In Oc­to­ber, The Ocean Cleanup’s sys­tem col­lected plastic from the Great Pa­cific Garbage Patch for the first time. But is this the best way of deal­ing with the plastic prob­lem?

BBC Wildlife Magazine - - CONTENTS - Alice Lip­scombe-South­well

Science writer Alice re­ports on the lat­est plastic ex­trac­tion tech­nol­ogy that is at­tempt­ing to clean up our wa­ters. “It’s clear that we can­not con­tinue liv­ing our lives as we al­ways have done,” she says.

There was a time when many of us ac­cepted a straw in our Fri­day-night cock­tail with­out a sec­ond thought. But in Oc­to­ber 2017, Blue Planet II hit our screens, open­ing eyes to the dam­age that plastic waste is caus­ing to the world’s oceans. While con­ser­va­tion­ists and marine sci­en­tists had long been aware of the is­sue, it was this series that brought the prob­lem hurtling into pub­lic con­scious­ness. Since then, many of us have tried to re­strict our use of sin­gle-use plas­tics, while gov­ern­ments have been urged to take ac­tion – in the UK alone, mi­crobeads in toi­letries have al­ready been banned, and from spring 2020 plastic stir­rers and straws will be re­stricted. Cur­rently, around 350 mil­lion tonnes of plastic are pro­duced each year – a large pro­por­tion of it sin­gle-use – and a whop­ping 12 mil­lion tonnes of the stuff en­ters our oceans, but fol­low­ing its move­ments is a tricky task. “There are def­i­nitely hotspots, such as gyres [see box, p34], but it is also pre­dicted that a lot of plastic sinks. We are do­ing re­search at the mo­ment, track­ing lit­ter’s move­ment,” says the Univer­sity of Ply­mouth’s Imo­gen Nap­per, who stud­ies plastic pol­lu­tion in the marine en­vi­ron­ment.

Pick­ing up the pieces

So what can be done to get plas­tics out of the ocean? One or­gan­i­sa­tion that’s try­ing to tackle the prob­lem is Nether­lands-based The Ocean Cleanup, which was set up by in­ven­tor Boyan Slat in 2013, when he was just 18 years old. It wants to de­ploy its ‘pas­sive sys­tems’ into the five ma­jor ocean gyres, to col­lect plastic for re­cy­cling.

While its first sys­tem failed in De­cem­ber 2018, in Oc­to­ber 2019 the or­gan­i­sa­tion tri­umphed. Af­ter de­sign tweaks and mod­i­fi­ca­tions, its lat­est de­vice, called Sys­tem 001/B, suc­cess­fully cap­tured and re­tained plastic de­bris from the in­fa­mous Great Pa­cific Garbage Patch in the North Pa­cific gyre. In a press re­lease, The Ocean Cleanup claimed that its sys­tem even scooped out mi­croplas­tics as small as 1mm. The or­gan­i­sa­tion es­ti­mates that a fleet of its sys­tems could clear half of the Great Pa­cific Garbage Patch in five years.

De­spite its name, the Great Pa­cific Garbage Patch isn’t a huge float­ing land­fill site that you could stroll across if the mood took you. In­stead, it’s like a rather un­pleas­ant mine­strone soup – but in place of chunks of veg­eta­bles and pasta, the water is filled with as­sorted plastic waste, in­clud­ing ‘mi­croplas­tics’ (smaller than 5mm). Plastic does not fully de­grade like or­ganic waste; in­stead, the ac­tion of the ocean and sun­light causes it to break down into tinier and tinier bits.

While it’s easy to un­der­stand how a plastic bag or piece of fish­ing line could

block the guts of a se­abird or turtle if they mis­took it for food, less is known about how mi­croplas­tics af­fect the ocean ecosys­tems, and it’s cur­rently an im­por­tant area of re­search for sci­en­tists. The size of mi­croplas­tics means they are small enough to make a tasty mouth­ful for the tini­est crea­tures, which po­ten­tially harms the or­gan­ism and also means that the chem­i­cals as­so­ci­ated with the plastic will ac­cu­mu­late up the food-chain.

Sys­tem 001/B may be suc­cess­fully cap­tur­ing plas­tics, but the Univer­sity of North Carolina Ashville’s Re­becca Helm, who spe­cialises in open-ocean ecosys­tems, says that it is catch­ing many ‘neuston’ at the same time. The neuston is a group of or­gan­isms such as snails, sea slugs and plank­ton that live at, or just be­low, the ocean sur­face. Some­times, these in­ver­te­brates oc­cur in such enor­mous num­bers that they’re like a liv­ing is­land. “It’s re­ally the only ecosys­tem that ex­ists firmly wedged be­tween the at­mos­phere and the ocean,” says Helm. “It’s preyed upon by birds from above – there are a lot of seabirds that eat neuston – and also an­i­mals from be­low.”

This ecosys­tem is still poorly un­der­stood, and, ac­cord­ing to Helm, there might not be any clear way that The Ocean Cleanup’s sys­tem could be adapted so it wouldn’t be im­pact­ful. “The re­al­ity is we don’t know if these an­i­mals are al­ways mixed with the plastic or only some of the time,” she says.

As these an­i­mals are soft-bod­ied, buoy­ant and live near the sur­face, they can­not swim away or es­cape if they get stuck.

