[Federal Register Volume 83, Number 87 (Friday, May 4, 2018)]
[Notices]
[Pages 19701-19710]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-09499]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF800
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Confined Blasting Operations in the
East Channel by the U.S. Army Corps of Engineers During the Tampa
Harbor Big Bend Channel Expansion Project in Tampa Harbor, Tampa,
Florida
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of Incidental Harassment Authorization (IHA).
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA), as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the U.S. Army Corps of Engineers, Jacksonville District, (USACE) for
authorization to take one species of marine mammal incidental to
confined blasting in the East Channel of the Big Bend Channel in Tampa
Harbor, Tampa, Florida.
DATES: The IHA will be valid from April 1, 2019 through March 31, 2020.
FOR FURTHER INFORMATION CONTACT: Dale Youngkin, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the IHA and
supporting documents, as well as a list of the references cited in this
document, may be obtained online at: www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems accessing these documents, please call
the contact listed above.
SUPPLEMENTARY INFORMATION:
[[Page 19702]]
Background
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
authorization is provided to the public for review.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant), and if the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such takings
are set forth.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal. 16 U.S.C. 1362(13).
Except with respect to certain activities not pertinent here, 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). 16 U.S.C. 1362(18)(A).
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment.
Accordingly, NMFS adopted the USACE's Supplemental Environmental
Assessment (EA) (August, 2017). After independent evaluation of the
document and review of comments submitted in response to the proposed
IHA notice, NMFS has concluded that the USACE's EA includes adequate
information analyzing the effects on the human environment of issuing
the IHA and issued our ow Finding of No Significant Impact (FONSI).
NMFS' FONSI is available for review on our website at http://www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Summary of Request
On August 8, 2017, NMFS received a request from USACE for an IHA to
take marine mammals incidental to confined blasting within the East
Channel of the Tampa Harbor Big Bend Channel Expansion Project in
Tampa, Florida. USACE's request is for take of a small number of the
Tampa Bay stock of bottlenose dolphins (Tursiops truncatus) by Level B
harassment only. Neither USACE nor NMFS expect mortality to result from
this activity and, therefore, an IHA is appropriate.
NMFS previously issued an IHA to USACE for similar work in the
Miami Harbor (77 FR 49278, August 15, 2012). However, ultimately, USACE
did not perform any confined blasting under that IHA. Prior to that,
NMFS issued an IHA to the USACE for similar work in the Miami Harbor
Phase II Project in 2005 (70 FR 21174, April 25, 2005) and 2003 (68 FR
32016, May 29, 2003).
Description of Proposed Activity
A detailed description of the planned USACE project is provided in
the Federal Register notice for the proposed IHA (83 FR 11968; March
19, 2018). Since that time, no changes have been made to the planned
activities. Therefore, we provide only a summary here. Please refer to
the Federal Register Notice for the full description of the specified
activity.
USACE plans to conduct confined underwater blasting within the East
Channel as part of the Tampa Harbor Big Bend Channel Expansion Project
in Tampa, FL. The purpose of the confined underwater blasting is to
break up rock in the existing East Channel to allow for dredging
necessary to widen and deepen the existing channel.
Due to coordination with the U.S. Fish and Wildlife Service (USFWS)
to avoid potential impacts to manatees, the USACE will be restricted to
the months of April-October for blasting activities. In addition to the
seasonal restriction for blasting activities, the USACE has proposed
restricting the number of blasting events to a maximum of 42 events,
and the maximum weight of each charge will be 18 kg (40 lbs)/charge,
for a total of 725 kg (1,600 lbs) per each blasting event.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see ``Proposed
Mitigation'' and ``Proposed Monitoring and Reporting'').
Comments and Responses
A notice of NMFS's proposal to issue an IHA to the USACE was
published in the Federal Register on March 19, 2018 (83 FR 11968). That
notice described the USACE's activity, the marine mammal species that
may be affected by the activity, and the anticipated effects on marine
mammals. During the 30-day public comment period, NMFS received one
comment letter from the Marine Mammal Commission (Commission). The
Commission concurred with NMFS' preliminary findings and recommended
that NMFS issue the IHA, subject to the inclusion of the proposed
mitigation, monitoring, and reporting measures as provided in the
notice of the proposed IHA.
Comment 1: The Commission recommended that NMFS enumerate the
number of bottlenose dolphins that could be taken during the planned
activities by applying standard rounding rules before summing the
numbers of estimated takes across days of activities.
Response: Calculating predicted take is not an exact science and
there are arguments for taking different mathematical approaches in
different situations, and for making qualitative adjustments in other
situations. NMFS is currently engaged in developing a protocol to guide
more consistent take calculation given certain circumstances. We
believe, however, that the methodology for this action remains
appropriate and the the low likelihood of take in combination with
implementation of monitoring and mitigation measures will avoid any
take of marine mammals by Level A harassment.
Comment 2: The Commission recommended several items for NMFS to
ensure are incorporated into either the final hydroacoustic monitoring
plan or the IHA itself. In addition, the Commission stated these items
would likely need to be stipulated by the USACE in its hydroacoustic
monitoring contract.
Response: NMFS coordinated with the USACE in regard to the
hydroacoustic monitoring plan. As stated in the MMC comment, USACE has
indicated that they would need to have a contractor on board prior to
development of the hydroacoustic monitoring plan. USACE agreed to
develop the hydroacoustic monitoring
[[Page 19703]]
plan in coordination with NMFS, and agreed to provide NMFS with a draft
plan for review at least 30 days prior to beginning the blasting
activities. However, the information provided by the MMC was shared
with USACE and NMFS will require this information to be included in
hydroacoustic monitoring plan prior to approval of the plan and has
incorporated this information into the IHA itself.
