Despite their name, microplastics are huge players in pollution around the world. These fibers, beads and debris (defined as less than 5 mm in size) permeate nearly all environments, especially the ocean. To track the issue, researchers are now looking for these sea-floating specks more than 300 miles away in space.
Recent research in scientific report It details how microplastics appear to flow along floating patches of oily and soapy substances called surfactants that make distinct footprints in ocean currents. These footprints are detectable by NASA’s Cyclone Global Navigation Satellite System (CYGNSS), a network of eight hurricane surveillance satellites, and tracking them will help map the spread of microplastics for cleanup and regulation. can support the efforts of
“In general, there is insufficient data on the concentration of microplastics in the ocean,” said Yulin Pan, a marine engineer and study co-author at the University of Michigan. The computer models and trawl samples are useful but incomplete, Pan adds.
The CYGNSS satellite radar measures sea surface roughness caused by wind-generated waves. In 2021, her CYGNSS researchers noticed that the radar was detecting a unique smooth area with few waves and small. Scientists noticed these anomalies juxtaposed with the infamous Great Pacific Garbage Patch and appeared to correlate with levels of microplastics in the water. It was used to track the flow of microplastics at spots.
But researchers still don’t know the mechanism behind the smoothness and whether it might be related to factors other than microplastics, such as marine organisms, other debris and chemical interactions. Determining the impact of microplastics is “difficult in the absence of adequate training data if there are microplastics in some parts of the ocean and we can remove them all and test again,” he said. , said Michel DiBenedetto, a mechanical engineer at the University of Washington. He studies the fluid dynamics of microplastics and was not involved in new research.
For research, Pang and his CYGNSS colleagues took the next best step. They used his 750,000-gallon indoor wave tank to simulate real-world ocean currents. They found that microplastics alone did not produce matching patches of smoothness at reported marine concentrations. . These chemicals, which affect wave activity by lowering the surface tension of water, often accompany microplastics as a by-product of plastic formation and decomposition, and are carried in the same ocean currents. Because satellites can easily spot the smoothing effect of surfactants, the substance could act as a tracer of the movement of microplastics, the researchers say.
DiBenedetto says tracking surfactants is a “worth pursuing” tactic, but more information is needed about its relationship to microplastics in the field. , the CYGNSS team is working with a National Oceanic and Atmospheric Administration research vessel to compare satellite data with water samples from the Great Pacific Garbage Patch. This comparison should further solidify the correlation between surfactants and microplastics, Pan says.
Microplastics “can persist for a very long time,” DiBenedetto says. “If you want to invest in a solution, you want to know how plastic naturally migrates. You can look for it.”
