The EU is tapping into the potential of offshore wind farms to grow seafood, including blue mussels, sugar kelp, oyster and sea lettuce (Ulva), as a promising new approach to tackle impending seafood shortage concerns due to overfishing.

The Multi-Use Offshore Platforms Demonstrators for Boosting Cost-effective and Eco-friendly Production (UNITED) project has received funding from the EU and has five pilots located in three European seas- Baltic Sea, North Sea and the Mediterranean Sea.

The project aims to utilize the same area originally designated for an offshore wind farm for other compatible activities, such as seaweed, mussel or oyster farming.

“Wild seafood stocks are decreasing due to environmental reasons and overfishing for decades. Sustainable offshore aquaculture can, therefore, help to lower the pressure on wild stocks while covering the increasing demand for seafood,” Dr. Eva Strothotte, lead for the UNITED German pilot, tells Food Ingredients First.

“Within the German pilots located in the North and Baltic Seas, we focus on globally occurring cosmopolitan low trophic species (mussels and macroalgae) that have already shown excellent suitability in aquaculture.”

She tells us that low trophic aquaculture species are preferred for offshore cultivation because they offer various benefits as they require the least care or input.

“Mussels, for instance, feed on the water column through filtration, while algae produce their energy through photosynthesis.”

Moreover, the offshore location’s unique environment means “year-round availability of wind” for the offshore wind farms and suitable water temperature for higher survival rates of blue mussels and high biomass growth rates.

“This comes as global aquaculture production is projected to increase by 132% compared to its current status by 2030,” she continues.

Multiple seafood species
The multi-use concept is adaptable to various seafood species depending on the location and the local regulation, highlights Dr. Annelies Declercq, professor at the University of Ghent in Belgium, who leads the UNITED Belgian offshore project.

“The integration of seaweed and oyster cultivation with wind farm structures demonstrates innovative space utilization, showcasing an efficient use of offshore space. This approach addresses spatial limitations in coastal areas and fosters sustainable development.”

Moreover, the offshore structures provide stability for both seaweed and oyster growth, fostering a “synergistic relationship” that can increase yield and enhance survival rates.

While the Belgian plant focuses on sugar kelp in seaweed cultivation and European flat oyster, he says there is potential for “cultivating mussels, clams and other finfish, offering a diverse range of high-quality seafood products based on market demand and site conditions.”

Meanwhile, the integrated approach allows manufacturers to optimize space and share vessel time, allowing for more efficient logistics and reduced operational costs.

Environmentally conscious seafood
Dr. Declercq notes that F&B manufacturers can derive significant economic and sustainability benefits from the integrated cultivation of seaweed and the European flat oyster.

“While we currently focus on one strain of oysters, specifically the endemic European flat oyster, there is ongoing research to ensure the preservation of genetic diversity within this species,” he explains. “Our investigation includes understanding the origin of the settled oysters observed on the substrates we introduced.”

“The integrated concept of seaweed and oyster cultivation plays a pivotal role in boosting aquaculture and driving seafood innovation on multiple fronts. This innovative approach encourages a paradigm shift toward more eco-friendly aquaculture practices.”

Dr. Declercq expects the project will contribute to the “ongoing evolution of sustainable aquaculture models,” shaping a more environmentally conscious future for seafood production.

Sustainable yield enhancement
A nclick="updateothersitehits('Articlepage','External','OtherSitelink','EU bolsters seafood innovation through offshore aquaculture','EU bolsters seafood innovation through offshore aquaculture','338803','https://www.nature.com/articles/s43247-023-01116-6', 'article','EU bolsters seafood innovation through offshore aquaculture');return no_reload();">study titled “Multi-use of offshore wind farms with low-trophic aquaculture can help achieve global sustainability goals” by the Aarhus University in Denmark found that allocating 10% of projected wind farm areas to blue mussel and sugar kelp aquaculture in the North Sea-Baltic Sea transition zone could yield 18 metric tons of fresh weight/hectare/year and increase current harvest 26 times.

Marie Maar, professor at the Department of Ecoscience at the university who worked on the study, tells Food Ingredients First: “Multi-use in confined offshore areas will allow other areas to be less impacted or designated as marine protected areas. Offshore wind farms with low trophic aquaculture such as bivalves and seaweed could provide sustainable energy, nutritious seafood and ecosystem services through nutrients and carbon capture and utilization.”

“In the EU OLAMUR and the Danish WIN@sea projects, we investigate the potential for growing blue mussels, oysters, sugar kelp and sea lettuce in the North Sea and Baltic Sea offshore wind farms. In the Baltic Sea, the low salinity will hamper most cultured species’ growth. We are testing how the different species perform and if some species could be adapted to the low salinity,” reveals Maar.

Maar says service boats that maintain the windmills should also inspect the aquaculture farms to avoid major crop biomass losses (Aarhus University).

WIN@sea is an Offshore Low Trophic Aquaculture in Multi-use Scenario Realization in North and Baltic Seas project funded by the EU.

However, Maar warns that offshore location makes the aquaculture units more exposed to waves, strong currents and storms with the risk of losing equipment and crop biomass, which can be tackled by service boats that maintain the windmills, also inspecting the aquaculture farm.

“This saves time and allows the aquaculture farmer to react fast and avoid major losses of the crop biomass.”

Meanwhile, Annette Bruhn, project manager at WIN@sea and senior researcher at the Department of Ecoscience at the university and co-author of the study states that the food production from low trophic aquaculture in marine multi-use areas can be used to feed both humans and animals and contribute to “relieving the pressure on land for future food production.”

The multi-use of ocean space has the potential to support the United Nations’ Sustainable Development Goals (SDGs), in particular SDG2 (zero hunger), SDG 12 (responsible production and consumption), SDG 13 (climate action), SDG 14 (life under water) and SDG 17 (partnership for the goals), underscores the study.