State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Department of Water Resources (DWR), China Institute of Water Resources and Hydropower Research, Beijing, 100038, PR China.
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, Department of Water Resources (DWR), China Institute of Water Resources and Hydropower Research, Beijing, 100038, PR China.
J Environ Manage. 2021 Jul 15;290:112572. doi: 10.1016/j.jenvman.2021.112572. Epub 2021 Apr 21.
Dams have reduced longitudinal river connectivity (LRC) worldwide, impairing habitat and migration opportunities for many freshwater fish species. However, national assessments linking LRC and threatened inland fish species distributions are lacking. Here, we show the trends in the LRC in China over the past 60 years, and quantitatively analyse their implications for threatened inland fish species. The average LRC in China decreased from 93.5% in 1960 to 25.1% in 2018, and the significant deterioration in LRC occurred over the last 20 years. Water resource regions with a high number of threatened fish species are concentrated in southern China, and the degree of threat to inland fish species increases with a decreasing average LRC. A total of 125 inland fish species are threatened by habitat degradation and loss, which is mainly caused by the construction of dams. Intrinsic factors and pollution are two other key threats to fish species in addition to the reduction of LRC. The results of this study can help us better understand the trends in LRC in China and their implications for inland fishes. Meanwhile, this study provides guidance for river management to help preserve biological diversity, including enhancing management of natural reserve areas, establishing ecological compensation mechanisms, preventing biological invasion, and monitoring and evaluation of restoration efforts.
大坝减少了全球范围内的河流纵向连通性（LRC），损害了许多淡水鱼类的栖息地和洄游机会。然而，缺乏将 LRC 与受威胁内陆鱼类物种分布联系起来的国家评估。在这里，我们展示了过去 60 年来中国 LRC 的变化趋势，并定量分析了它们对受威胁内陆鱼类物种的影响。中国的平均 LRC 从 1960 年的 93.5%下降到 2018 年的 25.1%，LRC 的显著恶化发生在过去 20 年。受威胁鱼类物种数量较多的水资源区集中在中国南方，内陆鱼类物种受到的威胁程度随着平均 LRC 的降低而增加。共有 125 种内陆鱼类因栖息地退化和丧失而受到威胁，这主要是由于大坝的建设造成的。除了 LRC 的减少外，内在因素和污染是鱼类物种的另外两个关键威胁。本研究的结果可以帮助我们更好地了解中国 LRC 的变化趋势及其对内陆鱼类的影响。同时，本研究为河流管理提供了指导，以帮助保护生物多样性，包括加强自然保护区管理、建立生态补偿机制、防止生物入侵以及监测和评估恢复工作。
