The ocean is not as quiet as one may think. It contains many natural sound sources: wind, waves and earthquakes; but also the sounds of many of its inhabitants: marine mammals, fish and invertebrates. As the human use of the oceans has increased so has new sound sources been added. These sources include ships, surveys for natural ressources, sonars and offshore construction works and because the noise can negatively affect the ecosystems in various ways, we must understand the nature of these effects in order to restore and maintain good environmental status in our seas.
At Aarhus University, within the Bioacoustics Research group, we have a long tradition for studies on how animals use sound to orient and communicate, but also how human-made noise affects the same animals. The Bioacoustics Research group is composed of people from Department of Ecoscience (under professor Jakob Tougaard) and people from Department of Biology (under professor Peter T. Madsen) and physically placed in the same builing on the main campus in Aarhus.
The project will study harbour porpoises in Bay of Aarhus with particular focus on how the human activities in the bay affects the distribution and behaviour of the porpoises. This will be done by deploying monitoring stations with passive acoustic listening devices that can detect and store the ultrasonic orientation sounds that porpoises emit almost continuously. These recording stations are able to detect porpoises day and night for extended periods of time (months), as long as the animals are within a few hundred meters of the recorder.