Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Aldo's Seawall Replacement Project in Santa Cruz, California, 13892-13906 [2019-06885]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 67 (Monday, April 8, 2019)]
[Notices]
[Pages 13892-13906]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-06885]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG627


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Aldo's Seawall Replacement Project 
in Santa Cruz, California

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the Santa Cruz Port District 
(Port District) for authorization to take marine mammals incidental to 
the Aldo's Seawall Replacement Project in Santa Cruz, California (CA). 
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting 
comments on its proposal to issue an incidental harassment 
authorization (IHA) to take marine mammals incidental to the specified 
activities. NMFS is also requesting comments on a possible one-year 
renewal that could be issued under certain circumstances and if all 
requirements are met, as described in Request for Public Comments at 
the end of this notice. NMFS will consider public comments prior to 
making any final decision on the issuance of the requested MMPA 
authorizations and agency responses will be summarized in the final 
notice of our decision.

DATES: Comments and information must be received no later than May 8, 
2019.

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

FOR FURTHER INFORMATION CONTACT: Amy Fowler, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) 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 incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable 
[adverse] impact'' on the affected species or stocks and their habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance, and on the availability of such species or stocks 
for taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (incidental harassment authorizations with 
no anticipated serious injury or mortality) of the Companion Manual for 
NOAA Administrative Order 216-6A, which do not individually or 
cumulatively have the potential for significant impacts on the quality 
of the human environment and for which we have not identified any 
extraordinary circumstances that would preclude this categorical 
exclusion. Accordingly, NMFS has preliminarily determined that the 
issuance of the proposed IHA qualifies to be categorically excluded 
from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On August 27, 2018, NMFS received a request from the Port District 
for an IHA to take marine mammals incidental to the Aldo's Seawall 
Replacement Project in the Santa Cruz Small Craft Harbor (harbor). The 
application was deemed adequate and complete on March 21, 2019. The 
Port District's request is for take of four species of marine mammals 
by Level B harassment and Level A harassment. Neither the Port District 
nor NMFS expects serious injury or mortality to result from this 
activity and, therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    The Port District is planning to replace the existing seawall 
located below Aldo's Restaurant along the southwest bank of the Santa 
Cruz Small Craft Harbor beginning in June 2019. The original seawall 
was constructed between 1963 and 1964 and has deteriorated to the point 
that Aldo's Harbor Restaurant voluntarily closed in

[[Page 13893]]

2016. The proposed project involves demolishing the existing restaurant 
structure and timber pile supported restaurant deck, modifying a dock 
gangway landing, removing timber piles supporting the public wharf, 
removing and reinstalling rip-rap to accept the new sheet pile wall, 
predrilling for new sheet piles, and installing a new steel sheet pile 
seawall with concrete pile cap and tie-backs in front of the existing 
seawall. Removing old timber piles and installing new steel sheet piles 
has the potential to harass marine mammals within the harbor and 
outside of the harbor in Monterey Bay.

Dates and Duration

    Construction would occur between June 15 and November 1, 2019. 
Construction timing is restricted by salmonid migration to avoid and 
minimize potential impacts to steelhead trout (Oncorhynchus mykiss) 
that may occur in the harbor. Construction would occur only during 
daylight hours and during low tide, as feasible. The entire project is 
expected to take 18 weeks, with approximately 28 days of in-water work. 
Four timber piles would be removed over two days. Ninety sheet piles 
would be driven over 15 days at a rate of six piles per day. The 
remaining nine days of in-water work would involve pre-drilling to 
prepare the substrate for driving of sheet piles, and removing and 
reinstalling rip-rap around the seawall.

Specific Geographic Region

    The harbor is located in Santa Cruz, California, off of Monterey 
Bay (see Figure 1 of the IHA application). The lower portion of the 
harbor runs primarily north-south while the upper portion (north of the 
Murray Street bridge) extends to the northeast (see Figures 2a and 2b 
in the IHA application). The harbor is less than 300 feet (ft) (91.4 
meters (m)) wide at the mouth. The entrance to the harbor is marked by 
Walton Lighthouse, which sits atop a rock jetty extending into Monterey 
Bay. Aldo's Restaurant is located on the west side of the harbor. The 
harbor is entirely developed, consisting of docks, boat launches, a 
boat yard, and other facilities that provide harbor support services.

Detailed Description of Specific Activity

    The existing Aldo's restaurant, concrete foundation, and timber 
pile supported deck will be removed. The existing timber piles 
supporting the deck will remain. All structure removal will occur above 
the water and sound levels associated with the demolition are not 
likely to be significantly different from noise associated with regular 
harbor activities, such as large boat and vehicle traffic. Existing 
structure removal is not expected to result in take of marine mammals, 
and therefore will not be discussed further in this document.
    On the south side of the restaurant, a portion of the existing rip-
rap will be temporarily removed and stockpiled to prevent interference 
with installing the new seawall, and the remaining rip-rap will be 
protected in place. Approximately 300-400 square ft (91-122 square m) 
of rip-rap will be removed. This activity would occur at low tide and 
no equipment would enter the water. Following installation of the new 
seawall, the rip-rap that was previously removed and stockpiled would 
be reinstalled. Removal and subsequent replacement of rip-rap is not 
expected to result in take of marine mammals, and therefore will not be 
discussed further in this document.
    On the north side of the restaurant, the gangway to AA-dock and a 
portion of the public wharf (see Figure 2a in the IHA application) 
would be temporarily removed to allow sheet pile installation. 
Following installation of the new seawall, the existing aluminum 
gangway to AA-dock would be reinstalled. The portion of the existing 
public wharf that was removed would be reframed and replaced in-kind. 
Modification of the gangway and public wharf are not expected to result 
in take, and therefore will not be discussed further in this document.
    Four 16 inch (in) (40.6 centimeter (cm)) timber piles supporting 
the public wharf would be permanently removed. These piles would be 
removed using a vibratory driver to reduce the extraction effort and 
the likelihood that the pile would break. The piles would be removed 
using land-based equipment. No new timber piles would be installed.
    The existing steel sheet pile wall, tie-rods, and concrete anchors 
would be abandoned in place. The new steel sheet pile wall would be 
installed on the water side of the existing seawall, with rock placed 
in the void between the existing and new walls. The new seawall would 
extend approximately two feet further into harbor waters than the 
existing seawall. The new seawall will be composed of 90 0.5 m (1.6 ft) 
steel sheet piles, which will be driven in pairs.
    Prior to installing the sheet piles, the contractor would pre-drill 
the substrate, drilling three 15 cm (6 in) diameter holes to the tip 
elevation for each pair of sheet piles. Pre-drilling would use land-
based equipment, with only the auger in the water. Pre-drilling is 
expected to occur over five days but the actual duration of drilling 
activities is expected to be much shorter. NMFS has authorized take in 
association with certain types of drilling in other project (e.g., 84 
FR 4777; February 19, 2019), but those typically have much larger holes 
being drilled and/or othr circumstances leading to an expectation of 
louder sound levels than are expected here. Because of the small 
drilled hole size and short duration of drilling, acoustic impacts from 
pre-drilling are not expected to rise to the level of a take, take is 
not proposed to be authorized here and the effects of pre-drilling will 
not be discussed further in this document.
    The 90 sheet piles will be driven over approximately 15 days, at a 
rate of six piles per day. The contractor would first use a vibratory 
hammer to sink the sheet piles through the soil over the bedrock 
(sandstone). Once the sheet piles have been sunk into the substrate, 
the contractor would use an impact hammer to drive the sheet piles into 
the substrate to a maximum depth of embedment of 2-2.5 m (7-8 ft). 
Based on the varying density of the bedrock and the required depth of 
embedment, each sheet pile would require a maximum of 300 strikes (600 
strikes per pair) from the impact hammer.

