Abundance of picophytoplankton in the Subantarctic and subtropical frontal zones was found to be 106-107 cells/l. Biomass of eucaryotes and procaryotes reached 2 g/m**2 and accounted for 1-15% of total phytoplankton biomass. A deep peak in the distribution of phytoplankton abundance was found at 40-120 m. Maximum number of dividing cyanobacteria cells occurred at depths of 40-60 m. An estimate of picophytoplankton production shows that picophytoplankton accounts for 30-40% of total primary production.

Supplement to: Mikaelyan, A S (1987): Picophytoplankton of subantarctic waters of the Pacific Ocean. Oceanology, 27(5), 615-620