Steelies Spooked by Hot Weather
by Eric Barker
Adult steelhead counts at Lower Granite Dam are climbing after slowing to a trickle last week.
The July hot spell is likely responsible for bottlenecking the run below Lower Granite Dam.
"It's exactly what we would expect," said Bill Horton, salmon and steelhead coordinator for the Idaho Department of Fish and Game at Boise.
Horton welcomed the break in the hot spell as good news for fish and fishermen.
"The drop off in temperature we just had recently was very, very fortuitous," he said. "When we have serious delays in the fish movement, we have a lot of mortality that is unexplained. They just go away."
During the first two weeks of July, the daily adult steelhead counts at the dam, 35 miles west of Lewiston, climbed from more than 50 per day to a high of 259 July 13. But the counts dropped during the last days of the month and early this month when high temperatures in the Lewiston-Clarkston Valley were often 100 degrees or warmer. During that period water temperatures above the dam climbed into the high 70s.
Steelhead counts at other Snake River dams slowed during the hot spell, but not as dramatically as the counts at Lower Granite Dam.
State and federal salmon and water managers decreased the flow out of Dworshak Reservoir Tuesday to about 9,900 cubic feet per second. The flow of cold water will likely be reduced again next week to about 9,000 cfs, according to Cindy Henriksen of the U.S. Army Corps of Engineers Reservoir Control Center. The water is intended to cool the Snake River.
Horton said shorter days and cooler nights in the mountain headwaters should also help nudge water temperatures down.
Through Tuesday, 3,930 adult steelhead had been counted at Lower Granite Dam. That is slightly ahead of the 10 year average of 3,271.
The Clearwater River is open to catch-and-release steelhead fishing.
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