                                   Table 1--Summary of Pile Driving Activities
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                                                                                                   Maximum daily
           Pile type                 Method          Number of     Piles per day    Strikes per      duration
                                                       piles                           pile           (hours)
----------------------------------------------------------------------------------------------------------------
16 in timber..................  Vibratory                      4               2             N/A               6
                                 removal.
0.5 m steel sheet.............  Vibratory                     90               6             N/A               6
                                 installation.
0.5 m steel sheet.............  Impact                        90               6             300             N/A
                                 installation.
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[[Page 13894]]

    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the IHA application summarize available 
information regarding status and trends, distribution and habitat 
preferences, and behavior and life history, of the potentially affected 
species. Additional information regarding population trends and threats 
may be found in NMFS's Stock Assessment Reports (SAR; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence in 
the harbor and surrounding waters of Monterey Bay and summarizes 
information related to the population or stock, including regulatory 
status under the MMPA and ESA and potential biological removal (PBR), 
where known. For taxonomy, we follow Committee on Taxonomy (2018). PBR 
is defined by the MMPA as the maximum number of animals, not including 
natural mortalities, that may be removed from a marine mammal stock 
while allowing that stock to reach or maintain its optimum sustainable 
population (as described in NMFS's SARs). While no mortality is 
anticipated or authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Pacific SARs. All values presented in Table 2 are the most 
recent available at the time of publication and are available in the 
2017 SARs (Caretta et al., 2018) and draft 2018 SARs (available online 
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                    Table 2--Marine Mammals With Potential Presence Within the Proposed Project Area
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                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Common bottlenose dolphin.......  Tursiops truncatus.....  California Coastal.....  -/-; N              453 (0.06, 346, 2011).        2.7       >2.0
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Monterey Bay...........  -/-; N              3,715 (0.51, 2,480,            25          0
                                                                                                             2011).
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                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California sea lion.............  Zalophus californianus.  U.S....................  -/-; N              257,606 (N/A, 233,515,     14,011       >319
                                                                                                             2014).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  California.............  -/-; N              30,968 (N/A, 27,348,        1,641         43
                                                                                                             2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.

    All species that could potentially occur in the proposed project 
areas are included in Table 2. As described below, all four species 
(with four managed stocks) temporally and spatially co-occur with the 
activity to the degree that take is reasonably likely to occur, and we 
have proposed authorizing it. In addition, the southern sea otter 
(Enhydra lutris nereis) may be found in the harbor. However, southern 
sea otters are managed by the U.S. Fish and Wildlife Service and are 
not considered further in this document.
Harbor Seal
    Harbor seals are residential year-round within the harbor, 
primarily utilizing harbor docks as nighttime haulout locations. The 
greatest numbers of hauled-out seals have been observed in the harbor 
at B, F, and FF docks, as well as the floating docks near the small 
boat launch (between docks F and FF) and the boat yard docks (T) (see 
Figures 2a and 2b in the IHA application). Most seals leave the harbor 
shortly after dawn, but some remain and forage within the harbor. The 
greatest concentrations of foraging seals are typically just south of 
the Murray Street Bridge by the Live Bait dock (Dock S) (see Figure 2a 
in the IHA application). During the molting season, seals have been 
observed remaining at their nighttime haulouts several hours after 
dawn. Molting season in Santa Cruz is estimated to occur between late 
April and July (Seal Conservancy 2017; Vanderhoof and Allen 2005). 
During 2018 surveys, molting was observed from June through July 10. 
The harbor is not a known rookery for harbor seals; the closest known 
rookeries are Elkhorn Slough, Lover's Point State Marine

[[Page 13895]]

