Organochlorine concentrations, whole body weights, and lipid content of black skimmers wintering in Mexico and in South Texas, 1983

The degree of organochlorine contamination in black skimmers and their food items was determined from sites in Mexico and Texas. DDE was found in all skimmer carcasses, ranging up to 12 ppm in Texas birds and up to 10 ppm in those from Mexico. PCBss occurred in 83% of the samples, but residues were low overall. Chlordane isomers were found is six samples, but residues were less than 0.3 ppm in all instances. Data suggest that birds wintering in Mexico did not encounter heavy DDE exposure. ( 9 references, 2 tables, )