Proposed Rule2023-08924
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Coastal Virginia Offshore Wind Commercial Project Offshore of Virginia
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
May 4, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the Virginia Electric and Power Company, doing business as Dominion Energy Virginia (Dominion Energy), for Incidental Take Regulations (ITR) and an associated Letter of Authorization (LOA) pursuant to the Marine Mammal Protection Act (MMPA). The requested regulations would govern the authorization of take, by Level A harassment and Level B harassment, of small numbers of marine mammals over the course of 5 years (2024-2029) incidental to construction of the Coastal Virginia Offshore Wind Commercial (CVOW-C) project offshore of Virginia within the Bureau of Ocean Energy Management (BOEM) Commercial Lease of Submerged Lands for Renewable Energy Development on the Outer Continental Shelf (OCS) Lease Area OCS- A 0483 (Lease Area) and associated Export Cable Routes. Project activities likely to result in incidental take include pile driving activities (impact and vibratory) and site assessment surveys using high-resolution geophysical (HRG) equipment. NMFS requests comments on its proposed rule. NMFS will consider public comments prior to making any final decision on the promulgation of the requested ITR and issuance of the LOA; agency responses to public comments will be summarized in the final notice of our decision. The proposed regulations, if promulgated, would be effective February 5, 2024, through February 4, 2029.
Full Text
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[Federal Register Volume 88, Number 86 (Thursday, May 4, 2023)]
[Proposed Rules]
[Pages 28656-28777]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-08924]
[[Page 28655]]
Vol. 88
Thursday,
No. 86
May 4, 2023
Part II
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 217
Takes of Marine Mammals Incidental to Specified Activities; Taking
Marine Mammals Incidental to the Coastal Virginia Offshore Wind
Commercial Project Offshore of Virginia; Proposed Rule
Federal Register / Vol. 88 , No. 86 / Thursday, May 4, 2023 /
Proposed Rules
[[Page 28656]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 230424-0110]
RIN 0648-BL74
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Coastal Virginia Offshore Wind
Commercial Project Offshore of Virginia
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; proposed letter of authorization; request for
comments.
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SUMMARY: NMFS has received a request from the Virginia Electric and
Power Company, doing business as Dominion Energy Virginia (Dominion
Energy), for Incidental Take Regulations (ITR) and an associated Letter
of Authorization (LOA) pursuant to the Marine Mammal Protection Act
(MMPA). The requested regulations would govern the authorization of
take, by Level A harassment and Level B harassment, of small numbers of
marine mammals over the course of 5 years (2024-2029) incidental to
construction of the Coastal Virginia Offshore Wind Commercial (CVOW-C)
project offshore of Virginia within the Bureau of Ocean Energy
Management (BOEM) Commercial Lease of Submerged Lands for Renewable
Energy Development on the Outer Continental Shelf (OCS) Lease Area OCS-
A 0483 (Lease Area) and associated Export Cable Routes. Project
activities likely to result in incidental take include pile driving
activities (impact and vibratory) and site assessment surveys using
high-resolution geophysical (HRG) equipment. NMFS requests comments on
its proposed rule. NMFS will consider public comments prior to making
any final decision on the promulgation of the requested ITR and
issuance of the LOA; agency responses to public comments will be
summarized in the final notice of our decision. The proposed
regulations, if promulgated, would be effective February 5, 2024,
through February 4, 2029.
DATES: Comments and information must be received no later than June 5,
2023.
ADDRESSES: Submit all electronic public comments via the Federal e-
Rulemaking Portal. Go to <a href="http://www.regulations.gov">www.regulations.gov</a> and enter NOAA-NMFS-2023-
0030 in the Search box. Click on the ``Comment'' icon, complete the
required fields, and enter or attach your comments.
Instructions: Comments sent by any other method, to any other
address or individual, or received after the end of the comment period,
may not be considered by NMFS. All comments received are a part of the
public record and will generally be posted for public viewing on
<a href="http://www.regulations.gov">www.regulations.gov</a> without change. All personal identifying
information (e.g., name, address), confidential business information,
or otherwise sensitive information submitted voluntarily by the sender
will be publicly accessible. NMFS will accept anonymous comments (enter
``N/A'' in the required fields if you wish to remain anonymous).
FOR FURTHER INFORMATION CONTACT: Kelsey Potlock, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of Dominion Energy's Incidental Take Authorization (ITA)
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-other-energy-activities-renewable">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable</a>. In case of
problems accessing these documents, please call the contact listed
above (see FOR FURTHER INFORMATION CONTACT).
Purpose and Need for Regulatory Action
This proposed rule, if promulgated, would provide a framework under
the authority of the MMPA (16 U.S.C. 1361 et seq.) to allow for the
authorization of take of marine mammals incidental to construction of
the CVOW-C project within the Lease Area and along export cable
corridors to landfall locations in Virginia. NMFS received a request
from Dominion Energy for 5-year regulations and a LOA that would
authorize take of individuals of 21 species of marine mammals (seven
species by Level A harassment and Level B harassment and 21 species by
Level B harassment only), comprising 22 stocks, incidental to Dominion
Energy's construction activities. No mortality or serious injury is
anticipated or proposed for authorization. Please see below for
definitions of harassment. Please see the Legal Authority for the
Proposed Action section below for definitions of harassment, serious
injury, and incidental take.
Legal Authority for the Proposed Action
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, regulations are
promulgated (when applicable), and public notice and an opportunity for
public comment are provided.
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, the availability of the species or stocks for taking for
certain subsistence uses (referred to as ``mitigation''), and
requirements pertaining to the mitigation, monitoring and reporting of
the takings are set forth.
As noted above, no serious injury or mortality is anticipated or
proposed for authorization in this proposed rule. Relevant definitions
of MMPA statutory and regulatory terms are included below:
<bullet> Take--to harass, hunt, capture, or kill, or attempt to
harass, hunt, capture, or kill any marine mammal (16 U.S.C. 1362, 50
CFR 216.3);
<bullet> Incidental taking--an accidental taking. This does not
mean that the taking is unexpected, but rather it includes those
takings that are infrequent, unavoidable or accidental (see 50 CFR
216.103);
<bullet> Serious Injury--any injury that will likely result in
mortality (50 CFR 216.3);
<bullet> Level A harassment--any act of pursuit, torment, or
annoyance which has the potential to injure a marine mammal or marine
mammal stock in the wild (16 U.S.C. 1362); and
<bullet> Level B harassment--any act of pursuit, torment, or
annoyance which 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 (16 U.S.C. 1362).
[[Page 28657]]
Section 101(a)(5)(A) of the MMPA and the implementing regulations
at 50 CFR part 216, subpart I, provide the legal basis for proposing
and, if appropriate, issuing 5-year regulations and associated LOA.
This proposed rule also establishes required mitigation, monitoring,
and reporting requirements for Dominion Energy's proposed activities.
Summary of Major Provisions Within the Proposed Rule
The major provisions of this proposed rule include:
<bullet> Authorize take of marine mammals by Level A harassment
and/or Level B harassment. No mortality or serious injury of any marine
mammal is proposed to be authorized;
<bullet> Establish a seasonal moratorium on pile driving during the
months of highest North Atlantic right whale (Eubalaena glacialis)
presence in the project area (November 1st-April 30th);
<bullet> Require both visual and passive acoustic monitoring by
trained, NOAA Fisheries-approved Protected Species Observers (PSOs) and
Passive Acoustic Monitoring (PAM) operators before, during, and after
the in-water construction activities;
<bullet> Require training for all Dominion Energy personnel that
would clearly articulate all relevant responsibilities, communication
procedures, marine mammal monitoring and mitigation protocols,
reporting protocols, safety, operational procedures, and requirements
of the ITA and ensure that all requirements are clearly understood by
all participating parties;
<bullet> Require the use of sound attenuation device(s) during all
vibratory and impact pile driving of wind turbine generators (WTG) and
offshore substations (OSS) foundation piles to reduce noise levels;
<bullet> Delay the start of pile driving if a North Atlantic right
whale is observed at any distance by the PSO on the pile driving or
dedicated PSO vessel;
<bullet> Delay the start of pile driving if other marine mammals
are observed entering or within their respective clearance zones;
<bullet> Shut down pile driving (if feasible) if a North Atlantic
right whale is observed or if other marine mammals enter their
respective shut down zones;
<bullet> Conduct sound field verification monitoring during a
minimum of three WTGs and all three OSS foundation installation events
to measure in situ noise levels for comparison against the model
results;
<bullet> Implement soft starts during impact pile driving and using
the least hammer energy possible;
<bullet> Implement ramp-up for high-resolution geophysical (HRG)
site characterization survey equipment prior to operating at full
power;
<bullet> Implement various vessel strike avoidance measures;
<bullet> Increase awareness of North Atlantic right whale presence
through monitoring of the appropriate networks and VHF Channel 16, as
well as reporting any sightings to the sighting network;
<bullet> Implement Best Management Practices (BMPs) during
fisheries monitoring research surveys and activities to reduce the risk
of marine mammals being considered at-risk or of interacting with
deployed gear; and
<bullet> Require frequent scheduled and situational reporting
including, but not limited to, information regarding activities
occurring, marine mammal observations and acoustic detections, and
sound field verification monitoring results.
National Environmental Policy Act (NEPA)
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 evaluate the proposed action (i.e., promulgation of
regulations and subsequent issuance of a 5-year LOA) and alternatives
with respect to potential impacts on the human environment.
Accordingly, NMFS proposes to adopt the BOEM Environmental Impact
Statement (EIS), provided our independent evaluation of the document
finds that it includes adequate information analyzing the effects of
promulgating the proposed regulations and LOA issuance on the human
environment. NMFS is a cooperating agency on BOEM's EIS. BOEM's CVOW-C
Draft Environmental Impact Statement for Commercial Wind Lease OCS-A
0483 (DEIS), was made available for public comment through a Notice of
Availability on December 16, 2022 (87 FR 77135), available at <a href="https://www.boem.gov/renewable-energy/state-activities/CVOW-C">https://www.boem.gov/renewable-energy/state-activities/CVOW-C</a>. The DEIS had a
60-day public comment period; the comment period was open from December
16, 2022 to February 14, 2023. Additionally, BOEM held three virtual
public hearings on January 25, 2023, January 31, 2023, and February 2,
2023.
Information contained within Dominion Energy's ITA application and
this proposed rule collectively provide the environmental information
related to these proposed regulations and associated 5-year LOA for
public review and comment. NMFS will review all comments submitted in
response to this proposed rule prior to concluding our NEPA process or
making a final decision on the requested 5-year ITR and associated LOA.
Fixing America's Surface Transportation Act (FAST-41)
This project is covered under Title 41 of the Fixing America's
Surface Transportation Act, or ``FAST-41.'' FAST-41 includes a suite of
provisions designed to expedite the environmental review for covered
infrastructure projects, including enhanced interagency coordination as
well as milestone tracking on the public-facing Permitting Dashboard.
FAST-41 also places a 2-year limitations period on any judicial claim
that challenges the validity of a Federal agency decision to issue or
deny an authorization for a FAST-41 covered project (42 U.S.C. 4370m-
6(a)(1)(A)).
Dominion Energy's proposed project is listed on the Permitting
Dashboard. Milestones and schedules related to the environmental review
and permitting for the CVOW-C project can be found at <a href="https://www.permits.performance.gov/permitting-project/coastal-virginia-offshore-wind-commercial-project">https://www.permits.performance.gov/permitting-project/coastal-virginia-offshore-wind-commercial-project</a>.
Summary of Request
On February 16, 2022, NMFS received a request from Dominion Energy
for the promulgation of a 5-year ITR and issuance of an associated LOA
to take marine mammals incidental to construction activities associated
with the CVOW-C project offshore of Virginia in the Lease Area and
associated export cable routes. Dominion Energy's request is for the
incidental, but not intentional, take of a small number of 21 marine
mammal species (comprising 22 total stocks) by Level B harassment and
by Level A harassment for seven marine mammal species, comprising 7
stocks. Neither Dominion Energy nor NMFS expects serious injury or
mortality to result from the specified activities, and Dominion Energy
did not request and NMFS is not proposing to authorize mortality or
serious injury of any marine mammals species or stock.
In response to our comments and following extensive information
exchanges with NMFS, Dominion Energy submitted a final, revised
application on August 5, 2022, that NMFS deemed adequate and complete
on August 12, 2022. The final version of the application is available
on NMFS' website at https://www.fisheries.noaa.gov/action/incidental-
take-authorization-dominion-
[[Page 28658]]
energy-virginia-construction-coastal-virginia.
On September 15, 2022, NMFS published a notice of receipt (NOR) of
the adequate and complete application in the Federal Register (87 FR
56634), requesting comments and soliciting information related to
Dominion Energy's request during a 30-day public comment period. During
the NOR public comment period, NMFS received one public comment letter
from another Federal agency (the United States Geological Survey
(USGS)) and one public comment letter from an environmental non-
government organization (the Southern Environmental Law Center). NMFS
has reviewed all submitted material and has taken these into
consideration during the drafting of this proposed rule.
In June 2022, Duke University's Marine Spatial Ecology Laboratory
released updated habitat-based marine mammal density models (Roberts et
al., 2016; Robert and Halpin, 2022). Because Dominion Energy applied
marine mammal densities to their analysis in their application,
Dominion Energy submitted a final Updated Density and Take Estimation
Memo (herein referred to as Updated Density and Take Estimation Memo)
on January 10, 2023 that included marine mammal densities and take
estimates based on these new models which NMFS posted on our website in
May 2023.
In January 2023, BOEM informed NMFS that the proposed activity had
changed from what is presented in the adequate and complete MMPA
application. Specifically, the changed proposed activity involved the
reduction of maximum WTGs built (from 205 to 202 WTGs) as under the
original Project Design Envelope (PDE) and the OSSs would be located in
the vessel transit routes. Under the 202 build-out, three WTGs would be
removed and the three OSSs would be shifted into these WTG positions.
However, in late-January 2023, Dominion Energy confirmed that their
Preferred Layout of 176 WTGs is the base case for construction, but
that they could possibly need up to 7 WTGs re-piled in alternate
positions due to unstable sediment conditions, which could necessitate
up to 183 independent piling events. WTG positions have been removed
from consideration for one or more of the following reasons:
impracticable due to foundation technical design risk, shallow gas
presence, commercial shipping and navigation risk concerns, erosion
risk, and presence of a designated fish haven. Based on the information
provided, NMFS carried forward the analysis assuming a total build-out
of 176 WTGs plus seven re-piled WTGs (a total of 183 independent piling
events for WTGs) and the 3 originally planned OSSs. Due to the
significant reduction of turbines from the original proposed action
found in the adequate and complete ITA application (reduction of
approximately 14 percent), Dominion Energy, in consultation with NMFS,
provided an updated proposed action summary, revised exposure
estimates, revised take requests, and an updated piling schedule in
mid-February 2023 (herein referred to as the Revised Proposed Action
Memo). NMFS posted this to our website in May 2023.
NMFS has previously issued six Incidental Harassment Authorizations
(IHAs) to Dominion Energy. Two of those IHAs, issued in 2018 (83 FR
39062; August 8, 2018) and 2020 (85 FR 30930, May 21, 2020) supported
the development of the Coastal Virginia Offshore Wind project, known as
the CVOW Pilot Project (wherein two turbines were constructed). The
remaining four IHAs (two of which were modified IHAs) were high
resolution site characterization surveys within and around the CVOW-C
Lease Area (see 85 FR 55415, September 8, 2020; 85 FR 81879, December
17, 2020 (modified 2020 IHA); 86 FR 21298, April 22, 2021 (modified
2021 IHA); and 87 FR 33730, June 3, 2022).
To date, Dominion Energy has complied with all the requirements
(e.g., mitigation, monitoring, and reporting) of the previous IHAs.
Information regarding Dominion Energy's take estimates and monitoring
results may be found in the Estimated Take section. The monitoring
reports can be found on NMFS' website, along with the relevant,
previously issued IHAs: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-other-energy-activities-renewable</a>.
On August 1, 2022, NMFS announced proposed changes to the existing
North Atlantic right whale vessel speed regulations (87 FR 46921;
August 1, 2022) to further reduce the likelihood of mortalities and
serious injuries to endangered right whales from vessel collisions,
which are a leading cause of the species' decline and a primary factor
in an ongoing Unusual Mortality Event. Should a final vessel speed rule
be issued and become effective during the effective period of this ITR
(or any other MMPA incidental take authorization), the authorization
holder would be required to comply with any and all applicable
requirements contained within the final rule. Specifically, where
measures in any final vessel speed rule are more protective or
restrictive than those in this or any other MMPA authorization,
authorization holders would be required to comply with the requirements
of the rule. Alternatively, where measures in this or any other MMPA
authorization are more restrictive or protective than those in any
final vessel speed rule, the measures in the MMPA authorization would
remain in place. The responsibility to comply with the applicable
requirements of any vessel speed rule would become effective
immediately upon the effective date of any final vessel speed rule and,
when notice is published on the effective date, NMFS would also notify
Dominion Energy if the measures in the speed rule were to supersede any
of the measures in the MMPA authorization such that they were no longer
required.
Description of the Specified Activities
Overview
Dominion Energy's CVOW-C project would allow the Commonwealth of
Virginia to meet its clean energy goal of achieving 100 percent clean
energy by 2045 through the implementation of up to 5,200 megawatts (MW)
of offshore wind-generated energy, as established in the Virginia Clean
Economy Act (HB 1526/SB 851; <a href="https://lis.virginia.gov/cgi-bin/legp604.exe?201+ful+CHAP1193+hil&201+ful+CHAP1193+hil">https://lis.virginia.gov/cgi-bin/legp604.exe?201+ful+CHAP1193+hil&201+ful+CHAP1193+hil</a>). To achieve
this, Dominion Energy has proposed to construct and operate CVOW-C in
state and Federal waters of the Atlantic Ocean in the Lease Area that
is capable of producing between 2,500 and 3,000 MW of renewable energy
and would be the largest offshore wind project in the United States at
the time of its construction.
