The total amount of microplastics deposited at the bottom of the Mediterranean Sea has tripled in the past two decades, with a development consistent with the type and volume of consumption of plastic products by human societies in the main urban centers in the north and southeast of the sea, according to a study prepared by researchers at the University of Environmental Science and Technology Institute. Autonomous Barcelona (ICTA-UAB) and the Department of the Built Environment at Aalborg University (AAU-BUILD).
The study, published in the December 6 issue of the journal “Environmental Science & Technology”, shows that microplastics are preserved unchanged in marine sediments, and that the mass of microplastics that is buried on the sea floor keeps pace with the increase in microplastics. Plastic production at the global level from 1965 to 2016.
While almost all open oceans and seas of the world are polluted with microplastics, the Mediterranean Sea has become a hotspot for pollution with this type of material, due to the large population density on its coasts from all sides, which makes it a trap for plastic debris.
In a statement to Al Jazeera Net via e-mail, the lead author of the study, Laura Sanchez, a doctoral researcher at the University of Barcelona, said that the results clearly show that the quantities of plastic particles deposited at the bottom of the Mediterranean sea since 2000 have increased 3 times more than in the past two decades, due to the increasing dependence on plastic. Globally hence the increase of this type of pollutants.
Sanchez added that the sediment analyzed had remained unchanged on the sea floor since it was deposited decades ago, which allowed the research team to see how the accumulation of polyethylene and polypropylene particles from packaging, bottles and food film, as well as polyester from synthetic fibers in clothing fabrics, increased during the two decades. the last two.
According to the researcher, the plastic materials submerged at the bottom of the Mediterranean Sea, once they are deposited on the sea floor, are no longer biodegradable, either because of the decreased chances of them being exposed to corrosion, oxygen or light.
The fracturing process occurs mainly in beach sediments, at the sea surface, or in the water column. Once the material is deposited on the sea floor, the chances of decomposition are minimal, so plastics have remained since the 1960s on the sea floor, leaving the footprint of human pollution in the darkest parts of the planet.
Advanced monitoring technology
The researchers collected a group of sediments from the Mediterranean Sea and then used advanced imaging technology to study the microplastics they contained.
This allowed them to fill in an important gap about the accumulation of microplastic particles in marine sediments, and to understand how they change or not change after they become embedded in the sediment, according to the press release published on the University of Barcelona website.
The sediments were collected in November 2019, on board the ship Sarmiento de Gamboa, on an expedition that sailed from Barcelona to Tarragona in Spain.
The researchers chose the western Mediterranean as the study area as the rivers there were identified as hotspots and an important source of many pollutants, from microplastics to chemicals.
Researchers believe that more than 229,000 tons of plastic waste leak into the Mediterranean every year, the equivalent of more than 500 shipping containers per day. This amount is expected to double by 2040.
Countries such as Egypt, Italy and Turkey are the most countries in the Mediterranean basin dumping plastic waste into the sea through their river mouths or coastal residential communities.