Impact/Purpose:

To assess the benefits and potential conflicts of re-establishing healthy beaver populations in three reaches of the Skagit River basin in order to restore key beaver pond and off channel rearing habitat for outmigrating salmonids.

Description:

Beaver ponds provide numerous habitat functions including reduction of storm flows and erosion potential, maintenance of stream flow during summer low flow periods, retention of fine sediment and nutrients, and elevation of water-tables. Some studies have estimated the pre-European beaver population of North America at 10-60 animals per mile of stream or river. The fur trade, followed by sharp reduction in the quantity and quality of riparian habitat through land use conversions, nearly wiped out beaver populations. Recent studies have shown how loss of beaver ponds and their associated wetland habitat has reduced the carrying capacity for juvenile coho salmon (Onchorynchus kisutch) in large Pacific Northwest drainage basins. The loss of these refugia habitats may have contributed to declining stream temperatures, and the loss of this keystone wetland habitat-forming species has also been hypothesized as one of the contributing factors in the decline of important summer and winter rearing habitat for coho and chinook salmon. Under an EPA 104 (b)(3) grant, the Skagit Systems Cooperative is estimating historic beaver populations and associated beaver pond complexes within the Skagit river basin, and identifying and testing methods to reestablish beaver and beaver pond-forming processes. This is part of the salmonid recovery initiative in the Puget Sound basin.

Record Details: