An approach to differentiate net photosynthetic and other biochemical production and consumption of oxygen in estuarine water bodies and aquaculture systems

Photosynthetic production in water plays a vital role on the fertility aquatic ecosystems influencing the dissolved oxygen level and organic productivity. Although there are several methods such as cell count, chlorophyll estimation, 14C technique and light and dark bottle oxygen technique to assess the photosynthetic production in water, every method has its own merits, demerits and limitations. Moreover, the methods adopted in the open sea water are being applied directly in the shallow estuarine and other shallow backwater systems, which do not always give reliable results due to the influence of other microorganisms. This paper proposes an Improvement in the formula to assessment of oxygen which has been tested using a series of data collected from the shallow estuarine waters of the 'Mangalvanam' (mangrove biotope) at Cochin.