Salmon die-off discovered on Oregon's John Day River

JOHN DAY, Ore. (AP) — More than 100 spring chinook salmon have been found dead in the Middle Fork of the John Day River, apparently falling victim to high temperatures this month, the Oregon Department of Fish and Wildlife said Thursday.

Spring chinook salmon migrate to the John Day River in May where they rest in pools until they spawn in September.

Forty-one carcasses were found near the mouth of Big Boulder Creek and 62 were found at the mouth of Vinegar Creek, the ODFW said. Resident rainbow trout and mountain whitefish were also found dead.

"It is common for some salmon to succumb to quickly rising water temperatures, but this year's heat wave seems to have taken an unusually heavy toll," ODFW Fisheries Biologist Tim Unterwegner said.

Many of the fish were believed to have died the first week in July when temperatures in the river climbed 8 degrees. Stream temperatures measured up to 84 degrees, over the usual lethal limit for chinook salmon.

There was no indication the fish died from pollutants, disease or fishing, the ODFW said.