Acid Precipitation: Effects on Fish

Extensive depletion of valuable fish stocks has occurred in Norway, Sweden, and parts of eastern North America as a result of acidification in dilute lakes and streams. Recruitment failure, resultning from the toxic action of acid waters on eggs and larval fishes, is the primary cause of population extinction. Acid stress during periods of snow melt has been reported to produce mass mortality of trout populations in rivers of Southern Norway. Acid tolerance in fish is a complex function of both ecological and genetically fixed factors.