If it works—great! However, the concept has only been tested with scale models and computer simulations. The Times wrote that environmental experts are wary that the booms might fail to catch much plastic, but simultaneously scoop up wildlife:

“There’s worry that you can’t remove the plastic without removing marine life at the same time,” said George Leonard, chief scientist at the Ocean Conservancy. “We know from the fishing industry if you put any sort of structure in the open ocean, it acts as a fish-aggregating device.”

... It is unclear how well the boom would fare on the open ocean, where it faces high winds, corrosive salt water and other environmental challenges. And then there’s the question of whether it is possible to clean half of the garbage patch in just five years.

“I think the big challenge here is not the long-term goal but the short-term goal,” Mr. Leonard said on Saturday. “Can it remove plastic at all?”


One purported issue with the design, per Business Insider, is that much of the plastic that is deposited into the ocean has already broken down and sunk much deeper than the 10-foot plastic skirt is capable of reaching. Another is that if marine life begins to accumulate on the surface (“biofouling”), it could be weighed down and plastic will just float over it. In addition to the risk of wildlife entanglement, there’s a “medium risk” acknowledged in an environmental assessment performed by Ocean Cleanup that sea turtles would be attracted to the boom and begin eating the collected plastic.

According to Wired, Ocean Cleanup said that they have designed the boom to have no risk of entanglement, though there is concern objects like rogue fishing nets could become ensnared on the structure and trap wildlife. Wired added that some experts wonder if it is a pollution risk in and of itself:

“I sort of wonder what kinds of microplastics this thing is going to be generating on its own, assuming that it’s even functioning exactly as designed,” says oceanographer Kara Lavender Law of the Sea Education Association. Worse yet, the thing could snap in a storm. “If it’s shedding nano-size particles and then gets smashed into 200-meter-long pieces, you’re really covering the whole size range there.”


Oceanographer Kim Martini, who worked on an external review of the project years ago, wrote in a blog post flagged by Business Insider that a better solution may be to deploy the booms near sources of plastic pollution, where they could trap garbage before it becomes an issue.

21-year-old Ocean Cleanup founder Boyan Slat told Sky News he agreed that the concept has not yet been proven to work, but “If we don’t clean it up now, all of it will become micro plastics and then we are in a much worse state than we are today. This is the best way we could figure out how to do it. If there are better ways, we’d love to know.”


California Coastal Commission marine debris program manager Eben Schwartz told shark researcher David Shiffman of Southern Fried Science that “To make the claim, as The Ocean Cleanup Project is, that they will ‘clean the oceans’ by 2040 or whenever is disingenuous and misleading, when it will, at best, clean a very small percentage of what’s found on the surface.”

[New York Times]

Correction: A previous version of this article misstated Ocean Cleanup as claiming it “could clear the garbage patch in as little as half a decade.” As noted in the quoted NYT section, it claims to be capable of clearing half of it on that timeframe. We regret the error.