Monitoring ringed seal (Phoca hispida) activity by means of acoustic telemetry

1991 ◽  
Vol 69 (5) ◽  
pp. 1178-1182 ◽  
Author(s):  
Christian Lydersen
Keyword(s):  
Acoustic Telemetry ◽  
Dive Depth ◽  
Dive Duration ◽  
Ringed Seal ◽  
Diurnal Pattern ◽  
Phoca Hispida ◽  
Late Afternoon ◽  
Continuous Activity

This study was conducted in Kongsfjorden, Svalbard (78°55′N, 12°30′E), from May 6 to 13, 1989. An adult ringed seal (Phoca hispida) female was live captured and equipped with an acoustic depth–time transmitter to obtain information on diving and haul-out activities. A total of 153 h continuous activity, including 1321 diving cycles, was recorded. Of the total time, 38.2% was spent underwater, 16.6% breathing at the surface, and 45.2% hauling out on the ice. Excluding haul-out periods, the seal was submerged for 69.7% and at the surface for 30.3% of the total time spent in the water. Mean dive duration was 2.7 ± 2.7 (SD) min, and mean dive depth was 10.6 ± 9.0 m. Maximum recorded dive duration was 17 min, and maximum recorded dive depth was 40 m. Recorded activities showed a diurnal pattern, with most of the diving activities in the late afternoon and at night and most of the haul-out activity in the morning and during the day.

Ringed seal diving behavior in the breeding season

1996 ◽  
Vol 74 (8) ◽  
pp. 1547-1555 ◽  
Author(s):  
Brendan P. Kelly ◽  
Douglas Wartzok
Keyword(s):  
Breeding Season ◽  
Light Level ◽  
Dive Depth ◽  
Dive Duration ◽  
Ringed Seal ◽  
Diving Behavior ◽  
Adult Males ◽  
Phoca Hispida ◽  
Oxygen Stores ◽  
Lactating Females

The behavior of 14 ringed seals (Phoca hispida) diving under shore-fast sea ice was monitored acoustically during the spring breeding season. Frequent dives with extended periods at depth by subadult and adult seals, including lactating females, were interpreted to be foraging dives. Median dive durations were less than 10.0 min for all seals, and the maximal observed duration was 26.4 min. The maximal observed dive depth, 222 m, was limited by water depth in the study area. Modal dive depths were between 10 and 45 m for breeding-age males and between 100 and 145 m for subadult males and postparturient females. Median dive durations were 4.0 min for adult males and 7.5 min for adult females. Body mass was a better predictor of maximal dive duration (r2 = 0.94) than was age, but maximal durations were shorter than were predicted using measures of oxygen stores and presumed metabolic rates. There was no consistent relationship between light level and the frequency or depth of dives.

Diving in ringed seal (Phoca hispida) pups during the nursing period

1993 ◽  
Vol 71 (5) ◽  
pp. 991-996 ◽  
Author(s):  
Christian Lydersen ◽  
Mike O. Hammill
Keyword(s):  
Short Duration ◽  
Average Duration ◽  
Dive Duration ◽  
Ringed Seal ◽  
Young Age ◽  
White Coat ◽  
Polar Bears ◽  
Phoca Hispida ◽  
Study Activity ◽  
The Mean

In this study, activity and diving performance of nursing ringed seal (Phoca hispida) pups were quantified using time–depth recorders. A total of 1040 h of activity, including 7506 diving cycles, was collected from three female pups. The pups spent 50.3% of their time in the water and 49.7% hauled out on the ice. When the pups were in the water, 20.5% of the time was spent actively diving, while 79.5% of the recorded wet time was spent at the surface. Most of the dives were shallow and of short duration. Mean dive duration was 59.1 ± 63.5 s (SD). Maximum dive durations for the three pups were 5.8, 7.5, and 12 min. Maximum recorded depths were 12, 35, and 89 m. These depths represented the bottom in the area where each pup was situated. The average duration of haul-out sessions where nursing could take place was 6.3 ± 1.6 h, and the time between these sessions was 8.2 ± 3.2 h. The mean number of breathing holes found per pup was 8.7 ± 3.5. The large proportion of time spent in the water, the development of diving skills at an extremely young age, the use of multiple breathing holes, and the prolonged white-coat stage are all interpreted to be evolutionary responses to strong predation pressure, mainly from polar bears.

Diving activity in nursing bearded seal (Erignathus barbatus) pups

1994 ◽  
Vol 72 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Christian Lydersen ◽  
Mike O. Hammill ◽  
Kit M. Kovacs
Keyword(s):  
Short Duration ◽  
Mass Gain ◽  
Dive Depth ◽  
Dive Duration ◽  
Diurnal Pattern ◽  
Bearded Seal ◽  
Erignathus Barbatus ◽  
The Mean

In this study we used time-depth recorders to quantify the diving activity of four nursing bearded seal (Erignathus barbatus) pups over a 10-day period. The pups were 4–7 days old at the start of the experiments. Their daily mass gain was 3.3 ± 0.4 kg (mean ± SD). A total of 530 h, which included 6248 dives, was recorded from the four pups. The pups spent an average of 53% of the recorded time in the water and 47% of the time hauled out. When the pups were in the water they were submerged 42% of the time, while 58% of the time was spent at the surface. Most dives were shallow and of short duration. Dive depth and duration were 10 ± 10 m and 62 ± 46 s and the maximum recorded values were 84 m and 5.5 min, respectively. The pups spent more time in the water and increased the number of long dives and the mean dive duration with age. The duration of haul-out intervals where nursing could take place was 1.93 ± 2.01 h, with a recorded maximum of 8.25 h. The time between these haul-out intervals was 2.18 ± 2.44 h, with a maximum of 9.73 h. A diurnal pattern in haul-out activity was documented; pups spent significantly more time hauled out from 07:00 to 10:00 and from 21:00 to 24:00 than during the rest of the day.

