Effective Population Size and Connectivity of Bull Trout in the Imnaha River Subbasin 2006 Annual Report

Bull trout (Salvelinus confluentus) were listed as threatened on November 1, 1999

(USFWS 1999). Previously, the Columbia River distinct population segment (DPS) of bull trout

had been listed as threatened since June 10, 1998. Factors contributing to the listing of bull trout

include range wide declines in distribution, abundance and habitat quality. Land and water uses

that alter or disrupt habitat requirements of bull trout can threaten the persistence of the species.

Examples of such activities include: water diversions, dams, timber extraction, mining, grazing,

agriculture, and channelization of streams. These threats are prevalent throughout the Columbia

River basin (USFWS 2000, 2002a) in addition to other threats such as nonnative fish competition

and/or hybridization, poaching, and past fish eradication projects.

Author(s)
Justin Cook
Publication date
Type of document
Report
Facility
Coho Salmon eggs incubating and hatching at Quilcene NFH in WA State.
The Columbia River Fish and Wildlife Conservation Office collaborates with local, state and Tribal partners to conserve, restore, and improve native fish and aquatic resources throughout Oregon and along the Columbia River. We study wild and hatchery aquatic organisms and their populations, support...
Program
A man is fishing in a boat with three young girls. The kids are excitedly pulling a fish out of the water.
Healthy fisheries and waters are the foundation of America’s outdoor traditions and give us the freedom to fish, boat, and enjoy the benefits of outdoor recreation. The Fish and Aquatic Conservation programs work with states, tribes, and communities to provide a comprehensive approach to freshwater...
Species
Bull trout and kokanee salmon underwater

Bull trout (Salvelinus confluentus) are members of the family Salmonidae and are char native Washington, Oregon, Idaho, Nevada, Montana and western Canada. Compared to other salmonids, bull trout have more specific habitat requirements that appear to influence their distribution and abundance....

FWS Focus
Ecosystem
FWS and DOI Region(s)