Reserve, and Point Lobos (25-50 kilometers (km) (15.5-31 miles (mi)) 
south and southeast of the harbor).
California Sea Lion
    Adult male California sea lions are resident in Monterey Bay 
outside of breeding season, and juvenile males are present in Monterey 
Bay year-round. California sea lions are visitors to the harbor, 
occasionally using the harbor for foraging and the docks and other 
harbor features for haulouts. Larger numbers of California sea lions 
may be present in the harbor waters when fish runs occur within the 
harbor. Weather, currents, seasonal upwelling conditions, and other 
oceanographic factors periodically bring anchovies, sardines, and other 
prey species into the harbor, drawing larger numbers of birds and 
pinnipeds. California sea lions are primarily observed using the docks 
of the lower harbor (south of the Murray Street bridge, see Figure 2a 
in the IHA application). The closest rookeries are Ano Nuevo Island (35 
km (21.7 mi) northwest) and the Farallon Islands (120 km (74.6 mi) 
northwest) (Marine Mammal Center 2018; Wheeler 2001; Keith et al., 
1984).
Bottlenose Dolphin
    A resident population of over 50 coastal bottlenose dolphins occurs 
in Monterey Bay (Hwang et al., 2014). Sixty-eight uniquely marked 
individuals were observed during surveys in the early 1990s (Feinholz 
1996). This population preferentially uses the northern part of 
Monterey Bay but some of the photo-identified dolphins have been 
observed as far south as the Southern California Bight (Hwang et al., 
2014). Bottlenose dolphins are not known to occur within the harbor 
itself, but may be present in the nearshore waters immediately outside 
the mouth of the harbor.
Harbor Porpoise
    Resident harbor porpoises are known to occur in the coastal waters 
of Monterey Bay. The bathymetry of the northern Monterey Bay results in 
a relatively high density of harbor porpoises in the nearshore areas 
(Jacobsen et al., 2017; Jacobsen et al., 2015). Porpoises in the 
northern part of Monterey Bay represent approximately 15 percent of the 
stock (Forney et al., 2014). Harbor porpoises are the most common 
nearshore cetacean in Monterey Bay and although they have not been 
observed within the harbor, they have been observed outside the harbor 
(Forney pers. comm. 2018).

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Four marine mammal species (two cetacean and two pinniped (one otariid 
and one phocid) species) have the reasonable potential to co-occur with 
the proposed survey activities. Please refer to Table 2. Of the 
cetacean species that may be present, one is classified as a mid-
frequency cetacean (i.e., all delphinid and ziphiid species and the 
sperm whale), and one is classified as a high-frequency cetacean (i.e., 
harbor porpoise and Kogia spp.).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The Negligible Impact Analysis 
and Determination section considers the content of this section, the 
Estimated Take section, and the Proposed Mitigation section, to draw 
conclusions regarding the likely impacts of these activities on the 
reproductive success or survivorship of individuals and how those 
impacts on individuals are likely to impact marine mammal species or 
stocks.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).

[[Page 13896]]

    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al. 1995). The result is that, depending 
on the source type and its intensity, sound from the specified activity 
may be a negligible addition to the local environment or could form a 
distinctive signal that may affect marine mammals.
    In-water construction activities associated with the project would 
include impact pile driving, vibratory pile driving, and vibratory pile 
removal. The sounds produced by these activities fall into one of two 
general sound types: Impulsive and non-impulsive. Impulsive sounds 
(e.g., explosions, gunshots, sonic booms, impact pile driving) are 
typically transient, brief (less than 1 second), broadband, and consist 
of high peak sound pressure with rapid rise time and rapid decay (ANSI 
1986; NIOSH 1998; ANSI 2005; NMFS 2018). Non-impulsive sounds (e.g. 
aircraft, machinery operations such as drilling or dredging, vibratory 
pile driving, and active sonar systems) can be broadband, narrowband or 
tonal, brief or prolonged (continuous or intermittent), and typically 
do not have the high peak sound pressure with raid rise/decay time that 
impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). The distinction 
between these two sound types is important because they have differing 
potential to cause physical effects, particularly with regard to 
hearing (e.g., Ward 1997 in Southall et al. 2007).
    Two types of pile hammers would be used on this project: impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels, a potentially injurious combination (Hastings and Popper 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak SPLs may be 
180 dB or greater, but are generally 10 to 20 dB lower than SPLs 
generated during impact pile driving of the same-sized pile (Oestman et 
al. 2009). Rise time is slower, reducing the probability and severity 
of injury, and sound energy is distributed over a greater amount of 
time (Nedwell and Edwards 2002; Carlson et al. 2005).
    The likely or possible impacts of the Port District's proposed 
activity on marine mammals could involve both non-acoustic and acoustic 
stressors. Potential non-acoustic stressors could result from the 
physical presence of the equipment and personnel; however, any impacts 
to marine mammals are expected to primarily be acoustic in nature. 
Acoustic stressors include effects of heavy equipment operation during 
pile installation and removal and drilling.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal is the primary means by which 
marine mammals may be harassed from the Port District's specified 
activity. In general, animals exposed to natural or anthropogenic sound 
may experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al. 2007). In general, exposure to 
pile driving and drilling noise has the potential to result in auditory 
threshold shifts and behavioral reactions (e.g., avoidance, temporary 
cessation of foraging and vocalizing, changes in dive behavior). 
Exposure to anthropogenic noise can also lead to non-observable 
physiological responses such an increase in stress hormones. Additional 
noise in a marine mammal's habitat can mask acoustic cues used by 
marine mammals to carry out daily functions such as communication and 
predator and prey detection. The effects of pile driving and drilling 
noise on marine mammals are dependent on several factors, including, 
but not limited to, sound type (e.g., impulsive vs. non-impulsive), the 
species, age and sex class (e.g., adult male vs. mom with calf), 
duration of exposure, the distance between the pile and the animal, 
received levels, behavior at time of exposure, and previous history 
with exposure (Wartzok et al. 2004; Southall et al. 2007). Here we 
discuss physical auditory effects (threshold shifts) followed by 
behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al. 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960; 
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al. 
2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al. 2008), there are no empirical data measuring PTS in 
marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS 2018). Based on data from cetacean TTS measurements (see 
Southall et al. 2007), a TTS of 6 dB is considered the minimum 
threshold shift clearly larger than any day-to-day or session-to-
session variation in a subject's normal hearing ability (Schlundt et 
al. 2000; Finneran et al. 2000, 2002). As described in Finneran (2015), 
marine