Dominion Energy's precursor pilot project (i.e., CVOW Pilot
Project) was a 12 MW, two-turbine test project and the first to be
installed in Federal waters. Designed as a research/test project, the
two turbines associated with the CVOW Pilot Project became operational
in October 2020 approximately 27 miles (mi; 43.45 kilometers (km)) off
of Virginia Beach, Virginia. Information on this Pilot Project was used
to inform the proposed CVOW-C project. More information on the Pilot
Project can be found on BOEM's website (<a href="https://www.boem.gov/renewable-energy/state-activities/coastal-virginia-offshore-wind-project-cvow">https://www.boem.gov/renewable-energy/state-activities/coastal-virginia-offshore-wind-project-cvow</a>)
and in the IHA authorized by NMFS in May 2020 for BOEM Lease Area OCS-
A-0497 (<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-offshore-wind-construction-activities">https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-offshore-wind-construction-activities</a>).
[[Page 28659]]
CVOW-C would consist of several different types of permanent
offshore infrastructure, including up to 176 wind turbine generators
(WTGs; e.g., such as the Siemens Gamesa SG-14-222 DD 14-MW model with
power boost technology potentially allowing up to 14.7-MW, equating to
a total of 2,587.2-MW for full build-out), three offshore substations
(OSS), and inter-array and substation interconnect cables. Dominion
Energy plans to install WTG and OSS foundations via a joint-
installation approach using both vibratory and impact pile driving.
Dominion Energy would also conduct the following supporting activities:
temporarily install and remove, by vibratory pile driving, up to nine
cofferdams to connect the offshore export cables to onshore facilities;
temporarily install and remove, by impact pile driving and a pipe
thruster, respectively, up to 108 goal posts (12 goal posts for each of
nine Direct Pipe locations) to guide casing pipes; permanently install
scour protection around WTG and OSS foundations; permanently install
and perform trenching, laying, and burial activities associated with
the export cables from the OSSs to shore-based switching and sub-
stations and WTG inter-array cables; annually perform, using active
acoustic sources with frequencies of less than 180 kilohertz (kHz),
high-resolution vessel-based site characterization geophysical (HRG)
surveys; and intermittently perform, via a modified dredge, and a pot-
based monitoring approach, fishery monitoring surveys to enhance
existing data for specific benthic and pelagic species of concern.
Vessels would transit within the project area and between ports and the
wind farm to transport crew, supplies, and materials to support
construction activities. All offshore cables would be connected to
onshore export cables at the sea-to-shore transition point via
trenchless installation (i.e., underground tunneling utilizing micro
tunnel boring installation methodologies) in a parking lot found west
of the firing range at the State Military Reservation located in
Virginia Beach, Virginia. From the sea-to-shore transition point,
onshore underground export cables are then connected in series to
switching stations/substations, overhead transmission lines, and
ultimately to the grid connection.
Marine mammals exposed to elevated noise levels during impact and
vibratory pile driving and site characterization surveys may be taken,
by Level A harassment and/or Level B harassment, depending on the
specified activity.
Dates and Duration
Dominion Energy anticipates that activities with the potential to
result in incidental take of marine mammals would occur throughout all
five years of the proposed regulations which, if issued, would be
effective from February 5, 2024, through February 4, 2029. Based on
Dominion Energy's proposed schedule, the installation of all permanent
structures would be completed by the end of October 2025. More
specifically, the installation of WTG foundations is expected to occur
between May 1st-October 31st of 2024 and 2025, over approximately 12
months (6 months within each year). OSS jacket foundations using pin
piles would be installed between May 1st-October 31st, 2024 and 2025.
However, delays due to weather or other unanticipated and unforeseen
events may require Dominion Energy to install some foundations in 2026.
If this occurs, foundation installation would occur between the
predetermined pile driving seasonal window (May 1st-October 31st in
2026) and occur over 6 months. However, as this would represent a shift
in the schedule, rather than additional piles being installed, the
proposed activities would still maintain the same amount of take
proposed for authorization, both annual maximum and five-year total.
The temporary structures used for nearshore cable landfall construction
(i.e., temporary cofferdams and temporary goal posts) would be
installed and subsequently removed between May 1st-October 31st, 2024.
Lastly, Dominion Energy anticipates HRG survey activities using
boomers, sparker, and Compressed High-Intensity Radiated Pulses
(CHIRPs) to occur annually and across the five-year period. Up to 65
days of surveys are planned in 2024, 249 are planned in 2025, 58 are
planned in 2026, and 368 survey days are planned annually in each of
2027 and 2028. No surveys are planned to occur in 2029. These surveys
may occur across the entire CVOW-C Lease Area and Export Cable Routes
and may take place at any time of year.
Dominion Energy has provided a schedule for all of their proposed
construction activities (Table 1). Based on the schedule presented, no
activities (installation, removal, or HRG surveys) are planned to occur
in 2029, even though part of this year would fall within the five-year
effective period of the proposed regulations. This table also presents
a breakdown of the timing and durations of the activities proposed to
occur during the construction and operation of the CVOW-C project.
Table 1--CVOW-C's Construction and Operations Schedule During the Effective Period of the LOA a
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Project activity Expected timing Expected duration (approximate)
----------------------------------------------------------------------------------------------------------------
Scour Protection Pre-Installation........ Q2 through Q4 of 2024....... 9 months.
Q2 through Q4 of 2025....... 9 months.
WTG Foundation Installation \b\ \e\...... Q2 through Q4 of 2024....... 6 months.
Q2 through Q4 of 2025....... 6 months.
Scour Protection Post-installation....... Q2 through Q4 of 2024....... 9 months.
Q2 through Q4 of 2025....... 9 months.
OSS Foundation Installation \b\ \e\...... Q2 through Q4 of 2024....... 6 months.
Q2 through Q4 of 2025....... 6 months.
Cable Landfall Construction (Goal Posts Q1 through Q4 of 2024....... 6 months.
and Cofferdams) \h\.
HRG Surveys \c\ \d\...................... Q1 2024 through Q4 2028..... Any time of year.
Site Preparation......................... Q1 2024 through Q2 2024..... 6 months.
Inter-array Cable Installation........... Q2 2025 through Q4 2026..... 19 months.
Export Cable Installation................ Q3 2024 through Q3 2025..... 14 months.
Fishery Monitoring Surveys: \f\ \g\
[[Page 28660]]
Surf Clam............................ Q2 2023..................... 1 week.
Whelk................................ Q2 2023 through Q1 2025..... 24 months.
Black Sea Bass....................... Q2 2023 through Q1 2025..... 24 months.
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Note: ``Q1, Q2, Q3, and Q4'' each refer to a quarter of the year, starting in January and comprising 3 months
each. Therefore, Q1 represents January through March, Q2 represents April through June, Q3 represents July
through September, and Q4 represents October through December.
\a\ While the effective period of the proposed regulations would extend a few months into 2029, no activities
are proposed to occur in 2029 by Dominion Energy so these were not included in this table.
\b\ Activities would only occur between May 1st through October 31st annually.
\c\ Activities would begin in February 2024, upon the issuance of a LOA, and continue through construction and
post-construction.
\d\ For HRG surveys, Dominion Energy anticipates up to 65 days of surveys would occur during the pre-
construction period (2024), up to 307 days during the primary construction years (2025 and 2026), and up to
736 days would be needed during the post-construction years (2027 and 2028) with a 50/50 split of 368 days
each year. No surveys are planned for 2029.
\e\ Dominion Energy anticipates that all WTGs and OSS foundations will be installed by October 31st, 2025;
however, unanticipated delays may require some foundation pile driving to occur in 2026.
\f\ Some fishery monitoring survey activities are planned prior to February 2024 but are not included here as
they would not occur during the effective dates of the ITR and LOA.
\g\ Dates displayed here are for field work, as that would be the only component that could impact marine
mammals.
\h\ Although cable landfall activities are anticipated to occur over 9-12 months total, activities capable of
harassing marine mammals would only occur for the specified duration described here as other activities
necessary for landfall construction (i.e., area preparation, material transportation, etc.) would also occur.
Dominion Energy anticipates that the first 40 WTGs would become
operational in 2025, after foundation installation is completed and
after all necessary components (such as array cables, OSSs, export
cables routes, and onshore substations) are installed. Up to 120
additional WTGs would be commissioned/operational in 2026. Dominion
Energy anticipates that all turbines would be commissioned by 2027,
with the last 16 being operational that year.
Specific Geographic Region
Dominion Energy would construct the CVOW-C project in Federal and
state waters offshore of Virginia within the BOEM Lease Area OCS-A 0483
and associated Export Cable Routes (Figure 1). The Lease Area covers
approximately 456.5 km\2\ (112,799 acres) and is located approximately
27 mi (43.5 km) east of Virginia Beach, Virginia. The water depths in
the Lease Area range from 19.9 m to 38.1 m (65 to 125 ft) while water
depths along the Export Cable Routes range from 0 to 28 m (0 to 92 ft).
Cable landfall construction work would be conducted in shallow water
(temporary cofferdams would be in water 3.3 m (10.83 ft) deep, and the
goal posts would be at depths of 22.9 m (75 ft)). Sea surface
temperatures range from 32 to 88 degrees Fahrenheit ([deg]F; 0 to 31
degrees Celsius ([deg]C)) while the depth-averaged annual water
temperature is 56.39 [deg]F (13.55 [deg]C) (NOAA n.d.B). Cables would
come ashore adjacent to the western boundary of the State Military
Reservation firing range in Virginia Beach.
Dominion Energy's specified activities would occur along a portion
of the Mid-North Atlantic continental shelf that experiences various
concurrent processes that shape the overall geology of the region.
These processes include glacio-eustatic sea level change (i.e., a
change in sea level due to the uptake or release of water from glaciers
and polar ice), drainage from Chesapeake Bay, and storm-related effects
to sedimentation. The basin structure in which the CVOW-C project area
is located, the Baltimore Canyon Trough, is oriented northeast to
southwest and consists of a wedge of sediments that thicken to the east
(Dominion Energy, 2023).
The Mid-Atlantic Bight, where the CVOW-C project would be located,
spans from Cape Hatteras, North Carolina to Cape Cod, Massachusetts and
continues to extend into the west Atlantic to the 100-m isobath. The
oceanographic conditions along the Mid-Atlantic Bight are comparable to
the conditions found along the Mid-Atlantic East Coast, where summer
months are warmer and winter months are milder. The area is known for
its high levels of primary productivity, specifically in the nearshore
and estuarine regions, where coastal phytoplankton tend to bloom in the
winter and summer. Given the proximity to the continental shelf, this
area forms an important habitat for various benthic and fish species,
as well as forms important habitat for fin whales, humpback whales,
North Atlantic right whales, and other large whales as they migrate
through the area. The CVOW-C project area is located within the Mid-
Atlantic Bight and relatively flat with ``very gentle to gentle
slopes'', as described by the BOEM classification found in the CVOW-C
Construction and Operations Plan (COP) (Dominion Energy, 2023). In the
Export Cable Routes, the seafloor slopes are less than 1 degree (``very
gentle'' based again on the BOEM classification; Dominion Energy,
2023). The most significant slopes can be found on the flanks of
morphological features and other topographic highs where the seabed
gradient ranges up to 4 degrees (Dominion Energy, 2023). The most
prominent seabed features with the project area are pronounced sand
ridges that create a ridge and swale topography. In the northeastern
portion of the project area, the heights of the sand ridges are lower,
topographic variation across the ridges is reduced, seafloor bathymetry
is deeper, and water depths are less variable.
A complete mapping of the seabed has identified a low number of
boulders present on the seafloor (Dominion Energy, 2023). Only 10
boulders and 110 seabed targets interpreted as possible boulders have
sizes greater than 1 m (3 ft). No patterns were identified in the
location of boulders across the Lease Area and Export Cable Routes.
The seafloor in the CVOW-C project area is dynamic and changes over
time due to current, tidal flows, and wave conditions. The benthic
habitat of the project area contains a variety of seafloor substrates,
physical features, and associated benthic organisms. The soft bottom
sediments in the project area are reflective of the rest of the Mid-
Atlantic Bight region, and characterized
[[Page 28661]]
by fine sand as well as gravel and silt/sand mixes (Milliman, 1972;
Steimle and Zetlin, 2000). Underwater soils in the area are known to be
soft, with two specific soils noted that could increase the risk of
pile run (Dominion Energy, 2023). The presence of bedforms, mobile
sediments, and potential for scouring exist in the project area
(Dominion Energy, 2023). However, the paleochannel strata is not
considered a weak layer due to stiffness and strength values being
within normal ranges and as such, is not considered a hazard to cable
or foundation installation (Dominion Energy, 2023). The dominant
benthic fauna within the Lease Area are annelids, mollusks, and
arthropods (Dominion Energy, 2023).
Additional information on the underwater environment's physical
resources can be found in CVOW-C's COP (Dominion Energy, 2023)
available at <a href="https://www.boem.gov/renewable-energy/state-activities/coastal-virginia-offshore-wind-project-construction-and">https://www.boem.gov/renewable-energy/state-activities/coastal-virginia-offshore-wind-project-construction-and</a>.
BILLING CODE 3510-22-P
[[Page 28662]]
[GRAPHIC] [TIFF OMITTED] TP04MY23.081
[[Page 28663]]
BILLING CODE 3510-22-C
Figure 1--The CVOW-C Project Area
Detailed Description of Specified Activities
Below, we provide detailed descriptions of Dominion Energy's
activities, explicitly noting those that are anticipated to result in
the take of marine mammals and for which incidental take authorization
is requested. Additionally, a brief explanation is provided for those
activities that are not expected to result in the take of marine
mammals.
WTG and OSS Foundations
Dominion Energy proposes to install up to 176 WTGs on monopile
foundations and 3 OSSs on jacket foundations. They anticipate all WTG
foundations could be installed between May 1st through October 31st in
2024 and 2025, over the course of six months in each year. However, it
may be possible that monopile installation associated with the WTG
foundations would need to continue into a third year (2026), depending
on construction logistics and local and environmental conditions that
may influence Dominion Energy's ability to maintain the planned
construction schedule. If this is determined to be necessary, WTG
foundations would only be installed between May 1st through September
30th of 2026. However, this schedule shift would not change NMFS'
proposed determinations as the total number of piles would remain the
same. While this shift is unlikely to occur, the proposed rulemaking
does retain flexibility in addressing unforeseen circumstances.
However, all foundations would be installed during the effective period
of this proposed rule, if issued. OSS jacket foundations would most
likely be installed in August 2024; however, they could be installed
anytime between May 1st through October 31st. For both types of
foundations, Dominion Energy has committed to not installing from
November 1st through April 30th, annually.
A WTG monopile foundation typically consists of a single steel
tubular section, with several sections of rolled steel plate welded
together. Each monopile would have a maximum diameter tapering from 7.5
m (24.6 ft) at the top to 9.5 m (31 ft) at the seafloor (collectively
referred to as a 9.5/7.5-m monopile). WTGs would be spaced
approximately 0.75 nautical miles (nm; 1.39 km) in an east-west
direction and 0.93 nm (1.72 km) in a north-south direction and will
have an average penetration depth of 42 m (138 ft; between 30 m and 46
m per Attachment Z-3 of Appendix A in Dominion Energy's ITA
application). Although only 176 WTGs would be installed, seven
foundations may need to be re-installed at a different location; hence
Dominion Energy has accounted for up to 183 WTG individual piling
events in its analysis, which we have carried forward with in this
proposed rule.
Each OSS installed by Dominion Energy would be supported by a
jacket foundation. A piled jacket foundation is formed by a steel
lattice construction (comprising tubular steel members and welded
joints) secured to the seabed by means of hollow steel pin piles
attached to the jacket. Each jacket foundation would consist of up to
four pin piles. In total, Dominion Energy would install up to 3 OSSs
for a total of 12 pin piles. Up to two pin piles would be installed per
day. Pin piles will have a maximum diameter of 2.8 m (9.2 ft) each and
will be installed vertically. The maximum penetration depth of each pin
pile would be 82 m (269 ft).
Given the project area's soil conditions, the installation of both
WTG monopile foundations and OSS jacket foundations would necessitate
the use of both vibratory and impact pile driving to avoid pile run
(also known as ``punch-through''). Pile run can occur when a monopile
or a pin pile rapidly penetrates in an uncontrolled manner through a
weak layer of soil, due to the soil resistance being lower than the
weight of the pile and hammer (transferring impulsive energy to the
pile). Pile runs can occur instantaneously and through a depth of
meters to dozens of meters. A pile run incident can have severe
negative consequences, both for the safety of personnel aboard the
installation vessel and significant risk of damage to equipment. To
mitigate this risk, Dominion Energy would first perform vibratory
hammering, which would allow for a more controllable installation
process when installing piles in soft sediments as the vibrohammer is
directly in contact with the pile (see Figures 2 through 5 in Dominion
Energy's ITA application), as opposed to installation using the impact
hammer (see Figures 6 and 7 in Dominion Energy's ITA application). Once
the pile run risk depth has been passed, the method of installation
would transition from a vibratory hammer to an impact hammer. It is
anticipated the transition from a vibratory hammer to an impact hammer
would require approximately 1.2 hours wherein no pile driving would
occur. Once installation of the monopile and/or pin pile is complete,
the pile driving vessel would move to the next installation location.
While Dominion Energy states that not all piles will require the use of
the vibrohammer in conjunction with the impact hammer, it was
considered more conservative to analyze all installed piles using this
dual approach as it is not yet known how many would require the dual
installation method. No concurrent pile driving at multiple locations
would occur.
