[Federal Register Volume 80, Number 82 (Wednesday, April 29, 2015)]
[Notices]
[Pages 23774-23784]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-09915]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD829


Taking of Marine Mammals Incidental to Specified Activities; 
Construction of the East Span of the San Francisco-Oakland Bay Bridge

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

ACTION: Notice; request for comments.

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SUMMARY: NMFS has received a request from the California Department of 
Transportation (CALTRANS) for an incidental take authorization to take 
small numbers of California sea lions, Pacific harbor seals, harbor 
porpoises, and gray whales, by harassment, incidental to construction 
activities associated with the East Span of the San Francisco-Oakland 
Bay Bridge (SF-OBB) in California. Pursuant to the Marine Mammal 
Protection Act (MMPA), NMFS is requesting comments on its proposal to 
issue an authorization to CALTRANS to incidentally take, by harassment, 
small numbers of marine mammals for a period of 1 year.

DATES: Comments and information must be received no later than May 29, 
2015.

ADDRESSES: Comments on the application should be addressed to Rob 
Pauline, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service, 1315 East-West Highway, 
Silver Spring, MD 20910-3225. The mailbox address for providing email 
comments is [email protected]. NMFS is not responsible for email 
comments sent to addresses other than the one provided here. Comments 
sent via email, including all attachments, must not exceed a 10-
megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. All Personal Identifying Information (for 
example, name, address, etc.) voluntarily submitted by the commenter 
may be publicly accessible. Do not submit Confidential Business 
Information or otherwise sensitive or protected information.
    The application used in this document may be obtained by visiting 
the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. Documents cited in this notice may also be viewed, by 
appointment, during regular business hours, at the aforementioned 
address.

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

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''

[[Page 23775]]

    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for a one-year authorization to 
incidentally take small numbers of marine mammals by harassment, 
provided that there is no potential for serious injury or mortality to 
result from the activity. Section 101(a)(5)(D) establishes a 45-day 
time limit for NMFS review of an application followed by a 30-day 
public notice and comment period on any proposed authorizations for the 
incidental harassment of marine mammals. Within 45 days of the close of 
the comment period, NMFS must either issue or deny the authorization.

Summary of Request

    On December 15, 2014 CALTRANS submitted its most recent request to 
NOAA requesting an IHA for the possible harassment of small numbers of 
California sea lions (Zalophus californianus), Pacific harbor seals 
(Phoca vitulina richardsii), harbor porpoises (Phocoena phocoena), and 
gray whales (Eschrichtius robustus) incidental to construction 
associated with a replacement bridge for the East Span of the SF-OBB, 
in San Francisco Bay (SFB, or Bay), California.

Description of the Specified Activity

    An IHA was previously issued to CALTRANS for this activity on 
January 8, 2014 (79 FR 2421; January 14, 2014), based on activities 
described on CALTRANS' IHA application dated April 13, 2013. That IHA 
expired on January 7, 2015. Since the construction activity would last 
for approximately an additional two years after the expiration of the 
current IHA, CALTRANS requests to renew its IHA. In its IHA renewal 
request, CALTRANS also states that there has been no change in the 
scope of work for the SF-OBB Project from what was outlined in its 
April 13, 2013 IHA application project description, the Federal 
Register notice for the proposed IHA (78 FR 60852; October 2, 2013), 
and the Federal Register notice for the issuance of that IHA (79 FR 
2421; January 14, 2013). This stage of the project will include the 
mechanical dismantling of marine foundations of the East Span of the 
bridge as well as the installation of approximately 200 steel piles. 
These activities will be covered under the proposed IHA. Refer to these 
documents for a detailed description of CALTRANS' SF-OBB construction 
activities.
    Construction activities for the replacement of the SF-OBB east span 
commenced in 2002 and are expected to be completed in 2016 with the 
completion of the bike/pedestrian path and eastbound on ramp from Yerba 
Buena Island. The new east span is now open to traffic. On November 10, 
2003, NMFS issued the first project-related IHA to the Department, 
authorizing the take of small numbers of marine mammals incidental to 
the construction of the SFOBB Project. The Department has been issued a 
total of seven subsequent IHAs for the SFOBB Project to date, excluding 
the application currently under review.

Description of Marine Mammals in the Area of the Specified Activity

    General information on the marine mammal species found in 
California waters can be found in Carretta et al. 2013, which is 
available at the following URL: http://www.nmfs.noaa.gov/pr/sars/pdf/pacific2013.pdf. Refer to that document for information on these 
species.
    The marine mammals most likely to be found in the SF-OBB area are 
the California sea lion, Pacific harbor seal, and harbor porpoise. From 
December through May gray whales may also be present in the SF-OBB 
area. Information on California sea lion, harbor seal, and gray whale 
was provided in the November 14, 2003 (68 FR 64595), Federal Register 
notice; information on harbor porpoise was provided in a Supplemental 
Environmental Assessment (SEA), which analyzed the potential impacts to 
marine mammals that would result from the modification of the original 
action. A Finding of No Significant Impact (FONSI) was signed on August 
5, 2009. These documents were referenced in the December 13, 2010 (75 
FR 77617) Federal Register notice of IHA. A copy of the SEA and FONSI 
is available upon request.

Potential Effects on Marine Mammals and Their Habitat

    CALTRANS and NMFS have determined that open-water pile driving and 
pile removal, as well as dredging and dismantling of concrete 
foundation of existing bridge by saw cutting, flame cutting, mechanical 
splitting, drilling, pulverizing and/or hydro-cutting, as outlined in 
the project description, have the potential to result in behavioral 
harassment of California sea lions, Pacific harbor seals, harbor 
porpoises, and gray whales that may be swimming, foraging, or resting 
in the project vicinity while pile driving is being conducted.
    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift (TS), which is 
the loss of hearing sensitivity at certain frequency ranges (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be 
permanent (PTS), in which case the loss of hearing sensitivity is 
unrecoverable, or temporary (TTS), in which case the animal's hearing 
threshold will recover over time (Southall et al. 2007). Since marine 
mammals depend on acoustic cues for vital biological functions, such as 
orientation, communication, finding prey, and avoiding predators, 
marine mammals that incur PTS or TTS may have reduced fitness in 
survival and reproduction, either permanently or temporarily. Repeated 
noise exposure that leads to TTS could cause PTS.
    When PTS occurs, there is physical damage to the sound receptors in 
the ear. In severe cases, there can be total or partial deafness, while 
in other cases the animal has an impaired ability to hear sounds in 
specific frequency ranges (Kryter, 1985). There is no specific evidence 
that exposure to pulses of sound can cause PTS in any marine mammal. 
However, given the possibility that mammals close to a sound source can 
incur TTS, it is possible that some individuals might incur PTS. Single 
or occasional occurrences of mild TTS are not indicative of permanent 
auditory damage, but repeated or (in some cases) single exposures to a 
level well above that causing TTS onset might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals, based on anatomical similarities. PTS might 
occur at a received sound level at least several decibels above that 
inducing mild TTS if the animal were exposed to strong sound pulses 
with rapid rise time. Based on data from terrestrial mammals, a 
precautionary assumption is that the PTS threshold for impulse sounds 
(such as pile driving pulses as received close to the source) is at 
least 6 dB higher than the TTS threshold on a peak-pressure basis and 
probably greater than 6 dB (Southall et al., 2007). On a sound exposure 
level (SEL) basis, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB for 
there to be risk of PTS. Thus, for cetaceans, Southall et al. (2007) 
estimate that the PTS threshold might be an M-weighted SEL (for the 
sequence of received pulses) of approximately 198 dB re 1 [mu]Pa\2\-s 
(15 dB higher than the TTS threshold for an impulse). Given the higher 
level of sound necessary to cause PTS as compared with TTS, it is 
considerably less likely that PTS could occur.
    Measured source levels from impact pile driving can be as high as 
214 dB re

