Peter Lennihan/AP

Ocean Noise Too Loud for Marine Mammals, Says Animal Welfare Group

September 16, 2008 01:03 PM
by Cara McDonough
A new report says noise levels can block the animals’ communication and disrupt feeding. Activists want humans to tone it down.

No Peace for Whales

In a new report, The International Fund for Animal Welfare (Ifaw) says that, in some regions, levels of ocean noise from ships and other sources are doubling every decade, and protective measures for the whales, dolphins and other marine mammals affected by the noise is falling.

“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 BBC quoted Robbie Marsland, U.K. director of Ifaw, as saying.

The issue is one that various animal welfare groups have addressed for years, and that has even made its way to high courts in the United States.

The problem is that animals like dolphins and various whales use both low and high frequency noises to communicate and locate their prey, and noise produced by ships’ engines and propellers, and by seismic air guns used in oil and gas exploration can interfere with that process, according to the group’s report, titled “Ocean Noise: Turn it down.”

Ocean noise exists all over the world. In a story on Ifaw’s recommendations, Australian newspaper The Age reports that the noise problem has grown there due to increasingly busy waterways surrounding the country. According to the country’s ports corporations’ figures, 9,000 ships docked at five eastern seaboard ports in 2006-07, including 3,500 in Melbourne and 2,600 in Sydney.

Ifaw’s recommendation that humans tone down the noise is already being taken seriously by some. Pressure from conservation groups has led to restrictions on the use of sonar by the U.S. Navy, and some oil and gas exploration companies now limit their use of seismic air guns.
But Ifaw says it’s not enough, and that in sensitive areas the noises should be completely prohibited. Such legislation may be difficult to enact, however, due to the fact that the high seas, where most of the noise is generated, are largely unregulated, according to the BBC.

Background: Past studies; ocean noise issue goes to Supreme Court

The Ifaw report is only the latest in a growing body of evidence that human noise from ships and other sources may disrupt the lives of marine mammals.

In June 2002, National Geographic reported that Christopher Clark, a bioacoustics researcher at Cornell University, had co-authored a study on the effects of noises from commercial sea vessels and military sonar on the communication of blue and fin whales.

His study found that the whales sing their songs at a frequency of about 20 hertz—slightly below the range of human hearing—and because “the human contribution to ocean noise is also dominated by the low frequency sounds produced by shipping vessels, oil and gas exploration, and military activities, researchers fear the cacophony may disrupt or drown out the ocean banter of marine animals and could possibly damage their hearing.”

The ocean noise issue has made its way to America’s highest court. The U.S. Supreme Court announced in June that it would examine the case of a federal judge who ruled that the U.S. Navy should alter its use of sonar to protect whales and dolphins off the California coast, reported the Christian Science Monitor.

The issue was whether the judge and a panel of the Ninth Circuit Court of Appeals, which upheld the judge’s ruling, “overstepped their authority by enforcing environmental regulations at the expense of national defense training in wartime.”

The case arose after a group of environmental and animal protection groups, led by the Natural Resources Defense Council, filed a lawsuit in March 2007 seeking to protect the marine mammals living off the California coast from the sonar used by the Navy to detect submarines.

The Supreme Court has not yet ruled on the case.

Related Topic: Saving the whales

There has been good and bad news regarding the plight of whales in recent months.

In August, the International Union for Conservation of Nature released a report that said that some large whales, including the humpback, minke and southern right whale are making a comeback after facing near extinction, due to curbs on whale hunting in the 1980s. All three whale types have increased in population and have been taken off lists of threatened species.

Other conservationists have a different take. FindingDulcinea reported in July that some groups say ending a 22-year-old whaling ban will allow for tighter monitoring of whales and could thus save some species from extinction. Researchers gathered at the 59th meeting of the International Whaling Commission in Santiago, Chile, however, could not agree on the issue, leaving it unanswered.

Other recent whale news is discouraging to those involved in the fight to save the animals. In Iceland, whale meat is showing up on restaurant menus again. Commercial whaling resumed in the country following a 20-year ban, including limited hunting of minke whales, one of the most numerous of whale species in the waters there. Those interested in trying whale meat are now able to sample items such as minke whale sashimi, but some Icelanders remain uncomfortable with the idea of hunting and eating whales.

Reference: International Fund for Animal Welfare


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