The migration of sockeye salmon from the ocean to inland parts of the Northwest has been deadly this year. Hotter than normal temperatures early in the summer warmed up low-flowing rivers, and more than a quarter million sockeye are dead or dying in the Columbia River and its tributaries.
But Idaho Fish and Game biologist Mike Peterson says the conditions are allowing scientists to observe just how resilient salmon can be in warmer water.
“What we may see this year is that these fish are holding in these cold water refuge areas," says Peterson, "and once water temperatures decrease to a certain point we may see some of these fish start to move upstream again.”
He says he expects fewer fish to make it to the Sawtooth Basin near Stanley to spawn this year, but some are surviving the trek. The first salmon made it to the area on Monday.
Peterson is watching to see if more fish arrive, but do so later than normal.
“We don’t know whether or not these fish are capable of finding a cold water refuge that they can hold out in and then continue their migration later in time.”
If some fish are have waited out the unusually warm water, they could be on the move again soon. Cooler weather has allowed water temperatures to drop the last few weeks.
Find Frankie Barnhill on Twitter @FABarnhill
Copyright 2015 Boise State Public Radio