Media report that millions of metric tons of plastic waste enter the ocean every year, but beyond that, little is known where they will eventually go. When researchers tracked their paths in the marine environment, they found the highest concentration of microplastics on the sea floor on record. In the process, deep ocean flows become conveyor belts for this waste.
In late March, scientists at the University of Manchester published a research paper describing the results of a tank experiment that simulated the flow of sediment on the seabed. In the experiment, scientists discovered an underwater avalanche that pushes tiny plastic fibers from shore into the deep sea.
Now, a new study from the same team builds on this knowledge and then works with other researchers across Europe to explore how ocean currents shape the flow of deep-sea plastic waste. The team collected sediment samples from the Mediterranean Sea, and then they began analyzing them and the ocean currents around them to understand their composition and how they formed.
This means that researchers need to separate tiny plastic particles from sediments in the lab and use infrared spectra to determine different types of plastic. In the process, the team collected a total of 1.9 million pieces of plastic debris, the highest concentration of plastic fragments on the seafloor on record, and the result of ocean currents gathering them in certain places.
It is reported that the team found that most of the seafloor microplastics from textiles and clothing fibers. Given their abundance and the way they are transported in the marine environment, the team compared these particles to any sedimentthat that can be found on the seabed.
“Unfortunately, plastic has become a new type of sediment particle that is distributed on the ocean floor along with sand, mud and nutrients,” said Florian Pohl, Ph.D., of Durham University, who was involved in the study. As a result, our research shows that sediment transport processes such as ocean currents can concentrate plastic particles in certain locations on the ocean floor. “
These findings could help researchers better understand how and why these hotspots are formed at specific locations, which will provide a broader understanding of how plastics are transmitted in the marine environment.