Distribution, abundance and biology of ringed seals (Phoca hispida): an overview
The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as i...
Published in: | NAMMCO Scientific Publications |
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Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Septentrio Academic Publishing
1998
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Subjects: | |
Online Access: | https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979 https://doi.org/10.7557/3.2979 |
id |
ftunitroemsoe:oai:ojs.henry.ub.uit.no:article/2979 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
University of Tromsø: Septentrio Academic Publishing |
op_collection_id |
ftunitroemsoe |
language |
English |
topic |
ringed seals Phoca hispida distribution abundance reproduction |
spellingShingle |
ringed seals Phoca hispida distribution abundance reproduction Reeves, Randall R Distribution, abundance and biology of ringed seals (Phoca hispida): an overview |
topic_facet |
ringed seals Phoca hispida distribution abundance reproduction |
description |
The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as in the Baltic Sea and Karelian lakes. No clear-cut boundaries are known to separate ringed seal stocks in marine waters. Adult seals are thought to be relatively sedentary, but sub-adults sometimes disperse over long distances. Stable ice with good snow cover is considered the most productive habitat although production in pack ice has been little studied. Populations appear to be structured so that immature animals and young adults are consigned to sub-optimal habitat during the spring pupping and breeding season. Annual production in ringed seal populations, defined as thepup percentage in the total population after the late winter pupping season, is probably in the order of 18-24%. Most estimates of maximum sustainable yield are in the order of 7%.The world population of ringed seals is at least a few million. Methods of abundance estimation have included aerial surveys, dog searches and remote sensing of lairs and breathing holes, acoustic monitoring, correlation analysis by reference to sizes of polar bear populations, and inference from estimated energy requirements of bear populations. Aerial strip survey has been the method of choice for estimating seal densities over large areas. Adjustment factors to account for seals not hauled out at the time of the survey, for seals that dove ahead of the aircraft, and for seals on the ice within the surveyed strip but not detected by the observers, are required for estimates of absolute abundance.Male and female ringed seals are sexually mature by 5-7 years of age (earlier at Svalbard). Pupping usually occurs in March or early April and is followed by 5-7 weeks of lactation. Breeding takes place in mid to late May, and implantation is delayed for about 3 months. In at least some parts of their range, ringed seals feed mainly on schooling gadids from late autumn through early spring andon benthic crustaceans and polar cod (Boreogadus saida) from late spring through summer. Little feeding is done during the moult, which takes place in late spring and early summer. Pelagic crustaceans offshore and mysids inshore become important prey in late summer and early autumn in some areas. Ringed seals have several natural predators, the most important of which is the polar bear in most arctic regions. Arctic foxes (Alopex lagopus) kill a large percentage of pups in someareas.From a conservation perspective, the ringed seal appears to be secure. Levels of exploitation of arctic populations have usually been considered sustainable, except in the Okhotsk Sea. Large fluctuations in production of ringed seals in the Beaufort Sea and Amundsen Gulf are thought to be driven by natural variability in environmental conditions. While concern has been expressed about thepotential impacts of industrial activity and pollution on ringed seals, such impacts have been documented only in limited areas. Because of their ubiquitous occurrence and availability for sampling, ringed seals are good subjects for monitoring contaminant trends in Arctic marine food chains. |
format |
Article in Journal/Newspaper |
author |
Reeves, Randall R |
author_facet |
Reeves, Randall R |
author_sort |
Reeves, Randall R |
title |
Distribution, abundance and biology of ringed seals (Phoca hispida): an overview |
title_short |
Distribution, abundance and biology of ringed seals (Phoca hispida): an overview |
title_full |
Distribution, abundance and biology of ringed seals (Phoca hispida): an overview |
title_fullStr |
Distribution, abundance and biology of ringed seals (Phoca hispida): an overview |
title_full_unstemmed |
Distribution, abundance and biology of ringed seals (Phoca hispida): an overview |
title_sort |
distribution, abundance and biology of ringed seals (phoca hispida): an overview |
publisher |
Septentrio Academic Publishing |
publishDate |
1998 |
url |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979 https://doi.org/10.7557/3.2979 |
geographic |
Arctic Canada Greenland Okhotsk Svalbard |
geographic_facet |
Arctic Canada Greenland Okhotsk Svalbard |
genre |
