The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council. |
Thursday, January 31, 2008 - 11:20 AM
Where Did The Fish Go? A Big Return on a Small Investment
A. Scott Feldhausen, Salmon Field Office, Bureau of Land Management, 1206 South Challis Street, Salmon, ID 83467
Between 2002 and 2006, the Bureau of Land Management (BLM) Salmon Field Office partnered with Idaho Department of Fish and Game (IDFG) and several other cooperators to fund a multi-year radio telemetry study, using funds from the Challenge Cost Share (CCS) program. The purpose of the study was to determine how body size, foraging ecology, and seasonal activity influenced the home range size of adult bull trout (Salvelinus confluentus) and adult westslope cutthroat trout (Oncorhynchus clarki lewisi) in the upper Salmon River basin, Idaho. Bull trout (Salvelinus confluentus) within the Klamath and Columbia River Basins were listed as threatened under the Endangered Species Act, in 1998. Historically, these large fluvial fish, which reside in the main river systems during most of the year and spawn in smaller tributary streams, depended on the large returns of salmon as a food source, feeding on the eggs and juveniles. Reduced salmon runs and the loss of access to tributaries due to irrigation water withdrawals have greatly reduced their numbers. Extremely limited data existed on presence/absence of these fish in both the large rivers and their natal streams.
Although the research supported prevailing opinions regarding the importance of stream connectivity and the variety of habitats necessary for the persistence of bull trout and westslope cutthroat trout populations, the results also challenged many of the assumptions of local fisheries biologists on the scale of connectivity necessary. The knowledge learned is being used to guide both the day to day management of the aquatic resources in the Salmon Field Office, as well as helping prioritize aquatic restoration projects at the landscape and local level on all lands in the upper