Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Construction of Two Liquefied Natural Gas Terminals, Texas, 27365-27388 [2020-09830]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 85, Number 90 (Friday, May 8, 2020)]
[Notices]
[Pages 27365-27388]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-09830]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XA123]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Construction of Two Liquefied 
Natural Gas Terminals, Texas

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

ACTION: Notice; proposed incidental harassment authorizations; request 
for comments on proposed authorizations and possible renewals.

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SUMMARY: NMFS has received requests from Rio Grande LNG, LLC (Rio 
Grande) and, separately, Annova LNG Common Infrastructure (Annova) for 
authorization to take marine mammals incidental to pile driving and 
removal associated with the construction of two separate LNG terminals 
in the Brownsville Ship Channel (BSC), Cameron County, Texas. Pursuant 
to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments 
on its proposal to issue two separate incidental harassment 
authorizations (IHAs; one to Rio Grande and one to Annova) to 
incidentally take marine mammals during the specified activities. NMFS 
is also requesting comments on possible one-year renewals that could be 
issued under certain circumstances and if all requirements are met, as 
described in Request for Public Comments at the end of this notice. 
NMFS will consider public comments prior to making any final decision 
on the issuance of the requested MMPA authorizations and agency 
responses will be summarized in the final notice of our decisions.

DATES: Comments and information must be received no later than June 8, 
2020.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-
marine-mammal-protection-act without change. All personal identifying 
information (e.g., name, address) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

FOR FURTHER INFORMATION CONTACT: Jaclyn Daly, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-
marine-mammal-protection-act. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

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

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    These actions are consistent with categories of activities 
identified in Categorical Exclusion B4 (incidental harassment 
authorizations with no anticipated serious injury or mortality) of the 
Companion Manual for NOAA Administrative Order 216-6A, which do not 
individually or cumulatively have the potential for significant impacts 
on the quality of the human environment and for which we have not 
identified any extraordinary circumstances that

[[Page 27366]]

would preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed IHAs 
qualifies to be categorically excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making final decisions on the 
IHA requests.

Summary of Request

    On August 20, 2019, NMFS received a request from Rio Grande for an 
IHA to take marine mammals incidental to pile driving associated with 
the construction of a LNG terminal in the BSC. Rio Grande submitted a 
revised application on November 21, 2019 that was deemed adequate and 
complete on December 19, 2019. Rio Grande's request is for take of a 
small number of three species of marine mammals, by Level B harassment 
only. Rio Grande, Annova and NMFS do not expect serious injury or 
mortality to result from these activities and, therefore, an IHA is 
appropriate.
    Separately, on June 27, 2019, NMFS received a request from Annova 
for an IHA to take marine mammals incidental to pile driving associated 
with the construction of a LNG terminal in the BSC. Annova submitted a 
revised application on February 28, 2020 that was deemed adequate and 
complete on March 2, 2020. Annova's request is for take of a small 
number of three species of marine mammals, by Level B harassment only. 
Neither Annova nor NMFS expects serious injury or mortality to result 
from this activity and, therefore, an IHA is appropriate.
    Given the two projects and potential impacts are nearly identical 
in scope, the projects are located in the same waterway (the BSC), and 
the same species/stocks are potentially affected, we are utilizing this 
single Federal Register notice to notify the public of our proposed 
issuance of the two separate authorizations.

Description of Proposed Activity

Overview

    Rio Grande and Annova are each proposing to construct an LNG 
terminal in the Brownsville Ship Channel, Texas. The purpose of each 
project is to construct and operate an LNG terminal for purposes of 
international export. The LNG terminals would be located across from 
each other on opposite banks of the BSC. Both projects require pile 
driving and removal. Rio Grande proposes to install 12 42-48-inch (in) 
piles and remove 5 small timber piles over 9 days. Annova proposes to 
install and remove 16 24-in temporary piles and install 4 96 
impermanent breasting dolphin piles over 16 days. Due to the nature of 
the activities and potential presence of dolphins in the BSC, both 
applicants have requested authorization for the take of marine mammals 
incidental to pile driving and removal. Rio Grande's proposed IHA would 
be valid July 1, 2020 through June 30, 2021. Annova's proposed IHA 
would be valid March 1, 2021 through February 28, 2021.

Dates and Duration

    Rio Grande has indicated pile driving activities could occur 
starting in July 1, 2020, but actual start dates will be based on 
receipt of all certifications, authorizations, and necessary permits. 
Rio Grande has indicated pile driving would be limited to daylight 
hours; however, dredging may occur at any time. Pile driving and 
removal would occur for no more than 8 days (note the application 
states 12 days; however, the applicant clarified removal of the five 
timber navigation piles would occur in one day, not five).
    Annova pile driving would occur beginning in 2021, contingent upon 
receipt of all certifications, authorizations, and necessary permits. 
Annova has requested the proposed IHA would be valid for one-year 
starting March 1, 2021. Annova has indicated pile driving would be 
limited to daylight hours; however, dredging may occur at any time. 
Pile driving and removal would occur for no more than 16 days.

Specific Geographic Region

    The Laguna Madre system is a long (109 kilometers (km)) backwater 
bay separated from the Gulf of Mexico by Padre Island. The waters of 
Laguna Madre are approximately 439 square miles (mi\2\) and are 
hypersaline (saltier than typical sea water) due to the shallow water, 
limited freshwater inflow, and limited surface water exchange with the 
Gulf of Mexico (USACE 2014). It is subdivided into two lagoons referred 
to as the Upper Laguna Madre (approximately 40 mi long) and the Lower 
Laguna Madre (approximately 60 mi long). Substrate includes hard rock 
reefs, sand, mudflats, and extensive sea grass beds with an average 
depth of one meter (m), excluding dredged shipping channels that extend 
up to approximately 3.7 m in depth.
    The BSC is located within the southernmost portion of Lower Laguna 
Madre. Both projects would be constructed in the BSC. The BSC is a man-
made, marine navigation channel that connects to the Gulf of Mexico and 
forms the western terminus of the Gulf Intracoastal Waterway system. 
The BSC is a deep-draft navigation channel connecting the deepwater 
Port of Brownsville to the Gulf of Mexico via the Brazos Santiago Pass 
and is an established shipping corridor between the Texas mainland and 
South Padre Island. The BSC is approximately 12.8 m (42 feet (ft)) deep 
and 27.4 km (17 miles (mi)) long. At the terminal sites, it is 
approximately 300 m wide. A turning basin located at the western 
terminus of the BSC is approximately 11 m (36 ft) deep and 365.8 m 
(1,200 ft) wide (Port of Brownsville 2019a).
    The Rio Grande terminal site would be located on the northern shore 
of the BSC. The site is comprised of a shallow estuarine open water 
lagoon with estuarine emergent marsh and mudflats around its perimeter. 
The western boundary of the Terminal site is the Bahia Grande Channel, 
which was constructed in 2005 to connect the BSC and the Bahia Grande 
to restore tidal exchange to the Bahia Grande (USFWS 2015). As part of 
a comprehensive restoration plan, channels were constructed between the 
basins in the Bahia Grande system, and future plans include widening 
the Bahia Grande Channel from approximately 10.4 m (34 ft) to 76.3 m 
(250 ft) to increase tidal exchange via the BSC (Ocean Trust 2009; 
USFWS 2010).
    The Annova terminal would be located opposite and slightly west of 
the Rio Grande terminal. The bank of the BSC at the site is non-
vegetated; the channel is a poor habitat for seagrass due to 
disturbance from drawdowns and return surges associated with normal 
tidal movement and human-induced actions such as vessel traffic.
    Fishing in the BSC is diverse. Anglers can reasonably expect to 
encounter snook, mangrove snapper, ladyfish, speckled trout, redfish, 
black drum, sheepshead, jack crevalle, lookdowns, etc. The shrimp 
fishery fleet docks at the terminus of the BSC and actively fishes the 
BSC. The vessels transit past both terminal sites inbound to the marina 
and dolphins have been observed following these shrimp boats, likely 
foraging on discarded bycatch (Ronje et al., 2018, Piwetz and 
Whitehead, 2019).

Detailed Description of Specific Activity

Rio Grande
    Rio Grande proposes to construct a natural gas liquefaction 
facility and liquefied natural gas (LNG) export terminal (Terminal) in 
Cameron County,

[[Page 27367]]

Texas, along the north embankment of the Brownsville Ship Channel 
(BSC)(Figure 1). The purpose of the project is to develop, own, 
operate, and maintain a natural gas pipeline system to access natural 
gas from the Agua Dulce Hub and an LNG export facility in south Texas 
to export 24.5 million metric tons (27 million U.S. tons) per annum of 
natural gas that provides an additional source of firm, long-term, and 
competitively priced LNG to the global market.
[GRAPHIC] [TIFF OMITTED] TN08MY20.015

    The terminal would be located on approximately 3.04 square 
kilometers (km\2\) (750.4 acres) of a 3.98-km2 (984.2-acre) parcel of 
land along the northern shore of the BSC in Cameron County, Texas, 
approximately 16 km (9.8 statute miles) east of Brownsville and about 
3.5 km (2.2 mi) west of Port Isabel (see Figure 1). The Terminal, which 
is currently expected to begin operations in late 2023, would have a 
minimum 20-year life span (which could be extended to a 50-year life 
span). It would receive natural gas via a proposed Pipeline System, 
which would connect the Terminal to the existing infrastructure near 
the natural gas Agua Dulce hub interconnection in Nueces County. All 
pipeline work is conducted on land and there are no potential impacts 
on marine mammals from this work; therefore, pipeline work will not be 
discussed further.
    The terminal site includes the following major facilities: six 
liquefaction trains; four full-containment LNG storage tanks; docking 
facilities for two LNG vessels, turning basin, and material offloading 
facility (MOF); LNG truck loading facilities with four loading bays; 
and Pipeline System's Compressor Station 3, a metering site, and the 
interconnection to the Pipeline System. In-water pile driving 
associated with construction of the LNG Loading and Vessel Berthing 
Area, turning basin, MOF, and Tug Berth have the potential to harass 
marine mammals. Rio Grande would also remove existing navigation 
markers. We describe these construction activities below.

LNG Loading and Vessel Berthing Area

    Two LNG vessel loading berths would be constructed along the south-
central boundary of the Terminal to accommodate simultaneous loading of 
two LNG vessels (see Figure 2). The berths would be recessed into the 
Terminal property so that loading LNG vessels, separated by 76 m (250 
ft), would not encroach on the navigable channel boundaries of the BSC. 
Construction of the loading berths would require dredging to a depth of 
up to -14 m (43 ft plus 2 ft allowable overdepth) mean lower low water

[[Page 27368]]

(MLLW) (-13-m [43 ft] plus -0.6 m [2 ft] of allowable overdepth). No 
pile driving in-water is associated with this part of the project.

