Notice2024-13000
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Furie Operating Alaska, LLC Oil and Gas Activities in Cook Inlet, Alaska
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
June 14, 2024
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Furie Operating Alaska, LLC (Furie) for authorization to take marine mammals incidental to oil and gas activities in Cook Inlet, Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue two consecutive incidental harassment authorizations (IHAs) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, 1-year renewal that could be issued for either or both of the two IHAs under certain circumstances and if all requirements are met, as described in Request for Public Comments at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorizations and agency responses will be summarized in the final notice of our decision.
Full Text
<html>
<head>
<title>Federal Register, Volume 89 Issue 116 (Friday, June 14, 2024)</title>
</head>
<body><pre>
[Federal Register Volume 89, Number 116 (Friday, June 14, 2024)]
[Notices]
[Pages 51102-51132]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-13000]
[[Page 51101]]
Vol. 89
Friday,
No. 116
June 14, 2024
Part III
Department of Commerce
-----------------------------------------------------------------------
National Oceanic and Atmospheric Administration
-----------------------------------------------------------------------
Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to Furie Operating Alaska, LLC Oil and Gas
Activities in Cook Inlet, Alaska; Notice
Federal Register / Vol. 89 , No. 116 / Friday, June 14, 2024 /
Notices
[[Page 51102]]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD682]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Furie Operating Alaska, LLC Oil and
Gas Activities in Cook Inlet, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorizations; request
for comments on proposed authorizations and possible renewals.
-----------------------------------------------------------------------
SUMMARY: NMFS has received a request from Furie Operating Alaska, LLC
(Furie) for authorization to take marine mammals incidental to oil and
gas activities in Cook Inlet, Alaska. Pursuant to the Marine Mammal
Protection Act (MMPA), NMFS is requesting comments on its proposal to
issue two consecutive incidental harassment authorizations (IHAs) to
incidentally take marine mammals during the specified activities. NMFS
is also requesting comments on a possible one-time, 1-year renewal that
could be issued for either or both of the two IHAs under certain
circumstances and if all requirements are met, as described in Request
for Public Comments at the end of this notice. NMFS will consider
public comments prior to making any final decision on the issuance of
the requested MMPA authorizations and agency responses will be
summarized in the final notice of our decision.
DATES: Comments and information must be received no later than July 15,
2024.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service and should be submitted via email to
<a href="/cdn-cgi/l/email-protection#92dbc6c2bcd6f3e4fbe1d2fcfdf3f3bcf5fde4"><span class="__cf_email__" data-cfemail="c38a9793ed87a2b5aab083adaca2a2eda4acb5">[email protected]</span></a>. 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-oil-and-gas">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-oil-and-gas</a>. In
case of problems accessing these documents, please call the contact
listed below.
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-oil-and-gas">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-oil-and-gas</a> without change. All personal
identifying information (e.g., name, address) voluntarily submitted by
the commenter may be publicly accessible. Do not submit confidential
business information or otherwise sensitive or protected information.
FOR FURTHER INFORMATION CONTACT: Leah Davis, Office of Protected
Resources, NMFS, (301) 427-8401.
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 proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is 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 the 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 the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
Accordingly, NMFS is preparing an Environmental Assessment (EA) to
consider the environmental impacts associated with the issuance of the
proposed IHA. NMFS' EA will be made available at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-oil-and-gas">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-oil-and-gas</a> at the time of publication. We will
review all comments submitted in response to this notice prior to
concluding our NEPA process or making a final decision on the IHA
request.
Summary of Request
On July 19, 2023, NMFS received a request from Furie for two
consecutive IHAs to take marine mammals incidental to oil and gas
activities in Cook Inlet, Alaska. The application was deemed adequate
and complete on April 5, 2024. Furie's request is for take of 12
species of marine mammals, by Level B harassment and, for harbor seals,
Level A harassment. Neither Furie nor NMFS expect serious injury or
mortality to result from this activity and, therefore, an IHA is
appropriate.
Description of Proposed Activity
Overview
From April 1, 2024, through March 31, 2025 (Year 1), and from April
1, 2025 through March 31, 2026 (Year 2), Furie is planning to conduct
the following oil and gas activities in Middle Cook Inlet, Alaska. In
Year 1, Furie proposes to relocate the Enterprise 151 jack-up
production rig (Enterprise 151 or rig) to the Julius R. Platform (JRP)
site, install up to two conductor piles using an impact hammer, and
conduct production drilling of up to two natural gas wells at the JRP
with the Enterprise 151 rig (or a similar rig) across 45-180 days.
During Year 2, Furie proposes to relocate the Enterprise 151 rig to the
JRP site again, potentially install one to two conductor piles using an
impact hammer (depending on whether either or both of these piles are
installed or not during Year 1), and conduct additional production
drilling at the JRP. Furie proposes to conduct the rig towing and pile
driving activities between April 1 and November 15 each year, but if
favorable ice conditions occur outside of that period, it may tow the
rig or pile drive outside of that period. Noise produced by rig towing
and installation of the conductor piles may result in take, by Level B
harassment, of marine mammals, and for harbor seals, also Level A
harassment. Thus references to tugging activities herein refer to
[[Page 51103]]
activities where tugs are under load with the rig.
Dates and Duration
NMFS anticipates that the proposed Year 1 IHA would be effective
for 1 year beginning mid-to-late 2024, and the proposed Year 2 IHA
would be effective for one year beginning mid-to-late 2025. The final
effective dates would be determined based upon when Furie anticipates
being able to secure the rig from another operator in Cook Inlet. As
noted above, Furie expects to conduct the rig towing and pile driving
activities between April 1 and November 15 each year, but if favorable
ice conditions occur outside of that period, it may tow the rig or pile
drive outside of that period. Furie will conduct impact installation of
conductor piles during daylight hours only, and it will only conduct
rig towing at night if necessary to accommodate a favorable tide.
Production drilling may be conducted 24 hours per day.
Specific Geographic Region
Furie's proposed activities would take place in Cook Inlet, Alaska.
For the purposes of this project, lower Cook Inlet refers to waters
south of the East and West Forelands; middle Cook Inlet refers to
waters north of the East and West Forelands and south of Threemile
River on the west and Point Possession on the east; and upper Cook
Inlet refers to waters north and east of Beluga River on the west and
Point Possession on the east. The JRP is located in middle Cook Inlet,
approximately 8 miles due south of Tyonek, Alaska, and approximately 10
miles offshore from the shoreline to the southeast of the JRP.
The southernmost area of operation during Furie's Year 1 and Year 2
drilling projects is the Rig Tenders Dock, located in Nikiski, Alaska,
where the Enterprise 151 rig overwinters. The Rig Tenders Dock is in
lower Cook Inlet, approximately 2.3 miles south of the East Foreland.
The northernmost location at which Furie may assume operatorship of the
Enterprise 151 rig is Hilcorp Alaska LLC's (Hilcorp) Bruce platform,
located 6.4 miles (10.3 kilometers (km)) northwest of the JRP. Hilcorp
has stated that they do not intend to conduct work at the Tyonek
platform in 2024 or 2025, and therefore, Furie does not intend to
operate or tow the Enterprise 151 north of the Bruce platform. The
Tyonek platform is within the Susitna Delta Exclusion Zone identified
in Hilcorp's IHAs (87 FR 62364, October 14, 2022). If Hilcorp does
conduct work at the Tyonek platform, it would maintain operatorship and
control of the Enterprise 151 until the tow is underway with lines taut
and the Enterprise 151 is under tug power. As a result, Hilcorp would
maintain responsibility for any applicable mitigation measures in their
current IHA that must be met before a tow may be initiated. Once the
tow is underway, Furie representatives would take over operatorship of
the Enterprise 151.
Furie expects to tow the Enterprise 151 once or twice each season.
The origin of the first rig tow before Furie's use at the JRP and the
destination of the tow after use at the JRP is yet to be determined, as
Hilcorp also intends to use the Enterprise 151 for similar work in the
same region of Cook Inlet, so Furie and Hilcorp must coordinate the use
of the Enterprise 151. Furie may assume operatorship of the Enterprise
151 from Hilcorp mid-season, pass operatorship to Hilcorp mid-season,
or be the sole operator of the rig if Hilcorp does not use it.
If Furie is the first to operate the Enterprise 151 in a season,
the origination of the first tow is likely to begin at the Rig Tenders
Dock and would end at the JRP. If Furie is the sole operator of the
Enterprise 151 within a season, the rig would be returned to Rig
Tenders at the end of the production drilling operation. However, if
Hilcorp is the first to use the Enterprise 151 rig, the origination of
Furie's tow could be any of Hilcorp's assets (i.e., platforms or well
locations within the lease areas operated by Hilcorp). If Hilcorp uses
the Enterprise 151 after Furie, operatorship and responsibility for the
rig tow will pass to Hilcorp when it is towed from JRP to one of its
Cook Inlet assets.
A map of the specific area in which Furie plans to operate is
provided in figure 1.
[[Page 51104]]
[GRAPHIC] [TIFF OMITTED] TN14JN24.432
Detailed Description of the Specified Activity
Year 1
Tug Towing and Positioning- Furie proposes to conduct production
drilling at the JRP with the Enterprise 151 rig (or a similar rig; see
Furie's IHA application for additional information about the Enterprise
151 rig). A jack-up rig is not self-propelled and requires vessels
(tugs or heavy-lift ships) to transport it to an offshore drilling
location. The Enterprise 151 has a buoyant triangular hull, allowing it
to be towed like a barge. The rig will be towed to the JRP by up to
three ocean-going tugboats. (Table 2 describes potential rig tow
origins and destinations.) Upon arrival at the JRP, a fourth tugboat
may join the other three for up to 1 hour to complete the precise
positioning of the rig next to the JRP. The tugboats are expected to be
rated between 4,000 horsepower (hp) and 8,000 hp. Specifications of the
proposed tugs are provided in table 1.
Table 1--Tugboat Specifications
----------------------------------------------------------------------------------------------------------------
Vessel Activity Length Width Gross tonnage
----------------------------------------------------------------------------------------------------------------
M/V Bering Wind................. Towing and 22 m (72 ft)...... 10 m (33 ft)...... 144.
positioning the
jack-up rig.
M/V Anna T...................... Towing and 32 m (105 ft)..... 11 m (36 ft)...... 160.
positioning the
jack-up rig.
[[Page 51105]]
M/V Bob Franco.................. Towing and 37 meters (121 ft) 11 meters (36 ft). 196.
positioning the
jack-up rig.
M/V TBD......................... Positioning the Unknown........... Unknown........... Unknown.
jack-up rig.
----------------------------------------------------------------------------------------------------------------
Note: m= meters, ft= feet.
Several factors will determine the duration that the tugboats are
towing the Enterprise 151, including the origin and destination of the
towing route (e.g., Rig Tenders Dock, the JRP, one of Hilcorp's
platforms) and the tidal conditions. For safety reasons, a high slack
tide is required to access the shallow water near the dock at Rig
Tenders Dock, whether beginning a tow or returning the Enterprise 151.
In all other locations, a slack tide at either high or low tide is
required to attach the tugs to the rig and float it off position or to
position the rig and detach from it. Potential tug power output for
these scenarios is discussed in further detail in the Estimated Take of
Marine Mammals section.
The specific towing origin and destination of the Enterprise 151
depends on whether Hilcorp contracts to use the Enterprise 151 before
or after Furie in the same season. For example, Furie may assume
operatorship of the Enterprise 151 at the beginning of the season from
the Rig tenders dock, or it may assume operatorship mid-season at one
of Hilcorp's platforms or drilling locations (rather than at the Rig
Tenders Dock), and tow the rig to the JRP. However, Hilcorp may assume
operatorship and begin towing the rig from the JRP to one of their
platforms or drilling locations. As a result, Furie may tow the rig
once or twice within the season, beginning at several potential
locations. However, if Furie operates the Enterprise 151 last, or is
the only operator, the second tow of the season would return the
Enterprise 151 to the Rig Tenders Dock. Table 2 displays the potential
scenarios.
Table 2--Potential Rig Tow Origins and Destinations
------------------------------------------------------------------------
Scenario Tow #1 Tow #2
------------------------------------------------------------------------
Furie is Sole Operator.......... Furie tows from Furie tows from
the Rig Tenders the JRP to the
Dock to the JRP. Rig Tenders Dock.
Furie Early Season, Hilcorp Late Furie tows from Hilcorp tows from
Season. the Rig Tenders the JRP to a
Dock to the JRP. Hilcorp-operated
platform or drill
site.
Hilcorp Early Season, Furie Late Furie tows from a Furie tows from
Season \1\. Hilcorp-operated the JRP to the
platform or drill Rig Tenders Dock.
site to the JRP.
------------------------------------------------------------------------
\1\ One potential variation to this scenario may result if Hilcorp
operates the Enterprise 151 early season and conducts work at the
Tyonek platform or elsewhere within the North Cook Inlet Unit. The
Tyonek platform is within the Susitna Delta Exclusion Zone identified
in Hilcorp's IHAs (87 FR 62364, October 14, 2022). If Hilcorp does
conduct work at the Tyonek platform, it would maintain operatorship
and control of the Enterprise 151 until the tow is underway with lines
taut and the Enterprise 151 is under tug power. As a result, Hilcorp
would maintain responsibility for any applicable mitigation measures
in their existing IHA that must be met before a tow may be initiated.
Once the tow is underway, Furie representatives will take over
operatorship of the Enterprise 151.
A tow starting at the Rig Tenders Dock would begin at high slack
tide, pause near the Offshore Systems Kenai (OSK) Dock to wait for
currents to slow (up to three hours), then arrive at the JRP at the
next high slack tide (approximately 12 hours after departure). Once the
tugs arrive at the JRP, there is a 1- to 2-hour window when the slack
tide current velocity is slow (1 to 2 knots), allowing the tugs to
position the Enterprise 151 rig and pin the legs to the bottom. Upon
return, the tugs would be secured to the Enterprise 151 at the JRP on a
high slack tide, float off location, and transit south with the
outgoing tide south towards Nikiski, Alaska. The tow will likely pause
near OSK to wait for the tide cycle to return to a high flood before
moving near the Rig Tenders Dock to bring it close to shore on high
slack. Therefore, the tugs will be under load, typically at half-power
or less, for up to 14 hours during mobilization to the JRP from Rig
Tenders or demobilization in reverse order.
If the rig tow begins at a Hilcorp platform or drill site
(excluding the northern locations), then the Enterprise 151 may be
lowered, secured to the tugs, and floated off location during low slack
to take advantage of the flood tide to tow the rig north or east to the
JRP. In this scenario, the total tow duration is expected to be
approximately 8 hours, allowing for the 6 hours between the low slack
and high slack and an additional 1 to 2 hours to position the rig.
The tugs may abort the first positioning attempt until favorable
conditions return if it takes longer than anticipated and the current
velocity exceeds 3 to 4 knots. If so, the tugs will move the rig
nearby, where the legs can be temporarily lowered to the seafloor to
secure it. The tugs will remain close by, jogging in the current until
the positioning attempt can be resumed. The tugs usually complete the
positioning on the first attempt, but they may be under power for
approximately five additional hours if a second attempt is needed.
The tugs will generally attempt to transport the rig by traveling
with the tide, except when circumstances threaten human safety,
property, or infrastructure. The rig may need to be towed against the
tide to a safe harbor if a slack tide window is missed or extreme
weather events occur.
Conductor Pipe Installation--Active wells occupy four of the six
well slots within the caisson (monopod leg) of the JRP. During Year 1,
Furie intends to drill up to two natural gas wells, either
``grassroots'' or ``sidetrack'' wells. A grassroots well requires
drilling a new wellbore from the surface to the gas-bearing formations,
and requires all new components from the surface to the bottom depth,
including a conductor pipe, surface and subsurface casing, cement,
production liner, tubulars, chokes, sleeves, and a wellhead. A
sidetrack well is a new branch drilled from within an existing well. A
sidetrack well requires fewer new
[[Page 51106]]
components because many existing components, such as the conductor
pipe, surface casing, and wellhead, are re-used.
The conductor pipe is the uppermost portion of a gas well and
supports the initial sedimentary part of the well, preventing the
surface layers from collapsing and obstructing the wellbore. The pipe
also facilitates the return of cuttings from the drill head and
supports the wellhead components.
Furie expects to install a 20-inch conductor pipe in each of the
two empty well slots in Year 1 but expects to complete only one
grassroots well and one sidetrack well in Year 1. Furie would install
the conductor pipe with an impact hammer Delmag D62 impact hammer (see
Furie's IHA application for additional hammer details). As the pipe is
driven into the sediment, the sections are connected either by welding
or drivable quick connections. Once installed, the conductor pipes
remain a permanent component of the natural gas wells. Installation of
each conductor pile is anticipated to take approximately 2 days, with
70 percent of the installation occurring on day 1, and the remaining 30
percent of the installation occurring on day 2. Furie will conduct the
pile driving during daylight hours only.
Drilling Operations--Furie proposes to conduct production drilling
activities after the conductor pipe installation is complete and the
Enterprise 151 is positioned at the JRP. Furie expects to drill up to
two wells each year, which could be any combination of new grassroots
wells or sidetrack wells, to maintain or increase natural gas
production levels to meet critical local energy needs.
