congresos y reuniones científicas
The Influence of Suspension-feeding Bivalves on the Pelagic Food Webs of Shallow Enclosed Bays
DJ LONSDALE; RM CERRATO; DA CARON; R HOLLAND; A MASS; L HOLT; RA SCHAFFNER; J PAN
Providence, Rhode Island, USA
Congreso; 19th Biennial Conference of the Estuarine Research Federation; 2007
Estuarine Research Federation
Bivalve and microzooplankton community grazing on natural plankton assemblages were measured in an embayment of the PeconicBay estuary (Long Island, New York, USA) to determine the relative importance of each community on plankton mortality. The bivalve populations consisted of a re-stocked population of Mercenaria mercenaria (hard clam) and natural populations of Geukensia demissa (ribbed mussel) and Mya arenaria (soft-shell clam). Total grazing pressure on phytoplankton by bivalves (i.e., percent bay volume cleared per day) was substantial, similar to microzooplankton, and sometimes approached or exceeded the daily flushing rate of the embayment. The experiments also showed that bivalves removed ciliates and eggs of the calanoid copepod Acartia tonsa from the plankton, suggesting that bivalve-induced mortality was likely an important regulatory mechanism of zooplankton. These findings demonstrate a complex trophic role for benthic suspension feeders in shallow estuaries. While the effects of restoring shellfish populations will likely be beneficial to an estuarine ecosystem by ameliorating some effects of eutrophication, we cannot fully predict the resultant changes in pelagic food web structure.