Researchers examined the effects of five different chemical digestive aids on common plastics using low, medium, and high levels of zooplankton and have published the results in a new article in Science of the Total Environment.
Professor Sophie Leterme and researcher Elise Tuuri monitor microplastics in South Australian fresh and marine environments. (Image credit: Flinders University)
Plastic pollution is the leading form of marine litter, with ever-increasing levels of plastic waste pouring into streams and oceans every year, says Flinders University Ph.D. candidate Elise Tuuri.
“Plastic pollution is found in deep-sea and shoreline sediments, surface waters, and in marine biota. This has far-reaching impacts on ecosystems, including harm to marine animals, and has the potential to impact food webs and habitats,” she says.
“If scientists can find a way to determine the association of microplastics with zooplankton, we have a chance to understand and potentially curb damage from microplastics.”
Microplastics (particles less than 5 mm) are turning up in the guts of fish and shellfish, and there is concern about the safety of seafood. They can also occur in drinking water and other food products. Both plastics and chemical additives can be toxic.
The exponential growth of plastic production from 2 million metric tonnes in 1950 to 380 million metric tonnes in 2015 has made plastic pollution the predominant form of anthropogenic marine litter globally. Production is set to triple by 2050.
(Image credit: Flinders University)
Using cultured zooplankton kept in controlled conditions, the Flinders University researchers were able to examine the effects of five different chemical digestive aids—acid, two different alkaline, enzymatic, and oxidative—on common plastics (polyamide, polyethylene, polyethylene terephthalate, polypropylene, and polystyrene).
Professor Sophie Leterme, coauthor of the study recently published in Science of the Total Environment, says the various methods resulted in varying degrees of damage to the chemical and physical makeup of these commonly found environmental microplastic pollutants.
Flinders Professor Leterme, director of the ARC Centre for Biofilm Research and Innovation, says reporting microplastic abundances via these methods could help with the collection of data about microplastic particles.
Microplastics found in a South Australian waterway seen under a light microscope. (Image credit: Flinders University)
“This will enable us to understand the environmental and health impacts, and develop effective strategies to mitigate marine pollution,” she says.
The article, Efficacy of chemical digestion methods to reveal undamaged microplastics from planktonic samples (2024), by Elise M. Tuuri, Jason R. Gascooke, and Sophie C. Leterme, has been published in Science of the Total Environment DOI: 10.1016/j.scitotenv.2024.174279.
Researchers acknowledge the Kaurna people as Traditional Owners and ongoing Custodians of the lands and waters where this work was conducted.
Other acknowledgments: Dr. Tuuri’s study was partly funded by a Royal Society of South Australia Small Research Grant and an Australian Government Research Training Program (RTP) Scholarship. It was also supported by Flinders Microscopy and Microanalysis research facility at Flinders University and the SA node of the Australian National Fabrication Facility, funded under the National Collaborative Research Infrastructure Strategy.
