Spatial distribution, seston removal, and potential competitive interactions of the bivalves Corbicula fluminea and Elliptio complanata, in a coastal plain stream

SUMMARY.

• 1 Within the past 10 years the introduced exotic bivalve, Corbicula fluminea, has spread from the Savannah River through a riverine swamp into a third-order blackwater tributary on the Savannah River Site (SRS). We examined the effects of this invasion on a native bivalve, Elliptio cornplanata, and on seston concentration in the stream.
• 2 Corbicula fluminea has not yet colonized the entire stream and its distribution limit is coincident with the occurrence of gravel beds.
• 3 Corbicula fluminea appears to cause localized reduction of seston concentration and may rapidly clear the sediment boundary layer of food. There was no evidence of a negative impact on the distribution of the native bivalve in spite of high measured rates of water clearance by C. fluminea.