Marine Mammals; Incidental Take During Specified Activities; Proposed Incidental Harassment Authorization, 18077-18083 [2018-08559]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 83, Number 80 (Wednesday, April 25, 2018)]
[Notices]
[Pages 18077-18083]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-08559]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

[FWS-R8-ES-2018-N012; FXES111608MSSO0]


Marine Mammals; Incidental Take During Specified Activities; 
Proposed Incidental Harassment Authorization

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of application and proposed incidental 
harassment authorization; request for comments.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), have 
received an application from the United States Coast Guard (USCG) for 
authorization to take small numbers of marine mammals by harassment 
incidental to the replacement of pier piles and the potable water line 
at USCG Station Monterey in Monterey County, California. In accordance 
with provisions of the Marine Mammal Protection Act of 1972, as 
amended, we request comments on our proposed authorization for the 
applicant to incidentally take, by harassment, small numbers of 
southern sea otters during a 1-year authorization period beginning on 
or before June 15, 2018. We anticipate no take by injury or death and 
include none in this proposed authorization, which would be for take by 
harassment only.

DATES: Comments and information must be received by May 25, 2018.

ADDRESSES: Comment submission: You may submit comments by any one of 
the following methods:
    1. U.S. mail or hand-delivery: Stephen P. Henry, Field Supervisor, 
Ventura Fish and Wildlife Office, 2493 Portola Road, Suite B, Ventura, 
CA 93003.
    2. Fax: 805-644-3958, attention to Stephen P. Henry, Field 
Supervisor.
    3. Electronic mail (email): [email protected]. Please 
include your name and U.S. mail address in your message.
    Document availability: Electronic copies of the incidental 
harassment authorization request, the Marine Mammal Monitoring Plan, 
the draft supplemental environmental assessment, and other supporting 
materials, such as the list of references used in this notice, may be 
obtained by writing to the address specified above, telephoning the 
contact listed in FOR FURTHER INFORMATION CONTACT, or visiting the 
internet at https://www.fws.gov/ventura/endangered/species/info/sso.html. Documents cited in this notice may also be viewed, by 
appointment, during regular business hours, at the aforementioned U.S. 
mail address.

FOR FURTHER INFORMATION CONTACT: Lilian Carswell, Southern Sea Otter 
Recovery & Marine Conservation Coordinator, (805) 677-3325, or by email 
at [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the Marine Mammal Protection Act 
of 1972, as amended (MMPA; 16 U.S.C. 1371 (a)(5)(A) and (D)), authorize 
the Secretary of the Interior 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, provided that we make 
certain findings and either issue regulations or, if the taking is 
limited to harassment, provide a notice of a proposed authorization to 
the public for review and comment.
    We may grant authorization to incidentally take small numbers of 
marine mammals if we find that the taking will have a negligible impact 
on the species or stock(s) and will not have an unmitigable adverse 
impact on the availability of the species or stock(s) for subsistence 
uses. As part of the authorization process, we prescribe permissible 
methods of taking and other means of effecting the least practicable 
impact on the species or stock and its habitat, and requirements 
pertaining to the monitoring and reporting of such takings.
    The term ``take,'' as defined by the MMPA, means to harass, hunt, 
capture, or kill, or to attempt to harass, hunt, capture, or kill, any 
marine mammal. Harassment, as defined by the MMPA, means ``any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild [the MMPA calls this 
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 [the MMPA calls 
this Level B harassment].''
    The statutory terms ``negligible impact,'' ``small numbers,'' and 
``unmitigable adverse impact'' are defined in the Code of Federal 
Regulations at 50 CFR 18.27, the Service's regulations governing take 
of small numbers of marine mammals incidental to specified activities. 
``Negligible impact'' is defined 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.'' The term ``small 
numbers'' is also defined in the regulations as ``a portion of a marine 
mammal species or stock whose taking would have a negligible impact on 
that species or stock.'' However, we do not rely on the definition of 
``small numbers'' here, as it conflates the terms ``small numbers'' and 
``negligible impact,'' which we recognize as two separate and distinct 
requirements. See NRDC v. Evans, 232 F. Supp. 2d 1003, 1025 (N.D. 
Cal.). Instead, in our small numbers determination, we evaluate whether 
the number of marine mammals likely to be taken is small relative to 
the size of the overall population.
    ``Unmitigable adverse impact'' is determined in reference to 
impacts on the availability of the species or stock(s) for subsistence 
uses. It is defined as ``an impact resulting from the specified 
activity (1) that is likely to reduce the availability of the species 
to a level insufficient for a harvest to meet subsistence needs by (i) 
causing the marine mammals to abandon or avoid hunting areas, (ii) 
directly displacing subsistence users, or (iii) placing physical 
barriers between the marine mammals and the subsistence hunters; and 
(2) that cannot be sufficiently mitigated by other measures to increase 
the availability of marine mammals to allow subsistence needs to be 
met.'' Because this subsistence provision applies only to the taking of 
any marine mammal by any Indian, Aleut, or Eskimo who resides in Alaska 
and who dwells on the coast of the North Pacific

[[Page 18078]]

Ocean or the Arctic Ocean (16 U.S.C. 1371(b)), it is relevant to 
northern sea otters (Enhydra lutris kenyoni) in Alaska but not to 
southern sea otters.

