterman, 1998). Peak hearing sensitivities in air 
are shifted to lower frequencies; the effective upper hearing limit is 
approximately 36 kHz (Schusterman, 1974). The best range of sound 
detection is from 2-16 kHz (Schusterman, 1974). Kastak and Schusterman 
(2002) determined that hearing sensitivity generally worsens with 
depth--hearing thresholds were lower in shallow water, except at the 
highest frequency tested (35 kHz), where this trend was reversed. 
Octave band sound levels of 65-70 dB above the animal's threshold 
produced an average temporary threshold shift (TTS; discussed later in 
POTENTIAL EFFECTS OF THE SPECIFIED ACTIVITY ON MARINE MAMMALS) of 4.9 
dB in the California sea lion (Kastak et al., 1999).

Steller Sea Lions

    Species Description--Steller sea lions are the largest members of 
the Otariid (eared seal) family. Steller sea lions show marked sexual 
dimorphism, in which adult males are noticeably larger and have 
distinct coloration patterns from females. Males average approximately 
1,500 lb (680 kg) and 10 ft (3 m) in length; females average about 700 
lb (318 kg) and 8 ft (2.4 m) in length. Adult females have a tawny to 
silver-colored pelt. Males are characterized by dark, dense fur around 
their necks, giving a mane-like appearance, and light tawny coloring 
over the rest of their body (NMFS, 2008a). Steller sea lions are 
distributed mainly around the coasts to the outer continental shelf 
along the North Pacific Ocean rim from northern Hokkaido, Japan through 
the Kuril Islands and Okhotsk Sea, Aleutian Islands and central Bering 
Sea, southern coast of Alaska and south to California. The population 
is divided into the western and the eastern distinct population 
segments (DPSs) at 144[deg] W (Cape Suckling, Alaska). The western DPS 
includes Steller sea lions that reside in the central and western Gulf 
of Alaska, Aleutian Islands, as well as those that inhabit coastal 
waters and breed in Asia (e.g., Japan and Russia). The eastern DPS 
extends from California to Alaska, including the Gulf of Alaska.
    Status--Steller sea lions were listed as threatened range-wide 
under the ESA in 1990. After division into two DPSs, the western DPS 
was listed as endangered under the ESA in 1997, while the eastern DPS 
remained classified as threatened. Animals found

[[Page 23567]]

in the Region of Activity are from the eastern DPS (NMFS, 1997a; 
Loughlin, 2002; Angliss and Outlaw, 2005). The eastern DPS breeds in 
rookeries located in southeast Alaska, British Columbia, Oregon, and 
California. While some pupping has been reported recently along the 
coast of Washington, there are no active rookeries in Washington. A 
final revised species recovery plan addresses both DPSs (NMFS, 2008a).
    NMFS designated critical habitat for Steller sea lions in 1993. 
Critical habitat is associated with breeding and haul-out sites in 
Alaska, California, and Oregon, and includes so-called `aquatic zones' 
that extend 3,000 ft (900 m) seaward in state and federally managed 
waters from the baseline or basepoint of each major rookery in Oregon 
and California (NMFS, 2008a). Three major rookery sites in Oregon 
(Rogue Reef, Pyramid Rock, and Long Brown Rock and Seal Rock on Orford 
Reef at Cape Blanco) and three rookery sites in California (Ano Nuevo 
I, Southeast Farallon I, and Sugarloaf Island and Cape Mendocino) are 
designated critical habitat (NMFS, 1993). There is no designated 
critical habitat within the Region of Activity.
    Factors that have previously been identified as threats to Steller 
sea lions include reduced food availability, possibly resulting from 
competition with commercial fisheries; incidental take and intentional 
kills during commercial fish harvests; subsistence take; entanglement 
in marine debris; disease; pollution; and harassment. Steller sea lions 
are also sensitive to disturbance at rookeries (during pupping and 
breeding) and haul-out sites.
    The Recovery Plan for the Steller Sea Lion (NMFS, 2008a) states 
that the overall abundance of Steller sea lions in the eastern DPS has 
increased for a sustained period of at least three decades, and that 
pup production has increased significantly, especially since the mid-
1990s. Between 1977 and 2002, researchers estimated that overall 
abundance of the eastern DPS had increased at an average rate of 3.1 
percent per year (NMFS, 2008a; Pitcher et al., 2007). NMFS' most recent 
stock assessment report estimates that population for the eastern DPS 
is a minimum of 52,847 individuals; this estimate is not corrected for 
animals at sea, and actual population is estimated to be within the 
range 58,334 to 72,223 (Allen and Angliss, 2010). The minimum count for 
Steller sea lions in Oregon and Washington was 5,813 in 2002 (Pitcher 
et al., 2007; Allen and Angliss, 2010). Counts in Oregon have shown a 
gradual increase from 1,486 animals in 1976 to 4,169 animals in 2002 
(NMFS, 2008b).
    The abundance of the eastern DPS of Steller sea lions is increasing 
throughout the northern portion of its range (southeast Alaska and 
British Columbia), and stable or increasing in the central portion 
(Oregon through central California). Surveys indicate that pup 
production in Oregon increased at 3 percent per year from 1990-2009, 
while pup production in California increased at 5 percent per year 
between 1996 and 2009, with the number of non-pups reported as stable. 
The best available information indicates that, overall, the eastern DPS 
has increased from an estimated 18,040 animals in 1979 to an estimated 
63,488 animals in 2009; therefore the overall estimated rate of 
increase for this period is 4.3 percent per year (NMML, 2012).
    In the far southern end of Steller sea lion range (Channel Islands 
in southern California), population declined significantly after the 
1930s--probably due to hunting and harassment (Bartholomew and 
Boolootian, 1960; Bartholomew, 1967)--and several rookeries and haul-
outs have been abandoned. The lack of recolonization at the 
southernmost portion of the range (e.g., San Miguel Island rookery), 
despite stability in the non-pup portion of the overall California 
population, is likely a response to a suite of factors including 
changes in ocean conditions (e.g., warmer temperatures) that may be 
contributing to habitat changes that favor California sea lions over 
Steller sea lions (NMFS, 2007) and competition for space on land, and 
possibly prey, with species that have experienced explosive growth over 
the past three decades (California sea lions and northern elephant 
seals [Mirounga angustirostris]). Although recovery in California has 
lagged behind the rest of the DPS, this portion of the DPS' range has 
recently shown a positive growth rate (NMML, 2012). While non-pup 
counts in California in the 2000s are only 34 percent of pre-decline 
counts (1927-47), the population has increased significantly since 
1990.
    Despite the abandonment of certain rookeries in California, pup 
production at other rookeries in California has increased over the last 
20 years and, overall, the eastern DPS has increased at an average 
annual growth rate of 4.3 percent per year for 30 years. Even though 
these rookeries might not be recolonized, their loss has not prevented 
the increasing abundance of Steller sea lions in California or in the 
eastern DPS overall.
    Because the eastern DPS of Steller sea lion is currently listed as 
threatened under the ESA, it is therefore designated as depleted and 
classified as a strategic stock under the MMPA. However, the eastern 
DPS has been considered a potential candidate for removal from listing 
under the ESA by the Steller sea lion recovery team and NMFS (NMFS, 
2008), based on observed annual rates of increase. Although the stock 
size has increased, the status of this stock relative to its Optimum 
Sustainable Population (OSP) size is unknown. The overall annual rate 
of increase of the eastern stock has been consistent and long-term, and 
may indicate that this stock is reaching OSP.
    Behavior and Ecology--Steller sea lions forage near shore and in 
pelagic waters. They are capable of traveling long distances in a 
season and can dive to approximately 1,300 ft (400 m) in depth. They 
also use terrestrial habitat as haul-out sites for periods of rest, 
molting, and as rookeries for mating and pupping during the breeding 
season. At sea, they are often seen alone or in small groups, but may 
gather in large rafts at the surface near rookeries and haul-outs. 
Steller sea lions prefer the colder temperate to sub-arctic waters of 
the North Pacific Ocean. Haul-outs and rookeries usually consist of 
beaches (gravel, rocky or sand), ledges, and rocky reefs. In the Bering 
and Okhotsk Seas, sea lions may also haul-out on sea ice, but this is 
considered atypical behavior (NOAA, 2010a).
    Steller sea lions are gregarious animals that often travel or haul 
out in large groups of up to 45 individuals (Keple, 2002). At sea, 
groups usually consist of female and subadult males; adult males are 
usually solitary while at sea (Loughlin, 2002). In the Pacific 
Northwest, breeding rookeries are located in British Columbia, Oregon, 
and northern California. Steller sea lions form large rookeries during 
late spring when adult males arrive and establish territories (Pitcher 
and Calkins, 1981). Large males aggressively defend territories while 
non-breeding males remain at peripheral sites or haul-outs. Females 
arrive soon after and give birth. Most births occur from mid-May 
through mid-July, and breeding takes place shortly thereafter. Most 
pups are weaned within a year. Non-breeding individuals may not return 
to rookeries during the breeding season but remain at other coastal 
haul-outs (Scordino, 2006).
    Steller sea lions are opportunistic predators, feeding primarily on 
fish and cephalopods, and their diet varies geographically and 
seasonally (Bigg, 1985; Merrick et al., 1997; Bredesen et al., 2006; 
Guenette et al., 2006). Foraging habitat is primarily shallow,

[[Page 23568]]

nearshore and continental shelf waters; freshwater rivers; and also 
deep waters (Reeves et al., 2008; Scordino, 2010).
    In Oregon, Steller sea lions are found on offshore rocks and 
islands. Most of these haul-out sites are part of the Oregon Islands 
National Wildlife Refuge and are closed to the public (ODFW, 2010). 
Oregon is home to the largest breeding site in U.S. waters south of 
Alaska, with breeding areas at Three Arch Rocks (Oceanside), Orford 
Reef (Port Orford), and Rogue Reef (Gold Beach). Steller sea lions are 
also found year-round in smaller numbers at Sea Lion Caves and at Cape 
Arago State Park.
    Although Steller sea lions occur primarily in coastal habitat in 
Oregon and Washington, they are present year-round in the lower 
Columbia River, usually downstream of the confluence of the Cowlitz 
River (ODFW, 2008). However, adult and subadult male Steller sea lions 
have been observed at Bonneville Dam, where they prey primarily on 
sturgeon and salmon that congregate below the dam. In 2002, the USACE 
began monitoring seasonal presence, abundance, and predation activities 
of marine mammals in the Bonneville Dam tailrace (Tackley et al., 
2008b). Steller sea lions have been documented every year since 2003; 
observations have steadily increased to 75 Steller sea lions in 2010, 
the most on record and almost triple the number of the previous year 
(26 individuals) (Stansell et al., 2009, 2010).
    Steller sea lions use the Columbia River for travel, foraging, and 
resting as they move between haul-out sites and the dam. There are no 
known haul-out sites within the portions of the Region of Activity 
occurring in the Columbia River, Willamette River, or North Portland 
Harbor. The nearest known haul-out in the Columbia River is a rock 
formation (Phoca Rock) approximately 8 mi (13 km) downstream of 
Bonneville Dam (approximately 26 mi (42 km) upstream from the project 
site). Steller sea lions are also known to haul out on the south jetty 
at the mouth of the Columbia River, near Astoria, Oregon. There are no 
rookeries located in or near the Region of Activity. The nearest 
Steller sea lion rookery is on the northern Oregon coast at Oceanside 
(ODFW, 2010), approximately 70 mi (113 km) south of Astoria, i.e., more 
than 150 mi (240 km) from the Region of Activity.
    Steller sea lions arrive at the dam in late fall (Tackley et al., 
2008b), although occasionally individuals are sighted near Bonneville 
Dam in the months of September, October, and November (Stansell et al., 
2009, 2010). Steller sea lions are present at the dam through May, and 
can travel between the dam and the mouth of the Columbia River several 
times during these months (Tackley et al., 2008b). Table 14 compiles 
data from surface observations by the USACE for the Bonneville Dam 
tailrace. If arrival and departure dates were not available, the timing 
of surface observations within the January through May study period 
were recorded. Because regular observations in the study period 
generally began when California sea lions are observed below Bonneville 
Dam, and sometimes reports stated that observations stopped as sea lion 
numbers dropped, the observation dates only give a general idea of 
first arrival and departure for Steller sea lions. Because tracking 
data indicate that sea lions travel at fast rates between hydrophone 
locations above and below the CRC project area (Brown et al., 2010), 
dates of first arrival at Bonneville Dam and departure from the dam are 
assumed to coincide closely with potential passage timing through the 
CRC project area.

                                    Table 14--Arrival and Departure Dates for Steller Sea Lions Below Bonneville Dam
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   2002              2003       2004       2005       2006       2007       2008       2009       2010
--------------------------------------------------------------------------------------------------------------------------------------------------------
Arrival.................................  n/a...................   \1\ 3-03   \1\ 2-24   \1\ 4-11   1,2 2-10   1,2 1-08   1,3 1-11   1,4 1-14   1,6 1-08
Departure...............................  n/a...................   \1\ 6-02   \1\ 5-30   \1\ 5-31   1,2 5-31   1,2 5-26   \1\ 5-31   \5\ 5-19       6-04
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Dates are dates observations were taken and not when sea lions were first seen. Observations were made in 2002, but no Steller sea lions were
  observed. In 2005 through 2007, observations were made intermittently until sea lions were seen consistently (Tackley et al., 2008a). Observation
  dates for 2006-07 from Scordino 2010.
\2\ In 2006 and 2007 Steller sea lions were seen regularly in the tailrace area from January to early March. Report notes anecdotal information on
  sightings of Steller sea lions in November and December. Report states that after March when hazing activities began, fewer Steller sea lions were
  observed through May (Tackley et al., 2008a).
\3\ Steller sea lions were known to be catching and consuming sturgeon in the Bonneville Dam tailrace and farther downstream as early as November 2007
  (Tackley et al., 2008b).
\4\ Steller sea lions were known to be catching and consuming sturgeon in the Bonneville Dam tailrace and farther downstream as early as October 2008
  (Stansell et al., 2009).
\5\ Observations ended because few sea lions were present.
\6\ Steller sea lions were observed downriver of the Bonneville Dam tailrace as early as September 2009 (Stansell et al., 2010).

    Based on the information presented in Table 14, Steller sea lions 
are expected to pass the project site beginning with a few individuals 
as early as September and most individuals in January through early 
June. Stansell et al. (2009, 2010) show that Steller sea lion abundance 
below Bonneville Dam increases through approximately mid-April, and 
then drops through about the end of May.
    ODFW tagged eight Steller sea lions with acoustic and/or satellite-
linked transmitters from March 30 through May 4, 2010 (Wright, 2010a). 
Data show that the eight individuals only made one or two roundtrips 
from Bonneville during the months they were tracked. This study is 
ongoing and more information will be available in the future to 
determine both the number of roundtrips from Bonneville and the time to 
transit between Bonneville and the mouth of the Columbia River. 
Although transit times between the mouth of the Columbia River and 
Bonneville Dam are not available for Steller sea lions, they are 
available for California sea lions. The PSMFC leads a tagging and 
tracking program for California sea lions, which has observed that the 
transit time for California sea lions between Astoria and Bonneville 
Dam is 30-36 hours upstream and 15 hours downstream (CRC, 2010). 
Similar transit times are assumed here for Steller sea lions. Steller 
sea lions have generally been observed at Bonneville Dam between early 
January and late May, although individuals have been noted at the dam 
as early as September (Stansell et al., 2010). Thus, Steller sea lions 
are likely to be transiting in the Columbia River and North Portland 
Harbor during the time that in-water work would take place.
    Acoustics--Like all pinnipeds, the Steller sea lion is amphibious; 
while all foraging activity takes place in the water, breeding behavior 
is carried out on land in coastal rookeries (Mulsow

[[Page 23569]]

and Reichmuth 2008). On land, territorial male Steller sea lions 
regularly use loud, relatively low-frequency calls/roars to establish 
breeding territories (Schusterman et al., 1970; Loughlin et al., 1987). 
The calls of females range from 0.03 to 3 kHz, with peak frequencies 
from 0.15 to 1 kHz; typical duration is 1.0 to 1.5 sec (Campbell et 
al., 2002). Pups also produce bleating sounds. Individually distinct 
vocalizations exchanged between mothers and pups are thought to be the 
main modality by which reunion occurs when mothers return to crowded 
rookeries following foraging at sea (Mulsow and Reichmuth, 2008).
    Mulsow and Reichmuth (2008) measured the unmasked airborne hearing 
sensitivity of one male Steller sea lion. The range of best hearing 
sensitivity was between 5 and 14 kHz. Maximum sensitivity was found at 
10 kHz, where the subject had a mean threshold of 7 dB. The underwater 
hearing threshold of a male Steller sea lion was significantly 
different from that of a female. The peak sensitivity range for the 
male was from 1 to 16 kHz, with maximum sensitivity (77 dB re: 1[mu]Pa-
m) at 1 kHz. The range of best hearing for the female was from 16 to 
above 25 kHz, with maximum sensitivity (73 dB re: 1[mu]Pa-m) at 25 kHz. 
However, because of the small number of animals tested, the findings 
could not be attributed to either individual differences in sensitivity 
or sexual dimorphism (Kastelein et al., 2005).

Background on 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 derived using auditory evoked 
potential techniques, anatomical modeling, and other data, Southall et 
al. (2007) designate functional hearing groups for marine mammals and 
estimate the lower and upper frequencies of functional hearing of the 
groups. The functional groups and the associated frequencies are 
indicated below (though animals are less sensitive to sounds at the 
outer edge of their functional range and most sensitive to sounds of 
frequencies within a smaller range somewhere in the middle of their 
functional hearing range):
     Low frequency cetaceans (mysticetes): Functional hearing 
is estimated to occur between approximately 7 Hz and 22 kHz;
     Mid-frequency cetaceans (dolphins, larger toothed whales, 
beaked and bottlenose whales): Functional hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High frequency cetaceans (true porpoises, river dolphins, 
Kogia sp.): Functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz; and
     Pinnipeds in water: functional hearing is estimated to 
occur between approximately 75 Hz and 75 kHz, with the greatest 
sensitivity between approximately 700 Hz and 20 kHz.
    As mentioned previously in this document, three species of 
pinnipeds are likely to occur in the Region of Activity.

Potential Effects of the Specified Activity on Marine Mammals

    CRC's in-water construction and demolition activities (e.g., pile 
driving and removal) introduce sound into the marine environment, and 
have the potential to have adverse impacts on marine mammals. The 
potential effects of sound from the proposed activities associated with 
the CRC project may include one or more of the following: Tolerance; 
masking of natural sounds; behavioral disturbance; non-auditory 
physical effects; and temporary or permanent hearing impairment 
(Richardson et al., 1995). However, for reasons discussed later in this 
document, it is unlikely that there would be any cases of temporary or 
permanent hearing impairment resulting from these activities. As 
outlined in previous NMFS documents, the effects of sound on marine 
mammals are highly variable, and can be categorized as follows (based 
on Richardson et al., 1995):
     The sound may be too weak to be heard at the location of 
the animal (i.e., lower than the prevailing ambient sound level, the 
hearing threshold of the animal at relevant frequencies, or both);
     The sound may be audible but not strong enough to elicit 
any overt behavioral response;
     The sound may elicit reactions of varying degrees and 
variable relevance to the well being of the marine mammal; these can 
range from temporary alert responses to active avoidance reactions such 
as vacating an area until the stimulus ceases, but potentially for 
longer periods of time;
     Upon repeated exposure, a marine mammal may exhibit 
diminishing responsiveness (habituation), or disturbance effects may 
persist; the latter is most likely with sounds that are highly variable 
in characteristics and unpredictable in occurrence, and associated with 
situations that a marine mammal perceives as a threat;
     Any anthropogenic sound that is strong enough to be heard 
has the potential to result in masking, or reduce the ability of a 
marine mammal to hear biological sounds at similar frequencies, 
including calls from conspecifics and underwater environmental sounds 
such as surf sound;
     If mammals remain in an area because it is important for 
feeding, breeding, or some other biologically important purpose even 
though there is chronic exposure to sound, it is possible that there 
could be sound-induced physiological stress; this might in turn have 
negative effects on the well-being or reproduction of the animals 
involved; and
     Very strong sounds have the potential to cause a temporary 
or permanent reduction in hearing sensitivity, also referred to as 
threshold shift. In terrestrial mammals, and presumably marine mammals, 
received sound levels must far exceed the animal's hearing threshold 
for there to be any temporary threshold shift (TTS). For transient 
sounds, the sound level necessary to cause TTS is inversely related to 
the duration of the sound. Received sound levels must be even higher 
for there to be risk of permanent hearing impairment (PTS). In 
addition, intense acoustic or explosive events may cause trauma to 
tissues associated with organs vital for hearing, sound production, 
respiration and other functions. This trauma may include minor to 
severe hemorrhage.

