February 10, 2021

Over the last century, the orchestra of the ocean has drastically changed. What was once a perfectly composed symphony of whistling wildlife and calming waves, is now an ear-piercing rock concert. In our most recent exposé, we saw how anthropogenic noises have considerably altered the Arctic environment. There, unwanted sounds are threatening the lives of many marine species, especially beluga whales, but the damage from noise pollution goes even further than that. A new study has found that other marine soundscapes have not fared any better in the face of relentless anthropogenic noise. Compiling data from over 10,000 scientific papers, researchers closely examined the repercussions of noise pollution in marine environments. Humans are most certainly drowning out ocean wildlife. The noise is deafening.

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That noise is coming from a vast mix of human activities. The study estimates that shipping on its own has led to a 32-fold increase in noise levels over the last fifty years. Coastal construction, drilling, and mining are also major contributors. In the North Sea, marine noise pollution is literally explosive. Bombs from World War II are still being detonated there seventy years later. It is a similar story in both Southeast Asia and coastal Africa where dynamite fishing remains popular. The blasts are quite disruptive for any life forms. And let’s not forget about sonar radar and seismic surveys. Human introduced noises to marine ecosystems are just about never-ending.

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All this culminates into a struggle for marine wildlife to interact with their environment. The study found that in the presence of noise pollution, animal behaviors change dramatically. Marine animals typically flee noisy areas. In the process though, they leave food and breeding opportunities behind. Communication between animals of the same species also becomes more difficult. As does avoiding predators. Time magazine’s Aryn Baker describes the situation best. “It’s so loud down there that fish can’t even hear themselves think, let alone get a meal, find a date or dodge the dinner plate,” she explains.

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There is some good news. Surprisingly, noise pollution is readily fixed. Once the noise is eliminated, so too are the behavioral changes. Evidence of this notion was made clear during COVID-19 lockdowns. During that time, researchers saw a reduction in ocean sounds by 20%. The slight decline in noise was enough to bring various marine animals the closest to shore they had been seen in years. In our absence, nature thrived. With this knowledge, our next steps become clear. Policies should be put in place to regulate ship noise. As the researchers note, new technologies, such as noise-reducing propellers, could also help lower noise levels. Changing the ocean soundtrack back into a sweet symphony is possible but if we don’t, we may just silence ocean life for good.

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Humans Are Making Oceans Noisier, Harming Marine Life | Time by ARYN BAKER

The soundscape of the Anthropocene ocean | Science by CARLOS M. DUARTE ET AL.

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