Georgina Smith/CIAT.

Book: Fish, Sediment and Dams in the Mekong

How hydropower development affects water productivity and food supply

The Mekong river and its tributaries are being harnessed to produce electricity at a very rapid pace. This river basin is also home to one of the largest inland fisheries in the world. 

What are the affects of hydropower development on fish populations in the basin? A new book, Fish, Sediment and Dams in the Mekong, aims to answer this and other urgent questions.


Mekong fisheries are robust, in part, because of the river's rich sediment load. Sediments play a very important role in all aspects of the life of a river fish, including respiration, nutrition, reproduction, migration and habitat. In turn, communities in the basin depend heavily on these fisheries and for their own nutrition and livelihoods.

Unfortunately, hydropower reservoirs can stop sediments and fish from flowing downstream, which influences the river ecology and fish populations, as well as nutrient flows and river health. A drop in the number of fish in the basin will have significant implications for economic well being and growth, nutrition and food security, and biodiversity.

Research conducted by WordFish on the topic has been compiled in the hopes that having more complete information on the possible effects of hydropower development would lead to better policy making and investment practices.

The book echoes a report recently published in Science Magazine, co-authored by WorldFish Senior Scientist Eric Baran, which calls for a more holistic planning process that takes into account the cumulative effects of hydropower development. The report looks at how hydropower dams are threatening the biodiversity and fisheries of major rivers, including the Mekong, and advocates for clearly analyzing the benefits of riparian ecosystem services, which are massively important and economically significant,in order to better understand the trade-offs.