Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries
Abstract Harbour porpoise (Phocoena phocoena) bycatch for Norwegian commercial gillnet fisheries from 2006 to 2018 was estimated using a traditional ratio estimator and generalized additive linear mixed models, with weight of fish landed and number of gillnet hauls as proxies for fishing effort. Est...
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Oxford University Press (OUP)
2020
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Online Access: | http://dx.doi.org/10.1093/icesjms/fsaa186 http://academic.oup.com/icesjms/article-pdf/77/7-8/3039/35589110/fsaa186.pdf |
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croxfordunivpr:10.1093/icesjms/fsaa186 2024-06-23T07:52:57+00:00 Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries Moan, André Skern-Mauritzen, Mette Vølstad, Jon Helge Bjørge, Arne Zhou, Shijie Norwegian Seafood Research Fund Norwegian Ministry of Trade, Industry and Fisheries 2020 http://dx.doi.org/10.1093/icesjms/fsaa186 http://academic.oup.com/icesjms/article-pdf/77/7-8/3039/35589110/fsaa186.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model ICES Journal of Marine Science volume 77, issue 7-8, page 3039-3049 ISSN 1095-9289 journal-article 2020 croxfordunivpr https://doi.org/10.1093/icesjms/fsaa186 2024-06-11T04:22:05Z Abstract Harbour porpoise (Phocoena phocoena) bycatch for Norwegian commercial gillnet fisheries from 2006 to 2018 was estimated using a traditional ratio estimator and generalized additive linear mixed models, with weight of fish landed and number of gillnet hauls as proxies for fishing effort. Estimates were derived from data collected with a contracted reference fleet of small coastal vessels and scaled up to the whole fleet using data from landing statistics. Bycatch estimates exhibited large yearly variations, ranging from 1151 to 6144 porpoises per year. Bycatch estimates in 4 of the last 5 years were significantly less than in the preceding 2 years. The best ratio-based and model-based yearly bycatch estimates were 1580 porpoises [coefficient of variation, (C.V.) 0.10, 95% confidence interval (CI) 1302–1902] and 1642 porpoises (C.V. 0.15, 95% CI 1165–2142), respectively. About 75% of bycaught porpoises were taken in the cod (Gadus morhua) and monkfish (Lophius piscatorius) fisheries, while the rest were taken in a variety of different gillnet fisheries. Our results suggest that bycatch of harbour porpoise in Norwegian gillnet fisheries has been unsustainable for several of the last 13 years but are currently within international bycatch limits due to a recent reduction in monkfish fishing effort. Article in Journal/Newspaper Gadus morhua Harbour porpoise Phocoena phocoena Oxford University Press ICES Journal of Marine Science 77 7-8 3039 3049 |
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Open Polar |
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Oxford University Press |
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croxfordunivpr |
language |
English |
description |
Abstract Harbour porpoise (Phocoena phocoena) bycatch for Norwegian commercial gillnet fisheries from 2006 to 2018 was estimated using a traditional ratio estimator and generalized additive linear mixed models, with weight of fish landed and number of gillnet hauls as proxies for fishing effort. Estimates were derived from data collected with a contracted reference fleet of small coastal vessels and scaled up to the whole fleet using data from landing statistics. Bycatch estimates exhibited large yearly variations, ranging from 1151 to 6144 porpoises per year. Bycatch estimates in 4 of the last 5 years were significantly less than in the preceding 2 years. The best ratio-based and model-based yearly bycatch estimates were 1580 porpoises [coefficient of variation, (C.V.) 0.10, 95% confidence interval (CI) 1302–1902] and 1642 porpoises (C.V. 0.15, 95% CI 1165–2142), respectively. About 75% of bycaught porpoises were taken in the cod (Gadus morhua) and monkfish (Lophius piscatorius) fisheries, while the rest were taken in a variety of different gillnet fisheries. Our results suggest that bycatch of harbour porpoise in Norwegian gillnet fisheries has been unsustainable for several of the last 13 years but are currently within international bycatch limits due to a recent reduction in monkfish fishing effort. |
author2 |
Zhou, Shijie Norwegian Seafood Research Fund Norwegian Ministry of Trade, Industry and Fisheries |
format |
Article in Journal/Newspaper |
author |
Moan, André Skern-Mauritzen, Mette Vølstad, Jon Helge Bjørge, Arne |
spellingShingle |
Moan, André Skern-Mauritzen, Mette Vølstad, Jon Helge Bjørge, Arne Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries |
author_facet |
Moan, André Skern-Mauritzen, Mette Vølstad, Jon Helge Bjørge, Arne |
author_sort |
Moan, André |
title |
Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries |
title_short |
Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries |
title_full |
Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries |
title_fullStr |
Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries |
title_full_unstemmed |
Assessing the impact of fisheries-related mortality of harbour porpoise ( Phocoena phocoena) caused by incidental bycatch in the dynamic Norwegian gillnet fisheries |
title_sort |
assessing the impact of fisheries-related mortality of harbour porpoise ( phocoena phocoena) caused by incidental bycatch in the dynamic norwegian gillnet fisheries |
publisher |
Oxford University Press (OUP) |
publishDate |
2020 |
url |
http://dx.doi.org/10.1093/icesjms/fsaa186 http://academic.oup.com/icesjms/article-pdf/77/7-8/3039/35589110/fsaa186.pdf |
genre |
Gadus morhua Harbour porpoise Phocoena phocoena |
genre_facet |
Gadus morhua Harbour porpoise Phocoena phocoena |
op_source |
ICES Journal of Marine Science volume 77, issue 7-8, page 3039-3049 ISSN 1095-9289 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/icesjms/fsaa186 |
container_title |
ICES Journal of Marine Science |
container_volume |
77 |
container_issue |
7-8 |
container_start_page |
3039 |
op_container_end_page |
3049 |
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1802644398554480640 |