Evaluate Status of Pacific Lamprey in the Clearwater River Drainage, Idaho. Annual Report 2001.

Technical Information Center Oak Ridge Tennessee

关键词: Bonneville Power Administration;    Aquatic ecosystems;    Dams;    Drainage;    Habitat;   

RP-ID  :  DE2004834372

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Recent decline of Pacific lamprey Lampetra tridentata adult migrants to the Snake River drainage has focused attention on the species. Adult Pacific lamprey counted passing Ice Harbor Dam fishway averaged 18,158 during 1962-69 and 361 during 1993-2000. Human resource manipulations in the Snake River and Clearwater River drainages have altered ecosystem habitat in the last 120 years, likely impacting the productive potential of Pacific lamprey habitat. Timber harvest, stream impoundment, road construction, grazing, mining, and community development have dominated habitat alteration in the Clearwater River system and Snake River corridor. Hydroelectric projects in the Snake River corridor impact juvenile/larval Pacific lamprey outmigrants and returning adults. Juvenile and larval lamprey outmigrants potentially pass through turbines, turbine bypass/collection systems, and over spillway structures at the four lower Snake River hydroelectric dams. Clearwater River drainage hydroelectric facilities have impacted Pacific lamprey populations to an unknown degree. The Pacific Power and Light Dam on the Clearwater River in Lewiston, Idaho, restricted chinook salmon Oncorhynchus tshawytscha passage in the 1927-1940 period, altering the migration route of outmigrating Pacific lamprey juveniles/larvae and upstream adult migrants (1927-1972).