Pilot Sampling for Heavy Metals in Fish Flesh from Killarney Lake, Coeur d'Alene River System, Idaho

Mining and smelting activities on the South Fork of the Coeur d'Alene River in northern Idaho since 1885 have contributed massive amounts of metals-rich tailings to the river. Recent environmental studies have generally demonstrated an improved condition in the Coeur d'Alene River, lateral lakes, and downstream Lake Coeur d' Alene since the early monitoring. We sampled largemouth bass (Hicropterus salmoides), northern pike (Esox lucius), black crappie (Pomoxis nigromaculatus), brown bullhead (Ictalurus nebulosus), and yellow perch (Perea flavescens) from Killarney Lake, a lateral lake on the Coeur d' Alene River in northern Idaho and analyzed edible flesh for concentrations of zinc, lead, mercury, cadmium, copper, and arsenic. Mean concentrations (n=lO) of zinc were highest in yellow perch (4.79 mg/kg -wet weight) and lowest in brown bullheads (2.95 mg/kg), considerably lower than the 45 mg/kg action level from the literature. Mean concentrations (n=10) of copper ranged from 0.265 mg/kg in black crappie to 0.31 mg/kg in yellow perch, northern pike and largemouth bass, also well below the recommended action level of 20 mg/kg. Mean concentrations (nlO) of lead ranged from 0.014 mgjkg in largemouth bass to 0.183 mg/kg in brown bullheads, compared to the 3.50 mg/kg action level. Mean concentrations (n10) of cadmium ranged from 0.018 to 0.04 mg/kg, highest in brown bullheads and lowest in northern pike. Action levels listed in the literature for cadmium were 0.07 mg/kg. Mean mercury concentrations ranged from 0.034 mg/kg in brown bullheads to 0.093 mg/kg in yellow perch, also less than the 1 mg/kg action level. Concentrations of arsenic were generally below detection limits (