[Federal Register Volume 86, Number 96 (Thursday, May 20, 2021)]
[Notices]
[Pages 27410-27428]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-10685]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB068]


Taking of Marine Mammals Incidental to Specific Activities; 
Taking of Marine Mammals Incidental to Pile Driving and Removal 
Activities During Construction of the Hoonah Marine Industrial Center 
Cargo Dock Project, Hoonah, Alaska

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

ACTION: Notice; issuance of an incidental harassment authorization.

-----------------------------------------------------------------------

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 Hoonah (City) to incidentally harass, by Level A and Level 
B harassment, marine mammals during pile driving activities associated 
with construction upgrades of a cargo dock at the city-owned Hoonah 
Marine Industrial Center (HMIC) in Port Frederick Inlet on Chichagof 
Island in Hoonah, Alaska.

DATES: This Authorization is effective for one year from issuance.

FOR FURTHER INFORMATION CONTACT: Stephanie Egger, 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/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, or for anyone who is unable to comment via electronic mail, 
please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

Summary of Request

    On October 28, 2020 NMFS received a request from the City for an 
IHA to take marine mammals incidental to pile driving and removal 
during construction upgrades of a cargo dock at the HMIC in Port 
Frederick Inlet on Chichagof Island in Hoonah, Alaska. The application 
was deemed adequate and complete on February 2, 2021. The applicant's 
request is for take of nine species of marine mammals by Level B 
harassment and five species by Level A harassment. Neither the City nor 
NMFS expects serious injury or mortality to result from this activity 
and, therefore, an IHA is appropriate.

Description of Planned Activity

    The purpose of this project is to make upgrades to the HMIC. 
Upgrades to the site include the installation of three breasting 
dolphins, a sheet pile bulk cargo dock, fender piles, and a catwalk. 
The planned upgrades are needed to continue safely accommodating barges 
and other vessels delivering essential goods to the City. The planned 
project at the HMIC is located in Port Frederick Inlet, approximately 
0.8 kilometers (km) (0.5 miles) northwest of downtown Hoonah 0.24 km 
(0.15 miles) east of the State of Alaska Ferry Terminal in Southeast 
Alaska.
    The City is only accessible by air and water. Small amounts of 
cargo are transported into the community by plane; however, the 
majority is delivered weekly by barges from April through September 
(AML 2020). When

[[Page 27411]]

weather permits, front load barges utilize a gravel landing located 
next to the existing City dock. The gravel landing provides a makeshift 
location to unload heavy cargo using a ramp and forklifts. During 
winter months, inclement weather events, and for more frequent 
deliveries, locals utilizes the Alaska Marine Highway System (AMHS) 
ferries and the local ferry terminal.
    The purpose of HMIC cargo dock project is to make improvements to 
the existing gravel landing to enable barges to land during all 
conditions. The project is needed because the existing facility cannot 
provide consistent and safe berthing for barges. Once the project is 
completed, the City will be able to reliably receive goods year-round 
and in all weather conditions. Currently, Alaska Marine Line barges 
offers seasonal ramp barge service into the City; however, this project 
will allow for year-round, weekly deliveries by ocean going barges.
    The project includes pile driving and removal over 110 working days 
(not necessarily consecutive) beginning in spring and extending through 
the summer of 2021 as needed. Approximately 50 days of vibratory and 28 
days of impact hammering will occur. An additional 35 days of drilling/
down-the-hole (DTH) will occur to stabilize the piles. The project 
would involve installing breasting dolphins, a solid fill sheet pile 
dock, and fender.
    Construction of the three breasting dolphins would include:
    [ssquf] Installation of 10 temporary 30-inch (in) diameter steel 
piles as templates to guide proper installation of permanent piles 
(these piles would be removed prior to project completion); and
    [ssquf] Installation of 9 permanent 36-in diameter steel piles
    [cir] Breasting Dolphin 1--(1) vertical 36-in steel pile and (2) 
36-in batter steel piles
    [cir] Breasting Dolphin 2--(1) vertical 36-in steel pile and (2) 
36-in batter steel pile
    [cir] Breasting Dolphin 3--(1) vertical 36-in steel pile and (2) 
36-in batter steel pile
    Construction of the bulk cargo dock would include (see Figure 4; 
Appendix A: Sheets 3-4 of the application):
    [ssquf] Installation of 20 temporary 30-in steel piles as templates 
to guide proper installation of permanent H-piles (these piles would be 
removed prior to project completion);
    [ssquf] Installation of 12 permanent H-piles to guide proper 
installation of sheets;
    [ssquf] Installation of 500 permanent sheet piles (130 linear 
feet); and
    [ssquf] Filling the area within sheet piles with 9,600 cubic yards 
of fill
    Installation of the fender piles would include (see Figure 4; 
Appendix A: Sheet 3 of the application):
    [ssquf] Installation of 20 temporary 30-in steel piles as templates 
to guide proper installation of permanent fender piles (these piles 
would be removed prior to project completion);
    [ssquf] Installation of 6 permanent 20-in fender piles in front of 
sheet pile cargo dock

Construction Sequence

    In-water construction of the HMIC cargo dock components is expected 
to occur via the following sequence:
    (1) Vibrate twenty 30-inch temporary piles to use as a guide to 
install H-piles for the cargo dock.
    (2) Vibrate and impact 12 H-piles to depth to hold the sheets into 
place.
    (3) Remove the temporary piles.
    (4) Using the H-piles as a guide, vibrate and impact 500 sheets 
into place to create a barrier prior to placing fill.
    (5) Using an excavator place 9,600 cubic yards of fill within the 
newly constructed cargo dock frame.
    After the completion of the cargo dock, the barge will move over to 
install the six fender piles at the existing city dock face using the 
following sequence:
    (1) Vibrate 20 temporary 30-inch piles a minimum of ten feet into 
bedrock to create a template to guide installation of the permanent 
piles.
    (2) Weld a frame around the temporary piles.
    (3) Within the frame: Vibrate, impact, and socket six permanent 20-
inch fender piles into place.
    (4) Remove the frame and temporary piles.
    (5) Perform this sequence at the other six fender pile locations.
    The three breasting dolphins will be constructed as the barge moves 
off shore and will install temporary and permanent piles as follows:
    (1) Vibrate 10 temporary 30-inch piles a minimum of ten feet into 
bedrock to create a template to guide installation of the permanent 
piles.
    (2) Weld a frame around the temporary piles.
    (3) Within the frame: Vibrate, impact, and socket one vertical and 
two batter 36-inch pile into place.
    (4) Remove the frame and temporary piles.
    (5) Perform this sequence at the second and third location working 
farther from the shoreline.
    Please see Table 1 below for the specific amount of time required 
to install and remove piles.

Installation and Removal of Temporary (Template) Piles

    Temporary 30-in steel piles would be installed and removed using a 
vibratory hammer (Table 1).

Installation of Permanent Piles

    The permanent H-piles, 20-in, and 36-in piles would be installed 
through sand and gravel with a vibratory hammer until advancement 
stops. Then, the pile will be driven to depth with an impact hammer. If 
design tip elevation is still not achieved, the contractor will utilize 
a drill to secure the pile. (Note: This DTH method can also be referred 
to as DTH drilling. It is referred to as DTH throughout this document.) 
Pile depths are expected to be approximately 12 m to 21 m (40 to 70 
feet (ft)) below the mudline and estimated to take approximately 1.25-
10.5 hours (hrs) per pile to complete.
    The permanent sheets would be installed using a vibratory hammer 
and impact hammer following the same criteria as above to achieve 
design tip elevation (Table 1). It is expected that it will take around 
20 minutes to install each sheet.

                                                                          Table 1--Pile Driving and Removal Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                         Project component
                                  --------------------------------------------------------------------------------------------------------------------------------------------------------------
                                           Temporary                  Temporary
                                              pile                       pile                                                  Permanent pile installation
                                          installation                 removal
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Vibratory Hammer
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Diameter of Steel Pile (inches)..  30.......................  30.......................  36.......................  H-piles.................  Sheets..................  20.
# of Piles.......................  50.......................  50.......................  9........................  12......................  500 (130lf).............  6.
Max # Piles Vibrated per Day.....  4........................  4........................  4........................  4.......................  30 sheets...............  3.
Vibratory Time per Pile (min)....  15.......................  15.......................  15.......................  15......................  15......................  15.

[[Page 27412]]

 
Vibratory Time per Day (min).....  60.......................  60.......................  60.......................  60......................  450 (7.5 hr)............  45.
Number of Days...................  12.5.....................  12.5.....................  2.25.....................  3.......................  17......................  2.
Vibratory Time Total.............  12 hrs 30 mins...........  12 hrs 30 mins...........  2 hr 15 mins.............  3 hrs...................  292 hrs.................  1 hr 30 min.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Impact Hammer
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Diameter of Steel Pile (inches)..  .........................  .........................  36.......................  H-piles.................  Sheets..................  20.
# of Piles.......................  .........................  .........................  9........................  12......................  500 (130lf).............  6.
Max # Piles Impacted per Day.....  .........................  .........................  2........................  5.......................  5 sheets................  2.
Impact Time per Pile (min).......  .........................  .........................  15.......................  5.......................  5.......................  5.
Impact Time per Day (min)........  .........................  .........................  30.......................  20......................  25......................  10.
Number of Days...................  .........................  .........................  4.5 day..................  3.......................  17 days.................  3.
Impact Time Total................  .........................  .........................  2 hr 15 mins.............  1 hr....................  1 hr 30 mins............  30 min.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Drilling/DTH
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Diameter of Steel Pile (inches)..  .........................  .........................  36.......................  H-Piles.................  ........................  20.
Total Quantity...................  .........................  .........................  9........................  12......................  ........................  6.
Anchor Diameter..................  .........................  .........................  33.......................  20......................  ........................  20.
Max # Piles Anchored per Day.....  .........................  .........................  2........................  2.......................  ........................  2.
Time per Pile....................  .........................  .........................  5-10 hrs.................  3-4 hrs.................  ........................  1 hr.
Actual Time Spent Driving per      .........................  .........................  60 min...................  60 min..................  ........................  60 min.
 Pile.
Time per Day.....................  .........................  .........................  12 hrs (max).............  12 hrs (max)............  ........................  12 hrs (max).
Actual Time Spent Driving per Day  .........................  .........................  72 mins (1 hr 12 mins;     2 hrs (max).............  ........................  1 hr (max).
                                                                                          max).
Blows per pile...................  .........................  .........................  27,000-54,000............  20,000..................  ........................  15,000.
Number of Days...................  .........................  .........................  15 days..................  17 days.................  ........................  3 days.
Drilling Total Time..............  .........................  .........................  45-90 hours..............  20 hours................  ........................  4 hours.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    In addition to the activities described above, the planned action 
will involve other in-water construction and heavy machinery 
activities. Other types of in-water work including with heavy machinery 
will occur using standard barges, tug boats, and positioning piles on 
the substrate via a crane (i.e., ``stabbing the pile'').
    A detailed description of the planned Hoonah Cargo Dock project is 
provided in the Federal Register notice for the proposed IHA (86 FR 
12630; March 4, 2020).

