Plastic waste pollutes the world’s oceans – but how many exactly? A research team now wants to use new calculations to create facts for the Mediterranean on the basis of which the garbage can be combated.
Athens – shopping bags, water bottles, styrofoam, microparticles – according to a recent study, around 3760 tons of plastic drift on the surface of the Mediterranean alone.
It is a “shocking amount”, write scientists from the Greek Center for Marine Research (HCMR) about their results presented in the journal “Frontiers in Marine Science”. Shocking above all because, apart from the floating plastic, a large part of the material sinks to the sea floor.
According to the team led by Kostas Tsiaras from the HCMR, the Mediterranean Sea is a hotspot for plastic pollution because many stretches of coast are densely populated. Added to this are factors such as tourism, fishing, shipping and, last but not least, geography – the water exchange between the inland sea and the Atlantic is comparatively low.
Using a new calculation model, the scientists have determined that around 17,600 tons of plastic end up in the Mediterranean every year. 3760 tons of these are currently floating on the surface. Around 2800 tonnes (16 percent) of the total amount sink partly to the sea floor, the rest (84 percent) is washed up on beaches.
According to estimates, more than 250,000 tons of plastic waste swim in the oceans worldwide. “Simulations of the distribution of plastic in the ocean are currently characterized by a high degree of uncertainty,” explained Tsiaras. This is mainly due to the complexity of the processes. While the plastic bag floats on the surface for a long time, other plastic parts sink quickly; some are ingested by marine organisms or break down into small pieces. In addition, there are wind, waves and currents that drive the plastic over long distances.
The scientists’ study takes such factors into account. As a result, the experts have identified regions in which a particularly large amount of plastic ends up in the sea. Your new calculation model could help to examine the benefits of measures to contain the pollution and to develop and implement countermeasures in a more targeted manner, said Tsiaras. dpa
