The size structure of phytoplankton biomass and productivity
and the specific growth rates (m) of the picoplankton (i.e., < 3mm fraction) were
examined in six Hawaiian embayments. The portion of total phytoplankton
chlorophyll present in the < 10 mm and < 3 mm fractions ranged from 38 to 62
percent and 16 to 52 percent, respectively. Picoplankton accounted for between
34 and 63 percent of total community photosynthesis. Picoplankton growth
rates ranged from 0.056 to 0.202/h (0.97 to 3.62 doublings/day). The rapid
growth rates in these aquatic environments probably result from inputs of
terrestrially derived nutrients; the m values for the picoplankton fraction are
thought to represent upper limits for growth rates of the total population