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to the City was 
published in the Federal Register on March 4, 2021 (86 FR 12630). 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 Defenders of Wildlife (Defenders). The 
comment letter is available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. Please the letter for full detail regarding 
the comments and rationale.
    Comment: Defenders asserts NMFS has failed to demonstrate the 
authorized take numbers are small. Defenders requests that the agency 
lower the Level B harassment take for all species. The number of 
allotted takes for a project should not equate to the number of 
predicted maximum sightings of that species. According to Defenders, 
large take authorizations represent significant proportions of the 
stocks in and of themselves, and those takes can impact many more 
animals in the stock. The commenters state that large take numbers 
accounting for the maximum estimate of animals to be seen during the 
course of the project do not promote any mitigation or protection for 
marine mammals in the area.
    Response: NMFS disagrees with the Defenders assessment that we 
failed to demonstrate authorized take numbers are small. As discussed 
in the Small Numbers section of the proposed IHA and this final IHA, 
seven of the nine marine mammal stocks estimated total take are 
approximately 11 percent or less of the stock abundance. There are no 
official stock abundances for harbor porpoise and minke whales; 
however, as previously discussed in the notice of proposed IHA (86 FR 
12630; March 4, 2020), for the abundance information that is available, 
the estimated takes are small percentages of the stock abundance. For 
harbor porpoise, the abundance for the Southeast Alaska stock is likely 
more represented by the aerial surveys that were conducted as these 
surveys had better coverage and were corrected for observer bias. Based 
on this data, the estimated take could potentially be approximately 4 
percent of the stock abundance. For minke whales, in the northern part 
of their range they are believed to be migratory and so few minke 
whales have been seen during three offshore Gulf of Alaska surveys that 
a population estimate could not be determined. With only twelve 
estimated takes for this species, the percentage of take in relation to 
the stock abundance is likely to be very small. NMFS finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks. NMFS disagrees with the Defenders 
request to decrease the Level B harassment take for all species based 
on the calculations as Defenders asserted that the number of allotted 
takes for a project should not equate to the number of predicted 
maximum sightings of that species. In some of the estimated take 
calculations NMFS used a maximum number of species seen for its take 
calculations (e.g. Pacific white-sided dolphin). Using a maximum number 
of species seen is an acceptable way to estimate take and can be 
conservative when no density estimates are available. According to 
Defenders, large take authorizations represent significant proportions 
of the stocks in and of themselves, and those takes can impact many 
more animals in the stock. As discussed above NMFS made its small 
numbers determination based on the calculated take estimates compared 
to species abundance and all species were under NMFS' small numbers 
threshold of one-third of the best available population abundance. See 
the Small Numbers section, alter in this document, for more 
information.
    Comment: Defenders states NMFS has not demonstrated that impacts to 
the

[[Page 27413]]

humpback whale DPSs will be negligible. Defenders states that NMFS must 
better explain how it reaches its conclusion and, as discussed below, 
how it is effecting the least practicable adverse impact on humpback 
whales DPSs.
    Response: 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). 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. 
NMFS disagrees with much of what the Commenter asserts. First, we have 
carefully explained our interpretation of the least practicable adverse 
impact standard and how it applies to both stocks and individuals, in 
the Mitigation Measures section. Further, we have applied the standard 
correctly in this IHA in requiring measures that reduce impacts to 
individual marine mammals in a manner that reduces the probability and/
or severity of population-level impacts. Specifically for humpback 
whales, for the effectiveness of mitigation, the shutdown zones are 
larger than the Level A harassment zones which, in combination with the 
fact that the zones are so small to begin with, is expected to avoid 
the likelihood of Level A harassment for all humpback whales. Regarding 
behavioral disturbance from pile driving activities, exposures to 
elevated sound levels produced during pile driving activities may cause 
behavioral responses by an animal, but they are expected to be mild and 
temporary. Any reactions and behavioral changes for humpback whales are 
expected to subside quickly when the exposures cease and are unlikely 
to have any effects on individual fitness, let alone population 
effects. For effects on habitat, as previously discussed in the notice 
of proposed IHA, the HMIC Cargo Dock project would likely not impact 
any marine mammal habitat since its proposed location is within an area 
that is currently used by large shipping vessels and in between two 
existing, heavily-traveled docks, and within an active marine 
commercial and tourist area. In addition, impacts to marine mammal prey 
species are expected to be minor and temporary. The abundance of 
humpbacks in Port Frederick changes seasonally with the availability of 
prey. Humpbacks are generally present in large numbers from late fall-
early winter through mid- to late spring, but are infrequent to 
uncommon during the mid-summer months when herring are absent. The 
project should be completed mostly, if not all, during the spring and 
some into the summer months.
    Comment: Defenders claims that NMFS must more accurately define 
``group size'' for humpback whales, and states that NMFS defines a 
maximum humpback group size as eight individuals for all months of the 
year, but cites no support for that maximum group size. The commenter 
goes on to suggest that NMFS must state how the agency is defining this 
term for the purpose of mitigating harm caused by this project. 
Additionally, Defenders states that regardless of how ``group'' is 
defined, humpback group size in Southeast Alaska varies dramatically 
throughout the year depending on prey availability and social group 
dynamics.
    Response: The largest group of 8 humpback whales was observed most 
often in the previous Hoonah observer reports submitted to NMFS as part 
of the 2016 and 2019 Hoonah Berth cruise ship terminal projects 
(reports can be found here: https://www.fisheries.noaa.gov/action/incidental-take-authorization-pile-driving-and-removal-activities-during-construction-cruise). On occasion, higher numbers have been 
reported for humpback whales during the prior Hoonah projects; however, 
those generally occurred late summer into the fall. For example, on 3 
days there were slightly higher numbers of 13 whales observed (July and 
October 2019). The abundance of humpbacks in Port Frederick changes 
seasonally with the availability of prey and are not as common in 
larger numbers during the mid-summer months when herring are absent. 
Because the project will occur during the spring and extend into the 
summer months, NMFS believes it was appropriate to use the largest 
group of whales that were generally seen during this time period for 
its calculated take estimation during the proposed IHA and for this 
final IHA.
    Comment: Defenders agrees with NMFS requiring PSOs for this project 
and for other nearshore marine construction projects as a mitigation 
measure in addition to appropriate time and space restrictions. 
However, Defenders encourages NMFS to provide formal PSO monitoring 
guidelines and requirements for reporting takes. In addition to NMFS 
requiring PSOs to report marine mammal sighting estimates as ``min/max/
best,'' NMFS should require these estimates to be documented in the 
final publicly available report.
    Response: NMFS does provide formal requirements for the PSOs to 
report during monitoring of the project. These are clearly described in 
the Monitoring and Reporting sections in the proposed and final Federal 
Register notice for these actions as well as in the actual IHA. The 
reporting, inclusive of estimated number of animals (min/max/best), are 
already required in the final publically available reports that NMFS 
posts to the website for every construction project at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities#active-authorizations.
    Comment: Defenders states that NMFS should require an additional 
PSO for easily photo identifiable species. Defenders encourages NMFS to 
mandate an additional PSO who is solely dedicated to photo-
identification work. Defenders encourages NMFS to incorporate photo 
identification work into protected species observing primarily because 
this will allow PSOs to more reliably determine if individual animals 
are exposed to multiple takes, even if PSOs do not or cannot 
successfully match an individual in known identification catalogs.
    Response: NMFS thanks Defenders for their comment on requiring 
PSO's to incorporate photo identification work into their monitoring 
requirements. Should the PSOs for this project submit any photos of 
easily identifiable species, such as humpback whales, as part of their 
final report, NMFS will share these with the appropriate individuals in 
the agency, scientists, and other managers for possible identification. 
However, NMFS does not agree that it is necessary to assign a PSO 
solely to conduct photo-identification work and does not agree with the 
recommendation.
    Comment: Defenders states NMFS must discuss effects of multiple 
takes to individual humpback whales as they could be the same 
individual humpback whales exposed to multiple Level B harassment 
takes. The commenter states that it is inappropriate to assume that if 
a whale is displaced from its preferred site, then it will find the 
same success in another area. For these reasons, Defenders states that 
NMFS must address the impacts of cumulative Level B harassment takes 
being concentrated on the same individual whales, both to those whales 
and to the stock as a whole.
    Response: NMFS acknowledges that an individual may be taken on more 
than one day. However, as discussed in the Negligible Impact Analysis 
and

[[Page 27414]]

