Corvallis, Ore. (AP) — A study of mountain streams in the West over the past 60 years finds the hottest temperatures of summer and the lowest water levels of fall are converging — which is bad news for Salmon.
The authors say the convergence gives salmon less time to recover from the stress of warm water before the stress of low water hits — 20 to 30 days less time.
The study was based on stream flow records between 1950 and 2010 from 22 sites in Oregon, Washington, California, Nevada, Montana and Idaho.
Researchers from Oregon State University, the U.S. Forest Service and the U.S. Geological Survey cited other research indicating climate change is behind the convergence, producing lower snowpacks in winter and earlier snowmelt in spring.
The study appears in the journal Hydrobiologia.
louise wagenknecht
Louise Wagenknecht worked for the Forest Service for 31 years and has written two books about her life in the Klamath Mountains of northern California. She writes from the wilds of eastern Idaho.
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Louise – one has to wonder how many streams are being diverted, well into summer, for pastureland, due to drought conditions.
I saw a few a areas for the first time( as in irrigation ditches) this past summer, in my neck of the woods, that normally would of been dry but were open from streams, to channel water into pastures.
No salmon making their way up these streams but how has it impacted the aquatic life who live in those streams.
This phenomenon is happening even in places like the South Fork Salmon River where there is no agriculture or diversions. Water temps are very high in the summer and runoff is happening more quickly in the spring.
I was pondering central Idaho in the vicinity of the South Fork of the Salmon on Google Earth last night. New photos and imagry go up on a continuing basis. Much of it is unrecognizable since I visited it 15, 10, even 5 years ago.
I have to wonder how much the temporary? deforestation of its many headwater streams from wildfires over the last 12 years has had on the South Fork’s water temperatures?
Even before the fires there were problems with pre-spawn mortality on the SFSR. I think that there are a lot of reasons for this but water temperature is the biggest.
If water temperatures get too high then any injury, from nitrogen burns caused by spill over the dams to angler injuries, can become infected with a fungus that can quickly overwhelm the fish.
Keep in mind, spring and summer chinook salmon enter the Bonneville river in April-June, arrive to their natal river in late May-mid July, and don’t spawn until early August to mid September. That is a long time in fresh water without food and a failing immune system.
Add any other stress to the adult population and there are some real problems in store. This is on top of the high mortality caused during the out migration of these fish to the ocean caused by EIGHT dams on the Lower Snake and Columbia Rivers.