浒苔绿潮暴发对南黄海海域溶解有机物的影响

Effects of the occurrence of green tide(Ulva prolifera blooms)on dissolved organic matters in the Southern Yellow Sea

通过2017年南黄海海域多个航次的现场调查数据,对浒苔绿潮暴发过程中溶解有机物的变化特征及影响因素进行了分析.结果表明,南黄海海域溶解有机碳(DOC)分布高值区主要集中分布在南黄海西北部和苏北近岸海域,陆源输入影响显著.利用三维荧光-平行因子分析(EEMs-PARAFAC)鉴别出南黄海海域溶解有机物荧光组分(FDOM)主要有4种:3种类腐殖质组分(C1、C2和C3)和1种类蛋白质组分C4.4种荧光组分平面分布特征相似,都与盐度呈明显的负相关.随着浒苔绿潮的暴发,南黄海海域DOC浓度和FDOM显著增加,溶解有机氮(DON)及溶解有机磷(DOP)则减少.随着浒苔绿潮沉降消亡,DOC浓度有所下降但仍高于浒苔绿潮暴发前,浒苔爆发区FDOM浓度升高,表层水体中C2和C4升高最为显著,分别增加了11.3%和12.6%;DOP、DON以及DON/DOC均逐渐升高.浒苔绿潮的暴发及消亡对南黄海海域溶解有机物的含量及时空分布影响显著.

Through the maritime survey data from multiple cruises in the southern Yellow Sea in 2017,the variations and influencing factors of dissolved organic matter in the process of green tide(Ulva prolifera blooms)were analyzed.The high-value areas of dissolved organic carbon(DOC)were mainly located in the northwestern part of the southern Yellow Sea and that near the northern Jiangsu,indicating that the terrigenous input was one of the main resources of DOC to this area.The EEMs-Parallel factor analysis(EEMs-PARAFAC)method identified four fluorescent dissolved organic matter(FDOM)in the southern Yellow Sea:three terrestrial humic-like(C1,C2,C3)and one protein-like(C4)fluorescent components.The spatial distributions of the four fluorescent components were similar and had a significant negative correlation with salinity.As the green tide outbroke in the southern yellow sea,DOC and FDOM concentrations increased significantly,while dissolved organic nitrogen(DON)and dissolved organic phosphorus(DOP)concentrations were decreased.With the gradual disappearance of the green tide,the DOC concentration was going down but still slightly higher than that before the outbreak of green tide,instead the fluorescence intensities of C2 and C4 in surface waters were increased by 11.3%and 12.6%,respectively.During this period,DOP,DON and DON/DOC were also increased.The outbreak of the green tide in the South Yellow Sea had significant impacts on the spatiotemporal distribution of dissolved organic matter.