PHYTOPLANKTON PIGMENTS AND GROWTH-RATES, AND MICROZOOPLANKTON GRAZING IN A LARGE TEMPERATE ESTUARY

We used the dilution method to measure phytoplankton growth and microzooplankton grazing at 2 stations in Chesapeake Bay, USA, during spring, summer, and fall. Differential growth among phytoplankton taxa and selectivity of microzooplankton grazing were evaluated through the measurement of taxon-specific pigments. Some taxa showed consistently high growth rates (e.g. zeaxanthin, dn indicator of cyanobacteria, always exceeded chlorophyll a in growth, ranging up to 2.52 d-1), while others varied widely. Across all experiments and pigments, microzooplankton grazing was correlated with phytoplankton growth rates and was significant in the removal of phytoplankton biomass, often equalling or exceeding growth estimates.