A free diver surrounded by plastic pollution
SEBNE COSKUN/ANADOLU AGENTION Via Getty Images
Microplastics do not only flow the surface of the sea. A global study of the small particles reveals that they are prevalent throughout the water column – even at the deepest depths – which can affect the ocean’s ability to remove carbon from the atmosphere.
“These are millions of metric tons of these things throughout the interior of the ocean,” says Tracy Mance at Florida Atlantic University.
Mance and his colleagues have undergone microplastic measurements made in the last decade from nearly 2,000 places around the world. While most microplastic measurements focused on the low surface of the sea, the data set included samples from a variety of depths, including the deepest parts of the sea.
They found that microplastics have been recorded almost everywhere people have looked for them. It included the Mariana ditch, where more than 13,000 microplastic partical partic partic partic per year. Cubic meters were measured almost 7 kilometers down.
The researchers were surprising to see the smallest partikuli are almost elegantly distributed throughout the water column – not sinking or floating on the surface, but suspended. “We expect to find plastic at the bottom of the sea and at the top of the sea. But not everywhere,” says Aron Stubbins at Northeastern University in Massachusetts.
They also found that polymers in these plastic account for a significant part of the carbon party fluid surroundings. At depths of 2000 meters, where there is less biological activity than closer to the surface, they make up up to 5 percent of the carbon.
The ecological consequences of this are largely unknown, but one is that bubble wrap consumed by plankton could reduce the amount of carbon sinking into the depth of their fecal pellets and dead bodies. That could inhibit the ocean’s ability to take co up2 From the atmosphere via the biological carbon pump, stubbins say. However, he points out that we are far from able to estimate the size of this effect. “We are currently discovering the extent of plastic over the sea,” he says.
“It can be ignored a long time by chemists or biologists trying to out how big chunks of the world seas work,” says Douglas McCauley at the University of California Santa Barbara. He says the study helps explain discrepancies between estimates of the millions of tons of plastic flowing into the sea and the amount that is unclear measured there. “It did not disappear, unfortunate. It is distributed in microplastic form over the water column,” he says.
Topics: