This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Our oceans have effectively become trash dumps where massive quantities of plastic end up. So much so, in fact, that the largest offshore plastic accumulation zone has been labeled the Great Pacific Garbage Patch.
In new research published in the journal Communications Earth & Environment, scientists investigated whether decades of plastic pollution are changing the color of the ocean near this patch. And what they found could give us a new way to monitor plastic pollution at sea. Microplastics are formed when larger plastic items break down over time or are intentionally manufactured at that microscopic size.
Either way, tracking them is remarkably difficult. While it is relatively easy to spot large floating debris from far away, microplastics can be as small as a fraction of a micrometer. They are nearly impossible to scoop out at scale or detect using standard satellite infrared tools.
So a completely different strategy is needed. Instead of trying to spot floating litter directly, scientists realized they could look at the color of oceans. That's because it is influenced by what is dissolved or suspended in the water, including plankton, organic matter and potentially plastic particles.
Building on this idea, Shea Cheatham, Daniel Koestner and Børge Hamre at the University of Bergen in Norway set out to determine how microplastics might affect the ocean's color. They examined three separate 20-year sets of satellite data (from 2002 to 2022) covering the region around the Great Pacific Garbage Patch, located in the eastern North Pacific Ocean. The research team found that areas in and around this zone had become progressively brighter in blue and green light over time.
This was noticeably different from waters farther away, which did not show the same shift. That being said, they could not link the color change directly to microplastics from the satellite images alone. "The observation of spectral brightening consistent with a modeled increase in suspended microplastic concentration does not, in itself, indicate that microplastics are the root cause of the perceived brightening," wrote the study authors.
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