After the Enterprise 151 is positioned next to the JRP, the rig
will jack up so that the hull is initially approximately 5 to 10 ft out
of the water. To set the spud cans on the bottoms of the legs securely
into the seafloor and ensure stability, the Enterprise 151 has
specialized ``preload'' tanks within the hull that are filled with
seawater and designed to add weight to the hull. The preload is
conducted while the hull is only slightly out of the water to maintain
a lower center of gravity until full settling and stability are
achieved. After preloading, the seawater is discharged, and the hull is
raised so that the drilling derrick can be cantilevered over the top
deck of the JRP and positioned over a well slot.
Offshore support vessels (OSVs) support all operating offshore
platforms in Cook Inlet throughout the open water season and will be
used during Furie's planned drilling operations to transport equipment
and supplies between the OSK Dock and the Enterprise 151. During
production drilling, an average of two daily vessel trips are expected
between the OSK Dock and the rig. No take of marine mammals is
anticipated from the operation of OSVs, and OSVs are not discussed
further in this application beyond the explanation provided here.
Because vessels will be in transit, exposure to vessel noise will be
temporary, relatively brief and will occur in a predictable manner, and
also the sounds are of relatively lower levels. Elevated background
noise from multiple vessels and other sources can interfere with the
detection or interpretation of acoustic cues, but the brief exposures
to OSVs would be unlikely to disrupt behavioral patterns in a manner
that would qualify as take.
Helicopters will transport personnel and supplies from shore to the
rig and platform during production drilling activities. Helicopters
would be required to follow the mitigation measures described in the
Proposed Mitigation section of this notice (e.g., helicopters must
maintain an altitude of 1,500 ft (457 m)), and therefore, take from
helicopter activity is not anticipated, and helicopter activity is not
discussed further aside from the mitigation discussion in the Proposed
Mitigation section.
Other potential sources of sound from the Enterprise 151 include
the operation of the diesel generators, mud and cement pumps, and
ventilation fans. In 2016, while the Randolph Yost jack-up rig was
drilling at the JRP, Denes and Austin (2016) characterized drilling and
mud pumping sound as 158 decibels (dB) root mean square (rms) at 1 m
and 148.8 dB rms at 1 m, respectively. In 2011, while the Enterprise
151 was conducting exploration drilling in Furie's Kitchen Lights Unit
lease area, Marine Acoustics Inc. (2011) performed a sound source
verification (SSV) near the JRP in water depths ranging from 24.4 to
27.4 m (80 to 90 ft). The SSV measured sound from the diesel generator
engines at 137 dB re 1 [mu]Pa rms at 1 meter within the frequency
bandwidth of 141 to 178 hertz (Hz). The SSV also identified the PZ-10
mud pump and ventilation fans as minor sources of underwater sound.
Based on the 137 dB re 1 microPascal ([mu]Pa) rms measured at 1 m, the
Level B harassment isopleth was estimated to be 50 m from the jack-up
leg or drill riser. As such, drilling, mud pumping, and generator noise
are not anticipated to result in take of marine mammals, and these
activities are not discussed further.
Year 2
In Year 2, Furie would use the same tugboat arrangement to tow the
Enterprise 151 to and from the JRP and position it, as described above
for Year 1. Furie proposes to drill up to two wells in Year 2 that
could be either new grassroots wells, sidetracks, or a combination of
each. Furie intends to conduct additional production drilling in Year 2
at the JRP with the Enterprise 151 rig (or a similar rig). Furie
expects to install both conductor pipes at the JRP in Year 1, but one
or both may be installed in Year 2 instead (though no more than two
will be installed over the course of both seasons because only two well
slots remain to accept new conductors).
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 3 lists all species or stocks for which take is expected and
proposed to be authorized for this activity and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. 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 serious injury or mortality is anticipated or proposed
to be authorized here, PBR and annual serious injury and mortality from
anthropogenic sources are included here as gross indicators of the
[[Page 51107]]
status of the species or stocks 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' 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' U.S. 2022 SARs. All values presented in table 3 are the most
recent available at the time of publication (including from the draft
2023 SARs) and are available online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 3--Species \1\ Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock abundance
ESA/MMPA status; (CV, Nmin, most Annual M/SI
Common name Scientific name Stock strategic (Y/N) \2\ recent abundance PBR \4\
survey) \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray Whale................... Eschrichtius Eastern N Pacific... -, -, N............. 26,960 (0.05, 801 131
robustus. 25,849, 2016).
Family Balaenidae:
Family Balaenopteridae
(rorquals):
Fin Whale.................... Balaenoptera Northeast Pacific... E, D, Y............. UND \5\ (UND, UND, UND 0.6
physalus. 2013).
Humpback Whale............... Megaptera Hawai[revaps]i...... -, -, N............. 11,278 (0.56, 127 27.09
novaeangliae. 7,265, 2020).
Humpback Whale............... Megaptera Mexico-North Pacific T, D, Y............. N/A \6\ (N/A, N/A, UND 0.57
novaeangliae. 2006).
Humpback Whale............... Megaptera Western North E, D, Y............. 1,084 \7\ (0.088, 3.4 5.82
novaeangliae. Pacific. 1,007, 2006).
Minke Whale.................. Balaenoptera AK.................. -, -, N............. N/A\8\ (N/A, N/A, N/ UND 0
acutorostrata. A).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer Whale................. Orcinus orca........ Eastern North -, -, N............. 1,920 (N/A, 1,920, 19 1.3
Pacific Alaska 2019).
Resident.
Killer Whale..................... Orcinus orca........ Eastern North -, -, N............. 587 (N/A, 587, 5.9 0.8
Pacific Gulf of 2012).
Alaska, Aleutian
Islands and Bering
Sea Transient.
Pacific White-Sided Dolphin...... Lagenorhynchus N Pacific........... -, -, N............. 26,880 (N/A, N/A, UND 0
obliquidens. 1990).
Family Monodontidae (white
whales):
Beluga Whale................. Delphinapterus Cook Inlet.......... E, D, Y............. 279 \9\ (0.061, 0.53 0
leucas. 267, 2018).
Family Phocoenidae (porpoises):
Dall's Porpoise.............. Phocoenoides dalli.. AK.................. -, -, N............. UND \10\ (UND, UND, UND 37
2015).
Harbor Porpoise.............. Phocoena phocoena... Gulf of Alaska...... -, -, Y............. 31,046 (0.21, N/A, UND 72
1998).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
CA Sea Lion.................. Zalophus U.S................. -, -, N............. 257,606 (N/A, 14,011 >321
californianus. 233,515, 2014).
Steller Sea Lion............. Eumetopias jubatus.. Western............. E, D, Y............. 49,837 \11\ (N/A, 299 267
49,837, 2022).
Family Phocidae (earless seals):
Harbor Seal.................. Phoca vitulina...... Cook Inlet/Shelikof -, -, N............. 28,411 (N/A, 807 107
Strait. 26,907, 2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; Committee on Taxonomy (2022)).
\2\ 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.
\3\ NMFS marine mammal SARs online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>.
CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ 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.
\5\ The best available abundance estimate for this stock is not considered representative of the entire stock as surveys were limited to a small portion
of the stock's range. Based upon this estimate and the Nmin, the PBR value is likely negatively biased for the entire stock.
\6\ Abundance estimates are based upon data collected more than 8 years ago and, therefore, current estimates are considered unknown.
\7\ The best estimates of abundance for the stock (1,084) and the portion of the stock migrating to summering areas in U.S. waters (127) were derived
from a reanalysis of the 2004-2006 SPLASH data (Wade 2021). Although these data are more than fifteen years old, the estimates are still considered
valid minimum population estimates.
\8\ Reliable population estimates are not available for this stock. Please see Friday et al. (2013) and Zerbini et al. (2006) for additional information
on numbers of minke whales in Alaska.
[[Page 51108]]
\9\ On June 15, 2023, NMFS released an updated abundance estimate for endangered Cook Inlet beluga whales in Alaska (Goetz et al. 2023). Data collected
during NOAA Fisheries' 2022 aerial survey suggest that the whale population is stable or may be increasing slightly. Scientists estimated that the
population size is between 290 and 386, with a median best estimate of 331. In accordance with the MMPA, this population estimate will be incorporated
into the Cook Inlet beluga whale SAR, which will be reviewed by an independent panel of experts, the Alaska Scientific Review Group. After this
review, the SAR will be made available as a draft for public review before being finalized.
\10\ The best available abundance estimate is likely an underestimate for the entire stock because it is based upon a survey that covered only a small
portion of the stock's range.
\11\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys.
As indicated above, all 12 species (with 14 number managed stocks)
in table 3 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. In addition, the
northern sea otter may be found in Cook Inlet, Alaska. However,
northern sea otters are managed by the U.S. Fish and Wildlife Service
and are not considered further in this document.
Gray Whale
The stock structure for gray whales in the Pacific has been studied
for a number of years and remains uncertain as of the most recent
(2022) Pacific SARs (Carretta et al. 2023). Gray whale population
structure is not determined by simple geography and may be in flux due
to evolving migratory dynamics (Carretta et al. 2023). Currently, the
SARs delineate a western North Pacific (WNP) gray whale stock and an
eastern North Pacific (ENP) stock based on genetic differentiation
(Carretta et al. 2023). WNP gray whales are not known to feed in or
travel to upper Cook Inlet (Conant and Lohe, 2023; Weller et al. 2023).
Therefore, we assume that gray whales near the project area are members
of the ENP stock.
An Unusual Mortality Event (UME) for gray whales along the West
Coast and in Alaska occurred from December 17, 2018 through November 9,
2023. During that time, 146 gray whales stranded off the coast of
Alaska. The investigative team concluded that the preliminary cause of
the UME was localized ecosystem changes in the whale's Subarctic and
Arctic feeding areas that led to changes in food, malnutrition,
decreased birth rates, and increased mortality (see <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-gray-whale-unusual-mortality-event-along-west-coast-and">https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-gray-whale-unusual-mortality-event-along-west-coast-and</a> for more
information).
Gray whales occur infrequently in Cook Inlet, but can occur
seasonally during spring and fall in the lower inlet (Bureau of Ocean
Energy Management (BOEM) 2021). Migrating gray whales pass through the
lower inlet during their spring and fall migrations to and from their
primary summer feeding areas in the Bering, Chukchi, and Beaufort seas
(Swartz 2018; Silber et al. 2021; BOEM 2021).
Some gray whales remain in certain coastal areas in the Pacific
Northwest, including lower Cook Inlet, instead of migrating to the
Arctic in summer (Moore et al. 2007). Several surveys and monitoring
programs have sighted gray whales in lower Cook Inlet (Shelden et al.
2013; Owl Ridge 2014; Lomac-MacNair et al. 2013, 2014; Kendall et al.
2015, as cited in Weston and SLR 2022). Gray whales are occasionally
seen in mid- and upper Cook Inlet, Alaska, but they are not common. In
2020, a young male gray whale was stranded in the Twentymile River near
Girdwood for over a week before swimming back into Turnagain Arm. The
whale did not survive and was found dead in west Cook Inlet later that
month (NOAA Fisheries 2020). One gray whale was sighted in Knik Arm
near the POA in upper Cook Inlet in May of 2020 during observations
conducted during construction of the Petroleum and Cement Terminal
project (61N 2021). The sighting occurred less than a week before the
reports of the gray whale stranding in the Twentymile River and was
likely the same animal. In 2021, one small gray whale was sighted in
Knik Arm near Ship Creek, south of the POA (61N 2022a). Although some
sightings have been documented in the middle and upper Inlet, the gray
whale range typically only extends into the lower Cook Inlet region.
Humpback Whale
Humpback whales have been observed during marine mammal surveys
conducted in Cook Inlet, with the majority sighted in lower Cook Inlet
south of Kalgin Island. Eighty-three groups containing an estimated 187
humpbacks were sighted during the Cook Inlet beluga whale aerial
surveys conducted by NMFS from 1994 to 2012 (Shelden et al. 2013).
Surveys conducted north of the forelands have documented small numbers
in middle Cook Inlet. Vessel-based observers participating in the
Apache Corporation's 2014 survey operations recorded three humpback
whale sightings near Moose Point in upper Cook Inlet and two sightings
near Anchor Point, while aerial and land-based observers recorded no
humpback whale sightings, including in the upper Inlet (Lomac-MacNair
et al. 2014). In 2015, during the construction of Furie's platform and
pipeline, four groups of humpback whales were documented. Another group
of 6 to 10 unidentified whales, thought to be either humpback or gray
whales, was sighted approximately 15 km northeast of the JRP. Large
cetaceans were visible near the project (i.e., whales or blows were
visible), for 2 hours out of the 1,275 hours of observation conducted
(Jacobs 2015). During SAExploration's 2015 seismic program, three
humpback whales were observed in Cook Inlet, including two near the
Forelands and one in lower Cook Inlet (Kendall et al. 2015 as cited in
Weston and SLR 2022). Hilcorp did not record any sightings of humpback
whales from their aerial or rig-based monitoring efforts in 2023
(Horsley and Larson 2023).
The most comprehensive photo-identification data available suggest
that approximately 89 percent of all humpback whales in the Gulf of
Alaska are from the Hawaii stock, 11 percent are from the Mexico stock,
and less than 1 percent are from the WNP stock (Wade, 2021).
Individuals from different stocks are known to intermix in feeding
grounds. There is no designated critical habitat for humpback whales in
or near the Project area (86 FR 21082, April 21, 2021), nor does the
project overlap with any known biologically important areas (BIAs).
Minke Whale
Minke whales are most abundant in the Gulf of Alaska during summer
and occupy localized feeding areas (Zerbini et al. 2006). During the
NMFS annual and semiannual surveys of Cook Inlet, minke whales were
observed near Anchor Point in 1998, 1999, 2006, and 2021 (Shelden et
al. 2013, 2015, 2017, 2022; Shelden and Wade 2019) and near Ninilchik
and the middle of lower Cook Inlet in 2021 (Shelden et al. 2022).
Minkes were sighted southeast of Kalgin Island and near Homer during
Apache's 2014 survey (Lomac-MacNair et al. 2014), and one was observed
near Tuxedni Bay in 2015 (Kendall et al. 2015, as cited in Weston and
SLR 2022). During Hilcorp's seismic survey in lower Cook Inlet in the
fall of 2019, eight minke whales were observed (Fairweather Science
2020). In 2018, no minke whales were observed during observations
conducted for the Cross Inlet Pipeline (CIPL) project near Tyonek
(Sitkiewicz et al. 2018). Minke whales were also not recorded during
[[Page 51109]]
Hilcorp's aerial or rig-based monitoring efforts in 2023 (Horsley and
Larson 2023).
Fin Whale
Fin whales are usually observed as individuals traveling alone,
although they are sometimes observed in small groups. Rarely, large
groups of 50 to 300 fin whales can travel together during migrations
(NMFS 2010a). Fin whales in Cook Inlet have only been observed as
individuals or in small groups. Sightings of fin whales in Cook Inlet
are rare; most occur near the entrance. From 2000 to 2022, 10 sightings
of 26 estimated individual fin whales in lower Cook Inlet were observed
during NMFS aerial surveys (Shelden et al. 2013, 2015, 2017, 2022;
Shelden and Wade 2019). None were observed in the area of Furie's
proposed drilling project. In the fall of 2019, during Hilcorp's
seismic survey in lower Cook Inlet, eight sightings of 23 fin whales
were documented, suggesting greater numbers may use the area in the
fall than previously estimated (Fairweather Science 2020). Hilcorp did
not record any sightings of fin whales from their aerial or rig-based
monitoring efforts in 2023 (Horsley and Larson 2023)
Beluga Whale
NMFS designated Cook Inlet beluga whales as depleted under the MMPA
in 2000 and listed the population as endangered under the ESA in 2008
(73 FR 62919, October 10, 2008) when it failed to recover following a
moratorium on subsistence harvest (65 FR 34590, May 31, 2000). In April
2011, NMFS designated critical habitat for the beluga under the ESA (76
FR 20180, April 11, 2011). NMFS finalized the Conservation Plan for the
Cook Inlet beluga in 2008 (NMFS 2008a) and the Recovery Plan for Cook
Inlet beluga whales in 2016 (NMFS 2016a). Between 2008 and 2018, Cook
Inlet belugas experienced a decline of about 2.3 percent per year (Wade
et al. 2019). The decline overlaps with the northeast Pacific marine
heatwave that occurred from 2014 to 2016 in the Gulf of Alaska,
significantly impacting the marine ecosystem (Suryan et al. 2020, as
cited in Goetz et al. 2023). The most recent abundance estimate
calculated an average annual increase between 0.2 and 0.9 percent
between 2012 and 2022 (Goetz et al. 2023).
Threats that have the potential to impact this stock and its
habitat include the following: Changes in prey availability due to
natural environmental variability, ocean acidification, and commercial
fisheries; climatic changes affecting habitat; predation by killer
whales; contaminants; noise; ship strikes; waste management; urban
runoff; construction projects; and physical habitat modifications that
may occur as Cook Inlet becomes increasingly urbanized (Moore et al.
