2013, Xodus Group, Buchan Deep, Marine Noise Desk Study series https://portal.medin.org.uk/portal/start.php?tpc=015_65000966-7de6-47b5-86c0-8207e5b8b09f Noise is readily transmitted underwater and there is potential for sound emissions from construction and operation of Hywind to affect marine mammals and fish. By using a floating structure, the installation noise is much reduced by removing the need for driven piles. However, there are likely to be noise impacts due to operation of the turbines as well as other construction activities, such as cable installation and use of vessels. At long ranges the introduction of additional noise could potentially cause short-term behavioural changes, for example to the ability of cetaceans to communicate and to determine the presence of predators, food, underwater features and obstructions. At close ranges and with high noise source levels, permanent or temporary hearing damage might occur, while at very close range, gross physical trauma is possible. The report in this series provides a high level overview of the potential impacts due to underwater noise from Hywind on the surrounding environment. In particular, the report reviews the underwater noise measurements and analysis previously undertaken by Statoil on the Hywind I demonstrator installed offshore Norway, to assess operational noise from the turbines. The report also makes recommendations for the types of impacts identified should be addressed in the EIA in terms of marine noise. 20130716