Life history patterns of freshwater resident and sea-run migrant brown trout in Norway
life history, history, Brown trout, trout, Norway
Journal or Book Title
Transactions of the American Fisheries Society
Brown trout (Salmo trutta) in Vangsvatnet Lake, Norway, include freshwater residentsthat mature sexually without any sea run and migrants that smoltify and migrate between freshwater and the sea one or more years before maturing. Migrants leave Vangsvatnet Lake duringspring and move in coastal waters up to 100 km from the lake outlet before they return to theirhome river in summer or autumn; older migrants return earlier than younger migrants, sexuallymature fish before immatures. Both residents and migrants spawn together in tributaries toVangsvatnet Lake. Young brown trout (parr) grow in the tributaries and lake; lake dwellers growfaster than stream dwellers. Parr that become migrants at age 2 grow faster than parr that become residents, but parr that become migrants at age 4 and older grow more slowly than thosethat become residents.