DYNAMIC CHARACTERISTICS OF COMMUNITY STRUCTURE AND SEASONAL VARIATION OF FISHERY SPECIES IN THE BOHAI SEA, CHINA

The structural patterns and the seasonal dynamics of fishery species were studied in the Bohai Sea, based on fishery-independent data surveyed in each season sampling stations. A total of 88 fishery species belonging to 64 families were recorded, in detail 43 fishes, 29 crustaceans, 12 molluscas, three echinoderms and one species of scyphozoan. Among them, 21 species commonly found throughout the study period defined as 'common' species, and eight species those were the highest contributors defined as 'dominant' species (based on SIMPER analysis, their cumulative contribution was more than 70%). Maximum abundance was recorded in the summer season while species number was higher in both summer and autumn season. Among the community parameters, species richness (3.79), diversity (2.31) and Simpson indices (0.88) peaked in the autumn season whereas species evenness (0.95) was in the winter. However, species diversity, evenness, and Simpson indices were lower in the summer season (0.57, 0.18 and 0.18, respectively) while species richness was in the winter (1.65). Multivariate PCoA analysis revealed that there was a significant seasonal variation in fisheries assemblages. Furthermore, ANOSIM (Global R = 0.467, P = 0.01) indicated a distinct community structure of fishery species between the four seasons. Thus, this result suggests that fisheries assemblages might be influenced by the seasonal dynamics of the ecological condition of the Bohai Sea.