Fish Habitat Attributes of Reference and Managed Watersheds with Special Reference to the Location of Bull Charr (Salvelinus confluentus) Spawning Sites in the Upper Spokane River Ecosystem, Northern Idaho

On the Idaho Panhandle National Forests, bull charr and westslope cutthroat trout (Oncorhynchus clarki lewisi) are indicator species in the Forest Plan, listed as sensitive species by Region 1 of the USDA Forest Service and as species of special concern by the Idaho Department of Fish and Game. To address the needs of these species, and especially the bull charr with the recent petition for listing under the Endangered Species Act (ESA), the Idaho Panhandle National Forests began habitat typing unentered and entered watersheds in the upper Spokane River ecosystem in 1991. A physical habitat typing protocol developed in Region 5 of the USDA Forest Service and modified for the waters of northern Idaho was used to monitor any changes in fish habitat which may have occurred due to land management prescription. Of the attributes described by the methodology, mean residual pool volume and residual pool depth from managed and reference watersheds have been emphasized in analysis because of the value of pools in the stream ecology of bull charr and westslope cutthroat trout for rearing and overwintering habitat. Changes in the quality (volume and depth) and frequency of pool habitat (as a percent of the total length of stream), as a result of channel destabilization has a negative influence on carrying capacity as demonstrated by distribution and abundance of the two species in the Coeur d’Alene and St. Joe rivers, and appears to influence the distribution of spawning bull charr. Fish habitat attribute data from stream reaches of unentered watersheds in the upper St. Joe basin provide a reasonable standard by which to judge deviations seen in stream reaches of basins of similar geology, channel type, elevation, and forest type where management activities have occurred. These data have been fundamental to facilitating the development of a strategy to maintain ecosystems capable of supporting viable assemblages of bull charr and other native fishes. Fish Habitat Attributes of Reference and Managed Watersheds with Special Reference to the Location of Bull Charr (Salvelinus confluentus) Spawning Sites in the Upper Spokane River Ecosystem, Northern Idaho David Cross Loren Everest Forest Fisheries Program Manager District Fisheries Biologist Idaho Panhandle National Forests Pineridge District, Sierra National Forest 1201 Ironwood Dr. P.O. Box 559 Coeur d'Alene, ID 83814 Prather, CA 93651 USDA Forest Service S 5 St. Maries River St. Jo e R ive r No rth F ork S t. oe So uth For k C oeur D'Ale ne ittle North Fork Ceur D' Ale ne C oe ur D 'A le ne Ri ve r er Marble Creek Coeur D'Alene Lake