Alopex lagopus Amundsen Gulf Arctic Beaufort Sea Boreogadus saida Greenland karelia* karelian okhotsk sea Phoca hispida polar bear polar cod ringed seal Svalbard Ursus maritimus Alaska |
genre_facet |
Alopex lagopus Amundsen Gulf Arctic Beaufort Sea Boreogadus saida Greenland karelia* karelian okhotsk sea Phoca hispida polar bear polar cod ringed seal Svalbard Ursus maritimus Alaska |
op_source |
NAMMCO Scientific Publications; Vol 1: Ringed Seals in the North Atlantic; 9-45 2309-2491 1560-2206 10.7557/3.1 |
op_relation |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979/2852 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979 doi:10.7557/3.2979 |
op_rights |
Copyright (c) 1998 Randall R Reeves http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.7557/3.2979 https://doi.org/10.7557/3.1 |
container_title |
NAMMCO Scientific Publications |
container_volume |
1 |
container_start_page |
9 |
_version_ |
1766350364025552896 |
spelling |
ftunitroemsoe:oai:ojs.henry.ub.uit.no:article/2979 2023-05-15T13:19:56+02:00 Distribution, abundance and biology of ringed seals (Phoca hispida): an overview Reeves, Randall R 1998-06-30 application/pdf https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979 https://doi.org/10.7557/3.2979 eng eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979/2852 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2979 doi:10.7557/3.2979 Copyright (c) 1998 Randall R Reeves http://creativecommons.org/licenses/by/3.0/ CC-BY NAMMCO Scientific Publications; Vol 1: Ringed Seals in the North Atlantic; 9-45 2309-2491 1560-2206 10.7557/3.1 ringed seals Phoca hispida distribution abundance reproduction info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1998 ftunitroemsoe https://doi.org/10.7557/3.2979 https://doi.org/10.7557/3.1 2021-08-16T16:41:30Z The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as in the Baltic Sea and Karelian lakes. No clear-cut boundaries are known to separate ringed seal stocks in marine waters. Adult seals are thought to be relatively sedentary, but sub-adults sometimes disperse over long distances. Stable ice with good snow cover is considered the most productive habitat although production in pack ice has been little studied. Populations appear to be structured so that immature animals and young adults are consigned to sub-optimal habitat during the spring pupping and breeding season. Annual production in ringed seal populations, defined as thepup percentage in the total population after the late winter pupping season, is probably in the order of 18-24%. Most estimates of maximum sustainable yield are in the order of 7%.The world population of ringed seals is at least a few million. Methods of abundance estimation have included aerial surveys, dog searches and remote sensing of lairs and breathing holes, acoustic monitoring, correlation analysis by reference to sizes of polar bear populations, and inference from estimated energy requirements of bear populations. Aerial strip survey has been the method of choice for estimating seal densities over large areas. Adjustment factors to account for seals not hauled out at the time of the survey, for seals that dove ahead of the aircraft, and for seals on the ice within the surveyed strip but not detected by the observers, are required for estimates of absolute abundance.Male and female ringed seals are sexually mature by 5-7 years of age (earlier at Svalbard). Pupping usually occurs in March or early April and is followed by 5-7 weeks of lactation. Breeding takes place in mid to late May, and implantation is delayed for about 3 months. In at least some parts of their range, ringed seals feed mainly on schooling gadids from late autumn through early spring andon benthic crustaceans and polar cod (Boreogadus saida) from late spring through summer. Little feeding is done during the moult, which takes place in late spring and early summer. Pelagic crustaceans offshore and mysids inshore become important prey in late summer and early autumn in some areas. Ringed seals have several natural predators, the most important of which is the polar bear in most arctic regions. Arctic foxes (Alopex lagopus) kill a large percentage of pups in someareas.From a conservation perspective, the ringed seal appears to be secure. Levels of exploitation of arctic populations have usually been considered sustainable, except in the Okhotsk Sea. Large fluctuations in production of ringed seals in the Beaufort Sea and Amundsen Gulf are thought to be driven by natural variability in environmental conditions. While concern has been expressed about thepotential impacts of industrial activity and pollution on ringed seals, such impacts have been documented only in limited areas. Because of their ubiquitous occurrence and availability for sampling, ringed seals are good subjects for monitoring contaminant trends in Arctic marine food chains. Article in Journal/Newspaper Alopex lagopus Amundsen Gulf Arctic Beaufort Sea Boreogadus saida Greenland karelia* karelian okhotsk sea Phoca hispida polar bear polar cod ringed seal Svalbard Ursus maritimus Alaska University of Tromsø: Septentrio Academic Publishing Arctic Canada Greenland Okhotsk Svalbard NAMMCO Scientific Publications 1 9 |