[[Page 23776]]

1 [mu]Pa @1 m. Although no marine mammals have been shown to experience 
TTS or PTS as a result of being exposed to pile driving activities, 
experiments on a bottlenose dolphin (Tursiops truncates) and beluga 
whale (Delphinapterus leucas) showed that exposure to a single water 
gun pulse at a received level of 207 kPa (or 30 psi) peak-to-peak (p-
p), which is equivalent to 228 dB (p-p) re 1 [mu]Pa, resulted in a 7 
and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. 
Thresholds returned to within 2 dB of the pre-exposure level within 4 
minutes of the exposure (Finneran et al. 2002). No TTS was observed in 
the bottlenose dolphin. Although the source level of pile driving from 
one hammer strike is expected to be much lower than the single watergun 
pulse cited here, animals exposed for a prolonged period to repeated 
hammer strikes could receive more noise exposure in terms of sound 
exposure level (SEL) than from the single watergun pulse (estimated at 
188 dB re 1 [mu]Pa\2\-s) in the aforementioned experiment (Finneran et 
al. 2002).
    Noises from dismantling of marine foundations by mechanical means 
include, but are not limited to, saw cutting, mechanical splitting, 
drilling and pulverizing. Saw cutting and drilling constitute non-pulse 
noise, whereas mechanical splitting and pulverizing constitute impulse 
noise. Although the characteristics of these noises are not well 
studied, noises from saw cutting and drilling are expected to be 
similar to vibratory pile driving, and noises from mechanical splitting 
and pulverizing are expected to be similar to impact pile driving, but 
at lower intensity, due to the similar mechanisms in sound generating 
but at a lower power outputs. CALTRANS states that drilling and saw 
cutting are anticipated to produce underwater sound pressure levels 
(SPLs) in excess of 120 dB RMS, but are not anticipated to exceed the 
180 dB re 1 [mu]Pa (RMS). The mechanical splitting and pulverizing of 
concrete with equipment such as a hammer hoe has the potential to 
generate high sound pressure levels in excess of 190 dB re 1 [mu]Pa 
(RMS) at 1 m.
    However, in order for marine mammals to experience TTS or PTS, the 
animals have to be close enough to be exposed to repeated high 
intensity pulsed noise levels for prolonged period of time. Based on 
the best scientific information available, the expected received sound 
levels are far below the threshold that could cause TTS or the onset of 
PTS.
    In addition, chronic exposure to excessive, though not high-
intensity, noise could cause masking at particular frequencies for 
marine mammals that utilize sound for vital biological functions. 
Masking can interfere with detection of acoustic signals such as 
communication calls, echolocation sounds, and environmental sounds 
important to marine mammals. Therefore, under certain circumstances, 
marine mammals whose acoustical sensors or environment are being 
severely masked could also be impaired from maximizing their 
performance fitness in survival and reproduction.
    Masking occurs at the frequency band which the animals utilize. 
Therefore, since noise generated from in-water pile driving during the 
SF-OBB construction activities is mostly concentrated at low frequency 
ranges, it may have less effect on high frequency echolocation sounds 
by harbor porpoises. However, lower frequency noises are more likely to 
affect detection of communication calls and other potentially important 
natural sounds such as surf and prey noise. It may also affect 
communication signals when they occur near the noise band and thus 
reduce the communication space of animals (e.g., Clark et al. 2009) and 
cause increased stress levels (e.g., Foote et al. 2004; Holt et al. 
2009).
    Masking can potentially impact the species at population, 
community, or even ecosystem levels, as well as individual levels. 
Prolonged masking affects both senders and receivers of the signals and 
could have long-term effects on marine mammal species and populations. 
Recent science suggests that low frequency ambient sound levels have 
increased by as much as 20 dB (more than 3 times in terms of SPL) in 
the world's oceans from pre-industrial periods, and most of these 
increases are from distant shipping (Hildebrand 2009). All 
anthropogenic noise sources, such as those from vessels traffic, pile 
driving, dredging, and dismantling existing bridge by mechanic means, 
contribute to the elevated ambient noise levels, thus intensifying 
potential for masking.
    Nevertheless, the sum of noise from the proposed SF-OBB 
construction activities is confined in an area of inland waters (San 
Francisco Bay) that is bounded by landmass, therefore, the noise 
generated is not expected to contribute to increased ocean ambient 
noise. Due to shallow water depth near the Oakland shore, dredging 
activities are mainly used to create a barge access channel to 
dismantle the existing bridge. Therefore, underwater sound propagation 
from dredging is expected to be poor due to the extreme shallowness of 
the area to be dredged.
    Finally, exposure of marine mammals to certain sounds could lead to 
behavioral disturbance (Richardson et al. 1995), such as: Changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities, 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping), avoidance of 
areas where noise sources are located, and/or flight responses (e.g., 
pinnipeds flushing into water from haulouts or rookeries).
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Southall et 
al. 2007), especially if the detected disturbances appear minor. The 
consequences of behavioral modification could be expected to be 
biologically significant if the change affects growth, survival, or 
reproduction. Some of these significant behavioral modifications 
include:
     Drastic change in diving/surfacing patterns (such as those 
thought to be causing beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The proposed project area is not believed to be a prime habitat for 
marine mammals, nor is it considered an area frequented by marine 
mammals. Therefore, behavioral disturbances that could result from 
anthropogenic noise associated with SF-OBB construction and dismantling 
activities are expected to affect only a limited number of marine 
mammals on an infrequent basis.
    Currently NMFS uses 160 dB re 1 [mu]Pa (RMS) at received level for 
impulse noises (such as impact pile driving, mechanic splitting and 
pulverizing) as the onset of marine mammal behavioral harassment, and 
120 dB re 1 [mu]Pa (RMS) for non-impulse noises (vibratory pile 
driving, saw cutting, drilling, and dredging).
    As far as airborne noise is concerned, based on airborne noise 
levels measured and on-site monitoring conducted during 2004 under a 
previous IHA, noise levels from the East Span project did not result in 
the harassment of harbor seals hauled out on Yerba Buena Island (YBI). 
Also, noise levels from the East Span project are not expected to

[[Page 23777]]

result in harassment of the sea lions hauled out at Pier 39 as airborne 
and waterborne sound pressure levels (SPLs) would attenuate to levels 
below where harassment would be expected by the time they reach that 
haul-out site, 5.7 km (3.5 miles) from the project site. Therefore, no 
pinniped hauled out would be affected as a result of the proposed pile-
driving. A detailed description of the acoustic measurements is 
provided in the 2004 CALTRANS marine mammal and acoustic monitoring 
report for the same activity (CALTRANS 2005).
    Short-term impacts to habitat may include minimal disturbance of 
the sediment where individual bridge piers are constructed. Long-term 
impacts to marine mammal habitat will be limited to the footprint of 
the piles and the obstruction they will create following installation. 
However, this impact is not considered significant as the marine 
mammals can easily swim around the piles of the new bridge, as they 
currently swim around the existing bridge piers.

