Offshore wind power and fisheries: Partners or adversaries?

by Thomas Jensen
Fishing vessel in front of wind park

User interests intensify competition for land at sea

This article was featured in Eurofish Magazine 5 2023.

Offshore wind power is one of the central pillars of EU climate policy, which, as stipulated in the Paris Climate Agreement, envisages a 55% reduction in greenhouse gases by 2030 compared to 1990. The expansion of offshore wind power, however, requires drastic changes in the use of sea space, which will further exacerbate conflicts among user groups that have been smouldering for some time now. Downturns threaten fishing in particular.

Europe’s climate protection goals are increasing the competition for space at sea where there is a struggle for every square meter in the North and Baltic Seas: traditional users such as fisheries have long been fighting with ship owners, raw material suppliers, the military and environmental and nature conservationists over the scarce sea space. Now offshore wind farm operators have been added to that list, who are asserting their interests with arguments for climate protection and the energy transition. They are supported by many EU politicians, because the European Union is striving to become climate-neutral by 2050. The ambitious goal of the European Green Deal envisages expanding offshore wind energy capacity from the current 12 GW to at least 60 GW in 2030 and up to 300 GW in 2050. More than three quarters of this wind energy is to be generated in the North Sea and Baltic Sea areas, which are particularly attractive for offshore wind fields due to stable wind conditions and shallow water. There are already 110 offshore wind farms with over 5,000 individual turbines in UK and EU waters. Too little, say politicians; too much, however, protest a number of other users who are supposed to accept more and more restrictions.
Although the offshore wind industry cannot complain about a lack of support and reports record expansions almost every year – in 2020, for example, a capacity increase of 7.1 GW was recorded – it too is increasingly reaching its limits. For “mega projects” with more than one GW of capacity, there is often a lack of space, because a regulatory framework that adequately takes into account the needs of all user groups has so far been lacking. If the EU targets for the ­expansion of offshore wind energy by 2050 are implemented one-to-one, the land requirement would increase by a factor of 15! This simple fact alone gives an idea of the enormous potential for conflict with other users, including fisheries, which have long complained about the lack of attention and help from politicians. Neither does it help much that the EU Commission, in the directive on maritime spatial planning (2014/89/EU), calls on all member states to take the interests of fisheries and ­aquaculture into account in addition to the development of the energy industry. Fishermen and aquaculture producers should have a say in where wind turbines are built, says Dutch MEP Peter van Dalen. New wind turbines should not be built until it is clear what impact they are likely to have on the economy, the environment and biodiversity. However, it remains questionable whether the legitimate demand can actually influence decisions. There is a significant concern that the approval procedures for wind farms, which already pose a major challenge for the expansion of the offshore wind industry, could further impede progress.

Traditional fishing rights are increasingly being curtailed

Space is getting tight in the North and Baltic Seas, even though both seas combined cover an area of a good 950,000 km2. In the medium term, however, almost 10% of this is reserved for wind farms and is therefore hardly accessible for other maritime activities. Fishing, in particular, is to be restricted, as fishing grounds are increasingly being lost as a result of massive offshore expansion. Because trawling is banned in wind fields, fishermen miss out on some of their traditional bottom fish and crustacean catches. In view of the record investments in the energy industry in Europe – 26.3 billion Euro were invested in offshore wind farms in 2020 alone – the losses suffered by fishermen are likely to be only a marginal matter for politicians, especially since the direct and indirect costs of the loss of fishing grounds cannot be precisely quantified. However, the displeasure of fishermen and other user groups is growing and can no longer be ignored. Attempts are being made to defuse the impending permanent conflict and to achieve a kind of “peaceful coexistence” between the interest groups through participatory maritime spatial planning. That should be difficult, as even conservationists are protesting fearing long-term damage to marine ecosystems, marine fauna and flora and migratory birds. They call for turning the tables and looking for areas for wind power expansion before new wind fields are decided upon. Certainly, offshore energy plays a crucial role in meeting our energy needs. However, it is vital to establish limits and ensure responsible development. The North and Baltic Seas are already full to the brim. After all, wind farms already take up several hundred square kilometres of sea surface and drastically change the appearance, not just visually. Marine ecosystems are indeed facing numerous challenges due to various human activities. Factors such as climate change, eutrophication, pollution, shipping, gravel and sand quarrying, as well as oil and natural gas extraction, have collectively placed significant stress on marine ecosystems.