Per monopile, use of the vibrohammer is estimated to occur for
approximately 30 to 60 minutes (depending on if the pile uses a
standard driving or hard-to-drive scenario, respectively) to firmly
stabilize the foundation pile. A 72 minute (1.2 hour) pause to allow
for the vibratory hammer to be exchanged with an impact hammer would
occur. Then, the impact hammer would be used for approximately three
hours (constituting approximately 3 hours for 3,240-3,720 total hammer
strikes, with more strikes needed if the pile is considered difficult
to install). A joint standard and hard-to-drive scenario (Scenario 3)
for the installation of up to two monopiles in a single day may require
up to 90 minutes of vibratory pile driving followed by up to 6,960
hammer strikes. In all situations, the impact hammer would drive the
pile until it reaches its target embedment depth (approximately 42 m
(138 ft) for monopiles). The three possible WTG monopile installation
scenarios are laid out in Table 2 below:
Table 2--WTG Monopile Scenarios With Scenario-Specific Installation Characteristics
----------------------------------------------------------------------------------------------------------------
Number of WTG Maximum vibratory
Installation scenario monopiles hammer duration Maximum impact Impact hammer
installed (minutes) hammer strikes energy (kJ)
----------------------------------------------------------------------------------------------------------------
Scenario 1 (Standard).................. 1 60 3,240 4,000
Scenario 2 (Hard-to-drive)............. 1 30 3,720 4,000
[[Page 28664]]
Scenario 3 (Standard and Hard-to-drive) 2 90 6,960 4,000
----------------------------------------------------------------------------------------------------------------
For pin piles, vibratory pile driving is anticipated to require
approximately 120 minutes (2 hours), a 72 minute (1.2 hours) pause in
activities, and then continue with impact pile driving using a hammer
energy up to 3,000 kJ, resulting in a total estimate of 15,210 hammer
strikes. As with WTG foundations, the impact hammer would drive the pin
pile until it reaches its target embedment depth (approximately 82 m
(269 ft) for pin piles). A maximum of two pin piles would be driven per
day. Each OSS jacket foundation would take approximately five days to
install with a total of 30 days needed for the completion of all three
OSSs (n=3) with all of their pin piles (n=12). This 30-day period does
include periods of non-pile driving time where other activities related
to the jacket foundations may be installed.
The current construction schedule assumes foundation installation
would occur in 2024 and 2025; however, as previously discussed in the
Dates and Duration section, limited installation of WTGs may need to be
installed in 2026 if the project falls off of the construction
schedule. Given an estimated installation schedule, Dominion Energy
expects that up to 95 monopile foundations would be installed in 2024
and up to 88 monopiles would be installed in 2025. If pile driving must
occur in this 3rd year, installation would only occur across a five
month period (May 1st through September 30th, 2026). All WTG and OSS
foundation installation would occur during daylight hours only. The
only exception would be if, for safety reasons, ceasing pile driving
activities would compromise both the health of humans and the
environment or if ceasing the pile driving would cause instability and
integrity concerns on the project. In most cases, one pile would be
installed per day, although two may be installed during some months. No
concurrent pile driving is planned or proposed to occur. The same
exception described above for WTG foundations applies to OSS
foundations where integrity or safety concerns may necessitate the pile
to be finished after sunset. The proposed WTG and OSS pile driving
schedule can be found in Table 3 below that describes the construction
schedule on both an annual and monthly basis.
Table 3--Proposed Pile Driving Schedule for the CVOW-C Project of 176 WTGs and 3 OSSs, Plus 7 Possible WTG Re-Piling Events
--------------------------------------------------------------------------------------------------------------------------------------------------------
Days when two
Total proposed number of Number of hard- Number of monopiles may be
Year \b\ Month piles to-drive piles standard piles installed per
day
--------------------------------------------------------------------------------------------------------------------------------------------------------
2024................................... May............................... 18....................... 5 13 1
June.............................. 25....................... 6 19 6
July.............................. 26....................... 7 19 6
August............................ 2 monopiles; 12 pin piles 1 1 1
September......................... 13....................... 3 10 0
October........................... 11....................... 1 10 0
----------------------------------------------------------------------------
2024 Annual Total.................. .................................. 95 monopiles; 12 pin 23 72 14
piles \a\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
2025................................... May............................... 16....................... 6 10 1
June.............................. 22....................... 8 14 6
July.............................. 24....................... 8 16 6
August............................ 20....................... 6 14 6
September......................... 5........................ 2 3 0
October........................... 1........................ 1 0 0
----------------------------------------------------------------------------
2025 Annual Total.................. .................................. 88 monopiles............. 31 57 19
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Included only if seven re-piling events are necessary.
\b\ While Dominion Energy plans for all pile driving to be completed by the end of the 2025 piling period (end of October 2025), unforeseen
circumstances may necessitate that piling would need to continue into 2026. While not planned or anticipated, the proposed rule would allow for
flexibility in shifting certain activities with the understanding that the maximum estimated takes would not exceed the amount described in the
proposed rule.
Cable Landfall Construction
To support the connection of the offshore cable with the onshore
cable, Dominion Energy would install both temporary goal posts and
temporary cofferdams approximately 1,000 m (3,281 ft) offshore of the
State Military Reservation in Virginia Beach, Virginia. These
activities are two components of a broader set of activities conducted
during cable landfall construction. The goal posts and cofferdams would
support work associated with installing casing pipes housing the export
cables. Dominion Energy would install the 9 casing pipes approximately
50 ft apart from each other at the cable landfall construction site
using a Trenchless Installation approach. Using a tunneling approach
similar to horizontal directional drilling (HDD), a boring machine
would excavate the ground while simultaneously pushing strings of steel
casing pipes along umbilical lines
[[Page 28665]]
using rollers or other movable support structures behind the boring
drill using a pipe thruster machine. The export cables would be fed
through these pushed casing pipes, which would terminate at an onshore
exit point located west of the firing range from the State Military
Reservation.
Temporary goal posts (made up of 42-in diameter steel pipe piles)
would be installed between each exit location and would be used to
guide the progress and movement of the casing pipes and to provide
lateral stability. Temporary cofferdams are used to aid cable pull in
as the cable is fed through the underground tunnel (located 6.6 ft (2
m) below the seabed). A technical description of the Trenchless
Installation approach can be found in Section 1 of Dominion Energy's
ITA application.
Trenchless installation requires the use of extensive equipment
that would be staged at the onshore location for the cable. However,
only the equipment required to extract the boring device, post-
tunneling, is temporarily staged at the onshore exit location. Despite
the extensive equipment necessary for this activity (see the ITA
application for details), most of it is not expected to result in the
take of marine mammals as the source levels are all generally very low.
Even the pipe thruster does not vibrate or make noise and simply pushes
the pipe forward with the boring device. Because of this, only the
aspects for cable landfall construction that could cause the take of
marine mammals (i.e., impact and vibratory pile driving) is discussed
further. The aspects of landfall construction that could cause the
harassment of marine mammals is specifically due to the installation of
steel pipe piles for goal posts and the installation and removal of
sheet piles for cofferdams.
The goal posts would consist of 1.07 m (42 in) steel pipe piles
that would be installed using an impact hammer for up to 130 minutes
daily (a maximum of 2 installed per day). The duration of each strike
of the impact hammer would be between 0.5-2 seconds in duration and
necessitate approximately 260 strikes per pile. Up to 12 goal posts are
required at each of the 9 casing pipe locations; hence 108 goal posts
would be installed. Given there are 12 goal posts per each of the nine
Direct Pipe locations, a total of 108 piles would be installed. Given
up to 2 piles would be installed per day, there could be 520 strikes
per day. To install all goal posts, Dominion Energy would conduct pile
driving for 54 days.
Once installed, the goal posts can be removed using equipment not
expected to generate any underwater acoustic noise as the majority of
the force applied would be to overcome the skin friction of the
material that is embedded in the substrate. This is expected to consist
of pulling/tugging of the piles using mechanical or hydraulic equipment
and take a similar amount of time of installation (i.e., a total of 54
days for removal, although no take is expected). Based on Dominion
Energy's schedule, which includes both installation and removal of the
goal posts, these activities are expected to occur in 2024, between May
1st-October 31st, and necessitate approximately 6 months for complete
installation and removal. Given no take is expected from the removal of
goal posts, only the 54 days for installation of 108 total pipe piles
has been carried forward into the Estimated Take of Marine Mammals
section.
Dominion Energy also anticipates that up to nine temporary
cofferdams, which would only be installed and removed via vibratory
pile driving, may be necessary during cable landfall construction
activities. These would be located at the Nearshore Trenchless
Installation Punch-Out location, where the export cables would
transition (via underground drilling) to the onshore cable landing
location, to facilitate the preferred approach of lowering of the
Direct Pipe burial underground (approximately 2 m (6.6. ft) below the
seabed) to reduce the need for additional cable protections and to
minimize the release of sediments and drilling fluids into the water.
Each temporary cofferdam would consist of 30 to 40 steel sheet piles
measuring 0.51 m (20 in) in diameter arranged in a predetermined
configuration (270 to 360 steel sheet piles total for all nine
cofferdams). Vibratory pile drivers would be used to both install and
remove the steel sheet piles. Each sheet pile would necessitate
approximately 2 to 3 minutes of active drive time for installation, at
a maximum installation rate of 20 sheet piles per day (up to 40-60
minutes daily). To allow for flexibility in the plan, Dominion Energy
has assumed installation will take approximately 3 days (180 minutes
total) per cofferdam. Removal of these sheet piles would also occur by
a vibratory driver and is estimated to take approximately the same
amount of time to remove as it was to install for a total of 3 days per
cofferdam. A single cofferdam would take a total of 6 days to install
and remove. In total, pile driving (installation and removal)
associated with all cofferdams would occur over 54 non-consecutive
days.
Collectively, Dominion Energy estimates that the installation and
removal of all necessary components for cable landfall activities that
have the potential to result in take of marine mammals (i.e., pile
driving of goal posts and cofferdams) would take 108 days. However,
within this 45 week period, activities not expected to harass marine
mammals would also be occurring (e.g., area preparation, material
transportation, equipment staging, etc.) as the activities necessary
for the installation and removal of all relevant goal posts and
cofferdams are not consecutive. Therefore, Dominion Energy has
estimated that activities potentially resulting in the take of marine
mammals would only be occurring for approximately 6 months between May
1st through October 31st, 2024, which is what is described here.
Although temporary cofferdam installation and removal is anticipated to
occur from May 1st through October 31st of 2024 and take approximately
6 months, per Dominion Energy's construction schedule, both
installation and removal will not occur within a consecutive 6 days
(the total number of days for installation and removal to occur) but
may instead occur at different points during the 6 month estimated
duration.
High-Resolution Geophysical Surveys
HRG surveys would be conducted to identify any seabed debris and to
support micro-siting of the WTG and OSS foundations and all cable
routes. After construction is complete, HRG surveys would be conducted
to ensure that all underwater project components have been properly
installed. These surveys may utilize acoustic equipment such as
multibeam echosounders, side scan sonars, shallow penetration sub-
bottom profilers (SBPs) (e.g., Compressed High-Intensity Radiated
Pulses (CHIRPs) non-parametric SBP), medium penetration sub-bottom
profilers (e.g., sparkers and boomers), and ultra-short baseline
positioning equipment, some of which are expected to result in the take
of marine mammals. Surveys would occur annually, with durations
dependent on the activities occurring in that year (i.e., construction
years versus operational years). Of the HRG equipment types proposed
for use, the following sources have the potential to result in take of
marine mammals:
<bullet> Shallow penetration sub-bottom profilers (SBPs) to map the
near-surface stratigraphy (top 0 to 5 m (0 to 16 ft) of sediment below
seabed). A CHIRP system emits sonar pulses that increase in frequency
over time. The pulse length frequency range can be adjusted to meet
[[Page 28666]]
project variables. These are typically mounted on the hull of the
vessel or from a side pole.
<bullet> Medium penetration SBPs (boomers) to map deeper subsurface
stratigraphy as needed. A boomer is a broad-band sound source operating
in the 3.5 Hz to 10 kHz frequency range. This system is typically
mounted on a sled and towed behind the vessel.
<bullet> Medium penetration SBPs (sparkers) to map deeper
subsurface stratigraphy as needed. A sparker creates acoustic pulses
from 50 Hz to 4 kHz omni-directionally from the source that can
penetrate several hundred meters into the seafloor. These are typically
towed behind the vessel with adjacent hydrophone arrays to receive the
return signals.
Table 4 identifies all the representative survey equipment that may
be used during the CVOW-C proposed project.
Table 4--Acoustic Sources Planned for Use During the CVOW-C Proposed Project and Their Operational Parameters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Operating
Equipment classification Representative equipment frequencies Lp Lp,pk Primary beam width Pulse duration
(kHz) (degrees) (millisecond)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Subsea Positioning/ultra-short baseline Sonardyne Ranger 2 USBL..... 35-55 188 191 90......................... 1
(USBL). EvoLogics S2CR.............. 48-78 178 186 Horizontally 500-600
Omnidirectional.
ixBlue Gaps................. 20-30 191 194 200........................ 9-11
Multibeam Echosounder.................... R2Sonics 2026............... 170-450 191 221 0.45 x 0.45-1 x 1.......... 0.015-1.115
Synthetic Aperture Sonar (SAS), combined Kraken Aquapix.............. 337 210 213 >135 vertical, 1 horizontal 1-10
bathymetry/sidescan \a\.
Side Scan Sonar \a\...................... EdgeTech 4200 dual frequency 300 and 600 \b\ 206 \b\ 212 140........................ 5-10
Parametric SBP........................... Innomar SES-2000 Medium 100. 2-22 241 247 2.......................... 0.07-1
NonParametric SBP........................ EdgeTech 216 CHIRP.......... 2-16 193 196 15-25...................... 5-40
EdgeTech 512 CHIRP.......... 0.5-12 \c\ 177 \c\ 191 16-41...................... 20
Medium Penetration Seismic............... Geo Marine Dual 400 Sparker 0.25-4 \d\ 200 \d\ 210 Omnidirectional............ 0.5-0.8
800J.
Applied Acoustics S-Boom 0.5-3.5 \e\ 203 \e\ 213 \f\ 60..................... 10
(Triple Plate Boomer 1000J).
Magnetometer (Towed)..................... Geometrics G882............. 200 192 190 7.......................... 1.13
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: dB re 1 [micro]Pa m--decibels referenced to 1 MicroPascal at 1 meter; kHz--kilohertz.
\a\ The operating frequencies of these sources are above all relevant marine mammal hearing thresholds (>180 kHz) and are not expected to cause take by
harassment of marine mammals.
\b\ The source level is based on data from Crocker and Franantonio (2016) using the EdgeTech 4200 at 100 percent power and 100 kHz as a proxy.
\c\ The source level is based on data from Crocker and Franantonio (2016) using the EdgeTech 512i at 100 percent power as a proxy.
\d\ The source level is based information provided by the source manufacturer in the supplemental attachment to the ITA application called ``Noise Level
Stacked 400--tuned''.
\e\ The source level is based on data from Crocker and Franantonio (2016) using the Applied Acoustic S-Boom with CSP-N Energy Source set at 1,000 joules
as a proxy.
\f\ The beam width is based on data from Crocker and Franantonio (2016) using the Applied Acoustics S-Boom as a proxy.
As shown in Table 4 above, multibeam echosounders and side scan
sonars used by Dominion Energy operate at frequencies above 180 kHz,
which is outside of any marine mammal hearing range. Hence, take from
these sources is not anticipated. In addition, due to the
characteristics of non-impulsive sources (i.e., Ultra-Short BaseLine
(USBL), Innomar, and other parametric sub-bottom profilers), take is
not anticipated due to operating characteristics like very narrow beam
width which limit acoustic propagation. Finally, Dominion Energy may
also use magnetometers; however, this equipment does not have an
acoustic output, hence no take is anticipated. No harassment can be
reasonably expected from the operation of any of these sources;
therefore, they are not considered further in this proposed action. The
sources that have the potential to result in harassment to marine
mammals include CHIRPs, boomers, and sparkers.
HRG surveys would utilize between two or three vessels working
concurrently in different sections of the Lease Area and Export Cable
Routes. Both vessels would be operating several kilometers apart at any
one time. On average, 58 km (36 mi) would be surveyed each survey day,
per vessel, at a speed of approximately 2.4 km/hour (1.3 kts) on a 24-
hour basis although some vessels may only operate during daylight hours
(survey vessels operating for 12-hours). During the five-years the
proposed rule would be effective an estimated area of 64,264 km\2\
(24,812.5 mi\2\; 15,879,980.2 acres) will be surveyed across the CVOW-C
project area.
HRG site characterization surveys would occur annually and
throughout the five years of the proposed authorization with duration
dependent on the activities occurring in that year (i.e., construction
versus non-construction year). However, HRG survey activities would not
commence earlier than February 5, 2024 (i.e., the effective date of the
proposed rule). The HRG survey schedule assumes 24-hour operations and
does account for periods of potential downtime due to inclement weather
or technical malfunctions. HRG surveys are anticipated to operate at
any time of year for a maximum of 1,108 active sound source days (i.e.,
days in which an acoustic source would be used) over the five-year
project. Up to 65 days are anticipated pre-construction, 307 are
anticipated to occur during the primary construction years (2025 and
2026), and 736 would occur the post-construction years (368 survey days
annually). While the effective period of the proposed rulemaking would
continue through a few months in 2029, no activities are planned to
occur during this year so none are described here. An approximated
schedule for Dominion Energy's HRG survey effort is shown in Table 5.
As Dominion Energy is not sure of the exact geographic locations of the
survey effort, these values cannot cleanly be broken up between the
Lease Area and the Export Cable Routes. However, the values presented
in Table 5 provide a comprehensive accounting of the total survey
effort anticipated to occur, annually, by Dominion Energy.
