There's a mind-boggling amount of trash in the world's oceans, with much of it collected in five regions known as gyres.

On September 8, a group called The Ocean Cleanup plans to deploy a plastic-cleanup system to the largest of those gyres, known as the Great Pacific Garbage Patch.

The system was designed by Boyan Slat, a 24-year-old Dutch innovator.

Several experts argue that the cleanup system won't work and will do more harm than good.

The best solution might be stopping plastic before it gets into the water.

On September 8, a massive and controversial plastic-cleanup system will be launched into the Pacific Ocean.

The goal of the system — created by The Ocean Cleanup, a nonprofit organization founded in 2013 by Boyan Slat, a 24-year-old Dutch innovator — is to remove plastic debris from the now-famous marine area known as the Great Pacific Garbage Patch. Located in the North Pacific Ocean, it's actually less of a patch and more like a swirling vortex more than three times the size of Spain and more than twice the size of Turkey or Texas.

By 2050, the amount of plastic in the oceans is expected to outweigh all the fish there. That garbage kills marine life, destroys ecosystems that people depend on to live, and even makes its way into the food supply, causing fish to absorb chemicals that contaminate the seafood we eat.

But while dealing with plastic pollution is urgent, several experts say that The Ocean Cleanup's plans are unlikely to be effective and could cause more harm than benefit.

Last year, Slat told Business Insider that he believed the project's cleanup arrays, once fully deployed, would allow the group to "clean up 50% of the patch in five years."

The system will eventually consist of at least 60 arrays, and the group is inviting corporations and private groups to sponsor their own arrays as well.

"Our goal is to have a full-scale operation running by 2020," an Ocean Cleanup representative said via email.

The Ocean Cleanup

The Ocean Cleanup's ambitious, shifting solution

A survey of 15 experts in ocean plastic pollution by the shark researcher David Shiffman found that it is unlikely that massive floating devices could clean up a significant amount of plastic without harming marine life or adding more garbage to the situation.

Most of those experts had concerns about The Ocean Cleanup's project.

Over the years, The Ocean Cleanup's plans have changed dramatically. Slat's original concept involved mooring a massive plastic-collecting trap to the seabed almost 3 miles below — something many scientists said was unlikely to be possible. One massive multi-mile trap evolved to become a series of smaller, long, U-shaped floating arrays. These were designed with underwater anchors that would allow them to move slowly through the water, so faster-moving plastic would run into the arrays and get trapped by underwater screens.

The organization now says it has realized the underwater anchors won't be stable, so the new array features a different design: A nearly 2,000-foot-long U-shaped boom will float atop the water unanchored, with a 10-foot screen to trap plastic below.

This should allow the system to more effectively trap plastic so that boats can pick it up every few months and take it to shore for recycling, according to The Ocean Cleanup.

But since the design has changed several times, it's hard to know how well the latest system will aggregate plastic once it is fully operational.

"As with any novel technology, success is not guaranteed, but this is exactly why we test, test, and test again. Until the final risks and uncertainties have been mitigated, System 001 is still labeled a 'beta system,'" a representative for the group told Business Insider. The design could continue to change in the future as well.

A serious plastic problem in the ocean

No matter how you measure it, there's a mind-boggling amount of plastic in the world's oceans.

More than 320 million metric tons of plastic are produced every year. Every little bit of plastic that gets tossed into the ocean or swept downstream out to sea either sinks or is picked up by currents. Much of it is eventually carried into one of five massive ocean regions called gyres. Enough plastic converges in these regions that many refer to them as "garbage patches."

The area targeted by The Ocean Cleanup is often referred to as the Great Pacific Garbage Patch — it's the best-known of these patches and is often referred to as the largest gyre, though the National Oceanic and Atmospheric Administration says there's no reliable measurement of the size of any of these regions.

The Ocean Cleanup researchers have estimated that there are at least 1.8 trillion pieces of plastic in the water, weighing 79,000 metric tons. According to their research, 1.7 trillion pieces are tiny microplastics, but more than 90% of the overall plastic mass comes from larger pieces of plastic — frequently from lost fishing nets — that has yet to break down into smaller pieces.

