Estimates of primary produetion of benthic microflora were carried out in the Santos tropical estuary, on the southern coast of Brazil (24ºS, 46ºW). The samples were obtained seasonally over a one-year period. Six stations with different environ mental conditions were chosen. The samples, which consisted of the upper 2 mm of the sediment, were collected in the intertidal zone, according to Grøntved's (1960) methodology. The mean annual value of primary production was 45 mgC/m²/h, ranging from 1. 0 to 301.0 mgC/m²/h. The highest values were observed at the more sheltered stations, which contained the highest amount of organic material and, the highest input of polluted material. The epipsammic algae contributed with 40% of the total production while the epipelic ones contributed with 60%. The mean value for dark fixation of14C was 63%
Benthos; Micro-organisms; Primary-production; Intertidal zone; Sediments; Estuaries; Santos