Proposed Mitigation Measures

    In order to issue an incidental take authorization under section 
101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods 
of taking pursuant to such activity, and other means of effecting the 
least practicable adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses.
    For the proposed CALTRANS SF-OBB construction activities, CALTRANS 
worked with NMFS and proposed the following mitigation measures to 
minimize the potential impacts to marine mammals in the project 
vicinity. The primary purpose of these mitigation measures is to detect 
marine mammals within or about to enter designated exclusion zones 
corresponding to NMFS current injury thresholds and to initiate 
immediate shutdown or power down of the piling hammer, making it very 
unlikely potential injury or TTS to marine mammals would occur, and to 
reduce the intensity of Level B behavioral harassment.

Use of Noise Attenuation Devices

    To reduce impact on marine mammals, CALTRANS shall use a marine 
pile driving energy attenuator (i.e., air bubble curtain system), or 
other equally effective sound attenuation method (e.g., dewatered 
cofferdam) for all impact pile driving, with the exception of pile 
proofing.

Establishment of Exclusion and Level B Harassment Zones

    Before the commencement of in-water construction activities, which 
include impact pile driving, vibratory pile driving, and mechanical 
dismantling of existing bridge, CALTRANS shall establish ``exclusion 
zones'' where received underwater sound pressure levels (SPLs) are 
higher than 180 dB (rms) and 190 dB (rms) re 1 [mu]Pa for cetaceans and 
pinnipeds, respectively, and ``Level B behavioral harassment zones'' 
where received underwater sound pressure levels (SPLs) are higher than 
160 dB (rms) and 120 dB (rms) re 1 [mu]Pa for impulse noise sources 
(impact pile driving) and non-impulses noise sources (vibratory pile 
driving and mechanic dismantling), respectively. Before the sizes of 
actual zones are determined based on hydroacoustic measurements, 
CALTRANS shall establish these zones based on prior measurements 
conducted during SF-OBB constructions, as described in Table 1 of this 
document.

                      Table 1--Temporary Exclusion and Level B Harassment Zones for Various Pile Driving and Dismantling Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
      Pile driving/dismantling                               Distance to  120 dB re   Distance to  160 dB    Distance to  180 dB    Distance to  190 dB
             activities                   Pile size (m)        1 [mu]Pa (rms) (m)    re 1 [mu]Pa (rms) (m)  re 1 [mu]Pa (rms) (m)  re 1 [mu]Pa (rms) (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Driving..................  24....................  2,000.................  NA...................  NA...................  NA
                                     36....................  2,000.................  NA...................  NA...................  NA
                                     Sheet pile............  2,000.................  NA...................  NA...................  NA
Attenuated Impact Driving..........  24....................  NA....................  1,000................  235..................  95
 
36.................................  NA....................  1,000.................  235..................  95...................
Unattenuated Proofing..............  24....................  NA....................  1,000................  235..................  95
 
36.................................  NA....................  1,000.................  235..................  95...................
Unattenuated Impact Driving........  H-pile................  NA....................  1,000................  235..................  95
Dismantling........................  ......................  2,000.................  NA...................  100..................  100
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Once the underwater acoustic measurements are conducted during 
initial test pile driving, CALTRANS shall adjust the size of the 
exclusion zones and Level B behavioral harassment zones, and monitor 
these zones accordingly.
    NMFS-approved marine mammal observers (MMOs) shall conduct initial 
survey of the exclusion zones to ensure that no marine mammals are seen 
within the zones before impact pile driving of a pile segment begins. 
If marine mammals are found within the exclusion zone, impact pile 
driving of the segment would be delayed until they move out of the 
area. If a marine mammal is seen above water and then dives below, the 
contractor would wait 15 minutes for pinnipeds and harbor porpoise and 
30 minutes for gray whales. If no marine mammals are seen by the 
observer in that time it can be assumed that the animal has moved 
beyond the exclusion zone. This 15-minute criterion is based on 
scientific evidence that harbor seals in San Francisco Bay dive for a 
mean time of 0.50 minutes to 3.33 minutes (Harvey and Torok, 1994), and 
the mean diving duration for harbor porpoises ranges from 44 to 103 
seconds (Westgate et al., 1995).
    Once the pile driving of a segment begins it cannot be stopped 
until that segment has reached its predetermined depth due to the 
nature of the sediments underlying the Bay. If pile driving stops and 
then resumes, it would potentially have to occur for a longer time and 
at increased energy levels. In sum, this would simply amplify impacts 
to marine mammals, as they would endure potentially higher SPLs for 
longer periods of time. Pile segment lengths

[[Page 23778]]

and wall thickness have been specially designed so that when work is 
stopped between segments (but not during a single segment), the pile 
tip is never resting in highly resistant sediment layers. Therefore, 
because of this operational situation, if seals, sea lions, or harbor 
porpoises enter the safety zone after pile driving of a segment has 
begun, pile driving will continue and marine mammal observers will 
monitor and record marine mammal numbers and behavior. However, if pile 
driving of a segment ceases for 30 minutes or more and a marine mammal 
is sighted within the designated exclusion zone prior to commencement 
of pile driving, the observer(s) must notify the Resident Engineer (or 
other authorized individual) immediately and continue to monitor the 
exclusion zone. Operations may not resume until the marine mammal has 
exited the exclusion zone.

Soft Start

    Although marine mammals will be protected from Level A harassment 
(i.e., injury) through marine mammal observers monitoring a 190-dB 
exclusion zone for pinnipeds and 180-dB exclusion zone for cetaceans, 
mitigation may not be 100 percent effective at all times in locating 
marine mammals. Therefore, in order to provide additional protection to 
marine mammals near the project area by allowing marine mammals to 
vacate the area prior to receiving a potential injury, CALTRANS and its 
contractor will also ``soft start'' the hammer prior to operating at 
full capacity. This should expose fewer animals to loud sounds both 
underwater and above water. This would also ensure that, although not 
expected, any pinnipeds and cetaceans that are missed during the 
initial exclusion zone monitoring will not be injured.

