Columbia and Snake River temperatures regularly exceed 70 degrees

Memo to Northwest writers, reporters, editorialists and columnists - July 30, 2013

For the week July 22-28, water temperatures were 70 degrees F or higher 35 times at four federal dams on the Columbia and Snake Rivers passable to salmon. All readings at Ice Harbor Dam on the Snake River surpassed 70 degrees during this week, and readings at The Dalles Dam surpassed 70 degrees July 24-28:



ICE HARBOR DAM:


July 22 forebay (above dam)   70.6 F tailrace (below dam) 71 F

July 23 forebay   70.7 F tailrace   71.5 F


July 24 forebay   71.1 F tailrace   71.5 F

July 25 forebay   71.1 F tailrace   71.5 F

July 26 forebay   71.1 F tailrace   71.5 F

July 27 forebay   71.1 F tailrace   71.5 F

July 28 forebay   71.1 F tailrace   71.2 F

THE DALLES DAM:

July 24 tailrace 70.1 F

July 25 forebay 70.1 F tailrace 70.3 F

July 26 forebay 70.4 F tailrace 70.4 F

July 27 forebay 70.5 F tailrace 70.7 F

July 28 forebay 70 F tailrace 70.2 F


BONNEVILLE DAM:


July 25 forebay 70.2 F tailrace 70.2 F

July 26 tailrace 70.7 F

July 27 tailrace 70.2 F

JOHN DAY DAM: 


July 25 forebay 70.3 F tailrace 70.1 F

July 26 forebay 70.6 F tailrace 70.5 F

July 27 forebay 70.7 F tailrace 70.7 F


July 28 forebay 70.9 F tailrace 70.9 F

Research has examined the effects of warm water on Columbia Basin fall chinook and summer steelhead, two species that generally initiate their upstream migration to spawn in the summer. The results showed significant delays in upstream migration when temperatures exceeded 68 degrees F [1], and delays for up to 61% of migrating steelhead when temperatures are above normal.[2]

Maintaining thermal refuges (areas of cooler water) below warm water areas will become steadily more important as temperatures increase and extend over longer periods.

We hope you will consider writing or reporting on rising Columbia and Snake River temperatures, and what can be done about them. Thank you.


Columbia-Snake temperatures can be found here:
http://www.fpc.org/tempgraphssl/NETFullYear_tempgraph.aspx


For more information, please contact:

Joseph Bogaard, deputy director, (206) 286-4455, x103; joseph@wildsalmon.org
Gilly Lyons, policy director, (503) 975-3202; gilly@wildsalmon.org

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[1] Goniea, T.M., et al., 2006. “Behavioral Thermoregulation and Slowed Migration by Adult Fall Chinook Salmon in Response to High Columbia River Water Temperatures.” Transactions of the American Fisheries Society 135: 408-419.

[2] High, B., C.A. Peery, and D.H. Bennett, 2006. “Temporary Straying of Columbia River Summer Steelhead into Coolwater Areas and its Effects on Migration Rates.” Transactions of the American Fisheries Society 135: 519-538.