Fishery Resource Survey in Poyang Lake and Coves During 2020-2021
In this study,we carried out a two-year fishery resource survey in Poyang Lake and its coves in 2020 and 2021,focusing on species composition,diversity,and community structure dynamics.We aimed to understand the fishery resource status of the Poyang Lake and its adjacent waters after a ten-year ban on fishing,and provide scientific evidence to develop protection measures and promote the mainte-nance of fishery resources.A total of 84 surveys with accurately located sampling sites were conducted at the Hukou,Lushan,Duchang,Yongxiu,Nanjishan,Ruihong and Poyang sections of Poyang Lake in 2020 and 2021.The species of all specimens were identified and total length,body length and body weight were measured.Scales of 9 fish species,including Mylopharyngododon piceus,Ctenopharyngodon idel-lus and Hypophthalmichthys molitrix were collected for age determination.A total of 14 333 fish from 93 species,19 families and 11 orders were collected,with a total weight of 10 300.048 kg and absolute domi-nance by Cyprinidae(52 species,55.91％).The number of dominant species ranged from 2-7 for the 7 sta-tions,among which only 2 dominant species were observed at the Hukou station,but 7 species at Duch-ang and Poyang.Shannon-Wiener diversity,Margalef richness and Pielou evenness indices of the fish community were in the range of 2.158-2.909,4.265-6.459 and 0.617-0.822,respectively.Compared to fishery resource data for 2012,the major economic fishes in 2021 were longer in body length by 6.1％-61.26％,heavier in body weight by 15.14％-291.57％,and had a better age structure.There was a marked decrease in the proportion of 1 and 2 year-olds and a marked increase in the proportion of 3 and 4 year-olds.Among the total species collected,Siniperca chuatsi was one of the species displaying the changes described above and benefitting from the ten-year ban on fishing.However,it should be pointed out spe-cifically that the number of M.piceus was still low,and no individuals at 4 years or older were collected,but the proportion of 2 year-old individuals did increase significantly.In conclusion,the current survey,carried out after the ten-year fishing ban,provides data for evaluating the effect of the fishing ban in Poy-ang Lake and its tributaries.
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