Human activity in the North Sea is on the rise. Motorized cargo shipping, construction and operation of oil platforms and wind farms, military activities, fisheries, and the extraction of sand all lead to an increase in unnatural underwater noise levels. Potentially harmful impact of these anthropogenic sounds on marine animal life includes deterrence, disturbance, and interference of signals for communication or other relevant acoustic cues. In this project we will 1) assess and model the natural and anthropogenic noise distribution, 2) assess experimentally the effect of anthropogenic noise, from a variety of sources, on health and behaviour of fish, and 3) relate the anthropogenic noise distribution to the distribution and habitat use of marine mammals.