[Federal Register Volume 89, Number 70 (Wednesday, April 10, 2024)]
[Notices]
[Pages 25238-25249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-07565]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD550]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Columbia Gulf East Lateral XPRESS 
Project

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: Pursuant to the regulations implementing the Marine Mammal 
Protection Act (MMPA) as amended, notification is hereby given that 
NMFS has issued an incidental harassment authorization (IHA) to 
Columbia Gulf, LLC (Columbia Gulf) to incidentally harass, by Level B 
harassment only, marine mammals during pile driving activities 
associated with the East Lateral XPRESS construction project (the 
Project) in Barataria Bay, Louisiana. There are no changes from the 
proposed authorization in this final authorization.

DATES: This authorization is effective from December 1, 2023, to 
November 30, 2024.

ADDRESSES: Electronic copies of the application and supporting 
documents, as well as a list of the references cited in this document, 
may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. In case of problems accessing these documents, 
please call the contact listed below.

FOR FURTHER INFORMATION CONTACT: Cara Hotchkin, 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 monitoring and 
reporting of the takings. The definitions of all applicable MMPA 
statutory terms cited above are included in the relevant sections 
below.

Summary of Request

    On March 3, 2023, NMFS received a request from TC Energy/Columbia 
Gulf Transmission, LLC for an IHA to take marine mammals incidental to 
construction activities that include pile driving to install: (1) a 
point of delivery metering station (POD), and (2) a tie-in facility 
(TIF) in Barataria Bay. The Project is intended to provide feed fuel 
for on-shore Liquefied Natural Gas (LNG) compressor stations. The 
application was deemed adequate and complete on June 5, 2023. Columbia 
Gulf's request is for take of bottlenose dolphin (Tursiops truncatus, 
Barataria Bay Estuarine System stock, BBES) by Level B harassment only. 
Neither Columbia Gulf nor NMFS expects serious injury or mortality to 
result from this activity and, therefore, an IHA is appropriate.

Description of Specified Activity

Overview

    Columbia Gulf proposes to construct two new compressor stations, a 
new meter station, approximately 8 miles (13 kilometers) of new 30-inch 
diameter natural gas pipeline lateral, two new mainline valves, a TIF, 
launcher and receiver facilities, and other auxiliary appurtenant 
facilities all located in St. Mary, Lafourche, Jefferson, and 
Plaquemines parishes, Louisiana. A summary of all construction 
activities necessary to complete all elements of the Project are shown 
in table 1.

                                      Table 1--All Elements of the Project
           [Bolded elements include in-water activities that may result in the take of marine mammals]
----------------------------------------------------------------------------------------------------------------
                                                                Pipeline milepost
              Facility                       Parish                 location                 Description
----------------------------------------------------------------------------------------------------------------
                                               Pipeline Facilities
----------------------------------------------------------------------------------------------------------------
30-inch Pipeline Lateral...........  Jefferson.............  0.00-2.47.............  Install approximately 13.1
                                     Plaquemines...........  2.47-8.14.............   kilometers (8.14) miles of
                                                                                      new 30-inch- diameter
                                                                                      pipeline lateral.
----------------------------------------------------------------------------------------------------------------

[[Page 25239]]

 
                                             Aboveground Facilities
----------------------------------------------------------------------------------------------------------------
Centerville Compressor Station.....  St. Mary..............  66.50 \a\, 66.70 \b\,   Construct a new gas-fired
                                                              67.00 \c\.              compressor station with a
                                                                                      23,470 hp compressor unit,
                                                                                      which will interconnect
                                                                                      with Columbia Gulf's
                                                                                      existing EL-100, EL-200,
                                                                                      and EL-300 pipelines.
----------------------------------------------------------------------------------------------------------------
Golden Meadow Compressor Station...  Lafourche.............  149.50 \c\............  Construct a new gas-fired
                                                                                      compressor station with a
                                                                                      23,470 hp compressor unit,
                                                                                      which will interconnect
                                                                                      with Columbia Gulf's
                                                                                      existing EL-300 pipeline.
Point of Delivery Meter Station....  Plaquemines...........  8.14..................  Construct one POD meter
                                                                                      station at the terminus of
                                                                                      the new 30-inch pipeline
                                                                                      lateral on an existing
                                                                                      platform shared with
                                                                                      Venture Global Gator
                                                                                      Express, LLC. A 30-inch
                                                                                      pig receiver will also be
                                                                                      installed at the POD Meter
                                                                                      Station.
Tie-in Facility....................  Jefferson.............  0.00..................  Install a new TIF situated
                                                                                      on a new platform at the
                                                                                      intersection of the new 30-
                                                                                      inch pipeline and Columbia
                                                                                      Gulf's existing EL-300
                                                                                      pipeline. A 30-inch pig
                                                                                      launcher will also be
                                                                                      Installed at the TIF.
Valves and Other Ancillary           Jefferson.............  0.00, 1.71 \c\........  Install one new 30-inch
 Facilities.                                                                          mainline valve assembly on
                                                                                      the new 30-inch pipeline
                                                                                      lateral and one new 24-
                                                                                      inch mainline valve
                                                                                      assembly Columbia Gulf's
                                                                                      existing EL-300 pipeline.
                                                                                      Both mainline valve
                                                                                      assemblies will be
                                                                                      situated on the new TIF
                                                                                      platform.
----------------------------------------------------------------------------------------------------------------
\a\ Milepost is associated with Columbia Gulf's existing EL-100 pipeline.
\b\ Milepost is associated with Columbia Gulf's existing EL-200 pipeline.
\c\ Milepost is associated with Columbia Gulf's existing EL-300 pipeline.

