CNN — 

At the mouth of the Motagua, Guatemala’s longest river, 40 million pounds (18 million kilograms) of trash pours into the ocean each year.

It is one of the most polluted rivers in Central America, winding 302 miles (486 kilometers) through Guatemala before flowing into the Gulf of Honduras and, ultimately, the Caribbean Sea. By some estimates, the trash carried downstream by the Motagua River makes up roughly 2% of the total plastic waste that enters the world’s oceans each year.

“Every 60 seconds, a dump truck full of plastic is entering the ocean (globally),” Alex Schulze, co-founder and CEO of 4ocean, a US-based startup that wants to end plastic pollution, told CNN.

Schulze founded 4ocean in 2017 along with his friend Andrew Cooper following a surfing trip in Bali, Indonesia, where they were shocked by the overwhelming quantity of plastic pollution in the ocean. The company collects trash from oceans, rivers and coastlines and converts it into products such as bracelets, building materials or fuel, which it then sells. Whatever the company cannot recycle, it sends to a landfill. Today, it has teams in Guatemala, the US state of Florida, and Indonesia and estimates it has collected more than 37 million tons of trash since 2017.

In Guatemala, in addition to trash-collecting missions undertaken by locally hired crews, the company installed a boom, a floating fence-like barrier, 30 miles (48 kilometers) upstream from the mouth of the Motagua River. Made of a durable fabric, the boom is designed to catch debris before it enters the bay, without disturbing wildlife.

“We hope to stop most of the trash and plastic that’s coming down the Río Motagua from inland during the rainy season before it reaches the ocean,” said Kevin Kuhlow, 4ocean’s country manager for Guatemala.

But the rainy season initially took a toll on the boom itself. Last year, a heavy storm dislodged the boom and fragments of it washed away downstream. To prevent this from happening again, 4ocean dug holes into the riverbed to securely anchor the system.