Turning Basin

    A 457.2-m (1,500-foot)-diameter turning basin would be constructed 
to the east of the LNG vessel loading berths to accommodate turning 
maneuvers of the LNG vessels calling on the Terminal. LNG vessels would 
be escorted into the BSC and turning basin via tug boats, rotated in 
the turning basin, and then placed adjacent to a loading berth with the 
bow facing downstream (i.e., eastward). The turning basin would be 
partially recessed into the terminal site, but the area of the turning 
basin would encroach on the navigable channel of the BSC such that 
channel transit would be temporarily precluded until the LNG vessels 
were moored at the berth. As with the loading berths, the turning basin 
would be dredged to a depth of up to -13.1 m (-43 ft plus 2 ft 
allowable overdepth). The navigable channel is maintained at -12.8 m (-
42 ft) MLLW and would be deepened to -15.8 m (-52 ft) plus 0.6 m (2 ft) 
allowable overdepth and an additional 0.6 m (2 ft) for advanced 
maintenance dredging. An in-water Private Aid to Navigation (PATON) 
consisting of two steel 48-in pipe piles would be installed just 
outside of the footprint of the turning basin.

MOF and Tug Basin

    Rio Grandewould construct a MOF along the western extent of the 
Terminal site, adjacent to the BSC. The MOF would primarily be used 
during construction for marine delivery of bulk materials and larger or 
prefabricated equipment as an alternative to road transportation; 
however, it would be maintained for the life of the terminal for 
periodic delivery of bulk materials. The MOF, which would require a 
dredged depth of up to -7.6 m (-25 ft) MLLW plus 0.6 m (2 ft) advanced 
maintenance allowance, would be constructed of a steel sheet pile 
bulkhead on land. Fencing would be placed around the MOF to control 
access and separate it from the adjacent wetlands on the west side of 
the terminal site; access would be through the western LNG terminal 
entrance. The MOF would be capable of berthing two barges 
simultaneously. Rio Grande anticipates that 880 barges would deliver 
materials to the MOF during the first 5 years of construction, although 
deliveries would continue as needed for the remainder of construction 
and into operations. Bulk materials delivered to the MOF would include 
the crushed sand or stone necessary for concrete fabrication. Ten 42-in 
piles would be installed in-water at the tug berth to support 
construction.

Removal of Existing Navigation Aids

    RGLNG proposes to relocate one of the USCG fixed navigation aids in 
the BSC waterway. Pile driving would include in-water removal of five 
12-in-diameter timber piles at the existing navigation aid location 
using a vibratory hammer. A double bubble curtain would be deployed 
during all vibratory hammer operations to reduce noise generated by the 
hammer. The new navigation aid would be installed on land near the 
shoreline. All five piles would be removed on the same day at a rate of 
one pile removed every 20 minutes.
    In total, Rio Grande would install 12 piles associated with the 
marine facilities and remove five existing 12-in timber, navigation 
piles. (Table 1).

                                          Table 1--In-Water Pile Driving and Removal Activities for Rio Grande
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                                                                                         Source level (dB) \1\
               Area                     Pile size/type              Method          ------------------------------  Piles per     Duration   Total piles
                                                                                        SEL       RMS      Peak        day         (days)
--------------------------------------------------------------------------------------------------------------------------------------------------------
PATON at the LNG Berth............  \2\ 48-in (steel)....  Vibratory...............     161.2     161.2       n/a            1            2            2
                                                           Impact..................     179.7     191.6     205.5
Removal of USCG Navigation Aid....  12-in (timber).......  Vibratory...............       \3\       \3\       n/a        \5\ 5        \5\ 1            5
                                                                                        145.0     145.0
Tug Berth.........................  \4\ 42-in (steel)....  Vibratory...............     161.2     161.2       n/a            2            5           10
                                                           Impact..................     179.7     191.6     205.5
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\1\ Source levels presented here account for use of a bubble curtain; therefore, they represent a 7dB reduction from unattenuated source levels.
\2\ 48-in pile source levels represent a -7 dB reduction from median values presented in Austin et al (168 dB rms (vibratory) and 198.6 dB rms and 186.6
  dB SEL (diesel impact hammer).
\3\ The 145 dB SL represents a -7dB reduction from 152 dB; 152 dB represents the highest RMS value measured at 16 m during removal of timber piles at
  Port Townsend (Laughlin, 2011).
\4\ Rio Grande conservatively applied 48-in pile source levels measured at the Port of Alaska (Austin et al. 2016) to 42-in pile source level estimate.
\5\ Rio Grande's application indicates pile removal of the five 12-in timber piles would occur at a rate of one pile per day for five days. The
  applicant later clarified this was a mistake in interpreting the engineer's intent and that all five piles would be removed on the same day.

Rock Armoring at the MOF

    East of the MOF, channel embankments and the top slope of the 
shoreline (to a depth of -0.6 m [-2 ft] MLLW) would be graded to a 1:3 
slope, stabilized with bedding stone overlain by geotextile fabric, and 
then covered with riprap (i.e., rock armoring) (see Section 1.3.2 for 
further discussion of dredging activities). In the marine berths and 
turning basin, where vessel activity could erode the underwater channel 
slopes, the shoreline would be dredged to a 1:3 slope and stabilized 
with riprap to a depth of -13.1 m (-43 ft) MLLW. The rock armoring 
would extend to the top of the slope at elevation +1.8 m (+6 ft) North 
American Vertical Datum of 1988 and would tie in to the MOF bulkhead. 
The installation of rock armor does not generate in-water noise levels 
to the extent harassment is anticipated; therefore, this activity will 
not be discussed further.

Dredging

    RGLNG would dredge the berthing areas and turning basin to a depth 
of -13.1 m (-43 ft) MLLW, with a -0.6 m (-2 foot) allowable over-
dredge. The sides of the berthing areas and turning basin would be 
contoured at a 1:3 slope. The MOF would be excavated and dredged to a 
depth of -7.6 m (-25 ft) MLLW plus 0.6 m (2 ft) advanced maintenance 
allowance), to allow barges and shallow-draft vessels to directly

[[Page 27369]]

offload bulk materials at the Terminal site. RGLNG would install rock 
armoring to provide scour protection from propeller wash on the slope 
parallel to the shoreline. About 476,317.7 m\3\ (623,000 yd\3\) of 
material would be excavated along the shoreline and outside the 
federally maintained BSC by land-based equipment for the construction 
of the berthing areas, turning basin, and MOF. This material would be 
directly placed at the Terminal site for fill. An additional 29,817.6 
m\3\ (39,000 yd\3\) of material would be dredged from the MOF using a 
mechanical dredge from the shoreline. Approximately 4.6 million m\3\ 
(6.1 million yd\3\) of material would be dredged from the berths and 
turning basin using water-based equipment. Material would be dredged 
using a hydraulic dredge and temporary pipeline and placed at a U.S. 
Army Corps of Engineers (USACE)-approved dredged-material-placement 
area. The placement area will be on the southern shoreline. Although 
the temporary dredge material pipeline will cross the BSC, it will be 
completely submerged and will rest on the bottom of the BSC while 
dredging activities take place. NMFS does not anticipate harassment to 
marine mammals from dredging nor is it likely the presence of the 
pipeline would be perceived as a barrier to dolphins. Therefore, 
harassment from dredging by Rio Grande is not anticipated or proposed 
to be authorized, and this activity is not discussed further.

Annova LNG

    Annova is proposing to site, construct, and operate facilities 
necessary to liquefy and export natural gas along the south bank of the 
BSC (Figure 2). The purpose of the Project is to operate a mid-scale 
natural gas liquefaction facility along the South Texas Gulf Coast for 
exporting LNG to international markets via LNG carriers through United 
States and international waters. The terminal will include a new LNG 
export facility with a nameplate capacity of 6.0 million metric tons 
per annum (6.6 million U.S. tons) and a maximum output at optimal 
operating conditions of 6.95 million metric tons (7.66 million U.S. 
tons) per year of LNG for export. The project site is located on a 2.96 
km\2\ (731-acre) property adjacent to the BSC on land owned by the 
Brownsville Navigation District (BND). The property, located at 
approximate mile marker 8.2 on the south bank of the BSC, has direct 
access to the Gulf of Mexico via the Brazos Santiago Pass.
BILLING CODE 3510-22-P

[[Page 27370]]

[GRAPHIC] [TIFF OMITTED] TN08MY20.016

BILLING CODE 3510-22-C
    Natural gas will be delivered to the facility via a third-party 
intrastate pipeline. The natural gas delivered to the site via the feed 
gas pipeline will be treated, liquefied, and stored on-site in two 
single-containment LNG storage tanks, each with a net capacity of 
approximately 160,000 cubic m (m\3\) (42.3 million gallons). The LNG 
will be pumped from the storage tanks to the marine facilities, where 
it will be loaded

[[Page 27371]]

onto LNG carriers at the berthing dock using cryogenic piping.
    The facilities for the Project include the following major 
components: gas pretreatment facilities; liquefaction facilities (six 
liquefaction trains and six approximately 72,000-horsepower electric 
motor-driven compressors); two LNG storage tanks; boil-off gas handling 
system; flare system; marine facilities; control, administration, and 
support buildings; an access road; fencing and barrier wall; and 
utilities (power, water, and communication). Similar to Rio Grande, in-
water work with the potential to cause harassment to marine mammals 
includes construction of the marine facilities.
    The marine facilities will include a 457 m (1,500-foot) diameter 
turning basin and widened channel approach areas to the turning basin 
(see Figure 2). LNG carriers will dock on the loading platform at the 
south side of the turning basin. The marine facilities include the 
following components: Loading platform and berth for one LNG carrier, 
including turning basin and access areas along the BSC; cryogenic 
pipelines and vapor return lines; aids to navigation; MOF, mooring and 
breasting dolphins; and tug berth area.
    The proposed project involves installation and removal of 16 
temporary 24-in diameter steel piles and installation of four 96-in 
diameter steel breasting dolphin piles (see Table 2). The 16 temporary 
steel piles will provide support during installation of the breasting 
dolphins (four temporary piles for each breasting dolphin). Each 
temporary pile will be installed using a vibratory and impact hammer. 
Installation of the temporary piles will occur in stages, initially 
with a vibratory hammer followed by an impact hammer. Once installation 
of the breasting dolphin piles is complete, all temporary piles will be 
removed using a vibratory hammer.

