Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities
Atlantic salmon in aquaculture act as reservoir hosts and vectors of parasites like salmon lice and this parasite is shown to harm wild salmonid populations. In this study, n = 29,817 tagged Atlantic salmon were studied in four release trials. Half of the released fish were given prophylactic treatm...
Published in: | Journal of Applied Ecology |
---|---|
Main Authors: | , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2020
|
Subjects: | |
Online Access: | https://hdl.handle.net/11250/2676067 https://doi.org/10.1111/1365-2664.13612 |
id |
ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2676067 |
---|---|
record_format |
openpolar |
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 Bøhn, Thomas Gjelland, Karl Øystein Serra Llinares, Rosa Maria Finstad, Bengt Primicerio, Raul Nilsen, Rune Karlsen, Ørjan Sandvik, Anne Dagrun Skilbrei, Ove Tommy Elvik, Kristine Marit Schrøder Skaala, Øystein Bjørn, Pål Arne Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities |
topic_facet |
VDP::Zoologiske og botaniske fag: 480 VDP::Zoology and botany: 480 |
description |
Atlantic salmon in aquaculture act as reservoir hosts and vectors of parasites like salmon lice and this parasite is shown to harm wild salmonid populations. In this study, n = 29,817 tagged Atlantic salmon were studied in four release trials. Half of the released fish were given prophylactic treatment against lice, the other half represented sham control fish. We used a nested design comparing years with low and high lice density and seasonal dynamics in infestation pressure. The released Atlantic salmon thus experienced highly variable lice infestation pressures, which we linked to survival and growth in returning fish. The fish were released in a protected ‘National Salmon Fjord’ and n = 559 Atlantic salmon were recaptured after spending 1–4 years at sea. In most experimental groups 1%–2.5% of the fish were recaptured at return. However, survival of unprotected fish was extremely low for the trial released at the highest density of lice: only 0.03% of these Atlantic salmon returned to the river, compared to 1.86% in the protected group. 1. Atlantic salmon in aquaculture act as reservoir hosts and vectors of parasites like salmon lice and this parasite is shown to harm wild salmonid populations. 2. In this study, n = 29,817 tagged Atlantic salmon were studied in four release trials. Half of the released fish were given prophylactic treatment against lice, the other half represented sham control fish. We used a nested design comparing years with low and high lice density and seasonal dynamics in infestation pressure. The released Atlantic salmon thus experienced highly variable lice infestation pressures, which we linked to survival and growth in returning fish. The fish were released in a protected ‘National Salmon Fjord’ and n = 559 Atlantic salmon were recaptured after spending 1–4 years at sea. 3. In most experimental groups 1%–2.5% of the fish were recaptured at return. However, survival of unprotected fish was extremely low for the trial released at the highest density of lice: only 0.03% of these Atlantic salmon returned to the river, compared to 1.86% in the protected group. 4. Synthesis and applications. We document that high lice density can cause more than 50 times higher mortality risk in Atlantic salmon on their sea migration, even in a fjord with protected status. Fine‐tuned and hard‐to‐predict year‐to‐year differences in timing, both for the wild smolt migration and the population build‐up of lice released from aquaculture, means life or death to wild salmon. Management actions such as spatial segregation of farmed fish and lice (e.g. closed farm pens), and/or moving farms away from vulnerable habitats for wild salmonids (fjords and coastal areas), may be needed to ensure sustainable coexistence of wild and farmed Atlantic salmon. publishedVersion This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. |
format |
Article in Journal/Newspaper |
author |
Bøhn, Thomas Gjelland, Karl Øystein Serra Llinares, Rosa Maria Finstad, Bengt Primicerio, Raul Nilsen, Rune Karlsen, Ørjan Sandvik, Anne Dagrun Skilbrei, Ove Tommy Elvik, Kristine Marit Schrøder Skaala, Øystein Bjørn, Pål Arne |
author_facet |
Bøhn, Thomas Gjelland, Karl Øystein Serra Llinares, Rosa Maria Finstad, Bengt Primicerio, Raul Nilsen, Rune Karlsen, Ørjan Sandvik, Anne Dagrun Skilbrei, Ove Tommy Elvik, Kristine Marit Schrøder Skaala, Øystein Bjørn, Pål Arne |
author_sort |
Bøhn, Thomas |
title |
Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities |
title_short |
Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities |
title_full |
Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities |
title_fullStr |
Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities |
title_full_unstemmed |
Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities |
title_sort |
timing is everything: survival of atlantic salmon salmo salar postsmolts during events of high salmon lice densities |
