南海西北部表层沉积硅藻的分布特征与环境分析

基于南海西北部表层沉积物中的硅藻分析,阐明表层沉积硅藻的分布特征,探讨硅藻与环境的对应关系及指示意义。结果表明,研究区内硅藻以热带—亚热带种和近岸种为主;硅藻丰度差异显著,近岸浅水区丰度相对较低,陆坡、河口和上升流区丰度整体较高;硅藻组合类型复杂。硅藻分布面貌受区域的温度、盐度、营养盐、水深、海流、底质类型等因素的控制较为明显。硅藻组合对海流和水团的影响范围具有指示意义。

DISTRIBUTION PATTERN OF DIATOM IN SURFACE SEDIMENTS OF THE NORTHWESTERN SOUTH CHINA SEA AND ITS ENVIRONMENTAL IMPLICATIONS

Diatoms from the surface sediments of the Northwestern South China Sea were studied,aiming at revelation of the relationship between the distribution pattern of diatom and the geo-environment,and the usage of diatom for interpretation of the marine environment.The results indicate：a）the diatom floras are dominated by tropical-subtropical species and coastal-neritic species in this case.b）The abundances of diatoms are quite different regionally.They are lower in the shallow water of offshore area in general,but higher in the slope,estuary and upwelling regions.c）Diatom＇s distribution patterns are obviously controlled by environment factors,such as temperature,salinity,nutrient,water depth,current and substrate,and so on.d）Diatom assemblages are complicated and could be used to indicate the current system and water mass movement.