摘要:
于2014年5月和9月对桑沟湾不同养殖区营养盐分布、浮游植物粒级结构和微型浮游植物(nanophy- toplankton, 2~20 μm)、微微型浮游植物(picophytoplankton, 0.2~2 μm)细胞不同结合态磷含量及影响因素进行了研究。结果表明：受养殖活动的影响，桑沟湾营养盐分布具有明显的季节变化，春季营养盐浓度低于秋季，春季和秋季磷酸盐是桑沟湾浮游植物生长的限制性营养盐；春季叶绿素a (Chla)含量从湾口向湾顶逐渐降低，浮游植物以nano-级浮游植物为主，秋季Chla与春季分布趋势相反，从湾口向湾顶逐渐升高，浮游植物以nano-级和pico-级为主，春季和秋季，从湾口向湾顶浮游植物呈小型化趋势；桑沟湾微型和微微型浮游植物细胞总磷均以细胞内结合态磷为主，占细胞总磷的比例为64%~93%，微型浮游植物细胞不同结合态磷的含量显著高于微微型浮游植物。微型和微微型浮游植物细胞总磷和细胞内结合态磷的含量与营养盐的相关性分析结果显示，微型浮游植物细胞总磷和细胞内结合态磷的含量与DIP、DSi有显著的正相关关系(r ≥ 0.796)，而微微型浮游植物细胞不同结合态磷的含量与各项营养盐均没有显著的相关性(r < |0.402|)。
Abstract:
Nutrient distribution, phytoplankton size structure and phytoplankton cell associated phosphorus characters of nanophytoplankton and picophytoplankton were studied during the two cruises in May and September of 2014. The results show that nutrients distributions have seasonal variation in Sanggou Bay due to aquaculture activities. Nutrient concentrations are lower in spring than in autumn. In spring and autumn, phosphorus would limit phytoplankton growth. Content of Chlo-rophyll a decreases from the east of Sanggou Bay to the west in spring, while in autumn the dis-tribution trend is opposite. Phytoplankton is mainly dominated by nanophytoplankton in spring, while in autumn both nano- and pico-phytoplankton are the dominance of the community. From bay mouth to bay head, average size of phytoplankton is reduced both in spring and autumn. In- tracellular phosphorus is dominance of nano- and pico-phytoplankton total cellular phosphorus, which contributes to 64% - 93%. The results of correlation analysis between cell associated phos- phorus contents and nutrients indicated a distinct positive correlation between total cellular phos-phorus, intracellular phosphorus of nanophytoplankton and DIP, DSi (r ≥ 0.796), but no correlation between cell associated phosphorus of picophytoplankton and nutrients (r < |0.402|).