Radiotelemetry investigations of adult Pacific lamprey migration behavior : evaluation of modifications to improve passage at Bonneville Dam, 2000

Hydropower dams on the Columbia River may contribute to declines in abundance of Pacific lamprey Lampetra tridentata by restricting access of adults to historical spawning locations. From 1997 to 1999, we used radiotelemetry to examine passage of adult lamprey through specific areas at Bonneville, The Dalles, and John Day Dams. These studies indicated that lamprey have the greatest difficulty entering the fishways (particularly at spillway entrances) and passing through collection/transition areas and count stations at these dams. Contract no. E96950021