The haddock larva, a minuscule, transparent being, is a cornerstone of the marine ecosystem. As a vital food source and energy transfer link from plankton to larger fish, its role cannot be overstated. Yet, this creature is often a victim of human progress, highlighting a looming global challenge: is it possible to reconcile environmental protection with massive human undertakings?

That question is now in the spotlight in Belgium with the EU-supported project Princess Elisabeth Island, an offshore energy hub located in the Belgian North Sea. The colossal project aims to build the world’s first artificial energy island. It takes its funding from the EU’s post-Covid-19 Recovery and Resilience Facility, and the Belgian government sees it as a crucial component of the country’s accelerating energy transition.

Yet despite the environmental benefits of shifting to green energy, the project can also potentially disrupt marine ecosystems through noise pollution, habitat alteration, and the displacement of crucial species – like the haddock larva – whose survival and distribution are significantly impacted by the low-frequency noise produced by offshore wind turbines.

Offshore wind and the eco-industrial revolution

The European Union has set ambitious goals to dramatically increase renewable energy production by 2030. The revised Renewable Energy Directive mandates that at least 42.5 per cent of the EU’s energy consumption come from renewable sources, with an ultimate target of 45 per cent. To achieve this, there is a strong push for technologies like electric vehicles and green water transport. However, the cornerstone of this sustainable energy revolution is large-scale offshore wind farms, the Global Wind Energy Council (GWEC) states. According to GWEC, these massive structures will cover thousands of square kilometres of ocean, marking a historic industrialisation of marine environments.

Globally, the offshore wind industry is rapidly expanding, with countries like China and the US investing heavily in the sector. According to the International Renewable Energy Agency (IRENA), the industry’s capacity should grow by 7.2 terawatts to meet the 2030 target of 11 TW needed to achieve a fully decarbonised energy system by 2050. In this context, the G20 countries’ role – noted in the COP28 targets – is crucial. These nations are required to increase their green energy generation from less than 3 TW in 2022 to 9.4 TW by the end of the decade to combat climate change and, thus, limit global warming to 1.5 degrees Celsius.

This is also the Belgian government’s key argument for its firm stance on the development of Princess Elisabeth: that the energy hub is environmentally friendly and sustainable. During a visit to the Princess Elisabeth Island shipyard in Ritthem, the Netherlands, outgoing Belgian Premier Alexander De Croo and Federal Minister for Energy Tinne Van der Straetenpraised the project as a pillar of Belgium’s green transition. “The energy island flagship project for the Recovery Plan embodies three of its defining features: investment in infrastructure, deployment of innovative solutions and acceleration of the ecological transition.” The pair say that modern renewable energy frameworks like the island act as a blueprint and can go hand-in-hand with ecological preservation, “thereby setting the standard for many future projects in the North Sea, the centre of Europe’s ambitions for offshore wind power development.”

The North Sea is rapidly emerging as the epicentre of Europe’s energy transition. Its strategic location, coupled with favourable wind conditions, has positioned it as a prime location for large-scale offshore wind farms. For EU countries, the North Sea offers a unique opportunity to diversify energy sources, reduce reliance on fossil fuels, and accelerate the shift towards a low-carbon economy. As Common Futures – an energy transition consultancy – highlights, the region’s potential for offshore wind, green hydrogen production, and energy storage is immense. However, realising this potential requires a coordinated, international approach. That’s why the UK has also capitalised on the North Sea, leading the charge in offshore wind technology and deployment with the oil and gas industry through the North Sea Transition Deal. However, the UK has also granted hundreds of new licences for further exploration of North Sea oil and gas.

The North Sea is rapidly emerging as the epicentre of Europe’s energy transition.

An ambitious energy venture

The energy island aims to connect at least 3.5 GW of offshore wind energy to the onshore grid by 2026. It is being built using 23 massive concrete blocks, each weighing 22,000 tonnes, with a base made of 2.3 million cubic metres of local sand. The EU Commission also envisions this as a pioneering international power hub aimed at centralising offshore wind energy production, contributing to the bloc’s goal of reaching 300 GW of offshore wind capacity by 2050, and facilitating cross-border electricity trade, particularly with the UK and Denmark.

At the end of 2022, the Belgian government took a crucial step to kickstart the colossal undertaking: it greenlit investment for Elia Transmission Belgium, allowing the company to construct the foundations of the energy island. The aims of the initiative were clear: to contribute both to environmental sustainability and the digital transition. Elia Group says it will utilise eco-friendly materials and smart construction techniques to minimise waste creation and disturbance of the seabed. The company has also announced plans to employ data sensors and advanced analytics to monitor the health and performance of the wind energy produced on Elisabeth Island as well as its successful integration into the wider electricity grid.

Following the completion of the front-end engineering design (FEED) phase and environmental studies in October 2022, the consortium TM EDISON secured permits to build the five-hectare island connected to the mainland by underwater cables. The project is predicted to be completed in April 2026.

