Ocean microplastics can drift for years or sink rapidly: Analysis reveals two distinct pathways
Their findings showed that concentrations of small microplastics suspended in the ocean range from 1,000 to 10,000 particles per cubic meter. The team also discovered that small microplastics sink to the depths of the ocean in two distinct ways: some attain near-neutral buoyancy and drift at specific depths, while others sink rapidly to the deep sea.
Background on microplastics and their challenges
Since the advent of plastic in the early 20th century, plastic waste and pollution have been a global issue. As plastics degrade, they break off into smaller pieces. When they reach less than 5 mm in size, they are called microplastics.
“When these microplastics degrade further to 10–300 µm, we call them small microplastics. Many researchers are investigating the distribution and movement of microplastics in the ocean. However, when they reach that size, they become harder to collect and analyze,” explains Professor Atsuhiko Isobe of Kyushu University Research Institute for Applied Mechanics and one of the researchers who led the study.
