I’m the founder and chief executive of The Ocean Cleanup, a non-profit organization based in Rotterdam, the Netherlands, that aims to remove plastic pollution from the oceans. My team and I do this in two main ways: by dragging nets across areas where plastic accumulates, such as the Great Pacific Garbage Patch, a collection of debris in the North Pacific Ocean; and by intercepting waste in rivers before it reaches the sea. We want to reduce ocean plastic pollution by 90% by 2040.

This photo was taken in Guatemala near the mouth of the Motagua River, downstream of Guatemala City and a huge landfill. Every year, around 20,000 tonnes of plastic flow down the river into the Caribbean Sea. In mid-2022, we put an eight-metre-high avalanche fence across the river to catch the plastic. Soon after, heavy rains washed about one million kilogrammes of waste down the river in 20 minutes, causing the foundations of our fence to fail. In the picture, I’m assessing the aftermath of that event. We are now engineering an improved version of the barrier, which we hope will be in place before the next rainy season.

There’s much we don’t understand about plastic pollution in the oceans. When we started, we knew about the Great Pacific Garbage Patch, but we didn’t know how big it was or how much plastic enters the oceans every year. Plastic can take decades to break down — in the Pacific garbage patch, much of the rubbish is from the 1990s, and we have even found items from the 1960s.

The Ocean Cleanup has more than 100 staff members, including scientists. We try to be a haven for researchers who want to do applied research and make a difference. So far, we’ve removed around two million kilogrammes of rubbish from rivers and the ocean, including about 200,000 kilogrammes from the Pacific garbage patch. That’s only a tiny amount — about 0.2% of what we estimate is in the garbage patch. But we hope to dramatically increase the amount of plastic removed.