Description of Marine Mammals in the Area of Specified Activities
A detailed description of the species likely to be affected by the
USACE confined blasting project, including brief introductions to the
species and relevant stocks as well as available information regarding
population trends and threats, and information regarding local
occurrence, are provided in USACE's application and the Federal
Register notice for the proposed IHA (83 FR 11968; March 19, 2018). We
are not aware of any changes in the status of these species and stocks;
therefore, detailed descriptions are not provided here. Please refer to
the Federal Register notice for these descriptions. Table 1 lists all
marine mammal species with potential occurrence in the project area;
however, only bottlenose dolphin (Tursiops truncatus) have the
potential to be affected by the USACE proposed activities, so other
species are not discussed further in this document. Please also refer
to additional species information available in the NMFS Atlantic Ocean
Stock Assessment Reports (SARs) s at http://nmfs.noaa.gov/pr/sars/region.htm.
Table 1--Marine Mammals With Potential Occurrence in the Project Area
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Occurrence in project Stock population ESA status MMPA status
Species Habitat area estimate \1\ \2\ \3\ PBR
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Humpback whale (Megaptera Pelagic, nearshore Rare..................... 823--Gulf of Maine NL NC 13
novaengliae). waters and banks. Stock.
Minke whale (Balaenoptera Coastal, offshore... Rare..................... 2,591--Canadian East NL NC 14
acutorostrata). Coast Stock.
Bryde's whale (Balaenoptera Pelagic and coastal. Rare..................... 33--Northern Gulf of NL S 0.03
brydei). Mexico Stock.
Sei whale (Balaenoptera borealis) Primarily offshore, Rare..................... 357--Nova Scotia EN S 0.5
pelagic. Stock.
Fin whale (Balaenoptera physalus) Slope, mostly Rare..................... 1,618--Western North EN S 2.5
pelagic. Atlantic Stock.
Blue whale (Balaenoptera Pelagic and coastal. Rare..................... 440--Western North EN S 0.9
musculus). Atlantic Stock.
Sperm whale (Physeter Pelagic, deep seas.. Rare..................... 763--Northern Gulf EN S 1.1
macrcephalus). of Mexico Stock.
Dwarf sperm whale (Kogia sima)... Offshore, pelagic... Rare..................... 186--Northern Gulf NL NC 0.9
of Mexico Stock.
Gervais' beaked whale (Mesoplodon Pelagic, slope and Rare..................... 149--Northern Gulf NL NC 0.8
europaeus). canyons. of Mexico Stock.
Sowerby's beaked whale Pelagic, slope and Rare..................... 7,092--Western North NL NC 0.8
(Mesoplodon bidens). canyons. Atlantic Stock.
Blainville's beaked whale Pelagic, slope and Rare..................... 149--Northern Gulf NL NC 0.8
(Mesoplodon densirostris). canyons. of Mexico Stock.
Cuvier's beaked whale (Ziphius Pelagic, slope and Rare..................... 74--Northern Gulf of NL NC 0.4
cavirostris). canyons. Mexico Stock.
Killer whale (Orcinus orca)...... Widely distributed.. Rare..................... 28--Northern Gulf of NL NC 0.1
Mexico Stock.
Short-finned pilot whale Inshore and offshore Rare..................... 2,415--Northern Gulf NL NC 15
(Globicephala macrorhynchus). of Mexico Stock.
False killer whale (Pseudorca Pelagic............. Rare..................... NA--Northern Gulf of NL NC Unknown
crassidens). Mexico Stock.
Melon-headed whale (Peponocephala Pelagic............. Rare..................... 2,335--Northern Gulf NL NC 13
electra). of Mexico Stock.
Pygmy killer whale (Feresa Pelagic............. Rare..................... 152--Northern Gulf NL NC 0.8
attenuata). of Mexico Stock.
Risso's dolphin (Grampus griseus) Pelagic, shelf...... Rare..................... 2,442--Northern Gulf NL NC 16
of Mexico Stock.
Common bottlenose dolphin Offshore, inshore, Common................... 564--Tampa Bay Stock NL S Unknown
(Tursiops truncatus). coastal, and \4\.
estuaries.
Rough-toothed dolphin (Steno Pelagic............. Rare..................... 624--Northern Gulf NL NC 3
bredanensis). of Mexico Stock.
Fraser's dolphin (Lagenodelphis Shelf and slope..... Rare..................... NA--Northern Gulf of NL NC Unknown
hosei). Mexico Stock.
Striped dolphin (Stenella Coastal, shelf and Rare..................... 1,849--Northern Gulf NL NC 10
coeruleoalba). slope. of Mexico Stock.
Pantropical spotted dolphin Coastal, shelf and Uncommon................. 50,880--Northern NL NC 407
(Stenella attenuata). slope. Gulf of Mexico
Stock.
Atlantic spotted dolphin Coastal to pelagic.. Uncommon................. NA--Northern Gulf of NL NC Unknown
(Stenella frontalis). Mexico Stock.
Spinner dolphin (Stenella Mostly pelagic...... Uncommon................. 11,441--Northern NL NC 62
longirostris). Gulf of Mexico
Stock.
[[Page 19704]]
Clymene dolphin (Stenella Coastal, shelf and Uncommon................. 129--Northern Gulf NL NC 0.6
clymene). slope. of Mexico Stock.
