Micropolymers reduce the carbon that the ocean drags to the bottom

Madrid. Microplastics can reduce the ocean’s ability to help offset the climate crisis by slowing the rate at which carbon is drawn from the sea surface to the depths.

This is the conclusion of a new study published in the journal Marien Chemistryauthored by Northeastern University researcher Aron Stubbins.

For millennia, the ocean has been part of a carbon sink process in which dead phytoplankton clump together and fall to the depths of the ocean in showers of what looks like marine snowsays Stubbins, professor of marine and environmental sciences.

The resulting carbon sequestration is a marine version of how Earth’s trees and plants take carbon from the atmosphere and store it in the soil, he says in a statement.

But research shows that microplastics in the ocean are slowing the process by making the marine snow be more buoyant, Stubbins points out.

Plastics want to float. If phytoplankton grow on these in biofilms, rather than as free-living organisms, that changes the buoyancy of the phytoplankton when it dies.says the Northeastern University researcher.

Basically, plastics are slowing the rate of sinking of marine snow, potentially reducing the efficiency with which the ocean can remove carbon dioxide from the atmosphere.he points out.

For the study, the researchers grew the tiny single-celled plankton in tanks with and without exposure to microplastics.

They then carried out their own version of a race to the bottom. They placed regular clumps of phytoplankton in a measuring cylinder filled with seawater and placed it laced with microplastics in another cylinder.

The speed with which they sank was timed. The plastic ones were slower, about 20 percentStubbins mentioned.

The study carried out, in collaboration with the University of New Hampshire, shows that the slowdown in the rate of decline of marine snow mixed with microplastics comes at a time when carbon sequestration is more important than ever.

As that carbon sinks, it is transported to deeper areas of the ocean.Stubbins said. It is very important to know to what extent the ocean compensates for warming due to human carbon dioxide emissions.