Primary Production in the Southwest Sargasso Sea January - February, 1960

Primary production was measured at 22 stations in the Sargasso Sea South of Bermuda during the winter of 1960. The mean rate of production was 0.05 g carbon assimilated/m²/day as measured by C¹⁴ uptake and 0.09 as estimated from chlorophyll and radiation measurements. The low values appear to be typical of the tropical Atlantic and reflect nutrient impoverishment resulting from stratification of the surface layers.

Five-fold variations in solar radiation had little effect upon and showed no correlation with rates of primary production indicating that light is not a limiting or contributing factor at those latitudes.

There are indications of a diurnal periodicity in C¹⁴ uptake and chlorophyll concentrations, twenty-four hour C¹⁴ uptake experiments initiated in daytime giving lower values than those begun at night while lower chlorophyll values were measured at night than during daylight.