Delta Flows: The Role that Delta’s play in sustaining basin-scale fisheries in the Mekong and Irrawaddy Rivers

  • Research & Development
  • Apr 2017 - Oct 2018
  • Partners: National Univ. of Laos, Research Institute for Aquaculture No 2, Can Tho Univ., Yangon Technical Univ., Min. of Livestock, Fisheries and Rural Dev., Myanmar Institute for Integrated Dev., U-IHE, Charles Sturt Uni.
  • Donor: Stichting IHE
  • Donor Programme: DGIS - UNESCO-IHE Programmatic Cooperation
East Asia and Pacific
East Asia and Pacific

The basins of both the Mekong and Irrawaddy Rivers are complex social-ecological systems providing resources to support large, reliant local populations. Migratory fish species are a major resource provided by both rivers and an essential component of food security in delta and upstream areas. But fisheries are threatened by plans to fragment the rivers with the construction of dams and alter their flows to prioritise energy generation. This fragmentation cuts off critical migration pathways and flow alterations disrupt habitats required for different life stages of key fish species. It has been long suspected that many large upstream migrant fish in both systems possibly originate from the ocean. If this is true, then the planned future mainstem dams will effectively destroy whole species by blocking access to critical habitat. If hard data on fish migration can be obtained now, there is a substantial opportunity to either alter their planning on such dams, and move them away from migratory routes, or at a minimum to ensure they incorporate adequate fish migration facilities. Once the dams are built, it will be too late. Our proposed work will test whether these assumptions are true. The first step in the project will be a capacity building workshop on delta fisheries in both basins, current state of knowledge and innovative technologies to use to map migratory pathways. Leading on from that working together with researchers, authorities and communities in the delta regions of both basins we will collect information on the most important subsistence, commercial and endangered fish species. From the information gathered, the key species identified will be sampled, and using innovative technology (otolith microchemistry) the key migratory patterns of these fish will be able to be analysed and key migratory species identified. Through another partners workshop this information will then be discussed in relation to informing planning, policy and management, and preliminary guidelines designed.