[[Page 13897]]

mammal studies have shown the amount of TTS increases with cumulative 
sound exposure level (SELcum) in an accelerating fashion: At 
low exposures with lower SELcum, the amount of TTS is 
typically small and the growth curves have shallow slopes. At exposures 
with higher higher SELcum, the growth curves become steeper 
and approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al. 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and five species of pinnipeds exposed to a limited 
number of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (Finneran 2015). TTS was not observed in trained 
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to 
impulsive noise at levels matching previous predictions of TTS onset 
(Reichmuth et al. 2016). In general, harbor seals and harbor porpoises 
have a lower TTS onset than other measured pinniped or cetacean species 
(Finneran 2015). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species. No data are 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), Finneran (2015), and Table 5 in NMFS (2018). Installing piles 
requires a combination of impact pile driving and vibratory pile 
driving. For the project, these activities would not occur at the same 
time and there would likely be pauses in activities producing the sound 
during each day. Given these pauses and that many marine mammals are 
likely moving through the action area and not remaining for extended 
periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal and drilling also has the potential to behaviorally disturb 
marine mammals. Available studies show wide variation in response to 
underwater sound; therefore, it is difficult to predict specifically 
how any given sound in a particular instance might affect marine 
mammals perceiving the signal. If a marine mammal does react briefly to 
an underwater sound by changing its behavior or moving a small 
distance, the impacts of the change are unlikely to be significant to 
the individual, let alone the stock or population. However, if a sound 
source displaces marine mammals from an important feeding or breeding 
area for a prolonged period, impacts on individuals and populations 
could be significant (e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 
2005).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are 
highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al. 1995; Wartzok et al. 2003; Southall et al. 
2007; Weilgart 2007; Archer et al. 2010). Behavioral reactions can vary 
not only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al. 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). In 
general, pinnipeds seem more tolerant of, or at least habituate more 
quickly to, potentially disturbing underwater sound than do cetaceans, 
and generally seem to be less responsive to exposure to industrial 
sound than most cetaceans. Please see Appendices B-C of Southall et al. 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al. 
2001; Nowacek et al. 2004; Madsen et al. 2006; Yazvenko et al. 2007). A 
determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    In 2016, the Alaska Department of Transportation and Public 
Facilities (ADOT&PF) documented observations of marine mammals during 
construction activities (i.e., pile driving and down-hole drilling) at 
the Kodiak Ferry Dock (see 80 FR 60636 for Final IHA Federal Register 
notice). In the marine mammal monitoring report for that project (ABR 
2016), 1,281 Steller sea lions were observed within the behavioral 
disturbance zone during pile driving or drilling (i.e., documented as 
Level B harassment take). Of these, 19 individuals demonstrated an 
alert behavior, 7 were fleeing, and 19 swam away from the project site. 
All other animals (98 percent) were engaged in activities such as 
milling, foraging, or fighting and did not change their behavior. In 
addition, two sea lions approached within 20 meters of active vibratory 
pile driving activities. Three harbor seals were observed within the 
disturbance zone during pile driving activities; none of them displayed 
disturbance behaviors. Fifteen killer whales and three harbor porpoise 
were also observed within the Level B harassment zone during pile 
driving. The killer whales were travelling or milling while all harbor 
porpoises were travelling. No signs of disturbance were noted for 
either of these species. Given

[[Page 13898]]

the similarities in activities and habitat and the fact the same 
species are involved, we expect similar behavioral responses of marine 
mammals to the specified activity. That is, disturbance, if any, is 
likely to be temporary and localized (e.g., small area movements). 
Monitoring reports from other recent pile driving projects have 
observed similar behaviors.
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al. 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g. on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked. The 
harbor houses hundreds of small craft vessels that transit through the 
harbor waters on a regular basis; therefore, background sound levels in 
the harbor are already elevated.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal that have the potential to cause behavioral harassment, 
depending on their distance from pile driving activities. Cetaceans are 
not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels exceeding the acoustic thresholds. We recognize that pinnipeds 
in the water could be exposed to airborne sound that may result in 
behavioral harassment when looking with their heads above water. Most 
likely, airborne sound would cause behavioral responses similar to 
those discussed above in relation to underwater sound. For instance, 
anthropogenic sound could cause hauled-out pinnipeds to exhibit changes 
in their normal behavior, such as reduction in vocalizations, or cause 
them to temporarily abandon the area and move further from the source. 
However, these animals would previously have been `taken' because of 
exposure to underwater sound above the behavioral harassment 
thresholds, which are in all cases larger than those associated with 
airborne sound. Thus, the behavioral harassment of these animals is 
already accounted for in these estimates of potential take. Therefore, 
we do not believe that authorization of incidental take resulting from 
airborne sound for pinnipeds is warranted, and airborne sound is not 
discussed further here.

Marine Mammal Habitat Effects

    The Port District's construction activities within the harbor could 
have localized, temporary impacts on marine mammal habitat by 
increasing in-water sound pressure levels and slightly decreasing water 
quality. Construction activities are of short duration and would likely 
have temporary impacts on marine mammal habitat through increases in 
underwater sound. Increased noise levels may affect acoustic habitat 
(see masking discussion above) and adversely affect marine mammal prey 
in the vicinity of the project area (see discussion below). During 
impact pile driving, elevated levels of underwater noise would ensonify 
the harbor where both fish and mammals may occur and could affect 
foraging success.
    In-water pile driving and pile removal would also cause short-term 
effects on water quality due to increased turbidity. Local currents are 
anticipated to disburse suspended sediments produced by project 
activities at moderate to rapid rates depending on tidal stage. The 
Port District would employ standard construction best management 
practices, thereby reducing any impacts. Therefore, the impact from 
increased turbidity levels is expected to be discountable.

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in Monterey Bay and does not include 
any BIAs or ESA-designated critical habitat. Foraging efforts within 
the harbor are minimal, and the narrow mouth of the harbor would 
restrict sound transmission into Monterey Bay to a narrow band of sound 
in the southeastern direction. Pile installation/removal and drilling 
may temporarily increase turbidity resulting from suspended sediments. 
Any increases would be temporary, localized, and minimal. The Port 
District must comply with state water quality standards during these 
operations by limiting the extent of turbidity to the immediate project 
area. In general, turbidity associated with pile installation is 
localized to about a 25-foot radius around the pile (Everitt et al. 
1980). Cetaceans are not expected to enter the harbor and be close 
enough to the project pile driving areas to experience effects of 
turbidity, and any pinnipeds would likely be transiting the area and 
could avoid localized areas of turbidity. Therefore, the impact from 
increased turbidity levels is expected to be discountable to marine 
mammals. Furthermore, pile driving and removal at the project site 
would not obstruct movements or migration of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity in Monterey Bay.
    The duration of the construction activities is relatively short, 
with pile driving and removal activities expected to take only 17 days. 
Each day, construction would occur for only a few hours during the day. 
Impacts to habitat and prey are expected to be temporary and minimal 
based on the short duration of activities.