publisher |
Wiley |
publishDate |
2020 |
url |
https://hdl.handle.net/11250/2676067 https://doi.org/10.1111/1365-2664.13612 |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
1149-1160 57 Journal of Applied Ecology 6 |
op_relation |
https://hdl.handle.net/11250/2651128 Havforskningsinstituttet: 14650 Norges forskningsråd: 221404 Norsk institutt for naturforskning: 160022/F40 Journal of Applied Ecology. 2020, 57 (6), 1149-1160. urn:issn:0021-8901 https://hdl.handle.net/11250/2676067 https://doi.org/10.1111/1365-2664.13612 cristin:1806324 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1111/1365-2664.13612 |
container_title |
Journal of Applied Ecology |
container_volume |
57 |
container_issue |
6 |
container_start_page |
1149 |
op_container_end_page |
1160 |
_version_ |
1766358588297576448 |
spelling |
ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2676067 2023-05-15T15:28:13+02:00 Timing is everything: Survival of Atlantic salmon Salmo salar postsmolts during events of high salmon lice densities Bøhn, Thomas Gjelland, Karl Øystein Serra Llinares, Rosa Maria Finstad, Bengt Primicerio, Raul Nilsen, Rune Karlsen, Ørjan Sandvik, Anne Dagrun Skilbrei, Ove Tommy Elvik, Kristine Marit Schrøder Skaala, Øystein Bjørn, Pål Arne 2020 application/pdf https://hdl.handle.net/11250/2676067 https://doi.org/10.1111/1365-2664.13612 eng eng Wiley https://hdl.handle.net/11250/2651128 Havforskningsinstituttet: 14650 Norges forskningsråd: 221404 Norsk institutt for naturforskning: 160022/F40 Journal of Applied Ecology. 2020, 57 (6), 1149-1160. urn:issn:0021-8901 https://hdl.handle.net/11250/2676067 https://doi.org/10.1111/1365-2664.13612 cristin:1806324 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no CC-BY 1149-1160 57 Journal of Applied Ecology 6 VDP::Zoologiske og botaniske fag: 480 VDP::Zoology and botany: 480 Peer reviewed Journal article 2020 ftntnutrondheimi https://doi.org/10.1111/1365-2664.13612 2020-09-09T22:33:33Z Atlantic salmon in aquaculture act as reservoir hosts and vectors of parasites like salmon lice and this parasite is shown to harm wild salmonid populations. In this study, n = 29,817 tagged Atlantic salmon were studied in four release trials. Half of the released fish were given prophylactic treatment against lice, the other half represented sham control fish. We used a nested design comparing years with low and high lice density and seasonal dynamics in infestation pressure. The released Atlantic salmon thus experienced highly variable lice infestation pressures, which we linked to survival and growth in returning fish. The fish were released in a protected ‘National Salmon Fjord’ and n = 559 Atlantic salmon were recaptured after spending 1–4 years at sea. In most experimental groups 1%–2.5% of the fish were recaptured at return. However, survival of unprotected fish was extremely low for the trial released at the highest density of lice: only 0.03% of these Atlantic salmon returned to the river, compared to 1.86% in the protected group. 1. Atlantic salmon in aquaculture act as reservoir hosts and vectors of parasites like salmon lice and this parasite is shown to harm wild salmonid populations. 2. In this study, n = 29,817 tagged Atlantic salmon were studied in four release trials. Half of the released fish were given prophylactic treatment against lice, the other half represented sham control fish. We used a nested design comparing years with low and high lice density and seasonal dynamics in infestation pressure. The released Atlantic salmon thus experienced highly variable lice infestation pressures, which we linked to survival and growth in returning fish. The fish were released in a protected ‘National Salmon Fjord’ and n = 559 Atlantic salmon were recaptured after spending 1–4 years at sea. 3. In most experimental groups 1%–2.5% of the fish were recaptured at return. However, survival of unprotected fish was extremely low for the trial released at the highest density of lice: only 0.03% of these Atlantic salmon returned to the river, compared to 1.86% in the protected group. 4. Synthesis and applications. We document that high lice density can cause more than 50 times higher mortality risk in Atlantic salmon on their sea migration, even in a fjord with protected status. Fine‐tuned and hard‐to‐predict year‐to‐year differences in timing, both for the wild smolt migration and the population build‐up of lice released from aquaculture, means life or death to wild salmon. Management actions such as spatial segregation of farmed fish and lice (e.g. closed farm pens), and/or moving farms away from vulnerable habitats for wild salmonids (fjords and coastal areas), may be needed to ensure sustainable coexistence of wild and farmed Atlantic salmon. publishedVersion This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. Article in Journal/Newspaper Atlantic salmon Salmo salar NTNU Open Archive (Norwegian University of Science and Technology) Journal of Applied Ecology 57 6 1149 1160 |