Significance of biomass and light availability to phytoplankton productivity in San Francisco Bay

Abstract

Primary productivity was measured monthly at 6 sites within San Francisco Bay, USA, throughout 1980. The sites were chosen to represent a range of estuarine environments with respect to salinity, phytoplankton community composition, turbidity, and water depth. Annual net production over the photic zone ranged from 95 to 150 C m super(-2), and was highest in regions of lowest turbidity. Daily photic zone net productivity PN sub(pd) ranged from 0.05 to 2.2 g C m super(-2) d super(-1), and was significantly correlated with the composite parameter B I sub(o)/ epsilon (where B = phytoplankton biomass/I sub(o) = daily surface insolation/epsilon = attenuation coefficient). Linear regression of PN sub(pd) against B I sub(o)/ epsilon indicated that most (82%) of the spatio-temporal variability in primary productivity within this estuary is explained by variations in light availability and phytoplankton biomass.