[[Page 28667]]
Table 5--Proposed HRG Survey Schedule for the CVOW-C Project
------------------------------------------------------------------------
Duration
Survey segment Year (days) \a\
------------------------------------------------------------------------
Pre-Lay Surveys......................... 2024 65
As-Built Surveys and Pre-Lay Surveys.... 2025 249
As-Built Surveys........................ 2026 58
Post-Construction Surveys............... 2027 368
Post-Construction Surveys............... 2028 368
------------------------------------------------------------------------
\a\ As multiple vessels (i.e., two survey vessels) may be operating
concurrently across the project area, each day that a survey vessel is
operating counts as a single survey day. For example, if two vessels
are operating in one of the Export Cable Routes and one is operating
in the Lease Area, but both are operating concurrently, this counts as
two survey days.
Cable Laying and Installation
Cable burial operations would occur both in the Lease Area and
export cable routes from the least area to shore. The inter-array
cables would connect the 176 WTGs to any one of the three OSSs. Cables
within the Export Cable Routes would carry power from the OSSs to shore
at the landfall location near the firing range at the State Military
Reservation in Virginia Beach, Virginia. The offshore export and inter-
array cables would be buried in the seabed at a target depth of up to
0.8 m (2.6 ft) to 3 m (9.8 ft), although the exact depth will depend on
the substrate in the area.
Cable laying, cable installation, and cable burial activities
planned to occur during the construction of the CVOW-C project may
include the following: jet plowing, jet trenching, chain cutting,
hydro-plowing (simultaneous lay and burial), mechanical plowing
(simultaneous lay and burial), pre-trenching (both simultaneous and
separate lay and burial), mechanical trenching (simultaneous lay and
burial), and/or other available technologies. As the noise levels
generated from cable laying and installation work are low, the
potential for take of marine mammals to result is discountable.
Dominion Energy is not requesting and NMFS is not proposing to
authorize take associated with cable laying activities. Therefore,
cable laying activities are not analyzed further in this document.
Site/Seafloor Preparation
Prior to installation activities, Dominion Energy would conduct
debris clearance, pre-lay grapnel runs, Unexploded Ordnance/Munitions
and Explosives of Concern (UXO/MEC) relocation, and pre-lay surveys.
While Dominion Energy does not expect any sandwave clearance or boulder
removal activities to occur, planned vessel use described below in
Table 6 indicates that these activities may occur. Because of this, we
include additional information on what these activities may entail and
how they would affect marine mammals.
Typically for offshore construction projects, some dredging may be
required prior to cable laying due to the presence of sandwaves.
Sandwave clearance is typically undertaken where cable exposure is
predicted over the lifetime of a project due to seabed mobility. This
facilitates cable burial below the reference seabed. Alternatively,
sandwave clearance may be undertaken where slopes become greater than
approximately 10 degrees (17.6 percent), which could cause instability
to the burial tool. Dominion Energy does not anticipate any sandwave
clearance (Dominion Energy, 2023). However, while unanticipated, if it
becomes necessary to remove sandwaves, Dominion Energy will clear the
area using subsea excavation methods. The work could be undertaken by
traditional dredging methods such as a trailing suction hopper.
Controlled flow excavation may be used to induce water currents to
force the seabed into suspicion, where it would otherwise be directed
to eventually settle (Dominion Energy, 2023). In some cases, pre-
sweeping of the sandwaves may be necessary to provide a sufficient
excavated platform at the base of the sandwave for tool installation.
Surveys using multi-beams and other equipment may be necessary to
inform on the seabed conditions before and after sandwave clearance and
cable lay activities (Dominion Energy, 2023).
For monopile and jacket foundation installation, seafloor
preparation could include required boulder clearance and removal of any
obstructions within the Seafloor Preparation Area at each foundation
location. Scour protection installation will occur prior to and/or
after installation and will involve a rock dumping vessel placing scour
at each foundation location.
For export cable installation, seafloor preparation typically
includes required sandwave leveling, boulder clearance, and removal of
any out of service cables. Boulder clearance trials are normally
performed prior to wide-scale seafloor preparation activities to
evaluate efficacy of boulder clearing techniques. Additionally, pre-lay
grapnel runs may be undertaken to remove any seafloor debris along the
Export Cable Routes. A specialized vessel will tow a grapnel rig along
the centerline of each cable to recover any debris to the deck for
appropriate licensed disposal ashore, where practicable. Concrete
mattress separation layers may also be installed at cable routes prior
to cable installation for both in-service assets as well as out-of-
service assets that cannot be safely removed and pose a risk to the
CVOW-C Export Cable Routes.
Boulder clearance may also be required in targeted locations to
clear boulders along the Export Cable Routes, inter-array cable routes,
and/or foundations prior to installation. Boulder removal can be
performed using a combination of methods to optimize clearance of
boulder debris of varying size and frequency. Removal is based on pre-
surveys to identify location, size, and density of boulders. Surveys
previously performed by Dominion Energy have indicated that no boulders
over 0.5 m, or any other subsea obstructions, have been identified in
the project area (Dominion Energy, 2023). If boulders are encountered
during installation activities, Dominion Energy would move them from
the Export Cable Routes, using either subsea grabs, or ploughs, and
then relocate them to areas as close as possible to the original
location of the undersea object (Dominion Energy, 2023). Boulder
removal, if necessary to occur based on information obtained during
pre-construction surveys, would be performed prior to the installation
of the Export Cable Routes and would be completed by a support vessel.
A boulder grab or a boulder plow may be used to complete boulder
removal prior to installation. A boulder grab involves a grab most
likely deployed from a dynamic positioning offshore support vessel
being lowered to the seabed, over the targeted boulder. Once
``grabbed'', the boulder is relocated away from the cable route and/or
foundation location.
[[Page 28668]]
Boulder clearance using a boulder plow is completed by a high-bollard
pull vessel, with a towed plow generally forming an extended V-shaped
configuration, splaying from the rear of the main chassis. The V-shaped
configuration displaces any boulders to the extremities of the plow,
thus clearing the corridor. A tracked plow with a front blade similar
to a bulldozer may also be used to push boulders away from the
corridor. The size of boulders that can be relocated is dependent on a
number of factors including the boulder weight, dimensions, embedment,
density and ground conditions. Typically, boulders with dimensions less
than 2.5 m (8 ft) can be relocated with standard tools and equipment.
Effects from seafloor preparation on marine mammals are expected to
be short-term, low intensity, and unlikely to qualify as a take.
Dredging, sandwave leveling, and boulder clearance is expected to be
extremely localized at any given time, and NMFS expects that any marine
mammals would not be exposed at levels or durations likely to disrupt
behavioral patterns (i.e., migrating, foraging, calving, etc.).
Therefore, the potential for take of marine mammals to result from
these activities is so low as to be discountable. Dominion Energy did
not request and NMFS is not proposing to authorize any takes associated
with seabed preparation activities; therefore, they are not analyzed
further in this document.
Vessel Operation
Dominion Energy would utilize a variety of vessels to construct the
CVOW-C project. Vessels may be used for direct installation or
construction activities, surveys, protected species resource
monitoring, and for crew and/or supply transfers. All route plans for
all vessels would be designed to meet the industry guidelines and best
practices in accordance with the International Chamber of Shipping
guidance. All vessels would utilize Automatic Identification Systems
(AIS) for all aspects of the project, as required by the United States
Coast Guard. AIS would be required to monitor the number of vessels and
traffic patterns for analysis and compliance with vessel speed
requirements. All vessels will operate in accordance with applicable
rules and regulations for maritime operation within U.S. Federal and
state waters.
The largest vessels are expected to be used during the WTG
installation phase with floating/jack-up crane barges, cable-laying
vessels, supply/crew vessels, and/or associated tugs and barges
transporting construction equipment and materials. Large work vessels
(e.g., jack-up installation vessels and DP cable-laying vessels) for
WTG and OSS foundation installation will generally transit to the work
location and remain in the area until installation is complete. These
large vessels will move slowly over a short distance between work
locations. In contrast, other vessels will travel between several ports
and the Lease Area over the course of the construction period following
mandatory vessel speed restrictions (see Proposed Mitigation section).
These vessels will range in size from smaller crew transport boats to
tug and barge vessels. However, construction crews responsible for
assembling the WTGs will hotel onboard installation vessels at sea,
thus limiting the number of crew vessel transits expected during the
installation of the Lease Area.
While marine mammals may respond to the presence of a vessel, given
the predictable movement and ubiquitous presence of vessels in the
marine environment, and especially the variable sizes, which consist of
smaller support vessels that are predominate during offshore wind
development, exposure to transiting vessels would not generally be
expected to result in the disruption of marine mammal behavioral
patterns such that a take would occur. As part of various vessel-based
construction activities, including cable laying and construction
material delivery, dynamic positioning thrusters may be utilized to
hold vessels in position or move slowly. Sound produced through use of
dynamic positioning thrusters is similar to that produced by transiting
vessels, and dynamic positioning thrusters are typically operated
either in a similarly predictable manner or used for short durations
around stationary activities. Construction-related vessel activity,
including the use of dynamic positioning thrusters, is not expected to
result in take of marine mammals. Dominion Energy did not request and
NMFS does not propose to authorize any take associated with vessel
activity.
Dominion Energy has executed a lease agreement for a portion of the
existing Portsmouth Marine Terminal facility in the city of Portsmouth,
Virginia, to serve as a Construction Port (Sections 1-3, Dominion
Energy, 2023). The Construction Port would be used to stage and store
the monopiles and relevant transition pieces and to stage and store and
pre-assemble wind turbine generation components. Dominion Energy is
also currently evaluating several alternatives to lease portions of
existing port facilities in the Hampton Roads, Virginia area for an
operation and maintenance facility for the CVOW-C proposed project. The
preferred location is Lambert's Point, located on a brownfield site in
Norfolk, Virginia, although existing facilities at the Virginia Port
Authority's Portsmouth Marine Terminal or Newport News Marine Terminal
may also be viable options. These ports will continue to assist
Dominion Energy to support offshore construction, assembly and
fabrication, crew transfers, and logistics.
Vessel types and usage estimated to occur during the entire five-
year effective period of the proposed rule, if issued, is shown in
Table 6. NMFS references the reader to Dominion Energy's COP for
additional information on vessels planned for use during the CVOW-C
proposed project (Dominion Energy, 2023).
Table 6--Proposed Project Vessel Use During the 5-Year CVOW-C Project \1\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Days on
project,
Vessel role Vessel class Number of Breadth Length (ft) Draft (ft) including Most likely operating Frequency of transit Transit destination
vessels (ft) spare period
positions
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Scour Protection Installation..... Fall Pipe Vessel..... 1 106 507 25 657 10/2023 to 12/2024 Weekly.............. Canada/USA.
and 02/2025 to 10/
2025.
[[Page 28669]]
Transport Monopile/Transition U.S. Barge........... 2 105 400 20 823 04/2024 to 12/2025... (188+17)/2 = 103 Portsmouth, VA.
Pieces from U.S. Port to cycles in total for
Installation Site. all barges.
Tugs for Monopile/Transition Piece U.S. Ocean-going Tug. 3 41 132 18 823 04/2024 to 12/2025... 103 + 52 = 155 Portsmouth, VA.
Transport Barges. cycles in total.
Monopile/Transition Piece/Offshore Heavy Lift Vessel 1 161 711 36 804 04/2024 to 12/2025... Monthly............. Europe/Hampton Roads,
Substation Installation. (HLV). VA.
Noise Monitoring.................. Crew Transfer Vessel 2 34 84 7 512 05/2024 to 10/2024 Daily............... Portsmouth, VA.
(CTV). and 05/2025 to 10/
2025.
Noise Mitigation.................. Platform Support 1 100 454 29 512 05/2024 to 10/2024 2 cycles in total + Portsmouth, VA.
Vessel. and 05/2025 to 10/ X due to bad
2025. weather.
Crew Transfer..................... CTV.................. 1 23 65 6 822 04/2024 to 12/2025... Every 2\nd\ day..... Portsmouth, VA.
Jacket Installation............... DP HLV............... 1 161 710 36 ........... ..................... Monthly............. Europe/Hampton Roads,
VA.
Noise Monitoring for Jacket Crew Transfer Vessel 2 34 84 7 ........... ..................... Daily............... Portsmouth, VA.
Installation. (CTV).
Noise Mitigation for Jacket Platform Support 1 100 454 29 ........... ..................... Daily............... Portsmouth, VA.
Installation. Vessel.
Transport Jackets/TopSides From EU HLV.................. 1 138 568 35 186 11/2024 to 04/2025... 3 cycles in total... Europe.
Port to Installation Site.
Assist Tugboat For Topside U.S. Ocean-going Tug. 1 35 112 19 ........... ..................... Daily............... Hampton Roads, VA.
Installation.
Offshore Cable Commissioning DP2 JUV.............. 2 230 132 20 288 11/2024 to 07/2025... N/A................. N/A.
(Contingency Vessel).
Nearshore Trenchless Installation. Drill Rig Spread..... 2 40 9 N/A 262 09/2023 to 02/2024... N/A (staged at the Hampton Roads, VA.
direct pipe punch-
out locations).
Nearshore Marine Assistance....... U.S. Multi Purpose 2 40 92 14 262 ..................... Weekly.............. Portsmouth, VA.
Support Vessel
(Multicat).
Nearshore Marine Assistance....... U.S. Tug (Small)..... 1 35 112 19 262 ..................... Weekly.............. Portsmouth, VA.
Landfall.......................... Landfall Beach Spread 1 N/A N/A N/A 523 01/2023 to 04/2024 Weekly.............. Hampton Roads, VA.
and.
Shore Pull-in..................... U.S. Pull-in Support 1 105 400 20 523 07/2024 to 09/2025... Weekly.............. Portsmouth, VA.
Barge.
Shore Pull-in..................... U.S. Workboat (Tug).. 4 41 132 18 523 ..................... Weekly.............. Portsmouth, VA.
Cable Lift Jack-Up Installation JUV.................. 1 105 144 13 ........... ..................... .................... .......................
Vessel (Contingency Vessel).
Pre-lay Grapnel Run............... Multipurpose Support 1 59 266 19 77 ..................... Weekly.............. Portsmouth, VA.
Vessel.
Pre-installation Survey........... Survey Vessel........ 1 234 187 10 180 ..................... Weekly.............. Portsmouth, VA.
[[Page 28670]]
Cable Laying and Burial........... Shallow-draft Cable 1 110 401 18 523 ..................... Monthly............. Europe/Hampton Roads,
Lay Vessel. VA.
Anchor Handling................... Multi Purpose Support 2 40 92 14 523 ..................... Daily............... Hampton Roads, VA.
Vessel (Multicat).
Transport Cable................... Multi Purpose Support 3 79 289 15 131 ..................... Single Trip......... Europe/Hampton Roads,
Vessel. VA.
Cable Burial...................... Hydroplow (Jetting).. 1 20 53 14 523 ..................... N/A................. Europe/Hampton Roads,
VA.
Crew Transfer..................... CTV.................. 1 34 87 10 523 ..................... Every 2nd Day....... Portsmouth, VA.
As-built Survey................... Survey Vessel........ 1 234 87 10 46 ..................... Weekly.............. Portsmouth, VA.
Pre-lay Survey (Offshore Export Survey Vessel........ 34 87 10 10 180 1/2023 to 04/2024 and Weekly.............. Portsmouth, VA.
Cable). 08/2024 to 09/2025
and 11/2025 to 02/
2026.
Cable Laying and Burial (Offshore Deep-draft Cable Lay 1 106 528 22 535 ..................... Monthly............. Hampton Roads, VA.
Export Cable). Vessel.
Cable Laying and Burial (Offshore Deep-draft Cable Lay 1 39 110 9 470 ..................... Monthly............. Europe/Hampton Roads,
Export Cable). Vessel. VA.
Cable burial (Offshore Export Trenching Support or 1 105 529 25 604 ..................... Monthly............. Europe/Hampton Roads,
Cable). Cable Laying Vessel. VA-.
Cable burial (Offshore Export Trenching Support or 1 112 561 28 605 ..................... Monthly............. Europe/Hampton Roads,
Cable). Cable Laying Vessel. VA-.
Cable burial (Offshore Export Burial Tool (Post-lay 2 25 46 19 1,209 ..................... Monthly............. Europe/Hampton Roads,
Cable). Jetting). VA-.
Offshore Jointing Vessel (Offshore ..................... 1 23 565 6 ........... ..................... Monthly............. Europe/Hampton Roads,
Export Cable). VA.
Pre-lay Grapnel Run (Inter Array Multipurpose Support 1 26 92 9 109 01/2023 to 04/2024 Weekly.............. Portsmouth, VA.
Cable). Vessel. and 11/2024 to 05/
2026.
Pre-lay Survey (Inter-Array Cable) Survey Vessel........ 1 23 85 5 52 ..................... Weekly.............. Portsmouth, VA.
Cable Laying and burial (Inter- Deep-draft Cable Lay 1 106 528 25 558 ..................... Every 60 days....... Europe/Hampton Roads,
Array Cable). Vessel. VA.
Multipurpose Service Vessel (Inter- W2W.................. 2 76 292 18 303 ..................... Monthly............. Hampton Roads, VA.
Array Cable).
Crew Transfer (Inter-Array Cable). CTV.................. 2 23 65 6 558 ..................... Every 2nd Day....... Portsmouth, VA.
Cable Burial (Inter-Array Cable).. Trenching Support 1 105 529 37 559 ..................... Every 60 days....... Hampton Roads, VA.
Vessel or Cable
Laying Vessel.
Cable Burial (Inter-Array Cable).. Burial tool (Post-lay 1 25 46 19 558 ..................... Every 60 days....... Hampton Roads, VA.
Jetting).
As-built Survey (Inter-Array Deep draft Cable Lay 1 106 528 25 38 ..................... Weekly.............. Portsmouth, VA.
Cable). Vessel.
WTG Installation.................. JUV.................. 1 184 472 23 923 08/2025 to 02/2027... Vessel 1: Every 10- Vessel 1: Portsmouth,
14 days Vessel 2: N/ VA Vessel 2: N/A.
A.
