The mass of invisible microplastics found in the upper waters of the Atlantic Ocean could amount to as much as 21 million tonnes, according to new research. The study focussed on polyethylene, polypropylene and polystyrene, which are commercially the most prominent plastic types.
The mass of invisible microplastics found in the upper waters of the Atlantic Ocean could amount to 12 to 21 million tonnes, according to new research.
This figure is only for three of the most common types of plastic litter in a limited size range, but it is comparable in magnitude to estimates of all plastic waste that has entered the Atlantic Ocean over the past 65 years: 17 million tonnes. This suggests that the supply of plastic to the ocean have been substantially underestimated.
Lead author Dr Katsiaryna Pabortsava from the National Oceanography Centre (NOC) said in a statement: “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. Our research is the first to have done this across the entire Atlantic, from the UK to the Falklands.”
The seawater samples were collected during the 26th Atlantic Meridional Transect expedition in September to November 2016. The researchers filtered large volumes of seawater at three selected depths in the top 200 metres and detected and identified plastic contaminants using state-of-the-art spectroscopic imaging technique.
Their study focussed on polyethylene, polypropylene and polystyrene, which are commercially most prominent and also most littered plastic types.
Image credit: Agustin Rafael Reyes, flickr/Creative Commons