Shrimp and Rice

Research partners hammer out a protocol to control inflows of seawater in the Mekong Delta, satisfying the needs, and improving the income, of shrimp and rice farmers alike

The rapid development of aquaculture in the river deltas of Southeast Asia has brought conflicts over access to water. Policymakers and planners need to take into account the water requirements of ecosystems and the needs of the people who depend on them for their livelihoods when planning water allocations.

Increasing shrimp production in the Mekong Delta of Vietnam has precipitated conflicts between rice farmers and shrimp farmers over access to water. Rice farmers require freshwater for irrigating rice in the dry season, while shrimp farmers require brackish water during this low-flow period. To expand the freshwater zone for rice production, the government built dams and sluice gates on the Ca Mau Peninsula to block inflows of the brackish water — which are critical to producing shrimp. The conflict came to a head in Bac Lieu Province, when in 2001 shrimp farmers destroyed a major diversion to allow the flow of brackish water inland to service their production systems.

A rice farmer plants paddy in freshwater. Water managers and provincial authorities adopted guidelines and recommendations provided by IRRI, IWMI and WFC, to manage the conflicting demands for fresh water and brackish water between rice farmers and shrimp farmers, by providing suitable quality water to rice farmers in the eastern part of the Mekong delta whilst keeping the western part dedicated to shrimp production.

With support from the United Kingdom’s Department for International Development and the Challenge Program on Water and Food , a collaboration of the International Rice Research Institute ( IRRI), International Water Management Institute (IWMI) and WorldFish Centerwas initiated to establish viable options to address the conflict between rice and shrimp farmers. A participatory process joined farmers, fishers, water managers, and local and provincial government authorities to develop an agreed land-use zoning map and a protocol for operating the sluice gates based on modeled scenarios for regulating the salinity of rivers and canals.

IWMI researchers, together with colleagues from IRRI, Can Tho University and Nong Lam University, succeeded in improving and applying a hydraulic and salinity model for analyzing different options for operating the sluice gates to control water salinity, and they communicated their findings to decision makers. Water managers and provincial authorities have adopted the guidelines and management recommendations to manage the conflicting demands for water between the two different interest groups, simultaneously providing suitable water to rice farmers in the eastern part of the province while keeping the western part dedicated to shrimp production.

Surveys undertaken from 2000 to 2005 have shown that, as a result of a more structured approach to managing water in the area, fishery production has improved significantly. The annual per capita gross domestic product of approximately 800,000 people in Bac Lieu Province has increased from US$248 to $648. In addition, the income of the poor communities living in areas with acid sulfate soils has increased by 3 fold, and no conflicts have occurred between the two water-user groups since 2002.