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Russell Wangersky: The damage we’re doing runs deep

Don’t think we’re affecting every single part of this world? Talk to the hungry shrimp.

Russell Wangersky

More to the point, collect the deepest of deep-water amphipods and see what nasty human waste they are carrying around in their flesh.

You couldn’t get further away from humans than the bottoms of the Mariana Trench, in the North Pacific, and the Kermadec Trench, near New Zealand.

More than 10,000 metres below the surface, you’d think that if any place on Earth would be safe from our greasy fingerprints, those would be the sorts of places.

No humans have even been close to being there. Now, researchers have dropped an ocean lander in free fall to the bottom of each of the respective trenches, and later recovered it by signaling the device to release its ballast weights. Amphipods were trapped using a delightful “odour plume” of mackerel the beasties could smell — but not eat, to prevent them from picking up pollutants that way.

That’s because the scientists doing the research were looking for two persistent pollutants, both manmade chemicals — polychlorinated biphenyls (PCBs) and a newer flame-retardant, polybrominated biphenyl ethers (PBDEs).

The resulting paper, “Bioaccumulation of persistent organic pollutants in the deepest ocean fauna,” was published in the journal Nature by Alan J. Jamieson, Tamas Malkocs, Stuart B. Piertney, Toynubo Fujii and Zulin Zhang. It was published online on Feb. 13 — you can read it here: http://go.nature.com/2lItenj

Now, this is the type of research that business-centric governments despise. It can’t be “monetized,” it doesn’t build faster trains or improve the function of microprocessors.

In fact, the more business-centred a government is, the less likely they’ll be happy about funding research that might even be seen as inhibiting the freedom of industrial processes, especially when the research finds that — pardon the language — we’re crapping in our own backyards. And our living rooms. And our fridges. And pretty much everywhere else.

What did the study find?

“The salient finding was that PCBs and PBDEs were present in all samples across all species at all depths in both trenches,” the scientists wrote. “Contaminant levels were considerably higher than documented for nearby regions of heavy industrialization, indicating bioaccumulation of anthropogenic contamination and inferring that these pollutants are pervasive across the world’s oceans and to full ocean depth.”

And the pollution isn’t just at minimum measurable levels; no, we leave a mark that’s much larger than that. “Indeed, in the Mariana, the highest levels of PCBs were fifty times more contaminated than crabs from paddy fields fed by the Liaohe River, one of the most polluted rivers in China. The only Northwest Pacific location with values comparable to the Mariana Trench is Suruga Bay, Japan, a highly industrialized area with historically heavy usage of organochlorine chemicals,” the scientists wrote.

The reason for the deep-water contamination? The suggestion is that there’s both an industrial cause, and a more individual one. The industrial cause is the original release of the pollutants through incineration and spills. The other is everybody’s love of the convenience of plastics, which are now also everywhere in the world’s oceans as tiny, broken-down plastic shards.

“First, the high levels of the Mariana PCBs may originate from proximity to the industrialized regions in the Northwest Pacific and the North Pacific Subtropical Gyre, famed for its reputation as the ‘Great Pacific Garbage Patch.’ As such, it is located beneath a mass accumulation of trapped plastic debris that ultimately sinks as the plastics degrade and fragment, transporting persistent organic pollutants to depth,” the scientists suggest.


Human impact on the Earth is real and broad-based, from the edges of the atmosphere to the deepest oceans.

What we hate to admit is that we deny it primarily to protect the comforts of our own lifestyles.

Russell Wangersky is TC Media’s Atlantic regional columnist. He can be reached at russell.wangersky@tc.tc — Twitter: @Wangersky.

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