Summary of Request

    In February 2017, we received a request from the USCG (Applicant) 
for MMPA authorization to take by harassment southern sea otters 
(Enhydra lutris nereis) incidental to the replacement of pier piles and 
the potable water line at USCG Station Monterey in Monterey Harbor, 
California. We received a revised request on July 11, 2017. The 
Applicant requested and received incidental harassment authorization 
(IHA) for the same project in 2014 but was not able to initiate work at 
that time. Other than revised dates, the project is essentially 
unchanged. The Applicant proposes to remove and replace 17 timber piles 
that structurally support the patrol boat pier (Pier), replace the 
existing potable water line, and improve associated structures to 
maintain the structural integrity of the Pier and potable water line. 
Pile-driving activities would be limited to the period from June 15 to 
October 15. Other construction activities associated with the project 
are not expected to affect sea otters and may occur at any time. A 
detailed description of the proposed action is contained in the revised 
incidental harassment authorization request submitted to us by the USCG 
(Amec Foster Wheeler 2017). The proposed action is expected to result 
in take, by Level B Harassment only, of sea otters.

Description of the Activity

    The proposed action would involve removing the existing timber 
deck, timber stringers, steel pile caps, steel support beams, and 
hardware to access the 17 timber piles that need to be replaced. The 
timber piles, which are approximately 16 to 18 inches (in) (41 to 46 
centimeters (cm)) in diameter and covered with polyvinyl chloride (PVC) 
wraps, would be removed by means of a vibratory extractor. Each timber 
pile would be replaced with a steel pipe pile 14 in (36 cm) in diameter 
installed using a vibratory hammer. Each steel pipe pile would be 
positioned and installed in the footprint of the extracted timber pile. 
Pile proofing would be conducted via impact hammer. If, due to 
substrate or breakwater armor, a pipe pile is unable to be driven to 30 
feet (ft) (9 meters (m)) below the mud line using a vibratory hammer, 
then an impact hammer would be used. If the pile cannot be driven with 
an impact hammer, the pipe pile would be posted onto the armor stone. 
The steel pipe piles would not be filled with concrete. Materials and 
hardware removed to allow access to conduct pile work would be replaced 
with in-kind materials.
    Sound attenuation measures, including implementation of a bubble 
curtain and cushion pads during impact pile driving, would be used. 
Pile extraction and driving equipment would be located on a barge. No 
staging would be located on the existing wharf. To facilitate 
supplementary monitoring of effects on sea otters in or near the 
project area, the Service has requested, and the USCG has agreed to 
provide, 24-hour advance notice of pile-driving activity and a record 
of the start and stop times of all pile-driving activities once they 
are completed.

a. Timing of Activity

    Project construction would require a maximum of 60 work days. Pile 
extraction and driving activities would occur between June 15 and 
October 15. Pile-driving activities are expected to require 3 to 8 days 
of the total construction time, with an average of 2 to 3 piles removed 
and installed per day. Driving time would be approximately 20 minutes 
per pile for vibratory or impact pile driving. Vibratory extraction of 
the existing piles would take approximately 10 minutes per pile. In 
total, approximately 510 minutes (8.5 hours) of underwater and airborne 
noise are anticipated to be generated by pile driving/extraction 
activities over the course of the project.

b. Geographic Location of Activity

    The USCG Station Monterey is located at 100 Lighthouse Avenue, in 
the city and county of Monterey, California. The Pier is on the eastern 
portion of the USCG Station's waterfront facility, along a jetty that 
extends approximately 1,300 ft (396 m) east into Monterey Harbor. The 
Pier and floating docks are on the southern side of the jetty.

