Helping fish to migrate and breed in the Lower Mekong Basin

As hydropower development increases in the Lower Mekong Basin, there are concerns about the impacts on fisheries which provide significant socio-economic value to the basin population. AWP has partnered with the Mekong River Commission, GIZ and Charles Sturt University (CSU) to test methods to monitor how fish pass through dams.

The Lower Mekong Basin (LMB) is currently in the midst of a hydropower “boom”, with multiple hydropower dams currently slated for the mainstream, and many more for its tributaries.

Hydropower growth will contribute to increasing energy supplies, but may disrupt river connectivity and have an impact on the ecological health and productivity of the LMB upon which many people support their livelihoods and income.

There is a specific concern for potential impacts on the LMB’s fishery because of its immense socio-economic value.

The fishery has an annual first-sale worth of around $US17 billion, and supplies between 47% and 80% of the animal protein intake of the local people (48% for Lao PDR, 47% for Thailand, 80% for Cambodia and 59% for Vietnam). There is a pressing need to ensure that hydropower development, which is projected to improve the standard of living for Lower Mekong citizens, does not impact a primary source of protein and micronutrients.

The barrier effects of hydropower dams can inhibit some fish species from completing essential life stages by limiting access to refuge, feeding, breeding and nursery habitat. The operational aspects, such as “hydropeaking” of flows during peak power generation periods, can also significantly mess with the natural cycles of fish.

To try and better understand the impacts of hydropower, especially over the long-term, the Mekong River Commission (MRC) recently launched the piloting of the Joint Environment Monitoring (JEM) Programme for Mekong mainstream hydropower projects at two Mekong mainstream hydropower projects located at Xayaburi and in the Don Sahong area, in northern and southern Lao PDR, respectively.

The Australian Water Partnership (AWP) has partnered with the MRC, GIZ and Charles Sturt University (CSU) to test the MRC’s pilot fish passage monitoring guidelines and methods.

This includes trialling various cutting-edge fish tracking technologies for potential use in the MRC’s pilot study, and running training sessions on the use of these technologies for regional institutions. Most importantly, it also involves close collaboration with in-country partners from fisheries and energy line agencies. This has involved developing and implementing training activities so that in-country partners can implement the monitoring activities over the long term.

The project team has already successfully tested two different fish tracking technologies and built institutional capacity in regional organisations, such as the MRC and national research centres, in using the technologies.

The work has required close consultation with villagers in the region, engagement with lower Mekong countries, training activities for government staff with the aim of minimising the future impacts of hydropower on people in the LMB.

These outcomes will help optimise the adoption and implementation of fish passage monitoring guidelines, to benchmark long-term changes in fisheries resources arising from hydropower development.

Featured image: Surgeons from AUSVET, NUoL and LARReC performing surgery on an Asian red tailed catfish near Don Sahong in July 2022. (Credit: Wayne Robinson)
In article images: Surgeons from LARReC performing surgery on Mekong fish near Don Sahong  | Surgeons from LARReC releasing fish after surgery near Don Sahong  (Credit: Wayne Robinson)
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