Determination section, the authorized take is not expected to affect 
the reproductive success or survivorship of any individual marine 
mammal, particularly humpback whales. Given the lack of any impacts on 
the reproduction or survival of any affected individuals, there will be 
no effects on any species' annual rates of recruitment or survival in 
that year, and therefore no basis to suggest that impacts would accrue 
in a manner that would have a non-negligible impact on an affected 
species. During monitoring of the Hoonah Berth II cruise ship terminal 
project, zero humpback whales were sighted in June 2019. In July 2019, 
sightings were of a single individual, a pair, and a group of five 
humpback whales exhibiting traveling, diving, and foraging behaviors 
for a total of 23 humpback whales that were taken by Level B harassment 
over 16 days of in-water work. In August of 2019, there were 15 takes 
by Level B harassment over 8 days of in-water work and consisted of a 
single individual, a pair, and a group of four humpback whales 
exhibiting breaching, slapping, swimming, milling, traveling, diving, 
and foraging behaviors. Based on this observational data of low numbers 
of animals from June through August, even if some animals were repeated 
takes it would not be at a level that would impact the reproduction or 
survival of any affected individuals, let alone a species or stock.
    Comment: Defenders states that NMFS should require temporal 
restrictions based around humpback whale bubble net feeding, based on 
the commenter's interpretation that the pile driving activity may 
disrupt bubble net feeding. The commenter notes the importance of this 
type of feeding activity.
    Response: Humpback whales are relatively generalized in their 
feeding compared to some other baleen whales. In the Northern 
Hemisphere, known prey includes: Euphausiids (krill); copepods; 
juvenile salmonids; herring; Arctic cod; walleye pollock; pteropods; 
and cephalopods (Johnson and Wolman 1984, Perry et al. 1999, Straley et 
al. 2018).
    According to the Biologically Important Areas dataset (Ferguson et 
al. 2015), the ensonified area and surrounding waters are important 
feeding habitat for humpback whales throughout the spring, summer, and 
fall. Feeding habitat from March through May exists just outside Port 
Frederick and thus outside the ensonified area, but is present in the 
vessel transit portion of the action area. From June through August, 
important areas for humpback whales include most of Port Frederick and 
the ensonified area. In the fall from September through November, 
important feeding habitat for humpback whales shifts along the eastern 
side of Port Frederick. There is no information to suggest that there 
would be sufficient impacts to feeding humpback whales, particularly 
during bubble netting, to indicate that the mitigation measure 
recommended by the commenter is warranted.
    Humpback whales produce sounds less frequently in their summer 
feeding areas. Feeding groups produce distinctive sounds ranging from 
20 hertz (Hz) to 2 kilohertz (kHz), with median durations of 0.2-0.8 
seconds and source levels of 175-192 decibel (dB) (Thompson et al. 
1986). These sounds are attractive and appear to rally animals to the 
feeding activity (D'Vincent et al. 1985, Sharpe and Dill 1997). The 
project will occur in an industrialized harbor, where vessel sounds and 
dock activity occurs frequently. We expect any additional contributions 
to masking from project activities would be very small and of short 
duration relative to the existing conditions and would not impact 
humpback whales that are bubble feeding. The short duration and limited 
affected area project-related noise will likely result in an 
insignificant amount of masking. Any masking that could possibly rise 
to Level B harassment would occur concurrently within the zones of 
behavioral harassment already estimated for vibratory pile driving, and 
which have already been taken into account in the analysis.
    Comment: Defenders states that NMFS must include updated best 
available science regarding marine mammal noise criteria NMFS, citing 
Southall et al., 2019 as recommending separation of baleen whale 
hearing groups into multiple categories for the purpose of assessing 
likely noise impacts. The commenter further asserts that consideration 
of Southall et al., 2019 would require NMFS to reevaluate the shut down 
zone sizes, especially for baleen whales.
    Response: Thus far, no new information has been published or 
otherwise conveyed that would fundamentally change the assessment of 
impacts or conclusions of this IHA regarding current weighting 
functions and permanent threshold shift (PTS) and temporary threshold 
shift (TTS) thresholds and therefore calculated isopleths. Furthermore, 
the recent peer-reviewed updated marine mammal noise exposure criteria 
by Southall et al. (2019) provide identical PTS and TTS thresholds to 
those provided in NMFS' Acoustic Technical Guidance. NMFS acknowledges 
Southall et al. (2019)'s discussion of potential revised organization 
for hearing groups. However, the authors do not provide any new 
weighting functions or thresholds. Therefore, there is no new 
information available that would change the calculated shutdown zones 
for any marine mammals, including mysticetes. NMFS' Revised Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (NMFS 2018) (Acoustic Technical Guidance), which was 
used in the assessment of effects for this IHA, compiled, interpreted, 
and synthesized the best available scientific information for noise-
induced hearing effects for marine mammals to derive updated thresholds 
for assessing the impacts of noise on marine mammal hearing, including 
the articles that Defenders referenced that were published subsequent 
to the publication of the first version of the Acoustic Technical 
Guidance in 2016. The new data included in those articles are 
consistent with the thresholds and weighting functions included in the 
current version of the Acoustic Technical Guidance (NMFS, 2018). NMFS 
will continue to review and evaluate new relevant data as it becomes 
available and consider the impacts of those studies on the Acoustic 
Technical Guidance to determine what revisions/updates may be 
appropriate.
    Comment: Defenders states that NMFS should assess the available 
sound propagation reduction technologies and that it is unclear from 
the proposal what the range of available technologies and strategies is 
to mitigate noise and other project impacts--i.e., to effect the least 
practicable impacts on marine mammals. Defenders also states that NMFS 
must address the technologies and approaches available to minimize 
project impacts on marine mammals and state how it is ensuring that 
those impacts are minimized, specifically expressing an interest in 
bubble curtains.
    Response: NMFS has assessed the available sound propagation 
reduction technologies, as recommended by the commenter. However, as 
discussed in greater detail in the Potential Effects of Specified 
Activities on Marine Mammals and their Habitat section of the notice of 
proposed IHA, and in the Negligible Impact Analysis and Determination 
section of this notice, only temporary, minor impacts on individual 
marine mammals are anticipated. Therefore, NMFS has determined that the 
expected effects of the action do not warrant the significant

[[Page 27415]]

additional expense associated with a requirement to use, for example, 
bubble curtains. The use of bubble curtains is also likely to extend 
the overall duration of the project. As a result, while the use of 
bubble curtains may reduce the intensity of a given take event on an 
individual, it may result in increased take events overall and in a 
longer duration of effect to marine mammal habitat in general.
    Comment: Defenders states that if the first phase of this project 
is satisfactorily completed with the inclusion of the recommended 
mitigations and corrections and minimal Level B harassment take of 
marine mammals, Defenders supports the City receiving renewal for the 
continuation of the dock construction.
    Response: NMFS appreciates Defenders feedback on a possible renewal 
in the future for this work.

Changes From the Proposed IHA to Final IHA

    For the purposes of our ESA Section 7 consultation, NMFS made a 
slight change in the way we describe the number of ESA-listed Mexico 
Distinct Population Segment (DPS) humpback whales and the Western DPS 
(WDPS) Steller sea lions in the Estimated Take section. This does not 
change our authorized number of total estimated take of humpback whales 
(880 humpback whales) from the Central North Pacific stock or the total 
estimated take of Steller sea lions (550). For the Mexico DPS of 
humpback whales, there was a slight error in the proportion used 
(0.0601) in the proposed IHA, now changed in this final IHA (0.061), 
multiplied by the total estimated take (880 humpback whales) increased 
the probable take of Mexico DPS from 53 to 54 whales. Again, this is 
used to describe how many ESA-listed species would likely be taken for 
ESA Section 7 consultation purposes, and does not change the total take 
estimate authorized for this IHA for the Central North Pacific stock of 
humpback whales. For Steller sea lions, NMFS is now using an updated 
estimate from Hastings et al. 2020 to describe the proportion of 
Western DPS Steller sea lions that may be found in the area. In the 
proposed IHA, NMFS assumed 39 sea lions would be anticipated from the 
Western DPS (0.0702 proportion of the total animals (L. Jemison draft 
unpublished Steller sea lion data, 2019) and taken by Level B 
harassment. In this final IHA, NMFS assumes that the percentage of 
Steller sea lions which may be found in the action area from the WDPS 
is now estimated at 0.014 proportion of the total animals (Hastings et 
al. 2020). Therefore, NMFS expects that 8 individual WDPS Steller sea 
lions may be exposed to Level B harassment (550 x 0.014 = 7.7 (rounded 
up to 8)). Because there are now fewer WDPS Steller sea lions estimated 
to be taken for Level B harassment, this slightly increased the 
proportion of Eastern DPS Steller sea lions that would likely be taken 
from 511 to 542 sea lions. These revised numbers do not change the 
authorized total estimated take (550) of Steller sea lions through the 
IHA.

Description of Marine Mammals in the Area of Specified Activities

    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 (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/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 2 lists all species with expected potential for occurrence in 
the project area 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 (2020). 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' SARs). While no mortality is anticipated or authorized here, PBR 
and annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. Pacific and Alaska SARs (Carretta et al., 2020; Muto et 
al., 2020). All MMPA stock information presented in Table 2 is the most 
recent available at the time of publication and is available in the 
2019 SARs (Caretta et al., 2020; Muto et al., 2020) and draft 2020 SARs 
(available online at: www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                                  Table 2--Marine Mammal Occurrence in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         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 Eschrichtiidae:
    Gray Whale......................  Eschrichtius robustus..  Eastern N Pacific......  -, -, N             26,960 (0.05, 25,849,         801        131
                                                                                                             2016).
Family Balaenopteridae (rorquals):
    Minke Whale.....................  Balaenoptera             Alaska.................  -, -, N             N/A (see SAR, N/A, see        UND          0
                                       acutorostrata.                                                        SAR).
    Humpback Whale..................  Megaptera novaeangliae.  Central N Pacific......  -, -, Y             10,103 (0.3, 7,891,            83         26
                                                               (Hawaii and Mexico DPS)                       2006).
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 27416]]

 
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer Whale....................  Orcinus orca...........  Alaska Resident........  -, -, N             2,347 (N/A, 2347,              24          1
                                                                                                             2012).
                                                               Northern Resident......  -, -, N             302 (N/A, 302, 2018)..        2.2        0.2
                                                               West Coast Transient...  -, -, N             349 (na/349; 2018)....        3.5        0.4
    Pacific White-Sided Dolphin.....  Lagenorhynchus           N Pacific..............  -, -, N             26,880 (N/A, N/A,             UND          0
                                       obliquidens.                                                          1990).
Family Phocoenidae (porpoises):
    Dall's Porpoise.................  Phocoenoides dalli.....  AK.....................  -, -, N             83,400 (0.097, N/A,           UND         38
                                                                                                             1991).
    Harbor Porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -, -, Y             see SAR (see SAR, see     see SAR         34
                                                                                                             SAR, 2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and sea lions):
    Steller Sea Lion................  Eumetopias jubatus.....  Western DPS............  E, D, Y             52,932 (see SAR,              318        255
                                                                                                             52,932, 2019).
                                                               Eastern DPS............  T, D, Y             43,201 a (see SAR,          2,592        112
                                                                                                             43,201, 2017).
Family Phocidae (earless seals):
    Harbor Seal.....................  Phoca vitulina.........  Glacier Bay/Icy Strait.  -, -, N             7,455 (see SAR, 6,680,        120        104
                                                                                                             2017).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.