Description of Marine Mammals in the Area of the Activity

    Several species of marine mammals occur in the proposed 
construction area, including the Pacific harbor seal (Phoca vitulina), 
California sea lion (Zalophus californianus), harbor porpoise (Phocoena 
phocoena), Risso's dolphin (Grampus griseus), bottlenose dolphin 
(Tursiops truncatus), killer whale (Orcinus orca), humpback whale 
(Megaptera novaeangliae) and gray whale (Eschrichtius robustus). These 
species are under the jurisdiction of the National Marine Fisheries 
Service (NMFS) and are considered under a separate proposed IHA notice 
(82 FR 42986; September 13, 2017). The only marine mammal species under 
the jurisdiction of the Service that occurs in the proposed 
construction area is the southern sea otter.
    Southern sea otters are listed as threatened under the Endangered 
Species Act of 1973, as amended (ESA) (42 FR 2965; January 14, 1977), 
and, because of their threatened status, are automatically considered 
``depleted'' under the MMPA (16 U.S.C. 1362(1)(C)). The State of 
California also recognizes the sea otter as a fully protected mammal 
(Fish and Game Code section 4700) and as a protected marine mammal 
(Fish and Game Code section 4500). All members of the sea otter 
population in California are descendants of a small group that survived 
the fur trade and persisted near Big Sur, California. Historically 
ranging from at least as far north as Oregon (Valentine et al. 2008) to 
Punta Abreojos, Baja California, Mexico, in the south, sea otters 
currently occur in only two areas of California. The mainland 
population ranges from San Mateo County to Santa Barbara County, and a 
translocated population exists at San Nicolas Island, Ventura County. 
The 2017 California-wide index of abundance is 3,186 individuals 
(www.werc.usgs.gov/seaottercount). Additional general information on 
status and trends of the southern sea otter may be found in the 5-year 
review and stock assessment report, available at https://www.fws.gov/ventura/endangered/species/info/sso.html.
    Sea otters occur in the Monterey Bay Harbor area year round. Census 
data indicate that there are, on average, 5.4 sea otters per 1,640 ft 
(500 m) of coastline within Monterey Harbor and in adjacent shoreline 
areas from Mussel Point to Del Monte Beach (ATOS 371-382; U.S. 
Geological Survey (USGS) 2017). The number of sea otters present at any 
one time in a particular location depends on a number of factors, 
including the availability of kelp canopy, the location of rafting 
sites, and individual sea otters' behavior. Sea otters typically use 
the harbor area to rest and to forage, with some sea otters feeding on 
mussels under the pier at or near the project location. Sea otters also 
occasionally use a passage through the rocks near the project location 
to access the kelp beds north of the jetty from the harbor (M. 
Staedler, Monterey Bay Aquarium Sea Otter Research and Conservation 
Program, pers. comm. 2014, 2017).

[[Page 18079]]