[[Page 28671]]
Transport WTGs from U.S. port to U.S. Barge........... 2 100 400 20 792 ..................... Approximately every Portsmouth, VA.
installation site. 3 days.
Transport WTGs from U.S. Port to U.S. Ocean-going Tug. 2 41 132 18 792 ..................... Approximately every Portsmouth, VA.
Installation Site. 3 days.
Assist Tugboat.................... U.S. Ocean-going Tug. 1 35 112 19 ........... ..................... Approximately every Hampton Roads, VA.
3 days.
Commissioning Spread.............. Multi-role subsea 1 52 354 18 792 08/2025 to 04/2027... Bi-weekly........... Portsmouth, VA.
Support Vessel with
W2W.
Site Security..................... Safety vessel, 1 Varies Varies Varies 1.8684 09/2023 to 08/2027... Bi-weekly........... Portsmouth, VA.
Nearshore Trenchless
Installation.
Removing Sandwaves (Contingency Trailer Suction 1 92 480 30 117.6 2023................. Daily............... Portsmouth, VA.
Vessel). Hopper Dredger.
Boulder Pickering (Contingency Anchor Handling Tug + 2 46 146 21 117.6 2023................. Weekly.............. Portsmouth, VA.
Vessel). Crane Barge.
Boulder Ploughing (Contingency Anchor Handling Tug + 1 36 190 11 157.2 2023................. Weekly.............. Portsmouth, VA.
Vessel). Towed Plow.
Crossing Protection (Concrete Fall Pipe Vessel or 1 46 146 21 126 2024 to 2026......... Between 2 and 27 Portsmouth, VA.
Mattresses). Deep Draft Cable Lay cycles.
Vessel.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Note: N/A means not applicable and--means the information was not provided by Dominion Energy.
\1\ While most of these vessels are planned for construction, not all would be used. However, NMFS has opted to include all possible vessels with all available information to provide the best
possible understanding of what vessels may be involved in the CVOW-C proposed project.
Helicopter Usage
Dominion Energy may supplement vessel-based transport with
helicopter usage to transfer crew to and from both the shore and the
Lease Area (crew transfer vessels described in Table 6 above does not
consider helicopter use and thus, is a conservative estimate).
Helicopter usage would align with the best practices from the Federal
Aviation Administration and other relevant stakeholders when
determining routes and altitudes for travel. Helicopter use is expected
primarily from 2024-2026 at a rate of up to four roundtrip flights per
week, equating to 208 roundtrips annually and up to 624 roundtrips
total. Project-related aircraft would only occur at low altitudes over
water during takeoff and landing at an offshore location where one or
more vessels are located. Helicopters produce sounds that can be
audible to marine mammals; however, most sound energy from aircraft
reflects off the air-water interface as only sound radiated downward
within a 26-degree cone penetrates below the surface water (Urick,
1972). Due to the intermittent nature and the small area potentially
ensonified by this sound source for a very limited duration, Dominion
Energy did not request, and NMFS is not proposing to authorize take of
marine mammals incidental to helicopter flights; therefore, this
activity will not be discussed further in this proposed action.
Fisheries Monitoring Surveys
Dominion Energy plans to undertake fisheries monitoring surveys, in
partnership with the Virginia Institute of Marine Sciences (VIMS),
Atlantic surf clam (Spisula solidissima) fishers, black sea bass
(Centropristis striata) fishers, whelk (Buccinidae spp.) fishers,
Rutgers University, and the Virginia Marine Resource Commission (VMRC),
as required by BOEM to support the regulatory filings for renewable
energy projects proposed in the Atlantic Lease Areas (30 CFR
585.627(a)(3)). Fisheries monitoring surveys have been designed in
accordance with recommendations set forth by the Responsible Offshore
Science Alliance (ROSA) Offshore Wind Project Monitoring Framework and
Guidelines (<a href="https://www.rosascience.org/offshore-wind-and-fisheries-resources/">https://www.rosascience.org/offshore-wind-and-fisheries-resources/</a>; ROSA, 2021), which is based extensively on existing BOEM
guidance for providing information on fisheries during work related to
offshore wind projects (<a href="https://www.boem.gov/sites/default/files/renewable-energy-program/Regulatory-Information/BOEM-Fishery-Guidelines.pdf">https://www.boem.gov/sites/default/files/renewable-energy-program/Regulatory-Information/BOEM-Fishery-Guidelines.pdf</a>; BOEM, 2019). Dominion Energy would sample black sea
bass and whelks using pots with weighted groundlines and Atlantic surf
clams using a novel dredge tow (designed by Rutgers University and
other industry experts). The pot/trap surveys will have a two-day soak
time. Dominion Energy will be using on-demand fishing systems aimed at
reducing the entanglement risk to protected species. These systems
include, but are not limited to, spooled systems, buoy and stowed
systems, lift bag systems, and grappling (more information on these
systems can be found at https://www.fisheries.noaa.gov/new-england-
[[Page 28672]]
mid-atlantic/marine-mammal-protection/developing-viable-demand-gear-
systems#:~:text=Line%20wrapped%20around%20a%20buoyant%20spool%20is%20tet
hered,retrieve%20it%2C%20and%20the%20gear%20on%20the%20string). The
survey tows completed by this dredge will be shorter than typical
commercial tows. Dredge tows do not inherently have the potential to
result in take of marine mammals. Pot-based surveys may, absent
mitigation, result in the take of marine mammals. However, Dominion
Energy would implement mitigation and monitoring measures to avoid
taking marine mammals, including, but not limited to: monitoring for
marine mammals before and during dredging and gear deployment
activities, not deploying or pulling gear in certain circumstances,
maintaining marine mammal watches at least 15 minute before to both the
deployment and retrieval of the gear, and moving to a new sampling
location if a marine mammal appears at risk of interactions with the
gear. A full description of the mitigation measures can be found in the
Proposed Mitigation section. Dominion Energy had also proposed to
conduct trawl surveys; however, they subsequently removed trawling from
their plans. Hence, trawl surveys would not occur.
With the implementation of these measures, Dominion Energy does not
anticipate, and NMFS is not proposing, to authorize take of marine
mammals incidental to fishery surveys. Given no take is anticipated
from these surveys, impacts from fishery surveys will not be discussed
further in this document aside from listing the required mitigation
measures (see Proposed Mitigation section).
Description of Marine Mammals in the Area of Specified Activities
Thirty-nine marine mammal species under NMFS' jurisdiction have
geographic ranges within the western North Atlantic OCS (Hayes et al.,
2022), with six of these being protected under the Endangered Species
Act (ESA). However, for reasons described below, Dominion Energy has
requested and NMFS proposes to authorize take of only 21 species
(comprising 22 stocks) of marine mammals. Sections 3 and 4 of Dominion
Energy's application summarize available information regarding status
and trends, distribution and habitat preferences, and behavior and life
history of the potentially affected species (Dominion Energy, 2023).
NMFS fully considered all of this information, and we refer the reader
to these descriptions in the application, incorporated here by
reference, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS's 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's website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Of the 39 marine mammal species and/or stocks with geographic
ranges that include the CVOW-C project area found in the coastal and
offshore waters of Virginia (Table 11 in Dominion Energy's ITA
application), 17 are not expected to be present or are considered rare
or unexpected in the project area based on sighting and distribution
data; they are, therefore, not discussed further beyond the explanation
provided here. Specifically, the following cetacean species are known
to occur offshore of Virginia but are not expected to occur in the
project area due to the location of preferred habitat outside the Lease
Area and Export Cable Routes, based on the best available information:
dwarf sperm whale (Kogia sima), Fraser's dolphin (Lagenodelphis hosei),
killer whale (Orcinus orca), pygmy killer whale (Feresa attenuata),
rough-toothed dolphin (Steno bredanensis), spinner dolphin (Stenalla
longirostris orientalis), striped dolphin (Stenella coeruleoalba),
white-beaked dolphin (Lagenorhynchus albirostris), Cuvier's beaked
whale (Ziphius cavirostris), four species of Mesoplodont beaked whales
(Mesoplodon densitostris, M. europaeus, M. mirus, and M. bidens), and
the blue whale (Balaenoptera musculus). Two species of phocid pinnipeds
are also uncommon in the CVOW-C project area, including: harp seals
(Pagophilus groenlandica) and hooded seals (Cystophora cristata). In
addition, the Florida manatees (Trichechus manatus; a sub-species of
the West Indian manatee) has been previously documented as an
occasional visitor to the Mid-Atlantic region during summer months
(Morgan et al., 2002; Cummings et al., 2014). However, manatees are
managed by the U.S. Fish and Wildlife Service (USFWS) and are not
considered further in this document.
None of the aforementioned species were observed during HRG surveys
conducted by Dominion Energy in and around Virginia from 2018-2021
based on monitoring reports received for previously issued high-
resolution site characterization IHAs (85 FR 55415, September 8, 2020;
85 FR 81879, December 17, 2020; 86 FR 21298, April 22, 2021), for the
construction of the CVOW Pilot Project (85 FR 30930, May 21, 2020) or
Unexploded Ordnance/Munitions and Explosives of Concern (UXO/MEC)-
specific surveys (83 FR 39062, August 8, 2018). However, four marine
mammal species that might otherwise be considered rare were detected
through PAM/visually observed by marine mammal monitors during work
under these previous IHAs. These include: false killer whales (one
acoustically detected, four observed), pygmy sperm whales (one
acoustically detected, one observed), Clymene dolphin (five observed),
and melon-headed whales (one acoustically detected, five recorded).
Although these were detected in low numbers, these observations/
detections did occur within locations near the CVOW-C project area
where NMFS considers it reasonably likely that some individuals may be
observed during the five-year effective period of the proposed
rulemaking. Because of this, NMFS has proposed to authorize take of
these species.
Table 7 lists all species and stocks for which take is expected and
proposed to be authorized for this action, 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) level, 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 (16 U.S.C.
1362(20)) and can be found in NMFS's SARs. While no mortality is
anticipated or proposed for authorization here, PBR and annual serious
injury and mortality from anthropogenic sources are included here as
gross indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Atlantic and Gulf of Mexico SARs. All values presented in
Table 7 are the most recent available at
[[Page 28673]]
the time of publication and are available in NMFS' final 2021 SARs
(Hayes et al., 2022) and draft 2022 SARs available online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports</a>.
Table 7--Marine Mammal Species \5\ Likely to Occur Near the Project Area That May Be Taken by Dominion Energy's Proposed Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Annual
ESA/ MMPA status; Stock abundance (CV, mortalities
Common name Scientific name Stock strategic (Y/ Nmin, most recent PBR or serious
N)\1\ abundance survey) \2\ injuries (M/
SI) \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenidae:
North Atlantic right whale...... Eubalaena glacialis.... Western Atlantic...... E, D, Y 338 (0; 332; 2020) \5\ 0.7 8.1
Family Balaenopteridae (rorquals):
Fin whale....................... Balaenoptera physalus.. Western North Atlantic E, D, Y 6,802 (0.24; 5,573; 11 1.8
2016).
Humpback whale.................. Megaptera novaeangliae. Gulf of Maine......... -, -, Y 1,396 (0; 1,380; 2016) 22 12.15
Minke whale..................... Balaenoptera Canadian Eastern -, -, N 21,968 (0.31; 17,002; 170 10.6
acutorostrata. Coastal. 2016).
Sei whale....................... Balaenoptera borealis.. Nova Scotia........... E, D, Y 6,292 (1.02; 3,098; 6.2 0.8
2016).
Family Physeteridae:
Sperm whale..................... Physeter macrocephalus. North Atlantic........ E, D, Y 4,349 (0.28; 3,451; 3.9 0
2016).
Family Kogiidae:
Pygmy sperm whale \7\ \8\....... Kogia breviceps........ Western North Atlantic -, -, N 7,750 (0.38; 5,689; 46 0
2016).
Family Delphinidae:
Atlantic spotted dolphin........ Stenella frontalis..... Western North Atlantic -, -, N 39,921 (0.27; 32,032; 320 0
2016).
Atlantic white-sided dolphin.... Lagenorhynchus acutus.. Western North Atlantic -, -, N 93,233 (0.71; 54,433; 544 27
2016).
Bottlenose dolphin.............. Tursiops truncatus..... Western North -, -, N 62,851 (0.23; 51,914; 519 28
Atlantic--Offshore. 2016).
Southern Migratory -, -, Y 3,751 (0.6; 185; See 23 0-18.3
Coastal. SAR).
Clymene dolphin \7\............. Stenella clymene....... Western North Atlantic -, -, N 4,237 (1.03; 2,071; 21 0
2016).
Common dolphin.................. Delphinus delphis...... Western North Atlantic -, -, N 172,897 (0.21; 1,452 390
145,216; 2016).
False killer whale \7\.......... Pseudorca crassidens... Western North Atlantic -, -, N 1,791 (0.56; 1,154; 12 0
2016).
Melon-headed whale \7\.......... Peponocephala electra.. Western North Atlantic -, -, N UNK (UNK; UNK; 2016).. UNK 0
Long-finned pilot whale \6\..... Globicephala melas..... Western North Atlantic -, -, N 39,215 (0.3; 30,627; 306 29
2016).
Short-finned pilot whale \6\.... Globicephala Western North Atlantic -, -, Y 28,924 (0.24, 23,637, 236 136
macrorhynchus. See SAR).
Pantropical spotted dolphin..... Stenella attenuata..... Western North Atlantic -, D, N 6,593 (0.52, 4,367, 44 0
See SAR).
Risso's dolphin................. Grampus griseus........ Western North Atlantic -, -, N 35,215 (0.19; 30,051; 301 34
2016).
Family Phocoenidae (porpoises):
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise................. Phocoena phocoena...... Gulf of Maine/Bay of -, -, N 95,543 (0.31; 74,034; 851 16
Fundy. 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Gray seal \4\................... Halichoerus grypus..... Western North Atlantic -, -, N 27,300 (0.22; 22,785; 1,389 4,453
2016).
Harbor seal..................... Phoca vitulina......... Western North Atlantic -, -, N 61,336 (0.08; 57,637; 1,729 339
2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS' marine mammal stock assessment reports can be found online at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> assessments. CV is the coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, ship strike).
\4\ NMFS' stock abundance estimate (and associated PBR value) applies to the U.S. population only. Total stock abundance (including animals in Canada)
is approximately 451,431. The annual M/SI value given is for the total stock.
\5\ 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)).
\6\ Although both species are described here, the requested take for both short-finned and long-finned pilot whales has been summarized into a single
group (pilot whales spp.).
\7\ While these species were not originally included in Dominion Energy's request, given recorded sightings/detections of these species during previous
Dominion Energy IHAs in the same general area, NMFS has included these as species that may be harassed (by Level B harassment only) during the five-
year effective period of this proposed rulemaking.
\8\ Estimate is for Kogia spp. only.
[[Page 28674]]
As indicated above, all 21 species and 22 stocks in Table 7
temporally and spatially co-occur with the activity to the degree that
take is reasonably likely to occur. Four of the marine mammal species
for which take is requested are listed as threatened or endangered
under the ESA, including North Atlantic right, fin, sei, and sperm
whales. In addition to what is included in Sections 3 and 4 of Dominion
Energy's ITA application (<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-construction-coastal-virginia">https://www.fisheries.noaa.gov/action/incidental-take-authorization-dominion-energy-virginia-construction-coastal-virginia</a>), the 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 NMFS'
website (<a href="https://www.fisheries.noaa.gov/species-directory/marine-mammals">https://www.fisheries.noaa.gov/species-directory/marine-mammals</a>), we provide further detail below informing the baseline for
select species (e.g., information regarding current Unusual Mortality
Events (UME) and known important habitat areas, such as Biologically
Important Areas (BIAs) (Van Parijs, 2015). There are no ESA-designated
critical habitats for any species within the CVOW-C project area.
Under the MMPA, a UME is defined as ``a stranding that is
unexpected; involves a significant die-off of any marine mammal
population; and demands immediate response'' (16 U.S.C. 1421h(6)). As
of April 13, 2023, five UMEs are considered active, with four of these
occurring along the U.S. Atlantic coast for various marine mammal
species; of these, the most relevant to the CVOW-C project are the
North Atlantic right whale and the humpback whale, given the prevalence
of these species in the project area. A more recent UME is active for
the Northeast pinnipeds (harbor and gray seals) but has only been
recorded in Maine, which is outside the project area. Two other UMEs,
one for the Atlantic minke whale from 2017-2022 and one for the
Northeast pinnipeds (harbor and gray seals) from 2018-2020, are
considered non-active and are pending closure. More information on
UMEs, including all active, closed, or pending, can be found on NMFS'
website at <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events">https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusual-mortality-events</a>.
Below we include information for a subset of the species that
presently have an active or recently closed UME occurring along the
Atlantic coast, or for which there is information available related to
areas of biological significance. For the majority of species
potentially present in the specific geographic region, NMFS has
designated only a single generic stock (e.g., ``western North
Atlantic'') for management purposes. This includes the ``Canadian east
coast'' stock of minke whales, which includes all minke whales found in
U.S. waters and is also a generic stock for management purposes. For
humpback and sei whales, NMFS defines stocks on the basis of feeding
locations, i.e., Gulf of Maine and Nova Scotia, respectively. However,
references to humpback whales and sei whales in this document refer to
any individuals of the species that are found in the specific
geographic region. Any areas of known biological importance (including
the BIAs identified in La Brecque et al., 2015) that overlap spatially
with the project area are addressed in the species sections below.
North Atlantic Right Whale
The North Atlantic right whale has been listed as Endangered since
the ESA was enacted in 1973. They were recently uplisted from
Endangered to Critically Endangered on the International Union for
Conservation of Nature (IUCN) Red List of Threatened Species (Cooke,
2020). The uplisting was due to a decrease in population size (Pace et
al., 2017), an increase in vessel strikes and entanglements in fixed
fishing gear (Knowlton et al., 2012; Daoust et al., 2017; Davis and
Brillant, 2019; Sharp et al., 2019; Moore et al., 2021; Knowlton et
al., 2022), and a decrease in birth rate (Pettis et al., 2021; Reed et
al., 2022). The Western Atlantic stock is considered depleted under the
MMPA (Hayes et al., 2022). There is a recovery plan (NOAA Fisheries,
2005) for the North Atlantic right whale, and NMFS completed 5-year
reviews of the species in 2012,2017, and 2022 which concluded no change
to the listing status is warranted.
