Abstract:

Sediment samples for benthic meiofauna analysis (number and composition) were collected on 2018-07-17 and 2019-06-18 from a twelve tank experimental mesocosm system located at Louisiana Universities Marine Consortium (LUMCON) in Cocodrie, Louisiana to document conditions prior to oil exposure treatments. Meiofauna were identified to the lowest possible taxonomic level.

Suggested Citation:

Rabalais, Nancy N. , Shivrudrappa, Shivakumar. 2019. Meiofauna from an experimental mesocosm system prior to oiling: 2018-07-17 and 2019-06-18. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-ztag-8s25

Purpose:

To collect pre-oiling baseline data prior to controlled oil dosed exposures in mesocosm experiments simulating the Louisiana subtidal ecosystem for the purpose of examining the impact of oiling on benthic meiofauna communities.

Data Parameters and Units:

Date: Date samples were collected from the mesocosm tanks (MM/DD/YYYY), Mesocosm Tank #: User-defined identifier assigned to each mesocosm tank, Major Taxa: The major taxonomic group to which each macroinvertebrate counted belongs, Family: The taxonomic family to which each macroinvertebrate counted belongs, Genus: The Genus to which each macroinvertebrate counted belongs, Species: The species to which each macroinvertebrate counted belongs, Number: The total number of individual macroinvertebrates counted for each Major Taxa, Family, Genus, and Species combination observed, Notes: Any other information or notes that the sorter may have noticed.

Methods:

For each meiofauna sample (one per mesocosm tank), two 60 ml syringe cores (modified 60ml plastic syringes with the tip cut off) were collected. Prior to sampling, syringe plungers were removed and the syringe cores were placed on the sediment surface and pushed to a depth of approximately 2-3 cm. Plungers were placed back into the syringes to create vacuum pressure so that the sediment plug could be removed. Excess sediment was extruded from the core and approximately the top 1 cm was placed into a glass sample jar and fixed with a 10% formaldehyde solution stained with Rose Bengal. In the lab samples were sieved with distilled water over a series of 0.5-mm and 63-µm sieves to remove fine sediment and debris, and the 63-µm sediment and associated organisms were retained. The debris was returned to 70% ethanol until the sample was counted. To perform counting and taxonomic determinations, the preserved sample was poured into a zooplankton counting wheel and each organism was counted individually on a dissecting microscope until the whole sample had been counted. A compound microscope was used to aid in determining taxonomic designation of individuals. Nematodes were not designated any further than major taxa (nematode) and copepods were not determined past family designation. All other organisms were identified to the lowest possible taxonomic group.

Individual Files: