Organic matter determines the exchange of nutrients at sediment-water interface in coastal bays  

作　　者：Jiasen Zhong Ehui Tan Chunwei Fu Guiyi Ma Yongkai Chang Zhixiong Huang Jingchao Yin Fengying Li Jianzhong Su Min Xu Zhenzhen Zheng Jian’an Liu Yu Han Shuh-Ji Kao 

机构地区：[1]State Key Laboratory of Marine Resources Utilization in the South China Sea,School of Ecology and Environment and School of Marine Science and Engineering,Hainan University,Haikou 570228,China [2]Collaborative Innovation Center of Marine Science and Technology,Hainan University,Haikou 570228,China

出　　处：《Acta Oceanologica Sinica》2025年第1期72-85,共14页海洋学报(英文版)

基　　金：The Major Science and Technology Plan of Hainan Province under contract No.ZDKJ2021008;the Hainan Provincial Natural Science Foundation of China under contract No.623RC456;the Hainan Province Science and Technology Special Fund under contract Nos ZDYF2021SHFZ064 and ZDYF2022SHFZ056;the Collaborative Innovation Center of Marine Science and Technology in Hainan University under contract No.XTCX2022HYC19.

摘　　要：The exchange of inorganic nutrients at the coastal sediment-water interface(SWI)plays a crucial role in regulating the nutrient budget in overlying water.The related studies mainly focus on the mid-to high-latitude regions,leaving a significant gap in the quantitative assessment of nutrient exchange and environmental controls at the SWI in lowlatitude coastal regions.We quantitatively assess the exchange of inorganic nutrients at the SWI in three tropical bays(Dongzhai Harbor,Xiaohai Lagoon,Qinglan Harbor).Sediments act as a source of ammonium,phosphate,and silicate,but for nitrate,sediments can be both a source and sink,although with substantial spatial and temporal variations in their fluxes.Labile organic matter is a critical regulator for the fluxes of inorganic nutrients at the SWI.The sedimentary nutrients input with high N/P molar ratio will alter the nutrient stoichiometry to mitigate the nitrogen limitation in coastal waters.However,the internal sediment release in these tropical bays plays a relative weak role in contributing to the nutrient addition in comparison with the other external nutrient sources including riverine input,submarine groundwater discharge,and atmospheric deposition.According to the global compilation on SWI nutrient fluxes,we propose that water column primary production and external inputs to interpret the variation in exchange and fluxes of nutrients at the SWI in different ecosystems.Such a conceptual understanding of these chain biogeochemical processes involving external nutrient input,primary production,particulate organic matter settling,and the accumulation and release of inorganic nutrients in sediments will be helpful for the scientific-based pollution prevent and control in coastal waters.

关 键 词：tropical bay sediment-water interface nutrient exchange labile organic matter source/sink 

分 类 号：X55[环境科学与工程—环境工程]