Developing a shared environmental responsibility principle for distributing cost of restoring marine habitats destroyed by industrial harbors

For decades, industrial harbor expansion has been destroying coastal marine ecosystems. Many estuaries are sites for industrial harbors and critical fish nursery habitat. Considering fish population decreases and the global biodiversity crisis, restoring these habitats is justified and supported by international institutions. However, restoration programs can be prohibitively costly, particularly when considering the Polluter Pays Principle. While harbors destroy nurseries, at the same time they generate benefits for society and contribute to the public interest. This raises questions of who is responsible for environmental degradation and who can afford environmental restoration costs? One way to allocate restoration costs is in proportion of those who have benefitted from harbor activities. This paper addresses these questions by calculating burdensharing scenarios with input-output matrix equations. These scenarios are based on a shared producer and consumer responsibility approach to distribute restoration costs among stakeholders that use, either directly or indirectly, harbor services. The scenarios are applied to the Seine estuary, France, and calculated as a function of sectorial value-added as well as direct and indirect economic linkages between economic sectors and harbor activities. Economic linkages with final consumers (e.g., households) are also included. The shared environmental responsibility calculation developed in this paper shares restoration costs for previously damaged marine habitats between a wide-range of economic agents, thereby preventing industrial harbors from bearing expensive restoration costs alone, and making restoration more likely.