Tolerance

    Numerous studies have shown that underwater sounds from industrial 
activities are often readily detectable by marine mammals in the water 
at distances of many kilometers. However, other studies have shown that 
marine mammals at distances more than a few kilometers away often show 
no apparent response to industrial activities of various types (Miller 
et al., 2005). This is often true even in cases when the sounds must be 
readily audible to the animals based on measured received levels and 
the hearing sensitivity of that mammal group. Although various baleen 
whales, toothed whales, and (less frequently) pinnipeds have been shown 
to react behaviorally to underwater sound from sources such as airgun 
pulses or vessels under some conditions, at other times, mammals of all 
three types have shown no overt reactions (e.g., Malme et al., 1986; 
Richardson et al., 1995; Madsen and Mohl, 2000; Croll et al., 2001; 
Jacobs and Terhune, 2002; Madsen et al., 2002;

[[Page 23570]]

Miller et al., 2005). In general, pinnipeds seem to be more tolerant of 
exposure to some types of underwater sound than are baleen whales. 
Richardson et al. (1995) found that vessel sound does not seem to 
strongly affect pinnipeds that are already in the water. Richardson et 
al. (1995) went on to explain that seals on haul-outs sometimes respond 
strongly to the presence of vessels and at other times appear to show 
considerable tolerance of vessels, and Brueggeman et al. (1992) 
observed ringed seals (Pusa hispida) hauled out on ice pans displaying 
short-term escape reactions when a ship approached within 0.16-0.31 mi 
(0.25-0.5 km).

Masking

    Masking is the obscuring of sounds of interest to an animal by 
other sounds, typically at similar frequencies. Marine mammals are 
highly dependent on sound, and their ability to recognize sound signals 
amid other sound is important in communication and detection of both 
predators and prey. Background ambient sound may interfere with or mask 
the ability of an animal to detect a sound signal even when that signal 
is above its absolute hearing threshold. Even in the absence of 
anthropogenic sound, the marine environment is often loud. Natural 
ambient sound includes contributions from wind, waves, precipitation, 
other animals, and (at frequencies above 30 kHz) thermal sound 
resulting from molecular agitation (Richardson et al., 1995).
    Background sound may also include anthropogenic sound, and masking 
of natural sounds can result when human activities produce high levels 
of background sound. Conversely, if the background level of underwater 
sound is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked. 
Ambient sound is highly variable on continental shelves (Thompson, 
1965; Myrberg, 1978; Chapman et al., 1998; Desharnais et al., 1999). 
This results in a high degree of variability in the range at which 
marine mammals can detect anthropogenic sounds.
    Although masking is a phenomenon which may occur naturally, the 
introduction of loud anthropogenic sounds into the marine environment 
at frequencies important to marine mammals increases the severity and 
frequency of occurrence of masking. For example, if a baleen whale is 
exposed to continuous low-frequency sound from an industrial source, 
this would reduce the size of the area around that whale within which 
it can hear the calls of another whale. The components of background 
noise that are similar in frequency to the signal in question primarily 
determine the degree of masking of that signal. In general, little is 
known about the degree to which marine mammals rely upon detection of 
sounds from conspecifics, predators, prey, or other natural sources. In 
the absence of specific information about the importance of detecting 
these natural sounds, it is not possible to predict the impact of 
masking on marine mammals (Richardson et al., 1995). In general, 
masking effects are expected to be less severe when sounds are 
transient than when they are continuous. Masking is typically of 
greater concern for those marine mammals that utilize low frequency 
communications, such as baleen whales and, as such, is not likely to 
occur for pinnipeds in the Region of Activity.

Disturbance

    Behavioral disturbance is one of the primary potential impacts of 
anthropogenic sound on marine mammals. Disturbance can result in a 
variety of effects, such as subtle or dramatic changes in behavior or 
displacement, but the degree to which disturbance causes such effects 
may be highly dependent upon the context in which the stimulus occurs. 
For example, an animal that is feeding may be less prone to disturbance 
from a given stimulus than one that is not. For many species and 
situations, there is no detailed information about reactions to sound.
    Behavioral reactions of marine mammals to sound are difficult to 
predict because they are dependent on numerous factors, including 
species, maturity, experience, activity, reproductive state, time of 
day, and weather. If a marine mammal does react to an underwater sound 
by changing its behavior or moving a small distance, the impacts of 
that change may not be important to the individual, 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 the animals could be important. In general, pinnipeds seem 
more tolerant of, or at least habituate more quickly to, potentially 
disturbing underwater sound than do cetaceans, and generally seem to be 
less responsive to exposure to industrial sound than most cetaceans. 
Pinniped responses to underwater sound from some types of industrial 
activities such as seismic exploration appear to be temporary and 
localized (Harris et al., 2001; Reiser et al., 2009).
    Because the few available studies show wide variation in response 
to underwater and airborne sound, it is difficult to quantify exactly 
how pile driving sound would affect pinnipeds. The literature shows 
that elevated underwater sound levels could prompt a range of effects, 
including no obvious visible response, or behavioral responses that may 
include annoyance and increased alertness, visual orientation towards 
the sound, investigation of the sound, change in movement pattern or 
direction, habituation, alteration of feeding and social interaction, 
or temporary or permanent avoidance of the area affected by sound. 
Minor behavioral responses do not necessarily cause long-term effects 
to the individuals involved. Severe responses include panic, immediate 
movement away from the sound, and stampeding, which could potentially 
lead to injury or mortality (Southall et al., 2007).
    Southall et al. (2007) reviewed literature describing responses of 
pinnipeds to non-pulsed sound in water and reported that the limited 
data suggest exposures between approximately 90 and 140 dB generally do 
not appear to induce strong behavioral responses in pinnipeds, while 
higher levels of pulsed sound, ranging between 150 and 180 dB, will 
prompt avoidance of an area. It is important to note that among these 
studies, there are some apparent differences in responses between field 
and laboratory conditions. In contrast to the mid-frequency 
odontocetes, captive pinnipeds responded more strongly at lower levels 
than did animals in the field. Again, contextual issues are the likely 
cause of this difference. For airborne sound, Southall et al. (2007) 
note there are extremely limited data suggesting very minor, if any, 
observable behavioral responses by pinnipeds exposed to airborne pulses 
of 60 to 80 dB; however, given the paucity of data on the subject, we 
cannot rule out the possibility that avoidance of sound in the Region 
of Activity could occur.
    In their comprehensive review of available literature, Southall et 
al. (2007) noted that quantitative studies on behavioral reactions of 
pinnipeds to underwater sound are rare. A subset of only three studies 
observed the response of pinnipeds to multiple pulses of underwater 
sound (a category of sound types that includes impact pile driving), 
and were also deemed by the authors as having results that are both 
measurable

[[Page 23571]]

and representative. However, a number of studies not used by Southall 
et al. (2007) provide additional information, both quantitative and 
anecdotal, regarding the reactions of pinnipeds to multiple pulses of 
underwater sound.
     Harris et al. (2001) observed the response of ringed, 
bearded (Erignathus barbatus), and spotted seals (Phoca largha) to 
underwater operation of a single air gun and an eleven-gun array. 
Received exposure levels were 160 to 200 dB. Results fit into two 
categories. In some instances, seals exhibited no response to sound. 
However, the study noted significantly fewer seals during operation of 
the full array in some instances. Additionally, the study noted some 
avoidance of the area within 150 m of the source during full array 
operations.
     Blackwell et al. (2004) is the only cited study directly 
related to pile driving. The study observed ringed seals during impact 
installation of steel pipe pile. Received underwater SPLs were measured 
at 151 dB at 63 m. The seals exhibited either no response or only brief 
orientation response (defined as ``investigation or visual 
orientation''). It should be noted that the observations were made 
after pile driving was already in progress. Therefore, it is possible 
that the low-level response was due to prior habituation.
     Miller et al. (2005) observed responses of ringed and 
bearded seals to a seismic air gun array. Received underwater sound 
levels were estimated at 160 to 200 dB. There were fewer seals present 
close to the sound source during air gun operations in the first year, 
but in the second year the seals showed no avoidance. In some 
instances, seals were present in very close range of the sound. The 
authors concluded that there was ``no observable behavioral response'' 
to seismic air gun operations.
    During a Caltrans installation demonstration project for retrofit 
work on the East Span of the San Francisco Oakland Bay Bridge, 
California, sea lions responded to pile driving by swimming rapidly out 
of the area, regardless of the size of the pile-driving hammer or the 
presence of sound attenuation devices (74 FR 63724).
    Jacobs and Terhune (2002) observed harbor seal reactions to 
acoustic harassment devices (AHDs) with source level of 172 dB deployed 
around aquaculture sites. Seals were generally unresponsive to sounds 
from the AHDs. During two specific events, individuals came within 141 
and 144 ft (43 and 44 m) of active AHDs and failed to demonstrate any 
measurable behavioral response; estimated received levels based on the 
measures given were approximately 120 to 130 dB.
    Costa et al. (2003) measured received sound levels from an Acoustic 
Thermometry of Ocean Climate (ATOC) program sound source off northern 
California using acoustic data loggers placed on translocated elephant 
seals. Subjects were captured on land, transported to sea, instrumented 
with archival acoustic tags, and released such that their transit would 
lead them near an active ATOC source (at 0.6 mi depth [939 m]; 75-Hz 
signal with 37.5-Hz bandwidth; 195 dB maximum source level, ramped up 
from 165 dB over 20 min) on their return to a haul-out site. Received 
exposure levels of the ATOC source for experimental subjects averaged 
128 dB (range 118 to 137) in the 60- to 90-Hz band. None of the 
instrumented animals terminated dives or radically altered behavior 
upon exposure, but some statistically significant changes in diving 
parameters were documented in nine individuals. Translocated northern 
elephant seals exposed to this particular non-pulse source began to 
demonstrate subtle behavioral changes at exposure to received levels of 
approximately 120 to 140 dB.
    Several available studies provide information on the reactions of 
pinnipeds to non-pulsed underwater sound. Kastelein et al. (2006) 
exposed nine captive harbor seals in an approximately 82 x 98 ft (25 x 
30 m) enclosure to non-pulse sounds used in underwater data 
communication systems (similar to acoustic modems). Test signals were 
frequency modulated tones, sweeps, and bands of sound with fundamental 
frequencies between 8 and 16 kHz; 128 to 130 3 dB source 
levels; 1- to 2-s duration (60-80 percent duty cycle); or 100 percent 
duty cycle. They recorded seal positions and the mean number of 
individual surfacing behaviors during control periods (no exposure), 
before exposure, and in 15-min experimental sessions (n = 7 exposures 
for each sound type). Seals generally swam away from each source at 
received levels of approximately 107 dB, avoiding it by approximately 
16 ft (5 m), although they did not haul out of the water or change 
surfacing behavior. Seal reactions did not appear to wane over repeated 
exposure (i.e., there was no obvious habituation), and the colony of 
seals generally returned to baseline conditions following exposure. The 
seals were not reinforced with food for remaining in the sound field.
    Reactions of harbor seals to the simulated sound of a 2-megawatt 
wind power generator were measured by Koschinski et al. (2003). Harbor 
seals surfaced significantly further away from the sound source when it 
was active and did not approach the sound source as closely. The device 
used in that study produced sounds in the frequency range of 30 to 800 
Hz, with peak source levels of 128 dB at 1 m at the 80- and 160-Hz 
frequencies.
    Ship and boat sound do not seem to have strong effects on seals in 
the water, but the data are limited. When in the water, seals appear to 
be much less apprehensive about approaching vessels. Some would 
approach a vessel out of apparent curiosity, including noisy vessels 
such as those operating seismic airgun arrays (Moulton and Lawson, 
2002). Gray seals (Halichoerus grypus) have been known to approach and 
follow fishing vessels in an effort to steal catch or the bait from 
traps. In contrast, seals hauled out on land often are quite responsive 
to nearby vessels. Terhune (1985) reported that northwest Atlantic 
harbor seals were extremely vigilant when hauled out and were wary of 
approaching (but less so passing) boats. Suryan and Harvey (1999) 
reported that Pacific harbor seals commonly left the shore when 
powerboat operators approached to observe the seals. Those seals 
detected a powerboat at a mean distance of 866 ft (264 m), and seals 
left the haul-out site when boats approached to within 472 ft (144 m).
    Southall et al. (2007) also compiled known studies of behavioral 
responses of marine mammals to airborne sound, noting that studies of 
pinniped response to airborne pulsed sounds are exceedingly rare. The 
authors deemed only one study as having quantifiable results.
     Blackwell et al. (2004) studied the response of ringed 
seals within 500 m of impact driving of steel pipe pile. Received 
levels of airborne sound were measured at 93 dB at a distance of 63 m. 
Seals had either no response or limited response to pile driving. 
Reactions were described as ``indifferent'' or ``curious.''
    Efforts to deter pinniped predation on salmonids below Bonneville 
Dam began in 2005, and have used Acoustic Deterrent Devices (ADDs), 
boat chasing, above-water pyrotechnics (cracker shells, screamer shells 
or rockets), rubber bullets, rubber buckshot, and beanbags (Stansell et 
al., 2009). Review of deterrence activities by the West Coast Pinniped 
Program noted ``USACE observations from 2002 to 2008 indicated that 
increasing numbers of California sea lions were foraging on salmon at 
Bonneville Dam each year, salmon predation rates increased, and the 
deterrence efforts were having little

[[Page 23572]]

effect on preventing predation'' (Scordino, 2010). In the USACE status 
report through May 28, 2010, boat hazing was reported to have limited, 
local, short term impact in reducing predation in the tailrace, 
primarily from Steller sea lions. ODFW and the WDFW reported that sea 
lion presence did not appear to be significantly influenced by boat-
based activities and several ``new'' sea lions (initially unbranded or 
unknown from natural markings) continued to forage in the observation 
area in spite of shore- and boat-based hazing. They suggested that 
hazing was not effective at deterring naive sea lions if there were 
large numbers of experienced sea lions foraging in the area (Brown et 
al., 2010). Observations on the effect of ADDs, which were installed at 
main fishway entrances in 2007, noted that pinnipeds were observed 
swimming and eating fish within 20 ft (6 m) of some of the devices with 
no deterrent effect observed (Tackley et al., 2008a, 2008b; Stansell et 
al., 2009, 2010). Many of the animals returned to the area below the 
dam despite hazing efforts (Stansell et al., 2009, Stansell and 
Gibbons, 2010). Relocation efforts to Astoria and the Oregon coast were 
implemented in 2007; however, all but one of fourteen relocated animals 
returned to Bonneville Dam within days (Scordino, 2010).
    No information on in-water sound levels of hazing activities at 
Bonneville Dam has been published other than that ADDs produce 
underwater sound levels of 205 dB in the 15 kHz range (Stansell et al., 
2009). Durations of boat-based hazing events were reported at less than 
30 minutes for most of the 521 boat-based events in 2009, but ranged up 
to 90 minutes (Brown et al., 2009). Durations of boat-based hazing 
events were not reported for 2010. However, 280 events occurred over 44 
days during a five-month period using a total of 4,921 cracker shells, 
777 seal bombs, and 97 rubber buckshot rounds (Brown et al., 2010). 
Based on knowledge of in-water sound from construction activities, the 
CRC project believes that sound levels from in-water construction and 
demolition activities that pinnipeds would be potentially exposed to 
are not as high as those produced by hazing techniques.
    In addition, sea lions are expected to quickly traverse through and 
not remain in the project area. Tagging studies of California sea lions 
indicate that they pass hydrophones upriver and downriver of the CRC 
project site quickly. Wright et al. (2010) reported minimum upstream 
and downstream transit times between the Astoria haul-out and 
Bonneville Dam (river distance approximately 20 km) were 1.9 and 1 day, 
respectively, based on fourteen trips by eleven sea lions. The transit 
speed was calculated to be 4.6 km/hr in the upstream direction and 8.8 
km/hr in the downstream direction. Data from the six individuals 
acoustically tagged in 2009 show that they made a combined total of 
eleven upriver or downriver trips quickly through the CRC project site 
to or from Bonneville Dam and Astoria (Brown et al., 2009). Data from 
four acoustically tagged California sea lions in 2010 also indicate 
that the animals move though the area below Bonneville Dam down to the 
receivers located below the CRC project site rapidly both in the 
upriver or downriver directions (Wright, 2010). Although the data apply 
to California sea lions, Steller sea lions and harbor seals similarly 
have no incentive to stay near the CRC project area, in contrast with a 
strong incentive to quickly reach optimal foraging grounds at the 
Bonneville Dam, and are thus expected to also pass the project area 
quickly. Therefore, pinnipeds are not expected to be exposed to a 
significant duration of construction sound.
    It is possible that deterrence of passage through the project area 
could be a concern. However, given the 800-m width of the Columbia 
River and the rarity of impact pile driving on opposite sides of the 
river (approximately 1-2 days total throughout the approximately 4-year 
construction period), passage should not be hindered. Vibratory 
installation or removal of piles at more than one pier complex would 
likely occur at the same time on occasion during construction and 
demolition. During construction and demolition, space limitations due 
to barge size and limitations on the amount of equipment available are 
anticipated to be limiting factors for the contractor. Vibratory 
installation of steel casings, pipe piles, and sheet piles are 
calculated to exceed behavioral disturbance thresholds at large 
distances; thus, the entire width of the channel would be affected by 
sound above the disturbance threshold even if only one pier complex was 
being worked on. However, because these sound levels are lower than 
those produced by ADDs at Bonneville Dam--which have shown only limited 
efficacy in deterring pinnipeds--and because pinnipeds transiting the 
Region of Activity will be highly motivated to complete transit, 
deterrence of passage is not anticipated to occur.
    Debris Removal--The reactions of pinnipeds to sound from debris 
removal (a non-pulsed sound) have received virtually no study. Previous 
studies indicate that dredging sound has resulted in avoidance 
reactions in marine mammals; however, the number of studies is small 
and limited to only a handful of locations. Thomsen et al. (2009) 
caution that, given the limited number of studies, the existing 
published data may not be representative and that it is therefore 
impossible to extrapolate the potential effects from one area to the 
next.
    In a review of the available literature regarding the effects of 
dredging sound on marine mammals, Richardson et al. (1995) found 
studies only related to whales and porpoises, and none related to 
pinnipeds. The review did, however, find studies related to the 
response of pinnipeds to ``other construction activities'', which may 
be applicable to dredging sound. Three studies of ringed seals during 
construction of artificial islands in Alaska showed mostly mild 
reactions ranging from negligible to temporary local displacement. 
Green and Johnson (1983, as cited in Richardson et al. [1995]) observed 
that some ringed seals moved away from the disturbance source within a 
few kilometers of construction. Frost and Lowry (1988, as cited in 
Richardson et al. [1995]) and Frost et al. (1988, as cited in 
Richardson et al., 1995) noted that ringed seal density within 3.7 km 
of construction was less than seal density in areas located more than 
3.7 km away. Harbor seals in Kachemak Bay, Alaska, continued to haul 
out despite construction of hydroelectric facilities located 1,600 m 
away. Finally, Gentry and Gilman (1990) reported that the strongest 
reaction to quarrying operations on St. George Island in the Bering Sea 
was an alert posture when heavy equipment occurred within 100 m of 
northern fur seals.
    There are no established levels of underwater debris removal sound 
shown to cause injury to pinnipeds. However, since the maximum expected 
debris removal sound levels on the CRC project are below the 
established injury threshold, it is unlikely that this activity would 
produce sound levels that are injurious to pinnipeds. Additionally, the 
limited body of literature does not include any reports of injuries 
caused by sound from underwater excavation. Debris removal sound is 
likely to exceed the disturbance threshold for only a short distance 
from the source (approximately 631 m). Specific responses to sound 
above this level may range from no response to avoidance to minor 
disruption of migration and/or feeding. Alternatively, pinnipeds may 
become habituated to elevated sound levels (NMFS, 2005; Stansell, 
2009). This is consistent with the literature,

