Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment

In fisheries management, assessing year-class strength and recruitment to commercial stocks is essential, but can be difficult to do for fish species where the young stages are inaccessible to ship-based surveys. This is true for the northeast Arctic saithe Pollachius virens, where the juveniles spe...

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Published in:Marine Ecology Progress Series
Main Authors: Lorentsen, Svein Håkon, Anker-Nilssen, Tycho, Erikstad, Kjell E
Format: Article in Journal/Newspaper
Language:English
Published: Inter-Research 2018
Subjects:
Online Access:http://hdl.handle.net/11250/2483030
https://doi.org/10.3354/meps12440
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spelling ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2483030 2023-05-15T15:16:17+02:00 Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment Lorentsen, Svein Håkon Anker-Nilssen, Tycho Erikstad, Kjell E 2018 http://hdl.handle.net/11250/2483030 https://doi.org/10.3354/meps12440 eng eng Inter-Research Andre: Norwegian Ministry of Climate and Environment Andre: Norwegian Environment Agency Andre: Norwegian Ministry of Petroleum and Energy Marine Ecology Progress Series. 2018, 586, 193-201. urn:issn:0171-8630 http://hdl.handle.net/11250/2483030 https://doi.org/10.3354/meps12440 cristin:1543091 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no CC-BY 193-201 586 Marine Ecology Progress Series VDP::Zoologiske og botaniske fag: 480 VDP::Zoology and botany: 480 Journal article Peer reviewed 2018 ftntnutrondheimi https://doi.org/10.3354/meps12440 2019-09-17T06:53:33Z In fisheries management, assessing year-class strength and recruitment to commercial stocks is essential, but can be difficult to do for fish species where the young stages are inaccessible to ship-based surveys. This is true for the northeast Arctic saithe Pollachius virens, where the juveniles spend their first years in coastal kelp forests and therefore cannot be assessed before they enter the pelagic stock at 3 yr of age. However, as top predators in marine ecosystems, coastal seabirds might prey on the same cohort 2−3 yr earlier. Long-term studies of European shag Phalacrocorax aristotelis at a colony in central Norway have revealed strong links between the birds’ breeding performance and the availability of 0 and 1 yr old saithe in their diet. Following this, we wanted to explore if shag diet can be used as an early indicator of saithe recruitment by comparing it with abundance indices obtained by fisheries research. Our results indicate that the occurrence of 0 yr old saithe in the shag diet is a poor predictor of saithe recruitment 3 yr later. However, both the pre- and post-hatch biomass and the number and frequency of occurrence of 1 yr old saithe show a strong positive relationship with indices obtained from scientific surveys 2 yr later, indicating that shag diet can be used as an early and reasonably reliable predictor of saithe recruitment. We suggest implementing the occurrence of 1 yr old saithe in the shag diet as a supplementary tool for an adaptive management of the fisheries on young saithe. Phalacrocorax aristotelis · Central Norway · Diet · Fish stock recruitment indicator · Pollachius virens publishedVersion © The authors 2018. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited. Article in Journal/Newspaper Arctic NTNU Open Archive (Norwegian University of Science and Technology) Arctic Norway Marine Ecology Progress Series 586 193 201
institution Open Polar
collection NTNU Open Archive (Norwegian University of Science and Technology)
op_collection_id ftntnutrondheimi
language English
topic VDP::Zoologiske og botaniske fag: 480
VDP::Zoology and botany: 480
spellingShingle VDP::Zoologiske og botaniske fag: 480
VDP::Zoology and botany: 480
Lorentsen, Svein Håkon
Anker-Nilssen, Tycho
Erikstad, Kjell E
Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment
topic_facet VDP::Zoologiske og botaniske fag: 480
VDP::Zoology and botany: 480
description In fisheries management, assessing year-class strength and recruitment to commercial stocks is essential, but can be difficult to do for fish species where the young stages are inaccessible to ship-based surveys. This is true for the northeast Arctic saithe Pollachius virens, where the juveniles spend their first years in coastal kelp forests and therefore cannot be assessed before they enter the pelagic stock at 3 yr of age. However, as top predators in marine ecosystems, coastal seabirds might prey on the same cohort 2−3 yr earlier. Long-term studies of European shag Phalacrocorax aristotelis at a colony in central Norway have revealed strong links between the birds’ breeding performance and the availability of 0 and 1 yr old saithe in their diet. Following this, we wanted to explore if shag diet can be used as an early indicator of saithe recruitment by comparing it with abundance indices obtained by fisheries research. Our results indicate that the occurrence of 0 yr old saithe in the shag diet is a poor predictor of saithe recruitment 3 yr later. However, both the pre- and post-hatch biomass and the number and frequency of occurrence of 1 yr old saithe show a strong positive relationship with indices obtained from scientific surveys 2 yr later, indicating that shag diet can be used as an early and reasonably reliable predictor of saithe recruitment. We suggest implementing the occurrence of 1 yr old saithe in the shag diet as a supplementary tool for an adaptive management of the fisheries on young saithe. Phalacrocorax aristotelis · Central Norway · Diet · Fish stock recruitment indicator · Pollachius virens publishedVersion © The authors 2018. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited.
format Article in Journal/Newspaper
author Lorentsen, Svein Håkon
Anker-Nilssen, Tycho
Erikstad, Kjell E
author_facet Lorentsen, Svein Håkon
Anker-Nilssen, Tycho
Erikstad, Kjell E
author_sort Lorentsen, Svein Håkon
title Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment
title_short Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment
title_full Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment
title_fullStr Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment
title_full_unstemmed Seabirds as guides for fisheries management: European shag Phalacrocorax aristotelis diet as indicator of saithe Pollachius virens recruitment
title_sort seabirds as guides for fisheries management: european shag phalacrocorax aristotelis diet as indicator of saithe pollachius virens recruitment
publisher Inter-Research
publishDate 2018
url http://hdl.handle.net/11250/2483030
https://doi.org/10.3354/meps12440
geographic Arctic
Norway
geographic_facet Arctic
Norway
genre Arctic
genre_facet Arctic
op_source 193-201
586
Marine Ecology Progress Series
op_relation Andre: Norwegian Ministry of Climate and Environment
Andre: Norwegian Environment Agency
Andre: Norwegian Ministry of Petroleum and Energy
Marine Ecology Progress Series. 2018, 586, 193-201.
urn:issn:0171-8630
http://hdl.handle.net/11250/2483030
https://doi.org/10.3354/meps12440
cristin:1543091
op_rights Navngivelse 4.0 Internasjonal
http://creativecommons.org/licenses/by/4.0/deed.no
op_rightsnorm CC-BY
op_doi https://doi.org/10.3354/meps12440
container_title Marine Ecology Progress Series
container_volume 586
container_start_page 193
op_container_end_page 201
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