Vietnam’s premier inland fishing ground is the Mekong Delta, in particular its seasonally flooded areas. Fishing is concentrated at the end of the August-to-November flood period, when receding floodwaters force fish to migrate from floodplains into rivers and canals.
The area devoted to aquaculture in the Mekong Delta grew by 39% from 2000 to 2006, reaching 7,238 square kilometers in 2007, or 71% of the national area. Aquaculture production in the Mekong Delta that year was 72% of the Vietnamese total. Floodplain aquaculture has not significantly developed, however, as the government has prioritized intensifying rice culture. In 2000, WorldFish and the Research Institute for Aquaculture No. 2 (RIA2) tested the economic and technical feasibility of community-based fish culture (CBFC) on floodplains. Although CBFC was found technically adapted to the environment, economically interesting and socially acceptable, only recently have local governments begun to experiment with extensively culturing carp in polyculture, tilapia and freshwater prawns.
Fishing Harbour, Vietnam
In the project landscape, rice paddies are delimited by protective dikes, embankments and canals. Fish culture was implemented in flood areas that permitted two rice crops per year, from December to March and from May or June to August. A third rice crop was possible where flood height and duration were shorter and paddies could be protected from flooding in August and September, as at two project hamlets.
The technical setting and organization of collectives was decided together with beneficiaries and local partners: RIA2 researchers and Department of Fisheries (DoF) extension staff to provide technical and management support, commune and district DoF officials to monitor the project, and potential stakeholders. Following site selection, newly formed CBFC groups established regulations and elected a management committee. The production model was extensive, relying on food naturally available in the water body.
The flooded rice fields selected for CBFC were entirely under private ownership. Membership in the CBFC group was limited to those who owned land within the project site, though this was not anticipated at project inception. Some groups shared benefits equally, while others shared according to the size of households’ landholding within the project site.
Most of the sites established in the provinces of Can Tho, An Giang, Dong Thap and Vinh Long in 2006 did not continue for a second year of trials. Trials at one hamlet continued until 2009 but with a pause in 2008. Four new sites were established in 2007 and 2008.
Summary of Outcomes
The first year of CBFC saw two groups in Can Tho achieve yields of 236 kilograms per hectare (kg/ha) and 242 kg/ha, and a group in Dong Thap achieve 1,937 kg/ha. However, the sites were small, with few households involved. The most favorable sustained yields in a single hamlet ranged from 124 kg/ha to 179 kg/ha.
Fingerlings of red tilapia, grass carp, silver barb and snakehead all survived poorly in the first year and were not stocked in subsequent years. The survival rates of all stocked species rarely exceeded 50%. Poor survival was frequently attributed to fingerlings that were too small (but nevertheless expensive). In addition to low fingerling survival rates, the cited constrains were poaching, low water levels and short grow-out periods. Conflicts with other resource users undermined production at one hamlet.Wild fish continued to contribute significantly to productivity during the intervention. Benefit-sharing arrangements allowed the wild fish catch to be estimated during the project at only one hamlet, where it increased by 4-5 fold over previous years. Farmers explained that enclosures prevented wild fish from migrating to canals as floodwaters receded. The effects of enclosure on fish migration and fish productivity in rice fields requires further investigation.
Where flooding was low enough to permit enclosing individual household plots, most participants preferred to discontinue CBFC in favor of individual fish culture or, more generally, a third rice crop. However, approaches to CBFC are evolving among groups of households that favor it in a few enclosed rice paddies. In provinces bordering Cambodia, deep floodwaters make CBFC more attractive.CBFC group leadership, management and benefit-sharing arrangements pose challenges. In the trials, weak community institutions could not ensure enclosures’ maintenance or protection from poachers. Marketing is another challenge, as prices are low at harvest time in markets glutted with wild catch.