Fish and amphibian egg cultures were used to determine the embryopathic effects of cadmium, mercury, and zinc released from natural and metal-enriched sediments, and to develop egg culture bioassay procedures suitable for monitoring bottom sediments for hazardous contaminants. Eggs of the narrow-mouthed toad (Gastrophryne carolinensis), goldfish (Carassius auratus), and rainbow trout (Salmo gairdnei) were cultured in contaminant-free water added to natural and metal-enriched sediments. Exposure was initiated after fertilization (toad, goldfish) or at 10 days prehatching (trout) and maintained continuously through 4-10 days posthatching. Sediments were enriched with 0.1-100 ppm cadmium and mercury and 1.0-1000 ppm zinc.
Natural control sediments contained average concentrations of 0.052 ppm mercury, 1.0 ppm cadmium, and 108.2 ppm zinc. Substantial frequencies of mortality and teratogenesis occurred for all 3 animal species when eggs were cultured over natural elements further enriched with as little as 0.1-1.0 ppm cadmium or mercury and 1-10ppm zinc. Survival of trout embryos and alevins closely paralleled sediment test concentrations. The sediment TL50 concentrations for trout stages cultured from 10 days prehatching through 10 days posthatching were approximately 1ppm for mercury, 2.15 ppm for cadmium, and 210.6 ppm for zinc. Sediment metals were substantially more lethal to eggs and embryos than to free-living larvae or fry.
Supported in part by the Office of Water Research and Technology, U.S. Department of the Interior, as authorized under the Water Resources Research Act of 1964.
Birge, Wesley J.; Black, Jeffrey A.; Westerman, Albert G.; Francis, Paul C.; and Hudson, Jarvis E., "Embryopathic Effects of Waterborne and Sediment-Accumulated Cadmium, Mercury and Zinc on Reproduction and Survival of Fish and Amphibian Populations in Kentucky" (1977). KWRRI Research Reports. 204.