                                             Table 2--In-Water Pile Driving and Removal Scenarios for Annova
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Source level (dB) \1\
               Area                     Pile size/type              Method          ------------------------------  Piles per     Duration   Total piles
                                                                                        SEL       RMS      Peak        day         (days)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Breasting Dolphin (temporary).....  24-in (steel)........  Vibratory \1\...........     165.0     165.0       n/a            4        \3\ 8           16
                                                           Impact \2\..............     171.0     187.0     207.0
Breasting Dolphins (permanent)....  96-in (steel)........  Vibratory \1\...........     170.0     170.0       n/a          0.5        \4\ 8            4
                                                           Impact \2\..............     188.0     198.0     213.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Vibratory driving and removal source levels do not account for use of a bubble curtain. Source: Caltrans (2015), Table I.2-2.
\2\ Impact driving source levels account for use of a bubble curtain (i.e., -7 dB from unattenuated source level). Source: Caltrans (2015), Table I.2-1.
\3\ Includes four days for installation and four days for removal.
\4\ Four of the eight days include both vibratory and impact hammering; the remaining four days include impact hammering only.

Dredging

    Annova LNG will dredge the marine berth using a hydraulic cutter 
dredge. The berth will be dredged to the final design depth of -13.7 m 
(-45 ft) mean lower low water, plus 0.9 m (3 ft) for advance 
maintenance and over depth, with side slopes at a ratio of 3:1 where 
sheet piling is not used. Material removed by land-based excavation 
will be used for on-site fill where possible or placed on the Project 
site to support landscaping and final grading. Annova LNG proposes to 
use the existing Dredged Material Placement Area (DMPA) 5A or 5B, 
located just west of the Project site, to dispose of dredged material 
not used as fill on-site. Dredged material will be moved to the DMPA 
through an approximately 2.6 km (1.6-mi)-long, floating dredged 
material pipeline that will be temporarily anchored along the south 
shore of the BSC. The dredged material pipeline will be marked with 
navigation lights and reflective signs and monitored to ensure the 
safety of area traffic. Dredging for the marine berth is estimated to 
occur in two, 10-hour shifts, six days per week. Noise from dredging is 
not anticipated to harass marine mammals and the dredge material 
pipeline will not cross the BSC, avoiding potential impacts (e.g., 
entrapment) to marine mammals. Therefore, dredging will not be 
discussed further.
    Proposed mitigation, monitoring, and reporting measures for Annova 
are described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of Rio Grande and Annova's applications summarize 
available information regarding status and trends, distribution and 
habitat preferences, and behavior and life history, of the potentially 
affected species. Additional information regarding population trends 
and threats may be found in NMFS's Stock Assessment Reports (SARs; 
https://www.fisheries.noaa .gov/national/marine-mammal-protection/
marine-mammal-stock-assessments) and more general information about 
these species (e.g., physical and behavioral descriptions) may be found 
on NMFS's website (https://www.fisheries.noaa.gov/find-species).
    Table 3 lists all species with expected potential for occurrence in 
the BSC and adjacent Laguna Madre and summarizes information related to 
the population or stock, including regulatory status under the MMPA and 
ESA and potential biological removal (PBR), where known. For taxonomy, 
we follow Committee on Taxonomy (2019). PBR is defined by the MMPA as 
the maximum number of animals, not including natural mortalities, that 
may be removed from a marine mammal stock while allowing that stock to 
reach or maintain its optimum sustainable population (as described in 
NMFS's SARs). While no mortality is anticipated or authorized here, PBR 
and annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species

[[Page 27372]]

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 values presented in Table 3 are 
the most recent available at the time of publication and are available 
in the draft 2019 SARs (available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-
mammal-stock-assessment-reports).

                                             Table 3--Marine Mammals Potentially Present in the Action Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      ESA/MMPA     Stock abundance (CV,
                                                                                      status;        Nmin, most recent                         Annual M/
            Common name                Scientific name             Stock          Strategic (Y/N)    abundance survey)            PBR            SI \3\
                                                                                        \1\                 \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin............  Tursiops truncatus...  Laguna Madre.........  N, Y             unknown.............  UND.................        0.4
                                                           Western Coastal GoM..  N, N             20,161 (0.17,         175.................        0.6
                                                                                                    17,491, 2012).
    Atlantic spotted dolphin......  Stenella frontalis...  Northern GoM.........  N, N             37,611 (0.28, unk,    Undet...............         42
                                                                                                    2004).
    Rough-toothed dolphin.........  Steno bredanensis....  Northern GoM.........  N, N             \5\ 624 (0.99, 311,   2.5.................    \6\ 1.2
                                                                                                    2009).
--------------------------------------------------------------------------------------------------------------------------------------------------------
 1--Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
 2--NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance.
 3--These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.
 4--The abundance estimate reported in the latest stock assessment report for common bottlenose dolphin Gulf of Mexico Bay, Sound, and Estuary stocks is
  80 animals. However, this estimate is considered outdated as it is based on surveys from 1992-1993 (Blaylock and Hoggard 1994). Recent photo-
  identification surveys by Piwetz and Whitehead (2019) in Lower Laguna Madre identified 109 individuals; however, the authors note even this estimate
  is lower than a minimum population estimate.
 5--This abundance estimate is reported in the latest stock assessment report for rough-toothed dolphins in the Northern Gulf of Mexico stock (Hayes et
  al. 2018). This estimate is considered outdated (more than 8 years old) and is based on surveys from 2009 (Garrison 2016). It does not include
  continental shelf waters and does not correct for unobserved animals. Data combined from 1992-2009 resulted in an estimate of 4,853 (CV=0.19) (Roberts
  et al. 2016).
 6--Total human M/SI considers the mean annual M/SI from fishery observer related interactions from 2010-2014 and two stranded animals with signs of
  human-caused mortality (i.e., 0.8 + 0.4).

    All species that could potentially occur in the proposed project 
areas are included in Table 3. As described below, three species (with 
four managed stocks) temporally and spatially co-occur with the 
activity to the degree that take is reasonably likely to occur, and we 
have proposed authorizing it.
    In addition, the West Indian manatee (Trichechus manatus manatus) 
may be found in the Laguna Madre. However, manatees are managed by the 
U.S. Fish and Wildlife Service and are not considered further in this 
document.

Bottlenose Dolphins

    Bottlenose dolphins are found throughout the world in both offshore 
and coastal waters, including harbors, bays, gulfs, and estuaries, as 
well as nearshore coastal waters, deeper waters over the continental 
shelf, and even far offshore in the open ocean. Bottlenose dolphins may 
travel alone or in groups, and the groups continually break apart and 
reform. Their travel is characterized by persistent movement in a 
consistent direction. They use breeding, playing, aggression, and 
gentle body contact (such as rubbing) as ways to have social 
interactions with one another. Bottlenose dolphins can thrive in many 
environments and feed on a variety of prey, such as fish, squid, and 
crustaceans (e.g., crabs and shrimp). They use different techniques to 
pursue and capture prey, searching for food individually or 
cooperatively. For example, they can work to bring fish together into 
groups (herding). They then take turns charging through the schools to 
feed. They may also trap schools of fish against sand bars and 
seawalls. They also use passive listening and/or high frequency 
echolocation to locate prey.
    The Gulf of Mexico hosts 36 stocks of bottlenose dolphins, as 
designated for management purposes by NMFS: 1 offshore stock, 1 
continental shelf stock, 3 coastal stocks, and 31 Northern Gulf of 
Mexico Bay, Sound, and Estuary (BSE) stocks, seven of which occur in 
Texas (Waring et al. 2016; Hayes et al. 2019). Distinguishing between 
individuals of each coastal and BSE stock is difficult as members of 
these stocks have nearly identical physical characteristics and often 
have overlapping range boundaries. Coastal and estuarine stocks can 
partially overlap in their ranges, with estuarine dolphins observed in 
coastal waters and coastal dolphins observed in estuarine waters (e.g., 
Bassos-Hull et al. 2013; Laska et al. 2011; Maze and W[uuml]rsig 1999). 
The two stocks that may be present in the ensonified area are the 
Laguna Madre BSE stock and western Gulf of Mexico coastal stock.
Laguna Madre Stock
    Bottlenose dolphins are found throughout the Laguna Madre estuary. 
The abundance of the entire Laguna Madre stock is considered 
``unknown'' for management purposes. In August of 2016, the Marine 
Mammal Stranding Network conducted boat-based surveys to search for an 
injured entangled dolphin reported in the extreme southern portion of 
lower Laguna Madre (Ronje et al., 2018). Over the course of the 4 days 
of surveys, 46 dolphin group sightings were recorded, estimated at 60 
individuals. In 2018 and 2019, Piwetz and Whitehead (2019) conducted 5 
surveys covering 365.4 km in the southern portion of the lower Laguna 
Madre to better understand dolphin distribution and abundance. Dolphin 
sightings were consistent along the BSC until the industrial section 
(Figure 3), beginning around the Brownsville Fishing Harbor, spanning 
approximately 6.5 km to the west where the channel ultimately 
terminates. Dolphins were observed in the Brazos Santiago Pass, several 
of which travelled to the end of the pass around the Boca Chica Jetty, 
where waters are turbulent and dolphins have been observed foraging. In 
the lower Laguna Madre, north of the Queen Isabella Causeway, dolphins 
were concentrated around the deeper waters of the Gulf Intracoastal 
Waterway (GIWW). Overall, 33 groups of dolphins were recorded. Calves 
(n = 15) were present in 33 percent (n = 11) of the total group 
sightings and comprised 10

[[Page 27373]]

percent (n = 15) of the total number of dolphins sighted. Preliminary 
photo-ID analysis includes 109 individuals, 95 of which are considered 
distinct or marginally distinct based on dorsal fin nicks and notches. 
These surveys only covered the southern portion of the lower Laguna 
Madre, a small portion of the stock's home range. As expected, the 
nonasymptotic nature of the discovery curve (accumulation curve) 
indicates that the sampling effort has not yet identified all, or even 
most, of the individuals that use this region. Of the distinct or 
marginally distinct individuals, 42 percent (n = 28) were sighted on 
more than one survey day and 6 percent (n = 6) were observed in both 
the winter and summer seasons, suggesting at least some degree of site 
fidelity. In summary, the preliminary results presented in Piwetz and 
Whitehead (2019) show that bottlenose dolphins use the lower Laguna 
Madre area, primarily deeper channels and passes, present day use is 
likely greater than the outdated SAR abundance estimate, and a number 
of individuals show some degree of site fidelity.
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[GRAPHIC] [TIFF OMITTED] TN08MY20.017