In-Water Construction Effects on Potential Prey (Fish)

    Construction activities would produce continuous (i.e., vibratory 
pile driving) and pulsed (i.e. impact driving) sounds. Fish react to 
sounds that are especially strong and/or intermittent low-frequency 
sounds. Short duration, sharp

[[Page 13899]]

sounds can cause overt or subtle changes in fish behavior and local 
distribution. Hastings and Popper (2005) identified several studies 
that suggest fish may relocate to avoid certain areas of sound energy. 
Additional studies have documented effects of pile driving on fish, 
although several are based on studies in support of large, multiyear 
bridge construction projects (e.g., Scholik and Yan 2001, 2002; Popper 
and Hastings 2009). Sound pulses at received levels of 160 dB may cause 
subtle changes in fish behavior. SPLs of 180 dB may cause noticeable 
changes in behavior (Pearson et al. 1992; Skalski et al. 1992). SPLs of 
sufficient strength have been known to cause injury to fish and fish 
mortality.
    The most likely impact to fish from pile driving and drilling 
activities at the project area would be temporary behavioral avoidance 
of the area. The duration of fish avoidance of this area after pile 
driving stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. In general, impacts to marine 
mammal prey species are expected to be minor and temporary due to the 
short timeframe for the project.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect fish in the project area. Increased 
turbidity is expected to occur in the immediate vicinity (on the order 
of 10 feet or less) of construction activities. However, suspended 
sediments and particulates are expected to dissipate quickly within a 
single tidal cycle. Given the limited area affected and high tidal 
dilution rates any effects on fish are expected to be minor or 
negligible. In addition, best management practices would be in effect, 
which would limit the extent of turbidity to the immediate project 
area.
    In summary, given the short daily duration of sound associated with 
individual pile driving and drilling events and the relatively small 
areas being affected, pile driving and drilling activities associated 
with the proposed action are not likely to have a permanent, adverse 
effect on any fish habitat, or populations of fish species. Thus, we 
conclude that impacts of the specified activity are not likely to have 
more than short-term adverse effects on any prey habitat or populations 
of prey species. Further, any impacts to marine mammal habitat are not 
expected to result in significant or long-term consequences for 
individual marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the vibratory and impact pile hammers has the potential to result in 
disruption of behavioral patterns for individual marine mammals. There 
is also some potential for auditory injury (Level A harassment) to 
result, primarily for high frequency cetaceans and phocids, because 
predicted auditory injury zones are larger than for mid-frequency 
species and otariids. However, due to the shape of the harbor and the 
small overall ensonified area (see Figure 3 in IHA application), 
auditory injury in high frequency cetaceans is not expected nor 
proposed to be authorized. Auditory injury may occur in phocids within 
the inner harbor area. The proposed mitigation and monitoring measures 
are expected to minimize the severity of such taking to the extent 
practicable.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the proposed take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive intermittent (e.g., impact pile driving) sources.
    The Port District's proposed activity includes the use of 
continuous (vibratory pile driving and removal) and impulsive (impact 
pile driving) sources, and therefore the 120 and 160 dB re 1 [mu]Pa 
(rms) thresholds are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). The Port District's proposed activity 
includes the use of impulsive (impact pile driving) and non-impulsive 
(vibratory pile driving and removal) sources.

[[Page 13900]]

    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa2s. In this Table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighted function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving and removal). The entire lower harbor (see Figure 2a in 
the IHA application) and a small, narrow band extending southeast from 
the mouth of the harbor into Monterey Bay (see Figure 3 in the IHA 
application) may be ensonified by project activities. Vessel traffic 
within the harbor and out in Monterey Bay may contribute to elevated 
background noise levels which may mask sounds produced by the project.
    The distances to the Level A and Level B harassment thresholds were 
calculated based on source levels from similar pile driving activities 
in California and Washington. The Port District utilized in-water 
measurements generated by the Greenbusch Group (2018) from the Seattle 
Pier 62 project (83 FR 39709) to establish proxy sound source levels 
for vibratory removal of the 16-inch timber piles. The results 
determined unweighted rms ranging from 140 dB to 169 dB. NMFS analyzed 
source measurements at different distances for all 63 individual timber 
piles that were removed at Pier 62 and normalized the values to 10 m. 
The results showed that the median is 152 dB SPLrms. This value was 
used as the source level for vibratory removal of 16-inch timber piles 
(Table 4). For vibratory and impact installation of steel sheet piles, 
the Port District utilized reference source levels of vibratory and 
impact driving of 24-inch (0.6 m) steel sheet piles from CalTrans 
Technical Guidance for Assessment and Mitigation of the Hydroacoustic 
Effects of Pile Driving on Fish (Buehler et al., 2015). Vibratory 
driving of 24-inch (0.6 m) AZ steel sheet piles was found to have a 
range of source levels between 160 and 165 dB (rms) at 10 m, but the 
typical source level was 160 dB rms (Table 4). The proposed project 
involves slightly smaller 0.5 m steel sheet piles, but the CalTrans 
source levels are the best available proxy.

                               Table 4--Source Levels for Pile Driving Activities
----------------------------------------------------------------------------------------------------------------
                                                 SPLRMS (dB)
           Activity              SPLPK (dB)                       SEL (dB)                   Source
----------------------------------------------------------------------------------------------------------------
Vibratory timber pile removal             n/a             152             n/a  Greenbusch Group 2018.
Vibratory sheet pile                      175             160             160  Buehler et al., 2015.
 installation.
Impact sheet pile                         205             190             180  Buehler et al., 2015.
 installation.
----------------------------------------------------------------------------------------------------------------

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

    TL = B * Log10 (R 1/R 2),

Where:

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R 1 = the distance of the modeled SPL from the driven 
pile, and
R 2 = the distance from the driven pile of the initial 
measurement

    A practical spreading value of fifteen is often used under 
conditions, such as at the harbor, where water increases with depth as 
the receiver moves away from the shoreline, resulting in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions. Practical spreading loss is 
assumed here.

