Dataset title: Monthly monitoring fluorescence data for Shark River Slough and Taylor Slough, Everglades National Park, Florida, USA (FCE LTER) for 2012 to Present Dataset ID: doi:10.6073/pasta/d1abed5732fe4f4b086e092fb85bf431 Dataset Creator Name: John Kominoski Position: Associate Professor Organization: Florida International University Address: 11200 SW 8th Street Miami, FL 33199 United States Phone: 3053487117 Email: jkominos@fiu.edu URL: https://kominoskilab.com Metadata Provider Name: John Kominoski Position: Associate Professor Organization: Florida International University Address: 11200 SW 8th Street Miami, FL 33199 United States Phone: 3053487117 Email: jkominos@fiu.edu URL: https://kominoskilab.com Dataset Abstract Dissolved organic matter plays an important role in biogeochemical processes in aquatic environments such as elemental cycling, microbial loop energetics, and the transport of materials across landscapes. Since most of N (> 90%) and P (around 90%) is in the organic form in the oligotrophic subtropical Florida Coastal Everglades (FCE), study of the source and dynamics of dissolved organic matter (DOM) in the ecosystem is crucial for the better understanding of the biogeochemical cycling of nutrients. FCE are composed of estuaries with distinct regions with different biogeochemical processes. Freshwater marsh primarily receives terrestrial input and local autochthonous vegetation production. Mangrove ecotone, nevertheless, is affected by the tidal contributions from Florida Bay and local mangrove production. Florida Bay (FB) is a wedge-shaped shallow oligotrophic estuary which lays south of the Everglades, the bottom of which is covered with a dense biomass of seagrass. The sources of both freshwater and nutrients in FCE are difficult to quantify, owing to the non-point source nature of runoff from the Everglades and the dendritic cross channels in the mangroves. Furthermore, the combination of multiple DOM sources (freshwater marsh vegetation, mangroves, phytoplankton, seagrass, etc.), and the potential seasonal variability of their relative contribution, along with the history of (photo)chemical and microbial diagenetic processing, and complex advective circulation, makes the study of DOM dynamics in FCE particularly difficult using standard schemes of estuarine ecology. Quantitative information of DOM is very useful to investigate the biogeochemical cycling of DOM to a certain degree, however, qualitative information is necessary to better understand the source and dynamics of DOM. Since fluorescence spectroscopic techniques are very sensitive, quick and simple, they have been applied to investigate the fate of DOM in estuaries. Geographic Coverage Bounding Coordinates Geographic description: SRS1d West bounding coordinate: -80.6537 East bounding coordinate: -80.6537 North bounding coordinate: 25.7463 South bounding coordinate: 25.7463 Geographic description: SRS2 West bounding coordinate: -80.78520999999999 East bounding coordinate: -80.78520999999999 North bounding coordinate: 25.54973 South bounding coordinate: 25.54973 Geographic description: SRS3 West bounding coordinate: -80.85328 East bounding coordinate: -80.85328 North bounding coordinate: 25.46821 South bounding coordinate: 25.46821 Geographic description: SRS4 West bounding coordinate: -80.96431 East bounding coordinate: -80.96431 North bounding coordinate: 25.409760000000002 South bounding coordinate: 25.409760000000002 Geographic description: SRS5 West bounding coordinate: -81.03235 East bounding coordinate: -81.03235 North bounding coordinate: 25.37702 South bounding coordinate: 25.37702 Geographic description: SRS6 West bounding coordinate: -81.07795 East bounding coordinate: -81.07795 North bounding coordinate: 25.36463 South bounding coordinate: 25.36463 Geographic description: TS1a West bounding coordinate: -80.5903 East bounding coordinate: -80.5903 North bounding coordinate: 25.42389 South bounding coordinate: 25.42389 Geographic description: TS2 West bounding coordinate: -80.6069 East bounding coordinate: -80.6069 North bounding coordinate: 25.403570000000002 South bounding coordinate: 25.403570000000002 Geographic description: TS3 West bounding coordinate: -80.66272 East bounding coordinate: -80.66272 North bounding coordinate: 