Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands
This study presents the first fully corrected abundance estimates for the harbour porpoise (Phocoena phocoena) for Iceland and the Faroe Islands. In both regions reliable estimates are needed to assess the impact of by-catch and other threats to harbour porpoises. Aerial surveys with harbour porpois...
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Language: | English |
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Septentrio Academic Publishing
2020
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Online Access: | https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939 https://doi.org/10.7557/3.4939 |
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ftunitroemsoe:oai:ojs.henry.ub.uit.no:article/4939 2023-10-09T21:50:15+02:00 Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands Gilles, Anita Gunnlaugsson, Thorvaldur Mikkelsen, Bjarni Pike, Daniel G. Víkingsson, Gísli 2020-08-17 application/pdf image/tiff image/jpeg image/png https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939 https://doi.org/10.7557/3.4939 eng eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5331 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5773 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5774 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5775 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5776 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5777 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5778 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5332 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939 doi:10.7557/3.4939 Copyright (c) 2020 Anita Gilles, Thorvaldur Gunnlaugsson, Bjarni Mikkelsen, Daniel G. Pike, Gísli A. Víkingsson https://creativecommons.org/licenses/by/4.0 NAMMCO Scientific Publications; Vol. 11 (2019): Sightings Surveys in the North Atlantic: 30 years of counting whales 2309-2491 1560-2206 10.7557/3.11 harbour porpoise abundance estimate Iceland Faroe Islands aerial survey distance sampling cetacean info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2020 ftunitroemsoe https://doi.org/10.7557/3.493910.7557/3.11 2023-09-20T23:07:55Z This study presents the first fully corrected abundance estimates for the harbour porpoise (Phocoena phocoena) for Iceland and the Faroe Islands. In both regions reliable estimates are needed to assess the impact of by-catch and other threats to harbour porpoises. Aerial surveys with harbour porpoise as a secondary and main target species were conducted in the summers of 2007 and 2010 in Icelandic and in Faroese coastal waters respectively. In Iceland, the cue counting procedure was used (which also produces the data required for line transect analysis), while in the Faroese, standard line transect sampling was applied, following the SCANS-II (Small Cetacean Abundance in the North Sea) survey protocol. In both surveys, identical aircraft surveyed at an altitude of 600 ft and a speed of 90–100 kn. Only data collected during Beaufort Sea States (BSS) lower than 3 and during good or moderate porpoise sighting conditions were used for abundance estimates. Abundance estimates were corrected using stratified estimates of esw (incorporating g(0)) values derived during the SCANS-II survey in 2005 as principal observers took part in this survey as well. In Iceland, realised effort in good or moderate harbour porpoise sighting conditions totalled 8,289 km in 13 survey strata, where 77 sightings (109 individuals) were made by the experienced harbour porpoise observer only. In Faroese waters, only part of the area inside the 300 m depth curve could be surveyed and 1,564 km were surveyed in good or moderate porpoise sighting conditions, yielding 39 sightings (49 individuals). The total abundance estimates were 43,179 porpoises (CV=0.45; 95% CI: 31,755–161,899) for Icelandic coastal waters and 5,175 porpoises (CV=0.44; 95% CI: 3,457–17,637) for Faroese waters. Article in Journal/Newspaper Beaufort Sea Faroe Islands Harbour porpoise Iceland Phocoena phocoena University of Tromsø: Septentrio Academic Publishing Faroe Islands NAMMCO Scientific Publications 11 |
institution |
Open Polar |
collection |
University of Tromsø: Septentrio Academic Publishing |
op_collection_id |
ftunitroemsoe |
language |
English |
topic |
harbour porpoise abundance estimate Iceland Faroe Islands aerial survey distance sampling cetacean |
spellingShingle |
harbour porpoise abundance estimate Iceland Faroe Islands aerial survey distance sampling cetacean Gilles, Anita Gunnlaugsson, Thorvaldur Mikkelsen, Bjarni Pike, Daniel G. Víkingsson, Gísli Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands |
topic_facet |
harbour porpoise abundance estimate Iceland Faroe Islands aerial survey distance sampling cetacean |
description |
This study presents the first fully corrected abundance estimates for the harbour porpoise (Phocoena phocoena) for Iceland and the Faroe Islands. In both regions reliable estimates are needed to assess the impact of by-catch and other threats to harbour porpoises. Aerial surveys with harbour porpoise as a secondary and main target species were conducted in the summers of 2007 and 2010 in Icelandic and in Faroese coastal waters respectively. In Iceland, the cue counting procedure was used (which also produces the data required for line transect analysis), while in the Faroese, standard line transect sampling was applied, following the SCANS-II (Small Cetacean Abundance in the North Sea) survey protocol. In both surveys, identical aircraft surveyed at an altitude of 600 ft and a speed of 90–100 kn. Only data collected during Beaufort Sea States (BSS) lower than 3 and during good or moderate porpoise sighting conditions were used for abundance estimates. Abundance estimates were corrected using stratified estimates of esw (incorporating g(0)) values derived during the SCANS-II survey in 2005 as principal observers took part in this survey as well. In Iceland, realised effort in good or moderate harbour porpoise sighting conditions totalled 8,289 km in 13 survey strata, where 77 sightings (109 individuals) were made by the experienced harbour porpoise observer only. In Faroese waters, only part of the area inside the 300 m depth curve could be surveyed and 1,564 km were surveyed in good or moderate porpoise sighting conditions, yielding 39 sightings (49 individuals). The total abundance estimates were 43,179 porpoises (CV=0.45; 95% CI: 31,755–161,899) for Icelandic coastal waters and 5,175 porpoises (CV=0.44; 95% CI: 3,457–17,637) for Faroese waters. |
format |
Article in Journal/Newspaper |
author |
Gilles, Anita Gunnlaugsson, Thorvaldur Mikkelsen, Bjarni Pike, Daniel G. Víkingsson, Gísli |
author_facet |
Gilles, Anita Gunnlaugsson, Thorvaldur Mikkelsen, Bjarni Pike, Daniel G. Víkingsson, Gísli |
author_sort |
Gilles, Anita |
title |
Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands |
title_short |
Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands |
title_full |
Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands |
title_fullStr |
Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands |
title_full_unstemmed |
Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands |
title_sort |
summer abundance of harbour porpoises (phocoena phocoena) in the coastal waters of iceland and the faroe islands |
publisher |
Septentrio Academic Publishing |
publishDate |
2020 |
url |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939 https://doi.org/10.7557/3.4939 |
geographic |
Faroe Islands |
geographic_facet |
Faroe Islands |
genre |
Beaufort Sea Faroe Islands Harbour porpoise Iceland Phocoena phocoena |
genre_facet |
Beaufort Sea Faroe Islands Harbour porpoise Iceland Phocoena phocoena |
op_source |
NAMMCO Scientific Publications; Vol. 11 (2019): Sightings Surveys in the North Atlantic: 30 years of counting whales 2309-2491 1560-2206 10.7557/3.11 |
op_relation |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5331 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5773 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5774 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5775 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5776 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5777 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5778 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939/5332 https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4939 doi:10.7557/3.4939 |
op_rights |
Copyright (c) 2020 Anita Gilles, Thorvaldur Gunnlaugsson, Bjarni Mikkelsen, Daniel G. Pike, Gísli A. Víkingsson https://creativecommons.org/licenses/by/4.0 |
op_doi |
https://doi.org/10.7557/3.493910.7557/3.11 |
container_title |
NAMMCO Scientific Publications |
container_volume |
11 |
_version_ |
1779313314006827008 |