Keywords: Bangladesh, fisheries, floodplains, rice, irrigation, surface water abstraction, simulation, fish production, fish catches, diversification, winter crops, alternative crops
The effects of surface water abstraction for rice irrigation on floodplain fish production in Bangladesh
Abstraction of surface water for irrigation poses a serious threat to the sustainability of floodplain fisheries in Bangladesh. Previous fisheries research has accorded a central role to dry-season (Rabi) water maintenance in safeguarding the health of the fishery, but rice irrigation water abstraction dries up water bodies at a rapid rate. Having reviewed various aspects of this water abstraction problem, we employ a dynamic-pool fisheries model to simulate the effects of abstraction on fish production. Simulations indicate the problem is indeed very serious, with every hectare of surface water based irrigation reducing total fish catch in the modelled area by 272 kg, and abstraction to irrigate more than 500 hectares of the 6,773 hectares area modelled causing a complete collapse in the fishery. A review of feasible solutions indicates that winter diversification out of rice is one of the few widely applicable solutions available, due to the significantly lower water requirements of alternative winter crops.