The potential for biodiversity offsetting in the marine environment

The marine environment faces increasing anthropogenic pressure and declining trends in biodiversity, in many cases caused by changes in land-use and urbanisation. Such activities normally require environmental impacts to be... [ view full abstract ]

The marine environment faces increasing anthropogenic pressure and declining trends in biodiversity, in many cases caused by changes in land-use and urbanisation. Such activities normally require environmental impacts to be addressed with an aim to conserving biodiversity - yet biodiversity losses are still occurring, in turn, suggesting that existing environmental consenting frameworks are not functioning efficiently. Most planning frameworks embed the mitigation hierarchy (avoid, mitigate, compensate) as a key process by which impacts are managed. While it should be a last resort, compensation has proven difficult to implement and regulate, to the point where compensation is sometimes seen as little more than justification for environmentally damaging action. Consequently, biodiversity offsetting has been developed as an approach to strengthen compensatory action with an explicit aim of achieving ‘no net loss’ of biodiversity. However, the approach has also provoked much controversy and questions about its feasibility and underlying ethics.

While offsetting has predominantly been developed in the terrestrial environment there is evidence of its application in marine and coastal estates, although not always in line with standards necessary to achieve the aim of ‘no net loss’ of biodiversity. Indeed, it is not clear whether it is possible to achieve the ‘no net loss’ aim of biodiversity offsetting in the complex marine environment, particularly where there is often great uncertainty in ecosystem functioning and impact pathways. The need to seek equivalence between loss and offset will require a valuation metric operational at a range of scales and accounting for a vast array of stakeholders. Using case studies I outline the methods by which offsets have been implemented in the marine environment and present an analysis of the challenges and opportunities for achieving ‘no net loss’ of biodiversity.