2000, Lowry et al. 2006, Hobbs et al. 2015, NMFS 2016). Another source
of Cook Inlet beluga whale mortality in Cook Inlet is predation by
transient-type (mammal-eating) killer whales (NMFS 2016b; Shelden et
al. 2003). No human-caused mortality or serious injury of Cook Inlet
beluga whales through interactions with commercial, recreational, and
subsistence fisheries, takes by subsistence hunters, and or human-
caused events (e.g., entanglement in marine debris, ship strikes) has
been recently documented and harvesting of Cook Inlet beluga whales has
not occurred since 2008 (NMFS 2008b).
Generally, female beluga whales reach sexual maturity at 9 to 12
years old, while males reach maturity later (O'Corry-Crowe 2009);
however, this can vary between populations. For example, in Greenland,
males in a population of beluga whales were found to reach sexual
maturity at 6 to 7 years of age and females at 4 to 7 years. (Heide-
Joregensen and Teilmann 1994). Suydam (2009) estimated that 50 percent
of females were sexually mature at age 8.25 and the average age at
first birth was 8.27 years for belugas sampled near Point Lay. Mating
behavior in beluga whales typically occurs between February and June,
peaking in March (Burns and Seaman 1986; Suydam 2009). In the Chukchi
Sea, the gestation period of beluga whales was determined to be 14.9
months, with a calving interval of 2 to 3 years and a pregnancy rate of
0.41, declining after 25 years of age (Suydam 2009). Calves are born
between mid-June and mid-July and typically remain with the mother for
up to 2 years of age (Suydam 2009).
Several studies (Johnson et al. 1989; Klishin et al. 2000; Finneran
et al. 2002; Erbe 2008; White et al. 1978; Awbrey et al. 1988; Ridgway
et al. 2001; Finneran et al. 2005; Castellote et al. 2019) describe
beluga whale hearing capabilities. One study on beluga whales captured
and released in Bristol Bay, Alaska measured hearing ranges at 4 to 150
(kilohertz) kHz with greatest variation between individuals at the high
end of the auditory range in combination with frequencies near the
maximum sensitivity (Castellote et al. 2014). All animals tested heard
well up to 128 kHz, with two individuals hearing up to 150 kHz
(Castellote et al. 2014). Beluga whales are included in the NMFS-
identified mid-frequency functional hearing group.
The Cook Inlet beluga stock remains within Cook Inlet throughout
the year (Goetz et al. 2012a). The ecological range of Cook Inlet
belugas has contracted significantly since the 1970s. From late spring
to fall, nearly the entire population is now found in the upper inlet
north of the forelands, with a range reduced to approximately 39
percent of the size documented in the late 1970s (Goetz et al. 2023).
The recent annual and semiannual aerial surveys (since 2008) found that
approximately 83 percent of the population inhabits the area between
the Beluga River and Little Susitna River during the survey period,
typically conducted in early June. Some aerial survey counts were
performed in August, September, and October, finding minor differences
in the numbers of belugas in the upper inlet compared to June,
reinforcing the importance of the upper inlet habitat area (Young et
al. 2023).
Two areas, consisting of 7,809 square kilometers (km\2\) of marine
and estuarine environments considered essential for the species'
survival and recovery, were designated critical habitat. Area 1 of the
Cook Inlet beluga whale critical habitat encompasses all marine waters
of Cook Inlet north of a line connecting Point Possession (61.04[deg]
N, 150.37[deg] W) and the mouth of Threemile Creek (61.08.55[deg] N,
151.04.40[deg] W), including waters of the Susitna, Little Susitna, and
Chickaloon Rivers below the mean higher high water line (MHHW). This
area provides important habitat during ice-free months and is used
intensively by Cook Inlet beluga between April and November for feeding
and other biological functions (NMFS 2016a). Critical Habitat Area 2
encompasses some of the fall and winter feeding grounds in middle Cook
Inlet.
Since 1993, NMFS has conducted annual aerial surveys in June, July,
or August to document the distribution and abundance of beluga whales
in Cook Inlet. The collective survey results show that beluga whales
have been consistently found near or in river mouths along the northern
shores of middle and upper Cook Inlet. In particular, beluga whale
groups are seen in the Susitna River Delta, Knik Arm, and along the
shores of Chickaloon Bay. Small groups had also been recorded farther
south in Kachemak Bay, Redoubt Bay (Big River), and Trading Bay
(McArthur River) prior to 1996, but very rarely thereafter. Since the
mid-1990s, most beluga whales have been concentrated in shallow areas
near river mouths north and east of Beluga River
[[Page 51110]]
and Point Possession (Hobbs et al. 2008). Based on these aerial
surveys, there is a consistent pattern of beluga whale presence in the
northernmost portion of Cook Inlet from June to October (Rugh et al.
2000, 2004a, 2004b, 2005, 2006, 2007).
Though Cook Inlet beluga whales occur throughout the inlet at any
time of year, generally they spend the ice-free months in the upper
Cook Inlet, shifting into deeper waters in middle Cook Inlet in winter
(Hobbs et al. 2008). In 1999, one beluga whale was tagged with a
satellite transmitter, and its movements were recorded from June
through September of that year. Since 1999, 18 beluga whales in upper
Cook Inlet have been captured and fitted with satellite tags to provide
information on their movements during late summer, fall, winter, and
spring. Using location data from satellite-tagged Cook Inlet belugas,
Ezer et al. (2013) found most tagged whales were in the lower to middle
inlet during January through March, near the Susitna River Delta from
April to July) and in the Knik and Turnagain Arms from August to
December. The transmitters collected data for as little as a few days
and up to 293 days with at least some data obtained each calendar
month. None of the tagged belugas left the inlet. All but three
remained north of the forelands for the duration of transmission, and
those that traveled south did so only briefly (Shelden et al. 2018).
In the winter, belugas are more widely dispersed based on aerial
surveys, opportunistic sighting reports, and tagging results, with
animals found between Kalgin Island and Point Possession. In November,
beluga whales remained in Knik Arm, Turnagain Arm, and Chickaloon Bay,
similar to locations observed in September. Later in winter (January
into March), belugas were sighted near Kalgin Island and in deeper
waters offshore. However, even when ice cover exceeds 90 percent in
February and March, belugas travel into Knik Arm and Turnagain Arm
(Hobbs et al. 2005).
During the spring and summer, beluga whales are generally
concentrated near the warmer waters of river mouths where prey
availability is high and predator occurrence is low (Moore et al.
2000). Beluga whales in Cook Inlet are believed to mostly calve between
mid-May and mid-July, and concurrently breed between late spring and
early summer (NMFS 2016a), primarily in upper Cook Inlet. Beluga
movement was correlated with the peak discharge of seven major rivers
emptying into Cook Inlet. Boat-based surveys from 2005 to the present
(McGuire and Stephens 2017), and initial results from passive acoustic
monitoring across the entire inlet (Castellote et al. 2016) also
support seasonal patterns observed with other methods, and other
surveys confirm Cook Inlet belugas near the Kenai River during summer
months (McGuire and Stephens 2017).
During the summer and fall, beluga whales are concentrated near the
Susitna River mouth, Knik Arm, Turnagain Arm, and Chickaloon Bay
(Nemeth et al. 2007) where they feed on migrating eulachon
(Thaleichthys pacificus) and salmon (Onchorhyncus spp.; Moore et al.
2000). Data from tagged whales (14 tags between July and March 2000
through 2003) show beluga whales use upper Cook Inlet intensively
between summer and late autumn (Hobbs et al. 2005). Critical Habitat
Area 1 encompasses this summer distribution.
Using the June aerial survey data from 1994 to 2008, Goetz et al.
(2012) constructed a model of summer habitat preference for the entire
Cook Inlet. The model identified a positive geographic association with
rivers with prey species (primarily eulachon and salmon), shallow tidal
flats, and sandy substrate and a negative association with sources of
anthropogenic disturbance. A heat map of the summer habitat was
generated, with 1 km\2\ cells ranging from 0 to 1.12 belugas per km\2\.
The areas of highest concentration were the Susitna River delta (from
the Beluga River to the Little Susitna River), upper Knik Arm, and
Chickaloon Bay. Each area has generally large salmon runs, shallow
tidal flats, and little anthropogenic disturbance. The location of the
JRP and the towing routes between the Rig Tenders Dock and the JRP are
areas of predicted low density in the summer months.
As late as October, beluga whales tagged with satellite
transmitters continued to use Knik Arm and Turnagain Arm and Chickaloon
Bay, but some ranged into lower Cook Inlet south to Chinitna Bay,
Tuxedni Bay, and Trading Bay (McArthur River) in the fall (Hobbs et al.
2005). Data from NMFS aerial surveys, opportunistic sighting reports,
and satellite-tagged beluga whales confirm they are more widely
dispersed throughout Cook Inlet during the winter months (November to
April), with animals found between Kalgin Island and Point Possession.
In November, beluga whales moved between Knik Arm, Turnagain Arm, and
Chickaloon Bay, similar to patterns observed in September (Hobbs et al.
2005). By December, beluga whales were distributed throughout the upper
to middle Cook Inlet. From January into March, they moved as far south
as Kalgin Island and slightly beyond in central offshore waters. Beluga
whales also made occasional excursions into Knik Arm and Turnagain Arm
in February and March despite ice cover greater than 90 percent (Hobbs
et al. 2005).
Wild et al. (2023) delineated a Small and Resident Population BIA
in Cook Inlet that is active year-round and overlaps Furie's proposed
project area. The authors assigned the BIA an importance score of 2, an
intensity score of 2, a data support score of 3, and a boundary
certainty score of 2. These scores indicate that the BIA is of moderate
importance and intensity, the authors have high confidence that the
population is small and resident and in the abundance and range
estimates of the population, and the boundary certainty is medium (see
Harrison et al. (2023) for additional information about the scoring
process used to identify BIAs).
During Apache's seismic test program in 2011 along the west coast
of Redoubt Bay, lower Cook Inlet, a total of 33 beluga whales were
sighted during the survey (Lomac-MacNair et al. 2013). During Apache's
2012 seismic program in mid-inlet, a total of 151 sightings consisting
of an estimated 1,463 beluga whales were observed (Lomac-MacNair et al.
2014). During SAExploration's 2015 seismic program, a total of eight
sightings of 33 estimated individual beluga whales were visually
observed during this time period and there were two acoustic detections
of beluga whales (Kendall et al. 2015). During Harvest Alaska's recent
CIPL project on the west side of Cook Inlet in between Ladd Landing and
Tyonek Platform, a total of 143 beluga whale sightings (814
individuals) were observed almost daily from May 31 to July 11, even
though observations spanned from May 9 through September 15 (Sitkiewicz
et al. 2018). There were two beluga whale carcasses observed by the
project vessels in the 2019 Hilcorp lower Cook Inlet seismic survey in
the fall which were reported to the NMFS Marine Mammal Stranding
Network (Fairweather Science 2020). Both carcasses were moderately
decomposed when they were sighted by the protected species observers
(PSOs). Daily aerial surveys specifically for beluga whales were flown
over the lower Cook Inlet region, but no beluga whales were observed.
In 2023, Hilcorp recorded 21 sightings of more than 125 beluga whales
during aerial surveys and an additional 21 opportunistic sightings that
included approximately 81 beluga whales (Horsley and Larson, 2023).
Hilcorp did not record any sightings of
[[Page 51111]]
beluga whales from their rig-based monitoring efforts (Horsley and
Larson, 2023)
Killer Whale
Killer whales from the Alaska Resident stock and the Gulf of
Alaska, Aleutian Islands, and Bering Sea Transient stock occur in lower
Cook Inlet but rarely in middle and upper Cook Inlet. Recent studies
have documented the movements of Alaska Resident killer whales from the
Bering Sea into the Gulf of Alaska as far north as southern Kodiak
Island (Muto et al. 2017).
Killer whales have been sighted near Homer and Port Graham in lower
Cook Inlet (Shelden et al. 2003, 2022; Rugh et al. 2005). Resident
killer whales from pods often sighted near Kenai Fjords and Prince
William Sound have been occasionally photographed in lower Cook Inlet
(Shelden et al. 2003). The availability of salmon influences when
resident killer whales are more likely to be sighted in Cook Inlet.
Killer whales were observed in the Kachemak and English Bay three times
during aerial surveys conducted between 1993 and 2004 (Rugh et al.
2005). Transient killer whales were increasingly reported to feed on
belugas in the middle and upper Cook Inlet in the 1990s.
During the 2015 SAExploration seismic program near the North
Foreland, two killer whales were observed (Kendall et al. 2015, as
cited in Weston and SLR 2022). Killer whales were observed in lower
Cook Inlet in 1994, 1997, 2001, 2005, 2010, 2012, and 2022 during the
NMFS aerial surveys (Shelden et al. 2013, 2022). Eleven killer whale
strandings have been reported in Turnagain Arm: six in May 1991 and
five in August 1993. During the Hilcorp lower Cook Inlet seismic survey
in the fall of 2019, 21 killer whales were documented (Fairweather
Science 2020). Throughout 4 months of observation in 2018 during the
CIPL project in middle Cook Inlet, no killer whales were observed
(Sitkiewicz et al. 2018). In September 2021, two killer whales were
documented in Knik Arm in upper Cook Inlet, near the POA (61N 2022a).
Hilcorp did not record any sightings of fin whales from their aerial or
rig-based monitoring efforts in 2023 (Horsley and Larson 2023).
Pacific White-Sided Dolphin
Pacific white-sided dolphins are common in the Gulf of Alaska's
pelagic waters and Alaska's nearshore areas, British Columbia, and
Washington (Ferrero and Walker 1996, as cited in Muto et al. 2022).
They do not typically occur in Cook Inlet, but in 2019, Castellote et
al. (2020) documented short durations of Pacific white-sided dolphin
presence using passive acoustic recorders near Iniskin Bay (6 minutes)
and at an offshore mooring located approximately midway between Port
Graham and Iniskin Bay (51 minutes). Detections of vocalizations
typically lasted on the order of minutes, suggesting the animals did
not remain in the area and/or continue vocalizing for extended
durations. Visual monitoring conducted during the same period by marine
mammal observers on seismic vessels near the offshore recorder did not
detect any Pacific white-sided dolphins (Fairweather Science 2020).
These observational data, combined with anecdotal information, indicate
that there is a small potential for Pacific white-sided dolphins to
occur in the Project area. On May 7, 2014, Apache Alaska observed three
Pacific white-sided dolphins during an aerial survey near Kenai. This
is one of the only recorded visual observations of Pacific white-sided
dolphins in Cook Inlet; they have not been reported in groups as large
as those estimated in other parts of Alaska (e.g. 92 animals in NMFS'
IHAs for Tongass Narrows).
Harbor Porpoise
Harbor porpoises prefer shallow coastal waters less than 100 m in
depth (Hobbs and Waite 2010). They are common in nearshore areas of the
Gulf of Alaska, Shelikof Strait, and lower Cook Inlet (Dahlheim et al.
2000). Harbor porpoises are often observed in lower Cook Inlet in
Kachemak Bay and from Cape Douglas to the West Foreland (Rugh et al.
2005).
Harbor porpoises have been observed during most aerial surveys
conducted in Cook Inlet since 1993. They are frequently documented in
Chinitna and Tuxedni Bays on the west side of lower Cook Inlet (Rugh et
al. 2005), with smaller numbers observed in upper Cook Inlet between
April and October. There were 137 groups comprised of 190 individuals
documented between May and August during Apache's 2012 seismic program
(Lomac-MacNair et al. 2013). Kendall et al. (2015, as cited in Weston
and SLR 2022) documented 52 groups comprised of 65 individuals north of
the Forelands during SAExploration's 2015 seismic survey. Two groups
totaling three harbor porpoises were observed in the fall of 2019
during Hilcorp's lower Cook Inlet seismic survey (Fairweather Science
2020). Four monitoring events were conducted at the POA in Anchorage
between April 2020 and August 2022, during which 42 groups of harbor
porpoises comprised of 50 individual porpoises were documented over 285
days of observation (61N 2021, 2022a, 2022b, and 2022c). One harbor
porpoise was observed during Hilcorp's monitoring boat-based monitoring
efforts in June 2023 (Horsley and Larson 2023).
Dall's Porpoise
The Dall's porpoise range in Alaska includes lower Cook Inlet, but
very few sightings have been reported in upper Cook Inlet. Observations
have been documented near Kachemak Bay and Anchor Point (Owl Ridge
2014; BOEM 2015). Dall's porpoises were observed (two groups of three
individuals) during Apache's 2014 seismic survey which occurred in the
summer months (Lomac-MacNair et al. 2014). In August 2015, one Dall's
porpoise was reported in the mid-inlet north of Nikiski during
SAExploration's seismic program (Kendall et al. 2015 as cited in Weston
and SLR 2022). During aerial surveys in Cook Inlet, they were observed
in Iniskin Bay, Barren Island, Elizabeth Island, and Kamishak Bay
(Shelden et al. 2013). Ten groups totaling 30 Dall's porpoises were
observed in the fall of 2019 during Hilcorp's lower Cook Inlet seismic
survey (Fairweather Science 2020). No Dall's porpoises were observed
during the CIPL project monitoring program in middle Cook Inlet in 2018
(Sitkiewicz et al. 2018). Hilcorp recorded one sighting of a Dall's
porpoise from their rig-based monitoring efforts in the project area in
2023 (Horsley and Larson, 2023).
