福建兴化湾溶解无机氮、溶解无机磷时空变化及营养状态评价

根据2007年3月至12月福建省兴化湾海域的水质监测结果,重点分析了该海域溶解无机氮(DIN)、溶解无机磷(DIP)的分布特征及其影响因素,并采用有机污染指数和富营养化指数对兴化湾海域的富营化水平进行了评价。结果表明:兴化湾海域富营养化主要污染物是DIN、DIP,其含量主要受径流排放和海洋浮游植物生长等因素的影响。春夏季节浮游植物生长繁殖旺盛,但雨水增多,最终导致了DIP、DIN含量的升高。秋季水温下降,浮游植物生长繁殖逐渐减弱,DIP、DIN的含量也逐渐升高。兴化湾富营养化水平加重,2007年的富营养化指数是2000年的5.7倍,主要体现在DIN、DIP等指标的升高。

Temporal-spatial variation of dissolved inorganic nitrogen and dissolved inorganic phosphorus in seawater and assessments on nutrient level of the Xinghua Bay

We studied the distribution characteristics of dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphorus(DIP), as well as their affecting factors in water of the Xinghua Bay based on the monitoring data of water quality from March to December, 2007.Besides,we assessed the nutrient level in the bay using organic pollution index and eutrophication index.The results showed that DIN and DIP were major pollutants resulting in eutrophication in the bay,which were mainly affected by runoff discharge and marine phytoplankton growth.In spring and summer seasons,phytoplankton grew and reproduced rapidly,and the rainfall increased,eventually leading to an increase of DIP and DIN concentrations.In autumn,water temperature decreased;phytoplankton grew and reproduced slowly;DIP and DIN concentrations also increased.Eutrophication became more and more serious in the Xinghua Bay.The eutrophication index in 2007 was 5.7 times higher than that in 2000,representing by the increased indexes of DIN and DIP.