Residues of organochlorine chemicals and concentrations of heavy metals in ciconiforme eggs in relation to diet and habitat

Abstract

Abstract Residues of organochlorine pollutants and heavy metals were determined in 50 aquatic organisms of five species, 31 eggs of four species of wading birds, water, and sediment collected at Doñana National Park, (Spain) during the nesting season 1983 and 1984. The species analyzed were the Spanish frog (Rana perezi), the American crayfish (Procambarus clarkii), the grey mullet (Mugil capito), the common carp (Cyprinus carpio), the European eel (Anguilla anguilla), the purple heron (Ardea purpurea), the grey heron (Ardea cinerea), the white stork (Ciconia ciconia), and the little egret (Egretta garzetta). DDE and PCBs were detected in all samples. ?,‐HCH, ?‐HCH, TDE, DDT,dieldrin, and heptachlor epoxide were also detected, but less frequently. Aldrin, heptachlor, and dichlorobenzophenone were not detected. Hg, Cd, Pb, Cu, and Zn were detected in all samples. The levels of contaminants investigated are generally below the levels known to cause direct effects on survival or reproduction. Biomagnification of the organochlorine pollutants and Hg is clearly illustrated; there is no evidence of accumulation of Cd, Pb, Cu, and Zn along a food chain.