He Jiayang, Liu Hao, Bi Xianda, Wu Zhiqiang
Guangxi Academy of Fishery Sciences, Ministry of Agriculture and Rural Affairs, China (Guangxi)-ASEAN Key Laboratory of Comprehensive Exploitation and Utilization of Aquatic Germplasm Resources, Nanning 530021, China.
Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
Biology (Basel). 2025 Jun 30;14(7):796. doi: 10.3390/biology14070796.
Amid declining fish diversity and human pressures in freshwater ecosystems, robust basin-scale assessments are vital for effective fisheries management. This study collated nearly four decades of fishery yields from the Pearl and Yangtze Rivers to identify conservation priorities in the Pearl River Basin. It introduced a novel cumulative effect indicator based on zeta diversity-a biodiversity pattern metric-integrated with cumulative effects analysis for management decision-making. The research employed a multi-site generalized dissimilarity model to examine the non-linear relationships between fish species composition (ζ) and human pressures, environmental factors, and geospatial variations across elevation gradients. The cumulative effect indicator, reflecting responses to anthropogenic stress when assessing ζ (related to β diversity), helped evaluate basins for conservation or restoration needs based on their unique or homogenized biotic communities. The results suggest that ζ diversity in low-elevation sub-basins has a stronger filtering effect on ζ by human pressures than in mid- to high-elevation sub-basins, where community aggregation is more random. The impact varied with diversity aspects (nestedness vs. turnover) and zeta order. A negative correlation between cumulative effects and community uniqueness validated the novel cumulative effect indicator's effectiveness for guiding restoration in the Pearl River Delta, potential fishing bans, and karst conservation. This approach offers a theoretical basis for prioritizing areas for freshwater fish diversity conservation and fishing restrictions in the Pearl River Basin.
在淡水生态系统中鱼类多样性下降和人类压力增大的背景下，强有力的流域尺度评估对于有效的渔业管理至关重要。本研究整理了珠江和长江近四十年的渔业产量，以确定珠江流域的保护重点。它引入了一种基于ζ多样性（一种生物多样性模式指标）的新型累积效应指标，并将其与累积效应分析相结合用于管理决策。该研究采用多站点广义相异模型，来检验鱼类物种组成（ζ）与人类压力、环境因素以及海拔梯度上的地理空间变化之间的非线性关系。在评估ζ（与β多样性相关）时，累积效应指标反映了对人为压力的响应，有助于根据流域独特或同质化的生物群落来评估其保护或恢复需求。结果表明，低海拔子流域的ζ多样性对ζ的人类压力过滤效应比中高海拔子流域更强，在中高海拔子流域群落聚集更为随机。这种影响因多样性方面（嵌套性与周转率）和ζ阶数而异。累积效应与群落独特性之间的负相关验证了新型累积效应指标在指导珠江三角洲恢复、潜在禁渔和喀斯特地区保护方面的有效性。这种方法为珠江流域淡水鱼类多样性保护和捕捞限制区域的优先排序提供了理论依据。
