Rigs and farms, or are they reefs?

Large-scale development of offshore energy installations may result in some significant environmental threats but it can also bring important benefits, both to nature and to society. Careful management and monitoring are necessary to maximize those benefits and minimize the risks.

A European lobster residing under an offshore energy foundation.

Offshore renewable energy technology is being developed mostly in the European Union (EU) but is also being explored in the US, Japan, India and Eastern Africa. By 2030, the number of wind turbines in the EU is expected to be around 25,000, with wind farms covering up to 20,000 km² of the European continental shelf. At the same time, there are also 3.5 million offshore oil and gas rigs worldwide and over 4,500 of them around USA coastal waters.

The impacts of this large-scale offshore development on biodiversity are still uncertain. On the one hand, noise disturbance, electromagnetic fields and migration barriers have had some negative effects on fish, marine mammals, birds and seabed communities. But on the other hand, the installations create ‘no-take zones’ around them and their underwater parts can function as artificial reefs, which leads to a greater abundance of many species.

IUCN’s recent report Greening Blue Energy takes a closer look at these impacts. According to its findings, foundations of energy installations increase the variety of habitats and marine biodiversity by attracting many fish species, such as cod and flatfish. Offshore renewable energy farms can also increase the abundance of species such as sand eel, cod, whiting and sole while oil rigs increase the abundance of rockfishes and other species by providing artificial reefs. An example of those can be found off the Louisiana coast where artificial reefs represent 90% of the hard seabed surface.

Artificial reefs, like natural coral reefs, are extremely important not only for the environment but also for people, especially those living in developing countries. They protect coastlines from storm damage, reduce beach erosion and provide homes, breeding areas, nurseries and food for many economically-important marine species. They also form an important link in cycling nutrients from land to the ocean. Reefs and the species they support are an important source of protein and livelihood such as through fishing and tourism for many people.

Similar to natural coral reefs, foundations of offshore energy installations can benefit local ecosystems and societies in many ways. But special care must be taken to minimize the negative impacts associated with these installations such as oil spills and harming marine protected areas.

“Incorporating the development of offshore energy installations in integrated marine management decisions could reduce the overall negative effects of human activities in the area while proper, broad spatial planning, mainly during the construction and decommissioning phases of the development could maximize the benefits for biodiversity and local communities,” says Georgios Sarantakos of IUCN’s Global Marine Programme.

For more information, please contact:

Georgios Sarantakos, IUCN Global Marine Programme, e-mail: georgios.sarantakos@iucn.org


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