[Federal Register Volume 85, Number 129 (Monday, July 6, 2020)]
[Notices]
[Pages 40250-40266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-14376]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XA252]
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; issuance of incidental harassment authorizations.
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SUMMARY: Pursuant to the Marine Mammal Protection Act (MMPA), NMFS has
hereby issued an incidental harassment authorization (IHA) to Rio
Grande LNG LLC (Rio Grande) and, separately, Annova LNG Common
Infrastructure (Annova), authorizing the take of small numbers of
marine mammals incidental to the construction of two liquefied natural
gas (LNG) terminals in the Brownsville Ship Channel (BSC), Texas.
DATES: The Rio Grande IHA is effective July 1, 2020 through June 31,
2021. The Annova IHA is effective March 1, 2021 through February 28,
2022.
ADDRESSES: Electronic copies of the application, IHAs, 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 below.
FOR FURTHER INFORMATION CONTACT: Jaclyn Daly, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are 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.
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. Neither Rio Grande nor NMFS expects serious injury or mortality
to result from these activities and NMFS has not authorized it.
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 NMFS has not authorized it.
Description of Specified Activity
Overview
Rio Grande and Annova are each planning to construct an LNG
terminal in the BSC, 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
[[Page 40251]]
removal. Rio Grande will install 12 42-48-inch (in) piles and remove 5
small timber piles over 8 days. Annova will 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 to take marine mammals incidental to pile driving and
removal and NMFS has issued such authorization.
Dates and Duration
Rio Grande's IHA is effective July 1, 2020 through June 30, 2021.
Pile driving would be limited to daylight hours; however, other
project-related activities may occur at any time. Pile driving and
removal would occur for no more than 8 days.
Annova's IHA is effective March 1, 2021 through February 28, 2022.
Pile driving would be limited to daylight hours; however, other
project-related activities may occur at any time. Pile driving and
removal would occur for no more than 16 days.
Specific Geographic Region
The projects would be constructed with the BSC which is located in
the southernmost portion of the Lower Laguna Madre system. We provided
a complete description of Laguna Madre and the BSC in our notice of
proposed IHA. Please see that notice for details of the specific
geographic region and maps.
Detailed Description of Specific Activity
Rio Grande
Rio Grande plans to construct a natural gas liquefaction facility
and liquefied natural gas (LNG) export terminal (Terminal) in Cameron
County, 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.
BILLING CODE 3510-22-P
[GRAPHIC] [TIFF OMITTED] TN06JY20.004
[[Page 40252]]
BILLING CODE 3510-22-C
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 mi) 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
(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 Grande would 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
Rio Grande plans 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 day Duration Total piles
SEL RMS Peak (days)
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PATON at the LNG Berth................. 48-in (steel) \2\........ 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\ 145.0 \3\ 145.0 n/a \5\ 5 \5\ 1 5
Tug Berth.............................. 42-in (steel) \4\........ 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 7decible (dB) reduction from unattenuated source levels.
\2\ 48-in pile source levels (SL) represent a -7 dB reduction from median values presented in Austin et al. (168.2 dB rms measured at 10 m (vibratory) and, for impact driving pile IP5,
estimated SL of 198.6 dB rms at 10 m and 186.7 dB SEL and 212.5 dB peak measured at 11 m.
\3\ The 145 dB SL represents a -7dB reduction from 152 dB; 152 dB represents the highest root mean square (RMS) value measured at 16 m during removal of timber piles at Port Townsend
(Laughlin, 2011).
\4\ Rio Grande conservatively applied 48-in pile IP5 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.
[[Page 40253]]
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 in
Rio Grande's application 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
Rio Grande 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
offload bulk materials at the Terminal site. Rio Grande 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 cubic
yards (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 nor is authorized, and this activity is not discussed
further.
Annova
Annova plans 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.