Potential Impacts of the Proposed Action on Sea Otters

    In this section we provide a qualitative discussion of the 
potential impacts of the proposed project. The ``Estimated Take by 
Incidental Harassment'' section later in this document includes a 
quantitative analysis of the number of individuals that may be taken by 
Level B harassment as a result of this activity.
    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). A 
permanent threshold shift (PTS) is said to occur when the loss of 
hearing sensitivity is unrecoverable, whereas a temporary threshold 
shift (TTS) is said to occur when the animal's hearing threshold 
recovers over time (Southall et al. 2007). Noise exposures resulting in 
TTS can cause PTS if repeated over time. Chronic exposure to excessive, 
but not high-intensity, noise can cause masking at the frequency band 
that some animals utilize for vital biological functions (Clark et al. 
2009). Noise can also cause other forms of disturbance when marine 
mammals alter their normal patterns of behavior to move away from the 
source.
    Many marine mammals depend on acoustic cues for vital biological 
functions, such as orientation, communication, locating prey, and 
avoiding predators. Sea otter vocalizations include in-air screams used 
by mothers and pups to maintain contact when separated and a suite of 
other low-intensity, short-range, in-air signals that are likely used 
in close-range social interactions (Kenyon 1969, McShane et al. 1995). 
However, sea otters are not known to communicate underwater, nor are 
they known to use acoustic information to orient or to locate prey. 
Ghoul and Reichmuth (2014) conducted controlled laboratory hearing 
tests to obtain aerial and underwater audiograms for a captive adult 
male sea otter and to evaluate his hearing in the presence of ambient 
noise. In air, the sea otter's hearing was similar to that of a sea 
lion but less sensitive to high-frequency (greater than 22 kHz) and 
low-frequency (less than 2 kHz) sounds than terrestrial mustelids. 
Under water, the sea otter was able to detect signals as low as 0.125 
kHz (at 116 dB re 1 [micro]Pa) and as high as 38.1 kHz (at 141 dB re 1 
[micro]Pa), with best hearing sensitivity in the range of 8 and 16 kHz.
    Although the sea otter's hearing was most similar to that of a sea 
lion, the sea otter had a narrower bandwidth of best hearing 
sensitivity (3.7 octaves) than either the sea lion (6.7 octaves) or 
harbor seal (8.6 octaves) and a pronounced reduction in sensitivity at 
frequencies below 1 kHz, where sounds could not be detected at levels 
below 100 dB re 1 [micro]Pa. At frequencies of 2 kHz or lower, the 
auditory threshold (level at which a sound becomes audible) was 12 to 
34 dB higher for the sea otter than for the sea lion. In studies of 
auditory masking, signal-to-noise ratios required for signal detection 
(critical ratios) were 25 to 34 dB, more than 10 dB above those 
measured in pinnipeds, suggesting that sea otters have a poor capacity 
to detect acoustic signals in background noise relative to other marine 
carnivores. In particular, critical ratios for the sea otter at 
frequencies below 2 kHz indicate that low-frequency sounds are likely 
to be more difficult for sea otters to detect above low-frequency noise 
relative to other marine mammals.
    Controlled behavioral studies of responses of sea otters to noise 
have not been conducted, but observational studies have not indicated 
any particular behavioral sensitivity to noise, (Riedman 1983, 1984). 
Observed responses of wild sea otters to disturbance are highly 
variable, probably reflecting the level of noise and activity to which 
they have been exposed and become acclimated over time and the 
particular location and social or behavioral state of that individual. 
Sea otters appeared to be relatively undisturbed by pile-driving 
activities in Elkhorn Slough during the construction of the Parsons 
Slough Sill, with many showing no response to pile driving and 
generally reacting more strongly to passing vessels associated with 
construction than to the sounds of machinery (Elkhorn Slough National 
Estuarine Research Reserve (ESNERR) 2011). However, these animals were 
likely acclimated to loud noises, as they occupied an area near an 
active railroad track, which produced in-air sound levels comparable to 
those produced by the vibratory driving of H piles (ESNERR 2011).
    The most likely effect of the proposed project on sea otters is 
behavioral disturbance due to pile-driving noise and activity. 
Potentially affected areas include the harbor and the area immediately 
north of the jetty. Underwater and airborne noise generated by pile 
replacement work may cause sea otters that rest or forage within or 
near the harbor to relocate temporarily to nearby areas. Behavioral 
changes resulting from disturbance could include startle responses, the 
interruption of resting behaviors (while in water or hauled out on 
nearby docks), and changes in foraging patterns. Most likely, sea 
otters would move away from the noise source and would be temporarily 
displaced from the pile replacement work area.
    NMFS has developed acoustic exposure criteria to define Level A 
harassment (injury) and Level B harassment (disturbance) resulting from 
project-related noise for the marine mammals under its jurisdiction 
(i.e., cetaceans and pinnipeds other than walruses). Since the Coast 
Guard first received an IHA for this project, NMFS has adopted new 
criteria for assessing Level A impacts, which the Service adopts for 
use here. For otariid pinnipeds (sea lions and fur seals) exposed to 
non-impulsive underwater noise (such as vibratory pile driving and 
removal), NMFS currently uses a cumulative 24-hour sound exposure level 
of 219 dB re 1 [micro]Pa\2\s as the threshold for Level A harassment, 
which is based on the estimated onset of physical injury as defined by 
the onset of PTS (NMFS 2016), and 120 dB re 1 [micro]Pa as the 
threshold for Level B harassment, although this threshold is not based 
on direct data.
    For otariid pinnipeds exposed to impulsive underwater noise (such 
as impact hammering of piles), NMFS uses an unweighted peak sound 
pressure level of 232 dB re 1 [micro]Pa or cumulative 24-hour sound 
exposure level of 203 dB re 1 [micro]Pa\2\s as the threshold for Level 
A harassment (NMFS 2016) and 160 dB re 1 [micro]Pa as the threshold for 
Level B harassment. For pinnipeds other than harbor seals exposed to 
airborne noise, NMFS uses 100 dB re 20 [micro]Pa as a guideline, but 
not formal threshold, for the onset of Level B harassment (79 FR 13991; 
March 12, 2014). NMFS does not have a guideline for the onset of Level 
A harassment of pinnipeds by airborne noise (A. Scholik-Schlomer, 
Office of Protected Resources, Marine Mammal and Sea Turtle 
Conservation Division, pers. comm. 2014). However, Southall et al. 
(2007) propose an injury criterion (estimated PTS onset) for sea lions 
exposed to airborne noise of 172.5 dB re 20 [micro]Pa.
    In the absence of formal noise exposure thresholds specific to sea 
otters, but in light of evidence suggesting that the hearing of sea 
otters is generally comparable to that of other marine carnivores 
(e.g., sea lions), although with relatively poorer sensitivity (higher 
hearing thresholds) at low frequencies, we generally use the 
thresholds, guidelines, and criteria developed by NMFS for sea lions 
(otariid pinnipeds) as proxies. However, since the Coast Guard first 
received an

[[Page 18080]]

