Dillingham, Alaska, United States |
From the Koyukuk River, to the Kuskokwim, to Norton Sound, to Bristol Bay’s Igushik River, unusually warm temperatures across Alaska this summer led to die-offs of unspawned chum, sockeye and pink salmon. Warm waters also sometimes this summer acted as a “thermal block” — essentially a wall of heat salmon don’t swim past, delaying upriver migration.