    A detailed description of the of the species likely to be affected 
by the City's 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 (86 FR 
12630; March 4, 2020) since that time, we are not aware of any changes 
in the status of these species and stocks; therefore, detailed 
descriptions are not provided here. Please refer to that Federal 
Register notice for these descriptions. Please also refer to NMFS' 
website (https://www.fisheries.noaa.gov/find-species) for generalized 
species accounts.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    Acoustic effects on marine mammals during the specified activity 
can occur from vibratory and impact pile driving as well as DTH. The 
effects of underwater noise from the City's planned activities have the 
potential to result in Level A and B harassment of marine mammals in 
the vicinity of the action area. The effects of pile driving on marine 
mammals are dependent on several factors, including the size, type, and 
depth of the animal; the depth, intensity, and duration of the pile 
driving sound; the depth of the water column; the substrate of the 
habitat; the standoff distance between the pile and the animal; and the 
sound propagation properties of the environment. With both types, it is 
likely that the pile driving could result in temporary, short term 
changes in an animal's typical behavioral patterns and/or avoidance of 
the affected area. The Federal Register notice for the proposed IHA (86 
FR 12630; March 4, 2020) 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 (86 FR 
12630; March 4, 2020).

Anticipated Effects on Marine Mammal Habitat

    The main impact issue associated with the planned activity would be 
temporarily elevated sound levels and the associated direct effects on 
marine mammals. The most likely impact to marine mammal habitat occurs 
from pile driving effects on likely marine mammal prey (i.e., fish) 
near where the piles are installed. Impacts to the immediate substrate 
during installation and removal of piles are anticipated, but these 
would be limited to minor, temporary suspension of sediments, which 
could impact water quality and visibility for a short amount of time, 
but which would not be expected to have any effects on individual 
marine mammals. Impacts to substrate are therefore not discussed 
further. These potential effects are discussed in detail in the Federal 
Register notice for the proposed IHA (84 FR 18495; May 1, 2019), 
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.
    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,

[[Page 27417]]

breathing, nursing, breeding, feeding, or sheltering (Level B 
harassment).
    Take of marine mammals incidental to the City's pile driving and 
removal activities (as well as during DTH) could occur as a result of 
Level A and Level B harassment. Below we describe how the potential 
take is estimated. As described previously, no mortality is anticipated 
or authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the planned take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source (e.g., frequency, predictability, duty cycle), the environment 
(e.g., bathymetry), and the receiving animals (hearing, motivation, 
experience, demography, behavioral context) and can be difficult to 
predict (Southall et al., 2007, Ellison et al., 2012). Based on what 
the available science indicates and the practical need to use a 
threshold based on a factor that is both predictable and measurable for 
most activities, NMFS uses a generalized acoustic threshold based on 
received level to estimate the onset of behavioral harassment. NMFS 
predicts that marine mammals are likely to be behaviorally harassed in 
a manner we consider Level B harassment when exposed to underwater 
anthropogenic noise above received levels of 120 dB reference pressure 
1 [mu]Pascal (re 1 [mu]Pa) root-mean-square (rms) for continuous (e.g., 
vibratory pile driving) and above 160 dB re 1 [mu]Pa (rms) for 
intermittent sources (e.g., impact pile driving). The City's planned 
activity includes the use of continuous (vibratory pile driving) and 
impulsive (impact pile driving) sources, and therefore the 120 and 160 
dB re 1 [mu]Pa (rms) are applicable. DTH noise is considered to produce 
noise with both impulsive and continuous characteristics. Therefore, 
DTH is considered to be a continuous noise source for purposes of 
evaluating potential Level B harassment, resulting in a conservative 
approach to the analysis.
    Level A Harassment--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. The 
technical guidance identifies the received levels, or thresholds, above 
which individual marine mammals are predicted to experience changes in 
their hearing sensitivity for all underwater anthropogenic sound 
sources, and reflects the best available science on the potential for 
noise to affect auditory sensitivity by:
    [ssquf] Dividing sound sources into two groups (i.e., impulsive and 
non-impulsive) based on their potential to affect hearing sensitivity;
    [ssquf] Choosing metrics that best address the impacts of noise on 
hearing sensitivity, i.e., sound pressure level (peak SPL) and sound 
exposure level (SEL) (also accounts for duration of exposure); and
    [ssquf] Dividing marine mammals into hearing groups and developing 
auditory weighting functions based on the science supporting that not 
all marine mammals hear and use sound in the same manner.
    These thresholds were developed by compiling and synthesizing the 
best available science, and are provided in Table 4 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.
    The City's planned activities includes the use of continuous non-
impulsive (vibratory pile driving) and impulsive (impact pile driving) 
sources. DTH pile installation includes drilling (non-impulsive sound) 
and hammering (impulsive sound) to penetrate rocky substrates (Denes et 
al. 2016; Denes et al. 2019; Reyff and Heyvaert 2019). DTH pile 
installation was initially thought be a primarily non-impulsive noise 
source. However, Denes et al. (2019) concluded from a study conducted 
in Virginia, nearby the location for this project, that DTH should be 
characterized as impulsive based on Southall et al. (2007), who stated 
that signals with a >3 dB difference in sound pressure level in a 
0.035-second window compared to a 1-second window can be considered 
impulsive. Therefore, DTH pile installation is treated as both an 
impulsive and non-impulsive noise source. In order to evaluate Level A 
harassment, DTH pile installation activities are evaluated according to 
the impulsive criteria. Overall, the approach to analysis of the DTH 
installation technique ensures that the largest ranges to effect for 
both Level A and Level B harassment are accounted for in the take 
estimation process.

                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
                                                (Auditory Injury)
----------------------------------------------------------------------------------------------------------------
                                                    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.........

[[Page 27418]]

 
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 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. 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.

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

TL = B * log10(R1/R2),

where
B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log(range)). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log(range)). As is 
common practice in coastal waters, here we assume practical spreading 
loss (4.5 dB reduction in sound level for each doubling of distance). 
Practical spreading is a compromise that is often used under conditions 
where water depth increases as the receiver moves away from the 
shoreline, resulting in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions.
Sound Source Levels
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. There are source level 
measurements available for certain pile types and sizes from the 
similar environments recorded from underwater pile driving projects in 
Alaska (e.g., JASCO Reports--Denes et al., 2016 and Austin et al., 
2016) that were evaluated and used as proxy sound source levels to 
determine reasonable sound source levels likely result from the City's 
pile driving and removal activities (Table 5). Many source levels used 
were more conservative as the values were from larger pile sizes.

                                      Table 5--Assumed Sound Source Levels
----------------------------------------------------------------------------------------------------------------
                Activity                       Sound source level  at 10 meters              Sound source
----------------------------------------------------------------------------------------------------------------
                                         Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
20-inch fender pile permanent...........  161.9 SPL.................................  The 20-in fender and 30-
30-inch steel pile temporary              161.9 SPL.................................   inch-diameter source
 installation.                            161.9 SPL.................................   level for vibratory
30-inch steel pile removal..............                                               driving are proxy from
                                                                                       median measured source
                                                                                       levels from pile driving
                                                                                       of 30-inch-diameter piles
                                                                                       to construct the
                                                                                       Ketchikan Ferry Terminal
                                                                                       (Denes et al. 2016, Table
                                                                                       72).
36-inch steel pile permanent............  168.2 SPL.................................  The 36-inch-diameter pile
                                                                                       source level is proxy
                                                                                       from median measured
                                                                                       source levels from pile
                                                                                       driving of 48-inch
                                                                                       diameter piles for the
                                                                                       Port of Anchorage test
                                                                                       pile project (Austin et
                                                                                       al. 2016, Table 16).
H-pile installation permanent...........  168 SPL...................................  The H-pile source level is
                                                                                       proxy from median
                                                                                       measured source levels
                                                                                       from vibratory pile
                                                                                       driving of H piles for
                                                                                       the Port of Anchorage
                                                                                       test pile project (Yurk
                                                                                       et al. 2015 as cited in
                                                                                       Denes et al. 2016,
                                                                                       Appendix H Table 2).

[[Page 27419]]

 
Sheet pile installation.................  160 SPL...................................  The sheet source level is
                                                                                       proxy from median
                                                                                       measured source levels
                                                                                       from vibratory pile
                                                                                       driving of 24-inch sheets
                                                                                       for Berth 30 at the Port
                                                                                       of Oakland, CA (Buehler
                                                                                       et al. 2015; Table I.6-
                                                                                       2).
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
36-inch steel pile permanent............  186.7 SEL/198.6 SPL.......................  The 36-inch diameter pile
                                                                                       source level is a proxy
                                                                                       from median measured
                                                                                       source level from impact
                                                                                       hammering of 48-inch
                                                                                       piles for the Port of
                                                                                       Anchorage test pile
                                                                                       project (Austin et al.,
                                                                                       2016, Tables 9 and 16).
20-inch fender pile installation          161 SEL/174.8 SPL.........................  The 20-inch diameter pile
 permeant.                                                                             source levels are proxy
                                                                                       from median measured
                                                                                       source levels from
                                                                                       vibratory driving of 24-
                                                                                       inch piles for the Kodiak
                                                                                       Ferry Terminal project
                                                                                       (Denes et al. 2016)
H-pile installation permanent and Sheet   163 SEL/177 SPL...........................  H-Pile and Sheets
 pile installation.                                                                    Impacting source levels
                                                                                       are proxy from median
                                                                                       measured source levels
                                                                                       from pile driving H-piles
                                                                                       and sheets for the Port
                                                                                       of Anchorage test pile
                                                                                       project (Yurk et al. 2015
                                                                                       as cited in Denes et al.
                                                                                       2016, Appendix H Table
                                                                                       1).
----------------------------------------------------------------------------------------------------------------
                                              DTH Pile Installation
----------------------------------------------------------------------------------------------------------------
36-inch steel pile permanent............  164 SEL/166 SPL...........................  The DTH sound source proxy
20-inch fender pile installation          154 SEL/166 SPL...........................   of 164 dB SEL is from 42-
 temporary.                               154 SEL/166 SPL...........................   in piles, Reyff 2020 and
H-pile installation permanent (20-inch                                                 Denes et al. 2019; while
 hole).                                                                                the 154 dB SEL is based
                                                                                       on 24-in piles, Denes et
                                                                                       al. 2016.
----------------------------------------------------------------------------------------------------------------

Level A Harassment
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources (such as from 
impact and vibratory pile driving and DTH), NMFS User Spreadsheet 
(2020) predicts the closest distance at which, if a marine mammal 
remained at that distance the whole duration of the activity, it would 
not incur PTS. Inputs used in the User Spreadsheet (Tables 6 and 7), 
and the resulting isopleths are reported below (Table 8).

