Salmon and Beaver Dams
Beaver and Atlantic and Pacific salmon co-evolved in the same freshwater streams over millennia. They are all critically important Keystone species who create tremendous benefits for myriads of other species. Recent scientific research by Dr. Michael Pollock at NOAA and many others have proven what is intuitively clear, that beaver dams have a net beneficial effect on salmonids, improving their growth, survival, and now their recovery. For these reasons beavers are now highly prized in all salmon producing waterways in the Pacific Northwest.
Since beaver dam benefits are so significant, on the west coast when beavers are scarce or streams are badly incised, salmon and watershed restoration specialists are building Beaver Dam Analogs (BDA) to imitate the dams that beavers build naturally and for free. Even these manmade beaver dams are showing positive effects on salmon recovery.
There are challenges however. Beaver damming of road culverts as well as many of the flow devices used to manage beaver damming can create barriers to salmonid movement. In addition, precipitation pattern changes and reductions due to climate change can adversely affect juvenile and adult salmon movement in many areas of their range. For these reasons in 2012 Beaver Solutions began work on redesigning flow devices to improve fish passage.
In 2013 Mike Callahan and a team from Snohomish County in Washington state partnered to install an innovative flow device prototype designed to allow adult Coho salmon to easily migrate upstream past two beaver dams. The fish-friendly flow device is called the Snohomish Pond Leveler and it was a great success! Click here to see this flow device in action.
The bottom line: More Beavers = More Salmon
Watch the Video: The Snohomish Pond Leveler