Noisy ships drown out ocean serenity
NOISE pollution is posing an increasing threat in oceans by deafening marine animals, forcing global shipping regulators to find ways to solve the problem.
Seismic surveys for oil and gas exploration and military sonar are already restricted because of the dangers of the high intensity sound bursts damaging the senses used by whales and other sea life to navigate the deep.
But the noise from tens of thousands of ships at sea is so common that it could interfere with critical life functions of marine animals, according to a US Government submission calling for action by the International Maritime Organisation.
Australian coastal waters are among those becoming increasingly busy. According to ports corporations' figures, 9000 individual ships called at five eastern seaboard ports in 2006-07, including 3500 in Melbourne and 2596 in Sydney.
The US wants the International Maritime Organisation to develop ways of making ships quieter and introduce changes to the way they operate to minimise noise.
The International Fund for Animal Welfare, which says proliferating noise is invisible but potentially deadly, said Australia needed to support these moves.
"Humanity is literally drowning out marine mammals," said Jorge Luis Basave, a fund campaigner in Sydney.
In a report released today, Ocean Noise: Turn It Down, the fund said gross tonnage of commercial vessels had quadrupled in less than 40 years to 605 million tonnes in 2003, with a similar increase in propulsion power.
Marine life such as whales and dolphins use sound in the ocean depths to find prey, communicate with mates and competitors, or judge water depth.
But studies are finding that shipping noise is increasingly interfering with their ability to hear.
A US Marine Mammal Commission report last year said shipping noise occurred in the frequency band baleen whales used to communicate.