Toxicity of chlorine and three non-oxidizing molluscicides to the fouling pest mussel Limnoperna fortunei

DANIEL CATALDO, DEMETRIO BOLTOVSKOY AND MÓNICA POSE

Journal of the American Water Works Association (AWWA)

Año: 2003 vol. 95 p. 66 - 78

The freshwater Asiatic mussel Limnoperna fortunei invaded the Paraná-Uruguay (Argentina) river system around 1990. In the time elapsed it has spread extensively and has now become a major nuisance for many industrial and domiciliary water supply systems. Adults of L. fortunei were exposed to chlorine (as free available oxidant; permanent exposure for up to 47 days), and to 3 non-oxidizing commercial molluscicides (ClamTrol CT2, H130M and Bayluscide WP70; 2 days of exposure and 6-10 days of post-exposure) at concentrations between 0.25 and 100 ppm, at 15, 20 and 25°C  (59, 68 and 77°F). At 25°C (77°F) chlorine was effective at all concentrations (1 to 100 ppm) yielding 100% mortalities in 11-17 days. At 15 and 20°C (59 and 68°F) only 5 ppm and higher concentrations resulted in total kills after 3-6 weeks of exposure. ClamTrol was had little effect at 1 ppm at all temperatures, whereas at 20 and 25°C (68 and 77°F) 2.5 ppm attained 80-90% mortalities on the third day of post-exposure. At 15°C (59°F) all concentrations tested of H130M tested failed to kill 100% of the mussels exposed; at 20°C (68°F) only doses above 10 ppm eliminated all the molluscs; whereas at 25°C (77°F) all concentrations down to 2.5 ppm were 100% effective in one week or less. Bayluscide was the most toxic of the compounds tested, yielding over 50% mortalities at all temperatures at ³1 ppm. In all cases, and especially with chlorine, toxicity was very substantially enhanced at higher temperatures.