[[Page 23573]]

which reports only the following behavioral responses to these types of 
sound sources: No reaction, alertness, avoidance, and habituation. NMFS 
(2005) posits that continuous sound levels of 120 dB rms may elicit 
responses such as avoidance, diving, or changing foraging locations.
    Debris removal is only estimated to occur for up to 7 days over the 
4-year construction period in North Portland Harbor. If this activity 
overlaps with pinniped presence, behavioral disturbance is expected to 
be brief and temporary, and restricted to individuals that are 
transiting the North Portland Harbor portion of the Region of Activity. 
Because many of the individual pinnipeds transiting the Region of 
Activity are already habituated to hazing at Bonneville Dam and to high 
levels of existing noise throughout the lower Columbia River, it is 
expected that they would not be especially sensitive to a marginal 
increase in existing noise. Thus, due to the short duration of this 
sound, its location only in North Portland Harbor and the high level of 
existing disturbance throughout the lower Columbia River, sound 
generated from debris removal is not expected to result in disturbance 
that would rise to the level of Level B harassment.
    Vessel Operations--Various types of vessels, including barges, tug 
boats, and small craft, would be present in the Region of Activity at 
various times. Vessel traffic would continually traverse the in-water 
CRC project area, with activities centered on Piers 2 through 7 of the 
Columbia River and the new North Portland Harbor bents. Such vessels 
already use the Region of Activity in moderately high numbers; 
therefore, the vessels to be used in the Region of Activity do not 
represent a new sound source, only a potential increase in the 
frequency and duration of these sound source types.
    There are very few controlled tests or repeatable observations 
related to the reactions of pinnipeds to vessel noise. However, 
Richardson et al. (1995) reviewed the literature on reactions of 
pinnipeds to vessels, concluding overall that pinnipeds showed high 
tolerance to vessel noise. One study showed that, in water, sea lions 
tolerated frequent approach of vessels at close range. Because the 
Region of Activity is heavily traveled by commercial and recreational 
craft, it seems likely that pinnipeds that transit the Region of 
Activity are already habituated to vessel noise, thus the additional 
vessels that would occur as a result of CRC project activities would 
likely not have an additional effect on these pinnipeds. Therefore, CRC 
project vessel noise in the Region of Activity is unlikely to rise to 
the level of Level B harassment.
    Physical Disturbance--Vessels, in-water structures, and over-water 
structures have the potential to cause physical disturbance to 
pinnipeds, although in-water and over-water structures would cover no 
more than 20 percent of the entire channel width at one time (CRC, 
2010). As previously mentioned, various types of vessels already use 
the Region of Activity in high numbers. Tug boats and barges are slow 
moving and follow a predictable course. Pinnipeds would be able to 
easily avoid these vessels while transiting through the Region of 
Activity, and are likely already habituated to the presence of numerous 
vessels, as the lower Columbia River and North Portland Harbor receive 
high levels of commercial and recreational vessel traffic. Therefore, 
vessel strikes are extremely unlikely and, thus, discountable. 
Potential encounters would likely be limited to brief, sporadic 
behavioral disturbance, if any at all. Such disturbances are not likely 
to result in a risk of Level B harassment of pinnipeds transiting the 
Region of Activity.

Hearing Impairment and Other Physiological Effects

    Temporary or permanent hearing impairment is a possibility when 
marine mammals are exposed to very strong sounds. Non-auditory 
physiological effects might also occur in marine mammals exposed to 
strong underwater sound. Possible types of non-auditory physiological 
effects or injuries that may occur in mammals close to a strong sound 
source include stress, neurological effects, bubble formation, and 
other types of organ or tissue damage. It is possible that some marine 
mammal species (i.e., beaked whales) may be especially susceptible to 
injury and/or stranding when exposed to strong pulsed sounds, 
particularly at higher frequencies. Non-auditory physiological effects 
are not anticipated to occur as a result of CRC activities. The 
following subsections discuss the possibilities of TTS and PTS.
    TTS--TTS, reversible hearing loss caused by fatigue of hair cells 
and supporting structures in the inner ear, 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. TTS can last from 
minutes or hours to (in cases of strong TTS) days. 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.
    NMFS considers TTS to be a form of Level B harassment rather than 
injury, as it consists of fatigue to auditory structures rather than 
damage to them. Pinnipeds have demonstrated complete recovery from TTS 
after multiple exposures to intense sound, as described in the studies 
below (Kastak et al., 1999, 2005). The NMFS-established 190-dB 
criterion is not considered to be the level above which TTS might 
occur. Rather, it is the received level above which, in the view of a 
panel of bioacoustics specialists convened by NMFS before TTS 
measurements for marine mammals became available, one could not be 
certain that there would be no injurious effects, auditory or 
otherwise, to pinnipeds. Therefore, exposure to sound levels above 190 
dB does not necessarily mean that an animal has incurred TTS, but 
rather that it may have occurred. 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.
    Human non-impulsive sound exposure guidelines are based on 
exposures of equal energy (the same sound exposure level [SEL]; SEL is 
reported here in dB re: 1 [micro]Pa\2\-s/re: 20 [micro]Pa\2\-s for in-
water and in-air sound, respectively) producing equal amounts of 
hearing impairment regardless of how the sound energy is distributed in 
time (NIOSH, 1998). Until recently, previous marine mammal TTS studies 
have also generally supported this equal energy relationship (Southall 
et al., 2007). Three newer studies, two by Mooney et al. (2009a,b) on a 
single bottlenose dolphin (Tursiops truncatus) either exposed to 
playbacks of U.S. Navy mid-frequency active sonar or octave-band sound 
(4-8 kHz) and one by Kastak et al. (2007) on a single California sea 
lion exposed to airborne octave-band sound (centered at 2.5 kHz), 
concluded that for all sound exposure situations, the equal energy 
relationship may not be the best indicator to predict TTS onset levels. 
Generally, with sound exposures of equal energy, those that were 
quieter (lower SPL) with longer duration were found to induce TTS onset 
more than those of louder (higher SPL) and shorter duration. Given the 
available data, the received level of a single seismic pulse (with no 
frequency weighting) might need to be approximately 186 dB SEL in order 
to produce brief, mild TTS.
    In free-ranging pinnipeds, TTS thresholds associated with exposure 
to

[[Page 23574]]

brief pulses (single or multiple) of underwater sound have not been 
measured. However, systematic TTS studies on captive pinnipeds have 
been conducted (e.g., Bowles et al., 1999; Kastak et al., 1999, 2005, 
2007; Schusterman et al., 2000; Finneran et al., 2003; Southall et al., 
2007). Specific studies are detailed here:
     Finneran et al. (2003) studied responses of two individual 
California sea lions. The sea lions were exposed to single pulses of 
underwater sound, and experienced no detectable TTS at received sound 
level of 183 dB peak (163 dB SEL).
    There were three studies conducted on pinniped TTS responses to 
non-pulsed underwater sound. All of these studies were performed in the 
same lab and on the same test subjects, and, therefore, the results may 
not be applicable to all pinnipeds or in field settings.
     Kastak and Schusterman (1996) studied the response of 
harbor seals to non-pulsed construction sound, reporting TTS of about 8 
dB. The seal was exposed to broadband construction sound for 6 days, 
averaging 6 to 7 hours of intermittent exposure per day, with SPLs from 
just approximately 90 to 105 dB.
     Kastak et al. (1999) reported TTS of approximately 4-5 dB 
in three species of pinnipeds (harbor seal, California sea lion, and 
northern elephant seal) after underwater exposure for approximately 20 
minutes to sound with frequencies ranging from 100-2,000 Hz at received 
levels 60-75 dB above hearing threshold. This approach allowed similar 
effective exposure conditions to each of the subjects, but resulted in 
variable absolute exposure values depending on subject and test 
frequency. Recovery to near baseline levels was reported within 24 
hours of sound exposure.
     Kastak et al. (2005) followed up on their previous work, 
exposing the same test subjects to higher levels of sound for longer 
durations. The animals were exposed to octave-band sound for up to 50 
minutes of net exposure. The study reported that the harbor seal 
experienced TTS of 6 dB after a 25-minute exposure to 2.5 kHz of 
octave-band sound at 152 dB (183 dB SEL). The California sea lion 
demonstrated onset of TTS after exposure to 174 dB and 206 dB SEL.
    Southall et al. (2007) reported one study on TTS in pinnipeds 
resulting from airborne pulsed sound, while two studies examined TTS in 
pinnipeds resulting from airborne non-pulsed sound:
     Bowles et al. (unpubl. data) exposed pinnipeds to 
simulated sonic booms. Harbor seals demonstrated TTS at 143 dB peak and 
129 dB SEL. California sea lions and northern elephant seals 
experienced TTS at higher exposure levels than the harbor seals.
     Kastak et al. (2004) used the same test subjects as in 
Kastak et al. 2005, exposing the animals to non-pulsed sound (2.5 kHz 
octave-band sound) for 25 minutes. The harbor seal demonstrated 6 dB of 
TTS after exposure to 99 dB (131 dB SEL). The California sea lion 
demonstrated onset of TTS at 122 dB and 154 dB SEL.
     Kastak et al. (2007) studied the same California sea lion 
as in Kastak et al. 2004 above, exposing this individual to 192 
exposures of 2.5 kHz octave-band sound at levels ranging from 94 to 133 
dB for 1.5 to 50 min of net exposure duration. The test subject 
experienced up to 30 dB of TTS. TTS onset occurred at 159 dB SEL. 
Recovery times ranged from several minutes to 3 days.
    The sound level necessary to cause TTS in pinnipeds depends on 
exposure duration; with longer exposure, the level necessary to elicit 
TTS is reduced (Schusterman et al., 2000; Kastak et al., 2005, 2007). 
For very short exposures (e.g., to a single sound pulse), the level 
necessary to cause TTS is very high (Finneran et al., 2003). Impact 
pile driving associated with CRC would produce maximum underwater 
pulsed sound levels estimated at 210 dB peak and 176 dB SEL with 10 dB 
of attenuation from an attenuation device (214 dB peak and 186 dB SEL 
without an attenuation device). Summarizing existing data, Southall et 
al. (2007) assume that pulses of underwater sound result in the onset 
of TTS in pinnipeds when received levels reach 212 dB peak or 171 dB 
SEL. They did not offer criteria for non-pulsed sounds. These 
recommendations are presented in order to discuss the likelihood of TTS 
occurring during the CRC project. The literature does not allow 
conclusions to be drawn regarding levels of underwater non-pulsed sound 
(e.g., vibratory pile installation) likely to cause TTS. With a sound 
attenuation device, TTS is not likely to occur based on estimated 
source levels from the CRC project. Without a sound attenuation device, 
it is estimated that the extent of the area in which underwater sound 
levels could potentially cause TTS is somewhere in between the extent 
of where the injury threshold occurs and the extent of where the 
disturbance threshold occurs (described previously in this document).
    Impact pile driving would produce initial airborne sound levels of 
approximately 112 dB peak at 160 ft (49 m) from the source, as compared 
to the level suggested by Southall et al. (2007) of 143 dB peak for 
onset of TTS in pinnipeds from multiple pulses of airborne sound. It is 
not expected that airborne sound levels would induce TTS in individual 
pinnipeds.
    Although underwater sound levels produced by the CRC project may 
exceed levels produced in studies that have induced TTS in pinnipeds, 
there is a general lack of controlled, quantifiable field studies 
related to this phenomenon, and existing studies have had varied 
results (Southall et al., 2007). Therefore, it is difficult to 
extrapolate from these data to site-specific conditions for the CRC 
project. For example, because most of the studies have been conducted 
in laboratories, rather than in field settings, the data are not 
conclusive as to whether elevated levels of sound would cause pinnipeds 
to avoid the Region of Activity, thereby reducing the likelihood of 
TTS, or whether sound would attract pinnipeds, increasing the 
likelihood of TTS. In any case, there are no universally accepted 
standards for the amount of exposure time likely to induce TTS. 
Lambourne (in CRC, 2010) posits that, in most circumstances, free-
roaming Steller sea lions are not likely to remain in areas subjected 
to high sound levels long enough to experience TTS unless there is a 
particularly strong attraction, such as an abundant food source. While 
it may be inferred that TTS could theoretically result from the CRC 
project, it is impossible to quantify the magnitude of exposure, the 
duration of the effect, or the number of individuals likely to be 
affected. Exposure is likely to be brief because pinnipeds use the 
Region of Activity for transiting, rather than breeding or hauling out. 
In summary, it is expected that elevated sound would have only a 
negligible probability of causing TTS in individual seals and sea 
lions.
    PTS--When PTS occurs, there is physical damage to the sound 
receptors in the ear. In some cases, there can be total or partial 
deafness, whereas in other cases, the animal has an impaired ability to 
hear sounds in specific frequency ranges.
    There is no specific evidence that exposure to underwater 
industrial sounds can cause PTS in any marine mammal (see Southall et 
al., 2007). However, given the possibility that marine mammals might 
incur TTS, there has been further speculation about the possibility 
that some individuals occurring very close to industrial activities 
might incur PTS. Richardson et al. (1995) hypothesized that PTS

[[Page 23575]]

caused by prolonged exposure to continuous anthropogenic sound is 
unlikely to occur in marine mammals, at least for sounds with source 
levels up to approximately 200 dB. Single or occasional occurrences of 
mild TTS are not indicative of permanent auditory damage in terrestrial 
mammals. Studies of relationships between TTS and PTS thresholds in 
marine mammals are limited; however, existing data appear to show 
similarity to those found for humans and other terrestrial mammals, for 
which there is a large body of data. PTS might occur at a received 
sound level at least several decibels above that inducing mild TTS.
    Southall et al. (2007) propose that sound levels inducing 40 dB of 
TTS may result in onset of PTS in marine mammals. The authors present 
this threshold with precaution, as there are no specific studies to 
support it. Because direct studies on marine mammals are lacking, the 
authors base these recommendations on studies performed on other 
mammals. Additionally, the authors assume that multiple pulses of 
underwater sound result in the onset of PTS in pinnipeds when levels 
reach 218 dB peak or 186 dB SEL. In air, sound levels are assumed to 
cause PTS in pinnipeds at 149 dB peak or 144 dB SEL (Southall et al., 
2007). Sound levels this high are not expected to occur as a result of 
the proposed activities.
    The potential effects to marine mammals described in this section 
of the document do not take into consideration the proposed monitoring 
and mitigation measures described later in this document (see the 
PROPOSED MITIGATION and PROPOSED MONITORING AND REPORTING sections). It 
is highly unlikely that marine mammals would receive sounds strong 
enough (and over a sufficient duration) to cause PTS (or even TTS) 
during the proposed CRC activities. When taking the mitigation measures 
proposed for inclusion in the regulations into consideration, it is 
highly unlikely that any type of hearing impairment would occur as a 
result of CRC's proposed activities.

Anticipated Effects on Marine Mammal Habitat

    Construction activities would likely impact pinniped habitat in the 
Columbia River and North Portland Harbor by producing temporary 
disturbances, primarily through elevated levels of underwater sound, 
reduced water quality, and physical habitat alteration associated with 
the structural footprint of the CRC bridges. Other potential temporary 
changes are passage obstruction and changes in prey species 
distribution during construction. Permanent changes to habitat would be 
produced primarily through the presence of new bridge piers in the 
Columbia River and in North Portland Harbor and removal of the existing 
piers in the Columbia River. A limited amount of debris removal in the 
North Portland Harbor may occur.
    The underwater sounds would occur as short-term pulses (i.e., 
minutes to hours), separated by virtually instantaneous and complete 
recovery periods. These disturbances are likely to occur several times 
a day for up to a week, 2-14 weeks per year, for 6 years (5 years of 
activity would be authorized under this rule). Water quality impairment 
would also occur as short-term pulses (i.e., minutes to hours) during 
construction, most likely due to erosion during precipitation events, 
and would continue due to stormwater runoff for the design life of CRC. 
Physical habitat alteration due to modification and replacement of 
existing in-water and over-water structures would also occur 
intermittently during construction, and would remain as the final, as-
built project footprint for the design life of CRC.
    Elevated levels of sound may be considered to affect the in-water 
habitat of pinnipeds via impacts to prey species or through passage 
obstruction (discussed later). However, due to the timing of the in-
water work and the limited amount of pile driving that may occur on a 
daily basis, these effects on pinniped habitat would be temporary and 
limited in duration. Very few harbor seals are likely to be present in 
any case, and any pinnipeds that do encounter increased sound levels 
would primarily be transiting the action area in route to or from 
foraging below Bonneville Dam where fish concentrate, and thus unlikely 
to forage in the action area in anything other than an opportunistic 
manner. The direct loss of habitat available during construction due to 
sound impacts is expected to be minimal.