Conservationists have concerns about the potential negative impact on marine biodiversity and endangered species due to the continued growth of offshore wind turbines, while fishermen frequently express worries about the potential harm to their economic well-being. Fishing is taboo or at least severely restricted in wind farms and within a radius of a few hundred meters in almost all EU member states. Even where fishing would theoretically be possible, fishermen often do without it. The risk of the boat ramming into a facility and damaging it or of the fishing gear getting caught and lost is far too great. Insurance premiums for vehicles that are allowed on wind farms are hardly affordable and without insurance cover the areas are effectively closed to fishermen. These restrictions mainly affect smaller fishermen who cannot switch to more distant fishing grounds or exchange fishing gear at short notice.

Both negative and ­positive effects

The installation, operation and maintenance of offshore wind turbines can all have harmful effects. This affects some fish species, marine mammals and benthic communities on the seabed, whilst above the water, sea and migratory birds may be disturbed during their migration season or sometimes even collide with the turbine rotors. During the construction phase, the noise from pile-driving the foundations and the resulting turbidity plume will without doubt drive marine animals from their traditional habitats temporarily. The increased noise level of the wind turbines is also expected to have a certain deterrent effect later on during operation. It cannot be ruled out with absolute certainty that important resting and many feeding areas will be lost. However, it is disputed whether such fears are actually justified. On the other hand, many scientific studies give the all-clear: the consequences of laying the foundations of wind turbines can only be verified in the short term and are comparatively minor.

The sediment turbulence during the construction phase drives flatfish such as plaice and sole out of the sediment only for a short time. They leave their hiding places in the ground and show increased swimming activity. Pelagic zone species such as mackerel and horse mackerel leave the areas but quickly return once the agitated sediment has settled. In the meantime, there are increasing reports that the marine fauna and flora benefit greatly from the scour heaps and the introduction of large stones to protect the plant foundations. The hard substrates act like small reefs on which algae and mussels settle, which then subsequently attracts other inhabitants, especially crabs and other crustaceans as well as small fish species from gobies to sea scorpions. Within the North Sea and Baltic Sea, which are typically characterized by sandy and soft sea beds, these hard substrate islands serve as “magnet points” that inexplicably attract sizeable fish species, including cod and pollock. This stands out in an otherwise relatively poorly structured marine environment. This effect can certainly be compared to the use of the controversial FAD (Fish Aggregation Device) in tuna fishing. These are clear indications that some fish species use the wind farms as retreats, perhaps even as a “nursery” for their offspring, which would also benefit life in the surrounding area. Experts refer to such relationships as the “transfer” or “spill over” effect.

Rock fills for ­foundations enliven the undersea environment


A study by the University of Ghent provides evidence that the plaice in the North Sea is one of the beneficiaries of wind energy. The flatfish find optimal feeding conditions near the artificial reefs, which has a positive effect on their development and growth. The study was able to show that they stayed in the vicinity of the turbines during the summer months and even preferred certain wind turbines. The population of edible crabs (Cancer pagurus) has also increased significantly around the rocky scour protection of the foundations and could be a worthwhile fishing resource if there were more demand. One of the essential prerequisites for this is, of course, that suitable concepts for fishing co-use of the offshore wind fields with passive fishing gear such as pots are developed. The joint use of these areas could be a first step towards defusing spatial conflicts. In Great Britain and also in Denmark, passive crab fishing with fishing baskets in the vicinity of wind farms is actually already permitted. Such possibilities are being examined in Germany, however until now, any fishing within the safety zones has been prohibited. Among other things, with the argument that the wind energy areas also serve to protect nature.

In fact, this cannot be completely dismissed. On the one hand, many experts assume that the construction of the wind farms will not cause any serious changes in the diversity and wealth of species in the North Sea or Baltic Sea. On the other hand, it cannot be denied that the wind farms are creating new ecosystems in the sea that have a positive effect on the biodiversity of the local underwater world. The placement of rock-fill around the wind turbines area actually creates an artificial reef, which serves as a valuable habitat for a wide variety of animals and plants. For many environmental organisations, however, this is far from enough. If they have their way, at least half of the North and Baltic Seas should be free of any economic use. They regard fishing and shipping as the main threats to the marine environment. Given the current tense spatial utilization situation, achieving this requirement appears to be quite unrealistic at present. However, the EU Commission’s offshore strategy also suggests increasing the proportion of marine nature protection areas to 30 percent in alignment with the EU biodiversity strategy. A third of this should be strictly protected, i.e. free from human influences. So far, this only applies to one percent of all the areas.

