Abundances of Naked Amoebae and Macroflagellates in Central New York Lakes: Possible Effects by Zebra Mussels

Zebra mussels (Dreissena polymorpha) are bivalve mollusks that have invaded and altered the ecology of many North American lakes and rivers. To identify possible ecological effects of zebra mussels on naked amoebae, this study compared abundances of sediment and water column naked amoebae in shallow water zones of four lakes with and four lakes without zebra mussels. Additional data was collected on the density of macroflagellates. Although no statistically significant difference in naked amoebae density was found, higher ratios of sediment to water column naked amoebae abundances in zebra mussel lakes were observed due to increased naked amoebae abundances in the sediments. However, we did not observe a concomitant decrease in water column naked amoebae abundances. Flagellate abundances revealed no significant differences between the two lake types. Taken together, the data show that naked amoebae and flagellates thrive in shallow water zones of zebra mussel lakes and that the filter feeding activities of zebra mussels and reported reduced water column protists abundances may be offset by the flocculation of protists from the rich zebra mussel colonies.