IHA for this project, we have determined that the Level B threshold of 
120 dB re 1 [micro]Pa for non-impulsive noise such as vibratory pile 
driving is not applicable to sea otters. The 120 dB re 1 [micro]Pa 
threshold is based on studies conducted by Malme et al. in the 1980s, 
during which gray whales were exposed to experimental playbacks of 
industrial noise. Based on the behavioral responses of gray whales to 
the playback of drillship noise during a study at St. Lawrence Island, 
Alaska, Malme et al. (1988) concluded that ``exposure to levels of 120 
dB or more would probably cause avoidance of the area by more than one-
half of the gray whales.'' Sea otters do not occur at St. Lawrence 
Island, Alaska, but similar playback studies that were conducted off 
the coast of California (Malme 1983, 1984) included a sea otter 
monitoring component (Riedman 1983, 1884). The 1983 and 1984 studies 
detected probabilities of avoidance in gray whales comparable to those 
reported in Malme et al. (1988), but there was no evidence of 
disturbance reactions or avoidance in sea otters.
    Gray whales are in the group of marine mammals (baleen whales) 
believed to be most sensitive to low-frequency sounds, with an 
estimated audible frequency range of approximately 10 Hz to 30 kHz 
(Finneran 2016). In contrast, sea otters have relatively poor hearing 
sensitivity at frequencies below 2 kHz (Ghoul and Reichmuth 2014). Most 
of the acoustic energy generated by vibratory pile driving is limited 
to frequencies lower than 2 kHz, with greatest pressure spectral 
densities at frequencies below 1 kHz (Dahl et al. 2015). As a result, 
much of the noise generated by vibratory pile driving is expected to be 
inaudible or marginally audible to sea otters. During a previous 
project that occurred in Elkhorn Slough, Monterey County, project-
related monitoring of sea otter behavior in areas exposed to underwater 
sound levels ranging from approximately 135-165 dB re 1 [micro]Pa 
during vibratory pile driving (ESNERR 2011) showed no clear pattern of 
disturbance or avoidance in relation to these levels of underwater 
sound exposure.
    Based on the lack of disturbance or any other reaction by sea 
otters to the 1980s playback studies and the absence of a clear pattern 
of disturbance or avoidance behaviors attributable to underwater sound 
levels up to about 160 dB re 1 [micro]Pa resulting from vibratory pile 
driving, we use 160 dB re 1 [micro]Pa as the threshold for Level B 
harassment underwater for both impulsive and non-impulsive sources. For 
Level A harassment resulting from non-impulsive underwater noise, we 
use a threshold of 219 dB re 1 [micro]Pa\2\s (cumulative 24-hour sound 
exposure level). For Level A harassment resulting from impulsive 
underwater noise, we use a threshold of 232 dB re 1 [micro]Pa 
(unweighted peak sound pressure level) or 203 dB re 1 [micro]Pa\2\s 
(cumulative 24-hour sound exposure level). For Level B harassment 
resulting from airborne noise, we use the 100 dB re 20 [micro]Pa 
guideline that NMFS uses for in-air Level B harassment of pinnipeds 
other than harbor seals. For Level A harassment resulting from airborne 
noise, we use the Southall et al. (2007) criterion of 172.5 dB re 20 
[micro]Pa for sea lions to approximate the airborne noise levels that 
may cause injury to sea otters.
    Underwater and airborne sound levels expected to be produced during 
the proposed project are analyzed in Appendix A to Amec Foster Wheeler 
(2017). Figures 5-1 and 5-2 of Amec Foster Wheeler (2017) approximate 
the modeled extent of underwater noise resulting from vibratory pile 
driving and extraction and impact pile driving. This analysis has been 
revised slightly to reflect the following changes: The source sound 
pressure level has been revised downward to 182 dB for impact hammering 
(originally 195 dB, but 187 dB was determined to be more representative 
for 14-in (36-cm) piles based on WSDOT (2010), which is further reduced 
by 5 dB by use of a sound curtain) and to 162 dB for vibratory 
extraction/driving (originally 168 dB, but 162 dB was determined to be 
more representative for 14-in (36-cm) piles based on Caltrans (2015)). 
The distance to the 160-dB threshold (i.e., the radius of the area 
exposed to sound levels equal to or exceeding 160 dB) for vibratory 
pile driving is 46 ft (14 m). The distance to the 160-dB threshold for 
impact pile driving, based on modeled attenuated noise transmission, is 
249 ft (76 m) to the north and northeast (through the breakwater) and 
961 ft (293 m) in all other directions. The distance to the 219-dB 
threshold for vibratory pile driving is 3 ft (0.9 m), whereas the 
distance to the 203-dB cumulative 24-hour sound exposure level 
threshold for impact pile driving is 6.6 ft (2.0 m).
    Expected levels of airborne noise are based on measurements made 
during the Navy Test Pile Project in Bangor, Washington, for 18-in (46-
cm) piles. Because airborne noise data for 14-in (36-cm) piles were not 
available, the modeled distances to the Level B 100-dB guideline (66 ft 
(20 m) for vibratory pile driving and 197 ft (60 m) for impact driving) 
(Amec Foster Wheeler 2017) are overestimates. Nevertheless, anticipated 
maximum noise levels based on 18-in (46-cm) piles (102 dB for vibratory 
driving and extraction and 112 dB for impact driving at a distance of 
33 ft (10 m)) are well below the noise levels that may cause injury to 
sea otters. Noise thresholds and the modeled extent of sound pressure 
levels for underwater and airborne noise are summarized in Table 1.

 Table 1--Noise Thresholds and Modeled Extent of Sound Pressure Levels (SPLs) for Underwater and Airborne Noise
----------------------------------------------------------------------------------------------------------------
                                                          Modeled  extent                       Modeled  extent
                                          Threshold,       of  underwater       Guideline,     of  airborne SPLs
                                       underwater  (dB   SPLs (distance to   airborne  (dB re     (distance to
                                       re 1 [micro]Pa)     threshold) (m)     20 [micro]Pa)     threshold)  (m)
----------------------------------------------------------------------------------------------------------------
Level A non-impulsive...............                219                0.9              172.5                n/a
Level A impulsive...................                203                2.0              172.5                n/a
Level B non-impulsive...............                160                 14                100             *** 20
Level B impulsive...................                160               * 76                100             *** 60
                                                                    ** 293
----------------------------------------------------------------------------------------------------------------
* North and northeast through breakwater.
** All other directions.
*** Distances are overestimates because they are based on data for 18-in (46-cm) piles; airborne sound data for
  14-in (36-cm) piles were not available.


