Groundbreaking system to prevent collisions between whales and sea-craft
from Inventors and Remarkable People (103 articles)
The world’s first whale anti-collision systems (WACS) Photo: Rolex (Copyright)
Image Gallery ( 7 images )February 25, 2008 The unlucky passenger who died when a high-speed ferry rammed into a sperm whale in the Canary islands was the world’s first known victim of a new form of pollution – ocean noise.
Worldwide, the number of ships and pleasure craft that come into collision with large sea creatures is climbing inexorably – and the insurance bill with it – as numbers of both vessels and whales multiply and the sea-lanes become more crowded.
The cause of the accident, says marine biologist and Rolex Awards for Enterprise Laureate Michel André, most probably lay in damage to the whale’s sensitive hearing apparatus caused by the rising roar of man-made noise throughout the oceans. The whale was stone deaf – and simply didn’t hear the ferry coming in time to avoid it.
What no-one expected when conservationists forced an end to commercial whaling was that whale numbers would one day rebuild sufficiently to become a hazard to sea craft. But in places where marine traffic is heavy, vessels fast and whale numbers expanding, violent encounters are increasingly common. Where the ship is large the whale comes off second best, but in the case of cruisers, yachts and smaller vessels, damage can be mutually serious - even deadly.
We often speak of the “silent deep”, but the exact opposite is true. Sink a few metres into the ocean, and light begins to fade. At 40 metres you enter endless night, where eyes are of little use and hearing is all. Here, noise moves five times faster - and much farther - than on land. High frequency sounds decay rapidly but low frequency noise can travel right around the planet using a special “sound channel” in the oceans, centred about a kilometre down. The oceans are the true realm of sound.
Most sea creatures – from whales and dolphins to fish, squid and shrimps – respond to sound, and many produce it. They use it to hunt and to avoid the hunters, to find mates and food, to guide schools of fish, to navigate, to send messages and transmit warnings, to establish territories and warn off competitors, to stun prey and deceive predators, to “illuminate” their surroundings acoustically, to avoid obstacles and sense changes in water and conditions. They click bones and grind teeth. They use drum-tight bladders and special sonic organs to chirp, grunt, sing and boom. They belch gases and liquids. They vibrate special organs or their entire bodies. They gather to form great choirs. Sounds emitted by sea creatures span the range from 0.1 hertz to 300 kilohertz.
Far from the “silent deep”, the oceans are a raucous uproar.
Into this age-long tumult, in the blink of an evolutionary eye, has entered a new thunder: the throb of mighty engines and the thrash of propellers as 60,000 huge vessels plough the world’s sea lanes; the hammer of diesels and scream of outboards as 4 million fishing boats and more than 10 million ferries and pleasure craft surge to and fro; the thump and ping of military and fishing sonars; the deafening crash of seismic ships seeking oil and gas; the blare of acoustic harassment devices; the grinding of drills and dredges; the low-frequency growl of scientific experiments designed to monitor global warming.
Scientists report that background noise in the ocean has increased 15 decibels in the last half-century and 1000-fold since the industrial age began. This is enough, scientists say, to mask and scramble the normal sounds of ocean life going about its business.
