文献类型：期刊文献

英文题名：Assessing Seasonal Nitrate Contamination by Nitrate Dual Isotopes in a Monsoon-Controlled Bay with Intensive Human Activities in South China

作者：Li, Jiacheng[1];Cao, Ruixue[1];Lao, Qibin[1,2];Chen, Fajin[1];Chen, Chunqing[1];Zhou, Xin[1];Meng, Yafei[1];Zhu, Qingmei[1]

机构：[1]Guangdong Ocean Univ, Coll Ocean & Meteorol, Zhanjiang 524088, Peoples R China;[2]State Ocean Adm, Marine Environm Monitoring Ctr Beihai, Beihai 536000, Peoples R China

年份：2020

卷号：17

期号：6

外文期刊名：INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH

收录：SSCI(收录号：WOS:000529342300111)、SCI-EXPANDED(收录号：WOS:000529342300111)、、Scopus(收录号：2-s2.0-85082017392)、WOS

基金：This work was supported by the China National Key Research and Development Plan Project (2016YFC1401403), National Natural Science Foundation of China (U1901213, 41466010, 41676008), International Science and Technology Cooperation Programme (GASI-IPOVAI-04), Guangdong Natural Science Foundation of China (2016A030312004), and the Project of Enhancing School with Innovation of Guangdong Ocean University (GDOU2016050260).

语种：英文

外文关键词：nitrate dual isotopes; nitrate sources; Bayesian isotope mixing model; Zhanjiang Bay

外文摘要：Nitrate (NO3-) dual isotope analysis was performed in Zhanjiang Bay, which is a closed bay with intensive human activities in South China, to investigate seasonal changes in the main NO3- sources and their biogeochemical processes in the monsoon-controlled climate. The relatively low N/P ratios in Zhanjiang Bay suggests that nitrogen (N) is a limiting nutrient, which indicates that the increase of N is favorable for phytoplankton proliferation. However, a sufficient amount of ammonium was found in our study area owing to intensive human activities, which can support biological processes. Thus, less NO3- biological processes were found, indicating that NO3- isotopic characteristics may reveal details of the mixing from various sources. The Bayesian mixing model showed that NO3- in the upper bay originated from manure (43%), soil N (30%), N fertilizer (17%), and N precipitation (10%) during winter, which reflects the local human activities; while NO3- sources during summer were mainly N fertilizer (36%), soil N (32%), and manure (31%), indicating the source as the runoff from the upper river basin. Our results suggest that nitrate dual-isotope was very useful for tracing the main NO3- sources in the condition of the sufficient ammonium, and runoff exerted an important impact on the shift in NO3- sources between both the local source and the source from the upper river basin during the two seasons in this monsoon-controlled bay.