Power Down and Shut-down

    Although power down and shut-down measures will not be required for 
pile driving and removal activities for reasons explained above, these 
measures are required for mechanical dismantling of the existing 
bridge. The contractor performing mechanical dismantling work will stop 
in-water noise generating machinery when marine mammals are sighted 
within the designated exclusion zones.

Mitigation Conclusions

    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and considered a range of other measures in the context of 
ensuring that NMFS prescribes the means of effecting the least 
practicable impact on the affected marine mammal species and stocks and 
their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
     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.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of noises generated from ice overflight surveys, or other 
activities expected to result in the take of marine mammals (this goal 
may contribute to 1, above, or to reducing harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of noises generated from ice overflight surveys, or 
other activities expected to result in the take of marine mammals (this 
goal may contribute to 1, above, or to reducing harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of noises generated from ice overflight surveys, or other 
activities expected to result in the take of marine mammals (this goal 
may contribute to a, above, or to reducing the severity of harassment 
takes only).
    5. Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    6. For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of the applicant's proposed measures NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means of effecting the least practicable impact on marine 
mammals species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting Measures

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking''. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the proposed action area.
    Monitoring measures prescribed by NMFS should accomplish one or 
more of the following general goals:
    1. An increase in the probability of detecting marine mammals, both 
within the mitigation zone (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    2. An increase in our understanding of how many marine mammals are 
likely to be exposed to levels of noises generated from ice overflight 
surveys that we associate with specific adverse effects, such as 
behavioral harassment, TTS, or PTS;
    3. An increase in our understanding of how marine mammals respond 
to stimuli expected to result in take and how anticipated adverse 
effects on individuals (in different ways and to varying degrees) may 
impact the population, species, or stock (specifically through effects 
on annual rates of recruitment or survival) through any of the 
following methods:
    [ssquf] Behavioral observations in the presence of stimuli compared 
to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);
    [ssquf] Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict received level, distance from source, and other 
pertinent information);

[[Page 23779]]

    [ssquf] Distribution and/or abundance comparisons in times or areas 
with concentrated stimuli versus times or areas without stimuli;
    4. An increased knowledge of the affected species; and
    5. An increase in our understanding of the effectiveness of certain 
mitigation and monitoring measures.

Proposed Monitoring Measures

(1) Visual Monitoring
    Besides using monitoring for implementing mitigation (ensuring 
exclusion zones are clear of marine mammals before pile driving begins 
and power down and shut-down measures for mechanical bridge 
dismantling), marine mammal monitoring will also be conducted to assess 
potential impacts from CALTRANS construction activities. CALTRANS will 
implement onsite marine mammal monitoring for 100% of all unattenuated 
impact pile driving of H-piles for 180- and 190-dB re 1 [micro]Pa 
exclusion zones and 160-dB re 1 [micro]Pa Level B harassment zone, 
attenuated impact pile driving (except pile proofing) and mechanical 
dismantling for 180- and 190-dB re 1 [micro]Pa exclusion zones. 
CALTRANS will also monitor 20% of the attenuated impact pile driving 
for the 160-dB re 1 [micro]Pa Level B harassment zone, and 20% of 
vibratory pile driving and mechanic dismantling for the 120-dB re 1 
[micro]Pa Level B harassment zone.
    Monitoring of the pinniped and cetacean exclusion zones shall be 
conducted by a minimum of three qualified NMFS-approved MMOs. 
Observations will be made using high-quality binoculars (e.g., Zeiss, 
10 x 42 power). MMOs will be equipped with radios or cell phones for 
maintaining contact with other observers and CALTRANS engineers, and 
range finders to determine distance to marine mammals, boats, buoys, 
and construction equipment.
    Data on all observations will be recorded and will include the 
following information:
    (1) Location of sighting;
    (2) Species;
    (3) Number of individuals;
    (4) Number of calves present;
    (5) Duration of sighting;
    (6) Behavior of marine animals sighted;
    (7) Direction of travel; and
    (8) When in relation to construction activities did the sighting 
occur (e.g., before, ``soft-start'', during, or after the pile driving 
or removal).
    The reactions of marine mammals will be recorded based on the 
following classifications that are consistent with the Richmond Bridge 
Harbor Seal survey methodology (for information on the Richmond Bridge 
authorization, see 68 FR 66076, November 25, 2003): (1) No response, 
(2) head alert (looks toward the source of disturbance), (3) approach 
water (but not leave), and (4) flush (leaves haul-out site). The number 
of marine mammals under each disturbance reaction will be recorded, as 
well as the time when seals re-haul after a flush.
(2) Hydroacoustic Monitoring
    The purpose of the underwater sound monitoring during dismantling 
of concrete foundations via mechanical means is to establish the 
exclusion zones of 180 dB re 1 [micro]Pa (rms) for cetaceans and 190 dB 
re 1 [micro]Pa (rms) for pinnipeds. Monitoring will occur during the 
initial use of concrete dismantling equipment with the potential to 
generate sound pressure levels in excess of 180 dB re 1 [micro]Pa 
(rms). Monitoring will likely be conducted from construction barges 
and/or boats. Measurements will be taken at various distances as needed 
to determine the distance to the 180 and 190 dB re 1 [micro]Pa (rms) 
contours.
    The purpose of underwater sound monitoring during impact pile 
driving will be to verify sound level estimates and confirm that sound 
levels do not equal or exceed 180 dB re 1 [micro]Pa (rms).

Proposed Reporting Measure

    CALTRANS will notify NMFS prior to the initiation of the pile 
driving and dismantling activities for the removal of the existing east 
span. NMFS will be informed of the initial sound pressure level 
measurements for both pile driving and foundation dismantling 
activities, including the final exclusion zone and Level B harassment 
zone radii established for impact and vibratory pile driving and marine 
foundation dismantling activities.
    Monitoring reports will be posted on the SFOBB Project's biological 
mitigation Web site (www.biomitigation.org) on a weekly basis if in-
water construction activities are conducted. Marine mammal monitoring 
reports will include species and numbers of marine mammals observed, 
time and location of observation and behavior of the animal. In 
addition, the reports will include an estimate of the number and 
species of marine mammals that may have been harassed as a result of 
activities.
    In addition, CALTRANS will provide NMFS with a draft final report 
within 90 days after the expiration of the IHA. This report should 
detail the monitoring protocol, summarize the data recorded during 
monitoring, and estimate the number of marine mammals that may have 
been harassed due to pile driving. If no comments are received from 
NMFS within 30 days, the draft final report will constitute the final 
report. If comments are received, a final report must be submitted 
within 30 days after receipt of comments.
    In addition, NMFS would require CALTRANS to notify NMFS' Office of 
Protected Resources and NMFS' Stranding Network within 48 hours of 
sighting an injured or dead marine mammal in the vicinity of the 
construction site. CALTRANS shall provide NMFS with the species or 
description of the animal(s), the condition of the animal(s) (including 
carcass condition if the animal is dead), location, time of first 
discovery, observed behaviors (if alive), and photo or video (if 
available).
    In the event that an injured or dead marine mammal is found by 
CALTRANS that is not in the vicinity of the SF-OBB construction site, 
CALTRANS would report the same information as listed above as soon as 
operationally feasible to NMFS.

