珠江口赤潮爆发过程中水体及表层沉积物间隙水中营养盐与叶绿素的变化特征

发布时间：2018-07-09 14:48

本文选题：赤潮 + 营养盐扩散通量　；参考：《海洋通报》2016年04期

【摘要】：为探讨夜光藻赤潮爆发时期,珠江口沉积物营养盐的分布与释放特征及其对水体和沉积物中叶绿素Chl-a、脱镁叶绿酸Pha-a分布的影响,于2015年1月对珠江口进行了采样分析。研究发现,在赤潮爆发期间水体中的NO3-N、NH4-N含量较高,占DIN的比例分别为59%、32.8%。表层水体中营养盐含量均高于底层,这是因为表层水体主要受陆源污染,营养物质含量较高,而在底层水体中,由于赤潮中后期浮游生物沉降到底层,消耗了底层的营养物质,使其浓度低于表层。PO4-P和Si O3-Si的分布特点与前者相似,其平均值分别为0.019 mg/L、0.74 mg/L。与此同时,沉积物间隙水中的营养物质不断向水体中释放,促进了水体中浮游植物的生长繁殖,从而为夜光藻赤潮的爆发提供丰富饵料。此外,浮游植物的生长与沉积物/水界面之间的NH4-N、Si O3-Si扩散通量呈现极显著相关关系(P0.01),此时沉积物起到了污染源的作用。沉积物中叶绿素Chl-a和脱镁叶绿酸Pha-a的含量均较高,尤其在赤潮污染严重海域含量分别高达1.16和3.2μg/g,并且Pha-a的含量与水柱总Chl-a呈现极显著相关(P0.01),这是因为赤潮期间衰老或死亡的浮游植物及夜光藻沉降到表层沉积物所致。因此,赤潮的爆发可显著提升底栖生产力水平。
[Abstract]:In order to investigate the distribution and release characteristics of nutrients in sediments of the Pearl River Estuary during the outbreak of the red tide of noctiluca and their effects on the distribution of chlorophyll Chl-a and Pha-a in water and sediment, a sampling analysis was carried out in the Pearl River Estuary in January 2015. It was found that the content of no _ 3-NN NH _ 4-N in the water during the red tide outbreak was high and the proportion of din was 593.832. 8% respectively. The nutrient content in the surface water is higher than that in the bottom, which is because the surface water is mainly polluted by land sources, and the nutrient content is high. In the bottom water, the plankton subsidence to the bottom layer in the middle and late stages of the red tide consumes the nutrients of the bottom layer. The distribution characteristics of PO4-P and SiO3-Si are similar to those of the former, and the average values are 0.019 mg / L ~ 0.74 mg 路L ~ (-1), respectively. At the same time, nutrients from sediment interstitial water are released into the water, which promotes the growth and reproduction of phytoplankton in the water, thus providing a rich diet for the outbreak of noctiluca red tide. In addition, there was a significant correlation between phytoplankton growth and NH _ 4-N _ N _ 2O _ 3-Si diffusion flux at the sediment / water interface (P0.01), where the sediment acted as a source of pollution. The contents of chlorophyll Chl-a and Pha-a were higher in sediments. Especially in the seriously polluted areas of red tide, the content of Pha-a was as high as 1.16 渭 g / g and 3.2 渭 g / g, respectively, and the content of Pha-a was significantly correlated with the total Chl-a of water column (P0.01), which was caused by the sedimentation of phytoplankton and noctiluca into the surface sediments during the red tide. Therefore, the outbreak of red tide can significantly improve the level of benthic productivity.
【作者单位】：中国科学院南海海洋研究所热带海洋生物资源与生态重点实验室;中国科学院大学;
【基金】：公益性行业(农业)科研专项(201403008)
【分类号】：X55

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