Studies on Seasonal Variations in Primary Productivity and Related Water Quality Parameters in Freshwater Fish Ponds in Coastal Andhra Pradesh, India

Abstract

The present study was designed to demonstrate the seasonal variations in physico-chemical parameters in sh ponds and carried out for one year at monthly intervals in ten sh ponds. Maximum value of Gross Primary Production (GPP) and Net Primary Production (NPP) is observed during pre-monsoon and subsequently the lower values during monsoon season correspond to the attenuation of light. A signicant variation in seasonal community respiration was noticed during the study period. Seasonal uctuations in gross and net primary production values were quite apparent in surface waters and showed a bimodal type of distribution. The values were generally high during post winter months (March to June) and low during winter (January) and monsoon months (July and August). The dissolved oxygen content and chlorophyll-a were correlated with increase in temperature and light transparency during the pre-monsoon period whereas the phosphate concentrations were measured maximum in monsoon followed by pre-monsoon and post-monsoon suggested the accumulation of inorganic nutrients through terrestrial catchments