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BILLING CODE 3510-22-C
    Observed behavioral states included slow travel, fast travel, 
probable feed, feed (several observations of fish in mouth), mill, and 
social. The small sample size precluded robust statistical analysis; 
however, the current trend indicates that foraging and socializing may 
occur more within the BSC than other sub-areas of the lower Laguna 
Madre (Piwetz and Whitehead, 2019).
    Within the BSC, commercial fishing trawlers may play a role in the 
occurrence of coastal bottlenose dolphins within the BSC, with coastal 
dolphins following trawlers into the estuary. Interaction with the 
shrimp fishery is a common occurrence on the Atlantic and Gulf coasts 
(e.g., Siegal et al. 2015; Greenman and McFee, 2014). During the 
summer, Piwetz and Whitehead (2019) observed five of 33 groups of 
dolphins following shrimp trawlers and foraging on discarded bycatch 
either behind the trawler or directly off the stern. Ronje (2016) noted 
dolphins inside the BSC were usually observed slowly travelling, often 
in the direction of tidal movement or behind shrimp trawlers during the 
morning hours and that dolphins were observed as far as the Brownsville 
Fishing Harbor, where a number of commercial fisheries vessels were 
docked. Given the BSC is a dead-end channel, in-bound dolphins 
traveling past the proposed terminals would also have to pass the 
terminals as they leave the BSC.
    Dolphins in Laguna Madre are subject to several anthropogenic 
stressors. Dolphin tourism vessels and commercial fishing charters were 
observed pursuing groups of dolphins in the region (Ronje et al., 
2018). Dolphins often follow shrimp trawlers, feeding on discarded 
catch, a behavior, which can increase gear interaction risk. The BSC 
and GIWW is dredged by the U.S. Army Corps of Engineers. In addition to 
potential threats from vessel and fishing activities, the BSC is a busy 
industrial port that exports hazardous materials such as chemical and 
petroleum products. There are no records of major oil spills in LM in 
the recent past. However, given that ships and barges regularly use the 
GIWW and the ports in LM, as well as the presence of pipelines and 
wells, smaller spills have occurred via leaks or minor collisions or 
accidents (Sharma et al., 1997). For example, in 2009 an oil slick 
formed around Port Isabel and tar balls washed up on beaches, with no 
known source of an oil spill (Brownsville Herald, 2009).
Western Gulf of Mexico Coastal Stock
    During aerial surveys in 2011 and 2012, the abundance estimates for 
the Gulf of Mexico western coastal stock of bottlenose dolphins were 
based upon tracklines and sightings in waters from the shoreline to the 
20-m isobath and between the Texas-Mexico border and the Mississippi 
River Delta. This stock's boundaries abut other bottlenose dolphin 
stocks, namely the Northern Coastal Stock, Continental Shelf Stock and 
several bay, sound and estuary stocks in Texas and Louisiana, and while 
individuals from different stocks may occasionally overlap, it is not 
thought that significant mixing or interbreeding occurs between them.
    Bottlenose dolphins are known to become entangled in, or ingest 
recreational and commercial fishing gear (Wells and Scott 1994; 
Gorzelany 1998; Wells et al. 1998; Wells et al. 2008), and some are 
struck by vessels (Wells and Scott 1997; Wells et al. 2008). Since 
1990, there have been 14 bottlenose dolphin die-offs or Unusual 
Mortality Events (UMEs) in the northern Gulf of Mexico, and 7 of these 
have occurred within the boundaries of the Western Coastal Stock and 
may have affected the stock. Sources of these UMEs include 
morbillivirus, low salinity, the Deepwater Horizon oil spill, and 
harmful algal blooms (Hayes et al., 2015).
    Total U.S. fishery-related mortality and serious injury for this 
stock is not known, but at a minimum is greater than 10 percent of the 
calculated PBR and, therefore, cannot be considered to be insignificant 
and approaching zero mortality and serious injury rate. The status of 
this stock relative to OSP in the Gulf of Mexico EEZ is unknown. There 
are insufficient data to determine the population trends for this 
stock.

Atlantic Spotted Dolphins

    Estimates of immigration rates between the western North Atlantic 
shelf population and the Gulf of Mexico stock were less than 1 percent 
per year (Viricel and Rosel 2014), which is well below the 10 percent 
per year threshold for demographic independence (Hastings 1993), 
thereby supporting separate stocks for Gulf of Mexico and western North 
Atlantic shelf populations. In the Gulf of Mexico, Atlantic spotted 
dolphins occur primarily from continental shelf waters 10-200 m deep to 
slope waters <500 m deep and are present year-round. However, it has 
been suggested that this species may move inshore seasonally during 
spring, but data supporting this hypothesis are limited (Caldwell and 
Caldwell 1966; Fritts et al. 1983). Viricel and Rosel (2014) also found 
support for two demographically independent populations within the 
northern Gulf of Mexico. One population primarily occupied shelf waters 
from the Texas-Mexico border eastward to Cape San Blas, Florida while 
the second population was concentrated over the Florida shelf in the 
eastern Gulf of Mexico and stretched westward to the Florida panhandle. 
However, NMFS identifies one stock in the project area: The Northern 
Gulf of Mexico stock.
    The commercial fisheries that interact, or that potentially could 
interact, with this stock in the Gulf of Mexico are the pelagic 
longline fishery and the Southeastern U.S. Atlantic/Gulf of Mexico 
shrimp trawl fishery. No ongoing habitat threats are provided in the 
SAR with the exception of ongoing health impacts from the 2010 
Deepwater Horizon oil spill.

Rough-Toothed Dolphins

    Rough-toothed dolphins occur in oceanic and to a lesser extent 
continental shelf waters in the northern Gulf of Mexico (i.e., U.S. 
Gulf of Mexico) (Figure 1; Fulling et al. 2003; Mullin and Fulling 
2004; Maze-Foley and Mullin 2006). Although there are only a few 
records from Gulf of Mexico waters beyond U.S. boundaries (e.g., 
Jefferson and Schiro 1997, Ortega Ortiz 2002), rough-toothed dolphins 
almost certainly occur throughout the oceanic Gulf of Mexico (Jefferson 
et al. 2008), which is also composed of waters belonging to Mexico and 
Cuba where there is currently little information on cetacean species 
abundance and distribution. This is a transboundary stock and the 
abundance estimates are for U.S. waters only.
    The estimated mean annual fishery-related mortality and serious 
injury for this stock during 2010-2014 was 0.8 rough-toothed dolphins 
due to interactions with the pelagic longline fishery (Hayes et al., 
2018). This stock was also affected by the Deepwater Horizon oil spill.

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).

[[Page 27375]]

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 4.

           Table 4--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen  7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans          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).
Otariid pinnipeds (OW) (underwater)   60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Three marine mammal species (all mid-frequency cetaceans) have the 
reasonable potential to co-occur with the proposed pile driving and 
removal activities.

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 by Incidental Harassment 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 by Incidental Harassment 
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.
    In-water construction activities associated with the project would 
include impact pile driving, vibratory pile driving, and dredging. The 
sounds produced by these activities fall into one of two general sound 
types: Impulsive and non-impulsive. Impulsive sounds (e.g., explosions, 
gunshots, sonic booms, impact pile driving) are typically transient, 
brief (less than 1 second), broadband, and consist of high peak sound 
pressure with rapid rise time and rapid decay (ANSI 1986; NIOSH 1998; 
ANSI 2005; NMFS 2018). Non-impulsive sounds (e.g. aircraft, vessels, 
machinery operations such as drilling or dredging, vibratory pile 
driving, and active sonar systems) can be broadband, narrowband or 
tonal, brief or prolonged (continuous or intermittent), and typically 
do not have the high peak sound pressure with raid rise/decay time that 
impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). 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).
    Two types of pile hammers would be used on this project: Impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels, a potentially injurious combination (Hastings and Popper 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push the pile into the sediment. Vibratory 
hammers produce significantly less sound than impact hammers and the 
nature of the noise (i.e., no sharp rise times) reduce the probability 
and severity of marine mammal auditory injury (Nedwell and Edwards 
2002; Carlson et al. 2005).
    The potential impacts of Rio Grande and Annova's proposed 
activities on marine mammals would be caused by acoustic stressors. Any 
non-auditory injury from potential non-acoustic stressors such as 
vessel movement and rock armoring is de minimis due to the nature of 
the work (e.g., barges are stationary) and the proposed mitigation for 
any vessels (e.g., tugs) to slow in the presence of marine mammals or, 
for Rio Grande, delay placement of rock armoring if marine mammals 
approach within 10 m. Therefore, here we focus on acoustic stressors 
resulting from both projects: Pile installation and removal and 
dredging.

Acoustic Impacts

    In general, animals exposed to natural or anthropogenic sound may 
experience physical and psychological effects, ranging in magnitude 
from none to severe (Southall et al. 2007). Exposure to in-water 
construction noise has the potential to result in auditory threshold 
shifts and behavioral reactions (e.g., avoidance, temporary cessation 
of foraging and vocalizing, changes in dive behavior) and/or lead to 
non-observable physiological responses such an increase in stress 
hormones ((Richardson et al., 1995; Gordon et al., 2004; Nowacek et 
al., 2007; Southall et al., 2007; Gotz et al., 2009). Additional noise 
in a marine mammal's habitat can mask acoustic cues used by marine 
mammals to carry out daily functions such as communication and predator 
and prey detection. The effects of elevated noise exposure are 
dependent on several factors, including, but not limited to, sound type 
(e.g., impulsive vs. non-impulsive), the species, age and sex class 
(e.g., adult male vs. mom with calf), duration of exposure, the 
distance between the pile and the animal, received levels, behavior at 
time of exposure, and previous history with exposure (Wartzok et al. 
2004; Southall et al. 2007).