Steller Sea Lion
Most Steller sea lions in Cook Inlet occur south of Anchor Point on
the east side of lower Cook Inlet, with concentrations near haulout
sites at Shaw Island and Elizabeth Island and by Chinitna Bay and
Iniskin Bay on the west side (Rugh et al. 2005). Steller sea lions are
rarely seen in upper Cook Inlet (Nemeth et al. 2007). About 3,600 sea
lions use haulout sites in the lower Cook Inlet area (Sweeney et al.
2017), with additional individuals venturing into the area to forage.
There is no designated critical habitat for Steller sea lions in the
mid- or upper inlet, nor are there any known BIAs for Steller sea lions
within the project area.
Several surveys and monitoring programs have documented Steller sea
lions throughout Cook Inlet, including in upper Cook Inlet in 2012
(Lomac-MacNair et al. 2013), near Cape Starichkof in 2013 (Owl Ridge
2014), in middle and lower Cook Inlet in 2015 (Kendall et al. 2015, as
cited in Weston and SLR 2022), in middle Cook Inlet in 2018 (Sitkiewicz
et al. 2018), in lower
[[Page 51112]]
Cook Inlet in 2019 (Fairweather Science 2020), and near the Port of
Alaska (POA) in Anchorage in 2020, 2021, and 2022 (61N 2021, 2022a,
2022b, and 2022c).
California Sea Lion
The few California sea lions observed in Alaska typically do not
travel further north than Southeast Alaska. They are often associated
with Steller sea lion haulouts and rookeries (Maniscalco et al. 2004).
Sightings in Cook Inlet are rare, with two documented during the Apache
2012 seismic survey (Lomac-MacNair et al. 2013) and anecdotal sightings
in Kachemak Bay. None were sighted during the 2019 Hilcorp lower Cook
Inlet seismic survey (Fairweather Science 2020), the CIPL project in
2018 (Sitkiewicz et al. 2018), or the 2023 Hilcorp aerial or rig-based
monitoring efforts (Horsley and Larson, 2023).
Harbor Seal
In the spring and summer, harbor seals display an affinity for
coastal haulout areas for feeding, breeding, pupping, and molting,
while ranging further offshore and outside of Cook Inlet during the
winter. High-density areas include Kachemak Bay, Iniskin Bay, Iliamna
Bay, Kamishak Bay, Cape Douglas, and Shelikof Strait. Up to a few
hundred seals seasonally occur in middle and upper Cook Inlet (Rugh et
al. 2005), with the highest concentrations found near the Susitna River
during eulachon and salmon runs (Nemeth et al. 2007; Boveng et al.
2012), but most remain south of the forelands (Boveng et al. 2012).
More than 200 haulout sites are documented in lower Cook Inlet
(Montgomery et al. 2007) and 18 in middle and upper Cook Inlet (London
et al. 2015). Of the 18 in middle and upper Cook Inlet, nine are
considered ``key haulout'' locations where aggregations of 50 or more
harbor seals have been documented. Seven key haulouts are in the
Susitna River delta, and two are near the Chickaloon River. The two
haulout locations closest to the JRP are located at Middle Ground
Shoal, which becomes inundated with water at most high tides (London et
al. 2015).
Harbor seals have been sighted in Cook Inlet during every year of
the aerial surveys conducted by NMFS and during all recent mitigation
and monitoring programs in lower, middle, and upper Cook Inlet (61N
2021, 2022a, 2022b, and 2022c; Fairweather Science 2020; Kendall et al.
2015 as cited in Weston and SLR 2022; Lomac-MacNair et al. 2013, 2014;
Sitkiewicz et al. 2018).
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al. 1995; Wartzok and Ketten,
1999; Au and Hastings, 2008). To reflect this, Southall et al. (2007,
2019) recommended that marine mammals be divided into hearing groups
based on directly measured (behavioral or auditory evoked potential
techniques) or estimated hearing ranges (behavioral response data,
anatomical modeling, etc.). Note that no direct measurements of hearing
ability have been successfully completed for mysticetes (i.e., low-
frequency cetaceans). Subsequently, NMFS (2018) described generalized
hearing ranges for these marine mammal hearing groups. Generalized
hearing ranges were chosen based on the approximately 65 dB threshold
from the normalized composite audiograms, with the exception for lower
limits for low-frequency cetaceans where the lower bound was deemed to
be biologically implausible and the lower bound from Southall et al.
(2007) retained. Marine mammal hearing groups and their associated
hearing ranges are provided in table 4.
Table 4--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
Generalized hearing
Hearing group range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales).... 7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins, toothed 150 Hz to 160 kHz.
whales, beaked whales, bottlenose whales).
High-frequency (HF) cetaceans (true porpoises, 275 Hz to 160 kHz.
Kogia, river dolphins, Cephalorhynchid,
Lagenorhynchus cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true seals). 50 Hz to 86 kHz.
Otariid pinnipeds (OW) (underwater) (sea lions 60 Hz to 39 kHz.
and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al. 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al. 2006; Kastelein et al. 2009; Reichmuth et al.
2013). This division between phocid and otariid pinnipeds is now
reflected in the updated hearing groups proposed in Southall et al.
(2019).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take of Marine Mammals section, and the Proposed Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship of individuals
and whether those impacts are reasonably expected to, or reasonably
likely to, adversely affect the species or stock through effects on
annual rates of recruitment or survival.
Description of Sound Sources
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far (ANSI 1995). The sound level of an area is
defined by the total acoustical energy being generated by known and
unknown sources. These sources may
[[Page 51113]]
include physical (e.g., waves, wind, precipitation, earthquakes, ice,
atmospheric sound), biological (e.g., sounds produced by marine
mammals, fish, and invertebrates), and anthropogenic sound (e.g.,
vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20 dB
from day to day (Richardson et al. 1995). The result is that, depending
on the source type and its intensity, sound from a specified activity
may be a negligible addition to the local environment or could form a
distinctive signal that may affect marine mammals.
The proposed project includes the use of three to four tugs towing
a jack-up rig as well as impact pile driving of conductor piles. The
sounds produced by these activities fall into one of two general sound
types: impulsive and non-impulsive. Impulsive sounds (e.g., explosions,
sonic booms, impact pile driving) are typically transient, brief (less
than 1 second), broadband, and consist of high peak sound pressure with
rapid rise time and rapid decay (ANSI 1986; NIOSH 1998; NMFS 2018).
Non-impulsive sounds (e.g., machinery operations such as drilling or
dredging, vibratory pile driving, underwater chainsaws, and active
sonar systems) can be broadband, narrowband or tonal, brief or
prolonged (continuous or intermittent), and typically do not have the
high peak sound pressure with rise/decay time that impulsive sounds do
(ANSI 1995; NIOSH 1998; NMFS 2018). The distinction between impulsive
and non-impulsive sound sources is important because they have
differing potential to cause physical effects, particularly with regard
to hearing (e.g., Ward 1997 in Southall et al. 2007).
An impact hammer that operates by repeatedly dropping and/or
pushing a heavy piston onto a pile to drive the pile into the
substrate. Sound generated by impact hammers is considered impulsive.
Towing the rig would emit consistent low levels of noise into a
small portion of Cook Inlet for an extended period of time. Furie's
tugging and positioning activities would occur for approximately 20-25
hours over 2 days at the beginning and end of the drilling season in
Year 1 and in Year 2. Unlike projects that involve discrete noise
sources with known potential to harass marine mammals (e.g., pile
driving, seismic surveys), both the noise sources and impacts from the
tugs towing the rig are less well documented. The various scenarios
that may occur during this project extend from tugs in a stationary
mode positioning the drill rig to pulling the rig at nearly full power
against strong tides. Our assessments of the potential for harassment
of marine mammals incidental to Furie's tug activities specified here
are conservative in light of the general Level B harassment exposure
thresholds, the fact that NMFS is still in the process of developing
analyses of the impact that non-quantitative contextual factors have on
the likelihood of Level B harassment occurring, and the nature and
duration of the particular tug activities analyzed here.
The proposed project has the potential to harass marine mammals
from exposure to noise and the physical presence of working vessels
(e.g., tug configuration and pile driving equipment) as well as
associated noise with pile driving and the moving and positioning of
the rig. In this case, NMFS considers potential for harassment from the
collective use of these technologies working in a concentrated area
(relative to the entire Cook Inlet) for an extended period of time (for
tugging, when making multiple positioning attempts) and noise created
when moving and positioning the rig using tugs, as well as impact
installation of the conductor piles. Essentially, the project area will
become a concentrated work area in an otherwise non-industrial setting
for a period of several days.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from tugs and pile driving equipment is the primary means
by which marine mammals may be harassed from Furie's specified
activities. In general, animals exposed to natural or anthropogenic
sound may experience physical and psychological effects, ranging in
magnitude from none to severe (Southall et al. 2007). Generally,
exposure to pile driving and tugging has the potential to result in
auditory threshold shifts (TS) and behavioral disturbance (e.g.,
avoidance, temporary cessation of foraging and vocalizing, changes in
dive behavior). Exposure to anthropogenic noise can also lead to non-
observable physiological responses such as an increase in stress
hormones. Additional noise in a marine mammal's habitat can mask
acoustic cues used by marine mammals to carry out daily functions such
as communication and predator and prey detection. The effects of pile
driving and tugging noise on marine mammals are dependent on several
factors, including, but not limited to, sound type (e.g., impulsive vs.
non-impulsive), the species, age and sex class (e.g., adult male vs.
mother with calf), duration of exposure, the distance between the sound
source and the animal, received levels, behavior at time of exposure,
and previous history with exposure (Wartzok et al. 2003; Southall et
al. 2007). Here we discuss physical auditory effects (TSs) followed by
behavioral effects and potential impacts on habitat.
NMFS defines a noise-induced TS as ``a change, usually an increase,
in the threshold of audibility at a specified frequency or portion of
an individual's hearing range above a previously established reference
level'' (NMFS 2018). The amount of TS is customarily expressed in dB
(ANSI 1995, Yost 2007). A TS can be permanent (PTS) or temporary (TTS).
As described in NMFS (2016), there are numerous factors to consider
when examining the consequence of TS, including, but not limited to,
the signal temporal pattern (e.g., impulsive or non-impulsive),
likelihood an individual would be exposed for a long enough duration or
to a high enough level to induce a TS, the magnitude of the TS, time to
recovery (seconds to minutes or hours to days), the frequency range of
the exposure (i.e., spectral content), the hearing and vocalization
frequency range of the exposed species relative to the signal's
frequency spectrum (i.e., how animal uses sound within the frequency
band of the signal; e.g., Kastelein et al. 2014), and the overlap
between the animal and the source (e.g., spatial, temporal, and
spectral). When analyzing the auditory effects of noise exposure, it is
often helpful to broadly categorize sound as either impulsive--noise
with high peak sound pressure, short duration, fast rise-time, and
broad frequency content--or non-impulsive. For example, when
considering auditory effects, impact pile driving is treated as an
impulsive source. The sounds produced by tugs towing and
[[Page 51114]]
positioning the rig are characterized as non-impulsive sounds.
Permanent Threshold Shift--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB TS
approximates PTS onset (see NMFS 2018 for review). PTS levels for
marine mammals are estimates, because there are limited empirical data
measuring PTS in marine mammals (e.g., Kastak et al. 2008), largely due
to the fact that, for various ethical reasons, experiments involving
anthropogenic noise exposure at levels inducing PTS are not typically
pursued or authorized (NMFS 2018).
Temporary Threshold Shift--TTS is a temporary, reversible increase
in the threshold of audibility at a specified frequency or portion of
an individual's hearing range above a previously established reference
level (NMFS 2018). Based on data from cetacean TTS measurements (see
Finneran 2015 for a review), a TTS of 6 dB is considered the minimum TS
clearly larger than any day-to-day or session-to-session variation in a
subject's normal hearing ability (Schlundt et al. 2000; Finneran et al.
2002; Finneran 2015). As described in Finneran (2016), marine mammal
studies have shown the amount of TTS increases with cumulative sound
exposure level (SEL<INF>cum</INF>) in an accelerating fashion: At low
exposures with lower SEL<INF>cum,</INF> the amount of TTS is typically
small and the growth curves have shallow slopes. At exposures with
higher SEL<INF>cum,</INF> the growth curves become steeper and approach
linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during times when hearing
is critical, such as for successful mother/calf interactions, could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al. 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Many studies have examined noise-induced hearing loss in marine
mammals (see Finneran (2015) and Southall et al. (2019) for summaries).
For cetaceans, published data on the onset of TTS are limited to the
captive bottlenose dolphin (Tursiops truncatus), beluga whale, harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis),
and for pinnipeds in water, measurements of TTS are limited to harbor
seals, elephant seals (Mirounga angustirostris), and California sea
lions. These studies examine hearing thresholds measured in marine
mammals before and after exposure to intense sounds. The difference
between the pre-exposure and post-exposure thresholds can be used to
determine the amount of TS at various post-exposure times. The amount
and onset of TTS depends on the exposure frequency. Sounds at low
frequencies, well below the region of best sensitivity, are less
hazardous than those at higher frequencies, near the region of best
sensitivity (Finneran and Schlundt 2013). At low frequencies, onset-TTS
exposure levels are higher compared to those in the region of best
sensitivity (i.e., a low frequency noise would need to be louder to
cause TTS onset when TTS exposure level is higher), as shown for harbor
porpoises and harbor seals (Kastelein et al. 2019a, 2019b, 2020a,
2020b). In addition, TTS can accumulate across multiple exposures, but
the resulting TTS will be less than the TTS from a single, continuous
exposure with the same sound exposure level (SEL; Finneran et al. 2010;
Kastelein et al. 2014; Kastelein et al. 2015a; Mooney et al. 2009).
This means that TTS predictions based on the total, cumulative SEL will
overestimate the amount of TTS from intermittent exposures such as
sonars and impulsive sources. Nachtigall et al. (2018) and Finneran
(2018) describe the measurements of hearing sensitivity of multiple
odontocete species (bottlenose dolphin, harbor porpoise, beluga, and
false killer whale (Pseudorca crassidens)) when a relatively loud sound
was preceded by a warning sound. These captive animals were shown to
reduce hearing sensitivity when warned of an impending intense sound.
Based on these experimental observations of captive animals, the
authors suggest that wild animals may dampen their hearing during
prolonged exposures or if conditioned to anticipate intense sounds.
Another study showed that echolocating animals (including odontocetes)
might have anatomical specializations that might allow for conditioned
hearing reduction and filtering of low-frequency ambient noise,
including increased stiffness and control of middle ear structures and
placement of inner ear structures (Ketten et al. 2021). Data available
on noise-induced hearing loss for mysticetes are currently lacking
(NMFS 2018).
Activities for this project include tugging and impact pile
driving. Tugging is a transient activity, and there would likely be
pauses in pile driving during each day that it occurs. Given the nature
of these activities and the fact that many marine mammals are likely
moving through the project areas and not remaining for extended periods
of time, the potential for TS declines.
Behavioral Disturbance
Finally, exposure of marine mammals to certain sounds could result
in behavioral disturbance (Richardson et al. 1995), not all of which
constitutes harassment under the MMPA. The onset of behavioral
disturbance from anthropogenic noise depends on both external factors
(e.g., characteristics of noise sources and their paths) and the
receiving animals (e.g., hearing, behavioral state, experience,
demography) and is difficult to predict (Southall et al. 2007, 2021).
Currently NMFS uses a received level of 160 dB re 1 micro Pascal
([mu]Pa) rms to predict the onset of Level B harassment from impulse
noises (such as impact pile driving), and 120 dB re 1 [mu]Pa (rms) for
continuous noises (such as operating dynamic positioning (DP)
thrusters), although in certain circumstances there may be contextual
factors that alter our assessment. Furie's activity includes the use of
continuous (tug towing and positioning) and impulsive (impact pile
driving) sources, and therefore the RMS SPL thresholds of 120 and 160
dB re 1 [mu]Pa are applicable.
Disturbance may result in changing durations of surfacing and
dives, number of blows per surfacing, moving direction and/or speed,
reduced/increased vocal activities; changing/cessation of certain
behavioral activities (such as socializing or feeding), visible startle
response or aggressive behavior (such as tail/fluke slapping or jaw
clapping), avoidance of areas where sound sources are located, and/or
flight responses. Pinnipeds may increase their haul-out time, possibly
to avoid in-water disturbance (Thorson and Reyff 2006). These potential
behavioral
[[Page 51115]]
responses to sound are highly variable and context-specific and
reactions, if any, depend on species, state of maturity, experience,
current activity, reproductive state, auditory sensitivity, time of
day, and many other factors regarding the source eliciting the response
(Richardson et al. 1995; Wartzok et al. 2004; Southall et al. 2007).
