Could a vast rubber boom clean up tonnes of ocean plastic?

They’re calling it “Boomy McBoomface”. A bizarre object afloat in the North Sea looks like a string of enormous rubber sausages, but is really part of an audacious plan to finally start pulling our plastic waste out of the sea.

There are at least 244,000 tonnes of plastic floating in the oceans, with some estimates suggesting that 9 million tonnes of the stuff may have entered the oceans since the 1970s. Vast gyres of plastic are circulating in the mid-Pacific, and these are now being targeted by the Ocean Cleanup project, a foundation in Delft, the Netherlands.

Its goal is to install a 100-kilometre-long V-shaped boom in the middle of the Pacific, which will collect plastic lapping against it. The waste gets pushed towards the V’s apex, where the litter and debris can be collected and sent for recycling.

The idea is unproven and expensive. A feasibility study published in 2014 estimated that such a boom could clean up half the plastic in the gyres in only 10 years – but at cost of about £300 million.

It also remains to be seen how effective such a method might be. The boom can only collect plastic that is on the sea surface, but we don’t yet know how much of the plastic in our oceans is floating.

Undeterred, the team is going ahead with their biggest trial yet. “We’re not saying this will work,” says team leader Boyan Slat, who is already a well-known figure in the Netherlands at the age of 22. “We’re saying, let’s give it a try.”

This week in the Hague, the team unveiled their latest prototype, a 100-metre-long boom that, predictably, acquired its name in a Twitter contest. On Thursday, the boom was towed out to 23 kilometres off the coast of the Netherlands.

Slat says the primary purpose of this £3 million test is simply to see if the boom can withstand the area’s strong currents and storms. It’s not clear whether the boom’s anchors – which are cheaper than those usually used for permanent structures at sea – will keep it in place over the year-long trial.

One of the team’s researchers, oceanographer Julia Reisser, says it is also a chance to test the boom’s ability to collect plastic.

“We plan to chuck a load of biodegradable plastic, or maybe ice, which has about the same buoyancy as plastic, in front of it and see how much is caught and how much flows under,” she says. A drone with a precision camera will track each piece.

“A few years ago, this would seem berserk: to think you could clean up the ocean,” said Sharon Dijksma, the Netherlands environment minister, at the launch. “But now we’re clearing a space in the North Sea to test it.”

The Netherlands government is providing a third of the funding for the test. But the project has not been spared criticism, with some suggesting that marine life might get trapped in it.