REPRODUCTIVE SUCCESS AND BIOCHEMICAL EFFECTS IN TREE SWALLOWS (TACHYCINETA BICOLOR) EXPOSED TO CHLORINATED HYDROCARBON CONTAMINANTS IN WETLANDS OF THE GREAT LAKES AND ST LAWRENCE RIVER BASIN, USA AND CANADA

摘要

Reproduction and biochemical indicators (vitamin A, ethoxyresorufin-O-deethylase [EROD], highly carboxylated por- phyrins) of contaminant effects, and concentrations of organochlorine residues were measured in tree swallows from wetlands within the watersheds of the Great Lakes and the St. Lawrence River, USA and Canada. To assess the vitamin A sources in the tree swallow diets, insects were collected, by ligature, from nestlings at four of these sites. Diet samples were analyzed for retinol and a- and beta-carotene. Marked differences were found in chlorinated hydrocarbon residues in eggs and nestlings among sites, however we did not find any significant differences in hatching or fledging sucdess. The maximum polychlorinated biphynul (PCB) concentration found was 11.1 mu g/gin eggs from Akwesasne Reserve. New York, USA. on the St. Lawrence River, whereas the highest p,p'-DDE concentration of 2.57 mu g/g was found in eggs from Mud Creek,Ontario, Canada, in the Lake Erie watershed. Concentrations of other organochlorine pesticides and chlorobenzenes were low and not variable among sites. Significant differences in hepatic EROD activity, retinol and retinyl palmitate, and uroporphyrin in nestling birds existed among sites. Ethoxyresorufin O- deethylase activity was highest and retinol and retinyl palmitate were lowest at Cornwall lsland, Ontario, Canada, in the St. Lawrence River, whereas porphyrins were highest at Toronto and Hamilton harbors, Ontario, Canada, in Lake Ontario. Ethoxyresorufin O- deethylase induction was significantly and negatively correlated with nestling