BREEDING AND RELEASING YANGTZE STURGEON OF IN THE UPPER REACHES OF THE YANGTZE RIVER DURING THE EARLY STAGE OF FISHING BAN
In order to scientifically evaluate the breeding and releasing of Yangtze sturgeon in the upper reaches of the Yangtze River,we analyzed the recovery of Yangtze sturgeon field populations based on the fishery monitoring data of three river sections,namely,Yibin,Luzhou,and Hejiang,from 2021 to 2023.During the monitoring period,a total of 849 Yangtze sturgeon were collected from the three sections,with body lengths ranging from 14.70 to 93.00 cm[mean length(45.19±14.01)cm].The dominant group,with body lengths ranging from 25.10 to 65.00 cm,comprised 88.98% of the total.The body weights ranged from 24.0 to 6850.0 g[mean weight(892.7±960.8)g],with the dominant group's weights between 0 and 1250.0 g,accounting for 83.18% of the total.The analysis showed that(1)the average body lengths and body weights of Yangtze sturgeon monitored in 2022 and 2023 were significantly higher than those in 2021(P＜0.05),and the mean values of body lengths exceeded those of the released group in the same year;(2)the moni-tored Yangtze sturgeon groups showed positive anisotropic growth,with weight increasing at a faster rate than body length.Significant difference in growth condition factors and anisotropic growth parameters were observed between Yibin and Hejiang sections(P＜0.05),influenced by location and time(P＜0.01);(3)the catch per unit effort of Yangtze sturgeon ranged from 0.1 to 35.0 ind./(net·d),with significant seasonal variations(P＜0.05);(4)following increased release efforts by major organizations from 2018 to 2023,alongside the implementation of a 10-year fishing ban on the Yangtze River starting in 2021,the number of Yangtze sturgeon collected during the monitoring period increased significantly.The results showed that the Yangtze sturgeon resources in the upper reaches of the Yangtze River are gradually recovering after the fishing ban,with good growth condition,suggesting that the breeding and releasing is initially apparent.
Upper Yangtze RiverEarly stage of fishing banStocking and releasingBody length-weightYangtze sturgeon
万方数据
维普
