Pore-water distribution and quantification of diffusive benthic fluxes of nutrients in the Huanghai and East China Seas sediments

作     者：NI Jianyu LIU Xiaoya CHEN Qijiang LIN Yian 

作者机构：Key Laboratory of Submarine Geosciences of State Oceanic Administration Hangzhou 310012 China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China Laboratory of Marine Ecosystem and Biogeochemistry of State Oceanic Administration Hangzhou 310012 China 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2006年第25卷第1期

页      面：90-99页

核心收录：

学科分类：0710[理学-生物学] 070704[理学-海洋地质] 0709[理学-地质学] 0908[农学-水产] 07[理学] 0707[理学-海洋科学] 

基　　金：supported by the Major State Basic Research Program of China under contract No.G1999043704 the National Natural Science Foundation of China under contract No.40206012 

主　　题：nutrients pore-water benthic flux Huanghai and East China Seas 

摘      要：The distribution of nitrate, nitrite, ammonia, phosphate and silicate in pore-water and their exchange between sediments and overlying waters （benthic flux） were determined at nine locations on the shelve of Huanghai and East China Seas. On the basis of the redox potential of sediments and nutrients distributions in the pore-waters, it is found that the benthic sediments are being in a suboxic to anoxic environment in the Huanghai and East China Seas. The nutrients distribution in the pore-waters is mainly controlled by the sediment environment, and ammonia is the major inorganic nitrogen in the pore-waters. On the basis of benthic fluxes of nutrients calculated us- ing Fick＇s first law, there is remarkable efflux of ammonia, dissolved inorganic nitrogen（DIN）, phosphate and silicate from the sediments to the overlying waters in the study area, and their benthic fluxes are 299.3-2 214.8, 404.4-2 159.5 , 5.5-18.8 and 541.3-1 781.6 μmol/（m^2·d） respectively, and perhaps they are the major source of dissolved inorganic nitrogen, phosphate and silicate for the overlying water. At most stations, the nitrate flux was from the overlying waters to the sediments, which suggests that suboxic organic matter decomposition via denitrification is dominated in the most area of Huanghai and East China Seas. High benthic fluxes appearing in the coastal area and relatively low benthic fluxes occurring in the shelf area are found and are consistent with pri- mary productivity zoning in the study area. On the other hand, the ammonia flux displays an exponential decrease with water depth increase and an exponential increase with the bottom water temperature. However, others do not display this trend.