Recapture of cultured salmon following a large-scale escape experiment
A large-scale escape experiment using 1031 adult Atlantic salmon Salmo salar L. was performed in the Hardangerfjord in western Norway to study the dispersal of escaped salmon, evaluate the effect of a gill-net fishery targeting escaped salmonids and test whether surface trawling is an effective way...
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Language: | English |
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Inter Research
2010
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Online Access: | http://hdl.handle.net/11250/117032 https://doi.org/10.3354/aei00011 |
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ftimr:oai:imr.brage.unit.no:11250/117032 2023-05-15T15:31:50+02:00 Recapture of cultured salmon following a large-scale escape experiment Skilbrei, Ove Jørgensen, Terje 2010-10-19 application/pdf http://hdl.handle.net/11250/117032 https://doi.org/10.3354/aei00011 eng eng Inter Research urn:issn:1869-7534 urn:issn:1869-215X http://hdl.handle.net/11250/117032 http://dx.doi.org/10.3354/aei00011 107-115 1 Aquaculture Environment Interactions 2 farmed fish escape fiskerømning atlantic salmon atlantisk laks fish farming fiskeoppdrett gill net garn trawling tråling recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Aquaculture: 922 Journal article Peer reviewed 2010 ftimr https://doi.org/10.3354/aei00011 2021-09-23T20:15:31Z A large-scale escape experiment using 1031 adult Atlantic salmon Salmo salar L. was performed in the Hardangerfjord in western Norway to study the dispersal of escaped salmon, evaluate the effect of a gill-net fishery targeting escaped salmonids and test whether surface trawling is an effective way of recapturing escaped salmon in a large fjord system. The salmon of mean weights 1.56 and 5.5 kg were released from 2 commercial fish farms in late September 2006. All fish were tagged with external tags, and 48 were also equipped with acoustic transmitters. A surface pair-trawl (50 m wide and 8 m deep) was constructed to optimize catchability and maneuverability in the fjord environment. Trawling was unsuccessful, and caught only 6 simulated escapees. Telemetry data confirmed that the fish were available along the towing tracks, and we assume that towing speed and/or trawl size may have been suboptimal with regard to avoidance by fish in the fjord environment. Gillnetting proved to be an efficient method of recapture. The total reported recapture rate (of 114 fishers) was 40%, but a significantly higher recapture rate (67%) of the more highly rewarded acoustic transmitters, and the distribution of the fish in time and space, suggest that the actual catch may have been substantially higher. Approximately 90% of the catches were taken within 40 km of the release sites over the course of 4 wk. We conclude that a significant proportion of escaped adult salmon can be recaptured if the catch effort within the fjord basin is widespread and lasts for at least 4 wk. Article in Journal/Newspaper Atlantic salmon Salmo salar Institute for Marine Research: Brage IMR Garn ENVELOPE(160.425,160.425,66.302,66.302) Norway Aquaculture Environment Interactions 1 2 107 115 |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
topic |
farmed fish escape fiskerømning atlantic salmon atlantisk laks fish farming fiskeoppdrett gill net garn trawling tråling recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Aquaculture: 922 |
spellingShingle |
farmed fish escape fiskerømning atlantic salmon atlantisk laks fish farming fiskeoppdrett gill net garn trawling tråling recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Aquaculture: 922 Skilbrei, Ove Jørgensen, Terje Recapture of cultured salmon following a large-scale escape experiment |
topic_facet |
farmed fish escape fiskerømning atlantic salmon atlantisk laks fish farming fiskeoppdrett gill net garn trawling tråling recapture gjenfangst VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Aquaculture: 922 |
description |
A large-scale escape experiment using 1031 adult Atlantic salmon Salmo salar L. was performed in the Hardangerfjord in western Norway to study the dispersal of escaped salmon, evaluate the effect of a gill-net fishery targeting escaped salmonids and test whether surface trawling is an effective way of recapturing escaped salmon in a large fjord system. The salmon of mean weights 1.56 and 5.5 kg were released from 2 commercial fish farms in late September 2006. All fish were tagged with external tags, and 48 were also equipped with acoustic transmitters. A surface pair-trawl (50 m wide and 8 m deep) was constructed to optimize catchability and maneuverability in the fjord environment. Trawling was unsuccessful, and caught only 6 simulated escapees. Telemetry data confirmed that the fish were available along the towing tracks, and we assume that towing speed and/or trawl size may have been suboptimal with regard to avoidance by fish in the fjord environment. Gillnetting proved to be an efficient method of recapture. The total reported recapture rate (of 114 fishers) was 40%, but a significantly higher recapture rate (67%) of the more highly rewarded acoustic transmitters, and the distribution of the fish in time and space, suggest that the actual catch may have been substantially higher. Approximately 90% of the catches were taken within 40 km of the release sites over the course of 4 wk. We conclude that a significant proportion of escaped adult salmon can be recaptured if the catch effort within the fjord basin is widespread and lasts for at least 4 wk. |
format |
Article in Journal/Newspaper |
author |
Skilbrei, Ove Jørgensen, Terje |
author_facet |
Skilbrei, Ove Jørgensen, Terje |
author_sort |
Skilbrei, Ove |
title |
Recapture of cultured salmon following a large-scale escape experiment |
title_short |
Recapture of cultured salmon following a large-scale escape experiment |
title_full |
Recapture of cultured salmon following a large-scale escape experiment |
title_fullStr |
Recapture of cultured salmon following a large-scale escape experiment |
title_full_unstemmed |
Recapture of cultured salmon following a large-scale escape experiment |
title_sort |
recapture of cultured salmon following a large-scale escape experiment |
publisher |
Inter Research |
publishDate |
2010 |
url |
http://hdl.handle.net/11250/117032 https://doi.org/10.3354/aei00011 |
long_lat |
ENVELOPE(160.425,160.425,66.302,66.302) |
geographic |
Garn Norway |
geographic_facet |
Garn Norway |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
107-115 1 Aquaculture Environment Interactions 2 |
op_relation |
urn:issn:1869-7534 urn:issn:1869-215X http://hdl.handle.net/11250/117032 http://dx.doi.org/10.3354/aei00011 |
op_doi |
https://doi.org/10.3354/aei00011 |
container_title |
Aquaculture Environment Interactions |
container_volume |
1 |
container_issue |
2 |
container_start_page |
107 |
op_container_end_page |
115 |
_version_ |
1766362351132475392 |