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.
1995; NRC 2003; Wartzok et al. 2004). The biological significance of
many of these behavioral disturbances is difficult to predict,
especially if the detected disturbances appear minor. However, the
consequences of behavioral modification could be biologically
significant if the change affects growth, survival, and/or
reproduction, which depends on the severity, duration, and context of
the effects.
In consideration of the range of potential effects (PTS to
behavioral disturbance), we consider the potential exposure scenarios
and context in which species would be exposed to pile driving and tug-
related activity. Cook Inlet beluga whales may be present in low
numbers during the work; therefore, some individuals may be reasonably
expected to be exposed to elevated sound levels, including briefly
those that exceed the Level B harassment threshold for continuous or
impulsive noise. However, beluga whales are expected to be transiting
through the area, given this work is proposed primarily in middle Cook
Inlet (as described in the Description of Marine Mammals in the Area of
Specified Activities section), thereby limiting exposure duration, as
belugas in the area are expected to be headed to or from the
concentrated foraging areas farther north near the Beluga River,
Susitna Delta, and Knik and Turnigan Arms. Similarly, humpback whales,
fin whales, minke whales, gray whales, killer whales, California sea
lion, and Steller sea lions are not expected to remain in the area of
the tugs. Dall's porpoise, harbor porpoise, and harbor seal have been
sighted with more regularity than many other species during oil and gas
activities in Cook Inlet but due to the transitory nature of porpoises,
they are unlikely to remain at any particular well site for the full
duration of the noise-producing activity. Because of this and the
relatively low-level sources, the likelihood of PTS and TTS over the
course of the tug activities is discountable. Harbor seals may linger
or haul-out in the area but they are not known to do so in any large
number or for extended periods of time (there are no known major haul-
outs or rookeries coinciding with the well sites). Here we find there
is small potential for TTS over the course of tug activities but again,
PTS is not likely due to the nature of tugging. Potential for PTS and
TTS due to pile driving is discussed further in the Estimated Take
section.
Given most marine mammals are likely transiting through the area,
exposure is expected to be brief but, in combination with the actual
presence of the tug and rig configuration as well as conductor pipe
pile driving, may result in animals shifting pathways around the work
site (e.g., avoidance), increasing speed or dive times, or cessation of
vocalizations. The likelihood of no more than a short-term, localized
disturbance response is supported by data indicating belugas regularly
pass by industrialized areas such as the Port of Anchorage; therefore,
we do not expect abandonment of their transiting route or other
disruptions of their behavioral patterns. We also anticipate some
animals may respond with such mild reactions to the project that the
response would not be detectable. For example, during low levels of tug
power output (e.g., while tugs may be operating at low power because of
favorable conditions), the animals may be able to hear the work but any
resulting reactions, if any, are not expected to rise to the level of
take.
While in some cases marine mammals have exhibited little to no
obviously detectable response to certain common or routine
industrialized activity (Cornick et al. 2011), it is possible some
animals may at times be exposed to received levels of sound above the
Level B harassment threshold. This potential exposure in combination
with the nature of the tug and rig configuration (e.g., difficult to
maneuver, potential need to operate at night) and pile driving
activities means it is possible that take could occur over the total
estimated period of activities.
Masking
Since many marine mammals rely on sound to find prey, moderate
social interactions, and facilitate mating (Tyack 2008), noise from
anthropogenic sound sources can interfere with these functions, but
only if the noise spectrum overlaps with the hearing sensitivity of the
marine mammal (Southall et al. 2007; Clark et al. 2009; Hatch et al.
2012). Chronic exposure to excessive, though not high-intensity, noise
could cause masking at particular frequencies for marine mammals that
utilize sound for vital biological functions (Clark et al. 2009).
Acoustic masking is when other noises such as from human sources
interfere with animal detection and/or interpretation of acoustic
signals such as communication calls, echolocation sounds, and
environmental sounds important to marine mammals. Therefore, under
certain circumstances, marine mammals whose acoustical sensors or
environment are being severely masked could also be impaired from
maximizing their fitness for survival and reproduction.
Masking occurs in the frequency band that the animals utilize.
Since noises generated from tugs towing and positioning are mostly
concentrated at low frequency ranges, with a small concentration in
high frequencies as well, these activities likely have less effect on
mid-frequency echolocation sounds by odontocetes (toothed whales) such
as Cook Inlet beluga whales. However, lower frequency noises are more
likely to affect detection of communication calls and other potentially
important natural sounds such as surf and prey noise. Low-frequency
noise may also affect communication signals when they occur near the
frequency band for noise and thus reduce the communication space of
animals (e.g., Clark et al. 2009) and cause increased stress levels
(e.g., Holt et al. 2009). Unlike TS, masking, which can occur over
large temporal and spatial scales, can potentially affect the species
at population, community, or even ecosystem levels, in addition to
individual levels. Masking affects both senders and receivers of the
signals and, at higher levels for longer durations, could have long-
term chronic effects on marine mammal species and populations. However,
the noise generated by the tugs will not be concentrated in one
location or for more than 5 hours per positioning attempt, and up to
two positioning attempts at the same site. Further, noise generated by
impact pile driving will be intermittent and will occur over a maximum
of 2 days per year.
Marine Mammal Habitat Effects
Furie's proposed activities could have localized, temporary impacts
on marine mammal habitat, including prey, by increasing in-water sound
pressure levels and, for pile driving, slightly decreasing water
quality. Increased noise levels may affect acoustic habitat and
adversely affect marine mammal prey in the vicinity of the project
areas (see discussion below). Elevated levels of underwater noise would
ensonify the project areas where both fishes and
[[Page 51116]]
mammals occur and could affect foraging success.
The total seafloor area likely impacted by the pile driving
associated with the project is relatively small compared to the
available habitat in Cook Inlet. Avoidance by potential prey (i.e.,
fish) of the immediate area due to the temporary loss of this foraging
habitat is possible. The duration of fish and marine mammal avoidance
of this area after pile driving stops is unknown, but a rapid return to
normal recruitment, distribution, and behavior is anticipated. Any
behavioral avoidance by fish or marine mammals of the disturbed area
would still leave significantly large areas of fish and marine mammal
foraging habitat in the nearby vicinity.
Increased turbidity near the seafloor is not anticipated, as
installation of the conductor piles would occur within the monopod leg
of the platform.
Effects on Potential Prey
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., fish). Marine mammal
prey varies by species, season, and location. Here, we describe studies
regarding the effects of noise on known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick and Mann 1999; Fay 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al. 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds that are especially strong and/or intermittent
low-frequency sounds, and behavioral responses such as flight or
avoidance are the most likely effects. Short duration, sharp sounds can
cause overt or subtle changes in fish behavior and local distribution.
The reaction of fish to noise depends on the physiological state of the
fish, past exposures, motivation (e.g., feeding, spawning, migration),
and other environmental factors. Hastings and Popper (2005) identified
several studies that suggest fish may relocate to avoid certain areas
of sound energy. Additional studies have documented effects of pile
driving on fish; several are based on studies in support of large,
multiyear bridge construction projects (e.g., Scholik and Yan 2001,
2002; Popper and Hastings 2009). Several studies have demonstrated that
impulse sounds might affect the distribution and behavior of some
fishes, potentially impacting foraging opportunities or increasing
energetic costs (e.g., Fewtrell and McCauley 2012; Pearson et al. 1992;
Skalski et al. 1992; Santulli et al. 1999; Paxton et al. 2017).
However, some studies have shown no or slight reaction to impulse
sounds (e.g., Pena et al. 2013; Wardle et al. 2001; Jorgenson and
Gyselman 2009).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours
for one species. Impacts would be most severe when the individual fish
is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al. 2012b; Casper et al. 2013).
For pile driving, the most likely impact to fishes at the project
site would be temporary avoidance of the area. The duration of fish
avoidance of this area after pile driving stops is unknown, but a rapid
return to normal recruitment, distribution, and behavior is
anticipated. For tugging activities, much of the tugging would be
mobile during transport of the rig, and the tugging noise that occurs
during rig positioning would be temporary, similar to pile driving.
In summary, given the short daily duration of sound associated with
individual pile driving events and the relatively small areas being
affected, as well as the temporary and mostly transitory nature of the
tugging, Furie's activities are not likely to have a permanent, adverse
effect on any fish habitat, or populations of fish species. Any
behavioral avoidance by fish of the disturbed area would still leave
significantly large areas of fish and marine mammal foraging habitat in
the nearby vicinity. Thus, we conclude that impacts of the specified
activities are not likely to have more than short-term adverse effects
on any prey habitat or populations of prey species. Further, any
impacts to marine mammal habitat are not expected to result in
significant or long-term consequences for individual marine mammals, or
to contribute to adverse impacts on their populations.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization through the IHA, which will inform NMFS'
consideration of ``small numbers,'' the negligible impact
determinations, and impacts on subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Takes proposed for authorization would primarily be by Level B
harassment, as use of the acoustic sources (i.e., pile driving and tug
towing and positioning) has the potential to result in disruption of
behavioral patterns for individual marine mammals. We note here that
given the slow, predictable, and generally straight path of tug towing
and positioning, the likelihood of a resulting disruption of marine
mammal behavioral patterns that would qualify as harassment is
considered relatively low, however, at the request of the applicant, we
have quantified the potential take from this activity, analyzed the
impacts, and proposed its authorization. There is also some potential
for auditory injury (Level A harassment) to result to phocids because
of species occurrence and because predicted auditory injury zones are
larger than for mid-frequency and otariid species. Auditory injury is
unlikely to occur for low-frequency, mid-frequency, high-frequency, or
otariid species. The proposed mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent
practicable.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the proposed take numbers are estimated.
[[Page 51117]]
For acoustic impacts, 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) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the proposed take estimates.
Acoustic Thresholds
NMFS recommends the use of 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 or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al. 2007, 2021, Ellison et al. 2012). Based
on what the available science indicates and the practical need to use a
threshold based on a metric that is both predictable and measurable for
most activities, NMFS typically uses a generalized acoustic threshold
based on received level to estimate the onset of behavioral harassment.
NMFS generally predicts that marine mammals are likely to be
behaviorally harassed in a manner considered to be Level B harassment
when exposed to underwater anthropogenic noise above root-mean-squared
pressure received levels (RMS SPL) of 120 dB re 1 [mu]Pa for continuous
(e.g., vibratory pile driving, drilling) and above RMS SPL 160 dB re 1
[mu]Pa for non-explosive impulsive (e.g., seismic airguns) or
intermittent (e.g., scientific sonar) sources. Generally speaking,
Level B harassment take estimates based on these thresholds are
expected to include any likely takes by TTS as, in most cases, the
likelihood of TTS occurs at distances from the source smaller than
those at which behavioral harassment is likely. TTS of a sufficient
degree can manifest as behavioral harassment, as reduced hearing
sensitivity and the potential reduced opportunities to detect important
signals (conspecific communication, predators, prey) may result in
changes in behavior patterns that would not otherwise occur.
Furie's proposed activity includes the use of continuous (tugs
towing rig) and impulsive (impact pile driving) sources, and therefore
the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are applicable.
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 from
two different types of sources (impulsive or non-impulsive). Furie's
proposed activity includes the use of impulsive (impact pile driving)
and non-impulsive (tugs towing and positioning rig) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 5--Thresholds Identifying the Onset of PTS
------------------------------------------------------------------------
PTS onset acoustic thresholds *
(received level)
Hearing group ---------------------------------------
Impulsive Non-impulsive
------------------------------------------------------------------------
Low-Frequency (LF) cetaceans.... Cell 1: Lpk,flat: Cell 2: LE,LF,24h:
219 dB; 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) cetaceans.... Cell 3: Lpk,flat: Cell 4: LE,MF,24h:
230 dB; 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) cetaceans... Cell 5: Lpk,flat: Cell 6: LE,HF,24h:
202 dB; 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) Cell 7: Lpk,flat: Cell 8: LE,PW,24h:
(underwater). 218 dB; 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) Cell 9: Lpk,flat: Cell 10:
(underwater). 232 dB; LE,OW,24h: 219
LE,OW,24h: 203 dB. 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 are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss (TL)
coefficient.
The sound field in the project area is the existing background
noise plus additional noise from the proposed project. Marine mammals
are expected to be affected via sound generated by the primary
components of the project (i.e., pile driving and tug towing and
positioning). The calculated distance to the farthest Level B
harassment isopleth is approximately 4,483 m (2.8 miles (mi)).
[[Page 51118]]
The project includes impact installation of up to two 20-inch
conductor pipe piles in each year. The monopod leg of the JRP will
encase the well slot, which will encase the conductor pipes; therefore,
some attenuation is expected during conductor pipe pile installation.
However, water-filled isolation casings (such as the well slot and
caisson at the JRP) are expected to provide limited sound attenuation
(Caltrans 2015). Due to the well slot's reflective surfaces and the
monopod leg's caisson inside the JRP, some attenuation of the impact
noise is expected before reaching the open water. However, lacking
project-specific empirical data for a 20-inch conductor installed
within a well slot located within a monopod leg, the unaltered sound
source levels (SSLs) from U.S. Navy (2015) are used to calculate Level
A harassment and Level B harassment isopleths.
For tug activities, as described in 87 FR 27597 (May 9, 2022),
Hilcorp conducted a literature review of available source level data
for tugs under load in varying power output scenarios. Table 6 below
provides values of measured source levels for tugs varying from 2,000
to 8,200 horsepower. For the purposes of this table, berthing
activities could include tugs either pushing or pulling a load. The
SSLs appear correlated to speed and power output, with full power
output and higher speeds generating more propeller cavitation and
greater SSLs than lower power output and lower speeds. Additional tug
source levels are available from the literature but they are not
specific to tugs under load but rather measured values for tugs during
activities such as transiting, docking, and anchor pulling. For a
summary of these additional tug values, see table 7 in Hilcorp's 2022
IHA application, available at <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0">https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0</a>.
Table 6--Literature Values of Measured Tug Source Levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source level
Vessel Vessel length Speed (knots) Activity @1 m (re: 1 Horsepower Reference
(m) [micro]Pa)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Eagle................................ 32 9.6 Towing barge............ 173 6,770 Bassett et al. 2012.
Valor................................ 30 8.4 Towing barge............ 168 2,400 .......................
Lela Joy............................. 24 4.9 Towing barge............ 172 2,000 .......................
Pacific Eagle........................ 28 8.2 Towing barge............ 165 2,000 .......................
Shannon.............................. 30 9.3 Towing barge............ 171 2,000 .......................
James T Quigg........................ 30 7.9 Towing barge............ 167 2,000 .......................
Island Scout......................... 30 5.8 Towing barge............ 174 4,800 .......................
Chief................................ 34 11.4 Towing barge............ 174 8,200 .......................
Lauren Foss.......................... 45 N/A Berthing barge.......... 167 8,200 Austin et al. 2013.
Seaspan Resolution................... 30 N/A Berthing at half power.. 180 6,000 Roberts Bank Terminal 2
Technical Report 2014.
Seaspan Resolution................... 30 N/A Berthing at full power.. 200 6,000 .......................
--------------------------------------------------------------------------------------------------------------------------------------------------------
The Roberts Bank Terminal 2 Technical Report (2014), although not
in Cook Inlet, includes repeated measurements of the same tug operating
under different speeds and loads. This allows for a comparison of
source levels from the same vessel at half power versus full power,
which is an important distinction for Furie's activities, as a small
fraction of the total time spent by tugs under load will be at greater
than 50 percent power. The Seaspan Resolution's half-power berthing
scenario has a sound source level of 180 dB re 1 [mu]Pa at 1 m. In
addition, the Roberts Bank Report (2014) analyzed 650 tug transits
under varying load and speed conditions and reported mean tug source
levels of 179.3 dB re 1 [mu]Pa at 1 m; the 25th percentile was 179.0 dB
re 1 [mu]Pa at 1 m, and 5th percentile source levels were 184.9 dB re 1
[mu]Pa at 1 m.
Based solely on the literature review, a source level of 180 dB for
a single tug under load would be appropriate. However, Furie's use of a
three tug configuration would increase the literature source level to
approximately 185 dB at 1 m (Lawrence et al. 2022, as cited in Weston
and SLR 2022).
As described above in the Detailed Description of the Specific
Activity section, based on in situ measurements of Hilcorp's tug and a
review of the available literature of tugs under load described above,
NMFS finds that a source level of 185 dB re 1 [micro]Pa is appropriate
for Furie's three tug configuration for towing the rig.
As described above in the Detailed Description of the Specific
Activity section, Furie may need to use four tugs to position the rig
at the JRP. The SPL<INF>RMS</INF> of 185 dB for three tugs at 50
percent power implies each tug individually has a source level of 180.2
dB SPL<INF>rms</INF> because the addition of three equal-intensity
sound signals adds 4.8 dB to the sound level of a single source
(Engineering Toolbox 2023). Each doubling of sound intensity adds 3 dB
to the baseline (Engineering Toolbox 2023), and four tugs represents
two doublings of a single source. Therefore, adding 6 dB to the 180.2
dB baseline results in an expected SSL of 186.2 dB rms SPL for the use
of four tugs. Source levels for each activity are presented in table 7.
