Partnering with Beaver to Improve Fish Habitat An Example of Cheap and Cheerful Restoration to P
Anthropogenic activities such as timber harvest, agriculture, and grazing have greatly altered the habitat of salmon and steelhead in streams of western North America. Perhaps equally as important but rarely mentioned as a major impact to fish habitat is the great reduction of beaver. Beaver were distributed in high densities across much of North America prior to European settlement, however intense trapping more than century ago nearly exterminated beaver in several regions. Although salmonids have coexisted with beaver for millions of years, skepticism exists about the benefits dam building activities play. In fact, removal of beaver dams from streams is still a management activity employed in some states to try to improve salmonid fisheries. Thus, it is not surprising that using dam building beavers as a means of restoring streams is uncommon. Channel incision is a degraded state of fish habitat that is found ubiquitously throughout the world. We have suggested that beaver dams and beaver dam analogs can greatly accelerate the recovery of incised channels. We conducted a watershed scale experiment where we built beaver dam analogs to encouraged beavers to build dams to improve fish habitat in an incised stream. We observed several rapid changes to the stream environment following restoration. We also found survival, abundance, and production of juvenile steelhead increased following these changes. We believe management of streams that include beaver as part of the environment will benefit salmonid populations.