Degree Name

Doctor of Philosophy


Australian National Centre for Ocean Resources and Security (ANCORS)


A range of multilateral agreements exists to prevent pollution of the oceans from various sources. Yet it would seem this framework has failed to prevent the continuing flow of plastic waste into the marine environment. This research provides the first analysis of the international and regional legal and policy framework to assess the adequacy of provisions in establishing a duty to prevent marine plastic debris.

The central contributing factor is one of differing jurisdictions resulting in varying levels of duty established in the different maritime zones and on land. The Law of the Sea Convention provides various rights to States according to these jurisdictions, constrained by defined duties to protect. From the global commons of the high seas to the strict principle of sovereignty on land, the duty to prevent all sources of marine plastic debris is dispersed across landlocked, coastal, port and flag States. Three case studies help deconstruct the problem and guide the research through the existing legal and policy framework. State obligations are analysed within the context of the case studies, leading to reviews of the shortcomings and suggestions for improvements.

The research finds the international policy framework to have established a clear duty to prevent ocean-based sources of marine plastic debris, but supporting measures to enable these global prohibitions are fragmented. The duty to prevent land-based sources of marine plastic debris is found to be too vague and geographic coverage too limited to be of value. It is within the territorial jurisdiction of States that by far the most marine plastic debris originates, and yet it is in this jurisdiction that the obligations established under multilateral agreements are eroded by the principle of State sovereignty. No international legally binding agreement for the prevention of land-based sources of marine pollution exists. Regional instruments adopted do not focus sufficiently on pollution by plastics and those that do are voluntary.

The analysis leads to two possible approaches that a new legally binding international agreement could take should the global community agree that land-based sources of this pollutant require targeted global standards. The first approach is based on a waste reduction approach, following the traditional view of marine debris as an issue of inadequate solid waste management. The second approach aims to reduce the consumption of virgin materials by globally regulating the feedstock of the plastics industry. This research suggests this is achievable by legislating the minimum post-consumer content to be included in plastic products.

Both approaches require effective collection services at the local level. For this reason, the research has considered the feasibility of a global fund to prevent marine plastic debris. Analogous financial mechanisms of international scale are reviewed and a model for a new fund is outlined. Elements such as common but differentiated responsibilities are factored in, as well as how State contribution to the global stock of marine plastic debris can be calculated. These allow for the identification of hotspots and prioritisation of deliverables from the fund.