Table 7--SSLs for Project Activities
------------------------------------------------------------------------
SSL
Sound source ---------------------------------------
SEL SPLRMS
------------------------------------------------------------------------
3 tugs at 50 percent power...... .................. 185 dB at 1 m.
4 tugs at 50 percent power...... .................. 186.2 dB at 1 m.
Conductor pipe pile (20 in, 184 dB at 1 m..... 193 dB at 10 m.
impact).
------------------------------------------------------------------------
[[Page 51119]]
Several factors will determine the duration that the tugboats are
towing the Enterprise 151, including the origin and destination of the
towing route (e.g., Rig Tenders Dock, the JRP, one of Hilcorp's
platforms) and the tidal conditions. The power output will be variable
and influenced by the prevailing wind direction and velocity, the
current velocity, and the tidal stage. To the extent feasible,
transport will be timed with the tide to minimize towing duration and
power output.
TL is the decrease in acoustic intensity as an acoustic pressure
wave propagates out from a source. TL parameters vary with frequency,
temperature, sea conditions, current, source and receiver depth, water
depth, water chemistry, and bottom composition and topography. The
general formula for underwater TL is:
TL = B * Log10 (R1/R2),
Where
TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement
Absent site-specific acoustical monitoring with differing measured
TL, a practical spreading value of 15 is used as the TL coefficient in
the above formula. Site-specific TL data for pile driving at the JRP
site are not available; therefore, the default coefficient of 15 is
used to determine the distances to the Level A harassment and Level B
harassment thresholds for conductor pile driving.
For its tugging activities, Hilcorp contracted SLR Consulting to
model the extent of the Level B harassment isopleth as well as the
extent of the Level A harassment isopleth for their proposed tugging
using three tugs. Rather than applying practical spreading loss, SLR
Consulting created a more detailed propagation loss model in an effort
to improve the accuracy of the results by considering the influence of
environmental variables (e.g., bathymetry) at Hilcorp's specific well
sites. Modeling was conducted using dBSea software. The fluid parabolic
equation modeling algorithm was used with 5 Pad[eacute] terms (see pg.
57 in Hilcorp's application, available at <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0">https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0</a>, for more detail)
to calculate the TL between the source and the receiver at low
frequencies (1/3-octave bands, 31.5 Hz up to 1 kHz). For higher
frequencies (1 kHz up to 8 kHz) the ray tracing model was used with
1,000 reflections for each ray. Sound sources were assumed to be
omnidirectional and modeled as points. The received sound levels for
the project were calculated as follows: (1) One-third octave source
spectral levels were obtained via reference spectral curves with
subsequent corrections based on their corresponding overall source
levels; (2) TL was modeled at one-third octave band central frequencies
along 100 radial paths at regular increments around each source
location, out to the maximum range of the bathymetry data set or until
constrained by land; (3) The bathymetry variation of the vertical plane
along each modeling path was obtained via interpolation of the
bathymetry dataset which has 83 m grid resolution; (4) The one-third
octave source levels and TL were combined to obtain the received levels
as a function of range, depth, and frequency; and (5) The overall
received levels were calculated at a 1 m depth resolution along each
propagation path by summing all frequency band spectral levels.
Bathymetry data used in the model was collected from the NOAA
National Centers for Environmental Information (AFSC 2019). Using
NOAA's temperature and salinity data, sound speed profiles were
computed for depths from 0 to 100 m for May, July, and October to
capture the range of possible sound speed depending on the time of year
Hilcorp's work could be conducted. These sound speed profiles were
compiled using the Mackenzie Equation (1981) and are presented in table
8 of Hilcorp's application (available at <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0">https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0</a>). Geoacoustic
parameters were also incorporated into the model. The parameters were
based on substrate type and their relation to depth. These parameters
are presented in table 9 of Hilcorp's application (available at <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0">https://www.fisheries.noaa.gov/action/incidental-take-authorization-hilcorp-alaska-llc-oil-and-gas-activities-cook-inlet-alaska-0</a>).
Detailed broadband sound TL modeling in dBSea used the source level
of 185 dB re 1 [mu]Pa at 1 m calculated in one-third octave band levels
(31.5 Hz to 64,000 Hz) for frequency dependent solutions. The
frequencies associated with tug sound sources occur within the hearing
range of marine mammals in Cook Inlet. Received levels for each hearing
marine mammal group based on one-third octave auditory weighting
functions were also calculated and integrated into the modeling
scenarios of dBSea. For modeling the distances to relevant PTS
thresholds, a weighting factor adjustment was not used; instead, the
data on the spectrum associated with their source was used and
incorporated the full auditory weighting function for each marine
mammal hearing group.
Furie plans to use the tugs towing the rig for two functions, rig
positioning and towing. The activity was divided into two parts
(stationary and mobile) and two approaches were taken for modeling the
relevant isopleths.
SLR's model, described above, calculated the Level B harassment
isopleth propagating from three tugs towing a jack-up rig at 25
locations between Hilcorp platforms and well sites and the Rig Tenders
Dock in Nikiski, Alaska. The average Level B harassment isopleth across
all locations and seasons was determined to be 3,850 m (Weston and SLR
2022). Given that Furie is conducting the same three tug activity as
Hilcorp, also in middle Cook Inlet, Furie estimates, and NMFS concurs,
that 3,850 m is also an appropriate estimate of its Level B harassment
zone for tugging using three tugs. Similarly, Hilcorp modeled Level A
harassment zones for each hearing group; Furie proposed using these
Level A harassment zones for its towing and positioning activities
using three tugs, and NMFS concurs. These zones are included in table
8.
As described in the Description of Proposed Activity section, when
positioning the rig, Furie may use four tugs for up to 1 hour. Hilcorp
did not model a Level B harassment zone accounting for the use of four
tugs. Furie estimated the Level B harassment zones for tugging and
positioning with four tugs using a sound source level of 186.2 dB and a
TL of 18.129.
NMFS estimated the Level A harassment zones from the use of four
tugs using its User Spreadsheet and the Level A harassment zones
modeled by Hilcorp for the use of three tugs. First, NMFS calculated
the Level A harassment zones for the three tug scenario using the User
Spreadsheet (sound source level of 185 dB, 5 hours of sound production,
and a propagation loss coefficient of 18.129). Next, NMFS calculated
the Level A harassment zones for the ``combined scenario'' (use of
three tugs for 5 hours and four tugs for 1 hour, combined). NMFS then
calculated the ratio between the three tug scenario and the combined
scenario. For all hearing groups the combined scenario Level A
harassment isopleths are 13.8 percent larger than the three tug
scenario. Rather than using the Level A harassment isopleths for the
combined
[[Page 51120]]
scenario that were calculated using the User Spreadsheet, NMFS applied
a 13.8 percent increase to the three tug Level A harassment isopleths
modeled by Hilcorp, given that those isopleths are more conservative
than the isopleths NMFS calculated using the User Spreadsheet. The
Level A harassment isopleths that Furie will implement are included in
table 10.
The Level B harassment isopleth from the use of four tugs is 4,483
m, as described in Furie's application and included in table 6,
calculated using a sound source level of 186.2 dB SPL. NMFS concurs and
proposes a Level B harassment zone of 4,483 m for tugging and
positioning using four tugs (table 10).
Table 8--User Spreadsheet Inputs (Source Levels Provided in Table 7)
----------------------------------------------------------------------------------------------------------------
Number of Transmission
Source strikes per Number of loss
pile piles per day coefficient
----------------------------------------------------------------------------------------------------------------
Conductor pipe pile, Day 1 (70 percent installation)............ 6,100 0.7 15
Conductor pipe pile, Day 2 (30 percent installation)............ 0.3
----------------------------------------------------------------------------------------------------------------
Table 9--Level A Harassment Isopleths Calculated Using NMFS' User Spreadsheet, and Used To Determine the Ratio
Between the Three Tug Scenario and Three and Four Tugs Combined Scenario
----------------------------------------------------------------------------------------------------------------
Level A harassment isopleth (m)
-------------------------------------------------------------------------------
Scenario High-
Low- Frequency Mid- Frequency Frequency Phocid Otariid
Cetaceans Cetaceans Cetaceans Pinnipeds Pinnipeds
----------------------------------------------------------------------------------------------------------------
Three Tug Scenario Level A 17.2 9.7 178.9 9.1 0.9
harassment Isopleth............
Combined Scenario Level A 19.6 11.0 203.6 10.3 1.0
harassment Isopleth............
----------------------------------------------------------------------------------------------------------------
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically overestimates of
some degree, which may result in an overestimate of potential take by
Level A harassment. However, this optional tool offers the best way to
estimate isopleth distances when more sophisticated modeling methods
are not available or practical. For stationary sources such as
conductor pipe pile driving and rig positioning, the optional User
Spreadsheet tool predicts the distance at which, if a marine mammal
remained at that distance for the duration of the activity, it would be
expected to incur PTS. For mobile sources such as tugging, the optional
User Spreadsheet tool predicts the closest distance at which a
stationary animal would not be expected to incur PTS if the sound
source traveled by the stationary animal in a straight line at a
constant speed. Inputs used in the optional User Spreadsheet tool, and
the resulting estimated isopleths, are reported below.
Table 10--Level A Harassment and Level B Harassment Isopleths From Tugging and Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A Level B harassment isopleths (m)
Sound source harassment -------------------------------------------------------------------------------
isopleths (m) LF MF HF PW OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Conductor pipe pile, 70 percent installation............ 3,064 109 3,650 1,640 119 1,585
Conductor pipe pile, 30 percent installation............ 1,742 62 2,075 932 68
Tugging/Positioning, 3 Tugs \1\......................... 95 78 679 69 0 3,850
Tugging/Positioning, 4 Tugs \2\......................... 108 89 773 79 1 4,483
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ These zones are results from Hilcorp's modeling.
\2\ For otariids, Hilcorp's model estimated a Level A harassment zone of 0 during tugging/positioning with three tugs. Therefore, for four tugs, NMFS
applied the Level A harassment zone calculating with the User Spreadsheet.
Marine Mammal Occurrence
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform the take calculations.
Densities for marine mammals in Cook Inlet were derived from NMFS'
Marine Mammal Laboratory (MML) aerial surveys, typically flown in June,
from 2000 to 2018 (Rugh et al. 2005; Shelden et al. 2013, 2015, 2017,
2019). While the surveys are concentrated for a few days in June
annually, which may skew densities for seasonally present species, they
are still the best available long-term dataset of marine mammal
sightings available in Cook Inlet. (Note that while more recent surveys
have been conducted and published (Shelden et al. 2022; Goetz et al.
2023), the surveyed area was not included in either report, therefore
they were not used to calculate density). Density was calculated by
summing the total number of animals observed and dividing the number
sighted by the area surveyed.
[[Page 51121]]
The total number of animals observed accounts for both lower and upper
Cook Inlet. There are no density estimates available for California sea
lions and Pacific white-sided dolphins in Cook Inlet, as they are so
infrequently sighted. Densities are presented in table 11.
Table 11--Marine Mammal Densities
------------------------------------------------------------------------
Density (individuals/
Species km\2\)
------------------------------------------------------------------------
Humpback whale.................................... 0.00177
Minke whale....................................... 0.000009
Gray whale........................................ 0.000075
Fin whale......................................... 0.000311
Killer whale...................................... 0.000601
Beluga (Trading Bay).............................. 0.004453-0.015053
Beluga (North Cook Inlet)......................... 0.001664
Dall's porpoise................................... 0.000154
Harbor porpoise................................... 0.004386
Pacific white-sided dolphin....................... 0
Harbor seal....................................... 0.241401
Steller sea lion.................................. 0.007609
California sea lion............................... 0
------------------------------------------------------------------------
For the beluga whale density, Furie, and subsequently NMFS, used
the Goetz et al. (2012) habitat-based model. This model is derived from
sightings and incorporates depth soundings, coastal substrate type,
environmental sensitivity index, anthropogenic disturbance, and
anadromous fish streams to predict densities throughout Cook Inlet. The
output of this model is a beluga density map of Cook Inlet, which
predicts spatially explicit density estimates for Cook Inlet belugas.
Using the resulting grid densities, average densities were calculated
for two regions applicable to Furie's operations. The densities
applicable to the area of activity (i.e., the North Cook Inlet Unit
density for middle Cook Inlet activities and the Trading Bay density
for activities in Trading Bay) are provided in table 11 and were
carried forward to the take estimates. Likewise, when a range is given,
the higher end of the range was conservatively used to calculate take
estimates (i.e., Trading Bay in the Goetz model has a range of 0.004453
to 0.015053; 0.015053 was used for the take estimates).
Take Estimation
Here we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and proposed for authorization in each IHA.
Year 1 IHA
As described above, Furie plans to conduct rig towing and
positioning and may install up to two conductor piles using an impact
hammer in Year 1. To estimate take by Level B harassment from tugging,
for each species, Furie summed the estimated take for towing the rig at
the beginning of the season, positioning the rig, and towing the rig at
the end of the season. To estimate take for towing the rig (beginning
and end of season), Furie multiplied the area of the Level B harassment
zone (316.1 km\2\; inclusive of the full potential tug path of 35 km)
by the species density (table 11). To estimate take for positioning the
rig, Furie multiplied the maximum area of the Level B harassment zone
(63.1 km\2\, four tugs) by the species density (table 11), by the
number of potential positioning attempts (two attempts). NMFS concurs
that this method for estimating take from tugging activities is
appropriate.
To estimate take by Level B harassment from installation of
conductor piles, Furie multiplied the Level B harassment zone (7.98
km\2\) by the species density (table 11) by the estimated number of
days that conductor pile installation would occur (4 days, 2 per pile).
The Level B harassment zone used in the calculation conservatively
assumes 70 percent installation of a conductor pile on a given day, and
therefore, on 2 of the 4 days that conductor piles would be installed,
the Level B harassment zone would likely be smaller. NMFS concurs that
this method for estimating take from pile driving activities is
appropriate.
NMFS summed the estimated take by Level B harassment from tugging
and pile driving activities for each species. For species where the
total calculated take by Level B harassment is less than the estimated
group size for that species, NMFS rounded up the take by Level B
harassment proposed for authorization to the anticipated group size.
Take proposed for authorization during Year 1 activities is included in
table 12.
Based on the analysis described above, NMFS does not propose to
authorize take by Level A harassment related to Furie's tugging
activity. For mobile tugging activity, the distances to the PTS
thresholds for high frequency cetaceans (the only hearing group for
which modeling results in a Level A harassment zone greater than 0 m)
are smaller than the overall size of the tug and rig configuration,
making it unlikely a cetacean would remain close enough to the tug
engines for a long enough duration to incur PTS. For stationary
positioning of the rig, the PTS isopleths are up to 679 m for high
frequency cetaceans, but calculated with the assumption that an animal
would remain within several hundred meters of the rig for the full 5
hours of noise-producing activity which is unlikely. Therefore, take by
Level A harassment due to stationary or mobile tugging is neither
anticipated nor proposed for authorization.
For conductor pile installation, NMFS anticipates take by Level A
harassment for harbor seal only. For all other species, calculated take
by Level A harassment takes is less than one. Considering that along
with the low likelihood that an individual of these species would enter
and remain within the Level A harassment zone for long enough to incur
PTS, particularly in consideration of implementation of required
shutdown zones, Furie did not request, nor does NMFS propose to
authorize, take by Level A harassment. For harbor seal, NMFS proposes
to authorize three takes by Level A harassment, conservatively rounded
up from 2.7 Level A harassment takes calculated.
Table 12--Estimated Take by Level B Harassment, by Species, Activity, and in Total, Year 1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Rig tow, 3 tugs Rig positioning, 4 tugs Conductor pile installation
------------------------------------------------------------------------------------------------ Total year 1
Calculated Calculated Calculated estimated take Proposed take
Species Ensonified take by Level Ensonified take by Level Ensonified take by Level by Level B by Level B
area (km\2\) B harassment area (km\2\) B harassment area (km\2\) B harassment harassment harassment \a\
\1\ \2\ \3\ \4\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.................................................. 316.1 1.2 63.1 0.2 7.89 0.06 1.5 3
Minke whale..................................................... .............. 0.006 .............. 0.001 .............. 0.0003 0.007 3
Gray whale...................................................... .............. 0.04 .............. 0.009 .............. 0.002 0.05 3
Fin whale....................................................... .............. 0.2 .............. 0.04 .............. 0.01 0.3 2
Killer whale.................................................... .............. 0.4 .............. 0.08 .............. 0.02 0.5 10
Beluga (Trading Bay)............................................ .............. 0.5 .............. 0.2 .............. 0.05 0.8 11
Beluga (NCI).................................................... .............. 4.8 .............. NA .............. NA 4.8 ..............
