Abstract
Abundance and composition of tintinnid and phytoplankton species were followed in central Long Island Sound from Aug. 1979-Oct. 1980. In all, 28 tintinnid spp. were observed; the greatest diversity occurred between Sept. and April. Highest tintinnid concentrations occurred in summer, with concentrations of .gtoreq. 103 individuals l-1 observed only when nanophytoplankton concentrations equalled or exceeded 1.3 .times. 105 cells l-1. 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 .apprx. 27% of the annual primary production from this region. Tintinnids are an integral part of the Long Island Sound plankton community, equal in importance to copepods.