复州湾表层沉积硅藻的组合特征

Characteristics of diatom assemblages in surface sediments of Fuzhou Bay

通过对复州湾内湾附近8个不同深度的海底表层沉积物做硅藻分析、种群优势度进行计算,查明复州湾表层沉积硅藻的优势种主要包括Paralia sulcata、Coscinodiscus radiatus、C.excentrcus和Rhaphoneis surirella等9种.且优势度最高的3种硅藻P.sulcata、C.radiatus和C.excentrcus均为内湾指标种,与样品采集点的地貌位置相吻合.根据硅藻咸水种、半咸水种、淡水种占比的水平分布特征,对不同样品的硅藻组合、所处地貌位置与样品粒度的关系以及硅藻鉴定结果的聚类分析等进行了探讨.初步判明复州湾表层硅藻的组合主要受到夏季辽东湾向西南方向流动的沿岸流以及复州河与红沿河的河流的影响,另外不同的地貌部位和距离河口的远近也对硅藻组合产生较为明显的影响.

Results of diatom analyzing and dominance calculating on 8 sediment samples of different depths indicates that dominant species are Paralia sulcate, Coscinodiscus radiates, C. excentrcus, Rhaphoneis surirella and 6 other species. P. sulcata, C. radiates and C. excentrcus are the highest dominant species as inner bay indicators fitting well to the environment of sampling sites. The relations of diatom assemblages and its locational landform to the sediment particle sizes were analyzed with clustering according to the species composition of marine, brackish water and fresh-water distributed horizontally. Preliminary findings show that the diatom assemblages are affected by cur-rents of Fuzhou River and Hongyan River and the alongshore SE current in Liaodong Bay in addition to the location-al landform and distance from the estuarine.