Research into plastic in the ocean advances further

The first part of the research to map plastic particles in the ocean has been successfully completed, researchers said on Friday. The European Space Agency (ESA) is working with the Dutch institute Deltares to develop satellites that can orbit the Earth to detect plastic in the world's seas.

Scientists currently estimate that about 10 million tons of plastic disappear into the seas every year, but researchers only know where 1% of the plastic ends up. "That can also be explained," said Peter de Maagt, head of the ESA team developing the antennas that will eventually be mounted on the satellite. "With studies of plastic waste in the ocean, scientists are fishing for plastic from a boat. In fact, it is difficult to determine how much plastic is one hundred kilometers to the left or right." That is why the ESA thinks that satellites should offer a solution to map a large part of the plastic.

In the first phase of the study, a large basin at Deltares was used. It is a kind of swimming pool 75 meters long, 9 meters wide and 1.3 meters deep in which the waves of the Atlantic Ocean can be simulated, explains Anton de Fockert, a sea current expert at Deltares. "We tested many different types of plastic in that basin, including pieces of plastic that we found ourselves in the river."

De Maagt explains that the measuring equipment was first set up for the basin without plastic in it. "After these tests, we threw a lot of plastic into the pool, just to see if our measuring equipment picked it up. We found out that it could be detected very clearly. So we started throwing smaller and smaller particles of plastic into the pool."

The particles ranged from plastic bottles, to Styrofoam, and even whole or partial straws. The more particles gathered together in the bath, the easier the measuring equipment picked up. But also small amounts were picked up by the equipment. "The tests showed that it should be possible to detect the amount of plastic that we know is in the ocean," says De Maagt.

In the next step, the researchers will test a number of theories in the Deltares bath. After that, the intention is to test the measuring equipment with a drone or aircraft on a lake or the North Sea. "Nature is capricious, there are always effects that you cannot model in the basin," De Maagt says.