Offshore Wind Farms in the North Sea: Hidden Consequences for Marine Ecosystems

Strategic Insights -

The expansion of renewable energy in the North Sea through the construction of offshore wind farms has led to an increase in artificial hard substrates in a predominantly soft-bottom marine area. Researchers at the Alfred Wegener Institute for Polar and Marine Research have investigated the impact of these wind farms on the underlying ecosystem functioning, revealing significant consequences for marine life. According to the study, offshore wind turbines constitute benthic secondary production hotspots, with 71% of fouling production on turbines being released into the surrounding sediment. This has led to a local production "halo" effect around turbines, affecting approximately 11% of the wind farm area.

Key Takeaways:

  • The expansion of offshore wind farms in the North Sea has resulted in an increase in artificial hard substrates, with significant consequences for the marine ecosystem.
  • Offshore wind turbines constitute benthic secondary production hotspots, with 71% of fouling production being released into the surrounding sediment.
  • The local production "halo" effect around turbines affects approximately 11% of the wind farm area, depending on the configuration of the wind farm.
  • The changes in benthic energy flow may lead to previously unknown changes at the ecosystem level, from plankton communities to apex predators.
  • The study found that secondary production of fouling communities on turbine foundations was on average 80 times higher than that of soft-substrate communities.
  • Annual release of organic carbon from fouling communities on turbines was estimated to be -221 ± 825 gC m y (SD).
  • Researchers used a large combined dataset to model the secondary production of fouling communities on turbine foundations and of soft-bottom fauna inside and outside offshore wind farms.

Statistics:

  • 71% of fouling production on turbines is released to the surrounding sediment.
  • Secondary production of fouling communities on turbine foundations was estimated to be 80 times higher than that of soft-substrate communities.
  • Annual release of organic carbon from fouling communities on turbines was estimated to be -221 ± 825 gC m y (SD).
  • The local production "halo" effect around turbines affects approximately 11% of the wind farm area.

Sources:

  • Offshore wind turbines constitute benthic secondary production hotspots on and around constructions. Journal of Environmental Management, 2025;393:126922.
  • Alfred Wegener Institute for Polar and Marine Research: Jenny Dannheim, Alfred Wegener Institute for Polar and Marine Research, PO Box 120161, Bremerhaven, 27515, Germany.