Phytoplankton biomass and productivity of different size fractions in the Vellar estuarine system, southeast coast of India

Abstract

Chlorophyll a (chl-a) and the gross production of different size fractions of phytoplankton were measured in both the Vellar estuary (st. A, July 20, 1988) and the Pichavaram mangrove (st. B, July 18, 1988). The largest quantity of chl-a was found in the fraction of 5-10 mu m at both stations; 3.6 mu g.l(-1) (33% of total chl-a) at st. A, 6.5 mu g.l(-1) (51% of total chl-a) at st. B. Similarly, the highest gross production was found in the fraction of 5-10 mu m at both stations; 49 mgC.m(-3).h(-1) (20% of total gross production) at st. A, 32 mgC.m(-3).h(-1) (22% of total gross production) at st. B. This suggested that phytoplankton of 5-10 mu m was important contributor to the primary production in this ecosystem at the time of this study.