Microplastics have reached the most remote parts of the planet and become part of the food chain. On a small invertebrate in Antarctica, a team of researchers from the University of Siena in Italy, the National Dublin University in Ireland and the Trieste Synchrotron Radiation Laboratory in Italy discovered the latest evidence.
Plastic pollution has become one of the most important environmental issues in the world. From the snow in the Arctic and the highest peak of Mount Everest to the deepest part of the ocean floor, microplastic fragments exist in almost every ecosystem. A new study recently published in the Royal Society's "Biology Letters" showed that the research team found traces of polystyrene fragments in the Antarctic soil of the clams, confirming that microplastics have reached the most remote land on earth Food chain.
According to the study, most of the previous research on microplastics focused on aquatic ecosystems, especially marine ecosystems, while pollution on land was ignored. Scientists have only recently begun to study the pollution of microplastics in soil and terrestrial food networks. This study provides the first evidence of the penetration of microplastics into the Antarctic terrestrial food chain.
As early as the 1980s, scientists have observed large plastic fragments (greater than 1 cm) floating or stranded in Antarctica. Recently, medium plastic fragments (1–10 mm) and microplastic fragments (1–1000 μm) were found in surface water and sediments north of 60° south latitude. Marine mammals and seabirds in the Antarctic Islands have been entangled in plastic, or swallowed plastic fragments. Reports indicate that the spread of antibiotic resistance in Antarctic waters is related to stranded plastics.
Less than 1% of Antarctica is not covered by ice. Small and isolated land and freshwater systems are mainly composed of microbial communities, mossy banks and a few invertebrates. The soil micro-arthropods have adapted to an extreme but stable environment before the last glacial period, and together with microorganisms and nematodes form a simple but functional food network.
What surprised the research team was a type of crocodile insect called Cryptopygus antarcticus. This invertebrate, which is only 1 millimeter long, lives in the soil and feeds on moss, algae, and lichens. In February 2016, on the Fields Peninsula in King George Island, Antarctica, researchers discovered a piece of polystyrene foam washed onto the beach on which this creature relies. It is no different from our common plastic packaging, which is covered with moss, algae and lichen.
In order to determine whether the springtail worm was adversely affected by polystyrene, the researchers took the sample back to the laboratory. They used infrared spectroscopy to spy on the organism's digestive system and found a small amount of microplastic fragments in their bodies. In their report, they said that microplastics may first be ingested by algae, moss, and lichen on the surface of the plastic foam, and then enter the body when the clams eat.
The researchers pointed out that, although the clams are small, they are considered to be one of the main terrestrial species in Antarctica in areas not covered by ice. If the species is threatened by microplastics, it will have a huge impact on the area.
Elisa Bergami of the University of Siena, in an AFP report, said that ingestion of plastics by clams may cause microplastics to be redistributed to the surface of the soil and passed to their common predator-- Moss mites. At the same time, the microplastics in the springballs may flow through the food chain to larger animals such as penguins and seals, posing a new threat to Antarctica, which is facing multiple pressures such as global warming.
It has become a fact that microplastics have entered remote Antarctic soil, which means that it has penetrated deeply into the soil food network and may have become part of the soil biogeochemical cycle. In the future, researchers plan to conduct in-depth quantitative research, focusing on the impact of plastic pollution on ecosystems.
Surging News Reporter Yang Yang Intern Li Antian