I. Data Set Descriptors A. Title: Patricia M. Medeiros. 2019. DOM composition changes in Altamaha River and Sapelo Sound estuaries measured by FT-ICR mass spectrometry from September 2015 to September 2016. Georgia Coastal Ecosystems LTER Data Catalog (data set ORG-GCET-1904; http://gce-lter.marsci.uga.edu/public/app/dataset_details.asp?accession=ORG-GCET-1904) B. Accession Number: ORG-GCET-1904 C. Description 1. Originator(s): Name: Patricia M. Medeiros Address: Department of Marine Sciences UGA Marine Sciences Building Athens, Georgia 30602-3636 Country: USA Email: medeiros@uga.edu 2. Abstract: Dissolved organic matter (DOM) is a large and complex mixture of compounds with source inputs that differ with location, season and environmental conditions. Here, we investigated drivers of DOM composition changes in a marsh-dominated estuary off the southeastern U.S. Monthly water samples were collected at a riverine and estuarine site from September 2015 to September 2016, and bulk, optical, and molecular analyses were conducted on samples before and after dark incubations. Results showed that river discharge was the primary driver changing the DOM composition at the mouth of the Altamaha River. For discharge higher than ~ 150 m3 s-1, DOC concentrations and the terrigenous character of the DOM increased approximately linearly with river flow. For low discharge conditions, a clear signature of salt marsh-derived compounds was observed in the river. At the head of Sapelo Sound, changes in DOM composition were primarily driven by river discharge and possibly by summer algae blooms. Microbial consumption of DOC was larger during periods of high discharge at both sites, potentially due to the higher mobilization and influx of fresh material to the system. The Georgia coast was hit by Hurricane Matthew in October 2016, which resulted in a large input of carbon to the estuary. The DOC concentration was ~ 2 times higher and DOM composition was more aromatic with a stronger terrigenous signature compared to the seasonal maximum observed earlier in the year during peak river discharge conditions. This suggests that extreme events notably impact DOM quantity and quality in estuarine regions. 3. Study Type: Graduate Thesis Study 4. Study Themes: Organic Matter/Decomposition, Chemistry 5. LTER Core Areas: Organic Matter 6. Georeferences: none 7. Submission Date: Apr 11, 2019 D. Keywords: Altamaha River, biogeochemistry, carbon cycling, dissolved organic carbon, DOM, GCE, Georgia, Georgia Coastal Ecosystems, hydrology, LTER, Organic Matter, Sapelo Island, Sapelo Sound, terrigenous, USA II. Research Origin Descriptors A. Overall Project Description 1. Project Title: Georgia Coastal Ecosystems LTER Project III 2. Principal Investigators: Name: Merryl Alber Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: malber@uga.edu 3. Funding Period: Nov 01, 2012 to Nov 01, 2018 4. Objectives: The research proposed for GCE-III is designed to address how variations in salinity and inundation, driven by climate change and anthropogenic factors, affect biotic and ecosystem responses at different spatial and temporal scales, and to predict the consequences of these changes for habitat provisioning and carbon (C) sequestration across the coastal landscape. 5. Abstract: The Georgia Coastal Ecosystems (GCE) LTER is located along three adjacent sounds on the Atlantic coast and includes both intertidal marshes and estuaries. Long-term drivers of climate change, sea level rise and human alterations of the landscape will cause transitions in dominant habitat types (state changes) within the GCE domain by changing the amounts and patterns of water delivery across the landscape. These changes in water delivery can be conceptualized as presses and pulses in river inflow, local runoff, groundwater input, and tidal inundation, which will in turn manifest themselves as changes in salinity and inundation patterns in the domain. The research proposed for GCE-III is designed to address how variations in salinity and inundation, driven by climate change and anthropogenic factors, affect biotic and ecosystem responses at different spatial and temporal scales, and to predict the consequences of these changes for habitat provisioning and carbon (C) sequestration across the coastal landscape. The goals are to: 1) Track long-term changes in climate and human actions in the watershed and adjacent uplands, and evaluate the effects of these drivers on domain boundary conditions. 