Filtration of green algae and cyanobacteria by freshwater mussels in the partitioned aquaculture system

The freshwater mussel Elliptio complanata was provided water containing green algae and cyanobacteria delivered from the Partitioned Aquaculture System (PAS) at eight how rates to determine algal filtration rates as mg of particulate organic carbon (POC)/kg wet tissue weight per h. The dominant taxon in cyanobacterial waters was Microcystis while the dominant taxa in green algal waters were Scenedesmus and Ankistrodesmus. The cell counts of Scenedesmus and Ankistrodesmus were the only algal taxa that were significantly different between the incoming water and water filtered by mussels. Filtration rates of POC obtained from green algal water were significantly greater than from cyanobacteria-dominated waters at all flow rates. A significant increase in mean filtration rate was observed as how rates increased. The filtration rate of green algae increased as POC concentration increased, peaking at 28 mg C/L. A maximum filtration rate was not observed with cyanobacterial waters.