A study estimates that, at a depth of 200 meters, there are 12 to 21 million tons of plastic.
It is already known that, unfortunately, there is a large mass of “invisible” microplastics in the Atlantic Ocean. But according to a new study, this material is 10 times more abundant in Atlantic waters than expected.
The study was conducted by the UK’s National Oceanography Centre (NOC) and published in August in the journal Nature Communications. According to the article, there are between 12 and 21 million tons of microplastic at a depth of 200 meters.
“If we assume that the concentration of microplastics we measured at around 200 meters deep is representative of that in the water mass to the seafloor below with an average depth of about 3000 meters, then the Atlantic Ocean might hold about 200 million tons of plastic litter,” said Richard Lampitt, the study’s co-author and a member of the NOC.
The initial estimate was that the Atlantic Ocean had received “only” about 17 million tons of microplastics in the past 65 years.
The analysis was carried out by Lampitt and researcher Katsiaryna Pabortsava, who also works at the NOC, and was based on seawater samples collected in 2016, at three different depths up to 200 meters.
The study focused on the three most common types of plastic litter: polyethylene, polypropylene, and polystyrene, which are also the most commercialized and discarded types in the world.
“Previously, we couldn’t balance the mass of floating plastic we observed with the mass we thought had entered the ocean since 1950. This is because earlier studies hadn’t been measuring the concentrations of ‘invisible’ microplastic particles beneath the ocean surface,” Pabortsava said.
According to the researchers, to understand the risk that this pollution poses to humanity, they need to study the amount and characteristics of the material, how it reaches the oceans, what is its toxicity and how it degrades.
The study shows that scientists, until then, had a poor understanding of these factors, impairing the understanding of the problem as a whole.