对广东大亚湾海域1997年7月至1998年6月期间中肋骨条藻Skeletonema costatum种群动态及其与环境因子之间的关系进行研究。结果表明, 中肋骨条藻在该海湾全年出现, 有春季与秋季两个藻细胞密度高峰期, 其中秋季时的藻密度最大。1998年4—6月密集采样期间, 各站位中肋骨条藻种群数量变动基本上呈现出表层密度高于底层的趋势, 各站位间的数量变动具有一定的空间差异, 呈现出养殖区、生活区等近岸海域藻细胞密度高于远岸海域的趋势。中肋骨条藻高频率、高密度出现的温度范围为25—26℃, 盐度范围为30.6‰—31.6‰, 溶解性无机氮 (dissolved inorganic nitrogen, DIN)、可溶性无机磷 (dissolved inorganic phosphorus, DIP)和SiO32?-Si范围分别为9.2—78.3、3.7—5.9和564.0—1054.6µg•L?1。相关性分析表明, 影响大亚湾海域中肋骨条藻种群数量的主要环境因子有SiO32?-Si、DIN、化学需氧量 (chemical oxygen demand, COD)和氮磷比值, 同时水温、溶解氧 (dissolved oxygen, DO)也在一定程度上影响着中肋骨条藻的种群动态。

Population dynamics of Skeletonema costatum from July 1997 to June 1998 at the Daya Bay, Guangdong Province was investigated. The influence of environmental factors on the temporal and spatial distribution of S. costatum was also ana-lyzed. Results showed that S. costatum existed all year round with two cell density peaks in spring and autumn (cell density in autumn was higher than that in spring). In general, cell density of S. costatum in the surface water was higher than that in the bottom water at the Daya Bay. Cell density varied spatially among the sampling stations, showing a trend that cell density in the near-shore aquaculture area and living area was higher than that in the off-shore area from April to June of 1998. The en-vironmental conditions for high-frequency and high-density S. costatum were temperature 25.0?26.0℃, salinity 30.6‰?  31.6‰, DIN (dissolved inorganic nitrogen) 9.2?78.3µg•L?1, DIP (dissolved inorganic phosphorus) 3.7?5.9µg•L?1, and  SiO32?-Si 564.0?1054.6µg•L?1. Correlation analysis indicated that SiO32?-Si, DIN, COD (chemical oxygen demand), and ratio of N to P were the major environmental factors controlling the cell density of S. costatum. In addition, temperature and DO(dissolved oxygen) also affected the growth of S. costatum to some extent.