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← The dangers of a noisy ocean -- and how we can quiet it down

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Showing Revision 8 created 03/11/2020 by Oliver Friedman.

  1. This is the sound of orcas
    off the coast of Vancouver.
  2. (Whale chirps and squeaks)

  3. They make these fantastic sounds
    not just to communicate,

  4. but also sometimes to echolocate,
  5. to find their way around and to find food.
  6. But that can be tricky sometimes,
  7. because, well, here is the sound
    of a ship passing by,
  8. recorded underwater.
  9. (Screeching oscillating sound)

  10. You know, when we think
    about marine pollution,

  11. I think we usually think about plastics.
  12. Maybe toxic chemicals,
  13. or even ocean acidification
    from climate change.
  14. As a science journalist who often writes
    about environmental issues,
  15. those are the things
    that have passed my desk
  16. over the past 10 years or so.
  17. But as I recently realized
  18. when I was writing a feature
    for the science journal "Nature,"
  19. noise is another
    important kind of pollution.
  20. One that often gets ignored.
  21. You know, maybe you've heard
    of the dark-skies movement,

  22. which aimed to raise awareness
    of the issue of light pollution
  23. and create pockets of unilluminated night,
  24. so that people and animals
  25. could enjoy more natural cycles
    of light and dark, night and day.
  26. Well, in much the same way,
  27. there are people now raising awareness
  28. of the issue of noise pollution
  29. and trying to create
    pockets of quiet in the ocean,
  30. so that marine life can enjoy
    a more natural soundscape.
  31. This is important.

  32. Noise isn't just an irritation.
  33. It can cause chronic stress,
  34. or even physical injury.
  35. It can affect marine life's ability
    to find food and mates
  36. and to listen out for predators and more.
  37. Think of all the sounds
    we inject into the ocean.
  38. Perhaps one of the most dramatic
    is the seismic surveys
  39. used to look for oil and gas.
  40. Air guns produce loud blasts,
  41. sometimes every 10 to 15 seconds,
  42. for months on end.
  43. And they use the reflections
    of these sounds
  44. to map the ground beneath.
  45. It can sound like this.
  46. (Explosion sounds)

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

  48. the construction of things
    like offshore wind farms,
  49. sonar
  50. and of course, the nearly constant drone
    from more than 50,000 ships
  51. in the global merchant fleet.
  52. Now the natural ocean itself
    isn't exactly quiet.

  53. If you put your head under the water,
  54. you can hear cracking ice, wind, rain,
  55. singing whales, grunting fish,
  56. even snapping shrimp.
  57. Altogether, that can create a soundscape
  58. of maybe 50 to 100 decibels,
  59. depending on where and when you are.
  60. But mankind's addition to that
    has been dramatic.

  61. It's estimated that shipping has added
    three decibels of noise to the ocean
  62. every 10 years in recent decades.
  63. That might not sound like a lot,
  64. but decibels are on a logarithmic scale,
  65. like the Richter scale for earthquakes.
  66. So a small number can actually
    represent a large change.
  67. Three decibels means a doubling
    of noise intensity in the ocean.
  68. A doubling.
  69. And that's only an estimate,

  70. because no one is actually keeping track
    of how noisy the ocean is
  71. all around the world.
  72. There is a body called
    the International Quiet Ocean Experiment,
  73. and one of their missions
  74. is to try and plug the hole in that data.
  75. So for example, last year,
  76. they managed to convince
    the Global Ocean Observation System
  77. to start including noise
  78. as one of their essential
    variables for monitoring,
  79. alongside things
    like temperature and salinity.
  80. We do know some things.

