As economic development and urbanisation reshapes the Mekong region, Cambodia is taking steps to balance infrastructure growth with environmental sustainability.
As economic development and urbanisation reshapes the Mekong region, Cambodia is taking steps to balance infrastructure growth with environmental sustainability.
Cambodia has become just the second country in the region, behind Laos, to build fish passages, an innovative solution to the challenges posed by irrigation and hydropower projects on fish migration.
Australia continues to play a crucial role in advancing sustainable fisheries in the Mekong region, with the Australian Centre for International Agricultural Research (ACIAR) committing AUD $18 million ($11.3 million) in 2025 to fisheries research in Cambodia, Laos, Thailand and Vietnam.
Speaking at the 2nd Lower Mekong Basin Fish Passage Conference on February 5, Wendy Umberger, CEO of ACIAR, highlighted Australia’s dedication to supporting fish-friendly infrastructure and policy initiatives.
“Through strategic partnerships, we are driving innovation and capacity building to ensure the long-term sustainability of Mekong fisheries,” she said.
A $5.2 million initiative under the – Mekong-Australia Partnership–Water, Energy Climate Programme – is being directed toward the adoption of fish passage technology in Laos and Cambodia and technical skills development in Vietnam and Thailand, as well as policy advocacy to promote fish-friendly infrastructure.
Cambodia has already made significant progress in constructing fishways, with two already built in Siem Reap province, one in Kampong Chhnang and another nearing completion in Kampong Speu.
Local communities gain more fish yield from the Sleng fishway, as it allows fish to return to their spawning grounds. ACIAR
Khun Savoeun, secretary of state for the Ministry of Agriculture, Forestry, and Fisheries, acknowledged the crucial role of the fishways in restoring fish migration patterns.
He also pointed out that factors such as deforestation and climate change continue to threaten fish populations.
“Fish no longer migrate as they naturally would due to development, but the fishways offer them a path to their traditional breeding grounds,” he explained.
“Fish provide 50-80% of the animal protein consumed by millions in the Mekong Basin,” noted Umberger.
“However, expanding irrigation and hydropower projects threaten these vital populations, impacting food security and economic stability,” she warned.
She said balancing economic development with environmental conservation is critical. The fish passage research is restoring fish populations and ensuring communities continue to benefit from the river’s natural resources.
ACIAR's CEO, Wendy Umberger, addresses the 2nd Lower Mekong Fish Passage Conference 2025 in Siem Reap. Hong Raksmey
Savoeun highlighted the necessity of fishways for both restoring fish migration and enhancing fisheries yields.
“Though we don’t know the exact percentage increase in fish population, after the construction of the fish passage, we observed fish using this route to lay eggs, produce more offspring, and seek food,” he explained.
For nearly 15 years, ACIAR has worked with partners such as Charles Sturt University and Alinea International to develop fish passage technology.
Research led by Professor Lee Baumgartner identified over 7,500 barriers to fish migration in the Lower Mekong, prompting the strategic installation of fish ladders.
The first fish passage in Laos enabled the movement of 177 fish species, including three on the IUCN Red List.
In November 2023, Cambodia inaugurated its first fishway, the Sleng Fishway, located in Sleng village, Kralanh District, Siem Reap province.
The structure is expected to benefit over 20,000 individuals across 31 villages by increasing fish availability and improving food security.
The project is projected to increase fishing income for up to 5,000 families and help preserve over 100 local fish species, marking a crucial step towards sustainable fisheries management in Cambodia.
Ensuring free fish migration is not just an environmental concern – it is essential for public health.
Australian ambassador to Cambodia, Derek Yip, underscored the role of small fish in maternal and childhood nutrition.
“Small fish, often consumed whole, provide essential calcium and amino acids critical for early childhood development and maternal health,” he said.
In riverine communities, women play a vital role in managing household food security, relying on fish as a major protein source.
Yip also noted that effective water management is crucial in Cambodia, where irrigation is essential due to the country’s reliance on rice production, a key contributor to livelihoods and exports.
Indonesia plans to open its first fishway near Jakarta in April 2025, demonstrating a growing recognition of fishways as a cost-effective solution to challenges posed by irrigation and hydropower development.