    Construction of the Project will temporarily impact 2.79 acres, 
permanently alter 0.02 acres and include in-water activity that may 
result in take of marine mammals in Barataria Bay. Specifically, in 
order to provide fuel supply services to onshore LNG compressor 
stations, Columbia Gulf proposes pile driving to construct a new POD 
Meter Station on an existing platform and a new TIF at the terminus of 
a new 30-inch lateral pipeline. Project activities include 
installation, by impact hammer, of 20 18-inch concrete piles and 104 
36-inch spun cast piles. The new POD Meter Station will include the 
installation of three 16-inch meter runs and related facilities. The 
new POD Meter Station will be constructed at the site of an existing 
platform, and construction will require the installation of four new 
18-inch square concrete piles to protect a 30-inch- diameter riser. 
Pipelines will be installed by jetting and dredging with displaced 
sediment precipitating back to the substrate or being side-cast 
adjacent to the trench, respectively.
    The new TIF will be situated on a new 180 foot (ft; 55 meter (m)) 
long by 80 ft (24.3 m) wide platform supported by 104 36-inch-diameter 
spun cast and 4 18-inch-diameter concrete piles. Two 24-inch-diameter 
and one 30-inch-diameter risers will be protected by 12 8-inch diameter 
concrete piles. The TIF will include a boat landing measuring 10 ft (3 
m) long by 10 ft (3 m) wide that will be used for maintenance and 
servicing of the platform.

Dates and Duration

    Construction was planned to begin in January 2024 in order to meet 
a planned in-service date of April 2025. Pile driving within Barataria 
Bay will occur within a 3 month period within the 1-year effective 
dates of the IHA, from December 1, 2023, through November 30, 2024. 
Pile driving activity will be intermittent, conducted in accordance 
with project phasing requirements, and as such will not be continuous 
throughout the 3-month period. Pile driving activities will take place 
from 7 a.m. to 7 p.m. (adjusted as appropriate to conduct work during 
daylight hours), and may occur on any day of the week (five piles per 
day). In-water work is planned to occur on between 25 and 42 days. The 
pile specifications and method of installation are presented in table 
2, below.
    A detailed description of the Project is provided in the Federal 
Register notice for the proposed IHA (88 FR 61530, September 7, 2023). 
Since that time, no changes have been made to the pile driving 
activities described in the notice. Therefore, a detailed description 
is not provided here. Please refer to that Federal Register notice for 
the description of the specific activity.
BILLING CODE 3510-22-P

[[Page 25240]]

[GRAPHIC] [TIFF OMITTED] TN10AP24.009

BILLING CODE 3510-22-C

Figure 1--Map of Project Area and Features

[[Page 25241]]



                                                            Table 2--Pile Driving Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                     Number of                          Proxy pile for    Impact strikes                    Strikes per       Days of
            Location                   piles      Pile diameter/type     calculations        per pile      Piles per day        day        installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tie-in Facility.................             104  36'' Spun Cast      36'' Concrete                4,800               5          24,000              24
                                                   Concrete Piles.     (round, hollow)
Tie-in Facility.................              16  18'' Concrete                           ..............  ..............  ..............  ..............
                                                   (round).
Point of Delivery Platform......               4  18'' Concrete                           ..............  ..............  ..............               1
                                                   (square).
                                 -----------------------------------------------------------------------------------------------------------------------
    Total.......................             120  ..................  ..................  ..............  ..............  ..............              25
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Comments and Responses

