长荡湖国家级水产种质资源保护区保护对象资源现状调查与分析OA

To understand the spatio-temporal distribution characteristics of the protected species in the Changdang lake national aquatic germplasm resources reserve and to provide countermeasures and suggestions for the conservation of fish-ery resources in the reserve,from 2022 to 2024,a study was conducted on the resource changes of protected species such as Macrobrachium nipponense,Cyprinus carpio,Carassius auratus,Channa argus,Cultrichthys erythropterus,Pel-teobagrus fulvidraco,and Siniperca chuatsi in the reserve,as well as their relationship with environmental factors,by combining fishing surveys and environmental DNA detection.The results showed that the resources of M.nipponense,C.erythropterus,and P.fulvidraco were recovering,with their catch per unit effort(CPUE)increasing year by year from 2022 to 2024.The CPUE of S.chuatsi and C.auratus generally showed an upward trend,but there were large fluctua-tions between years;both the body length and weight of C.erythropterus,P.fulvidraco,S.chuatsi,and C.carpio have increased significantly,the body lengths increased by 78.3％,46.3％,51.4％,and 23.5％,respectively,and their body weights increased by 267.8％,131.1％,257.8％,and 70.8％respectively;the linear regression results indicated that the abundance of M.nipponense,P.fulvidraco,and S.chuatsi increased significantly with the years(P＜0.05);the re-dundancy analysis results showed that total nitrogen explained 25.8％of the species distribution and was a key environ-mental factor,and total nitrogen and volatile phenols were the main environmental factors affecting the community struc-ture of the protected species at present;the resource quantities of various protected species showed significant differences at different sampling points;the environmental DNA technology demonstrated high sensitivity in detecting low-density or hard-to-capture species,which combined with traditional survey techniques can provide a more accurate reflection of the actual distribution of protected objects.The study showed that the conservation of aquatic biological resources in the re-serve had achieved significant results,but the recovery effect of protected species such as C.argus and C.carpio was still not obvious,and it was suggested to take measures such as ecological restoration,improving water quality and strengthe-ning the monitoring and assessment of aquatic resources.