我国黄海浒苔绿潮暴发海域环境因子季节性变化及年际变化分析

【目的】掌握环境因子与浒苔绿潮之间的相互影响关系,为绿潮形成机制研究和半岛绿潮灾害防治提供科学资料。【方法】通过整理收集浒苔绿潮暴发重点海域的历史数据和现场调查数据,系统分析浒苔绿潮暴发期间以及浒苔绿潮暴发前后关键环境因子(温度、盐度、pH值、溶解氧DO、无机氮、磷酸盐和叶绿素a)的季节性变化、年际变化。【结果】南黄海海域表层海水温度2—8月份呈上升趋势,年际变化不大;盐度季节性和年际变化幅度不大;pH值2—8月份呈现先下降后升高再下降的趋势,历年来2月份呈上升趋势,8月份呈下降趋势;DO浓度2—8月份呈现先下降后升高再下降的趋势,年际变化很小;无机氮浓度2—8月份呈现先上升后下降的趋势,历年来2月份比较稳定,8月份呈下降趋势;磷酸盐季节性变化无规律,年际变化不大;浒苔绿潮暴发期间底层海水叶绿素a浓度高于表、中层。【结论】表层海水温度、盐度和无机氮都适宜于浒苔的生长,这是导致浒苔发生发展,乃至导致绿潮发生的区域环境因素;浒苔绿潮与DO、磷酸盐关系不明显;浒苔暴发导致浮游植物的生长受到极大限制。

Analysis of the Seasonal and Inter-annual Changes of Environmental Factors in Enteromorpha prolifera Green Tide Outbreak in the Yellow Sea

Objective] The interaction between environmental factors and green tide was mastered to provide scientific data for the study of the formation mechanism of green tide and the prevention of the disaster. Methods] The historical data and field researches in the outbreak area of green tide were used in analyzing seasonal and inter-annual changes of key environmental factors(T, salt, pH, DO, DIN, PO₄^3--P and chla) during and before the outbreak of the green tide. Results] In the South Yellow Sea, the temperature was on the rise from February to August, with little inter-annual change. The seasonal and inter-annual changes of the salinity were little. pH showed a tendency to drop first and then rise and then fall from February to August, and showed an upward trend over the years in February and a downward trend in August. DO showed a tendency to drop first and then rise and then fall from February to August, and inter-annual variation of DO was little. DIN showed a tendency to rise first and then fall from February to August, and showed an stable trend over the years in February and a downward trend in August. The seasonal variations of PO₄^3--P was irregular, with little inter-annual variation. The concentration of chlorophyll a in the bottom seawater was higher than that in the surface and middle layer during the outbreak of the green tide. Conclusion] The temperature, salinity, and inorganic nitrogen of surface water are all suitable for the growth of Enteromorpha prolifera, which are regional environment factors for Enteromorpha prolifera occurrence and development, even the occurrence of green tide. The relationship between the turquoise tide and DO and phosphate is not obvious. The growth of phytoplankton is greatly limited by the outbreak of green tide.