Abstract
Acceleration of the transition to renewables is supported by societal, political, and commercial interests.
This includes a massive increase in offshore wind capacity: the EU targets at least 60 GW by 2030 and
300 GW by 2050. Some effects of offshore wind farms (OWFs) are relatively well studied, particularly
noise effects and ecological impacts. However, generating an understanding of chemical emissions
released from offshore operations, for example corrosion protection, presents unique challenges. While
it is possible to estimate emissions from, for example, galvanic (Al-Zn-In) anodes, sources such as river
systems may obfuscate signals from OWF activities. Furthermore, environmental values for relevant
analytes such as technologically critical elements (TCEs) including rare earths, Ga, and In, are lacking. [1] The Anemoi project targets an understanding of chemical emissions from offshore wind in the North
Sea. While similar analyses have been undertaken in Germany as a part of the OffChEm project (2017 –
2022) and non-chemical impacts have been studied in Belgium, this is a novel dataset for Belgian OWFs.
Presented here are results of two years of data from 43 sampling locations in Belgium, including high-
and low-impact reference sites, which were chosen according to sediment composition, bathymetry,
and sediment transport modeling. Seawater samples were analyzed via seaFAST-ICP-MS/MS, with focus
on TCEs and elements considered tracers for offshore emissions. Relevant elements such as In (LOD
0.01 ng L-1, LOQ 0.03 ng L-1, measured < LOQ – 0.05 ng L-1) are presented from >30 total analytes. Initial
values from 2023 indicate lower levels of most trace- and heavy metals in Belgium than Germany. [2,3,4]
This dataset provides an opportunity to investigate chemical emissions from the target structures, plus
background values for TCEs and other infrequently studied elements. The low limits of detection and
wide range of analytes offered by this method allows a detailed analysis of the status of the study area.
Simultaneous sampling in Germany continues an established time series, contextualizing the new case
study. Results of this project are essential to build an understanding of short- and long-term impacts on
the marine environment. This knowledge and established timeseries can provide a baseline for
monitoring programs, assisting an effective and responsible transition to renewables.
References
[1] European Commission; 2020, COM(2020) 741 final.
[2] Bundesamt für Seeschifffahrt und Hydrographie and Helmholz-Zentrum Hereon; Chemical Emissions from
Offshore Wind Farms: Summary of the Project “OffChEm”, 2022, 01 – 15.
[3] V. Van Lancker, et al; Belgian Science Policy, 2007, D/2007/1191/49, 125.
[4] A. Reese, et al.; Chemosphere, 2020, Volume 257, 127 – 182
