04-08-2013, 07:50 PM
I was planning a trip up there to float fish a river this year but we cancled due to last years collapse. Gunna sit out a few years to see what happens. I wouldnt be surprised if something similiar is happining to "our" fish. Theres been a lot of speculation as to why Snake basin springers return at a lower rate than other stocks. One issue has always been dam mortality either direct or indirect (delayed)
Theres a new study out that looks at whether passing thru all the dams may be causing delayed mortality in the on snake river spring chinook smolts. The study compares mortality rates for snake river vs lower river spring chinook smolts. What they found was the two groups had similiar mortality rates. They speculate that IF additional mortaliy due to the dams occurs it happens after the smolts leave the estuary environmment.
I found it interesting they had similar mortality rates. However since the Snake fish are passing 8 dams and the mortality rate is 2-10% at each dam, delayed mortality is somewhat of a moot point. If your already looking at 50% or more mortality on the outgoing year class
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Theres a new study out that looks at whether passing thru all the dams may be causing delayed mortality in the on snake river spring chinook smolts. The study compares mortality rates for snake river vs lower river spring chinook smolts. What they found was the two groups had similiar mortality rates. They speculate that IF additional mortaliy due to the dams occurs it happens after the smolts leave the estuary environmment.
I found it interesting they had similar mortality rates. However since the Snake fish are passing 8 dams and the mortality rate is 2-10% at each dam, delayed mortality is somewhat of a moot point. If your already looking at 50% or more mortality on the outgoing year class
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