Decommissioning Impacts on Offshore Marine Ecosystems

As offshore energy and infrastructure installations reach their end of operational life, the process of decommissioning has emerged as a critical environmental and ecological concern. Decommissioning encompasses decisions on whether to fully remove, partially remove or repurpose marine installations such as oil and gas platforms and offshore wind foundations. These choices bear directly on ecosystem structure, biodiversity and habitat connectivity. Decommissioned structures may function as artificial reefs, providing habitat complexity that can enhance local species richness, biomass and trophic interactions. Conversely, removal operations can disturb benthic communities, resuspend sediments and eliminate established biotic assemblages. The global scale of forthcoming decommissioning activities—driven by energy transitions and ageing infrastructure—underscores the urgency of synthesising ecological evidence to guide policy, balance ecosystem services and ensure sustainable outcomes for marine biodiversity.

Research from Nature Portfolio

Recent studies have employed meta-analysis and network modelling to clarify ecological outcomes of decommissioning options. A comprehensive meta-analysis of over five hundred effect sizes across artificial structures revealed that while marine installations often support diverse communities, there is limited proof that their conversion into reefs invariably yields net ecological benefits. Differences in habitat type, taxonomic groups and ecological metrics introduce marked variability, suggesting that a one-size-fits-all approach to reefing may misjudge regional context and species requirements. Earlier foundational work applied biophysical dispersal models and graph theory to demonstrate that networks of offshore installations can function as stepping stones, enhancing larval connectivity for protected species across national boundaries. These findings highlight both the potential conservation significance of retained structures and the need for site-specific evaluation of ecological networks before removal.

Decommissioning Impacts on Offshore Marine Ecosystems publication trend

The graph below shows the total number of articles in decommissioning impacts on offshore marine ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Decommissioning: The planned process of retiring offshore infrastructure, including options for removal, partial removal or conversion into other uses.

Marine artificial structure (MAS): Any human-made installation in the marine environment, such as oil and gas platforms, wind turbine foundations or subsea pipelines.

Artificial reef (AR): A submerged structure intentionally placed or retained to mimic natural reefs, providing habitat complexity and potential conservation or fishery benefits.

Novel ecosystem: An altered ecological community that arises and persists following significant human modification, exhibiting new species assemblages and functions.

References

1. A global meta-analysis of ecological effects from offshore marine artificial structures. Nature Sustainability (2024).
2. Challenges of evidence-informed offshore decommissioning: an environmental perspective. Trends in Ecology & Evolution (2023).
3. To what extent can decommissioning options for marine artificial structures move us toward environmental targets?. Journal of Environmental Management (2023).
4. Ocean sprawl facilitates dispersal and connectivity of protected species. Scientific Reports (2018).