[[Page 27376]]

    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 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 
corresponds with the area where the signal is audible to the animal and 
of sufficient intensity to elicit behavioral or physiological 
responsiveness. Third is a zone 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 discuss three categories of potential acoustic-driven effects 
on marine mammals: (1) Physical auditory effects (threshold shifts), 
(2) behavioral effects and (3) potential impacts on marine mammal 
habitat.
    Auditory Effects--NMFS defines a noise-induced threshold shift (TS) 
as a change, usually an increase, in the threshold of audibility at a 
specified frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al. 2014b), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al. 1958, 1959; Ward 1960; 
Kryter et al. 1966; Miller 1974; Ahroon et al. 1996; Henderson et al. 
2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al. 2008), there are no empirical data measuring PTS in 
marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--A temporary, reversible increase 
in the threshold of audibility at a specified frequency or portion of 
an individual's hearing range above a previously established reference 
level (NMFS 2018). Based on data from cetacean TTS measurements (see 
Southall et al. 2007), a TTS of 6 dB is 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, 2002). As described in Finneran (2016), 
marine mammal studies have shown the amount of TTS increases with 
cumulative sound exposure level (SELcum) in an accelerating fashion: At 
low exposures with lower SELcum, the amount of TTS is typically small 
and the growth curves have shallow slopes. At exposures with higher 
higher SELcum, the growth curves become steeper and approach linear 
relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al. 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor 
porpoise (Phocoena phocoena), and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and five species of pinnipeds exposed to a limited 
number of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (Finneran 2015). However, the existing marine 
mammal TTS data come from a limited number of individuals within these 
species. No data are available on noise-induced hearing loss for 
mysticetes. For summaries of data on TTS in marine mammals or for 
further discussion of TTS onset thresholds, please see Southall et al. 
(2007), Finneran and Jenkins (2012), Finneran (2015), and Table 5 in 
NMFS (2018).
    Installing piles requires a combination of impact pile driving and 
vibratory pile driving while removing piles involves only a vibratory 
hammer. For the projects considered in the proposed IHAs, these 
activities would not occur at the same time, a limited number of piles 
would be installed and removed per day, and there would likely be 
pauses in activities such that noise from pile operations is not 
continuous. Given these considerations, and that any dolphins are 
likely moving through the action area and not remaining for extended 
periods of time, the potential for PTS is de minimis (and we are not 
proposing to authorize any Level A harassment take) and the potential 
for TTS is low.
    Behavioral Effects--Behavioral disturbance may include a variety of 
effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. Disturbance may result in changing durations 
of surfacing and dives, number of blows per surfacing, or moving 
direction and/or speed; reduced/increased vocal activities; changing/
cessation of certain behavioral activities (such as socializing or 
feeding); visible startle response or aggressive behavior (such as 
tail/fluke slapping or jaw clapping); avoidance of areas where sound 
sources are located. Behavioral responses to sound are highly variable 
and context-specific and any reactions depend on numerous intrinsic and 
extrinsic factors (e.g., species, state of maturity, experience,

[[Page 27377]]

current activity, reproductive state, auditory sensitivity, time of 
day), as well as the interplay between factors (e.g., Richardson et al. 
1995; Wartzok et al. 2003; Southall et al. 2007; Weilgart 2007; Archer 
et al. 2010). Behavioral reactions can vary not only among individuals 
but also within an individual, depending on previous experience with a 
sound source, context, and numerous other factors (Ellison et al. 
2012), and can vary depending on characteristics associated with the 
sound source (e.g., whether it is moving or stationary, number of 
sources, distance from the source). Please see Appendices B-C of 
Southall et al. (2007) for a review of studies involving marine mammal 
behavioral responses to sound. In general, if a marine mammal responds 
to a stimulus by changing its behavior (e.g., through relatively minor 
changes in locomotion direction/speed or vocalization behavior), the 
response may or may not constitute taking at the individual level, and 
is unlikely to affect the stock or the species as a whole.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al., 2009). The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure.
    As noted above, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with 
captive marine mammals have showed pronounced behavioral reactions, 
including avoidance of loud sound sources (Ridgway et al., 1997; 
Finneran et al., 2003). Observed responses of wild marine mammals to 
loud pulsed sound sources (typically seismic airguns or acoustic 
harassment devices) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
    Available studies show wide variation in response to underwater 
sound; therefore, it is difficult to predict specifically how any given 
sound in a particular instance might affect marine mammals perceiving 
the signal. If a marine mammal reacts briefly to an underwater sound by 
changing its behavior temporarily (e.g., ceases foraging, moving a 
small distance away from the source), the impacts of the change are 
unlikely to be significant to the individual, let alone the stock or 
population. However, if a sound source displaces marine mammals from an 
important feeding or breeding area for a prolonged period, impacts on 
individuals and populations could be significant (e.g., Lusseau and 
Bejder 2007; Weilgart 2007; NRC 2005). There are broad categories of 
potential marine mammal responses to anthropogenic noise, which we 
describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely, and 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,b). Variations in dive behavior may 
reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at the time of the exposure and the 
type and magnitude of the response. Due to the very shallow water 
depths in the BSC, we do not anticipate dolphins would alter dive 
behavior. They may; however, remain submerged for longer periods of 
time as they avoid the area.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al. 
2001; Nowacek et al. 2004; Madsen et al. 2006; Yazvenko et al. 2007). A 
determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal. Due to the narrowness of the BSC, noise from pile 
operations does not propagate to the degree it would in the more open 
waters of the Laguna Madre; therefore, the potential area for foraging 
disruption is very small compared to available foraging habitat.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005b, 2006; Gailey et 
al., 2007).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
(Eubalaena glacialis) have been observed to shift the frequency content 
of their calls upward while reducing the rate of calling in areas of 
increased anthropogenic noise (Parks et al., 2007b). In some cases, 
animals may cease sound production during production of aversive 
signals (Bowles et al., 1994).
    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 
(Eschrictius robustus) are known to change direction--deflecting from 
customary migratory paths--in order to avoid noise from seismic

[[Page 27378]]

surveys (Malme et al., 1984). Avoidance may be short-term, with animals 
returning to the area once the noise has ceased (e.g., Bowles et al., 
1994; Goold 1996; Stone et al., 2000; Morton and Symonds, 2002; Gailey 
et al., 2007). 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). Given that other acoustic stressors are 
already present within the BSC and dolphins continue to utilize the 
BSC, it is unlikely dolphins would avoid the BSC in response to 
relatively brief pile driving noise during LNG terminal construction.
    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). 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, marine mammal strandings (Evans 
and England 2001). 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.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil 1997; Fritz et al., 2002; Purser and Radford 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg 
2000). In many cases, an animal's first and sometimes most economical 
(in terms of energetic costs) response is behavioral avoidance of the 
potential stressor. Autonomic nervous system responses to stress 
typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker 2000; Romano 
et al., 2002b) and, more rarely, studied in wild populations (e.g., 
Romano et al., 2002a). For example, Rolland et al. (2012) found that 
noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003).
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al. 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g.,

[[Page 27379]]

sensitivity, frequency range, critical ratios, frequency 
discrimination, directional discrimination, age or TTS hearing loss), 
and existing ambient noise and propagation conditions.
    Masking of natural sounds can result when human activities produce 
high levels of background sound at frequencies important to marine 
mammals. Conversely, if the background level of underwater sound is 
high (e.g. on a day with strong wind and high waves), an anthropogenic 
sound source would not be detectable as far away as would be possible 
under quieter conditions and would itself be masked. The BSC hosts 
numerous recreational and commercial vessels; therefore, background 
sound levels in the BSC are already elevated above ambient by these 
activities.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007b; Di Iorio and Clark 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore 2014). Masking can be tested 
directly in captive species (e.g., Erbe 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to sustained elevated ambient sound levels, thus 
intensifying masking.
    The biological significance of many of the behavioral effects is 
difficult to predict, especially if the detected disturbances appear 
minor. Consequences of behavioral modification could be biologically 
significant if the change affects growth, survival, or reproduction. 
Example significant behavioral modifications that could potentially 
lead to effects on growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those thought to cause beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Longer-term habitat abandonment due to loss of desirable 
acoustic environment; and
     Longer-term cessation of feeding or social interaction.
    We do not expect dolphins exposed to pile driving noise to respond 
in the intense manners described above. Pile driving and removal 
associated with projects is very brief (about couple hours (at most) 
per day for 8 to 20 non continuous days and the area of ensonification 
to sound levels above NMFS harassment thresholds is very small (1 to 5 
km\2\). While we anticipate marine mammals to behaviorally react to 
pile driving noise, such as avoiding the area, increasing swim speeds 
and ceasing behavior such as socializing and foraging, we expect 
dolphins would return to pre-exposure behavior shortly after exiting 
the ensonified zone. As these individual- level effects are low, we do 
not anticipate that harassment to any individual would lead to adverse 
impacts on a given marine mammal stock's annual rates of recruitment of 
survival.

Marine Mammal Habitat Effects

    The area likely impacted by the projects is relatively small 
compared to the available habitat for all impacted species and stocks, 
and does not include any ESA-designated critical habitat. There are no 
known foraging hotspots or other bottom structure of significant 
biological importance to marine mammals in the BSC. Therefore, the main 
impact issue associated with the proposed activities would be 
temporarily elevated sound levels and the associated direct effects on 
marine mammals, as discussed previously in this document. The primary 
potential acoustic impacts to marine mammal habitat are associated with 
elevated sound levels produced by vibratory and impact pile driving and 
removal in the area.
    In-water pile driving activities would also cause short-term 
effects on water quality due to increased turbidity. Any increases in 
turbidity and suspended sediments would be temporary, localized, and 
minimal. In general, turbidity associated with pile installation is 
localized to a few meters from the pile.
    Potential avoidance by dolphin prey (e.g., fish, shrimp) of the 
immediate area is also possible. Short duration, sharp sounds can cause 
overt or subtle changes in fish behavior and local distribution 
(summarized in Popper and Hastings 2009). Hastings and Popper (2005) 
reviewed several studies that suggest fish may relocate to avoid 
certain areas of sound energy. Additional studies have documented 
physical and behavioral effects of pile driving on fish, although 
several are based on studies in support of large, multiyear bridge 
construction projects (e.g., Scholik and Yan 2001, 2002; Popper and 
Hastings 2009). Sound pulses at received levels of 160 dB may cause 
subtle changes in fish behavior. The SPLs associated with pile driving 
may cause noticeable changes in behavior (Pearson et al. 1992; Skalski 
et al. 1992). SPLs of sufficient strength have been known to cause 
injury to fish and fish mortality (summarized in Popper et al. 2014).
    The use of a double bubble curtain by both applicants during impact 
pile driving will greatly reduce the potential for fish injury or 
mortality. Therefore, we anticipate impacts to prey will be primarily 
behavioral in nature. The exact duration of fish avoidance of this area 
after pile driving is unknown, but a rapid return to normal 
recruitment, distribution and behavior is anticipated. Any behavioral 
avoidance by fish of the disturbed area would still leave significantly 
large areas of fish and marine mammal foraging habitat in the nearby 
vicinity.
    The duration of the construction activities is relatively short. 
Rio Grande and Annova pile driving and removal activities would occur 
for 8 and 20 non-consecutive days, respectively. Impacts to habitat and 
prey are expected to be minimal based on the use of a double bubble 
curtain during all impact driving and short duration of activities. 
Further, the BSC (a man-made canal) is a very small portion of marine 
mammal habitat within Laguna Madre.
    Permanent impacts to marine mammal habitat will be limited to the 
presence of the terminal post-

