Plastic waste in Mallorca. | A. Espejo

The study Quantifying Transboundary Plastic Pollution in Marine Protected Areas Across the Mediterranean Sea has found that 70% of macroplastics floating in the waters of the Balearic Islands come from Algeria.

Researchers from Australia, Greece and Italy presented this information at the recent Congress of Marine Protected Areas in Palma. They used a model for plastic drift based on Lagrangian mechanics, the aim of which was to predict the accumulation of plastics in certain areas of the Mediterranean.

The study concludes, among other things, that the size of plastics is directly related to their dispersion and their final destination. The larger the plastic, the more it is displaced, meaning that local efforts to reduce plastic pollution in protected areas are insufficient. The study stresses that "cooperation between Mediterranean countries is crucial for implementing appropriate plans against plastic pollution in their territorial waters, especially in protected ones".

Marine pollution by plastics has multiplied by ten since 1980. It is estimated that more than 10,000 tonnes of waste are deposited in the Mediterranean Sea each year. In 2015, scientists warned that "from an ecological point of view and from the perspective of marine surveillance, the case of the Mediterranean is of particular importance with regard to plastic pollution". "This semi-closed basin, with restricted water outlets, is one of the most polluted regions in the world." The situation has got worse since 2015.

The damage caused by macroplastics on marine ecosystems has regularly been highlighted. Turtles, for instance, can become entangled in plastic litter, sometimes with fatal consequences. This litter is ingested, which can also be fatal.

* Macroplastics are plastic items with a diameter of five millimetres and more; microplastics are plastic objects smaller than 5 millimetres.