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The Alaska Beluga Whale Committee co-manages three western Alaska beluga whale Delphinapterus leucas, stocks with the National Marine Fisheries Service, NOAA, and has conducted studies on stock identity, distribution, abundance, and subsistence harvests. Studies of mitochondrial DNA revealed substantial differentiation among belugas that use summering areas in Bristol Bay, the eastern Bering Sea, and the eastern Chukchi Sea, and there is little overlap in their seasonal distributions. The Bristol Bay stock summers in bays in inner Bristol Bay and winters in outer Bristol Bay. Abundance estimates from aerial surveys increased by more than 4% per year during 1994-2005. Survey counts in 2016 were similar to 2004-2005 indicating that the population may now be stable. Survey results and a genetics mark-recapture study indicate a population of approximately 2,000 whales. The average annual Alaska Native subsistence harvest over the past decade (23) is below the calculated potential biological removal (PBR; 39-43). The eastern Bering Sea beluga stock concentrates in summer off the Yukon River Delta and in Norton Sound and in winter moves offshore in the eastern Bering Sea. Abundance has been estimated at approximately 9,242 based on aerial survey data collected in 2017. The average annual subsistence harvest, plus the estimated number of struck and lost belugas, is 215 and exceeds the PBR calculated from this abundance estimate (201), but the abundance estimate is thought to be biased low and local and traditional knowledge does not indicate any decrease in abundance or availability. The eastern Chukchi Sea stock is migratory, wintering in the northern Bering Sea, moving north through the eastern Chukchi Sea in spring, and summering in the Beaufort Sea and Arctic Ocean. It is large, estimated at approximately 20,000 animals based on 2012 aerial surveys. The average annual subsistence harvest (57) is well below PBR (293). Few significant threats to persistence of western Alaska beluga stocks have been identified, although climate warming and declines in sea ice and industrial activities related to resource development and increases in commercial shipping are of concern and could pose challenges in the future. Continued monitoring of population size and trend, subsistence harvest, and health of western Alaska belugas is warranted. [ABSTRACT FROM AUTHOR]

The article presents the results of the Alaska Beluga Whale Committee (ABWC) surveys on the trend in aerial counts of belugas in Bristol Bay, Alaska from 1993-2005. Data from 28 complete counts show that the estimated rate of increase over the 12-year period was 4.8 per year. This suggests that either the population was below the environmental carrying capacity in the early 1990s or that factors limiting population increase were mitigated following that period. It points out that the review of possible changes in human-caused mortality, predation and prey availability did not show a single cause of the increase.

The eastern Steller sea lion (Eumetopias jubatus) population comprises animals that breed along the west coast of North America between California and southeastern Alaska. There are currently 13 major rookeries (>50 pups): five in southeastern Alaska, three in British Columbia, two in Oregon, and three in California. Overall abundance has increased at an average annual rate of 3.1% since the 1970s. These increases can largely be attributed to population recovery from predator-control kills and commercial harvests, and abundance is now probably as high as it has been in the last century. The number of rookeries has remained fairly constant (n = 11 to 13) over the past 80 years, but there has been a northward shift in distribution of both rookeries and numbers of animals. Based on the number of pups counted in a population-wide survey in 2002, total pup production was estimated to be about 11,000 (82% in southeastern Alaska and British Columbia), representing a total population size as approximately 46,000-58,000 animals. [ABSTRACT FROM AUTHOR]

Movement patterns of Alaska harbor seal pups were studied using satellite telemetry during 1997-2000. Mean tracking duration was 277.3 d (SD 105.8) for Tugidak Island pups (n = 26) and 171.2 d (108.3) for Prince William Sound (PWS) pups (n = 27). Movements were similar for males and females and were largely restricted to the continental shelf. Multiple return trips of >75 km from the natal area and up to ∼3 wk duration were most common, followed by movements restricted to <25 km from the natal area; one way movements from the natal site were rare. Distances moved and home range sizes remained relatively stable or increased gradually from July through winter, then decreased markedly through spring. Monthly movements (maximum distance from tagging location, mean distance from haul-outs to at-sea locations, and home range size) were significantly greater for Tugidak vs. PWS pups. Six of seven pups from each region that traveled farthest and were tracked the longest had returned to their tagging site when their last location was recorded, indicating philopatry or limited dispersal during their first year of life. Seal pups exhibited similar movement patterns in the distinct habitats of the two regions, but differed in the spatial extent of their movements. [ABSTRACT FROM AUTHOR]

