Carson Alday Margaret Lamont Daniel Catizone Hannah B. Vander Zanden 2025 spreadsheet https://doi.org/10.5066/P14TEHAT These datasets contain the carbon and nitrogen stable isotope data from diamondback terrapin epidermis tissue and a variety of sampled prey items. This data was collected to determine potential diet items for diamondback terrapins in northwest Florida. This data can be used to compare carbon and nitrogen isotope values of diamondback terrapin epidermis as well as the isotopic values of their potential prey. Author ORCIDs: Alday, C.L.(0000-0001-9962-8647);Lamont, M.M.(0000-0001-7520-6669);Catizone, D.J.(0000-0002-7030-4208);Vander Zanden, H.B.(0000-0003-3366-5116) 20180521 20211011 ground condition Complete None planned St. Joseph Bay, FL -85.4874 -85.1756 29.9228 29.6200 ISO 19115 Topic Category biota None Stable isotope analysis diamondback terrapin USGS Thesaurus carbon isotope analysis aquatic ecosystems USGS Metadata Identifier USGS:67506ef3d34ea60e89434aab Common geographic areas Gulf of America (Gulf of Mexico) None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Carson L Alday USGS - SOUTHEAST REGION Biologist mailing and physical

WARC - Gainesville,WARC - GVL - South Modular

Gainesville FL 32653 352-378-8181 calday@usgs.gov All isotope values were derived directly from mass spectrometer results produced at the University of Florida. All trays included standards to ensure isotope value results were accurate and the machine was calibrated correctly. Any results that produced inaccurate values for the standards were not included. Data fall within expected ranges and values with no duplications. The data set includes stable isotope values of carbon and nitrogen for diamondback terrapins as well as several marine animals sampled as potential prey. These data span 2018-2021 collected from St. Joseph Bay, FL located in the Northern Gulf of America. All isotope samples for this study were processed at the Department of Geological Sciences, University of Florida, Gainesville, Florida, USA, using a Carlo Erba NA 1500 CNS elemental analyzer (Thermo Scientific, Waltham, Massachusetts, USA) interfaced via a ConFlo II to a DeltaV Advantage isotope ratio mass spectrometer (Thermo Electron, Waltham, Massachusetts, USA). Stable isotope ratios of the sample relative to an isotope standard were expressed in delta notation: Delta notation = (Rsample/Rstandard − 1) with units per mil (‰) where Rsample and Rstandard are the corresponding ratios of heavy to light isotopes (13C/12C and 15N/14N) in the sample and an international standard, respectively. 2024 Terrapin_iso_data_release.csv Comma Separated Value (CSV) file containing isotope data for the diamondback terrapin epidermis samples. Producer Defined d15N A measure of the ratio of the two stable isotopes of nitrogen, 15 N: 14 N. d: delta Producer Defined NA No data Producer defined 5.578598947 9.277216262 per mil d13C An isotopic signature, a measure of the ratio of stable isotopes 13 C : 12 C. d: delta Producer Defined NA No data available Producer defined -16.9 -8.87 per mil Sex The sex of the sampled terrapin Producer Defined Female Sample was taken from a female terrapin Producer defined Male Sample was taken from a male terrapin Producer defined Age The age class of the sampled terrapin Producer Defined Adult The sampled terrapin was an adult Producer defined Juvenile The sampled terrapin was a juvenile Producer defined SPL Straight plastron length of the terrapin Producer Defined 6.7 16.4 cm Terp_prey_data_release.csv Comma Separated Value (CSV) file containing isotope data for the prey samples Producer Defined Class The grouping that the organism that was sampled was placed into for the associated manuscript. Producer Defined Crustacean Placed into class crustacean Producer defined Gastropod Placed into class gastropod Producer defined Mangrove Placed into class mangrove Producer defined Spartina grass Placed into class spartina Producer defined Species The species name of the organism that was sampled. Producer Defined Barnacles Species type barnacle Producer defined Blue crab Species type blue crab Producer defined Fiddler crab Species type fiddler crab Producer defined Hermit crab Species type hermit crab Producer defined Crown Conch Species type crown conch Producer defined Periwinkle Species type periwinkle Producer defined Black mangrove leaves Species type black mangrove leaves Producer defined Red mangrove leaves Species type red mangrove leaves Producer defined Spartina grass Species type spartina grass Producer defined Nitrogen A measure of the ratio of the two stable isotopes of nitrogen, 15 N: 14 N. d: delta Producer Defined 2.531339267 9.004569064 Carbon An isotopic signature, a measure of the ratio of stable isotopes 13 C : 12 C. d: delta Producer Defined -27.62766565 -11.14546661 U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 USA 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government Digital Data https://doi.org/10.5066/P14TEHAT None 20250602 Carson L Alday USGS - SOUTHEAST REGION Biologist mailing and physical

WARC - Gainesville,WARC - GVL - South Modular

Gainesville FL 32653 352-378-8181 calday@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999