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www.sea-technology.com March 2016 / st 25 H uman-generated underwater noise and its impact on the marine envi- ronment is a growing issue for scientists, regulators and industry. On the regulatory side, in the U.S., a group of experts from universities and environmental agencies have called for underwater noise stan- dards. In Europe, the Marine Strategy Framework Directive (MSFD) requires the monitoring of a set of indicators to assess underwater noise, such as type, duration and level. In Northern Europe, there is a strong focus on human noise versus specifc species interaction; for instance, the im- pact of pile driving on harbor porpoises, a protected marine mammal that is an icon of the North Sea. Leading the way in noise regulations, Germany, via its Federal Maritime and Hydrographic Agency, BSH, defned an underwater noise level threshold limi- tation of sound exposure level (SEL) at 160 dB at 750 m from the monopiles for offshore wind farm construction to mini- mize their impact on surrounding marine species. Necessity of Reliable, Real-Time Noise Info Offshore wind operators in the North Sea must now ensure they do not ex- ceed this threshold during installation of monopiles and, thus, demonstrate their ability to adapt and control their noise mitigation strategy. With a SEL limitation, a slight difference in measurement and calculation of un- derwater noise level can affect a regulation decision and paralyze construction operations. Moreover, in order to prove that companies meet this critical threshold requirement, governments are increas- ingly imposing shorter deadlines for the provision of reports on the underwater noise generated. For instance, licences for the installation of wind turbine foundations in Germany now typically require reporting of underwater noise levels to be submitted within 48 hr. of installation of each offshore wind turbine foundation. It is then crucial for an operator to solve a dual problem: to measure their noise emission level in the feld as accu- rately as possible, while also providing real-time feedback to regulators. This is why the RB-SDA14 rugged underwater noise monitoring buoy has been developed by RTsys. This buoy focuses on two key objectives. The frst objective was to pro- Underwater Noise- Monitoring Buoy Real-Time Monitoring for Wind Farm Construction By Luc Simon The RB-SDA14 noise-monitoring buoy deployed at the Gode Wind farm.