Community structure of fishery resources from the Nanshawaters of Pearl River Estuary in autumn

According to the fisheries resources data collected from the Nansha waters of Pearl River Estuary in November 2015, we investigated the community structure, dominant species and diversity of fishery resources in this area, and 40 fishery species, mainly fishes and crustaceans, were found, including 21 demersal fishes, 3 pelagic fishes and 16 crustaceans. The index of relative importance (IRI) was used to measure ecological dominance of species to decide the role each species played in the community. The dominant species were Charybdis acuta and Parapenaeopsis hungerfordii in autumn, whose IRIs were higher than 1 000. The range of catch rates in weight was 0.63~11.15 kg·h^-1 (average:4.23 kg·h^-1). The range of catch rates in individual number was 84~885 ind·h^-1 (average:433 ind·h^-1). The average Shanon-Wiener diversity index (H′), Pielou evenness index (J′) value and Margalef richness index (D) of fishery resources in autumn were 2.07, 1.64 and 0.59, respectively. The analysis shows that sizes of the catch were generally small, and the catch mainly consisted of small commercial crustaceans and juveniles of commercial fishes. The spatial distribution of diversity of catches had little variation of in all stations. Compared with the fisheries catches in autumn 2002, the species diversity declines and the community structure is relatively simple at present.