Migration Timing of Adult Chinook Salmon into the Togiak River, Alaska, Watershed: Is There Evidence for Stock Structure?

Variation in the timing of migration to freshwaters to spawn is one important dimension of the life history variation within individual salmon stocks. That variable has important implications for developing sustainable fisheries that simultaneously exploit multiple populations within the same geographic area. We examined the variation in migration timing of adult Chinook Salmon Oncorhynchus tshawytscha within the Togiak River system of southwest Alaska to determine whether fish that spawned in different habitats migrated into freshwater from the ocean at different times. In particular, we evaluated whether there were watershed-wide effects of body size, sex, spawning location, and year on the timing of spawning-run migration into the [...]