Good news from Antarctica: researchers have examined emperor penguins and found no evidence of microplastics in their stomachs. The study, conducted by the University of Basel and the Alfred-Wegener Institute, is an important assessment of environmental pollution at the South Pole.
The researchers studied a colony of emperor penguins in Atka Bay, a remote area on the northeastern edge of the Ekström Ice Shelf. "We had already conducted studies of water samples there and discovered microplastics, albeit in low concentrations," explains Clara Leistenschneider, a doctoral candidate in the Department of Environmental Sciences at the University of Basel. The impact of pollution on the animals living there, however, was still largely unexplored.
To determine the level of microplastic contamination in the emperor penguins’ food sources, researchers analyzed the gizzard contents of 41 chicks found dead in the colony. They visually identified 85 potential plastic particles up to half a millimeter in size under the microscope and used spectral analysis to determine these particles’ properties.
Surprisingly, none of these particles were actually microplastics. The putative contamination was either natural materials - such as animal hair or plant matter - or clothing fibers and airborne particles that had entered the samples during processing. The researchers did not detect any synthetic polymers in the gizzards, as they report in the journal Science of the Total Environment.
Despite these positive findings, the future of the penguin colony remains uncertain. A rise in tourism and commercial fishing in the Southern Ocean may lead to an increase in local sources of microplastics. Currents may also carry flotsam from northern seas to Antarctica. The more trash that fills the world’s oceans, the more likely the contamination of the emperor penguins’ food web.
"It’s not too late for Antarctica, though," Leistenschneider stresses. To reduce the flow of plastic waste into our oceans - and ultimately to Antarctica - action must be taken at the source. Recycling and proper waste disposal, for instance, can help reduce the pollution. The Alfred-Wegener Institute plans to monitor the Atka Bay emperor penguin colony regularly to track the process of contamination over the long term.
Clara Leistenschneider et al.
No evidence of microplastic ingestion in emperor penguin chicks (Aptenodytes forsteri) from the Atka Bay colony (Dronning Maud Land, Antarctica)
Science of the Total Environment (2022), DOI: 10.1016/j.scitotenv.2022.158314