BENTHIC FORAMINIFERAL DISTRIBUTION IN SURFACE SEDIMENTS OF ZHUJIANG ESTUARY AND ITS ENVIRONMENTAL IMPLICATIONS

134 grab surface sediments were collected from the Zhujiang River estuary with the support of projects 908-01-CJ14 and 908-01-CJ15. In the sediment samples discovered are 106 benthic foraminiferal species belonging to 68 genera and 3 suborders, including 65 Hyaline, 21 porcellaneous and 20 agglutinated species. Benthic foraminiferal species at different locations of the Zhujiang River estuary is examined for abundance, number of species and compound diversity H(S). Foraminiferal abundance, number of species and diversity increased rapidly from the estuary to shallow sea. Foraminiferal abundance changes from several to tens of thousands; number of species changes from 1 to 48 and diversity does from 1 to 3. Factor analysis and Pearson correlation matrix was performed on foraminiferal census data of species content higher than 2% which are present in at least three samples. 3 factors were obtained accounting for 87.2% of the total variance. Two benthic foraminiferal subgroups and one group, Ammonia beccarii-Elphidium nakanokawaense subgroup、Ammonia beccarii-Haplophragmoides canariensis subgroup and Hanzawaia nipponica-Elphidium advenum-Ammonia compressiuscula group, were classified according to factor score of foraminiferal genus. Further, there is some kind of relationship between the foraminaferal distribution and environment. Water depth and salinity control foraminiferal distribution and community structure, and sediment type, water dynamics and sedimentary rate affect its ecological structure as well.