New Approach to Noise Surveys at Sea
09/09/2004
A new subsea acoustic information system, called ISAAC, has been launched by BMT Cordah Ltd, to help assess the impact of underwater noise on marine species. ISAAC is the culmination of a two year research and development project and has been designed to be intuitive to use by both non-experts and specialists. Underwater noise can originate from many different offshore operations, including oil and gas exploration, pipeline laying, dredging, ocean surveying equipment and wind farms. Recent evidence suggests noise can adversely affect marine mammal populations by disrupting normal feeding and breeding behaviour and causing physiological damage.
ISAAC uses a Gaussian ray tracing approach to determine the way acoustic ray paths travel between source and target position including those reflected from the sea surface and sea bed. The ray paths may refract with changes in water density, salinity, temperature and sea bed type. Users of the system are able to determine the spatial extent of noise propagation and whether noise generated from subsea activities exceeds sensitivity levels for various species such as whales and dolphins.
The new tool is also compatible with existing BMT software systems under the Visual Marine Information System framework which is used for pollution control and search and rescue applications.