[[Page 18081]]

Potential Effects of the Proposed Action on Sea Otter Habitat

    No permanent impacts on habitat are proposed or would occur as a 
result of this project. The Proposed Action would not increase the 
Pier's existing footprint, and no new structures would be installed 
that would result in the loss of additional habitat. Therefore, no 
restoration of habitat would be necessary. A temporary, small-scale 
loss of foraging habitat may occur if sea otters leave the area during 
pile extraction and driving activities.

Potential Impacts on Subsistence Needs

    The subsistence provision of the MMPA does not apply.

Mitigation Measures

    The USCG has proposed the following measures to prevent Level A 
harassment (injury) and to reduce the extent of potential effects from 
Level B harassment (disturbance) to marine mammals.
    1. Timing restrictions. All work would be conducted during daylight 
hours to facilitate visual observation of the Level A and Level B 
zones.
    2. Noise attenuation. A bubble curtain and cushion pads would be 
used during all impact pile driving to reduce underwater sound levels. 
Prior to impact driving, pre-drilling would be used to create a hole 
for the new pile to a depth of approximately 5 ft (1.5 m) above the 
required pile tip elevation to reduce friction, noise, and turbidity 
during installation.
    3. Exclusion zones and shutdown measures. Exclusion zones based on 
the area exposed to sound levels equal to or exceeding those expected 
to cause PTS would be implemented to protect marine mammals from Level 
A harassment. If a sea otter is observed in the exclusion zone, pile 
extraction or driving would not commence until the individual has been 
observed outside of the zone or has not been observed for at least 15 
minutes. If the sea otter entered the exclusion zone, a stop-work order 
would be issued. Work would not re-commence until the sea otter was 
sighted well outside of the exclusion zone or was not observed for at 
least 15 minutes. The modeled PTS isopleths relevant to sea otters are 
only 3 ft (0.9 m) for vibratory driving and extraction and 6.6 ft (2 m) 
for impact driving (Table 1); these would be verified based on in-situ 
source level and sound propagation measurements. However, the radius of 
the Level A exclusion zone for sea otters would be extended to at least 
33 ft (10 m) to prevent injury from machinery. USCG would implement 
shutdown measures if the number of authorized takes reached the limit 
under the IHA and if sea otters were sighted within the vicinity of the 
project area and were approaching the Level B harassment zone during 
in-water construction activities.
    4. Level B harassment zone. USCG would monitor the Level B 
harassment zone. Because impact hammering and vibratory driving would 
both be used in the project, the Level B harassment zone for all pile-
driving activities would be set based on the greatest extent of sound 
pressure levels equal to or exceeding the thresholds summarized in 
Table 1. Because the distance to the threshold is greatest for 
underwater noise produced by impact hammering, the Level B harassment 
zone would have a minimum radius of 249 ft (76 m) to the north and 
northeast (through the breakwater) and 961 ft (293 m) in all other 
directions based on the modeled extent of underwater SPLs. This zone 
would be adjusted, as necessary, based in-situ source level and sound 
propagation measurements.
    5. Soft-start for impact pile driving. For impact pile 
installation, contractors will provide an initial set of three strikes 
from the impact hammer at 40 percent energy, followed by a 1-minute 
waiting period, then two subsequent three-strike sets. Each day, USCG 
will use the soft-start technique at the beginning of impact pile 
driving and before resuming work if impact pile driving has ceased for 
more than 30 minutes.

Monitoring and Reporting

    The USCG would implement two detailed monitoring plans prior to and 
during pile replacement activities: An acoustic monitoring plan and a 
marine mammal monitoring plan. The acoustic monitoring plan would 
ensure that measurements are recorded to provide data on actual noise 
levels during construction and to ensure that the marine mammal 
exclusion zone and Level B harassment zone are sized appropriately 
relative to acoustic thresholds. Specifically, USCG would conduct in-
situ monitoring during the installation of five piles and removal of 
five piles (see the acoustic monitoring plan for more details). The 
marine mammal monitoring plan would provide details on data collection 
for each marine mammal species observed in the project area during the 
construction period.
    Monitoring would be conducted by Service-approved observers who are 
familiar with sea otters and their behavior. The observers would 
conduct baseline monitoring for 2 days during the week prior to pile 
removal and driving. During pile removal and driving activities, three 
observers would monitor the exclusion zone and Level B harassment zone 
from the best vantage point possible (the Pier itself, the jetty, or 
adjacent boat docks in the harbor) to determine if sea otters were 
approaching the exclusion zone and to record behavioral responses to 
noise within the Level B harassment zone. The exclusion zone would be 
monitored for 30 minutes prior to, during, and after pile removal and 
driving. If a sea otter is within the exclusion zone, the start of 
extraction or driving would be delayed until no sea otters were sighted 
within the zone for a minimum of 15 minutes. If a sea otter approached 
the exclusion zone, the observation would be reported to the 
construction manager, and the individual would be watched closely. If 
the sea otter entered the exclusion zone, a stop-work order would be 
issued. The lead monitor would not allow work to re-commence until the 
sea otter was sighted well outside of the exclusion zone or was not 
observed for at least 15 minutes.
    The following information would be documented for each sea otter 
observed at any range while pile driving or extraction activities are 
occurring:
    (A) Date and time that monitored activity begins and ends;
    (B) Construction activities occurring during each observation 
period;
    (C) Weather parameters (e.g., percent cover, visibility);
    (D) Water conditions (e.g., sea state, tide state);
    (E) Numbers of individuals, sex and age class (if possible), and 
flipper tag color and location;
    (F) Description of behavioral patterns, including bearing and 
direction of travel, distance from pile-driving activity, and specific 
activity (swimming at surface, swimming below surface, spyhopping, 
foraging, grooming, interacting with another sea otter, resting on 
water, resting while hauled out, etc.);
    (G) Distance from pile-driving activities to sea otters and 
distance from the sea otters to the observation point;
    (H) Locations of all marine mammal observations; and
    (I) Other human activity in the area.
    Daily observation sheets would be compiled on a weekly basis and 
submitted with a weekly monitoring report that summarized the 
monitoring results, construction activities, and environmental 
conditions. USCG would be required to submit a draft marine mammal 
monitoring report within 90 days after completion of the in-water 
construction work or the expiration of

