Linking carbon exchange between coastal wetland and shelf environments

Christopher Osburn, North Carolina State University, closburn@ncsu.edu (Presenter)
Thomas S. Bianchi, University of Florida, tbianchi@ufl.edu
Eurico D'Sa, Louisiana State University, ejdsa@lsu.edu
Dong Ko, Naval Research Laboratory, ko@nrlssc.navy.mil
Nick Ward, University of Florida, nickdward@gmail.com
Zachary S. Tait, North Carolina State University, zstait@ncsu.edu
Ishan Joshi, Louisiana State University, ijoshi1@lsu.edu

The focus of this project is to optimize algorithms that integrate optical and chemical data of dissolved organic matter (DOM) based on proxies of predicted flux from marshes to coastal waters through estuaries. Many studies of DOM in coastal waters have documented focus on rivers, where discharge is ca. 0.25 Pg C y-1; however, coastal wetlands (including marshes) are important sources of DOM and CDOM, both of which originate as ‘blue carbon’ – carbon derived from primary production in vegetated coastal wetlands. The position of these wetlands in the global landscape represents a key interface between terrestrial and marine ecosystems. The proposed study will investigate two estuarine complexes in the Gulf of Mexico (Apalachicola and Barataria Bays) for the quality and quantity of exported DOM and its relationship to optical parameters and geochemical properties (remote sensing reflectance and dissolved inorganic carbon, lignin phenols, pigments, fatty acids, amino acids, and CO2). In particular, we investigate DOM absorbance and fluorescence – optical properties which can be correlated to water leaving radiances and synoptic observations of ocean color. Further, these optical properties will be related to isotopic measurements and organic biomarkers representative of terrestrial and marine endmembers. Preliminary results from Apalachicola Bay show distinct differences in the optical and biogeochemical properties within the bay. Further, the saturation of dissolved CO2 appears to be related to signals in DOM fluorescence and salinity. For example, CO2 concentrations ranged from roughly 3100 to 320 ppm along the river to marine continuum, with systematic changes in the optical properties of DOM. The cumulative results of these field measurements and remote sensing efforts will potentially help constrain carbon cycling dynamics across coastal regimes.

Presentation: 2015_Poster_Osburn_105_174.pdf (1130k)

Presentation Type:  Poster

Session:  Theme 2: Landscapes to coasts: understanding Earth system connections   (Mon 1:30 PM)

Associated Project(s): 

• Osburn, Christopher: Linking Carbon Exchange Between Coastal Wetland and Shelf Environments: A Case Study in the Barataria Bay, Northern Gulf of Mexico ...details

Poster Location ID: 105