Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to In-Water Demolition and Construction Activities Associated With a Harbor Improvement Project in Statter Harbor, Alaska, 11066-11079 [2019-05668]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 57 (Monday, March 25, 2019)]
[Notices]
[Pages 11066-11079]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-05668]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG506


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to In-Water Demolition and 
Construction Activities Associated With a Harbor Improvement Project in 
Statter Harbor, Alaska

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 City of Juneau to incidentally harass, by Level A and Level B 
harassment, marine mammals during construction activities associated 
with harbor improvements at Statter Harbor in Auke Bay, Alaska

DATES: This authorization is effective from October 1, 2019 to 
September 30, 2020.

FOR FURTHER INFORMATION CONTACT: Sara Young, 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/

[[Page 11067]]

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 was 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.
    The NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as it applies to a ``military 
readiness activity.'' The definitions of all applicable MMPA statutory 
terms cited above are included in the relevant sections below.

Summary of Request

    On February 12, 2018, NMFS received a request from the City of 
Juneau for an IHA to take marine mammals incidental to harbor 
improvement projects in Statter Harbor, Alaska. The original 
application covered three years of potential work and was revised to 
one year of work on March 9, 2018. A series of exchanges regarding 
acoustic analyses continued until a meeting was held on June 21, 2018. 
An additional revision was received on August 8, 2018. The application 
was deemed adequate and complete on September 18, 2018. The City of 
Juneau's request is for take of a small number of harbor seal, harbor 
porpoise, humpback whale, and Steller sea lion by Level B harassment 
and Level A harassment. Neither the City of Juneau nor NMFS expects 
serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate.

Description of Activity

    The harbor improvements described in the application include 
demolition and disposal of the existing boat launch ramp and timber 
haulout pier, dredging of the planned harbor basin with offshore 
disposal, excavation of bedrock within the basin by blasting from a 
temporary fill pad, and construction of a mechanically stabilized earth 
wall. In our notice of proposed IHA, we stated work was expected to 
begin in April. Due to administrative delays and other permitting 
needs, we were notified by the City of Juneau that work is now expected 
to occur between October 1, 2019 and September 30, 2020. The expected 
allocation of days for each activity is as follows: Two to ten days of 
vibratory pile removal, 30-45 days of dredging and dredge disposal, 15 
days of in-water fill placement and removal, and two days of blasting. 
To be conservative, 12-hour work days were used to analyze construction 
noise. The daily construction window for blasting and dredging will 
begin no sooner than 30 minutes after sunrise to allow for initial 
marine mammal monitoring to take place and will end 30 minutes before 
sunset to allow for post-activity monitoring.
    The activities will occur at Statter Harbor in Auke Bay, Alaska 
which is in the southeast portion of the state. See Figures 1 and 4 in 
the application for detailed maps of the project area. Statter Harbor 
is located at the most northeasterly point of Auke Bay.
    A detailed description of the planned harbor improvements project 
is provided in the Federal Register notice for the proposed IHA (83 FR 
52394; October 17, 2018). Since that time, no changes have been made to 
the planned activities. Therefore, a detailed description is not 
provided here. Please refer to that Federal Register notice for 
detailed description of the specified activity.

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to the City of Juneau 
was published in the Federal Register on October 17, 2018 (83 FR 
52394). That notice described, in detail, the City's activity, the 
marine mammal species that may be affected by the activity, and the 
anticipated effects on marine mammals. During the 30-day public comment 
period, NMFS received comments from the Marine Mammal Commission. For 
full details of the comments, please see the Commission's letter, which 
is available online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#active-authorizations. The comments and our response are 
provided below.
    Comment: The Commission recommends that NMFS estimate and 
ultimately authorize takes of marine mammals by Level B harassment 
during all activities involving explosives, including single detonation 
events, for this and all future IHAs.
    Response: NMFS believes that the best scientific evidence available 
indicates that it is appropriate to use a behavioral onset threshold 
for multiple detonations and to consider detonations with microdelays 
between them as a single detonation. The two blasts conducted by 
Statter Harbor are confined blasts with charge detonations separated by 
microdelays, constituting a single detonation event per day with blasts 
occurring for a total of two days.
    Comment: The Commission recommends that NMFS require the City of 
Juneau to conduct hydroacoustic monitoring of blasting activity and 
provide data from the first blast event to NMFS for review prior to the 
second blasting event. The Commission also states that NMFS should 
adjust Level A and B harassment zones if necessary prior to the second 
blasting event.
    Response: NMFS disagrees with the Commission that hydroacoustic 
monitoring of the two blasts conducted at Statter Harbor should be 
required. The blasts are considered single detonation events with only 
two total blasts proposed, occurring on two separate days. It is still 
unknown how close together the two blasting days would occur, and is 
likely not enough time to analyze data and develop a hydroacoustic 
monitoring report, submit to NMFS for review, and make adjustments 
accordingly. Additionally, the City plans to conduct blasting as 
quickly and efficiently as possible so as not to overlap with the 
beginning of harbor seal pupping season, as harbor seals are resident 
in the area. Therefore, this requirement may result in more severe 
impacts to local harbor seals through delay of the second blast.

