Bioaccumulation of copper in Cambarus georgiea

Abstract

With new developments for the use of copper, such as coated copper sulfates as algicides, it is important to understand both the acute and chronic toxicity impacts of copper on native aquatic fauna. Crustacean physiology is very sensitive to pollution of freshwater systems from anthropogenic sources; as such, crayfish are key bioindicator species. We tested the impact of chronic low exposure of cupric sulfate (5.0 lg/L) for 30 days on the hepatopancreas, gills, and tail muscle tissues of Cambarus georgiea. The relative dry organ mass (% total body mass) was significantly lower (p < 0.05) in the tail muscle of the exposed group, compared to the control group. Tissue concentration of copper (lM/g dry mass) was also significantly higher in the tail muscle of the exposed group, compared to the control group. This finding is different to the current literature in other species of crayfish and crustacea, which have found that acute exposure to copper leads to accumulation in the hepatopancreas and gills, rather than in tail muscle. C. georgiea is endemic to the hypoxic altitudes of the Blue Ridge Mountain Province, therefore, we suggest that this species likely evolved to sequester copper in the tail muscle in order to prioritize the functional demands of the hepatopancreas and gills within its natural habitat.