The world's deepest ocean trenches are packed with pollution

I hope that the global conversation on ecological protection can evolve from climate change to tangible effects, like pollution and ocean acidification, just as climate change evolved from the use of the term global warming.<p>Ocean acidification in particular ought to be an issue even climate skeptics can acknowledge is a problem. Unlike climate change, which can be difficult to communicate due to its abstract nature (we had heat last summer and snow last winter so what&#x27;s changing?), you can plainly test acidification with two cups of water - tap and sparkling - and a pair of litmus slips to show the difference. Then expand on how all the carbon in the atmosphere does that to the oceans, and then demonstrate what that does to life in the oceans, from the algae and plankton to the fish people eat.<p>Overall I think that focusing on precise tangible issues that people can observe for themselves is a better way to communicate the need for ecological protection than to be completely correct in a large and abstract assessment that people might have trouble following.<p>Only problem is it&#x27;s hard to sex up the term &quot;ocean acidification.&quot; For something like that we&#x27;d need an attention-grabbing shorthand, like &quot;melty fishy death water.&quot;

Given that polychlorinated biphenyls are so much more abundant in the deep sea trenches than even &quot;In grossly polluted areas, like the Liao River in China&quot; the scientist in me suspects that something other than pollution might be at play.<p>Perhaps deep sea organisms synthesize polychlorinated biphenyls as an adaptive response? (weirder things are known...) Or perhaps the chemical degradation of polychlorinated biphenyls is inhibited by the environment?

<i>Precisely why the Mariana trench has such elevated levels of polychlorinated biphenyls remains unclear. Dr Jamieson suspects it has to do with the trench’s proximity to the North Pacific Subtropical Gyre, a whirlpool hundreds of kilometres across that has amassed enormous quantities of plastics over the years, and which has the potential to send the pollutants that bind to those plastics deep into the ocean as the plastics degrade and descend.</i><p>I think that this guess is likely to be right. It would take a very long time for fluid convection and diffusion to transport these pollutants to such depths. But particles of plastic that are higher-density than water will collect a lot of these strongly hydrophobic pollutants on their surfaces and sink deeply much faster than convection&#x2F;diffusion operate.<p>There is a &quot;missing plastic&quot; question in environmental science. We see a lot of plastic trash near the surface in oceans, but the visible amount is much less than the amount humans seem to be adding to the ocean each year.<p><a href="http:&#x2F;&#x2F;www.sciencemag.org&#x2F;news&#x2F;2014&#x2F;06&#x2F;ninety-nine-percent-oceans-plastic-missing" rel="nofollow">http:&#x2F;&#x2F;www.sciencemag.org&#x2F;news&#x2F;2014&#x2F;06&#x2F;ninety-nine-percent-o...</a><p>Where is the &quot;missing&quot; plastic? It seems likely that some of it is sinking to the ocean floor, either because the plastic itself is denser than water or because it builds up denser-than-water growths on its surface. Finding polychlorinated biphenyls and brominated ethers concentrated at such depths is, IMO, pretty convincing evidence for plastics and the pollutants concentrated on their surfaces sinking into the benthic zone.<p>(Another part of the missing plastic may be gone due to colonization and <i>digestion</i> of plastics by natural hydrocarbon-eaters; see &quot;Life in the “Plastisphere”: Microbial Communities on Plastic Marine Debris&quot; for a really fascinating paper about this phenomenon.<p><a href="https:&#x2F;&#x2F;www.researchgate.net&#x2F;profile&#x2F;Tracy_Mincer&#x2F;publication&#x2F;237094808_Life_in_the_Plastisphere_Microbial_Communities_on_Plastic_Marine_Debris&#x2F;links&#x2F;0c96053397631e606c000000&#x2F;Life-in-the-Plastisphere-Microbial-Communities-on-Plastic-Marine-Debris.pdf" rel="nofollow">https:&#x2F;&#x2F;www.researchgate.net&#x2F;profile&#x2F;Tracy_Mincer&#x2F;publicatio...</a> )<p>It&#x27;s rather alarming to find such concentrated pollution so far away from its human sources. But at the risk of sounding callous, it&#x27;s kind of good news for humans and our critical ecosystem services: these very deep ocean regions are relatively isolated from most seafood eaten by humans, and from the photic zone whose photosynthesis is an important part of the carbon cycle. If persistent pollution has to partition somewhere, partitioning into the deepest parts of the ocean is about the best case scenario for surface life.

A bit off-topic, but...<p>&quot;If Mount Everest were flipped upside down into it, there would still be more than 2km of clear water between the mountain’s base and the top of the ocean&quot;<p>This statement always bugs me, the elevation at Everest&#x27;s base is already ~14,000ft. Its prominence is not its full elevation. When you try to have someone imagine &quot;flipping it upside down&quot;, a person wouldn&#x27;t typically consider including the surrounding terrain, but simply ignore the fact that it&#x27;s already at great elevation.

Sounds like even more problems for a prospective future undersea colony beyond the crushing weight of pressure.

Most of the plastic in the ocean comes from street litter in coastal cities. If you smoke, that includes cigarette butts (the filters are not natural cellulose anymore), as well as the plastic wrapped around the package that so many let fall to the sidewalk.

The Economist summary says the amphipods that were found to contain PCBs were collected by baiting traps with mackerel.<p>I don&#x27;t have access to the original research report, but I wonder if they analyzed the mackerel for those pollutants?

If this doesn&#x27;t end bad for humans it sure will when it&#x27;s the plot of a sci-fi horror movie.

Some day it would be awesome to build swarms of autonomous deep-sea robots. Ahhh... imagine if they ate tiny plastic like plankton for whales haha.<p>I know just bs, not a novel idea, until you do it just spewing smoke.<p>So much to learn still, I&#x27;m currently oriented to web dev not hardware programming but I have a hardware friend though, math friend, pieces will fit someday perhaps.<p>The ocean is such a mystery&#x2F;entrancing.<p>Just imagine if you had a bunch of robots just out there doing there thing and you could &quot;ssh&quot; into them by satellite haha would be nuts.