Acoustic sensors provide a wealth of information about marine processes that are either too far or too complex for direct observation. In the 1980s, sonars could map areas the size of a football pitch. Now, we can map objects the size of a football, following them and mapping their surroundings. The oceans are very noisy, but we can now distinguish the different sources of sound and understand what they tell us about the environment and human activities. Going from shelf to shore and drawing heavily on field results, these concepts will be illustrated with different examples of marine habitats around the world, the monitoring of conventional and renewable energy activities, and the effects of climate change in the Arctic. Often designed and tested in our laboratory facilities, these new techniques are used with many collaborators around the world, amongst which NOC and Aberdeen (FLOWBEC subsea platform, for de-risking of marine renewables) and different Arctic research facilities.
