Narwhal Abundance in the Eastern Canadian High Arctic in 2013
In summer, narwhals (Monodon monoceros) migrate from Baffin Bay to northeastern Canada and northwest Greenland, where they are hunted by Inuit for subsistence. To prevent localized depletion, management of narwhals is based on summer stocks. The High Arctic Cetacean Survey (HACS), conducted in Augus...
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2020
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ftdoajarticles:oai:doaj.org/article:e7e65a53a8eb429b97d66d782dfe307b 2023-05-15T15:01:49+02:00 Narwhal Abundance in the Eastern Canadian High Arctic in 2013 Thomas Doniol-Valcroze Jean-François Gosselin Daniel G. Pike Jack W. Lawson Natalie C. Asselin Kevin Hedges Steven H. Ferguson 2020-11-01T00:00:00Z https://doi.org/10.7557/3.5100 https://doaj.org/article/e7e65a53a8eb429b97d66d782dfe307b EN eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/NAMMCOSP/article/view/5100 https://doaj.org/toc/1560-2206 https://doaj.org/toc/2309-2491 doi:10.7557/3.5100 1560-2206 2309-2491 https://doaj.org/article/e7e65a53a8eb429b97d66d782dfe307b NAMMCO Scientific Publications, Vol 11 (2020) narwhal Baffin Bay summer stocks abundance aerial survey double-platform Ecology QH540-549.5 article 2020 ftdoajarticles https://doi.org/10.7557/3.5100 2022-12-31T09:50:12Z In summer, narwhals (Monodon monoceros) migrate from Baffin Bay to northeastern Canada and northwest Greenland, where they are hunted by Inuit for subsistence. To prevent localized depletion, management of narwhals is based on summer stocks. The High Arctic Cetacean Survey (HACS), conducted in August 2013, was the first survey to estimate abundance of all 4 Canadian Baffin Bay narwhal summer stocks, as well as putative stocks in Jones Sound and Smith Sound, in the same summer. Narwhal abundance was estimated using a double-platform aerial survey. Distance sampling methods were used to estimate detection probability away from the track line. Mark-recapture methods were used to correct for the proportion of narwhals missed by visual observers on the track line (i.e., perception bias). We used a data-driven approach to identify single and duplicate sightings, using 4 covariates to compare differences in sightings made by front and rear observers based on: time of sighting, declination angle, group size, and species identity. Abundance in fjords was estimated using density surface modelling to account for their complex shape and uneven coverage. Estimates were corrected for availability bias (narwhals that are not available for detection because they are submerged when the aircraft passes overhead) using a new analysis of August dive behaviour data from narwhals equipped with satellite-linked time depth recorders. Corrected abundance estimates were 12,694 (95% CI: 6,324–25,481) for the Jones Sound stock; 16,360 (95% CI: 3,833–69,836) for the Smith Sound stock; 49,768 (95% CI: 32,945–75,182) for the Somerset Island stock; 35,043 (95% CI: 14,188–86,553) for the Admiralty Inlet stock; 10,489 (95% CI: 6,342–17,347) for the Eclipse Sound stock; and 17,555 (95% CI: 8,473–36,373) for the East Baffin Island stock. Total abundance for these 6 stocks was estimated at 141,908 (95% CI: 102,464–196,536). Sources of uncertainty arise from the high level of clustering observed, in particular in Admiralty Inlet, Eclipse Sound, and ... Article in Journal/Newspaper Arctic Baffin Bay Baffin Bay Baffin Island Baffin Eclipse Sound Greenland inuit Jones Sound Monodon monoceros narwhal* Smith sound Somerset Island Directory of Open Access Journals: DOAJ Articles Arctic Baffin Bay Baffin Island Canada Greenland Smith Sound ENVELOPE(-73.996,-73.996,78.419,78.419) Somerset Island ENVELOPE(-93.500,-93.500,73.251,73.251) Jones Sound ENVELOPE(-86.000,-86.000,76.002,76.002) Eclipse Sound ENVELOPE(-78.998,-78.998,72.635,72.635) Admiralty Inlet ENVELOPE(-86.000,-86.000,72.501,72.501) NAMMCO Scientific Publications 11 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
narwhal Baffin Bay summer stocks abundance aerial survey double-platform Ecology QH540-549.5 |
spellingShingle |
narwhal Baffin Bay summer stocks abundance aerial survey double-platform Ecology QH540-549.5 Thomas Doniol-Valcroze Jean-François Gosselin Daniel G. Pike Jack W. Lawson Natalie C. Asselin Kevin Hedges Steven H. Ferguson Narwhal Abundance in the Eastern Canadian High Arctic in 2013 |
topic_facet |