  81. We know that sonar can be as loud,
    or nearly as loud,
  82. as an underwater volcano.
  83. A supertanker can be as loud
    as the call of a blue whale.
  84. The noises we add to the ocean
    come in all different frequencies
  85. and can travel great distances.
  86. Seismic surveys off the East Coast
    of the United States
  87. can be heard in the middle
    of the Atlantic.
  88. In the 1960s, they did an experiment
  89. where they set off a loud noise
    off the coast of Perth, Australia,
  90. and they detected it
    as far away as Bermuda,
  91. 20,000 kilometers away.
  92. So what does all this
    sound like to marine life,

  93. what do they hear?
  94. It's kind of difficult to describe.
  95. Sound travels further, faster in water
    than it does in air,
  96. and it also packs a different punch.
  97. So sound of the same pressure
    will have a different intensity
  98. whether you measure it
    in the air or underwater.
  99. Then there's the fact that whales
    don't have ears exactly like human ears.
  100. Creatures like zooplankton
  101. don't even have what you would
    consider to be ears.
  102. So what does this mean,
  103. what is the impact
    on all this marine life?
  104. Perhaps the easiest thing
    for scientists to assess

  105. is the effect of acute noise,
  106. really loud sudden blasts
  107. that might cause physical injury
    or hearing loss.
  108. Beaked whales, for example,
    can go into panicked dives
  109. when exposed to loud noises,
  110. which may even give them
    a condition similar to the bends.
  111. In the 1960s, after the introduction
    of more powerful sonar technologies,
  112. the number of incidents of mass
    whale strandings of beaked whales
  113. went up dramatically.
  114. And it's not just marine mammals,
  115. fish, if they stray too close
    to the source of a loud sound,
  116. their fish bladders may actually explode.
  117. The airgun blasts from seismic surveys
  118. can mow down a swath of zooplankton,
  119. the tiny creatures near the base
    of the food chain,
  120. or can deform scallop larvae
    while they're developing.
  121. Well, what about chronic noise,

  122. the more pervasive issue
    of raising background noise
  123. from things like shipping?
  124. That can mask or drown out
    the natural soundscape.
  125. Some whales have responded to this
    by literally changing their tune,
  126. a little bit like people
    shouting to be heard in a noisy nightclub.
  127. And some fish will spend more time
    patrolling their borders
  128. and less time caring for their young,
  129. as if they're on high alert.
  130. Chronic noise can affect
    people too, of course.

  131. Studies have shown
    that people living near busy airports
  132. or really busy highways
  133. may have elevated levels
    of cardiovascular disease.
  134. And students living
    under busy flight paths
  135. may do worse on some educational tests.
  136. And even while I was
    researching this subject,
  137. they were actually blasting out
    about three meters of solid granite
  138. from the lot across from my home office
  139. to make room for a new house,
  140. and the constant jittering
    of the rock hammer
  141. was driving me completely insane.
  142. And whenever the workers
    stopped for a moment,
  143. I could feel my shoulders relax.
  144. This effect has been seen in whales, too.

  145. After the terrorist attacks of 9/11,
  146. international shipping largely
    ground to a halt for a little while
  147. in the waters off the East Coast
    of the United States.
  148. And in that lull,
  149. researchers noticed that endangered
    right whales in that region
  150. had fewer chemical markers of stress
    in their feces samples.
  151. As one researcher I spoke to likes to say,
  152. "We were stressed,
    but the whales weren't."
  153. Now you have to remember,

  154. we have evolved to be a visual species.
  155. We really rely on our eyes.
  156. But marine life relies on sound
  157. the way that we rely on sight.
  158. For them, a noisy ocean
  159. may be as befuddling and even dangerous
  160. as a dense fog is for us.
  161. And maybe sometimes that just means
    being a little more stressed,
  162. maybe sometimes it means
    spending a little less time with the kids.
  163. Maybe some species can adapt.
  164. But some researchers worry
    that for endangered species
  165. already on the brink,
  166. noise may be enough
    to push them over the edge.
  167. So take, for example,
    the southern resident killer whales

  168. that live in the waters
    off my hometown of Vancouver.
  169. There are only 75, maybe 76, animals left
  170. in this population.
  171. And they're facing a lot of challenges.
  172. There are chemical pollutants
    in these waters,
  173. and they are running low on the salmon
    that they really rely on for food.
  174. And then there's noise.
  175. When researchers studied these
    and similar killer whales,
  176. they found that they spend
    between 18 and 25 percent less time
  177. feeding in the presence
    of loud boat noise.
  178. And that's a lot for a species
    that's already struggling
  179. to find enough food to thrive.
  180. The good news, as I heard
    from all the researchers I spoke to,