[[Page 51122]]
Dall's porpoise................................................. .............. 0.1 .............. 0.01 .............. 0.005 0.1 6
Harbor porpoise................................................. .............. 2.8 .............. 0.3 .............. 0.1 3.2 12
Pacific white-sided dolphin..................................... .............. 0.000 .............. 0.000 .............. 0.000 0.000 3
Harbor seal..................................................... .............. 152.6 .............. 15.2 .............. 7.6 175.4 176
Steller sea lion................................................ .............. 4.8 .............. 0.5 .............. 0.2 5.5 6
California sea lion............................................. .............. 0.000 .............. 0.000 .............. 0.000 0.000 2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ This zone assumes a 35 km towing distance (the farthest potential distance that Furie may need to tow the rig).
\2\ Level B harassment zone area x density x 2 (towing at beginning and end of season), with the exception of Cook Inlet beluga whale. For Cook Inlet beluga whale, Furie used the Trading Bay
density for the initial rig tow since the density is predicted to be higher there than in the North Cook Inlet Lease Unit (located offshore in middle Cook Inlet), and Furie may tug the rig
though that area. Furie used the NCI density to estimate take for the end of season tow. NMFS concurs and has used these two separate densities in its analysis.
\3\ Level B harassment zone (63.1 km\2\) x species density (table 11), x number of potential positioning attempts (2).
\4\ Level B harassment zone (7.89 km\2\) x species density (table 11) x estimated number of days that conductor pile installation would occur (4).
Explanations for species for which take proposed for authorization
is greater than calculated take are included below.
Several recent surveys and monitoring programs have documented
groups of humpback whales ranging up to 14 whales in size. During the
annual survey, Shelden et al. (2022) recorded a group of three humpback
whales west of Kachemak Bay in June of 2022. Past annual aerial surveys
have documented groups up to 12 in number (Shelden et al. 2013, 2015,
2016, 2019). During Hilcorp's lower Cook Inlet seismic survey, group
size ranged from 1 to 14 (Fairweather Science 2020). During monitoring
of the Harvest Alaska CIPL project (the closest to Furie's Action
Area), two sightings of three humpbacks were reported. During
construction of the JRP in 2015, a group of 6 to 10 unidentified
whales, thought to be either gray whales or humpbacks, was observed
approximately 15 km northeast of the platform (Jacobs 2015). There were
two sightings of three humpback whales observed near Ladd Landing north
of the Forelands during the Harvest Alaska CIPL project (Sitkiewicz et
al. 2018). Furie requested, and NMFS is proposing to authorize, three
takes of humpback whale by Level B harassment in Year 1. This estimate
accounts for the potential of take of a group of two animals and a
solitary animal.
Groups of up to three minke whales have been recorded in recent
years, including one group of three southeast of Kalgin Island (Lomac-
MacNair et al. 2014). Other recent surveys in Cook Inlet typically have
documented minkes traveling alone (Shelden et al. 2013, 2015, 2017;
Kendall et al. 2015, as cited in Weston and SLR 2022; Fairweather
Science 2020). As the occurrence of minke whales is expected to be less
in middle Cook Inlet than lower Cook Inlet and considering the observed
group sizes, Furie requested, and NMFS is proposing to authorize, three
takes of minke whale by Level B harassment in Year 1 to account for the
potential of take of a group of three minke whales.
During Apache's 2012 seismic program, nine gray whales were
observed in June and July (Lomac-MacNair et al. 2013). During Apache's
seismic program in 2014, one gray whale was observed (Lomac-MacNair et
al. 2014). During construction of the JRP in 2015, 1 gray whale was
documented approximately 5 km from the platform, and a group of 6 to 10
unidentified whales, thought to be either gray whales or humpbacks, was
observed approximately 15 km northeast of the platform (Jacobs 2015).
During SAExploration's seismic survey in 2015, the 2018 CIPL project,
and Hilcorp's 2019 seismic survey, no gray whales were observed
(Kendall et al. 2015; Sitkiewicz et al. 2018; Fairweather Science,
2020). None were observed during the 2018 CIPL project in middle Cook
Inlet (Sitkiewicz et al. 2018). In 2020 and 2021, one gray whale was
reported in each season at the POA (61N 2021, 2022a). The documented
occasional presence of gray whales near and north of the project area
suggests that gray whale density may be seasonally higher than the
relatively low density suggested by the aerial surveys. Considering the
project area is in middle Cook Inlet where sightings of gray whales are
less common, Furie requested, and NMFS is proposing to authorize, take
of three gray whales in Year 1.
During seismic surveys conducted in 2019 by Hilcorp in the lower
Cook Inlet, fin whales were recorded in groups ranging in size from one
to 15 individuals (Fairweather, 2020). During the NMFS aerial surveys
in Cook Inlet from 2000 to 2018, 10 sightings of 26 estimated
individual fin whales in lower Cook Inlet were observed (Shelden et al.
2013, 2015, 2016, 2019). Furie requested, and NMFS is proposing to
authorize, take of one group of two fin whales (the lower end of the
range of common group sizes) in Year 1.
Killer whales are typically sighted in pods of a few animals to 20
or more (NOAA, 2022a). During seismic surveys conducted in 2019 by
Hilcorp in the lower Cook Inlet, 21 killer whales were observed, either
as single individuals or in groups ranging in size from 2 to 5
individuals (Fairweather, 2020). Furie requested 10 takes by Level B
harassment in Year 1 to account for 2 groups of 5 animals. NMFS concurs
and proposes to authorize 10 takes by Level B harassment of killer
whale.
The 2018 MML aerial survey (Shelden and Wade 2019) estimated a
median group size of approximately 11 beluga whales, although group
sizes were highly variable (2 to 147 whales) as was the case in
previous survey years (Boyd et al. 2019). Over 3 seasons of monitoring
at the POA, 61N reported groups of up to 53 belugas, with a median
group size of 3 and a mean group size of 4.4 (61N 2021, 2022a, 2022b,
and 2022c). Additionally, vessel-based surveys in 2019 observed beluga
whale groups in the Susitna River Delta (roughly 24 km [15 miles] north
of the Tyonek Platform) that ranged from 5 to 200 animals (McGuire et
al. 2022). The very large groups seen in the Susitna River Delta are
not expected in Trading Bay or offshore areas near the JRP or the
towing route for the Enterprise 151. However, smaller groups (i.e.,
around the median group size) could be traveling through to access the
Susitna River Delta and other nearby coastal locations, particularly in
the shoulder seasons when belugas are more likely to occur in middle
Cook Inlet. Few if any takes of beluga whale are anticipated
[[Page 51123]]
during impact installation of the conductor piles. Therefore, Furie
requested, and NMFS is proposing to authorize, 11 takes by Level B
harassment of beluga whale in Year 1.
Dall's porpoises typically occur in groups averaging between 2 and
12 individuals (NOAA, 2024b). During seismic surveys conducted in 2019
by Hilcorp in the lower Cook Inlet, Dall's porpoises were observed in
groups ranging in size from two to seven individuals (Fairweather,
2020). The 2012 Apache survey recorded two groups of three individual
Dall's porpoises (Lomac-MacNair, 2014). Because occurrence of Dall's
porpoise is anticipated to be less in middle Cook Inlet than lower Cook
Inlet, the smaller end of documented group sizes (three individuals) is
used. NMFS is proposing to authorize six takes (two groups of three
animals) by Level B harassment of Dall's porpoise in Year 1.
Shelden et al. (2014) compiled historical sightings of harbor
porpoises from lower to upper Cook Inlet that spanned from a few
animals to 92 individuals. The 2018 CIPL project that occurred just
north of the Action Area in Cook Inlet reported 29 sightings of 44
individuals (Sitkiewicz et al. 2018). While the duration of days that
the tugs are towing a jack-up rig will be less than the CIPL project,
given the increase in sightings of harbor porpoise in recent years, the
sighting of harbor porpoise during Hilcorp's rig move in June 2022, and
the inability to shut down the tugs, Furie requested, and NMFS is
proposing to authorize, 12 takes by Level B harassment of harbor
porpoise. This accounts for two potential groups of six animals.
Calculated take of Pacific white-sided dolphin was zero because the
estimated density is zero. However, in 2014, during Apache's seismic
survey program, three Pacific white-sided dolphins were reported
(Lomac-MacNair et al. 2014). They are considered rare in most of Cook
Inlet, including in the lower entrance, but their presence was
documented in Iniskin Bay and mid-inlet through passive acoustic
recorders in 2019 (Castellote et al. 2020). Furie conservatively
requested three takes based on the potential that a group similar in
size to that encountered in 2014 could occur within the Level B
harassment zone during project activities. NMFS concurs, and has
conservatively proposed to authorize three takes of Pacific white-sided
dolphin by Level B harassment.
Calculated take of California sea lions was zero because the
assumed density in Cook Inlet is zero. Any potential sightings would
likely be of lone out of habitat individuals. Two solitary individuals
were seen during the 2012 Apache seismic survey in Cook Inlet (Lomac-
MacNair et al. 2013). Furie requested two takes based on the potential
that two lone animals could be sighted over a year of work, as was seen
during Apache's year of work. NMFS concurs, and has conservatively
proposed to authorize two takes of California sea lion by Level B
harassment.
Year 2 IHA
Given that Furie intends to conduct the same activities in Year 2
as in Year 1, take by Level A harassment and Level B harassment
proposed for authorization for Year 2 is the same as that proposed for
authorization for Year 1 (table 12).
Table 13--Take Proposed for Authorization as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Year 1 Year 2
---------------------------------------------------------------
Abundance Total take Take as a Total take Take as a
Species Stock (Nbest) (Level A and percentage of (Level A and percentage of
Level B stock Level B stock
harassment) abundance harassment) abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale......................... Hawaii (Hawaii DPS)............ 11,278 3 <1 3 <1
Mexico-North Pacific (Mexico \1\ N/A .............. N/A .............. N/A
DPS).
Western North Pacific.......... 1,084 .............. <1 .............. <1
Minke whale............................ Alaska......................... \2\ N/A 3 N/A 3 N/A
Gray whale............................. Eastern Pacific................ 26,960 3 <1 3 <1
Fin whale.............................. Northeast Pacific.............. \3\ UND 2 N/A 2 N/A
Killer whale........................... Eastern North Pacific Alaska 1,920 10 <1 10 <1
Resident.
Eastern North Pacific Gulf of 587 .............. <1 .............. <1
Alaska, Aleutian Islands, and
Bering Sea Transient.
Beluga................................. Cook Inlet..................... \4\ 279 11 3.9 11 3.9
Dall's porpoise........................ Alaska......................... \5\ UND 6 N/A 6 N/A
Harbor porpoise........................ Gulf of Alaska................. 31,046 12 <1 12 <1
Pacific white-sided dolphin............ North Pacific.................. 26,880 3 <1 3 <1
Harbor seal............................ Cook Inlet/Shelikof............ 28,411 179 <1 179 <1
Steller sea lion....................... Western U.S.................... \6\ 49,932 6 <1 6 <1
California sea lion.................... U.S............................ 257,606 2 <1 2 <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Abundance estimates are based upon data collected more than 8 years ago and, therefore, current estimates are considered unknown.
\2\ Reliable population estimates are not available for this stock. Please see Friday et al. (2013) and Zerbini et al (2006) for additional information
on numbers of minke whales in Alaska.
\3\ The best available abundance estimate for this stock is not considered representative of the entire stock as surveys were limited to a small portion
of the stock's range.
\4\ On June 15, 2023, NMFS released an updated abundance estimate for endangered Cook Inlet beluga whales in Alaska (Goetz et al. 2023). Data collected
during NOAA Fisheries' 2022 aerial survey suggest that the whale population is stable or may be increasing slightly. Scientists estimated that the
population size is between 290 and 386, with a median best estimate of 331. In accordance with the MMPA, this population estimate will be incorporated
into the Cook Inlet beluga whale SAR, which will be reviewed by an independent panel of experts, the Alaska Scientific Review Group. After this
review, the SAR will be made available as a draft for public review before being finalized. When the number of instances of takes is compared to this
median abundance, the percent of the stock proposed for authorization is 3.3 percent.
\5\ The best available abundance estimate is likely an underestimate for the entire stock because it is based upon a survey that covered only a small
portion of the stock's range.
\6\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys.
Proposed Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock
[[Page 51124]]
for taking for certain subsistence uses. 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 the 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, NMFS
considers 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, as
well as subsistence uses. 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 and impact on
operations.
In addition to the measures described in detail below, Furie will
conduct briefings between conductor pipe installation supervisors,
vessel captains and crew, and the marine mammal monitoring team before
the start of all in-water work and when new personnel join the work to
explain responsibilities, communication procedures, marine mammal
monitoring protocol, and operational procedures.
Mitigation for Rig Tugging/Positioning
NMFS anticipates that there is a discountable potential for marine
mammals to incur PTS from the tugging and positioning, as source levels
are relatively low, non-impulsive, and animals would have to remain at
very close distances for multiple hours to accumulate acoustic energy
at levels that could damage hearing. Therefore, we do not believe there
is reasonable potential for Level A harassment from rig tugging or
positioning. However, Furie will implement a number of mitigation
measures designed to reduce the potential for and severity of Level B
harassment, and minimize the acoustic footprint of the project.
Protected Species Observers
Furie will station PSOs at the highest possible vantage point on
either the rig or on one of the tugs.
Pre-Clearance and Post-Activity Monitoring
The tugs towing a rig are not able to shut down while transiting or
positioning the rig. Furie will maneuver the tugs towing the rig such
that they maintain a consistent speed (approximately 4 knots or less[7
km/hr]) and avoid multiple changes of speed and direction to make the
course of the vessels as predictable as possible to marine mammals in
the surrounding environment, characteristics that are expected to be
associated with a lower likelihood of disturbance.
During tugging activities, Furie would implement a clearance zone
of 1,500 m around the rig for all marine mammals other than Cook Inlet
beluga whales. This proposed clearance zone was determined to be
appropriate as it is approximately twice as large as largest Level A
harassment zone (table 10) and is a reasonable distance within which
cryptic species (e.g., porpoises, pinnipeds) could be observed. For
Cook Inlet beluga whales, Furie would implement a clearance zone that
extends as far as PSOs can feasibly observe for Cook Inlet beluga
whales. Prior to commencing new activities during daylight hours or if
there is a 30-minute lapse in operational activities, the PSOs will
monitor the clearance zone for marine mammals for 30 minutes (i.e.,
pre-clearance monitoring). (Note, transitioning from towing to
positioning without shutting down would not be considered commencing a
new operational activity.) If no marine mammals are observed within the
relevant clearance zone during this pre-clearance monitoring period,
tugging activities may commence. If a marine mammal(s) is observed
within the relevant clearance zone during the pre-clearance monitoring
period, tugging activities would be delayed, unless the delay
interferes with the safety of working conditions. Operations would not
commence until the PSO(s) observe that: (1) the non-Cook Inlet beluga
whale animal(s) is outside of and on a path away from the clearance
zone; (2) the Cook Inlet beluga whale is no longer detected at any
range; or (3) for non-ESA-listed species, 15 minutes have elapsed
without observing the marine mammal, or for ESA-listed species, 30
minutes have elapsed without observing the marine mammal. Once the PSOs
have determined one of those conditions are met, operations may
commence. PSOs would also conduct monitoring for marine mammals through
30 minutes post-completion of any tugging activity each day, and after
each stoppage of 30 minutes or greater.
During nighttime hours or low/no-light conditions, night-vision
devices (NVDs) shown to be effective at detecting marine mammals in
low-light conditions (e.g., Portable Visual Search-7 model, or similar)
would be provided to PSOs to aid in their monitoring of marine mammals.
Every effort would be made to observe that the relevant clearance zone
is free of marine mammals by using night-vision devices and or the
naked eye, however it may not always be possible to see and clear the
entire clearance zones prior to nighttime transport. Prior to
commencing new operational activities during nighttime hours, or if
there is a 30-minute lapse in operational activities in low/no-light
conditions, the PSOs must observe the extent visible while using night
vision devices for 30 minutes (i.e., pre-clearance monitoring). If no
marine mammals are observed during this pre-clearance period, tugging
activities may commence. If a marine mammal(s) is observed within the
pre-clearance monitoring period, tugging activities would be delayed,
unless the delay interferes with the safety of working conditions.
Operations would not commence until the PSO(s) observe that: (1) the
animal(s) is outside of the observable area; or (2) for non-ESA-listed
species, 15 minutes have elapsed without observing the marine mammal,
or for ESA-listed species, 30 minutes have elapsed without observing
the marine mammal Once the PSOs have determined one of those conditions
are met, operations may commence.
PSOs must scan the waters for at least 30 minutes after tugging and
positioning activities have been completed each day, and after each
stoppage of 30 minutes or greater.
Should a marine mammal be observed during towing or positioning of
the rig, the PSOs will monitor and carefully record any reactions
observed until the towing or positioning has concluded. PSOs will also
collect behavioral information on marine mammals sighted during
monitoring efforts.
Nighttime Work
Furie will conduct tug towing operations with the tide, resulting
in a low power output from the tugs towing the rig, unless human safety
or equipment integrity is at risk. Due to the nature of tidal cycles in
Cook Inlet, it is possible the most favorable tide for the towing
operation will occur during
[[Page 51125]]
nighttime hours. Furie will only operate the tug towing activities at
night if necessary to accommodate a favorable tide. Prior to commencing
operational activities during nighttime hours or low/no-light
conditions, Furie must implement the pre-clearance measures described
above.
