Flood Control Threatens Coho Salmon

May 11, 2015

 

Observers visiting the rivers and seasonal tributaries of Southern Oregon and Northern California can see the legacy of the 1964 winter flood.  The warm southern branch of the polar jet stream called the  “pineapple express” brought December rain for 23 days, melting deep snow and causing widespread flooding that uprooted trees and floated homes downstream.

People who recall the flood could also remember a time when coho salmon ran so thick in the rivers they could be scooped with pitchforks.

Seeking to avoid future catastrophe, new dams controlled flows and bulldozers clanked down streams straightening the channels, building levees, and removing all the dead logs, including some deeply buried and perfectly preserved ancient logs.  In November 2014, the National Marine Fisheries Service released its recovery plan for Southern Oregon’s coho salmon that concluded the region’s coho were in danger of extinction.

Today, it is being recognized that the measures taken to control flooding without fully understanding the needs of the fish disturbed a complex natural system and contributed to the decline of the spawning

coho.

In the search for solutions, some are pinning their hopes on the restoration efforts of natural beaver dams that build complex streams.

Sources: "State of the Beaver 2015." Network of Oregon Watershed Councils. N.p., 2014. Web. 18 Apr. 2015. http://www.surcp.org/beavers/conference.html; Shockey, Jakob. High extinction risk for Applegate Coho. Applegate, Ore.: 2015. Print.