Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut
To support management objectives in Canada and Greenland, joint research between the Department of Fisheries and Oceans and Greenland Institute of Natural Resources was begun in 2005. Direct counts were used to determine the Minimum Counted Population (MCP) in summer around SE Baffin Island. Aerial...
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| Format: | Article |
| Language: | English |
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Septentrio Academic Publishing
2014-12-01
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| Series: | NAMMCO Scientific Publications |
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| Online Access: | https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2615 |
| _version_ | 1818435566728904704 |
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| author | Robert EA Stewart Erik W Born Rune Dietz Anna K Ryan |
| author_facet | Robert EA Stewart Erik W Born Rune Dietz Anna K Ryan |
| author_sort | Robert EA Stewart |
| collection | DOAJ |
| description | To support management objectives in Canada and Greenland, joint research between the Department of Fisheries and Oceans and Greenland Institute of Natural Resources was begun in 2005. Direct counts were used to determine the Minimum Counted Population (MCP) in summer around SE Baffin Island. Aerial surveys examined the coast from roughly the Saddleback Island in northern Hudson Strait to Isabella Bay on eastern Baffin Island but concentrated on the area between Loks Land and Cape Dyer. The maximum count was obtained on 3–4 September 2007 during boat surveys. The MCP ranged from 716 (in 2006) to 1,056 (2007). Using the largest MCP adjusted with published maximum estimates of the proportion of walrus hauled out concurrently, we estimated 1,420 (95% CI: 1,219–1,622) walrus were present. In addition, four walrus had been fitted with satellite relayed data logger tags prior to the maximum counts in 2007. Using the simple proportion of ‘tags dry’ on 3 September to adjust counts on 3 and 4 September 2007 provided an estimate of 2,102 (CI = MCP-4,482). Using the proportion of time dry immediately preceding the survey to adjust the maximum count produced an estimate of 2,502 (CI = 1,660–3,345) walrus were present in Hoare Bay. We conclude approximately 2,100–2,500 walrus were present in Hoare Bay in late summer 2007. This number is a negatively biased estimator of the population of walrus around SE Baffin Island and in the Hudson Bay–Davis Strait stock as a whole. Broader survey coverage in a short period and more detailed information on the movement of walrus between Greenland and Canada and the summer dispersal of these animals within Canada are required to improve population estimates. |
| first_indexed | 2024-12-14T16:54:56Z |
| format | Article |
| id | doaj.art-aeef1edca24b4b70be7f8ebf522fef33 |
| institution | Directory Open Access Journal |
| issn | 1560-2206 2309-2491 |
| language | English |
| last_indexed | 2024-12-14T16:54:56Z |
| publishDate | 2014-12-01 |
| publisher | Septentrio Academic Publishing |
| record_format | Article |
| series | NAMMCO Scientific Publications |
| spelling | doaj.art-aeef1edca24b4b70be7f8ebf522fef332022-12-21T22:54:00ZengSeptentrio Academic PublishingNAMMCO Scientific Publications1560-22062309-24912014-12-019014115710.7557/3.26152421Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, NunavutRobert EA Stewart0Erik W Born1Rune Dietz2Anna K Ryan3Fisheries and Oceans Canada, Freshwater InstituteGreenland Institute of Natural ResourcesDepartment of Bioscience, Aarhus UniversityDepartment of Fisheries and Oceans, Freshwater InstituteTo support management objectives in Canada and Greenland, joint research between the Department of Fisheries and Oceans and Greenland Institute of Natural Resources was begun in 2005. Direct counts were used to determine the Minimum Counted Population (MCP) in summer around SE Baffin Island. Aerial surveys examined the coast from roughly the Saddleback Island in northern Hudson Strait to Isabella Bay on eastern Baffin Island but concentrated on the area between Loks Land and Cape Dyer. The maximum count was obtained on 3–4 September 2007 during boat surveys. The MCP ranged from 716 (in 2006) to 1,056 (2007). Using the largest MCP adjusted with published maximum estimates of the proportion of walrus hauled out concurrently, we estimated 1,420 (95% CI: 1,219–1,622) walrus were present. In addition, four walrus had been fitted with satellite relayed data logger tags prior to the maximum counts in 2007. Using the simple proportion of ‘tags dry’ on 3 September to adjust counts on 3 and 4 September 2007 provided an estimate of 2,102 (CI = MCP-4,482). Using the proportion of time dry immediately preceding the survey to adjust the maximum count produced an estimate of 2,502 (CI = 1,660–3,345) walrus were present in Hoare Bay. We conclude approximately 2,100–2,500 walrus were present in Hoare Bay in late summer 2007. This number is a negatively biased estimator of the population of walrus around SE Baffin Island and in the Hudson Bay–Davis Strait stock as a whole. Broader survey coverage in a short period and more detailed information on the movement of walrus between Greenland and Canada and the summer dispersal of these animals within Canada are required to improve population estimates.https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2615walrusOdobenus rosmarusCanadaGreenlandminimum counted populationaerial surveysabundance |
| spellingShingle | Robert EA Stewart Erik W Born Rune Dietz Anna K Ryan Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut NAMMCO Scientific Publications walrus Odobenus rosmarus Canada Greenland minimum counted population aerial surveys abundance |
| title | Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut |
| title_full | Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut |
| title_fullStr | Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut |
| title_full_unstemmed | Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut |
| title_short | Estimates of Minimum Population Size for Walrus near Southeast Baffin Island, Nunavut |
| title_sort | estimates of minimum population size for walrus near southeast baffin island nunavut |
| topic | walrus Odobenus rosmarus Canada Greenland minimum counted population aerial surveys abundance |
| url | https://septentrio.uit.no/index.php/NAMMCOSP/article/view/2615 |
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