Session D5: Using a Waterfall System as a Natural Laboratory to Inform the Design of Fish Passes in the Mekong

Abstract: The Mekong Basin features 103 long distance migratory fish species contributing 800,000 tonnes per year to the regional inland fishery. At Khone Falls in southern Laos, the Mekong River splits into multiple channels and flows through numerous waterfalls that constitute a major obstacle to fish migrations across the basin. We present here the approach and methodology of a new research project using the Khone Falls bottleneck as a natural laboratory to inform the design of fish passes in the Mekong. This project is based on systematic gathering of local ecological knowledge, combined with hydrological measurements and river geomorphological characterization in multiple sites. The project will produce a matrix detailing, for the dominant Mekong migratory species, flow conditions and river conditions passable, preferred or not passable to fish. This information will help design fish ladders better adapted to native fish species, thus contributing to improved mitigation of the impact of hydropower dams on food security and fish biodiversity in the Mekong Basin

ラオスにおける水生生物の多様性 : ウー川水系の水産資源利用と管理

京都大学0048新制・課程博士博士(地域研究)甲第16976号地博第128号新制||地||42(附属図書館)29651京都大学大学院アジア・アフリカ地域研究研究科東南アジア地域研究専攻(主査)教授 岩田 明久, 教授 小林 繁男, 准教授 竹田 晋也, 准教授 古澤 拓郎学位規則第4条第1項該当Doctor of Area StudiesKyoto UniversityDA

Freshwater fisheries conservation can increase biodiversity

We evaluate the impact of a fisheries management program centered on the definition of Fish Conservation Zones on biodiversity, measured as the number of species caught in the last 12 months. Data comes from a set of 32 villages in central Lao PDR, of which half participated in the program, and the remaining are a set of matched control villages. The estimated causal effects are large (an increase between 29 and 32 species) and robust to the potential importance of unmeasured confounders. We also show that initial conditions may matter, as the program seems particularly effective in villages with high probability of participating in the program. These results are particularly important given the paucity of evidence regarding the impact of conservation programs on biodiversity, particularly in the context of freshwater ecosystems. Further directions of research suggested by these results are discussed