Susitna Delta
The Tyonek platform is within the Susitna Delta Exclusion Zone
identified in Hilcorp's IHAs (87 FR 62364, October 14, 2022). If
Hilcorp does conduct work at the Tyonek platform, it would maintain
operatorship and control of the Enterprise 151 until the tow is
underway with lines taut and the Enterprise 151 is under tug power.
Once the tow is underway, Furie representatives will take over
operatorship of the Enterprise 151.
Out of concern for potential disturbance to Cook Inlet beluga
whales in sensitive and essential habitat, Furie would maintain a
distance of 2.4 km from the mean lower-low water (MLLW) line of the
Susitna River Delta (Beluga River to the Little Susitna River) between
April 15 and November 15. The dates of applicability of this exclusion
zone have been expanded based on new available science, including
visual surveys and acoustic studies, which indicate that substantial
numbers of Cook Inlet beluga whales continue to occur in the Susitna
Delta area through at least mid-November (M. Castellote, pers. comm.,
T. McGuire, pers. comm.). Of note, Furie does not expect to operate in
this area, but if it does, this measure would apply.
Mitigation for Conductor Pile Installation
NMFS proposes that Furie must implement the following measures for
impact driving of conductor piles.
Shutdown Zones
The purpose of a shutdown zone is generally to define an area
within which shutdown of the activity would occur upon sighting of a
marine mammal (or in anticipation of an animal entering the defined
area). Construction supervisors and crews, PSOs, and relevant Furie
staff 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. Further,
Furie must implement shutdown zones as described in table 14. Furie
states that if a shutdown or delay occurs, impact installation of the
conductor pipe will not commence or resume until the animal has
voluntarily left and been visually confirmed to be 100 m beyond the
shutdown zone and on a trajectory away from the zone, or 30 minutes
have passed without subsequent detections. If Cook Inlet beluga whales
are observed within or approaching the Level B harassment zone for
conductor pipe installation, impact installation of the conductor pipe
will be delayed or halted until the beluga(s) have voluntarily left and
been visually confirmed to be 100 m beyond the Level B harassment zone
and on a trajectory away from the zone, or 30 minutes have passed
without subsequent detections.
Table 14--Shutdown Zones for Conductor Pipe Pile Driving
------------------------------------------------------------------------
Shutdown zone
Hearing group (m)
------------------------------------------------------------------------
Low-frequency Cetaceans................................. 2,000
Mid-frequency Cetaceans................................. 110
High-frequency Cetaceans................................ 400
Phocids................................................. 400
Otariids................................................ 120
------------------------------------------------------------------------
Protected Species Observers
Furie will establish a monitoring location on the JRP at the
highest possible vantage point to monitor to the maximum extent
possible in all directions. Monitoring is described in more detail in
the Proposed Monitoring and Reporting section, below.
Pre- and Post-Activity Monitoring
Monitoring must take place from 30 minutes prior to initiation of
pile driving activity (i.e., pre-start clearance monitoring) through 30
minutes post-completion of pile driving activity. Pre-start clearance
monitoring must be conducted during periods of visibility sufficient
for the lead PSO to determine that the shutdown zones indicated in
table 14 are clear of marine mammals. Pile driving may commence
following 30 minutes of observation when the determination is made that
the shutdown zones are clear of marine mammals. If a marine mammal is
observed entering or within the shutdown zones, pile driving activity
must be delayed or halted. If pile driving 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 for 15 minutes (for non-ESA-listed
species) or 30 minutes (for ESA-listed species) have passed without re-
detection of the animal. With the exception of Cook Inlet beluga
whales, if a marine mammal for which take by Level B harassment is
authorized is present in the Level B harassment zone but beyond the
relevant shutdown zone, activities may begin and Level B harassment
take would be recorded.
Monitoring for Level A and Level B Harassment
PSOs would monitor the shutdown zones and beyond to the extent that
PSOs can see. Monitoring beyond the shutdown zones enables observers to
be aware of and communicate the presence of marine mammals in the
project areas outside the shutdown zones and thus prepare for a
potential cessation of activity should the animal enter the shutdown
zone.
Soft Start
Soft-start procedures are used to provide additional protection to
marine mammals by providing warning and/or giving marine mammals a
chance to leave the area prior to the hammer operating at full
capacity. For impact pile driving, soft start requires contractors to
provide an initial set of three strikes at reduced energy, followed by
a 30-second waiting period, then two subsequent reduced-energy strike
sets. 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.
Mitigation for Helicopter Activities
Helicopters must transit at an altitude of 1,500 ft (457 m) or
higher, to the extent practicable, while adhering to Federal Aviation
Administration flight rules (e.g., avoidance of cloud ceiling, etc.),
excluding takeoffs and landing. If flights must occur at altitudes less
than 1,500 ft due to environmental conditions, aircraft must make
course adjustments, as needed, to maintain at least a 1,500- foot
separation from all observed marine mammals. Helicopters must not hover
or circle above marine mammals. A minimum transit altitude is expected
to reduce the potential for disturbance to marine mammals from
transiting aircraft.
Based on our evaluation of Furie's proposed measures, as well as
other measures considered by NMFS (i.e., the extended clearance zone
for beluga whales), for both IHAs, NMFS has preliminarily determined
that the proposed mitigation measures provide the means of effecting
the least practicable impact on the affected species or stocks and
their habitat,
[[Page 51126]]
paying particular attention to rookeries, mating grounds, and areas of
similar significance, and on the availability of such species or stock
for subsistence uses.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. 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:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> 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 activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> Mitigation and monitoring effectiveness.
Monitoring
Furie would abide by all monitoring and reporting measures
contained within the IHA, if issued, and their Marine Mammal Monitoring
and Mitigation Plan (see Appendix B of Furie's application). A summary
of those measures and additional requirements proposed by NMFS is
provided below.
A minimum of two NMFS-approved PSOs will be on-watch during all
activities wherein the rig is attached to the tugs for the duration of
the project. PSOs will be stationed aboard a tug or the rig during tug
towing and positioning and may use a combination of equipment to
perform marine mammal observations and to verify the required
monitoring distance from the project site, including 7 by 50 binoculars
and NMFS approved NVDs for low light and nighttime operations. A
minimum of two NMFS-approved PSOs will be stationed on the JRP at the
highest possible vantage point to monitor to the maximum extent
possible in all directions during pile driving. PSOs would be
independent of the activity contractor (for example, employed by a
subcontractor) and have no other assigned tasks during monitoring
periods. At least one PSO would have prior experience performing the
duties of a PSO during an activity pursuant to a NMFS-issued Incidental
Take Authorization or Letter of Concurrence. Other PSOs may substitute
other relevant experience (including relevant Alaska Native traditional
knowledge), education (degree in biological science or related field),
or training for prior experience performing the duties of a PSO. Where
a team of three or more PSOs is required, a lead observer or monitoring
coordinator must be designated. The lead observer must have prior
experience performing the duties of a PSO during an activity pursuant
to a NMFS-issued incidental take authorization.
PSOs would also have the following additional qualifications:
<bullet> PSOs must be able to conduct field observations and
collect data according to assigned protocols;
<bullet> PSOs must have experience or training in the field
identification of marine mammals, including the identification of
behaviors;
<bullet> PSOs must have sufficient training, orientation, or
experience with the tugging operation to provide for personal safety
during observations;
<bullet> PSOs must have sufficient writing skills to record
required information including but not limited to the number and
species of marine mammals observed; dates and times when in-water
tugging activities were conducted; dates, times, and reason for
implementation of mitigation (or why mitigation was not implemented
when required); and marine mammal behavior; and
<bullet> PSOs must have the 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.
Reporting
Furie would submit interim monthly reports for all months in which
tugs towing, holding, or positioning the rig occurs. Monthly reports
would include a summary of marine mammal species and behavioral
observations, delays, and tugging activities completed. They also must
include an assessment of the amount of tugging remaining to be
completed, in addition to the number of Cook Inlet beluga whales
observed within estimated harassment zones to date.
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of the tug towing rig activities
for the year. It will include an overall description of work completed,
a narrative regarding marine mammal sightings, and associated marine
mammal observation data sheets in an electronic format. Specifically,
the report must include the following information:
<bullet> Date and time that monitored activity begins or ends;
<bullet> Activities occurring during each observation period,
including (a) the type of activity, (b) the total duration of each type
of activity, (c) the number of attempts required for positioning, (d)
when nighttime operations were required (e) whether towing against the
tide was required, (f) the number and type of piles that were driven
and the method (e.g., impact, vibratory, down-the-hole), and (g) total
number of strikes for each pile.
<bullet> PSO locations during marine mammal monitoring;
<bullet> Environmental conditions during monitoring periods (at the
beginning and end of the PSO shift and whenever conditions change
significantly), including Beaufort sea state, tidal state, and any
other relevant weather conditions, including cloud cover, fog, sun
glare, overall visibility to the horizon, and estimated observable
distance;
<bullet> Upon observation of a marine mammal, (a) name of PSO who
sighted the animal(s) and PSO location and
[[Page 51127]]
activity at time of sighting, (b) time of sighting, (c) identification
of the animal(s) (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, (d) distance and location of
each observed marine mammal relative to the tugs or pile being driven
for each sighting, (e) estimated number of animals (min/max/best
estimate), (f) estimated number of animals by cohort (adults,
juveniles, neonates, group composition, etc.), (g) animal's closest
point of approach and estimated time spent within the harassment zone,
(h) description of any marine mammal behavioral observations (e.g.,
observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity (e.g., no response or changes in behavioral state such as
ceasing feeding, changing direction, flushing, or breaching);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> 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(s), if any.
If no comments are received from NMFS within 30 days, the draft
summary report will constitute the final report. If NMFS submits
comments, Furie will submit a final summary report addressing NMFS
comments within 30 days after receipt of comments.
In the event that personnel involved in Furie's activities discover
an injured or dead marine mammal, Furie must report the incident to the
Office of Protected Resources (OPR), NMFS
(<a href="/cdn-cgi/l/email-protection#91c1c3bfd8c5c1bfdcfefff8e5fee3f8fff6c3f4e1fee3e5e2d1fffef0f0bff6fee7"><span class="__cf_email__" data-cfemail="0d5d5f2344595d234062636479627f64636a5f687d627f797e4d63626c6c236a627b">[email protected]</span></a> and <a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d9908d89f7bdb8afb0aa99b7b6b8b8f7beb6af">[email protected]</a>) and to the
Alaska regional stranding network as soon as feasible. If the death or
injury was clearly caused by the specified activity, Furie must
immediately cease the 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 IHAs. The Holder
must not resume their activities until notified by NMFS.
The report must include the following information:
(i) Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
(ii) Species identification (if known) or description of the
animal(s) involved;
(iii) Condition of the animal(s) (including carcass condition if
the animal is dead);
(iv) Observed behaviors of the animal(s), if alive;
(v) If available, photographs or video footage of the animal(s);
and
(vi) 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 impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), 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' 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 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).
To avoid repetition, the majority of our analysis applies to all
the species listed in table 13, except for Cook Inlet beluga whale and
harbor seal, given that many of the anticipated effects of this project
on different marine mammal stocks are expected to be relatively similar
in nature. For Cook Inlet beluga whales and harbor seals, there are
meaningful differences in anticipated individual responses to
activities, impact of expected take on the population, or impacts on
habitat; therefore, we provide a separate independent detailed analysis
for Cook Inlet beluga whales and harbor seals following the analysis
for other species for which we propose take authorization.
NMFS has identified several key factors which may be employed to
assess the level of analysis necessary to conclude whether potential
impacts associated with a specified activity should be considered
negligible. These include (but are not limited to) the type and
magnitude of taking, the amount and importance of the available habitat
for the species or stock that is affected, the duration of the
anticipated effect on the individuals, and the status of the species or
stock. The potential effects of the specified activity on humpback
whales, minke whales, gray whales, fin whales, killer whales, Dall's
porpoises, harbor porpoises, Pacific white-sided dolphins, Steller sea
lions, and California sea lions are discussed below. These factors also
apply to Cook Inlet beluga whales and harbor seals; however, additional
analysis for Cook Inlet beluga whales and harbor seals is provided in a
separate subsection below.
Furie's tugging activities associated with this project, as
outlined previously, have the potential to harass marine mammals.
Specifically, the specified activities may result in take, in the form
of Level B harassment, from underwater sounds generated by tugs towing,
holding, and positioning a rig. Potential takes could occur if marine
mammals are present in zones ensonified above the thresholds for Level
B harassment, identified above, while activities are underway.
Furie's planned activities and associated impacts would occur
within a limited area of the affected species' or stocks' ranges over a
total of 4 days each year for tugging, and 2 days for pile driving. The
intensity and duration of take by Level B harassment would be minimized
through use of mitigation measures described herein. Further the amount
of take proposed to be authorized is small when compared to stock
abundance (table 13). In addition, NMFS does not anticipate that
serious injury or mortality would occur as a result of Furie's planned
activity given the nature of the activity, even in the absence of
required mitigation.
Exposures to elevated sound levels produced during tugging and pile
driving activities may cause behavioral disturbance of some individuals
within the vicinity of the sound source. Behavioral responses of marine
mammals to Furie's tugging activities are expected to be mild, short
term, and temporary. Effects on individuals that are taken by Level B
harassment, as enumerated in the Estimated Take
[[Page 51128]]
section, on the basis of reports in the literature as well as
monitoring from other similar activities conducted by Furie (Horsley
and Larson, 2023), would likely be limited to behavioral response such
as increased swimming speeds, changing in directions of travel and
diving and surfacing behaviors, increased respiration rates, or
interrupted foraging (if such activity were occurring) (Ridgway et al.
1997; Nowacek et al. 2007; Thorson and Reyff, 2006; Kendall and Cornick
2015; Goldbogen et al. 2013b; Blair et al. 2016; Wisniewska et al.
2018; Piwetz et al. 2021). Marine mammals within the Level B harassment
zones may not present any visual cues they are disturbed by activities,
or they may become alert, avoid the area, leave the area, or have other
mild responses that are not observable such as increased stress levels
(e.g., Rolland et al. 2012; Lusseau, 2005; Bejder et al. 2006; Rako et
al. 2013; Pirotta et al. 2015b; P[eacute]rez-Jorge et al. 2016). They
may also exhibit increased vocalization rates (e.g., Dahlheim 1987;
Dahlheim and Castellote 2016), louder vocalizations (e.g., Frankel and
Gabriele 2017; Fournet et al. 2018), alterations in the spectral
features of vocalizations (e.g., Castellote et al. 2012), or a
cessation of communication signals (e.g., Tsujii et al. 2018). However,
as described in the Potential Effects of Specified Activities on Marine
Mammals and Their Habitat section, marine mammals observed near Furie's
tugging activities have shown little to no observable reactions to
tugging activities (Horsley and Larson 2023).
Tugs pulling, holding, and positioning a rig are slow-moving as
compared to typical recreational and commercial vessel traffic.
Assuming an animal was stationary, exposure to sound above the Level B
harassment threshold from the moving tug configuration (which comprises
most of the tug activity being considered) would be on the order of
minutes in any particular location. The slow, predictable, and
generally straight path of this activity is expected to further lower
the likelihood of more than low-level responses to the sound. Also,
this slow transit along a predictable path is planned in an area of
routine vessel traffic where many large vessels move in slow straight-
line paths, and some individuals are expected to be habituated to these
sorts of sounds. While it is possible that animals may swim around the
project area, avoiding closer approaches to the boats, we do not expect
them to abandon any intended path. Further, most animals present in the
region would likely be transiting through the area; therefore, any
potential exposure is expected to be brief. Based on the
characteristics of the sound source and the other activities regularly
encountered in the area, it is unlikely Furie's planned tugging
activities would be of a duration or intensity expected to result in
impacts on reproduction or survival.
Effects on individuals that are taken by Level B harassment during
pile driving, on the basis of reports in the literature as well as
monitoring from other similar activities, would likely be limited to
reactions such as increased swimming speeds, increased surfacing time,
or interrupted foraging (if such activity were occurring; e.g., Thorson
and Reyff 2006; HDR, Inc. 2012; Lerma 2014; ABR 2016). Most likely,
individuals would simply move away from the sound source and be
temporarily displaced from the areas of pile driving and removal. If
sound produced by project activities is sufficiently disturbing,
animals are likely to simply avoid the area while the activity is
occurring, particularly as the project is expected to occur over a
maximum of just 2 days of in-water pile driving during each year.
Most of the species present in the region would only be present
temporarily based on seasonal patterns or during transit between other
habitats. These temporarily present species would be exposed to even
smaller periods of noise-generating activity, further decreasing the
impacts. Most likely, individual animals would simply move away from
the sound source and be temporarily displaced from the area. Takes may
also occur during important feeding times. The project area though
represents a small portion of available foraging habitat and impa
[…truncated; see source link]Indexed from Federal Register on June 14, 2024.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.