The world literature on the toxicity to fish of simple and complex cyanides, nitriles, cyanogen chloride, thiocyanates, and cyanates is reviewed. Differently determined limits of toxicant concentrations tolerated by various fishes are compared, and their variation with exposure time, the pH, temperature, and dissolved oxygen and mineral content of the water, body size, age, acclimation, etc., is examined. Interactions of free cyanide with other toxic water pollutants also are considered. Available data on effects of sublethal levels of free cyanide on growth, food consumption and utilization, swimming ability, behavior, etc., and observations on avoidance reactions of fish to the toxicant are summarized and their ecological significance is discussed. Some conclusions regarding acceptable concentrations of free cyanide in receiving waters are presented.

Prepared by the Dept. of Fisheries and Wildlife, Oregon State University, under grant no. R-802459. "Grant no. R-802459." Includes bibliographical references (pages 145-154).