                  Table 6--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                             User spreadsheet input--vibratory pile driving spreadsheet tab A.1 vibratory pile driving used.
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            30-in piles     30-in piles    20-in fender
                                                            (temporary      (temporary         piles        36-in piles       H-piles       Sheet piles
                                                             install)        removal)       (permanent)     (permanent)     (permanent)     (permanent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL)..................................           161.9           161.9           161.9           168.2             168             160
Weighting Factor Adjustment (kHz).......................             2.5             2.5             2.5             2.5             2.5             2.5
Number of piles within 24-hr period.....................               4               4               4               4               4              30
Duration to drive a single pile (min)...................              15              15              15              15              15              15
Propagation (xLogR).....................................              15              15              15              15              15              15
Distance of source level measurement (meters)+..........              10              10              10              10              11              10
--------------------------------------------------------------------------------------------------------------------------------------------------------


                    Table 7--NMFS Technical Guidance (2020) User Spreadsheet Input To Calculate PTS Isopleths for Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                User Spreadsheet Input--Impact pile driving spreadsheet tab E.1 impact pile driving used.
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           20-in fender
                                            36-in piles     36-in pile         piles       20-in fender       H-pile       H-pile (DTH)     Sheet piles
                                            (permanent)        (DTH)        (permanent)     pile (DTH)      (permanent)                     (permanent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Level (Single Strike/shot SEL)...           186.7             164             161             154             163             154             163
Weighting Factor Adjustment (kHz).......               2               2               2               2               2               2               2
Number of strikes per pile..............             100  ..............              35  ..............              35  ..............              35
Strike rate (avg. strikes per second)...  ..............              15  ..............              15  ..............              15  ..............
Number of piles per day.................               2               2               2               2               5               2               5
Propagation (xLogR).....................              15              15              15              15              15              15              15
Distance of source level measurement                  10              10              10              10              15              10              15
 (meters)+..............................
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 27420]]


                     Table 8--NMFS Technical Guidance (2020) User Spreadsheet Outputs To Calculate Level A Harassment PTS Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         User spreadsheet output                                                      PTS isopleths (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Level A harassment
                                                                         -------------------------------------------------------------------------------
              Activity                    Sound source level  at 10 m                                          High-
                                                                          Low- frequency  Mid- frequency     frequency        Phocid          Otariid
                                                                             cetaceans       cetaceans       cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
20-in steel fender pile installation  161.9 SPL.........................             7.8             0.7            11.6             4.8             0.3
30-in steel pile temporary            161.9 SPL.........................             7.8             0.7            11.6             4.8             0.3
 installation.
30-in steel pile removal............  161.9 SPL.........................             7.8             0.7            11.6             4.8             0.3
36-in steel permanent installation..  168.2 SPL.........................            20.6             1.8            30.5            12.5             0.9
H-pile installation.................  168 SPL...........................            22.0             2.0            32.5            13.4             0.9
Sheet pile installation.............  160 SPL...........................            22.4             2.0            33.2            13.6             1.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel permanent installation..  186.7 SEL/198.6 SPL...............           602.7            21.4           717.9           322.5            23.5
20-in fender pile installation......  161 SEL/174.8 SPL.................             5.8             0.2             6.9             3.1            0.21
H-pile installation.................  163 SEL/177 SPL...................            21.8             0.8            25.9            11.6             0.8
Sheet pile installation.............  163 SEL/177 SPL...................            21.8             0.8            25.9            11.6             0.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           DTH
--------------------------------------------------------------------------------------------------------------------------------------------------------
36-in steel permanent installation..  164 SEL/166 SPL...................         1,225.6            43.6         1,459.9           655.9            47.8
20-in steel fender pile installation  154 SEL/166 SPL...................           264.1             9.4           314.5           141.3            10.3
H-pile installation.................  154 SEL/166 SPL...................           264.1             9.4           314.5           141.3            10.3
--------------------------------------------------------------------------------------------------------------------------------------------------------

Level B Harassment
    Utilizing the practical spreading loss model, the City determined 
underwater noise will fall below the behavioral effects threshold of 
120 dB rms for marine mammals at the distances shown in Table 9 for 
vibratory pile driving/removal, and DTH. With these radial distances, 
and due to the occurrence of landforms (See Figure 5 and 8 of the IHA 
Application), the largest Level B harassment zone calculated for 
vibratory pile driving for 36-in steel piles and H-piles were larger 
than the 15,700 meters (m) from the source where land masses block 
sound transmission. For DTH, the largest radial distance was 11,659 m. 
For calculating the Level B harassment zone for impact driving, the 
practical spreading loss model was used with a behavioral threshold of 
160 dB rms. The maximum radial distance of the Level B harassment zone 
for impact piling equaled 3,744 m for 36-in piles m. Table 9 below 
provides all Level B harassment radial distances (m) during the City's 
planned activities.

                       Table 9--Radial Distances (Meters) to Relevant Behavioral Isopleths
----------------------------------------------------------------------------------------------------------------
               Activity                       Received level at  10 meters         Level B harassment zone (m) *
----------------------------------------------------------------------------------------------------------------
                                         Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
20-inch steel fender pile              161.9 SPL.................................  6,215 (calculated 6,213).
 installation.
30-inch steel temporary installation.  161.9 SPL.................................  6,215 (calculated 6,213).
30-inch steel removal................  161.9 SPL.................................  6,215 (calculated 6,213).
36-inch steel permanent installation.  168.2 SPL.................................  15,700 \a\ (calculated
                                                                                    16,343).
H-pile installation..................  168 SPL...................................  15,700 \a\ (calculated
                                                                                    17,434).
Sheet pile installation..............  160 SPL...................................  4,645 (calculated 4,642).
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
20-inch fender pile installation.....  161 SEL/174.8 SPL.........................  100 (calculated 97).
36-inch steel permanent installation.  186.7 SEL/198.6 SPL.......................  3,745 (calculated 3,744).
H-pile and Sheet pile installation...  163 SEL/177 SPL...........................  205 (calculated 204).
----------------------------------------------------------------------------------------------------------------
                                                       DTH
----------------------------------------------------------------------------------------------------------------
20-inch steel fender pile              166 SPL...................................  11,660 (calculated 11,659).
 installation.
36-inch steel temporary installation.  166 SPL...................................  11,660 (calculated 11,659).
H-pile installation..................  166 SPL...................................  11,660 (calculated 11,659).
----------------------------------------------------------------------------------------------------------------
* Numbers rounded up to nearest 5 meters. These specific rounded distances are for monitoring purposes rather
  than take estimation.
\a\ Although the calculated distance to Level B harassment thresholds extends these distances, all Level B
  harassment zones are truncated at 15,700m from the source where land masses block sound transmission.


[[Page 27421]]

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. Potential exposures to impact pile driving, vibratory 
pile driving/removal and DTH noises for each acoustic threshold were 
estimated using group size estimates and local observational data. As 
previously stated, take by Level B harassment as well as small numbers 
of take by Level A harassment will be considered for this action. Take 
by Level B and Level A harassment are calculated differently for some 
species based on monthly or daily sightings data and average group 
sizes within the action area using the best available data. Take by 
Level A harassment is being authorized for three species (Dall's and 
harbor porpoise and harbor seal) where the Level A harassment isopleths 
are larger for pile driving of 36-in steel piles and DTH of 36-in 
piles, and is based on average group size multiplied by the number of 
days of impact pile driving for 36-in piles and DTH of 36-in piles. 
Distances to Level A harassment thresholds for other project activities 
(vibratory pile driving/removal, DTH and impact driving of smaller pile 
sizes) are considerably smaller compared to impact pile driving of 36-
in piles and DTH for 36-in piles, and mitigation is expected to avoid 
Level A harassment from these other activities.
Minke Whales
    There are no density estimates of minke whales available in the 
project area. These whales are usually sighted individually or in small 
groups of two or three, but there are reports of loose aggregations of 
hundreds of animals (NMFS 2018). One minke whale was sighted each year 
during the Hoonah cruise ship Berth I project (June 2015-January 2016; 
BergerABAM 2016) and during the Hoonah Berth II project (June 2019-
October 2019; SolsticeAK 2020).To be conservative based on group size, 
we predict that three minke whales in a group could be sighted each 
month over the 4-month project period for a total of 12 minke whale 
takes authorized by Level B harassment. No take by Level A harassment 
is authorized or anticipated to occur due to their rarer occurrence in 
the project area.
Humpback Whales
    There are no density estimates of humpback whales available in the 
project area. During the previous Hoonah Berth I project, humpback 
whales were observed on 84 of the 135 days of monitoring; most often in 
September and October (BergerABAM 2016). Additionally, during 
construction of the Hoonah Berth II project in 2019, humpback whales 
were observed in the action area on 45 of the 51 days of monitoring; 
most often in July and September. Up to 24 humpback sightings were 
reported on a single day (July 30, 2019), and a total of 108 
observations were recorded in harassment zones during project 
construction (SolsticeAK 2020).
    Based on a group size of eight animals, the general maximum group 
size observed in Southeast Alaska in all months of the year, NMFS 
estimates that 8 humpback whales could occur for each day of the 
project (110 days) for a total of 880 takes by Level B harassment. 
Under the MMPA, humpback whales are considered a single stock (Central 
North Pacific); however, we have divided them here to account for DPSs 
listed under the ESA. Using the stock assessment from Muto et al. 2020 
for the Central North Pacific stock (10,103 whales) and calculations in 
Wade et al. 2016; 9,487 whales are expected to be from the Hawaii DPS 
and 606 from the Mexico DPS. Therefore, for purposes of consultation 
under the ESA, we anticipate that 54 of the total takes would be of 
individuals from the Mexico DPS (880 x 0.061 = 53.68 (rounded up to 
54). No take by Level A harassment is authorized or anticipated to 
occur due to their large size and ability to be visibly detected in the 
project area if an animal should approach the Level A harassment zone.
Gray Whales
    There are no density estimates of gray whales available in the 
project area. Gray whales travel alone or in small, unstable groups, 
although large aggregations may be seen in feeding and breeding grounds 
(NMFS 2018e). Observations in Glacier Bay and nearby waters recorded 
two gray whales documented over a 10-year period (Keller et al., 2017). 
None were observed during Hoonah Berth I or II project monitoring 
(BergerABAM 2016, SolsticeAK 2020). We estimate a one gray whale x 
onesighting per month over the 4-month work period for a total of four 
gray whale takes authorized by Level B harassment. No take by Level A 
harassment is authorized or anticipated to occur due to their rarer 
occurrence in the project area, but also their large size and ability 
to be visibly detected in the project area if an animal should approach 
the Level A harassment zone.
Killer Whales
    There are no density estimates of killer whales available in the 
project area. Killer whales occur commonly in the waters of the project 
area, and could include members of several designated stocks that may 
occur in the vicinity of the project area. Whales are known to use the 
Icy Strait corridor to enter and exit inland waters and are observed in 
every month of the year, with certain pods being observed inside Port 
Frederick passing directly in front of Hoonah. Group size of resident 
killer whale pods in the Icy Strait area ranges from 42 to 79 and occur 
in every month of the year (Dahlheim pers. comm. to NMFS 2015). As 
determined during a line-transect survey by Dalheim et al. (2008), the 
greatest number of transient killer whale observed occurred in 1993 
with 32 animals seen over 2 months for an average of 16 sightings per 
month. Killer whales were observed infrequently during construction of 
Hoonah Berth I project. Usually a singular animal was observed, but a 
group containing eight individuals was seen in the project area on one 
occasion. A total of 24 animals were observed during in-water work for 
the Hoonah Bert I project (BergerABAM 2016). During construction of the 
Hoonah Berth II project, killer whales were observed on 8 days. Usually 
a single animal or pairs were observed, but a group containing five 
individuals was seen in the project area on one occasion. A total of 20 
animals were observed during in-water work on Hoonah Berth II project 
(SolsticeAK 2020). Using the largest group size for resident killer 
whales as discussed above, NMFS estimates that 79 killer whales 
(residents and transients) could occur each month during the 4-month 
project period for a total of 316 takes by Level B harassment. No take 
by Level A harassment is authorized or anticipated to occur to the 
ability to visibly detect these large whales and in most cases the 
small size of the Level A harassment zones.
Pacific White-Sided Dolphin
    There are no density estimates of Pacific white-sided dolphins 
available in the project area. Pacific white-sided dolphins have been 
observed in Alaska waters in groups ranging from 20 to 164 animals, 
with the sighting of 164 animals occurring in Southeast Alaska near 
Dixon Entrance (Muto et al., 2018). There were no Pacific white-sided 
dolphins observed during the 135-day monitoring period during the 
Hoonah Berth I project; however, a pod of two Pacific white-sided 
dolphins was