West Indian manatee (Florida Coastal, rivers, and Uncommon................. 6,620--Florida Stock T D ..............
manatee) (Trichechus manatus estuaries. \5\.
latirostris).
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\1\ NMFS Marine Mammal Stock Assessment Reports (Hayes et al., 2016) unless indicated otherwise.
\2\ U.S. Endangered Species Act: EN = endangered; T = threatened; NL = not listed.
\3\ U.S. Marine Mammal Protection Act: D = depleted; S = strategic; NC = not classified.
\4\ Wells et al., 1995.
\5\ Florida Fish and Wildlife Conservation Commission Survey Data (USFWS jurisdiction).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The Federal Register notice for the proposed IHA (83 FR 11968;
March 19, 2018) included a discussion of the effects of disturbance on
marine mammals and their habitat; therefore, that information is
summarized here. Please refer to the proposed IHA Federal Register
notice for more detailed information.
The USACE's proposed confined blasting activities have the
potential to take marine mammals by exposing them to impulsive noise
and pressure waves generated by detonations of explosives. Exposure to
energy, pressure, or direct strike has the potential to result in non-
lethal injury (Level A harassment), disturbance (Level B harassment),
serious injury, and/or mortality.
The potential effects of underwater detonations from the proposed
confined blasting activities may include one or more of the following:
Temporary or permanent hearing impairment, non-auditory physical or
physiological effects, behavioral disturbance, and masking (Richardson
et al., 1995; Gordon et al., 2004; Nowacek et al., 2007; Southall et
al., 2007). However, the effects of noise on marine mammals are highly
variable, often depending on species and contextual factors (based on
Richardson et al., 1995). Implementation of mitigation and monitoring
efforts will avoid mortality, serious injury, and Level A harassment
(PTS). Therefore, only Level B harassment (TTS and behavioral
harassment) are anticipated due to the USACE confined underwater
blasting activities.
While we anticipate that the specified activity may result in
marine mammals avoiding certain areas due to temporary ensonification,
this impact to habitat and prey resources would be temporary and
reversible. The main impact associated with the proposed activity would
be temporarily elevated noise levels and the associated direct effects
on marine mammals. Marine mammals are anticipated to temporarily vacate
the area of live detonations. However, these events are usually of
short duration, and we anticipate that animals will return to the
activity area during periods of non-activity. Thus, we do not
anticipate that the proposed activity would have any habitat-related
effects that could cause significant or long-term consequences for
individual marine mammals or their populations.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of whether the number of takes is ``small'' 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 and/or TTS for individual marine
mammals resulting from exposure to noise from underwater confined
blasting in the East Channel of the Big Bend Channel, Tampa Harbor.
Based on the nature of the activity and the anticipated effectiveness
of the mitigation measures (i.e., no blasting if marine mammals (or any
protected species) are within the East Channel, which encompasses the
entirety of the Level A take zone, as discussed in detail below in
Proposed Mitigation section), Level A harassment is neither anticipated
nor proposed to be authorized.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
Described in the most basic way, we estimate take by considering:
(1) Thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment or tissue damage; (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. Below, we
describe these components in more detail and present the proposed take
estimate.
Acoustic Thresholds
Using the best available science, NMFS has developed acoustic
thresholds that identify the received level of underwater sound above
which exposed marine mammals would be reasonably expected to be
behaviorally harassed (equated to Level B harassment) or to incur PTS
of some degree (equated to Level A harassment). Thresholds have also
been developed to identify the pressure levels above which animals may
incur different types of tissue damage from exposure to pressure waves
from explosive detonation.
These thresholds were developed by compiling and synthesizing the
best available science and soliciting input multiple times from both
the public and peer reviewers to inform the final product, and are
provided in the table below. The references, analysis, and methodology
used in the development of the thresholds are described in NMFS 2016
Technical Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
[[Page 19705]]
Table 2--NMFS' Current Thresholds and Criteria for Impact Analysis From the Use of Explosives for
Mid-Frequency Cetaceans
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GI
Hearing group Species Behavioral TTS PTS tract Lung injury Mortality
injury
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Mid-frequency cetaceans........ Most delphinids, 165 dB SELcum 170 dB 185 dB 237 dB 39.1 M1/3 (1 + [DRm/ 91.4 M1/3 (1 + [DRm/
medium and large SELcum; 224 SELcum; 230 10.081])1 / 2 Pa-sec 10.081])1 / 2 Pa-sec
toothed whales. dB PK. dB PK. Where: M = mass of Where: M = mass of
the animals in kg DRm the animals in kg DRm
= depth of the = depth of the
receiver (animal) in receiver (animal) in
meters. meters.
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Explosive sources--Based on the best available science, NMFS uses
the acoustic and pressure thresholds indicated in Table 2 above to
predict the onset of behavioral harassment, TTS, PTS, tissue damage,
and mortality.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds.
Radii for Level A and Level B harassment were calculated using
algorithms specifically developed for confined underwater blasting
operations by the NMFS (see Attachment B of the application, which
provides more detail and spreadsheet results). The algorithms compute
the cumulative sound exposure impact zone due to a pattern of charges.
The code calculates the total explosive energy from all charges through
a summation of the individual energy emanating from each charge as a
function of temporal and spatial separation of charges. Acoustical
transmission loss is assumed to occur through cylindrical spreading.
