Publications

Offshore wind energy production is a relatively sustainable yet fast-growing industry, contributing to the UN development goals on green energy and climate actions. Europe’s total offshore wind power capacity as of September 2023 is 32 GW ⁽¹⁾, only 20% of the European target to produce >150 GW by 2030.

The vast increase in offshore energy production urged different European countries to monitor the potential effects of offshore wind farms (OWFs) on the marine ecosystem, including the impact of underwater noise, the introduction of novel habitats, and the exclusion of fisheries. However, the potential risk of chemical emissions by OWF structures remains largely unknown though estimated to be small.

Offshore wind energy may offer many advantages: next to the aim of renewable energy production, offshore wind farms (OWFs) enable multi-purpose opportunities with nature conservation and aquaculture. OWFs may also affect the marine ecosystem. The environmental impact of OWFs is starting to be investigated regarding the effect of novel habitat introduction, underwater noise, electromagnetic fields, or exclusion of fisheries. However, the impact of chemical emissions from OWFs remains largely unknown. It is essential to account for these emissions at an early stage, to comprehensively assess the environmental impact with the objective of developing a future fit-for-purpose regulatory framework to protect the marine environment. This review compiled a literature-based list of potential OWF-related chemical emissions containing >200 organic and inorganic contaminants, including polymers. Compounds are categorised according to data source and emission type. Major gaps in assessing the impact of the compounds are identified, including challenges in environmental monitoring, numerical modelling and assessing the toxicity of individual and mixtures of chemical contaminants on marine organisms and humans consuming potential OWF aquaculture products. A risk-based prioritisation is essential to target the compounds of higher concern and overcome costs linked to assessing a wide variety of chemical contaminants. Although some countries have regulations to reduce OWF chemical emissions, standardized impact assessments or monitoring requirements for OWF-based chemical contaminants have not been established. This stresses the importance of providing more detailed information on occurrence, distribution and impact of OWF chemical emissions as an essential step towards sound ecosystem-based management of OWF installations.

Potentially hazardous particles from paints and functional coatings are an overlooked fraction of microplastic (MP) pollution since their accurate identification and quantification in environmental samples remains difficult. We have applied the most relevant techniques from the field of microplastic analysis for their suitability to chemically characterize anti-corrosion coatings containing a variety of polymer binders (LDIR, Raman and FTIR spectroscopy, Py-GC/MS) and inorganic additives (ICP-MS/MS). We present the basis of a possible toolbox to study the release and fate of coating particles in the (marine) environment. Our results indicate that, due to material properties, spectroscopic methods alone appear to be unsuitable for quantification of coating/paint particles and underestimate their environmental abundance. ICP-MS/MS and an optimized Py-GC/MS approach in combination with multivariate statistics enables a straightforward comparison of the multi-elemental and organic additive fingerprints of paint particles. The approach can improve the identification of unknown particles in environmental samples by an assignment to different typically used coating types. In future, this approach may

A vast number of artificial marine structures are currently installed offshore, and the rate of new installation is increasing. Especially offshore wind farms, a sub-type of artificial marine structures, are expected to grow significantly due to ambitious installation targets from international decision-makers. With increasing numbers of installed artificial marine structures, an assessment of possible adverse effects is more important than ever. To improve the environmental friendliness of artificial marine structures, an in-depth assessment of the transport and environmental fate of particle emissions is needed. The present work provides an overview of the involved processes of particle transport in the marine environment using the example of an offshore wind turbine. In this work, a first estimation on emission quantities is given for particulate emissions from marine structures, from which it is evident that emissions will increase in the next years due to an increasing number of marine structures.

Offshore wind farms (OWFs) play a key role in combating climate change, but the coatings used to protect submerged infrastructure can leach potentially harmful chemicals into the marine environment. These leachates may affect marine species colonizing OWF structures or being cultured near OWFs, such as blue mussels. To assess the impacts, we monitored valve gape behaviour and heart rate in Mytilus edulis exposed to coating leachates under controlled conditions, followed by a thermal ramping to assess potential constraints in their stress performance. Using non-targeted screening with two-dimensional gas chromatography and high-resolution mass spectrometry, we identified nine chemicals in the leachates plausibly assigned to the coatings, including alcohols, ketones, lactones, bromobenzenes, dibromophenols, and polycyclic aromatic hydrocarbons. At constant temperatures, exposed mussels showed both up to 12 % reduced and up to 18 % increased daily cardiac arrest compared to control mussels. However, during cardiac activity heart rate and valve gape were similar among treatments. Leachate exposure did not lead to reductions in fitness endpoints during the thermal ramping, i.e. the temperature at which heart rate was maximal (21.3 ± 0.4 °C) and valves started to close (19.2 ± 0.6 °C). Non-targeted screening does not allow for comparisons of chemical concentrations from field samples, yet the painted surface to volume of seawater ratio used here potentially led to much higher leachate concentrations than any environmentally relevant conditions. Future research on leachates from other OWF sources, such as sacrificial anodes, is needed to gain a comprehensive understanding of ecological risks and support sustainable OWF development.