[[Page 40254]]
[GRAPHIC] [TIFF OMITTED] TN06JY20.005
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 m\3\ (42.3 million gallons). The LNG will be
pumped from the storage tanks to the marine facilities, where it will
be loaded onto LNG
[[Page 40255]]
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-ft) 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 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 Activities for Annova
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Source level (dB) \1\
Area Pile size/type Method ------------------------------------------------ Piles per day Duration Total piles
SEL RMS Peak (days)
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Breasting Dolphin (temporary).......... 24-in (steel)............ Vibratory \1\............... 165.0 165.0 n/a 4 \3\ 8 16
Impact \2\.................. 171.0 187.0 200.0
Breasting Dolphins (permanent)......... 96-in (steel)............ Vibratory \1\............... 180.0 180.0 n/a 0.5 \4\ 8 4
Impact \2\.................. 188.0 198.0 213.0
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\1\ Vibratory driving and removal source levels do not account for use of a bubble curtain. Proxy source levels are from 24-in sheet piles and 72-in pipe piles. Source: Caltrans (2015), Table
I.2-2.
\2\ Source levels for impact driving are a -7fB reduction from the unattenuated source levels in Caltrans (2015) Table I.2.I. Unattenuated source levels are: 178 dB re 1 [micro]Pa\2\-s at 10
m, 194 dB re 1 [micro]Pa at 10 m, and 207 dB re 1 [micro]Pa at 10 m for 24-in piles and 195 dB re 1 [micro]Pa\2\-s at 10 m, 205 dB re 1 [micro]Pa at 10 m, and 220 dB re 1 [micro]Pa at 10 m
for 96-in piles.
\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 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 plans 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.
The required mitigation, monitoring, and reporting measures for Rio
Grande and Annova are described in detail later in this document
(please see Mitigation and Monitoring and Reporting) and the IHAs which
are posted online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations.
Comments and Responses
A notice of NMFS' proposal to issue the IHAs was published in the
Federal Register on May 8, 2020 (85 FR 27365). That notice described,
in detail, Rio Grande and Annova's proposed activities, the marine
mammal species that may be affected by the activities, the anticipated
effects on marine mammals and their habitat, proposed amount and manner
of take, and proposed mitigation, monitoring and reporting measures.
During the 30-day public comment period, NMFS received a comment letter
from the Marine Mammal Commission (Commission) and a member of the
public. Both letters may be accessed online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations.
Comment 1: The Commission recommended that NMFS (1) have its
experts in underwater acoustics and bioacoustics review and finalize as
soon as possible, its recommended proxy source levels for impact pile
driving of the various pile types and sizes, (2) compile and analyze
the source level data for vibratory pile driving of the various pile
types and sizes in the near term, and (3) ensure action proponents use
consistent and appropriate proxy source levels in all future
rulemakings and proposed IHAs.
Response: NMFS concurs with the Commission's recommendation and has
prioritized these efforts.
Comment 2: If NMFS applies source level data from Austin et al.
(2016), the Commission recommends that NMFS ensure that the sound
level, as well as the distance at which the measurement was taken, is
correct and consistent in all future rulemakings and proposed
incidental harassment authorizations.
Response: The Commission recommends consistent source levels are
applied; however, we do not agree this is necessary. The Commission
compared source levels from the Port of Alaska (POA) Petroleum and
Cement Terminal IHA and is concerned we did not apply identical source
levels here. In their application, the POA averaged median source level
values from two 48-in unattenuated piles (IP1 and IP5) during the POA
Test Pile Program. The
[[Page 40256]]
Commission failed to recognize that Rio Grande actually applied the
higher source level of the two unattenuated piles to both 42-in and 48-
in piles. NMFS considered this approach conservative and acceptable;
therefore, NMFS did not adjust the 42-in and 48-in source levels for
Rio Grande. NMFS did, however, correct the SL distance measurement for
SEL and peak levels to 11m, not 10m for the final IHA. The resulting
change to the Level A harassment isopleth is negligible and (from 18.5
m to 20.3 m). There is no change to the Level B harassment isopleth as
the RMS values in Austin et al (2016) are modeled at 10 m.
Comment 3: The Commission recommends that NMFS use the loudest [72-
in pile proxy] source level of 180 dB re 1[mu]Parms at 10 m
[for the installation of 96-in piles] rather than the typical source
level of 170 dB re 1 [mu]Parms at 10 m from Table I.2-2 in
Caltrans (2015).
