Long-distance anadromous migration in a fresh water specialist: The Lake Trout (Salvelinus namaycush)

Abstract

The Lake Trout, Salvelinus namaycush, is believed to be one of the most saline intolerant salmonid species, typically completing its life wholly in fresh water. Historical observations and more recent quantitative assessments have shown, however, that in some Arctic populations, Lake Trout can migrate to marine waters (i.e., display anadromy). In the four coastal Arctic populations of Lake Trout where anadromy has been confirmed, migrations to and from marine environments are relatively short (i.e., in the order of a few kilometres). In the Halokvik River on Victoria Island, we captured two anadromous Lake Trout in a weir used jointly for commercial fishing and stock assessment research. Both fish were captured during the fall upstream migration, some 50 km from their presumed fresh water spawning or overwintering locations. This observation extends the current knowledge regarding the distribution of anadromous populations in this species and suggests that migration to marine habitats can be much longer than previously expected.