The noisy ocean: Humans have made the world's seas a very loud place to live

The ocean has become a very noisy place.

The world's seas are much louder than they were in pre-industrial times, "becoming more and more a raucous cacophony as the noise from human activity has grown louder and more prevalent," according to a study published Thursday.

The noise has had an impact on marine animals worldwide, affecting their behavior, physiology and, in some cases, their overall survivability. Higher ocean noise levels can reduce the ability of animals to communicate with potential mates, other group members, their offspring or their feeding partners, the National Oceanic and Atmospheric Administration said.

“Sounds travel very far underwater. For fish, sound is probably a better way to sense their environment than light,” said Francis Juanes, an ecologist at the University of Victoria in Canada and a co-author of the paper.

Noise can also reduce an ocean animal's ability to hear environmental cues that are vital for survival, including those key to avoiding predators, finding food and navigating to preferred habitats, NOAA said.

The researchers sifted through thousands of data sets and research articles documenting changes in noise volume and frequency to assemble a comprehensive picture of how the ocean soundscape is changing – and how marine life is affected.

From the songs of whales to grinding arctic sea ice, the world's oceans' natural chorus is performed by a vast ensemble of geological and biological sounds, according to the study, which was led by Carlos Duarte, a marine ecologist at the Red Sea Research Center in Saudi Arabia.

For example, snapping shrimp make a sound resembling popping corn that stuns their prey. Humpback whale songs can resemble a violinist’s melodies.

But for more than a century, sounds from human activities on the high seas, such as fishing, shipping, recreational boating and development, have increasingly added to the mix, making modern oceans far noisier than ever before.

“For many marine species, their attempts to communicate are being masked by sounds that humans have introduced,” Duarte said.

That noise can travel long distances underwater, leading to increases and changes in ocean noise levels in many coastal and offshore habitats.

"This onslaught of noise, which far exceeds the Navy’s own safety limits for humans, can have a devastating effect on marine species – especially whales, who use their keen sense of hearing for almost everything they do," the Center for Biological Diversity said.

A humpback whale and her calf.
A humpback whale and her calf.

The study maps out how underwater noise affects countless groups of marine life, including zooplankton and jellyfish, according to The New York Times. “The extent of the problem of noise pollution has only recently dawned on us,” study co-author Christine Erbe, director of the Center for Marine Science and Technology at Curtin University in Perth, Australia, told The Times.

Surprisingly, it’s not just noises added – human activities have also made some areas of the ocean quieter, the study found. For example, the deterioration of habitats such as coral reefs and the hunting of large marine mammals, including highly vocal whales, has led to drastic declines in the abundance of sound-producing animals.

In addition, the loss of sea ice because of the planet's rapidly warming climate has drastically altered the natural acoustics of arctic marine environments.

“When people think of threats facing the ocean, we often think of climate change, plastics and overfishing. But noise pollution is another essential thing we need to be monitoring,” said Neil Hammerschlag, a University of Miami marine ecologist, who was not involved with the paper.

There is hope, however: The study authors argue that the harmful effects of noise pollution could rapidly decline through the mitigation and regulation of sources of marine noise.

“Changing ocean soundscapes have become the neglected ‘elephant in the room’ of global ocean change,” the study authors write. “In an era when societies increasingly look to the ‘blue economy’ as a source of resources and wealth, it is essential that ocean soundscapes be responsibly managed to ensure the sustainable use of the ocean.”

The study was published Thursday in the peer-reviewed journal Science, a publication of the American Association for the Advancement of Science.

Contributing: The Associated Press

This article originally appeared on USA TODAY: Ocean noise: Humans have made seas a very loud place to live