How the Ocean May Clean Itself

How the Ocean May Clean Itself

The Great Pacific Garbage Patch (GPGP), the target of a clean-up campaign launched by a Dutchman, Boyan Slat, and his non-profit, Ocean Cleanup, is a vast collection of debris from a variety of sources, totalling 79,000 metric tons of plastic, floating as a unit in the North Pacific, between Hawaii and California.

A good deal of mythology has grown up around this Patch, including the notion that it can be “seen from space” (it can not.) Ad executives seeking to popularize the issue of contamination of the oceans once gave the place a name, the Trash Isles, and signed up former US President Al Gore as its first citizen. They even petitioned the United Nations for recognition.  

A Truth

The literal truth about the matter, though, is: as a recent report by Slat’s scientists says, “[The] ocean plastic pollution within the GPGP is increasing exponentially and at a faster rate than in surrounding waters.”

Plastic floats simply because it is less dense than sea water. The plastic that makes up the GPGP got there by means of the North Pacific Subtropical Gyre, a large system of circulating ocean currents.

There are five (or six, it seems to vary with who is counting) great gyres in the oceans and each gyre has its own garbage patch, though the GPGP is the largest and the one with the best press agents.

Why This is Important

All this plastic matters. Marine creatures inhabiting or just passing through the patch swallow the plastic. Some effort has been made to quantify this: sea turtles in or near the patch have been found to have up to 74% of the dry weight of their diets composed of ocean plastic.

A recent report by scientists in the United Kingdom says that as of 2015 there were 5.25 trillion pieces of plastic trash in the world’s oceans, and projected that this figure could triple by 2025.

The UK Government Office for Science, in its report, “Future of the Sea,” noted that plastic “does not decompose, instead breaking down into ever smaller pieces” and the full effects of this emergence of micro-plastics are not yet known, but it clearly harms sea life.

Further, this micro-plastic can end up everywhere. A recent analysis by the State University of New York at Fredonia and Orb Media indicated that “93 percent of the bottled water tested showed some sign of microplastic contamination.”

It isn’t just marine life, then, that is affected by the build-up of plastic in the ocean. And large as it is, the GPGP may be taken as a synecdoche for something even larger, the throw-away habits of a global culture. As the UK report also says, the best response at a fundamental level will have to involve changing those habits, “introducing new biodegradable plastics, and potentially public awareness campaigns about marine protection -- addressing the out of sight, out of mind challenge.”

In the meantime, though, the GPGP is what it is: a huge garbage patch. Even the most blinkered and materialistic conception of practicality will take some note of this: vessel collisions with plastic generate $1 billion in vessel damages a year.

What to do about it

The clean-up campaign launching this summer involves a new machine, created with money raised through the Ocean Cleanup crowdfunding campaign.

The machine’s huge floating nets, or screens, will capture and allow giant tubes to suck the stubborn waste right out of the sea, transferring the waste to a flotilla of participating ships for transport to shore and recycling.

This giant floating scoop, a mile long from one end to the next, will get the project underway this summer. It is the first of its kind but, ultimately, Ocean Cleanup envisions using 60 of them.

Slat, who got this ball rolling with a TEDx talk six years ago, still speaks about it with visionary fervor: “The clean-up of the world’s oceans is just around the corner. Due to our attitude of ‘testing to learn’ until the technology is proven, I am confident that -- with our expert partners -- we will succeed in our mission.”

His TEDx talk is available on YouTube. In text form, it is here.

At the time of that talk, Slat expressed his conviction that the GPGP could “completely clean itself in just 5 years.”

He spoke of the ocean “cleaning itself” because the essence of his plan, and of the machine about to be launched, is that it lets the ocean’s own currents do a lot of the work. “Why move through the oceans if the oceans can move through you?” Relatedly, the machine is designed to be self-supported given their energy by “sun, currents, and waves.”

Will it pay for itself?

Part of Slat’s vision is that the ocean clean-up will pay for itself: indeed, it will generate a profit.

In his TEDx talk he said, “[I]f we sell the plastics received from the 5 gyres we’d make over $500 million and this is in fact more than the plan would cost to execute.” He doesn’t estimate how much more, and that estimate would be difficult. Would this large new source of supply for recycling plants depress the market value of such material?

But the idea is on its face plausible. On the matter of the economics of recycling, good news comes from the United Kingdom, where a new report prepared for the business group, Circular Economy Task Force, indicates that recycling could provide as much as 71% of the raw materials demanded by the kingdom’s producers of plastic packaging and products. At present, the UK finds itself stuck into a pattern of collecting plastics for recycling then exporting most of them. But (says the report) if industry focuses its attention in a systematic way, it will find that it can make better use of those recycled materials at home.

Likewise, industries around the world may find that they can make good use of the new source of used plastics that Slat’s machines will create.  

 

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