基于2005年长江口邻近海域春季现场调查资料,本文采用非线性拟合方法,构建了该海域春季硅藻藻华和甲藻藻华期间浮游植物生物量与无机营养盐、温度和盐度之间的定量关系方程,进而分析了春季硅、甲藻藻华发生的最适环境条件。结果表明,硅藻藻华出现的最适环境条件为:溶解态无机氮浓度10.1μmol/L、磷酸盐浓度0.21μmol/L、硅酸盐浓度6.39μmol/L、温度11.9℃、盐度30.5;甲藻藻华暴发的最适环境条件为:溶解态无机氮浓度3.98μmol/L、磷酸盐浓度0.18μmol/L、温度22.0℃、盐度27.2。上述硅、甲藻藻华发生的最适环境条件可作为硅、甲藻藻华形成的关键环境参数,为开展长江口邻近海域藻华形成和演替过程的数值模拟和参数优化提供参考。
On the basis of the 2005 survey data from the coastal waters adjacent to the Changjiang River estuary,nonlinear fitting methods were used to establish equations representing the quantitative relationships between phytoplankton biomass and inorganic nutrients, temperature and salinity during the diatom and dinoflagellate blooms. The optimum values of dissolved nitrogen, phosphate, silicate, temperature, and salinity for the diatom bloom were calculated to be 10.1μmol/L, 0.21 μmol/L, 6.39 μmol/L, 11.9℃, and 30.5, respectively, and those for the dinoflagellate bloom were 3.98μmol/L, 0.18μmol/L, 22.0℃, and 27.2, respectively. These optimum conditions could be treated as key environmental parameters that provide references for further studies on numerical simulation and parameter optimization of harmful algal blooms.