The SEL of the first detonation and each subsequent detonation is
summed and transmission loss of acoustic energy due to cylindrical
spreading is subtracted from the total SEL. Ultimately, the distance
where the received level falls to a set SEL is calculated by spherical
spreading of the total SEL (refer to section 6 and Attachment B of the
IHA application for more information on how this was modeled). However,
the proposed blasting would occur within the East Channel, which is
open to the Hillsborough Bay on the west side of the channel, but
confined by land on the north, east, and south sides of the channel.
NMFS and USACE agree that acoustic energy emanating from the East
Channel and into Hillsborough Bay would rapidly decrease as the energy
spreads to the north and south outside of the East Channel in the Bay.
Under these conditions, sound energy beyond a 45 degree angle, or a 45
degree cone shape outside of the channel mouth would attenuate, and
would not result in Level B take.
Level A and B take zones (km\2\) were calculated using the
calculated blasting radii. Some blasting radii are contained within the
water column or between the East Channel's north and south shorelines.
These areas therefore are circular in shape. However, larger blasting
radii extend beyond the channel's shorelines. In these cases, the areas
form an irregular polygon shape that are bounded by the channel's
shoreline to the north, east, and south and are cone-shaped outside of
the East Channel opening to Tampa/Hillsborough Bay. The areas of these
irregular polygon shapes were determined with computer software (Google
Earth Pro). This area was then multiplied by the density calculated for
common bottlenose dolphins in the project area, as this is the only
marine mammal species potentially occurring in the East Channel
(density information provided below). Figure 10 of the application
illustrates the take areas calculated for the largest blast pattern
consisting of 18.1 kg (40 lbs)/delay and 40 individual charges, which
was used to calculate estimated take for the confined blasting
activities. The Level A (PTS) harassment zone was calculated to be 0.14
square kilometers based on an isopleth of 378 m; the Level B TTS
harassment zone was calculated to be 2.85 square kilometers based on an
isopleth of 2,125 m; and the Level B behavioral harassment zone was
calculated to be 6 square kilometers based on an isopleth of 3,780 m.
We note here that Level A take is not anticipated due to the small
Level A harassment zone and density of bottlenose dolphins in the
proposed project area resulting in a low likelihood of Level A take for
any one blasting event combined with mitigation measures to avoid Level
A take.
Marine Mammal Occurrence/Density Calculation
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
As stated above, common bottlenose dolphins are the only species of
marine mammal anticipated to occur in the proposed project area. Using
photo-identification methods, Urian et al. (2009) identified 858
individual dolphins during their 6-year study in the Tampa Bay.
However, as state above, data from Wells et al. (1995) was used for the
abundance estimate of the Tampa Bay Stock of common bottlenose
dolphins, as Urian et al. (2009) was not an abundance estimate, but a
population structure study. The Wells et al. (1995) mark-resight method
provided the most conservative, or highest average, abundance of 564
common bottlenose dolphins within the 852-km\2\ study area. In order to
calculate take, the USACE made an assumption that the dolphins would be
evenly distributed throughout Tampa Bay. The number of dolphins per
square kilometer within this area is calculated as 0.66 (564 dolphins /
852 km\2\ = 0.66 dolphins/km\2\).
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
The USACE proposes a maximum charge weight of 725.7 kg (1,600 lbs)
as a conservatively high estimate for the total amount of explosives
that may be used in the largest blasting pattern. This is based on the
fact that the maximum charge weight per delay would not exceed 18.1 kg
(40 lbs)/delay for this project and the maximum number of charges per
pattern would not exceed 40. Please refer to Table 3 of the application
for the level of take associated with this charge weight as well as
other charge weights. Figure 10 of the application provides visual
representation of take areas plotted on an aerial photograph for 18.1
kg/delay.
A maximum of 42 blast events would occur over the one year period
of this IHA. Using the Tampa Bay Stock abundance estimate (n=564), the
density of common bottlenose dolphins occurring within the footprint of
the project (0.66 dolphins/km\2\), as well as the maximum charge weight
of 18.1 kg (40 lbs)/delay, the USACE is requesting Level B take for
behavioral harassment and/or TTS for up to 5.8 common bottlenose
dolphins per blast (refer to Table 3 of the application). Therefore,
[[Page 19706]]
using the maximum amount of explosives per blast event and the maximum
number of blast events, an estimated 244 Level B takes would occur over
the one-year period of this IHA (5.8 dolphin/blast x 42 detonations =
243.6 exposures). However, the number of dolphins subjected to TTS and/
or behavioral harassment is expected to be significantly lower for two
reasons. First, the USACE will implement a test blast program to
determine the smallest amount of explosives needed to fracture the rock
and allow mechanical removal. This test blast program would begin with
a single row pattern of charges, and would vary the number and charges/
pattern as well as the charge weight/delay to determine the minimum
needed and these test blasts would count toward the maximum of 42 total
blast events. The maximum 1,600 lb blasting pattern of 18.1 kg (40 lb)/
delay and 40 individual charges was used to calculate take due to the
uncertainty regarding the minimum needed charge/delay and individual
charges as well as uncertainty regarding the number of test blasts.
Therefore, there would not actually be 42 blast events with the full
pattern of 40 delays at full charge weight/delay (1,600 lb), as was
assumed in the take calculation, and the take estimate is a
conservative estimate. Second, we expect at least some of the exposures
to be repeat exposures of the same individuals, as discussed further in
the Small Numbers section below.
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 such
activity, ``and other means of effecting the least practicable impact
on such species or stock and its habitat, paying particular attention
to rookeries, mating grounds, and areas of similar significance, and on
the availability of such 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 such
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.
