title: Assessment of contamination and biomarker responses in two species of herons on the St. Lawrence river.
abstract: This study was undertaken to validate potential biomarkers of exposure and effects due to chemical contaminants in breeding colonies of the Great Blue Heron and the Black-crowned Night-Heron on the St. Lawrence River. Eggs and fledglings from both species were collected from many colonies along the River. The fledglings from colonies in freshwater and brackish water were more contaminated by mercury and PCBs than those from estuarine and gulf colonies. With respect to fledglings of the two heron species, some morphometric and blood biochemical measurements, including plasma thyroid hormones and retinol, were significantly different among colonies. Significant differences were also observed in liver retinoids, EROD and porphyrins among colonies. The results of this study suggest that plasma retinoids and thyroid hormones are good biomarkers of exposure and effects, and are sufficiently sensitive to reflect local and regional variations in contamination. Along with the measure of contaminants in egg and plasma, they constitute non-invasive biomarkers which represent an important criteria for long term monitoring of wildlife species. It is concluded that the Great Blue Heron is an appropriate sentinel species in the surveillance network for the St. Lawrence River.
authors.affiliation: Environment Canada, Canadian Wildlife Service, Ste-Foy, Quebec. louise.champoux@ec.gc.ca
authors.forename: Louise
authors.initials: L
authors.lastname: Champoux
authors.forename: Jean
authors.initials: J
authors.lastname: Rodrigue
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Desgranges
authors.forename: Suzanne
authors.initials: S
authors.lastname: Trudeau
authors.forename: Alice
authors.initials: A
authors.lastname: Hontela
authors.forename: Monique
authors.initials: M
authors.lastname: Boily
authors.forename: Philip
authors.initials: P
authors.lastname: Spear
mesh_terms: D000818:Animals; D000835:Animals, Wild; D015415:Biomarkers / Q000032:analysis; D001717:Birds; D004531:Eggs; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000009:adverse effects* / Q000493:pharmacokinetics*; D019216:Metals, Heavy / Q000009:adverse effects* / Q000493:pharmacokinetics*; D011078:Polychlorinated Biphenyls / Q000009:adverse effects* / Q000493:pharmacokinetics*; D011792:Quebec; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000493:pharmacokinetics
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls