Mercury Levels in the Sunfish, Lepomis gibbosus, Relative to pH and Other Environmental Variables of Precambrian Shield Lakes

Abstract

Growth rate and total mercury concentrations were determined in muscle tissue of pumpkinseed sunfish (Lepomis gibbosus) collected from 16 waters in south-central Ontario. Mean water pH ranged from 5.6 to 8.4. Growth rate is correlated positively with lake pH, whereas fish mercury levels are higher at lower pH. Differences in growth rate may be the result of both metal and acid stress in the lower pH waters. Pumpkinseed mercury levels can be accurately described by an equation incorporating chemical and physical lake variables.