Towards a management strategy for microplastic pollution in the Laurentian Great Lakes - Monitoring (Part 1)

Plastic contamination extends across all Great Lakes ecosystems, including in wildlife, with the potential for risk based on laboratory experiments and risk assessment. Due to widespread contamination, and based on evidence suggesting measurable risk, it is time for policy-makers to develop and implement monitoring programs to guide management . Here, we discuss the need for a monitoring strategy with clear guidelines. We synthesize the research that has been published across the Great Lakes, reporting on contamination, regions that have been the focus of study, and the methods used across matrices. Based on our findings, we suggest how research may inform guidelines and next steps – especially if microplastics are to be considered as a Toxic Chemicals sub-indicator under the Great Lakes Water Quality Agreement. Future monitoring, using standard and/or harmonized protocols for sampling and analysis, should build baselines across the basin and begin tracking how contamination changes to assess the health of the Great Lakes, to inform source-reduction, and to measure the effectiveness of policies aimed at reducing emissions of plastics to freshwater.