[[Page 27422]]

observed during construction of the Hoonah Bert II project (SolsticeAK 
2020). Using the largest group size for Pacific white-sided dolphins as 
discussed above, NMFS estimates 164 Pacific white-sided dolphins may be 
seen every other month over the 4-month project period for a total of 
328 takes by Level B harassment. No take by Level A harassment is 
authorized or anticipated to occur as the largest Level A harassment 
isopleths calculated were 43.6 m during DTH of 36-in piles and 21.4 m 
during impact pile driving of 36-in piles. The remaining isopleths were 
all under 10 m.
Dall's Porpoise
    Little information is available on the abundance of Dall's porpoise 
in the inland waters of Southeast Alaska. Dall's porpoise are most 
abundant in spring, observed with lower numbers in the summer, and 
lowest numbers in fall. Jefferson et al., 2019 presents abundance 
estimates for Dall's porpoise in these waters and found the abundance 
(N) in summer (N = 2,680, CV = 19.6 percent), and lowest in fall (N = 
1,637, CV = 23.3 percent). Dall's porpoise are common in Icy Strait and 
sporadic with very low densities in Port Frederick (Jefferson et al., 
2019). Dahlheim et al. (2008) observed 346 Dall's porpoise in Southeast 
Alaska (inclusive of Icy Strait) during the summer (June/July) of 2007 
for an average of 173 animals per month as part of a 17-year study 
period. During the previous Hoonah Berth I project, only two Dall's 
porpoise were observed, and were transiting within the waters of Port 
Frederick in the vicinity of Halibut Island. A total of 21 Dall's 
porpoises were observed on eight days during the Hoonah Berth II 
project in group sizes of 2 to 12 porpoise (SolsticeAK 2020).Therefore, 
NMFS' estimates 12 Dall's porpoise a week may be seen during the 4-
month project period for a total of 192 takes by Level B harassment. 
Because the calculated Level A harassment isopleths are larger for 
high-frequency cetaceans during DTH of 36-inch piles (1,459.9 m) and 
36-in impact pile driving (717.9 m) and the applicant would have a 
reduced shutdown zone at 200 m, NMFS predicts that some take by Level A 
harassment may occur. It is estimated that two Dall's porpoise could be 
taken by Level A harassment every 5 days over a 20-day period (15 days 
of DTH of 36-in piles + 5 days of 36-in impact pile driving) for a 
total of 8 takes by Level A harassment.
Harbor Porpoise
    Dahlheim et al. (2015) observed 332 resident harbor porpoises occur 
in the Icy Strait area, and harbor porpoise are known to use the Port 
Frederick area as part of their core range. During the Hoonah Berth I 
project monitoring, a total of 32 harbor porpoise were observed over 19 
days during the 4-month project. The harbor porpoises were observed in 
small groups with the largest group size reported was four individuals 
and most group sizes consisting of three or fewer animals. During the 
test pile program conducted at the Berth II project site in May 2018, 
eight harbor porpoises where observed over a 7-hour period (SolsticeAK 
2018). During the Hoonah Berth II project, 120 harbor porpoises were 
observed June through October. The largest group size reported was 
eight individuals, and most group sizes consisting of four or fewer 
animals (SolsticeAK 2020). NMFS estimates that four harbor porpoises 
per day could occur in the project area over the 4-month project period 
(110 days) for a total of 440 takes by Level B harassment. Because the 
calculated Level A harassment isopleths are larger for high-frequency 
cetaceans during DTH of 36-inch piles (1,459.9 m) and 36-in impact pile 
driving (717.9 m) and the applicant would have a reduced shutdown zone 
at 200 m, NMFS predicts that some take by Level A harassment may occur. 
It is estimated that four harbor porpoise could be taken by Level A 
harassment every 5 days over a 20-day period (15 days of DTH of 36-in 
piles + 5 days of 36-in impact pile driving) for a total of 16 takes by 
Level A harassment.
Harbor Seal
    There are no density estimates of harbor seals available in the 
project area. Keller et al. (2017) observed an average of 26 harbor 
seal sightings each month between June and August of 2014 in Glacier 
Bay and Icy Strait. During the monitoring of the Hoonah Berth I 
project, harbor seals typically occur in groups of one to four animals 
and a total of 63 seals were observed during 19 days of the 135-day 
monitoring period. In 2019, a total of 33 harbor seals were seen during 
the Hoonah Berth II project. Only solo individuals were sighted during 
that time (SolsticeAK 2020). NMFS estimates that three harbor seals per 
group, and two groups a day, could occur in the project area each month 
during the 4-month project period (110 days) for a total of 660 takes 
by Level B harassment. Because the calculated Level A harassment 
isopleths are larger for phocids during DTH of 36-inch piles (655.9 m) 
and 36-in impact pile driving (322.5 m), compared with the shutdown 
zone at 200 m, NMFS predicts that some take by Level A harassment may 
occur. It is estimated that one group of three harbor seals a day could 
be taken by Level A harassment over a 20-day period (15 days of DTH of 
36-in piles + 5 days of 36-in impact pile driving) for a total of 60 
takes by Level A harassment.
Steller Sea Lion
    There are no density estimates of Steller sea lions available in 
the project area. NMFS expects that Steller sea lion presence in the 
action area will vary due to prey resources and the spatial 
distribution of breeding versus non-breeding season. In April and May, 
Steller sea lions are likely feeding on herring spawn in the action 
area. Then, most Steller sea lions likely move to the rookeries along 
the outside coast (away from the action area) during breeding season, 
and would be in the action area in greater numbers in August and later 
months (J. Womble, NPS, pers. comm. to NMFS AK Regional Office, March 
2019). However, Steller sea lions are also opportunistic predators and 
their presence can be hard to predict.
    Steller sea lions typically occur in groups of 1-10 animals, but 
may congregate in larger groups near rookeries and haulouts. The 
previous Hoonah Berth I project observed a total of 180 Steller sea 
lion sightings over 135 days in 2015, amounting to an average of 1.3 
sightings per day (BergerABAM 2016). During a test pile program 
performed at the project location by the Hoonah Cruise Ship Dock 
Company in May 2018, a total of 15 Steller sea lions were seen over the 
course of 7 hours in one day (SolsticeAK 2018). During construction of 
the Hoonah Berth II project, a total of 197 Steller sea lion sightings 
over 42 days were reported, amounting to an average of 4.6 sightings 
per day (SolsticeAK 2020). NMFS estimates that five Steller sea lions 
per day could occur in the project area each month during the 4-month 
project period (110 days) for a total of 550 takes by Level B 
harassment. NMFS expects that the percentage of Steller sea lions which 
may be found in the action area from the WDPS is estimated at 1.4 
percent (Hastings et al. 2020). Therefore, NMFS expects that 8 
individual WDPS Steller sea lions may be exposed to Level B harassment 
(550 x 0.014 = 7.7 (rounded up to 8)). There is some evidence of 
Steller sea lions remaining in areas where there is a reliable food 
source. Should a Steller sea lion go undetected by a Protected Species 
Observer (PSO) and later observed within the Level A harassment zone, 
the City proposes mitigation measures (e.g., shutdowns), and it would 
be unlikely that an animal would accumulate

[[Page 27423]]

enough exposure for PTS to occur. Therefore, no take by Level A 
harassment is authorized or anticipated to occur as the largest Level A 
isopleths calculated were 47.8 m during DTH of 36-in piles and 23.5 m 
during impact pile driving of 36-in piles. The remaining isopleths were 
approximately 10 m or less.
    Table 10 below summarizes the authorized take for all the species 
described above as a percentage of stock abundance.

