This report seeks to share understanding of the roots of plastic polymer pathways to the Baltic Sea, then moves to defining the nature and extent of the problem, then passes to the impacts on sea ice habitat and marine species of the region. This is followed by a shift to focus on a sense of what is currently happening in the business world to slow or stop plastic effects, what is possible to anticipate for the future, and which responses from industry and regulation by government policy will be most plausible and effective in mitigating the impacts. This synthesis of the five reports fits both the thematic and geographic lines of inquiry and investigation, but it also combines them in a way that offers decision-makers a sound basis for taking measured action.