2013年夏季北黄海浮游植物群集

利用Utermöhl方法,对2013年夏季取得的北黄海浮游植物样品进行鉴定分析,共鉴定出浮游植物3门60属114种(不包括未定名种),其中,硅藻42属75种,甲藻16属37种,金藻2属2种。群落组成以硅藻为主,其次是甲藻,然后是金藻。调查海区浮游植物的生态类型以温带近岸性为主,主要优势种为:小等刺硅鞭藻 Dictyocha fibula、裸甲藻 Gymnodinium sp.、螺旋环沟藻 Gyrodinium spirale、蜂腰双壁藻 Diploneis bombus 和具槽帕拉藻 Paralia sulcata。浮游植物细胞丰度介于0.037 0 × 10³ ～ 32.3 × 10³ cells·L^-1,平均值为2.04 × 10³ cells·L^-1;浮游植物细胞丰度大致从近岸到外海呈逐步降低趋势,在北黄海西部近岸的表层水体达到最高值32.3 × 10³ cells·L^-1,调查区东南部靠近外海区域也出现了丰度高值区;浮游植物垂直分布总体特征是随水深的增加而减少,由近岸向外海逐步降低。香农-威纳多样性指数在调查区西南部较高,而Pielou均匀度指数则在东部呈现高值区域。典范对应分析(CCA)显示,影响浮游植物优势种丰度分布的主要因素是营养盐,而跟盐度和温度的相关性不明显。

Phytoplankton community of the northern Yellow Sea in summer 2013

A total of 3 phyla 60 genera and 114 taxa(not including undefined species) were identified by the Utermöhl method in the survey area. The major groups were diatom and dinoflagellate. The ecotypes of most phytoplankton were temperate and coastal species. The dominant species were Dictyocha fibula, Gymnodinium sp., Gyrodinium spirale, Diploneis bombus and Paralia sulcata. The cell abundance of phytoplankton ranged from 0.037 0× 10³ to 32.3 × 10³ cells·L^-1, with an average of 2.04 × 10³ cells·L^-1. The cell abundance of phytoplankton decreased offshore. Cell abundance was highest in west region of the northern Yellow Sea, about 32.3×10³cells·L^-1, and was also relatively high in southeast region in the survey area. The vertical distribution of phytoplankton was generally decreased with the increasing of water depth, and gradually decreased from coast to offshore. The Shannon-Wiener diversity was high in the southwest survey area, and the Pielou's evenness index was high in the eastern survey area. According to canonical correspondence analysis (CCA), the main factors that influence the abundance distribution of dominant species are nutrients, and the correlation with salinity and temperature is not obvious.