中文摘要：

珠江口黄茅海河口湾的表层沉积物100个站位样品中共发现有孔虫21属36种、介形虫16属20种。优势种组合分别为Ammoniabeccarii—QuingMefocH尻n口aknerianarotunda—Cavarotaliaannectens-Elphidiumadvenum和Neomonoceratinadelicata—Sinocytherideaimpressa—Bicornucytherebisanensis。有孔虫及介形虫的丰度和分异度均表现出“北低南高”，即口门低、向海高的特点。样品中有孔虫和介形虫属种的去趋势对应分析（DCA）表明，盐度是影响该区有孔虫和介形虫分布的最重要因素，其次是水动力条件，水深对有孔虫和介形虫的分布也有一定影响，但并非主要控制性因素。由于受径流影响较大，河口湾北部的水体盐度较低、径流动力较强，不利于有孔虫和介形虫的生存，导致其丰度及分异度均较低。河口湾南部水体盐度升高，潮流动力较强，同时受众多岛屿屏障作用，环境较为稳定，有孔虫和介形虫的丰度和分异度均迅速上升。

英文摘要：

Foraminiferal and ostracod assemblages in 100 surface sediment samples collected from the Huangmao Bay of the Pearl River Estuary were analyzed, leading to the identification of a total of 36 fo- raminiferal species belonging to 21 genera and 20 ostracod species belonging to 16 genera. The dominantspecies of the two faunas with a relative abundance higher than 10% are Ammonia beccarii-Quinqueloculina akneriana rotunda-Cavarotalia annectens-Elphidium advenum and Neomonoceratina delicata-Sinocytheridea impressa-Bicornucythere bisanensis, respectively. The abundance and diversity of foraminifers and ostra- cods increase gradually seawards across the estuary. The Detrended Correspondence Analysis of foraminif- eral and ostracod species suggested that the most important factor affecting the distribution of foraminifers and ostracods in the surface sediments of the Huangmao Bay is water salinity, followed by hydrodynamics. Besides, water depth has also a certain effect on the faunal distribution but not the main controlling factor. As a result of freshwater influencing, the environment of northern estuary is of low salinity and high water energy, which is not conducive to survival of foraminifers and ostracods, leading to a low abundance and diversity of the two faunas. On the other hand, because of the salinity increasing and the islands acting as the barrier to turbulent sedimentary environment, the abundance and diversity of foraminifers and ostra- cods increase rapidly in the southern estuary.