Shrimp polyculture: An economically viable and environmentally friendly farming system in low saline coastal region of Bangladesh

Shrimp polyculture with carp species has a great potential in economic development of Bangladesh. At present, shrimp polyculture technology is being most extensively used by shrimp farmers in the coastal regions of the country; however, the mechanism of scientific culture system is not well understood. Therefore, to evaluate the economic feasibility of shrimp (Penaeus monodon) polyculture with carp over mix culture of shrimp with prawn (Macrobrachium rosenbergii) and monoculture of shrimp, a study was conducted for a period of six months from July to December 2016 in selected ghers (modified low-lying rice fields with raised dykes, used for seasonal production of shrimp) at Kaliganj Upazila of Satkhira District, Bangladesh. Water quality was within the suitable range for shrimp culture. During the study period, environmental sustainability in terms of soil quality was achieved in polyculture of shrimp with carps and tilapia (Oreochromis niloticus). Growth performance and total yield of shrimp (2087.87±34.47 kg/ha) and prawn (1789.47±27.45 kg/ha) were also significantly (P<0.05) improved in polyculture of shrimp with carps and tilapia compared to shrimp monoculture and mix culture of prawn and shrimp, respectively. The economic sustainability was also found to achieve in polyculture of shrimp with carps and tilapia (Oreochromis niloticus) in terms of the Benefit-cost ratio (BCR), which was significantly (P<0.05) higher (2.49±0.03) compared to other culture systems (1.96±0.06 in shrimp monoculture and 1.26±0.03 in shrimp and prawn mix culture).