Response: We have accepted the Commission's recommendation for this
particular project but note future decisions regarding appropriate
proxy levels will be considered on a case-by-case basis. As
acknowledged by the Commission, this results in no change to the Level
B harassment zones given the narrow channel. Application of the 180dB
rms source level does slightly extend the calculated Level A harassment
isopleth (from 1.2 m to 5.4 m) when considering the full 20 minutes of
vibratory pile driving per day; however, the Level A harassment
isopleth remains less than 20 m shutdown zone for this activity.
Therefore, the recommendation does not result in any change to Annova's
IHA.
Comment 4: The Commission again recommends that NMFS (1) refrain
from using a 7-dB reduction factor and (2) consult with acousticians,
including those at the University of Washington-Applied Physics
Laboratory, regarding the appropriate source level reduction factor to
use to minimize near-field (<100 m) and far-field (>100 m) effects on
marine mammals or use the data NMFS has compiled regarding source level
reductions at 10 m for near-field effects and assume no source level
reduction for far-field effects for all relevant rulemakings and
proposed IHAs.
Response: NMFS disagrees with the Commission regarding this issue,
and does not adopt the recommendation. NMFS has previously outlined our
rationale for the bubble curtain source level reduction factor (e.g.,
84 FR 64833, November 25, 2019; 84 FR 28474, June 19, 2019) in response
to a similar comment from the Commission. NMFS will additionally
provide a detailed explanation of its decision within 120 days, as
required by section 202(d) of the MMPA.
Comment 5: The Commission recommends that NMFS revise its standard
condition for ceasing in-water heavy machinery activities to include
movement of the barge to the pile location and positioning of the pile
on the substrate, as well as the other activity examples, in all draft
and final incidental take authorizations involving pile driving and
removal.
Response: The Commission's recommendation is not fully practicable
and is unnecessary for the following reasons. Barges are pushed by
tugs. A tug pushing a barge is not able to cease entirely; it must
maintain control of the barge and steerage capabilities. The draft IHAs
already contain a measure that indicates vessels must reduce speeds in
the presence of a marine mammal which is the more appropriate way to
address any concerns from interaction with barges and vessels. With
respect to other activities, the condition included in the draft IHAs
provide examples and is not limited to those specifically identified.
Because any machinery to lift and place piles is considered ``heavy
machinery'', the placement of the pile is already covered in this
measure. The condition remains as presented in the draft IHAs.
Comment 6: The Commission recommends that NMFS include in the final
authorizations for Rio Grande and Annova the requirement that work must
occur only during daylight hours.
Response: NMFS does not concur and does not adopt the
recommendation. Both applicants have indicated they intent to conduct
pile driving and removal activities during daylight hours only.
However, if work needs to extend into the night, work may only be
conducted under conditions where there is full visibility of the
shutdown zone. Condition 4(d)(ii) in each IHA requires that pile
driving and removal must cease if the shutdown zone is not visible.
Comment 7: The Commission recommends that an additional protected
species observer (PSO) be deployed at the western edge of the Level B
harassment zones from the outset of the projects to ensure that
dolphins entering the Level B harassment zones from either end of the
BSC would be detected.
Response: The Commission provided this comment during informal
correspondence with NMFS and we responded with rationale for why we
were not requiring a third PSO for either project unless the trigger
identified in the proposed IHA was met (i.e., the applicant reached 75
percent of takes). The Commission's letter did not acknowledge our
prior response on this topic. In summary, NMFS does not require the
entire Level B harassment monitoring area be covered and there is
already a requirement that the applicants extrapolate take from any
area that is not able to be monitored in their final report. There will
be a PSO positioned at the pile driving site and a second PSO on the
eastern (seaward) edge of the Level B harassment zone. As described in
the notice of proposed IHAs, dolphins travel the BSC, primarily using
the tides. Because dolphins travel up and down the BSC, they are likely
to be documented by the PSOs on site and reasonable extrapolation of
takes are possible with the two required PSOs. Adding a third PSO at
the onset of the pile driving for the project to cover the entire
monitoring zone is not necessary and we have not included it. The
trigger to add a third PSO if 75 percent of takes are reached remains
in the IHAs.
Comment 8: The Commission recommends that NMFS require Rio Grande
and Annova to keep a daily running tally of the total Level B
harassment takes, based on both observed and extrapolated takes, to
ensure timely implementation of measures to avoid exceeding authorized
take limits.
Response: We agree that Rio Grande and Annova must ensure they do
not exceed authorized takes but do not concur with the recommendation.