[[Page 11068]]

    Comment: The Commission states that if NMFS believes that 
authorization for taking marine mammals incidental to vessel transit by 
tug is not warranted, that NMFS should find that authorization for take 
of marine mammals incidental to dredging is also not warranted. 
Furthermore, the Commission recommends that NMFS determine which 
activities warrant incidental take authorizations under the MMPA and 
apply that approach consistently for all actions.
    Response: NMFS makes determinations on whether take should be 
authorized for specific activities on a case by case basis while 
factoring in project-specific considerations. While NMFS does not 
generally think noise generated from dredging is likely to result in 
take, the dredging that is planned for this action occurs directly in 
an area known to be habitat for a resident harbor seal population and 
will occur for an extended period. This project constitutes a grouping 
of activities in a small geographic area, where marine mammals are 
known to be resident, and the presence of these activities could 
disrupt their behavioral patterns. While we do not think that dredging 
by itself is likely to result in take, the combination of factors 
presented in this specific circumstance, in conjunction with other 
activities in a confined harbor area that is consistently inhabited by 
harbor seals, leads us to conclude that dredging presents the potential 
to harass marine mammals.
    Comment: The Commission recommends that NMFS refrain from 
implementing its proposed renewal process and instead use abbreviated 
Federal Register notices and reference existing documents to streamline 
the IHA process. If NMFS adopts the proposed renewal process, the 
Commission recommends that NMFS provide the Commission and the public a 
legal analysis supporting its conclusion that the process is consistent 
with section 101(a)(5)(D) of the MMPA.
    Response: The notice of the proposed IHA (83 FR 52394; October 17, 
2018) expressly notifies the public that under certain, limited 
conditions an applicant could seek a renewal IHA for an additional 
year. The notice describes the conditions under which such a renewal 
request could be considered and expressly seeks public comment in the 
event such a renewal is sought. Additional reference to this 
solicitation of public comment has recently been added at the beginning 
of the FR notices that consider renewals, requesting input specifically 
on the possible renewal itself. NMFS appreciates the streamlining 
achieved by the use of abbreviated FR notices and intends to continue 
using them for proposed IHAs that include minor changes from previously 
issued IHAs, but which do not satisfy the renewal requirements. 
However, we believe our method for issuing renewals meets statutory 
requirements and maximizes efficiency. However, importantly, such 
renewals will be limited to circumstances where: The activities are 
identical or nearly identical to those analyzed in the proposed IHA; 
monitoring does not indicate impacts that were not previously analyzed 
and authorized; and, the mitigation and monitoring requirements remain 
the same, all of which allow the public to comment on the 
appropriateness and effects of a renewal at the same time the public 
provides comments on the initial IHA. NMFS has, however, modified the 
language for future proposed IHAs to clarify that all IHAs, including 
renewal IHAs, are valid for no more than one year and that the agency 
will consider only one renewal for a project at this time. In addition, 
notice of issuance or denial of a renewal IHA will be published in the 
Federal Register, as they are for all IHAs. The option for issuing 
renewal IHAs has been in NMFS' incidental take regulations since 1996. 
We will provide any additional information to the Commission and 
consider posting a description of the renewal process on our website 
before any renewal is issued utilizing this process.

Description of Marine Mammals in the Area of Specified Activities

    Seven species of marine mammal have been documented in southeast 
Alaska waters in the vicinity of Statter Harbor. These species are: 
Harbor seal, harbor porpoise, Dall's porpoise, killer whale, humpback 
whale, minke whale, and Steller sea lion. Of these species, only three 
are known to occur in Statter Harbor: Harbor seal, Steller sea lion, 
and humpback whale.
    Sections 3 and 4 of the 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/draft-marine-mammal-stock-assessment-reports) 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 
Statter Harbor 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 (2017). 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. Alaska Region Draft 2018 SAR (Muto et al, 2018). All values 
presented in Table 1 are the most recent available at the time of 
publication and are available in the Draft 2018 SAR (Muto et al, 2018).

[[Page 11069]]



                                             Table 1--Species With the Potential to Occur in Statter Harbor
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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 Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals):
    Humpback whale..................  Megaptera noveangliae..  Central North Pacific..  E, D,Y              10,103 (0.3, 7,891,            83         26
                                                                                                             2006).
    Minke whale.....................  Balaenoptera             Alaska.................  -;N                 N/A...................        Und          0
                                       acutorostrata.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Northern Resident......  -;N                 261 (N/A, 261, 2011)..       1.96          0
    Killer whale....................  Orcinus orca...........  Gulf of Alaska           -;N                 587 (N/A, 587, 2012)..       5.87          1
                                                                transient.
    Killer whale....................  Orcinus orca...........  West Coast Transient...  -;N                 243 (N/A, 243, 2009)..        2.4          0
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -; Y                975 (0.14, 872, 2012).        8.7         34
    Dall's porpoise.................  Phocoenoides dalli.....  Alaska.................  -;N                 83,400 (0.097, N/A,           Und         38
                                                                                                             1991).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Western DPS............  E/D; Y              54,267 (N/A; 54,267,          326        252
                                                                                                             2017).
    Steller sea lion................  Eumetopias jubatus.....  Eastern DPS............  T/D; Y              41,638 (N/A, 41,638,         2498        108
                                                                                                             2015).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Lynn Canal.............  -; N                9,478 (N/A, 8,605,            155         50
                                                                                                             2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: www.nmfs.noaa.gov/pr/sars/. 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.
Note--Italicized species are not expected to be present and take is not authorized.