2) Describe temporal and spatial variability in physical, chemical, geological and biological, and to evaluate how they are affected by variations in river inflow and other boundary conditions. 3) Characterize the responses of three dominant habitats in the domain to pulses and presses in salinity and inundation. 4) Describe patterns of habitat provisioning and C sequestration and export in the GCE domain, and to evaluate how these might be affected by changes in salinity and inundation. These efforts will be synthesized into a synoptic understanding of both biotic and ecosystem responses to variations in salinity and inundation driven by climate change and human activities, which will be used to assess thresholds between habitats and the potential for state changes in the domain. 6. Funding Source: NSF OCE 1237140 B. Sub-project Description 1. Site Description a. Geographic Location: GCE1 -- Eulonia, Georgia, USA GCE-AL -- Altamaha River, Georgia, USA Coordinates: GCE1 -- NW: 081 25 42.53 W, 31 32 48.30 N NE: 081 24 38.64 W, 31 32 48.30 N SE: 081 24 38.64 W, 31 32 02.27 N SW: 081 25 42.53 W, 31 32 02.27 N GCE-AL -- NW: 081 34 56.32 W, 31 24 05.05 N NE: 081 14 16.57 W, 31 24 05.05 N SE: 081 14 16.57 W, 31 17 45.72 N SW: 081 34 56.32 W, 31 17 45.72 N b. Physiographic Region: GCE1 -- Lower coastal plain GCE-AL -- Estuary and tidal marsh c. Landform Components: GCE1 -- Intertidal salt marsh bordering maritime forest GCE-AL -- Intertidal marsh bordering sounds, tidal channels and creeks d. Hydrographic Characteristics: GCE1 -- Site contains the upper reaches of the Sapelo River, and is subject to 2-3m semi-diurnal tides GCE-AL -- Site encompasses the Altamaha River estuary and nearby tidal creeks, and is subject to 2-3.4m semi-diurnal tides. High freshwater input from the Altamaha River, one of the largest rivers in the Southeastern United States. e. Topographic Attributes: GCE1 -- Flat, with elevations ranging from 0-3m above mean low tide GCE-AL -- Flat, with elevations ranging from 0-3.4m above mean low tide f. Geology, Lithology and Soils: GCE1 -- unspecified GCE-AL -- unspecified g. Vegetation Communities: GCE1 -- Vegetation is 3/4 Juncus and 1/4 Spartina alterniflora, and upland area is heavily forested. GCE-AL -- unspecified h. History of Land Use and Disturbance: none recorded i. Climate: Climate summary for Sapelo Island, Georgia, based on NWS data from 1980-2010: Daily-aggregated Values: Mean (sample standard deviation) mean air temperature: 20.09°C (7.28°C) minimum air temperature: 15.02°C (7.96°C) maximum air temperature: 24.82°C (6.98°C) total precipitation: 3.26mm (10.3mm) Yearly-aggregated Daily Values: Mean (sample standard deviation) total precipitation (1980-2010): 1124mm (266mm) 2. Experimental or Sampling Design a. Design Characteristics: One year collection of DOM samples in the Altamaha River and Sapelo Sound in order to analyze how hydrology influences DOM composition and biodegradation. b. Permanent Plots: none c. Data Collection Duration and Frequency: DOM samples were collected once a month from September 2015 and September 2016 in the Altamaha River and Sapelo Sound using 20 L carboys. Beginning of Observations: Sep 15, 2015 End of Observations: Sep 11, 2016 3. Research Methods a. Field and Laboratory Methods: Method 1: Sample Processing -- After collection, DOM samples were filtered through 0.2 µm Pall Supor membrane filters into polycarbonate bottles, acidified to pH 2 (HCl), and DOM was extracted using solid phase extraction (SPE) with Agilent Bond Elut PPL cartridges. The DOM extracts (SPE-DOM) were then eluted using methanol, concentrated using ultra-pure nitrogen gas, and stored at -20°C in the dark for FT-ICR MS analysis. Method 2: Incubation -- Triplicate riverine and estuarine DOM samples underwent in-lab dark incubations. Samples were filtered through 0.7 µm Whatman GF/F