25.25241 South bounding coordinate: 25.25241 Geographic description: TS4 West bounding coordinate: -80.52209 East bounding coordinate: -80.52209 North bounding coordinate: 25.31472 South bounding coordinate: 25.31472 Geographic description: TS5 West bounding coordinate: -80.52024 East bounding coordinate: -80.52024 North bounding coordinate: 25.29479 South bounding coordinate: 25.29479 Geographic description: TS6a West bounding coordinate: -80.64908 East bounding coordinate: -80.64908 North bounding coordinate: 25.21418 South bounding coordinate: 25.21418 Geographic description: TS7a West bounding coordinate: -80.63911 East bounding coordinate: -80.63911 North bounding coordinate: 25.1908 South bounding coordinate: 25.1908 Geographic description: TS9 West bounding coordinate: -80.48978000000001 East bounding coordinate: -80.48978000000001 North bounding coordinate: 25.17693 South bounding coordinate: 25.17693 Geographic description: TS10 West bounding coordinate: -80.68097 East bounding coordinate: -80.68097 North bounding coordinate: 25.02477 South bounding coordinate: 25.02477 Geographic description: TS11 West bounding coordinate: -80.93798000000001 East bounding coordinate: -80.93798000000001 North bounding coordinate: 24.91293 South bounding coordinate: 24.91293 Temporal Coverage Start Date: 2012 End Date: 2020 Data Table Entity Name: FCE1234 Entity Description: Data from long term DOM study in Taylor and Shark Sloughs Object Name: FCE1234.csv Data Format Number of Header Lines: 1 Attribute Orientation: column Field Delimiter: , Number of Records: Attributes Attribute Name: Site Attribute Label: Site Attribute Definition: Location of sample collection Storage Type: string Measurement Scale: SRS1d= Shark River Slough 1d SRS2= Shark River Slough 2 SRS3= Shark River Slough 3 SRS4= Shark River Slough 4 SRS5= Shark River Slough 5 SRS6= Shark River Slough 6 TS10= Taylor Slough 10 TS11= Taylor Slough 11 TS1a= Taylor Slough 1a TS2= Taylor Slough 2 TS3= Taylor Slough 3 TS6a= Taylor Slough 6a TS7a= Taylor Slough 6b TS9= Taylor Slough 9 Missing Value Code: Attribute Name: Month Attribute Label: Month Attribute Definition: Month of year when samples were collected Storage Type: float Measurement Scale: Units: unitless Number Type: integer Missing Value Code: Attribute Name: Year Attribute Label: Year Attribute Definition: Year samples were collected Storage Type: float Measurement Scale: Units: unitless Number Type: integer Missing Value Code: Attribute Name: Date Attribute Label: Date Attribute Definition: Numerical month and year when samples were collected Storage Type: dateTime Measurement Scale: Missing Value Code: Attribute Name: Sample_Name Attribute Label: Sample Name Attribute Definition: Sample location and date of collection Storage Type: string Measurement Scale: Sample location and date of collection Missing Value Code: Attribute Name: Sample_ID Attribute Label: Sample ID Attribute Definition: Sample location and date of collection for completed samples Storage Type: string Measurement Scale: Sample location and date of collection for completed samples Missing Value Code: Attribute Name: dilution_factor Attribute Label: dilution factor Attribute Definition: Amount of dilution (using MilliQ water) of original sample Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: FI_(FI370) Attribute Label: FI (FI370) Attribute Definition: Fluorescence Index at excitation 370 nm (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: BIX_(FI310) Attribute Label: BIX (FI310) Attribute Definition: Biological Index at excitation 310 nm (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: HIX_(FI254) Attribute Label: HIX (FI254) Attribute Definition: Humification Index at excitation 254 nm (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: Abs254 Attribute Label: Abs254 Attribute Definition: Absorbance at 254 nm at 1 cm path length (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: DOC_umol_L Attribute Label: DOC_umol_L Attribute Definition: Dissolved organic carbon concentration Storage Type: float Measurement Scale: Units: micromolsPerLiter Number Type: real Missing Value Code: Attribute Name: DOC_mg_L Attribute Label: DOC_mg_L Attribute Definition: Dissolved organic carbon concentration Storage Type: float Measurement