[[Page 13901]]

    Using the practical spreading loss model, the Port District 
determined the distance where the noise will fall below the behavioral 
effects threshold for both continuous (vibratory pile driving and 
removal) and intermittent (impact pile driving) sources (120 and 160 dB 
dB re 1 [mu]Pa (rms), respectively). These distances are shown in Table 
6 below.
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources (such as pile 
driving), NMFS User Spreadsheet predicts the closest distance at which, 
if a marine mammal remained at that distance the whole duration of the 
activity, it would not incur PTS. Inputs used in the User Spreadsheet, 
and the resulting isopleths are reported below.

              Table 5--User Spreadsheet Input Parameters Used for Calculating Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
                                                                 Vibratory pile driving   Vibratory pile removal
              Parameter                  Impact pile driving          (sheet pile)            (timber pile)
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used.................  (E.1) Impact pile        (A.1) Vibratory pile     (A.1) Vibratory pile
                                        driving.                 driving.                 driving.
Source Level.........................  180 dB SEL.............  160 dB RMS.............  152 dB RMS.
Weighting Factor Adjustment (kHz)....  2......................  2.5....................  2.5.
Number of strikes per pile...........  300....................  N/A....................  N/A.
Number of piles per day..............  6......................  N/A....................  N/A.
Activity Duration (hours) within 24-   N/A....................  6......................  6.
 hour period.
Propagation (xLogR)..................  15LogR.................  15LogR.................  15LogR.
Distance of source level measurement   10.....................  10.....................  10.
 (meters).
----------------------------------------------------------------------------------------------------------------


  Table 6--Calculated Distances to Level A Harassment and Level B Harassment Isopleths During Pile Installation
                                                   and Removal
----------------------------------------------------------------------------------------------------------------
                                                 Level A harassment zone (meters)
                                 ----------------------------------------------------------------     Level B
             Source                                    High-                                        Harassment
                                   Mid-frequency     frequency        Phocid          Otariid      Zone (meters)
                                     cetacean        cetacean        pinniped        pinniped
----------------------------------------------------------------------------------------------------------------
Impact pile driving.............              33           1,111             499              36           1,000
Vibratory pile driving (sheet                  2              29              12               1           4,642
 pile)..........................
Vibratory pile removal (timber               < 1               8               3             < 1           1,359
 pile)..........................
----------------------------------------------------------------------------------------------------------------

    While the calculated distances to the Level A and Level B 
harassment isopleths are up to 4,642 m, the project occurs within a 
nearly completely enclosed harbor, with only a narrow mouth leading out 
into the larger Monterey Bay. The harbor is approximately 152 m wide at 
the project site, and the furthest extent sound could travel in a 
straight line within the harbor is approximately 610 m (see Figures 2a 
and 2b in the IHA application). Depending on the pile location, sound 
may travel out the mouth of the harbor, but only in a small narrow band 
extending to the southeast (see Figure 3 in the IHA application). 
Therefore, while the calculated distances to thresholds are large, the 
actual ensonified area is significantly constrained by land.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    Harbor seals and California sea lions are regular occupants of the 
harbor. Monitors from EcoSystems West conducted surveys of harbor docks 
in May and June 2018 to determine the number of pinnipeds expected to 
occur during the project. As stated previously, harbor seals are known 
to use the harbor docks and other structures for nighttime haulouts. 
Most surveys occurred at dawn to count the number of pinnipeds that may 
be present at the beginning of each day of construction. Additional 
daytime monitoring occurred in July and August 2018 during harbor 
maintenance activities. These daytime surveys included counts of 
pinnipeds hauled out and in the water. The maximum number of hauled out 
harbor seals was 23 while up to three seals were observed in the water 
during the day. Up to four California sea lions were observed using the 
harbor during the day. Harbor porpoises and bottlenose dolphins do not 
typically occur within the harbor, but may transit through the narrow 
band of ensonified area that extends to the southeast of the harbor 
entrance (see Figure 3 in the IHA application).

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    Level B Harassment--Level B takes of harbor seals and California 
sea lions were estimated by multiplying the highest number of animals 
observed within the harbor (23 harbor seals and four California sea 
lions) by the days of activity (17 days). Level B harassment

[[Page 13902]]

take of harbor porpoises and bottlenose dolphins was estimated using 
mean group size and the likelihood that a group of animals may enter 
the ensonified area during the project. Mean group size of harbor 
porpoises traveling through northern Monterey Bay was assumed to be 
1.75 animals (Forney et al., 2014) and we assume that a group of 
porpoises may pass through the ensonified band every other day during 
construction (eight days total). Mean group size of bottlenose dolphins 
was assumed to be eight animals (Weller et al., 2016) and we assume 
that a group of dolphins may pass through the ensonified band every 
other day during construction (eight days).
    Level A Harassment --Level A harassment takes of harbor seals were 
estimated by multiplying the highest number of seals observed in the 
water during the day (three seals) by the number of days of impact pile 
driving (15 days). Level A harassment is only expected and proposed to 
be authorized for harbor seals during impact pile driving, due to the 
relatively small Level A harassment isopleths for other species and 
other activities. Mitigation measures (described in detail below) are 
expected to eliminate any potential for Level A harassment of 
California sea lions within the harbor. While the Level A harassment 
zone for harbor porpoises is greater than that of harbor seals, harbor 
porpoises are not expected to occur within the narrow band of sound 
that may exceed the harassment threshold for sufficient duration to 
experience Level A harassment (see Figures 1 and 3 in the IHA 
application). Take of harbor porpoises by Level A harassment has not 
been requested and is not proposed to be authorized.

        Table 7--Estimated Take by Level A and Level B Harassment, by Species and Stock, Resulting From Proposed Port District Project Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                               Proposed
                                                                 Level B      Level A      Days of    Total level  Total level     Total       take as
               Species                         Stock            takes per    takes per     activity      B take       A take      proposed    percentage
                                                                   day          day                                                 take       of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal.........................  California.............           23            3        17\a\          391           45          436         1.41
California sea lion.................  U.S....................            4            0           17           68            0           68         0.03
Bottlenose dolphin..................  California Coastal.....            8            0         8\b\           64            0           64         14.1
Harbor porpoise.....................  Monterey Bay...........            2            0         8\b\           16            0           16         0.43
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Days of activity for Level A take calculations is only 15 days of impact pile driving.
\b\ Harbor porpoises and bottlenose dolphins are expected to occur within the ensonified area every other day during construction activities.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.

