Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Aldo's Seawall Replacement Project in Santa Cruz, California, 22820-22829 [2019-10429]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 97 (Monday, May 20, 2019)]
[Notices]
[Pages 22820-22829]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-10429]


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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; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the Santa Cruz Port District (Port District) to incidentally harass, by 
Level A and Level B harassment only, marine mammals during pile driving 
activities associated with the Aldo's Seawall Replacement Project in 
Santa Cruz, California (CA).

DATES: This authorization is effective from June 1, 2019 through May 
31, 2020.

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.

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 was for take of four species of marine mammals 
by Level B harassment and Level A harassment. Neither the Port District 
nor NMFS expect serious injury or mortality to result from this 
activity and therefore, an IHA is appropriate.

Description of Activity

    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. The 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. Four 16-inch (in) (40.6 centimeter (cm)) timber piles 
supporting the public wharf will be permanently removed using a 
vibratory hammer. Ninety steel sheet piles will be installed using 
vibratory and impact hammers. Sounds produced by these activities may 
result in take, by Level A and Level B harassment, of marine mammals 
within and outside of the harbor.
    In-water work associated with the project is expected to occur on 
28 non-consecutive days between June 15, 2019 and November 1, 2019. 
Work will be limited to daylight hours only, and timed to occur at low 
tide, as feasible.
    A detailed description of the planned activities is provided in the 
Federal Register notice announcing the proposed IHA (84 FR 13892; April 
8, 2019). Since that time, no changes have been made to the Port 
District's planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for the 
description of the specific activity.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to the Port District was 
published in the Federal Register on April 8, 2019 (84 FR 13892). That 
notice described, in detail, the Port District's activity, the marine 
mammal species that may be affected by the activity, the anticipated 
effects on marine mammals and their habitat, proposed amount and manner 
of take, and proposed mitigation, monitoring and reporting measures. On 
May 6, 2019, NMFS received a comment letter from the Marine Mammal 
Commission (Commission); the Commission's recommendations and our 
responses are provided here, and the comments have been posted online 
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. The Commission 
recommended that NMFS issue the IHA, subject to inclusion of the 
proposed mitigation, monitoring, and reporting measures.
    Comment 1: The Commission questioned whether the public notice 
provisions for IHA Renewals fully satisfy the public notice and comment 
provision in the MMPA and discussed the potential burden on reviewers 
of reviewing key documents and developing comments quickly. Therefore, 
the Commission recommended that NMFS use the IHA Renewal process 
sparingly and selectively for activities expected to have the lowest 
levels of impacts to marine mammals and that require less complex 
analysis.
    Response: NMFS has taken a number of steps to ensure the public has 
adequate notice, time, and information to be able to comment 
effectively on IHA Renewals within the limitations of

[[Page 22821]]

processing IHA applications efficiently. The Federal Register notice 
for the initial proposed IHA (84 FR 13892; April 8, 2019) had 
previously identified the conditions under which a one-year Renewal IHA 
might be appropriate. This information is presented in the Request for 
Public Comments section of the initial proposed IHA and thus encourages 
submission of comments on the potential of a one-year renewal as well 
as the initial IHA during the 30-day comment period. In addition, when 
we receive an application for a Renewal IHA, we publish a notice of the 
proposed IHA Renewal in the Federal Register and provide an additional 
15 days for public comment, for a total of 45 days of public comment. 
We will also directly contact all commenters on the initial IHA by 
email, phone, or, if the commenter did not provide email or phone 
information, by postal service to provide them the opportunity to 
submit any additional comments on the proposed Renewal IHA.
    NMFS also strives to ensure the public has access to key 
information needed to submit comments on a proposed IHA, whether an 
initial IHA or a Renewal IHA. The agency's website includes information 
for all projects under consideration, including the application, 
references, and other supporting documents. Each Federal Register 
notice also includes contact information in the event a commenter has 
questions or cannot find the information they seek.
    Regarding the Commission's comment that Renewal IHAs should be 
limited to certain types of projects, NMFS has explained on its website 
and in individual Federal Register notices that Renewal IHAs are 
appropriate where the continuing activities are identical, nearly 
identical, or a subset of the activities for which the initial 30-day 
comment period applied. Where the commenter has likely already reviewed 
and commented on the initial proposed IHA for these activities, the 
abbreviated additional comment period is sufficient for consideration 
of the results of the preliminary monitoring report and new information 
(if any) from the past year.

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 1 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 1 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 1--Marine Mammals With Potential Presence Within the 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).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.


[[Page 22822]]

    A detailed description of the species likely to be affected by the 
project, including brief introductions to the species and relevant 
stocks as well as available information regarding population trends and 
threats, and information regarding local occurrence, were provided in 
the Federal Register notice for the proposed IHA (84 FR 13892; April 8, 
2019); since that time, we are not aware of any changes in the status 
of these species and stocks; therefore, detailed descriptions are not 
provided here. Please refer to that Federal Register notice for these 
descriptions. Please also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the Port District's activities 
for the Aldo's Seawall Replacement Project have the potential to result 
in behavioral harassment of marine mammals in the vicinity of the 
action area. The Federal Register notice for the proposed IHA (84 FR 
13892; April 8, 2019) included a discussion of the effects of 
anthropogenic noise on marine mammals, therefore that information is 
not repeated here; please refer to the Federal Register notice (84 FR 
13892; April 8, 2019) for that information.

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized 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 will 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, phocids, and otariids, 
because predicted auditory injury zones are larger than for mid-
frequency species. 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 
authorized. Auditory injury may occur in phocids and otariids within 
the inner harbor area during impact pile driving. The 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 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 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 a 
permanent threshold shift (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 decibels (dB) re 1 microPascal ([mu]Pa) (root 
mean square (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 
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 activity includes the 
use of impulsive (impact pile driving) and non-impulsive (vibratory 
pile driving and removal) sources.
    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.

