Observations of neonate ringed seals, Phoca hispida , after early break-up of the sea ice in Prince Albert Sound, Northwest Territories, Canada, spring 1998

Polar Biology ◽  
2001 ◽  
Vol 24 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Thomas G. Smith ◽  
Lois A. Harwood
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Phoca Hispida ◽  
Ringed Seals ◽  
Break Up

Winter Distribution of Ringed Seals (Phoca hispida) in the Barrow Strait Area, Northwest Territories, Determined by Underwater Vocalizations

1985 ◽  
Vol 42 (7) ◽  
pp. 1238-1243 ◽  
Author(s):  
Wendy Calvert ◽  
Ian Stirling
Keyword(s):  
Northwest Territories ◽  
Habitat Quality ◽  
Human Activity ◽  
High Arctic ◽  
Diel Cycle ◽  
Phoca Hispida ◽  
Winter Distribution ◽  
Ringed Seals ◽  
Habitat Variables

In order to assess underice distribution of ringed seals (Phoca hispida) in winter, we made recordings from 23 to 30 April 1982 at 32 sites chosen to represent different habitats in the High Arctic. By regressing the vocalization rate at each site against variables for habitat quality, we found that sites in smooth interisland channels had significantly more vocalizations than sites in bays, and sites with frequent human activity had vocalization rates similar to the overall average. Although differences in vocalization rates correlated with some measured and estimated habitat variables, there was too much overlap between sites for vocalization rate alone to be useful in separating suitable and unsuitable pupping habitat. Recordings made at one site over 4 d showed a diel cycle in which vocalization rate was highest from about 08:30 to 16:30 and lowest at night.

Factors affecting the distribution and abundance of ringed seal structures in Barrow Strait, Northwest Territories

1989 ◽  
Vol 67 (9) ◽  
pp. 2212-2219 ◽  
Author(s):  
M. O. Hammill ◽  
T. G. Smith
Keyword(s):  
Northwest Territories ◽  
Ringed Seal ◽  
Phoca Hispida ◽  
Factors Affecting ◽  
Habitat Features ◽  
Ringed Seals ◽  
Over The Top ◽  
The Relationship ◽  
Important Habitat ◽  
Habitat Variables

The relationship between the distribution of ringed seals, Phoca hispida, and habitat was examined in Barrow Strait, Northwest Territories. Density of seal breathing holes was used as an index of seal abundance. Birth lairs were associated with the largest snowdrifts. Lair formation can occur within 24 h after a snowdrift forms over the top of a breathing hole. Seal structures were associated with ridges consisting of ice pieces 15–25 cm thick projecting upwards to a height of 80–150 cm. In 1975 and 1986, the combination of date of ice consolidation and snow depth were the most important habitat features affecting the distribution of ringed seals structures. This was also true with respect to distribution of birth lairs and undefined haul-out lairs, but no relationship was identified between density of structures used by males and habitat. Snow cover and date of ice consolidation were not identified as important habitat variables in 1984 and 1985 when overall distribution of ice in Barrow Strait was very different. Birth lairs were not seen before 4 April, but were found in increasing frequency as the season progressed. Male structures were evident in late March, but were not found after mid-May.

Use of artificial subice air pockets by wild ringed seals (Phoca hispida)

1974 ◽  
Vol 52 (8) ◽  
pp. 1092-1093 ◽  
Author(s):  
Allen R. Milne
Keyword(s):  
Sea Ice ◽  
Air Bubbles ◽  
Phoca Hispida ◽  
Scuba Divers ◽  
Ringed Seals ◽  
Naturally Occurring ◽  
Drainage Channels ◽  
Fast Ice ◽  
Air Pockets

Ringed seals were observed to inhale exhaust air expelled by SCUBA divers who were diving under 1.9-m thick, 1-year-old fast ice in Lancaster Sound during mid-April, 1973, The underside of the sea ice was imperfectly flat so that some of the bubbles of exhaust air coalesced into large lenticular bubbles 1 to 3 cm in depth, and these, on occasions, were partially inhaled by seals. Between dives, separated in time by as little as 3 h, all the under-ice air bubbles, large and small, vanished. It is assumed that the buoyant air migrated upward into the sea ice by the progressive displacement of brine in drainage channels. Although the exhaust air was readily used by ringed seals, it is unlikely that naturally occurring air pockets can persist beneath 1 -year-old sea ice to enable seals to extend their under-ice travels.

Haul-out behaviour and densities of ringed seals (Phoca hispida) in the Barrow Strait area, N.W.T.

1979 ◽  
Vol 57 (10) ◽  
pp. 1985-1997 ◽  
Author(s):  
Kerwin J. Finley
Keyword(s):  
Wind Speed ◽  
Early Morning ◽  
Maximum Density ◽  
Stable Population ◽  
The Sun ◽  
High Wind ◽  
Phoca Hispida ◽  
High Wind Speed ◽  
Ringed Seals ◽  
Calm Weather

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.

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

1997 ◽  
Vol 54 (4) ◽  
pp. 914-921 ◽  
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.

The scent of rutting male ringed seals(Phoca hispida)

1992 ◽  
Vol 226 (4) ◽  
pp. 681-689 ◽  
Author(s):  
M. Ryg ◽  
Y. Solberg ◽  
C. Lydersen ◽  
T. G. Smith
Keyword(s):  
Phoca Hispida ◽  
Ringed Seals

scholarly journals Albedo of Melting Sea Ice in the Southern Beaufort Sea

1971 ◽  
Vol 10 (58) ◽  
pp. 101-104 ◽  
Author(s):  
M.P. Langleben
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Melting Period ◽  
Fast Ice ◽  
Made In

AbstractTwo Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equation A = 0.59 —0.32P where P is the degree of puddling of the surface.

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

1987 ◽  
Vol 65 (4) ◽  
pp. 1021-1027 ◽  
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.

Biotransformation of PCBs in Relation to Phase I and II Xenobiotic-Metabolizing Enzyme Activities in Ringed Seals (Phoca hispida) from Svalbard and the Baltic Sea

2008 ◽  
Vol 42 (23) ◽  
pp. 8952-8958 ◽  
Author(s):  
Heli Routti ◽  
Robert J. Letcher ◽  
Augustine Arukwe ◽  
Bert van Bavel ◽  
Nigel G. Yoccoz ◽  
...  
Keyword(s):  
Phase I ◽  
Baltic Sea ◽  
Enzyme Activities ◽  
Phoca Hispida ◽  
The Baltic Sea ◽  
Ringed Seals ◽  
Metabolizing Enzyme ◽  
The Baltic ◽  
Phase I And Ii
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