Effects of flood control and drainage on fisheries in Bangladesh and the design of mitigating measures

Inland capture fisheries (open-water systems where naturally occurring fish are caught) are one of the main sources of animal protein in Bangladesh, and are an important sector of the economy. There is growing concern that flood control and drainage (FCD) projects have severely reduced fish stocks by reducing wetland areas and by blocking fish migration and dispersal routes. Results of surveys in 17 projects completed between 1970 and 1989 were consistent with this trend and show that projects with serious effects on fisheries may not be economically viable. However, a general decline in catches resulting from overfishing may also be a factor. The Bangladesh flood action plan forms a framework for accommodating mitigation of FCD effects on fish in the planning of future projects. Controlled flooding provides an opportunity to manage capture fisheries. Two types of measures are discussed: protecting wetlands within projects by building bunds to retain water during the dry season; and designing regulators that are operated to let adults of the commercially important but declining major carp escape to reach their spawning grounds, and which allow the passage into the projects of the surface layers of water containing spawn and fry of the same species during the monsoon peak. Projects can be planned and designed to be ‘fish friendly’ using such measures, but this will only be effective if they are managed and operated in ways that are consistent with this objective. This requires the active involvement of local fishing communities, and reconciliation of conflicting interests between farmers and fisherfolk.