Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021)
Abstract Johnsen et al. (2021) present a model that predicts lice-induced mortality of virtual post-smolt (VPS) Atlantic salmon migrating from 401 Norwegian salmon rivers. An important feature of this model is that the source of lice is farmed salmon. The model predicts lice-induced mortalities exce...
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Online Access: | http://dx.doi.org/10.1093/icesjms/fsab206 https://academic.oup.com/icesjms/article-pdf/78/10/3847/41772698/fsab206.pdf |
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croxfordunivpr:10.1093/icesjms/fsab206 2023-12-31T10:04:44+01:00 Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) Jansen, Peder A Gjerde, Bjarne Byron, Carrie 2021 http://dx.doi.org/10.1093/icesjms/fsab206 https://academic.oup.com/icesjms/article-pdf/78/10/3847/41772698/fsab206.pdf en eng Oxford University Press (OUP) https://creativecommons.org/licenses/by/4.0/ ICES Journal of Marine Science volume 78, issue 10, page 3847-3851 ISSN 1054-3139 1095-9289 Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2021 croxfordunivpr https://doi.org/10.1093/icesjms/fsab206 2023-12-06T09:03:50Z Abstract Johnsen et al. (2021) present a model that predicts lice-induced mortality of virtual post-smolt (VPS) Atlantic salmon migrating from 401 Norwegian salmon rivers. An important feature of this model is that the source of lice is farmed salmon. The model predicts lice-induced mortalities exceeding 30% for VPS from 82 rivers, 10–30% for 140 rivers, and less than 10% for 179 rivers. These are high numbers and have contributed to mandatory reductions in the production of farmed salmon in two of the 13 management areas in Norway. In this comment, the model used by Johnsen et al. (2021) is evaluated. Mortality estimates from observed lice numbers on post-smolts caught by trawling in outer fjord areas are compared with the model predicted mortalities for VPS migrating from rivers draining into the corresponding fjords. It is found that Johnsen et al. (2021) systematically overestimates lice-induced mortality for VPS compared to estimates from trawled smolt from corresponding fjords. The present analysis thus contradicts the concluding remark in Johnsen et al. (2021), that: “The estimated lice level on modelled post-smolts is shown to coincide with the level observed on captured wild post-smolt”. Article in Journal/Newspaper Atlantic salmon Oxford University Press (via Crossref) ICES Journal of Marine Science 78 10 3847 3851 |
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Open Polar |
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Oxford University Press (via Crossref) |
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croxfordunivpr |
language |
English |
topic |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
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Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography Jansen, Peder A Gjerde, Bjarne Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) |
topic_facet |
Ecology Aquatic Science Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract Johnsen et al. (2021) present a model that predicts lice-induced mortality of virtual post-smolt (VPS) Atlantic salmon migrating from 401 Norwegian salmon rivers. An important feature of this model is that the source of lice is farmed salmon. The model predicts lice-induced mortalities exceeding 30% for VPS from 82 rivers, 10–30% for 140 rivers, and less than 10% for 179 rivers. These are high numbers and have contributed to mandatory reductions in the production of farmed salmon in two of the 13 management areas in Norway. In this comment, the model used by Johnsen et al. (2021) is evaluated. Mortality estimates from observed lice numbers on post-smolts caught by trawling in outer fjord areas are compared with the model predicted mortalities for VPS migrating from rivers draining into the corresponding fjords. It is found that Johnsen et al. (2021) systematically overestimates lice-induced mortality for VPS compared to estimates from trawled smolt from corresponding fjords. The present analysis thus contradicts the concluding remark in Johnsen et al. (2021), that: “The estimated lice level on modelled post-smolts is shown to coincide with the level observed on captured wild post-smolt”. |
author2 |
Byron, Carrie |
format |
Article in Journal/Newspaper |
author |
Jansen, Peder A Gjerde, Bjarne |
author_facet |
Jansen, Peder A Gjerde, Bjarne |
author_sort |
Jansen, Peder A |
title |
Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) |
title_short |
Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) |
title_full |
Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) |
title_fullStr |
Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) |
title_full_unstemmed |
Comment on “Salmon lice-induced mortality of Atlantic salmon post-smolt during migration in Norway” by Johnsen et al . (2021) |
title_sort |
comment on “salmon lice-induced mortality of atlantic salmon post-smolt during migration in norway” by johnsen et al . (2021) |
publisher |
Oxford University Press (OUP) |
publishDate |
2021 |
url |
http://dx.doi.org/10.1093/icesjms/fsab206 https://academic.oup.com/icesjms/article-pdf/78/10/3847/41772698/fsab206.pdf |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_source |
ICES Journal of Marine Science volume 78, issue 10, page 3847-3851 ISSN 1054-3139 1095-9289 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1093/icesjms/fsab206 |
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ICES Journal of Marine Science |
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78 |
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10 |
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3847 |
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3851 |
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1786836145178411008 |