Scale: Units: milligramsPerLiter Number Type: real Missing Value Code: Attribute Name: SUVA254 Attribute Label: SUVA254 Attribute Definition: Specific UV Absorbance at 254 nm with 1 cm path length (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: slp274_295 Attribute Label: slp274_295 Attribute Definition: Slope of excitation from 274 to 295 nm (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: slp350_400 Attribute Label: slp350_400 Attribute Definition: Slope of excitation from 350 to 400 nm (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: SR Attribute Label: SR Attribute Definition: Slope ratio (division of slope of 275 to 295 nm by slope of 350 to 400 nm), unitless Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Attribute Name: ES_E3 Attribute Label: ES_E3 Attribute Definition: Ratio of the absorbance from 250 to 365 nm (unitless) Storage Type: float Measurement Scale: Units: unitless Number Type: real Missing Value Code: Methods Method Step Description Sampling Description Water samples were collected monthly during February 2012 to December 2020 from a total of 14 sampling stations located in the coastal estuaries of the southern tip of the Florida Peninsula, USA. These stations were established for an on-going water quality monitoring program (http://www.serc.fiu.edu/wqmnetwork). Sampling stations can be largely grouped into 3 distinct districts based on the geomorphological features, that is, Florida Bay (FB, 3 sampling stations), Shark River Slough (SRS, 6 sampling stations), and Taylor Slough (TSPH, 8 sampling stations). Surface water samples were taken from the these stations. The samples were collected using pre-washed, brown Nalgen polyethylene bottles (Nalge Nunc International). Salinity of the water samples was measured in the field using an Orion salinity meter. The samples were stored on ice and returned to the laboratory within 8 h for analysis. Subsamples for spectroscopic analysis were filtered through precombusted Whatman GF/F glass fiber filters once received in the laboratory and analyzed immediately. Method Step Description Total organic carbon (TOC) concentrations were analyzed by a high-temperature combustion method with a Shimadzu TOC-5000A TOC analyzer. In advance the analysis, samples were acidified with 3M HCl, and purged with N2 gas to remove inorganic C. Ancillary physical and chemical parameters were measured using standar methods as part of on-going estuarine water quality monitoring program http://www.serc.fiu.edu/wqmnetwork. Detailed methods will be found elsewhere. For escitation-emission matrix (EEM) measurements, fluorescences spectra were measured with a Jobin-Yvon-Horiba (France) Aqualog-2 fluorometer equipped with a 150-W continuous output xenon arc lamp under condition of 5.7-nm excitation and 2-nm emission slit widths and a 0.25 second response time. Forty-four emission scans were acquired at excitation wavelengths (lamda ex) between 240 and 455 nm at 5 nm intervals. Them emission wavelengths were scanned from lamda ex + 10 nm to lamda ex + 250 nm at 2 nm intervals (Coble et al., 1993 and Coble, 1996). All fluorescence spectra were acquired in ratio mode, whereby the sample (emission signal, S) and reference (excitation lamp output, R) signals were collected and the ratio (S/R) was calculated. The ratio mode eliminates the influence of possible fluctuation and wavelength dependency of excitation lamp output. Several post-acquisition steps were involved in the correction of the fluorescence spectra. First, an inner filter corrections was applied to the fluorescence data according to McKnight et al. (2001). After inner filter corrections the sample EEM underwent spectral subtraction of the Milli-Q water to remove most of the effects due to Raman scattering. Instrument bias related to wavelength dependent efficiencies of the specific instrument's optical components (gratings, mirrors, etc.) were then corrected by applying multiplication factors, supplied by the manufacturer, for both excitation and emission wavelengths for the range of observations. Finally, the fluorescence intensity values were converted to quinine sulfate unit (QSU;1QSU=1 ngL-1 of quinine sulfate monohydroxide) to facilitate inter-laboratory comparisons (Coble et al., 1993). From the 370 nm scan a fluorescence index (FI) was calculated (McKnight et al., 2001). The humification index (HIX) was quantified as the area under the emission curve between 435-480 nm divided by the area under the emission curve between 300-345 nm, for excitation at 254 nm (Zsolnay et al. 1999). The biological index (BIX), an indicator of the relative contribution of new autochthonous production to the DOM pool, was calculated as the emission at 380 nm divided by the emission at 430 nm, for excitation at 310 nm (Huguet et al. 2009). The slope ratio (SR), a measure of the average molecular weight, was calculated as the best-fir slope of the natural-log of abosorbance from 275 to 295 nm divided by the best-fit slope of the natural-log of absorbance from 350 to 400 nm (Helms et al. 2008). Milli-Q water was used as a reference for all fluorescence analysis. UV-visible measurements of the water samples were carried out with 1cm quartz UV-visible cells at room temperature (20 degrees C), using a Varian CARY 50 Bio UV-visible spectrophotometer. Milli-Q water was used as the reference. Quality Control: Fluorescence measurements are corrected for internal absorbance quenching. Fluorescence spectra are corrected for internal instrument configuration using excitation and emission correction factors. For DOC, Humic carbon and carbohydrate data, we create calibration curves with standards and then graph the data. ==================== Data Sources ========================= Battin, T J 1998. Dissolved organic matter and its optical properties in a blackwater tributary of the upper Orinoco river, Venezuela. Organic Geochemistry, 28: 561-569. Chen, Meilian L. 2010. Comparative study of dissolved organic matter from groundwater and surface water in the Florida costal Everglades using multi-dimensional spectrofluorometry combined with multivariate statistics. Applied Geochemistry, 25: 872-880. De Souza Sierra, M M 1997. Spectral identification and behavior of dissolved organic fluorescence material during estuarine mixing processes. Marine Chemistry, 58: 51-58. Donard, O F 1989. High-sensitivity fluorescence spectroscopy of Mediterranean waters using a conventional or a pulsed laser excitation source. Marine Chemistry, 27: 117-136. Helms, John R. 2008. Absorption spectral slopes and slope ratios as indicators of molecular weight, source, and photobleaching of chromophoric dissolved organic matter. Limnology and Oceanography, 53(3): 955-969. Huguet, A., Vacher, L., Relexans, S., Saubusse, S., Froidefond, J.M. and Parlanti, E., 2009. Properties of fluorescent dissolved organic matter in the Gironde Estuary. Organic Geochemistry, 40(6):706-719. Lu, X Q 2003. Molecular characterization of dissolved organic matter in freshwater wetlands of the Florida Everglades. Water Research, 37: 2599-2606. McKnight, Diane M 2001. Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity. Limnology and Oceanography, 46: 38-48. Stedmon, Colin A. 2003. Tracing dissolved organic matter in aquatic environments using a new approach to fluorescence spectroscopy . Marine Chemistry, 82: 239-254. Weishaar, James L. 2003. Evaluation of Specific Ultraviolet Absorbance as an Indicator of the Chemical Composition and Reactivity of Dissolved Organic Carbon . Environmental Science and Technology, 37: 4702-4708. Yamashita, Youhei 2010. Dissolved organic matter characteristics across a subtropical wetland's landscape: Application of optical properties in the assessment of environmental dynamics. Ecosystems, 13: 1006-1019. Zsolnay, A., Baigar, E., Jimenez, M., Steinweg, B. and Saccomandi, F., 1999. Differentiating with fluorescence spectroscopy the sources of dissolved organic matter in soils subjected to drying. Chemosphere, 38(1): 45-50. =========================================================== Instrumentation Whatman 0.7um glass fiber filters, Shimadzu TOC-5000A Analyzer, Jobin Yvon Horiba (France) Aqualog-2 fluorometer, Varian CARY 50 Bio UV visible spectrophotometer Maintenance Maintenance of the dataset will be performed by the creator. Dataset Contact Name: John Kominoski Position: Associate Professor Organization: Florida International University Address: 11200 SW 8th Street Miami, FL 33199 United States Phone: 3053487117 Email: jkominos@fiu.edu URL: https://kominoskilab.com