[[Page 18082]]

the IHA (if issued), whichever comes earlier. The report would include 
data from marine mammal sightings as described above. The marine mammal 
monitoring report would also include total takes, takes by day, and 
stop-work orders for each species. The Service would have an 
opportunity to provide comments on the report, and if the Service had 
comments, USCG would address the comments and submit a final report to 
the Service within 30 days.
    In the unanticipated event that the specified activity clearly 
causes the take of a sea otter in a manner prohibited by the IHA (if 
issued), such as an injury (Level A harassment), serious injury, or 
mortality, USCG would immediately cease the specified activities and 
immediately report the incident to the Service's Southern Sea Otter 
Recovery Coordinator and Monterey Bay Aquarium's sea otter 24-hour 
emergency line. The report would be required to include the following 
information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Description of the animal(s) involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s).
    Activities would not resume until the Service reviewed the 
circumstances of the prohibited take. The Service would work with USCG 
to determine what is necessary to minimize the likelihood of additional 
prohibited take and ensure MMPA compliance. USCG would not be permitted 
to resume activities until it implemented any necessary measures to 
minimize the likelihood of additional prohibited take and received 
notification by the Service via letter, email, or telephone.
    In the event that the USCG discovered an injured or dead sea otter, 
and the lead monitor determined that the cause of the injury or death 
was unknown or unrelated to the specified activities, USCG would 
immediately report the incident to the Service's Southern Sea Otter 
Recovery Coordinator and Monterey Bay Aquarium's sea otter 24-hour 
emergency line. The report would be required to include the same 
information identified in the paragraph above. Activities would be 
permitted to continue while the Service reviewed the circumstances of 
the incident. The Service would work with USCG to provide for the 
implementation of measures, if appropriate, to minimize the likelihood 
of prohibited take.

Estimated Take by Incidental Harassment

    Based on the proposed construction methodology and mitigation, 
including use of an exclusion zone, no Level A harassment is 
anticipated as a result of the proposed project. Behavioral harassment 
(Level B) will be considered to have occurred when sea otters enter the 
Level B harassment zone. We use the greatest modeled extent of sound 
pressure levels from Table 1 (the Level B zone for impulsive underwater 
noise) as the area within which to estimate the maximum number of sea 
otters that could be exposed to noise exceeding Level B thresholds 
during the estimated maximum 8 days of pile extraction and removal. An 
average of two or three piles would be installed and removed per day, 
totaling an estimated 60 to 70 minutes of pile driving per day. 
Assuming that an individual sea otter can be taken only once during a 
24-hour period, we calculate the number of takes using the following 
formula: Take Estimate = n multiplied by area of influence multiplied 
by 8 days of activity, where: n is the number of sea otters per linear 
km of coastline and area of influence is the Level B harassment zone 
for impulsive underwater noise. Because the final take estimate must be 
a whole number, values are rounded up to the next whole number before 
multiplying by the number of days of exposure.
    The area of influence encompasses the harbor area and the area 
immediately to the north and northeast of the breakwater, less than one 
linear km of coastline. Because, on average, 5.4 sea otters are 
expected per 1,640 ft (500 m) of coastline (USGS 2017), a maximum of 11 
sea otters are expected to be exposed to pile-driving noise per day 
over 8 days, for a total of 88 takes.

