三亚湾春秋浮游植物分布及其与环境因子的关系

为了解三亚湾浮游植物的群落结构特征及其与环境因子之间的关系，笔者于2019年春（4月份）、秋（9月份）两季对三亚湾12个站位的浮游植物及水质进行了网采取样调查。春季采样记录浮游植物共6门82种，秋季共鉴定出浮游植物4门85种，其中硅藻门和甲藻门种类组成占优势，春、秋季硅藻门分别占55种和67种（分别占浮游植物总种类数的67.07%和78.82%）。三亚湾春季浮游植物优势种共4种，分别为角毛藻属（Chaetoceros sp.）、印度角毛藻（Chaetoceros indicus）、三角新角藻（Neoceratium tripos）和薄壁几内亚藻(Guinardia flaccida)，其中，角毛藻属（Chaetoceros sp.）为第一优势种。秋季调优势种共9种，分别为菱形海线藻(Thalassionema nitzschioides)、热带骨条藻(Skeletonema tropicum)、霍氏半管藻(Hemiaulus hauckii)、日本星杆藻(Asterionella japonica)、丹麦细柱藻(Leptocylindrus danicus)、劳氏角毛藻(Chaetoceros lorenzianus)、柔弱拟菱形藻(Pseudo-nitzschia delicatissima)、窄隙角毛藻(Chaetoceros affinis)和异角毛藻(Chaetoceros diversus)，其中，菱形海线藻为第一优势种。春季多样性指数、均匀度指数和丰富度指数平均分别为3.33、0.80、2.26；秋季多样性指数、均匀度指数和丰富度指数平均分别为4.05、0.79、3.09。RDA分析结果显示，春季总磷、氨氮和水温是影响浮游植物群落组成的主要因素，秋季总氮、盐度和电导率对浮游植物的群落结构影响最大。

Phytoplankton distribution and its relationship with related environmental factors in Sanya Bay in spring and autumn

In recent years the economy has developed rapidly in Sanya City, Hainan Province. With the rapid development of tourism, Gulf port construction, aquaculture and other industries, the ecological environment of the coastal waters in Sanya Bay has attracted much attention. In order to understand the relationship between the phytoplankton community structure and environmental factors in Sanya Bay, a sampling survey of phytoplankton and seawater quality at 12 survey stations near the coast of Sanya Bay was made in April and September 2019. The results showed that there are a total number of 82 species of phytoplankton identified in Spring, and a total number of 85 species identified in Autumn, in which diatoms and dinoflagellates were predominant in species composition and cell abundance. There were 4 and 9 dominant species in Spring and Autumn, respectively. Chaetoceros sp, Chaetoceros indicus, Neoceratium tripos and Guinardia flaccida were dominant species in Spring, and Chaetoceros sp was the first dominant species. Thalassionema nitzschioides, Skeletonema tropicum, Hemiaulus hauckii, Asterionella japonica, Leptocylindrus danicus, Chaetoceros lorenzianus and Chaetoceros diversus were dominant species in Autumn, and Thalassionema nitzschioides was the first dominant species. The average Shannon-Wiener diversity index, Pielou evenness index and Margalef diversity index were 3.33, 3.27, 2.26 in Spring, respectively, and 4.05, 0.79, 3.09 in Autumn, respectively. The redundancy analysis showed that the main factors affecting the phytoplankton structure were total phosphorus, ammonia nitrogen and water temperature in Spring, and total nitrogen, salinity and conductivity in Autumn.