SLU and Vattenfall evaluate the impact of wind power on fish and biodiversity

Twenty years ago, the Swedish Board of Fisheries conducted pioneering surveys of fish for the construction of what is now Sweden's largest offshore wind farm; the Vattenfall Lillgrund in Öresund. The operational phase started in 2007 and during the following three years, researchers conducted extensive studies to follow up on the wind farm’s effects on fish.

Now it's time for follow-up and new field studies at Lillgrund – within the framework of the WIND4COCO project.

"We will revisit some of the studies of the previous monitoring programme to find out how the fish community in the area has developed over a longer period of time. This provides a unique opportunity to study the long-term effects of offshore wind farms”, says Lena Bergström, researcher at the Department of Aquatic Resources (SLU Aqua) and lead of the WIND4COCO project.

The previous test fishing showed that certain fish species aggregated in the vicinity of the wind turbines, reflecting a so-called reef effect. On the other hand, the total amount of fish in the wind farm area did not change, as the general temporal dynamics of fish inside the wind farm were the same as in two external reference areas.

"In order to obtain comparable results, we will use exactly the same methodology as in the previous control program. But we will also supplement with surveys using underwater video to get an even more detailed picture of the biodiversity”, says Lena Bergström.

The project will also investigate whether and how commercial fishing could coexist with offshore wind farms. Here, the researchers will test the use of selective fishing gear and evaluate the general potential for certain fishing inside offshore wind farms.

“With the ongoing expansion of offshore wind, it is important to explore how we can most efficiently make use of the available space offshore. The WIND4COCO project offers an excellent opportunity to investigate the coexistence between offshore wind and fisheries, by testing the potential of using selective fishing gear within the wind farm”, says Tim Wilms, Bioscience Expert at Vattenfall.

The results will be presented in workshops with stakeholders, to discuss coexistence issues, wind farm designs, and the design of future monitoring programmes.

The project is funded by a research grant from the Swedish Environmental Protection Agency and by Vattenfall, and runs from 2024 to 2027. Vattenfall is also contributing time and expertise to carry out the studies at Lillgrund wind farm.

The full name of the project is Wind Power in the Marine Ecosystem: Knowledge for Sustainable Development in Coexistence with Nature Conservation and Fisheries.

Contacts

Lena Bergström, researcher, Department of Aquatic Resources (SLU Aqua), SLU

Johan Senneroe, media relations, Vattenfall