Movements and dispersal of farmed Atlantic salmon following a simulated-escape event

• Published in: Environmental biology of fishes Vol. 96; no. 8; pp. 927 - 939
• Main Authors: Solem, Øyvind, Hedger, Richard D., Urke, Henning A., Kristensen, Torstein, Økland, Finn, Ulvan, Eva M., Uglem, Ingebrigt
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-08-2013; Springer Nature B.V
• Subjects: Animal Systematics/Taxonomy/Biogeography; Aquaculture; Biogeography; Biomedical and Life Sciences; Biotelemetry; Environment; Fish farms; Fjords; Freshwater & Marine Ecology; Life Sciences; Marine; Nature Conservation; Rivers; Salmo salar; Salmon; Simulation; Spatial distribution; Zoology; ANE, Norway; Escape patterns; Atlantic salmon; Acoustic telemetry; Fish farms
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-012-0088-0

One of the major challenges for understanding the ecological impact of escaped farmed Atlantic salmon (
Salmo salar
L.) is predicting their dispersal patterns after an escape event. Here, we quantify the behaviour of escaped farmed salmon using a simulated-escape experiment within a Norwegian fjord system. Thirty-seven individuals were tagged with acoustic transmitters and their spatial distribution, horizontal movements and diving behaviour was monitored throughout the fjord and accompanying rivers using 29 acoustic receivers. A rapid movement away from the release site occurred. There was no movement into the rivers feeding the fjord and there was no preference for residence at the fish farms: nearly a third of the individuals had a final detection in the outer part of the fjord and no detections occurred from approximately 2 months after release. As it is unlikely that all fish died or remained undetected within the study area it is reasonable to assume that a substantial proportion of the fish moved out of the fjord system. If a recapture program is not implemented immediately after an escape event, we recommend spreading potential recapture efforts over a relatively large area.