Impacts to Prey Species

    Fish are the primary dietary component of pinnipeds in the Region 
of Activity. The Columbia River and North Portland Harbor provides 
migration and foraging habitat for sturgeon and lamprey, migration and 
spawning habitat for eulachon, and migration habitat for juvenile and 
adult salmon and steelhead, as well as some limited rearing habitat for 
juvenile salmon and steelhead.
    Impact pile driving would produce a variety of underwater sound 
levels. Underwater sound caused by vibratory installation would be less 
than impact driving (Caltrans, 2009; WSDOT, 2010b). Oscillating and 
rotating steel casements for drilled shafts are not likely to elevate 
underwater sound to a level that is likely to cause injury or that 
would cause adverse changes to fish behavior on a long-term basis.
    Literature relating to the impacts of sound on marine fish species 
can be divided into categories which describe the following: (1) 
Pathological effects; (2) physiological effects; and (3) behavioral 
effects. Pathological effects include lethal and sub-lethal physical 
damage to fish; physiological effects include primary and secondary 
stress responses; and behavioral effects include changes in exhibited 
behaviors of fish. Behavioral changes might be a direct reaction to a 
detected sound or a result of anthropogenic sound masking natural 
sounds that the fish normally detect and to which they respond. The 
three types of effects are often interrelated in complex ways. For 
example, some physiological and behavioral effects could potentially 
lead ultimately to the pathological effect of mortality. Hastings and 
Popper (2005) reviewed what is known about the effects of sound on fish 
and identified studies needed to address areas of uncertainty relative 
to measurement of sound and the responses of fish. Popper et al. (2003/
2004) also published a paper that reviews the effects of anthropogenic 
sound on the behavior and physiology of fish. Please see those sources 
for more detail on the potential impacts of sound on fish.
    Underwater sound pressure waves can injure or kill fish (e.g., 
Reyff, 2003; Abbott and Bing-Sawyer, 2002; Caltrans, 2001; Longmuir and 
Lively, 2001; Stotz and Colby, 2001). Fish with swim bladders, 
including salmon, steelhead, and sturgeon, are particularly sensitive 
to underwater impulsive sounds with a sharp sound pressure peak 
occurring in a short interval of time (Caltrans, 2001). As the pressure 
wave passes through a fish, the swim bladder is rapidly squeezed due to 
the high pressure, and then rapidly expanded as the underpressure 
component of the wave passes through the fish. The pneumatic pounding 
may rupture capillaries in the internal organs as indicated by observed 
blood in the abdominal cavity and maceration of the kidney tissues 
(Caltrans, 2001). Although eulachon lack a swim bladder, they are also 
susceptible to general pressure wave injuries including hemorrhage and 
rupture of internal organs, as described

[[Page 23576]]

above, and damage to the auditory system. Direct take can cause 
instantaneous death, latent death within minutes after exposure, or can 
occur several days later. Indirect take can occur because of reduced 
fitness of a fish, making it susceptible to predation, disease, 
starvation, or inability to complete its life cycle. Effects to prey 
species are summarized here and are outlined in more detail in NMFS' 
biological opinion.
    There are no physical barriers to fish passage within the Region of 
Activity, nor are there fish passage barriers between the Region of 
Activity and the Pacific Ocean. The proposed project would not involve 
the creation of permanent physical barriers; thus, long-term changes in 
pinniped prey species distribution are not expected to occur.
    Nevertheless, impact pile-driving would likely create a temporary 
migration barrier to all life stages of fish using the Columbia River 
and North Portland Harbor, although this would be localized. Cofferdams 
and temporary in-water work structures also may create partial barriers 
to the migration of juvenile fish in shallow-water habitat. Impacts to 
fish species distribution would be temporary during in-water work and 
hydroacoustic impacts from impact pile driving would only occur for 
limited periods during the day and only during the in-water work window 
established for this activity in conjunction with ODFW, WDFW, and NMFS. 
The overall effect to the prey base for pinnipeds is anticipated to be 
insignificant.
    Prey may also be affected by turbidity, contaminated sediments, or 
other contaminants in the water column. The CRC project involves 
several activities that could potentially generate turbidity in the 
Columbia River and North Portland Harbor, including pile installation, 
pile removal, installation and removal of cofferdams, installation of 
steel casings for drilled shafts, and debris removal. Because these 
actions would take place in a sandy substrate and would be limited to a 
small area and a brief portion of the work period, the increase in 
turbidity is expected to be small. Turbidity is not expected to cause 
mortality to fish species in the Region of Activity, and effects would 
probably be limited to temporary avoidance of the discrete areas of 
elevated turbidity (anticipated to be no more than 300 ft [91 m] from 
the source) for approximately 4-6 hours at a time (CRC, 2010), or 
effects such as abrasion to gills and alteration in feeding and 
migration behavior for fish close to the activity. Therefore, turbidity 
would likely have only insignificant effects to fish and, thus, 
insignificant effects on pinnipeds.
    The CRC project would minimize, avoid, or contain much of the 
potential sources of contamination, minimizing the risk of exposure to 
prey species of pinnipeds. The CRC project team would, in advance of 
in-water work, perform an extensive search for evidence of 
contamination, pinpointing the location, extent, and concentration of 
the contaminants. Then, BMPs would be implemented to ensure that the 
CRC project: (1) Avoids areas of contaminated sediment or (2) enables 
responsible parties to initiate cleanup activities for contaminated 
sediments occurring from construction activities within the Region of 
Activity. These BMPs would be developed and implemented in coordination 
with regulatory agencies. Because the CRC project would identify the 
locations of contaminated sediments and use BMPs to ensure that they do 
not become mobilized, there is little risk that the prey base of 
pinnipeds would be significantly affected by or exposed to contaminated 
sediments.
    Though treatment of runoff would occur, the ability to remove 
pollutants to a level without effect upon fish or that does not 
synergistically combine with other sources is technologically limited 
and unfeasible. Exposure to these ubiquitous contaminants even in low 
concentrations is likely to affect the survival and productivity of 
salmonid juveniles in particular (e.g., Loge et al., 2006; Hecht et 
al., 2007; Johnson et al., 2007; Sandahl et al., 2007; Spromberg and 
Meador, 2006). Short-term exposure to contaminants such as pesticides 
and dissolved metals may disrupt olfactory function (Hecht, 2007) and 
interfere with associated behaviors such as foraging, anti-predator 
responses, reproduction, imprinting (odor memories), and homing (the 
upstream migration to natal streams). The toxicity of these pollutants 
varies with water quality speciation and concentration. Regarding 
dissolved heavy metals, Santore et al. (2001) indicate that the 
presence of natural organic matter and changes in pH and hardness 
affect the potential for toxicity (increase and decrease). 
Additionally, organics (living and dead) can adsorb and absorb other 
pollutants such as polycyclic aromatic hydrocarbons (PAHs). The 
variables of organic decay further complicate the path and cycle of 
pollutants.
    The release of contaminants is likely to occur. Wind and water 
erosion is likely to entrain and transport soil from disturbed areas, 
contributing fine sediments that are likely to contain pollutants, and 
the use of heavy equipment, including stationary equipment like 
generators and cranes, also creates a risk that accidental spills of 
fuel, lubricants, hydraulic fluid, coolants, and other contaminants may 
occur. Petroleum-based contaminants, such as fuel, oil, and some 
hydraulic fluids, contain PAHs, which are acutely toxic to salmonids 
and other aquatic organisms at high levels of exposure and cause 
sublethal adverse effects on aquatic organisms at lower concentrations 
(Heintz et al., 1999, 2000; Incardona et al., 2004, 2005, 2006).
    However, due to the relatively small amount of time that any heavy 
equipment would be in the water and the use of proposed conservation 
measures, including site restoration after construction is complete, 
any increase in contaminants is likely to be small, infrequent, and 
limited to the construction period. In-water and near-water 
construction would employ numerous BMPs and would comply with all 
required regulatory permits to ensure that contaminants do not enter 
surface water bodies. In the unlikely event of accidental release, BMPs 
and a Pollution Control and Contamination Plan (PCCP) would be 
implemented to ensure that contaminants are prevented from spreading 
and are cleaned up quickly. Therefore, contaminants are not likely to 
significantly affect fish and, thus, effects on pinnipeds are also 
likely to be insignificant.

Physical Loss of Prey Species Habitat

    The project would lead to temporary physical loss of approximately 
20,700 ft\2\ (2,508 m\2\) of shallow-water habitat. Project elements 
responsible for temporary physical loss include the footprint of the 
numerous temporary piles associated with in-water work platforms, work 
bridges, tower cranes, oscillator support piles, cofferdams, and barge 
moorings in the Columbia River and North Portland Harbor.
    The in-water portions of the new structures would result in the 
permanent physical loss of approximately 250 ft\2\ (23 m\2\) of 
shallow-water habitat at pier complex 7 in the Columbia River. 
Demolition of the existing Columbia River structures would permanently 
restore about 6,000 ft\2\ (557 m\2\) of shallow-water habitat, and 
removal of one large overwater structure would permanently restore 
about 600 ft\2\ (56 m\2\) of shallow-water habitat. Overall, there 
would be a net permanent gain of about 5,345 ft\2\ (497 m\2\) of 
shallow-water habitat in the Columbia River (CRC, 2010). At North 
Portland Harbor, there would be a permanent net loss of about 2,435 
ft\2\

[[Page 23577]]

(218 m\2\) of shallow-water habitat at all of the new in-water bridge 
bents. Note that all North Portland Harbor impacts are in shallow 
water.
    Physical loss of shallow-water habitat is of particular concern for 
rearing of subyearling migrant salmonids. In theory, in-water 
structures that completely block the nearshore may force these 
juveniles to swim into deeper-water habitats to circumvent them. Deep-
water areas represent lower quality habitat because predation rates are 
higher there. Studies show that predators such as walleye (Stizostedion 
vitreum), northern pike-minnow (Ptychocheilus oregonensis), and other 
predatory fish occur in deepwater habitat for at least part of the year 
(e.g., Johnson, 1969; Ager, 1976; Paragamian, 1989; Wahl, 1995; Pribyl 
et al., 2004). In the case of the CRC project, in-water portions of the 
structures would not pose a complete blockage to nearshore movement 
anywhere in the Region of Activity. Although these structures would 
cover potential rearing and nearshore migration areas, the habitat is 
not rare and is not of particularly high quality. Juveniles would still 
be able to use the abundant shallow-water habitat available for miles 
in either direction. Neither the permanent nor the temporary structures 
would necessarily force juveniles into deeper water, and therefore pose 
no definite added risk of predation.
    To the limited extent that the proposed actions do increase risk of 
predation, pinnipeds may accrue minor benefits. Alterations to adult 
eulachon and salmon behavior may make them more vulnerable to 
predation. Changes in cover that congregate fish or cause them to slow 
or pause migration would likely attract pinnipeds, which may then 
forage opportunistically. While individual pinnipeds are likely to take 
advantage of such conditions, it is not expected to increase overall 
predation rates across the run. Aggregating features would be small in 
comparison to the channel, and ample similar opportunities exist 
throughout the lower Columbia River.
    Physical loss of shallow-water habitat would have only negligible 
effects on foraging, migration, and holding of salmonids that are of 
the yearling age class or older. These life functions are not dependent 
on shallow-water habitat for these age classes. Furthermore, the lost 
habitat is not of particularly high quality. There is abundant similar 
habitat immediately adjacent along the shorelines of the Columbia River 
and throughout North Portland Harbor. The lost habitat represents only 
a small fraction of the remaining habitat available for miles in either 
direction. There would still be many acres of habitat for yearling or 
older age-classes of salmonids foraging, migrating, and holding in the 
Region of Activity. Physical loss of shallow-water habitat would have 
only negligible effects on eulachon and green sturgeon for the same 
reason. Thus, the effects to these elements of pinniped habitat would 
be minimal.
    The CRC project would cause a temporary physical loss of 
approximately 16,635 ft\2\ (1,545 m\2\) of deep-water habitat, 
consisting chiefly of coarse sand with a small proportion of gravel. 
CRC project elements responsible for temporary physical loss include 
the cofferdams and numerous temporary piles associated with in-water 
work platforms and moorings. The in-water portions of the new 
structures would result in the permanent physical loss of approximately 
6,300 ft\2\ (585 m\2\) of deep-water habitat at pier complexes 2 
through 7 in the Columbia River. Demolition of the existing Columbia 
River piers would permanently restore about 21,000 ft\2\ (1,951 m\2\) 
of deep-water habitat. Overall, there would be a net permanent gain of 
about 15,000 ft\2\ (1,394 m\2\) of deep-water habitat in the Columbia 
River.
    Although there would be a temporary net physical loss of deep-water 
habitat, this is not expected to have a significant impact on prey 
species. The lost habitat is not rare or of particularly high quality, 
and there is abundant similar habitat in immediately adjacent areas of 
the Columbia River and for many miles both upstream and downstream. The 
lost habitat would represent a very small fraction (less than one 
percent) of the remaining habitat available. Additionally, the in-water 
portions of the permanent and temporary in-water structures would 
occupy no more than about one percent of the width of the Columbia 
River. Therefore, the structures would not be likely to pose a physical 
barrier to fish migration.
    In addition, compensatory mitigation for direct permanent habitat 
loss to jurisdictional waters from permanent pier placement would occur 
in accordance with requirements set by USACE, Oregon Department of 
State Lands (DSL), Washington Department of Ecology, ODFW, and WDFW. To 
meet these requirements, CRC is proposing to restore habitat in the 
lower Lewis River and lower Hood River. At the Hood River site, one 
mile of a historic side channel would be reconnected to the lower Hood 
River and an existing 21-acre (8.5-ha) wetland, resulting in habitat 
benefits to salmonids and eulachon. At the Lewis River site, 
restoration of 18.5 acres (7.5 ha) of side channels would occur between 
the lower Lewis River and the lower Columbia River, resulting in 
habitat benefits to salmonid and other native species. Therefore, 
permanent habitat loss is expected to have a negligible impact to 
habitat for pinniped prey species.
    Due to the small size of the impact relative to the remaining 
habitat available, and the permanent benefits from habitat restoration, 
both temporary and permanent physical habitat loss are likely to be 
insignificant to fish and, thus, to the habitat and foraging 
opportunities of pinnipeds.

Passage Obstruction

    The new overwater bridge structures would permanently decrease the 
overall footprint of piers below the OHW in the Columbia River and 
permanently increase the overall footprint of the piers below the OHW 
in North Portland Harbor. The permanent changes would be to riverine 
habitat; no pinniped haul-out sites or rookeries would be affected. The 
effects to habitat in the action area would not result in significant 
changes to pinniped passage. Therefore, permanent changes due to bridge 
piers would not significantly affect pinnipeds.
    There are a variety of temporary structures that could potentially 
obstruct passage of pinnipeds including barges, moorings, tower cranes, 
cofferdams, and work platforms. Although there would be many such 
structures in the Region of Activity, they would cover no more than 
twenty percent of the entire channel width at one time. There would 
still be ample room for pinnipeds to navigate around these structures 
while transiting the action area. Pinnipeds may need to slightly alter 
their course as they move through the construction area to avoid these 
structures, but there is no potential for physical structures to 
completely block upstream or downstream movement. Due to the small size 
of the structures relative to the remaining portion of the river 
available, delays to pinniped movements would be negligible. Therefore, 
the effect of in-water and overwater structures on the ability of 
pinnipeds to pass upstream and downstream would be insignificant.
    The impact of temporary and permanent habitat changes from bridge 
construction is expected to be minimal to pinnipeds. The effects to 
pinnipeds from temporary and permanent habitat changes are summarized 
below.

[[Page 23578]]

     Sound disturbance: Temporary modification of habitat 
during in-water construction from elevated levels of sound may affect 
pinniped foraging; however, very few seals are in the Region of 
Activity and most sea lions are swimming upriver to forage below 
Bonneville Dam. Sound disturbance would not be continuous, would only 
occur temporarily as animals pass through the area and would be in the 
form of Level B harassment only.
     Passage obstruction: The permanent changes to the overall 
footprint of the bridges in the Columbia River and North Portland 
Harbor would not affect pinniped breeding habitat or haul-out sites and 
would not affect passage significantly. Temporary structures during 
construction would not cover more than twenty percent of the entire 
channel and are not likely to significantly affect the ability of 
pinnipeds to pass through the construction area or delay their 
movements.
     Changes in prey distribution and quality: The CRC project 
is likely to impact a small percentage of all salmon and steelhead runs 
that swim through the Region of Activity as a result of in-water work 
including pile installation. This impact would be temporary and would 
only occur during construction of the bridges in the Columbia River and 
North Portland Harbor and during demolition of the existing Columbia 
River Bridges. BMPs and minimization measures would avoid or limit the 
extent of the impact to prey species from sound, changes to water 
quality, and temporary structures. Short-term impacts to the prey base 
from project work do not represent a large part of the pinniped prey 
base in comparison to prey available through the entirety of their 
foraging range, which includes the Columbia River from Bonneville Dam 
to the mouth and foraging grounds off the Pacific Coast. Overall, 
effects to the prey base would be temporary, limited to the in-water 
work period over the CRC project duration, and would not cause 
measurable changes in the distribution or quality of prey available to 
pinnipeds.
     Physical changes to prey species habitat: The new bridge 
structures would permanently decrease the overall footprint of piers 
below the OHW in the Columbia River and permanently increase the 
overall footprint of the piers below the OHW in North Portland Harbor. 
Habitat mitigation for direct permanent habitat loss to fish from 
permanent pier placement would occur in the lower Lewis River and lower 
Hood River and would provide long-term benefits to fish species in the 
lower Columbia River, resulting in long-term benefits to the pinniped 
prey base. Therefore, permanent habitat loss is expected to have a 
negligible impact to habitat for pinniped prey species. Temporary 
physical loss of habitat from temporary structures would only occur 
during the period of in-water work in the Columbia River and North 
Portland Harbor. These temporary losses are not expected to 
significantly affect the prey base for pinnipeds.
    In conclusion, NMFS has preliminarily determined that CRC's 
proposed activities are not expected to have any habitat-related 
effects that could cause significant or long-term consequences for 
individual marine mammals or on the food sources that they utilize.

Proposed Mitigation

    In order to issue an incidental take authorization under section 
101(a)(5)(A) of the MMPA, NMFS must, where applicable, set forth the 
permissible methods of taking pursuant to such activity, and other 
means of effecting the least practicable adverse impact on such species 
or stock and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of such species or stock for taking for certain 
subsistence uses (where relevant). NMFS and CRC worked to devise a 
number of mitigation measures designed to minimize impacts to marine 
mammals to the level of least practicable adverse impact, described in 
the following.
    The results from hydroacoustic monitoring during the test pile 
project, as well as results from modeling the zones of influence (ZOIs) 
(both described previously in this document and in following sections), 
were used to develop mitigation measures for CRC pile driving and 
removal activities. ZOIs are often used to effectively represent the 
mitigation zone that would be established around each pile to prevent 
Level A harassment of marine mammals. In addition to the specific 
measures described later, CRC would employ the following general 
mitigation measures:
     All work would be performed according to the requirements 
and conditions of the regulatory permits issued by federal, state, and 
local governments. Seasonal restrictions, e.g., work windows, would be 
applied to the project to avoid or minimize potential impacts to 
protected species (including marine mammals) based on agreement with, 
and the regulatory permits issued by, DSL, WDFW, and USACE in 
consultation with ODFW, the U.S. Fish and Wildlife Service (USFWS), and 
NMFS.
     Briefings would be conducted between the CRC project 
construction supervisors and the crew, marine mammal observer(s), and 
acoustical monitoring team prior to the start of all pile-driving 
activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures. The CRC project would contact the 
Bonneville Dam marine mammal monitoring team to obtain information on 
the presence or absence of pinnipeds prior to initiating pile driving 
in any discrete pile driving time period described in the project 
description.
     CRC would comply with all applicable equipment sound 
standards and ensure that all construction equipment has sound control 
devices no less effective than those provided on the original equipment 
(i.e., equipment may not have been modified in such a way that it is 
louder than it was initially).
     Permanent foundations for each in-water pier would be 
installed by means of drilled shafts. This approach significantly 
reduces the amount of impact pile driving, the size of piles, and 
amount of in-water sound.
     Installation of piles using impact driving may only occur 
between September 15 and April 15 of the following year.
     On an average work day, six piles could be installed using 
vibratory installation to set the piles, with impact driving then used 
to drive the piles to refusal per project specifications to meet load-
bearing capacity requirements. This method reduces the number of daily 
pile strikes by over ninety percent.
     No more than two impact pile drivers may be operated 
simultaneously within the same water body channel.
     In waters with depths more than 2 ft (0.67 m), a bubble 
curtain or other sound attenuation measure would be used for impact 
driving of pilings, except when testing device performance. As 
described previously, testing of the sound attenuation device would 
occur approximately weekly. This would require up to 7.5 minutes of 
unattenuated driving per week. If a bubble curtain or similar measure 
is used, it would distribute small air bubbles around 100 percent of 
the piling perimeter for the full depth of the water column. Any other 
attenuation measure (e.g., temporary sound attenuation pile) must 
provide 100 percent coverage in the water column for the full depth of 
the pile. A performance test of the sound attenuation device in 
accordance with the approved hydroacoustic

[[Page 23579]]

monitoring plan would be conducted prior to any impact pile driving. If 
a bubble curtain or similar measure is utilized, the performance test 
would confirm the calculated pressures and flow rates at each manifold 
ring.
     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 50 m (164 ft), operations shall cease and/or 
vessels shall reduce speed to the minimum level required to maintain 
steerage and safe working conditions.

