State biologists say low returns of king salmon to Alaska are likely the result of problems in the ocean, not freshwater.
Department of Fish and Game biologist Tom Vania says that freshwater issues tend to be isolated to particular drainages.
He says widespread failures are tied to seawater issues.
King salmon leave their breeding streams as smolt and generally spend three to four years in the ocean.
Low returns this year are causing state regulators to restrict fishing throughout the state.
Vania says the cause of the return problem has not been identified but it's been building for at least five years.