Abstract:

This dataset lists the fatty acid composition (in percentage for 52 fatty acids) 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. Some of these samples were analyzed at Rutgers University (New Brunswick, NJ, USA) and others at the Ryerson University (Toronto, ON, Canada). The laboratory in which each sample was analyzed is listed in column D of file R4.x264.000-0053_2015_FA_Insects-Spiders-Infauna_sub1.xlsx, worksheet "FA_2015_Insects-Spiders-Infauna". This is important to note because some of the fatty acids measured by the two laboratories differ. If a fatty acid was 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 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, Jessica Johnson and Jennifer Pincin.

Suggested Citation:

Lopez-Duarte, Paola. 2019. Southern Louisiana marsh food webs: Fatty acid 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-v9gp-qd98

Purpose:

This dataset summarizes the fatty acid composition of multiple consumers and producers in southern Louisiana salt marshes. Fatty acids profiles of consumers reflect the fatty acids of their diet items, therefore these data can be used to understand predator-prey interactions.

Data Parameters and Units:

File R4.x264.000-0053_2015_FA_Insects-Spiders-Infauna_sub1.xlsx, worksheet "FA_2015_Insects-Spiders-Infauna": 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; FAA_Laboratory: where the samples were analyzed (Rutgers or Ryerson universities); Fatty acid composition of each sample measured as percentages for different fatty acids. Worksheet "FA_Information": Molecular formula; Scientific names, common names and types of the fatty acids reported in Worksheet FA_2015. Information is not provided for all of the listed fatty acids, only for those that are diet relevant. File subset_R4.x264.218-0001_For_2015_ FA_Insects-Spiders-Infauna.xlsx: A subset of the complete 2015 Food Web Sample Key file (GRIIDC dataset R4.x264.218:0001), containing only the samples in this fatty acid 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.

Methods:

The fatty acid composition was determined using gas chromatography, with fatty acid proportions calculated as a percentage of total peak area for relevant fatty acid peaks.

Instruments:

Rutgers samples: Shimadzu GC‌-2010 equipped with a Thermo Scientific TR-FAME Trace GC Column (60m x 0.25mm x 0.25um). Ryerson samples: Agilent Technologies 7890N gas chromatograph equipped with a 30-m J and W DB‌-23 column (0.25 mm I.D; 0.15 lm film thickness).

Individual Files: