大亚湾澳头水域浮游植物群落结构及周年数量动态

对1997年至1998年广东省大亚湾澳头水域的浮游植物群落进行调查和分析。结果发现浮游植物65属198种;硅藻在种类组成和数量上都比甲藻占有优势,存在春季和秋季高峰,主要优势类群依次是角毛藻、骨条藻、拟菱形藻等;甲藻只存在春季高峰,代表种类有裸甲藻、原甲藻等。主要优势种类的生长与调查水域的盐度没有明显关系,但全年水温的季节性变化对优势种类的消长影响显著。Simpson多样性指数、Shannon-Weaver多样性指数、均匀度的年平均值分别是0.611、2.107、0.557,多样性指数没有明显的季节变化规律和水平分布规律。  

Annual dynamics of phytoplankton community and abundance at Aotou Cove, Daya Bay: 1997-1998

In this study, phytoplankton community was investigated and analyzed fromJul. 1997 to Jun. 1998 in Daya Bay. A total of 198 phytoplankton species, belonging to 65 genera was recorded and in terms of species composition and abundance, diatoms dominated throughout the whole year. Dominant species of diatoms wereChaetoceros spp.,Skeletonema costatum,Pseudo-nitzschia spp. whereas dominant species of dinoflagellates wereGymnodinium spp.,Prorocentrum spp.. Phytoplankton abundance showed significant seasonal change and diatoms had two peaks in spring and autumn with dinoflagellates only one peak in spring. Horizontal distribution of phytoplankton abundance showed no obvious difference among the six stations investigated,but the cell density of S2 which near to the cage2fish cultural area was slightly less than the others. The relationships between major phytoplankton species(including three dominant diatoms and three dominant dinoflagellates) and water temperature, salinity wre analyzed respectively. The results showed that temperature and salinity had no limitary effect on the appearance of diatoms, meanwhile dinoflagellates appeared during 17-30℃, with optimal in 25℃. But seasonal change of temperature affected obviously on dominant speciespgrowth and depletion. The annual variation of diversity indexes(D,H＇) and evenness (E) of phytoplankton showed no clear seasonal and spatial pattern and the average values of them were 0.611,2.107,0.557 respectively. Compared with other bays in Southeast China Sea, the diversity indexes and evenness are commonly high except in early spring.