Can we solve our ocean noise problem?
The International Maritime Organization has also makes building quieter ships part of its missionand in 2014 described simple guidelines for engineers and makers to follow. That said, NGOs such as the World Wide Fund for Nature (WWF) noted that voluntary guidelines issued by the IMO have been largely ineffective in reducing anthropogenic ocean noiseand are asking for mandatory limitations. Natasha Brown, spokesperson for the IMO, said the IMO guidelines are currently being revised, offering Member States and NGOs the opportunity to submit proposals for further work and action on noise. submarine. “For mandatory measures, this should come from a proposal from a [IMO] State or Member States,” she adds.
Modernizing ships would also help reduce ocean noise. This tends to be more expensive than adjusting designs and parts for new ships, but it could be worth it if only the most problematic ships are targeted. One of Williams’ studies on the noise emanating from a fleet of 1,500 ships, 50% of the noise came from only 15% of the ships. So retrofitting these vessels with new noise reducing propellers would make a significant difference to the overall noise impact of the fleet.
Creating a financial incentive for private companies to build, buy and operate quieter ships could be another useful approach. Design tweaks already on the market, such as propellers that reduce cavitation, can also make ships more efficient and reduce carbon emissions, Williams says. For businesses looking to go greener, this added benefit may be what tips the balance.
Calming a noisy landscape
Although boat noise is the most common form of anthropogenic ocean noise, other sources also create problems.
The construction and operation of offshore wind farms is one of them. Many major structures at sea are built using pile driving, which can cause sudden bursts or pulses of loud underwater sound.
Louder or higher frequency sounds like these can cause more immediate damage to nearby marine life than more chronic, low-frequency sounds, says John Hildebrand, a professor of oceanography at the University of California. “At high intensities, noise may create physiological damage,” he says.
One way to reduce this noise is to create a bubble curtain around construction sites. It’s just what it sounds like, “a series of bubbles that almost form a wall and block out some of the sound from a source,” Bailey explains.
However, Chapuis notes that the operation of wind farms also produces “constant, low-frequency sound, which can represent a chronic source of noise, even if the levels are not so high”. Some researchers argue that this noise should be taken into account in the planning of the location of the wind turbinesas well as in environmental impact assessments of individual projects.
Aircraft can also produce significant underwater noise, especially when taking off and landing regularly at airports near bodies of water. Keeping runways away from areas with sensitive marine life could help stem the problem.