[[Page 22823]]



                     Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift
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                                                     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 weighting function (OF, 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 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 
meters (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 3). 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 3). The project involves 
slightly smaller 0.5 m steel sheet piles, but the CalTrans source 
levels are the best available proxy.

                               Table 3--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 (R1/R2),
Where:

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = 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.
    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 
5 below.
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume

[[Page 22824]]

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 4--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 5--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 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. Mean 
group size of bottlenose dolphins was assumed to be eight animals 
(Weller et al., 2016) and

[[Page 22825]]

we assume that a group of dolphins may pass through the ensonified band 
every other day during construction. In the Federal Register notice of 
proposed IHA (84 FR 13892; April 8, 2019), we used eight days to 
estimate the number of bottlenose dolphins and harbor porpoises that 
may be taken by Level B harassment. However, as noted by the 
Commission, if a group of bottlenose dolphins or harbor porpoises were 
to pass through the ensonified area on the first day of construction, 
and every other day after, the total number of days that these animals 
may be harassed would be nine days. Therefore, nine days is used here 
as the duration to estimate the number of bottlenose dolphins and 
harbor porpoises that may be taken.
    Level A Harassment--In the Federal Register notice of proposed IHA 
(84 FR 13892; April 8, 2019), 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 was only 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. However, during the public comment period, the 
Commission suggested that although only three harbor seals have been 
observed within the harbor during the day, because up to 23 harbor 
seals may utilize the harbor, Level A take of 23 harbor seals per day 
should be authorized. We agreed with the Commission's suggestion, and 
have increased the authorized takes by Level A harassment accordingly.
    Additionally, in the Federal Register notice of proposed IHA (84 FR 
13892; April 8, 2019), NMFS asserted that mitigation measures (see 
below) were expected to eliminate any potential for Level A harassment 
of California sea lions within the harbor. During the public comment 
period, the Commission suggested that NMFS authorize one take by Level 
A harassment of California sea lion per day of impact pile driving, due 
to the prevalence of California sea lions within the harbor and the 
potential for animals to enter the relevant Level A harassment zone 
before a shutdown can be initiated. NMFS agreed and has authorized one 
take of California sea lion by Level A harassment per day of impact 
pile driving (15 days).
    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 was not requested and has not been authorized.

            Table 6--Estimated Take by Level A and Level B Harassment, by Species and Stock, Resulting From Port District Project Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                              Authorized
                                                                 Level B      Level A      Days of    Total Level  Total Level     Total       take as
               Species                         Stock            takes per    takes per     activity      B take       A take     authorized   percentage
                                                                   day          day                                                 take       of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal.........................  California.............           23           23       \a\ 17          391          345          736         2.38
California sea lion.................  U.S....................            4            1           17           68           15           83         0.03
Bottlenose dolphin..................  California Coastal.....            8            0        \b\ 9           72            0           72         15.9
Harbor porpoise.....................  Monterey Bay...........            2            0        \b\ 9           18            0           18         0.48
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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.

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;

[[Page 22826]]

     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 the public comment period, the Commission noted that the 
shutdown zones proposed in the Federal Register notice of proposed IHA 
(84 FR 13892; April 8, 2019) should be modified for certain activities 
to be more consistent with the activity-specific Level A harassment 
zones. Specifically, the Commission suggested that the shutdown zone 
for vibratory removal of timber piles should be decreased from 25 m to 
10 m, the shutdown zone for vibratory installation of sheet piles 
should be reduced from 25 m to 15 for pinnipeds and increased from 25 m 
to 30 m for harbor porpoises, and the shutdown zone for impact driving 
of sheet piles should be 25 m for all pinnipeds. NMFS agrees with the 
Commission's suggestions, and has adjusted the shutdown zones 
accordingly (Table 7).
    Harbor porpoises and bottlenose dolphins are not 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 7). 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 7).

                           Table 7--Shutdown and Monitoring Zones by Project Activity
----------------------------------------------------------------------------------------------------------------
               Activity                      Shutdown zone (m)                      Monitoring zone
----------------------------------------------------------------------------------------------------------------
Vibratory removal of timber piles....  All species: 10..............  Entire observable harbor area.
Impact installation of steel sheet     Pinnipeds: 25. Harbor
 piles.                                 porpoise and bottlenose
                                        dolphin: At mouth of harbor.
Vibratory installation of steel sheet  Pinnipeds: 15. Harbor
 piles.                                 porpoise: 30.
All other in-water activities (e.g.,   10.
 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 measures, as well as 
other measures considered by NMFS, NMFS has determined that the 
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.

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 
action area. Effective reporting is critical both to compliance as well 
as ensuring that

[[Page 22827]]

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 
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 will 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 will 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 will 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 must 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);

[[Page 22828]]

     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 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 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 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

[[Page 22829]]

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 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 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 monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the Port 
District's 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 6 presents the number of animals that could be exposed to 
received noise levels that could cause Level A and Level B harassment 
for the Port District's activities. Our analysis shows that less than 
16 percent of each affected stock could be taken by harassment. The 
numbers of animals anticipated 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 Port District's 
activity (including the mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS 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.

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 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 determined that the issuance of the 
IHA qualifies to be categorically excluded from further NEPA review.

Endangered Species Act (ESA)

    No incidental take of ESA-listed species is authorized 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.

Authorization

    NMFS has issued an IHA to the Port District for the incidental take 
of marine mammals due to in-water construction work associated with 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.

    Dated: May 14, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-10429 Filed 5-17-19; 8:45 am]
 BILLING CODE 3510-22-P