2011年秋季北黄海浮游植物群落

2011年11月21—25日在北黄海海域对32个站位进行了生物采样，应用Utermohl方法对调查海域的浮游植物群落进行了研究．经115个样品的分析，共发现浮游植物3门31属64种．调查区浮游植物群落主要由硅藻和甲藻组成，还有少量的金藻，物种以暖温性和广布性物种为主，主要优势种为：具槽帕拉藻、虹彩圆筛藻、三角角藻、斯氏几内亚藻、梭形角藻和旋链角毛藻等．本次调查浮游植物细胞丰度平均值为4．2×10^3个／L；硅藻占浮游植物细胞丰度的比例最大，平均值为3．6x10^3个／L；其次为甲藻，平均值为O．95×10^3个／L．调查海域浮游植物细胞丰度分布不均匀，辽宁南岸海域最高，山东近岸海域其次，北黄海中部海域最低．细胞丰度在水体中的垂直分布趋势为先降低后升高，其中底层的细胞丰度主要由具槽帕拉藻和虹彩圆筛藻贡献．从断面分布上看，细胞丰度高值多集中在受陆源输入影响明显的近岸海域．调查区浮游植物群落多样性指数和均匀度指数均在北黄海北部海域较高，在近岸海域较低．与历史资料的对比发现，近30年来北黄海浮游植物群落结构比较稳定．

Phytoplankton Communities in the Northern Yellow Sea in Autumn 2011

Totally 115 phytoplankton water samples were collected from 32 stations in northern Yellow Sea from November 21 to 25 in 2011. The composition and abundance of the phytoplankton species were studied with Utermt3hl method. A total of 64 taxa which belong to 31 genera of 3 phyla were identified. The phytoplankton community was mainly composed of Bacillariophyta and Pyrrophyta, and there were also a few species belonging to Chrysophyta. Most of the ecotype of the phy- toplankton species was neritic or cosmopolitan. The dominant species were Paralia sulcata Cleve, Coscinodiscus oculus- iridis Ehrenberg, Ceratium tripos Nitzsch, Guinardia striata Hasle, Ceratium fusus Dujardin and Chaetoceros curvisetus Cleve, etc. The average of phytoplankton cell abundance was 4.2 ×10^3 cells/L, with cell abundance of Bacillariophyta averaging at 3.6 ×10^3 cells/L and Pyrrophyta averaging at 0.95 ×10^3 cells/L. Horizontally, cell abundance distributed unevenly in the surveyed area, with Liaoning coastal water ranking first, followed by Shandong coastal water, and the central part of northern YS ranking last. Vertically, phytoplankton cell abundance first decreased in the upper water, and then increased with the increase of depth. Near the bottom water, Par. sulcata and Cos. iridis were the dominant species. Sectionally, phytoplankton mainly concentrated in the coastal area under anthropogenic influences. Both Shannon-Wiener diversity index and Pielou＇s evenness index appeared higher in the northern part of northern YS. Compared with historical data, phytoplankton communities in northern YS didn＇t show significant alteration during the past 30 years.