Using Optical Properties to Quantify Fringe Mangrove Inputs to the Dissolved Organic Matter (DOM) Pool in a Subtropical Estuary

Authors

Kaelin M. Cawley, Southeast Environmental Research Center and Department of Chemistry and Biochemistry, Florida International University; Department of Civil, Environmental, and Architectural Engineering, University of Colorado at BouldeFollow
Youhei Yamashita, Faculty of Environmental Earth Science, Hokkaido UniversityFollow
Nagamitsu Maie, Department of Environmental Biosciences, School of Veterinary Medicine, Kitasato UniversityFollow
Rudolf Jaffe´, Southeast Environmental Research Center, Department of Chemistry and Biochemistry, Florida International University,Follow

Abstract

Dissolved organic carbon (DOC) concentration and dissolved organic matter (DOM) optical properties were analyzed along two estuarine river transects during the wet and dry seasons to better understand DOM dynamics and quantify mangrove inputs. A tidal study was performed to assess the impacts of tidal pumping on DOM transport. DOM in the estuaries showed non-conservative mixing indicative of mangrove-derived inputs. Similarly, fluorescence data suggest that some terrestrial humic-like components showed non-conservative behavior. An Everglades freshwater-derived fluorescent component, which is associated with soil inputs from the Northern Everglades, behaved conservatively. During the dry season, a protein-like component behaved conservatively until the mid-salinity range when non-conservative behavior due to degradation and/or loss was observed. The tidal study data suggests mangrove porewater inputs to the rivers following low tide. The differences in quantity of DOM exported by the Shark and Harney Rivers imply that geomorphology and tidal hydrology may be a dominant factor controlling the amount of DOM exported from the mangrove ecotone, where up to 21 % of the DOC is mangrove-derived. Additionally, nutrient concentrations and other temporal factors may control DOM export from the mangroves, particularly for the microbially derived fluorescent components, contributing to the seasonal differences. The wet and dry season fluxes of mangrove DOM from the Shark River is estimated as 0.27 × 10⁹ mg C d⁻¹ and 0.075 × 10⁹ mg C d⁻¹, respectively, and the Harney River is estimated as 1.9 × 10⁹ mg C d⁻¹ and 0.20 × 10⁹ mg C d⁻¹.

Comments

The definitive publisher-authenticated version is available online at http://dx.doi.org/10.1007/s12237-013-9681-5

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

Cawley, K., Y. Yamashita, N. Maie, R. Jaffe. 2013. Using Optical Properties to Quantify Fringe Mangrove Inputs to the Dissolved Organic Matter (DOM) Pool in a Subtropical Estuary. Estuaries and Coasts DOI: 10.1007/s12237-013-9681-5