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  • This is the sound of orcas off the coast of Vancouver.

  • (Whale chirps and squeaks)

  • They make these fantastic sounds not just to communicate,

  • but also sometimes to echolocate,

  • to find their way around and to find food.

  • But that can be tricky sometimes,

  • because, well, here is the sound of a ship passing by,

  • recorded underwater.

  • (Screeching oscillating sound)

  • You know, when we think about marine pollution,

  • I think we usually think about plastics.

  • Maybe toxic chemicals,

  • or even ocean acidification from climate change.

  • As a science journalist who often writes about environmental issues,

  • those are the things that have passed my desk

  • over the past 10 years or so.

  • But as I recently realized

  • when I was writing a feature for the science journal "Nature,"

  • noise is another important kind of pollution.

  • One that often gets ignored.

  • You know, maybe you've heard of the dark-skies movement,

  • which aimed to raise awareness of the issue of light pollution

  • and create pockets of unilluminated night,

  • so that people and animals

  • could enjoy more natural cycles of light and dark, night and day.

  • Well, in much the same way,

  • there are people now raising awareness

  • of the issue of noise pollution

  • and trying to create pockets of quiet in the ocean,

  • so that marine life can enjoy a more natural soundscape.

  • This is important.

  • Noise isn't just an irritation.

  • It can cause chronic stress,

  • or even physical injury.

  • It can affect marine life's ability to find food and mates

  • and to listen out for predators and more.

  • Think of all the sounds we inject into the ocean.

  • Perhaps one of the most dramatic is the seismic surveys

  • used to look for oil and gas.

  • Air guns produce loud blasts,

  • sometimes every 10 to 15 seconds,

  • for months on end.

  • And they use the reflections of these sounds

  • to map the ground beneath.

  • It can sound like this.

  • (Explosion sounds)

  • Then, there's the sound of the actual drilling for oil and gas,

  • the construction of things like offshore wind farms,

  • sonar

  • and of course, the nearly constant drone from more than 50,000 ships

  • in the global merchant fleet.

  • Now the natural ocean itself isn't exactly quiet.

  • If you put your head under the water,

  • you can hear cracking ice, wind, rain,

  • singing whales, grunting fish,

  • even snapping shrimp.

  • Altogether, that can create a soundscape

  • of maybe 50 to 100 decibels,

  • depending on where and when you are.

  • But mankind's addition to that has been dramatic.

  • It's estimated that shipping has added three decibels of noise to the ocean

  • every 10 years in recent decades.

  • That might not sound like a lot,

  • but decibels are on a logarithmic scale,

  • like the Richter scale for earthquakes.

  • So a small number can actually represent a large change.

  • Three decibels means a doubling of noise intensity in the ocean.

  • A doubling.

  • And that's only an estimate,

  • because no one is actually keeping track of how noisy the ocean is

  • all around the world.

  • There is a body called the International Quiet Ocean Experiment,

  • and one of their missions

  • is to try and plug the hole in that data.

  • So for example, last year,

  • they managed to convince the Global Ocean Observation System

  • to start including noise

  • as one of their essential variables for monitoring,

  • alongside things like temperature and salinity.

  • We do know some things.

  • We know that sonar can be as loud, or nearly as loud,

  • as an underwater volcano.

  • A supertanker can be as loud as the call of a blue whale.

  • The noises we add to the ocean come in all different frequencies

  • and can travel great distances.

  • Seismic surveys off the East Coast of the United States

  • can be heard in the middle of the Atlantic.

  • In the 1960s, they did an experiment

  • where they set off a loud noise off the coast of Perth, Australia,

  • and they detected it as far away as Bermuda,

  • 20,000 kilometers away.

  • So what does all this sound like to marine life,

  • what do they hear?

  • It's kind of difficult to describe.

  • Sound travels further, faster in water than it does in air,

  • and it also packs a different punch.

  • So sound of the same pressure will have a different intensity

  • whether you measure it in the air or underwater.

  • Then there's the fact that whales don't have ears exactly like human ears.

  • Creatures like zooplankton

  • don't even have what you would consider to be ears.

  • So what does this mean,

  • what is the impact on all this marine life?

  • Perhaps the easiest thing for scientists to assess

  • is the effect of acute noise,

  • really loud sudden blasts

  • that might cause physical injury or hearing loss.

  • Beaked whales, for example, can go into panicked dives

  • when exposed to loud noises,

  • which may even give them a condition similar to the bends.

  • In the 1960s, after the introduction of more powerful sonar technologies,

  • the number of incidents of mass whale strandings of beaked whales

  • went up dramatically.

  • And it's not just marine mammals,

  • fish, if they stray too close to the source of a loud sound,

  • their fish bladders may actually explode.

  • The airgun blasts from seismic surveys

  • can mow down a swath of zooplankton,

  • the tiny creatures near the base of the food chain,

  • or can deform scallop larvae while they're developing.

  • Well, what about chronic noise,

  • the more pervasive issue of raising background noise

  • from things like shipping?

  • That can mask or drown out the natural soundscape.

  • Some whales have responded to this by literally changing their tune,

  • a little bit like people shouting to be heard in a noisy nightclub.

  • And some fish will spend more time patrolling their borders

  • and less time caring for their young,

  • as if they're on high alert.