A delicate balancing act

Offshore renewable energy is a key pillar of Belgium’s sustainable development goals, and the Federal Planning Bureau’s 2021 report states that it can improve terrestrial aquatic ecosystems and reduce pollution in general. According to research, however, offshore wind farms can also lead to biodiversity loss, disturbances to marine mammals and birds, alterations in species composition, and changes in habitat structure.

Stefaan de Rynck, head of the European Commission’s Representation in Belgium, acknowledges these concerns and says that the EU is aware of them. De Rynck emphasises that national authorities have a legal obligation to carry out stringent environmental assessments prior to any offshore wind farm construction. He also underscores the importance of upholding these ecosystemic protection standards, especially the “do not significantly harm” principle.

As for economic harm, though, the issue is more complex. With limited space available in the North Sea, the fishing industry has expressed deep concern over the potential impact of the energy island on their activities. “The energy island further restricts fishing grounds, especially demersal and pelagic fisheries using towed gear,” says Rederscentrale, the Belgian fishing industry organisation. The trade association warns that lower catches – as a consequence of the entire Princess Elisabeth Zone being designated as a no-fishing area – will lead to “increased costs due to longer travel times” for fishers.

What the fishing industry omits, however, is how much the problem of overfishing is currently impacting the North Sea’s biodiversity. According to research by the European Environment Agency, fish exploitation “leads to the mortality of target and non-target species, disrupting predator-prey relationships and causing imbalances in the ecosystem.” If too many fish are caught, the balance of the ocean’s food chain ends up disrupted, with some animals losing out while others become too common. Moreover, the report says that “destructive fishing practices”, such as bottom trawling, “physically damage habitats, affecting both fish populations and benthic communities”.

Besides fishing, the North Sea marine ecosystem is suffering the harmful effects of oil and gas extraction on its biodiversity. A recent research report highlights how pollutants from these activities disrupt natural food webs and reduce species diversity. Scientists found that pollutants around oil platforms can be thousands of times higher than in the wider seabed, leading to a significant decline in top predators and specialists, with generalists taking over. In an article on the Natural History Museum website, Zelin Chen, the PhD student leading the research noted that the food web is “different and simpler close to the rig, with larger predators being more vulnerable to the changes than other species.”

Lastly, the environmental sustainability of the energy island itself is also in doubt. The EU Commission says the project is designed to respect the marine environment, incorporating several eco-friendly features – including “ledges on the island for vulnerable birds to nest and underwater structures” – to create a thriving artificial reef for marine life. However, the responsibility of carrying out environmental impact assessments falls on national authorities, not the EU. These evaluations, mandated by EU regulations such as the Environmental Impact Assessment Directive or the Habitats Directive, are crucial for ensuring that projects like Princess Elisabeth Island do not cause significant harm to the environment.

Energy gains vs. ecological strains

“The island itself will only have a limited impact,” the constructing Belgian firm Elia claims. The cumulative effects, discussed in the company’s Environmental Impact Report (EIR), highlight changes in “local morphology and bathymetry,” altering the shape and depth of the seabed in the local area. But that’s not all: additionally, the dredging process will cause “temporary disturbance” and “a moderate negative impact on turbidity”, i.e., increased water cloudiness along all potential alternative construction routes. Despite these risks, the Belgian government issued an environmental permit granting legal access to Elia for the construction and operation of the project on the condition of ensuring environmental protection and sustainability.  

According to the Belgian company, the entire Princess Elisabeth Zone was designated in the Marine Spatial Plan, an area considered suitable for offshore wind farm development. A strategic environmental impact assessment on the area in 2022 recommended implementing soft-start procedures and noise-mitigation technologies. The evaluation also states that, despite the potential harm to porpoises and other marine mammals caused by the noise from driving piles into the seabed for the wind turbines, the construction of the hub is “subject to an approved risk analysis, regulatory compliance and potential for future evaluation.” The company has, thus, committed to restoring the zone “to its original state” if it is deemed that the negative environmental impacts of the project outweigh its benefits.

Yet despite these reassurances, researchers remain doubtful. While the importance of offshore wind farms for a cleaner energy future is undeniable, it is equally essential to analyse the impact of low-frequency noise on marine life. These colossal structures generate a constant hum which can significantly alter underwater environments, potentially affecting the behaviour and distribution of species.

Wind farms come in various designs depending on the depth of the water: if in shallow coastal areas, their turbines are typically anchored to the seabed using monopiles or jacket foundations; if in deeper waters, they require floating platforms moored to the seabed. Regardless of the type of foundation, though, the process involves assembling massive turbine components and laying underwater cables to transmit electricity to onshore converter stations. In other words, it is noisy work.

According to research published by Alessandro Cresci, a postdoctoral research scientist at the Institute of Marine Research, “Atlantic cod larvae in the North Sea are drawn to the low-frequency noise produced by offshore wind farms.” This behaviour, Cresci suggests, “could be evolutionarily advantageous,” because it reminds them of their natural habitat with acoustics produced by both natural and artificial sources.” The latter, though, has “unintended consequences for their survival and distribution.” Through his research, Cresci has concluded that “the larvae’s swimming speeds and orientation towards the sound source could impact their dispersal trajectory, potentially modifying their spatial distribution, especially in areas near large-scale offshore wind facilities.”