                           Table 10--Take Estimates as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                     Level A          Level B
           Species               Stock (NEST)      harassment       harassment            Percent of stock
----------------------------------------------------------------------------------------------------------------
Minke Whale..................  N/A.............               0  12..............  N/A.
Humpback Whale...............  Central North                  0  880.............  8.7.
                                Pacific.
Gray Whale...................  Eastern North                  0  4...............  Less than 1 percent.
                                Pacific
                                (27,000).
Killer Whale.................  Alaska Resident                0  256.............  10.9 \a\
                                (2,347).                         33..............  10.9 \a\
                               Northern                          27..............  11.1.\a\
                                Resident (302).                  (Total 316).....
                               West Coast
                                Transient (243).
Pacific White-Sided Dolphin..  North Pacific                  0  328.............  Less than 1 percent.
                                (26,880).
Dall's Porpoise..............  Alaska (83,400)                8  144.............  Less than 1 percent.
                                \b\.
Harbor Porpoise..............  NA..............              16  440.............  NA.
Harbor Seal..................  Glacier Bay/Icy               60  660.............  8.9.
                                Strait (7,455).
Steller Sea Lion.............  Eastern U.S.                   0  542.............  1.26
                                (43,201).                        8...............  Less than 1 percent.
                               Western U.S.                      (Total 550).....
                                (53,624).
----------------------------------------------------------------------------------------------------------------
\a\ Take estimates are weighted based on calculated percentages of population for each distinct stock, assuming
  animals present would follow same probability of presence in project area.
\b\ Jefferson et al. 2019 presents the first abundance estimates for Dall's porpoise in the waters of Southeast
  Alaska with highest abundance recorded in spring (N = 5,381, CV = 25.4 percent), lower numbers in summer (N =
  2,680, CV = 19.6 percent), and lowest in fall (N = 1,637, CV = 23.3 percent). However, NMFS currently
  recognizes a single stock of Dall's porpoise in Alaskan waters and an estimate of 83,400 Dall's porpoises is
  used by NMFS for the entire stock (Muto et al., 2020).

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.

General

    The City will follow mitigation procedures as outlined in their 
Marine Mammal Monitoring Plan and as described below. In general, if 
poor environmental conditions restrict visibility full visibility of 
the shutdown zone, pile driving installation and removal as well as DTH 
will be delayed.

Training

    The City must ensure that construction supervisors and crews, the 
monitoring team, and relevant City staff are trained prior to the start 
of construction activity subject to this IHA, so that responsibilities, 
communication procedures, monitoring protocols, and operational 
procedures are clearly understood. New personnel joining during the 
project must be trained prior to commencing work

Avoiding Direct Physical Interaction

    The City must avoid direct physical interaction with marine mammals 
during construction activity. If a marine mammal comes within 10 m of 
such activity, operations must cease and vessels must reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions, as necessary to avoid direct physical interaction.

Shutdown Zones

    For all pile driving/removal and DTH activities, the City will 
establish a shutdown zone for a marine mammal species that is greater 
than its corresponding Level A harassment zone; except for a few 
circumstances during impact pile driving and DTH, where the shutdown 
zone is smaller (reduced to 200 m) than the Level A harassment zone for 
high frequency cetaceans and phocids due to the practicability of 
shutdowns on the applicant and to the potential difficulty of observing 
these animals in the larger Level A harassment zones. The calculated 
PTS isopleths were rounded up to a whole number to determine the actual 
shutdown zones that the applicant will operate under (Table 11). The 
purpose of a shutdown zone is generally to define an area within which 
shutdown of the activity would occur upon

[[Page 27424]]

sighting of a marine mammal (or in anticipation of an animal entering 
the defined area).

                         Table 11--Pile Driving Shutdown Zones During Project Activities
----------------------------------------------------------------------------------------------------------------
                                                                  Shutdown Zones
                                 -------------------------------------------------------------------------------
   Pile size, type, and method                                         High-
                                  Low- frequency  Mid- frequency     frequency        Phocid          Otariid
                                     cetaceans       cetaceans       cetaceans
----------------------------------------------------------------------------------------------------------------
                                         Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
20-in steel fender pile                       10              10              15              10              10
 installation...................
30-in steel pile temporary                    10              10              15              10              10
 installation...................
30-in steel pile removal........              10              10              15              10              10
36-in steel permanent                         25              10              35              15              10
 installation...................
H-pile installation.............              35              10              35              15              10
Sheet pile installation.........              25              10              35              15              10
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
36-in steel permanent                        625              25           200 *           200 *              25
 installation...................
20-in fender pile installation..              10              10              10              10              10
H-pile installation.............              25              10              30              15              10
Sheet pile installation.........              25              10              30              15              10
----------------------------------------------------------------------------------------------------------------
                                                       DTH
----------------------------------------------------------------------------------------------------------------
36-in steel permanent                      1,230              45           200 *           200 *              50
 installation...................
20-in steel fender pile                      265              10           200 *             145              15
 installation...................
H-pile installation.............             265              10           200 *             145              15
----------------------------------------------------------------------------------------------------------------
* Due to practicability of the applicant to shutdown and the difficulty of observing some species and low
  occurrence of some species in the project area, such as high frequency cetaceans or pinnipeds out to this
  distance, the shutdown zones were reduced and Level A harassment takes were requested during DTH and for
  impact pile driving of 36-in piles.

Soft Start

    The City must use soft start techniques when impact pile driving. 
Soft start requires contractors to provide an initial set of three 
strikes from the hammer at reduced energy, followed by a 30-second 
waiting period. Then two subsequent reduced-energy strike sets would 
occur. A soft start must be implemented at the start of each day's 
impact pile driving and at any time following cessation of impact pile 
driving for a period of 30 minutes or longer. Soft start is not 
required during vibratory pile driving and removal activities.

Vessels

    Vessels will adhere to the Alaska Humpback Whale Approach 
Regulations when transiting for project activities (see 50 CFR 216.18, 
223.214, and 224.103(b)). These regulations require that all vessels:
    [ssquf] Not approach within 91.44 m (100 yards (yd)) of a humpback 
whale, or cause a vessel or other object to approach within 91.44 m 
(100 yd) of a humpback whale;
    [ssquf] Not place vessel in the path of oncoming humpback whales 
causing them to surface within 91.44 m (100 yd) of vessel;
    [ssquf] Not disrupt the normal behavior or prior activity of a 
whale; and
    [ssquf] Operate at a slow, safe speed when near a humpback whale 
(safe speed is defined in regulation (see 33 CFR 83.06)).
    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the planned mitigation measures provide the means 
of 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 
planned 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:
    [ssquf] Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
    [ssquf] 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).
    [ssquf] Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
    [ssquf] How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
    [ssquf] Effects on marine mammal habitat (e.g., marine mammal prey 
species,

[[Page 27425]]

acoustic habitat, or other important physical components of marine 
mammal habitat).
    [ssquf] Mitigation and monitoring effectiveness.

Monitoring Zones

    The City will establish and observe monitoring zones for Level B 
harassment as presented in Table 9. The monitoring zones for this 
project are areas where SPLs are equal to or exceed 120 dB rms (for 
vibratory pile driving/removal and DTH) and 160 dB rms (for impact pile 
driving). These zones provide utility for monitoring conducted for 
mitigation purposes (i.e., shutdown zone monitoring) by establishing 
monitoring protocols for areas adjacent to the shutdown zones. 
Monitoring of the Level B harassment zones enables observers to be 
aware of and communicate the presence of marine mammals in the project 
area, but outside the shutdown zone, and thus prepare for potential 
shutdowns of activity.

Pre-Start Clearance Monitoring

    Pre-start clearance monitoring must be conducted during periods of 
visibility sufficient for the lead PSO to determine the shutdown zones 
clear of marine mammals. Pile driving and DTH may commence when the 
determination is made.

Visual Monitoring

    Monitoring must take place from 30 minutes (min) prior to 
initiation of pile driving and DTH activity (i.e., pre-start clearance 
monitoring) through 30 min post-completion of pile driving and DTH 
activity. If a marine mammal is observed entering or within the 
shutdown zones, pile driving and DTH activity must be delayed or 
halted. If pile driving or DTH is delayed or halted due to the presence 
of a marine mammal, the activity may not commence or resume until 
either the animal has voluntarily exited and been visually confirmed 
beyond the shutdown zone or 15 min have passed without re-detection of 
the animal. Pile driving and DTH activity must be halted upon 
observation of either a species for which incidental take is not 
authorized or a species for which incidental take has been authorized 
but the authorized number of takes has been met, entering or within the 
harassment zone.

PSO Monitoring Locations and Requirements

    The City will establish monitoring locations as described in the 
Marine Mammal Monitoring Plan. The City will monitor the project area 
to the extent possible based on the required number of PSOs, required 
monitoring locations, and environmental conditions. Monitoring will be 
conducted by PSOs from on land and from a vessel. For all pile driving 
and DTH activities, a minimum of one observer must be assigned to each 
active pile driving and DTH location to monitor the shutdown zones. 
Three PSOs must be onsite during all in-water activities as follows: 
PSO 1 stationed at the pile site on the existing City Dock, PSO 2 
stationed on Halibut Island facing south and PSO 3 stationed on a 
vessel running a transect through southern portion of the project area 
in Port Frederick. These observers must record all observations of 
marine mammals, regardless of distance from the pile being driven or 
during DTH.
    In addition, PSOs will work in shifts lasting no longer than 4 hrs 
with at least a 1-hr break between shifts, and will not perform duties 
as a PSO for more than 12 hrs in a 24[hyphen]hr period (to reduce PSO 
fatigue).
    Monitoring of pile driving will be conducted by qualified, NMFS-
approved PSOs. The City shall adhere to the following conditions when 
selecting PSOs:
    [ssquf] PSOs must be independent (i.e., not construction personnel) 
and have no other assigned tasks during monitoring periods.
    [ssquf] At least one PSO must have prior experience performing the 
duties of a PSO during construction activities pursuant to a NMFS-
issued incidental take authorization.
    [ssquf] Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field), or training.
    [ssquf] Where a team of three PSOs are required, a lead observer or 
monitoring coordinator shall be designated. The lead observer must have 
prior experience performing the duties of a PSO during construction 
activity pursuant to a NMFS-issued incidental take authorization.
    [ssquf] PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    The City will ensure that the PSOs have the following additional 
qualifications:
    [ssquf] Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    [ssquf] Experience and ability to conduct field observations and 
collect data according to assigned protocols;
    [ssquf] Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    [ssquf] Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    [ssquf] 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;
    [ssquf] 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; and
    [ssquf] Sufficient training, orientation, or experience with the 
construction operations to provide for personal safety during 
observations.

Notification of Intent To Commence Construction

    The City will inform NMFS OPR and the NMFS Alaska Region Protected 
Resources Division one week prior to commencing construction 
activities.

