Reports Claim Oceans Are “˜Too Noisy’ For Whales
A new report warns that levels of noise in the world’s oceans are causing serious problems for whales, dolphins and other marine mammals.
Undersea noise blocks animals’ communication and disrupts feeding, according to the International Fund for Animal Welfare (Ifaw).
Some say naval sonar has been linked to the mass deaths of some cetaceans.
The level of ocean noise in some regions is doubling each decade and Ifaw says protective measures are failing.
"Humanity is literally drowning out marine mammals," said Robbie Marsland, UK director of Ifaw.
"While nobody knows the precise consequences for specific animals, unless the international community takes preventive measures we are likely to discover only too late the terrible damage we’re causing."
The International Union for the Conservation of Nature (IUCN) concluded that ocean noise posed a significant threat in its global assessment of cetacean species.
Though not completely understood, whales and dolphins use sound in ways that are clearly important to their survival.
Baleen whales, such as blue and humpback whales, produce low frequency calls that can travel thousands of kilometers through water. Dolphins and toothed whales generate higher frequency clicks used to locate prey.
Ifaw concluded that a range of frequencies generated by ships’ engines and propellers, and by seismic airguns used in oil and gas exploration, can interfere with both these groups of species.
Research shows that the effective range of blue whale calls are only about one-tenth of what they were before the era of engine-driven commercial shipping, according to the report titled: Ocean Noise: Turn it down.
High-energy military sonar systems have also driven the mass strandings and deaths of beaked whales.
Experts say the sonar is thought to disrupt the animals’ diving behavior so much that they suffer a condition rather like "the bends" which human divers can contract if they surface too quickly.
Pressure from conservation groups has led to restrictions on the use of sonar by the US Navy.
Companies involved in oil and gas exploration limit their use of seismic airguns in some places.
However, Ifaw argues these restrictions are not enough.
It says the use of high-energy sonar and seismic airguns should be completely prohibited in sensitive areas. National legislation, such as the UK’s Marine Bill, should comprehensively restrict the exposure of cetaceans to noise.
The UK branch of the Whale and Dolphin Conservation Society (WDCS) has sounded alarm bells recently over oil and gas exploration in the Moray Firth, home to a small population of bottlenose dolphins.
The Ifaw report is one of several raising concern about ocean noise and say the real issue is most of the activities causing the problem – commercial shipping, mineral extraction – are part and parcel of the modern, interconnected economy.
They say a further obstacle to legislation is that much of the noise is generated on the high seas, which are largely unregulated.
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