    Notice of NMFS's proposal to issue an IHA to Columbia Gulf was 
published in the Federal Register on September 7, 2023 (88 FR 61530). 
That notice described, in detail, Columbia's activity, the marine 
mammal species that may be affected by the activity, and the 
anticipated effects on marine mammals. In that notice, we requested 
public input on the request for authorization described therein, our 
analyses, the proposed authorization, and any other aspect of the 
notice of proposed IHA, and requested that interested persons submit 
relevant information, suggestions, and comments.
    During the 30-day public comment period, NMFS received one comment 
letters from the Sierra Club. The Sierra Club expressed submitted a 
public comment expressing its concerns, providing recommendations, and 
attaching a March 2022 letter sent to NMFS' Southeast Regional Field 
Office on projects located further north in Barataria Bay. The Sierra 
Club also submitted a short cover letter transmitting more than 700 
signatures from individuals expressing general concern over the 
Columbia project's effect on the BBES stock of bottlenose dolphins and 
Barataria Bay as a whole. There were no other public comments 
submitted. A summary of the comments received from the Sierra Club and 
NMFS' response are provided below. The comments are available online 
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable. 
Please see the comment submissions at the link provided in order to 
access the complete set of comments and the accompanying rationale.
    Comment: In summary, the Sierra Club comments suggest that NMFS did 
not adequately consider the ongoing impacts to the Barataria Bay stock 
of bottlenose dolphins from the 2010 Deepwater Horizon (DWH) oil spill. 
Specifically, they asserted that, given the poor health of some of the 
individuals, some of the impacts we evaluated and predicted would be in 
the form of Level B harassment may actually manifest in the form of 
Level A harassment, and that a greater number of takes by Level B 
harassment may occur than are authorized or analyzed. They also suggest 
that NMFS should further consider the impact from this project in 
connection with impacts to the species from the numerous additional oil 
and gas infrastructure projects proposed in this area, and assess 
whether these projects will contribute to further impacts to this 
dolphin population.
    Response: This short duration, low impact construction project 
includes 25 to 42 non-consecutive days of in-water work spread out 
across a 3-month period. We expect lower-level acoustic exposures from 
a dolphin swimming through the comparatively small ensonified zone on a 
day or two. The Level B harassment zone is about 430 m and the Level A 
harassment zone is just under 50 m, and there is a mandatory 50-m 
monitored shutdown zone that is expected to avoid Level A harassment. 
As a result, we are authorizing 42 takes by Level B harassment of 
Barataria Bay bottlenose dolphins.
    NMFS' Federal Register notice of proposed IHA did consider the 
impact the DWH spill has had on the BBES stock. Even so, the agency 
made a preliminary negligible impact determination due to the nature of 
the specified activity as a whole and the estimated takes. While it may 
be true that the effects of exposure to the elevated sound levels of 
the pile driving might affect a dolphin in a more compromised condition 
(such as those that have been exposed to the DWH spill) in a slightly 
more severe way, the comments offer no information supporting the idea 
that Level A harassment (i.e., injury) could result, nor that there 
might be more Level B harassment than estimated.
    Given the small footprint of the activity, the small number of 
takes, and the very low likelihood that any individual dolphin will be 
taken on more than a few likely non-consecutive days, even given the 
potential more weakened state of any specific individual dolphin, there 
is no evidence that the activity will result in the Level A harassment 
of any individual, that the take by Level B harassment will be more 
numerous than authorized, or that the result of one animal incurring 
Level B harassment on 1 to a few days within 1 year from this activity 
will result in the scale of energetic impacts that could affect 
fitness, reproduction, or survival of any individual dolphins.
    Regarding the suggestion that NMFS consider the impacts of this 
project in conjunction with the impacts of numerous other oil and gas 
infrastructure projects in the area, section 101(a)(5)(D) of the MMPA 
specifies NMFS consider the impacts of the ``specified activity'' in 
making a negligible impact determination. The impacts of other 
activities are considered in the baseline of the analysis, as described 
in the notice for the proposed IHA. Specific to the two projects 
referenced in the Sierra Club letter, Venture Global's ``Gator 
Express'' and ``Plaquemines,'' construction on the latter project is 
not anticipated in the near future, and the Gator Express in-water work 
in Barataria Bay consists primarily of installation of small (12-in) 
piles, the impacts of which are be expected to be minor avoidance of a 
comparatively small impact area and not reasonably anticipated to 
change the baseline for Barataria Bay bottlenose dolphins. Further, 
while other projects that are not the subject of this IHA may have 
impacts on the Barataria Bay bottlenose dolphin population, the limited 
impacts authorized by this IHA will not significantly, incrementally 
increase the scale or severity of impacts, either alone or in 
combination, as determined in the analyses supporting NMFS' National 
Environmental Policy Act determination that a Categorical Exclusion is 
appropriate for this IHA.

[[Page 25242]]

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 BBES bottlenose dolphins. NMFS fully 
considered all of this information, including relevant citations which 
may be included here, and we refer the reader to these materials 
instead of reprinting the information. Additional information regarding 
population estimates and potential threats for BBES bottlenose 
dolphins, can be found in NMFS' Stock Assessment Reports (SARs) at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments and more information about this species 
in general (e.g., physical and behavioral descriptions) may be found on 
NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Take of BBES bottlenose dolphins may occur incidental to the 
specified activities described in the request for authorization. 
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 is provided in table 3. 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 authorized here, PBR and annual serious injury and 
mortality from anthropogenic sources are included here as gross 
indicators of the status of the species or stocks and other threats.

                                     Table 3--Marine Mammal Species Likely Impacted by the Specified Activities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        ESA/MMPA status;   Stock abundance  (CV,
             Common name                  Scientific name               Stock           Strategic (Y/N)      Nmin, most recent        PBR      Annual M/
                                                                                              \2\          abundance survey) \3\                SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin..............  Tursiops truncatus.....  Barataria Bay           -/-; Y             2,071 (0.06, 1,971,            18         160
                                                                Estuarine Stock.                           2019).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. 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, vessel 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.