filters and incubated during 80 days at temperature of collections. After incubations, samples were filtered through 0.2 µm Pall Supor membrane filters, collected and stored as described previously. Method 3: FT-ICR Mass Spectrometer analysis -- The molecular composition of the DOM extracts was analyzed on a 9.4 T Fourier transform-ion cyclotron resonance mass spectrometer (FT-ICR MS) with electrospray ionization (ESI; negative mode). A total of 150 scans were accumulated for each sample. Method 4: Absorbance measurements -- Absorbance measurements of water samples were taken using an Agilent 8453 UV-visible spectroscopy system. Absorbance was measured from wavelengths 190 nm to 1100 nm and was converted to absorption coefficients as in D’Sa et al. (1999). Spectral slope (S275-295) was calculated for the absorbance spectra between 275-295 nm and S is the slope fitting parameter (Helms et al., 2008). The ratio of absorbance at lambda=250 nm to lambda=365 nm (a250:a365) was also calculated for each sample. b. Protocols: Method 1: none Method 2: none Method 3: none Method 4: none c. Instrumentation: Method 1: none Method 2: none Method 3: 15T Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS; Bruker Daltonics) Method 4: none d. Taxonomy and Systematics: Method 1: not applicable Method 2: not applicable Method 3: not applicable Method 4: not applicable e. Speclies List: f. Permit History: Method 1: not applicable Method 2: not applicable Method 3: not applicable Method 4: not applicable 4. Project Personnel a. Personnel: 1: Patricia M. Medeiros 2: Maria L. Letourneau b. Affiliations: 1: University of Georgia, Athens, Georgia 2: University of Georgia, Athens, GA III. Data Set Status and Accessibility A. Status 1. Latest Update: 30-Apr-2019 2. Latest Archive Date: 30-Apr-2019 3. Latest Metadata Update: 30-Apr-2019 4. Data Verification Status: New Submission B. Accessibility 1. Storage Location and Medium: Stored at GCE-LTER Data Management Office Dept. of Marine Sciences Univ. of Georgia Athens, GA 30602-3636 USA on media: electronic data download (WWW) or compact disk 2. Contact Person: Name: Wade M. Sheldon, Jr. Address: Department of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: sheldon@uga.edu 3. Copyright Restrictions: not copyrighted 4. Restrictions: This information is licensed under a Creative Commons Attribution 4.0 International License (see: https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) has an ethical obligation to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. a. Release Date: Affiliates: Apr 11, 2019, Public: Jun 11, 2021 b. Citation: Data provided by the Georgia Coastal Ecosystems Long Term Ecological Research Project, supported by funds from NSF OCE 1237140 (data set ORG-GCET-1904) c. Disclaimer: The user assumes all responsibility for errors in judgement based on interpretation of data and analyses presented in this data set. 5. Costs: free electronic data download via WWW, distribution on CD may be subject to nominal processing and handling fee IV. Data Structural Descriptors A. Data Set File 1. File Name: ORG-GCET-1904_1_0.CSV 2. Size: 27 records 3. File Format: ASCII text (comma-separated value format) 3a. Delimiters: single comma 4. Header Information: 5 lines of ASCII text 5. Alphanumeric Attributes: 6. Quality Control Flag Codes: Q = questionable value, I = invalid value, E = estimated value 7. Authentication Procedures: 8. Calculations: 9. Processing History: Software version: GCE Data Toolbox Version 3.9.9 (07-Jan-2019) Data structure version: GCE Data Structure 1.1 (29-Mar-2001) Original data file processed: ResultsTable.txt (27 records) Data processing history: 30-Apr-2019: new GCE Data Structure 1.1 created ('newstruct') 30-Apr-2019: 27 rows imported from ASCII data file 'ResultsTable.txt' ('imp_ascii') 30-Apr-2019: 13 metadata fields in file header parsed ('parse_header') 30-Apr-2019: data structure validated ('gce_valid') 30-Apr-2019: automatically assigned study date metadata descriptors based on the range of date values in date/time columns (add_studydates) 30-Apr-2019: Name of column Dissolved Organic Carbon changed to Dissolved_Organic_Carbon; Name of