Oysters and mussels at risk of offshore wind farm metals
Researchers from the University of Portsmouth have warned that, while crucial for the clean energy transition, offshore wind farms could cause “significant ecosystem, economic, and human health risks” if thorough assessment is not carried out.
The potential for metals such as zinc, aluminium, and indium – a metal important to the production of flatscreen televisions – to build up in marine life such as oysters, mussels, and seaweed should, scientists have warned, give pause for thought before the government’s aggressive development plans for offshore wind farms within vulnerable marine areas are pursued.
Researchers from the University of Portsmouth have warned that, while crucial for the clean energy transition, offshore wind farms could cause “significant ecosystem, economic, and human health risks” if thorough assessment is not carried out.
This is because, says the study, of the potentially harmful levels of metal materials from current wind turbine protection measures that could leach into the surrounding water; posing risks not only to ecosystems but to seafood safety and human health, too.
Working in collaboration with Plymouth Marine Laboratory which, last year, detailed plans to launch an extensive research project into the potential impact of offshore wind farms on the surrounding marine environments, the study has found that the equipment installed in these wind farms in fact release thousands of tonnes of metals – including aluminium, zinc, and indium – each year into the surrounding water.
With wind farms set to play a major role in reducing the world’s reliance on fossil fuels and therefore its carbon emissions, this leaching effect is anticipated to grow “dramatically”. The UK currently has 13 gigawatts of offshore wind power generating capacity. The government has a target of reaching 100 gigawatts by 2050.
Professor Gordon Watson from the University’s School of the Environment and Life Sciences, said: “Offshore wind farms are a vital part of our clean energy future, but at the moment, there is limited data on how these metals affect the environment near operational offshore wind farms, so it’s hard to assess the full risks.
“We are definitely not saying stop building offshore wind farms, we just need to monitor them appropriately – especially as they continue to expand. The plans to scale up are ambitious and come with challenges that must be addressed.”

The current method for protecting turbines from rusting is to use anti-corrosive coatings. These, however, release metals into the ocean over time. The study, published in Nature’s npj Ocean Sustainability, estimated annual inputs of metals from current European wind farms to be: 3,219 tonnes of aluminium; 1,148 tonnes of zinc; and 1.9 tonnes of indium.
For zinc, this already exceeds the sum of all known direct inputs and river discharges into the North Atlantic from key European countries.
Seaweed and shellfish farms operating in close proximity to offshore wind farms, like the world’s first co-located commercial scale seaweed farm in the North Sea, will – naturally – be the most at risk. These could see metals from turbines build up in these species, leading to concentrations that could exceed safe limits for human consumption.
“Under current government expansion plans, these inputs could increase 12-fold by 2050, which raises serious concerns about the potential accumulation of metals in marine species like oysters, mussels, and seaweed, which are also likely to be cultured near wind farms,” said Professor Watson.
“Our research highlights the importance of keeping a close eye on the chemicals released by offshore windfarms, so we can monitor and manage the environmental impact.”
Scientists behind the study are, therefore, now calling for more comprehensive monitoring of water and sediments around wind farms, using corrosion-protection measures with fewer environmental impacts, and strong monitoring guidelines for co-locating aquaculture with wind farms.
“There are solutions to address these issues, but we need to take steps now to mitigate risks,” said Professor Watson. “We hope this research will provide a roadmap for policymakers and the wind energy industry to tackle these challenges effectively, before they cause unnecessary harm.”

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