Distribution and morphology of ventricular bands in the hearts of ringed seals

Numbers of ringed seals hauled out on the ice began to increase in early June. Numbers on the ice were highest from 0900 to 1500 hours Central Standard Time and lowest (average 40–50% of peak) in early morning. Seals commonly remained on the ice for several hours, and occasionally (during calm weather) for > 48 h. Numbers on the ice were reduced on windy days and possibly also on unusually warm, bright and calm days. Seals tended to face away from the wind (particularly with high wind speed) and oriented broadside to the sun. Seals usually occurred singly (60–70% of all groups) at their holes.Numbers of seals hauled out at Freemans Cove remained relatively constant during June (maximum density 4.86/km2), whereas at Aston Bay numbers increased dramatically to a maximum density of 10.44/km2 in late June. The increase was thought to be due to an influx of seals abandoning unstable ice. The density of seal holes at Freemans Cove (5.92/km2) was much higher than at Aston Bay (2.73/km2). The ratio of holes to the maximum numbers of seals (1.12:1) at Freemans Cove represents a first estimate of this relationship in an apparently stable population.

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Measurable Levels of Short‐Chain Chlorinated Paraffins (SCCPs) in Western Hudson Bay Fishes, But Limited Biomagnification from Fish to Ringed Seals

Environmental Toxicology and Chemistry ◽

10.1002/etc.5188 ◽

2021 ◽

Author(s):

Nadia Facciola ◽

Sara Pedro ◽

Magali Houde ◽

Aaron T. Fisk ◽

Steven H. Ferguson ◽

...

Keyword(s):

Short Chain ◽

Hudson Bay ◽

Ringed Seals ◽

Chlorinated Paraffins ◽

Western Hudson Bay

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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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The scent of rutting male ringed seals(Phoca hispida)

Journal of Zoology ◽

10.1111/j.1469-7998.1992.tb07509.x ◽

1992 ◽

Vol 226 (4) ◽

pp. 681-689 ◽

Cited By ~ 19

Author(s):

M. Ryg ◽

Y. Solberg ◽

C. Lydersen ◽

T. G. Smith

Keyword(s):

Phoca Hispida ◽

Ringed Seals

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Population parameters of ringed seals (Phoca hispida Schreber, 1775) in the Svalbard area

Canadian Journal of Zoology ◽

10.1139/z87-162 ◽

1987 ◽

Vol 65 (4) ◽

pp. 1021-1027 ◽

Cited By ~ 38

Author(s):

Christian Lydersen ◽

Ian Gjertz

Keyword(s):

Sex Ratio ◽

Ringed Seal ◽

Adult Males ◽

Population Parameters ◽

Phoca Hispida ◽

Age Class ◽

Ringed Seals ◽

Males And Females ◽

The Mean ◽

Sexually Mature

Samples were taken from 284 ringed seals (Phoca hispida) in the Svalbard area during April–July 1981 and March–April 1982. The age of 283 seals was determined by reading annuli in the cementum of the canine teeth. The mean age of the males was 11.3 years, and of the females, 14.9 years. Females were found to be significantly older than males. The mean length of sexually mature ringed seals was 128.9 cm for both sexes. The mean weight of adult males and females was 53.5 and 61.4 kg, respectively. Females were found to be significantly heavier than males. The sex ratio was 47.8% males and 52.2% females. Studies of microscopic sections of testis and epididymis from ringed seal males showed that 63, 75, and 80% of 5-, 6-, and 7-year-old animals, respectively, were sexually mature. The weights of testis and epididymis, diameters of tubuli, and the size of testis all showed a marked increase in the 5-year age-class. Macroscopic sections of ovaries from ringed seal females showed that 20, 60, and 80% of 3-, 4-, and 5-year-old animals, respectively, were sexually mature. The size of the ovaries showed a marked increase in the 5-year age-class. The ovulation rate of ringed seals from Svalbard was calculated to be 0.91.

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