The Mekong River, a vital resource flowing through Cambodia, Laos, Thailand, and Vietnam, plays a central role in the livelihoods of millions. 

Its fisheries provide crucial food and income, but growing pressures from urbanisation, energy dams and irrigation systems have significantly disrupted fish migration patterns. 

Australia and ASEAN have launched a collaborative effort which focuses on restoring these migration routes through fish passages, or fishways, which allow fish to bypass dams and other barriers.

Sponsored through the Mekong-Australia Partnership by the Australian Centre for International Agricultural Research (ACIAR) and the Department of Foreign Affairs and Trade, the project is working closely with Laos and Cambodia.

Today, it has expanded to include Vietnam and Thailand, with plans to include Indonesia in the near future.

The 2nd Lower Mekong Basin Fish Passage Conference, held in Siem Reap in February 2025, marked a significant milestone in this initiative. 

Derek Yip, Australian ambassador to Cambodia, addressed the opening of the conference. He highlighted the importance of the ongoing collaboration in safeguarding food security and promoting biodiversity. 

“ASEAN is particularly active in the Mekong subregion, including through 19 projects here in Cambodia, that have helped to introduce new knowledge, technological innovation and scientific research capabilities in agriculture and fisheries,” he explained.

His emphasis on cross-border collaboration within the region underscores the shared challenges and opportunities in the Mekong, where sustainable fisheries are critical for millions of people.

One of the primary goals of these projects is to ensure that development does not come at the cost of fish migration and biodiversity. 

Yip reflected on his visit to the Tonle Sap region in Cambodia, where he observed the balance between agricultural development and environmental preservation. 

“I saw how competing priorities like flood control and ensuring sufficient water for irrigation are critical to the lives and livelihoods of people here in Cambodia and across the Mekong,” he said.

ACIAR CEO Wendy Umberger also addressed the conference.

“Fishways are a proven solution for mitigating the impacts of irrigation development, ensuring healthy fish populations and providing lasting economic and social benefits for river-dependent communities.," she said.

Since 2010, ACIAR has worked with local governments, research institutions and communities in Laos and Cambodia, helping restore critical fish populations and mitigate the environmental impact of regional infrastructure projects.

Cambodia has already made significant progress in constructing fishways, with three already built, including two in Siem Reap, one in Kampong Chhnang and another nearing completion in Kampong Speu. 

Khun Savoeun, secretary of state for the Ministry of Agriculture, Forestry, and Fisheries, acknowledged the crucial role of the fishways in restoring fish migration. 

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.

The success in Cambodia and Laos has now expanded to Vietnam and Thailand, with countries across the Lower Mekong sub-region working to integrate fish passage solutions into their infrastructure projects. 

Umberger noted that the region’s experience has provided valuable insights for scaling these solutions across borders. 

“Our approach highlights the importance of scaling out innovations through partnerships and investments that address shared challenges,” she added.

Umberger highlighted that integrating fish passages into regional planning helps prevent ecological damage across the Lower Mekong Basin, protects fisheries crucial for food security and income, and strengthens community resilience and environmental sustainability.

Regional efforts will expand further, with Indonesia preparing to launch its first fish passage near Jakarta in April.

For over a decade, ACIAR has supported Charles Sturt University and collaborated with partner governments agencies in the Mekong region to restore fish populations.

“Balancing the needs of sustainable development with the health of ecosystems is more crucial than ever for the Mekong River Basin,” said Professor Lee Baumgartner of Charles Sturt University, who has led ACIAR-funded research efforts since 2010. 

“This conference provides a collaborative opportunity for sharing insights and strengthening partnerships to ensure food security and sustain the livelihoods of millions who rely on the Mekong,” he added.