The North Atlantic right whale population had only a 2.8 percent
recovery rate between 1990 and 2011, and an overall abundance decline
of 29.7 percent from 2011-2020 (Hayes et al., 2022). Since 2010, the
North Atlantic right whale population has been in decline (Pace et al.,
2017; Pace et al., 2021), with a 40 percent decrease in calving rate
(Kraus et al., 2016; Moore et al., 2021). North Atlantic right whale
calving rates dropped from 2017 to 2020, with zero births recorded
during the 2017-2018 season. The 2020-2021 calving season had the first
substantial calving increase in five years, with 20 calves born,
followed by 15 calves during the 2021-2022 calving season. However,
mortalities continue to outpace births, and best estimates indicate
fewer than 100 reproductively active females remain in the population.
NMFS' regulations at 50 CFR 224.105 designated nearshore waters of
the Mid-Atlantic Bight as Mid-Atlantic U.S. Seasonal Management Areas
(SMAs) for right whales in 2008. These specific SMAs were developed to
reduce the threat of collisions between ships and right whales around
their migratory route and calving grounds. As mentioned previously, the
Chesapeake Bay SMA is within the vicinity of the proposed project area
(<a href="https://apps-nefsc.fisheries.noaa.gov/psb/surveys/MapperiframeWithText.html">https://apps-nefsc.fisheries.noaa.gov/psb/surveys/MapperiframeWithText.html</a>). The SMA is currently active from November 1
through April 30 of each year and may be used by right whales for
migrating. As noted above in the Summary of Request section, NMFS is
proposing changes to the North Atlantic right whale speed rule (87 FR
46921; August 1, 2022).
The proposed project area (456.5 km\2\) spatially overlaps a
portion of the migratory corridor BIA (269,488 km\2\ (66,591,935
acres)) within which right whales migrate south to calving grounds
generally in November and December. A northward right whale migration
into feeding areas north of the project area occurs in March and April
(LaBrecque et al., 2015; Van Parijs et al., 2015). The proposed project
area is also in the vicinity of the currently established November 1st
through April 30th Chesapeake Bay SMA (73 FR 60173; October 10, 2008),
which may be used by right whales for various activities, including
migration. Due to the current status of North Atlantic right whales,
and the overlap of the proposed CVOW-C project with areas of biological
significance (i.e., a migratory corridor), the potential impacts of the
proposed project on right whales warrant particular attention.
In late fall, a portion of the right whale population (including
pregnant females) typically departs the feeding grounds in the North
Atlantic, moves south along the migratory corridor BIA, including
through the proposed project area, to right whale calving grounds off
Georgia and Florida. Right whales feed primarily on the copepod,
Calanus finmarchicus, a species whose availability and distribution has
changed both spatially and temporally over the last decade due to an
oceanographic regime shift that has been ultimately linked to climate
change (Meyer-Gutbrod et al., 2021; Record et al., 2019; Sorochan et
al., 2019). This distribution change in prey availability has led to
shifts in right whale habitat-use patterns over the same time period
(Davis et al., 2020;
[[Page 28675]]
Meyer-Gutbrod et al., 2022; Quintano-Rizzo et al., 2021, O'Brien et
al., 2022) with reduced use of foraging habitats in the Great South
Channel and Bay of Fundy and increased use of habitats within Cape Cod
Bay and a region south of Martha's Vineyard and Nantucket Islands
(Stone et al., 2017; Mayo et al., 2018; Ganley et al., 2019; Record et
al., 2019; Meyer-Gutbrod et al., 2021); these foraging habitats are all
located several hundred kilometers north of the project area. Passive
acoustic monitoring data demonstrates that since 2010, North Atlantic
right whale use of the mid-Atlantic and southeast has increased (Davis
et al., 2017). Observations of these transitions in right whale habitat
use, variability in seasonal presence in identified core habitats, and
utilization of habitat outside of previously focused survey effort
prompted the formation of a NMFS' Expert Working Group, which
identified current data collection efforts, data gaps, and provided
recommendations for future survey and research efforts (Oleson et al.,
2020). Recent research indicates understanding of their movement
patterns remains incomplete and not all of the population undergoes a
consistent annual migration (Davis et al., 2017; Gowan et al., 2019;
Krzystan et al., 2018). Non-calving females may remain in the feeding
grounds, during the winter in the years preceding and following the
birth of a calf to increase their energy stores (Gowen et al., 2019).
North Atlantic right whale presence within the CVOW-C project area
is predominantly seasonal with individuals likely to be transient and
migrating through the area. The highest density months for North
Atlantic right whales in this area are November through April, however,
mitigation measures include a restriction on pile driving during this
time period. Right whales have also been acoustically detected off
coastal Virginia year-round with detections during the late fall
(October-December) and late winter/early spring (February-March)
(Salisbury et al., 2016). Density data from Roberts and Halpin (2022)
confirm, of the months planned for construction (May through October),
the highest average density of right whales in the CVOW-C project area
occurs in May (0.00015 individuals/km\2\). However, based upon
sightings and acoustic detections, right whales are likely to be
present to some degree in or near the proposed project area throughout
the year (Salisbury et al., 2016; Davis et al., 2017; Cotter, 2019),
though we do not expect that the right whale presence would be in the
larger numbers typically associated with a foraging or calving ground.
Elevated right whale mortalities have occurred since June 7, 2017,
along the U.S. and Canadian coast, with the leading category for the
cause of death for this UME determined to be ``human interaction,''
specifically from entanglements or vessel strikes. As of April 13,
2023, there have been 36 confirmed mortalities (dead stranded or
floaters), 0 pending mortalities, and 33 seriously injured free-
swimming whales for a total of 69 whales. As of October 14, 2022, the
UME also considers animals (n=29) with sub-lethal injury or illness
(called ``morbidity'') bringing the total number of whales in the UME
to 98. Approximately 42 percent of the population is known to be in
reduced health (Hamilton et al., 2021), likely contributing to smaller
body sizes at maturation, making them more susceptible to threats and
reducing fecundity (Moore et al., 2021; Reed et al., 2022; Stewart et
al., 2022). More information about the North Atlantic right whale UME
is available online at: <a href="http://www.fisheries.noaa.gov/national/marine-life-distress/2017-2021-north-atlantic-right-whale-unusual-mortality-event">www.fisheries.noaa.gov/national/marine-life-distress/2017-2021-north-atlantic-right-whale-unusual-mortality-event</a>.
Humpback Whale
Humpback whales are found worldwide in all oceans, but were listed
as endangered under the Endangered Species Conservation Act (ESCA) in
June 1970. In 1973, the ESA replaced the ESCA, and humpbacks continued
to be listed as endangered.
On September 8, 2016, NMFS divided the once single species into 14
distinct population segments (DPS), removed the species-level listing,
and, in its place, listed four DPSs as endangered and one DPS as
threatened (81 FR 62259; September 8, 2016). The remaining nine DPSs
were not listed. The West Indies DPS, which is not listed under the
ESA, is the only DPS of humpback whales that is expected to occur in
the project area. Bettridge et al. (2015) estimated the size of the
West Indies DPS population at 12,312 (95 percent confidence interval
(CI) 8,688-15,954) whales in 2004-05, which is consistent with previous
population estimates of approximately 10,000-11,000 whales (Smith et
al., 1999; Stevick et al., 2003) and the increasing trend for the West
Indies DPS (Bettridge et al., 2015).
Humpback whales are migratory off coastal Virginia, moving
seasonally between northern feeding grounds in New England and southern
calving grounds in the West Indies (Hayes et al., 2022). However, not
all humpback whales migrate to the Caribbean during the winter as
individuals are sighted in mid- to high-latitude areas during this
season (Swingle et al., 1993; Davis et al., 2020). In addition to a
migratory pathway, the mid-Atlantic region also represents a
supplemental winter feeding ground for juveniles and mature whales
(Barco et al., 2002). Records of humpback whales off the U.S. mid-
Atlantic coast (New Jersey south to North Carolina) suggest that these
waters are used as a winter feeding ground from December through March
(Mallette et al., 2017; Barco et al., 2002; LaBrecque et al., 2015) and
represent important habitat for juveniles, in particular (Swingle et
al., 1993; Wiley et al., 1995). Mallette et al. (2017) documented site
fidelity of individual humpback whales to coastal Virginia waters
across seasons and years from 2012-2017. Based upon the analysis of
stomach contents from humpback whales that have previously stranded in
the coastal Virginia area, whales may feed upon Atlantic menhaden and
bay anchovy off coastal Virginia (Mallette et al., 2017).
Since January 2016, elevated humpback whale mortalities along the
Atlantic coast from Maine to Florida led to the declaration of a UME.
Partial or full necropsy examinations have been conducted on
approximately half of the 191 known cases (as of April 13, 2023). Of
the whales examined (approximately 90), about 40 percent had evidence
of human interaction, either ship strike or entanglement (<a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast">https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast</a>). While a
portion of the whales have shown evidence of pre-mortem vessel strike,
this finding is not consistent across all whales examined and more
research is needed. NOAA is consulting with researchers that are
conducting studies on the humpback whale populations, and these efforts
may provide information on changes in whale distribution and habitat
use that could provide additional insight into how these vessel
interactions occurred. More information is available at: <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast">https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2023-humpback-whale-unusual-mortality-event-along-atlantic-coast</a>.
Since December 1, 2022, the number of humpback strandings along the
mid-Atlantic coast, including Virginia off Virginia Beach, has been
elevated. In some cases, the cause of death is not yet known. In
others, vessel strike has been deemed the cause of death. As the
humpback whale population has grown,
[[Page 28676]]
they are seen more often in the Mid-Atlantic. Along the New York/New
Jersey/Virginia shore, these whales may be following their prey which
are reportedly close to shore in the winter. These prey also attract
fish that are of interest to recreational and commercial fishermen.
This increases the number of boats in these areas. More whales in the
water in areas traveled by boats of all sizes increases the risk of
vessel strikes. Vessel strikes and entanglement in fishing gear are the
greatest human threats to large whales.
Fin Whale
Fin whales frequently occur in the waters of the U.S. Atlantic
Exclusive Economic Zone (EEZ), principally from Cape Hatteras, North
Carolina northward and are distributed in both continental shelf and
deep water habitats (Hayes et al., 2022). Although fin whales are
present north of the 35-degree latitude region in every season and are
broadly distributed throughout the western North Atlantic for most of
the year, densities vary seasonally (Edwards et al., 2015; Hayes et
al., 2022). Acoustic detections suggest year-round presence in Virginia
waters, with the greatest number of detections occurring from August
through April (Davis et al., 2020). Acoustic observations of fin whale
singers from both the Atlantic Continental Shelf and deep-ocean areas
provide evidence of fin whale singing throughout these regions year-
round and support the conclusion that male fin whales are broadly
distributed throughout the western North Atlantic for most of the year
(Watkins et al., 1987; Clark and Gagnon, 2002; Morano et al., 2012;
Davis et al., 2020; Hayes et al., 2022).
The New England area represents a major feeding ground for fin
whales, with two known foraging BIAs in the general area. Fin whales
typically feed in the Gulf of Maine and the waters surrounding New
England, but their mating and calving (and general wintering) areas are
largely unknown (Hain et al., 1992, Hayes et al., 2022). Hain et al.
(1992) suggested calving occurs in the mid-Atlantic region from October
through January, yet this remains to be confirmed. However, given the
more southerly location of the Virginia Lease Area (located
approximately 516 km (320.6 mi) away from the Montauk Point BIA (2,933
km\2\ (724,760.1 acres); Hain et al., 1992; LaBrecque et al., 2015) and
approximately 695 km (431.9 mi) from the southern Gulf of Maine BIA
(18,015 km\2\; 4,451,603.4 acres). Therefore, there would be no overlap
from the CVOW-C project with either of the fin whale feeding BIAs.
Minke Whale
Minke whales are common and widely distributed throughout the U.S.
Atlantic EEZ (Cetacean and Turtle Assessment Program (CETAP), 1982;
Hayes et al., 2022), although their distribution has a strong seasonal
component. Individuals have often been detected acoustically in shelf
waters from spring to fall and more often detected in deeper offshore
waters from winter to spring (Risch et al., 2013). Minke whales are
abundant in New England waters from May through September (Pittman et
al., 2006; Waring et al., 2014), yet largely absent from these areas
during the winter, suggesting the possible existence of a migratory
corridor (LaBrecque et al., 2015). A migratory route for minke whales
transiting between northern feeding grounds and southern breeding areas
may exist to the east of the proposed project area, as minke whales may
track warmer waters along the continental shelf while migrating (Risch
et al., 2014). Overall, minke whale use of the project area is likely
highest during winter months when foundation installation would not be
occurring. No mating or calving grounds have been identified along the
U.S. Atlantic coast (LaBrecque et al., 2015).
There are two minke whale feeding BIAs identified in the southern
and southwestern section of the Gulf of Maine, including Georges Bank,
the Great South Channel, Cape Cod Bay and Massachusetts Bay, Stellwagen
Bank, Cape Anne, and Jeffreys Ledge from March through November,
annually (LeBrecque et al., 2015). However, these BIAs are located
north of the CVOW-C project area, at approximately 656 km (407.6 mi)
from the CVOW-C project area to the most southern BIA and would not
overlap the CVOW-C project area.
Since January 2017, elevated minke whale mortalities detected along
the Atlantic coast from Maine through South Carolina resulted in the
declaration of a UME. As of April 13, 2023, a total of 142 minke whales
have stranded during this UME. Full or partial necropsy examinations
were conducted on more than 60 percent of the whales. Preliminary
findings have shown evidence of human interactions or infectious
disease in several of the whales, but these findings are not consistent
across all of the whales examined, so more research is needed. This UME
has been declared non-active and is pending closure. More information
is available at: <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast">https://www.fisheries.noaa.gov/national/marine-life-distress/2017-2022-minke-whale-unusual-mortality-event-along-atlantic-coast</a>.
Sei Whale
The Nova Scotia stock of sei whales can be found in deeper waters
of the continental shelf edge of the eastern United States and
northeastward to south of Newfoundland (Mitchell, 1975; Hain et al.,
1985; Hayes et al., 2022). During spring and summer, the stock is
mainly concentrated in northern feeding areas, including the Scotian
Shelf (Mitchell and Chapman, 1977), the Gulf of Maine, Georges Bank,
the Northeast Channel, and south of Nantucket (CETAP, 1982; Kraus et
al., 2016; Roberts et al., 2016; Palka et al., 2017; Cholewiak et al.,
2018; Hayes et al., 2022). Sei whales have been detected acoustically
along the Atlantic Continental Shelf and Slope from south of Cape
Hatteras, North Carolina to the Davis Strait, with acoustic occurrence
increasing in the mid-Atlantic region since 2010 (Davis et al., 2020).
Although their migratory movements are not well understood, sei whales
are believed to migrate north in June and July to feeding areas and
south in September and October to breeding areas (Mitchell, 1975;
CETAP, 1982; Davis et al., 2020). Davis et al. (2020) acoustically
detected sei whales in offshore waters of the mid-Atlantic region
during the winter months. Very few sei whales were detected in the mid-
Atlantic during the summer (the primary time of year when foundation
installation would be occurring), with the exception of a detection
that lasted for two days off Virginia. Although sei whales generally
occur offshore, individuals may also move into shallower, more inshore
waters (Payne et al., 1990; Halpin et al., 2009; Hayes et al., 2022).
A sei whale feeding BIA occurs in New England waters from May
through November (LaBrecque et al., 2015). This BIA is located
approximately 600 km (372.8 mi) northeast of the project area and is
not expected to be impacted by project activities related to CVOW-C.
Phocid Seals
Since June 2022, elevated numbers of harbor seal and gray seal
mortalities have occurred across the southern and central coast of
Maine. This event has been declared a UME. Preliminary testing of
samples has found some harbor and gray seals positive for highly
pathogenic avian influenza. While the UME is not occurring in the CVOW-
C project area, the populations affected by the UME are the same as
those potentially affected by the project.
[[Page 28677]]
However, due to the two states being approximately 677.6 km (421 mi)
apart, by water (from the most northern point of Virginia to the most
southern point of Maine), NMFS does not expect that this UME would be
further conflated by the proposed activities related to the CVOW-C
project. Information on this UME is available online at: <a href="https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast">https://www.fisheries.noaa.gov/2022-2023-pinniped-unusual-mortality-event-along-maine-coast</a>.
The above event was preceded by a different UME, occurring from
2018-2020 (closure of the 2018-2020 UME is pending). Beginning in July
2018, elevated numbers of harbor seal and gray seal mortalities
occurred across Maine, New Hampshire, and Massachusetts. Additionally,
stranded seals have shown clinical signs as far south as Virginia,
although not in elevated numbers, therefore the UME investigation
encompassed all seal strandings from Maine to Virginia. A total of
3,152 reported strandings (of all species) occurred from July 1, 2018,
through March 13, 2020. Full or partial necropsy examinations have been
conducted on some of the seals and samples have been collected for
testing. Based on tests conducted thus far, the main pathogen found in
the seals is phocine distemper virus. NMFS is performing additional
testing to identify any other factors that may be involved in this UME,
which is pending closure. Information on this UME is available online
at: <a href="https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along">https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along</a>.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al. (2007) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
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 8.
Table 8--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 150 Hz to 160 kHz.
(dolphins, 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) 50 Hz to 86 kHz.