  181. is that you can do something
    relatively easily about ocean noise.
  182. Unlike the wicked problems
    of climate change
  183. and ocean acidification,
  184. you can just dial down
    the knob on ocean noise
  185. and see almost immediate impacts.
  186. So for example, in 2017,
  187. the Vancouver Fraser Port Authority
  188. started asking ships to simply slow down
  189. when going through the Haro Strait,
  190. where the southern resident killer whales
    are feeding in late summer.
  191. Slower ships are quieter ships.
  192. And because it's Canada, you can just ask,
  193. it can be voluntary.
  194. (Laughter)

  195. (Applause)

  196. In that 2017 trial,
    most of the ships complied,

  197. adding about half an hour
    to their travel time,
  198. and reducing noise by about 1.2 decibels
  199. or 24 percent of noise intensity.
  200. This year, they decided
    to extend the length of time
  201. and the area over which
    they're asking ships to slow down.
  202. So hopefully that has
    a positive impact for these whales.
  203. In 2017, the Vancouver
    Fraser Port Authority

  204. also introduced discounts in docking fees
  205. for ships that are physically
    designed to be quieter.
  206. You know, weirdly, a lot of the noise
    from a ship like this
  207. comes from the popping of tiny bubbles
    off the back of its propeller.
  208. And you can simply design a ship
    to do less of that
  209. and to be quieter.
  210. The International Maritime Organization
    has published a huge list of ways
  211. that boats can be made quieter.
  212. And they also have a target
  213. of reducing carbon dioxide emissions
    from global shipping
  214. by 50 percent by 2050.
  215. And the great news is that
    these two things go hand in hand.
  216. On the whole, a more
    efficient ship is a quieter ship.
  217. People have also invented quieter ways
    of hammering in the giant posts

  218. needed for giant
    wind turbines, like this one,
  219. and gentler ways of doing seismic surveys.
  220. And there are some incentives
    for using quieter technologies.
  221. The European Union, for example,
  222. has a healthy marine system
    directive for 2020.
  223. And one of the ways that they define
    a healthy marine system
  224. is by how much noise
    is going in those waters.
  225. But on the whole, most waters
    remain completely unregulated
  226. when it comes to ocean noise.
  227. But again, most of
    the scientists I spoke to

  228. said that there's real momentum
    right now in policy circles
  229. to pay attention to this issue
  230. and maybe do something about this issue.
  231. We already know enough to say
    that quieter seas are healthier seas.
  232. But now scientists are really scrambling
    to come up with the details.
  233. Just how quiet do we need to be?
  234. And where are the best places
    to make quiet or preserve quiet?
  235. And how best can we hush our noise?
  236. And you know, I'm not trying to tell you

  237. that noise is the biggest
    environmental problem on the planet
  238. or even in the ocean.
  239. But the point is that humankind
    has a lot of impacts
  240. on our environmental system.
  241. And these impacts don't act in isolation.
  242. They act together, and they multiply.
  243. So even for the ones
    that are not so obvious,
  244. we really need to pay attention to them.
  245. I'll tell you about one last experiment,

  246. just because it's so beautiful.
  247. So Rob Williams,
  248. one of the researchers who works
    on southern resident killer whales,
  249. also does some work in Bali.
  250. And there, they celebrate
    a Hindu tradition
  251. called nyepi, or a day of silence.
  252. And this day, apparently,
    is very strictly observed.
  253. No planes take off from the airport,
  254. no boats go out fishing,
  255. the tourists are gently led off the beach
    back into their hotel rooms.
  256. And Rob Williams put some
    hydrophones in the water there
  257. to see what the impact was,
  258. and it was dramatic.
  259. Sound levels dropped
    by six to nine decibels,
  260. about the same
    as in the waters after 9/11.
  261. For an "acoustic prospector"
    like Williams,
  262. which is what he calls himself,
  263. this silence is golden.
  264. Now he and other researchers
    can go back to this place
  265. and see what the fish choose to do
  266. with all this additional
    acoustic real estate.
  267. (Soft bubbling)

  268. I like to think of them
    having their own holiday,

  269. feasting and finding mates.
  270. Celebrating their own spot of calm
  271. in an otherwise noisy world.
  272. Thank you.

  273. (Applause)