The expansion of offshore wind farm development has the potential to bring about great benefits. Not only will the increase in renewable energy generation help in the fight against climate change, but through the introduction of new habitats into the marine environment, turbines can also act as artificial reefs, potentially increasing both species and habitat diversity.
For true artificial reef design and installation, a number of key factors need to be considered, including geographical location, size, orientation, complexity, durability, type of material, surrounding substratum, proximity to natural habitats, depth and water conditions (Perkol-
Finkel and Benayahu, 2005). Only purposely-planned artificial reefs can satisfy the full range of requirements for a truly successful reef, encouraging full colonisation and succession sequences, and becoming a useful tool for conservation or restoration of existing habitats / stocks / communities; however, with a bit more planning at the early stages of development, it should be possible for the development of offshore wind energy to satisfy a number of these requirements, and thereby become at least partially successful at creating habitat around its tower and foundation.
To illustrate the importance of structures placed within the marine environment, when four small oil platforms were removed from Californian waters in 1996, over 2000 tons of marine life were removed from the platform legs, and disposed of in landfill sites onshore (California Artificial Reef Enhancement Programme's website). Therefore, it is important to consider the decommissioning of any offshore turbines even before they are installed. Although it may not be feasible from a navigational safety point of view to leave all foundation structures in place once the towers and nacelles have been removed, it may be possible to leave some foundations in place, for example as part of an MPA once the wind farm itself has been decommissioned and removed.
A key aspect of the habitat creation argument is to get the issue wider appreciation at a higher industry level. If the gains to both the ecology and economy of the surrounding marine environment are known and understood more widely by developers, regulators and other stakeholder groups, then they may be able to form part of early discussions and negotiations with regards to specific project design and construction methods. Survey and research results should be published with an eye as to how they can be further utilised and adapted, with greater emphasis on the broader range of conservation, commercial or recreational gains which could be achieved.
Economics is another major aspect in offshore wind farm generation, another reason why better understanding of all implications, positive and negative, is essential. As described previously, the potential additional cost required to take full advantage of the habitat-creation potential of offshore wind farms may prove too great to convince developers, mindful of costs and profits, to alter plans and designs for their projects, without absolute evidence as to the benefits. However, given the potential for enhancement of commercial stocks, or conservation of particular communities or species, perhaps there is the possibility for local councils, fisheries associations or nature conservation groups to become involved, 'sponsoring' the installation of targeted scour protection, given the benefits that could be expected.
In conclusion, there is a large body of evidence for the benefits of artificial reefs in the marine environment, both intentionally designed and placed, and otherwise. Studies have shown that the introduction of almost any structure into the oceans will result in the colonisation of that structure, and that in many cases, this brings about increased productivity, rather than simply aggregating life from adjacent areas.
This increased productivity has the potential to bring about further benefits from both conservation and commercial perspectives, depending on the area in which the turbines are being installed, and whether any commercial / sensitive species already exist locally. The use of targeted scour protection could increase the capacity to help particular species, for example, through the installation of boulder protection in an area with a strong local lobster fishery. Using specially-designed materials may increase this beneficial capacity even further.
However, as with all young industries, there is still a need for greater understanding of both the impacts and potential benefits of offshore wind farms, and how the habitat-creation potential around the turbines and other infrastructure can be fully taken advantage of. Therefore, the results of all post-construction surveys, such as those discussed briefly previously in this chapter, should be collated and reviewed in detail, to gain an understanding of how colonisation works on specific foundation types, in specific areas, taking into account the communities already in existence in the receiving environment. Incorporating further survey results as they become available will increase this understanding, and give a range of time-frames for the study.
With careful consideration and planning then, the installation of wind turbines into the marine environment has the capacity to help combat climate change, and bring about benefits for not only the communities which already exist in the area, but potentially, introduce new such communities, with their subsequent commercial and conservational benefits.
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