Friday, August 31, 2012

Columbia River Salmon and Steelhead in Hot Water

So far this summer, the water temperatures in the Columbia River have exceeded 70 degrees for 80 days. Water temperatures above the mid-60s place tremendous stress on migrating salmon and steelhaed and 70 is considered the critical threshold where water temperatures become lethal to fish. Under these conditions fish are forced to delay migrations and seek cool water refugia, typically in tributaries of the Columbia which run cooler than the mainstem. Even with the available temperature refuges, many fish fall victim to the high water temperatures, and prespawn mortality in the Columbia system is thought to be high for summer migrating species. 

While the Columbia has always been warmer than many coastal rivers, dams which slow the flow of water and increase the river's surface area have exacerbated the problem tremendously. Combine that with the changes already underwater from climate change and we can expect warmer temperatures and reduced flow during summer. That means, unless something changes the future looks pretty bleak for salmon in the Snake and Columbia rivers. 

Removing the four Lower Snake River dams is the only way to ensure the survival of anadromous fish in the basin and must move forward. Unfortunately, entrenched politicians and lobbying interests continue to see the Columbia system as nothing more than a conduit for their economic aspirations, a means to and end which is cheap subsidized barging, freely flowing irrigation water, and hydroelectricity. While no one can deny the important benefits of irrigation and hydroelectricity, we must seek to strike a more healthy balance between these uses and the need to restore and protect salmon and steelhead in the Columbia and Snake. The lower four Snake River dams have got to go and we better move fast, otherwise wild salmon and steelhead will find themselves in increasingly hot water. 

More information in a good write up from Save our Wild Salmon:

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