Abstract: After many years integrated management of Yuandang Lake in Xiamen,the nectons are increased from 1 to 43 species, among which, 29 are fishes, 8 are prawns,and 6 are crabs.Their monthly average biomass and density are respectively 34.43 g·net^-1 and 0.77 tail·net^-1, and their quantitative distribution is in the order of outer lake>innerlake>east Hudong bridge,the seasonal dynamics of species is in the order of bummers>autumn>winter>spring.Liza carinatus,Tilapia nilotica and Stolephorus commersonii are the dominants.

Key words: Yuandang Lake, Necton, Species, chlorophyll content, vegetation index, principal component analysis, red edge parameters, hyperspectral, BP neural network