江苏省重点河湖库中本土和外来鱼类分布特征及影响因素OA

In this study,we systematically investigated the diversity and structure of native and exotic fish communities in 113 key rivers,lakes and reservoirs in Jiangsu Province using environmental DNA(eDNA).Further,we assessed differences in community composition and biomass of native and exotic fishes in various types of surface water in response to typical environmental stressors.A total of 289 na-tive fish species and 76 exotic fish species were detected during the survey in December 2023,and the proportions of native fish species in the rivers,lakes and reservoirs were similar,respectively accounting for 77.94％,75.85％and 76.05％of the total species number.The most abundant native fish species,both absolute and relative,in all types of surface water was Carassius auratus,and the exotic fish species with the highest relative abundances were Rhodeus uyekii in rivers,Micropterus salmoides in lakes and Chitala ornata in reservoirs.The community composition and biomass of the native and exotic fishes in rivers,lakes and reservoirs showed no significant geographic differences(P＞0.1)among the three major basins of Jiangsu Province(Taihu Lake,the lower Yangtze River and the Huaihe River),but environmental fac-tors did exert a significant effect on fish distribution.Water quality indicators such as ammonia nitrogen(NH3-N),total phosphorus(TP),and permanganate index(CODMn)had a significantly effect on the com-munity composition of native fishes,while land use type and surrounding population density had a larger impact on the community composition of exotic fish species.The random forest model indicated that the proportions of agricultural and urban land uses and dissolved oxygen(DO)were the most important pa-rameters affecting the biomass of native and exotic fishes.The findings of this study provide background data for systematizing the fish resources of Jiangsu Province and provide a scientific basis for protecting native fish and controlling exotic fish.