A new peer-reviewed study, a collaboration between the Interreg North Sea project Anemoi and ICES expert groups on Marine Chemistry (MCWG) and Offshore Renewable Energy (WGORE), provides one of the first comprehensive overviews of chemical emissions linked to offshore wind farms (OWFs) and other marine renewable energy (MRE) devices. Part of ICES broader efforts to assess the environmental impacts of renewable ocean infrastructure, the review combines expertise in marine chemistry, toxicology, and ecosystem science to identify emerging risks, knowledge gaps, and a path toward more informed development.
The study compiles a literature-based inventory of over 200 organic and inorganic contaminants potentially associated with OWFs including polymers, corrosion inhibitors, biocides, and metals. These may be released from turbine components, cable sheathing, corrosion protection systems like coatings and sacrificial anodes, or anti-fouling treatments among others. Yet despite the rapid expansion of offshore energy projects in European waters, reliable data on chemical use, discharge rates, and environmental behaviour remain sparse.
Why is there a lack of reliable data?
"While other environmental impacts from OWFs such as underwater noise, magnetic fields, collision risks for seabirds, or the artificial reef effect have been described, the chemical emissions from OWFs have been largely disregarded", says Pablo Zapata Corella, one of the study's lead authors. According to Zapata Corella, "This is because they were considered to be low to negligible if compared with other sources of marine chemical pollution such as maritime traffic or oil platforms". He adds that the lack of OWF chemical pollution monitoring programmes and assessments is related to the recent development and application of OWF technology.
A footprint still in the shadows
Though early findings suggest that emissions during normal OWF operations may be relatively low compared to other marine pollution sources, the authors caution against complacency. As the scale of deployment grows, even small discharges can become ecologically significant. Current monitoring remains patchy, often limited to individual projects, making it difficult to assess cumulative impacts or make regional comparisons.
What we don't know
The review identifies several key research gaps. First, there's limited public data on the composition, volume, timing, and location of chemical use and discharge, which is critical information for exposure assessments. Second, standardized methods for analyzing and modelling how contaminants move and transform in marine environments are lacking. Third, ecotoxicological data is often incomplete or based on freshwater species, limiting relevance to marine ecosystems. And finally, the sector lacks the consistent environmental standards that are applied in other regulated industries.
Laying the groundwork for action
To address these challenges, Anemoi, MCWG, and WGORE propose a research agenda with priorities that include creating chemical use inventories with industry, developing standardized monitoring protocols, and conducting targeted toxicology studies. The authors also recommend integrating this knowledge into cumulative effects assessments that reflect local conditions, project scale, and ecosystem sensitivity.
The review concludes that addressing the chemical risks of offshore renewables will require stronger transparency, improved data, and a collaborative approach between scientists, industry, and regulators. As the sector accelerates, so too must the frameworks that ensure marine ecosystems are protected alongside climate goals.
“This is a great example of ICES expert groups within the Human Activities, Pressures, and Impacts Steering Group (HAPISG) bringing their expertise together and collaborating with and supporting ongoing research projects like Anemoi", says Daniel Wood, co-chair of WGORE.
“And it has led to the co-creation of an integrated publication that combines expertise on offshore wind operations and developments, legislation, marine chemistry, emission modelling and impact monitoring and can be used to build practical solutions to address the science evidence produced", says Claire Mason, co-chair of MCWG. They agree that the work has had immediate impact, helping to justify the need to establish an OSPAR sub-group on the chemical emissions from renewable energy devices.
Why it matters
With the expansion of offshore wind, tidal, and floating renewable installations, the need to move from assumptions to evidence is urgent. This joint effort by ICES expert groups and the Anemoi project highlights the importance of science-based assessments and international coordination. By shining a light on the chemical dimension of marine renewables, ICES continues to provide impartial, science-based information to manage human activities that affect our seas and oceans.
Read the full paper: Chemical emissions from offshore wind farms: From identification to challenges in impact assessment and regulation, in Marine Pollution Bulletin.
