Yearly, at least 8 million tons of plastic end in the oceans, and by 2050 there will be more plastics than fish. Consequences include that we are eating, drinking, and breathing plastics, and that animals are dying by starvation and entanglement, among many other things.

The thesis asks how to construct a mix between public and private international initiatives to address the problem of the plastic soup, both recovering the existing and preventing further pollution. Four intermediate steps were taken: overview of the problem; highlighting aspects to avoid pitfalls in the North-South world dynamics; analysis of eleven international instruments; four case studies of private initiatives. Then economic tools were applied, summarizing lessons learned into aspects to guide an effective start of the mix and proposing an equation for action prioritization.