Mitigation for Marine Mammals and Their Habitat

    In addition to the measures described later in this section, the 
Port District will employ the following standard mitigation measures:
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water heavy machinery work other than pile driving 
(e.g., pre-drilling, etc.), if a marine mammal comes within 10 m, 
operations shall cease and equipment use reduced to minimum level 
required to maintain safe working conditions. This type of work could 
include the following activities: (1) Pre-drilling; or (2) positioning 
of the pile on the substrate via a land-based crane;
     Work may only occur during daylight hours, when visual 
monitoring of marine mammals can be conducted;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal and drilling 
will shut down immediately if such species are observed within or on a 
path towards the monitoring zone (i.e., Level B harassment zone); and
     If take reaches the authorized limit for an authorized 
species, pile installation will be stopped as these species approach 
the Level B harassment zone to avoid additional take.
    The following measures are also included in the mitigation 
requirements:
    Establishment of Shutdown Zone for Level A Harassment--For all pile 
driving and removal activities, the Port District must establish a 
shutdown zone. The purpose of a shutdown zone is generally to define an 
area within which shutdown of an activity would occur upon sighting of 
a marine mammal (or in anticipation of an animal entering the defined 
area). During all pile driving activities, a minimum shutdown zone of 
25 m would be enforced (Table 8). A 40 m shutdown zone would be used 
for California sea lions during impact pile driving to prevent Level A 
harassment exposure (Table 8). Harbor porpoises and bottlenose dolphins 
are not

[[Page 13903]]

expected to occur within the harbor, so instead of a standard shutdown 
distance, the Port District will be required to shutdown impact pile 
driving activities if these species are observed entering the harbor 
(Table 8). A Protected Species Observer (PSO) will be stationed within 
the harbor such that they have a view of the immediate area around the 
pile driving as well as the areas north (toward the back of the harbor) 
and south (toward the harbor entrance) of the project site.
    Establishment of Monitoring Zones for Level B Harassment--The 
calculated distances to the Level B harassment thresholds may exceed 
the distance within the harbor that sound may travel in a linear 
direction. The harbor is approximately 152 m wide at the project site, 
and the furthest extent sound could travel in a straight line within 
the harbor is approximately 610 m (see Figures 2a and 2b in the IHA 
application). Sound may transmit in a narrow band into Monterey Bay 
through the mouth of the harbor but the overall ensonified area is 
relatively small. As stated above, a PSO will be stationed within the 
harbor. Rather than a set distance-based monitoring zone, the PSOs will 
monitor the entire observable harbor area (Table 8).

       Table 8--Shutdown and Monitoring Zones by Project Activity
------------------------------------------------------------------------
          Activity              Shutdown zone (m)      Monitoring zone
------------------------------------------------------------------------
Vibratory removal of timber   All species: 25.....  Entire observable
 piles.                                              harbor area.
Impact installation of steel  Harbor seal: 25.....
 sheet piles.                 California sea lion:
                               40.
                              Harbor porpoise and
                               bottlenose dolphin:
                               At mouth of harbor.
Vibratory installation of     All species: 25.....
 steel sheet piles.
All other in-water            10..................
 activities (e.g., pre-
 drilling).
------------------------------------------------------------------------

    Soft Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
would be required to provide an initial set of strikes from the hammer 
at reduced energy, with each strike followed by a 30-second waiting 
period. This procedure would be conducted a total of three times before 
impact pile driving begins. Soft start would be implemented at the 
start of each day's impact pile driving and at any time following 
cessation of impact pile driving for a period of thirty minutes or 
longer. Soft start is not required during vibratory pile driving and 
removal activities.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal or 
drilling of 30 minutes or longer occurs, PSOs will observe the shutdown 
and monitoring zones for a period of 30 minutes. The shutdown zone will 
be cleared when a marine mammal has not been observed within the zone 
for that 30-minute period. If a marine mammal is observed within the 
shutdown zone, a soft-start cannot proceed until the animal has left 
the zone or has not been observed for 15 minutes. If the Level B 
harassment zone has been observed for 30 minutes and non-permitted 
species are not present within the zone, soft start procedures can 
commence and work can continue even if visibility becomes impaired 
within the Level B monitoring zone. When a marine mammal permitted for 
Level B harassment take is present in the Level B harassment zone, 
activities may begin and Level B harassment take will be recorded. As 
stated above, if the entire Level B harassment zone is not visible at 
the start of construction, piling or drilling activities can begin. If 
work ceases for more than 30 minutes, the pre-activity monitoring of 
both the Level B harassment and shutdown zone will commence.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations 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. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Marine Mammal Visual Monitoring

    Monitoring shall be conducted by NMFS-approved observers. A trained

[[Page 13904]]

observer shall be placed from the best vantage point(s) practicable to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable through communication with the equipment operator. 
Observer training must be provided prior to project start, and shall 
include instruction on species identification (sufficient to 
distinguish the species in the project area), description and 
categorization of observed behaviors and interpretation of behaviors 
that may be construed as being reactions to the specified activity, 
proper completion of data forms, and other basic components of 
biological monitoring, including tracking of observed animals or groups 
of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal and drilling activities. In 
addition, observers shall record all incidents of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions in concert with distance from piles being 
driven or removed. Pile driving/removal and drilling activities include 
the time to install or remove a single pile or series of piles, as long 
as the time elapsed between uses of the pile driving equipment is no 
more than 30 minutes.
    One PSO would be stationed at a location within the harbor that 
allows full monitoring of the area immediately around the piles being 
driven, as well as a view toward the back of the harbor and toward the 
harbor entrance. The PSO would scan the waters using binoculars, and/or 
spotting scopes if necessary, and would use a handheld GPS or range-
finder device to verify the distance to each sighting from the project 
site. All PSOs would be trained in marine mammal identification and 
behaviors and are required to have no other project-related tasks while 
conducting monitoring. In addition, monitoring will be conducted by 
qualified observers, who will be placed at the best vantage point(s) 
practicable to monitor for marine mammals and implement shutdown/delay 
procedures when applicable by calling for the shutdown to the hammer 
operator. The Port District would adhere to the following observer 
qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required;
    (ii) At least one observer must have prior experience working as an 
observer;
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience;
    (iv) Where a team of three or more observers are required, one 
observer shall be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer; and
    (v) The Port District shall submit observer CVs for approval by 
NMFS.
    Additional standard observer qualifications include:
     Ability to conduct field observations and collect data 
according to assigned protocols. Experience or training in the field 
identification of marine mammals, including the identification of 
behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving and removal and 
drilling activities. It will include an overall description of work 
completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report must include:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.
    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 addressing NMFS comments must be submitted 
within 30 days after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury, serious injury or mortality, the Port 
District would immediately cease the specified activities and report 
the incident to the Office of Protected Resources, NMFS, and the West 
Coast Regional Stranding Coordinator. The report would include the 
following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with the Port 
District to determine what is necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The Port District 
would not be able to resume their activities until notified by NMFS via 
letter, email, or telephone.
    In the event that the Port District discovers an injured or dead 
marine mammal, and the lead PSO determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition as described in the next 
paragraph), the Port District would immediately report the incident to 
the Office of Protected Resources, NMFS, and the NMFS West Coast 
Stranding Hotline and/or by email to the West Coast Regional Stranding 
Coordinator. The report would include the same information identified 
in the paragraph above. Activities would be able to continue while NMFS 
reviews the circumstances of the incident. NMFS would work with the 
Port District to determine whether modifications in the activities are 
appropriate.
    In the event that the Port District discovers an injured or dead 
marine mammal and the lead PSO determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate

