Population characteristics and contaminant burdens of the white sucker (Catostomus commersoni) from the St. Lawrence River near Cornwall, Ontario and Massena, New York.

The objective of this study was to measure and compare several physical and chemical characteristics of two white sucker (Catostomus commersoni) populations from the St. Lawrence River, near Cornwall, Ontario and Massena, New York, that could be used to address environmental quality issues in this area. Seven hundred and sixty-two white suckers from the St. Lawrence River were collected upstream and downstream of the Moses-Saunders power dam near Cornwall, Ontario and Massena, New York during 1994 and 1995. Upstream white suckers were shorter and weighed less at older ages, had a lower average fecundity, a greater mean egg diameter, lower condition factor at older ages, greater overall mean age, and a higher incidence of lip and body papillomas than the downstream fish. In addition, a total of 80 fish (40 fish upstream and 40 fish downstream) were analysed for organic chemical contaminants. The mean total concentration of 34 polycyclic aromatic hydrocarbon compounds (PAH), analysed in muscle tissue using GC-MS-SIM techniques, were significantly higher in white suckers caught upstream of the dam (75.2 $\pm$ 30.4 ng/g dry wt.) than in those caught downstream (53.6 $\pm$ 29.7 ng/g dry wt.). Concentrations of 132 polychlorinated biphenyl (PCB) congeners and 31 organochlorine pesticides were also analysed in muscle tissue using GC electron-capture detectors (ECD). Detectable levels of PCB and organochlorine pesticides were found in nearly all fish sampled. However, there was no statistical difference between organochlorine contaminant concentrations of upstream and downstream fish, except for total aldrin (3.4 $\pm$ 4.0 ng/g dry wt. upstream, 1.9 $\pm$ 2.7 ng/g dry wt. downstream). Concentrations of most organochlorine compounds increased linearly with lipid content, but not relationship was found between contaminant concentration and age of the fish, except for DDT and mirex. (Abstract shortened by UMI.