Aerial surveys were conducted during late May and early June 1996-99 in the central Beaufort Sea of Alaska, using strip-transect methods. The purpose of these surveys was to quantify and model the effects of environmental covariates on ringed seal counts and to provide density estimates that would be useful for evaluating trends in seal abundance. Total survey effort included 40 -88 transect lines per year covering 1198-2701 km². Observed densities ranged from 0.81 seals/km² in 1996 to 1.17 seals/km² in 1999. We examined the effects of habitat, weather, and time of day on observed seal densities, using univariate chi-square goodness-of-fit tests. We also used a multivariate generalized linear model to estimate the relationship between seal counts and covariates. Three habitat-related variables-water depth, location relative to the fast ice edge, and ice deformation-had substantial and consistent effects. The highest densities occurred at depths between 5 and 35 m. Densities were also highest in relatively flat ice and near the fast ice edge, declining both shoreward and seaward of that edge. Univariate analysis suggested that observed densities were generally highest at about 1200 h Alaska daylight time, but time was not a significant variable in the generalized linear models. Analyses of the effects of weather factors on seal counts were inconclusive. This was likely at least partially because temperature and wind speed were measured at survey altitude, rather than on the ice surface, and surveys were conducted only in weather considered suitable for hauling out. The final multivariate model did not account for a substantial proportion of the variation in seal counts. We think this result was largely due to date-related variation in the proportion of seals hauling out, an issue our surveys were not suited to address. [ABSTRACT FROM AUTHOR]

Reports on a study in which satellite-linked tags were attached to 49 subadult and adult harbor seals captured in Prince William Sound (PWS), Alaska, and their movements monitored during 1992-1997. Details of tracking and locating seals; Movements of juvenile and adult seals; Home ranges; Observations on movements; Mean monthly home ranges; Mean haul-out to at-sea distance; Conclusion that satellite-linked tags provided an effective means of monitoring and describing the full range of harbor seal movements in this region, with the exception of late summer when tags were shed during the molt.

Twenty eyes from 10 Pacific sleeper sharks Somniosus pacificus, infected with the copepod Ommatokoita elongata, were collected in Prince William Sound, Alaska, and the eyes of an additional 18 S. pacificus captured in the same area were inspected for copepods. Prevalence of infection by adult female O. elongata was 97% (n = 28); mean intensity of infection was 1.89 (+/-1SD = 0.32) adult female copepods per infected shark and 1.0 (+/- 1SD = 0.0) adult female copepods per infected eye. Five of the 20 collected eyes were infected by O. elongata chalimi, and 9 of 20 eyes had 1 to several remnants of bullae embedded in the cornea. Bullae were each associated with a corneal opacity, and anchoring plugs of chalimi were associated with pinpoint lesions in the cornea or conjunctiva. All eyes exhibited marked edema and erosion of the bulbar conjunctiva, and this torus-shaped lesion corresponded to each O. elongata adult female's presumed feeding and abrasion radius. Histological examinations revealed lesions in the anterior segment of eyes to be generally similar, but graded, in severity, and in all eyes they involved the conjunctiva, cornea, filtration angle, and iris. Epithelial lesions were characterized by corneal ulceration, dysplasia, hyperplasia, and heterophilic keratitis, and by ulcerative conjunctivitis accompanied by epithelial hyperplasia with rete peg formation. Disorganization of fibers, necrosis, mineralization, minimal heterophilic influx, and perilimbic neovascularization were associated with bullae in the corneal stroma. Within the limbus there was diffuse histiocytic and lymphocytic inflammation and marked lymphofollicular hyperplasia. Heterophilic and mononuclear anterior uveitis affecting the filtration angle and anterior surface of the iris was also observed in most eyes. One eye had a partial transcorneal prolapse of a ruptured lens, with degenerative changes in the ruptured lens and severe keratitis associated with the anchoring devices of an adult copepod and several chalimi. Fourteen eyes exhibited 1 to several, randomly distributed, small, round to irregular, corneal opacities or pits that were not associated with copepods, and it is likely that these opacities represented lesions associated with adult female or larval anchoring devices from past infections. The avascular cornea represents a niche that is somewhat shielded from host immune reactions, and this, and the fact that the general body surface of sleeper sharks is covered by tall and sharp placoid scales, may partially explain the corneal attachment of O. elongata adult females. It was concluded that O. elongata infections can lead to severe vision impairment in Pacific sleeper sharks but that these infections do not significantly debilitate hosts because they probably do not need to rely on acute vision for their survival.