[Ecological characteristics and seasonal variation of macrobenthos near the Ningjin coastal water of Shandong, East China].

The coastal water off Ningjin is located at the eastern end of the Shandong Peninsula, the boundary of the Northern and Southern Yellow Sea. In this paper, the ecological characteristics and seasonal variation of macrobenthic community in this region were studied, based on the investigation data collected from the four cruises in January (winter), April (spring), July (summer), and October (autumn), 2007. A total of 243 macrobenthic species were identified, of which, 96 species were of Polychaeta, 77 were of Crustacea, 43 were of Mollusca, 13 were of Echinodermata, and the rest 14 species were of other benthic groups. The dominant species varied with seasons, but Paralacydonia paradoxa (Polychaeta) and Amphioplus japonicus (Echinodermata) were dominant throughout the four seasons. The average biomass of the macrobenthos estimated from the four cruises was 9.5 g x m(-2), with the highest biomass during the spring cruise and the lowest one during the winter cruise. The average abundance estimated from the four cruises was 219.6 ind x m(-2), with the highest abundance during the winter cruise and the lowest one during the autumn cruise. The Shannon index (H) of the macrobenthos community varied from 2.82 to 3.23, the species richness index (D) varied from 2.28 to 2.75, and the species evenness index (J) varied from 0.82 to 0.86. The Bray-Curtis similarity cluster analysis and MDS ordination analyses indicated that there was a distinct distribution of macrobenthic communities from seashore to offshore, which was closely correlated with the spatial structure of bathymetry and the sediment type in the study region.