水东湾春、秋季浮游植物群落结构特征

Characteristics of phytoplankton community in Shuidong Bay in spring and autumn

根据2013年4月和10月2个航次的调查数据,对水东湾海域浮游植物种类组成、时空分布及多样性等群落特征进行了分析。共鉴定浮游植物4门69种,其中硅藻类59种,占85.51%;甲藻类8种,占11.59%;蓝藻和金藻类各1种,分别占1.45%。浮游植物丰度秋季(203.10×104个·m-3)是春季(22.89×104个·m-3)的8.87倍;春季湾外各站位高,秋季则湾内高。水东湾浮游植物优势度极高,春、秋两季均以中肋骨条藻(Skeletonema costatum)为第一优势种,优势度(Y)分别高达0.64和0.54。两季Shannon-Wiener多样性指数(H')、Pielou均匀度指数(J')春季(2.38,0.66)高于秋季(1.72,0.43),Margalef物种丰富度指数(D)均低于1。水东湾海域水质状况的生物多样性指数评价显示,该海域生态环境受到了一定程度的污染。

Based on the survey data collected from Shuidong Bay in April and October, 2013, we analyzed the species composition, spatial and temporal distribution and diversity of phytoplankton. A total of 69 species of phytoplankton belonging to four phylums were identified （59 species of Bacillariophyta, accounting for 85.51% ; 8 species of Pyrrophyta, accounting for 11.59% ; 1 species of Cy- anobacteria and 1 species of Chrysophyta, accounting for 1.45% ）. The abundance of phytoplankton in autumn （203.10 ×10^4 ind. m-3 ） was 8. 87 times higher than that in spring （22. 89 × 10^4ind .m-3 ）, and the abundances obtained from the sampling stations out- side the bay and inside the bay in spring and autumn were high. Skeletonema costatum was the first dominant species in spring and au- tumn, and the dominances were 0. 64 and 0. 54, respectively. Shannon-Wiener diversity index （ H＇ ） and Pielou evenness index （ J＇ ） were higher in spring （2. 38, 0. 66） than in autumn （ 1.72, 0. 43 ）. Margalef richness index （D） was lower than 1.00 in the two seasons. It is concluded that the Shuidong Bay had been polluted.