    All species that could potentially occur in the action areas are 
included in Table 1. It is unlikely the species italicized above in 
Table 1 are likely to venture far enough into the harbor to enter the 
acoustic isopleths where we expect take to occur. The spatial 
occurrence of minke whale and Dall's porpoise is such that take is not 
expected to occur, and they are not discussed further beyond the 
explanation provided here. While these species have been sighted in 
southeast Alaska more broadly, these sightings have been recorded for 
areas closer to the ocean. Auke Bay is separated from the Pacific by 
multiple barrier islands and Statter Harbor is located in the most 
inland section of the bay, making the occurrence of species 
infrequently sighted farther seaward even less likely. Killer whales 
are not known to occur frequently in Auke Bay, although they have been 
sighted infrequently, with no obvious temporal pattern to the 
sightings. While it is possible killer whales could enter Auke Bay 
during work, it is unlikely they would continue as far inland as 
Statter Harbor. If killer whales did venture into Statter Harbor to a 
distance where acoustic exposure would be a concern, they would be 
easily identifiable to observers stationed in the harbor for mitigation 
and monitoring purposes and a shutdown would be ordered. Therefore, 
take of killer whales from these activities is unlikely to occur and 
they are not considered further in this document. The work in Statter 
Harbor is in a very sheltered and inland harbor with a consistent 
sightings record of the three species considered further: Steller sea 
lion, humpback whale, and harbor seal. Harbor porpoise, while 
infrequently sighted near Statter Harbor, are considered further as 
their fast swim speeds and small size make detection to implement 
mitigation measures difficult.
    A detailed description of the species likely to be affected by the 
Statter Harbor 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 (83 FR 52394; October 17, 2018); 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.

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

[[Page 11070]]

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 decibels (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 hertz (Hz) and 35 
kilohertz (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 construction activities. Please refer to Table 1. Of the cetacean 
species that may be present, humpback whales are classified as low-
frequency cetaceans, and harbor porpoise are classified as high-
frequency cetaceans.

Potential Effects of Specified Activities on Marine Mammals and their 
Habitat

    The effects of underwater noise from blasting, vibratory pile 
removal, and dredging activities for the Statter Harbor 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 (83 FR 52394; October 17, 2018) 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 for that information.

Anticipated Effects on Habitat

    The main impact associated with the Statter Harbor improvement 
project will be temporarily elevated sound levels and the associated 
direct effects on marine mammals. The project will not result in 
permanent impacts to habitats used directly by marine mammals, such as 
haulout sites, but may have potential short-term impacts to food 
sources such as forage fish, etc, and minor impacts to the immediate 
substrate during installation and removal of piles and blasting during 
the project. These potential effects are discussed in detail in the 
Federal Register notice for the proposed IHA (53 FR 5394; October 17, 
2018), therefore that information is not repeated here; please refer to 
that Federal Register notice 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 explosives, vibratory pile removal, and dredging 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 from blasting, primarily for high frequency 
species and phocids because predicted auditory injury zones are larger 
than for low-frequency species and otariids. The mitigation and 
monitoring measures are expected to minimize the severity of such 
taking to the extent practicable. While the zones for slight lung 
injury are large enough that a marine mammal could occur within the 
zone (45 meters), the mitigation and monitoring measures, such as 
delaying blasting as long as possible until animals are no longer 
within the PTS zone, are expected to minimize the potential for such 
taking to the extent practicable, such that the potential for non-
auditory physical injury is considered discountable.
    As described previously, no mortality is anticipated or authorized 
for this activity. Of the activities for which take is requested, only 
blasting has the potential to result in mortality. When the isopleths 
within which mortality could occur were calculated, the zones were 
sufficiently small that the risk of mortality is considered 
discountable. 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

[[Page 11071]]

harassment) or to incur permanent threshold shift (PTS) of some degree 
(equated to Level A harassment). Thresholds have also been developed to 
identify the pressure levels above which animals may incur different 
types of tissue damage from exposure to pressure waves from explosive 
detonation.
    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. This threshold is not applied to single 
detonations as the sound is instantaneous in nature such that a 
behavioral harassment is not expected to result, although temporary 
threshold shift (TTS) may occur. A single detonation is not considered 
as being able to result in a disruption of behavioral patterns because 
the instantaneous sound is not likely to result in anything more 
prolonged than a brief startle response. 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 micro pascal ([mu]Pa) root mean square 
(rms) for continuous (e.g., vibratory pile-driving, drilling) and above 
160 dB re 1 [mu]Pa (rms) for intermittent (e.g., impact pile driving) 
sources.
    The City of Juneau's activity includes the use of continuous sounds 
(vibratory pile removal, dredging) and therefore the 120 dB re 1 [mu]Pa 
(rms) threshold for behavioral harassment is applicable. While the 
activity also includes impulsive sounds (blasting), the 160 dB re 1 
[mu]Pa (rms) threshold for behavioral harassment is not applicable, as 
behavioral harassment is not expected from single detonation events, 
although TTS is possible.
    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 City of Juneau's activity includes 
the use non-impulsive (dredging, vibratory pile 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.

                     Table 2--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 weighting 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.

    Explosive sources--Based on the best available science, NMFS uses 
the acoustic and pressure thresholds indicated in Table 3 to predict 
the onset of behavioral harassment, PTS, tissue damage, and mortality.

