|Document Type:||Contract Report|
|Title:||Adult fish delay at John Day Dam|
|Author/Editor:||David M. Damkaer, Douglas B. Dey|
|Publisher:||National Marine Fisheries Service|
|Contracting Agency:||U.S. Army Corps of Engineers. Portland, Oregon|
Migrating adult salmonids have been found to delay for an inordinate time before passing John Day Dam. The fishways and flows there are not substantially different from those at other large dams, in particular those at Bonneville and The Dalles, both downstream dams where apparently there are no such passage delays. Recent cooperative studies between the National Marine Fisheries Service and the U.S. Army Corps of Engineers have suggested that these migratory delays are related to and may be caused by industrial pollutants in the forebay of John Day Dam. In this study, we continued to observe distributions and concentrations of some inorganic pollutants, especially fluoride, and begun bioassay experiments to determine the effects on salmonids of low fluoride levels.