The Chishui River is the first to have a complete fishing-closure in the Yangtze River basin. To explore how fish assemblages changed following the implementation of the fishing closure, field surveys were conducted biannually in three reaches (upper, middle and lower) along its longitudinal gradient during 2007 to 2019. A total of 143 species from eight orders and 24 families was collected. Diversity index for all three reaches showed no significant changes through time. However, non-metric multidimensional scaling (NMDS) ordination analysis revealed significant temporal changes in the structure of fish assemblages for all reaches (P＜0.05 in all cases). Time-lag analysis further showed that the fish assemblages in the upstream had reverted to the early study periods (P＜0.05), with the relative abundance of some large-sized species (e.g., Onychostoma simum and Spinibarbus sinensis) returning to former levels immediately after fishing closure. Fish assemblages in the midstream and downstream reaches also showed trends to returning to the early study periods, but did not reach statistical significance (P > 0.05). These discrepancies might be attributed to varying human disturbances and the type of fish species composition along the longitudinal gradient.

赤水河是长江流域第一个实现全面封渔的河流。为探究禁渔期实施后鱼类群落的变化情况，2007年至2019年期间，沿其纵向梯度在三个河段（上、中、下）每半年进行一次实地调查。共计8目24科143种。集。所有三个河段的多样性指数都没有随着时间的推移而发生显着变化。然而，非度量多维标度（NMDS）排序分析显示所有河段鱼类组合结构的显着时间变化（P＜0.05在所有情况下）。时滞分析进一步表明上游鱼类群落已恢复到早期研究时期（P<0.05），与一些大型物种的相对丰度（例如，Onychostoma simum和倒刺吸虫）返回到前水平钓鱼闭合之后立即。中下游鱼类群落也呈现回归早期的趋势，但未达到统计学意义（P > 0.05）。这些差异可能归因于不同的人类干扰和沿纵向梯度的鱼类物种组成类型。