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Intertidal marsh as a source of dissolved inorganic carbon and a sink of nitrate in the Satilla River‐estuarine complex in the southeastern U.S.
Author(s) -
Cai WeiJun,
Wiebe William J.,
Wang Yongchen,
Sheldon Joan E.
Publication year - 2000
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.2000.45.8.1743
Subject(s) - estuary , intertidal zone , marsh , nitrate , dissolved organic carbon , environmental science , oceanography , salt marsh , denitrification , salinity , hydrology (agriculture) , alkalinity , ecology , wetland , nitrogen , geology , chemistry , biology , geotechnical engineering , organic chemistry
Total dissolved inorganic carbon (DIC), total alkalinity (TA), pH, and nitrate + nitrite (NO x ) data collected during the summer of 1996 in the Satilla River estuary in the southeastern U.S. were used to assess fluxes of DIC and NO x between intertidal marshes and estuarine waters and to model system NO x dynamics. Nitrate and nitrite are produced in the low‐salinity portion of the estuary. The intertidal marshes are sites of intensive respiration that export DIC to the estuary and remove NO x . An integrated view is presented on the nitrification and denitrification processes in the marsh/estuarine complex and their relationship to CO 2 generation rates. The distribution of NO x in the marsh and estuarine waters indicates that all NO x generated in the marsh‐estuary system is removed in the intertidal marshes, most likely via denitrification. Model analysis of NO x and river flow data for three seasons indicates that NO x distribution in the estuarine water is also determined by river flow rates. Export fluxes of NO x to the coastal ocean are insignificant in all seasons when compared to NO x production rates in the entire system; however, they are significantly higher than NO x inputs from the river end member in October 1996. Although only a small fraction (~10%) of DIC generated in the marshes is exported to the coastal sea and around 90% is lost to the atmosphere, it represents a nearly threefold increase in riverine DIC flux to the ocean.