Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments?
The decrease in groundfish stocks in the North Atlantic since the mid-1900s coupled with increases in grey seal populations is responsible for an enduring controversy between fishers and conservationists regarding the role seals have played in stock declines. We used a Bayesian state-space model to...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Online Access: | https://strathprints.strath.ac.uk/62100/ https://strathprints.strath.ac.uk/62100/1/Trijoulet_etal_CJFAS_2017_Grey_seal_predation_mortality_on_three_depleted_stocks_in_the_west_of_Scotland.pdf https://doi.org/10.1139/cjfas-2016-0521 |
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ftustrathclyde:oai:strathprints.strath.ac.uk:62100 2024-05-19T07:45:07+00:00 Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? Trijoulet, Vanessa Holmes, Steven J. Cook, Robin M. 2017-07-21 text https://strathprints.strath.ac.uk/62100/ https://strathprints.strath.ac.uk/62100/1/Trijoulet_etal_CJFAS_2017_Grey_seal_predation_mortality_on_three_depleted_stocks_in_the_west_of_Scotland.pdf https://doi.org/10.1139/cjfas-2016-0521 en eng https://strathprints.strath.ac.uk/62100/1/Trijoulet_etal_CJFAS_2017_Grey_seal_predation_mortality_on_three_depleted_stocks_in_the_west_of_Scotland.pdf Trijoulet, Vanessa <https://strathprints.strath.ac.uk/view/author/890031.html> and Holmes, Steven J. and Cook, Robin M. <https://strathprints.strath.ac.uk/view/author/824074.html> (2017 <https://strathprints.strath.ac.uk/view/year/2017.html>) Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? Canadian Journal of Fisheries and Aquatic Sciences <https://strathprints.strath.ac.uk/view/publications/Canadian_Journal_of_Fisheries_and_Aquatic_Sciences.html>. ISSN 1205-7533 Aquaculture. Fisheries. Angling Statistics Article PeerReviewed 2017 ftustrathclyde https://doi.org/10.1139/cjfas-2016-0521 2024-04-23T23:57:41Z The decrease in groundfish stocks in the North Atlantic since the mid-1900s coupled with increases in grey seal populations is responsible for an enduring controversy between fishers and conservationists regarding the role seals have played in stock declines. We used a Bayesian state-space model to investigate stock trends in the presence of grey seals and associated MSY reference points in the West of Scotland. This study provides new estimates of seal predation mortality on haddock and whiting and updates the estimates for cod, which together form the traditional main components of the mixed demersal fishery in this area. Grey seal predation mortality is greatest on cod resulting in estimates of total natural mortality higher than those used in the current ICES assessments. Seal predation mortality is low for haddock and whiting. Considering seal predation in stock assessments changes the scale of biomass and fishing mortality estimates for the three stocks. The estimates of F0.1 and FMSY are sensitive to seal predation for cod and whiting but not for haddock. In all cases MSY decreases with increased seal predation. Article in Journal/Newspaper North Atlantic University of Strathclyde Glasgow: Strathprints Canadian Journal of Fisheries and Aquatic Sciences 75 5 723 732 |
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Open Polar |
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University of Strathclyde Glasgow: Strathprints |
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ftustrathclyde |
language |
English |
topic |
Aquaculture. Fisheries. Angling Statistics |
spellingShingle |
Aquaculture. Fisheries. Angling Statistics Trijoulet, Vanessa Holmes, Steven J. Cook, Robin M. Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? |
topic_facet |
Aquaculture. Fisheries. Angling Statistics |
description |
The decrease in groundfish stocks in the North Atlantic since the mid-1900s coupled with increases in grey seal populations is responsible for an enduring controversy between fishers and conservationists regarding the role seals have played in stock declines. We used a Bayesian state-space model to investigate stock trends in the presence of grey seals and associated MSY reference points in the West of Scotland. This study provides new estimates of seal predation mortality on haddock and whiting and updates the estimates for cod, which together form the traditional main components of the mixed demersal fishery in this area. Grey seal predation mortality is greatest on cod resulting in estimates of total natural mortality higher than those used in the current ICES assessments. Seal predation mortality is low for haddock and whiting. Considering seal predation in stock assessments changes the scale of biomass and fishing mortality estimates for the three stocks. The estimates of F0.1 and FMSY are sensitive to seal predation for cod and whiting but not for haddock. In all cases MSY decreases with increased seal predation. |
format |
Article in Journal/Newspaper |
author |
Trijoulet, Vanessa Holmes, Steven J. Cook, Robin M. |
author_facet |
Trijoulet, Vanessa Holmes, Steven J. Cook, Robin M. |
author_sort |
Trijoulet, Vanessa |
title |
Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? |
title_short |
Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? |
title_full |
Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? |
title_fullStr |
Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? |
title_full_unstemmed |
Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? |
title_sort |
grey seal predation mortality on three depleted stocks in the west of scotland : what are the implications for stock assessments? |
publishDate |
2017 |
url |
https://strathprints.strath.ac.uk/62100/ https://strathprints.strath.ac.uk/62100/1/Trijoulet_etal_CJFAS_2017_Grey_seal_predation_mortality_on_three_depleted_stocks_in_the_west_of_Scotland.pdf https://doi.org/10.1139/cjfas-2016-0521 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://strathprints.strath.ac.uk/62100/1/Trijoulet_etal_CJFAS_2017_Grey_seal_predation_mortality_on_three_depleted_stocks_in_the_west_of_Scotland.pdf Trijoulet, Vanessa <https://strathprints.strath.ac.uk/view/author/890031.html> and Holmes, Steven J. and Cook, Robin M. <https://strathprints.strath.ac.uk/view/author/824074.html> (2017 <https://strathprints.strath.ac.uk/view/year/2017.html>) Grey seal predation mortality on three depleted stocks in the West of Scotland : what are the implications for stock assessments? Canadian Journal of Fisheries and Aquatic Sciences <https://strathprints.strath.ac.uk/view/publications/Canadian_Journal_of_Fisheries_and_Aquatic_Sciences.html>. ISSN 1205-7533 |
op_doi |
https://doi.org/10.1139/cjfas-2016-0521 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
75 |
container_issue |
5 |
container_start_page |
723 |
op_container_end_page |
732 |
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1799485067327700992 |