Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort
Abstract In the Norwegian Sea, assessment of diet composition relies on annual cruise activity combined with visual identification and weight determination of prey from fish stomachs. This weight-based method is labour intensive, and suggestions to reduce cost include moving from the weight-based to...
Published in: | ICES Journal of Marine Science |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Oxford University Press (OUP)
2023
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Online Access: | http://dx.doi.org/10.1093/icesjms/fsac240 https://academic.oup.com/icesjms/advance-article-pdf/doi/10.1093/icesjms/fsac240/48755073/fsac240.pdf |
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croxfordunivpr:10.1093/icesjms/fsac240 2023-05-15T17:47:06+02:00 Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort Mousing, Erik Askov Planque, Benjamin Arneberg, Per Bjørdal, Vilde Regine Keulder-Stenevik, Felicia Liebig, Penny Lee Mørk, Herdis Langøy Skern-Mauritzen, Mette Hunsicker, Mary Ministry of Trade, Industry and Fisheries Norwegian Research Council 2023 http://dx.doi.org/10.1093/icesjms/fsac240 https://academic.oup.com/icesjms/advance-article-pdf/doi/10.1093/icesjms/fsac240/48755073/fsac240.pdf en eng Oxford University Press (OUP) https://creativecommons.org/licenses/by/4.0/ CC-BY ICES Journal of Marine Science ISSN 1054-3139 1095-9289 Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2023 croxfordunivpr https://doi.org/10.1093/icesjms/fsac240 2023-01-20T11:05:20Z Abstract In the Norwegian Sea, assessment of diet composition relies on annual cruise activity combined with visual identification and weight determination of prey from fish stomachs. This weight-based method is labour intensive, and suggestions to reduce cost include moving from the weight-based to the occurrence-based method and/or reducing sampling effort. Studies have suggested that the occurrence-based method may be more robust while providing similar results as the weight-based method. Here we re-analyse data from >14.000 stomachs for herring, mackerel, and blue whiting. We compare diet composition estimates and quantify the uncertainty using both methods. We also quantify the impact of reducing sampling effort (number of trawl stations and fish per station) on the diet uncertainties. Our results confirm that occurrence-based estimates are more precise than those based on weight. In addition, they are better at capturing year-to-year fluctuations. The occurrence-based method provides similar results to the weight-based method. Differences between methods arise primarily from disparities in the mean weight of prey in stomachs. Decreasing the number of stations sampled leads to increased uncertainty, while reducing the sampling effort from 10 to 5 fish per station has little impact on uncertainty estimates. These results provide quantified insights to guide future diet monitoring programmes. Article in Journal/Newspaper Norwegian Sea Oxford University Press (via Crossref) Norwegian Sea ICES Journal of Marine Science |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
spellingShingle |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography Mousing, Erik Askov Planque, Benjamin Arneberg, Per Bjørdal, Vilde Regine Keulder-Stenevik, Felicia Liebig, Penny Lee Mørk, Herdis Langøy Skern-Mauritzen, Mette Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
topic_facet |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract In the Norwegian Sea, assessment of diet composition relies on annual cruise activity combined with visual identification and weight determination of prey from fish stomachs. This weight-based method is labour intensive, and suggestions to reduce cost include moving from the weight-based to the occurrence-based method and/or reducing sampling effort. Studies have suggested that the occurrence-based method may be more robust while providing similar results as the weight-based method. Here we re-analyse data from >14.000 stomachs for herring, mackerel, and blue whiting. We compare diet composition estimates and quantify the uncertainty using both methods. We also quantify the impact of reducing sampling effort (number of trawl stations and fish per station) on the diet uncertainties. Our results confirm that occurrence-based estimates are more precise than those based on weight. In addition, they are better at capturing year-to-year fluctuations. The occurrence-based method provides similar results to the weight-based method. Differences between methods arise primarily from disparities in the mean weight of prey in stomachs. Decreasing the number of stations sampled leads to increased uncertainty, while reducing the sampling effort from 10 to 5 fish per station has little impact on uncertainty estimates. These results provide quantified insights to guide future diet monitoring programmes. |
author2 |
Hunsicker, Mary Ministry of Trade, Industry and Fisheries Norwegian Research Council |
format |
Article in Journal/Newspaper |
author |
Mousing, Erik Askov Planque, Benjamin Arneberg, Per Bjørdal, Vilde Regine Keulder-Stenevik, Felicia Liebig, Penny Lee Mørk, Herdis Langøy Skern-Mauritzen, Mette |
author_facet |
Mousing, Erik Askov Planque, Benjamin Arneberg, Per Bjørdal, Vilde Regine Keulder-Stenevik, Felicia Liebig, Penny Lee Mørk, Herdis Langøy Skern-Mauritzen, Mette |
author_sort |
Mousing, Erik Askov |
title |
Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
title_short |
Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
title_full |
Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
title_fullStr |
Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
title_full_unstemmed |
Quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
title_sort |
quantifying diets for small pelagic fish: effects of weight versus occurrence methods and sampling effort |
publisher |
Oxford University Press (OUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1093/icesjms/fsac240 https://academic.oup.com/icesjms/advance-article-pdf/doi/10.1093/icesjms/fsac240/48755073/fsac240.pdf |
geographic |
Norwegian Sea |
geographic_facet |
Norwegian Sea |
genre |
Norwegian Sea |
genre_facet |
Norwegian Sea |
op_source |
ICES Journal of Marine Science ISSN 1054-3139 1095-9289 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1093/icesjms/fsac240 |
container_title |
ICES Journal of Marine Science |
_version_ |
1766151418513719296 |