                                         Table 3--Explosive Acoustic and Pressure Thresholds for Marine Mammals
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Level B harassment             Level A harassment             Serious injury
                                 ----------------------------------------------------------------------------------------------------
              Group                    Behavioral                                                                                          Mortality
                                       (multiple               TTS                  PTS              Gastro-             Lung
                                      detonations)                                              intestinal tract
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-freq cetacean...............  163 dB SEL.........  168 dB SEL or 213    183 dB SEL or 219   237 dB SPL......  39.1M\1/3\ (1+[D/   91.4M\1/3\ (1+[D/
                                                        dB SPLpk.            dB SPLpk.                             10.081])\1/2\ Pa-   10.081])\1/2\ Pa-
                                                                                                                   sec                 sec
                                                                                                                  where: M = mass of  where: M = mass of
                                                                                                                   the animals in kg.  the animals in kg
                                                                                                                  D = depth of        D = depth of
                                                                                                                   animal in m.        animal in m

[[Page 11072]]

 
High-freq cetacean..............  135 dB SEL.........  140 dB SEL or 196    155 dB SEL or 202
                                                        dB SPLpk.            dB SPLpk.
Phocidae........................  165 dB SEL.........  170 dB SEL or 212    185 dB SEL or 218
                                                        dB SPLpk.            dB SPLpk.
Otariidae.......................  183 dB SEL.........  188 dB SEL or 226    203 dB SEL or 232
                                                        dBpk.                dB SPLpk.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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.
    Vibratory removal--The closest known measurements of vibratory pile 
removal similar to this project are from the Kake Ferry Terminal 
project for vibratory extraction of an 18-inch (in) steel pile. The 
extraction of 18-in steel pipe pile using a vibratory hammer resulted 
in underwater noise levels reaching 156.2 dB rms at 7 meters (m) (Denes 
et al. 2016). The pile diameters for this project are smaller, thus the 
use of noise levels associated with the pile extraction at Kake may be 
somewhat conservative. For timber pile removal, the Seattle Pier 62/63 
sound source verification report contains an appendix with source 
measurements at different distances for 63 individual pile removals 
(WSDOT, 2015). When the data are normalized to 10 m, the median source 
level is 152 dB rms at 10 m.
    Dredging--For dredging, sound source data was used from bucket 
dredging operations in Cook Inlet, Alaska (Dickerson et al. 2001). 
Dredging in that project consisted of six distinct events, including 
the bucket striking the channel bottom, bucket digging, winch in/out as 
the bucket is lowered/raised, dumping of the material on the barge and 
emptying the barge at the disposal site. Although the waveform of the 
bucket strike has a high peak sound pressure with rapid rise time and 
rapid decay (characteristics typical of an impulsive sound source), the 
duration of the source signal was longer than what is often considered 
for an impulsive sound source, about 50 seconds, which is the 
approximate duration of one continuous noise signal from the dredging 
equipment. The events following the initial waveform impulse were of 
longer duration and were non-impulsive in form and therefore dredging 
was analyzed as a continuous source. Dickerson et al. (2001) took 104 
SPLrms measurements for the first five distinct phases of the dredging 
cycle and averaged them, including the impulse in the waveform of the 
dredge making contact with the substrate. These averages were distance 
corrected to determine an average SPL of 150.5 dB rms at 1 m for the 
bucket dredging process, with an assumed maximum duration of up to 50 
seconds, of non-impulsive, continuous noise.
    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, NMFS 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, the NMFS User Spreadsheet predicts the closest distance at 
which, if a marine mammal remained at that distance the whole duration 
of the activity, it will not incur PTS. Inputs used in the User 
Spreadsheet, and the resulting isopleths are reported below.

                                      Table 4--NMFS User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                                           Timber removal     Steel removal         Dredging
                                                        --------------------------------------------------------
                  Spreadsheet tab used                                                           A: Stationary:
                                                           A.1: Vibratory     A.1: Vibratory     Non-impulsive,
                                                            pile driving       pile driving        continuous
----------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL).................................                152              156.2              150.5
Weighting Factor Adjustment (kHz)......................                2.5                2.5                  2
a) Activity Duration (h) within 24-h period............  .................  .................                 11
Propagation (xLogR)....................................                 15                 15                 15
Distance of source level measurement (m) +.............                 10                  7                  1
# of piles/shots in a 24 h period......................                 16                  4  .................
Duration to drive (remove) a single pile (min).........                 20                 20  .................
----------------------------------------------------------------------------------------------------------------

    When using the inputs from Table 4, the outputs generated are 
summarized below in Table 5.

[[Page 11073]]



                                Table 5--NMFS User Spreadsheet Generated Outputs
                                            [User spreadsheet output]
----------------------------------------------------------------------------------------------------------------
                                                                 PTS Isopleth (meters)
                                     ---------------------------------------------------------------------------
             Source type                Low-frequency      High-frequency
                                          cetaceans          cetaceans       Phocid pinnipeds  Otariid pinnipeds
----------------------------------------------------------------------------------------------------------------
Timber removal......................                5.2                7.7                3.2                0.2
Steel Removal.......................                2.8                4.1                1.7                0.1
Dredging............................                0.7                0.6                0.4                0.0
----------------------------------------------------------------------------------------------------------------
                                 Level B Behavioral Harassment Isopleth (meters)
----------------------------------------------------------------------------------------------------------------
Timber removal......................                                    1359.36
Steel removal.......................                                    1813.14
Dredging............................                                    107.98
----------------------------------------------------------------------------------------------------------------
* Impulsive sounds have a dual metric threshold (SELcum and PK). Metric producing the largest isopleth should be
  used.