Monitoring and Shutdown

    Shutdown Zones--For all pile driving and removal activities, a 
shutdown zone (defined as, at minimum, the area in which SPLs equal or 
exceed 190 dB rms) would be established. The purpose of a shutdown zone 
is 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, serious injury, or death of 
marine mammals. Although hydroacoustic data from the test pile project 
indicate that radial distances to the 190-dB threshold would be less 
than 50 m, shutdown zones would conservatively be set at a minimum 50 
m. This precautionary measure is intended to further reduce any 
possibility of injury to marine mammals by incorporating a buffer to 
the 190-dB threshold within the shutdown area. Please see the 
discussion of ``Distance to Sound Thresholds'' and ``Test Pile 
Project'' under Description of Sound Sources, previously in this 
document.
    Disturbance Zones--For all pile driving and removal activities, a 
disturbance zone would be established. Disturbance zones are typically 
defined as the area in which SPLs equal or exceed 160 or 120 dB rms 
(for impact and vibratory pile driving, respectively). However, when 
the size of a disturbance zone is sufficiently large as to make 
monitoring of the entire area impracticable (as in the case of the 120-
dB zone here), the disturbance zone may be defined as some area that 
may reasonably be monitored. Here, the disturbance zone is defined for 
monitoring purposes as an area of 800 m radius. 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 PSOs 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).
    Monitoring Protocols--Initial monitoring zones are based on worst 
case values measured during the test pile project and with the 
attenuation device operating during impact driving, and are presented 
in Table 15. A minimum distance of 50 m is used for all shutdown zones, 
even if actual or initial calculated distances are less. A maximum 
distance of 800 m is used for all disturbance zones for vibratory pile 
driving, even if actual or calculated values are greater. Monitoring of 
the full disturbance zone for these activities is impracticable. The 
data collected during the test pile project consistently support the 
belief that the coefficient of transmission loss increases with 
increasing range from the source pile, out to at least 800 m. To 
provide the best estimate of transmission loss at a specific range, the 
data were interpolated to one meter increments using a quadratic 
interpolation routine. To establish a disturbance zone for impact pile 
driving, an iterative solution was computed based on the interpolated 
transmission loss data.

Table 15--Distance to Initial Shutdown and Disturbance Monitoring Zones for In-Water Sound in the Columbia River
                                            and North Portland Harbor
----------------------------------------------------------------------------------------------------------------
                                                                       Distance to monitoring zones (m) \1\
               Pile type                       Hammer type       -----------------------------------------------
                                                                    190 dB \2\      160 dB \2\      120 dB \2\
----------------------------------------------------------------------------------------------------------------
18-24 in steel pipe \3\...............  Impact..................              50             258             N/A
36-48 in steel pipe \4\...............  Impact..................              50             582             N/A
48-in steel pipe......................  Vibratory...............              50             N/A             800
120-in steel casing...................  Vibratory...............              50             N/A             800
Sheet pile............................  Vibratory...............              50             N/A             800
----------------------------------------------------------------------------------------------------------------
\1\ Monitoring zones based on worst case values measured during test pile project and with the attenuation
  device operating during impact driving. A minimum distance of 50 m is used for all shutdown zones, even if
  actual or initial calculated distances are less. A maximum distance of 800 m is used for all disturbance zones
  for vibratory pile driving, even if actual or calculated values are greater. For modeled values, see Tables 11
  and 12.
\2\ All values unweighted and relative to 1 [micro]Pa.
\3\ For 24-in pile, test pile data show a worst case source level of 191 dB rms with a worst-case attenuation of
  8 dB and transmission loss coefficient based on quadratic interpolation of test pile data of 16.3.
\4\ For 48-in pile, test pile data show a worst case source level of 201 dB RMS with a worst-case attenuation of
  11 dB, and transmission loss coefficient based on quadratic interpolation of test pile data of 17.0.

    Data from the test pile project suggest that the majority of the 
energy from vibratory driving occurs in frequencies below 1,000 Hz, 
with energy levels gradually falling off at higher frequencies (CRC, 
2011). For vibratory installation during the test pile study, the 
energy was not distinguishable above background levels by 800 m (2,625 
ft) for all but one pile. Therefore, although transmission loss data 
were not conclusive--only one pile produced a signal that could be 
distinguished at all three monitoring stations, above background sound 
that was much higher than was previously measured for the action area--
the modeled results for vibratory driving are validated by the 
empirical data, and it is likely that actual distances to the 120-dB 
threshold would be much less than modeled values. Piles were generally 
installed or extracted during the test pile study in less than 10 
minutes. Vibratory extraction of piles would conservatively be treated 
similarly to vibratory installation, with similar monitoring zones. As 
described previously in this document (see section on ``Test Pile 
Project''), a maximum SPL of 181 dB for vibratory installation was 
recorded, while a maximum SPL of 176 dB was recorded for vibratory 
extraction.

[[Page 23580]]

    The vibratory installation of steel casings and sheet piles was not 
measured as part of the test pile project. As noted in Table 11, 
modeled distance to the 120-dB isopleths resulting from vibratory 
installation of sheet pile was significantly less than that for 
vibratory installation of pipe pile. No published information is 
available on vibratory installation of 120-in (3 m) steel casings, 
which would be installed for drilled shafts. Published information from 
Caltrans (2007) shows that driving of 36-in pile produced up to 175 dB 
rms while driving of 72-in pile produced up to 180 dB rms, both 
measured at 5 m from the pile. By extrapolating from these published 
values, CRC assumes the energy imparted through a larger casing would 
be up to 10 dB rms (an order of magnitude) higher than the highest 
value for a 72-in pile. In the absence of specific data, the initial 
disturbance zone for vibratory installation of steel casings and sheet 
pile would be established at 800 m, as described previously for 
vibratory pile driving.
    In order to accomplish appropriate monitoring for mitigation 
purposes, CRC would have an observer stationed on each active pile 
driving barge to closely monitor the shutdown zone as well as the 
surrounding area. In addition, CRC would post one shore-based observer, 
whose primary responsibility would be to record pinnipeds in the 
disturbance zone and to alert barge-based observers to the presence of 
pinnipeds in the disturbance zone, thus creating a redundant alert 
system for prevention of injurious interaction as well as increasing 
the probability of detecting pinnipeds in the disturbance zone. CRC 
estimates that shore-based observers would be able to scan 
approximately 800 m (upstream and downstream) from the available 
observation posts; therefore, shore-based observers would be capable of 
monitoring the agreed-upon disturbance zone. Visibility would be 
somewhat reduced by the existing bridges in the upstream direction.
    As described, at least two observers would be on duty during all 
pile driving/removal activity. The first observer would be positioned 
on a work platform or barge where the entire 50 m shutdown zone is 
clearly visible, with the second shore-based observer positioned to 
observe the disturbance zone from either the north or south bank of the 
river, depending on where the work platform or barge is positioned. 
Protocols would be implemented to ensure that coordinated communication 
of sightings occurs between observers in a timely manner.
    When pile driving/removal is occurring simultaneously at multiple 
sites, each site would have one observer dedicated to monitoring the 
shutdown zone for that site. Depending on the location of activity 
sites and the spacing of equipment, additional shore-based observers 
may be required to provide complete observational coverage of each 
site's disturbance zone. That is, each site would have at least one 
observer, while one or multiple shore-based observers may be required.
    In summary:
     CRC would implement a minimum shutdown zone of 50 m radius 
around all pile driving and removal activity, including installation of 
steel casings. The 50-m shutdown zone provides a buffer for the 190-dB 
threshold but is also intended to further avoid the risk of direct 
interaction between marine mammals and the equipment.
     CRC would have a redundant monitoring system, in which one 
observer would be stationed on each pile driving barge, while one or 
multiple observers would be shore-based, as required to provide 
complete observational coverage of the reduced disturbance zone for 
each pile driving/removal site. The former would be capable of 
providing comprehensive monitoring of the proposed shutdown zones, and 
would likely be able to effectively monitor a distance, in both 
directions, of approximately 800 m (the distance for the vibratory pile 
driving disturbance zone). These observers' first priority would be 
shutdown zone monitoring in prevention of injurious interaction, with a 
secondary priority of counting takes by Level B harassment in the 
disturbance zone. The additional shore-based observer(s) would be able 
to monitor the same distances, but their primary responsibility would 
be counting of takes in the disturbance zone and communication with 
barge-based observers to alert them to pinniped presence in the action 
area.
     The shutdown and disturbance zones would be monitored 
throughout the time required to drive a pile. If a marine mammal is 
observed within the disturbance zone, a take would be recorded and 
behaviors documented. However, 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.
     All shutdown and disturbance zones would either be based 
on empirical, site-specific data, or would initially be based on data 
for similar sources. For all activities, in-situ hydroacoustic 
monitoring would be conducted to either verify or determine the actual 
distances to these threshold zones, and the size of the zones would be 
adjusted accordingly based on received SPLs. As noted previously, the 
minimum shutdown zone would always be 50 m.
    The following measures would apply to visual monitoring:
     If a small boat is used for monitoring, the boat would 
remain 50 yd (46 m) from swimming pinnipeds in accordance with NMFS 
marine mammal viewing guidelines (NMFS, 2004).
     If vibratory installation of steel pipe piles or casings 
occurs after dark, monitoring would be conducted with a night vision 
scope and/or other suitable device. Impact driving would only occur 
during daylight hours.
     If the shutdown zone is obscured by fog or poor lighting 
conditions, pile driving would not be initiated until the entire 
shutdown zone is visible. Work that has been initiated appropriately in 
conditions of good visibility may continue during poor visibility.
     The shutdown zone would be monitored for the presence of 
pinnipeds before, during, and after any pile driving activity. The 
shutdown zone would be monitored for 30 minutes prior to initiating the 
start of pile driving. If pinnipeds are present within the shutdown 
zone prior to pile driving, the start of pile driving would be delayed 
until the animals leave the shutdown zone of their own volition, or 
until 15 minutes elapse without resighting the animal(s).
     Monitoring would be conducted using binoculars. When 
possible, digital video or still cameras would also be used to document 
the behavior and response of pinnipeds to construction activities or 
other disturbances.
     Each observer would have a radio or cell phone for contact 
with other monitors or work crews. Observers would implement shut-down 
or delay procedures when applicable by calling for the shut-down to the 
hammer operator.
     A GPS unit or electric range finder would be used for 
determining the observation location and distance to pinnipeds, boats, 
and construction equipment.
    Monitoring would be conducted by qualified observers. In order to 
be considered qualified, observers must meet the following criteria:
     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.

[[Page 23581]]

     Advanced education in biological science, wildlife 
management, mammalogy, or related fields (bachelor's degree or higher 
is required).
     Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience).
     Experience or training in the field identification of 
pinnipeds, including the identification of behaviors.
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations.
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
pinnipeds 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 pinnipeds observed within a defined shutdown 
zone; and pinniped behavior.
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on pinnipeds 
observed in the area as necessary.
    Hydroacoustic Monitoring--Hydroacoustic monitoring would be 
conducted to determine actual values and distances to relevant acoustic 
thresholds, including for vibratory installation of steel casings and 
sheet piles. The initial disturbance zones would then be adjusted as 
appropriate on the basis of that information. If new zones are 
established based on SPL measurements, NMFS requires each new zone be 
based on the most conservative measurement (i.e., the largest zone 
configuration). Vibratory installation of steel pipe and sheet pile is 
not anticipated to produce underwater sound above the 190-dB injury 
threshold, while vibratory installation of steel casings is estimated 
to produce SPLs of 190 dB at a maximum distance of 5 m from the source. 
However, a minimum 50 m shutdown zone would be established for these 
activities as for impact driving. Table 15 shows initial distances for 
shutdown and disturbance zones for these activities.

Ramp-Up and Shutdown

    The objective of a ramp-up is to alert any animals close to the 
activity and allow them time to move away, which would expose fewer 
animals to loud sounds, including both underwater and above water 
sound. This procedure also ensures that any pinnipeds missed during 
shutdown zone monitoring would move away from the activity and not be 
injured. Although impact driving would occur from September 15 through 
April 15, and vibratory driving would occur year-round, ramp-up would 
be required only from January 1 through June 15 of any year, during the 
period of greatest potential overlap with pinniped presence in the 
project area. The following ramp-up procedures would be used for in-
water pile installation:
     A ramp-up technique would be used at the beginning of each 
day's in-water pile driving activities or if pile driving has ceased 
for more than 1 hour.
     If a vibratory driver is used, contractors would be 
required to initiate sound from vibratory hammers for 15 seconds at 
reduced energy followed by a 1-minute waiting period. The procedure 
would be repeated two additional times before full energy may be 
achieved.
     If a non-diesel impact hammer is used, contractors would 
be required to provide an initial set of strikes from the impact hammer 
at reduced energy, followed by a 1-minute waiting period, then two 
subsequent sets. The reduced energy of an individual hammer cannot be 
quantified because they vary by individual drivers. Also, the number of 
strikes would vary at reduced energy because raising the hammer at less 
than full power and then releasing it results in the hammer 
``bouncing'' as it strikes the pile, resulting in multiple ``strikes''.
     If a diesel impact hammer is used, contractors would be 
required to turn on the sound attenuation device (e.g., bubble curtain 
or other approved sound attenuation device) for 15 seconds prior to 
initiating pile driving to flush pinnipeds from the area.
    The shutdown zone would also be monitored throughout the time 
required to drive a pile (or install a steel casing). If a pinniped is 
observed approaching or entering the shutdown zone, piling operations 
would be discontinued until the animal has moved outside of the 
shutdown zone. Pile driving would resume only after the animal is 
determined to have moved outside the shutdown zone by a qualified 
observer or after 15 minutes have elapsed since the last sighting of 
the animal within the shutdown zone.

Work Zone Lighting

    If work occurs at night, temporary lighting would be used in the 
night work zones. During overwater construction, the contractor would 
use directional lighting with shielded luminaries to control glare and 
direct light onto work area, not surface waters.

Additional Mitigation Measures

    In addition, NMFS and CRC, together with other relevant regulatory 
agencies, have developed a number of mitigation measures designed to 
protect fish through prevention or minimization of turbidity and 
disturbance and introduction of contaminants, among other things. These 
measures have been prescribed under the authority of statutes other 
than the MMPA, and are not a part of this proposed rulemaking. However, 
because these measures minimize impacts to pinniped prey species 
(either directly or indirectly, by minimizing impacts to prey species' 
habitat), they are summarized briefly here. Additional detail about 
these measures may be found in CRC's application.
    Timing restrictions would be used to avoid in-water work when ESA-
listed fish are most likely to be present. Fish entrapment would be 
minimized by containing and isolating in-water work to the extent 
possible, through the use of drilled shaft casings and cofferdams. The 
contractor would provide a qualified fishery biologist to conduct and 
supervise fish capture and release activity to minimize risk of injury 
to fish. All pumps must employ fish screen that meet certain 
specifications in order to avoid entrainment of fish. A qualified 
biologist would be present during all impact pile driving operations to 
observe and report any indications of dead, injured, or distressed 
fishes, including direct observations of these fishes or increases in 
bird foraging activity.
    CRC would work to ensure minimum degradation of water quality in 
the project area, and would require the contractor to prepare a Water 
Quality Sampling Plan for conducting water quality monitoring for all 
projects occurring in-water in accordance with specific conditions. The 
Plan shall identify a sampling methodology as well as method of 
implementation to be reviewed and approved by the engineer. In 
addition, the contractor would prepare a Spill Prevention, Control, and 
Countermeasures (SPCC) Plan prior to beginning construction. The SPCC 
Plan would identify the appropriate spill containment materials; as 
well as the method of implementation. All equipment to be used for 
construction activities would be cleaned and inspected prior to 
arriving at the project site, to ensure no potentially hazardous 
materials are exposed, no leaks are present, and the equipment is 
functioning properly. Equipment that would be used below OHW would be 
identified; daily inspection and cleanup

[[Page 23582]]

procedures would insure that identified equipment is free of all 
external petroleum-based products. Should a leak be detected on heavy 
equipment used for the project, the equipment must be immediately 
removed from the area and not used again until adequately repaired.
    The contractor would also be required to prepare and implement a 
Temporary Erosion and Sediment Control (TESC) Plan and a Source Control 
Plan for project activities requiring clearing, vegetation removal, 
grading, ditching, filling, embankment compaction, or excavation. The 
BMPs in the plans would be used to control sediments from all 
vegetation removal or ground-disturbing activities.

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 effecting the least 
practicable adverse impact on the affected marine mammal species and 
stocks and their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
     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; and
     The practicability of the measure for applicant 
implementation.
    Based on our evaluation, NMFS has preliminarily determined that the 
mitigation measures proposed from both NMFS and CRC provide the means 
of effecting the least practicable adverse impact on marine mammal 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance. The 
proposed rule comment period will afford the public an opportunity to 
submit recommendations, views, and/or concerns regarding this action 
and the proposed mitigation measures.

Proposed Monitoring and Reporting

    In order to issue an incidental take authorization (ITA) for an 
activity, section 101(a)(5)(A) of the MMPA states that NMFS must, where 
applicable, set forth ``requirements pertaining to the monitoring and 
reporting of such taking''. The MMPA implementing regulations at 50 CFR 
216.104(a)(13) indicate that requests for ITAs must include the 
suggested means of accomplishing the necessary monitoring and reporting 
that would 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.
    CRC proposed a marine mammal monitoring plan in their application 
(see Appendix D of CRC's application). The plan may be modified or 
supplemented based on comments or new information received from the 
public during the public comment period. All methods identified herein 
have been developed through coordination between NMFS and the design 
and environmental teams at CRC. The methods are based on the parties' 
professional judgment supported by their collective knowledge of 
pinniped behavior, site conditions, and proposed project activities. 
Because pinniped monitoring has not previously been conducted at this 
site, aspects of these methods may warrant modification. Any 
modifications to this protocol would be coordinated with NMFS. A 
summary of the plan, as well as the proposed reporting requirements, is 
contained here.
    The intent of the monitoring plan is to:
     Comply with the requirements of the MMPA as well as the 
ESA section 7 consultation;
     Avoid injury to pinnipeds through visual monitoring of 
identified shutdown zones and shut-down of activities when animals 
enter or approach those zones; and
     To the extent possible, record the number, species, and 
behavior of pinnipeds in disturbance zones for pile driving and removal 
activities.
    As described previously, monitoring for pinnipeds would be 
conducted in specific zones established to avoid or minimize effects of 
elevated levels of sound created by the specified activities. Shutdown 
zones would not be less than 50 m, while initial disturbance zones 
would be based on site-specific data. Zones may be modified on the 
basis of actual recorded SPLs from acoustic monitoring.

