Between-watershed movements of two anadromous salmonids in the Arctic

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Jensen, Arne Johan, Diserud, Ola Håvard, Finstad, Bengt, Fiske, Peder, Rikardsen, Audun Håvard
• Other Authors: Jonsson, Bror
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2015
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Altaelva; Arctic; Salvelinus alpinus
• Online Access: http://dx.doi.org/10.1139/cjfas-2015-0015; http://www.nrcresearchpress.com/doi/full-xml/10.1139/cjfas-2015-0015; http://www.nrcresearchpress.com/doi/pdf/10.1139/cjfas-2015-0015

A long-term study in the River Halselva in the Arctic region of Norway demonstrated that movements between watersheds were considerably higher in anadromous brown trout (Salmo trutta) than anadromous Arctic char (Salvelinus alpinus). Fourteen smolt year classes of both species were captured in a fish trap, individually tagged, and thereafter registered each time they passed the trap during their migration between the sea and fresh water every summer. Annual mean survival (i.e., recovery rate) after the first entry to sea as smolts was estimated as 31.4% in Arctic char and 26.6% in brown trout. Most surviving Arctic char returned to the River Halselva to overwinter after the same summer that they migrated to sea as smolts. However, several brown trout overwintered one to four times in other watersheds, mainly the considerably larger River Altaelva, before most eventually returned to the River Halselva upon maturation. The substantial difference in movement rate between watersheds between Arctic char (2.2%) and brown trout (39.6%) is expected to be a consequence of local geographic conditions combined with different habitat preferences of the two species.