Toxic Effects of Cadmium on Three Generations of Brook Trout (Salvelinus fontinalis)

Abstract

Three generations of brook trout (Salvelinus fontinalis) were exposed to several concentrations of total cadmium (0.06–6.4 μg Cd/liter). Significant numbers of first- and second-generation adult males died during spawning at 3.4 μg Cd/liter. This concentration also significantly retarded growth of juvenile second- and third-generation offspring. The maximum acceptable toxicant concentration (MATC) for brook trout exposed to cadmium in Lake Superior water (hardness 44 mg/liter as CaCO 3, pH 7–8) lies between 1.7 and 3.4 μg Cd/liter. Cadmium-residue analyses of kidney, liver, gill, gonad, spleen, muscle, and red blood cells frown first- and second- generation trout indicated that kidney, liver, and gill tissue accumulated the greatest amounts of cadmium at each water exposure concentration. No significant increases in cadmium were measured in edible muscle at any of the cadmium water concentrations tested. Cadmium residues in kidney, liver, and gill tissue of fish frown all exposure concentrations reached equilibrium (μg Cd/g tissue) in both first- and second-generation trout after 20 weeks. Cadmium loss from gill tissue of second-generation trout placed in control water for 12 weeks was rapid; however, no loss was detectable from the liver and kidney.