[[Page 27380]]

construction. Rio Grande's terminal would be located along the existing 
shoreline; however, Annova's terminal would be located in currently 
what is uplands. Therefore, the area of marine mammal habitat will 
actually be increased in size due to dredging out of these uplands. 
However, the quality of this expanded habitat is likely poor due to the 
industrialized nature of the project.
    In its Final Environmental Impact Statement for both the Rio Grande 
and Annova terminals, the Federal Energy Regulatory Commission (FERC) 
included an Essential Fish Habitat (EFH) Assessment. EFH is present 
within the BSC. On February 15, 2019, and February 5, 2019, NMFS' 
Habitat Conservation Division concurred with FERC that the construction 
of the Rio Grande and Annova LNG terminals, respectively, would result 
in temporary, limited impacts to EFH. NMFS had no conservation 
recommendations for FERC on either project.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through these IHAs, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would be by Level B harassment only, in the form 
of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to pile driving and removal. Based on the 
nature of the activity and the anticipated effectiveness of the 
mitigation measures (i.e., shutdowns)--discussed in detail below in 
Proposed Mitigation section, Level A harassment is neither anticipated 
nor proposed to be authorized. Given the scope of work considered, no 
mortality or serious injury is anticipated or proposed to be authorized 
for this activity. The projects do have the potential to cause Level B 
(behavioral) harassment of dolphins within the BSC. Below we describe 
how the Level B harassment take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe the 
factors considered here in more detail and present the proposed take 
estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for intermittent (e.g., impact pile driving) sources.
    Both Rio Grande and Annova's activities include the use of 
continuous (vibratory pile driving and removal) and intermittent 
(impact pile driving) sound sources; therefore, the 120 and 160 dB re: 
1 [mu]Pa (rms) are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). Both Rio Grande and Annova proposed 
activities include the use of impulsive (impact pile driving) and non-
impulsive (vibratory pile driving and removal) sources.
    These thresholds are provided in the Table 5. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/
marine-mammal-acoustic-technical-guidance.

                     Table 5--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds \*\ (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB
                                          LE,PW,24h: 185 dB.

[[Page 27381]]

 
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

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

                     Table 6--Inputs Into NMFS PTS User Spreadsheet for Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
Input parameters                                Rio Grande......................              Annova
----------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used..........................                      E.1) Impact pile driving
                                               -----------------------------------------------------------------
Source Level (SELs-s).........................  179.7...........................             171             188
Source Level (SPLpk)..........................  205.5...........................             200             213
                                               -----------------------------------------------------------------
Weighting Factor Adjustment (kHz).............                                  2
                                               -----------------------------------------------------------------
Number of piles per day.......................  1 (48-in), 2 (42-in)............               4             0.5
Number of strikes per pile....................  400.............................             675           2,700
                                               -----------------------------------------------------------------
Propagation (xLogR)...........................                                 15
Distance of source level measurement (m)......                                 10
----------------------------------------------------------------------------------------------------------------


                    Table 7--Inputs Into NMFS PTS User Spreadsheet for Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
                                                  Rio Grande                               Annova
         Input parameters          -----------------------------------------------------------------------------
                                      12-in piles      48-in and 42-in             24-in               96-in
----------------------------------------------------------------------------------------------------------------
Source Level (RMS SPL) \1\........             145  161.2................  165..................             170
Number of piles per day...........               5  1 (48-in), 2 (42-in).  4....................             0.5
Duration to drive or remove a               \2\ 20  24...................  10 (install), 45                   20
 single pile (minutes).                                                     (remove) \3\.
----------------------------------------------------------------------------------------------------------------
Propagation (xLogR)...............                                       15
----------------------------------------------------------------------------------------------------------------
Distance from source level                      16  10...................  10...................              10
 measurement (m).
----------------------------------------------------------------------------------------------------------------
\1\ Source levels account for a -7db bubble curtain reduction from unattenuated source levels.
\2\ We note Rio Grande's application indicated it would take 480 minutes to remove each 12-in pile and 1 pile
  would be removed per day. Upon request from NMFS, the applicant later clarified this time reflected the
  removal of all five piles, including when the hammer would not be operating. The actual hammer operation time
  per pile is 20 minutes and all 5 piles would be removed in a single day.
\3\ We note Annova's application indicated it would take 60 minutes to remove each 24-in pile but the applicant
  later clarified this included time when the hammer would not be operating and that actual hammer time would
  be, at most, 45 minutes.


[[Page 27382]]

    The results of the User Spreadsheet are presented in Table 8. These 
distances represent the distance at which a dolphin would have to 
remain for the entire duration considered in the calculation and may be 
unrealistic (e.g., NMFS does not anticipate a dolphin would remain at 
18 m for the entire time it takes to install two 42-in piles with an 
impact hammer). In all cases, the peak Level A harassment threshold is 
not reached. For these reasons, the potential for Level A harassment 
take from all pile driving and removal is very small. However, for 
these proposed IHAs, the applicants have proposed shutdown zones 
greater than or equal to the outputs of the User Spreadsheet to further 
ensure the potential for all Level A harassment take is avoided.

                    Table 8--Level A Harassment Isopleths and Corresponding Ensonified Areas
----------------------------------------------------------------------------------------------------------------
                                                                                                   Level A area
                Pile type                         Hammer type            Level A isopleth (m)         (km\2\)
----------------------------------------------------------------------------------------------------------------
                                                   Rio Grande
----------------------------------------------------------------------------------------------------------------
42-in...................................  Vibratory.................  0.5.......................           <0.01
                                          Impact....................  18.4......................           <0.01
48-in-diameter steel tube piles.........  Vibratory.................  0.3.......................           <0.01
                                          Impact....................  11.6......................           <0.01
12-in-diameter timber piles \2\.........  Vibratory.................  0.1.......................           <0.01
----------------------------------------------------------------------------------------------------------------
                                                     Annova
----------------------------------------------------------------------------------------------------------------
24-in...................................  Vibratory.................  0.3 (install) 0.9 (remove)           <0.01
                                          Impact....................  10.9......................           <0.01
92-in...................................  Vibratory.................  1.2.......................           <0.01
                                          Impact....................  93.5......................            0.04
----------------------------------------------------------------------------------------------------------------

    To estimate the area ensonified to the Level B harassment 
thresholds, a basic calculation that incorporated the source levels 
provided in Table 9 and a practical spreading loss model was used to 
estimate distances to the respective intermittent (160 dB rms) and 
continuous (120 dB rms) thresholds. However, the width of the BSC is 
relatively narrow (approximately 300 m wide); therefore, the Level B 
harassment areas were clipped to account for land. Table 9 provides the 
calculated Level B harassment isopleths and area accounting for land.

                    Table 9--Level B Harassment Distances and Areas for Rio Grande and Annova
----------------------------------------------------------------------------------------------------------------
                                                                                                      Level B
                                                                                     Isopleth       harassment
                  Hammer type                    Pile size (source level dB rms)   distance (m)    area (km\2\)
                                                                                                        \1\
----------------------------------------------------------------------------------------------------------------
                                                   Rio Grande
----------------------------------------------------------------------------------------------------------------
Impact........................................  42- and 48-in...................           1,278            1.06
Vibratory.....................................  42- and 48-in...................           5,580            4.85
                                                12-in...........................             743            0.62
----------------------------------------------------------------------------------------------------------------
                                                     Annova
----------------------------------------------------------------------------------------------------------------
Impact........................................  24-in (187).....................             631            0.56
                                                96-in (198).....................           3,415         \2\ 1.0
Vibratory.....................................  24-in (165).....................          10,000         \2\ 1.0
                                                96-in (170).....................          21,544         \2\ 1.0
----------------------------------------------------------------------------------------------------------------
\1\ Ensonified areas are truncated by land. See Figures 4-6 in both Rio Grande and Annova's applications.
\2\ Although radii to Level B harassment isopleths are similar between applications, Annova's pile driving will
  take place setback from the shoreline inside a berthing area (currently on land but will be dug out--see
  Figures 4-6 in Annova's application) versus Rio Grande's pile driving which will be conducted along the
  current shoreline. The nature of the work creates much smaller ensonified areas for Annova.

Take Calculation and Estimation

    The abundance, distribution and density of marine mammals in Laguna 
Madre is poorly understood. Therefore, while the harassment areas 
described above are important for planning mitigation (e.g., shutdown 
to avoid Level A harassment) and monitoring, they are not part of the 
take estimate calculations. For both applicants, we have considered 
other quantitative information (e.g., group size and sighting rates) as 
well as behavior to estimate take.

Bottlenose Dolphins

    For bottlenose dolphins, both applicants first estimated density in 
the Laguna Madre using the number of individuals reported in Piwetz and 
Whitehead (2019), which was 109 dolphins. We note this is not an 
abundance estimate of the Laguna Madre stock as Piwetz and Whitehead 
(2019) conducted the surveys in a limited area of the lower Laguna 
Madre and the authors note the non-asymptotic nature of the [photo-
identification] discovery curve (accumulation curve) indicates that the 
sampling effort has not yet identified all, or even most, of the 
individuals that use this region. Regardless, both applicants used 
habitat data layers from Finkbeiner et al. (2009) to estimate the area 
of the Laguna Madre, removing the layers that were not dolphin habitat 
(e.g., land, emergent marsh, and mangroves), which resulted

