Beavers and Trout

The Winter 2015 issue of TROUT magazine featured an article by Phillip Monahan titled “The Complicated Relationship Between Beavers and Trout.”  It is very insightful and a suggested read for anyone interested in the dynamic between these two species.

A response by Green Bay TU Vice-President Lee Meyers was then published in the Spring 2016 issue of TROUT.  Below is Lee’s well-written letter (in the “Our Readers Write” section…page 13).

On Beavers and Trout…

I am glad that TROUT magazine did an article on this “classic confrontation.”  The article was fairly accurate and quoted an extensive 18-year research study in Wisconsin to prove the negative impacts of beaver to trout.  Beside the increase to the trout population of the main study stream, once all the beaver dams were removed from the stream system, there were five tributary “feeder” streams that had no trout before dam removal that began to produce natural brook trout after.  In northeast Wisconsin, there is a strong negative relationship between trout and beaver populations; as beaver populations go up, trout populations go down.  It’s not the beaver itself, but the dams they build that do the damage.  This damage is similar to the negative impacts of man-made low-head dams that, in recent years, Wisconsin has spent hundreds of thousands of dollars removing.  Humans are the “keystone” species, and our actions ultimately determine the condition of the ecosystem and habitat.  Man’s actions can control or in some cases promote beaver populations.  A good trout stream can quickly be turned into a muck-ridden quagmire, if beavers are allowed to cover the stream with dams.  Beaver dams also cause damage to roads and destroy valuable timber trees.  Hopefully, TU members will continue to fight for the control of beaver populations in Wisconsin in order to maximize fishing opportunities for trout.

Lee Meyers

Green Bay chapter member

Retired Fisheries Biologist