Marine Mammal Monitoring Report From Previous IHA

    The most recent marine mammal monitoring report describes the 
number of harbor seals and California sea lions that were observed 
within zones of influence (ZOIs) between January 8, 2014 and January 7, 
2015 that could result in behavioral harassment. Most of the 
observations of harbor seals within the behavioral zones occurred 
within the Coast Guard Cove or Clipper Cove. Monitoring of the 
vibratory and demolition activity was only required for 20% of the time 
when those activities occurred but there was often a mix of impact and 
vibratory driving; therefore, monitoring was conducted from 20-100% of 
the time for some construction projects. Table 7 of the 2014 monitoring 
report (CALTRANS 2015) summarizes all observations and estimates the 
total exposures of marine mammals if there was 100% monitoring for each 
construction or demolition project as requested by NMFS. The estimated 
number of exposures is 144 harbor seals which is above the limit of 50 
permitted under the Authorization. No sea lions, harbor porpoise or 
gray whales were observed.

Estimated Take by Incidental Harassment

    Marine mammal take estimates are based on marine mammal monitoring 
reports and marine mammal observations made during pile driving

[[Page 23780]]

activities associated with the SF-OBB construction work authorized 
under prior IHAs. Pacific harbor seals are the most commonly observed 
marine mammal (90% of observations during monitoring) near the east 
span of the San Francisco-Oakland Bay Bridge (SF-OBB). A harbor seal 
haul-out site is located on the south side of Yerba Buena Island (YBI) 
approximately 500 meters from the SF-OBB's closest pier, pier E2, and 
seals are often observed foraging in Coast Guard Cove (just east of the 
U.S. Coast Guard Station on YBI), and within Clipper Cove between YBI 
and Treasure Island. A third foraging site that is used less frequently 
is approximately 250-500 meters southeast of YBI over a small trench 
running west to east along the bottom of the San Francisco Bay (Bay). 
In addition, harbor seals are regularly observed moving north or south 
under the original SFOBB between Piers E2 and E3, but infrequently east 
of Pier E4.
    Harbor seal densities were calculated from 657 observations of 
harbor seals made during 210 days from 2000 to 2014 during monitoring 
for the East Span of the SFOBB. Two densities were calculated because 
of the higher density of seals observed foraging near YBI and Treasure 
Island. Foraging seals tended to remain in the area for several hours 
while transiting seals passing under the SFOBB were only observed 1-2 
times. Therefore, densities east of Pier E3-E8 are much lower than the 
density than west of Pier E3.
    The area of 2,000-meter threshold for the Level B behavioral 
harassment zone is 12.57 km\2\ (12,570,000 m\2\). Half of that area to 
the west of Piers E3-E8 (6.29 km\2\) would have a higher density due to 
the harbor seals that are frequently observed in the three foraging 
areas. The range of seals observed within the foraging areas is 0-8 
seals and the mean is 3.6 seals per day (combined for all three areas). 
The other half of the Level B harassment zone would have a lower 
density due to the infrequent observations of seals moving through the 
area. In addition the density of seals will vary with season therefore 
a density for the spring-summer season when seals spend more time 
onshore as they are pupping and molting and the fall/winter season. 
Table 2 shows estimated densities in the high and low density areas 
during the fall/winter and spring/summer seasons.

Table 2--Expected Harbor Seal Exposures for 2015 Based on the Area and Seasonal Density Estimates, and Number of
                                              Days of Pile Driving
----------------------------------------------------------------------------------------------------------------
                                                                   Days of pile     Harbor seal
           Density estimates                 Behavioral zone         driving *      density **       Exposures
----------------------------------------------------------------------------------------------------------------
Fall/Winter High Density..............  6.29 km\2\..............              64            0.77             311
Fall/Winter Low Density...............  6.29 km\2\..............              64             0.5              20
Spring/Summer High Density............  6.29 km\2\..............              64             0.3             121
Spring/Summer Low Density.............  6.29 km\2\..............              64            0.02               8
                                       -------------------------------------------------------------------------
    Total Exposures...................                                  460 seals
----------------------------------------------------------------------------------------------------------------
* It is assumed half of the pile driving days (64 days) will occur in each season.
** The area of the Behavioral Zone 12.59 km\2\ is divided in half for the high and low density areas for each
  season.

    This estimate for harbor seals is above the number of seals that 
have been permitted for take in previous IHAs that have been issued 
related to this project. However, the estimate presented here 
represents a more complete picture of the marine mammal density in the 
project area and the potential for exposure to project activities.
    California sea lions are based on CALTRANS observations over 15 
years of monitoring on the Bay Bridge, 2000 to 2014, including baseline 
monitoring in 2003 before bridge construction began. It should be noted 
that monitoring was not year round and there was little monitoring 
required during the period of mid-2010 to mid-2013 due to no pile 
driving. During 2013 and 2014, there was a large increase in pile 
driving to construct temporary falsework and for mechanical dismantling 
so the current estimates of animals do include recent monitoring. 
California sea lion numbers fluctuate from year to year. For example, 
in 2014 no sea lions were observed in the harassment zone, while in 
2004, 36 sea lions were recorded near the Bay Bridge construction areas 
during pile driving. The larger number of sea lions in 2004 was 
probably related to a run of herring that was near the Bay Bridge and 
sea lions were observed feeding on dense aggregations of herring in the 
area. Therefore, 50 sea lions is a conservative estimate.
    Harbor porpoises were observed near the tower of the new Bay Bridge 
in 2013 and 2014. Each of those was a single animal and far out of 
their normal range for the Bay. If 1 or 2 pods of porpoises were to 
enter the construction area, then there might be up to 6 takes (pod 
size of 2-3 porpoises). Based on this NMFS believes that an allowed 
take of up to 10 harbor porpoises is conservative, but reasonable.
    Gray whale take estimates were based on sighting reports collected 
by the Marine Mammal Center in Sausalito (the NMFS stranding facility 
for northern California). The Center collects whale sightings 
information from the general public, researchers, and the U.S. Coast 
Guard. For the gray whale, 5 permitted takes is likely to be a 
conservative, but reasonable, estimate as they have never been observed 
within any of the behavioral zones during monitoring. Additionally, 
there has only been one report of a gray whale swimming under the 
original East Span of the Bay Bridge a number of years ago.
    Based on these results, and accounting for a certain level of 
uncertainty regarding the next phase of construction, NMFS concludes 
that at maximum 460 harbor seals, 50 California sea lions, 10 harbor 
porpoises, and 5 gray whales could be exposed to noise levels that 
could cause Level B harassment as a result of the CALTRAN' SF-OBB 
construction activities. These numbers represent 1.5%, <0.01%, <0.01% 
and 0.10% of the California stock harbor seal, the U.S. stock 
California sea lion, the Eastern North Pacific stock gray whale, and 
the San Francisco-Russian River stock harbor porpoise, respectively 
(Table 3).

