Effect of Long-Term Exposure to Acid, Aluminum, and Low Calcium on Adult Brook Trout (Salvelinus fontinalis). 1. Survival, Growth, Fecundity, and Progeny Survival

Abstract

Adult brook trout (Salvelinus fontinalis) were exposed to concentrations of acid, Al, and Ca representative of acidic and acid-sensitive surface waters. At low pH (4.42–5.03), survival and growth were reduced by elevated Al concentrations (486 μg/L) and low Ca concentrations (0.5 mg/L). Fecundity (number of eggs per female) was reduced by exposure to some treatment combinations, but this effect was mediated through reduced growth; number of eggs per unit body weight was not related to treatment. Viability of eggs from ail parental exposures was high when incubated in neutral water. In spite of this high viability, eggs from parents exposed to low Ca concentrations showed greater mortality when incubated in the parental exposure conditions than did eggs from unexposed parents. Although the potential for such "carryover effects" cannot be discounted, we conclude that impairment of egg production is not a likely mechanism for loss of brook trout populations from acidic surface waters.