A Survey of Microplastics in Invertebrates in the Lake Champlain Basin

The goal of this research was to determine whether microplastics (MP) were ingested by aquatic macroinvertebrates resident to Lake Champlain. We did so by quantifying and characterizing (e.g., fragment, fiber, film, foam, pellet) microplastic particulate. In more recent samples, we have dried and weighed invertebrates to better assess uptake. Preliminary wet peroxide oxidation digests were performed on aquatic invertebrates (n = 301). Invertebrate specimens were collected across two classes (Insecta, Malacostra) and 7 orders including Coleoptera, Ephemeroptera, Hemiptera, Odonata, Trichoptera, Mysida, and Amphipodae. These representative organisms are an important part of the lake food web, serving as preferred food for higher vertebrates including fish and waterfowl. Aquatic macroinvertebrates in our sample possess unique feeding methods, such as filter feeding, scraping, piercing, shredding, scavenging, collecting/gathering, and predation. Our research indicated that fibers were the most common microplastic type uptaken by invertebrates. Preliminary results suggest that, Hydropsyche, a filter-feeding insect digested, the greatest mean number of MP’s (n=3). Lake Champlain macroinvertebrates contained on average 0.36 microplastic particles. There are limited reports of microplastics uptaken in aquatic invertebrates and this research provides baseline information for a guild that will be involved in trophic transfer. Results from this research serve to inform residents of the Lake Champlain watershed, anglers, non-profit lake organizations, as well as public health and government officials of the risks microplastics pose to aquatic biota and ultimately humans.