[[Page 23781]]



 Table 3--Estimates of the Possible Maximum Numbers of Marine Mammals Taken by Level B Harassment as a Result of
                              the Proposed CALTRANS' SF-OBB Construction Activities
----------------------------------------------------------------------------------------------------------------
                                                                                                      Percent
                  Species                                   Stocks                 Level B takes    population
                                                                                                     (percent)
----------------------------------------------------------------------------------------------------------------
                                                    Pinnipeds
----------------------------------------------------------------------------------------------------------------
Harbor seal................................  California.........................             460             1.5
California sea lion........................  U.S................................              50           <0.01
----------------------------------------------------------------------------------------------------------------
                                                    Cetaceans
----------------------------------------------------------------------------------------------------------------
Gray whale.................................  Eastern North Pacific..............               5           <0.01
Harbor porpoise............................  San Francisco-Russian River........              10            0.10
----------------------------------------------------------------------------------------------------------------

Analysis and Preliminary Determinations

Negligible Impact

    Negligible impact is ``an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes, alone, is not 
enough information on which to base an impact determination. In 
addition to considering estimates of the number of marine mammals that 
might be ``taken'', NMFS must consider other factors, such as the 
likely nature of any responses (their intensity, duration, etc.), the 
context of any responses (critical reproductive time or location, 
migration, etc.), as well as the number and nature of estimated Level A 
and Level B harassment takes, the number of estimated mortalities, 
effects on habitat, and the status of the species.
    To avoid repetition, the following discussion applies to the 
affected stocks of harbor seals, California sea lions, gray whales, and 
harbor porpoises, given that the best available information indicates 
that effects of the specified activity on individuals of those stocks 
will be similar, and there is no information about the population size, 
status, structure, or habitat use of the areas to warrant separate 
discussion.
    Pile driving activities associated with this project, as outlined 
previously, have the potential to disturb or displace marine mammals. 
Even when mitigation measures are employed, the specified activities 
may result in Level B harassment from underwater sounds generated from 
pile driving. Takes could occur if individuals of these species are 
present in the Level B harassment zone while pile driving is occurring.
    These low intensity, localized, and short-term noise exposures 
(i.e., 160 dB re 1 [mu]Pa (rms) from impulse sources and 120 dB re 1 
[mu]Pa (rms) from non-impulse sources), are expected to cause brief 
startle reactions or short-term behavioral modification by the animals. 
These brief reactions and behavioral changes are expected to disappear 
when the exposures cease. The maximum estimated 160 dB isopleths from 
impact pile driving is 500 m from the pile, and the estimated 120 dB 
maximum isopleths from vibratory pile driving is approximately 2,000 m 
from the pile. There is no pinniped haul-out area in the vicinity of 
the pile driving sites. There is no critical habitat or other 
biologically important area for marine mammals in the vicinity of the 
proposed SF-OBB construction area.
    The CALTRANS' specified activities have been described based on 
best estimates of the planned SF-OBB construction project within the 
proposed project area. Some of the noises that would be generated as a 
result of the proposed bridge construction and dismantling project, 
such as impact pile driving, are high intensity. However, the in-water 
pile driving for the piles would use small hammers and/or vibratory 
pile driving methods, coupled with noise attenuation mechanism such as 
air bubble curtains for impact pile driving. Therefore the resulting 
exclusion zones for potential TS are expected to be extremely small (< 
35 m) from the hammer. In addition, the source levels from vibratory 
pile driving are expected to be below the TS onset threshold. Given 
sufficient ``notice'' through use of soft start (for impact driving), 
marine mammals are expected to move away from a sound source that is 
annoying prior to its becoming potentially injurious. The high 
likelihood that marine mammal detection by trained observers under the 
environmental conditions described for the project area further enables 
the implementation of shutdowns to avoid injury, serious injury, or 
mortality. Therefore, NMFS does not expect that any animals would 
receive Level A (including injury) harassment or Level B harassment in 
the form of TTS from being exposed to in-water pile driving associated 
with SF-OBB construction project.
    The project is not expected to have significant adverse effects on 
affected marine mammals' habitat and would not significantly modify 
existing marine mammal habitat. The activities may cause some fish to 
leave the area of disturbance, thus temporarily impacting marine 
mammals' foraging opportunities in a limited portion of the foraging 
range; but, because of the short duration of the activities and the 
relatively small area of the habitat that may be affected, the impacts 
to marine mammal habitat are not expected to cause significant or long-
term negative consequences.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff, 
2006; HDR, 2012; Lerma, 2014). Most likely, individuals will simply 
move away from the sound source and be temporarily displaced from the 
areas of pile driving, although even this reaction has been observed 
primarily only in association with impact pile driving. In response to 
vibratory driving, several species of pinnipeds (which may become 
somewhat habituated to human activity in industrial or urban waterways) 
have been observed to orient towards and sometimes move towards the 
sound. The pile driving activities analyzed here are similar to, or 
less impactful than, numerous construction activities conducted in 
other similar locations, which have taken place with no reported 
injuries or mortality to

[[Page 23782]]

marine mammals, and no known long-term adverse consequences from 
behavioral harassment.
    Repeated exposures of individuals to levels of sound that may cause 
Level B harassment are unlikely to result in hearing impairment or to 
significantly disrupt foraging behavior. Thus, even repeated Level B 
harassment of some small subset of the affected stocks is unlikely to 
result in any significant realized decrease in fitness for the affected 
individuals, and thus would not result in any adverse impact to the 
stocks as a whole. Level B harassment will be reduced to the level of 
least practicable impact through use of mitigation measures described 
herein and, if sound produced by project activities is sufficiently 
disturbing, animals are likely to simply avoid the project area while 
the activity is occurring.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of injury, serious injury, or 
mortality may reasonably be considered discountable; (2) the 
anticipated incidents of Level B harassment are relatively small and 
consist of, at worst, temporary modifications in behavior; (3) the 
absence of any significant habitat within the project area, including 
rookeries, significant haul-outs, or known areas or features of special 
significance for foraging or reproduction; (4) the presumed efficacy of 
the proposed mitigation measures in reducing the effects of the 
specified activity. In combination, we believe that these factors, as 
well as the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activity will 
have only short-term effects on individuals and is not expected to 
impact annual rates of recruitment or survival.
    Therefore, based on the analysis contained herein of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the proposed 
monitoring and mitigation measures, NMFS preliminarily finds that the 
total marine mammal take from the CALTRAN'S SF-OBB construction project 
will have a negligible impact on the affected marine mammal species or 
stocks.