narwhal Baffin Bay summer stocks abundance aerial survey double-platform Ecology QH540-549.5 |
description |
In summer, narwhals (Monodon monoceros) migrate from Baffin Bay to northeastern Canada and northwest Greenland, where they are hunted by Inuit for subsistence. To prevent localized depletion, management of narwhals is based on summer stocks. The High Arctic Cetacean Survey (HACS), conducted in August 2013, was the first survey to estimate abundance of all 4 Canadian Baffin Bay narwhal summer stocks, as well as putative stocks in Jones Sound and Smith Sound, in the same summer. Narwhal abundance was estimated using a double-platform aerial survey. Distance sampling methods were used to estimate detection probability away from the track line. Mark-recapture methods were used to correct for the proportion of narwhals missed by visual observers on the track line (i.e., perception bias). We used a data-driven approach to identify single and duplicate sightings, using 4 covariates to compare differences in sightings made by front and rear observers based on: time of sighting, declination angle, group size, and species identity. Abundance in fjords was estimated using density surface modelling to account for their complex shape and uneven coverage. Estimates were corrected for availability bias (narwhals that are not available for detection because they are submerged when the aircraft passes overhead) using a new analysis of August dive behaviour data from narwhals equipped with satellite-linked time depth recorders. Corrected abundance estimates were 12,694 (95% CI: 6,324–25,481) for the Jones Sound stock; 16,360 (95% CI: 3,833–69,836) for the Smith Sound stock; 49,768 (95% CI: 32,945–75,182) for the Somerset Island stock; 35,043 (95% CI: 14,188–86,553) for the Admiralty Inlet stock; 10,489 (95% CI: 6,342–17,347) for the Eclipse Sound stock; and 17,555 (95% CI: 8,473–36,373) for the East Baffin Island stock. Total abundance for these 6 stocks was estimated at 141,908 (95% CI: 102,464–196,536). Sources of uncertainty arise from the high level of clustering observed, in particular in Admiralty Inlet, Eclipse Sound, and ... |
format |
Article in Journal/Newspaper |
author |
Thomas Doniol-Valcroze Jean-François Gosselin Daniel G. Pike Jack W. Lawson Natalie C. Asselin Kevin Hedges Steven H. Ferguson |
author_facet |
Thomas Doniol-Valcroze Jean-François Gosselin Daniel G. Pike Jack W. Lawson Natalie C. Asselin Kevin Hedges Steven H. Ferguson |
author_sort |
Thomas Doniol-Valcroze |
title |
Narwhal Abundance in the Eastern Canadian High Arctic in 2013 |
title_short |
Narwhal Abundance in the Eastern Canadian High Arctic in 2013 |
title_full |
Narwhal Abundance in the Eastern Canadian High Arctic in 2013 |
title_fullStr |
Narwhal Abundance in the Eastern Canadian High Arctic in 2013 |
title_full_unstemmed |
Narwhal Abundance in the Eastern Canadian High Arctic in 2013 |
title_sort |
narwhal abundance in the eastern canadian high arctic in 2013 |
publisher |
Septentrio Academic Publishing |
publishDate |
2020 |
url |
https://doi.org/10.7557/3.5100 https://doaj.org/article/e7e65a53a8eb429b97d66d782dfe307b |
long_lat |
ENVELOPE(-73.996,-73.996,78.419,78.419) ENVELOPE(-93.500,-93.500,73.251,73.251) ENVELOPE(-86.000,-86.000,76.002,76.002) ENVELOPE(-78.998,-78.998,72.635,72.635) ENVELOPE(-86.000,-86.000,72.501,72.501) |
geographic |
Arctic Baffin Bay Baffin Island Canada Greenland Smith Sound Somerset Island Jones Sound Eclipse Sound Admiralty Inlet |
geographic_facet |
Arctic Baffin Bay Baffin Island Canada Greenland Smith Sound Somerset Island Jones Sound Eclipse Sound Admiralty Inlet |
genre |
Arctic Baffin Bay Baffin Bay Baffin Island Baffin Eclipse Sound Greenland inuit Jones Sound Monodon monoceros narwhal* Smith sound Somerset Island |
genre_facet |
Arctic Baffin Bay Baffin Bay Baffin Island Baffin Eclipse Sound Greenland inuit Jones Sound Monodon monoceros narwhal* Smith sound Somerset Island |
op_source |
NAMMCO Scientific Publications, Vol 11 (2020) |
op_relation |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/5100 https://doaj.org/toc/1560-2206 https://doaj.org/toc/2309-2491 doi:10.7557/3.5100 1560-2206 2309-2491 https://doaj.org/article/e7e65a53a8eb429b97d66d782dfe307b |
op_doi |
https://doi.org/10.7557/3.5100 |
container_title |
NAMMCO Scientific Publications |
container_volume |
11 |
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1766333816785338368 |