“While the guidelines have been in place since 2014, their lack of uptake and overall failure to reduce underwater noise requires immediate attention. “Research from the Arctic Council has recently shown that Arctic underwater noise has significantly increased over the past few years,” Sarah Bobbe, Arctic program manager, at Ocean Conservancy, said. “The Arctic is a special case for underwater noise, as sound travels closer to the surface because of cold temperatures, and also travels much further,” Prior said. Propellers, hull form and on-board machinery were among the main causes of underwater noise. Propeller cavitation “Much, if not most, of the underwater noise is caused by propeller cavitation (the formation and implosion of water vapour cavities caused by the decrease and increase in pressure as water moves across a propeller blade – cavitation causes broadband noise and discrete peaks at harmonics of the blade passage frequency in the underwater noise spectrum).

Source: CBC News January 18, 2022 20:48 UTC