Technical Bulletin No. 0093: Some Preliminary Observations on the Avoidance Reactions of Salmonid Fishes to Pulp Mill Effluents

Careful experimentation on the avoidance reactions of kraft and sulfite mill effluents was made at the Council's Project at Oregon State College, under Professor R. E. Dimick. This work was accomplished with the advice and assistance of Dr. Peter Doudoroff, of the United States Public Health Service, who is conducting research at Oregon State College. The reactions of both juvenile chinook salmon and coho salmon were investigated. It appeared from this work that very high concentrations of spent sulfite liquor were necessary to produce avoidance reaction in these fish. Chinook salmon showed avoidance to concentrations of kraft mill effluent as low as 2.5%, although results at this dilution were rather inconsistent, 10% being the level at which consistent avoidance was noted. Coho salmon showed little or no avoidance of kraft effluent concentrations of up to 10%.