There is an accelerating shift away from oil and gas towards more renewable sources of energy. Many thousands of marine man-made structures (MMS) have been installed to service offshore hydrocarbon and renewable energy industries that provide energy for society. Thousands more structures are being installed to harness the power of the wind. For those MMS approaching the end of their operating life, urgent decisions are required to consider current decommissioning practices, and to support regulatory advice for those that may need to be decommissioned in the future. There are different requirements globally for decommissioning and consensus has not been reached on the optimal environmental outcomes. Aspirations for management systems that support sustainable activity while balancing long-term human and ecological needs, requires scientific consensus on the potential environmental consequences, both positive and negative, associated with the deployment and decommissioning of MMS in the marine environment. This will consider scales from individual MMS to regional seas and encompass ecosystems where MMS exist, from the continental shelves to the deep sea, and from the polar regions to the tropics.
Through a structured process the aim is to develop a view of the current scientific consensus based on the existing evidence base being established under INSITE I and II and other relevant global studies. We will produce a position paper setting out this consensus view on the environmental implications of deploying MMS at scale, leaving non-operational MMS in situ, or removing non-operational MMS. In order to develop and prioritize relevant science questions, we will identify relevant international policy commitments, their associated objectives and goals and the relevance of MMS to their achievement. The focus will be on ecosystem consequences, with a consensus built around the development, and prioritization, of relevant science questions. We will consider the societal consequences of ecosystem changes associated with different choices (including the trade-offs of choices), focusing on ecosystem services and societal goods and benefits. We will make recommendations based on the scientific consensus, and also determine where critical gaps exist in the evidence base.