Observations of mortality associated with extended open-water swimming by polar bears in the Alaskan Beaufort Sea

Polar Biology ◽  
2006 ◽  
Vol 29 (8) ◽  
pp. 681-687 ◽  
Author(s):  
Charles Monnett ◽  
Jeffrey S. Gleason
ARCTIC ◽  
2009 ◽  
Vol 61 (1) ◽  
pp. 14 ◽  
Author(s):  
Ian Stirling ◽  
Evan Richardson ◽  
Gregory W. Thiemann ◽  
Andrew E. Derocher

In April and May 2003 through 2006, unusually rough and rafted sea ice extended for several tens of kilometres offshore in the southeastern Beaufort Sea from about Atkinson Point to the Alaska border. Hunting success of polar bears (Ursus maritimus) seeking seals was low despite extensive searching for prey. It is unknown whether seals were less abundant in comparison to other years or less accessible because they maintained breathing holes below rafted ice rather than snowdrifts, or whether some other factor was involved. However, we found 13 sites where polar bears had clawed holes through rafted ice in attempts to capture ringed seals (Phoca hispida) in 2005 through 2006 and another site during an additional research project in 2007. Ice thickness at the 12 sites that we measured averaged 41 cm. These observations, along with cannibalized and starved polar bears found on the sea ice in the same general area in the springs of 2004 through 2006, suggest that during those years, polar bears in the southern Beaufort Sea were nutritionally stressed. Searches made farther north during the same period and using the same methods produced no similar observations near Banks Island or in Amundsen Gulf. A possible underlying ecological explanation is a decadal-scale downturn in seal populations. But a more likely explanation is major changes in the sea-ice and marine environment resulting from record amounts and duration of open water in the Beaufort and Chukchi seas, possibly influenced by climate warming. Because the underlying causes of observed changes in polar bear body condition and foraging behaviour are unknown, further study is warranted.


Polar Record ◽  
1988 ◽  
Vol 24 (148) ◽  
pp. 1-8 ◽  
Author(s):  
Ian Stirling

AbstractWildlife observations recorded at several offshore hydrocarbon exploration sites in the Beaufort Sea were examined to evaluate the hypothesis that polar bears Ursus maritimus are attracted to drill rigs, will be judged to represent a threat to humans there, and consequently will have to be deterred or destroyed. When polar bears came south with the pack ice in the autumn, they approached drillships or artificial islands, probably because they became curious or were attracted by unfamiliar smells. However, these bears did not usually remain in the area.In late winter, when most of the natural leads are frozen, the movement of compacted annual ice from east to west past permanent offshore drill rigs creates open cracks on the downstream side. Because of the open water there, seals are more abundant, more accessible, or both, and bears are attracted because of better hunting conditions. In mid to late winter some bears may remain in the area for several days or longer while hunting seals. This positive reinforcement may lead these bears to be attracted to other offshore rigs in the future. In the last five years four bears attracted to offshore rigs have been shot; thus the hypothesis was found to be valid. To date, the population is not under threat, but this could change if the number of offshore drill rigs operating through the winter were to increase.


2007 ◽  
Vol 18 (3) ◽  
pp. 218-221 ◽  
Author(s):  
Ian R. Rogers ◽  
Domhnall Brannigan ◽  
Amanda Montgomery ◽  
Nicole Khangure ◽  
Aled Williams ◽  
...  

Kinesiology ◽  
2018 ◽  
Vol 50 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Jose M. Saavedra ◽  
Ingi Einarsson ◽  
Damir Sekulić ◽  
Antonio Garcia-Hermoso

Sports ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 130 ◽  
Author(s):  
Jørgen Melau ◽  
Maria Mathiassen ◽  
Trine Stensrud ◽  
Mike Tipton ◽  
Jonny Hisdal

Low water temperature (<15 °C) has been faced by many organizers of triathlons and swim-runs in the northern part of Europe during recent years. More knowledge about how cold water affects athletes swimming in wetsuits in cold water is warranted. The aim of the present study was therefore to investigate the physiological response when swimming a full Ironman distance (3800 m) in a wetsuit in 10 °C water. Twenty triathletes, 37.6 ± 9 years (12 males and 8 females) were recruited to perform open water swimming in 10 °C seawater; while rectal temperature (Tre) and skin temperature (Tskin) were recorded. The results showed that for all participants, Tre was maintained for the first 10–15 min of the swim; and no participants dropped more than 2 °C in Tre during the first 30 min of swimming in 10 °C water. However; according to extrapolations of the results, during a swim time above 135 min; 47% (8/17) of the participants in the present study would fall more than 2 °C in Tre during the swim. The results show that the temperature response to swimming in a wetsuit in 10 °C water is highly individual. However, no participant in the present study dropped more than 2 °C in Tre during the first 30 min of the swim in 10 °C water.


2020 ◽  
Vol 745 ◽  
pp. 140978
Author(s):  
Jennifer Bourque ◽  
Jean-Pierre Desforges ◽  
Milton Levin ◽  
Todd C. Atwood ◽  
Christian Sonne ◽  
...  

2012 ◽  
Vol 90 (5) ◽  
pp. 663-676 ◽  
Author(s):  
A.M. Pagano ◽  
G.M. Durner ◽  
S.C. Amstrup ◽  
K.S. Simac ◽  
G.S. York

Polar bears ( Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004–2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.


Polar Biology ◽  
2016 ◽  
Vol 40 (4) ◽  
pp. 753-763 ◽  
Author(s):  
Jodie D. Pongracz ◽  
Andrew E. Derocher

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