How my TED talk on ocean noise collided with the pandemic
Exactly a year ago, I stood nervously on the TED stage in Edinburgh to deliver a talk about an under-appreciated form of marine pollution: noise.
Ocean noise is not as visible as plastics pollution, nor as talked about as ocean acidification. Most peoples’ everyday experience tells them that the ocean is a generally quiet place, and it is — above the waves. But pop your head under the water and you will hear a cacophony of fish gurgles, snapping shrimp, and the grind of far-off boats. I remember being in Hawaii once at the time of the humpback whale migration; after scanning the horizon fruitlessly for hours, not seeing a single sign of activity, I dove into the waves and was suddenly, surprisingly, surrounded by whale song.
People tend to think of noise pollution as simply an annoyance. But we can usually shelter ourselves from excessive noise, move away from it, and have respite at night — even still, noise pollution can have serious health impacts for humans. Marine life finds it harder to escape; they cannot cover their ears or go inside. Sound can travel for many, many kilometres underwater — depending on the volume and frequency it can go up to tens of thousands of kilometres. And there are a lot of noisy boats plying the seas.
As a science journalist, I stumbled into researchers who described themselves as “acoustic prospectors”, seeking out quiet patches of water to study and protect. When I wrote about it for Nature last year, I was astonished to learn that noise intensity under the waves roughly doubled every decade from 1950 to 2000. That’s thanks to increased shipping, along with seismic surveys used to hunt for oil and gas; the sonar from submarines; mining; the construction of things like wind farms; and more. The impact of noise on marine wildlife still isn’t perfectly understood, but it’s clear that it often isn’t good. Many marine animals have evolved to rely on sound the way that humans rely on sight; a noisy ocean can be like a befuddling fog that hinders them from finding food and mates.
In Edinburgh last July, I gave my talk, took a deep breath, and waited for it to be published on the TED website (they “trickle release” their talks a few at a time, so this can sometimes take months), hoping it would help to shift some perspectives and maybe even influence policies to help noise-battered wildlife. My talk was finally put online — on March 11, the day the World Health Organization declared the novel coronavirus outbreak a pandemic.
Back then, I found this timing rather unfortunate. “Who cares about whales right now?!?”, I thought. Too tied up with other concerns, I avoided tweeting my talk or spreading it on social media. There were bigger problems in the world.
Just a few months later, though, the two topics collided. Thanks to the pandemic, marine wildlife has been granted a small reprieve from mankind’s ocean noise. International shipping has slowed. Whale watching boats and cruise ships have been silenced by disuse. Many waters have been hushed.
For the scientists I talk to in my work as a journalist, the reprieve presents an amazing opportunity for a natural experiment. The same thing happened after the terrorist attacks of 9/11, when a decrease in shipping off the east coast of the United States presented an unprecedented drop in underwater noise. Researchers who were studying the feces samples of endangered right whales in that region noticed a decline in stress chemicals during that time; in the hush, the whales seem to relax.
The lead researcher from that 9/11 study tells me she isn’t currently doing any work on ocean noise. But many others are. The International Quiet Ocean Experiment (IQOE) — an umbrella group that helps to coordinate acoustic research in the ocean — is now helping to recruit researchers and listening stations to see how underwater noise is changing, and what impacts that might have. In their June newsletter the IQOE published a map of stations participating so far, with a call for more to join. They are working on creating a software package for everyone to use to analyze their hydrophone (underwater microphone) data, so that all the information is comparable in one big, global, cohesive whole.
So far, the IQOE tells me, only one study has so far been published analyzing how ocean noise has changed during the pandemic. This work was done off the coast of my hometown of Vancouver, where a population of endangered orca is facing particular problems from ocean noise. There are only 73 Southern Resident Killer Whales left. They already have a hard time finding enough salmon to eat; with noise pollution clogging up their echolocation, it’s even harder.
In January and February, as the novel coronavirus ravaged China and moved on to Europe, the port of Vancouver saw about a 13% reduction in shipping container activity; in the broad Vancouver area, the researchers found about a 22% reduction in traffic from ships that report their whereabouts. In the narrow channel between Vancouver Island and Vancouver, they found noise reductions of about 5.8 to 2.3 decibels. That might not sound like much, but decibels are on a logarithmic scale; an increase of 3dB corresponds to a doubling of noise. So the noise intensity offshore of Vancouver was reduced by more than half.
So far, the published data on ocean noise only goes up to March; the number crunching for the rest of the year hasn’t yet been published, so we’ll have to wait to see how quiet things got as shipping continued to be affected by the pandemic. But the waters greeting the Southern Resident Killer whales, which are just starting to swim back into the Georgia Strait for the season, will presumably be more peaceful this year. Researchers will hopefully be watching (pandemic allowing), using drones to film the whales from above to see whether they’re plump with food.
Changes to the soundscape are occurring on land too; people on social media have reported hearing more birdsong, perhaps because road traffic has been reduced. I reached out to several ornithologists, but none knew of any studies, yet, on how various national lockdowns might have affected birds and other sound-sensitive wildlife. Perhaps they too are enjoying the relative peace and quiet. Construction continues, of course, and there will always be cars on the road. But if there is a little less, the impacts may be felt. Birds have been shown to modify their songs in urban areas, for example — just as some whales alter their calls when the background noise goes up.
The good news is that ocean noise is not a so-called “wicked” problem made hard to solve by particularly sticky economics. There are straightforward ways to address underwater noise pollution, such as building quieter ships with better-designed engines or propellers — innovations that also tend to make them more fuel efficient, cheaper, and less polluting. It’s win-win-win. Plus, stop a source of noise and the effect is immediate, unlike with carbon dioxide emissions, the impacts of which persist for centuries after being spewed into the air.
What’s trickier, perhaps, is limiting companies from doing excessive seismic surveying, or asking companies ramming in drilling equipment or wind farm posts to quiet down when ocean life isn’t exactly filing excessive noise complaints. But there are some technologies and policies to help these things happen. Perhaps the pandemic will provide the studies, the media spotlight, and the incentive to push even more of them through.
