Researchers from Curtin University’s Centre for Marine Science and Technology (CMST) have completed a study mapping underwater sea noise levels along the coast of British Columbia.
The study used modelling tools developed at Curtin and mapped noise from thousands of ships over one year. It aimed to identify noise exposure levels in critical habitat for whales, dolphins, porpoises and other marine wildlife.
Dr Chrstine Erbe, Director of CMST and lead researcher for the project, said the research was innovative in that conventional models can only integrate a few sound sources at a time, while CMST’s novel approach could model a vast number of sources spread over large areas and for long durations. While only shipping results were used in the initial study, any other sources can be added.
“Very few people in the world have the sound-propagation modelling techniques that we have developed at Curtin,” Dr Erbe said. “Our techniques allow us to map underwater noise patterns on a large scale. We are able to gather significant amounts of data relatively quickly, and then generate a very accurate and comprehensive picture of acoustic levels and patterns.”
Dr Erbe said the study showed noise levels are high in the shipping routes leading into the ports of Vancouver, Seattle and Prince Rupert, exceeding limits of ‘good conservation status’ under the EU Marine Strategy Framework Directive.
However, it also showed many quiet ocean spaces still exist along the British Columbian coast, which could potentially serve as wildlife refuges.
“Human-generated noise from shipping and other sources is now a persistent feature of many marine environments,” Dr Erbe said. “It poses an increasing threat to marine mammals that use sound to navigate, hunt, avoid predators and find mates.
“Our results will assist the British Columbian government and conservation groups in the management of sensitive ecosystems and endangered species by incorporating the acoustic quality of habitats into their marine planning. The data can then help determine the effective spending of resources, and ensure compliance with the EU Marine Strategy Framework Directive.”
The CMST study provides a useful model that could be applied to other parts of the world, including areas in Australia where pristine environments co-exist with busy shipping lanes.
“The Great Barrier Reef is one such area where a fragile ecosystem is facing increased shipping volume due to resources development in Queensland,” Dr Erbe said. “Ningaloo Reef, listed as a World Heritage Area in 2011, could also potentially benefit from this type of modelling.”
“We have the tools now to model noise footprints of a large number of sources of various types over large areas and long durations. The next step is to apply what we know about noise impacts and to chart zones where different types of impacts – such as hearing impacts, masking of communication and behavioural disturbances – are likely to occur.”
This British Columbian research was funded by the World Wildlife Fund of Canada and has been published in the Journal of the Acoustical Society of America. It is available at http://asadl.org/jasa/resource/1/jasman/v132/i5/pEL423_s1