利用2006年7-8月(夏季)、2007年4-5月(春季)和2007年10-12月(秋季)珠江丰水期、平水期和枯水期3个航次在南中国海北部珠江口附近海域4条由河口、近岸到深水区调查断面的数据, 研究大型底栖动物多样性由河口-近岸-深水的变化趋势及与环境因子的关系。春季、夏季和秋季分别获得大型底栖动物273、256和148种, 各季节均以环节动物种类最多, 节肢动物次之。大型底栖动物种类数、丰度、生物量和Shannon-Wiener多样性指数均由河口向近岸海域升高, 再由近岸向外海深水区降低。Pielou均匀度深水区最高, 其次为近岸。河口和深水区大型底栖动物k-优势度曲线位于近岸浅水域曲线之上, 表明生物多样性由河口向近岸升高, 而由近岸向深水则降低。大型底栖动物与环境因子Pearson相关性分析表明, 春、秋季大型底栖动物种类数、丰度和生物量与水深呈显著的负相关, 秋季种类多样性指数和均匀度也与水深呈显著的负相关性, 而夏季仅生物量与水深呈显著的负相关; 春、秋季大型底栖动物种类数、生物量、丰度、多样性指数和种类均匀度与盐度的相关性不显著, 但是夏季大型底栖动物种类数、丰度、多样性指数和种类均匀度与盐度呈显著正相关。单位面积(0.2 m²)内, 珠江口及邻近海域大型底栖动物在近岸浅水区较深水区和河口生物多样性高, 且生物量丰富。

To study the relationship between macrobenthic fauna and environmental factors, we investigated four transects from coast to deep-sea waters near the Pearl Estuary in the northern South China Sea from July -August 2006 (Summer, wet season), April-May 2007 (Spring, normal water season), and October-December 2007 (Autumn, dry season). A total of 273 species, 256 species and 148 species were identified in spring, summer and autumn, respectively. Macrobenthic fauna belonging to the Annelida phylum had the greatest species richest, followed by Arthropoda, Mollusca, and Echinodermata. The species richness, abundance and biomass of macrobenthic fauna increased from estuary sites to coastal sites, and decreased from coastal sites to deep-sea sites. The Shannon-Wiener index of macrobenthic fauna was higher in coastal sites than those in estuary and deep-sea sites. The species evenness of macrobenthic fauna was the highest in deep-sea sites, followed by coast and estuary sites. The k-dominance curves of macrobenthic fauna were higher in estuary and deep-sea sites than that in coastal sites. These results show that the macrobenthic biodiversity was the highest in coastal sites. Species richness, abundance, and biomass of macrobenthic fauna are negatively correlated with water depth in spring and autumn, but only biomass of macrobenthic fauna is negatively correlated with water depth in summer. The species richness, abundance, Shannon-Wiener index, and species evenness of macrobenthic fauna are positively correlated with salinity in the bottom of the water column in summer, but are not correlated in spring and autumn.