南极普里兹湾海域夏季表层悬浮颗粒物物质组分研究

COMPOSITION OF SUMMER SURFICIAL SUSPENDED PARTICLES IN THE PRYDZ BAY,ANTARCTICA

基于对第29次南极考察中在普里兹湾海域的53个站的表层水样的悬浮颗粒物含量测定和颗粒物电镜扫描图像和能谱半定量分析,研究了普里兹湾海域表层悬浮颗粒物的物质组成与分布特征,分析了其控制因素,进一步探讨了悬浮颗粒物的絮凝作用。结果显示：夏季普里兹湾海域表层悬浮颗粒物的含量为0.08~1.66mg/L,平均为0.43mg/L,整体上呈现近岸高于外海,东部高于西部的分布趋势。悬浮颗粒物以单颗粒组分为主,其中以硅藻和放射虫等硅质生物为主的生物颗粒占绝对优势,矿物颗粒相对较少,其他颗粒介于前两者之间;集合体组分平均约为10%,包括硅藻集合体、微型藻类集合体、矿物集合体、有机包膜和混杂集合体等。影响夏季普里兹湾海域悬浮颗粒物物质组分及其分布的主要因素包括悬浮颗粒物物质来源、海洋环流和海底地形等。悬浮颗粒物的絮凝过程包括胞外聚合物、透明胞外聚合物和海雪等几种类型,絮凝集合体的形成可以促进颗粒物的沉降。

53samples of surficial suspended particulates have been collected in the Prydz Bay by the 29 th China Antarctic scientific expedition.The compositions of surficial suspended particles are measured with the scanning electron microscope（SEM）and energy-dispersive spectroscopy（EDS）.The types and distributions of both the single particles and aggregates in the surficial suspended particles are analyzed and their controlling factors discussed.The results show that the concentration of summer surficial suspended particles range from 0.08 to 1.66mg/L,with an average of 0.43mg/L in the Prydz Bay,of which the high value is distributed mainly in the near-shore area.The biological particles dominate and are high in both the southeastern near-shore area and the northwestern deep-water area.Mineral particles are relatively low and the content of other particles was between the two groups of particles.The average content of aggregate is about 10%in all the surficial suspended particles.The types of aggregates of surficial suspended particles include diatom aggregate,mini-type algae aggregate,mineral aggregate,organic film and miscellaneous aggregates,etc.The controlling factors of the distributions and compositions of surficial suspended particles in the Prydz Bay include marine topography,marine currents system and the terrigenous materials supply.Suspension flocculation processes mainly involve extracellular polymeric substances（EPS）,transparent exopolymer particles（TEP）and marine snow.The flocculation of suspended particles accelerates the sinking of suspended particles and plays a very important role in the depositional process.