Researchers warn of the overlap between offshore wind farms and areas of high biodiversity 

A predictive model suggests that seabirds and marine mammals forage in the same areas where wind potential is most significant and that their populations may be at risk if wind farms are built there.

This is one of the key findings of a study published in the Journal of Environmental Management, the result of a collaboration among researchers from the Miguel Hernández University of Elche (UMH), the University of Murcia, the Complutense University of Madrid, and the University of Alicante.

The authors propose developing risk maps before the spatial planning of offshore wind farms to avoid harmful impacts on biodiversity.

Offshore wind energy is expanding rapidly worldwide as part of the response to the climate crisis. However, as highlighted in the study, including UMH ecologist Juan Manuel Pérez-García, understanding its potential ecological effects is essential to ensuring sustainable development.

Professor Pérez-García, who has previously researched the impact of onshore wind farms on bird populations, emphasizes that “from the planning stages through to operation, offshore wind turbines can affect wildlife in many ways.”

While some effects may be positive—such as the creation of de facto marine sanctuaries in areas where fishing is banned—negative effects are also evident, including collisions, underwater noise, and habitat disturbance.

One of the main challenges is anticipating whether high concentrations of marine wildlife will be present in areas selected for turbine installation. “We can’t monitor every animal in the sea, so we need to estimate where they’re likely to be using mathematical models,” Pérez-García explains.

To this end, the study proposes using the structure of marine food webs—from phytoplankton to top predators—to predict the foraging grounds of seabirds and marine mammals. Based on this approach, the authors created global risk maps by overlaying biodiversity hotspots with wind power density data, indicating where wind farms are most likely to be developed.

Their model revealed a “bottom-up” trophic control: the richness of seabird and marine mammal species depends on the biomass of lower trophic levels, such as phytoplankton, zooplankton, and fish.

“Interestingly, it’s not fish diversity that matters most, but biomass: having a large amount of available food is more important than having a variety of species,” says Pérez-García. Some species feed directly on plankton, while others rely on fish that consume these microscopic organisms. This pattern enables researchers to predict likely foraging zones.

The results show widespread overlap between feeding areas and regions with high wind potential, especially in the Northern Hemisphere. In contrast, the Southern Hemisphere shows less overlap. However, the authors caution that this may be due to data scarcity rather than a lower actual risk.

“These risk maps are a key tool to foresee potential conflicts between conservation and energy development,” Pérez-García stresses. “The goal isn’t to slow down the energy transition, but to make it compatible with biodiversity.”

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The study also highlights that many high-risk areas for marine fauna lie outside marine protected areas (MPAs), limiting their ability to buffer impacts. The authors recommend, therefore, expanding and strengthening MPAs, integrating ecological data into marine spatial planning, and establishing “exclusion zones” where biodiversity conservation takes precedence over energy development.

They say governments must be equipped with robust spatial planning tools grounded in up-to-date, independent scientific knowledge to achieve this. “We need to understand what species are doing, where they go, and where their resources are,” they insist.

In this context, tracking birds using GPS devices is seen as a critical tool. These trackers could help pinpoint high-risk crossing zones and assess behavior. For instance, some studies have found that certain birds avoid offshore wind farms. The next step will be to determine whether turbines disrupt feeding patterns—not just in seabirds but also in marine mammals.

More information: Jon Morant et al, Potential feeding sites for seabirds and marine mammals reveal large overlap with offshore wind energy development worldwide, Journal of Environmental Management (2024). DOI: 10.1016/j.jenvman.2024.123808