From studies into marine biology it is known that the behaviour of large sea mammals as well as fish can be influenced by background noise. Cavitation of ship propellers has been identified as a main source of this background noise. The EU requires Member States to demonstrate that levels of underwater noise do not harm marine life. It is believed that cavitation noise from shipping traffic is largely responsible for low frequency ambient noise. A need has therefore arisen for an improved understanding of the correlation between cavitation and background noise in the seas.
The aim of the SONIC project is to develop tools to investigate and mitigate the effects of underwater noise generated by shipping, both in terms of the footprint of an individual ship (a “noise footprint”) and of the spatial distribution of sound from a large number of ships contributing to the sound (a “noise map”).
The SONIC project will investigate underwater radiated noise from shipping as this represents a significant percentage of the source of background noise for sea mammals. The main focus will be on understanding and modelling cavitation related noise, but machinery noise will also be investigated. The project will investigate different techniques to model cavitation noise numerically and experimentally in dedicated facilities, and techniques to measure noise levels in the sea. Finally, a methodology will be developed to calculate the noise footprint of individual ships, and the noise map for a given sea.
SONIC will deliver the technical knowledge required for mapping, measuring and mitigating noise from shipping. The results of the SONIC project will contribute to quieting the oceans and improving the well-being of marine life.