The role of the Cooperative Science and Monitoring Initiative (CSMI) is to direct enhanced monitoring and research activities across each of the Laurentian Great Lakes to provide relevant information to address the science priorities of each Lake Partnership (established under the Lakewide Management Annex of the 2012 Great Lakes Water Quality Agreement). CSMI is an intensive effort to collect information on the health of one Great Lake each year, cycling through the lakes on a five-year period. In 2020/2021, it was Lake Michigan’s turn (over a two-year period due to COVID). This is an executive summary of the 2020/2021 research results and the associated white paper containing more specific information.