Hot Water Treatment (Chronic Upper Lethal Temperature) Mitigates Biofouling by the Invasive Asian MusselLimnoperna fortuneiin Industrial Installations

Abstract

Since its introduction in South America around 1990, the freshwater mussel Limnoperna fortunei has become a major fouling pest for most industrial plants that use raw river or lake water, chiefly for cooling purposes. We assessed the tolerance of the mussel to upper lethal temperatures as an economical and environmentally innocuous method of controlling its fouling in industrial installations. Survival of juvenile (7 ± 2 mm in length) and adult (21 ± 2 mm) individuals, acclimated to 12 and 28 °C, was evaluated under laboratory conditions. At 38-43 °C, all mussels die after 0.7 to 17.5 h, regardless of acclimation temperature and size class. At 34-36 °C, total mortality takes 25.0 to 644.3 h, regardless of the size of the animals, but mussels acclimated at 12 °C die significantly faster that those acclimated at 28 °C. Comparison of these results with the range of conditions currently used in the industry indicates that heat treatment is a viable alternative for an efficient control of this Asian mussel in fouled systems.