Application of excitation emission matrix fluorescence monitoring in the assessment of spatial and seasonal drivers of dissolved organic matter composition: Sources and physical disturbance controls

Authors

N. Maie, Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International University and Department of Bio-environmental Sciences, School of Veterinary Medicine, Kitasato UniversityFollow
Y. Yamashita, Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International University and Faculty of Environmental Earth Sciences, Hokkaido UniversityFollow
R. M. Cory, Department of Environmental Sciences and Engineering, University of North Carolina
Joseph N. Boyer, Southeast Environmental Research Center and Department of Earth and Environment, Florida International UniversityFollow
Rudolf Jaffe´, Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International UniversityFollow

Abstract

The environmental dynamics of dissolved organic matter (DOM) were characterized for a shallow, subtropical, seagrass-dominated estuarine bay, namely Florida Bay, USA. Large spatial and seasonal variations in DOM quantity and quality were assessed using dissolved organic C (DOC) measurements and spectrophotometric properties including excitation emission matrix (EEM) fluorescence with parallel factor analysis (PARAFAC). Surface water samples were collected monthly for 2 years across the bay. DOM characteristics were statistically different across the bay, and the bay was spatially characterized into four basins based on chemical characteristics of DOM as determined by EEM-PARAFAC. Differences between zones were explained based on hydrology, geomorphology, and primary productivity of the local seagrass community. In addition, potential disturbance effects from a very active hurricane season were identified. Although the overall seasonal patterns of DOM variations were not significantly affected on a bay-wide scale by this disturbance, enhanced freshwater delivery and associated P and DOM inputs (both quantity and quality) were suggested as potential drivers for the appearance of algal blooms in high impact areas. The application of EEM-PARAFAC proved to be ideally suited for studies requiring high sample throughput methods to assess spatial and temporal ecological drivers and to determine disturbance-induced impacts in aquatic ecosystems.

Comments

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Maie, N., Y. Yamashita, R. Cory, J.N. Boyer, R. Jaffe. 2012. Application of excitation emission matrix fluorescence monitoring in the assessment of spatial and seasonal drivers of dissolved organic matter composition: Sources and physical disturbance controls. Applied Geochemistry 27(4): 917-929.