Abstract
This document is the first technical deliverable of the study carry out to address the topic "Underwater Noise guidance for Offshore Renewable Energy (ORE) developers", under the Marine Institute’s Research for Policy Awards 2023. The study has been split into two sections, both approached under the ORE perspective. The first addresses the monitoring and reporting of underwater acoustic noise, the subject of this document. The second section covers mitigation measures and thresholds for underwater noise and is presented in a separate deliverable.
The methodology used in the study was based on a desktop review of literature on the topic (grey and peer-reviewed), as well as of regulations (national, regional and international levels) applicable to the management of UAN in offshore developments. A review and analysis of best practices in jurisdictions other than Ireland, as well as consultation of relevant stakeholders, has also been undertaken.
Following a brief introduction to the subject of monitoring and reporting of underwater acoustic noise (UAN), and some definitions of terminology, the report first presents the context, referencing a scope already pre-defined, of UAN generated by human activities during the various stages of ORE developments (pre-construction, construction, operation and decommissioning). It followed from this review that the most impactful activity during these stages is pile-driving, that is, the installation of fixed infrastructure in the seabed through mechanical percussion (or vibration) at the surface by specialised vessels.