Spatial and Temporal Distribution Characteristics of Fish in Hechuan Section of the Qujiang River Based on Hydroacoustic Method
To assess the spatial and temporal distribution characteristics of fish resources and the amount of existing resources in Hechuan Section of the Qujiang River,and to provide certain data support and scientific basis for the management and protection of fishery resources in this Section of the Qujiang River.Simrad EY60 echosounder was used to investigate the hydroacoustic detection in Hechuan Section of the Qujiang River in April 2019(Spring)and October 2019(Autumn).The results of the study showed that the spatial and temporal distribution of fish was uneven,with mean densities of fish tended to decrease in most horizontal or vertical areas during the study period.The horizontal distribution of fish in the Hechuan section of the Qiujiang River was uneven,the average density of fish in spring was:right bank of the river＞left bank of the river＞center of the river,and the average density of fish in Autumn was:left bank of the river＞right bank of the river＞center of the river.The vertical distribution of fish was uneven,with fish densities in spring:lower layer＞middle layer＞upper layer,and in Autumn:middle layer＞lower layer＞upper layer.Fish body lengths ranged from 3.94 to 62.37 cm in Spring,with an average length of 15.67 cm,and the fish that accounted for the largest proportion of body lengths were 3.94 cm.In Autumn,the body lengths of fish in the section were the same as in spring,and the fish that accounted for the largest proportion of body lengths were 5.56 cm and 6.99 cm.The average body mass of fish in the spring and autumn of Hechuan section of the Qiujiang River was 20.01 g,with the highest proportion of body mass in the spring being 0.32 g,and the highest proportion in the autumn being 0.89 and 1.78 g.The results of the survey suggest that the distribution of fish biomass in the Hechuan section of the Qiujiang River is uneven,and that fish are mainly concentrated in potential spawning or baiting grounds for fish,which should be paid special attention to in the future management of regional fisheries resources,and that ecological regulation and protection in the basin should be further strengthened.
the Qujiang Riverhydroacousticspatial distributionfishery resources
万方数据
维普
