Manila Bulletin

Ocean’s deep­est part filled with toxic pol­lu­tants, study re­veals

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MOSCOW (PNA/Sput­nik) – "Ex­tra­or­di­nary lev­els" of pol­lu­tion have been found in the Mar­i­ana Trench, the deep­est part of the Earth’s oceans.

Pol­lu­tants from the 1970s have ac­cu­mu­lated among the crus­taceans that live there, con­tam­i­nat­ing life 11,000 me­ters be­low sea level.

The study, con­ducted by re­searchers from the Univer­sity of Aberdeen and the James Hut­ton In­sti­tute and pub­lished in Na­ture, found that pol­lu­tion was per­va­sive and in­tense within the Mar­i­ana and the sim­i­larly deep Ker­madec Trench.

The pol­lu­tant in ques­tion is called a per­sis­tent or­ganic pol­lu­tant (POP), or­ganic com­pounds that do not biode­grade. The en­vi­ron­men­tal dev­as­ta­tion these com­pounds can cause, as they are nearly im­pos­si­ble to re­move once they are in­tro­duced to an en­vi­ron­ment, is sig­nif­i­cant.

In ad­di­tion, POPs have been linked to dis­rup­tions in the en­docrine and re­pro­duc­tive pro­cesses of an­i­mals.

POPs do not de­grade, and so when dumped in the ocean they would ac­cu­mu­late in­side an­i­mals. Those an­i­mals would then sink into deep trenches like the Mar­i­ana when they died, at which point their bod­ies would be eaten by scav­engers.

As a re­sult, POPs are now heav­ily present in the bod­ies of the Mar­i­ana Trench’s crus­taceans. The re­port claims the pol­lu­tion lev­els to be on par with the dump­ing grounds used by Chi­nese plas­tics man­u­fac­tur­ers.

“In crea­tures that live in shal­lower waters, ex­po­sure to POPs can re­duce re­pro­duc­tive suc­cess and thus pop­u­la­tion growth. It’s hard to study deeper an­i­mals alive un­der con­trolled con­di­tions but can as­sume the pol­lu­tants have a sim­i­lar ef­fect,” wrote study lead Alan Jamieson in an opin­ion piece on The Con­ver­sa­tion.

“The re­al­ity is that the deep sea just isn’t that re­mote, and the great depth and pres­sures are only an imag­i­nary de­fense against the ef­fects of what we do ‘up here.’ The bot­tom line is that the deep sea – most of planet Earth – is any­thing but ex­empt from the con­se­quences of what hap- pens above it, and it’s about time we ap­pre­ci­ated that.”

In re­cent decades, gov­ern­ments had be­gun to re­al­ize the dan­gers of POPs. Poly­chlo­ri­nated biphenyl (PCB), a POP used for things like coolant and trans­former fluid, was banned world­wide in the ’70s when it was found to cause birth de­fects and other health prob­lems.

In 2001, the Stock­holm Con­ven­tion was drafted which elim­i­nated POP pro­duc­tion in most of the world. Only a small hand­ful of coun­tries have not rat­i­fied the treaty, in­clud­ing Turk­menistan, Uzbek­istan, South Su­dan, and the United States.

An­other ma­jor risk to ocean life is plas­tic pol­lu­tion, brought on by plas­tic mi­crobeads present in soaps and sham­poos. They go down the drain and end up in the oceans, where they present a dan­ger to marine life.

“It seems that once again, we have a shock­ing ex­am­ple of our own stu­pid­ity, as peo­ple grad­u­ally re­al­ize that plas­tic mi­crobeads are, fun­nily enough, made of plas­tic, and that stuff that goes down the sink doesn’t mag­i­cally dis­ap­pear into an­other di­men­sion,” wrote Jamieson.

The United King­dom passed a ban on plas­tic mi­crobeads in some prod­ucts in late 2016. New Zealand passed a full ban in Jan­uary, 2017.

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