Study areas and sampling sites
Poyang Lake (28°4′-29°46′N, 115°49′-116°46′E), the largest freshwater lake in China, situated in the south bank of the middle reaches of the Yangtze River (Wu et al., 2021). The lake receives inflows from five tributary rivers in the basin, drains into the Yangtze River at Hukou after regulation and storage (Song et al., 2021). In this study, we collected samples from 5 sites (Hukou County, Xingzi County, Duchang County, Wucheng Town, Poyang County) in the Poyang Lake (Fig. 1).