Microplastic pollution of Ulothrix Filamentous Algae in Western Lake Superior

Abstract

Lake Superior and the St. Louis River Estuary (SLRE) are important ecological and economical resources for the Upper Midwest as waterways, fisheries, and recreation destinations—however, these essential waterbodies may be contaminated with microplastics. Microplastics (MPs) are small, pervasive (< 5mm) pieces of plastic that take the form of fibers, films and fragments. Microplastics have been found in Lake Superior, but their source and distribution are still unclear. This project is part of a collaboration between UW-Madison and UW-Superior investigating this question on a large scale in the water column, beach sediment, and aquatic organisms. We collected 30 samples of shoreline filamentous algae (Ulothrix) from 5 sites in the SLRE and Two Harbors during June 2021 in order to investigate the distribution and presence of MPs in aquatic organisms.