Homogenization of Macroinvertebrate Assemblages and Asiatic Clam Corbicula fluminea Invasion in a River of the Arid Patagonian Plateau, Argentina

LABAUT, YENY; DARRIGRAN, GUSTAVO; MACCHI, PABLO A.; ARCHUBY, FERNANDO M.

Frontiers in Environmental Science

Frontiers in Environmental Sciences

Lugar: Lausanne; Año: 2021 vol. 9 p. 1 - 13

The invasion of the Asiatic clam Corbicula fluminea in South America has already reachedPatagonia. Despite the well-known direct and indirect impacts that this species exerts onfresh-water ecosystems, particularly on benthic communities, few studies have beenundertaken on its effect on the composition and structure of aquatic macroinvertebrateassemblages. This study evaluated the effects of the invasion of the Asiatic clam C.fluminea on the aquatic macroinvertebrate assemblages of the Limay River, one of themost important rivers of the arid plateau of Argentinian Patagonia. As this river is currently inthe process of being invaded, it was possible to compare invaded and non-invaded sites.Invaded sites displayed a certain homogenization of their constituent species andfunctional composition. Non-metric multidimensional scaling, similarity analysis andsimilarity percentages showed negative or positive influence of the presence of thisspecies on the abundance of some taxa, due to competition for resources in this lowproductivityPatagonian ecosystem. The deposition of the faeces and pseudo-faeces of C.fluminea enriches the organic content of the sediments. However, its pedal feeding canfunction as a competitive strategy: by consuming its own deposited organic matter whenfood is scarce, the amount available to other macroinvertebrates is reduced. This paper isthe first contribution on the impact of this invasion on northern Patagonia?s aquaticmacroinvertebrate assemblages.