SALEM, Ore. (AP) – State wildlife officials are blaming warm water in the northwest for unusually high numbers of chinook salmon carcasses found in the Willamette, Clackamas and Santiam rivers.

The Statesman Journal reports wildlife officials say the rivers and some tributaries are warmer than the 60 degrees at which the species becomes more susceptible to disease, injury and stress.

A state wildlife official says salmon dying from warm water before they can spawn increases concern for the species. Most spring chinook fall off in the fall.

The warmer waters have not stopped one of the strongest chinook runs this year into the Willamette Basin.

As of June 13, a fish-counting station reported about 9,000 more chinook passing upstream than the 50-year average of 41,000.