Findings

    We propose the following findings regarding this action:

Negligible Impact

    We find that any incidental take by harassment that is reasonably 
likely to result from the proposed project would not adversely affect 
the sea otter by means of effects on rates of recruitment or survival 
and would, therefore, have no more than a negligible impact on the 
stock. In making this finding, we considered the best available 
scientific information, including: (1) The biological and behavioral 
characteristics of the species; (2) information on distribution and 
abundance of sea otters within the area of the proposed activity; (3) 
the potential sources of disturbance during the proposed activity; and 
(4) the potential response of sea otters to disturbance.
    The estimated 88 takes (for approximately 11 sea otters) are 
expected to result in negligible impact because sea otters do not 
appear to be particularly sensitive to noise (and often do not react 
visibly to it) and because any behavioral reactions to noise are 
expected to be temporary and of short duration.
    The mitigation measures outlined above are intended to minimize the 
number of sea otters that could be harassed by the proposed activity. 
Any impacts to individuals are expected to be limited to Level B 
harassment of short duration. Responses of sea otters to project-
related noise would most likely be common behaviors such as diving and/
or swimming away from the source of the disturbance. No take by injury 
or death is anticipated. Because any Level B harassment that occurs 
would be of short duration, and because no take by injury or death is 
anticipated, we find that the anticipated harassment caused by the 
proposed activities is not expected to adversely affect the species or 
stock through effects on annual rates of recruitment or survival.
    Our finding of negligible impact applies to incidental take 
associated with the proposed activity as mitigated through this 
authorization process. This authorization establishes monitoring and 
reporting requirements to evaluate the potential impacts of the 
authorized activities, as well as mitigation measures designed to 
minimize interactions with, and impacts to, sea otters.

Small Numbers

    For small numbers take analysis, the statute and legislative 
history do not expressly require a specific type of numbers analysis, 
leaving the determination of ``small'' to the agency's discretion. The 
sea otter population in California consists of approximately 3,186 
animals. The number of sea otters that could potentially be taken by 
harassment in association with the proposed project is approximately 11 
animals (0.3 percent of the population size). While many of the same 
sea otters are likely to remain in the area throughout the duration of 
pile-driving activities, some turnover may occur, particularly if the 8 
days of pile-driving activity are interspersed over several

[[Page 18083]]

months. Turnover of sea otters in the area would slightly increase the 
total number of animals exposed to project-related noise; however, we 
expect that number would remain small. We find that the number of sea 
otters utilizing the affected area is small relative to the size of the 
population.

Impact on Subsistence

    The subsistence provision of the MMPA does not apply to southern 
sea otters.

Endangered Species Act

    The proposed activity will occur within the range of the southern 
sea otter, which is listed as threatened under the ESA. The Applicant 
has initiated interagency consultation under section 7 of the ESA with 
the Service's Ventura Fish and Wildlife Office. We will complete intra-
Service section 7 consultation on our proposed issuance of the IHA.

National Environmental Policy Act (NEPA)

    The impacts associated with the project are described in a draft 
supplemental environmental assessment (EA) prepared on behalf of the 
USCG. The Service will review the EA and decide either to adopt it or 
prepare its own NEPA document before making a determination on the 
issuance of an IHA. Our analysis will be completed prior to issuance or 
denial of the IHA and will be available at https://www.fws.gov/ventura/endangered/species/info/sso.html.

Government-to-Government Relations With Native American Tribal 
Governments

    In accordance with the President's memorandum of April 29, 1994, 
``Government-to-Government Relations with Native American Tribal 
Governments'' (59 FR 22951), Executive Order 13175, Secretarial Order 
3206, the Department of the Interior's manual at 512 DM 2, and the 
Native American Policy of the Service (January 20, 2016), we readily 
acknowledge our responsibility to communicate meaningfully with 
federally recognized Tribes on a Government-to-Government basis. We 
have evaluated possible effects on federally recognized Indian Tribes 
and have determined that there are no effects.

Proposed Authorization

    The Service proposes to issue an IHA for small numbers of sea 
otters harassed incidentally by the Applicant while the Applicant is 
completing waterfront repairs at USCG Station Monterey during a 1-year 
authorization period beginning on or before June 15, 2018. 
Authorization for incidental take beyond this period would require a 
request for renewal.
    The final IHA would incorporate the mitigation, monitoring, and 
reporting requirements discussed in this proposal. The Applicant would 
be responsible for following those requirements. These authorizations 
would not allow the intentional taking of sea otters.
    If the level of activity exceeded that described by the Applicant, 
or the level or nature of take exceeded those projected here, the 
Service would reevaluate its findings. The Secretary may modify, 
suspend, or revoke an authorization if the findings are not accurate or 
the conditions described in this notice are not being met.

Request for Public Comments

    The Service requests interested persons to submit comments and 
information concerning this proposed IHA. Consistent with section 
101(a)(5)(D)(iii) of the MMPA, we are opening the comment period on 
this proposed authorization for 30 days (see DATES).
    Before including your address, phone number, email address, or 
other personal identifying information in your comment, you should be 
aware that your entire comment--including your personal identifying 
information--may be made publicly available at any time. While you can 
ask us in your comment to withhold your personal identifying 
information from public review, we cannot guarantee that we will be 
able to do so.

    Dated: March 1, 2018.
Angela Picco,
Acting Regional Director, Pacific Southwest Region.
[FR Doc. 2018-08559 Filed 4-24-18; 8:45 am]
BILLING CODE 4333-15-P