The Scottish Government supports plans to develop a large number of offshore wind farms (OWF) in Scottish territorial waters and the exclusive economic zone. The installation of foundations for offshore wind turbines often involves pile driving operations using large hydraulic hammers which introduce significant noise into the marine environment. Piling noise has the potential to impact both marine mammals and fish.
The primary objectives of this study were to undertake a review of available underwater noise abatement systems (NAS) in relation to their applicability for pile-driving operations for OWF construction in Scottish waters. Parameters of interest were: efficacy in noise reduction and the resulting benefit to marine fauna, practicality of use, cost, and impact/influence on the construction schedule. A secondary objective was to consider the applicability of existing NAS to mitigate noise generated by controlled explosions of unexploded ordnance. The study was based on a review of peer-reviewed publications and relevant ‘grey’ literature, combined with a questionnaire-based survey followed up by interviews with system-suppliers and end-users of NAS.
This review reflects available information, together with the knowledge, experience and opinions of NAS-suppliers and NAS-users, and does not necessarily reflect those of the authors or of Scottish Natural Heritage. This is not a detailed evaluation of which system can or cannot be deployed in specific wind farm areas.