As discussed previously, the USACE will confine the blasts within
the East Channel by boring holes into the existing rock, placing
explosive charges within the holes, and stemming the holes in order to
greatly reduce the energy released into the water column from the
blasts (estimated to reduce the amount of energy by 60-90 percent
versus open water blasting). In addition to utilizing the confined
blasting, the following conditions will be incorporated into the
project specifications to reduce the risk of impacts to marine mammals:
Confined blasting will be restricted to the East Channel
only;
Blasting will be restricted to the months of April through
October (this is to avoid impacts to Florida manatee, but may also
serve to avoid impacts if there are seasonal increases in Tampa Bay/
proposed project area during the fall/winter as reported by Scott et
al. (1989), and discussed above);
The blasting plan shall be provided for NMFS review at
least 30 days prior to work, and the blasting plan must include
detailed information about the protected species watch program as well
as details about proposed blasting events (to be submitted to NMFS
headquarters Protected Species Division as well as the NMFS Southeast
Regional Office, the State Fish and Wildlife Commission (FWC) Office,
and USFWS);
[cir] The blasting plan shall include:
[ssquf] A list of the observers, their qualifications, and
positions for the watch, including a map depicting the proposed
locations for boat or land-based observers. Qualified observers must
have prior on-the-job experience observing for protected marine species
(such as dolphins, manatees, marine turtles, etc.) during previous in-
water blasting events where the blasting activities were similar in
nature to this project;
[ssquf] The amount of explosive charge proposed, the explosive
charge's equivalency in TNT, how it will be executed (depth of
drilling, stemming information, etc.), a drawing depicting the
placement of the charges, size of the safety radius and how it will be
marked (also depicted on a map), tide tables for the blasting event(s),
and estimates of times and days for blasting events (with an
understanding this is an estimate, and may change due to weather,
equipment, etc.). Certain blasting restrictions will be imposed
including the following: (1) Individual charge weights shall not exceed
18.1 kg (40 lbs)/delay, and (2) the contractor shall not exceed a total
of 42 blast events during the blast window.
[ssquf] Hydroacoustic monitoring will be performed for each blast
event, up to the maximum of 42 blast events. A hydroacoustic monitoring
plan will be developed in coordination with NMFS HQ Permits and
Conservation Division, and will be submitted to NMFS for review at
least 30 days prior to commencement of the blasting activities. As part
of this hydroacoustic monitoring, the contractor shall:
[cir] Describe hydroacoustic measurement methods. The sampling rate
of the recording devices (i.e., hydrophone and/or pressure transducer)
shall be specified to ensure the necessary frequencies (10 Hz-40 kHz)
and pressure signals (at least 1 MHz) are recorded and the appropriate
filter (band pass) is used. The type of hydrophone proposed for use
shall also be described and shall be appropriate for collecting
measurements of underwater detonations as well as ambient measurements
in the far field (i.e., low vs high sensitivity). The plan shall
specify that recording devices shall be placed in the near field (at 10
m) and sufficiently in the far field (and away from shipping lanes) to
collect the relevant data.
[cir] Describe analytical methods. The plan shall specify that
pressure signals must be analyzed using appropriate signal processing
methods and applicable equations. The various impulse metrics will be
calculated using time series data. Cumulative sound exposure levels
(SELcum) will be calculated using a linear summation of
acoustic intensity. Weighted cumulative sound exposure thresholds will
be used to estimate the various ranges.
[[Page 19707]]
The hydroacoustic monitoring plan shall stipulate that the
contractor will:
[cir] Record the SEL and SPL associated with each blasting event;
[cir] Record the associated work (including borehole drilling and
fish scare charges) as separate recordings;
[cir] Provide nearby hydrophone records of drilling operations of
30 minutes over three early contract periods at least 18 hours apart.
[cir] Provide hydrophone or transducer records within the contract
area of three continuous 10-minute quiet periods (over three early
contract periods) at least 18 hours apart or prior to the contractor's
full mobilization to the site, and 10 close-approaches of varied vessel
sizes. This information will be provided as both an Excel file and
recording for each hydrophone (.wav file) shall include: GPS location
of the hydrophone (to be located outside of the range that would cause
clipping); Water depth to the sediment/rock bottom (to be placed at the
shallower of 9.84 ft (3 m) depth of the mid-water column depth); and
Information regarding the blast pattern or drilling.
[cir] Provide a report that includes the appropriate metrics (i.e.,
impulse in Pa-sec or psi-msec; peak sound levels; and SELcum
for the entire blast event); appropriate statistics (i.e., median,
mean, minimum, and maximum); and relevant information (i.e., number of
delays per blast event, total net explosive weight of each blast event,
sediment characteristics/types, hydrophone depths and distances to the
closest and farthest delay, water depth, power specral data).
In addition to review of the blasting plan, NMFS's
Southeast Region Office and local stranding network shall be notified
at the beginning (24 hours prior) and after (24 hours after) any
blasting;
For each explosive charge placed, three zones will be
calculated, denoted on monitoring reports and provided to protected
species observers before each blast for incorporation in the watch plan
for each planned detonation. All of the zones will be noted by buoys
for each of the blasts. These zones are:
[cir] Level A Take Zone: The Level A Take Zone is equal to the
radius of the PTS Injury Zone. As shown in the application in Table 3,
as well as Figure 10, all other forms of injurious take (i.e. gastro-
intestinal injury, lung injury) and mortality have smaller radii than
the PTS Injury Zone. Detonation shall not occur if a protected species
is known to be (or based on previous sightings, may be) within the
Level A Take Zone;
[cir] Exclusion Zone: A zone which is the Level A Take Zone + 152.4
m (500 ft). Detonation will not occur if a protected species is known
to be (or based on previous sightings, may be) within the Exclusion
Zone;
[cir] Level B Take Zone: The Level B Take Zone extends from the
Exclusion Zone to the Behavior Zone radius. Detonation shall occur if a
protected species is within the Level B Take Zone. Any protected
species within this zone shall be monitored continuously and, if they
are within the Level B Take Zone during detonation, then they shall be
recorded on monitoring forms. Note that the Level B Take Zone should
begin immediately beyond the end of the Level A Take Zone. However, the
USACE proposes to implement an Exclusion Zone. Also, the area
immediately beyond the Level B Take Zone shall also be monitored for
protected species.
No blasting shall occur within East Channel if dolphins or
any other protected species are present within the East Channel (Note:
the Level A harassment zone is entirely within the East Channel, which
is why no Level A harassment is proposed for authorization);
Protected species observers (PSOs) shall begin the watch
program at least one hour prior to the scheduled start of the blasting
activities, and will continue for at least one hour after blast
activities have completed;
The watch program shall consist of a minimum of six PSOs
with a designated lead observer. Each observer shall be equipped with a
two-way radio that shall be dedicated exclusively to the watch. Extra
radios shall be available in case of failures. All of the observers
shall be in close communication with the blasting subcontractor in
order to halt the blast event if the need arises. If all observers do
not have working radios and cannot contact the primary observer and the
blasting subcontractor during the pre-blast watch, the blast shall be
postponed until all observers are in radio contact. Observers will also
be equipped with polarized sunglasses, binoculars, a red flag for
backup visual communication, and a sighting log with a map to record
sightings;
All blasting events will be weather dependent. Climatic
conditions must be suitable for adequate viewing conditions. Blasting
will not commence in rain, fog or otherwise poor weather conditions,
and can only commence when the entire Level A Take Zone, Exclusion
Zone, and Level B Take Zone are visible to observers;
The PSO program will also consist of a continuous aerial
survey conducted as approved by the Federal Aviation Administration
(FAA). The blasting event shall be halted if an animal is spotted
approaching or within the Exclusion Zone. An ``all-clear'' signal must
be obtained from the aerial observer before detonation can occur. Note
that all observers must give the ``all-clear'' signal before blasting
can commence. The blasting event shall be halted immediately upon
request of any of the observers. If animals are sighted, the blast
event shall not take place until the animal moves out of the Exclusion
Zone on its own volition. Animals shall not be herded away or harassed
into leaving. Specifically, the animals must not be intentionally
approached by project watercraft. Blasting may only commence when 30
minutes have passed without an animal being sighted within or
approaching the Exclusion Zone or Level A Take Zone;
If multiple blast events take place in one day, blast
events shall be separated by a minimum of six hours;
After each blast, the observers and contractors shall meet
and evaluate any problems encountered during blasting events and
logistical solutions shall be presented to the Contracting Officer.
Corrections to the watch shall be made prior to the next blasting
event. If any one of the aforementioned conditions (bullet points
directly above) is not met prior to or during the blasting, the
contractor as advised by the watch observers shall have the authority
to terminate the blasting event, until resolution can be reached with
the Contracting Officer. The USACE will contact FWC, USFWS and NMFS;
If an injured or dead protected species is sighted after
the blast event, the watch observers shall contact the USACE and the
USACE will contact the resource agencies at the following phone
numbers:
[cir] FWC through the Manatee Hotline: 1-888-404-FWCC and 850-922-
4300;
[cir] USFWS Jacksonville: 904-731-3336;
[cir] NMFS Southeast Region: 772-570-5312, and Emergency Stranding
Hotline--1-877-433-8299.
The observers shall maintain contact with the injured or
dead protected species to the greatest extent practical until
authorities arrive. Blasting shall be postponed until consultations are
completed and determinations can be made of the cause of injury or
mortality. If blasting injuries are documented, all demolition
activities shall cease. The USACE will then submit a revised plan to
FWC, NMFS and USFWS for review.
Based on our evaluation of the applicant's proposed measures, NMFS
has determined that the proposed
[[Page 19708]]
mitigation measures provide the means effecting the least practicable
impact on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance.
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.
With some exceptions, the USACE will rely upon the same monitoring
protocol developed for the Port of Miami project in 2005 (Barkaszi,
2005) and published in Jordan et al., 2007. A summary of that protocol
is summarized here.
A watch plan will be formulated based on the required monitoring
radii and optimal observation locations. The watch plan will consist of
at least six observers including at least one (1) aerial observer, two
(2) boat-based observers, and two (2) observers stationed on the drill
barge (Figures 12, 13, 14, & 15). The 6th observer will be placed in
the most optimal observation location (boat, barge or aircraft) on a
day-by-day basis depending on the location of the blast and the
placement of dredging equipment. There shall also be one lead observer.
This process will insure complete coverage of the three zones as well
as any critical areas. The watch will begin at least 1 hour prior to
each blast and continue for one half-hour after each blast (Jordan et
al 2007).
Boat-based observers will be placed on vessels with viewing
platforms. The boat observers will cover the Level B Take Zone where
waters are deep enough to safely operate the vessel. The aerial
observer will fly in a helicopter with doors removed at an average
height of 500 ft. The helicopter will drop lower if they need to
identify something in the water. This will provide maximum visibility
of all zones as well as exceptional maneuverability and the needed
flexibility for continual surveillance without fuel stops or down time,
and the ability to deliver post-blast assistance. The area being
monitored is a high traffic area, surrounded by an urban environment
where animals are potentially exposed to multiple overflights daily,
and prior experience has shown that this activity is not anticipated to
result in take of marine mammals in the area.
