China is using an artificial intelligence-driven fish identification system to monitor species travelling through a fishway on a hydropower dam on the Yarlung Tsangpo River, Tibet’s largest river. The technology has replaced labour-intensive manual counting with automated, round-the-clock monitoring designed to identify and track species unique to the Tibet autonomous region.
The system is operating at the 116-metre-tall Zangmu Hydropower Station, which began operating on the middle reaches of the Yarlung Tsangpo in 2015. According to Global Times, the fishway at the facility has helped around 570,000 rare fish swim upstream since the station began operating.
Yang Xiaocheng, director of safety and environmental protection at the dam, told Global Times that monitoring indicated that fish populations in the middle reaches of the river remained stable and had not declined because of the hydropower station. He said aquatic ecology and animal and plant life throughout the middle gorge section of the river had instead shown positive changes.
The monitoring system is part of efforts to assess whether man-made fishways can reduce the ecological disruption caused by dams. Hydropower facilities provide flood protection and renewable electricity, but dams can also restructure natural water bodies and block fish from reaching feeding and spawning grounds, potentially limiting reproduction.
The Zangmu fishway was designed specifically for local conditions. Team members travelled to Canada and the United States to study other projects before developing the structure, which was built with a gentle incline to accommodate local cold-water species with weaker swimming abilities than species in North America. The system also uses an optimal flow speed intended to encourage fish to swim upstream.
Seven fish species unique to the river pass through the fishway, including protected species such as Glyptosternon maculatum, a catfish found at high altitudes. Zhang Lianming, a design engineer at the dam, said that when completed, the fishway was the largest and highest-altitude project of its kind in China and demonstrated that fishways could be constructed for dams more than 40 metres high.
Initially, fish passing through the route were monitored manually from an observation room window. As the number of migrating fish increased, however, the process became slow and could not provide sufficiently accurate figures. An AI-based identification system trained using historical footage was subsequently introduced to improve monitoring efficiency.
Using sonar and optical technologies, the system identifies species, counts fish and analyses characteristics including swimming posture and fin features, achieving 95 per cent accuracy. It also records migration timing and water temperature to assess the effectiveness of the fishway. The resulting information is shared with research institutes and other hydropower facilities in China.
The use of technology reflects broader efforts internationally to monitor aquatic species around large infrastructure projects. Advanced systems incorporating drones, AI and 3D stereo cameras are used in the US by the Alaska Fisheries Science Centre, while Innovasea has partnered with Nova Scotia Power in Canada to develop technology for detecting, classifying and counting fish passing through hydroelectric dams.
At Zangmu, conservation efforts also include a breeding and release programme. According to Global Times, just under 2 million fish have been returned to the wild from the facility since it opened, with the programme intended to support the stability of rare fish populations in the Yarlung Tsangpo.
The technology is being deployed as China expands hydropower development along the river. A massive 60-gigawatt dam is currently being built on the lower reaches of the Yarlung Tsangpo in Medog county, close to the disputed border with India. With a planned capacity three times larger than the Three Gorges Dam, the project has raised concerns over potential environmental effects both in Tibet and downstream in India, where the river is known as the Brahmaputra, and Bangladesh.
The experience at Zangmu therefore provides an example of how China is combining hydropower infrastructure with automated ecological monitoring, while the scale of future development along the river continues to focus attention on the challenge of balancing energy production with the protection of aquatic ecosystems.