New plastic debris is constantly streaming into the oceans from coastlines, with much of it eventually arriving at one of these five gyres. Along the way, plastic breaks down into smaller and smaller pieces. The Ocean Cleanup's team is mainly focused on larger pieces of plastic near the surface.

"The plastic that reaches the patch all the way from land is of certain density and buoyancy," the representative said. "This plastic is floating within the top few meters of the water column, as found in our vertical distribution research."

Some researchers who have studied the problem say most of the plastic in the region is already broken down and found deeper underwater. That would make cleaning the plastic out of the water a far more complex task, if it's possible at all.

"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," Eben Schwartz, the marine-debris program manager at the California Coastal Commission, told Shiffman.

The Ocean Cleanup

Major questions about safety

Some researchers also worry that a large floating system will aggregate marine life, which may feed off the plastic and get trapped in the debris.

The Ocean Cleanup says that it has designed the system to move slowly, giving creatures time to swim away, and that since the screen is impenetrable, it can't trap creatures like a net could. The current should flow under the screen, carrying drifting organisms below it.

Plastic will be removed periodically, and people will always check for marine life before doing so, according to the organization.

The nonprofit recently conducted and released an Environmental Impact Assessment, concluding that the system posed mostly low risks of environmental harms (with a medium risk of sea turtles feeding on collected plastic).

But all the researchers Shiffman spoke with said the system would either probably or definitely kill marine life.

Whether the system will even be able to effectively trap plastic at the ocean's surface is still an open question, Kim Martini, an oceanographer, recently told the Canadian Broadcasting Company. It's likely that once things start to grow on the structures, they could be weighed down enough that plastic just flows over them, she said.

It's possible that storms or waves could eventually turn the arrays into debris, though The Ocean Cleanup says it has designed them to withstand large weather systems.

Even if The Ocean Cleanup can capture some amount of plastic, recycling it will still be a problem. Unlike with glass and aluminum, plastic recycling doesn't work well in the first place. Plastics break down into more degraded, lower-quality materials over time and may not be able to be recycled at all. Materials that have been degraded by ocean water and sunlight are even less likely to be turned into anything useful.

The group said samples collected on past expeditions were still recyclable and of "surprisingly good quality." It is still investigating recycling methods to figure out the best way to use the plastic.

Solving the plastic problem

By questioning whether The Ocean Cleanup's system can effectively remove a significant amount of plastic from the ocean, critics aren't saying that dealing with plastic pollution is hopeless — they're arguing for more effective solutions.

Most of these solutions involve stopping plastic from making its way out to sea.

Martini has argued that the group's arrays should be placed off the shores where most plastic enters the ocean.

The Ocean Cleanup says its goal is to focus on the gyres for now since there's already plastic there that "must be removed to prevent it from photodegrading and breaking down into microplastics, making it harder to remove and making it easier to mistake for food by sealife."

But the group does acknowledge that without stopping the flow of plastics from the shore, there's no way to keep the gyres plastic-free. "It would be nothing short of disheartening if we had to go back out to clean up again after a few years," the representative said. The Ocean Cleanup says it is considering other cleaning systems closer to shore in the future.

Other groups are also attempting to collect plastic before it goes out to sea. The Ocean Conservancy has collected more than 200 million pounds of trash from beaches, and Baltimore has a trash-collecting water wheel that has trapped more than 1.8 million pounds of trash in the Inner Harbor since May 2014.

As Rick Stafford, a professor of marine biology and conservation, wrote for The Conversation, local governments could incentivize proper disposal of plastic and eventually phase out disposable single-use plastics overall.

Eliminating single-use plastic waste would be a massive transformation for society — think of how many wrappers you tear off food products every day. But creating products meant to be used only once means that much of that waste is getting piled up somewhere. Since it's hard to effectively recycle plastic in the first place, much of that waste eventually makes it out to sea.

If we really want to stop that, the best way is probably to cut it off at the source and reduce our use of plastic overall.