As previously stated, blasting cannot commence until the entire
Level A Take Zone, Exclusion Zone, and Level B Take Zone are visible to
monitors, and would not commence in rain, fog, or other adverse weather
conditions. The visibility below the surface of the water is naturally
poor, so animals are not anticipated to be seen below the surface.
However, animals surfacing in these turbid conditions are still
routinely spotted from the air and from the boats, thus the overall
observer program is not compromised, only the degree to which animals
are tracked below the surface. Observers must confirm that all
protected species are out of the Exclusion Zone and the Level A Take
Zone for 30 minutes before blasting can commence.
All observers will be equipped with marine-band VHF radios, maps of
the blast zone, polarized sunglasses, and appropriate data sheets.
Communications among observers and with the blaster is critical to the
success of the watch plan. The aerial observer will be in contact with
vessel and drill-barge based observers as well as the drill barge crew
with regular 15-minute radio checks throughout the watch period.
Constant tracking of animals spotted by any observer will be possible
due to the amount and type of observer coverage and the communications
plan. Watch hours will be restricted to between two hours after sunrise
and one hour before sunset. The watch will begin at least one hour
prior to the scheduled blast and is continuous throughout the blast.
Watch continues for at least 60 minutes post blast at which time any
animals that were seen prior to the blast are visually re-located
whenever possible and all observers in boats and in the aircraft
assisted in cleaning up any blast debris.
If any protected species are spotted during the watch, the observer
will notify the lead observer, aerial observer, and/or the other
observers via radio. The animal will be located by the aerial observer
to determine its range and bearing from the blast pattern. Initial
locations and all subsequent observations will be plotted on maps.
Animals within or approaching the Exclusion Zone will be tracked by the
aerial and boat based observers until they exit the Exclusion Zone. As
stated earlier, animals that exit the Exclusion Zone and enter the
Level B Take Zone will also be monitored. The animal's heading shall be
monitored continuously until it is confirmed beyond the Level B Take
Zone. Anytime animals are spotted near the Exclusion Zone, the drill
barge and lead observer will be alerted as to the animal's proximity
and some indication of any potential delays it might cause.
If an animal is spotted inside the Exclusion Zone and not re-
observed, no blasting will be authorized until at least 30 minutes has
elapsed since the last sighting of that animal. The watch will continue
its countdown up until the T-minus five (5) minute point. At this time,
the aerial observer will confirm that all animals are outside the
Exclusion Zone and that all holds have expired prior to clearing the
drill barge for the T-minus five (5) minute notice. A fish-scare charge
will be fired at T-minus five (5) minutes and T-minus one (1) minute to
minimize effects of the blast on fish that may be in the area of the
blast pattern by scaring them from the blast area.
[[Page 19709]]
An actual postponement in blasting will only occur when a protected
species is located within or is approaching the Exclusion Zone at the
point where the blast countdown reaches the T-minus five (5) minutes.
At that time, if an animal is in or near the Exclusion Zone, the
countdown will be put on hold until the Exclusion Zone is completely
clear of protected species and all 30-minute sighting holds have
expired.
Within 30 days after completion of all blasting events, the primary
PSO shall submit a report to the USACE, who will provide it to FWC,
NMFS and USFWS providing a description of the event, number and
location of animals seen and what actions were taken when animals were
seen. Any problems associated with the event and suggestions for
improvements shall also be documented in the report.
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).
For reasons stated previously in this document, the specified
activities associated with the USACE's confined blasting activities in
the East Channel of Big Bend Channel, Tampa Harbor are not likely to
cause PTS, or other non-auditory injury, gastro-intestinal injury, lung
injury, serious injury, or death to affected marine mammals. As a
result, no take by injury, serious injury, or death is anticipated or
authorized, and the potential for temporary or permanent hearing
impairment is very low and would be minimized through the incorporation
of the required monitoring and mitigation measures.
Approximately 244 instances of take to some smaller number of
Atlantic bottlenose dolphins from the Tampa Bay Stock are anticipated
to occur in the form of short-term, minor, hearing impairment (TTS) and
associated behavioral disruption due to the instantaneous duration of
the confined blasting activities. While some other species of marine
mammals may occur in the Tampa Harbor, only common bottlenose dolphins
are anticipated to be potentially impacted by the USACE's confined
blasting activities.
For bottlenose dolphins within the proposed action area, there are
no known designated or important feeding and/or reproductive areas in
the proposed project area, which consists of a man-made channel with a
history of maintenance dredging. Many animals perform vital functions,
such as feeding, resting, traveling, and socializing, on a diel cycle
(i.e., 24-hour cycle). Behavioral reactions to noise exposure (such as
disruption of critical life functions, displacement, or avoidance of
important habitat) are more likely to be significant if they last more
than one diel cycle or recur on subsequent days (Southall et al.,
2007). Consequently, a behavioral response lasting less than one day
and not recurring on subsequent days is not considered particularly
severe unless it could directly affect reproduction or survival
(Southall et al., 2007). The USACE's proposed confined blasting action
at the Tampa Harbor, Big Bend Channel's East Channel includes up to two
planned blasting events per day over multiple days; however, they are
very short in duration and in a relatively small area surrounding the
blast holes (compared to the range of the animals) located solely with
the East Channel, and are only expected to potentially result in
momentary exposures and reactions by marine mammals in the proposed
action area, which would not be expected to accumulate in a manner that
would impact reproduction or survival.
