Coastal ecosystems face increasing exposure to multiple stressors, including environmental change, land-based inputs, and overfishing. However, how to systematically analyze the dynamic patterns of rebuilding stocks jointly driven by environmental changes and human activities, and construct a comprehensive evaluation framework for ecological restoration effectiveness under complex habitat conditions, has become the core difficulty in current research.
To address this challenge, the research team led by Prof. ZHANG Hui from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) quantified the adaptation mechanisms and sensitivity thresholds that shape the rebuilding of fishery stocks under multiple stressors on a long-time scale.
The study was published in Journal of Environmental Management on Nov. 28.
As an important fishery stock in China, Portunus trituberculatus once experienced a sharp decline in resources due to overfishing and habitat degradation. In recent years, its abundance has partially recovered through measures such as stock enhancement, making it a typical rebuilding stock among China's marine fishery resources.、
Taking this stock as the research object, the research team constructed a multi-factor analytical system by analyzing nearly 15 years of monitoring data on biological resources and habitat environments in the Yangtze River Estuary and its adjacent waters, forming a complete analytical framework covering resource assessment, driver analysis, sensitivity ranking, and interaction effect evaluation.
The results show that the stock biomass of this species in the Yangtze River Estuary exhibits significant seasonal variation, with its spatial distribution showing a seasonal migration pattern. Among various driving factors, sediment concentration and runoff have significant impacts on the biomass of this species. Sensitivity analysis further indicates that biomass is most sensitive to changes in runoff. Interaction effect analysis revealed a clear trade-off between stock enhancement and fishing pressure: excessively high fishing intensity can substantially weaken the resource supplement effect of stock enhancement.
Building on these findings, the team constructed a four-dimensional evaluation framework of "environmental regulation - land-based source control - balance of human activities - adaptation of interaction effects" and formulated targeted resource management strategies. This framework breaks through the limitations of traditional single-species assessment and can adapt to the fishery resource assessment needs of different marine areas through parameter adjustment, providing a scientific basis for regional marine ecological protection and the sustainable development of fisheries.
"Our results provide important scientific support for the fishery stock restoration and sustainable fisheries management in China," said Prof. ZHANG.
Research route and analytical framework. (Image by IOCAS)
(Text by SUN Xu, ZHANG Hui)
Media Contact:
ZHANG Yiyi
Institute of Oceanology
E-mail: zhangyiyi@qdio.ac.cn
(Editor: ZHANG Yiyi)