珠江口黄茅海底质沉积中介形类的生态类型及其分布特征

黄毅 吴洁 殷征欣 关瑶 倪锦锋

摘要：文章通过对黄茅海底质沉积样品中的介形类生态类型进行研究，探讨其空间分布特征。研究结果显示：研究区内出现的介形类可划分为4种生态类型，总体表现为以近岸广盐型分子占主导地位，优势度极高;浅海多盐-真盐型分子次之;而广海真盐型和淡水-微盐型分子丰度很低。根据黄茅海河口湾的水体条件，可大致将研究区划分为5种亚环境区，各区内的介形类生态类型组成也存在较大差别，表现出不同的空间分布特征。介形类分布受海水盐度控制最大，其次为水动力条件。在水体盐度小、水动力条件强的河流入海口及其影响区域，介形类丰度小，且生态类型单一;而在黄茅海河口湾南部海域，由于海水底层盐度全年在15‰以上，水动力条件适宜，介形类丰度总体较高，生态类型增多。

关键词：珠江口;黄茅海河口湾;介形类;生态类型;分布特征

Abstract：In this study，the ecological types of ostracod in bottom sediments of Huangmaohai estuary were analyzed to discuss their spatial distribution characteristics.The results showed that the ostracod could be divided into four ecological types in the study area.The dominant ecological type is the coastal euryhaline type，followed by the marine poly euhaline type.Besides，the abundance of the marine euhaline type and the freshwater  slightly brackish type are very low.According to the water conditions of Huangmaohai estuary，the study area could be divided into 5 sub-environmental areas，and the composition of the ecological types of ostracod in each area is also quite different，showing the different spatial distribution characteristics.The results showed that the distribution of ostracod is mainly controlled by the salinity of seawater，followed by the hydrodynamic condition.In the estuaries of river with low salinity and strong hydrodynamic conditions，the abundance of ostracod is low and the ecological type is single.But the area in the southern estuary is different which shows the higher abundance and more ecological types of ostracod because of the bottom salinity of seawater is above 15‰ all year and the hydrodynamic conditions are suitable.

Key words：Pearl River Estuary，Huangmaohai Estuary，Ostracod，Ecological types，Distribution characteristics

微体动物介形类是生存环境范围较广的甲壳动物，常可见于海水、半咸水和淡水环境。介形类因其能敏感地反映水体盐度、温度、水动力条件、底质等环境参数[1]，在地质学尤其是在分析海陆交互的河口地区环境上，具有重要的研究意义。因此，微体动物中除了有孔虫继续被充分研究和利用外，基于微体动物介形类的研究方法也成为探讨河口地带环境变化的手段之一。

近年來对珠江口地区介形类微体动物的研究前人已有涉及[2-12]，主要集中在伶仃洋海域表层沉积物或者三角洲钻孔样品。……