NMFS is not responsible for ensuring that an applicant does not operate
in violation of an issued IHA.
Comment 9: The Commission recommends that NMFS refrain from issuing
renewals for any authorization and instead use its abbreviated Federal
Register notice process, which is similarly expeditious and fulfills
NMFS's intent to maximize efficiencies. If NMFS continues to propose to
issue renewals, the Commission recommends that it (1) stipulate that a
renewal is a one-time opportunity (a) in all Federal Register notices
requesting comments on the possibility of a renewal, (b) on its web
page detailing the renewal process, and (c) in all draft and final
authorizations that include a term and condition for a renewal and, (2)
if NMFS declines to adopt this recommendation, explain fully its
rationale for not doing so.
Response: NMFS does not fully agree with the Commission and,
therefore, does not adopt the Commission's recommendation. However, we
have identified that the renewal process is a one-time opportunity in
Federal
[[Page 40257]]
Register notices requesting comments, draft and final authorizations,
and have updated our web page. Regarding the remainder of the
recommendations, NMFS will provide a detailed explanation of its
decision within 120 days, as required by section 202(d) of the MMPA.
Comment 10: A member of the public provided a letter that included
concerns about various aspects of the project and other existing
conditions in Laguna Madre including operational impacts of the project
(e.g., discharges of thermal water from the regasification process, LNG
tanker water ballast), impacts to sea turtles, habitat impacts from
recreational and commercial fishing, safety of storage of chemicals,
Response: These concerns are outside the scope of the one-year IHAs
that authorize harassment to marine mammals from pile driving.
Comment 11: A member of the public claims take by Level A
harassment may occur given that animals forage and calve within the BSC
and must pass the project sites given the dead-end nature of the canal.
Response: Level A harassment equates to injury of a marine mammal.
This could occur through non-auditory and auditory pathways. NMFS
conducted a complete analysis of the potential for auditory injury
(i.e., permanent thresholds shift (PTS)) and the commenter did not
provide reason that this analysis may be incorrect. The IHAs also
contain a 10 m shutdown distance for heavy equipment to prevent
physical injury and that vessels must slow in the presence of marine
mammals to reduce the already low risk of vessel interaction resulting
in injury. Therefore, the mechanism by which the commenter believes
injury may occur is unclear. NMFS has fully evaluated the potential for
Level A harassment and has found that taking by Level A harassment is
not reasonably anticipated and is not authorizing it.
Comment 12: A member of the public believes the renewal process is
vague and requested more information on how NMFS plans to review
reports for consideration of renewal, how long that review process will
need, and from who or whom reports will be generated.
Response: NMFS' website about the renewal process, including
criteria, is available on our website at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. The criteria for renewal are also
contained within the draft and final IHAs.
Comment 13: A member of the public had concerns that NMFS did not
address cumulative impacts to dolphins from other stressors, including,
but not limited to, fishing and an additional proposed LNG facility in
the BSC.
Response: The MMPA requires NMFS to consider impacts from the
specified activity contained within an IHA application. Existing
stressors to marine mammals (e.g., current estimated rates of mortality
and serious injury from commercial and recreational fishing) are
included in our baseline analysis and consideration of the status of
the stock. Cumulative impacts from other stressors are considered under
the National Environmental Policy Act (NEPA) and are evaluated within
the permitting agency's (in this case the Federal Regulatory Energy
Commission) Environmental Impact Statements for the two projects which
can be found at https://www.ferc.gov/industries/gas/enviro/eis/2019.asp.
Comment 15: A member of the public requested NMFS require Rio
Grande and Annova to use a double bubble curtain on all impact and
vibratory pile driving and removal.
Response: Applicants typically propose using a bubble curtain for
impact pile driving only as this method of pile installation is louder
than vibratory driving and produces sharp rise times, which has a
higher potential for causing auditory impairments (i.e., temporary
threshold shift (TTS) and PTS). Rio Grande conservatively proposed
using a double bubble curtain on all impact and vibratory pile driving
and removal. Annova proposed to use the double bubble curtain on all
impact pile driving which is the typical case. The duration of
vibratory driving for Annova is short, the pile driving would occur
within a basin confined on three sides which reduces noise propagation
into the BSC, and vibratory driving produces low source levels without
rapid rise times relative to impact pile driving. For these reasons,
NMFS is not requiring Annova use a bubble curtain during vibratory pile
driving. The use of a double bubble curtain during all impact driving
is required for both Rio Grande (as well as vibratory driving and
removal, as proposed by the applicant) and Annova.
