Abstract:In order to understand the ecological function of seagrass in coastal ecosystems in China，fouling organisms on the leaves of eelgrass Zostera marina L. in the area of Chu Island of Sanggou Bay was investigated from September 2008 to August 2009. Twenty nine species of organisms were found and the dominant species were Cocconeis scutellum, C. scutellum var. Pava, Halothrix lumbricalis, Punctaria latifolia, Chlorostoma rustica, Australaba sp. and Stenotis sp. In the spring, 9 diatom species, 7 macroalge species and 8 invertebrate species were found. Phaeophyta dominated the fouling species of eelgrass and the biomass reached the peak in April. Species of epiphytic macroalgae decreased in summer and the dominant fouling organisms were gastropoda. The number of diatom, macroalgae and invertebrate species were 8, 4 and 6, respectively. In autumn，diatom abundance reached the peak, while there were only four species of invertebrates. The number of epiphytic macroalgae species was the same as that of summer while the biomass of marcoalgae and invertebrates were less than that of the summer. No epiphytic macroalgae and invertebrate were found in winter, besides diatoms.
