Studies on the intestines of fish in the past show that they have been eating plastic since 1950
This from a biologist at Loyola University Chicago The research focused on microplastics, which are small fragments smaller than 5 mm after the decomposition of shopping bags, beverage bottles and other plastic items. Recently, scientists studying the impact of microplastics on marine life have made some worrying discoveries. For example, microplastics can cause fish aneurysms and reproductive changes, affect the cognitive ability of hermit crabs, and weaken the physical properties of mussels. They also found evidence of the spread of microplastics along the food chain, and research on the potential impact on humans found that microplastics may change the shape of lung cells.
The authors of this new study set out to study how microplastics accumulated over the past century and what this meant for fish in the past. So they went to the Field Museum in Chicago, where about 2 million fish specimens are kept in alcohol and underground collections.
Tim, associate professor of biology at Loyola University Chicago Hoellein said: “In the past 10 or 15 years, the public has realized that there is a problem with plastic in water. But in fact, since the invention of plastic, microorganisms may be exposed to plastic waste. We don’t know what the historical background looks like. Observing museum specimens is essentially a way for us to go back in time.”
This study paid special attention to four species of fish: largemouth bass, channel catfish, sandfish, and goby, all of which can be recorded from 2017 It dates back to 1900. To complete the study, the research team also collected fresh samples of these same species.
The main author of the paper, Loren Hou, said: “We will take these jars full of fish to find some ordinary samples, not the largest or the smallest, and then we will use a scalpel and forceps to dissect Their digestive tracts. We try to obtain at least 5 specimens every ten years.”
Afterwards, these digestive tracts are treated with hydrogen peroxide, the compound can break down all organic matter but leave behind any potential plastic . Scientists use microscopes to identify suspicious materials with smooth edges that may be microplastics, and then collaborate with researchers at the University of Toronto to confirm their chemical characteristics through Raman spectroscopy.
This shows that plastic did not appear until the middle of the last century, but when the plastic manufacturing industry was industrialized in the 1950s, the concentration of plastic began to soar. These plastics are found in the form of fibers. They come from polymers and a range of natural and synthetic textiles. Researchers describe this discovery and the significant increase in attention as “alarm bells” and “alarm bells.”
“We found that the content of microplastics in the intestines of these fishes basically increased with the increase in plastic production. This is the same pattern they found in marine sediments, which follows that plastic has nowhere to go. The general trend of being absent,” said Caleb McMahan, an ichthyologist at the Field Museum.