Search

Cumulative effects assessments are a legal requirement in many jurisdictions and are key to informing marine policy. However, practice does not yet deliver fit-for-purpose assessments relative to sustainable development and environmental protection obligations. The complexity of cumulative effect questions, which are embedded in complex social-ecological systems, makes multiple, methodologically diverse assessments a necessity. Using the expansion of marine renewable energy developments in European Union waters as a case study, this paper explores how social-ecological systems thinking and cumulative effects assessment theory can combine to structure CEAs that better support the management and regulation of maritime activities at regional scales. A general perspective for cumulative effects assessment is proposed to remove ambiguity of intent and to orient assessments towards a common objective. Candidate principles for practice are presented for consideration. These principles are integrated into a stepped assessment approach that seeks to improve cumulative effects assessments of localised activities relative to the information needs of decision-makers implementing the ecosystem approach.

Proponents of marine renewable energy worldwide highlight that regulatory and consenting procedures are a significant barrier to the upscaling of infrastructure required to transform the energy generation sector. Uncertainties about the cumulative effects of marine renewable energy developments cause substantial delays during the consenting process, which are exacerbated by the lack of clarity about how to assess cumulative effects. These obstacles have contributed to perceptions that this essential emerging industry receives disproportionate scrutiny relative to established maritime activities. However, alongside legislated targets to reduce carbon emissions, there are legal obligations to protect, maintain and improve the condition of the marine environment. As the imperative to halt the decline in the condition of the environment increases, so expectations of cumulative impact assessments grow and the risk of consenting delays persists. To investigate how robust current cumulative impact assessment practise is, a novel evaluation framework was developed and applied to Environmental Statements of the world's largest offshore wind farms, currently in United Kingdom waters. The framework was designed to evaluate cumulative impact assessments relative to the information needs of decision-makers tasked with managing cumulative effects. We found that current practise does not meet those needs, that there is dissonance between science and practise, and problematic variability between assessments was observed. Straightforward recommendations for improved practise are provided, which if implemented may ease the perceived regulatory burden by clarifying practise. We also highlight additional steps that could enable project-led cumulative impact assessments to better support regional marine management. The results and recommendations will be of interest to countries worldwide where marine renewable energy is emerging alongside ecosystem-approach and marine spatial planning aspirations.