[[Page 13905]]

to advanced decomposition, or scavenger damage), the Port District 
would report the incident to the Office of Protected Resources, NMFS, 
and the NMFS West Coast Stranding Hotline and/or by email to the West 
Coast Regional Stranding Coordinator, within 24 hours of the discovery. 
The Port District would provide photographs, video footage (if 
available), or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact 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 (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'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Pile driving and removal activities associated with the seawall 
replacement project as outlined previously, have the potential to 
disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level A harassment and 
Level B harassment from underwater sounds generated from pile 
installation and removal. Potential takes could occur if individuals of 
these species are present in the ensonified zone when these activities 
are underway.
    The takes from Level A and Level B harassment would be due to 
potential behavioral disturbance, TTS, and PTS. No mortality is 
anticipated given the nature of the activity and measures designed to 
minimize the possibility of injury to marine mammals. Level A 
harassment is only anticipated for harbor seals. The potential for 
harassment is minimized through the construction method and 
implementation of the planned mitigation measures (see Proposed 
Mitigation section above).
    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, Inc. 2012; Lerma 2014; ABR 2016). 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. The pile driving activities analyzed here are similar to, or 
less impactful than, numerous other construction activities conducted 
in northern California, which have taken place with no known long-term 
adverse consequences from behavioral harassment. Level B harassment 
will be reduced to the level of least practicable adverse 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 area while the activity is occurring. While 
vibratory driving associated with the proposed project may produce 
sound at distances of several kilometers from the project site through 
the mouth of the harbor, thus intruding on some habitat, the project 
site itself is located in a busy harbor and the majority of sound 
fields produced by the specified activities are contained within the 
harbor. Therefore, we expect that animals annoyed by project sound 
would simply avoid the area and use more-preferred habitats.
    In addition to the expected effects resulting from authorized Level 
B harassment, we anticipate that harbor seals may sustain some limited 
Level A harassment in the form of auditory injury. However, animals in 
these locations that experience PTS would likely only receive slight 
PTS, i.e., minor degradation of hearing capabilities within regions of 
hearing that align most completely with the energy produced by pile 
driving, i.e., the low-frequency region below 2 kHz, not severe hearing 
impairment or impairment in the regions of greatest hearing 
sensitivity. If hearing impairment occurs, it is most likely that the 
affected animal would lose a few decibels in its hearing sensitivity, 
which in most cases is not likely to meaningfully affect its ability to 
forage and communicate with conspecifics. As described above, we expect 
that marine mammals would be likely to move away from a sound source 
that represents an aversive stimulus, especially at levels that would 
be expected to result in PTS, given sufficient notice through use of 
soft start.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. 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.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     The Level A harassment exposures are anticipated to result 
only in slight PTS, within the lower frequencies associated with pile 
driving;
     The anticipated incidents of Level B harassment consist 
of, at worst, temporary modifications in behavior that would not result 
in fitness impacts to individuals;
     The specified activity and ensonified area is very small 
relative to the overall habitat ranges of all species and does not 
include habitat areas of special significance (BIAs or ESA-designated 
critical habitat); and
     The presumed efficacy of the proposed mitigation measures 
in reducing the effects of the specified activity to the level of least 
practicable adverse impact.
    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

[[Page 13906]]

measures, NMFS preliminarily finds that the total marine mammal take 
from the proposed activity will have a negligible impact on all 
affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    Table 7 presents the number of animals that could be exposed to 
received noise levels that could cause Level A and Level B harassment 
for the proposed activities. Our analysis shows that less than 15 
percent of each affected stock could be taken by harassment. The 
numbers of animals proposed to be taken for these stocks would be 
considered small relative to the relevant stock's abundances even if 
each estimated taking occurred to a new individual--an unlikely 
scenario.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the Port District for the Aldo's Seawall Replacement 
Project in Santa Cruz, CA from June 1, 2019 through May 31, 2020, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. A draft of the IHA itself is available 
for review in conjunction with this notice at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed pile 
driving project. We also request comment on the potential for renewal 
of this proposed IHA as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform our final decision on the request for MMPA 
authorization.
    On a case-by-case basis, NMFS may issue a second one-year IHA 
without additional notice when (1) another year of identical or nearly 
identical activities as described in the Specified Activities section 
is planned or (2) the activities would not be completed by the time the 
IHA expires and a second IHA would allow for completion of the 
activities beyond that described in the Dates and Duration section, 
provided all of the following conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA;
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted beyond the 
initial dates either are identical to the previously analyzed 
activities or include changes so minor (e.g., reduction in pile size) 
that the changes do not affect the previous analyses, take estimates, 
or mitigation and monitoring requirements; and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized;
     Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures remain the same and appropriate, 
and the original findings remain valid.

    Dated: April 3, 2019.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2019-06885 Filed 4-5-19; 8:45 am]
BILLING CODE 3510-22-P