Comment 16: A member of the public urged NMFS to require PSOs for
Rio Grande and Annova to engage and coordinate with local experts to
work with, collaborate, and coordinate dolphin monitoring,
observations, and data intake and documentation and requested more
information on the training and/or certification regimens for the PSOs
that they must undertake to be approved and qualified.
Response: NMFS cannot require an applicant to hire or work with
local experts without commitment from both parties and the commenter
did not identify any specific local experts. NMFS does; however, list
PSO qualification requirements, including training and experience, in
the IHAs. NMFS also requires PSOs contact the Marine Mammal Stranding
Network should any injured or deceased marine mammals be observed. The
IHAs also require that PSOs are independent and have no other project-
related duties.
Changes From the Proposed IHA to Final IHA
There were no changes between the proposed IHAs and final IHAs: The
description of specified activities, amount and type of authorized
take, by species, and all mitigation, monitoring and reporting measures
contained within the proposed IHAs were carried forward to the final
IHAs. We made some adjustments to information contained within the
analysis based on comments from the Commission; however, as described
in the Comments and Responses section above, these changes did not
result in any changes to the IHAs.
Description of Marine Mammals in the Area of Specified Activities
A detailed description of the species likely to be affected by Rio
Grande and Annova's proposed projects, including brief introductions to
the species and relevant stocks as well as available information
regarding population trends and threats, and information regarding
local occurrence, were provided in the Federal Register notice for the
proposed IHAs (85 FR 27365; May 8, 2020). Please refer to the proposed
IHAs Federal Register notice for these descriptions and the summary in
Table 3 below.
[[Page 40258]]
Table 3--Marine Mammals Potentially Present In the Action Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Bottlenose dolphin.............. Tursiops truncatus..... Laguna Madre........... N,Y unknown \4\........... UND 0.4
Western Coastal GoM.... N,N 20,161 (0.17, 17,491, 175 0.6
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 624 (0.99, 311, 2009) 2.5 \6\ 1.2
\5\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
We provided discussion of the potential effects of the specified
activity on marine mammals and their habitat in our Federal Register
notice of proposed IHAs (84 FR 63618; November 18, 2018). Therefore, we
do not reprint the information here but refer the reader to that
document. That document included a summary and discussion of the ways
that components of the specified activities may impact marine mammals
and their habitat, as well as general background information on sound.
The Estimated Take section later in this document includes a
quantitative analysis of the number of individuals that are authorized
to be taken by these activities. The Negligible Impact Analysis and
Determination section considers the content of this section and the
material it references, the Estimated Take section, and the 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.
Estimated Take
This section provides the means by which the number of incidental
takes authorized in the IHAs were derived, 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 the
Mitigation section, Level A harassment is neither anticipated nor
authorized. Given the scope of work considered, no mortality or serious
injury is anticipated or is authorized for this activity. The projects
do have the potential to cause Level B (behavioral) harassment of
dolphins within the BSC and we have authorized it. 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 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
[[Page 40259]]
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's 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 4--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.
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 5 and 6, respectively.
Table 5--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
[[Page 40260]]
Distance of source level measurement (m)...... 11 (Rio Grande), 10 (Annova)
----------------------------------------------------------------------------------------------------------------
Table 6--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.................. 180
Number of piles per day........... 5 1 (48-in), 2 (42-in). 4.................... N/A
Duration to drive or remove a \2\ 20 24................... 10 (install), 45 \4\ 20
single pile (minutes). (remove) \3\.
----------------------------------------------------------------------------------------------------------------
Propagation (xLogR)............... 15
----------------------------------------------------------------------------------------------------------------
Distance from source level 16 10................... 10................... 10
measurement (m).
----------------------------------------------------------------------------------------------------------------
\1\ Source levels for Rio Grande 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.
\4\ Annova is installing 0.5 piles per day. Total vibratory pile driving duration per day to install this 0.5
pile is 20 minutes.
