Just 2聽minutes ago, a sperm whale swam by about 4聽kilometres south of Cassis on the French Mediterranean coast. From my desk in London, I heard its clicks. Thanks to a new website, so can you.
The offers a live feed to 10 hydrophones sprinkled around European waters, and one in Canada. Several more are scheduled to come soon in Canada and in Asia.
The network鈥檚 primary aim is to record and archive long-term subsea noise so that researchers can study the effects of human activity on whales and dolphins.
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It is the brainchild of , a bioacoustician at the Technical University of Catalonia in Barcelona, Spain. He and his colleagues have spent the past 10 years placing hydrophones on the seabed, on existing research platforms that monitor earthquakes and tsunamis, for instance, or detect neutrino particles from space.
鈥淭hese observatories were already cabled to shore for geophysics and astrophysics data monitoring, so we took advantage of the existing network to install real-time acoustic data hubs on them,鈥� says Andr茅, who will demonstrate the system next month at in Rio de Janeiro, Brazil.
Name that song
鈥淭he system is powered from the shore, and streams audio data to a server where the signals are analysed and published directly on the internet,鈥� he says.
An algorithm developed by filters the different frequencies in the signal to identify specific sounds, including the songs of 26 species of whales and dolphins, and noise from human activities such as shipping, wind farms, oil and gas drilling, and seismic testing.
鈥淚t鈥檚 the first time we have been able to monitor acoustic events on a large temporal and spatial scale,鈥� says Andr茅. Until now, most experiments to monitor subsea noise have used temporary hydrophone installations and lasted only weeks.
Noise-shy sea life
With more hydrophones in the network the new system could reveal the effects of noise pollution on whales. Hydrophones can pick up sounds from baleen whales hundreds of kilometres away, so installations in different places could be used to triangulate an animal鈥檚 position and track its course. It should therefore be possible to determine if animals change course in response to bursts of noise, or alter their preferred routes because of new sources of noise like shipping routes or harbours.
鈥淭he data should help us understand whether long-term exposures, in areas with intense shipping, for instance, make animals move out of that area,鈥� says Roger Gentry, an adviser for the , set up in 2006 by the International Association of Oil and Gas Producers to investigate the effects of noise pollution on marine life.
鈥淎ndr茅 deserves a lot of credit for thinking in broad terms and using modern technology to make the oceans and marine mammals more familiar and accessible to us all.鈥�
Andr茅 says that it would be possible to place hydrophones on buoys around industrial offshore platforms and include these in the network. They could then provide real-time alerts when whales and dolphins pass nearby, so that noisy operations could be put on hold.
