Je veux savoir à propos de…

lotter on DSK11XQN23PROD with NOTICES1

Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Notices Dalls Porpoise Dalls porpoises are widely distributed across the entire North Pacific Ocean. They show some migration patterns, inshore and offshore and north and south, based on morphology and type, geography, and seasonality Muto et al., 2018. They are common in most of the larger, deeper channels in Southeast Alaska and are rare in most narrow waterways, especially those that are relatively shallow and/or with no outlets Jefferson et al., 2019. In Southeast Alaska, abundance varies with season.
Jefferson et al. 2019 recently published a report with survey data spanning from 1991 to 2012 that studied Dalls porpoise density and abundance in Southeast Alaska. They found Dalls porpoise were most abundant in spring, observed with lower numbers in summer, and lowest in fall. Their relative rarity is supported by Jefferson et al. 2019 presentation of historical survey data showing very few sightings in the Ketchikan area north of Metlakatla and conclusion that Dalls porpoise generally are rare in narrow waterways.
No systematic studies of Dalls porpoise abundance or distribution have occurred in Port Chester or Nichols Passage; however, Dalls porpoises have been consistently observed in Lynn Canal, Stephens Passage, upper Chatham Strait, Frederick Sound, and Clarence Strait Dahlheim et al. 2009.
The species is generally found in waters in excess of 183 m 600 ft deep, which do not occur in Port Chester. Despite generalized water depth preferences, Dalls porpoises may occur in shallower waters. Moran et al. 2018 recently mapped Dalls porpoise distributions in bays, shallow water, and nearshore areas of Prince William Sound, habitats not typically utilized by this species. If Dalls porpoises occur in the project area, they will likely be present in March or April, given the strong seasonal patterns observed in nearby areas of Southeast Alaska Dahlheim et al. 2009. Dalls porpoises are seen once a month or less within Port Chester and Nichols Passage in groups of less than 10 animals L. Bethel, personal communication, June 11, 2020 as cited in the application. In nearby Tongass Narrows, NMFS estimated that 15 Dalls porpoises per month may be present based on local reports of Dalls porpoises typically occuring in groups of 1015 animals in the area of Ketchikan Freitag 2017 cited in 85 FR
673. A recent monitoring report for Tongass Narrows reported no sighting of Dalls porpoise in May 2021report
VerDate Sep<11>2014

18:06 Jun 28, 2021

Jkt 253001

available at https
www.fisheries.noaa.gov/action/
incidental-take-authorization-alaskadepartment-transportation-ferry-berthimprovements.
Harbor Porpoise In the eastern North Pacific Ocean, the Bering Sea and Gulf of Alaska harbor porpoise stocks range from Point Barrow, along the Alaska coast, and the west coast of North America to Point Conception, California. The Southeast Alaska stock ranges from Cape Suckling, Alaska to the northern border of British Columbia. Within the inland waters of Southeast Alaska, harbor porpoises distribution is clustered with greatest densities observed in the Glacier Bay/
Icy Strait region and near Zarembo and Wrangell Islands and the adjacent waters of Sumner Strait Dahlheim et al., 2015.
There is no official stock abundance associated with the SARs for harbor porpoise. Both aerial and vessel based surveys have been conducted for this species. Aerial surveys of this stock were conducted in June and July 1997
and resulted in an observed abundance estimate of 3,766 harbor porpoise Hobbs and Waite 2010 and the surveys included a subset of smaller bays and inlets. Correction factors for observer perception bias and porpoise availability at the surface were used to develop an estimated corrected abundance of 11,146 harbor porpoise in the coastal and inside waters of Southeast Alaska Hobbs and Waite 2010. Vessel based spanning the 22year study 19912012 found the relative abundance of harbor porpoise varied in the inland waters of Southeast Alaska. Abundance estimated in 1991
1993 N = 1,076; percent CI = 910
1,272 was higher than the estimate obtained for 20062007 N = 604; 95
percent CI = 468780 but comparable to the estimate for 20102012 N = 975; 95
percent CI = 8571,109; Dahlheim et al., 2015. These estimates assume the probability of detection directly on the trackline to be unity g0 = 1 because estimates of g0 could not be computed for these surveys. Therefore, these abundance estimates may be biased low to an unknown degree. A range of possible g0 values for harbor porpoise vessel surveys in other regions is 0.5
0.8 Barlow 1988, Palka 1995, suggesting that as much as 50 percent of the porpoise can be missed, even by experienced observers.
Further, other vessel based survey data 20102012 for the inland waters of Southeast Alaska, calculated abundance estimates for the concentrations of harbor porpoise in the
PO 00000

Frm 00015

Fmt 4703

Sfmt 4703

34209

northern and southern regions of the inland waters Dahlheim et al. 2015.
The resulting abundance estimates are 398 harbor porpoise CV = 0.12 in the northern inland waters including Cross Sound, Icy Strait, Glacier Bay, Lynn Canal, Stephens Passage, and Chatham Strait and 577 harbor porpoise CV =
0.14 in the southern inland waters including Frederick Sound, Sumner Strait, Wrangell and Zarembo Islands, and Clarence Strait as far south as Ketchikan. Because these abundance estimates have not been corrected for g0, these estimates are likely underestimates.
The vessel based surveys are not complete coverage of harbor porpoise habitat and not corrected for bias and likely underestimate the abundance.
Whereas, the aerial survey in 1997, although outdated, had better coverage of the range and is likely to be more of an accurate representation of the stock abundance 11,146 harbor porpoise in the coastal and inside waters of Southeast Alaska. Although there have been no systematic studies or observations of harbor porpoises specific to Port Chester or Nichols Passage, there is potential for them to occur within the project area.
Approximately one to two groups of harbor porpoises are observed each week in group sizes of up to 10 animals around Driest Point, located 5 km 3.1
mi north of the Project location L.
Bethel, personal communication, June 11, 2020 as cited in the application.
Their small overall size, lack of a visible blow, low dorsal fins and overall low profile, and short surfacing time make harbor porpoises difficult to spot Dahlheim et al. 2015, likely reducing identification and reporting of this species, and these estimates therefore may be low. Harbor porpoises prefer shallower waters Dahlheim et al. 2015
and generally are not attracted to areas with elevated levels of vessel activity and noise such as Port Chester. In nearby Tongass Narrrows, NMFS
estimated that two groups of five harbor porpoises per month could be present 85 FR 673 based on local reports that harbor porpoises typically occur in groups of one to five animals and pass through in the area of Ketchikan 01
times a month Freitag 2017 as cited in 85 FR 673. A recent monitoring report for Tongass Narrows reported no sighting of harbor porpoise in May 2021
report available at https
www.fisheries.noaa.gov/action/
incidental-take-authorization-alaskadepartment-transportation-ferry-berthimprovements.

E:FRFM29JNN1.SGM

29JNN1