    Blasting--In our proposed IHA, historic data from an analog project 
were analyzed to create a conservative attenuation model for 
anticipated pressure levels from confined blasting in drilled shafts in 
underwater bedrock. Sound pressure data from the analog project were 
analyzed to compare source pressure levels to received impulse levels 
(Alaska Seismic, 2018). These models were used to predict distances to 
the peak level and impulse thresholds. Cumulative source levels from 
the analog project were used in conjunction with the NMFS 2018 updated 
User Spreadsheet Tool for predicting threshold shift isopleths for 
multiple detonations, after being corrected to a 1-m reference source 
level. The median of 10 measurements, consisting of detonations ranging 
from 19 to 78 individual holes for the detonation, resulted in a source 
level of 227.98 dB single shot SEL.
    However, during the public comment period, the Marine Mammal 
Commission noted some errors in the User Spreadsheet methodology for 
single detonations. Following consultation with the Commission, NMFS 
computed cumulative sound exposure impact zones from the blasting 
information by the City of Juneau. Peak source levels of the confined 
blasts were calculated based on Hempet et al. (2007), using a distance 
of eight feet and a weight of 95 pounds for a single charge. The total 
charge weight is defined as the product of the single charge weight and 
the number of charges. In this case, the number of charges is 75. 
Explosive energy was then computed from peak pressure of the single 
maximum charge, using the pressure and time relationship of a shock 
wave (Urick 1983). Due to time and spatial separation of each single 
charge by a distance of eight feet, the accumulation of acoustic energy 
is added sequentially, assuming the transmission loss follows 
cylindrical spreading within the matrix of charges. The sound exposure 
level (SEL) from each charge at its source can then be calculated, 
followed by the received SEL from each charge. Since the charges will 
be deployed in a grid of 8 ft by 8 ft apart, thus the received SELs 
from different charges to a given point will vary depending on the 
distance of the charges from the receiver. Without specific information 
regarding the layout of the charges, the modeling assumes a grid of 8 
by 9 charges with an additional three charges located in three 
peripheral locations. Among the various total SELs calculated, the 
largest value, SELtotal(max) is selected to calculate the impact range. 
Using the pressure versus time relationship above, the frequency 
spectrum of the explosion can be computed by taking the Fourier 
transform of the pressure (Weston, 1960). Frequency specific 
transmission loss of acoustic energy due to absorption is computed 
using the absorption coefficient, [alpha] (dB/km), summarized by 
Fran[ccedil]ois and Garrison (1982a, b). Seawater properties for 
computing sound speed and absorption coefficient were based on NMFS 
Alaska Fisheries Science Center report of mean measurements in Auke Bay 
(Sturdevant and Landingham, 1993). Transmission loss was calculated 
using the sonar equation:

TL = SELtotal(m)-SELthreshold

where SELthreshold is the Level A harassment threshold. The 
distances, R, where such transmission loss is achieved were computed 
numerically by combining both geometric transmission loss, and 
transmission loss due to frequency-specific absorption. A spreading 
coefficient of 20 is assumed to account for acoustic energy loss from 
the sediment into the water column. The outputs from this model are 
summarized in Table 6 below, and replace those values given for 
blasting previously in Table 5 of our Federal Register Notice of 
Proposed IHA.

                                              Table 6--Model Results of Impact Zones for Blasting in Meters
                                                                           [m]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Slight lung
                 Species                     Mortality        injury         GI tract       PTS: SELcum     PTS: SPLpk      TTS: SELcum     TTS: SPLpk
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low frequency ceteacean.................          3.9975          9.3445         26.0142             380          206.64            2120           412.3
High frequency cetacean.................         20.5573         48.0546         26.0142            1340          1462.9            4910          2918.8
Otariid.................................         13.9502         32.6100         26.0142              20        * 46.261           * 140          92.302

[[Page 11074]]

 
Phocid..................................         18.3762         42.9561         26.0142             180          231.85            1000          462.61
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For the dual criteria of SELcum and SPLpk, distances in bold are more predominant and were used in our analysis. The PTS and TTS distances for Steller
  sea lions resulting from the model seemed uncharacteristically small when compared to the other thresholds resulting from the model and were doubled
  to 93 m and 280 m respectively for take estimation, mitigation, and monitoring.

