Northwest Fisheries Science Center

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Document Type: Contract Report
Center: NWFSC
Document ID: 6372
Title: Adult fish delay at John Day Dam
Author/Editor: David M. Damkaer, Douglas B. Dey
Publication Year: 1984
Publisher: National Marine Fisheries Service
Contracting Agency: U.S. Army Corps of Engineers. Portland, Oregon
Pages: 26
Date: 1984

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.