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Adult Pacific Lamprey Trends and Abundance

Mid-Columbia Region

Adapted from Luzier, C.W., H.A. Schaller, J. K. Brostrom, C. Cook-Tabor, D.H. Goodman, R.D. Nelle, K. Ostrand, and B. Streif. 2011. Pacific Lamprey (Entosphenus tridentatus) Assessment and template for Conservation Measures. U.S. Fish and Wildlife Service, Portland, Oregon. 282 pp.

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alt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_textalt_text The uncertainty associated with estimating Pacific lamprey status and trends for many watersheds in the Middle Columbia River region is quite high due to the lack of targeted surveys, harvest records, and dam counts. Relying on best professional judgment, expansions of data from other species, and partial surveys for a limited area of the watershed, managers and researchers have estimated that up to 16,300 adult Pacific lamprey may comprise the Middle Columbia River region population. The managers and researchers also suggested that the short-term trend in abundance is declining-very/severely declining. The highest threats to the long-term persistence of Pacific lamprey in the Middle Columbia River region identified the Federal Columbia River Power System dams on the mainstem Columbia River followed by climate change, stream and floodplain degradation, water quality, dewatering and flow management, and tributary passage.