辽东湾表层沉积物中生物标志物记录的浮游藻类生物量和群落组成特征

ABUNDANCE AND COMMUNITY STRUCTURE OF THE PHYTOPLANKTON IN SURFACE SEDIMENTS RECORDED BY BIOMARKERS FROM LIAODONG BAY

对渤海辽东湾海域表层沉积物中浮游植物生物标志物的分布进行了研究。通过对辽东湾51个站位的调查研究发现,硅藻、甲藻和颗石藻这3种浮游植物的生物标志物含量分布规律不明显,为了消除粒度和沉积速率的影响,将这3种生物标志物总量与总有机碳(TOC)含量做比值,得到的相对含量从湾内到湾口随着离岸距离增加而增加,生物标志物指示的初级生产力与现场调查的结果一致,表明生物标志物法基本可以用来重建初级生产力。辽东湾海域初级生产力在湾口高于湾内,表明其主要控制因素是水体浊度而不是陆源营养盐的输入。辽东湾西侧菊花岛附近初级生产力的高值主要与人类养殖、陆源排污等导致的水体富营养化相关。生物标志物的相对比例结果显示,辽东湾两侧近岸区硅藻和甲藻相对贡献高,尤其是硅藻占据绝对优势,这主要与硅藻在高营养盐的情况下具有竞争优势有关,而在辽东湾中部发现高的颗石藻相对贡献与黄海暖流入侵路径相对应。

This paper reported the distribution of phytoplankton biomarkers in surface sediments of Liaodong Bay,Bohai Sea.The distribution of biomarkers of three phytoplankton species,diatoms,dinoflagellates and haptophytes was not obvious in 51 surface sediments from Liaodong Bay.Biomarker contents were normalized to the total organic carbon(TOC)to eliminate the influence of grain size and sedimentation rate,it was found that the relative content increased from the bay to the estuary in Liaodong Bay.The primary productivity indicated by biomarkers is consistent with the results from modern water column phytoplankton surveys,indicating that the biomarkers can be used to reconstruct the primary productivity.The primary productivity in the Liaodong Bay is higher than that in the Bay mouth,which indicates that the main controlling factor is the turbidity of the water column rather than the input of terrestrial nutrients.The high primary productivity near Juhua Island on the west side of Liaodong Bay is mainly related to eutrophication caused by human culture and land-based sewage discharge.The relative proportion of biomarkers showed that diatom and dinoflagellate contributed more to the coastal area of Liaodong Bay,especially diatom occupied an absolute advantage,which was mainly related to the competitive advantage of diatom under the condition of high nutrient salts,while high haptophytes was found in the middle of Liaodong Bay,which corresponded to the invasion path of the Yellow Sea Warm Current(YSWC).