The importance of offshore wind farms for a cleaner energy future is undeniable, but it is equally essential to analyse the impact of low-frequency noise on marine life.

According to another paper from Cresci, the constant, low-frequency operational noise of offshore wind turbines disrupts the “natural soundscape of the region,” potentially affecting marine community dynamics throughout the wind farm’s lifespan, and not just during the construction phase. While impacts vary between species and particularly vulnerable bottom-dwelling creatures – like lobsters and crabs – he says that “the noise issue is likely to worsen” as wind farms expand with larger turbines.

Steven Degraer from the Royal Belgian Institute of Natural Sciences/MARECO is another researcher advocating for a thorough analysis of the ecological impacts of the growing number of offshore wind farms in the southern North Sea. While Elia claims the construction of Elisabeth Island will be less noisy as it won’t involve pile-driving, Degraer suggests that wind turbine foundations can still disrupt nearby marine life. More specifically, while the “effect on hydrodynamics can have implications for fish populations,” these turbines can “impact macrobenthic communities,” which include bottom-dwelling organisms and certain species like blue mussels.

Finding the way forward

How then should the risks posed by offshore wind farms be averted?

The solution may lie in adopting an innovative approach dubbed Nature Inclusive Design (NID), which involves putting ecological principles at the heart of the design process through collaboration with experts in nature conservation and marine ecology.

A good example in this regard is the 4Sea Initiative, which also aims to address the environmental impact of energy hubs. The project mainly focuses on protecting marine flora and fauna by designing structures that minimise harm to birds, fish, mammals, and bats throughout the entire lifecycle of wind farms. The organisations involved in the project say that the initiative was born first and foremost to minimise noise pollution and electromagnetic radiation and to incorporate nature-friendly designs into wind farms. According to two participating NGOs, wind farm constructions should aim not only to preserve the natural habitat but also to enhance biodiversity in the area.”

The 4Sea Initiative also advocates for the preservation of restored habitats and natural values created during the initial construction of wind farms. To achieve such progress, a comprehensive understanding of the ecological complexities of marine environments is essential, along with the development of targeted conservation strategies. Thus, the initiative promotes an “open dialogue between environmental groups, marine scientists, and the offshore wind industry” to successfully carry out sustainable and green energy projects. In other words, the initiative aims to “find solutions that balance renewable energy production with environmental protection, biodiversity goals, and European directives.”

As Cresci also explains, such a multi-faceted approach involves carefully selecting wind farm locations, rigorously testing hypotheses, closely monitoring environmental impacts, utilising computer simulations, actively involving stakeholders, and conducting thorough risk assessments.

Meanwhile, it is also essential to consider other sources of renewable energy and the opportunities and challenges that they present. Scientists are exploring many promising alternatives, including wave power, advanced nuclear energy with newer reactor designs, and energy storage innovations such as long-lasting batteries and pumped-storage hydropower. However, an emerging frontrunner in the energy transition race is green hydrogen, generated through electrolysis using renewable energy sources.

The strategic production of green hydrogen – coupled with offshore wind – aligns with the European Union’s climate goals and fosters decarbonisation for hard-to-abate industries like steel and chemicals. According to one of the latest sector papers, the hydrogen output could have an “increased utilisation,” especially during periods of low electricity demand, as well as “higher energy storage potential,” leading to reduced curtailment of wind energy and allowing for better management of supply and demand. Moreover, green hydrogen could lead to increased capture prices for offshore wind energy, which means higher revenues from selling electricity when hydrogen production is factored in, making offshore wind projects more attractive financially.

That said, as with offshore wind farms, a cautious approach is a must given the potential negative impacts on marine ecosystems and local communities: another recent study on the North Sea says that the installation of hydrogen pipeline infrastructures, for instance, can include “potential disturbances to the seabed,” and it could “increase marine traffic, leading to higher risks of collisions between species.” Moreover, these projects may also “involve chemicals that could pose risks to marine life if spills or leaks occur.”

The North Sea is at the heart of Europe’s push towards renewable energy, and the Princess Elisabeth Island project is a flagship for this goal. While the promise of a clean energy future is exciting, it is essential to reconcile this vision with the preservation of the marine environment. As Degraer proclaims, we need to “internationalise cooperation across the wider North Sea region, where country boundaries have tended to hamper a regional approach.” Thus, ongoing monitoring, research, and open communication are essential to ensure that clean energy development and marine ecosystem health go hand-in-hand.

Only through this systematic and comprehensive process can we truly balance clean energy transition and development with the protection of marine ecosystems. Such a holistic approach is crucial to ensuring a sustainable future for both humans and marine life amidst the ongoing industrial revolution at our seas.