Marine plastic pollution: an environmental and socio-economic challenge for public policies
Plastic pollution currently represents a major challenge for economic thought, revealing the tensions between growth-based production systems and the planet's ecological limits. The issue of the impact of litter, and specifically plastics, on the marine environment is of increasing importance within the framework of Regional Seas Conventions (OSPAR, Barcelona) and the implementation of the Marine Strategy Framework Directive (MSFD). However, the scientific committees established to support these international public policies still do not sufficiently take into account the social and economic dimensions of plastic pollution. Against this backdrop, this thesis project was developed in collaboration with the leading scientific experts, focusing on the environmental aspects of marine litter within public policy frameworks (thematic and monitoring leads for MSFD Descriptor 10 "Marine Litter", members of dedicated working groups under the Regional Seas Conventions, etc.), in particular CEDRE.
This PhD project, led by Ms. Aanchal Jain, aims to develop and provide a coherent set of economic instruments to analyse the ecological, economic, and public policy consequences of marine litter. The project falls within the framework of the MSFD, which sets out a general objective in terms of marine environment protection (good environmental status of marine waters) and an action plan to achieve it. This thesis, which is jointly supervised by AMURE and CEDRE, aims to strengthen the bonds between the environmental, economic and social analysis work carried out on marine litter under the MSFD. CEDRE contributes its expertise on aquatic litter and provides its knowledge and data acquired through monitoring actions and the projects it conducts. Meanwhile, the research carried out as part of this PhD project will bring an economic perspective to the aquatic litter initiatives led by CEDRE.
Expert workshop on the evaluation of marine litter policies in France, November 2024
Towards an integrated approach to the environmental and socio-economic impacts of marine litter
This PhD thesis takes an interdisciplinary approach to develop concepts and tools to inform decision-makers in relation to plastic litter management. The research question is addressed using the DPSIR (Driver-Pressure-State-Impact-Responses) framework. The economy (Driver) is a source of plastic materials (Pressure), which modifies the environment (State) and affects society (Impact). Based on this conceptual foundation, the thesis develops an integrated analytical framework applied to marine macroplastic pollution in mainland France. It is organised into three main contributions:
The first contribution consists of developing an extended input-output model that explicitly integrates environmental releases into various ecological compartments. While existing models primarily represent economic flows and waste treatments, they rarely account for the fate of plastics when they escape from management circuits. This model reconnects economic plastic flows with their effective ecological destinations and highlights the economy/environment interface within a macroeconomic framework.
The second contribution consists in the analysis of impact chains linking plastic pollution trajectories to ecosystem degradation, risks to ecosystem services, and ultimately, human well-being. Drawing on work in ecotoxicology and ecosystem service assessment frameworks, this approach seeks to represent the ecological consequences of plastic litter without simplifying all types of damage into a single monetary metric. It adopts a pluralistic and multidimensional perception of environmental value, consistent with the principles of ecological economics.
The third contribution is a multi-criteria assessment framework specifically designed for plastic pollution mitigation policies. Conventional approaches often evaluate policies based on partial indicators — recycling rates, management costs, or economic efficiency — without truly measuring their ability to reduce ecological damage. The proposed framework, however, evaluates policy measures throughout the entire plastic lifecycle and explicitly correlates them with ecological objectives defined within a strong focus on sustainability.
The results demonstrate that plastic pollution is a structural consequence of current economic systems and requires governance forms based not on marginal adjustments, but on a structural transformation compatible with ecological constraints.
