Great cormorant diet data from the Norwegian coast ...
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 (P. c. carbo), breeding...
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Online Access: | https://dx.doi.org/10.5061/dryad.b5mkkwhcd https://datadryad.org/stash/dataset/doi:10.5061/dryad.b5mkkwhcd |
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ftdatacite:10.5061/dryad.b5mkkwhcd 2024-02-04T10:00:31+01:00 Great cormorant diet data from the Norwegian coast ... Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho 2021 https://dx.doi.org/10.5061/dryad.b5mkkwhcd https://datadryad.org/stash/dataset/doi:10.5061/dryad.b5mkkwhcd en eng Dryad https://dx.doi.org/10.1093/icesjms/fsab004 Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode cc0-1.0 FOS Biological sciences Dataset dataset 2021 ftdatacite https://doi.org/10.5061/dryad.b5mkkwhcd10.1093/icesjms/fsab004 2024-01-05T04:39:59Z 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 (P. c. 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 ... : Data collection Diet samples were collected between 2001 and 2016 from breeding colonies at five different sites spread along the Norwegian coastline (Table 1, Fig. 1): Røst (67.5° N, 12.0° E), Sklinna (65.2°N, 10.9° E), Frøya (63.8° N, 8.5°E), Rauna (58.1° N, 6.7° E) and Øra (59.2° N, 11.0° E). Røst, Sklinna and Frøya are breeding sites of the Atlantic subspecies, whereas Rauna and Øra hold the continental subspecies. Diet samples consisted of pellets, i.e. indigestible material that is regurgitated daily as a natural part of the digestive process. All samples were collected from the vicinity of nests, thus presumed to originate from breeding adults either directly or via their chicks. After collection, they were stored frozen until being analysed. Analyses of diet samples The treatment of the pellets followed previous work by Hillersøy and Lorentsen (2012). Soft parts were digested in a saturated solution of biological washing powder (Bio-tex®) kept at 50°C in an oven for 1−2 days. Fish otoliths were ... Dataset Gadus morhua Lofoten Norwegian Sea Røst DataCite Metadata Store (German National Library of Science and Technology) Frøya ENVELOPE(8.334,8.334,63.672,63.672) Lofoten Norwegian Sea Røst ENVELOPE(11.983,11.983,67.467,67.467) Sklinna ENVELOPE(11.000,11.000,65.200,65.200) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
FOS Biological sciences |
spellingShingle |
FOS Biological sciences Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho Great cormorant diet data from the Norwegian coast ... |
topic_facet |
FOS Biological sciences |
description |
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 (P. c. 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 ... : Data collection Diet samples were collected between 2001 and 2016 from breeding colonies at five different sites spread along the Norwegian coastline (Table 1, Fig. 1): Røst (67.5° N, 12.0° E), Sklinna (65.2°N, 10.9° E), Frøya (63.8° N, 8.5°E), Rauna (58.1° N, 6.7° E) and Øra (59.2° N, 11.0° E). Røst, Sklinna and Frøya are breeding sites of the Atlantic subspecies, whereas Rauna and Øra hold the continental subspecies. Diet samples consisted of pellets, i.e. indigestible material that is regurgitated daily as a natural part of the digestive process. All samples were collected from the vicinity of nests, thus presumed to originate from breeding adults either directly or via their chicks. After collection, they were stored frozen until being analysed. Analyses of diet samples The treatment of the pellets followed previous work by Hillersøy and Lorentsen (2012). Soft parts were digested in a saturated solution of biological washing powder (Bio-tex®) kept at 50°C in an oven for 1−2 days. Fish otoliths were ... |
format |
Dataset |
author |
Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho |
author_facet |
Dehnhard, Nina Langset, Magdalene Aglen, Asgeir Lorentsen, Svein-Håkon Anker-Nilssen, Tycho |
author_sort |
Dehnhard, Nina |
title |
Great cormorant diet data from the Norwegian coast ... |
title_short |
Great cormorant diet data from the Norwegian coast ... |
title_full |
Great cormorant diet data from the Norwegian coast ... |
title_fullStr |
Great cormorant diet data from the Norwegian coast ... |
title_full_unstemmed |
Great cormorant diet data from the Norwegian coast ... |
title_sort |
great cormorant diet data from the norwegian coast ... |
publisher |
Dryad |
publishDate |
2021 |
url |
https://dx.doi.org/10.5061/dryad.b5mkkwhcd https://datadryad.org/stash/dataset/doi:10.5061/dryad.b5mkkwhcd |
long_lat |
ENVELOPE(8.334,8.334,63.672,63.672) ENVELOPE(11.983,11.983,67.467,67.467) ENVELOPE(11.000,11.000,65.200,65.200) |
geographic |
Frøya Lofoten Norwegian Sea Røst Sklinna |
geographic_facet |
Frøya Lofoten Norwegian Sea Røst Sklinna |
genre |
Gadus morhua Lofoten Norwegian Sea Røst |
genre_facet |
Gadus morhua Lofoten Norwegian Sea Røst |
op_relation |
https://dx.doi.org/10.1093/icesjms/fsab004 |
op_rights |
Creative Commons Zero v1.0 Universal https://creativecommons.org/publicdomain/zero/1.0/legalcode cc0-1.0 |
op_doi |
https://doi.org/10.5061/dryad.b5mkkwhcd10.1093/icesjms/fsab004 |
_version_ |
1789965857018871808 |