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Communication at the NABS Annual meeting, Keystone, 2000
(157) RODENT CONTROLS ON ENDANGERED SALMON POPULATIONS.
M.M. Pollock. National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Blvd. East, Seattle, WA 98112
North American river networks contain extensive reaches dammed by beaver
(Castor canadensis), the spatial distribution of which controls fundamental
geomorphological and ecological processes. Of particular concern on the
Pacific Coast is that beaver ponds influence the distribution and abundance
of juvenile salmonids, most notably, coho salmon (Oncorhynchus kisutch),
populations of which are listed as “threatened” under the U.S. Endangered
Species Act (ESA). Studies of coho production from beaver ponds have
previously been limited to single or several ponds. Here we investigate the
current and historic distribution of beaver ponds in the Stillaguamish River
watershed, Washington, a 1771 km2 Pacific Northwestdrainage basin, and show
that the coho salmon carrying capacity of an entire watershed has been
greatly reduced through the loss of beaver ponds. Because beaver ponds also
provide habitat for biologically diverse communities, the results of our
study may be applicable to the conservation of other species, and suggests
how restoration of a keystone species can be central to the maintenance of
biodiversity. Finally, our analysis demonstrates large-scale control of fish
populations by rodents, and thus represents a novel relationship between
members of these two taxonomic classes.
Presented at 3:45 PM on Tuesday, May 30, 2000 in General Community Ecology II
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