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 
decibel (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]
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen         7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,      150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true          275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus cruciger &
 L. australis).
Phocid pinnipeds (PW) (underwater) (true     50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea     60 Hz to 39 kHz.
 lions 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).
    For more detail concerning these groups and associated frequency 
ranges,

[[Page 25243]]

please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from pile driving for Columbia 
Gulf's activities have the potential to result in behavioral harassment 
of marine mammals in the vicinity of the Project area. The notice of 
proposed IHA (88 FR 61530, September 7, 2023) included a discussion on 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from Columbia Gulf's construction 
activities on marine mammals and their habitat. That information and 
analysis is referenced in this final IHA determination and is not 
repeated here; please refer to the notice of proposed IHA (88 FR 61530, 
September 7, 2023).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which informed both NMFS' consideration of 
``small numbers'' and the negligible impact determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes are by Level B harassment only, in the form of 
disruption of behavioral patterns for individual marine mammals 
resulting from exposure to sound emanated from pile driving activity. 
Based on the nature of the activity and the anticipated effectiveness 
of the mitigation measures including the utilization of Protected 
Species Observers to monitor for marine mammals and implementation of 
pre-clearance and soft start protocols discussed in detail below in the 
Mitigation section, Level A harassment is neither anticipated nor 
authorized. Specifically, in-water construction activities will be 
completed in less than 3 months (a total of 25 to 42 days) and are not 
expected to result in serious injury or mortality to marine mammals 
within Barataria Bay. Based on calculated threshold distances for mid-
frequency cetaceans, an individual dolphin would need to remain within 
43 meters of the piles being driven through the entire day of pile 
driving activity in order for injury from cumulative exposure to occur. 
Given the mobility of bottlenose dolphins and the expected avoidance 
behavior of the species when encountering noise disturbance (i.e., pile 
driving), such a scenario is extremely unlikely to occur.
    The method for calculating take by Level B Harassment was described 
in the Federal Register notice announcing the proposed IHA and remains 
unchanged. Accordingly, the amount of authorized take is also the same 
as that presented in the proposed IHA.
    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 for 
example, permanent threshold shift (or PTS); (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 authorized 
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 (referenced 
to 1 microPascal (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 
estimates based on these behavioral harassment thresholds are expected 
to include any likely takes by Temporary Threshold Shift (TTS) as, in 
most cases, the likelihood of TTS occurs at distances from the source 
less 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 that would not otherwise occur. Columbia 
Gulf's Request for Authorization includes actions known to generate 
impulsive sound (impact pile driving) that may cause incidental 
harassment, and therefore the RMS SPL threshold of 160 re 1 [mu]Pa is 
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). The 
specified activity planned by Columbia Gulf includes the use of an 
impulsive source type and is planned to occur in an area where BBES 
bottlenose dolphins, a mid-frequency cetacean, are found.
    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, available at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

[[Page 25244]]



                     Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                         PTS onset thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lp,0-pk,flat: 219   Cell 2: LE,p,LF,24h: 199 dB.
                                          dB; LE,p,LF,24h: 183 dB
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lp,0-pk,flat: 230   Cell 4: LE,p,MF,24h: 198 dB.
                                          dB; LE,p,MF,24h: 185 dB
High-Frequency (HF) Cetaceans..........  Cell 5: Lp,0-pk,flat: 202   Cell 6: LE,p,HF,24h: 173 dB.
                                          dB; LE,p,HF,24h: 155 dB
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lp,0-pk.flat: 218   Cell 8: LE,p,PW,24h: 201 dB.
                                          dB; LE,p,PW,24h: 185 dB
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lp,0-pk,flat: 232   Cell 10: LE,p,OW,24h: 219 dB.
                                          dB; LE,p,OW,24h: 203 dB
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
  exposure level (LE,p) has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
  is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
  hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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 weighted
  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 thresholds will be exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area that may be ensonified to 
levels above the acoustic thresholds, including source levels and 
transmission loss coefficient.
    To calculate the ensonified area, Columbia Gulf used the NMFS User 
Spreadsheet and accompanying 2018 guidance. Columbia Gulf located data 
for impact installation of a 36 inch concrete pile (MacGillivray et 
al., 2007), measured at 50 meters, to serve as a suitable proxy source 
level for the 104 36-inch spun-cast piles selected for the project (see 
table 6). The applicant then elected to apply the source levels for the 
36-in proxy pile to all piles being driven, including the 20 18-inch 
piles, likely resulting in an overestimate of resulting noise from 
these smaller piles.
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry and bottom composition and 
topography. The general formula for underwater TL is:

TL = B * Log10 (R1/R2), where:
TL = Transmission loss in dB,
B = Transmission loss coefficient,
R1 = the distance of the modeled SPL from the driving pile, and
R2 = the distance from the driven pile of the initial measurement.

    Absent site-specific acoustic monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient. Site-specific transmission loss data for 
the project area in Barataria Bay is not available; therefore, the 
default coefficient of 15 is used to determine the distances to the 
Level A harassment and Level B harassment thresholds. 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 and accompanying 
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 the optional 
tool, we anticipate that the resulting isopleth estimates are typically 
overestimates of some degree, which may result in an overestimate of 
potential 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 pile driving, the 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. Inputs used in the 
option User Spreadsheet tool, and the resulting estimated isopleths, 
are reported in tables 6 and 7, below. The applicant applied a 15LogR 
propagation loss rate in the User Spreadsheet, and included a 5 dB 
attenuation factor for use of a bubble curtain which is consistent with 
NMFS recommendations.

                                       Table 6--Proxy Pile Characteristics
                                            [User spreadsheet input]
----------------------------------------------------------------------------------------------------------------
                                                       SLs                      Measured
             Pile type             ------------------------------------------   distance           Source
                                       dB Peak       dB rms        dB SEL          (m)
----------------------------------------------------------------------------------------------------------------
36'' concrete pile, Impact pile             186           174           160            50   MacGillivray et al.,
 driven (5 dB attenuated).                                                                   2007.
----------------------------------------------------------------------------------------------------------------

    To calculate the harassment zones, Columbia Gulf identified a 
representative location in the center of the TIF and second 
representative location in the center of the POD Meter Station and used 
these locations to calculate the harassment zones for each site. Given 
the close proximity of individual piles to one another, NMFS concurred 
with this approach. Columbia Gulf then accessed the User Spreadsheet to 
calculate the distance from each of the two representative pile driving 
locations to the furthest extent of Level A and Level B thresholds for 
mid-

[[Page 25245]]

frequency cetaceans. In order to ensure conservative results, the 
source level data for 36 inch piles was used as a proxy for all pile 
driving activities, including installation of smaller diameter piles.

     Table 7--Harassment Zone Isopleths Attributable to Pile Driving
------------------------------------------------------------------------
                                    Distance from representative sound
                                                  source
                                 ---------------------------------------
                                                          Behavioral
            Activity                 PTS: Level A     disturbance: Level
                                    harassment zone    B harassment zone
                                    (mid-frequency        (all marine
                                      cetaceans)           mammals)
------------------------------------------------------------------------
Impact pile driving in Barataria  43.2 m............  428.9 m.
 Bay \a\.
------------------------------------------------------------------------
\a\ User Spreadsheet output based on installation by impact hammer of
  (proxy) 36-inch-diameter concrete piles, and use of bubble curtains
  (estimated 5 dB reduction, per consultations with NMFS) (MacGillivray
  et al., 2007).

    Based on the User Spreadsheet outputs reflected in table 7, the 
Level B harassment zone would have a radius of approximately 428.9 m 
(m; 1,407.0 ft) from the source pile, or an approximate area of 0.58 
square kilometers (km\2\). The Level A zone would have a calculated 
radius of approximately 43.2 m (142.0 ft), or an approximate area of 
0.006 km\2\ (63,347 square feet (ft\2\)). Columbia Gulf plans to 
implement a 50 m shutdown zone that extends coverage beyond the 43.2 m 
Level A harassment zone indicated by the User Spreadsheet. As a result, 
given that detection of bottlenose dolphins within this distance is 
expected to be successful, no Level A take is anticipated to occur, or 
is authorized, as a result of project activities.

Marine Mammal Occurrence

    In order to estimate the distribution and density of BBES dolphins 
that may occur in the area affected by the specified activity, we 
turned to prior area-specific surveys and studies conducted in the Bay.
    Density estimates for Columbia Gulf's proposal reference the 
findings of the 2017 McDonald (et al.) study and an average of the 
calculated densities for each habitat region defined within the study 
area. Density estimates for bottlenose dolphins within Barataria Bay 
were derived from estimates calculated through vessel-based capture-
mark-recapture photo-ID surveys conducted during ten survey sessions 
from June 2010 to May 2014 (McDonald et al., 2017). Because the surveys 
were conducted during the DWH oil spill, the resulting density estimate 
does not account for mortality following the spill.
    The study was conducted from June 2010 to May 2014 and utilized 
vessel-based capture-mark-recapture photo ID surveys. The study area 
for these surveys included Barataria Bay and Pass, Bayou Rigaud, 
Caminada Bay and Pass, Barataria Waterway, and Bay des Ilettes. 
Densities varied in different areas within broader Barataria Bay, and 
the study area was divided into three (East, West, and Island) habitat 
regions to capture these observed density variations. Results were 
parsed and densities were calculated for each habitat region. Project 
activities may have some effect on both the East and West habitat 
regions, with estimated densities of 0.601 individuals per km\2\ and 
1.24 individuals per km\2\, respectively. Study results indicate 
density of 11.4 individuals per km\2\ for the Island region. Given 
uncertainties regarding fidelity to and transiting among habitat 
regions, the average densities for each habitat region in the study 
area are then averaged together to create an estimated density for the 
project area. NMFS concurs with this approach. Inclusion of the higher 
estimated density from the Island habitat region results in a 
cumulative average higher than the estimated density for the East and 
West habitat regions alone, and reflects a conservative approach. Based 
on this calculation and using the best available information for 
estimating density given the project type and location, the average 
bottlenose dolphin density for the project is estimated to be 2.83 
individuals per km\2\.

