Investigation of Improved Extensive Culture System of Shrimp with Special Reference to Soil-water Characteristics in South-West Region of Bangladesh

Abstract

Water and soil quality parameters are important catalyst for gaining sustainable shrimp                         and prawn production. In this context, an investigation was carried out to assess soil-water               quality and production parameters of 9 selected improved extensive shrimp Ghers in                  Bagerhat districts of Bangladesh over a growing cycle. The physico-chemical parameters of soil-water were measured and analyzed by standard methods. Total yield (3,138.46 kg/ha/cycle)                     of fishes was also calculated from the stocking and harvesting data. Most of the parameters                      of soil and water correlated significantly with each other suggesting a high degree of                interactions between different parameters in the system. A pattern of qualitative and               quantitative difference of zooplankton over phytoplankton was recorded in these farms               Therefore, a high degree of salinity fluctuation and iron deposition in waters was also documented. However, significantly lower concentrations of phosphorus in the soil indicated a net retention and trapping of phosphatic nutrients in the environment. Moreover cropping pattern was two cycles (fishes single, paddy single) per year, feeding frequencies was once in daily and fish production ranged from 2076 to 4640 kg/ha/cycle. The present findings indicate that improved                     extensive culture systems served as less health risk and economically viable for sustainable fish production.