Lichen and Moss as Biomonitors of Microplastic Pollution in the Boundary Waters Canoe Area Wilderness

Abstract

The Boundary Waters Canoe Area Wilderness (BWCAW) is known for its pristine lakes and natural beauty, but like all natural areas accessible to humans, this highly visited and beloved wilderness is contaminated with microplastics. Microplastics are small (< 5 mm) pieces of plastic that take the form of fibers, films, and fragments. Previous research has found microplastics in BWCAW lake water, soils, and invertebrates, but their source is unknown. To determine the extent to which recreational canoeists may contribute to this pollution, I sampled a common moss and lichen from canoe campsites and undisturbed shoreline areas over the course of a week-long canoe trip in June 2020. My study investigated two questions: 1. How much microplastic is present in moss and lichen in the BWCAW? 2.Does moss growing at lakeshore campsites in the BWCAW have more microplastics than sites that are unvisited?