Atlantic common bottlenose dolphins are the only species of marine
mammals under NMFS jurisdiction that are likely to occur in the
proposed action area. They are not listed as threatened or endangered
under the ESA; however the BSE stocks are considered strategic under
the MMPA. To reduce impacts on these stocks (and other protected
species in the proposed action area), the USACE must delay operations
if animals enter designated zones, and will not conduct blasting if any
dolphins (or other protected species) are located within the East
Channel. Due to the nature, degree, and context of the Level B
harassment anticipated and described in this notice as well as the
Proposed IHA notice (see ``Potential Effects on Marine Mammals and
Their Habitat'' section above and in 83 FR 11968, March 19, 2018)), the
activity is not expected to impact rates of recruitment or survival for
any affected species or stock, particularly given NMFS's and USACE's
plan to implement mitigation, monitoring, and reporting measures to
minimize impacts to marine mammals. Also, the confined blasting
activities are very short in duration and there are no known important
areas in the USACE's proposed action area. Additionally, the proposed
confined blasting activities would not adversely impact marine mammal
habitat.
As mentioned previously, NMFS estimates that one species of marine
mammals under its jurisdiction could be potentially affected by Level B
harassment over the course of the IHA. The population estimates for the
marine mammal species that may be taken by Level B harassment is
estimated to be 564 individuals. To protect these marine mammals in the
proposed action area, USACE are be required to cease or delay confined
blasting activities if any marine mammals enters designated exclusion
zone.
NMFS has determined, provided that the aforementioned mitigation
and monitoring measures are implemented, that the impact of conducting
the confined blasting activities in the East Channel of the Big Bend
Channel in the Tampa Harbor may result, at worst, in a temporary
modification in behavior and/or low-level physiological effects (Level
B harassment) of common bottlenose dolphins.
While behavioral modifications, including temporarily vacating the
area immediately after confined blasting operations, may be made by
these species to avoid the resultant underwater acoustic disturbance,
alternate areas are available within this area and the confined
blasting activities will be instantaneous and sporadic in duration. Due
to the nature, degree, and context of Level B harassment anticipated,
the proposed activity is not
[[Page 19710]]
expected to impact rates of annual recruitment or survival of any
affected species or stock, particularly given the NMFS and applicant's
plan to implement mitigation and monitoring measures that would
minimize impacts to marine mammals. Based on the analysis contained
herein of the likely effects of the specified activity on marine
mammals and their habitat, and taking into consideration the
implementation of the proposed monitoring and mitigation measures, NMFS
finds that the total marine mammal take from USACE's proposed confined
blasting operations would have a negligible impact on the affected
marine mammal species or stocks.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect the species or stock through
effects on annual rates of recruitment or survival:
No mortality is anticipated or authorized;
No injury is anticipated or authorized;
Take is limited to Level B harassment, and would be
expected to be mainly temporary and short-term behavioral disturbance
and potential for a small number of TTS takes;
The USACE's proposed confined blasting activities within
the East Channel includes up to two planned blasting events per day
over multiple days (up to a maximum of 42 blast events total), but
these would be very short in duration and in a small area relative to
the range of the animals; and
While temporary short-term avoidance of the area may occur
due to blasting activities, the proposed project area does not
represent an area of known biological importance such that temporary
avoidance would constitute an impact to the foraging, socialization,
and resting activities of bottlenose dolphins.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
the proposed activity will have a negligible impact on the affected
marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Section 101(a)(5)(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. Additionally, other qualitative factors may
be considered in the analysis, such as the temporal or spatial scale of
the activities.
As noted above, the number of instances of take proposed for
authorization equates to approximately 43 percent of the estimated
stock abundance if each instance represents a different individual
marine mammal. However, as noted above, NMFS anticipates that the
calculated number of exposures represents some repeated exposures of
some individuals; in other words, the number of exposures is likely an
overestimate of individuals. Urian et al. (2009) studied fine-scale
population structure of bottlenose dolphins in Tampa Bay, and concluded
that there are five discrete communities (that are not defined as
separate stocks) of bottlenose dolphins in Tampa Bay. They found
significant differences in location and association patterns among
these communities and note that all five communities differed
significantly in latitude, longitude, or both. Based on the range
patterns of these discrete communities, only one of these communities,
Community 5, is expected to occur in the USACE proposed project area.
The other four communities range farther south of the proposed project
location. In addition, Community 5 appeared to be the smallest
community of the five identified communities. Therefore, we conclude
that the takes associated with the USACE proposed confined blasting
actually represents no more than 20 percent of the total Tampa Bay
stock of bottlenose dolphins.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS finds that small numbers of
marine mammals will be taken relative to the population size of the
affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
preliminarily determined that the total taking of affected species or
stocks would not have an unmitigable adverse impact on the availability
of such species or stocks for taking for subsistence purposes.
Endangered Species Act (ESA)
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally, in this case with the NMFS Southeast Region
(SERO) Protected Resources Division Office, whenever we propose to
authorize take for endangered or threatened species.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Authorization
NMFS has issued an IHA to the USACE to take one species of marine
mammal incidental to confined blasting in the East Channel of the Big
Bend Channel in Tampa Harbor, Tampa, Florida provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated.
Dated: May 1, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2018-09499 Filed 5-3-18; 8:45 am]
BILLING CODE 3510-22-P