Methods used to calculate the potential impacts of offshore wind farms on seabird populations may be substantially overestimating likely effects, according to a report published by the Scottish Offshore Wind Energy Council. All offshore wind projects are required to carry out ornithological environmental impact assessments as part of the consenting process. These assessments examine how proposed developments could affect seabirds, including potential habitat loss, disturbance and collision risk. The results are used to determine whether projects should provide compensation, such as habitat improvements or measures to increase breeding seabird populations.
Guidance for these assessments is provided by the Scottish Government’s Marine Directorate and NatureScot, which recommend applying the precautionary principle when calculating potential impacts. This principle is intended to support decision-making where there is a risk of environmental harm but scientific evidence is uncertain.
The SOWEC report, Application of precaution in ornithology impact assessments for offshore wind project applications: Evaluation of current approaches, reviews how precaution is currently applied and identifies several issues. It finds that precaution is introduced at multiple stages of the assessment process, leading to compounded effects that can inflate predicted impacts beyond what is likely in reality. The report also notes that it is unclear to what extent impacts are being overestimated, raising concerns that some outcomes may not be biologically plausible or likely to occur.
According to the report, this approach may result in offshore wind projects being required to deliver higher levels of seabird compensation than are justified. In addition, current methods do not consider the probability of projected impacts actually occurring, meaning regulators may not be presented with a complete picture when making consenting decisions.
SOWEC recommends that precaution should be applied to the overall outputs of ornithological environmental impact assessments rather than to individual inputs. The report calls on NatureScot and the Scottish Government to consider these findings urgently and to move towards a more risk-based approach to offshore wind consenting.
The report was prepared by SLR Consulting on behalf of SOWEC, a partnership between the Scottish public sector and the offshore wind industry, and was published by Scottish Renewables, which co-chairs SOWEC.
