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Abstract
There are several areas in Canada that could receive acidic fallout. Only in the area that produces Canada's largest single source of sulfur oxides has there been appreciable research. In the Sudbury region of Ontario, Canada, fallout of sulfur oxides has been shown to be responsible for damage to vegetation, lakes and fishes. The acidic fallout has been shown to effect a rate of acidification in many lakes that over several decades has resulted in the extinction of many species of fishes. Fishes exhibit profound differences in acid tolerance but show some similarities in their physiological response to levels within the range of their individual susceptibilities. Prior to extinction most females of a particular species did not release their ova to be fertilized. The failure of females to spawn was coincident with an inability to maintain normal serum calcium levels. In some species growth was reduced despite an adequate supply of preferred food items. High concentrations of acid were considered to be the principle factor stressing the fish populations. Elevated concentrations of some heavy metals may add to the stress caused by high concentrations of acid. As a result of damage in one area to trees, lakes and fishes by the fallout of sulfur oxides the Canadian Government started court proceedings against the companies alleged to be responsible for the pollution. After 4 years the suit was settled out of court just days before the trial was scheduled to commence.
Parent Publication
Citation
Beamish, Richard J. 1976. Acidification of lakes in Canada by acid precipitation and the resulting effects on fishes. In: Dochinger, L. S.; Seliga, T. A., eds. Proceedings of the first international symposium on acid precipitation and the forest ecosystem; Gen. Tech. Rep. NE-23. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 479-498