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 authorized).

                                Table 8--Level B Harassment Takes Requested and Percentage of Stock Potentially Affected
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                          Percentage (%)
                                                                                                           Level B takes       Stock         of stock
       Pile driving location                Species           Estimated density      Level B harassment      requested       abundance      potentially
                                                                                            area           (individuals)   (individuals)    affected by
                                                                                                                                           level B take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tie-In Facility....................  Bottlenose Dolphin...  2.83 individuals per   0.58 km\2\...........              40           2,071            1.93
POD Meter Station..................                          km\2\.                                                    2                            0.10
                                                                                                         -----------------------------------------------
    Project Totals.................  .....................  .....................  .....................              42  ..............            2.03
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Level B harassment take estimates for pile driving activities were 
calculated using the density estimate described above, averaging across 
the three areas in Barataria Bay. The Level B harassment zone is 
calculated using source level data for 36-inch concrete piles 
(including use of bubble curtains) and assumes an even distribution of 
animals throughout the affected area. Initial Level B take estimates 
for TIF and POD Meter Station pile driving activity were calculated 
using the area of the Level B harassment zone (0.58 km \2\) multiplied 
by the calculated density (2.83 individuals per km \2\). This results 
in a daily take estimate of 1.64 individuals for pile driving at the 
TIF and the POD Meter Station. The daily Level B harassment estimate 
(1.64 individuals) was then multiplied by the number of days when pile 
driving will take place (24 days at the TIF and 1 day at the POD Meter 
Station) to calculate the number of requested takes for pile driving 
related to the Project. The estimated takes are indicated in table 8.
    Level A harassment is not anticipated to occur and authorization 
was not requested. In-water construction

[[Page 25246]]

activities will be completed within 1-2 months (a total of 25 to 42 
days) and are not expected to result in serious injury or mortality to 
marine mammals within Barataria Bay. Based on calculated threshold 
distances in Table 7 for mid-frequency cetaceans, an individual would 
need to remain within 142.0 ft of the piles being driven throughout the 
entire day of pile driving activities for cumulative exposure injury to 
occur. Given the mobility of bottlenose dolphins and the expected 
behavior of the species to avoid noise disturbance (i.e., pile 
driving), such a scenario is extremely unlikely to occur.

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 for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting 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. 
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.

Mitigation for Marine Mammals and Their Habitat

    As described below, Columbia Gulf will retain and deploy qualified 
Protected Species Observers to implement a clearance zone to ensure 
that BBES bottlenose dolphins are not present within 430 meters of the 
pile being driven when pile driving activities begin, and also a 50-
meter shutdown zone to ensure that dolphins and other marine mammals 
are not exposed to levels of construction noise associated with Level A 
harassment. A bubble curtain will be used to lower the overall levels 
of sound produced by the pile driving, and soft-start measures will 
allow for even lower sound levels when pile driving starts, allowing 
time for marine mammals to move away from the source before it gets 
louder. Columbia Gulf must implement the following mitigation measures:
    (a) The Holder must employ Protected Species Observers (PSOs) and 
establish monitoring locations as described in section 5 of this IHA. 
The Holder must monitor the Project area to the maximum extent possible 
based on the required number of PSOs, required monitoring locations, 
and environmental conditions.
    (b) Monitoring must commence 30 minutes prior to initiation of pile 
driving activity. (i.e., pre-start clearance monitoring) and be 
continuously maintained until 30 minutes post-completion of pile 
driving activity.
    (c) Pile driving may only begin if visibility is sufficient to 
allow monitoring of the entire pre-clearance zone (430 m) and the lead 
PSO determines that it has been clear of marine mammals for 30 
consecutive minutes.
    (d) If a marine mammal is observed entering or within the shutdown 
zone (50 m), pile driving activity must be suspended. Pile driving may 
only commence or resume as described in condition 4(e) of this IHA.
    (e) If pile driving is delayed due to the presence of a marine 
mammal in the pre-start clearance zone or the shutdown zone, the 
activity may not commence or resume until either the animal has 
voluntarily exited and been visually confirmed beyond the applicable 
protective zone, or after 15 minutes have passed without re-detection 
of the animal.
    (f) The Holder must employ soft-start procedures at the start of 
each day's pile driving activity, and at any time following cessation 
of impact pile driving that lasts for 30 minutes or longer. Soft-starts 
require an initial set of three strikes at reduced energy, followed by 
a 30-second waiting period, then two subsequent reduced-energy strike 
sets.
    (g) The Holder must use a bubble curtain during impact pile 
driving. The bubble curtain must be operated in a manner most likely to 
achieve optimal sound dampening performance. At a minimum, the Holder 
must adhere to the following performance standards:
    (i) The bubble curtain must distribute air bubbles around 100 
percent of the piling circumference for the full depth of the water 
column.
    (ii) The lowest bubble ring must be in contact with the substrate 
for the full circumference of the ring, and weights attached to the 
bottom ring shall ensure 100 percent substrate contact. No parts of the 
ring or other objects shall prevent full substrate contact.
    (iii) Air flow to the bubblers must be balanced around the 
circumference of the pile.
    (h) Pile driving activity must be halted (as described in condition 
4(d) of this IHA) upon observation, at any distance, of either a 
species for which incidental take is not authorized or a species for 
which incidental take has been authorized but the authorized number of 
takes has been met (as shown in table 1 of the IHA).
    (i) The Holder, construction supervisors and crews, PSOs, and other 
personnel must avoid direct physical interaction with marine mammals 
during construction. If a marine mammal comes within 10 meters of 
construction activity, operations must cease and vessels must reduce 
speed to the minimum level required to maintain steerage and safe 
working conditions, and take other actions as may be necessary to avoid 
direct physical interaction with the animal.
    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the planned mitigation measures provide the means 
of effecting the least practicable impact to BBES bottlenose dolphins 
and their habitat.

