江苏重点紫菜增养殖区环境质量状况评价

Assessment of Environment Quality in Important Porphyra yezoensis Mariculture Zones of Jiangsu Province

以2012—2016年海州湾紫菜增养殖区海域和如东紫菜增养殖区海域的养殖功能区监测调查结果为依据,综合分析和评价江苏重点紫菜增养殖区5年的环境质量状况及变化趋势,找出主要超标环境因子的变化特征,分别讨论了两个海域的富营养化状态及变化趋势.结果表明,5年来海州湾增养殖区的环境质量综合指数(EQI)呈逐年上升趋势,如东增养殖区的环境质量综合指数(EQI)呈先上升后保持稳定的趋势,2016年两个海域环境质量综合指数均达到98,为优良等级,满足增养殖区环境质量要求,海域环境质量状况较2012年均有所改善;海州湾增养殖区和如东增养殖区的主要超标环境因子分别是水质中的无机氮(DIN)与活性磷酸盐(PO_4^(3-));在富营养化状态方面,海州湾增养殖区自2013年起富营养化指数(EI)逐年降低,2016年该海域水体未达到富营养化水平;如东增养殖区水体富营养化指数(EI)5年中呈波动下降趋势,除2013年以外,其余各年均处于贫营养状态;C_N/C_P比值反映出目前海州湾增养殖区的浮游植物生长受磷限制,如东增养殖区的浮游植物生长主要受氮限制.

Based on the monitoring data in Porphyra yezoensis mariculture zones of Haizhou bay and Rudong from 2012 to 2016,this study comprehensively assessed the environment quality and variation trend of above zones in recent five years.This study found out the variation features of the main environmental factors and discussed the status as well as the trends of eutrophication phenomeno of these zones.The results showed that in recent five years the environmental quality index（EQI）of mariculture zone in Haizhou bay had raised up year by year and the EQI of Rudong had firstly risen up and kept stable afterwards.In the year of 2016,the scores of the EQI of these zones reached 98 with first class environmental quality level,which met the requirements of the mariculture zones.The environmental quality of these two zones had been improved compared to the year of 2012.The results also showed that the main pollution factor of mariculture zone in Haizhou bay and Rudong was inorganic nitrogen and active phosphate respectively.In the aspect of eutrophication,the eutrophication index（EI）of mariculture zone in Haizhou bay had declined since 2013 and had not reached the eutrophication level since 2016.In Rudong,EI was fluctuate declining in recent five years and had been fallen below the eutrophication level except 2013.The C_N/C_P reflected that the growth of the phytoplankton was restricted by phosphorus in mariculture zone in Haizhou bay and by nitrogen in Rudong.