2010年夏季广西北部湾沿岸浮游植物分布特征及其与环境因子的相关性

2010年6月4日至26日在广西北部湾沿岸共设46个站位凋查分析浮游植物群落结构特征,以及浮游植物数量与环境因子的相关性。结果共鉴定出浮游植物70属149种(含变种和变型),其中硅藻41属106种,占总物种数的71.14%,占总细胞丰度的95.81%;甲藻18属32种,占总物种数的21.48%,占总细胞丰度的1.44%。浮游植物平均密度为61.10×104 cell/L,硅藻平均细胞丰度为58.54×104 cell/L,甲藻类平均细胞丰度为0.88×104cell/L。浮游植物密集区在防城港海区,此外在北海营盘附近海域有一个较高的密度区。浮游植物丰度在茅尾海和钦州港近岸较低,其余海区的浮游植物数量分布态势为近岸高、外海低。浮游植物主要优势种为尖刺拟菱形藻(Pseudo-nitzschia pungens)、中肋骨条藻(Skeletonema costatum)、拟旋链角毛藻(Chaetocerospseudocurvisetus)、菱形海线藻(Thalassionema nitzschioides)、丹麦细柱藻(Leptocylindrus danicus)。尖刺拟菱形藻、拟旋链角毛藻密集区主要在防城港海区,而中肋骨条藻密集区主要在北海海区。浮游植物数量与温度、盐度及硝酸盐、亚硝酸盐、氨盐和硅酸盐无相关性,北海海区和防城港海区浮游植物丰度与活性磷酸盐呈显著正相关,磷在以上两个海区成为浮游植物生长的限制因子。

Distribution Features and Relation of Phytoplankton with Environment Factors in the Coastal Water of Guangxi in Summer 2010

We investigated the abundance and species composition of phytoplankton community in the coastal water of Guangxi (21.35~21.90''N, 118.00~119.70''E) during 4 to 26 June, 2010.A total of 149 species belonging to 70 genera of 6 classes were identified.Diatoms contributed to 71.1% of the total phytoplankton species number and 95.81% of the total phytoplankton cell abundance; followed by dinoflage1lates, which accounted for 21.48% of total phytoplankton species number and 1.44% of the total phytoplankton cell abundance.The average density was 61.10×10⁴ cell/L, was 58.54×10⁴ cell/L and 0.88×10⁴ cell/L for phytoplankton, diatom and dinoflagellate, respectively.Phytoplankton abundance had a lower value in Maowei sea and the coastal zone of Qinzhou port, in addition to the two areas, the quantitative distributions of phytoplankton presented a trend of being higher in the inner bay than in the outer bay.The dominant species were Pseudo-nitzschia pungens, Skeletonema costatum, Chaetoceros pseudocurvisetus, Thalassionema nitzschioides, Leptocylindrus danicus.P.pungens and C.pseudocurvisetus gathered in Fangchenggang sea area, while S.costatum gathered in the adjacent waters of Beihai.There were no significant relationships between phytoplankton abundance and temperature, salinity, nitrate, nitrite, ammonia salt and silicate.A positive relationship was found between phytoplankton abundance and phosphate in Beihai sea area and Fangchenggang sea area.Phosphorus was the limiting factor of phytoplankton in the above two sea areas.