汕尾近岸海域营养盐的时空分布及潜在富营养化评价

本文根据2016－2018年红海湾汕尾近岸海域3个站位32个航次的高频监测数据，对该区域营养盐的时空分布特征、影响因素及营养盐限制状况进行分析讨论，并结合潜在富营养化评价模式对该区域的富营养化风险进行评估。结果表明，红海湾汕尾近岸海域DIN符合第二类、第三类海水水质标准，PO₄-P符合第一类海水水质标准，基本满足海洋功能区划要求。营养盐的空间分布特征表现为距离汕尾市区越近营养盐浓度越高；年际变化表现为2016年各营养盐平均浓度高于2017年和2018年；季节变化规律复杂，不同年份不同营养盐均存在一定差异。相关性分析表明，营养盐的时空分布特征主要受降雨量、盐度、pH、叶绿素a、悬浮物等多种环境因子的影响。营养盐结构分析表明，红海湾汕尾近岸海域存在磷限制，尽管目前水体富营养化比例不高，但潜在富营养化风险较高，其中品清湖是高风险区，冬、春季是高发期。

Temporal-spatial distribution of nutrients and potential eutrophication assessment in Shanwei coastal area

The spatial-temporal distribution characteristics of nutrients, influencing factors and nutrient limitation in Shanwei coastal area of Honghai bay were analyzed, and the eutrophication risk was evaluated combined with the potential eutrophication assessment model, based on thirty-two cruises at three stations carried out during 2016－2018. The results showed that DIN in Shanwei coastal area met the second and third class seawater quality standard, and PO₄-P met the first class of seawater quality standard, which satisfied the requirements of marine functional zoning. The spatial distribution characteristics of nutrients showed that the closer it was to Shanwei city, the higher the nutrient concentration was; the interannual variation was that the average concentration of nutrients in 2016 is higher than that in 2017 and 2018; the seasonal variation was complex, there were certain differences in different years for different nutrients. Correlation analysis showed that the temporal-spatial distribution characteristics of nutrients were mainly affected by precipitation, salinity, pH, chlorophyll a, suspended particulate matter and other environmental factors. The nutrient structure analysis showed that there was phosphorus limitation in Shanwei coastal area of Honghai bay. Although the eutrophication ratio was relatively low, it suffered a high potential risk of eutrophication. Pinqing lake was the high risk area, and the high occurrence period was winter and spring.