Abstract:

This dataset lists the bulk stable isotope values (delta-13C, delta-15N, and delta-34S) for tissue samples collected in 2015 for the food web project within the Coastal Waters Consortium (CWC) II. It includes tissue samples of insects, spiders, isopods, infauna, and benthic microalgae from salt marshes in southern Louisiana. If isotopes were not measured, it is indicated as “NA”. Zero values represent measurements. Information gathered at the time of collection for each sample in this dataset can be found in the subset file of GRIIDC dataset R4.x264.218:0001 (2015 Food Web Sample Key) by referencing the CWC ID Number. Additional dataset authors are Olaf Jensen, Ken Able, Joel Fodrie, Michael Polito, Jill Olin, and Jessica Johnson.

Suggested Citation:

Lopez-Duarte, Paola. 2019. Southern Louisiana marsh food webs: Bulk stable isotope data for tissue samples collected from May to December 2015. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-kjj7-ms59

Purpose:

This dataset summarizes the bulk stable isotope values (delta-13C, delta-15N, and delta-34S) of multiple consumers and producers in southern Louisiana salt marshes. For each sample, the delta-13C and delta-34S values are indicators of energy sources, and delta-15N values indicate trophic position. Therefore, these data can be used to understand the food web structure in these salt marshes.

Data Parameters and Units:

File R4.x264.000-0054_2015_Bulk_SIA_Insects-Spiders-Infauna_sub1.xlsx, worksheet: SIA_2015: CWC_ID: user identified code assigned to every sample; Other_ID_1: code that may have been assigned by other groups who collected the sample; Other_ID_2: second code that may have been assigned by another laboratory or by the analytical facility; SIA_Laboratory: where the samples were analyzed (LSU or Windsor); delta-13C: stable carbon isotope values in %; %C: percent carbon; delta-15N: stable nitrogen isotope values in %; %N: percent nitrogen; C:N: the %C value divided by %N; delta-34S: stable sulfur isotope values in %; %S: percent sulfur. Notes: Internal information regarding sample processing. File subset_R4.x264.218-0001_For_2015_SIA_Insects-Spiders-Infauna_sub1.xlsx: A subset of the complete 2015 Food Web Sample Key file (GRIIDC dataset R4.x264.218:0001), containing only the samples in this bulk stable isotope dataset. CWC ID Number: code assigned by our group to every sample collected; Other ID Number: code that may have been assigned by other groups who collected the sample; Collection Date: month and year of collection; Site: names assigned by our group to different marsh sites; Latitude: in decimal degrees; Longitude: in decimal degrees; Habitat/Location (measurements in meters indicate distance from marsh edge): we use this parameter to identify where in the marsh (or relative to the marsh) the sample was collected. Gear: type of gear used to collect the sample; Node Group: refers to the functional group the species belongs to according to a diet literature review performed as part of a food web study (GRIIDC R4.x264.221:0002); Node Code: short version of node group; Common Name: generally used name; Scientific Name: genus and species, or only genus when species is unknown; n: number of individual animals that make up the sample; Total Length (mm): in millimeters; Fork Length (mm): in millimeters; Carapace width (mm): in millimeters; Weight (grams): in grams; Sex: male, female, or not available (unidentified); Tissue Collected: type of tissue (whole body, muscle, stomach, liver, hepatopancreas, plant) collected; Collection Notes: any additional information regarding collection, storage, or processing.

Instruments:

All CNS data were provided by the Stable Isotope Facility at the Great Lakes Institute for Environmental Research, University of Windsor, Ontario, Canada. Relative abundances of carbon (13C/12C) and nitrogen (15N/14N) were determined on a Thermo Finnigan DeltaPlus mass spectrometer (Thermo San Jose, California, USA) coupled with an elemental analyzer (Costech, Valencia, California, USA). Relative abundances of sulfur (34S/32S) are determined on a Delta V Plus mass spectrometer (Thermo) coupled to a Costech 4010 Elemental Combustion system and a ConFlo IV gas interface. For the purpose of sulfur analysis, the working gas utilizes the dual inlet capacity of the Delta V Plus allowing more controlled stability in gas delivery.

Error Analysis:

Analytical accuracy for delta-15N data is based on the National Institute of Standards and Technology (NIST) standards 8573, 8548, and 8549, and for delta-13C data on NIST standards 8542 and 8573. The analytical precision is based on the standard deviation of two standards (NIST bovine liver and fish muscle laboratory standard) for both isotopes. Analytical accuracy for delta-34S data is based on the National Institute of Standards and Technology (NIST) standards 8529 and 8555, and USGS 42. The analytical precision is based on the standard deviation of two standards (NIST bovine liver and tilapia internal laboratory standard).

Individual Files: