Chang Tao, Gong Zheng, Shang Kunyu, Hu Piao
Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
College of Life Sciences, Zaozhuang University, Zaozhuang 277160, China.
Animals (Basel). 2025 Mar 4;15(5):730. doi: 10.3390/ani15050730.
The riverine fish species are highly vulnerable and responsive to large-scale water diversion projects. These adverse impacts are more pronounced in the plateau river ecosystems, which may change the environmental conditions of fish habitats and community structure. We investigated the effects of various environmental factors on fish diversity in seven rivers of the Western Sichuan Plateau, which is the planned area of China's South-to-North Water Diversion Project. Twenty-two fish species, including eight exotic species, were collected during September 2023 (Autumn) and May 2024 (Spring). The fish communities exhibited no significant difference between seasons but had prominent variations among different rivers. The heterogeneity of fish communities was significantly and positively correlated with the geographical distance between the sampling sites (based on a projected coordinate system). Furthermore, the canonical correspondence analysis (CCA) illustrated that altitude contributed more to the distribution of fish species than other physicochemical factors, such as channel width, conductivity, and water temperature. Rivers at low altitudes are likely to be vulnerable to invasion of exotic fish. Our results demonstrated that the dispersal limitation by geographical distance and altitudinal gradient were the primary regulatory factors on the spatial differentiation of fish communities in the rivers of the study area, which reflected a high dependence of fish species on local habitats. As the water diversion project is implemented, more attention is expected to be paid to protecting fish habitats and regime shifts in fish communities. Additionally, the risk assessment of biological invasion under inter-basin water transfers and human activities should be carried out as soon as possible.
河流鱼类物种极易受到大规模调水工程的影响且反应敏感。这些不利影响在高原河流生态系统中更为明显，可能会改变鱼类栖息地的环境条件和群落结构。我们调查了川西高原七条河流中各种环境因素对鱼类多样性的影响，川西高原是中国南水北调工程的规划区域。在2023年9月（秋季）和2024年5月（春季）期间收集了22种鱼类，其中包括8种外来物种。鱼类群落在不同季节之间没有显著差异，但在不同河流之间存在显著变化。鱼类群落的异质性与采样点之间的地理距离（基于投影坐标系）显著正相关。此外，典范对应分析（CCA）表明，海拔高度对鱼类物种分布的影响比其他理化因素（如河道宽度、电导率和水温）更大。低海拔河流可能更容易受到外来鱼类入侵的影响。我们的结果表明，地理距离和海拔梯度造成的扩散限制是研究区域河流中鱼类群落空间分化的主要调节因素，这反映了鱼类物种对当地栖息地的高度依赖性。随着调水工程的实施，预计应更加关注保护鱼类栖息地和鱼类群落的状态转变。此外，应尽快开展跨流域调水和人类活动下生物入侵的风险评估。