Visual Monitoring

    The established shutdown and disturbance zones would be monitored 
by qualified marine mammal observers for mitigation purposes, as well 
as to document marine mammal behavior and incidents of Level B 
harassment, as described here. CRC's marine mammal monitoring plan (see 
Appendix D of CRC's application) would be implemented, requiring 
collection of sighting data for each pinniped observed during the 
proposed activities for which monitoring is required, including impact 
or vibratory installation of steel pipe or sheet pile or steel casings. 
A qualified biologist(s) would be present on site at all times during 
impact pile driving or vibratory installation or removal of steel pile 
or casings. Disturbance zones, briefly described previously under 
Proposed Mitigation, are discussed in greater depth here.
    Disturbance Zone Monitoring--Disturbance zones, described 
previously in Proposed Mitigation, are defined in Table 15 for 
underwater sound. Monitoring zones for Level B harassment from airborne 
sound would be 650 m for harbor seals and 196 m for sea lions 
(corresponding to the anticipated extent of airborne sound reaching 90 
and 100 dB, respectively). The size of the disturbance zone for 
vibratory pile installation or extraction would be approximately 800 m 
in both the upstream and downstream directions, corresponding with the 
area that can reasonably be monitored by a shore-based observer. Any 
sighted animals outside of this area would be recorded as takes, but it 
is impossible to guarantee that all animals would be observed or to 
make observations of fine-scale behavioral reactions to sound 
throughout this zone. Nevertheless, because any animals transiting the 
action area (and the larger disturbance zone) would pass through the 
monitored area, all animals may potentially be observed, and use of the 
smaller disturbance zone for monitoring purposes does not necessarily 
mean that a significant number of harassed animals would not be 
observed. Monitoring of disturbance zones would be implemented as 
described previously.
    The monitoring biologists would document all pinnipeds observed in 
the monitoring area. Data collection would include a count of all 
pinnipeds observed by species, sex, age class, their location within 
the zone, and their reaction (if any) to construction activities, 
including direction of movement, and type of construction that is 
occurring, time that pile driving begins and ends, any acoustic or 
visual disturbance, and time of the observation. Environmental 
conditions such as wind speed, wind direction, visibility, and 
temperature would also be recorded. No monitoring would be conducted 
during inclement weather that creates potentially hazardous conditions, 
as determined by the biologist, nor would monitoring be conducted when 
visibility is significantly limited, such as during

[[Page 23583]]

heavy rain or fog. During these times of inclement weather, in-water 
work that may produce sound levels in excess of 190 dB rms would be 
halted; these activities would not commence until monitoring has 
started for the day.
    All monitoring personnel must have appropriate qualifications as 
identified previously, with qualifications to be certified by CRC (see 
Proposed Mitigation). These qualifications include education and 
experience identifying pinnipeds in the Columbia River and the ability 
to understand and document pinniped behavior. All monitoring personnel 
would meet at least once for a training session sponsored by CRC. 
Topics would include: Implementation of the protocol, identifying 
marine mammals, and reporting requirements.
    All monitoring personnel would be provided a copy of the LOA and 
final biological opinion for the project. Monitoring personnel must 
read and understand the contents of the LOA and biological opinion as 
they relate to coordination, communication, and identifying and 
reporting incidental harassment of pinnipeds.

Hydroacoustic Monitoring

    Hydroacoustic monitoring would be conducted on a representative 
number of piles or casings, according to protocols developed and 
approved by NMFS and USFWS. The number, size, and location of piles or 
casings monitored would represent the variety of substrates and depths, 
as necessary, in both the Columbia River and North Portland Harbor. 
Hydroacoustic monitoring would be conducted as necessary to measure 
representative source levels for impact and vibratory installation and 
removal of piles and casings. Measurements would represent a worst-case 
for size, depth, and substrate for all materials and installation 
methods. For standard underwater sound monitoring, one hydrophone 
positioned at 10 m from the pile is used. Some additional initial 
monitoring at several distances from the pile is anticipated to 
determine site-specific transmission loss and directionality of sound. 
This data would be used to establish the radii of the shutdown and 
disturbance zones for pinnipeds.
    One hydrophone would be placed at between 1 and 3 m above the 
bottom at a distance of 10 m from each pile being monitored. 
Hydrophones placed upriver and downriver (at the 200-, 400- and 800-
meter distances) would be placed at a depth greater than 5 m below the 
water surface or placed 1-3 meters above the bottom. A weighted tape 
measure would be used to determine the depth of the water. Each 
hydrophone would be attached to a nylon cord or a steel chain if the 
current is swift enough to cause strumming of the line. The nylon cord 
or chain would be attached to an anchor that would keep the line the 
appropriate distance from each pile. The nylon cord or chain would be 
attached to a buoy or raft at the surface and checked regularly to 
maintain the tightness of the line. The distances would be measured by 
a tape measure, where possible, or a range-finder for those hydrophones 
that are distant from the pile. There would be a direct line of sight 
between the pile and the hydrophone in all cases. GPS coordinates would 
be recorded for each hydrophone location.
    When the river velocity is greater than 1 m/s, a flow shield around 
each hydrophone would be used to provide a barrier between the 
irregular, turbulent flow and the hydrophone. River velocity would be 
measured concurrent to sound measurements. If velocity is greater than 
1 m/s, a correlation between sound levels and current speed would be 
made to determine whether the data is valid and should be included in 
the analysis. Hydrophone calibrations would be checked at the beginning 
of each day of monitoring activity. Prior to the initiation of pile 
driving, the hydrophones would be placed at the appropriate distances 
and depth as described.
    Prior to and during the pile driving activity environmental data 
would be gathered such as wind speed and direction, air temperature, 
humidity, surface water temperature, water depth, wave height, weather 
conditions, and other factors that could contribute to influencing the 
underwater sound levels (e.g., aircraft, boats). Start and stop time of 
each pile driving event and the time at which the bubble curtain or 
functional equivalent is turned on and off would be recorded. The chief 
construction inspector would supply the acoustics specialist with a 
description of the substrate composition, hammer model and size, hammer 
energy settings and any changes to those settings during the piles 
being monitored, depth pile driven, blows per foot for the piles 
monitored, and total number of strikes to drive each pile that is 
monitored.

Proposed Reporting

    Reports of data collected during monitoring would be submitted to 
NMFS weekly. The reporting would include:
     All data described previously under monitoring, including 
observation dates, times, and conditions; and
     Correlations of observed behavior with activity type and 
received levels of sound, to the extent possible.
    CRC would also submit a report(s) concerning the results of all 
acoustic monitoring. Acoustic monitoring reports would include:
     Size and type of piles.
     A detailed description of any sound attenuation device 
used, including design specifications.
     The impact hammer energy rating used to drive the piles, 
make and model of the hammer(s), and description of the vibratory 
hammer.
     A description of the sound monitoring equipment.
     The distance between hydrophones and depth of water at the 
hydrophone locations.
     The depth of the hydrophones.
     The distance from the pile to the water's edge.
     The depth of water in which the pile was driven.
     The depth into the substrate that the pile was driven.
     The physical characteristics of the bottom substrate into 
which the piles were driven.
     The total number of strikes to drive each pile.
     The background sound pressure level reported as the fifty 
percent CDF, if recorded.
     The results of the hydroacoustic monitoring, including the 
frequency spectrum, ranges and means including the standard deviation/
error for the peak and rms SPL's, and an estimation of the distance at 
which rms values reach the relevant marine mammal thresholds and 
background sound levels. Vibratory driving results would include the 
maximum and overall average rms calculated from 30-s rms values during 
the drive of the pile.
     A description of any observable pinniped behavior in the 
immediate area and, if possible, correlation to underwater sound levels 
occurring at that time.
    An annual report on marine mammal monitoring and mitigation would 
be submitted to NMFS, Office of Protected Resources, and NMFS, 
Northwest Regional Office. The annual reports would summarize 
information presented in the weekly reports and include data collected 
for each distinct marine mammal species observed in the project area, 
including descriptions of marine mammal behavior, overall numbers of 
individuals observed, frequency of observation, and any behavioral 
changes and the context of

[[Page 23584]]

the changes relative to activities would also be included in the annual 
reports. Additional information that would be recorded during 
activities and contained in the reports include: Date and time of 
marine mammal detections, weather conditions, species identification, 
approximate distance from the source, and activity at the construction 
site when a marine mammal is sighted.
    In addition to annual reports, NMFS proposes to require CRC to 
submit a draft comprehensive final report to NMFS, Office of Protected 
Resources, and NMFS, Northwest Regional Office, 180 days prior to the 
expiration of the regulations. This comprehensive technical report 
would provide full documentation of methods, results, and 
interpretation of all monitoring during the first 4.5 years of the 
regulations. A revised final comprehensive technical report, including 
all monitoring results during the entire period of the regulations, 
would be due 90 days after the end of the period of effectiveness of 
the regulations.

Adaptive Management

    The final regulations governing the take of marine mammals 
incidental to the specified activities at CRC would contain an adaptive 
management component. In accordance with 50 CFR 216.105(c), regulations 
for the proposed activity must be based on the best available 
information. As new information is developed, through monitoring, 
reporting, or research, the regulations may be modified, in whole or in 
part, after notice and opportunity for public review. The use of 
adaptive management would allow NMFS to consider new information from 
different sources to determine if mitigation or monitoring measures 
should be modified (including additions or deletions) if new data 
suggest that such modifications are appropriate.
    The following are some of the possible sources of applicable data:
     Results from CRC's monitoring from the previous year;
     Results from general marine mammal and sound research; or
     Any information which reveals that marine mammals may have 
been taken in a manner, extent or number not authorized by these 
regulations or subsequent LOAs.
    If, during the effective dates of the regulations, new information 
is presented from monitoring, reporting, or research, these regulations 
may be modified, in whole or in part, after notice and opportunity of 
public review, as allowed for in 50 CFR 216.105(c). In addition, LOAs 
would be withdrawn or suspended if, after notice and opportunity for 
public comment, the Assistant Administrator finds, among other things, 
that the regulations are not being substantially complied with or that 
the taking allowed is having more than a negligible impact on the 
species or stock, as allowed for in 50 CFR 216.106(e). That is, should 
substantial changes in marine mammal populations in the project area 
occur or monitoring and reporting show that CRC actions are having more 
than a negligible impact on marine mammals, then NMFS reserves the 
right to modify the regulations and/or withdraw or suspend LOAs after 
public review.

Estimated Take by Incidental Harassment

    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: ``any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild [Level A harassment]; or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering [Level B harassment].'' Take by Level B harassment only is 
anticipated as a result of CRC's proposed activities. Take of marine 
mammals is anticipated to be associated with the installation and 
removal of piles and installation of steel casings, via impact and 
vibratory methods, and debris removal. No take by injury, serious 
injury, or death is anticipated.
    Assumptions regarding numbers of pinnipeds and number of round 
trips per individual per year in the Region of Activity are based on 
information from ongoing pinniped research and management activities 
conducted in response to concern over California sea lion predation on 
fish populations concentrated below Bonneville Dam. An intensive 
monitoring program has been conducted in the Bonneville Dam tailrace 
since 2002, using surface observations to evaluate seasonal presence, 
abundance, and predation activities of pinnipeds. Minimum estimates of 
the number of pinnipeds present in the tailrace from 2002 through 2011 
are presented in Table 16. Bonneville Dam is the first dam on the 
river, located at RKm 235, and is upriver of the CRC project site, 
which is located at approximately RKm 170. The primary California sea 
lion haul-out in the Columbia River is located in the Columbia River 
estuary in Astoria, approximately 151 RKm downstream of the project. 
This haul-out is the site of trapping and tagging for research and 
monitoring of pinnipeds that reach the Bonneville Dam tailrace.

                         Table 16--Minimum Estimated Total Numbers of Pinnipeds Present at Bonneville Dam From 2002 Through 2011
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Species                               2002     2003     2004   2005 **    2006     2007     2008     2009     2010     2011
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion...........................................       30      104       99       81       72       71       82       54       89       54
Steller sea lion *............................................        0        3        3        4       11        9       39       26       75       89
Harbor seal...................................................        1        2        2        1        3        2        2        2        2        1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Data from Stansell et al. 2010, pers. comm. Stansell, 2011.
* Animals not uniquely identified through 2007. Numbers through 2007 represent the highest number seen on any one day for each year (Tackley et al.,
  2008a).
** Regular observations did not begin until March 18 in 2005; minimum estimate should likely be considered somewhat higher than these numbers (Tackley
  et al., 2008a).

    Monitoring began as a result of the 2000 FCRPS biological opinion, 
which required an evaluation of pinniped predation in the tailrace of 
Bonneville Dam. The objective of the study was to determine the timing 
and duration of pinniped predation activity, estimate the number of 
fish caught, record the number of pinnipeds present, identify and track 
individual California sea lions, and evaluate various pinniped 
deterrents used at the dam (Tackley et al., 2008a). The study period 
for monitoring was January 1 through May 31, beginning in 2002. During 
the study period pinniped observations began after consistent sightings 
of at least one animal occurred. Tackley et al. (2008a)

[[Page 23585]]

notes that sightings began earlier each year from 2002 to 2004. 
Although some sightings were reported earlier in the season, full-time 
observations began March 21 in 2002, March 3 in 2003, and February 24, 
2004 (Tackley et al., 2008a). In 2005 observations began in April, but 
in 2006 through 2010 observations began in January or early February 
(Tackley et al., 2008a, b; Stansell et al., 2009; Stansell and Gibbons, 
2010). California sea lion and Steller sea lion arrival and departure 
dates at Bonneville Dam are compiled from the reports above and were 
detailed previously in Table 13 and Table 14. If arrival and departure 
dates were not available, the timing of surface observations within the 
January through May study period were recorded. Because regular 
observations in the study period generally began as sea lions were 
observed below Bonneville Dam, and sometimes reports stated that 
observations stopped as sea lion numbers dropped, the observation dates 
only give a general idea of first arrival and departure. Because 
acoustic telemetry data indicate that sea lions travel at fast rates 
between hydrophone locations above and below the CRC project area (see 
Brown et al., 2010), dates of first arrival at Bonneville Dam and 
departure from the dam are assumed to coincide closely with potential 
passage timing through the CRC project area. Table 17 details 
observation effort by year; data is not yet available for observations 
in 2011.

              Table 17--Hours of Observation for Pinnipeds at the Bonneville Dam Tailrace, by Year
----------------------------------------------------------------------------------------------------------------
    2002         2003         2004         2005         2006         2007        2008        2009        2010
----------------------------------------------------------------------------------------------------------------
     662        1,356          553        1,108        3,647        4,433        5,131       3,455       3,609
----------------------------------------------------------------------------------------------------------------

     Pinniped species presence is determined by likelihood of 
occurrence near the CRC project construction activities based on 
general abundance at Bonneville Dam and the number of times individuals 
are estimated to make the trip to and from the dam in a year. 
Individuals observed at the dam are known to have passed the project 
site at least once; however, not all individuals that pass the project 
site would go all the way to the dam, although it is expected that the 
vast majority would. Therefore, the use of abundances at Bonneville Dam 
in estimating take would produce a slight underestimation. These 
estimates also assume that all pinnipeds that pass the project site 
would be exposed to project activities (e.g., pile installation would 
be occurring every time an individual passes the project site). 
However, project activities that may impact pinnipeds would not occur 
24 hours a day; therefore, this assumption results in an overestimate 
of exposures. Table 18 summarizes the estimated take.

Harbor Seal

    During most of the year, it is possible that small numbers of 
adults and subadults of both sexes may be expected to transit through 
the Region of Activity. In general, harbor seals remain close to haul-
out sites when foraging and resting. As described previously, there are 
no known harbor seal haul-out sites within or near the Region of 
Activity, with the nearest known haul-out sites at least 45 mi (72 km) 
downstream. Pupping sites are generally restricted to coastal estuaries 
and other areas along the Olympic Peninsula and Puget Sound.
    One to three harbor seals were documented below the dam in all 9 
years of surface observations. Estimates are minimums and are based on 
observations made only within the January through May timeframe, 
although harbor seals have been observed in very low numbers year-round 
near Bonneville Dam (Tackley et al., 2008a). However, based on salmon 
and steelhead run timing, as well as lamprey and smelt timing, seals 
would most likely occur during the same January through May period when 
sea lions are present. Based on the preceding information, CRC 
estimates a minimum of one to three adult or subadult harbor seals 
would be potentially exposed to in-water project activities each year. 
Based on the limited data available, CRC assumes that the number of 
individuals that actually pass by the CRC project area would be 
slightly higher than the highest minimum observed at the dam. CRC 
therefore conservatively estimates six individuals per year may 
potentially pass the project site. This may overestimate the number in 
some years. However, based on the consistency in the data, the number 
of individuals that have the potential to be exposed to project 
activities is likely to remain small in future years.
    The number of round trips made per individual year is difficult to 
discern from the limited data available. Because harbor seals are not 
uniquely identified in the observations at Bonneville Dam, repeat 
observations of the same individual may have been reported on different 
observation days. Only one to three harbor seals have been observed at 
Bonneville Dam in any year (although this may represent greater than 
three individuals). One may safely assume that each individual 
completes at least one round-trip past the project site, although it 
may be more; because of the lack of data regarding seal movement to and 
from the dam, it is difficult to justify a number of round-trips per 
individual. We do know that harbor seals occur only infrequently at the 
dam and, therefore, only a limited number of round-trips could occur 
per individual. CRC conservatively estimates that each individual may 
make up to two round-trips.
    Based on known pupping and haul-out locations, and the low number 
of observations of harbor seals at Bonneville Dam over the years, it is 
likely that very few harbor seals transit through the Region of 
Activity, and that those that do are subadults or adults. CRC 
conservatively estimates that up to six subadult or adult harbor seals 
(double the maximum number observed at Bonneville Dam to date) may 
transit the Region of Activity up to four times per year (two round-
trips).

