Ocean Noise Summary

Ocean Noise: Turn it down Executive Summary The world’s oceans have always been alive with sound, from the breaking of waves to the calls of marine animals. Yet today the oceans are noisier than ever before because of man-made ocean noise. This form of pollution has increased dramatically in recent decades, is set to increase yet further and poses a potentially major threat to marine animals worldwide. Beneath their upper reaches the oceans are totally dark. This means that most ocean creatures, from mammals to fish, rely almost completely on sound to communicate, navigate, find food, attract mates, detect predators and maintain group cohesion. This form of communication is highly effective in the oceans, where sound travels around five times faster than in air. Many species of toothed whale - including dolphins, porpoises, beaked whales, sperm whales and killer whales - use echolocation, while other marine animals such as seals, sea lions and walruses make other sounds. Marine mammal calls range widely in frequency from high-pitched 120-150 kilohertz (kHz) clicks to ultra low frequency 10-15 hertz (Hz) booms. They have evolved acute hearing to detect these calls in the vastness of the oceans: whales and dolphins devote three times more brain power to sound processing than any other mammals. Today, however, there is increasing evidence that these crucial calls are being masked and even drowned out by rapidly increasing man-made ocean noise. This poses serious questions about the continued ability of these animals to behave normally and survive. The cumulative effects of all the sources of ocean noise pollution may even pose threats to entire populations of some species.

Ocean noise pollution: the sources Commercial shipping is the single biggest contributor to ocean noise pollution, primarily via propeller noise. This background drone has risen with the numbers of ships under power: between 1965 and 2003 the world’s commercial fleet doubled in size. Today there are almost 100,000 merchant vessels of 100 gross tonnage (GT) and above. By 2025 the amount of cargo shipped internationally is forecast to at least double.

© IFAW

The two other major sources of ocean noise pollution are seismic airguns and sonar. Airguns are used extensively by the oil and gas industries. They bounce Noise from oil and gas exploration off Sakhalin Island sound off the sea floor in order to in Russia’s Far East is posing a major risk to the facilitate analysis of the Earth’s crust. critically endangered Western Pacific Gray whale. Repeated every few seconds for weeks or months at a time, they can generate a colossal 259 decibels (dB) at source. In one case seismic sounds propagated deep into the Atlantic were detectable more than 3,000 km from their sources. Sonar, meanwhile, is used by navies, fisheries and recreational vessels. Navies use Low Frequency Active (LFA) sonar and Mid-Frequency Active (MFA) sonar to detect and track submarines: they can generate 235 dB. Other ocean noise pollution sources include drilling, marine construction, off-shore oil and gas production and acoustic devices used to deter predatory animals.

Ocean Noise: Turn it down - Executive Summary

Ocean noise pollution: the effects

Stranded Cuvier’s beaked whales lie dead in Greece after a NATO naval exercise using sonar, May 1996

There is uncertainty over the precise effects of ocean noise pollution on marine wildlife. However, evidence of problems on a substantial scale has been growing since the phenomenon was first identified in the 1970s. There are three main areas of concern about the potential effects of ocean noise pollution:

© Pelagos Institute

• t hat it is disrupting those natural sounds on which marine species depend for survival; • that it may be causing behavioural changes that have been noted in marine mammals, including the abandonment of traditional habitat, alterations in diving patterns and changes in the types and timing of calls. It may also be interfering with feeding, breeding and calving; • that marine creatures are suffering physical injury (including hearing loss) with some even being killed by especially intense sounds, particularly high intensity naval sonar. In particular, there have been well-documented cases of fatal mass strandings of cetaceans following the use of military sonar in Greece, Madeira, Hawaii and coastal USA, the Virgin Islands, Spain, the Canary Islands and the Bahamas. The US Navy accepted that sonar used by its ships was the most likely cause for the beaching of 16 whales in the Bahamas in 2000. Ocean noise pollution in general is blamed for a reduction by nine-tenths in the distance over which blue whales can hear each other.

The case for urgent action The threat posed by ocean noise pollution has been recognised by many national and international bodies including the United Nations, whose Secretary-General described it in 2005 as one of five `current major threats to some populations of whales and other cetaceans’ and as one of 10 `main current and foreseeable impacts on marine biodiversity’. Many organisations have called for greater monitoring, research and multilateral action to help combat ocean noise pollution. In May 2008, following IFAW campaigning, the European Union adopted the Marine Strategy Framework Directive, the world’s first legal instrument to recognise man-made underwater noise as a form of pollution, requiring member states to `achieve the good environmental status of EU waters by 2020’. Meanwhile IFAW and other environmental organisations have taken specific joint actions to restrict US naval sonar use, winning two important court cases in the US in 2008. Additionally, in 2004 the Spanish government banned active naval sonar training within 50 nautical miles of the Canary Islands following a spate of whale strandings linked to sonar exercises, the first government action of its kind. The threat posed by ocean noise pollution is now so great, however, that IFAW believes more substantial and widespread action must be taken to reduce levels of background noise from man-made sources throughout the world’s oceans and to prevent the exposure of marine animals to harmful high intensity sounds like naval sonar. IFAW has proposed that ocean noise be tackled in the same way as other pollutants through a range of measures including raising awareness, voluntary measures such as industry codes of conduct and properly enforced regulations. IFAW has published more than a dozen international recommendations aimed variously at industry, governments, research institutions, international bodies, national authorities, enforcement agencies and all users of the oceans. These include calls for: • t he regulation of man-made ocean noise within all national and international legislation governing human activity at sea and the protection of marine life and ecosystems; • a ban on loud sound sources, including seismic airguns and sonar, in sensitive and protected areas designated for marine species vulnerable to ocean noise pollution; • noise reduction to be a key consideration from the design stage through to the operation of all types of vessels from jet skis to supertankers. IFAW believes that, while the exact consequences of ocean noise pollution on marine animals have yet to be quantified, unless the international community adopts such precautionary measures humanity is likely to discover only too late the damage it is causing.

For media enquiries contact IFAW’s Press Office on 0207 587 6700. For other queries or a copy of the report contact Andrew Howard at [email protected].

Ocean Noise: Turn it down - Executive Summary