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

Abstract

The invasion of the Asiatic clam Corbicula fluminea in South America has already reached Patagonia. Despite the well-known direct and indirect impacts that this species exerts on fresh-water ecosystems, particularly on benthic communities, few studies have been undertaken on its effect on the composition and structure of aquatic macroinvertebrate assemblages. 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 the most important rivers of the arid plateau of Argentinian Patagonia. As this river is currently in the process of being invaded, it was possible to compare invaded and non-invaded sites. Invaded sites displayed a certain homogenization of their constituent species and functional composition. Non-metric multidimensional scaling, similarity analysis and similarity percentages showed negative or positive influence of the presence of this species on the abundance of some taxa, due to competition for resources in this low-productivity Patagonian ecosystem. The deposition of the faeces and pseudo-faeces of C. fluminea enriches the organic content of the sediments. However, its pedal feeding can function as a competitive strategy: by consuming its own deposited organic matter when food is scarce, the amount available to other macroinvertebrates is reduced. This paper is the first contribution on the impact of this invasion on northern Patagonia’s aquatic macroinvertebrate assemblages.

Broadscale distribution, abundance, and habitat associations of the invasive Asian clam (Corbicula fluminea) in the lower Columbia River, USA

“…In South America, only one investigation, in the Parana River delta of Argentina (Boltovskoy et al, 1997), found greater C. fluminea abundance than our observations in the CR, whereas eight other South American studies reported abundances below those of the CR, including in the Argentinian lowlands (Reshaid et al, 2017;Reyna et al, 2013), Patagonia (Labaut et al, 2021), and tropical/subtropical areas of Brazil (França et al, 2007;Paschoal et al, 2015;Silveira et al, 2016) (Table 1).…”

Amazing Graze: Shifts in Jellyfish and Clam Distributions During Dry Years in the San Francisco Estuary

“…Invasive bivalves can also have widespread effects on water quality and on benthic invertebrate, phytoplankton, and zooplankton abundance, as exemplified by the zebra mussel (Dreissena polymorpha) invasion of the Laurentian Great Lakes (Strayer 2009), as well as many other aquatic ecosystems across North America (Higgins and Zanden 2010;Spear et al 2022;Lovejoy et al 2023). In another example, in the Potomac River on the East Coast of the US, the Asian clam (Corbicula fluminea) has had sweeping effects on the ecosystem, including water clarity, submersed vegetation, fish, and birds (Phelps 1994), with similar effects on additional aquatic systems in its invasive range (Europe and the Americas) (Crespo et al 2015;Labaut et al 2021;Ferreira-Rodríguez et al 2022) Consequences of invasive species can be exacerbated by extreme events, such as floods, droughts, and heat waves that allow populations of non-native species to flourish to the detriment of native species. For example, on the Iberian Peninsula, frequent droughts and a heavily managed water system have increased the dominance of wide-spread invasive species that have a high tolerance for disturbance (Ibáñez and Caiola 2013), and droughts in the San Francisco Estuary have been linked with the success and proliferation of invasive aquatic species in this region (Winder et al 2011).…”