Egg Hatchability and Tolerance of Brook Trout (<i>Salvelinus fontinalis</i>) Fry at Low pH

Abstract

Hatchability of brook trout (Salvelinus fontinalis) eggs incubated at pH 4.6, 5.0, 5.6 and 8.0 ranged from 76 to 91%. Differential mortality was experienced when subsequent swim-up fry were exposed to a different pH indicating an acclimation effect. This suggests that brook trout fry incubated at lower, but sublethal, pH levels are less likely to experience acid-induced mortality upon emergence than those incubated in spring upwellings. Key words: low pH, brook trout, egg and fry mortality, acclimation, acid precipitation, lake acidification