Small Numbers

    Table 3 demonstrates the numbers of animals that could be exposed 
to receive noise levels that could cause Level B behavioral harassment 
for the proposed work associated with the CALTRANS SF-OBB construction 
project. These estimates represent 1.5% of the California stock of 
harbor seal population (estimated at 30,968; Carretta et al. 2014), 
<0.01% of the U.S. stock of California sea lion population (estimated 
at 296,750; Carretta et al. 2014), <0.01% of the Eastern North Pacific 
stock of gray whale population (estimated at 20,990; Carretta et al. 
2014), and 0.10% of the San Francisco-Russian River stock of harbor 
porpoise population (estimated at 9,886; Carretta et al. 2014). These 
numbers constitute small percentages of the marine mammal stocks that 
may be taken.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the mitigation and monitoring 
measures, which are expected to reduce the numbers of marine mammals 
potentially affected by the proposed action, NMFS preliminarily finds 
that small numbers of marine mammals will be taken relative to the 
populations of the affected species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

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

Proposed Incidental Harassment Authorization

    This section contains a draft of the IHA itself. The wording 
contained in this section is proposed for inclusion in the IHA (if 
issued).
    (1) This Authorization is valid from May 18, 2015, through May 17, 
2016.
    (2) This Authorization is valid only for activities involving the 
construction and dismantling of the East Span of SF-OBB, California.
    (3) Species Impacted and Level of Takes
    (a) The species authorized for takings by incidental Level B 
harassment are the California sea lion (Zalophus californianus), 
Pacific harbor seal (Phoca vitulina richardsi), harbor porpoise 
(Phocoena phocoena), and gray whale (Eschrichtius robustus).
    (b) The taking of any marine mammal in a manner prohibited under 
this Authorization must be reported within 24 hours of the taking to 
the Director, West Coast Regional Office, National Marine Fisheries 
Service, Telephone (562) 980-4000 and the Director, Office of Protected 
Resources, National Marine Fisheries Service, Telephone (301) 427-8400.
    (4) The holder of this Authorization is required to cooperate with 
the National Marine Fisheries Service and any other Federal, state or 
local agencies monitoring the impacts of the activity on marine 
mammals. The holder must notify Monica DeAngelis of the West Coast 
Regional Office (phone: (562) 980-3232) at least 24 hours prior to 
starting activities.
(5) Prohibitions
    (a) The taking, by incidental Level B harassment only, is limited 
to the species listed under condition 3(a) above and by the numbers 
listed (see Table 3 of this Federal Register notice). The taking by 
Level A harassment, injury, serious injury, or death of these species 
or the taking by harassment, injury, serious injury, or death of any 
other species of marine mammal is prohibited and may result in the 
modification, suspension, or revocation of this Authorization.
(6) Mitigation Requirements
    (a) Use of Noise Attenuation Devices
    Pile driving energy attenuator (such as air bubble curtain system 
or dewatered cofferdam) shall be used for all impact pile driving of 
pipe piles, with the exception of pile proofing and H-piles.
    (b) Establishment and Monitoring of Exclusion and Level B 
Harassment Zones
    (i) For all in-water pile driving and mechanical dismantling 
activities, CALTRANS shall establish exclusion zones where received 
underwater sound pressure levels (SPLs) are higher than 180 dB (rms) 
and 190 dB (rms) re 1 [micro]Pa for cetaceans and pinnipeds, 
respectively, and Level B harassment zones where received underwater 
sound pressure levels (SPLs) are higher than 160 dB (rms) and 120 dB 
(rms) re 1 [micro]Pa for impulse noise sources (impact pile driving) 
and non-impulses noise sources (vibratory pile driving and mechanic 
dismantling), respectively.
    (ii) The sizes of the initial exclusion and Level B harassment 
zones for different types of activities are provided [See Table 1 in 
this Federal Register notice]. Once hydroacoustic measurements of pile 
driving and mechanical dismantling activities have been conducted, 
CALTRANS shall revise the sizes of the zones based on actual 
measurements.
    (iii) NMFS-approved MMOs shall conduct initial survey of the 
exclusion zone to ensure that no marine mammals are seen within the 
zone for 30 minutes before impact pile driving and mechanical 
dismantling of bridge foundation. If marine mammals are observed within 
the exclusion zones, impact pile driving and/or mechanical dismantling 
activity of the segment shall be delayed until they move out of the 
area. If a marine mammal is seen above

[[Page 23783]]

