Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018
A ship-based mosaic survey of Northeast Atlantic cetaceans was conducted over a 5-year period between 2014–2018. The area surveyed extends from the North Sea in the south (southern boundary at 53oN), to the ice edge of the Barents Sea and the Greenland Sea. Survey vessels were equipped with 2 indepe...
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| Format: | Article |
| Language: | English |
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Septentrio Academic Publishing
2020-07-01
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| Series: | NAMMCO Scientific Publications |
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| Online Access: | https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4694 |
| _version_ | 1818150072749129728 |
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| author | Deanna Leonard Nils Øien |
| author_facet | Deanna Leonard Nils Øien |
| author_sort | Deanna Leonard |
| collection | DOAJ |
| description | A ship-based mosaic survey of Northeast Atlantic cetaceans was conducted over a 5-year period between 2014–2018. The area surveyed extends from the North Sea in the south (southern boundary at 53oN), to the ice edge of the Barents Sea and the Greenland Sea. Survey vessels were equipped with 2 independent observer platforms that detected whales in passing mode and applied tracking procedures for the target species, common minke whales (Balaenoptera acutorostrata acutorostrata). Here we present abundance estimates for all non-target species for which there were sufficient sightings. We estimate the abundance of fin whales (Balaenoptera physalus) to be 11,387 (CV=0.17, 95% CI: 8,072–16,063), of humpback whales (Megaptera novaeangliae) to be 10,708 (CV=0.38, 95% CI: 4,906–23,370), of sperm whales (Physeter macrocephalus) to be 5,704 (CV=0.26, 95% CI: 3,374–9,643), of killer whales (Orcinus orca) to be 15,056 (CV=0.29, 95% CI: 8,423–26,914), of harbour porpoises (Phocoena phocoena) to be 255,929 (CV=0.20, 95% CI: 172,742–379,175), dolphins of genus Lagenorhynchus to be 192,767 (CV=0.25, 95% CI: 114,033–325,863), and finally of northern bottlenose whales (Hyperoodon ampullatus) to be 7,800 (CV=0.28, 95% CI: 4,373–13,913). Additionally, our survey effort in the Norwegian Sea in 2015 contributed to the 6th North Atlantic Sightings Survey (NASS) and the survey was extended into the waters north and east of Iceland around Jan Mayen island. This NASS extension, along with our Norwegian Sea survey in 2015, was used to estimate the abundance of fin whales, humpback whales, and sperm whales. All estimates presented used mark-recapture distance sampling techniques and were thus corrected for perception bias. Our estimates do not account for additional variance due to distributional shifts between years or biases due to availability or responsive movement. |
| first_indexed | 2024-12-11T13:17:07Z |
| format | Article |
| id | doaj.art-b10e95ba2cc649e296bd4924d3b3e2b6 |
| institution | Directory Open Access Journal |
| issn | 1560-2206 2309-2491 |
| language | English |
| last_indexed | 2024-12-11T13:17:07Z |
| publishDate | 2020-07-01 |
| publisher | Septentrio Academic Publishing |
| record_format | Article |
| series | NAMMCO Scientific Publications |
| spelling | doaj.art-b10e95ba2cc649e296bd4924d3b3e2b62022-12-22T01:06:01ZengSeptentrio Academic PublishingNAMMCO Scientific Publications1560-22062309-24912020-07-011110.7557/3.4694Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018Deanna Leonard0Nils Øien1Institute of Marine ResearchInstitute of Marine ResearchA ship-based mosaic survey of Northeast Atlantic cetaceans was conducted over a 5-year period between 2014–2018. The area surveyed extends from the North Sea in the south (southern boundary at 53oN), to the ice edge of the Barents Sea and the Greenland Sea. Survey vessels were equipped with 2 independent observer platforms that detected whales in passing mode and applied tracking procedures for the target species, common minke whales (Balaenoptera acutorostrata acutorostrata). Here we present abundance estimates for all non-target species for which there were sufficient sightings. We estimate the abundance of fin whales (Balaenoptera physalus) to be 11,387 (CV=0.17, 95% CI: 8,072–16,063), of humpback whales (Megaptera novaeangliae) to be 10,708 (CV=0.38, 95% CI: 4,906–23,370), of sperm whales (Physeter macrocephalus) to be 5,704 (CV=0.26, 95% CI: 3,374–9,643), of killer whales (Orcinus orca) to be 15,056 (CV=0.29, 95% CI: 8,423–26,914), of harbour porpoises (Phocoena phocoena) to be 255,929 (CV=0.20, 95% CI: 172,742–379,175), dolphins of genus Lagenorhynchus to be 192,767 (CV=0.25, 95% CI: 114,033–325,863), and finally of northern bottlenose whales (Hyperoodon ampullatus) to be 7,800 (CV=0.28, 95% CI: 4,373–13,913). Additionally, our survey effort in the Norwegian Sea in 2015 contributed to the 6th North Atlantic Sightings Survey (NASS) and the survey was extended into the waters north and east of Iceland around Jan Mayen island. This NASS extension, along with our Norwegian Sea survey in 2015, was used to estimate the abundance of fin whales, humpback whales, and sperm whales. All estimates presented used mark-recapture distance sampling techniques and were thus corrected for perception bias. Our estimates do not account for additional variance due to distributional shifts between years or biases due to availability or responsive movement.https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4694North Atlanticcetaceanabundanceline-transectfin whaleshumpback whales |
| spellingShingle | Deanna Leonard Nils Øien Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018 NAMMCO Scientific Publications North Atlantic cetacean abundance line-transect fin whales humpback whales |
| title | Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018 |
| title_full | Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018 |
| title_fullStr | Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018 |
| title_full_unstemmed | Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018 |
| title_short | Estimated Abundances of Cetacean Species in the Northeast Atlantic from Norwegian Shipboard Surveys Conducted in 2014–2018 |
| title_sort | estimated abundances of cetacean species in the northeast atlantic from norwegian shipboard surveys conducted in 2014 2018 |
| topic | North Atlantic cetacean abundance line-transect fin whales humpback whales |
| url | https://septentrio.uit.no/index.php/NAMMCOSP/article/view/4694 |
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