The biomass and primary productivity of phytoplankton assemblages from the marginal ice zone of the Fram Strait were investigated during June-July 1984 as part of the 1984 Marginal Ice Zone Experiment. The entire region was characterized by strong vertical stratification and reduced nutrient concentrations near the surface. Chlorophyll a levels were elevated at the ice edge and decreased both under the ice and away from the ice edge. Chlorophyll concentrations were greatest at the top of the pycnocline and averaged 2.9 #g L-• at 20 m. Primary productivity was also greatest at the ice edge, with daily integrated productivity averaging 426 mg C m -2 d -•. Small flagellates numerically dominated the assemblages. Growth rates, when corrected for detrital material, were close to their potential maximum for the temperatures encountered. Large differences between the water temperatures, nitrate concentrations, and chlorophyll a levels during similar periods in 1983 and 1984 were noted. These differences, in addition to the spatial and temporal variations in biological processes induced by mesoscale eddies, suggest that the interannual variability in marginal ice zones may have significant consequences to the region's food web dynamics.

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