INSITE Synthesis Project

Scientific experts from around the world agree that complete removal of man-made structures (MMS) may not be best option. A case-by-case approach, that takes into account trade-offs at a local level, is needed. Repurposing or abandoning were options that were identified as having the greatest potential to contribute to international environmental targets.

A global consensus

The INSITE Synthesis project collated the views of scientific experts worldwide to develop a scientific consensus that could inform policy and regulatory decisions regarding MMS in the marine environment. A position paper was developed, setting out the consensus view on the environmental implications of deploying MMS at scale, leaving non-operational MMS in situ, or removing non-operational MMS.

Experts, assemble!

Without consensus about decommissioning options, and with key evidence gaps remaining, it is difficult for policy to evolve. To address these issues, a global consortium of scientists that spanned 7 countries and 30 academic and government institutions was assembled. Using their local knowledge, expertise, and industry data, scientists explored 12 decommissioning options, from complete removal to the abandonment of structures. Discussions focused on the impact each decommissioning option would have on marine life and the extent to which each option would support the delivery of environmental targets.

Key Findings 

• Negative and positive impacts – While leaving oil rigs in place was generally viewed as environmentally harmful, some outcomes—such as the formation of habitats for commercially important marine species—were seen as beneficial.
• Abandonment the best option for meeting targets – interestingly, the panel concluded that abandoning or converting these structures into artificial reefs could offer the greatest support for achieving global environmental targets. This finding may appear counterintuitive, but many targets focus on what the environment can do for humans, rather than prioritising nature for its own sake.
• Case-by-case approach is needed – the panel emphasised that ecosystems do not respond uniformly to the presence of offshore infrastructure, with impacts varying depending on the ecological context. Furthermore, it was acknowledged that stakeholders may have different priorities in different regions which might align with different decommissioning options. Therefore, a case-by-case approach for decommissioning that accounts for trade-offs at a local level may be needed.

Flexible thinking for ageing structures

Current legislation (OSPAR Decision 98/3), requires full removal of structures as the legal default – unless an exception has been granted. For decision makers to consider a range of decommissioning options, there will need to be a change in policy. By bringing together scientific experts and creating a consensus on the need for case-by-case decommissioning decisions, the Synthesis project is moving the dial forwards in support of more flexible and evidenced-based decommissioning outcomes.