珠海横琴岛海域浮游植物的生态特征

根据2013年11月（秋季）、2014年5月（春季）、2015年2月（冬季）和8月（夏季）4个航次的调查数据，对横琴岛海域浮游植物物种组成、时空分布及多样性等群落结构特征进行了分析。结果显示:共鉴定出浮游植物4门140种，硅藻101种，占种类组成的72.14%；甲藻33种，占23.58%；绿藻3种，占2.14%；蓝藻3种，占2.14%。种类数秋季64种，春季和冬季均为52种，夏季36种。年均丰度范围为（2.7~20100.40）×104 ind/m3，均值为1613.43×104 ind/m3；该海域春夏季优势种较少，秋冬季优势种较多，春季仅有中肋骨条藻（Skeletonema costatum），夏季为中肋骨条藻和布氏双尾藻（Ditylum brightwellii），秋季为中肋骨条藻、中心圆筛藻（Coscinodiscus centralis）和琼氏圆筛藻（Coscinodiscus jonesianus），冬季为细弱海链藻（Thalassiosira subtilis）、密连角毛藻（Chaetoceros densus）等7种。多样性指数、均匀度指数、多样性阈值及丰富度指数均值冬季为2.52、0.63、1.67、0.80，秋季为2.46、0.63、1.64、0.80，夏季为1.78、0.52、0.98、0.53，春季为0.27、0.11、0.10、0.32。其中春季4项指数均很低，表明该海域浮游植物群落结构异常，海域生态环境受到了一定程度的污染破坏。相关分析得出:春季浮游植物丰度与环境因子无明显相关性；夏季浮游植物丰度与pH呈显著正相关（P＜0.01），与PO₄-P呈负相关（P＜0.05）；秋季浮游植物丰度与DIN呈正相关（P＜0.05）；冬季浮游植物丰度与盐度呈正相关（P＜0.05），而与DIN呈显著负相关（P＜0.01），与水温和PO₄-P呈负相关（P＜0.05）。

Ecological Characteristics of phytoplankton in Hengqin island sea area of Zhuhai City

Based on the four phytoplankton survey date in November 2013, May 2014, February and August 2015 in Hengqin island sea area, the species composition, spatial and temporal distribution and diversity of phytoplankton were analyzed.Results showed that a total of 140 phytoplankton species were identified in four phylum.101 species of Bacillariophyta, accounting for 72.14%; 33 species of Pyrrophyta, accounting for 23.58%; 3 species of Chlorophyta, accounting for 2.14%; 3 species of Cyanophyta, accounting for 2.14%.There were 64 species in autumn, 52 species in spring and winter, 36 species in summer.The annual abundance of phytoplankton ranged from 2.7×104 to 20100.40×104 ind/m3, averaged 1613.43×104 ind/m3.The dominant species of spring and summer were less, the dominant species were more in autumn and winter.The dominant species was only Skeletonema costatum in spring, Skeletonema costatum and Ditylum brightwellii were appearing in summer, Skeletonema costatum, Coscinodiscus centralis and Coscinodiscus jonesianus were appearing in autumn, while Thalassiosira subtilis and Chaetoceros densus seven kinds were appearing in winter.Shannon-Wiener diversity index (H'), Pielou evenness index (J'), Diversity threshold (Dv) and Margalef richness index (D) were 2.52, 0.63, 1.67, 0.80 in winter; were 2.46, 0.63, 1.64, 0.80 in autumn; were 1.78, 0.52, 0.98, 0.53 in summer; and were 0.27, 0.11, 0.10, 0.32 in spring.While four index were very low in spring, indicated that the community characteristics was unusual, and the ecological environment has been a certain degree of pollution and damage.There was no significant correlation between phytoplankton abundance and environmental factors in spring.Phytoplankton abundance was significantly positively correlated with pH (P < 0.01) in summer, and negatively correlated with active phosphate (P < 0.05).Phytoplankton abundance was positively correlated with inorganic nitrogen (P < 0.05) in autumn.In winter, phytoplankton abundance was positively correlated with salinity (P < 0.05), but significantly negatively correlated with inorganic nitrogen (P < 0.01), and negatively correlated with water temperature (P < 0.05) and active phosphate (P < 0.05).