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. Reliable densities are not available for Statter Harbor 
or the Auke Bay area. Generalized densities for the North Pacific are 
not applicable given the high variability in occurrence and density at 
specific inlets and harbors. Therefore, the applicant consulted 
opportunistic sightings data from oceanographic surveys in Auke Bay and 
sightings from Auke Bay Marine Station observation pier for Statter 
Harbor to arrive at a number of animals expected to occur within the 
harbor per day. For humpback whales, it is assumed that a maximum of 
two animals per day are likely to occur in the harbor. For Steller sea 
lions, the potential maximum daily occurrence of animals is 121 
individuals within the harbor. For harbor seals, the maximum daily 
occurrence of animals is 52 individuals.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    Because reliable densities are not available, the applicant 
requests take based on the above mentioned maximum number of animals 
that may occur in the harbor per day multiplied by the number of days 
of the activity. The applicant varied these calculations based on 
certain factors.
    Humpback whale--Based on the size of the harassment zone for 
dredging, in combination with the Mitigation outlined below, the 
applicant does not expect humpback whales to approach the dredging 
vessel and therefore is not requesting take of humpback whales from 
dredging. Because of the nature of blasting, there is no behavioral 
threshold associated with the activity, but TTS, which is a form of 
Level B harassment take, may occur. With a maximum take of two animals 
per day, multiplied by a maximum of 10 days of pile removal and two 
days of blasting (TTS), the applicant requests authorization of 24 
Level B harassment takes of humpback whale.
    Steller sea lion--For the final IHA it is still estimated that a 
maximum of 121 Steller sea lions may occur in outer Statter Harbor 
within one day. A maximum take of 121 animals per day for 10 days of 
pile removal is 1,210 Steller sea lions. Given the size of the Level B 
harassment zone for dredging (108 m), it is possible Steller sea lions 
may approach the source vessel. However, given the small size of the 
zone, the applicant reduced the number of animals expected to be 
sighted daily within the Level B harassment isopleth to be 10 animals 
per day for 45 days of dredging. This is reduced from the 60 sea lions 
per day that were estimated to occur within the dredging isopleth in 
the proposed IHA. However, because animals would not be expected to 
occur so close to the source every day, we assume that takes would 
occur on only half of dredging days, resulting in 225 estimated 
exposures of Steller sea lions from dredging. This second reduction in 
dredging takes was incorporated based on input from the Marine Mammal 
Commission during the public comment period suggesting that Steller sea 
lions are infrequently seen in the inner harbor. For blasting, the size 
of the TTS zone (280 m) increased from the distance estimated in the 
proposed IHA (57 m). Given the size of the revised zones for blasting 
and the location of the blasting close to shore and harbor structures, 
it is expected that a maximum of 106 Steller sea lions could occur 
within the inner harbor where the blasts will occur. Therefore, it is 
assumed that 106 sea lions may occur within the zone for two days of 
blasting, resulting in a potential Level B harassment take (TTS only) 
of 212 Steller sea lions. No more than 15 Steller sea lions are assumed 
to be within range of the PTS blasting isopleth (46.3 m, which has been 
conservatively doubled to 93 m), resulting in a total of 30 potential 
Level A harassment takes of Steller sea lion from blasting. While it is 
conservative to assume this many Steller sea lions may occur close to 
the blast source, they are regularly seen in the area and the 
explosives need to be detonated within a certain number of hours after 
being planted. It is possible that Steller sea lions could approach the 
source and the detonation could no longer be delayed, exposing Steller 
sea lions to sound levels that may induce PTS. This adds to a total of 
1,447 Level B takes and 30 Level A takes of Steller sea lion.
    Harbor seal--The largest known group size to occur in Statter 
Harbor is 52 individuals, which is the maximum number of takes per day 
used here. For 10 days of pile removal, using an assumed rate of 52 
individuals per day, the potential take of harbor seals is 520. For 45 
days of dredging, the estimated daily take was reduced by half due to 
the small size of the zone (26 individuals), resulting in an estimate 
of 1,170 takes. For blasting, the size of the Level A harassment 
isopleth increased from 71 m to 232 m. Therefore, we assume an 
increased abundance of harbor seals potentially present within the 
Level A harassment zone, i.e., all 52 assumed resident seals may occur 
within the Level A harassment zone during blasts on each of the two 
days of blasting for a total of 104 takes by Level A harassment. 
However, as these are the only harbor seals that could occur in the 
harbor, no additional seals are added as Level B harassment (TTS) 
exposures from blasting. Summed together, this would result in 1,690 
Level B takes and 104 Level A takes of harbor seal.
    Harbor porpoise--Very little is known about likelihood of 
occurrence of harbor porpoise in Statter Harbor but they are rarely 
observed in the area and we assume that may occur, while their cryptic 
nature makes it difficult to mitigate all potential for take. If it is 
assumed one pair could occur per day for 10 days of pile removal, this 
would result in potential take of 20 harbor porpoise. For 45 days of 
dredging, the estimated daily take was reduced by half due to the small 
size of the zone, which would result in take of 44 estimated takes of 
harbor porpoise. For two days of blasting, it is assumed three pairs of 
harbor porpoise (6 individuals) may occur each day in the TTS zone, for 
12 total TTS takes, and two pairs on each day may appear in the PTS 
zone, resulting in eight Level A harassment takes of harbor porpoise. 
This is an

[[Page 11075]]

increase from the estimated take number provided in the proposed IHA, 
reflecting the increase in zone size for blasting.
    The total number of takes authorized are summarized in Table 7 
below.

                                                                Table 7--Takes Authorized
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                           Total Level B   Total Level A
                                                            Takes from      Takes from    TTS takes from  PTS takes from    harassment      harassment
                                                           pile removal      dredging        blasting        blasting          takes           takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale..........................................              20               0               4               0              24               0
Steller sea lion........................................           1,210             225              12              30           1,447              30
Harbor seal.............................................             520           1,170               0             104           1,690             104
Harbor porpoise.........................................              20              44              12               8              76               8
--------------------------------------------------------------------------------------------------------------------------------------------------------

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.
    In addition to the measures described later in this section, the 
City of Juneau will employ the following standard mitigation measures:
     Conduct a briefing between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of 
construction, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water and over-water heavy machinery work, if a 
marine mammal comes within 10 m, operations must cease and vessels must 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions. This 10 m shutdown encompasses the Level A 
harassment zone for pile removal and dredging and therefore this 
requirement is not listed separately;
     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, pile removal and dredging will shut down 
immediately when the animals are sighted approaching the monitoring 
zones; and
     If take reaches the authorized limit for an authorized 
species, activity for which take is authorized will be stopped as these 
species approach the monitoring zones to avoid additional take of them.
    The following measures will apply to the City of Juneau's 
mitigation requirements:
    Establishment of Monitoring Zones for Level B--The City of Juneau 
will establish Level B monitoring zones or zones of influence (ZOI) 
which are areas where SPLs are equal to or exceed the 120 dB rms 
threshold during vibratory removal and dredging. Similar harassment 
monitoring zones will be established for the TTS isopleths associated 
with each functional hearing group for blasting activities. Monitoring 
zones provide utility for observing by establishing monitoring 
protocols for areas adjacent to the shutdown zones. Monitoring zones 
enable observers to be aware of and communicate the presence of marine 
mammals in the project area outside the shutdown zone and thus prepare 
for a potential cease of activity should the animal enter the shutdown 
zone. The Level B monitoring zones are depicted in Table 8.