California Sea Lion

    California sea lions are observed in the winter and spring (January 
through May) with only a limited number of exceptions. No haul-out 
sites are located within the Region of Activity and no breeding or 
pupping occurs in the Region of Activity. All animals documented in the 
Columbia River have been adult or juvenile males (Jeffries et al., 
2000). Table 16 presents numbers of California sea lions observed at 
Bonneville Dam. Numbers are presented as minimums, because not all sea 
lions are able to be uniquely identified in all observations and 
therefore may not be in the count. Tackley et al. (2008) noted that 
individuals were not uniquely identified prior to 2008; thus, the 
numbers of sea lions estimated from 2002 through 2007 were likely 
underestimated. During those years, Tackley et al. (2008) estimate that 
an additional 15 to 35 California sea lions may have been present, but 
observers were not able to uniquely identify them and therefore they 
are not represented

[[Page 23586]]

in the counts. In addition, the high number of 104 individuals present 
below the dam in 2003 occurred prior to hazing (started in 2005) or 
permanent removal (2008-2010) activities. CRC believes the high number 
is not representative of current levels, due to extensive efforts to 
deter sea lions.
    Permanent removal of forty individuals occurred from 2008-2010 
(Stansell et al., 2010). In 2010, the number of individual sea lions 
observed was a minimum of 89 individuals. Of the 89 individuals, 
fourteen were removed (Stansell et al., 2010). Typically, the 
percentage of individuals making their first appearance at Bonneville 
Dam has been approximately thirty percent; however, in 2010 the 
percentage of new individuals was approximately 65 percent (51 were 
first time visitors below the dam) (Stansell et al., 2010). The removal 
program is currently suspended by court order, further complicating the 
estimation of sea lion abundance at the dam in future years. Trends are 
particularly hard to discern because numbers passing the project site 
would be a reflection of the number of returning sea lions, numbers of 
sea lions successfully removed in future years (should the program be 
resumed), and numbers of new sea lions, none of which may be estimated 
on the basis of data indicating clear trends.
    Based on 2010 data, new animals would likely largely replace those 
removed (e.g., in 2010, fourteen animals were removed and 51 were first 
time visitors below the dam) and still possibly result in an overall 
increase in California sea lion numbers. It is possible that a more 
effective method of deterrence will be developed in the future, or 
continued removal efforts will result in the number of California sea 
lions stabilizing or decreasing in future years. However, spring 
Chinook (Oncorhynchus tshawytscha) returns to the Columbia River in 
2010 were the third largest on record since 1938 (CBB 2010), based on a 
preliminary summary (ODFW and WDFW 2010). If the numbers remain high or 
increase, it is possible that the numbers of sea lions foraging near 
Bonneville Dam may increase.
    CRC estimates that the number of sea lions passing the project site 
would be approximately 89 individuals (the minimum high count since 
significant effort toward sea lion deterrence began) annually. There is 
a substantial amount of uncertainty in this estimate; therefore, NMFS 
presents the take estimate with the caveat that the estimate of 
California sea lions potentially present in each year of in-water 
project work may need to be adapted using the most recent data and 
trends available in future years (see Adaptive Management).
    CRC examined satellite-linked and acoustic tracking reports of 
California sea lions to help estimate the number of times individual 
sea lions may pass the CRC project site. Tracking has been conducted on 
an almost annual basis since 2004. Based on data from 100 to 150 
animals, annual California sea lion round trips to the dam range from 
one to five trips per individual (CRC, 2010). Movements of 26 
satellite-tagged sea lions captured in the Columbia River during three 
non-breeding seasons (2003-04, 2004-05, and 2006-07) are described by 
Wright et al. (2010). Duration below the Bonneville Dam ranged from 2 
to 43 days (Wright et al., 2010). The authors noted that movements of 
sea lions captured in the Columbia River varied considerably within and 
across individuals, and that estimating the mean number of trips to 
Bonneville Dam in a given season is problematic given that many animals 
were tagged after they may have already made one or more such trips 
(Wright et al., 2010). In 2009, six California sea lions were tagged in 
early April with acoustic transmitters, and four of those tagged had 
relatively long datasets (approximately 1-1.5 months) (Brown et al., 
2009). After tagging, three of the animals made one round trip from 
Astoria to Bonneville Dam, and one made two round trips prior to final 
departure from Bonneville Dam by the end of May (Brown et al., 2009). 
The animals may have made additional trips prior to tagging in early 
April. Data from five animals tagged in 2010 indicate that at least one 
to four round-trips were made to Bonneville Dam from Astoria (Brown et 
al. 2010). Four animals were tagged in March or April for 22 to 51 
days. Of these four individuals, two made at least four trips, one made 
two trips and one made one trip. The fifth animal was tagged in May at 
the end of the season and departed immediately after capture. Again, 
the preliminary data do not include trips taken prior to tagging.
    Based on past data, the estimated number of times an individual sea 
lion would pass the CRC project site ranges from at least two to ten 
times per year (one to five roundtrips per year). However, the actual 
number is quite variable from individual to individual. Therefore, 
based on the data available, CRC conservatively estimates a maximum of 
ten trips (five round-trips) past the project site annually.
    In summary, CRC conservatively estimates that up to 89 California 
sea lions may travel through the Region of Activity, annually, in 
future years. The nearest haul-out site is 45 mi (72 km) from the 
Region of Activity, California sea lion hazing efforts at Bonneville 
Dam are expected to continue, and there is no information indicating 
that a large increase in the numbers of California sea lions traveling 
up the Columbia River to Bonneville Dam is likely. Each California sea 
lion could be behaviorally harassed ten times per year (five round-
trips).

Steller Sea Lion

    Exposure of Steller sea lions to elevated sound levels in the 
Region of Activity is likely to occur from November through May, when 
primarily adult and subadult male Steller sea lions typically forage at 
Bonneville Dam. Steller sea lions are known to migrate through the 
Region of Activity as they transit between the dam and the ocean during 
this time period, often making multiple round-trip journeys. Beginning 
in 2008, individual sea lions have also been present during September 
or October, but in low numbers (Stansell et al., 2009, 2010; Tackley et 
al., 2008b). Therefore, exposure during fall months is possible in very 
low numbers, but less likely.
    There are no Steller sea lion haul-outs or breeding sites in the 
Region of Activity. The nearest known haul-out is located approximately 
26 mi (42 km) upstream of the CRC project area, and the nearest 
breeding site is located more than 200 mi (322 km) from the CRC project 
area (NMFS, 2008b). Therefore, elevated sound levels would have no 
effect on individuals at breeding or haul-out sites.
    Similar to California sea lions, projections of Steller sea lion 
numbers estimated to pass the CRC project site during construction in 
future years are impossible to make with a high degree of confidence. 
Unlike California sea lions, ESA-listed Steller sea lions have not been 
subject to removal programs. Regular observations from 2002 through 
2011 showed an increase in minimum numbers observed from 0 to 89 
individuals, even though hazing efforts at the fish ladder entrances 
started in 2005 and vessel-based hazing began in 2006 (Scordino, 2010; 
Tackley et al., 2008a; Stansell et al., 2009). In 2010, the minimum 
number observed of 75 individuals was approximately triple the 2009 
minimum of 26 individuals (Stansell and Gibbons, 2010); however, the 
2009 minimum was reduced by one third from the 2008 minimum of 39.
    The minimum number of animals projected in future years would be 
expected to be at least 89 individuals

[[Page 23587]]

and may continue to increase based on recent past trends. However, 
there is very little certainty in this estimate, especially when it is 
projected into the future. It is possible a more effective method of 
deterrence would be developed in the future and the number of Steller 
sea lions may stabilize or decrease in future years. However, if trends 
in the numbers of fish continue, it is also possible that the number of 
Steller sea lions present would continue to increase.
    Acoustic and satellite-linked tracking data for Steller sea lions 
in the Columbia River are only available for six individuals, and most 
were only tracked for one month beginning at the end of March or during 
April of 2010 (CRC, 2010). Additional data are available from two 
individuals that were tagged with only satellite-linked transmitters 
(which do not provide in-river movement data). From the limited 
dataset, seven individuals made one round trip from marine areas, and 
one individual made two round trips (Wright, 2010a). The number of 
round trips made earlier in the season, prior to tagging, is not 
included in the estimate and could increase the number of trips per 
individual. Like California sea lions, considerable variation within 
and across individuals may exist. Acoustic and satellite-linked data 
collection efforts will continue in the future and will better inform 
the estimate of number of round-trips Steller sea lions are likely to 
make past the CRC project area.

Summary

    Based on past data, the number of times an individual Steller sea 
lion would pass the CRC project site ranges from a minimum of two to 
four times per year (one to two round-trips). Therefore, CRC estimates 
that individuals may transit the Region of Activity six times per year 
(three round-trips). As for California sea lions, the significant 
uncertainty associated with these estimates may require adaptation of 
the estimates using the most recent data and trends available (see 
Adaptive Management). Based on trends in Steller sea lions identified 
below Bonneville Dam in recent years, CRC conservatively estimates a 
tripling of the minimum of 75 individuals seen in 2010, to 225 
individuals that may transit the project site six times (three round-
trips) each per year.

                Table 18--Estimated Number of Individuals Exposed to Proposed Activities per Year
----------------------------------------------------------------------------------------------------------------
                                                              Estimated
                                        Sex/age class         number of     Estimated number of        Total
              Species                      affected          individuals       exposures per      estimated take
                                                              per year     individual per year *     per year
----------------------------------------------------------------------------------------------------------------
Harbor seal.......................  Adult males or                      6  4 (2 round-trips)....              24
                                     females.
California sea lion...............  Subadult or adult                  89  10 (5 round-trips)...             890
                                     males.
Steller sea lion..................  Subadult or adult                 225  6 (3 round-trips)....           1,350
                                     males.
----------------------------------------------------------------------------------------------------------------
* It is assumed that individuals exposed to CRC's proposed activities would be in transit to/from Bonneville Dam
  to forage. Trips to Bonneville Dam are assumed to be round-trips to/from the mouth of the Columbia River.

Negligible Impact and Small Numbers Analyses and Preliminary 
Determination

    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``* * * 
an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the takes occur.
    Incidental take, in the form of Level B harassment only, is likely 
to occur primarily as a result of pinniped exposure to elevated levels 
of sound caused by impact and vibratory installation and removal of 
pipe and sheet pile and steel casings. No take by injury, serious 
injury, or death is anticipated or would be authorized. By 
incorporating the proposed mitigation measures, including pinniped 
monitoring and shut-down procedures described previously, harassment to 
individual pinnipeds from the proposed activities is expected to be 
limited to temporary behavioral impacts. CRC assumes that all 
individuals traveling past the project area would be exposed each time 
they pass the area and that all exposures would cause disturbance. NMFS 
agrees that this represents a worst-case scenario and is therefore 
sufficiently precautionary. There are no pinniped haul-outs or 
rookeries located within or near the Region of Activity. The nearest 
haul-out for California sea lions and harbor seals is approximately 45 
mi (72 km) downriver from the Region of Activity, while the nearest 
known haul-out for Steller sea lions is approximately 26 mi (42 km) 
upstream from the Region of Activity.
    The shutdown zone monitoring proposed as mitigation, and the small 
size of the zones in which injury may occur, makes any potential injury 
of pinnipeds extremely unlikely, and therefore discountable. Because 
pinniped exposures would be limited to the period they are transiting 
the disturbance zone, with potential repeat exposures (on return to the 
mouth of the Columbia River) separated by days to weeks, the 
probability of experiencing TTS is also considered unlikely.
    These activities may cause individuals to temporarily disperse from 
the area or avoid transit through the area. However, existing traffic 
sound, commercial vessels, and recreational boaters already occur in 
the area. Thus, it is likely that pinnipeds are habituated to these 
disturbances while transiting the Region of Activity and would not be 
significantly hindered from transit. Behavioral changes are expected to 
potentially occur only when an animal is transiting a disturbance zone 
at the same time that the proposed activities are occurring.
    In addition, it is unlikely that pinnipeds exposed to elevated 
sound levels would temporarily avoid traveling through the affected 
area, as they are highly motivated to travel through the action area in 
pursuit of foraging opportunities upriver (NMFS, 2008e). Sea lions have 
shown increasing habituation in recent years to various hazing 
techniques used to deter the animals from foraging in the Bonneville 
tailrace area, including acoustic deterrent devices, boat chasing, and 
above-water pyrotechnics (Stansell et al., 2009). Many of the 
individuals that travel to the tailrace area return in subsequent years 
(NMFS, 2008). Therefore, it is likely that pinnipeds

[[Page 23588]]

would continue to pass through the action area even when sound levels 
are above disturbance thresholds.
    Although pinnipeds are unlikely to be deterred from passing through 
the area, even temporarily, they may respond to the underwater sound by 
passing through the area more quickly, or they may experience stress as 
they pass through the area. Sea lions already move quickly through the 
lower river on their way to foraging grounds below Bonneville Dam 
(transit speeds of 4.6 km/hr in the upstream direction and 8.8 km/hr in 
the downstream direction [Brown et al., 2010]). Any increase in transit 
speed is therefore likely to be slight. Another possible effect is that 
the underwater sound would evoke a stress response in the exposed 
individuals, regardless of transit speed. However, the period of time 
during which an individual would be exposed to sound levels that might 
cause stress is short given their likely speed of travel through the 
affected areas. In addition, there would be few repeat exposures for 
individual animals. Thus, it is unlikely that the potential increased 
stress would have a significant effect on individuals or any effect on 
the population as a whole.
    Therefore, NMFS finds it unlikely that the amount of anticipated 
disturbance would significantly change pinnipeds' use of the lower 
Columbia River or significantly change the amount of time they would 
otherwise spend in the foraging areas below Bonneville Dam. Pinniped 
usage of the Bonneville Dam foraging area, which results in transit of 
the action area, is a relatively recent learned behavior resulting from 
human modification (i.e., fish accumulation at the base of the dam). 
Even in the unanticipated event that either change was significant and 
animals were displaced from foraging areas in the lower Columbia River, 
there are alternative foraging areas available to the affected 
individuals. NMFS does not anticipate any effects on haul-out behavior 
because there are no proximate haul-outs within the areas affected by 
elevated sound levels. All other effects of the proposed action are at 
most expected to have a discountable or insignificant effect on 
pinnipeds, including an insignificant reduction in the quantity and 
quality of prey otherwise available.
    Any adverse effects to prey species would occur on a temporary 
basis during project construction. Given the large numbers of fish in 
the Columbia River, the short-term nature of effects to fish 
populations, and extensive BMPs and minimization measures designed by 
NMFS in cooperation with CRC to protect fish during construction, as 
well as conservation and habitat mitigation measures that would 
continue into the future, the project is not expected to have 
significant effects on the distribution or abundance of potential prey 
species in the long term. All project activities would be conducted 
using the BMPs and minimization measures, which are described in detail 
in NMFS' biological opinion, pursuant to section 7 of the ESA, on the 
effects of the CRC project on ESA-listed species. Therefore, these 
temporary impacts are expected to have a negligible impact on habitat 
for pinniped prey species.
    A detailed description of potential impacts to individual pinnipeds 
was provided previously in this document. The following sections put 
into context what those effects mean to the respective populations or 
stocks of each of the pinniped species potentially affected.

Harbor Seal

    The Oregon/Washington coastal stock of harbor seals consisted of 
about 25,000 animals in 1999 (Carretta et al., 2007). As described 
previously, both the Washington and Oregon portions of this stock have 
reached carrying capacity and are no longer increasing, and the stock 
is believed to be within its OSP level (Jeffries et al., 2003; Brown et 
al., 2005). The estimated take of 24 individuals per year by Level B 
harassment is small relative to a stable population of approximately 
25,000 (0.1 percent), and is not expected to impact annual rates of 
recruitment or survival of the stock.

California Sea Lion

    The U.S. stock of California sea lions was estimated to be 238,000 
in the 2007 Stock Assessment Report and may be at carrying capacity, 
although more data are needed to verify that determination (Carretta et 
al., 2007). Generally, California sea lions in the Pacific Northwest 
are subadult or adult males (NOAA, 2008). The estimated take of 890 
individuals per year is small relative to a population of approximately 
238,000 (0.4 percent), and is not expected to impact annual rates of 
recruitment or survival of the stock.

Steller Sea Lion

    The total population of the eastern DPS of Steller sea lions is 
estimated to be within a range from approximately 58,334 to 72,223 
animals with an overall annual rate of increase of 3.1 percent 
throughout most of the range (Oregon to southeastern Alaska) since the 
1970s (Allen and Angliss, 2010). In 2006, the NMFS Steller sea lion 
recovery team proposed removal of the eastern stock from listing under 
the ESA based on its annual rate of increase. CRC's take estimate is 
conservative, assuming a three-fold increase above the largest minimum 
count in 2010. An increase of this magnitude occurred from 2009 to 
2010, and so may be warranted; however, that 1-year increase is not 
necessarily a reliable indicator of future trends and so may result in 
an overestimate of future take. The total estimated take of 1,350 
individuals per year is small compared to a population of approximately 
65,000 (2.1 percent).
    For California and Steller sea lions, individuals that may be 
disturbed would be males, so the anticipated behavioral harassment is 
not expected to impact recruitment or survival of the stock. For all 
species, because the type of incidental harassment is not expected to 
actually remove individuals from the population or decrease 
significantly their ability to feed or breed, this amount of incidental 
harassment is anticipated to have a negligible impact on the stock.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the mitigation and monitoring 
measures, NMFS preliminarily finds that CRC's proposed activities would 
result in the incidental take of small numbers of marine mammals, by 
Level B harassment only, and that the total taking from CRC's proposed 
activities would have a negligible impact on the affected species or 
stocks.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

    There are no relevant subsistence uses of marine mammals implicated 
by this action. 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)

    On January 19, 2011, NMFS concluded consultation with FHWA and FTA 
under section 7 of the ESA on the proposed activities in the Columbia 
River and North Portland Harbor and issued a biological opinion. The 
finding of that consultation was that the proposed activities may 
adversely affect but are not likely to jeopardize the continued 
existence of the eastern DPS of Steller sea lions as well as a number

[[Page 23589]]

of ESA-listed fish. NMFS has preliminarily determined that issuance of 
these regulations and subsequent LOAs would not have any impacts beyond 
those analyzed in the 2011 biological opinion.

National Environmental Policy Act (NEPA)

    CRC released a Draft Environmental Impact Statement (EIS) for the 
proposed activities in May 2008. The draft EIS analyzed the potential 
environmental and community effects of five alternatives against the 
project's goals, as identified in the Statement of Purpose and Need. 
The Final EIS, released in September 2011, described additional 
analysis of potential environmental and community effects of the 
project and incorporated the comments received on the Draft EIS and 
public input received at more than 950 community briefings, workshops 
and public meetings. Following a 30-day review period, the CRC federal 
oversight agencies (FHWA and FTA) selected an alternative for the 
project and signed a record of decision (ROD) on December 7, 2011. 
Further information about CRC's NEPA process, as well as the EIS and 
ROD, is available at www.columbiarivercrossing.com. Because NMFS was 
not a cooperating agency in the development of CRC's EIS, NMFS will 
conduct a separate NEPA analysis for issuance of authorizations 
pursuant to section 101(a)(5)(A) of the MMPA for the activities 
proposed by CRC.

Information Solicited

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning the request and the content of the proposed 
regulations to govern the taking described herein (see ADDRESSES).

Classification

    The Office of Management and Budget (OMB) has determined that this 
proposed rule is not significant for purposes of Executive Order 12866.
    Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA), 
the Chief Counsel for Regulation of the Department of Commerce has 
certified to the Chief Counsel for Advocacy of the Small Business 
Administration (SBA) that this proposed rule, if adopted, would not 
have a significant economic impact on a substantial number of small 
entities. The SBA defines small entity as a small business, small 
organization, or a small governmental jurisdiction. Applying this 
definition, there are no small entities that are impacted by this 
proposed rule. This proposed rule impacts only the activities of CRC, 
which has submitted a request for authorization to take marine mammals 
incidental to bridge construction within the Columbia River, over the 
course of 5 years. CRC is a joint project of ODOT and WSDOT, in 
cooperation with FHWA and FTA. Project staff coordinates with state and 
local agencies in both Oregon and Washington, and also collaborates 
with federal agencies and tribal governments. CRC is not considered to 
be a small governmental jurisdiction under the RFA's definition. Under 
the RFA, governmental jurisdictions are considered to be small if they 
are ``governments of cities, counties, towns, townships, villages, 
school districts, or special districts, with a population of less than 
50,000, unless an agency establishes, after opportunity for public 
comment, one or more definitions of such term which are appropriate to 
the activities of the agency and which are based on such factors as 
location in rural or sparsely populated areas or limited revenues due 
to the population of such jurisdiction, and publishes such 
definition(s) in the Federal Register.'' Because this proposed rule 
impacts only the activities of CRC, which is not considered to be a 
small entity within SBA's definition, the Chief Counsel for Regulation 
certified that this proposed rule will not have a significant economic 
impact on a substantial number of small entities. As a result of this 
certification, a regulatory flexibility analysis is not required and 
none has been prepared.
    Notwithstanding any other provision of law, no person is required 
to respond to nor shall a person be subject to a penalty for failure to 
comply with a collection of information subject to the requirements of 
the Paperwork Reduction Act (PRA) unless that collection of information 
displays a currently valid OMB control number. This proposed rule 
contains collection-of-information requirements subject to the 
provisions of the PRA. These requirements have been approved by OMB 
under control number 0648-0151 and include applications for 
regulations, subsequent LOAs, and reports. Send comments regarding any 
aspect of this data collection, including suggestions for reducing the 
burden, to NMFS and the OMB Desk Officer (see ADDRESSES).

List of Subjects in 50 CFR Part 217

    Exports, Fish, Imports, Indians, Labeling, Marine mammals, 
Penalties, Reporting and recordkeeping requirements, Seafood, 
Transportation.

    Dated: April 10, 2012.
Alan D. Risenhoover,
Acting Deputy Assistant Administrator for Regulatory Programs, National 
Marine Fisheries Service.

