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Federal Register / Vol. 86, No. 33 / Monday, February 22, 2021 / Notices
comm., November 18, 2019, advised NMFS and AGDC to calculate beluga whale density using the 20142018
ASAMM data, as it is more recent and incorporates more years. Density estimates for beluga whale were calculated by dividing the average number of whales observed per km of transect effort whales/km in Table 9 by two times the effective strip width to encompass both sides of the transect line whales per km/2 ESW. The ESW for beluga whales from the Aero Commander aircraft is 0.614 km 0.38
mi Ferguson and Clarke 2013. Using the 2014 to 2018 data, the resulting summer density estimate included in the proposed IHA was 0.005 beluga whales/km2, and the fall density
analysis because the data is based on sighting effort outside of the barrier islands, and beluga whales rarely occur within the barrier islands, as evidenced by Block 1a ASAMM survey data. One beluga whale was observed in survey Block 1a in 2018. However, this sighting was a sighting on search, meaning that the sighting occurred off of the survey transect, and therefore was not included in the density calculation.
As noted in the Description of Marine Mammals in the Area of Specified Activities section of the proposed IHA
85 FR 43382; July 16, 2020, we do not expect beluga whales to be present during AGDCs winter/spring contingency pile driving period.

estimate included in the proposed IHA
was 0.001 beluga whales/km2. AGDC
conservatively used the higher summer density to estimate potential Level B
harassment takes, and NMFS concurred for the proposed IHA 85 FR 43382; July 16, 2020.
Inclusion of the recently-available 2019 ASAMM survey results for beluga whale in block 1 increased the summer beluga whale density to 0.009 whales/
km2 since publication of the proposed IHA. Therefore, as described further in the Take Calculation and Estimation section, below, NMFS used the updated summer density to calculate beluga whale Level A and Level B harassment take.
The resulting densities are expected to be overestimates for the AK LNG

TABLE 9BELUGA WHALE SIGHTING DATA FROM 2011 THROUGH 2019 AND RESULTING DENSITIES
Summer Year
Number of whales sighted
Transect effort km
Fall
Whales/km
Whales/km 2 a
Number of whales sighted
Transect effort km
Whales/km
Whales/km 2 a
2014
2015
2016
2017
2018
2019 c

13
37
0 4
6 63

1,393
1,262
1,914
3,003
2,491
1,643

0.009
0.029
0 0.001
0.002
0.038

0.008
0.024
0 0.001
0.002
0.031

9
3 1
0 0
1

1,538
1,663
2,360
1,803
1,535
2,055

0.006
0.002
0.0004
0 0
0.0005

0.005
0.001
0.0003
0 0
0.0004

Total

60

11,706

b 0.012

b 0.009

13

10,954

b 0.001

b 0.001

a Calculated b Value
using an effective strip width of 0.614 km.
represents average, not total, across all years.
included in the updated TOTAL row.

c Values
Ringed Seal Ringed seals are the most abundant species in the project area. They haul out on the ice to molt between late May and early June, and spring aerial surveys provide the most comprehensive density estimates available. Industry monitoring programs for the construction of the Northstar production facility conducted spring aerial surveys in the area surrounding West Dock from 1997 to 2002 Frost et al., 2002; Moulten et al., 2002b; Moulton et al., 2005;
Richardson and Williams, 2003. Spring
surveys are expected to provide the best ringed seal density information, as the greatest percentage of seals have abandoned their lairs and are hauled out on the ice Kelly et al., 2010. Densities were consistently very low in areas where the water depth was less than 10
ft. 3 m, and only sightings observed in water depths greater than 10 ft. 3 m have been included in the density calculations Moulton et al., 2002a, Moulton et al., 2002b, Richardson and Williams, 2003. The average observed spring ringed seal density from this monitoring effort was 0.548 seals/km2

Table 10. These densities are not corrected for unobserved animals, and therefore may result in an underestimated density. However, NMFS and AGDC do not expect this to be a concern, given that the density calculations conservatively only included sightings observed in water depths greater than 10 ft 3 m Moulton et al., 2002a, Moulton et al., 2002b, Richardson and Williams, 2003, while the water surrounding the project site is shallow less than 10 ft at the project site, and therefore densities are likely to be lower.

TABLE 10RINGED SEAL DENSITIES ESTIMATED FROM SPRING AERIAL SURVEYS CONDUCTED FROM 1997 TO 2002
Density seals/km2

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Year 1997
1998
1999
2000
2001
2002
Average

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