                                                         Table 8--Shutdown and Monitoring Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                              Monitoring zones                            Shutdown zones
                                                                   -------------------------------------------------------------------------------------
                              Source                                  High frequency     Low frequency
                                                                         cetacean          ceteacean          Phocid          Otariid       All species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Removal--Steel..........................................            1,820 m            1,820 m         1,820 m         1,820 m           10 m.
Vibratory Removal--Timber.........................................            1,360 m            1,360 m         1,360 m         1,360 m           10 m.
Dredging..........................................................              110 m              110 m           110 m           110 m           10 m.
Blasting (PTS)....................................................            1,465 m              380 m           235 m            95 m            N/A.
Blasting (TTS)....................................................            4,910 m            2,120 m         1,000 m           280 m            N/A.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 11076]]

    As shown, the largest Level B harassment zone is greater than 4,000 
m, making it unlikely that PSOs will be able to view the entire 
harassment area. Due to this, Level B harassment exposures will be 
recorded and extrapolated based upon the number of observed take and 
the percentage of the Level B harassment zone that was not visible.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
activity, or whenever a break in activity of 30 minutes or longer 
occurs, the observer 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, activity 
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, activity can commence in good visibility conditions. 
Work can continue even if visibility becomes impaired within the 
monitoring zone. When a marine mammal permitted for Level B harassment 
take is present in the monitoring zone, activities may begin and Level 
B harassment take will be recorded. As stated above, if the entire 
monitoring zone is not visible at the start of construction, activity 
can begin. If work ceases for more than 30 minutes, the pre-activity 
monitoring of both the monitoring zone and shutdown zone will commence.
    Charges for blasting will not be laid if marine mammals are within 
the shutdown zone or appear likely to enter the shutdown zone. However, 
once charges are placed, they cannot be safely left undetonated for 
more than 24 hours. For blasting, the TTS zone will be monitored for a 
minimum of 30 minutes prior to detonating the blasts. If a marine 
mammal is sighted within the TTS zone, blasting will be delayed until 
the zone is clear of marine mammals for 30 minutes. This will continue 
as long as practicable within the constraints of the blasting design 
but not beyond sunset on the same day as the charges cannot lay dormant 
for more than 24 hours, which may force the detonation of the blast in 
the presence of marine mammals. Charges will be laid as early as 
possible in the morning and stemming procedures will be used to fill 
the blasting holes to potentially reduce the noise from the blasts. 
Blasting will only be planned to occur in good visibility conditions, 
and at least 30 minutes after sunrise and at least one hour prior to 
sunset. The TTS zone will also be monitored for one hour post-blasting.
    Based on our evaluation of the applicant's measures, 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 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.

Visual Monitoring

    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after construction activities. In addition, observers must 
record all incidents of marine mammal occurrence, regardless of 
distance from activity, and must document any behavioral reactions in 
concert with distance from construction activities.
    Protected Species Observers (PSO) will be land-based observers. For 
dredging, pile removal, and blasting, one, two, and four PSOs will be 
required, respectively. Observers will be stationed at locations that 
provide adequate visual coverage for shutdown and monitoring zones. 
Potential observation locations are depicted in Figures 2 and 3 of the 
applicant's Marine Mammal Mitigation and Monitoring Plan. A minimum of 
one observer will be placed at a vantage point providing total coverage 
of the monitoring zones and for observation zones larger than 500 m, at 
least one other additional observer will be placed at the outermost 
float or other similar vantage point in order to observe the extend 
observation zone. During blasting, pre-blast monitoring, and post-blast 
monitoring, four observers will be on duty. Optimal observation 
locations will be selected based on visibility and the type of work 
occurring. All PSOs will 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. Monitoring of construction activities must be conducted by 
qualified PSOs (see below), who must have no other assigned tasks 
during monitoring periods. The applicant must adhere to the following 
conditions when selecting observers:
     Independent PSOs must be used (i.e., not construction 
personnel);
     At least one PSO must have prior experience working as a 
marine mammal observer during construction activities;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;

[[Page 11077]]

     Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction; and
     The applicant must submit PSO curriculum vitaes for 
approval by NMFS.
    The applicant must ensure that observers have the following 
additional qualifications:
     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, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
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.
    At least 24 hours prior to blasting, the City will notify the 
Office of Protected Resources, NMFS Alaska Regional Office, and the 
Alaska Regional Stranding Coordinator that blasting is planned to 
occur, as well as notify these parties within 24 hours after blasting 
that blasting actually occurred.
    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of construction 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 
construction activity;
     Distance from construction 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 a serious injury or mortality, The City of Juneau 
will immediately cease the specified activities and report the incident 
to the Office of Protected Resources, NMFS Alaska Regional Office, and 
the Alaska Regional Stranding Coordinator. The report will 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 will not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with The City of 
Juneau to determine what is necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The City of Juneau 
will not be able to resume their activities until notified by NMFS via 
letter, email, or telephone.
    In the event that The City of Juneau 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 City of Juneau will immediately report the incident to 
the Office of Protected Resources, NMFS, and the Alaska Regional 
Stranding Coordinator. The report will include the same information 
identified in the paragraph above. Activities will be able to continue 
while NMFS reviews the circumstances of the incident. NMFS will work 
with the City of Juneau to determine whether modifications in the 
activities are appropriate.
    In the event that the City of Juneau 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 City of Juneau will report the 
incident to the Office of Protected Resources, NMFS, and the NMFS 
Alaska Stranding Hotline and/or by email to the Alaska Regional 
Stranding Coordinator, within 24 hours of the discovery. The City of 
Juneau will provide photographs, video footage (if available), or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Coordinator.

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).
    As stated in the mitigation section, shutdown zones equal to or 
exceeding Level A isopleths shown in Table 8 for all activities other 
than blasting will be implemented. Serious injury or mortality is not 
anticipated nor

[[Page 11078]]

authorized. Behavioral responses of marine mammals to pile removal and 
dredging, if any, are expected to be mild and temporary due to the 
short term duration of the noise produced by the source as well as the 
relatively low source levels when compared with ambient levels in an 
area with high levels of anthropogenic activity. Given the short 
duration of noise-generating activities per day and that pile removal 
and dredging would occur for 55 days, any harassment would be 
temporary. The blasting will only occur across two days, with one blast 
scheduled on each day. In addition, the project includes generally low 
level sound sources, such as dredging and removal of piles much smaller 
than those frequently used in other construction projects. In addition, 
for all species except humpbacks, there are no known biologically 
important areas near the project zone that would be impacted by the 
construction activities. The region of Statter Harbor where the project 
will take place is located in a developed harbor area with regular 
marine vessel traffic. Although there is a resident harbor seal 
population, the area of construction is not known to be of important 
biological significance such as used for breeding or foraging. 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;
     There are no known biologically important areas within the 
project area;
     The City of Juneau will implement mitigation measures such 
as shut down zones for all in-water and over-water activities;
     Monitoring reports from similar work in Alaska have 
documented little to no effect on individuals of the same species 
impacted by the specified activities;
    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 
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 9 below shows take as a percent of population for each of the 
species listed above.

                   Table 9--Summary of Authorized Instances of Level A and Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                     Number of       Number of
            Species                 DPS/stock      Level B takes   Level A takes       Stock        Percent of
                                                     by stock        by stock        abundance    population \1\
----------------------------------------------------------------------------------------------------------------
Steller sea lion..............  Eastern DPS.....           1,418              29          41,638            3.48
                                Western DPS.....              29               1          53,303            0.06
Harbor seal...................  Lynn Canal......           1,690             104           9,478           18.93
Harbor porpoise...............  Southeast Alaska              76               8             975            8.62
Humpback whale................  Central North                 24               0          10,103            0.24
                                 Pacific Stock.
----------------------------------------------------------------------------------------------------------------

    Table 9 presents the number of animals that could be exposed to 
received noise levels that may result in Level A or Level B take for 
the construction at Statter Harbor. Our analysis shows that less than 
one third of the best available population estimate of each affected 
stock could be taken. Therefore, the numbers of animals authorized to 
be taken for all species would be considered small relative to the 
relevant stocks or populations even if each estimated taking occurred 
to a new individual--an extremely unlikely scenario. For pinnipeds, 
especially harbor seals and Steller sea lions, occurring in the 
vicinity of the project site, there will almost certainly be some 
overlap in individuals present day-to-day, and these takes are likely 
to occur only within some small portion of the overall regional stock.
    Based on the analysis contained herein of the 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. The project is not 
known to occur in an important subsistence hunting area. It is a 
developed area with regular marine vessel traffic and the project is 
one year of a multi-year harbor improvement effort that is already 
underway. The work at this harbor has been publicized and public input 
has been solicited on the overall improvement.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the mitigation and monitoring 
measures, NMFS has determined that there will not be an unmitigable 
adverse impact on subsistence uses from the City of Juneau's 
activities.

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 IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NAO 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 will preclude this 
categorical exclusion. Accordingly, NMFS has determined that the 
issuance

[[Page 11079]]

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

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the NMFS Alaska Regional 
Office, whenever we propose to authorize take for endangered or 
threatened species.
    There are two marine mammal species (western DPS Steller sea lion; 
Mexico DPS humpback whale) with confirmed occurrence in the project 
area that are listed as endangered under the ESA. The NMFS Alaska 
Regional Office issued a Biological Opinion on February 22, 2019 under 
section 7 of the ESA, on the issuance of an IHA to the City of Juneau 
under section 101(a)(5)(D) of the MMPA by the NMFS Office of Protected 
Resources. The Biological Opinion concluded that the action is not 
likely to jeopardize the continued existence of western DPS Steller sea 
lions or the Mexico DPS of humpback whales, and is not likely to 
destroy or adversely modify western DPS Steller sea lion critical 
habitat.

Authorization

    NMFS has issued an IHA to the City of Juneau for the potential 
harassment of small numbers of four marine mammal species incidental to 
the Statter Harbor improvements project in Auke Bay, Alaska, provided 
the previously mentioned mitigation, monitoring and reporting.

    Dated: March 20, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-05668 Filed 3-22-19; 8:45 am]
BILLING CODE 3510-22-P