Microplastic Accumulation in Freshwater Crayfish of the Boundary Waters Canoe Area Wilderness

Abstract

There has been growing global concern over microplastic pollution and accumulation and its impacts on ecological systems. Research has documented microplastic debris in marine, freshwater, and terrestrial habitats worldwide. Remote lake systems have been less studied, such as those found in the Boundary Waters Canoe Area Wilderness (BWCAW) in northern Minnesota. Previous work has shown that BWCAW lakes contain microplastics, but virtually nothing is known about microplastic loads within organisms living in those lakes. Marine studies have shown that crustaceans accumulate microplastics from their environment either by ingesting particles with their food or by entrapping particles in their gills. In this study we investigated two questions concerning BWCAW crayfish: 1) What is the relative importance of ingestion vs. gill entrapment for determining crayfish microplastic loads? 2) Do microplastic loads in crayfish increase at sites receiving heavier recreational canoe traffic?