The state Department of Environmental Protection requested the lifts at the Safe Harbor and Holtwood dams be shut down after snakeheads were spotted near Conowingo in the spring of 2020. At Conowingo, all of the fish are being trapped and sorted so the snakeheads can't go upriver. Shad collected at Conowingo are placed north of the Safe Harbor Dam. That's good news for fishermen who were concerned about the shad population.