(true 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 and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Twenty-one marine mammal species (19 cetacean species (5 mysticetes and
14 odontocetes) and 2 pinniped species (both phocid), consisting of 22
total stocks) have the reasonable potential to co-occur with the
proposed project activities (Table 7).
NMFS notes that in 2019, Southall et al. recommended new names for
hearing groups that are widely recognized. However, this new hearing
group classification does not change the weighting functions or
acoustic thresholds (i.e., the weighting functions and thresholds in
Southall et al. (2019) are identical to NMFS 2018 Revised Technical
Guidance). When NMFS updates our Technical Guidance, we will be
adopting the updated Southall et al. (2019) hearing group
classification.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
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 how those impacts on individuals are
likely to impact marine mammal species or stocks. General background
information on marine mammal hearing was provided previously (see the
Description of Marine Mammals in the Area of Specified Activities
section). Here, the potential effects of sound on marine mammals are
discussed.
Dominion Energy has requested authorization to take marine mammals
incidental to construction activities associated within the CVOW-C
project area. In the ITA application, Dominion Energy presented
analyses of potential impacts to marine mammals from use of acoustic
sources. NMFS carefully reviewed the information provided by Dominion
Energy and independently
[[Page 28678]]
reviewed applicable scientific research and literature and other
information to evaluate the potential effects of Dominion Energy's
activities on marine mammals.
The proposed activities include the placement of up to 179
permanent foundations (176 WTGs and 3 OSSs), temporary nearshore cable
landfall activities (i.e., cofferdams and goal posts), and site
characterization surveys (i.e., HRG surveys). There are a variety of
types and degrees of effects to marine mammals, prey species, and
habitat that could occur as a result of the project. Below we provide a
brief description of the types of sound sources that would be used in
the project, the types of impacts that can potentially result from
these sources and types of activities, and a brief discussion of the
anticipated impacts on marine mammals from the CVOW-C project
specifically, with consideration of the proposed mitigation measures.
Description of Sound Sources
This section contains a brief technical background on sound, on the
characteristics of certain sound types, and on metrics used in this
proposal inasmuch as the information is relevant to the specified
activity and to a discussion of the potential effects of the specified
activity on marine mammals found later in this document. For general
information on sound and its interaction with the marine environment,
please see, e.g., Au and Hastings (2008); Richardson et al. (1995);
Urick (1983) as well as the Discovery of Sound in the Sea (DOSITS)
website at <a href="https://dosits.org/">https://dosits.org/</a>.
Sound is a vibration that travels as an acoustic wave through a
medium such as a gas, liquid or solid. Sound waves alternately compress
and decompress the medium as the wave travels. These compressions and
decompressions are detected as changes in pressure by aquatic life and
man-made sound receptors such as hydrophones (underwater microphones).
In water, sound waves radiate in a manner similar to ripples on the
surface of a pond and may be either directed in a beam (narrow beam or
directional sources) or sound beams may radiate in all directions
(omnidirectional sources).
Sound travels in water more efficiently than almost any other form
of energy, making the use of acoustics ideal for the aquatic
environment and its inhabitants. In seawater, sound travels at roughly
1,500 meters per second (m/s). In air, sound waves travel much more
slowly at about 340 m/s. However, the speed of sound can vary by a
small amount based on characteristics of the transmission medium such
as water temperature and salinity.
The basic components of a sound wave are frequency, wavelength,
velocity, and amplitude. Frequency is the number of pressure waves that
pass by a reference point per unit of time and is measured in Hz or
cycles per second. Wavelength is the distance between two peaks or
corresponding points of a sound wave (length of one cycle). Higher
frequency sounds have shorter wavelengths than lower frequency sounds
and typically attenuate (decrease) more rapidly except in certain cases
in shallower water. The intensity (or amplitude) of sounds are measured
in decibels (dB), which are a relative unit of measurement that is used
to express the ratio of one value of a power or field to another.
Decibels are measured on a logarithmic scale, so a small change in dB
corresponds to large changes in sound pressure. For example, a 10 dB
increase is a ten-fold increase in acoustic power. A 20 dB increase is
then a 100-fold increase in power and a 30 dB increase is a 1000-fold
increase in power. However, a ten-fold increase in acoustic power does
not mean that the sound is perceived as being 10 times louder. Decibels
are a relative unit comparing two pressures; therefore, a reference
pressure must always be indicated. For underwater sound, this is 1
microPascal ([mu]Pa). For in-air sound, the reference pressure is 20
microPascal ([mu]Pa). The amplitude of a sound can be presented in
various ways; however, NMFS typically considers three metrics.
Sound exposure level (SEL) represents the total energy in a stated
frequency band over a stated time interval or event and considers both
amplitude and duration of exposure (represented as dB re 1 [mu]Pa2-s).
SEL is a cumulative metric; it can be accumulated over a single pulse
(for pile driving this is often referred to as single-strike SEL;
SELss) or calculated over periods containing multiple pulses
(SEL<INF>cum</INF>). Cumulative SEL represents the total energy
accumulated by a receiver over a defined time window or during an
event. The SEL metric is useful because it allows sound exposures of
different durations to be related to one another in terms of total
acoustic energy. The duration of a sound event and the number of
pulses, however, should be specified as there is no accepted standard
duration over which the summation of energy is measured. Sounds are
typically classified by their spectral and temporal properties.
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Root mean square is calculated by squaring
all of the sound amplitudes, averaging the squares, and then taking the
square root of the average (Urick, 1983). Root mean square accounts for
both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper, 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units than by peak pressures.
Peak sound pressure (also referred to as zero-to-peak sound
pressure or 0-pk) is the maximum instantaneous sound pressure
measurable in the water at a specified distance from the source, and is
represented in the same units as the rms sound pressure. Along with
SEL, this metric is used in evaluating the potential for PTS (permanent
threshold shift) and TTS (temporary threshold shift).
Sounds can be either impulsive or non-impulsive. The distinction
between these two sound types 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). Please see NMFS et
al. (2018) and Southall et al. (2007, 2019) for an in-depth discussion
of these concepts. Impulsive sound sources (e.g., airguns, explosions,
gunshots, sonic booms, impact pile driving) produce signals that are
brief (typically considered to be less than 1 second), broadband,
atonal transients (American National Standards Institute (ANSI), 1986,
2005; Harris, 1998; National Institute for Occupational Safety and
Health (NIOSH), 1998; International Organization for Standardization
(ISO), 2003) and occur either as isolated events or repeated in some
succession. Impulsive sounds are all characterized by a relatively
rapid rise from ambient pressure to a maximal pressure value followed
by a rapid decay period that may include a period of diminishing,
oscillating maximal and minimal pressures, and generally have an
increased capacity to induce physical injury as compared with sounds
that lack these features. Impulsive sounds are typically intermittent
in nature.
Non-impulsive sounds can be tonal, narrowband, or broadband, brief
or prolonged, and may be either continuous or intermittent (ANSI, 1995;
NIOSH, 1998). Some of these non-impulsive sounds can be transient
signals of short duration but without the essential properties of
pulses (e.g., rapid rise time). Examples of non-impulsive
[[Page 28679]]
sounds include those produced by vessels, aircraft, machinery
operations such as drilling or dredging, vibratory pile driving, and
active sonar systems.
Sounds are also characterized by their temporal component.
Continuous sounds are those whose sound pressure level remains above
that of the ambient sound with negligibly small fluctuations in level
(NIOSH, 1998; ANSI, 2005) while intermittent sounds are defined as
sounds with interrupted levels of low or no sound (NIOSH, 1998). NMFS
identifies Level B harassment thresholds based on if a sound is
continuous or intermittent.
Even in the absence of sound from the specified activity, the
underwater environment is typically loud due to ambient sound, which is
defined as environmental background sound levels lacking a single
source or point (Richardson et al., 1995). The sound level of a region
is defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., wind and
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds
produced by marine mammals, fish, and invertebrates), and anthropogenic
(e.g., vessels, dredging, construction) sound. A number of sources
contribute to ambient sound, including wind and waves, which are a main
source of naturally occurring ambient sound for frequencies between 200
Hz and 50 kHz (International Council for the Exploration of the Sea
(ICES), 1995). In general, ambient sound levels tend to increase with
increasing wind speed and wave height. Precipitation can become an
important component of total sound at frequencies above 500 Hz and
possibly down to 100 Hz during quiet times. Marine mammals can
contribute significantly to ambient sound levels as can some fish and
snapping shrimp. The frequency band for biological contributions is
from approximately 12 Hz to over 100 kHz. Sources of ambient sound
related to human activity include transportation (surface vessels),
dredging and construction, oil and gas drilling and production,
geophysical surveys, sonar, and explosions. Vessel noise typically
dominates the total ambient sound for frequencies between 20 and 300
Hz. In general, the frequencies of anthropogenic sounds are below 1
kHz, and if higher frequency sound levels are created, they attenuate
rapidly.
The sum of the various natural and anthropogenic sound sources that
comprise ambient sound at any given location and time depends not only
on the source levels (as determined by current weather conditions and
levels of biological and human 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 the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals. Underwater ambient sound in the Atlantic Ocean offshore of
Virginia comprises sounds produced by a number of natural and
anthropogenic sources. Human-generated sound is a significant
contributor to the acoustic environment in the project location.
Pile driving sounds are broadband, omni-directional sound sources.
Pile driving noise has the potential to result in harassment to marine
mammals if the animal is close enough to the sound source (with the
distances necessary to cause harassment dependent on source levels and
transmission loss rates). HRG sources; however, are more complex as
they vary widely (e.g., side scan sonars, sub-bottom profilers,
boomers, and sparkers). Recently, Ruppel et al. (2022) categorized HRG
sources into four tiers based on their potential to affect marine
animals. All HRG sources proposed for use by Dominion Energy fall into
the Tier 3 or Tier 4 category (note Tier 1 is the most impactful
category containing high-energy airguns). Tier 4 includes most high-
resolution geophysical, oceanographic, and communication/tracking
sources, which are considered unlikely to result in incidental take of
marine mammals and therefore termed de minimis. Tier 3 covers most
remaining non-airgun seismic sources, which either have characteristics
that do not meet the de minimis category (e.g., some sparkers), but
have anticipated impacts less than airguns and for which additional
mitigation may in some cases be able to avoid the likelihood of take,
or could not be fully evaluated in the paper (e.g., bubble guns, some
boomers). Some sparkers fell into Tier 3, as the study found that most
sparkers lack the frequency, beamwidth, and degree of exposure
characteristics to automatically meet the de minimis criteria.
Potential Effects of Underwater Sound on Marine Mammals and Their
Habitat
Anthropogenic sounds cover a broad range of frequencies and sound
levels and can have a range of highly variable impacts on marine life
from none or minor to potentially severe responses depending on
received levels, duration of exposure, behavioral context, and various
other factors. Broadly, underwater sound from active acoustic sources,
such as those in the CVOW-C project, can potentially result in one or
more of the following: temporary or permanent hearing impairment, non-
auditory physical or physiological effects, behavioral disturbance,
stress, and masking (Richardson et al., 1995; Gordon et al., 2003;
Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et al., 2009).
Non-auditory physiological effects or injuries that theoretically might
occur in marine mammals exposed to high level underwater sound or as a
secondary effect of extreme behavioral reactions (e.g., change in dive
profile as a result of an avoidance reaction) caused by exposure to
sound include neurological effects, bubble formation, resonance
effects, and other types of organ or tissue damage (Cox et al., 2006;
Southall et al., 2007; Zimmer and Tyack, 2007; Tal et al., 2015).
In general, the degree of effect of an acoustic exposure is
intrinsically related to the signal characteristics, received level,
distance from the source, and duration of the sound exposure, in
addition to the contextual factors of the receiver (e.g., behavioral
state at time of exposure, age class, etc.). In general, sudden, high
level sounds can cause hearing loss as can longer exposures to lower
level sounds. Moreover, any temporary or permanent loss of hearing will
occur almost exclusively for noise within an animal's hearing range. We
describe below the specific manifestations of acoustic effects that may
occur based on the activities proposed by Dominion Energy.
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First (at the greatest distance) is the area within which the
acoustic signal would be audible (potentially perceived) to the animal
but not strong enough to elicit any overt behavioral or physiological
response. The next zone (closer to the receiving animal) corresponds
with the area where the signal is audible to the animal and of
sufficient intensity to elicit behavioral or physiological
responsiveness. The third is a zone
[[Page 28680]]
within which, for signals of high intensity, the received level is
sufficient to potentially cause discomfort or tissue damage to auditory
or other systems. Overlaying these zones to a certain extent is the
area within which masking (i.e., when a sound interferes with or masks
the ability of an animal to detect a signal of interest that is above
the absolute hearing threshold) may occur; the masking zone may be
highly variable in size.
Below, we provide additional detail regarding potential impacts on
marine mammals and their habitat from noise in general, starting with
hearing impairment, as well as from the specific activities Dominion
Energy plans to conduct, to the degree it is available (noting that
there is limited information regarding the impacts of offshore wind
construction on marine mammals).
Hearing Threshold Shift
Marine mammals exposed to high-intensity sound or to lower-
intensity sound for prolonged periods can experience hearing threshold
shift (TS), which NMFS defines 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 expressed in decibels (NMFS, 2018). Threshold shifts can be
permanent, in which case there is an irreversible increase in the
threshold of audibility at a specified frequency or portion of an
individual's hearing range or temporary, in which there is reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range and the animal's hearing
threshold would fully recover over time (Southall et al., 2019).
Repeated sound exposure that leads to TTS could cause PTS.
When PTS occurs, there can be physical damage to the sound
receptors in the ear (i.e., tissue damage) whereas TTS represents
primarily tissue fatigue and is reversible (Henderson et al., 2008). In
addition, other investigators have suggested that TTS is within the
normal bounds of physiological variability and tolerance and does not
represent physical injury (e.g., Ward, 1997; Southall et al., 2019).
Therefore, NMFS does not consider TTS to constitute auditory injury.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals, and there is no PTS data for cetaceans. However,
such relationships are assumed to be similar to those in humans and
other terrestrial mammals. Noise exposure can result in either a
permanent shift in hearing thresholds from baseline (PTS; a 40 dB
threshold shift approximates a PTS onset; e.g., Kryter et al., 1966;
Miller, 1974; Henderson et al., 2008) or a temporary, recoverable shift
in hearing that returns to baseline (a 6 dB threshold shift
approximates a TTS onset; e.g., Southall et al., 2019). Based on data
from terrestrial mammals, a precautionary assumption is that the PTS
thresholds, expressed in the unweighted peak sound pressure level
metric (PK), for impulsive sounds (such as impact pile driving pulses)
are at least 6 dB higher than the TTS thresholds and the weighted PTS
cumulative sound exposure level thresholds are 15 (impulsive sound) to
20 (non-impulsive sounds) dB higher than TTS cumulative sound exposure
level thresholds (Southall et al., 2019). Given the higher level of
sound or longer exposure duration necessary to cause PTS as compared
with TTS, PTS is less likely to occur as a result of these activities,
but it is possible and a small amount has been proposed for
authorization for several species.
TTS is the mildest form of hearing impairment that can occur during
exposure to sound, with a TTS of 6 dB considered the minimum threshold
shift 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., 2000; Finneran et al., 2002). While experiencing TTS,
the hearing threshold rises, and a sound must be at a higher level in
order to be heard. In terrestrial and marine mammals, TTS can last from
minutes or hours to days (in cases of strong TTS). In many cases,
hearing sensitivity recovers rapidly after exposure to the sound ends.
There is data on sound levels and durations necessary to elicit mild
TTS for marine mammals, but recovery is complicated to predict and
dependent on multiple factors.
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. 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
depending on the degree of interference of marine mammals hearing. 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
occurs during a time 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 time when communication is
critical (e.g., for successful mother/calf interactions, consistent
detection of prey) could have more serious impacts.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocaena asiaeorientalis))
and six species of pinnipeds (northern elephant seal (Mirounga
angustirostris), harbor seal, ring seal, spotted seal, bearded seal,
and California sea lion (Zalophus californianus)) that were exposed to
a limited number of sound sources (i.e., mostly tones and octave-band
noise with limited number of exposure to impulsive sources such as
seismic airguns or impact pile driving) in laboratory settings
(Southall et al., 2019). There is currently no data available on noise-
induced hearing loss for mysticetes. For summaries of data on TTS or
PTS in marine mammals or for further discussion of TTS or PTS onset
thresholds, please see Southall et al. (2019) and NMFS (2018).
Recent studies with captive odontocete species (bottlenose dolphin,
harbor porpoise, beluga, and false killer whale) have observed
increases in hearing threshold levels when individuals received a
warning sound prior to exposure to a relatively loud sound (Nachtigall
and Supin, 2013, 2015; Nachtigall et al., 2016a, 2016b, 2016c;
Finneran, 2018; Nachtigall et al., 2018). These studies suggest that
captive animals have a mechanism to reduce hearing sensitivity prior to
impending loud sounds. Hearing change was observed to be frequency
dependent and Finneran (2018) suggests hearing attenuation occurs
within the cochlea or auditory nerve. Based on these observations on
captive odontocetes, the authors suggest that wild animals may have a
mechanism to self-mitigate the impacts of noise exposure by dampening
their hearing during prolonged exposures of loud sound or if
conditioned to anticipate intense sounds (Finneran, 2018, Nachtigall et
al., 2018).
Behavioral Effects
Exposure of marine mammals to sound sources can result in, but is
not limited to, no response or any of the following observable
responses: increased alertness; orientation or attraction to a sound
source; vocal modifications; cessation of feeding; cessation of social
interaction; alteration of movement or diving behavior; habitat
abandonment (temporary or permanent);
[[Page 28681]]
and in severe cases, panic, flight, stampede, or stranding, potentially
resulting in death (Southall et al., 2007). A review of marine mammal
responses to anthropogenic sound was first conducted by Richardson
(1995). More recent reviews address studies conducted since 1995 and
focused on observations where the received sound level of the exposed
marine mammal(s) was known or could be estimated (Nowacek et al., 2007;
DeRuiter et al., 2012 and 2013; Ellison et al., 2012; Gomez et al.,
2016). Gomez et al. (2016) conducted a review of the literature
considering the contextual information of exposure in addition to
received level and found that higher received levels were not always
associated with more severe behavioral responses and vice versa.
