春季东海近岸表层浮游植物群落结构及其与环境因子的关系

Phytoplankton communitystructure and its environmental controllingin the nearshore surface water of the East China Sea in spring

采用HPLC-CHEMTAX方法分析了2008年春季东海近岸海域的表层浮游植物群落结构及其与环境因子的关系。结果表明,调查区表层浮游植物优势类群为硅藻和甲藻,对叶绿素a的平均贡献率分别为42%和32%。硅藻和甲藻均适于生长在低温、低盐和高氮磷比的环境,但硅藻水华发生在温度较低、盐度较高、氮磷比较高的长江冲淡水与外海水交汇的盐度锋面上,而甲藻水华发生在温度较高、盐度较低、氮磷比较低的冲淡水与台湾暖流交汇的温度锋面上。LOWESS回归表明,叶绿素a和甲藻分别随温度和盐度升高呈先增后降的趋势,硅藻随温度和盐度变化波动较大。叶绿素a和硅藻随氮磷比升高而递增,甲藻随氮磷比的变化波动较大。

Using HPLC-CHEMTAX method,pigments data collected from the nearshore surface water of the East China Sea in spring of 2008 were analyzed for understanding phytoplankton community structure and relationships with environmental factors.Results showed that the dominant groups are diatoms and dinoflagellates,which averagely contributed to chlorophyll a （Chl a） up to 42％ and 32％,respectively.Both diatoms and dinoflagellates preferred in the environment with lower temperature,lower salinity,and higher N/P ratio,but the diatoms bloom occurred in the salinity front formed by the interaction of the Changjiang diluted water and the open ocean water which is higher in salinity and lower in temperature and N/P ratio,while the dinoflagellates bloom occurred in the temperature front formed by the interaction of the Changjiang diluted water and the Taiwan Warm Water which is higher in temperature,lower in salinity and N/P ratio.LOWESS results revealed that both Chl a and dinoflagellates increased incipiently and then decreased as temperature or salinity increasing,while relationships between diatoms and temperature or salinity showed a larger fluctuation.Both Chl a and diatoms increased as N/P ratio increasing,while the relationship between dinoflagellates and N/P ratio displayed a larger fluctuation.