Community structure and biodiversity of nekton near Oufei Beach of Wenzhou

Based on the bottom trawl surveys in May of 2013, we investigated the community structure and biodiversity of nekton near Oufei Beach of Wenzhou by traditional diversity analysis, abundance-biomass comparison curves, clustering analysis and non-metric multidimensional scaling. A total of 87 species were collected, including 55 species of fish, 18 species of shrimps, 10 species of crabs and 4 species of cephalopods. The dominant species were Amblychaeturichthys hexanema, Pampus argenteus and Harpodon nehereus; the important species were Lateolabrax maculatus, Collichthys lucidus and other 15 species. The densities of nekton quantity and weight were 304.6×10³ ind · km^-2 and 365.8 kg · km^-2, respectively. Cluster analysis and non-metric multidimensional scaling (NMDS) analysis reveal that the nekton community could be spatially clustered into three groups. ANOSIM analysis shows very significant difference in nekton species composition among all groups (R=0.463~0.807). The abundance and biomass curves (ABC) indicate that the nekton community was seriously disturbed, and the fast-growing, small-sized and opportunistic r-strategist was dominant in the nekton community. The Shannon-Wiener diversity index (H′), Pielou evenness index (J′) and Margalef species richness index (D) ranged from 1.31 to 3.74, 0.33 to 0.78, and 1.80 to 5.81, respectively.