Plastic accumulation in the oceans and in our environment has been a growing problem for longer than what most people seem to think. After World War II, plastic fragments have been building up and oceanographers have confirmed this buildup off the Californian coast.
In a recent report, researchers have looked into a sample of sediments that are at most 200 years old from the Californian coast. They have found that since the 19040s, the volume of microplastics found in these sediments doubles every 15 years. Of these volume, about 90 percent were synthetic fibers from clothes.
Lead author and Scripps Institution of Oceanography microplastics biologist, Jennifer Brandon, emphasized that our 'love of plastics' leaves a mark in nature. "This study shows that our plastic production is being almost perfectly copied in our sedimentary record," she said. "Our love of plastic is actually being left behind in our fossil record." She then said that their study could lead to a new method of defining the Anthropocene.
Their study, published in Science Advances, did not focus on the effects of plastic fragments in marine life and the environment, but the researchers still gave a warning as clothing production from synthetic materials continue to increase.
In an analysis, the researchers collected a box core that had samples from Santa Barbara Basin, which they chose to star in their study since it has a unique sediment structure. The Santa Barbara Channel had a high surface productivity and restricted water movement, resulting in an anaerobic bottom water, which minimizes bioturbation and allows the preservation of millimeter-scale seasonal laminae couplets. Each of these couplets would represent a year in their scale.
They then used Fourier transform infrared spectroscopy to identify plastic particles, which turned out to be a bit difficult because of the particle sizes. Comparing with the standard reference spectra however, 87.5 percent of the visually identified plastic particles matched with plastic polymers. From the box core sample were fibers, fragments, films, and spherical particles.
The researchers theorize that one day, the age of rocks and fossils could be determined by the amount of plastic fragments they contain.