[[Page 27383]]

in a 1,938 km\2\ area. Separately, they estimated the area of the BSC 
at 27 km\2\, for a total area of 1,965 km\2\. Using these inputs, both 
applicants calculated a density of 0.055 dolphins/km\2\ (109/1,965 = 
0.055). NMFS believes this approach is an underestimate since the 
surveys in Piwetz and Whitehead (2019) were confined to the lower 
Laguna Madre. Therefore, we applied the 109 animals to the survey area 
in the study. The report did not provide the survey area (only the 
combined area covered for all five days) but a rudementary GIS exercise 
yielded an approximate survey area of 140 km\2\. This results in a 
density of 0.76 dolphins/km\2\.
    When considering a density-based approach to calculate potential 
take, NMFS typically recommends the following equation: density x area 
x pile driving days. Using this equation and the NMFS-derived survey 
area of 140 km\2\, the resulting total take estimate for Rio Grande is 
approximately 29 ((0.76 dolphins/km\2\ x 4.85 km\2\ x 7 days) + (0.76 
dolphins/km\2\ x 0.62 km\2\ x 1 day) and approximately 12 for Annova 
(0.76 dolphins/km\2\ x 1.0 km x 16 days).
    While these calculations would be appropriate for more open water 
areas, the results are not realistic for the context of these projects. 
First, dolphins travel up and down the BSC therefore the potential for 
them to be exposed to pile driving noise is somewhat independent of the 
harassment zone sizes as all zones cross the entire width of the 
channel they are likely to travel into these zones on any given day 
(i.e., that all dolphins traveling the BSC will eventually pass the 
terminal sites and therefore have equal chances for exposure). Second, 
Rio Grande is conducting less work on fewer days than Annova. Given the 
likely daily occurrence for dolphins to be within the BSC, it is 
unrealistic to assume Rio Grande has the potential to have more than 
double the instances of take than Annova. For this reason, NMFS 
determined the resulting take based on density is not realistic and has 
instead estimated take based on sighting rates which considers an 
important parameter--the number of hours of pile driving.
    To derive a more realistic take estimate, NMFS considered the 
Piwetz and Whitehead (2019) data and the amount of pile driving 
proposed by each applicant. Piwetz and Whitehead (2019) observed 109 
dolphins over 26.72 hours of survey effort, resulting in an average of 
4.1 dolphins/hour. Rio Grande anticipates installing 12 piles and 
removing 5 piles over approximately 11.3 hours. Given the number of 
dolphins/hour, this results in a total take estimate of 46 (4.1 
dolphins per hour x 11.3 hours). Annova anticipates installing 20 piles 
and removing 16 of those 20 piles over approximately 15 hours. Given 
the number of dolphins/hour, this results in a total take estimate of 
62 takes (4.1 dolphins per hour x 15 hours). This amount of take more 
closely reflects the potential for both applicants to harass animals 
and allows for an adequate amount of take when considering another 
important parameter- group size. The average expected group size of 
dolphins in the BSC is 4.5 dolphins (Piwetz and Whitehead, 2019). The 
proposed amount of bottlenose dolphin take for Rio Grande and Annova is 
presented in Table 10 and 11, respectively.

Rough-Toothed and Atlantic Spotted Dolphins

    It is unlikely that rough-toothed dolphins or Atlantic spotted 
dolphins will occur in the BSC as these species typically inhabit 
coastal and offshore waters. We note that neither of these species were 
observed during opportunistic and planned surveys in 2016 through 2019 
(Ronje et al., 2018; Piwetz and Whitehead 2019). However, because there 
is a small risk that these animals may be exposed to project-related 
noise if they do enter the BSC during pile driving (e.g., a stranding 
event or other abnormal behavior), both Rio Grande and Annova have each 
requested take equating to the average group size of these species 
(Maze-Foley and Mullin 2006). These mean group sizes are 14 rough-
toothed dolphins and 26 Atlantic spotted dolphins (Table 10 and 11).

                 Table 10--Proposed Take for Rio Grande
------------------------------------------------------------------------
                                                              Level B
            Species                       Stock             harassment
                                                               take
------------------------------------------------------------------------
Bottlenose dolphin.............  Laguna Madre...........              46
                                 Western Gulf of Mexico   ..............
                                  Coastal.
Rough-toothed dolphin..........  N. Gulf of Mexico......              14
Atlantic spotted dolphin.......  N. Gulf of Mexico......              26
------------------------------------------------------------------------


                   Table 11--Proposed Take for Annova
------------------------------------------------------------------------
                                                              Level B
            Species                       Stock             harassment
                                                               take
------------------------------------------------------------------------
Bottlenose dolphin.............  Laguna Madre...........              62
                                 Western Gulf of Mexico   ..............
                                  Coastal.
Rough-toothed dolphin..........  N. Gulf of Mexico......              14
Atlantic spotted dolphin.......  N. Gulf of Mexico......              26
------------------------------------------------------------------------

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or

[[Page 27384]]

stocks and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    Both Rio Grande and Annova have proposed similar mitigation 
measures to ensure the least practicable adverse impact on marine 
mammals. Because dolphins are present within the Laguna Madre year-
round, we are not proposing any in-water work windows.
    Each IHA would contain the following mitigation measures:
    For in-water construction, heavy machinery activities other than 
pile driving (e.g., use of barge-mounted excavators, or dredging), if a 
marine mammal comes within 10 m, Rio Grande and Annova must cease 
operations and reduce vessel speed to the minimum level required to 
maintain steerage and safe working conditions. This measure is designed 
to prevent physical injury from in-water equipment.
    Rio Grande and Annova are required to conduct briefings for 
construction supervisors and crews, the monitoring team, and staff 
prior to the start of all pile driving activity, and when new personnel 
join the work, in order to explain responsibilities, communication 
procedures, the marine mammal monitoring protocol, and operational 
procedures.
    Two protected species observers (PSOs) must be stationed on land, 
barge, boat, or dock with full view of the shutdown zones (Table 12) 
and with direct view of the opposite shoreline to observe for marine 
mammals within the Level B harassment zone. If a marine mammal is 
observed within or approaching the shutdown zone, the PSOs will call 
for a shutdown.

                        Table 12--Shutdown Zones
------------------------------------------------------------------------
                                                                Shutdown
              Applicant                         Pile            zone (m)
------------------------------------------------------------------------
Rio Grande..........................  All piles..............         20
Annova..............................  24-in..................         20
                                      96-in..................        100
------------------------------------------------------------------------

    Marine mammal monitoring must take place from 30 minutes prior to 
initiation of pile driving activity through 30 minutes post-completion 
of pile driving activity. Pile driving may commence when observers have 
declared the shutdown zone clear of marine mammals. In the event of a 
delay or shutdown of activity resulting from marine mammals in the 
shutdown zone (Table 12), their behavior must be monitored and 
documented until they leave of their own volition, at which point the 
activity may begin or they have not been re-sighted within 15 minutes.
    If a marine mammal is entering or is observed within an established 
shutdown zone (Table 12), pile driving must be halted or delayed. Pile 
driving may not commence or resume until either the animal has 
voluntarily left and been visually confirmed beyond the shutdown zone 
or 15 minutes have passed without subsequent detections.
    Should environmental conditions deteriorate such that marine 
mammals within the entire shutdown zone would not be visible (e.g., 
fog, heavy rain), pile driving and removal must be delayed until the 
PSO is confident marine mammals within the shutdown zone could be 
detected.
    Rio Grande and Annova must use soft start techniques when impact 
pile driving. Soft start requires contractors to provide an initial set 
of strikes at reduced energy, followed by a thirty-second waiting 
period, then two subsequent reduced energy strike sets. A soft start 
must be implemented at the start of each day's impact pile driving and 
at any time following cessation of impact pile driving for a period of 
thirty minutes or longer.
    Rio Grande and Annova are required to employ a double bubble 
curtain during all impact pile driving and operate it in a manner 
consistent with the following performance standards: The bubble curtain 
must distribute air bubbles around 100 percent of the piling perimeter 
for the full depth of the water column; the lowest bubble ring must be 
in contact with the mudline for the full circumference of the ring, and 
the weights attached to the bottom ring shall ensure 100 percent 
mudline contact. No parts of the ring or other objects shall prevent 
full mudline contact; and air flow to the bubblers must be balanced 
around the circumference of the pile. Rio Grande also proposed 
operating a double bubble curtain during all vibratory pile driving and 
removal and we have accounted for its ability to attenuate noise in our 
analysis. Therefore, Rio Grande must also operate this double bubble 
curtain during vibratory driving and removal.
    If a species for which authorization has not been granted, or a 
species for which authorization has been granted but the authorized 
takes are met, is observed approaching or within the monitoring zone 
(Table 9), pile driving and removal activities must shut down 
immediately using delay and shut-down procedures. Activities must not 
resume until the animal has been confirmed to have left the area or 15 
minutes has elapsed without a subsequent sighting.
    In the case that 75 percent of the authorized take is met and two 
or more piles are left to be installed to complete the project, Rio 
Grande and Annova would implement additional monitoring and mitigation 
to ensure the authorized take is not exceeded. If this trigger is met, 
an additional PSO would be positioned at the western edge of the Level 
B harassment zone.
    Based on our evaluation of the applicants' proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.

[[Page 27385]]

    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    Marine mammal monitoring before, during, and after pile driving and 
removal must be conducted by NMFS-approved PSOs who are independent and 
have a degree in biological sciences or related training/field 
experience. NMFS considers the following qualifications when reviewing 
potential PSO's Curriculum Vitae (CV): Ability to conduct field 
observations and collect data according to assigned protocols, 
experience or training in the field identification of marine mammals, 
including the identification of behaviors, sufficient training, 
orientation, or experience with the construction operation to provide 
for personal safety during observations, writing skills sufficient to 
prepare a report of observations including but not limited to the 
number and species of marine mammals observed; dates and times when in-
water construction activities were conducted; dates, times, and reason 
for implementation of mitigation (or why mitigation was not implemented 
when required); and marine mammal behavior, and ability to communicate 
orally, by radio or in person, with project personnel to provide real-
time information on marine mammals observed in the area as necessary. 
Rio Grande and Annova must submit PSO CVs for approval by NMFS prior to 
the onset of pile driving.
    Each IHA holder must submit a draft report on all marine mammal 
monitoring conducted under their IHA within ninety calendar days of the 
completion of marine mammal monitoring. A final report must be prepared 
and submitted within thirty days following resolution of comments on 
the draft report from NMFS.
    The marine mammal report must contain information related to 
construction activities, weather conditions, the number of marine 
mammals observed, by species, relative to the pile location (e.g., 
distance and bearing), description of any marine mammal behavior 
patterns during observation, including direction of travel and 
estimated time spent within the Level A harassment and Level B 
harassment zones during pile driving and removal, if pile driving or 
removal was occurring at time of sighting, age and sex class, if 
possible, of all marine mammals observed, PSO locations during marine 
mammal monitoring, detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any, an extrapolation of the estimated takes by Level B harassment 
based on the number of observed exposures within the Level B harassment 
zone and the percentage of the Level B harassment zone that was not 
visible. Rio Grande and Annova must also submit all PSO datasheets and/
or raw sighting data to NMFS.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder must 
immediately cease the specified activities and report the incident to 
NMFS and the Southeast Marine Mammal Stranding Network. If the death or 
injury was clearly caused by the specified activity, the IHA-holder 
must immediately cease the specified activities until NMFS is able to 
review the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHA. The IHA-holder must not resume their activities until 
notified by NMFS. Reporting information must include information about 
the event, species, animal condition and behavior, and if possible, 
photographs.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, our analysis below applies to the issuance of 
an IHA to Rio Grande and, separately, issuance of an IHA to Annova, as 
both projects include construction of an LNG terminal in the same area 
of the BSC.
    Pile driving activities associated with both projects, as outlined 
previously, have the potential to disturb or displace marine mammals. 
Specifically, the specified activities may result in take, in the form 
of Level B harassment (behavioral disturbance) incidental to underwater 
sounds generated from pile driving. Harassment could occur if dolphins 
are present in relatively close proximity (1-5 km\2\) to pile driving 
and removal.
    No Level A harassment, serious injury or mortality is anticipated 
given the nature of the activities and measures designed to avoid the 
potential of injury (e.g., PTS) to marine mammals. The potential for 
these outcomes is minimized through the construction method and the 
implementation of the

