Elemental Composition of Bone from White Sucker (Catostomus commersoni) in Relation to Lake Acidification

Abstract

Bone was decalcified in fish from three acid lakes and manganese was increased greatly in bone of fish from the most acid lake. The mean centrum calcium content of white suckers (Catostomus commersoni) captured in George Lake (pH 4.65) was 16% lower than in white suckers from three lakes with near-neutral pH levels. In two other acid lakes, King (pH 5.08) and Crosson (pH 5.36), centrum calcium was reduced significantly in white suckers. Centrum manganese was elevated fivefold in white sucker from recently acidified George Lake, and tended to be elevated in this species from King Lake. White suckers from George Lake exhibited shorter caudal vertebrae and some of these fish had deformed caudal fins. These anomalies may be indicative of bone demineralization. All of the study lakes were located in south-central Ontario, including the La Cloche Mountains, North Bay, Algonquin, Haliburton, and Muskoka.Key words: lake acidification, bone composition, calcium, manganese, white sucker