Dinámica larval del mejillón dorado Limnoperna fortunei en el embalse de Aguas Corrientes, río Santa Lucía, Uruguay

Abstract

The golden mussel (Limnoperna fortunei) is an invasive exotic species that has several negative impacts in ecosystems worldwide. Santa Lucia River is the main drinking water source, supplying 60% of the total population of Uruguay. L. fortunei has been reported since 1996 in the basin, and nowadays is present in the three reservoirs that supply the water treatment plant. The aim of this study was to analyze the temporal dynamics of L. fortunei larvae in Aguas Corrientes reservoir (Santa Lucia River). We quantify diary L. fortunei larvae and phytoplankton, we also measure physicochemical parameters of water. L. fortunei larvae showed a seasonal dynamic and its development was promoted by temperatures up to 17°C. Temperature was the main variable controlling the presence of larvae. Once temperature was optimal for its reproduction, the reservoir level was the key variable to determine the presence of larvae. This shows the importance of flow managing in the reservoir in order to reduce golden mussel impacts during the reproductive season. We also propose two alternative regulation mechanisms of larvae, acting at two different scales: physiological and environmental.