[[Page 27386]]

planned mitigation measures. Rio Grande and Annova would utilize a 
double bubble curtain during all impact pile driving while Rio Grande 
has also committed to using the double bubble curtain during vibratory 
driving and removal. Specifically, vibratory and impact hammers will be 
the primary methods of installation. Piles will first be installed 
using vibratory pile driving. Vibratory pile driving produces lower 
SPLs than impact pile driving. The rise time of the sound produced by 
vibratory pile driving is slower, reducing the probability and severity 
of injury. Impact pile driving produces short, sharp pulses with higher 
peak levels and much sharper rise time to reach those peaks. When 
impact pile driving is used, implementation of soft start and shutdown 
zones significantly reduces any possibility of injury. Given sufficient 
``notice'' through use of soft starts (for impact driving), marine 
mammals are expected to move away from a sound source; thereby, 
lowering received sound levels.
    The proposed activities by Rio Grande and Annova are localized and 
of relatively short duration (8 and 16 days, respectively). The project 
area is also very limited in scope spatially (confined to a small area 
of the BSC). Localized (confined to the BSC) and short-term noise 
exposures produced by project activities may cause short-term 
behavioral modifications in dolphins. Surveys in the lower Laguna Madre 
indicate dolphin behavior is generally dominated by socializing, 
traveling (often in the direction of tidal movement), and foraging 
(Ronje et al., 2018; Piwetz and Whitehead, 2019). Dolphins were also 
observed foraging behind active commercial shrimp trawlers in the BSC 
as far as the Brownsville Fishing Harbor (Ronje et al. 2018). During 
another survey, commercial fishing trawlers were observed actively 
operating and 31 percent (n = 5) of groups were observed foraging 
behind trawlers or directly off the stern taking advantage of discarded 
bycatch (Piwetz and Whitehead, 2019).
    Another Texas waterway similar to the BSC, the Galveston Ship 
Channel, has been a hot spot for dolphin research in Texas. Dolphins 
regularly use the GSC to forage (57 percent of observed behavioral 
states) and socialize (27 percent), and for traveling (5 percent) 
(Piwetz, 2019). The author found when boats were present, the 
proportion of time dolphins spent socializing and foraging was 
significantly less than expected by chance. Swimming speeds increased 
significantly in the presence of small recreational boats, dolphin-
watching tour boats, shrimp trawlers, and when tour boats and shrimp 
trawlers were both present. We would expect animals in the BSC to 
respond similarly (e.g., decreased foraging and socializing) to pile 
driving. However, the activities considered in these IHAs (pile 
driving) would be stationary in nature and no vessels would be actively 
approaching dolphins nor would dolphins likely be attracted to pile 
driving as they are to shrimp trawls.
    In general, effects on individuals that are taken by Level B 
harassment will likely be limited to temporary reactions such as 
avoidance, increased swimming speeds, and decreased socializing and 
foraging behaviors. We would anticipate swim speeds would increase as 
dolphins move closer to the pile driving location (similar to how they 
react to vessels); however, this would move them quickly past the 
terminal and pre-pile driving exposure behavior would likely return 
quickly. Foraging and socializing behaviors may cease; however, these 
behaviors would also resume shortly thereafter. Level B harassment will 
be reduced to the level of least practicable adverse impact through use 
of mitigation measures described herein.
    The project also is not expected to have significant adverse 
effects on affected marine mammal habitat. Marine mammal habitat 
quality within the BSC varies. There is little development along the 
shoreline until the Brownsville Fishing Harbor, located approximately 8 
km west of the project sites, when the BCS becomes commercial/
industrial. Dolphin habitat in the BSC would be temporarily, indirectly 
impacted during the brief duration of pile driving for both projects. 
Direct impacts to dolphin habitat would not occur during Annova's 
construction as the site is currently uplands. For Rio Grande, direct 
impacts to foraging habitat would be minimal and temporary in nature 
during pile driving, primarily consisting of increased turbidity. 
Dredging would permanently deepen the channel at the Rio Grande 
terminal location; however, the entire BSC is a man-made canal that is 
dredged. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammal foraging 
opportunities in a limited portion of the foraging range. However, 
because of the short duration of the activities, the relatively small 
area of the habitat that may be affected, the impacts to marine mammal 
habitat are not expected to cause significant or long-term negative 
consequences.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
the proposed activities are not expected to adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival:
     No Level A harassment, mortality is anticipated or 
authorized.
     The anticipated incidents of Level B harassment consist 
of, at worst, temporary modifications in behavior that would not result 
in fitness impacts to individuals;
     The specified activity and ensonification area is very 
small (1-5 km\2\) relative to the overall habitat ranges of all species 
and does not include habitat areas of special significance; and
     The presumed efficacy of the proposed mitigation measures 
in reducing the effects of the specified activity to the level of least 
practicable adverse impact.
     The impacts to marine mammal habitat would be temporary in 
nature, primarily increased turbidity and noise.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from Rio Grande's specified activities and, separately, 
Annova's specified activities, will have a negligible impact on all 
affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    For coastal stocks (bottlenose, Atlantic spotted, and rough-toothed 
dolphins) the amount of proposed take is less than one percent of the 
population. There is no population estimate available for the Laguna 
Madre

[[Page 27387]]

stock of bottlenose dolphins. Two studies investigating dolphins in 
Lower Laguna Madre yielded approximately 60 in 2016 (Ronje et al., 
2018) and 109 individuals in 2018 and 2019 (Piwetz and Whitehead, 
2019). However, these surveys were very limited in space with respect 
to the stock range and the numbers reflect identified individuals. More 
specifically, Ronje et al. 2018 limited their survey to the extreme 
lower portion of Lower Laguna Madre while Piwetz and Whitehead (2019) 
acknowledge the non-asymptotic nature of the discovery curve 
(accumulation curve) indicates that the sampling effort has not yet 
identified all, or even most, of the individuals that use this region 
(presumably referring to lower Laguna Madre). The entire Laguna Madre 
stock range include upper and lower Laguna Madre.
    To estimate potential abundance, we looked for comparative 
ecosystems to estimate potential population size and trends in 
abundance estimates for other Gulf of Mexico BSE stocks. The Indian 
River Lagoon (IRL) in Florida is similar in configuration and length to 
Laguna Madre but is approximately half the size (539 km\2\ versus 1137 
km\2\). Similar to Laguna Madre, there are no recent stock estimates 
for the IRL; however, seasonal aerial surveys spanning the IRL from 
2002 and 2003 yielded a range of 362 (CV = 0.29) to 1316 (CV = 0.24) 
with an overall mean abundance of 662 dolphins (Hayes et al., 2016). 
For those Gulf of Mexico BSEs that have been more intensively studied 
in recent years, the trend demonstrates these BSEs support much larger 
stocks of bottlenose dolphins than previously believed. For example, 
the abundance estimates for the Barataria Bay, Mobile Bay, and 
Mississippi Sound stocks based on older data were estimated at 138, 
122, and 901 animals, respectively (Hayes et al. 2017). More recent 
surveys and analysis now estimate those stocks at 2,306, 1,393, and 
3,046 dolphins, respectively. For these reasons, it is reasonable to 
assume the entire Laguna Madre similarly supports several hundred to 
thousand animals.
    Finally, dolphins within the BSC have been documented as following 
the tides and shrimp trawls making their way back to the fleet docks 
which are located west of the terminal sites (Ronje et al. 2018). 
Because the BSC is a dead-end canal, dolphins traveling past the 
terminal sites in a westward direction must re-transit past the 
terminal sites to exit the BSC. This is likely to occur on the same day 
given the tides. While it is not possible to determine if pile driving 
would be occurring as animals are transiting both west and east of the 
terminal sites on any given day, it is possible some animals may be 
exposed to pile driving on more than one occasion on any given day 
(e.g., if pile driving is occurring in the morning and then several 
hours later, after a tide change). Therefore, the number of individual 
dolphins actually harassed may be less than the amount of take proposed 
to be authorized.
    In summary, surveys in Laguna Madre have been limited to lower 
Laguna Madre and the authors acknowledge the limitations of their 
studies for purposes of estimating stock size, the IRL (a lagoon 
similar in configuration and proximity to ocean waters as the BSC but 
approximately half the surface water area) supports hundreds to over 
1,000 animals, and trends of older stock estimates compared to more 
recent data for other Gulf of Mexico BSE stocks. For these reasons, it 
is likely the Laguna Madre stock estimate is, at minimum, several 
hundred animals. Further, the number of individuals taken may be less 
than the amount of take authorized. Therefore, for the Laguna Madre 
stock of bottlenose dolphins, we find that the total taking may 
reasonably be expected to represent less than one-third of the total 
likely population abundance.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals relative to the population size of the 
affected species or stocks may be taken incidental to Rio Grande's 
proposed activities and, separately, incidental to Annova's proposed 
activities.

Endangered Species Act (ESA)

    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue IHAs to both Rio Grande and Annova authorizing the take, by Level 
B harassment only, of small numbers of marine mammals provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. A draft of the proposed IHAs can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-
marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorizations, 
and any other aspect of this Notice of Proposed IHA for the proposed 
projects. We also request at this time comment on the potential Renewal 
of the proposed IHAs as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform decisions on the request for these IHAs or subsequent 
Renewal IHAs.
    On a case-by-case basis, NMFS may issue a one-year Renewal IHA 
following notice to the public providing an additional 15 days for 
public comments when (1) up to another year of identical or nearly 
identical, or nearly identical, activities as described in the 
Specified Activities section of this notice is planned or (2) the 
activities as described in the Specified Activities section of this 
notice would not be completed by the time the IHA expires and a Renewal 
would allow for completion of the activities beyond that described in 
the Dates and Duration section of this notice, provided all of the 
following conditions are met:
     A request for renewal is received no later than 60 days 
prior to the needed Renewal IHA effective date (recognizing that the 
Renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA);
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take);
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized; and
     Upon review of the request for Renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.


[[Page 27388]]


    Dated: May 1, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-09830 Filed 5-7-20; 8:45 am]
 BILLING CODE 3510-22-P