Interim Monthly Reports

    During construction, the City will submit brief, monthly reports to 
the NMFS Alaska Region Protected Resources Division that summarize PSO 
observations and recorded takes. Monthly reporting will allow NMFS to 
track the amount of take (including any extrapolated takes), to allow 
reinitiation of consultation in a timely manner, if necessary. The 
monthly reports will be submitted by email to [email protected]. 
The reporting period for each monthly PSO report will be the entire 
calendar month, and reports will be submitted by close of business on 
the 10th day of the month following the end of the reporting period.

Final Report

    The City will submit a draft report on all monitoring conducted 
under this IHA within 90 calendar days of the completion of monitoring 
or 60 calendar days prior to the requested issuance of any subsequent 
IHA for construction activity at the same location, whichever comes 
first. A final report must be prepared and submitted within 30 days 
following resolution of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 days of receipt of the draft 
report, the report shall be considered

[[Page 27426]]

final. All draft and final marine mammal monitoring reports must be 
submitted to [email protected] and [email protected]. 
The report must contain the informational elements described in the 
Marine Mammal Monitoring Plan and, at minimum, must include:
    [ssquf] Dates and times (begin and end) of all marine mammal 
monitoring;
    [ssquf] Construction activities occurring during each daily 
observation period, including:
    (i) How many and what type of piles were driven and by what method 
(e.g., impact, vibratory, DTH);
    (ii) Total duration of driving time for each pile (vibratory 
driving) and number of strikes for each pile (impact driving); and
    (iii) For DTH, duration of operation for both impulsive and non-
pulse components.
    [ssquf] PSO locations during marine mammal monitoring;
    [ssquf] (Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
    [ssquf] Upon observation of a marine mammal, the following 
information:
    (i) PSO who sighted the animal and PSO location and activity at 
time of sighting;
    (ii) Time of sighting;
    (iii) Identification of the animal (e.g., genus/species, lowest 
possible taxonomic level, or unidentified), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    (iv) Distance and bearing of each marine mammal observed to the 
pile being driven for each sighting (if pile driving and DTH was 
occurring at time of sighting);
    (v) Estimated number of animals (min/max/best);
    (vi) Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition etc.; Animal's closest point of approach 
and estimated time spent within the harassment zone.
    (vii) Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses to the activity (e.g., no response 
or changes in behavioral state such as ceasing feeding, changing 
direction, flushing, or breaching);
    [ssquf] Detailed information about implementation of any mitigation 
(e.g., shutdowns and delays), a description of specific actions that 
ensued, and resulting changes in behavior of the animal, if any; and
    [ssquf] All PSO datasheets and/or raw sightings data.

Reporting of Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the City will report the 
incident to the Office of Protected Resources 
([email protected]), NMFS (301-427-8401) and to the 
Alaska regional stranding network (877-925-7773) as soon as feasible. 
If the death or injury was clearly caused by the specified activity, 
the City will immediately cease the specified activities until NMFS OPR 
is able to review the circumstances of the incident and determine what, 
if any, additional measures are appropriate to ensure compliance with 
the terms of this IHA. The City will not resume their activities until 
notified by NMFS. The report must include the following information:
    [ssquf] Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    [ssquf] Species identification (if known) or description of the 
animal(s) involved;
    [ssquf] Condition of the animal(s) (including carcass condition if 
the animal is dead);
    [ssquf] Observed behaviors of the animal(s), if alive;
    [ssquf] If available, photographs or video footage of the 
animal(s); and
    [ssquf] General circumstances under which the animal was 
discovered.

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 that are larger 
than the Level A harassment zones will be implemented in the majority 
of construction days, which, in combination with the fact that the 
zones are so small to begin with, is expected to avoid the likelihood 
of Level A harassment for six of the nine species. For the other three 
species (harbor seals, Dall's and harbor porpoises), a small amount of 
Level A harassment has been conservatively authorized because the Level 
A harassment zones are larger than the planned shutdown zones during 
impact pile driving of 36-in piles and during DTH. However, we expect, 
given the nature of the activities and sound source and the 
unlikelihood that animals would stay in the vicinity of the pile-
driving for long, any PTS incurred would be expected to be of a low 
degree and unlikely to have any effects on individual fitness.
    Exposures to elevated sound levels produced during pile driving 
activities may cause behavioral responses by an animal, but they are 
expected to be mild and temporary. Effects on individuals that are 
taken by Level B harassment, on the basis of reports in the literature 
as well as monitoring from other similar activities, will likely be 
limited to reactions such as increased swimming speeds, increased 
surfacing time, or decreased foraging (if such activity were occurring) 
(e.g., Thorson and Reyff, 2006; Lerma, 2014). Most likely, individuals 
will simply move away from the sound source and be temporarily 
displaced from the areas of pile driving, although even this reaction 
has been observed primarily only in association with impact pile 
driving. These reactions and behavioral changes are expected to subside 
quickly when the exposures cease.
    To minimize noise during pile driving, the City will use pile caps 
(pile softening material). Much of the noise generated during pile 
installation comes

[[Page 27427]]

from contact between the pile being driven and the steel template used 
to hold the pile in place. The contractor will use high-density 
polyethylene or ultra-high-molecular-weight polyethylene softening 
material on all templates to eliminate steel on steel noise generation.
    During all impact driving, implementation of soft start procedures 
and monitoring of established shutdown zones will be required, 
significantly reducing the possibility of injury. Given sufficient 
notice through use of soft start (for impact driving), marine mammals 
are expected to move away from an irritating sound source prior to it 
becoming potentially injurious. In addition, PSOs will be stationed 
within the action area whenever pile driving/removal and DTH activities 
are underway. Depending on the activity, the City will employ the use 
of three PSOs to ensure all monitoring and shutdown zones are properly 
observed.
    The HMIC Cargo Dock would likely not impact any marine mammal 
habitat since its location is within an area that is currently used by 
large shipping vessels and in between two existing, heavily-traveled 
docks, and within an active marine commercial and tourist area. There 
are no known pinniped haulouts or other biologically important areas 
for marine mammals near the action area. In addition, impacts to marine 
mammal prey species are expected to be minor and temporary. Overall, 
the area impacted by the project is very small compared to the 
available habitat around Hoonah. The most likely impact to prey will be 
temporary behavioral avoidance of the immediate area. During pile 
driving/removal and DTH activities, it is expected that fish and marine 
mammals would temporarily move to nearby locations and return to the 
area following cessation of in-water construction activities. 
Therefore, indirect effects on marine mammal prey during the 
construction are not expected to be substantial.
    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:
    [ssquf] No mortality is anticipated or authorized;
    [ssquf] Minimal impacts to marine mammal habitat/prey are expected;
    [ssquf] The action area is located and within an active marine 
commercial and tourist area;
    [ssquf] There are no rookeries, or other known areas or features of 
special significance for foraging or reproduction in the project area;
    [ssquf] Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior; and
    [ssquf] The required mitigation measures (i.e. shutdown zones) are 
expected to be effective in reducing the effects of the specified 
activity.
    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 planned 
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 Section 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. When the predicted number of individuals to 
be taken is fewer than one third of the species or stock abundance, the 
take is considered to be of small numbers. Additionally, other 
qualitative factors may be considered in the analysis, such as the 
temporal or spatial scale of the activities.
    Seven of the nine marine mammal stocks authorized for take are 
approximately 11 percent or less of the stock abundance. There are no 
official stock abundances for harbor porpoise and minke whales; 
however, as discussed in greater detail in the Description of Marine 
Mammals in the Area of Specified Activities, we believe for the 
abundance information that is available, the estimated takes are likely 
small percentages of the stock abundance. For harbor porpoise, the 
abundance for the Southeast Alaska stock is likely more represented by 
the aerial surveys that were conducted as these surveys had better 
coverage and were corrected for observer bias. Based on this data, the 
estimated take could potentially be approximately 4 percent of the 
stock abundance. However, this is unlikely and the percentage of the 
stock taken is likely lower as the authorized take estimates are 
conservative and the project occurs in a small footprint compared to 
the available habitat in Southeast Alaska. For minke whales, in the 
northern part of their range they are believed to be migratory and so 
few minke whales have been seen during three offshore Gulf of Alaska 
surveys that a population estimate could not be determined. With only 
twelve authorized takes for this species, the percentage of take in 
relation to the stock abundance is likely to be very small.
    Based on the analysis contained herein of the planned 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

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.
    In September 2020, the Indigenous People's Council for Marine 
Mammals (IPCoMM), the Alaska Sea Otter and Steller Sea Lion Commission, 
Huna Totem Corporation, and the Hoonah Indian Association (HIA) were 
contacted to determine potential project impacts on local subsistence 
activities. No comments were received from IPCoMM or the Alaska Sea 
Otter and Steller Sea Lion Commission. On September 14, 2020, Huna 
Totem Corporation expressed support for the project and indicated that 
they do not anticipate any marine mammal or subsistence.
    The planned project is not likely to adversely impact the 
availability of any marine mammal species or stocks that are commonly 
used for subsistence purposes or to impact subsistence harvest of 
marine mammals in the region because construction activities are 
localized and temporary; mitigation

[[Page 27428]]

measures will be implemented to minimize disturbance of marine mammals 
in the project area; and the project will not result in significant 
changes to availability of subsistence resources.
    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's planned activities.
    Therefore, we believe there are no relevant subsistence uses of the 
affected marine mammal stocks or species implicated by this action. 
NMFS has determined that the total taking of affected species or stocks 
would not have an unmitigable adverse impact on the availability of 
such species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    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 whenever we propose to authorize take for 
endangered or threatened species, in this case with the Alaska Regional 
Office (AKRO).
    NMFS is authorizing take of Mexico DPS humpback whales, and Western 
DPS Steller sea lions which are listed under the ESA. The Permit and 
Conservation Division completed a Section 7 consultation with the AKRO 
for the issuance of this IHA. The AKRO's biological opinion states that 
the action is not likely to jeopardize the continued existence of 
Western DPS Steller sea lions or Mexico DPS humpback whales.

Authorization

    As a result of these determinations, NMFS authorizes an IHA to the 
City for conducting for the planned pile driving and removal activities 
as well as DTH during construction of the HMIC Cargo Dock Project, 
Hoonah Alaska for one year, beginning May 2021, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated.

    Dated: May 17, 2021.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2021-10685 Filed 5-19-21; 8:45 am]
BILLING CODE 3510-22-P