Aquatic ecosystems worldwide are facing accelerating degradation from climate change, human activity, and watershed development. Conventional assessment methods—evaluating water quality, biology, and habitat in isolation—remain fragmented and retrospective, missing the cross-scale interactions that drive ecosystem collapse.
In a new review article published in Water & Ecology , a research team led by Qiuwen Chen from Nanjing Hydraulic Research Institute proposed that watershed aquatic ecosystem health should be understood as a combined social–ecological and process-based property, rather than as a simple aggregation of water-quality or biological indicators.
“The main problem is fragmented diagnosis,” says Chen. “We track chemistry, species loss, and physical damage separately, yet none of these snapshots can reveal why the system is failing or where it is heading. We must treat the watershed as a coupled social–ecological system.”
Drawing on bibliometric evidence from the Web of Science and the China National Knowledge Infrastructure (CNKI), the authors traced how international frameworks—from the U.S. Rapid Bioassessment Protocol to the EU Water Framework Directive and China’s evolving river health initiatives—have expanded assessment coverage. Three persistent bottlenecks remain:
The review brought together three parallel research strands—biological integrity, habitat structure, and governance. “Only by integrating these dimensions can assessment move from static reporting to anticipatory decision-making,” says Chen.
In particular, four frontiers are reshaping the field:
The authors noted that the urgency is acute in China, where heavily engineered rivers, multi-source pollution, and climate extremes create complex trade-offs. “While China has advanced in digital twins and large-scale restoration, assessment must evolve from single-objective engineering to process-oriented governance that coordinates water resources, environments, and ecosystems across entire basins,” Chen explains. “Aquatic ecosystem health is not a biophysical scorecard—it emerges from interactions among ecology, land use, economics, institutions, and public values.”
The authors urged that future progress should include linking structure with process, science with governance, and upstream protection with downstream well-being.
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Contact the author:
Qiuwen Chen
-Center for Eco-Environment Research, Nanjing Hydraulic Research Institute, Nanjing 210029, China
-Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210098, China
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Water & Ecology
Systematic review
Not applicable
Challenges and future perspectives on watershed aquatic ecosystem health study
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.