Abstract:The method of bottom trawl from bottom can reduce the disturbance and physical influence of bottom trawl and protect the ecological environment of benthic organisms.In order to further research the impacts of bottom trawl operations on bottom fishery resources,special bottom trawl trials were conducted on 36 nets in September 2019 and September 2020 in the Xiongdi Fishing ground of Fujian,the changes of community structure of nekton in bottom and near bottom were analyzed and compared by using species composition,logarithmic mean of bottom trawl catch,dominance,abundance spectrum and diversity,etc.,and the effects of bottom trawling and off-bottom trawling on the community structure of nekton were revealed,which provided a basis for the scientific management of bottom trawl and the adjustment of the structure of inshore fishing.The results showed that there were 126 species of nekton in the catch of bottom trawling and 79 species of nekton in the catch of off-bottom trawling,and the total number and weight of nekton in the catch of bottom trawling were 3 times of that of in near bottom,and the logarithmic mean of bottom trawl catch was 0.36 higher than that of in the catch of off-bottom trawling,which indicated that bottom trawl catch was dominated by nekton in the bottom.The diversity,evenness and abundance of nekton in the catch of bottom trawling were 2.81,0.65 and 10.01,these values were all higher than that in the catch of off-bottom trawling(2.29,0.60 and 8.13,respectively).The catch miniaturization was more serious in the catch of bottom trawling,and the proportion of economic juvenile fish was higher in the catch of bottom trawling,which indicated the diversity and juvenile fish were more damaged by bottom trawling.The curve of abundance spectrum of nekton was steeper in the catch of off-bottom trawling,and the index of dominance was higher in the catch of off-bottom trawling(0.41),which indicated that the dominant species distribution of nekton was more concentrated and uneven in near bottom.