Due to both increased environmental concern and an increased reliance on energy imports, there has been a significant increase in investment in, and the use of, wind energy, including offshore wind farms, with twenty-nine developments built or proposed developments off the United Kingdom’s coastline alone. Despite the benefits of cleaner energy generation, since the earliest planning stages there have been concerns about the environmental impacts of wind farms, including fears for bird mortalities and noise affecting marine mammals. Many of these impacts have now been shown to have fewer detrimental effects that originally expected, and therefore the aim of this report is to try and determine whether another environmental concern – that of a loss of seabed due to turbine installation – is as significant as originally predicted.
Using details of the most commonly used turbine foundation, the monopile, and the methods of scour protection used around their bases – gravel, boulders and synthetic fronds – calculations for net changes in the areas and types of habitat were produced. It was found that gravel and boulder protection provide the maximum increase in habitat surface area (650m2 and 577m2 respectively), and although the use of synthetic fronds results in a loss of surface area of 12.5m2, it would be expected that the ecological usefulness and carrying capacity of the area would increase, therefore it would still be environmentally beneficial. Each of these methods would generate specific communities, and by increasing habitat heterogeneity within the area of the wind farm, could potentially improve biodiversity and abundances.
The study has shown that through careful planning and design at the earliest stages of development, it would be possible to further increase the role of offshore wind farm foundations as artificial reefs, with factors to consider, drawn from this report, including:
- Using all three main scour protection methods within a single development, to increase habitat diversity, including a range of hydrodynamic niches.
- Maximising surface area to allow greater levels of colonisation by benthic organisms, vital to begin the development of a food web.
- Incorporating specifically designed materials, such as reef balls, which have already been proven to aid colonisation, biodiversity and abundance.
- Matching dominant scour protection methods to existing local ecosystems and communities to provide support.