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

[[Page 25247]]

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:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     Mitigation and monitoring effectiveness.

Monitoring

    The following monitoring will be required during pile installation 
activities associated with the East Later XPRESS Project:
    (a) The Holder must establish at least one monitoring location that 
provides optimal visibility of the pre-clearance and shutdown zone for 
each location where pile driving will occur. For all pile driving 
activities, a minimum of one PSO must be assigned to each active pile 
driving location to log all marine mammal sightings and to monitor the 
shutdown zone.
    (b) PSOs must record all observations of marine mammals, regardless 
of distance from the pile being driven, as well as the additional data 
indicated in section 6 of this IHA.
    (c) Monitoring must be conducted by qualified, NMFS-approved PSOs, 
in accordance with the following conditions:
    (i) PSOs must be independent of the contractor conducting the 
specified pile driving activity (for example, employed by a 
subcontractor) and have no other assigned tasks during monitoring 
periods.
    (ii) At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization.
    (iii) Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field), or training 
for prior experience performing the duties of a PSO during construction 
activity pursuant to a NMFS-issued incidental take authorization.
    (iv) If a team of three or more PSOs is needed in order to meet 
monitoring requirements, a lead observer or monitoring coordinator must 
be designated. The lead observer must have prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization.
    (v) PSOs must be approved by NMFS prior to beginning any activity 
subject to this IHA.

Reporting

    Columbia Gulf is required to implement the following reporting 
measures:
    (a) Columbia Gulf must submit its draft marine mammal monitoring 
report for the Project describing all monitoring activities conducted 
under this IHA within 90 calendar days of the completion of monitoring, 
or 60 calendar days prior to the requested issuance of any subsequent 
IHA for construction activity at the same location, whichever comes 
first. A final report must be prepared and submitted within 30 calendar 
days following receipt of any NMFS comments on the draft report. If no 
comments are provided by NMFS within 30 calendar days of receipt of the 
draft report, the report shall be considered final.
    (b) All draft and final monitoring reports must be submitted to 
both [email protected] and [email protected].
    (c) The marine mammal monitoring report must contain the 
informational elements described in the Request for Authorization, and 
must include:
    (i) Dates and times (begin and end) of all marine mammal monitoring 
shifts;
    (ii) Construction activities occurring during each daily 
observation period, including:
    A. The number and type of piles that were driven and the method 
(e.g., impact, vibratory, down-the-hole);
    B. The number of strikes required to install each pile, or the 
duration that any vibratory equipment is in use.
    (iii) PSO locations during marine mammal monitoring;
    (iv) Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
    (v) Summary of all observations of marine mammals, including:
    A. Name and location of PSO who sighted the animal(s), bearing to 
the sighted animal, means of detection and potentially relevant human 
activity in the area (including construction 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 pile being driven at the time of 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 pre-start clearance and/or shutdown zone;
    H. Description of any marine mammal behavioral observations (e.g., 
observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses that may be attributable to 
construction activity (e.g., no response or changes in behavioral state 
such as ceasing feeding, changing direction, flushing, or breaching);
    I. Observations of skin and body condition, including atypical skin 
or body condition (if any) and potentially identifying marks or other 
novel physical characteristics.
    (vi) Number of marine mammals detected within the harassment zones, 
by species;
    (vii) 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; and
    (viii) An assessment of implementation and effectiveness of 
prescribed mitigation and monitoring measures.

