Abstract:
Picophytoplankton represented a mean value of >30% of the total chlorophyll a in winter and c20% in other seasons. In terms of total carbon fixation, values of 23% and 13% contribution were obtained. The picophytoplankton were composed of chroococcoid cyanobacterial cells at densities between 103 and 104 ml-1 together with larger eukaryote cells at densities up to 103 ml-1. Winter counts were lower than those for summer. Cyanobacteria displayed subsurface peak densities higher in the water column than the eukaryotes.