大亚湾日本星杆藻种群动态及其与环境因子的关系

Population dynamics of Asterionella japonica and its relationship with environmental factors in Daya Bay

研究了1997～1998年及1999和2000年春季大亚湾日本星杆藻(Asterionella.japonica)种群动态及其与环境因子之间的关系.日本星杆藻是大亚湾浮游植物常见优势种类,可在全年温度范围(14～32.8℃)内形成数量高峰,并发生水华.日本星杆藻在1998年和2000年春季不常出现,但1999年春丰富的营养盐含量及它们之间合适的比值、多变的水温、稳定的盐度和晴朗的天气使日本星杆藻迅速生长,并发生了水华,最高细胞密度达5255cells/mL.水华消耗了大量的营养,水华期间DIN、DIP和DSi分别下降了76.0%、69.7%和58.8%,而且营养元素的消耗特别是DIN的耗尽是水华消退的重要原因,而桡足类等浮游动物摄食也是水华消退的原因之一.

Population dynamics of Asterionella japonica and its relationship with environmental factors in Daya Bay were studied from 1997 to 1998 and the springs of 1999 and 2000. A. japonica was the common dominant species of phyto plankton in Daya Bay, which peaks and blooms occurred in temperatures range of 14~32.8℃ all through the year, and the algae blooms occurred. A. japonica seldom occurred in spring of 1998 and 2000; while abundant nutrient salt contents and their appropriate ratios, variable water temperature, stable salinity and sunny weather resulted in quick growth of A. japonica and the algae bloom occurred with the maximum density of 5255 cells/mL. The bloom used up large amount of nutrients and contents of DIN, DIP and DSi decreased 76.0%, 69.7%, 58.8% respectively during the bloom. Futhermore, the exhaustion of nutrient elements especially DIN was the key reason of the disappearance of the bloom, while feeding of zooplankton such as copepods also played role in bloom decline.