The results of the User Spreadsheet are presented in Table 7. 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 and the applicants
are required to shutdown pile driving should a marine mammal enter the
Level A harassment zones.
Table 7--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.................... 20.3...................... <0.01
48-in-diameter steel tube piles......... Vibratory................. 0.3....................... <0.01
Impact.................... 12.8...................... <0.01
12-in-diameter timber piles............. Vibratory................. 0.1....................... <0.01
----------------------------------------------------------------------------------------------------------------
Annova
----------------------------------------------------------------------------------------------------------------
24-in................................... Vibratory................. 0.3 (install) 0.9 (remove) <0.01
Impact.................... 10.9......................
92-in................................... Vibratory................. 5.4....................... <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 8 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 8 provides the
calculated Level B harassment isopleths and area accounting for land.
Table 8--Level B Harassment Distances and Areas for Rio Grande and Annova
----------------------------------------------------------------------------------------------------------------
Pile size (source level dB Isopleth distance Level B harassment
Hammer type rms) (m) area (km\2\) \1\
----------------------------------------------------------------------------------------------------------------
Rio Grande
----------------------------------------------------------------------------------------------------------------
Impact................................... 42- and 48-in.............. 1,278 1.06
[[Page 40261]]
Vibratory................................ 42- and 48-in.............. 5,580 4.85
12-in...................... 743 0.62
----------------------------------------------------------------------------------------------------------------
Annova
----------------------------------------------------------------------------------------------------------------
Impact................................... 24-in...................... 631 0.56
96-in...................... 3,415 \2\ 1.0
Vibratory................................ 24-in...................... 10,000 \2\ 1.0
96-in...................... 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 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\2\ 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
amount of bottlenose dolphin take authorized for Rio Grande and Annova
is presented in Table 9 and 10, 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
[[Page 40262]]
sizes are 14 rough-toothed dolphins and 26 Atlantic spotted dolphins
(Table 9 and 10).
Table 9--Authorized Take for Rio Grande
------------------------------------------------------------------------
Level B harassment
Species Stock 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 10--Authorized Take for Annova
------------------------------------------------------------------------
Level B harassment
Species Stock 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
------------------------------------------------------------------------
Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, 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 are required to enact 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, 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 PSOs must be stationed on land, barge, boat, or dock with full
view of the shutdown zones (Table 11) 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 11--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 11), 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 11), 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
[[Page 40263]]
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 30-second waiting period,
then two subsequent reduced energy strike sets. A soft start must be
implemented at the start of each day's impact pile driving and at any
time following cessation of impact pile driving for a period of 30
minutes or longer.
Rio Grande and Annova have stated that they will conduct all pile
driving during daylight hours, and both applicants 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 will operate a double bubble curtain during all vibratory pile
driving and removal and we have accounted for its use 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 8), 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 measures proposed by the applicants
and contained within the IHAs, NMFS has determined that the 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.
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.
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: 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 each PSO's curriculum vitae 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 90 calendar days of the
completion of marine mammal monitoring. A final report must be prepared
and submitted within 30 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
[[Page 40264]]
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 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 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 or 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
[[Page 40265]]
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 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;
The presumed efficacy of the mitigation measures in
reducing the effects of the specified activity to the level of least
practicable adverse impact; and
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 monitoring and mitigation
measures, NMFS 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 authorized take is less than one percent of the
population. There is no population estimate available for the Laguna
Madre 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
1137km\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
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 required mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS 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.
[[Page 40266]]
Endangered Species Act
Incidental take of ESA-listed species from the specified activities
is not expected or authorized. Therefore, NMFS determined that formal
consultation under section 7 of the ESA is not required for this
action.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
These actions are consistent with categories of activities
identified in Categorical Exclusion B4 (IHAs 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 would preclude this categorical exclusion.
Accordingly, the issuance of the IHAs has been categorically excluded
from further NEPA review.
Authorization
As a result of these determinations, NMFS has issued IHAs to both
Rio Grande and Annova authorizing the take, by Level B harassment only,
of small numbers of marine mammals provided the mitigation, monitoring,
and reporting requirements included in those IHAs are adhered to.
The IHAs can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
Dated: June 29, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2020-14376 Filed 7-2-20; 8:45 am]
BILLING CODE 3510-22-P