Abundance, Species Composition and Feeding Impact of Tintinnid Micro-Zooplankton in Central Long Island Sound

Abundance and composition of tintinnid and phytoplankton species were followed in central Long Island Sound from August 1979 to October 1980. In all, 28 tintinnid species were observed; the greatest diversity occurred between September and April. Highest tintinnid concentrations occurred in summer, with concentrations of 103 or more individuals I-' observed only when nanophytoplankton concentrations equalled or exceeded 1.3 X 105 cells I-'. Although necessary, the occurrence of small food, alone, was not a sufficient condition for high tintinnid densities. Tintinnids in central Long Island Sound exhibited the same order of magnitude yearly community ingestion rates as did the copepods. The tintinnids were responsible for removing approximately 27 % of the annual primary production from thls region. It is concluded that tintinnids are a n integral part of the Long Island Sound plankton community, equal in importance to copepods.