FIRST INSTRUMENTAL AERIAL SURVEY OF RINGED SEALS (PUSA HISPIDA) AND BEARDED SEALS (ERIGNATHUS BARBATUS) IN THE RUSSIAN ZONE OF THE CHUKCHI AND EAST-SIBERIAN SEAS IN SPRING 2016

An instrumental aerial survey was conducted in the Russian part of the Chukchi Sea and the eastern East-Siberian Sea in the spring of 2016 to investigate new technical capabilities for estimating abundance and distribution of ringed and bearded seals on the spring ice. Density of both species decreased with distance to the mainland; the largest concentrations of ringed seals were detected in coastal waters, including the Koluchinskaya and Chaunskaya Bays. Taking into account the portion of seals in the water (on average 32 %) and the portion of seals that were disturbed by the aircraft engine noise and dove (on average 30.2 % of ringed seals and 5.9 % of bearded seals), the number of ringed seals in the surveyed area was estimated as 50,839 (СI 95 %: 25,400–73,859; CV = 23.8 %), and the number of bearded seals as 14,590 (CI 95 %: 6,404–24,560; CV = 31.1 %). These estimates are considered to be biased low, primarily due to asynchronic collapse of the ringed seal snow lairs in different parts of the surveyed area, which caused a highly variable detection probability of this species that was difficult to account for.

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Trace elements in tissues of phocid seals harvested in the Alaskan and Canadian Arctic: influence of age and feeding ecology

Canadian Journal of Zoology ◽

10.1139/z05-053 ◽

2005 ◽

Vol 83 (5) ◽

pp. 726-746 ◽

Cited By ~ 55

Author(s):

Larissa-A Dehn ◽

Gay G Sheffield ◽

Erich H Follmann ◽

Lawrence K Duffy ◽

Dana L Thomas ◽

...

Keyword(s):

Trace Elements ◽

Molar Ratio ◽

Decay Function ◽

Phoca Largha ◽

Ringed Seals ◽

Opposite Trend ◽

Slow Decline ◽

Phocid Seals ◽

Pusa Hispida ◽

Bearded Seals

Concentrations of selected trace elements (Ag, Cu, Cd, Se, Zn, THg, and MeHg) were measured in tissues of subsistence-harvested ringed (Pusa hispida (Schreber, 1775)), bearded (Erignathus barbatus (Erxleben, 1777)), and spotted (Phoca largha Pallas, 1811) seals from Alaska and ringed seals from Canada. Most variables differed significantly in tissues of phocids analyzed. Concentration of renal Cd was highest in ringed seals from Canada and bearded seals from Alaska, while spotted seals had the lowest concentrations. Concentrations of Cd increased with age to a maximum in ringed and bearded seals, followed by a slow decline with increasing age. Spotted seals had the highest proportion of MeHg to THg (%MeHg) in liver and bearded seals the lowest ratio. THg in seal tissues followed the opposite trend. %MeHg in ringed and bearded seals followed a hyperbolic decay function with age, but was highly variable in spotted seals. Seals with lesions had a higher relative occurrence of MeHg in liver. The molar ratio of Se:THg in liver exceeded 1:1 in most seals and was negatively correlated with age in ringed and spotted seals. Hepatic Ag was higher in bearded seals than in ringed and spotted seals. A correlation of Ag with age was not documented.

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Ringed seal (Pusa hispida) breeding habitat on the landfast ice in northwest Alaska during spring 1983 and 1984

PLoS ONE ◽

10.1371/journal.pone.0260644 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0260644

Author(s):

Donna D. W. Hauser ◽

Kathryn J. Frost ◽

John J. Burns

Keyword(s):

Sea Ice ◽

Marine Mammals ◽

Environmental Changes ◽

Chukchi Sea ◽

Ringed Seal ◽

Breeding Habitat ◽

Future Research ◽

Ringed Seals ◽

Pusa Hispida ◽

Kotzebue Sound

There has been significant sea ice loss associated with climate change in the Pacific Arctic, with unquantified impacts to the habitat of ice-obligate marine mammals such as ringed seals (Pusa hispida). Ringed seals maintain breathing holes and excavate subnivean lairs on sea ice to provide protection from weather and predators during birthing, nursing, and resting. However, there is limited baseline information on the snow and ice habitat, distribution, density, and configuration of ringed seal structures (breathing holes, simple haul-out lairs, and pup lairs) in Alaska. Here, we describe historic field records from two regions of the eastern Chukchi Sea (Kotzebue Sound and Ledyard Bay) collected during spring 1983 and 1984 to quantify baseline ringed seal breeding habitat and map the distribution of ringed seal structures using modern geospatial tools. Of 490 structures located on pre-established study grids by trained dogs, 29% were pup lairs (25% in Kotzebue Sound and 33% in Ledyard Bay). Grids in Ledyard Bay had greater overall density of seal structures than those in Kotzebue Sound (8.6 structures/km2 and 7.1 structures/km2), but structures were larger in Kotzebue Sound. Pup lairs were located in closer proximity to other structures and characterized by deeper snow and greater ice deformation than haul-out lairs or simple breathing holes. At pup lairs, snow depths averaged 74.9 cm (range 37–132 cm), with ice relief nearby averaging 76 cm (range 31–183 cm), and ice deformation 29.9% (range 5–80%). We compare our results to similar studies conducted in other geographic regions and discuss our findings in the context of recent declines in extent and duration of seasonal cover of landfast sea ice and snow deposition on sea ice. Ultimately, additional research is needed to understand the effects of recent environmental changes on ringed seals, but our study establishes a baseline upon which future research can measure pup habitat in northwest Alaska.

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Distribution and abundance of ringed (Phoca hispida) and bearded seals (Erignathus barbatus) in western Hudson Bay

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f96-346 ◽

1997 ◽

Vol 54 (4) ◽

pp. 914-921 ◽

Cited By ~ 12

Author(s):

N J Lunn ◽

I Stirling ◽

S N Nowicki

Keyword(s):

Polar Bear ◽

Hudson Bay ◽

Phoca Hispida ◽

Current Estimate ◽

Ringed Seals ◽

Erignathus Barbatus ◽

The Mean ◽

Western Hudson Bay ◽

The Relationship ◽

Bearded Seals

We flew a medium-altitude, systematic, strip-transect survey for ringed (Phoca hispida) and bearded seals (Erignathus barbatus) over western Hudson Bay in early June 1994 and 1995. The mean density (per square kilometre) of ringed seals hauled out on the ice was four times higher in 1995 (1.690) than in 1994 (0.380). The 1994 survey appeared to underestimate seal abundance because it was flown too late. Ringed seals preferred high ice cover habitat (6 + /8 ice) and, within this habitat, favoured cracking ice and large floes. We found no consistent effect of either wind or cloud cover on habitat preference. We estimated a total of 1980 bearded seals and 140<|>880 ringed seals hauled out on the sea ice in June 1995. A recent review of the relationship between ringed seal and polar bear (Ursus maritimus) populations suggests that a visible population of this size should support a population of up to 1300 polar bears, which is in general agreement with the current estimate of 1250-1300 bears in western Hudson Bay.

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