Distribution, density and potential impacts of freshwater exotic mytilid Limnoperna fortunei

KARATAYEV VADIM; KARATAYEV ALEXANDER; BURLAKOVA LYUBOV; BOLTOVSKOY DEMETRIO

Syracuse, New York, USA

Congreso; Great Lakes Research Consortium, 19th Annual Student Faculty Conference 2009; 2009

State University of New York, College of Environmental Science and Forestry

The freshwater golden mussel, Limnoperna fortunei (Mytilidea, Bivalvia) is considered to be the most aggressive invader in the southern hemisphere.  In late 1980th – early 1990th Limnoperna invaded South America and has already spread into Argentina, Paraguay, Uruguay, Brazil, and Bolivia, causing significant ecological and economical impacts. We predict that in the near future Limnoperna is very likely to invade North America.  Limnoperna is a suspension feeder and much of its ecosystem effects are due to shifting energy and matter from the water column to benthic communities (benthic pelagic coupling).  Therefore, the overall ecosystem effects of Limnoperna will depend on their densities.  However, to date there was no information available about population densities of Limnoperna.  The focus of this study was to determine the density and distribution of L. fortunei across different substrates and depths in Rio Tercero Reservoir in Cordoba, Argentina, and compare obtained data with our previous results on zebra mussels (Dreissena polymorpha).  We found that Limnoperna distribution is limited to hard substrates including rocks, stable sand, submerged wood, and debris.  The highest densities were found on rocks, and the lowest on mud.  Therefore, the general pattern of distribution of the golden mussel within a waterbody was very similar to that of the zebra mussels.  However, we found that Limnoperna formed significantly higher densities than Dreissena, across all substrates and especially on rocks.  Therefore, potential impacts of Limnoperna on ecosystems they invade may be even stronger than that of zebra mussels.