莱州湾和桑沟湾养殖海区浮游植物的研究Ⅰ.

系统研究了中国北方两个典型养殖海湾浮游植物的周年变动。从莱州湾浮游植物全年分布来看,早春2～3月是细胞数量的高峰,此时的主要物种是中肋骨条藻(Skeletonema costatum(Grev．)Cleve)和角毛藻(Chaetoceros sp)等硅藻,形成明显的暴发性增长。莱州湾浮游植物的群落演替明显,硅藻和鞭毛藻类交替占优势：有4个月是硅藻占绝对优势,其他藻类很难见到;有4个月是硅藻占优势,甲藻或绿藻为次优势种;有4个月是以单细胞的金藻、绿藻或甲藻占优势。在8月份之前,3个采样点之间浮游植物在数量上差异不大;9月到12月份差异比较大,说明筏式养殖的扇贝对浮游植物数量有一定影响。另外,浮游植物优势种的年际变化,说明包括营养盐在内的海区环境因子可能发生了变化。

Study on phytoplankton in raft-culture areas of Laizhou Bay and Sanggou Bay

Annual fluctuation of phytoplankton in raft culture area of two bays in north China was studied. In Laizhou Bay, the density of phytoplankton peaked in March, when diatoms such as Skeletonema costatum (Grev.)Cleve and Chaetoceros sp. predominated, and a bloom was formed. The species succession was significant, with diatoms and flagellates dominated in turns, and red flood species, such as Noctiluca sp. and Peridinium sp., were also common members. Phytoplankton cell number among the sampling spots differed significantly from September to December, indicating the raft culture of scallop might affect the primary production of phytoplankton. The long term changes in predominant species was a sign of possible changes in environmental factors, including