Extracellular production and turn-over rates of phytoplankton in the Laccadive Sea (Lakshadweep)

Abstract

Extracellular production in the Laccadive Sea is high and ranges between 0 and 78% of total CO₂ assimilation by photosynthesizing phytoplankton. Average extracellular production at the surface is higher than in deeper layers within the euphotic zone which may be a consequence of light intensity. The relationship between chlorophyll a and extracellular production is discussed. Data from nearshore regions are compared to extracellular production from the Laccadive Sea. Turn-over rates of phytoplankton biomass have been calculated from the carbon equivalent weights of phytoplankton and particulate fixation rates. The occurrence of glycollic acid in this area is compared to dissolved carbohydrate values. The possible photosynthetic origin of glycollic acid is briefly discussed.