Using Optical Properties to Quantify Fringe Mangrove Inputs to the Dissolved Organic Matter (DOM) Pool in a Subtropical Estuary
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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.
KeywordsMangroves EEM-PARAFAC Everglades Estuaries Dissolved Organic Matter (DOM) Fluorescence Carbon Flux
The authors thank two anonymous reviewers for helpful comments. The authors also thank B. Pomenti, L. Belicka, and D. He for field assistance and the Southeast Environmental Research Center (SERC) water quality lab for DOC analyses. This project was supported by NSF through the FCE-LTER (DBI-0620409), by the DOI/NPS through a post-doctoral fellowship to KC and through the George Barley Chair to RJ. Partial support for this study through the NSF funded WSC program is also acknowledged. This is SERC contribution #632.
- Bouillon, S., A.V. Borges, E. Castaneda-Moya, K. Diele, T. Dittmar, N.C. Duke, E. Kristensen, S.Y. Lee, C. Marchand, J.J. Middelburg, V.H. Rivera-Monroy, T.J. Smith, and R.R. Twilley. 2008. Mangrove production and carbon sinks: a revision of global budget estimates. Global Biogeochemical Cycles 22, GB2013. doi: 10.1029/2007GB003052.CrossRefGoogle Scholar
- Bouillon, S., J.J. Middelburg, F. Dehairs, A.V. Borges, G. Abril, M.R. Flindt, S. Ulomi, and E. Kristensen. 2007. Importance of intertidal sediment processes and porewater exchange on the water column biogeochemistry in a pristine mangrove creek (Ras Dege, Tanzania). Biogeosciences 4: 311–322.CrossRefGoogle Scholar
- Chen, M., N. Maie, K. Parish, and R. Jaffé. 2013. Spatial and temporal variability of dissolved organic matter quantity and composition in an oilgotrophic subtropical coastal wetland. Biogeochemistry. doi: 10.1007/s10533-013-9826-4.
- Chen, M.L., R.M. Price, Y. Yamashita, and R. Jaffé. 2010. Comparative study of dissolved organic matter from groundwater and surface water in the Florida coastal Everglades using multi-dimensional spectrofluorometry combined with multivariate statistics. Applied Geochemistry 25: 872–880.CrossRefGoogle Scholar
- Gonsior, M., B.M. Peake, W.T. Cooper, D. Podgorski, J. D’Andrilli, and W.J. Cooper. 2009. Photochemically induced changes in dissolved organic matter identified by ultrahigh resolution fourier ion cyclotron resonance mass spectrometry. Environmental Science and Technology 43: 698–703.CrossRefGoogle Scholar
- Maie, N., Y. Yamashita, R.M. Cory, J.N. Boyer, and R. Jaffé. 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: 917–929.CrossRefGoogle Scholar
- Pisani, O., Y. Yamashita, and R. Jaffe. 2011. Photo-dissolution of flocculent, detrital material in aquatic environments: Contributions to the dissolved organic matter pool. Water Research 45: 3836–3844.Google Scholar
- Romigh M. 2005. Organic carbon flux at the mangrove soil-water column interface in the Florida Coastal Everglades. M.S., Texas A & M, Collage Station 45.Google Scholar
- Sutula, M.A., B.C. Perez, E. Reyes, D.L. Childers, S. Davis, J.W. Day, D. Rudnick, and F. Sklar. 2003. Factors affecting spatial and temporal variability in material exchange between the Southern Everglades wetlands and Florida Bay (USA). Estuarine, Coastal and Shelf Science 57: 757–781.CrossRefGoogle Scholar