Clean beaches through satellites?

A new study shows how satellite monitoring can help combat litter in the world’s oceans.

The Mediterranean, known for its picturesque coasts and tourist hotspots, is unfortunately also a hotspot for rubbish. Researchers from the Spanish University of Cadiz, in collaboration with the European Space Agency (ESA), have developed a method to monitor litter accumulations on the sea surface using satellite images. This technology makes it possible to identify so-called “litter windrows” – strip-shaped accumulations of floating rubbish – in real time. These litter windrows contain up to 10,000 times more litter than the surrounding waters, making them ideal targets for satellite monitoring.

Drastic facts and figures

Over a period of just over six years, 14,374 of these litter strips were recorded throughout the Mediterranean. The data shows that the highest concentrations of litter are found near the coast, particularly in heavily populated and industrialised areas. The south-western Alboran Sea (between the Iberian Peninsula and North Africa), the coast of Algeria, the Gulf of Gabes (Tunisia) and the coast of Calabria in Italy are particularly affected. The concentration of litter is particularly high at the northern end of the Adriatic, which is consistent with other studies that have found high levels of microplastic and man-made litter in these areas.

Influences of weather and currents

The study, published in the scientific journal “Nature Communications”, emphasises that environmental factors such as heavy rainfall and flood events have a significant influence on the distribution of litter. For example, record rainfall in spring 2018 led to a massive increase in the concentration of waste off the French Riviera. These findings show how important it is to take environmental conditions into account when planning measures against marine litter.

Marine litter pollution is not only a serious problem in Southeast Asia, but – as this study shows – has also reached Europe and requires action. Through a combination of technology, conscious consumer habits and active participation, together we can help to protect our oceans for future generations.

Further information and the full study can be found here.