water and then dives below, CALTRANS must delay activities 15 minutes 
for pinnipeds and harbor porpoise and 30 minutes for gray whale. If no 
marine mammals are seen by the observer in that time it may be assumed 
that the animal has moved beyond the relevant exclusion zone.
    (iv) If the time between pile-segment driving is less than 30 
minutes, a new 30-minute survey is unnecessary provided the MMOs 
continue observations during the interruption. If pile driving ceases 
for 30 minutes or more and a marine mammal is sighted within the 
designated exclusion zone(s) prior to the commencement of pile-driving, 
the observer(s) must notify the Resident Engineer (or other authorized 
individual) immediately (see condition 5(e)).
    (v) For pile driving activities, if a marine mammal is sighted 
within the exclusion zone after pile-driving has begun, CALTRANS must 
have a qualified MMO record the species, numbers and behaviors of the 
animal(s) and report to Monica DeAngelis at the West Coast Regional 
Office, National Marine Fisheries Service, (phone: (562) 980-3232) 
within 24 hours of the incident.
    (c) Soft Start
    CALTRANS and its contractor shall implement soft start, i.e., 
starting the pile driving hammer at the lowest power setting and 
gradually ramp up to full power, prior to operating pile driving 
hammers at full capacity for both impact and vibratory pile driving.
    (d) Power Down and Shut-down
    (i) For mechanical dismantling of bridge foundation, construction 
activities that generate underwater noise must be powered down or 
shutdown if a marine mammal is observed within the established 180 dB 
or 190 dB re 1 [mu]Pa exclusion zones for cetaceans or pinnipeds, 
respectively.
(7) Monitoring Requirements
    (a) General.
    (i) The holder of this Authorization must designate a minimum of 
three biologically-trained, on-site MMOs approved in advance by the 
National Marine Fisheries Service's West Coast Regional Office, to 
monitor the area for marine mammals before, during, and after pile 
driving activities; and before, during, and after mechanical 
dismantling of marine foundations.
    (ii) The National Marine Fisheries Service must be informed 
immediately of any proposed changes or deletions to any portions of the 
monitoring plan.
    (b) Visual Monitoring
    (i) CALTRANS shall implement onsite marine mammal monitoring for 
100% of all unattenuated impact pile driving of H-piles for 180- and 
190-dB re 1 [mu]Pa exclusion zones and 160-dB re 1 [mu]Pa Level B 
harassment zone, attenuated impact pile driving of pipe piles (except 
pile proofing) and mechanical dismantling for 180- and 190-dB re 1 
[mu]Pa exclusion zones.
    (ii) CALTRANS shall also monitor 20% of the attenuated impact pile 
driving for the 160-dB re 1 [mu]Pa Level B harassment zone, and 20% of 
vibratory pile driving and mechanic dismantling for the 120 dB re 1 
[mu]Pa Level B harassment zone.
    (iii) Marine mammal monitoring shall begin at least 30 minutes 
prior to the start of the activities, continue for the duration of 
construction activities, and until 30 minutes after the construction 
activities.
    (iv) Observations shall be made using high-quality binoculars 
(e.g., Zeiss, 10 x 42 power). MMOs shall be equipped with radios or 
cell phones for maintaining contact with other observers and CALTRANS 
engineers, and range finders to determine distance to marine mammals, 
boats, buoys, and construction equipment.
    (v) Data on all observations must be recorded and include the 
following information:
     Location of sighting;
     Species;
     Number of individuals;
     Number of calves present;
     Duration of sighting;
     Behavior of marine animals sighted;
     Direction of travel;
     When and where in relation to construction activities did 
the sighting occur (e.g., before, ``soft-start'', during, or after the 
pile driving or removal; distance from sound source; in or out of 
exclusion zone or Level B zone); and
     Other human activities in the area.
    (c) Hydroacoustic Measurements
    At the beginning of pile driving and mechanical dismantling of 
bridge foundation, CALTRANS shall conduct hydroacoustic measurements to 
verify the exclusion and Level B harassment zones.
(7) Reporting Requirements
    (a) CALTRANS shall notify NMFS of the initial sound pressure level 
measurements for both pile driving and foundation dismantling 
activities, including the final exclusion zone and Level B harassment 
zone radii established for impact and vibratory pile driving and marine 
foundation dismantling activities, within 72 hours after completion of 
the measurements.
    (b) Monitoring reports shall be posted on the SFOBB Project's 
biological mitigation Web site (www.biomitigation.org) on a weekly 
basis if in-water construction activities are conducted. Marine mammal 
monitoring reports shall include species and numbers of marine mammals 
observed, time and location of observation and behavior of the animal. 
In addition, the reports shall include an estimate of the number and 
species of marine mammals that may have been harassed as a result of 
activities.
    (c) CALTRANS shall provide NMFS with a draft final report within 90 
days after the expiration of the IHA. This report shall detail the 
monitoring protocol, summarize the data recorded during monitoring, and 
estimate the number of marine mammals that may have been harassed due 
to pile driving and mechanical dismantling of bridge foundations. If no 
comments are received from NMFS within 30 days, the draft final report 
would be considered the final report. If comments are received, a final 
report must be submitted within 30 days after receipt of comments.
(8) Notification of Injured or Dead Marine Mammals
    (a) In the unanticipated event that CALTRANS' construction 
activities clearly cause the take of a marine mammal in a manner 
prohibited by this Authorization, such as an injury (Level A 
harassment), serious injury or mortality (e.g., ship-strike, gear 
interaction, and/or entanglement), CALTRANS shall immediately cease 
construction operations and immediately report the incident to the 
Chief, Permits and Conservation Division, Office of Protected 
Resources, NMFS, at 301-427-8401 and/or by email to 
[email protected] and [email protected] and NMFS West Coast 
Regional Stranding Coordinator ([email protected]). The report 
must include the following information:
    (i) Time, date, and location (latitude/longitude) of the incident;
    (ii) Type of activity involved;
    (iii) Description of the incident;
    (iv) Status of all sound source use in the 24 hours preceding the 
incident;
    (v) Water depth;
    (vi) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (vii) Description of marine mammal observations in the 24 hours 
preceding preceding the incident;
    (viii) Species identification or description of the animal(s) 
involved;
    (ix) The fate of the animal(s); and
    (x) Photographs or video footage of the animal (if equipment is 
available).

[[Page 23784]]

    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with CALTRANS to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. CALTRANS may not resume 
their activities until notified by NMFS via letter, email, or 
telephone.
    (b) In the event that CALTRANS discovers an injured or dead marine 
mammal, and the lead MMO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
CALTRANS will immediately report the incident to the Chief, Permits and 
Conservation Division, Office of Protected Resources, NMFS, at 301-427-
8401, and/or by email to [email protected] and 
[email protected] and NMFS West Coast Regional Stranding Coordinator 
([email protected]). The report must include the same 
information identified in Condition 8(a) above. Activities may continue 
while NMFS reviews the circumstances of the incident. NMFS will work 
with CALTRANS to determine whether modifications in the activities are 
appropriate.
    (c) In the event that CALTRANS discovers an injured or dead marine 
mammal, and the lead MMO determines that the injury or death is not 
associated with or related to the activities authorized in Condition 3 
of this Authorization (e.g., previously wounded animal, carcass with 
moderate to advanced decomposition, or scavenger damage), CALTRANS 
shall report the incident to the Chief, Permits and Conservation 
Division, Office of Protected Resources, NMFS, at 301-427-8401, and/or 
by email to [email protected] and [email protected] and 
NMFS West Coast Regional Stranding Coordinator 
([email protected]) within 24 hours of the discovery. CALTRANS 
shall provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS. CALTRANS can 
continue its operations under such a case.
    (9) A copy of this Authorization must be in the possession of all 
contractors and marine mammal monitors operating under the authority of 
this Incidental Harassment Authorization.

National Environmental Policy Act (NEPA)

    NMFS prepared an Environmental Assessment (EA) for the take of 
marine mammals incidental to construction of the East Span of the SF-
OBB and made a Finding of No Significant Impact (FONSI) on November 4, 
2003. Due to the modification of part of the construction project and 
the mitigation measures, NMFS reviewed additional information from 
CALTRANS regarding empirical measurements of pile driving noises for 
the smaller temporary piles without an air bubble curtain system and 
the use of vibratory pile driving. NMFS prepared a Supplemental 
Environmental Assessment (SEA) and analyzed the potential impacts to 
marine mammals that would result from the modification of the action. A 
Finding of No Significant Impact (FONSI) was signed on August 5, 2009. 
The proposed activity and expected impacts remain within what was 
previously analyzed in the EA and SEA. Therefore, no additional NEPA 
analysis is warranted. A copy of the SEA and FONSI is available upon 
request (see ADDRESSES).

Endangered Species Act (ESA)

    NMFS has determined that issuance of the IHA will have no effect on 
ESA-listed marine mammals, as none are known to occur in the action 
area.

Proposed Authorization

    NMFS proposes to issue an IHA to CALTRANS for the potential 
harassment of small numbers of harbor seals, California sea lions, 
harbor porpoises, and gray whales incidental to construction of a 
replacement bridge for the East Span of the San Francisco-Oakland Bay 
Bridge in California, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. NMFS has 
preliminarily determined that the proposed activity would result in the 
harassment of only small numbers of harbor seals, California sea lions, 
harbor porpoises, and possibly gray whales and will have no more than a 
negligible impact on these marine mammal stocks.

    Dated: April 23, 2015.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2015-09915 Filed 4-28-15; 8:45 am]
 BILLING CODE 3510-22-P