The impact of typhoons on the biogeochemistry of dissolved organic matter in eutrophic bays in northwestern South China Sea  

作　　者：Xuan Lu Qibin Lao Fajin Chen Guangzhe Jin Chunqing Chen Qingmei Zhu 

机构地区：[1]College of Ocean and Meteorology,Guangdong Ocean University,Zhanjiang 524088,China [2]Polar and Marine Research Institute,College of Harbor and Coastal Engineering,Jimei University,Xiamen 361021,China [3]Key Laboratory for Coastal Ocean Variation and Disaster Prediction,Guangdong Ocean University,Zhanjiang 524088,China [4]Key Laboratory of Climate,Resources and Environment in Continental Shelf Sea and Deep Sea,Department of Education of Guangdong Province,Guangdong Ocean University,Zhanjiang 524088,China

出　　处：《Acta Oceanologica Sinica》2024年第6期15-31,共17页海洋学报（英文版）

基　　金：The National Natural Science Foundation of China under contract Nos 42276047, 92158201 and U1901213;the Entrepreneurship Project of Shantou under contract No.2021112176541391;the Scientific Research Start-Up Foundation of Shantou University under contract No.NTF20006。

摘　　要：Highly productive estuaries facilitate intense decomposition of dissolved organic matter(DOM) as a carbon source.However,the specific impacts of typhoons on DOM decomposition in eutrophic bays remain unclear.To address this issue,we investigated the spectral characteristics of DOM before and after Typhoon Ewiniar in Zhanjiang B ay,a eutrophic semi-enclosed bay in the northwestern South China Sea.The results revealed that intense microbial decomposition of DOM occurred during the pre-typhoon period because high nutrient inputs facilitated the mobilization of DOM in the bay.However,the intrusion of external seawater induced by the typhoon diluted the nutrient levels in Zhanjiang B ay,reducing the impact of microbial decomposition on DOM during the post-typhoon perio d.Nevertheless,the net addition of DOM occurred in Zhanjiang Bay during the post-typhoon period,possibly because of the decomposition of particulate organic matter(POM) and desorption of particulate matter.In addition,an increase in apparent oxygen utilization,a decrease in DO saturation and the reduced level of Chl a indicated that organic matter(OM) decomposition was enhanced and OM decomposition shifted to POM decomposition in Zhanjiang Bay after the typhoon.Overall,our study highlighted the shift in the intense OM decomposition from DOM to POM decomposition before and after typhoons in eutrophic bays,providing new insights into the response of typhoons to biogeo chemistry.

关 键 词：dissolved organic matter optical analyses decomposition TYPHOON northwestern South China Sea 

分 类 号：X55[环境科学与工程—环境工程] P593[天文地球—地球化学]