Length-Age Relations and PCB Content of Mature White Suckers from the Connecticut and Housatonic River Basins

Abstract

Length-age correlations of mature white suckers (Catostomus commersoni) were made using fish collected for organochlorine analysis in composite fish samples at 16 sites in the Connecticut River basin and seven sites in the Housatonic River basin. Compared to studies from Canadian lakes, the fish in these basins appeared smaller at a given age. Overall, the length-age relation appeared linear after maturity was reached, although the variability in this apparent growth rate was large among sites in both the Connecticut and Housatonic basins. Within the Housatonic basin, two sites with the lowest apparent growth rate were in parts of the river system that had high concentra- tions of PCBs in the sediment and fish tissue. However, within the Connecticut basin, apparent growth rates were relatively low at two sites where PCBs were not detected. Using the median ages of fish in the composite samples, compari- sons were made with the lipid fractions and the PCB concentrations of the samples. Age of fish had no apparent effect on the lipid fraction, although age of fish did appear to influence the PCB concentration of the sample. However, this was probably due to a sampling bias of selecting older fish at more contaminated sites.