Concentrations of Cd, Cu, Mn, Pb, and Zn in Fishes in a Highly Organic Softwater Pond

Abstract

Concentrations of Cd, Pb, and three essential metals (Cu, Mn, and Zn) in stocked bluegill (Lepomis macrochirus) and eight resident species of fish were studied in an acidic, highly organic pond on the southeastern U.S. coastal plain. Concentrations of Cu, Mn, and Zn in stocked and resident fish were apparently homeostatically controlled in liver tissue, axial musculature, and whole body. Concentrations of all metals studied in axial muscle tissue and whole body of stocked bluegill remained relatively constant after 200 d of residence in the pond. Analysis of concentration factors from pond water to whole stocked bluegill indicated that Pb in this system was less available to fish than in hardwater lakes. In contrast, Cd in the pond was as available to fish as in harder waters. Differences in relative availabilities of Cd and Pb were explained by the tendency of Pb to form complexes with naturally occurring organics. The need for metal-specific analysis of biological availability of metals in highly organic softwater systems is stressed. Key words: trace metal, availability, fish, soft water, concentration factor, organic water