Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids
Abstract Piscivorous wildlife is often perceived as competitors by humans. Great cormorants of the continental subspecies (Phalacrocorax carbo sinensis) in the Baltic and North Sea increase, while local cod (Gadus morhua) stocks decline. In contrast, numbers of the Atlantic subspecies (Phalacrocorax...
Published in: | ICES Journal of Marine Science |
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Language: | English |
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Oxford University Press (OUP)
2021
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Online Access: | http://dx.doi.org/10.1093/icesjms/fsab004 http://academic.oup.com/icesjms/article-pdf/78/3/1074/39399805/fsab004.pdf |
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croxfordunivpr:10.1093/icesjms/fsab004 2024-09-15T18:07:19+00:00 Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho Camphuysen, Kees Norwegian Ministry of Climate and Environment via the Norwegian Environment Agency Norwegian Ministry of Petroleum and Energy via the Norwegian Research Council Norwegian Oil and Gas Association 2021 http://dx.doi.org/10.1093/icesjms/fsab004 http://academic.oup.com/icesjms/article-pdf/78/3/1074/39399805/fsab004.pdf en eng Oxford University Press (OUP) https://creativecommons.org/licenses/by/4.0/ ICES Journal of Marine Science volume 78, issue 3, page 1074-1089 ISSN 1054-3139 1095-9289 journal-article 2021 croxfordunivpr https://doi.org/10.1093/icesjms/fsab004 2024-07-15T04:22:45Z Abstract Piscivorous wildlife is often perceived as competitors by humans. Great cormorants of the continental subspecies (Phalacrocorax carbo sinensis) in the Baltic and North Sea increase, while local cod (Gadus morhua) stocks decline. In contrast, numbers of the Atlantic subspecies (Phalacrocorax carbo carbo), breeding along the Norwegian and Barents Seas, have been relatively stable. We investigated the diet of both great cormorant subspecies in breeding colonies along the Norwegian Coast from Lofoten to the Skagerrak and estimated the biomass of fish consumed annually by great cormorants in Norwegian waters. The birds’ consumption was compared with estimated fish stock sizes and fishery catches. Cod and saithe (Pollachius virens) dominated the diet in the Norwegian Sea and wrasses in the North Sea and Skagerrak. Estimated total fish consumption of cod and saithe by great cormorants was <1.7% of estimated fish stocks and <9% of that of human catches and therefore considered minor. Cormorant consumption of wrasses amounted to 110% of human catches. The practice of using wrasses as cleaner fish in the salmon farming industry leads to a conflict with cormorants, and we urge for a better understanding and management of wrasse populations, taking ecosystem functioning and natural predation into account. Article in Journal/Newspaper Gadus morhua Lofoten Norwegian Sea Oxford University Press ICES Journal of Marine Science |
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Oxford University Press |
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English |
description |
Abstract Piscivorous wildlife is often perceived as competitors by humans. Great cormorants of the continental subspecies (Phalacrocorax carbo sinensis) in the Baltic and North Sea increase, while local cod (Gadus morhua) stocks decline. In contrast, numbers of the Atlantic subspecies (Phalacrocorax carbo carbo), breeding along the Norwegian and Barents Seas, have been relatively stable. We investigated the diet of both great cormorant subspecies in breeding colonies along the Norwegian Coast from Lofoten to the Skagerrak and estimated the biomass of fish consumed annually by great cormorants in Norwegian waters. The birds’ consumption was compared with estimated fish stock sizes and fishery catches. Cod and saithe (Pollachius virens) dominated the diet in the Norwegian Sea and wrasses in the North Sea and Skagerrak. Estimated total fish consumption of cod and saithe by great cormorants was <1.7% of estimated fish stocks and <9% of that of human catches and therefore considered minor. Cormorant consumption of wrasses amounted to 110% of human catches. The practice of using wrasses as cleaner fish in the salmon farming industry leads to a conflict with cormorants, and we urge for a better understanding and management of wrasse populations, taking ecosystem functioning and natural predation into account. |
author2 |
Camphuysen, Kees Norwegian Ministry of Climate and Environment via the Norwegian Environment Agency Norwegian Ministry of Petroleum and Energy via the Norwegian Research Council Norwegian Oil and Gas Association |
format |
Article in Journal/Newspaper |
author |
Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho |
spellingShingle |
Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
author_facet |
Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho |
author_sort |
Dehnhard, Nina |
title |
Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
title_short |
Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
title_full |
Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
title_fullStr |
Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
title_full_unstemmed |
Fish consumption by great cormorants in Norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
title_sort |
fish consumption by great cormorants in norwegian coastal waters—a human-wildlife conflict for wrasses, but not gadids |
publisher |
Oxford University Press (OUP) |
publishDate |
2021 |
url |
http://dx.doi.org/10.1093/icesjms/fsab004 http://academic.oup.com/icesjms/article-pdf/78/3/1074/39399805/fsab004.pdf |
genre |
Gadus morhua Lofoten Norwegian Sea |
genre_facet |
Gadus morhua Lofoten Norwegian Sea |
op_source |
ICES Journal of Marine Science volume 78, issue 3, page 1074-1089 ISSN 1054-3139 1095-9289 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1093/icesjms/fsab004 |
container_title |
ICES Journal of Marine Science |
_version_ |
1810444704527941632 |