How the oceans can clean themselves – A moonshot project

Boyan Slat outlines his ideas for harnessing the power of the ocean to clean up the five gyres.

Boyan Slat tells us that every year we produce about three hundred million tons of plastic, and much of that plastic finds its way to the ocean. Waves and wind break the plastic down into smaller pieces over time, but the waste remains and does not disappear. Red particles look like food so that animals eat them and die. Plastics also can be absorbed by the water and change the chemical makeup of the water.

Slat outlines the several reasons that cleanup of the five gyres would be difficult. Five separate moving areas have all different kinds of plastics. Sizes range from large nets to tiny molecules. Financially the cleanup would need to be justified, and the total amount of plastic in the oceans would need to be known.

Boyan’s inspiration came when he saw some senior citizens throwing plastic into the water. He realized that pollution might never stop and the solution to plastic cleanup would be a combination of cleaning what was already in the water and putting less new plastic in the system.

On a fact-finding mission Slat realized that the microscopic particles in the water were forty times more prevalent than large plastic pieces. A new challenge was to find a way to remove small particles without taking the plankton that sea creatures need to survive.

Using his own data and help from some maritime universities Slat estimated that there would be 7.25million tons of plastic in the gyres by 2020. Boyan’s radical proposal is that the great pacific gyre can completely clean itself in five years.

Slat’s solution is to use the same ocean currents that pulled the plastic out to sea, and fix the cleanup ships to the seabed while the currents move the water through the cleanup booms.

He found that the best shape for his anchored cleanup ships was a manta ray, mimicking the way that a ray floats through the water. Boyan imagines that an array of twenty four of these platforms could clean an entire ocean.

The plan is short on details, but Slat estimates that by selling the plastic taken from the water that the project could pay for itself. The idea of using swirling currents to cycle water through cleanup booms is fascinating, and I would love to see this project and its goals realized.