Southall et al. (2021) states that results demonstrate that some
individuals of different species display clear yet varied responses,
some of which have negative implications while others appear to
tolerate high levels and that responses may not be fully predictable
with simple acoustic exposure metrics (e.g., received sound level).
Rather, the authors state that differences among species and
individuals along with contextual aspects of exposure (e.g., behavioral
state) appear to affect response probability. Behavioral responses to
sound are highly variable and context-specific. Many different
variables can influence an animal's perception of and response to
(nature and magnitude) an acoustic event. An animal's prior experience
with a sound or sound source affects whether it is less likely
(habituation) or more likely (sensitization) to respond to certain
sounds in the future (animals can also be innately predisposed to
respond to certain sounds in certain ways) (Southall et al., 2019).
Related to the sound itself, the perceived nearness of the sound,
bearing of the sound (approaching vs. retreating), the similarity of a
sound to biologically relevant sounds in the animal's environment
(i.e., calls of predators, prey, or conspecifics), and familiarity of
the sound may affect the way an animal responds to the sound (Southall
et al., 2007, DeRuiter et al., 2013). Individuals (of different age,
gender, reproductive status, etc.) among most populations will have
variable hearing capabilities, and differing behavioral sensitivities
to sounds that will be affected by prior conditioning, experience, and
current activities of those individuals. Often, specific acoustic
features of the sound and contextual variables (i.e., proximity,
duration, or recurrence of the sound or the current behavior that the
marine mammal is engaged in or its prior experience), as well as
entirely separate factors such as the physical presence of a nearby
vessel, may be more relevant to the animal's response than the received
level alone. Overall, the variability of responses to acoustic stimuli
depends on the species receiving the sound, the sound source, and the
social, behavioral, or environmental contexts of exposure (e.g.,
DeRuiter et al., 2012). For example, Goldbogen et al. (2013)
demonstrated that individual behavioral state was critically important
in determining response of blue whales to sonar, noting that some
individuals engaged in deep (greater than 50 m) feeding behavior had
greater dive responses than those in shallow feeding or non-feeding
conditions. Some blue whales in the Goldbogen et al. (2013) study that
were engaged in shallow feeding behavior demonstrated no clear changes
in diving or movement even when received levels were high (~160 dB re
1[micro]Pa) for exposures to 3-4 kHz sonar signals, while deep feeding
and non-feeding whales showed a clear response at exposures at lower
received levels of sonar and pseudorandom noise. Southall et al. (2011)
found that blue whales had a different response to sonar exposure
depending on behavioral state, more pronounced when deep feeding/travel
modes than when engaged in surface feeding.
With respect to distance influencing disturbance, DeRuiter et al.
(2013) examined behavioral responses of Cuvier's beaked whales to mid-
frequency sonar and found that whales responded strongly at low
received levels (89-127 dB re 1[micro]Pa) by ceasing normal fluking and
echolocation, swimming rapidly away, and extending both dive duration
and subsequent non-foraging intervals when the sound source was 3.4-9.5
km away. Importantly, this study also showed that whales exposed to a
similar range of received levels (78-106 dB re 1[micro]Pa) from distant
sonar exercises (118 km away) did not elicit such responses, suggesting
that context may moderate reactions. Thus, distance from the source is
an important variable in influencing the type and degree of behavioral
response and this variable is independent of the effect of received
levels (e.g., DeRuiter et al., 2013; Dunlop et al., 2017a, 2017b;
Falcone et al., 2017; Dunlop et al., 2018; Southall et al., 2019).
Ellison et al. (2012) outlined an approach to assessing the effects
of sound on marine mammals that incorporates contextual-based factors.
The authors recommend considering not just the received level of sound
but also the activity the animal is engaged in at the time the sound is
received, the nature and novelty of the sound (i.e., is this a new
sound from the animal's perspective), and the distance between the
sound source and the animal. They submit that this ``exposure
context,'' as described, greatly influences the type of behavioral
response exhibited by the animal. Forney et al. (2017) also point out
that an apparent lack of response (e.g., no displacement or avoidance
of a sound source) may not necessarily mean there is no cost to the
individual or population, as some resources or habitats may be of such
high value that animals may choose to stay, even when experiencing
stress or hearing loss. Forney et al. (2017) recommend considering both
the costs of remaining in an area of noise exposure such as TTS, PTS,
or masking, which could lead to an increased risk of predation or other
threats or a decreased capability to forage, and the costs of
displacement, including potential increased risk of vessel strike,
increased risks of predation or competition for resources, or decreased
habitat suitable for foraging, resting, or socializing. This sort of
contextual information is challenging to predict with accuracy for
ongoing activities that occur over large spatial and temporal expanses.
However, distance is one contextual factor for which data exist to
quantitatively inform a take estimate, and the method for predicting
Level B harassment in this rule does consider distance to the source.
Other factors are often considered qualitatively in the analysis of the
likely consequences of sound exposure where supporting information is
available.
Behavioral change, such as disturbance manifesting in lost foraging
time, in response to anthropogenic activities is often assumed to
indicate a biologically significant effect on a population of concern.
However, individuals may be able to compensate for some types and
degrees of shifts in behavior, preserving their health and thus their
vital rates and population dynamics. For example, New et al. (2013)
developed a model simulating the complex social, spatial, behavioral
and motivational interactions of coastal bottlenose dolphins in the
Moray Firth, Scotland, to assess the biological significance of
increased rate of behavioral disruptions caused by vessel traffic.
Despite a modeled scenario in which vessel traffic increased from 70 to
470 vessels a year (a six-fold increase in vessel traffic) in response
to the
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construction of a proposed offshore renewables' facility, the dolphins'
behavioral time budget, spatial distribution, motivations and social
structure remained unchanged. Similarly, two bottlenose dolphin
populations in Australia were also modeled over 5 years against a
number of disturbances (Reed et al., 2020) and results indicate that
habitat/noise disturbance had little overall impact on population
abundances in either location, even in the most extreme impact
scenarios modeled.
Friedlaender et al. (2016) provided the first integration of direct
measures of prey distribution and density variables incorporated into
across-individual analyses of behavior responses of blue whales to
sonar and demonstrated a fivefold increase in the ability to quantify
variability in blue whale diving behavior. These results illustrate
that responses evaluated without such measurements for foraging animals
may be misleading, which again illustrates the context-dependent nature
of the probability of response.
The following subsections provide examples of behavioral responses
that give an idea of the variability in behavioral responses that would
be expected given the differential sensitivities of marine mammal
species to sound, contextual factors, and the wide range of potential
acoustic sources to which a marine mammal may be exposed. Behavioral
responses that could occur for a given sound exposure should be
determined from the literature that is available for each species, or
extrapolated from closely related species when no information exists,
along with contextual factors.
Avoidance and Displacement
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
(Eschrichtius robustus) and humpback whales are known to change
direction--deflecting from customary migratory paths--in order to avoid
noise from airgun surveys (Malme et al., 1984; Dunlop et al., 2018).
Avoidance is qualitatively different from the flight response but also
differs in the magnitude of the response (i.e., directed movement, rate
of travel, etc.). Avoidance may be short-term with animals returning to
the area once the noise has ceased (e.g., Malme et al., 1984; Bowles et
al., 1994; Goold, 1996; Stone et al., 2000; Morton and Symonds, 2002;
Gailey et al., 2007; D[auml]hne et al., 2013; Russel et al., 2016).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006; Forney et al., 2017). Avoidance of marine mammals during
the construction of offshore wind facilities (specifically, impact pile
driving) has been documented in the literature with some significant
variation in the temporal and spatial degree of avoidance and with most
studies focused on harbor porpoises as one of the most common marine
mammals in European waters (e.g., Tougaard et al., 2009; D[auml]hne et
al., 2013; Thompson et al., 2013; Russell et al., 2016; Brandt et al.,
2018).
Available information on impacts to marine mammals from pile
driving associated with offshore wind is limited to information on
harbor porpoises and seals, as the vast majority of this research has
occurred at European offshore wind projects where large whales and
other odontocete species are uncommon. Harbor porpoises and harbor
seals are considered to be behaviorally sensitive species (e.g.,
Southall et al., 2007) and the effects of wind farm construction in
Europe on these species has been well documented. These species have
received particular attention in European waters due to their abundance
in the North Sea (Hammond et al., 2002; Nachtsheim et al., 2021). A
summary of the literature on documented effects of wind farm
construction on harbor porpoise and harbor seals is described below.
Brandt et al. (2016) summarized the effects of the construction of
eight offshore wind projects within the German North Sea (i.e., Alpha
Ventus, BARD Offshore I, Borkum West II, DanTysk, Global Tech I,
Meerwind S[uuml]d/Ost, Nordsee Ost, and Riffgat) between 2009 and 2013
on harbor porpoises, combining PAM data from 2010-2013 and aerial
surveys from 2009-2013 with data on noise levels associated with pile
driving. Results of the analysis revealed significant declines in
porpoise detections during pile driving when compared to 25-48 hours
before pile driving began, with the magnitude of decline during pile
driving clearly decreasing with increasing distances to the
construction site. During the majority of projects, significant
declines in detections (by at least 20 percent) were found within at
least 5-10 km of the pile driving site, with declines at up to 20-30 km
of the pile driving site documented in some cases. Similar results
demonstrating the long-distance displacement of harbor porpoises (18-25
km) and harbor seals (up to 40 km) during impact pile driving have also
been observed during the construction at multiple other European wind
farms (Tougaard et al., 2009; Bailey et al., 2010; D[auml]hne et al.,
2013; Lucke et al., 2012; Haleters et al., 2015).
While harbor porpoises and seals tend to move several kilometers
away from wind farm construction activities, the duration of
displacement has been documented to be relatively temporary. In two
studies at Horns Rev II using impact pile driving, harbor porpoise
returned within 1-2 days following cessation of pile driving (Tougaard
et al., 2009, Brandt et al., 2011). Similar recovery periods have been
noted for harbor seals off England during the construction of four wind
farms (Brasseur et al., 2010; Carroll et al., 2010; Hamre et al., 2011;
Hastie et al., 2015; Russell et al., 2016). In some cases, an increase
in harbor porpoise activity has been documented inside wind farm areas
following construction (e.g., Lindeboom et al., 2011). Other studies
have noted longer term impacts after impact pile driving. Near Dogger
Bank in Germany, harbor porpoises continued to avoid the area for over
2 years after construction began (Gilles et al., 2009). Approximately
10 years after construction of the Nysted wind farm, harbor porpoise
abundance had not recovered to the original levels previously seen,
although the echolocation activity was noted to have been increasing
when compared to the previous monitoring period (Teilmann and
Carstensen, 2012). However, overall, there are no indications for a
population decline of harbor porpoises in European waters (e.g., Brandt
et al., 2016). Notably, where significant differences in displacement
and return rates have been identified for these species, the occurrence
of secondary project-specific influences such as use of mitigation
measures (e.g., bubble curtains, acoustic deterrent devices (ADDs)) or
the manner in which species use the habitat in the project area are
likely the driving factors of this variation.
NMFS notes the aforementioned studies from Europe involve
installing much smaller piles than Dominion Energy proposes to install
and, therefore, we anticipate noise levels from impact pile driving to
be louder. For this reason, we anticipate that the greater distances of
displacement observed in harbor porpoise and harbor seals documented in
Europe are likely to occur off Virginia. However, we do
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not anticipate any greater severity of response due to harbor porpoise
and harbor seal habitat use off Virginia or population-level
consequences similar to European findings. In many cases, harbor
porpoises and harbor seals are resident to the areas where European
wind farms have been constructed. However, off Virginia, harbor
porpoises are primarily transient (with higher abundances in winter
when impact pile driving would not occur) and a very small percentage
of the large harbor seal population are only seasonally present with no
rookeries established. In summary, we anticipate that harbor porpoise
and harbor seals will likely respond to pile driving by moving several
kilometers away from the source but return to typical habitat use
patterns when pile driving ceases.
Some avoidance behavior of other marine mammal species has been
documented to be dependent on distance from the source. As described
above, DeRuiter et al. (2013) noted that distance from a sound source
may moderate marine mammal reactions in their study of Cuvier's beaked
whales (an acoustically sensitive species), which showed the whales
swimming rapidly and silently away when a sonar signal was 3.4-9.5 km
away while showing no such reaction to the same signal when the signal
was 118 km away even though the received levels were similar. Tyack et
al. (1983) conducted playback studies of Surveillance Towed Array
Sensor System (SURTASS) low frequency active (LFA) sonar in a gray
whale migratory corridor off California. Similar to North Atlantic
right whales, gray whales migrate close to shore (approximately +2 kms)
and are low frequency hearing specialists. The LFA sonar source was
placed within the gray whale migratory corridor (approximately 2 km
offshore) and offshore of most, but not all, migrating whales
(approximately 4 km offshore). These locations influenced received
levels and distance to the source. For the inshore playbacks, not
unexpectedly, the louder the source level of the playback (i.e., the
louder the received level), whale avoided the source at greater
distances. Specifically, when the source level was 170 dB rms and 178
dB rms, whales avoided the inshore source at ranges of several hundred
meters, similar to avoidance responses reported by Malme et al. (1983,
1984). Whales exposed to source levels of 185 dB rms demonstrated
avoidance levels at ranges of +1 km. Responses to the offshore source
broadcasting at source levels of 185 and 200 dB, avoidance responses
were greatly reduced. While there was observed deflection from course,
in no case did a whale abandon its migratory behavior.
The signal context of the noise exposure has been shown to play an
important role in avoidance responses. In a 2007-2008 Bahamas study,
playback sounds of a potential predator--a killer whale--resulted in a
similar but more pronounced reaction in beaked whales (an acoustically
sensitive species), which included longer inter-dive intervals and a
sustained straight-line departure of more than 20 km from the area
(Boyd et al., 2008; Southall et al., 2009; Tyack et al., 2011).
Dominion Energy does not anticipate, and NMFS is not proposing to
authorize take of beaked whales and, moreover, the sounds produced by
Dominion Energy do not have signal characteristics similar to
predators. Therefore we would not expect such extreme reactions to
occur. Southall et al. 2011 found that blue whales had a different
response to sonar exposure depending on behavioral state, more
pronounced when deep feeding/travel modes than when engaged in surface
feeding.
One potential consequence of behavioral avoidance is the altered
energetic expenditure of marine mammals because energy is required to
move and avoid surface vessels or the sound field associated with
active sonar (Frid and Dill, 2002). Most animals can avoid that
energetic cost by swimming away at slow speeds or speeds that minimize
the cost of transport (Miksis-Olds, 2006), as has been demonstrated in
Florida manatees (Miksis-Olds, 2006). Those energetic costs increase,
however, when animals shift from a resting state, which is designed to
conserve an animal's energy, to an active state that consumes energy
the animal would have conserved had it not been disturbed. Marine
mammals that have been disturbed by anthropogenic noise and vessel
approaches are commonly reported to shift from resting to active
behavioral states, which would imply that they incur an energy cost.
Forney et al. (2017) detailed the potential effects of noise on
marine mammal populations with high site fidelity, including
displacement and auditory masking, noting that a lack of observed
response does not imply absence of fitness costs and that apparent
tolerance of disturbance may have population-level impacts that are
less obvious and difficult to document. Avoidance of overlap between
disturbing noise and areas and/or times of particular importance for
sensitive species may be critical to avoiding population-level impacts
because (particularly for animals with high site fidelity) there may be
a strong motivation to remain in the area despite negative impacts.
Forney et al. (2017) stated that, for these animals, remaining in a
disturbed area may reflect a lack of alternatives rather than a lack of
effects.
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996; Frid and Dill, 2002). The result of a flight response
could range from brief, temporary exertion and displacement from the
area where the signal provokes flight to, in extreme cases, beaked
whale strandings (Cox et al., 2006; D'Amico et al., 2009). However, it
should be noted that response to a perceived predator does not
necessarily invoke flight (Ford and Reeves, 2008), and whether
individuals are solitary or in groups may influence the response.
Flight responses of marine mammals have been documented in response to
mobile high intensity active sonar (e.g., Tyack et al., 2011; DeRuiter
et al., 2013; Wensveen et al., 2019), and more severe responses have
been documented when sources are moving towards an animal or when they
are surprised by unpredictable exposures (Watkins 1986; Falcone et al.,
2017). Generally speaking, however, marine mammals would be expected to
be less likely to respond with a flight response to either stationery
pile driving (which they can sense is stationery and predictable) or
significantly lower-level HRG surveys, unless they are within the area
ensonified above behavioral harassment thresholds at the moment the
source is turned on (Watkins, 1986; Falcone et al., 2017).
Diving and Foraging
Changes in dive behavior in response to noise exposure can vary
widely. They may consist of increased or decreased dive times and
surface intervals as well as changes in the rates of ascent and descent
during a dive (e.g., Frankel and Clark, 2000; Costa et al., 2003; Ng
and Leung, 2003; Nowacek et al., 2004; Goldbogen et al., 2013a, 2013b).
Variations in dive behavior may reflect interruptions in biologically
significant activities (e.g., foraging) or they may be of little
biological significance. Variations in dive behavior may also
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expose an animal to potentially harmful conditions (e.g., increasing
the chance of ship-strike) or may serve as an avoidance response that
enhances survivorship. The impact of a variation in diving resulting
from an acoustic exposure depends on what the animal is doing at the
time of the exposure, the type and magnitude of the response, and the
context within which the response occurs (e.g., the surrounding
environmental and anthropogenic circumstances).
Nowacek et al. (2004) reported disruptions of dive behaviors in
foraging North Atlantic right whales when exposed to an alerting
stimulus, an action, they noted, t
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