Abstract:

This dataset includes characterization of Louisiana marsh sediments, including bulk water and organic carbon content, from nineteen marsh sites that vary spatially and in terms of environmental characteristics such as natural and anthropogenic oiling history, inundation frequency, and vegetation type and cover. Samples were collected biannually from June 2012-October 2014. The data correspond to soft sediment core sections for which total bacterial communities are described, a component of a longitudinal study of marsh processes and health after the Deepwater Horizon oil spill. Bacterial community compositions from the marsh sediment are reported in R1.x139.143:0017, R1.x139.143:0018, R1.x139.143:0020, R1.x139.143:0019, R1.x139.143:0044, R1.x139.143:0045. Field measurements taken at the time of sample collection are available in complementary datasets R1.x139.143:0011, R1.x139.143:0012, R1.x139.143:0013, R1.x139.143:0015.

Suggested Citation:

Engel, Annette Summers. 2016. Sediment properties of Louisiana marshes, 2012-2014. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7TT4NW5

Purpose:

To report the water content and organic content of marsh inland soils and subtidal sediment from Louisiana from June 2012-October 2014.

Data Parameters and Units:

Sample ID, Location (Latitude-decimal degrees Longitude-decimal degrees), Collection date (Day-Month-Year), Sample Description, Geographic Location Name (a geographic description of the sampling site), Loss of ignition (LOI) Replicate ID (Sample ID and replicate number), LOI-110 Water (%), LOI-550 OC (%), standard deviation

Methods:

Sediment samples were collected biannually in June 2012, October 2012, May 2013, October 2013, May 2014 and October 2014. Inland soil and subtidal sediment cores were collected 5 m inland from the marsh edge and 1-2 m offshore, respectively. Sediment samples were sectioned in the field, transported on ice, and frozen at -20 degrees C. The following core sections were retained: A) 0-1cm, B) 1-2cm, C) 4-5cm, D) 9-10cm. These sediment samples were used for characterization of bacterial community composition, a component of a longitudinal study of marsh processes and health, for which data are reported separately. Water content and organic matter content were determined by weight loss upon heating to a prescribed temperature (Loss on Ignition, LOI). Sediment samples were thawed to room temperature, and approximately 3 grams of sediment were aseptically transferred to aluminum dishes in triple replicate. Sediment samples were dried at 110 degrees C in an oven for 16-24 hours, cooled to room temperature in desiccators, and then the weights of the solid, dry residues in the aluminum dishes were recorded. Replicate values are reported for percent weight loss from the wet sediment samples subjected to the drying procedure (LOI-110 Water %). Solid residues were then subjected to temperatures up to 550 degrees C in a furnace for exactly 6 hours, after which the residues were cooled in desiccators. The solid combustion residues were reweighed to determine the percent weight loss from the dry sediment weight (LOI-550 OC %). The average LOI values and standard deviation among treatment replicates are also reported for each sample and LOI procedure.

Individual Files: