红色赤潮藻主导的混合赤潮对浮游生物群落结构的影响——以浙江南部沿海为例

根据2016年6月中旬浙江南部沿海一次红色赤潮藻主导的混合赤潮的调查数据，分析了赤潮海域和非赤潮海域浮游生物的种类及丰度、优势种、多样性指数差异以及其与水环境因子的相关性。结果表明，该海域共鉴定出浮游植物22种，浮游动物20种，赤潮区浮游植物平均丰度显著高于非赤潮区，赤潮区与非赤潮区浮游动物平均丰度和生物量差异不显著。赤潮区浮游植物均匀度指数显著低于非赤潮区，而赤潮区和非赤潮区浮游动物各指数均差异不显著。赤潮发生对桡足类影响较大，其在赤潮区的种类和丰度均显著少于非赤潮区。主成分分析结果表明非赤潮区最主要优势种红色赤潮藻与氮磷浓度呈正相关，赤潮区则相反。浮游动物总丰度在非赤潮区及赤潮区均与叉状角藻丰度呈正相关，与有毒赤潮生物具刺膝沟藻丰度呈负相关。以上结果表明红色赤潮藻为主的混合赤潮爆发能够显著改变赤潮发生海域浮游生物的群落结构。

Effects of Akashiwo sanguinea-dominated algal blooms on the plankton community as observed from the coastal waters of southern Zhejiang,China

Based on the data collected from Akashiwo sanguinea-dominated algal blooms occurred in the coastal waters of southern Zhejiang province, in mid-June 2016, the species composition and abundance, dominant species, diversity indices of plankton community between algal bloom and non-bloom areas were compared, and the relationships of biodiversity to environmental factors were analyzed. A total of 22 phytoplankton and 20 zooplankton species were identified. The average abundance of phytoplankton in the bloom area was significantly higher than that in the non-bloom area. No significant difference in the average abundance and biomass of zooplankton was found between the bloom and non-bloom areas. The average evenness index of phytoplankton in the non-bloom area was significantly higher than that in the bloom area. However, and no significant difference in other biodiversity indices of zooplankton existed between the bloom and non-bloom areas. In addition, the number of copepod species and their abundances in the bloom area were significantly less than those in the non-bloom area. The results of principal component analysis for the dominant species and environmental variables showed that A. sanguinea abundance positively correlated with nutrients in the non-blooms area, but negatively correlated with the ones in the blooms area. The total zooplankton abundance was positively correlated with Ceratium furca both in the bloom and non-bloom areas, but negatively correlated with the abundance of Gonyaulax spinifera, a toxic dinoflagellate. These results indicate that the Akashiwo sanguinea-dominated algal blooms can significantly change the community structure of plankton.