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Federal Register / Vol. 86, No. 195 / Wednesday, October 13, 2021 / Proposed Rules TABLE 10DISTANCES TO RELEVANT BEHAVIORAL ISOPLETHS AND ENSONIFIED AREAS
Year section
Activity
Level B
harassment zone m/km2

Received level at 10 m
Vibratory Pile Driving Year Year Year Year Year Year Year Year Year
1 2
3 4
1 2
3 4
4

S45
S366, Year 2 Pier 1
LNG
S499/Pier 2
S45
S366, Year 2 Pier 1
LNG
S499/Pier 2
S499/Pier 2

14-in H-piles
14-in H-piles
14-in H-piles
14-in H-piles
22.5-in Z-shaped sheet piles
22.5-in Z-shaped sheet piles
22.5-in Z-shaped sheet piles
22.5-in Z-shaped sheet piles
31.5-in Z-shaped sheet piles

158
158
158
158
163
163
163
163
163

SPL
SPL
SPL
SPL
SPL
SPL
SPL
SPL
SPL

180
180
180
181
181
181
181

SEL/190
SEL/190
SEL/190
SEL/196
SEL/196
SEL/196
SEL/196

3,415 m/5.6 km2
3,415 m/5.8 km2
3,415 m/5.8 km2
3,415 m/5.7 km2
7,356 m/7.9 km2
7,356 m/8.3 km2
7,356 m/7.5 km2
7,356 m/7.5 km2
7,356 m/9.5.km2

Impact Pile Driving Year Year Year Year Year Year Year
1 2
3 4
1 2
4

S45
S366, Year 2 Pier 1
LNG
S499/Pier 2
S45
S366
S499/Pier 2

22.5-in Z-shaped sheet piles
22.5-in Z-shaped sheet piles
22.5-in Z-shaped sheet piles
31.5-in Z-shaped sheet piles
30-in piles
30-in piles
42-in piles

SPL
SPL
SPL
SPL
SPL
SPL
SPL

1,000
1,000
1,000
2,512
2,512
2,512
2,512

m/1.1
m/1.3
m/0.7
m/3.8
m/3.8
m/4.0
m/3.8

km2
km2
km2
km2
km2
km2
km2

Note: Distances to the Level B harassment zone may vary slightly of the same pile size, due to the section of work being conducted and how the produced sound would be directed see Figures 61 through 64 of the Navys application.

Marine Mammal Occurrence and Take Calculation and Estimation In this section we provide the information about the presence, density, or group dynamics of marine mammals that will inform the take calculations.
Potential exposures to impact pile and vibratory pile driving noise for each acoustic threshold were estimated using marine mammal density estimates N
from the Navy Marine Species Density Database NMSDD Navy 2017 for which data of monthly densities of species were evaluated in terms of minimum, maximum, and average annual densities within Narragansett Bay and multiplied by the zone of influence ZOI and the maximum days of pile driving take estimate = N ZOI days of pile driving. The pile type, size, and installation method that produce the largest ZOI were used to estimate exposure of marine mammals to noise
impacts. We describe how the information provided above is brought together to produce a quantitative take estimate in the species sections below.
Atlantic White-Sided Dolphins Atlantic white-sided dolphins occur seasonally, occurring primarily along the continental shelf with occasional unconfirmed opportunistic sightings in Narragansett Bay in fall and winter. The most recent observation of a pod of dolphins in Narragansett Bay was in October 2007 NUWC Division, 2011.
Construction activity could occur at any time of year and would be short-term and intermittent. Therefore, the average species density was determined to be appropriate for estimating takes of Atlantic white-sided dolphin. Based on density data for Narragansett Bay Navy 2017, the average density of Atlantic white-sided dolphin was determined to be 0.003/km2. This density was used to
estimate abundance of animals that could be present in the area for exposure. Using this information, 1 take was calculated for Years 1, 3, and 4 and 0 takes in Year 2 Table 11. However, the annual take by Level B harassment proposed for Atlantic white-sided dolphins has been increased to the average group size 16 NAVSEA
NUWC 2017 for Years 1, 3, and 4, because the calculated annual take is below the average group size. Therefore, the Navy requested and NMFS proposes 16 takes annually in Years 1, 3, and 4
0 in Year 2 for a total of 48 takes by Level B harassment of Atlantic whitesided dolphin Table 11. No takes by Level A harassment of Atlantic whitesided dolphin are anticipated. Because this species regular occurrence is in much deeper waters than the extent of the ZOI Hayes et al., 2019, expected takes of this species are extremely low.

TABLE 11PROPOSED TAKE FOR ATLANTIC WHITE-SIDED DOLPHIN
Calculated Level B
harassment
jspears on DSK121TN23PROD with PROPOSALS1

Construction year Year Year Year Year
1 2
3 4

Proposed Level B
harassment
S45
S366 and Pier 01
LNG
S499/Pier 2

1
0 1
1

16
0 16
16

Total

3

48

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