Fish ecologists Dr. Doug Peterson, from the U.S. Fish and Wildlife Service (USFWS), and Dr. Stephen Walsh, from the U.S. Geological Survey, arrived in Laos on June 16 for a ten-day visit under the auspices of the U.S.-funded Smart Infrastructure for the Mekong Program. During their visit they will help research river ecology and lend their expertise on building dams in a more fish-friendly manner. Drs. Peterson and Walsh will also meet with several Ministries, provincial offices, universities, and non-governmental organizations, and will conduct site visits at Xayaburi, and Champasak Provinces and the Paksan District. They will also evaluate existing scientific research capacity and work closely with the Department of Livestock and Fisheries, the Living Aquatic Resource Research Center (LARReC), and the Ministry of Energy and Mines, to craft a long-term research agenda.
The U.S. Department of Interior’s fish experts are conducting these assessments over the course of three visits to Laos. The first component of this project took place earlier this year in January, when U.S. fish biologists looked at fish migration patterns in Laos. This second component is being conducted by U.S. fish ecology experts looking at the life histories and critical geographic locations of main population groups for the most important commercial and subsistence species. The third U.S. team will come later this year to look at fish genetics.
At most dams, the tremendous turbulence of the water can hurt or disorient fish, and the blades of a turbine can strike them. A new study focuses on a third problem, barotrauma – damage that happens at some dams when a fish experiences an enormous change in pressure.
U.S. scientists have found that, depending on its specific path, a fish traveling through a dam can experience an enormous drop in pressure, similar to the change from sea level to the top of Mt. Everest, in an instant. Just as fast, as the waters swirl, the fish suddenly finds itself back at its normal pressure. These sudden changes can have a catastrophic effect on fish, and trying to keep minimum water pressure higher in all areas near the turbine is key for preventing barotrauma. Indeed, reducing the amount of pressure change to which a fish is exposed is a crucial component for any turbine that is truly “fish friendly.”
The Smart Infrastructure for the Mekong team’s final report, combining key findings of fish migration, fish ecology, and fish genetics assessments, will be presented to the Lao Living Aquatic Resource Research Center and the Ministry of Energy and Mines by the end of 2015.