Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway
Ringed seals, which are small phocid seals, range across the circumpolar Arctic, and have evolved in close association with sea ice and depend on it for all aspects of their life history. This research study compares age structure, reproductive parameters, body size and condition during three time p...
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doaj-4b81fbf6063b43888d8732bb29bdb7a72021-05-05T14:02:24Zeng Norwegian Polar InstitutePolar Research0800-03951751-83692020-06-0140011410.33265/polar.v40.53915391Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, NorwayMagnus Andersen0Kit M. Kovacs1Christian Lydersen2Norwegian Polar Institute, Fram Centre, Tromsø, NorwayNorwegian Polar Institute, Fram Centre, Tromsø, NorwayNorwegian Polar Institute, Fram Centre, Tromsø, NorwayRinged seals, which are small phocid seals, range across the circumpolar Arctic, and have evolved in close association with sea ice and depend on it for all aspects of their life history. This research study compares age structure, reproductive parameters, body size and condition during three time periods—1981–82 (n = 277), 2002–04 (n = 272) and 2012–18 (n = 212)—to study potential changes in demography in ringed seals in western Svalbard, Norway, an area that has undergone dramatic changes in sea-ice conditions during recent decades. Age distributions for the three time periods were similar, with the exception that the most recent period had a higher proportion of young animals. Age at sexual maturity for both sexes was similar for the two most recent periods, both being lower than in the 1980s. Ovulation rates did not vary significantly among the three periods (range 0.86–0.94). Pregnancy rates were only available for the most recent study period (0.71); this value falls within the range reported from other Arctic regions. Body length showed no clear temporal patterns; males were slightly longer in the most recent period, while females were slightly longer in the first period. Data from May in all periods suggest that body condition has not varied significantly through time. In conclusion, although the ringed seal breeding habitat in Svalbard has declined significantly in recent decades, demographic parameters appear to be largely unaffected. Life-history plasticity in combination with a small-scale regional variation in environmental conditions might explain the lack of changes in demography over time.https://polarresearch.net/index.php/polar/article/view/5391/13500climate changesea icearctic ecosystemrecruitmentbody growthbody condition |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Magnus Andersen Kit M. Kovacs Christian Lydersen |
spellingShingle |
Magnus Andersen Kit M. Kovacs Christian Lydersen Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway Polar Research climate change sea ice arctic ecosystem recruitment body growth body condition |
author_facet |
Magnus Andersen Kit M. Kovacs Christian Lydersen |
author_sort |
Magnus Andersen |
title |
Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway |
title_short |
Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway |
title_full |
Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway |
title_fullStr |
Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway |
title_full_unstemmed |
Stable ringed seal (Pusa hispida) demography despite significant habitat change in Svalbard, Norway |
title_sort |
stable ringed seal (pusa hispida) demography despite significant habitat change in svalbard, norway |
publisher |
Norwegian Polar Institute |
series |
Polar Research |
issn |
0800-0395 1751-8369 |
publishDate |
2020-06-01 |
description |
Ringed seals, which are small phocid seals, range across the circumpolar Arctic, and have evolved in close association with sea ice and depend on it for all aspects of their life history. This research study compares age structure, reproductive parameters, body size and condition during three time periods—1981–82 (n = 277), 2002–04 (n = 272) and 2012–18 (n = 212)—to study potential changes in demography in ringed seals in western Svalbard, Norway, an area that has undergone dramatic changes in sea-ice conditions during recent decades. Age distributions for the three time periods were similar, with the exception that the most recent period had a higher proportion of young animals. Age at sexual maturity for both sexes was similar for the two most recent periods, both being lower than in the 1980s. Ovulation rates did not vary significantly among the three periods (range 0.86–0.94). Pregnancy rates were only available for the most recent study period (0.71); this value falls within the range reported from other Arctic regions. Body length showed no clear temporal patterns; males were slightly longer in the most recent period, while females were slightly longer in the first period. Data from May in all periods suggest that body condition has not varied significantly through time. In conclusion, although the ringed seal breeding habitat in Svalbard has declined significantly in recent decades, demographic parameters appear to be largely unaffected. Life-history plasticity in combination with a small-scale regional variation in environmental conditions might explain the lack of changes in demography over time. |
topic |
climate change sea ice arctic ecosystem recruitment body growth body condition |
url |
https://polarresearch.net/index.php/polar/article/view/5391/13500 |
work_keys_str_mv |
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