A Comparison of Two Insect Collection Techniques in Oiled and Non-Oiled Salt Marshes in Louisiana

Insects are important components in coastal marsh ecosystems and can be used as an indicator of marsh health. Collections of insects in coastal marshes are usually made using either sweep nets or insect vacuums. Differences in these 2 methods have not been compared within the marsh ecosystem. Therefore, we compared collections made using these methods in oiled and non-oiled marshes along multiple transects on the Louisiana coast. We found that sweep net collections accounted for 5.9 times more individual arthropods and more total insect taxa when compared with the insect vacuum collections. Oiled marshes had greater total insect richness but similar abundance and average richness as non-oiled sites; however, we found some changes in insect community composition between sites. These results indicate that sweep net collections are an effective means to sample insects in marsh environments and that oil intrusion can lead to changes in arthropod community structure in coastal marshes.