column DOC_error changed to Dissolved_Organic_Carbon_SE; Name of column Spectral_Slope_error changed to Spectral_Slope_SE; Name of column a250:a365_error changed to a250:a365_S ('ui_editor') 30-Apr-2019: updated 1 metadata fields in the Dataset sections ('addmeta') 30-Apr-2019: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 30-Apr-2019: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement sections ('addmeta') 30-Apr-2019: Description of column a250:a365 edited; Name of column a250:a365 changed to a250_a365_ratio; Name of column a250:a365_SE changed to a250_a365_S ('ui_editor') 30-Apr-2019: updated 1 metadata fields in the Dataset sections ('addmeta') 30-Apr-2019: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 30-Apr-2019: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement sections ('addmeta') 30-Apr-2019: updated 6 metadata fields in the Data sections ('addmeta') 30-Apr-2019: updated 15 metadata fields in the Status, Data sections to reflect attribute metadata ('updatecols') 30-Apr-2019: parsed and formatted metadata ('listmeta') B. Variable Information 1. Variable Name: column 1. Collection_date column 2. Sample_Location column 3. Water_Temperature column 4. Salinity column 5. Dissolved_Organic_Carbon column 6. Dissolved_Organic_Carbon_SE column 7. Spectral_Slope column 8. Spectral_Slope_SE column 9. a250_a365_ratio column 10. a250_a365_SE column 11. Discharge 2. Variable Definition: column 1. Date of sample collection column 2. Location of sample collection column 3. Temperature of water at sample collection column 4. Salinity of water at sample collection column 5. Dissolved Organic Carbon column 6. Standard error of DOC measurements column 7. Spectral slope of 275-295 nm wavelength region column 8. Standard error of spectral slope column 9. The ratio of absorbance at 250 nm wavelength to 365 nm wavelength (a250:a365) column 10. Standard error of a250:a365 ratio column 11. Altamaha River discharge at sampling time. 3. Units of Measurement: column 1. YYYY-MM-DD column 2. none column 3. °C column 4. PSU column 5. µM column 6. µM column 7. 1/nm column 8. 1/nm column 9. none column 10. none column 11. m^3/s 4. Data Type a. Storage Type: column 1. string column 2. string column 3. floating-point column 4. floating-point column 5. floating-point column 6. floating-point column 7. floating-point column 8. floating-point column 9. floating-point column 10. floating-point column 11. floating-point b. Variable Codes: c. Numeric Range: column 1. (none) column 2. (none) column 3. 9.68 to 32.73 column 4. 0 to 31.53 column 5. 324 to 3672 column 6. 4 to 19 column 7. 12.24 to 16.82 column 8. 0.01 to 0.07 column 9. 4.48 to 6.78 column 10. 0.01 to 0.09 column 11. 63.36 to 1134.56 d. Missing Value Code: 5. Data Format a. Column Type: column 1. text column 2. text column 3. numerical column 4. numerical column 5. numerical column 6. numerical column 7. numerical column 8. numerical column 9. numerical column 10. numerical column 11. numerical b. Number of Columns: 11 c. Decimal Places: column 1. 0 column 2. 0 column 3. 1 column 4. 1 column 5. 0 column 6. 0 column 7. 2 column 8. 2 column 9. 2 column 10. 2 column 11. 0 6. Logical Variable Type: column 1. datetime (none) column 2. free text (none) column 3. data (continuous) column 4. data (continuous) column 5. calculation (continuous) column 6. calculation (continuous) column 7. calculation (continuous) column 8. calculation (continuous) column 9. calculation (continuous) column 10. calculation (continuous) column 11. data (continuous) 7. Flagging Criteria: column 1. none column 2. none column 3. none column 4. none column 5. none column 6. none column 7. none column 8. none column 9. none column 10. none column 11. none C. Data Anomalies: V. Supplemental Descriptors A. Data Acquisition 1. Data Forms: 2. Form Location: 3. Data Entry Validation: B. Quality Assurance/Quality Control Procedures: C. Supplemental Materials: D. Computer Programs: E. Archival Practices: F. Publications: not specified G. History of Data Set Usage 1. Data Request History: not specified 2. Data Set Update History: none 3. Review History: none 4. Questions and Comments from Users: none