Effect of Acute Exposure to Chlorine, Copper Sulfate, and Heat on Survival of New Zealnad Mud Snails

Abstract

The New Zealand mud snail (Potamopyrgus antipodarum) is a recent invader to aquatic systems in North America. The biology, ecology, and contemporary distribution of New Zealand mud snails in Europe and Australia suggest that the snail will spread rapidly in North America. Because the species can seal the opening of the shell with its operculum and survive out of water in a moist environment for long periods, improperly cleaned fishing and other gear may facilitate their dispersal. A proposed solution is to provide cleaning stations for sterilization of equipment at public access sites along snail-infested waters. We assessed the acute effectiveness of several commonly used biocides on New Zealand mud snails. Lethal exposure tests were conducted over short durations using chlorine (Cl) and copper sulfate (CuSO4) solutions, as well as heated water. Mortality of snails exposed to Cl at levels ranging from 500 to 3000 mg/L at all exposure durations rarely exceeded 30 percent. We observed similar results for dilute CuSO4 . Effectiveness increased with concentrations of CuSO4 with mortality generally exceeding 60 percent for 100 and 1000 mg/L at all durations. Exposure to hot water at temperatures of 45 °C for 60 sec or 50 °C for 15 sec killed most of the snails, which suggested this treatment offered the best option for sterilizing field equipment of those tested.