Offshore wind turbines create conditions for richer marine ecosystems

In addition to contributing to the energy transition, offshore wind power plants have a positive impact on marine life. A new study, conducted by researchers from Murdoch University in Australia and Dalian Ocean University in China, shows that offshore wind farms enhance marine ecosystems and contribute to greater diversity in aquatic food chains.

The massive steel towers of offshore wind turbines are new solid and rough surfaces on an otherwise sandy seabed and they function as artificial reefs. Together with submarine cables, they enable the formation of habitats for sessile organisms.

Sessile organisms, such as sponges, corals, sea anemones and shellfish, are permanently attached to a surface and cannot move independently. They feed by filtering particles from the water or by waiting for prey to pass by.

“These organisms act as critical food sources and habitat for other species, and this has flow-on effects for overall ecosystem diversity and health,” explained James Tweedley, one of the researchers.

Scientists from Murdoch University and Dalian Ocean University compared data collected in 2023 and 2024 at the Zhuanghe offshore wind farm in the northern Yellow Sea in China with data from a control area without wind turbines, located about six kilometers to the east.

Built between 2019 and 2021, it is the largest wind farm off the coast of northeastern China, at 1.35 GW. The researchers used the Ecopath with Ecosim software, into which they input biological and environmental data.

The results showed a greater number of functional groups and increased complexity of the marine food web in the wind farm area, particularly among macroinvertebrates and fish.

Fish in wind farm area are up to three times larger

According to the study, published in the journal Global Ecology and Conservation, more than 50% of the total biomass around wind turbine foundations consists of sessile organisms, such as blue mussels (Mytilus edulis) and other filter-feeding invertebrates.

“These benthic-dominated ecosystems are critical for nutrient cycling, diversifying food webs and even storing carbon,” said Neil Loneragan, one of Western Australia’s leading experts on fish and marine biology. According to him, these findings provide a foundation for understanding how offshore wind farms interact with ecosystem energy dynamics and fisheries resources in coastal waters.

Most fish groups exhibited significantly higher biomass in the wind farm area, particularly species that live and feed closer to the seabed. This finding is consistent with the results of other studies suggesting that offshore wind farms act as fish aggregation devices, the paper notes.

Estimates showed that the fish Hexagrammos otakii was up to twice as large in the wind farm area than outside it, while Sebastes schlegelii was more than three times larger, as was the predatory Asian rapa whelk.

While acknowledging the risks associated with exploration and construction, including habitat destruction and disturbance to birds, marine mammals, and fish, the authors pointed out that seabed disturbance can increase food availability as well.