Offshore wind farms act as de facto marine reserves

Marine biodiversity faces increasing threats, necessitating effective conservation strategies beyond just marine protected areas. As offshore wind farms (OWFs) expand to meet the demand for renewable energy, these could offer an additional benefit by restricting fishing, one of the greatest threats to marine ecosystems globally. However, this remains untested at scale. Here we assessed the impact of OWF construction on fishing effort across 34 European OWFs from 2016 to 2022. Our findings reveal a significant reduction in overall fishing effort up to 2.5 km beyond OWF borders. Seiners and trawlers are most restricted (up to 4.2 km and 3.7 km respectively), while fixed gear and dredge fisheries showed no significant reduction. These results highlight the de facto exclusionary effect of OWFs on fishing, extending well beyond their boundaries. This restrictive effect could be strategically leveraged to support marine conservation efforts, particularly in areas where conventional fisheries management has been insufficient.