    For reasons set forth in the preamble, 50 CFR part 217 is proposed 
to be amended as follows:

PART 217--REGULATIONS GOVERNING THE TAKE OF MARINE MAMMALS 
INCIDENTAL TO SPECIFIED ACTIVITIES

    1. The authority citation for part 217 continues to read as 
follows:

    Authority:  16 U.S.C. 1361 et seq.

    2. Subpart V is added to part 217 to read as follows:
Subpart V--Taking of Marine Mammals Incidental to Columbia River 
Crossing Project, Washington and Oregon
Sec.
217.210 Specified activity and specified geographical region.
217.211 Effective dates.
217.212 Permissible methods of taking.
217.213 Prohibitions.
217.214 Mitigation.
217.215 Requirements for monitoring and reporting.
217.216 Letters of Authorization.
217.217 Renewals and Modifications of Letters of Authorization.

Subpart V--Taking of Marine Mammals Incidental to Columbia River 
Crossing Project, Washington and Oregon


Sec.  217.210  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to Columbia River 
Crossing (CRC) and those persons it authorizes to conduct activities on 
its behalf for the taking of marine mammals that occurs in the area 
outlined in paragraph (b) of this section and that occurs incidental to 
bridge construction and demolition associated with the CRC project.
    (b) The taking of marine mammals by CRC may be authorized in a 
Letter of Authorization (LOA) only if it occurs in the Columbia River 
or North Portland Harbor, in the states of Washington and Oregon.


Sec.  217.211  Effective dates.

    [Reserved]


Sec.  217.212  Permissible methods of taking.

    (a) Under LOAs issued pursuant to Sec.  216.106 and Sec.  217.216 
of this chapter, the Holder of the LOA (hereinafter ``CRC'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  217.210(b) of this chapter, provided the 
activity is in compliance with all terms, conditions, and requirements 
of

[[Page 23590]]

the regulations in this subpart and the appropriate LOA.
    (b) The incidental take of marine mammals under the activities 
identified in Sec.  217.210(a) of this chapter is limited to the 
indicated number of Level B harassment takes of the following species:
    (1) Harbor seal (Phoca vitulina)--120 (an average of 24 annually)
    (2) California sea lion (Zalophus californianus)--4,450 (an average 
of 890 annually)
    (3) Steller sea lion (Eumetopias jubatus)--6,750 (an average of 
1,350 annually)


Sec.  217.213  Prohibitions.

    Notwithstanding takings contemplated in Sec.  217.212(b) of this 
chapter and authorized by a LOA issued under Sec.  216.106 and Sec.  
217.216 of this chapter, no person in connection with the activities 
described in Sec.  217.210 of this chapter may:
    (a) Take any marine mammal not specified in Sec.  217.212(b) of 
this chapter;
    (b) Take any marine mammal specified in Sec.  217.212(b) of this 
chapter other than by incidental, unintentional Level B Harassment;
    (c) Take a marine mammal specified in Sec.  217.212(b) of this 
chapter if NMFS determines such taking results in more than a 
negligible impact on the species or stocks of such marine mammal; or
    (d) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec.  216.106 and 
Sec.  217.216 of this chapter.


Sec.  217.214  Mitigation.

    (a) When conducting the activities identified in Sec.  217.210(a) 
of this chapter, the mitigation measures contained in the LOA issued 
under Sec.  216.106 and Sec.  217.216 of this chapter must be 
implemented. These mitigation measures include:
    (1) General Conditions:
    (i) Briefings shall be conducted between the CRC project 
construction supervisors and the crew, marine mammal observer(s), and 
acoustical monitoring team prior to the start of all pile driving 
activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures. The CRC project shall contact the 
Bonneville Dam marine mammal monitoring team to obtain information on 
the presence or absence of pinnipeds prior to initiating pile driving 
in any discrete pile driving time period described in the project 
description.
    (ii) CRC shall comply with all applicable equipment sound standards 
and ensure that all construction equipment has sound control devices no 
less effective than those provided on the original equipment.
    (iii) 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 50 m of such activity, operations shall cease and 
vessels shall reduce speed to the minimum level required to maintain 
steerage and safe working conditions.
    (2) Pile Installation:
    (i) Permanent foundations for each in-water pier shall be installed 
by means of drilled shafts.
    (ii) All piles shall be installed using vibratory driving to the 
extent possible. Installation of piles using impact driving may only 
occur between September 15 and April 15 of the following year, during 
daylight hours only. No more than two impact pile drivers may be 
operated simultaneously within the same water body channel.
    (iii) In waters with depths more than 2 ft (0.67 m), a bubble 
curtain or other sound attenuation measure shall be used for impact 
driving of pilings. If a bubble curtain or similar measure is used, it 
shall distribute small air bubbles around 100 percent of the piling 
perimeter for the full depth of the water column. Any other attenuation 
measure (e.g., temporary sound attenuation pile) must provide 100 
percent coverage in the water column for the full depth of the pile. A 
performance test of the sound attenuation device in accordance with the 
approved hydroacoustic monitoring plan shall be conducted prior to any 
impact pile driving. If a bubble curtain or similar measure is 
utilized, the performance test shall confirm the calculated pressures 
and flow rates at each manifold ring.
    (3) Shutdown and Monitoring:
    (i) Shutdown zone: For all impact pile driving and vibratory pile 
driving and removal, or installation of steel casings, shutdown zones 
shall be established. These zones shall include all areas where 
underwater sound pressure levels (SPLs) are anticipated to equal or 
exceed 190 dB re: 1 [mu]Pa rms. Shutdown zones shall be established on 
the basis of existing worst-case site-specific data for 24- or 48-in 
steel pile, as appropriate, collected by CRC with NMFS approval, and 
shall be adjusted as indicated by the results of acoustic monitoring 
conducted during the specified activities, but shall not be less than 
50 m radius.
    (ii) Disturbance zone: For all impact pile driving and vibratory 
pile driving or removal, disturbance zones shall be established. For 
impact pile driving, these zones shall include all areas where 
underwater SPLs are anticipated to equal or exceed 160 dB re: 1 [mu]Pa 
rms, and shall be established on the basis of existing worst-case site-
specific data for 24- or 48-in steel pile, as appropriate, collected by 
CRC with NMFS approval. The zones shall be adjusted as indicated by the 
results of acoustic monitoring conducted during the specified 
activities. The actual size of the zone for vibratory pile driving and 
removal that includes all areas where underwater SPLs equal or exceed 
120 dB re: 1 [mu]Pa rms shall be empirically determined and reported by 
CRC, and on-site biologists shall be aware of the size of this zone. 
However, because of its large size, monitoring of the entire zone may 
not be required but shall be conducted as described in paragraph (v) of 
this section.
    (A) Initial disturbance zones for vibratory installation or removal 
of steel pipe pile and sheet pile and vibratory installation of steel 
casings shall be set at 800 m. In-situ acoustic monitoring shall be 
performed to determine the actual distances to these zones, and the 
size of the zones shall be adjusted accordingly based on worst-case 
site-specific data for vibratory installation of steel sheet pile and 
steel casings, but the area to be visually monitored shall not be 
larger than 800 m.
    (B) [Reserved]
    (iii) Airborne sound: Disturbance zones for pile driving and 
removal activity and steel casing installation, to include all areas 
where airborne SPLs are anticipated to equal or exceed 90 dB re: 20 
[mu]Pa rms or 100 dB re: 20 [mu]Pa rms (for harbor seals and sea lions, 
respectively), shall be established. These zones shall be adjusted 
accordingly based on worst-case site-specific data collected during 
acoustic monitoring of the specified activities.
    (iv) The shutdown and disturbance zones shall be monitored 
throughout the time required to drive a pile. If a marine mammal is 
observed within or approaching the shutdown zone, activity shall be 
halted as soon as it is safe to do so, until the animal is observed 
exiting the shutdown zone or 15 minutes has elapsed. If a marine mammal 
is observed within the disturbance zone, a take shall be recorded and 
behaviors documented.
    (v) Monitoring of shutdown and disturbance zones shall occur for 
all pile driving and removal and steel casing installation activities. 
The following measures shall apply:
    (A) Shutdown and disturbance zones shall be monitored from a work

[[Page 23591]]

platform, barge, or other vantage point. If a small boat is used for 
monitoring, the boat shall remain 50 yd (46 m) from swimming pinnipeds. 
CRC shall at all times employ, at minimum, one Protected Species 
Observer (PSO) to be located on each barge or work platform engaging in 
pile driving or removal or steel casing installation and, at minimum, 
one PSO to be based on shore or at another appropriate vantage point, 
as determined by CRC. If a single shore-based PSO is unable to provide 
full observational coverage of disturbance zones when multiple pile 
driving or removal or steel casing installation activities are 
occurring simultaneously, additional shore-based PSOs shall be 
stationed so that such coverage is attained. For vibratory pile driving 
and removal or steel casing installation, CRC shall maintain 
comprehensive observation of a maximum disturbance zone of 800 m radial 
distance.
    (B) If the shutdown zone is obscured by fog or poor lighting 
conditions, pile driving or removal or steel casing installation shall 
not be initiated until the entire shutdown zone is visible. Pile 
driving or removal or steel casing installation may continue under such 
conditions if properly initiated.
    (C) The shutdown zone shall be monitored for the presence of 
pinnipeds before, during, and after any pile driving activity. The 
shutdown zone shall be monitored for 30 minutes prior to initiating the 
start of pile driving and for 30 minutes following the completion of 
pile driving. If pinnipeds are present within the shutdown zone prior 
to pile driving, the start of pile driving shall be delayed until the 
animals leave the shutdown zone of their own volition or until 15 
minutes has elapsed without observing the animal.
    (4) Ramp-up
    (i) A ramp-up technique shall be used at the beginning of each 
day's in-water pile driving activities and if pile driving resumes 
after it has ceased for more than 1 hour.
    (ii) If a vibratory driver is used, contractors shall be required 
to initiate sound from vibratory hammers for 15 seconds at reduced 
energy followed by a 1-minute waiting period. The procedure shall be 
repeated two additional times before full energy may be achieved.
    (iii) If a non-diesel impact hammer is used, contractors shall be 
required to provide an initial set of strikes from the impact hammer at 
reduced energy, followed by a 1-minute waiting period, then two 
subsequent sets.
    (iv) If a diesel impact hammer is used, contractors shall be 
required to turn on the sound attenuation device for 15 seconds prior 
to initiating pile driving.
    (5) Additional mitigation measures as contained in a LOA issued 
under Sec.  216.106 and Sec.  217.216 of this chapter.
    (b) [Reserved]


Sec.  217.215  Requirements for monitoring and reporting.

    (a) Visual Monitoring Program: (1) CRC shall employ PSOs during in-
water construction and demolition activities. All PSOs must receive 
advance NMFS approval after a review of their qualifications and NMFS-
approved training. The PSOs shall be responsible for visually locating 
marine mammals in the shutdown and disturbance zones and, to the extent 
possible, identifying the species. PSOs shall record, at minimum, the 
following information:
    (i) A count of all pinnipeds observed by species, sex, and age 
class.
    (ii) Their location within the shutdown or disturbance zone, and 
their reaction (if any) to construction activities, including direction 
of movement.
    (iii) Activity that is occurring at the time of observation, 
including time that pile driving begins and ends, any acoustic or 
visual disturbance, and time of the observation.
    (iv) Environmental conditions, including wind speed, wind 
direction, visibility, and temperature.
    (2) Monitoring shall be conducted using appropriate binoculars. 
When possible, digital video or still cameras shall also be used to 
document the behavior and response of pinnipeds to construction 
activities or other disturbances.
    (3) Each monitor shall have a radio or cell phone for contact with 
other monitors or work crews. Observers shall implement shut-down or 
delay procedures when applicable by calling for the shut-down to the 
hammer operator.
    (4) A GPS unit or electric range finder shall be used for 
determining the observation location and distance to pinnipeds, boats, 
and construction equipment.
    (5) No monitoring shall be conducted during inclement weather that 
creates potentially hazardous conditions, as determined by the 
biologist on-site. No monitoring shall be conducted when visibility in 
the shutdown zone is significantly limited, such as during heavy rain 
or fog. During these times of inclement weather, in-water work that may 
produce sound levels in excess of 190 dB rms must be halted; these 
activities may not commence until appropriate monitoring of the 
shutdown zone can take place.
    (b) Reporting--CRC must implement the following reporting 
requirements:
    (1) Reports of data collected during monitoring shall be submitted 
to NMFS weekly. The reports shall include:
    (i) All data required to be collected during monitoring, as 
described under 217.215(a) of this chapter, including observation 
dates, times, and conditions; and
    (ii) Correlations of observed behavior with activity type and 
received levels of sound, to the extent possible.
    (2) CRC shall also submit a report(s) concerning the results of all 
acoustic monitoring. Acoustic monitoring reports shall include:
    (i) Size and type of piles.
    (ii) A detailed description of any sound attenuation device used, 
including design specifications.
    (iii) The impact hammer energy rating used to drive the piles, make 
and model of the hammer(s), and description of the vibratory hammer.
    (iv) A description of the sound monitoring equipment.
    (v) The distance between hydrophones and depth of water at the 
hydrophone locations.
    (vi) The depth of the hydrophones.
    (vii) The distance from the pile to the water's edge.
    (viii) The depth of water in which the pile was driven.
    (ix) The depth into the substrate that the pile was driven.
    (x) The physical characteristics of the bottom substrate into which 
the piles were driven.
    (xi) The total number of strikes to drive each pile.
    (xii) The background sound pressure level reported as the fifty 
percent cumulative distribution function, if recorded.
    (xiii) The results of the hydroacoustic monitoring, including the 
frequency spectrum, ranges and means including the standard deviation/
error for the peak and rms SPLs, and an estimation of the distance at 
which rms values reach the relevant marine mammal thresholds and 
background sound levels. Vibratory driving results shall include the 
maximum and overall average rms calculated from 30-s rms values during 
the drive of the pile.
    (xiv) A description of any observable pinniped behavior in the 
immediate area and, if possible, correlation to underwater sound levels 
occurring at that time.
    (3) Reporting Injured or Dead Marine Mammals
    (i) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by a LOA (if 
issued), such as

[[Page 23592]]

an injury (Level A harassment), serious injury, or mortality, CRC shall 
immediately cease the specified activities and report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the Northwest Regional Stranding Coordinator, 
NMFS. The report must include the following information:
    (A) Time and date of the incident;
    (B) Description of the incident;
    (C) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (D) Description of all marine mammal observations in the 24 hours 
preceding the incident;
    (E) Species identification or description of the animal(s) 
involved;
    (F) Fate of the animal(s); and
    (G) Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with CRC to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. CRC may not resume 
their activities until notified by NMFS.
    (ii) In the event that CRC discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (e.g., in less than 
a moderate state of decomposition), CRC shall immediately report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the Northwest Regional Stranding 
Coordinator, NMFS.
    The report must include the same information identified in 
217.215(b)(3)(i) of this chapter. Activities may continue while NMFS 
reviews the circumstances of the incident. NMFS will work with CRC to 
determine whether additional mitigation measures or modifications to 
the activities are appropriate.
    (iii) In the event that CRC discovers an injured or dead marine 
mammal, and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in the LOA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), CRC shall report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the Northwest Regional Stranding Coordinator, 
NMFS, within 24 hours of the discovery. CRC shall provide photographs 
or video footage or other documentation of the stranded animal sighting 
to NMFS.
    (4) Annual Reports.
    (i) An annual report summarizing all pinniped monitoring and 
construction activities shall be submitted to NMFS, Office of Protected 
Resources, and NMFS, Northwest Regional Office (specific contact 
information to be provided in LOA) each year.
    (ii) The annual reports shall include data collected for each 
distinct marine mammal species observed in the project area. 
Description of marine mammal behavior, overall numbers of individuals 
observed, frequency of observation, and any behavioral changes and the 
context of the changes relative to activities shall also be included in 
the annual reports. Additional information that shall be recorded 
during activities and contained in the reports include: Date and time 
of marine mammal detections, weather conditions, species 
identification, approximate distance from the source, and activity at 
the construction site when a marine mammal is sighted.
    (5) Five Year Comprehensive Report.
    (i) CRC shall submit a draft comprehensive final report to NMFS, 
Office of Protected Resources, and NMFS, Northwest Regional Office 
(specific contact information to be provided in LOA) 180 days prior to 
the expiration of the regulations. This comprehensive technical report 
shall provide full documentation of methods, results, and 
interpretation of all monitoring during the first 4.5 years of the 
activities conducted under the regulations in this Subpart.
    (ii) CRC shall submit a revised final comprehensive technical 
report, including all monitoring results during the entire period of 
the LOAs, 90 days after the end of the period of effectiveness of the 
regulations to NMFS, Office of Protected Resources, and NMFS, Northwest 
Regional Office (specific contact information to be provided in LOA).


Sec.  217.216  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, CRC must apply for and obtain a LOA.
    (b) A LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed the expiration date of these regulations.
    (c) If an LOA expires prior to the expiration date of these 
regulations, CRC must apply for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by an LOA, CRC must apply 
for and obtain a modification of the LOA as described in Sec.  217.217 
of this chapter.
    (e) The LOA shall set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and on the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (f) Issuance of the LOA shall be based on a determination that the 
level of taking will be consistent with the findings made for the total 
taking allowable under these regulations.
    (g) Notice of issuance or denial of a LOA shall be published in the 
Federal Register within 30 days of a determination.


Sec.  217.217  Renewals and Modifications of Letters of Authorization.

    (a) A LOA issued under Sec.  216.106 and Sec.  217.216 of this 
chapter for the activity identified in Sec.  217.210(a) of this chapter 
shall be renewed or modified upon request by the applicant, provided 
that: (1) The proposed specified activity and mitigation, monitoring, 
and reporting measures, as well as the anticipated impacts, are the 
same as those described and analyzed for these regulations (excluding 
changes made pursuant to the adaptive management provision in Sec.  
217.217(c)(1) of this chapter), and (2) NMFS determines that the 
mitigation, monitoring, and reporting measures required by the previous 
LOA under these regulations were implemented.
    (b) For LOA modification or renewal requests by the applicant that 
include changes to the activity or the mitigation, monitoring, or 
reporting (excluding changes made pursuant to the adaptive management 
provision in Sec.  217.217(c)(1) of this chapter) that do not change 
the findings made for the regulations or result in no more than a minor 
change in the total estimated number of takes (or distribution by 
species or years), NMFS may publish a notice of proposed LOA in the 
Federal Register, including the associated analysis illustrating the 
change, and solicit public comment before issuing the LOA.
    (c) A LOA issued under Sec.  216.106 and Sec.  217.216 of this 
chapter for the activity identified in Sec.  217.210(a) of this chapter 
may be modified by NMFS under the following circumstances:
    (1) Adaptive Management--NMFS may modify (including augment) the 
existing mitigation, monitoring, or reporting measures (after 
consulting with CRC regarding the practicability of the modifications) 
if doing so creates a

[[Page 23593]]

reasonable likelihood of more effectively accomplishing the goals of 
the mitigation and monitoring set forth in the preamble for these 
regulations.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in an LOA:
    (A) Results from CRC's monitoring from the previous year(s).
    (B) Results from other marine mammal and/or sound research or 
studies.
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent or number not authorized by these regulations or 
subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, NMFS 
will publish a notice of proposed LOA in the Federal Register and 
solicit public comment.
    (2) Emergencies--If NMFS determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in Sec.  217.212(b) of this chapter, an LOA 
may be modified without prior notice or opportunity for public comment. 
Notice would be published in the Federal Register within 30 days of the 
action.

[FR Doc. 2012-9086 Filed 4-18-12; 8:45 am]
BILLING CODE 3510-22-P