Chromophoric dissolved organic matter (CDOM) optical properties were analyzed in Southern California coastal marine and salt marsh pore waters. Pore water was collected from eight coastal salt marsh sites during field studies in the summer and winter seasons. Coastal marine water was collected periodically over the summer and winter seasons to evaluate the degree of CDOM export from coastal salt marsh channels. CDOM source and transformation were evaluated using absorbance and fluorescence spectroscopy. Fluorescence intensities were depicted using 3D excitation-emission matrix (EEM) fluorescence spectroscopy. Terrestrial humic peaks A and C showed higher fluorescence intensity in deeper anaerobic waters and lower fluorescence intensity in shallow aerobic waters. Absorption coefficient and spectral slope showed an increase in anaerobic regions as a result of greater anaerobic microbial activity. High aromaticity and molecular weight were distinctive of greater humification with depth in the pore water. Parallel factor analysis (PARAFAC) was used to classify primary fluorophores and quantify optical differences at the various salt marsh sites. The optical distribution of CDOM in coastal waters suggests specific dependences on tidal contribution, microbial activity, and season.

Compared fluorescence characterization of salt marsh pore water using PARAFAC analysis

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.