基于eDNA技术与传统渔具方法的大渡河上游鱼类多样性及重要指示种川陕哲罗鲑的分布研究OA

The upper reaches of the Dadu River are a crucial water source and a key habitat for Hucho bleekeri,a first-class national protected wild animal in China and a flagship rare fish species in the upper Yangtze River.In April 2025,a fishery resource survey was conducted at 12 sites within the H.bleekeri habitat area of the upper Dadu River,using both environmental DNA(eDNA)technology and the tradi-tional fish collection method.Based on survey results,we systematically analyzed fish species composi-tion,community diversity,the current distribution of H.bleekeri,and compared the two methods for moni-toring fish.Our objectives were to provide scientific support for biodiversity conservation,ecological reg-ulation of hydropower projects,alien species control,habitat protection and H.bleekeri population restora-tion,and to assess eDNA technology for monitoring H.bleekeri within the larger fish community.A total of 32 fish species were recorded in the study area and eDNA metabarcoding proved highly effective in de-tecting fish biodiversity,successfully identifying 29 species.Only 12 species were captured by conven-tional fish collection methods and 9 species were identified by both approaches.H.bleekeri was not cap-tured using traditional fishing surveys but was successfully detected at sampling sites at Baiwan Town(BWX2)and Sha'erzong Town(SEZ4)using eDNA technology.Regarding fish community composition,the Cypriniformes order and Cyprinidae family were identified as the dominant groups by both eDNA technology and the fishing method,and Schizopygopsis chengi,Triplophysa stenura and Schizothorax davidi exhibited high dominance within the detected assemblages.Fish community diversity analysis re-vealed a statistically significant difference between the two monitoring methods.The Shannon diversity index,Simpson diversity index,and Margalef richness index were all significantly higher when calculated using eDNA detection data.Our findings demonstrate that the superior sensitivity of eDNA technology ef-fectively compensates for the deficiencies of traditional gear-based surveys.Combining the two fish sur-vey methods enhances the accuracy and completeness of fish diversity assessments,and provides critical baseline data and technical support for conserving regional fish resources.