2009年冬季东海浮游植物群集

Phytoplankton assemblages in East China Sea in winter 2009

2009年12月23日—2010年1月5日在东海海域(24°00'—32°00'N,120°00'—128°00'E)68个站位进行了水文、化学和生物的综合调查,应用Utermhl方法对调查海域的浮游植物群集进行了研究。经284个浮游植物采水样品的分析,共发现浮游植物4门67属171种(含13个未定种)。浮游植物群集主要由硅藻和甲藻组成,还有少量的蓝藻和金藻,物种以沿岸广温型为主,优势种为:具槽帕拉藻(Paralia sulcata)、菱形海线藻(Thalassionema nitzschioides)、柔弱伪菱形藻(Pseudo-nitzschia delicatissima)、安哥拉海链藻(Thalassiosira angulata=并基海链藻Thalassiosira decipens)和细弱海链藻(Thalassiosira subtilis)等。调查浮游植物细胞丰度介于0.356×103—142.578×103个/L,平均值为14.137×103个/L;硅藻占浮游植物细胞丰度的比例最大,介于0.356×103—142.578×103个/L,平均值为13.023×103个/L;其次为甲藻,细胞丰度介于0.356×103—11.378×103个/L,平均值为1.177×103个/L。调查海域表层浮游植物细胞丰度的平面分布由硅藻刻画,高值区出现在调查区北部即长江口东北部海域,甲藻在调查区南部和东南部丰度较高。细胞丰度在水体中的垂直分布趋势为先上升后下降,最大值出现在10m层。从断面分布上看,细胞丰度在调查区近岸和远岸较高、中部较低。Pearson相关性分析表明,调查区浮游植物细胞丰度与磷酸盐和硅酸盐浓度呈显著正相关,与温度呈显著负相关,与硝酸盐相关性不明显。

Totally 284 phytoplankton water samples were collected in a muhidisciplinary investigation in East China Sea （24° 00＇-32° 00＇ N, 120° 00＇--128° 00＇ E ） from December 23＇h 2009 to January 5＇h 2010. Phytoplankton species composition and assemblage structure were studied by Utermohl method. A total of 171 taxa which belong to 67 genera of 4 phyla were identified. The phytoplankton community was mainly composed of Bacillariophyta and Dinophyta, and there were also a few species belonging to Cyanophyta and Chrysophyta. Most of the ecotypes of phytoplankton were temperate coastal species, and dominant species were Paralia sulcata, Thalassionema nitzschioides, Pseudo-nitzschia delicatissima, Thalassiosira angulata and Thalassiosira subtilis etc. Cell abundance ranged from 0.356×103 to 142.578×103cells/L with an average of 14. 137 × 103 cells/L, of which Bacillariophyta was the major group ranging from 0. 356×103 to 142. 578×103 cells/L with an average of 13. 023×103 cells/L, followed by Dinophyta, ranging from 0. 356×103 to 11. 378 ×103 cells/L with an average of 1. 177×103cells/L. Horizontally, the surface distribution of cell abundance in survey area was mainlydominated by Bacillariophyta and the high value appeared in the sea northeast of Changjiang estuary. Dinophyta mostly concentrated in the southern and southeast part of the survey area where Kuroshio water flowed by. Vertically, the maximum of cell abundance was found in subsurface water, and along with the increase of the depth cell abundance firstly increased then decreased. According to the Pearson correlation analysis, the distribution of phytoplankton cell abundance was positively correlated with phosphate and silicata, negatively correlated with temperature, and nitrate＇s effect on cell abundance wasn＇t obvious.