the film
forum
library
tutorial
contact
Commentaries and editorials

Snake River Dams and SARs

by David A. Cannamela
Idaho Statesman, July 2, 2021

Survey of science literature (by Schaller et al.) shows delayed mortailty of Idaho's salmon to be around 75%.  Combined with 50% 'direct mortality' within the hydrosystem corridor, means that only one of eight juvenile salmon from Idaho survives the hydrosystem unscathed. HEAR THAT:  One of eight survives unscathed. For decades now, dam supporters, including the federal "dam agencies" and certain politicians, have used point estimates of juvenile salmon and steelhead survival to argue that the four lower Snake River dams are not the cause of the imperiled status of Idaho's runs. This is like using the instantaneous survival rate of an accident victim being ambulanced to the hospital, to conclude that he will survive. A 100% survival rate between mile markers means nothing and consoles no one when the accident proves fatal. Delayed mortality is mortality nonetheless.

Smolt-to-adult survival (SAR), the percentage of smolts that return as adults, is the metric that matters. Our stocks are on an extinction trajectory because their SARS are below replacement (2%). Meanwhile runs from the Deschutes, John Day, and Yakima systems, above two, three, and four dams, remain viable with SARS in the 2-6% range: Same time and place in the same ocean, which doesn't dole out differential mortality. The science is simple: The dammed lower Snake accounts for the extra mortality, delayed or instantaneous.

Congressman Simpson has seen the light. River restoration (via dam removal) and the resulting sustainable fish runs would bring us lasting cultural, spiritual, economic and ecological wealth.


David A. Cannamela, Boise
Snake River Dams and SARs
Idaho Statesman, July 2, 2021

See what you can learn

learn more on topics covered in the film
see the video
read the script
learn the songs
discussion forum
salmon animation