南麂列岛国家海洋自然保护区微、小型藻类生态研究Ⅱ.数量分布

Ecological studies on nanoalgae and microalgae in Nanji Islands National Marine Natural Conservation Area Ⅱ. Quantitative distribution

本文对南麂列岛国家海洋自然保护区不同生境中的微、小型藻类的丰度和季节变化及其与环境因子之间的关系进行了研究。海水中浮游藻类的年平均丰度为１２０×１０４个／ｍ３；沉积物中底栖藻类年平均丰度为２１６×１０４个／ｃｍ２；潮间带中微、小型藻类年平均丰度为１９６６０３个／ｇ或１７７９３个／ｃｍ２。海水中微、小型藻类丰度的季节变化为夏季高于秋季高于春季高于冬季；潮间带以个／ｃｍ２表示的藻类丰度的季节变化为春季高于夏季高于秋季高于冬季，这与大型海藻丰度的变化趋势基本相似；以个／ｇ表示的藻类丰度的季节变化为春季高于秋季高于冬季高于夏季，这与大型底栖动物总生物量的变化趋势完全一致。南麂海域微、小型藻类丰度与盐度、溶解氧浓度呈正相关，与营养盐（Ｎ、Ｐ、Ｓｉ）含量之间呈负相关。

he cell density and seasonal change of nano and microalgae in various habitats and the relations to some environmental factors are analysed in this paper. The average annual cell densities of nano and microalgae in the sea water, in the sediment and in the intertidal zone are 120×10 4 cells/m 3, 216×10 4 cells/cm 2 and 197×10 4 cells/g (or 17 793 5 cells/cm 2) respectively. The cell density of nano and microalgae in the sea water is bigger in summer than in autumn, in autumn than in spring, in spring than in winter. In the intertidal zone, it (when the density is expressed in cells/cm 2) is bigger in spring than in summer, in summer than in autumn and in autumn than in winter, which is similar to the seasonal change of cell density of macroalgae, and it (when the density is expressed in cells/g) is bigger in spring than in autumn, in autumn than in winter, in winter than in summer, which is in accord with the seasonal change of macrobenthos biomass. There is positive correlation between cell density of nano and microalgae and salinity and dissolved oxygen, while it is negatively correlated with nutrients (N P Si).