We tagged adult salmon with satellite tags in the River Lakselva in May. Surprisingly, three weeks later one of the ladies was already at Bear Island, far out in the Atlantic Ocean, 855 km away.
River Lakselva, where the tagged female came from, and the site at Bear Island where she was recorded three weeks later, are shown with yellow stars on the map. Photo: Eva B. Thorstad
Pop-up satellite archival tags
Satellite tags record data on depth, temperature and light as the fish is moving around. When the tag detaches from the fish, it floats to the surface, tell Argos satellites that “HEY, her I am” and transfers the data to our computers via the satellites.
The tags are programmed to detach from the fish at a certain date, usually in November-February, when we expect the salmon to be far out in the ocean. Unfortunately, some tags detach from the fish too early, which also happened for a salmon tagged this spring.
Supercool results from this female
Luckily, we still got interesting results from this fish. She had migrated at least 855 km during the three weeks from tagging and until the tag popped off (distance along the shortest possible route).
She was a large fish (110 cm long), but this is still an impressing migration. She had been swimming near the surface most of the time, but had also been diving to almost 300 m depth. Most of the time she was in cold water (4-5 °C). For a short time she was even at 1 °C, but might have thought this was too cold for a summer feeding vacation, because soon after she was back at 4-5 °C.
Want to read more?
Results on the Atlantic salmon ocean migration from earlier tagging of Atlantic salmon are published. If you want to read and cannot access the publications, please send us an e-mail (firstname.lastname@example.org, email@example.com) and we will provide a copy :)
Strøm, J.F., Rikardsen, A.H., Campana, S., Righton, D.A., Carr, J., Aarestrup, K., Stokesbury, M., Gargan, P., Javierre, P.C. & Thorstad, E.B. 2019. Ocean predation and mortality of adult Atlantic salmon. Scientific Reports 9:7890.
Strøm, J.F., Thorstad, E.B., Hedger, R.D. & Rikardsen, A.H. 2018. Revealing the full ocean migration of individual Atlantic salmon. Animal Biotelemetry 6:2.
Strøm, J.F., Thorstad, E.B., Chafe, G., Sørbye, S.H., Rikardsen, A.H. & Carr, J. 2017. Ocean migration of pop-up satellite archival tagged Atlantic salmon from the Miramichi River in Canada. ICES Journal of Marine Science 74: 1356-1370.