[[Page 25248]]

    (d) The Holder must submit all PSO datasheets and/or raw sighting 
data with the draft report.
    (e) Reporting injured or dead marine mammals.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Holder must report the 
incident to the Office of Protected Resources (OPR), NMFS 
([email protected] and [email protected]) and to 
the Southeast Region marine mammal stranding network (1-877-433-8299) 
as soon as is feasible. If the death or injury was clearly caused by 
the specified activity, the Holder must immediately cease the activity 
until NMFS OPR reviews the circumstances of the incident determines 
what, if any, additional measures are appropriate to ensure compliance 
with the terms of this IHA and notifies the holder of these findings 
and any additional requirements that must be met prior to re-initiation 
of the activity.
    The report of an injured or dead marine mammal 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 preamble for NMFS' implementing regulations published in the 
Federal Register (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).
    The BBES stock of bottlenose dolphins is considered a strategic 
stock because mortality attributable to human activity is thought to 
exceed PBR. However, potential effects of this project on BBES dolphins 
are limited to Level B harassment in the form of temporary avoidance of 
the construction area. As described above, no Level A harassment is 
expected or authorized. This short duration, low impact construction 
project includes 25 to 42 non-consecutive days of in-water work spread 
out across a 3-month period. We expect lower-level acoustic exposures 
from a dolphin swimming through the comparatively small ensonified zone 
on a day or two. The Level B harassment zone is about 430 m and the 
Level A harassment zone is just under 50 m, and the mandatory 50-m 
monitored shutdown zone is expected to avoid Level A harassment. Given 
the nature of the harassment, its temporary nature and planned 
mitigation, NMFS does not expect the take to affect the reproduction or 
survival of any individuals.
    The BBES stock of bottlenose dolphins is also considered a small 
and resident population, and the Project site is within an identified 
Biologically Important Area (BIA) for Small and Resident Populations 
(Lebreque et al., 2015). The BBES stock is present within the area 
year-round. However, the project area overlaps only a small portion of 
available habitat and the BIA, and adjacent areas of open water within 
the embayment will remain accessible to BBES dolphins throughout the 
construction process. In summary and as described above, the following 
factors primarily support our determination that the impacts resulting 
from this activity are not expected to adversely affect BBES bottlenose 
dolphins by reducing annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized; and no impacts to reproductive success or survival of any 
individual animals are expected.
     The required mitigation measures are expected to avoid any 
Level A harassment and to reduce the number and severity of takes by 
Level B harassment.
     Behavioral impacts and displacement that may occur in 
response to pile driving are expected to be limited in duration to 25 
to 42 days concurrent with the pile-driving activity.
     The pile driving activities do not impact any known 
important habitat areas such as calving grounds or unique feeding 
areas, and alternate habitat is readily available.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the planned monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the planned pile driving activity will have a negligible impact on BBES 
bottlenose dolphins.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock to determine whether an authorization is limited to small numbers 
of marine mammals. When the predicted number of individuals to be taken 
is fewer than one-third of the species or stock abundance, the take is 
considered to be of small numbers. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    Based on a conservative estimate of the number of takes that may 
occur as a result of Columbia's pile driving activities, less than two 
percent of the BBES population will be subject to take via Level B 
harassment. This is less than the one-third of the stock abundance and 
meets the criteria for small numbers described above.
    Based on the analysis contained herein of the planned activity 
(including the planned mitigation and monitoring measures) and the 
anticipated take of

[[Page 25249]]

marine mammals, NMFS finds that small numbers of marine mammals will be 
taken relative to the population size of the affected species or 
stocks.

Unmitigable Adverse Impact Analysis and Determination

    No subsistence uses of BBES bottlenose dolphins are known to occur. 
Therefore, NMFS has determined that the total taking of affected 
species or stocks will not have an unmitigable adverse impact on the 
availability of such species or stocks for taking for subsistence 
purposes.

Endangered Species Act

    Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.) 
requires that each Federal agency insure that any action it authorizes, 
funds, or carries out is not likely to jeopardize the continued 
existence of any endangered or threatened species or result in the 
destruction or adverse modification of designated critical habitat. To 
ensure ESA compliance for the issuance of IHAs, NMFS consults 
internally whenever we propose to authorize take for endangered or 
threatened species.
    No incidental take of ESA-listed species is authorized for this 
activity. Therefore, NMFS has determined that formal consultation under 
section 7 of the ESA is not required for this action.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NAO 216-6A, which do not 
individually or cumulatively have the potential for significant impacts 
on the quality of the human environment and for which we have not 
identified any extraordinary circumstances that would preclude this 
categorical exclusion. Accordingly, NMFS determined that the issuance 
of the IHA qualified to be categorically excluded from further NEPA 
review.

Authorization

    NMFS has issued an IHA to Columbia Gulf, LLC for the potential 
harassment of small numbers of marine mammal species incidental to the 
East Lateral XPRESS project in Barataria Bay, Louisiana, that includes 
the previously explained mitigation, monitoring, and reporting 
requirements.

    Dated: April 4, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2024-07565 Filed 4-9-24; 8:45 am]
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