Growth, Fecundity, and Energy Stores of White Sucker (Catostomus commersoni) from Lakes Containing Elevated Levels of Copper and Zinc

Abstract

White sucker (Catostomus commersoni) were collected from lakes with elevated levels of both copper (13–15 μg∙L−1) and zinc (209–253 μg∙L−1) and from control lakes. In all cases the fish reached maturity between 4 and 6 yr of age, and until 6 yr of age there were no differences in length or weight of fish collected from control and contaminated lakes. After this age, fish from contaminated sites were significantly smaller and shorter than those from control sites. In addition, female sucker from contaminated lakes failed to exhibit significant increases in either length or weight after the age of maturity. The fish from contaminated lakes also exhibited decreases in egg size and fecundity, no significant increases in fecundity with age, and an increased incidence of spawning failure. The failure of female fish to grow significantly after maturity, and the decreased energetic commitment to reproduction, suggests that the food base in the contaminated lakes was limiting the performance of the female sucker. These fish exhibited decreased muscle lipid stores, decreased serum lipid levels during the postspawning period, and an apparent decrease in visceral lipid stores during the autumn. There was no effect of collection site on body stores of liver glycogen, liver lipids, serum triglycerides, or total serum cholesterol. It is known that several major food groups were missing from the sediments of contaminated lakes and that sediments under water deeper than 5 m may be incapable of supporting macroinvertebrates. Most of the alterations in sucker growth and reproduction appear to be related to nutritional deficiencies as a result of the chronic effects of elevated sediment metals on the food base of the sucker.