The Ocean Cleanup (which did not re­spond to re­quests for com­ment), states on its web­site that it has carried out ex­ten­sive ob­ser­va­tion cam­paigns to un­der­stand how Sys­tem 001 might in­ter­act with marine life, and that “no sub­stan­tial in­ter­fer­ence with the ocean ecosys­tem were ob­served; nor did we ob­serve any en­tan­gle­ment or en­trap­ment of marine an­i­mals.” It also pledges to mon­i­tor pres­ence of marine life be­fore plastic is lifted out of the water.

Scratch­ing the sur­face

Some ex­perts won­der why The Ocean Cleanup is fo­cus­ing its ef­forts on the ocean sur­face in the first place. A 2016 study by en­vi­ron­men­tal con­sul­tancy Euno­mia found that just 1 per cent of marine plas­tics are at

the ocean sur­face, while 94 per cent ends up on the seabed. In fact, plas­tics are al­most ubiq­ui­tous and can be found locked within the ice at the poles, lurk­ing in the deep­est ocean trenches and scooped up by the hand­ful at the sea­side.

Ac­cord­ing to Laura Foster, head of clean seas at the Marine Con­ser­va­tion So­ci­ety, we should be con­cen­trat­ing our ef­forts on re­duc­ing our production of plas­tics, rather than clear­ing up rub­bish in the ocean. “One of the main is­sues with The Ocean Cleanup is that it sup­ports big in­dus­try’s nar­ra­tive that ocean plastic is a lit­ter prob­lem, rather than a production prob­lem,” she says. “Clean­ing up in the cur­rent sit­u­a­tion has been com­pared to try­ing to deal with an over­flow­ing bath with a tea­spoon… the so­lu­tion is found by turn­ing off the taps!”

Nap­per agrees that we need to re­duce our use of plas­tics, but also says that the best way to pre­vent plastic reach­ing the ocean is to stop it from land. “Land-based sources are the big­gest con­trib­u­tor to plastic in the ocean,” she says. “We also need to iden­tify the path­way from land into the ocean. We are cur­rently re­search­ing ma­jor river sys­tems to un­der­stand this move­ment.”

And The Ocean Cleanup has an an­swer for that. Back in Oc­to­ber, the team launched the In­ter­cep­tor, an au­ton­o­mous sys­tem that col­lects plastic from rivers be­fore it reaches the sea. So far, In­ter­cep­tors have been set up in Jakarta (In­done­sia), Klang (Malaysia) and Can Tho (Viet­nam), while a fourth will soon be in­stalled in the Do­mini­can Repub­lic. While es­ti­mates vary, ex­perts agree that the vast ma­jor­ity – up to 95 per cent – of ocean plastic ar­rives via rivers. The Ocean Cleanup says just one In­ter­cep­tor can scoop up 50,000kg of plastic per day, and the team has given it­self the goal of in­stalling the sys­tems in 1,000 of the most pol­lut­ing rivers by 2025. “I’m re­ally happy The Ocean Cleanup is go­ing in this di­rec­tion, I think it’s much more pro­duc­tive,” says Helm.

Foster agrees that clean­ing up the rivers is prefer­able to try­ing to ex­tract plas­tics from the oceans, as it is eas­ier to main­tain and mon­i­tor a river-based sys­tem than one lo­cated at sea. Plus, river lit­ter is more con­cen­trated com­pared to in the oceans.

Ex­perts agree that the vast ma­jor­ity of ocean plastic ar­rives via rivers.

“But again, we need to ad­dress why the ma­te­rial ends up in the river in the first place,” she says. “The

5p charge in the UK saw a huge re­duc­tion in the vol­ume of plastic bags on beaches and in the marine en­vi­ron­ment. This sort of model must be em­u­lated to fur­ther re­duce plastic pol­lu­tion.”

While it’s fan­tas­tic that wellmean­ing peo­ple and com­pa­nies are in­spired to find ways to elim­i­nate plastic from the en­vi­ron­ment, it’s clear that we can­not con­tinue liv­ing our lives as we al­ways have done, re­ly­ing on other peo­ple to tidy up our mess for us. “We just need to use less,” says Thomas Stan­ton from the School of Ge­og­ra­phy at the Univer­sity of Not­ting­ham. “We also need better waste man­age­ment fa­cil­i­ties, to en­sure that more plastic can be, and is, re­cy­cled.”

Once we’ve stopped plastic reach­ing our oceans, says Foster, the most ef­fi­cient place to start clean­ing up marine lit­ter is on beaches. With ev­ery­one in the UK no more than 113km from the sea, that’s some­thing we can all get on board with.

ALICE LIPS COMB ESOUTH WELL is production edi­tor at BBC Science Fo­cus.

The Ocean Cleanup’s sys­tem may col­lect plastic, but is it in­ad­ver­tently trap­ping marine life, too?

The largest mass of ocean plastic can be found in the North Pa­cific.

Right: blue sea dragons, here seen with a Por­tuguese man of war, are part of the neuston. Bottom right: The Ocean Cleanup can col­lect tiny plastic pieces.

Is col­lect­ing plastic from our oceans enough?

In­ven­tor Boyan Slat, CEO of The Ocean Cleanup.

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