Abstract
A key uncertainty associated with the marine renewable energy industry is the potential for negative effects of underwater noise due to installation activities and operation of marine energy converter systems (MECS) on sensitive marine species. Of particular concern is the potential for negative effect or impact on species such as marine mammals and fish that utilise underwater sound as part of their survival strategy. Techniques and equipment are being developed for the measurement of underwater noise in the harsh marine conditions typically found at marine energy sites in order to provide a detailed assessment of the acoustic environment to inform this uncertainty. However, there are currently no standard methods for measuring and reporting underwater noise, resulting in various and inconsistent methods being used, some of which are not informative to any useful extent.
The problem caused by this inconsistency and lack of robustness has been recognised by the acoustics and wider communities and there are various work-streams in progress to address this. This problem was also raised at the EMEC Monitoring Advisory Group (MAG) during the group’s routine review of the adequacy of a range of underwater acoustic monitoring studies that had been performed at the EMEC test sites. The group observed that there was a wide range of reporting approaches and assumptions, with a variety of parameters reported, and that each study was found to be lacking in some respect. This highlighted the need for consistency to be introduced during the initial discussion sessions between project developers and regulators, at which recommendations can be made by the Regulator. It was clear that there was a need for a ‘guide’ aimed at regulators, to enable them to make the appropriate level of detailed recommendation to project developers when discussing the scope of underwater acoustic monitoring to be undertaken.
Having identified this need, EMEC was able to gain funding from the Natural Environment Research Council (NERC) and in April 2013 facilitated an underwater acoustic workshop for marine renewables regulators and their advisors, with input from acoustics experts commissioned to deliver the training. The driver for the workshop was the recognition of the need for a greater appreciation amongst regulators of the key aspects of underwater acoustic data gathering. Specifically: what needs to be measured; how measurement should be undertaken; common pitfalls to avoid; and what to look for in an adequate data gathering and analysis report. The workshop provided an introduction to the basics of underwater acoustics, a review of underwater acoustic measuring systems and deployment methods, and an overview of propagation modelling techniques.
The workshop was attended by representatives from regulators throughout the UK and their statutory environmental advisors. This document provides a final report on the progress and outcomes of the project to the funder.