There are growing concerns that the large scale offshore wind farm construction activities expected over the coming decade might have negative effects on the North Sea harbour porpoise population.
Harbour porpoises have been found to respond to underwater noise generated by piling of wind farm foundations at large distances. While they have also been found to return once construction activity ceases, the significance of piling noise disturbance to the survival and reproduction of harbour porpoises is not understood. The result is considerable uncertainty for the industry and governments alike in the planning of offshore wind farms.
Recognising that improved knowledge on the impacts of piling noise will be critical to be able to expand offshore wind power in a cost-effective and timely manner in balance with a long-term viable North Sea harbour porpoise population, a group of five offshore wind developers led by Vattenfall joined forces to initiate and fund the international research program DEPONS.
The project has already yielded fundamental new insights into harbour porpoise responses to underwater piling noise as well as their small and large-scale general movement patterns. This information has been used for developing an agent-based model that can provide an evidence-based framework for the assessment of wind farm underwater noise impacts.
The target group for the outcome, which will all be made publicly available, is first of all regulators, advisors and other stakeholders involved in offshore wind farm development. The outcome will, however, be perfectly applicable for assessment of impacts of other human activities as well, and thereby contribute to an improved basis for the management and conservation of the North Sea harbour porpoise population.