  • Chronic noise can affect people too, of course.

  • Studies have shown that people living near busy airports

  • or really busy highways

  • may have elevated levels of cardiovascular disease.

  • And students living under busy flight paths

  • may do worse on some educational tests.

  • And even while I was researching this subject,

  • they were actually blasting out about three meters of solid granite

  • from the lot across from my home office

  • to make room for a new house,

  • and the constant jittering of the rock hammer

  • was driving me completely insane.

  • And whenever the workers stopped for a moment,

  • I could feel my shoulders relax.

  • This effect has been seen in whales, too.

  • After the terrorist attacks of 9/11,

  • international shipping largely ground to a halt for a little while

  • in the waters off the East Coast of the United States.

  • And in that lull,

  • researchers noticed that endangered right whales in that region

  • had fewer chemical markers of stress in their feces samples.

  • As one researcher I spoke to likes to say,

  • "We were stressed, but the whales weren't."

  • Now you have to remember,

  • we have evolved to be a visual species.

  • We really rely on our eyes.

  • But marine life relies on sound

  • the way that we rely on sight.

  • For them, a noisy ocean

  • may be as befuddling and even dangerous

  • as a dense fog is for us.

  • And maybe sometimes that just means being a little more stressed,

  • maybe sometimes it means spending a little less time with the kids.

  • Maybe some species can adapt.

  • But some researchers worry that for endangered species

  • already on the brink,

  • noise may be enough to push them over the edge.

  • So take, for example, the southern resident killer whales

  • that live in the waters off my hometown of Vancouver.

  • There are only 75, maybe 76, animals left

  • in this population.

  • And they're facing a lot of challenges.

  • There are chemical pollutants in these waters,

  • and they are running low on the salmon that they really rely on for food.

  • And then there's noise.

  • When researchers studied these and similar killer whales,

  • they found that they spend between 18 and 25 percent less time

  • feeding in the presence of loud boat noise.

  • And that's a lot for a species that's already struggling

  • to find enough food to thrive.

  • The good news, as I heard from all the researchers I spoke to,

  • is that you can do something relatively easily about ocean noise.

  • Unlike the wicked problems of climate change

  • and ocean acidification,

  • you can just dial down the knob on ocean noise

  • and see almost immediate impacts.

  • So for example, in 2017,

  • the Vancouver Fraser Port Authority

  • started asking ships to simply slow down

  • when going through the Haro Strait,

  • where the southern resident killer whales are feeding in late summer.

  • Slower ships are quieter ships.

  • And because it's Canada, you can just ask,

  • it can be voluntary.

  • (Laughter)

  • (Applause)

  • In that 2017 trial, most of the ships complied,

  • adding about half an hour to their travel time,

  • and reducing noise by about 1.2 decibels

  • or 24 percent of noise intensity.

  • This year, they decided to extend the length of time

  • and the area over which they're asking ships to slow down.

  • So hopefully that has a positive impact for these whales.

  • In 2017, the Vancouver Fraser Port Authority

  • also introduced discounts in docking fees

  • for ships that are physically designed to be quieter.

  • You know, weirdly, a lot of the noise from a ship like this

  • comes from the popping of tiny bubbles off the back of its propeller.

  • And you can simply design a ship to do less of that

  • and to be quieter.

  • The International Maritime Organization has published a huge list of ways

  • that boats can be made quieter.

  • And they also have a target

  • of reducing carbon dioxide emissions from global shipping

  • by 50 percent by 2050.

  • And the great news is that these two things go hand in hand.

  • On the whole, a more efficient ship is a quieter ship.

  • People have also invented quieter ways of hammering in the giant posts

  • needed for giant wind turbines, like this one,

  • and gentler ways of doing seismic surveys.

  • And there are some incentives for using quieter technologies.

  • The European Union, for example,

  • has a healthy marine system directive for 2020.

  • And one of the ways that they define a healthy marine system

  • is by how much noise is going in those waters.

  • But on the whole, most waters remain completely unregulated

  • when it comes to ocean noise.

  • But again, most of the scientists I spoke to

  • said that there's real momentum right now in policy circles

  • to pay attention to this issue

  • and maybe do something about this issue.

  • We already know enough to say that quieter seas are healthier seas.

  • But now scientists are really scrambling to come up with the details.

  • Just how quiet do we need to be?

  • And where are the best places to make quiet or preserve quiet?

  • And how best can we hush our noise?

  • And you know, I'm not trying to tell you

  • that noise is the biggest environmental problem on the planet

  • or even in the ocean.

  • But the point is that humankind has a lot of impacts

  • on our environmental system.

  • And these impacts don't act in isolation.

  • They act together, and they multiply.

  • So even for the ones that are not so obvious,

  • we really need to pay attention to them.

  • I'll tell you about one last experiment,

  • just because it's so beautiful.

  • So Rob Williams,

  • one of the researchers who works on southern resident killer whales,

  • also does some work in Bali.

  • And there, they celebrate a Hindu tradition

  • called nyepi, or a day of silence.

  • And this day, apparently, is very strictly observed.

  • No planes take off from the airport,

  • no boats go out fishing,

  • the tourists are gently led off the beach back into their hotel rooms.