Discarded or drifting in the ocean, plastic debris can form floating islands at the surface of the water. Researchers believe that a significant amount also sinks, despite the fact that it is harder to identify. In a new study published in Environmental Science & Technology, one team used computer modeling to find out how far lightweight plastic fragments can travel when they fall into the Mediterranean Sea to identify. In a new study published in Environmental Science & Technology, one team used computer modeling to find out how far lightweight plastic fragments can travel when they fall into the Mediterranean Sea. Their outcomes suggest these particles can float farther submerged than recently suspected.
Plastic pollution is ravaging the oceans, affecting everything from water bottles to old shopping bags. Not only is this flotsam and jetsam unattractive, but creatures can become caught in it or erroneously eat it. Additionally, plastic waste may release organic pollutants if it remains in the water.
The issue is generally noticeable on a superficial level, where flows can total this trash into huge, supposed trash patches. However, waste plastic also accumulates much more deeply. Algae and other organisms can cling to even the lightest of materials, and other processes can cause them to sink.
Pieces of this light plastic, which regularly measure 5 millimeters or less, have turned up a portion of a mile beneath the surface. Although researchers generally assume that plastic falls directly from the surface, they know little about what happens when plastic sinks. However, Alberto Baudena and his coworkers were concerned that this light plastic might not travel in such a straightforward manner.
They incorporated extensive data already collected on floating plastic pollution in the Mediterranean Sea into an advanced computer model designed to track plastic at sea to test this assumption. They then mimicked almost 7.7 million pieces of plastic circulated across the ocean and followed their virtual ways to profundities as incredible as about a portion of a mile.
According to their findings, the slower the pieces sank, the further away from their places of origin they were carried by currents, with the slowest pieces traveling approximately 175 miles laterally. The team found that their simulations were consistent with the data available in the Mediterranean, despite the limited number of underwater observations of plastic distribution.
Additionally, their simulations suggested that plastic might be pushed toward the coast by currents and that only about 20% of pollution near the coast comes from the country closest to it. The researchers say that because these particles travel a long distance, this plastic is more likely to interact with and harm marine life.
More information: Alberto Baudena et al, Low-Density Plastic Debris Dispersion beneath the Mediterranean Sea Surface, Environmental Science & Technology (2023). DOI: 10.1021/acs.est.2c08873
