Insects in the Marsh: Is Sweeping or Vacuuming More Effective for Collecting Ants on Barataria Dunes

Our group is working to quantify and understand the effect of stressors – i.e., hydrocarbons, dispersants, freshwater diversion, and other remediation-related human activities – on marsh and adjacent open water communities. Specifically, we are measuring the effects of stressors on soil strength, marsh grass roots and above-ground biomass, insect and spider populations, and selected mollusk species (in the marsh and adjacent open waters). Stressors have both direct and indirect effects because, as hydrocarbons degrade, these compounds enter food webs via primary consumers such as mollusks and insects/spiders. These primary consumers, in turn, serve as food sources for higher trophic levels such as frogs, fish, birds and, ultimately, humans. The effects of a stressor can cascade through the community as members of lower trophic levels undergo changes in growth rate, mortality, reproduction, and recruitment. As a result, species turnover occurs and food web configuration and stability are altered. Our goal is to provide a benchmark study in ecosystem change analysis, to identify precursors to ecosystem trajectories before alternative states are realized, and to address societal concerns about wetland stability. This preliminary data focuses on the most effective means of collecting insects in the marsh.