Phytoplankton photosynthesis, productivity, and species composition in a eutrophic estuary: comparison of bloom and non-bloom assemblages

During 2 periods in the late spring and early summer 1989, blooms in the Rhode River, Maryland, USA, were triggered by nutrient inputs from local and remote watersheds. Parameters of the photosynthesis-irradiance relationship increased in May when the bloom was dominated by Thalassiosira pseudonana, and decreased in June when the bloom was dominated by large dinoflagellates. Relative variability of quantum efficiency was a s great a s that of chlorophyll-specific absorption coefficient. Light-saturated photosynthetic rates were predictable based on species counts and previously published size-dependent, nutrient-saturated growth rates for diatoms and dinoflagellates.