Implementing a co-use policy can contribute to the resolution of ongoing conflicts

These few examples highlight the challenging and complex nature of developing comprehensive and holistic space utilization concepts that successfully address both ecological and economic considerations. There is a great danger that legitimate interests of the supposedly smaller users, which unfortunately include fisheries, are not adequately taken into account. The need for co-use, which involves a meaningful integration of various usage requirements, is becoming increasingly evident as it becomes challenging to address the numerous issues associated with the division of sea space without it. The energy transition, climate protection, and nature conservation are important societal goals, but it’s equally valid to consider the needs of the fisheries. There is no reason why aquaculture, such as algae and mussel farming, or passive fishing for high-quality fish and crab species, couldn’t be compatible with wind farms. In fact, in the Netherlands, efforts are under way to reintroduce oysters on the foundations of wind turbines. Belgium has already initiated modest aquaculture experiments in its wind farms.

However, disagreements and stand-offs often arise in situations where there is no consensus. In France, for example, a wind farm project in the Brittany Bay of Saint-Brieuc faced opposition and was blocked due to local protests. The project lacked sufficient public discussion and there were concerns about the absence of an environmental impact study. Many projects fail due to the resistance of fishermen and coastal communities, whose power and influence in France should not be underestimated. Banc de Guérande, an 80-turbine field off Saint-Nazaire in the Bay of Biscay, went into operation in November 2022 as the first offshore wind farm in France. Similar challenges are faced in the United States, where establishing offshore wind farms is also not easy. In Maine, construction is even prohibited by law, primarily due to concerns raised by local fisheries and environmental factors. Except for the relatively small Block Island offshore wind farm, there are no other commercial-scale projects along the US coasts.

Floating wind farms ­provide a ­promising ­solution to these ­challenges

By anchoring turbines in areas with water depths exceeding 100 meters, located further offshore, new opportunities emerge. Previously, water depths of around 60 meters were considered the upper limit for fixed-foundation wind farms. The steep drop-off of the seabed near the coast limits the construction of new wind fields in many areas. Floating systems, on the other hand, offer the advantage of being deployed in deeper waters, where wind conditions are more consistent, and conflicts with other users are minimized. Potential suitable areas for floating wind farms include the west coast of Ireland, the Portuguese Atlantic coast, the Mediterranean, and California. While still considered a niche technology, floating offshore wind farms have gained significant interest from energy investors. There are 230 projects with a total planned capacity of 185 gigawatt around the world. Great Britain leads the way with 33 gigawatts (GW), followed by Sweden (21 GW) and Ireland (19 GW). The excellent performance of floating offshore wind farms further supports their viability and potential. Hywind Scotland, probably the world’s first floating field, achieved the best result of all wind farms in Great Britain for the third year in a row with an average utilization rate of 57.1 percent.

This convincing performance has also debunked the primary argument of the remaining sceptics, particularly their claim that the technology is still prohibitively expensive. This notion is crumbling as the current price development demonstrates the increasing cost-effectiveness of floating offshore wind farms. In addition, floating systems have the advantage that they can be assembled inexpensively on land and then towed to their anchorage. This approach also allows for the easy return of floating systems, such as during scheduled maintenance work.

Relocating offshore wind farms to more distant areas from the coast would result in a reduction of the offshore wind footprint. This shift could potentially benefit fisheries by freeing up traditional fishing areas that were previously occupied by wind farms. However, it remains questionable whether this will actually take place if the EU biodiversity strategy and nature conservation stand in the way of this action. Another aspect that raises uncertainties is whether the dismantling of wind turbines would also require the removal of the stone foundations. These foundations, which function as artificial reefs, have proven to have a positive and revitalizing impact on marine ecosystems. Experts acknowledge the planned dismantling of wind turbines despite the positive impact of the stone foundations, as offshore wind turbines typically have an estimated average service life of 25 to 30 years.

Manfred Klinkhardt

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