The ringed seal (Phoca hispida) spring diet in northwestern Spitsbergen, Svalbard

1986 ◽  
Vol 4 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Ian Gjertz ◽  
Christian Lydersen
Keyword(s):  
Ringed Seal ◽  
Phoca Hispida

scholarly journals Mono-ortho and non-ortho substituted PCBs in Arctic ringed seal (Phoca hispida) from the Svalbard area: Analysis and determination of their toxic threat

Chemosphere ◽  
1993 ◽  
Vol 27 (1-3) ◽  
pp. 429-437 ◽  
Author(s):  
F.F. Daelemans ◽  
F. Mehlum ◽  
C. Lydersen ◽  
P.J.C. Schepens
Keyword(s):  
Ringed Seal ◽  
Phoca Hispida

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.

The breeding habitat of the ringed seal (Phoca hispida). The birth lair and associated structures

1975 ◽  
Vol 53 (9) ◽  
pp. 1297-1305 ◽  
Author(s):  
Thomas G. Smith ◽  
Ian Stirling
Keyword(s):  
Ursus Maritimus ◽  
Ringed Seal ◽  
Breeding Habitat ◽  
Polar Bears ◽  
Alopex Lagopus ◽  
Phoca Hispida ◽  
Arctic Foxes ◽  
Different Types ◽  
Amundsen Gulf

The subnivean lairs of the ringed seal (Phoca hispida) were studied in the Amundsen Gulf and Prince Albert Sound areas from 1971 through 1974. The structure of several different types of lairs are described. The existence of a birth-lair complex consisting of several closely adjacent lairs appears likely. The spacial distribution of lairs and lair types found on refrozen leads and in pressure ridges is described. Lairs were more abundant in inshore ice than in offshore ice. The function of subnivean lairs appears to be to provide thermal shelter, especially for neonate seals, and protection from predation by arctic foxes (Alopex lagopus) and polar bears (Ursus maritimus).

Estimating and Mitigating Perinatal Mortality in the Endangered Saimaa Ringed Seal (Phoca hispida saimensis) in a Changing Climate

2014 ◽  
Vol 51 (6) ◽  
pp. 526-534 ◽  
Author(s):  
Miina Auttila ◽  
Marja Niemi ◽  
Teresa Skrzypczak ◽  
Markku Viljanen ◽  
Mervi Kunnasranta
Keyword(s):  
Perinatal Mortality ◽  
Ringed Seal ◽  
Phoca Hispida ◽  
Changing Climate

Seasonal dive behaviour of lactating New Zealand fur seals (Arctocephalus forsteri)

1998 ◽  
Vol 76 (2) ◽  
pp. 350-360 ◽  
Author(s):  
R H Mattlin ◽  
N J Gales ◽  
D P Costa
Keyword(s):  
New Zealand ◽  
Dive Depth ◽  
Dive Duration ◽  
Early Summer ◽  
Late Winter ◽  
Individual Values ◽  
Dive Behaviour ◽  
Fur Seals ◽  
Fur Seal ◽  
Bay Islands

The dive behaviour of 18 female New Zealand fur seals (Arctocephalus forsteri) from Taumaka, Open Bay Islands, New Zealand (43°52'S, 168°53'E), was recorded during early (summer; December-February), mid (autumn; March-May), and late (winter; June-August) lactation. Mean dive depth, dive duration, and bottom time for dives >=6 m in depth increased from summer through winter. Variation in individual seal dive behaviour within a season accounted for approximately 11, 9, and 11% of the observed difference between seasons in dive depth, dive duration, and bottom time, respectively. Seasonal dive data (mean ± 1 SD) were as follows: summer: dive depth 30 ± 37 m, dive duration 1.4 ± 1.1 min, and bottom time 0.5 ± 0.6 min; autumn: dive depth 54 ± 47 m, dive duration 2.4 ± 1.3 min, and bottom time 1.0 ± 0.8 min; winter: dive depth 74 ± 64 m, dive duration 2.9 ± 1.5 min, and bottom time 1.2 ± 1.1 min. Maximum recorded dive depth was 274 m for a 5.67-min dive in autumn. Maximum duration was 11.17 min for a dive to 237+ m in winter. New Zealand fur seals are the deepest diving fur seal species reported thus far. The estimated theoretical aerobic dive limit was exceeded on 18.4% of dives (range of individual values 0.2-57.8%). Females (n = 12) were ashore about 1.8 days at a time during February through November, and this increased to about 4.3 days during December and January. Average time spent away from the rookery ranged from 3 to 15 days.

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