If you think this summer is hot for you consider the salmon and steelhead making their epic odyssey up the Columbia River heading home to Idaho.

Water temperatures exceeded 73 degrees, far warmer than the 68-70 degrees fishery managers say these cold water fish prefer this time of the year. The Clean Water Act requires temperatures 68 degrees and lower.

When temperatures rise to 72 degrees, salmon suffer unless they can find cold water refuges like the mouths of cold water stream like the Deschutes in Oregon or the White Salmon in Washington that come right out of the high country.

Water temperatures usually rise fast in July and peak in early August so this is the critical time in the migration for Snake River steelhead and fall Chinook. Often the steelhead in particular just hang in the cool refuge waters until the water cools off in September.

Research shows predation on fall salmon smolts increases during the warmer temperatures and already biologists have seen fall Chinook adapt their migration behavior to actually wait until the following spring to migrate.

This is not only a problem for the Columbia, which has dams all the way up its tributaries. The Fraser River in British Columbia has no dams and is expected to see it water temperature rise to 72 degrees this month.

That would be the highest temperature ever measured for the river in 100 years of collecting data, according to the newsletter Clearing Up.

Fish managers are doing what they can but they don’t have many options. They have increased releases of the 43-degree water from Dworshak Reservoir in an effort to cool the Snake River.

But 74 degree water was flowing out of Idaho Power’s Brownlee reservoir and in much higher flows to take meet the desires of we Idahoans to power our big screen televisions and air conditioners.

Up to 17 percent of the fall chinook collected at McNary Dam for barging downriver – about 18,000 fish -- died, Clearing Up reported.

What does all this mean?

Researchers found that the average temperature of the Columbia River at Bonneville Dam has risen 1 degree since 1960. If the forecasts are accurate it will rise another degree or more in the next 40 years.

That means the steelhead and fall Chinook must adapt or die, said noted salmon biologist Don Chapman of McCall.

“The steelhead are going to have to adapt to by moving in later or earlier,” Chapman said. “The fish that come in at the same time aren’t going to survive.”

The rising temperatures also means the pressure on Idaho Power to find a way to reduce the temperatures of the water coming out of Brownlee is going to increase, not drop.

That will likely add to our power bills one way or the other.