大亚湾海域2009—2015年氮、磷营养盐时空分布及富营养化评价

为了解大亚湾海域海水中氮(N)、磷(P)营养盐的时空分布情况及富营养化程度,于2009年4月和5月、2010年5月和6月、2012年2月、2015年1月和2月对大亚湾海域进行海水采样监测。结果表明,大亚湾海域不同功能区无机氮(DIN)和活性磷酸盐(PO4-P)浓度总体上为先增后降的趋势,DIN和PO4-P的时空分布由于受陆源污染、海水养殖等影响,浓度呈近海岸向远海岸递减的趋势。潜在富营养化评价表明,大亚湾海域整体上经历了由贫营养转为中度营养再转为贫营养的过程,其中一类功能区长年处于贫营养状态。总体上大亚湾平均氮磷比(N/P)接近或小于Redfield比值。

Spatio-temporal distribution and eutrophication assessment of nutrients in Daya Bay during 2009–2015

We investigated the spatio-temporal distribution characteristics and eutrophication of nutrients in Daya Bay in April and May 2009,May and June 2010,February 2012,as well as January and February 2015.Generally speaking,the contents of DIN and PO4-P increased first and then decreased.The spatio-temporal distribution of DIN and PO4-P was affected by terrestrial pollution,marine aquaculture,etc..The nutrient concentration decreased from coastal area to open sea.The evaluation of potential eutrophication indicates that the seawater in Daya Bay experienced a process from poor nutrition to moderate nutrition and then to poor nutrition.The seawater in the functional areas of Class I had been always in a state of poor nutrition.The average N/P ratio was lower than the Redfield value(16)in the monitoring period.