关键词: 崇明北滩, 群落, 优势种, 生物多样性

Abstract: Studies on fish community on north beach of Chongming island were carried out during 1994~2003 and several indexes were used to describe the biodiversity of the community. Fishes of 10 orders,19 families, 29 genera and 33 species were collected from this area. The ecological types of the fish were consisted of migrated fishes between the Chagnjiang River and the sea, fishes in estuary and fishes in the sea, and smallsized fishes were more than others. Dominant species were Coilia mystus, Collichthys lucidus and Pseudosciaena polyactis. Average characters of diversity during the past ten years were analysed that Margalef′s index was 0.84，Wilhm′s index was 1.51, Pielou′s index was 0.63 and McNaughton′s index was 0.67. The miniaturization of economical fishes became evidently. Unfavorable influence of water pollution and irrigation engineering works should be paid more attention and the use of choiceless nets should be controlled strictly.

Key words: Chongming Island, north beach community, dominant species, biodiversity