As nations prepare to meet in Uruguay to negotiate a new Global Plastics Treaty, a new study has revealed the discovery of synthetic plastic fibres in air, seawater, sediment and sea ice sampled in the Antarctic Weddell Sea. The field research was carried out by scientists from the University of Oxford and Nekton (a not-for-profit research institute) during an expedition to discover Sir Ernest Shackleton's ship, the Endurance. The results are published in the journal Frontiers in Marine Science.
Polarised Light Microscopy image of polyester textile fibre found in one of the Antarctic samples. Image credit: Nekton 2022.Fibrous polyesters, primarily from textiles, were found in all samples. The majority of microplastic fibres identified were found in the Antarctic air samples, revealing that Antarctic animals and seabirds could be breathing them.
'The issue of microplastic fibres is also an airborne problem reaching even the last remaining pristine environments on our planet', stated co-author Lucy Woodall, a Professor in the University of Oxford's Department of Biology and Principal Scientist at Nekton. 'Synthetic fibres are the most prevalent form of microplastic pollution globally and tackling this issue must be at the heart of the Plastic Treaty negotiations.' Professor Woodall was the first to reveal the prevalence of plastic in the deep sea in 2014.
A modelling analysis of air trajectories revealed that areas with higher numbers of fibres were associated with winds coming from southern South America. The discovery reveals that the Antarctic Circumpolar Current and the associated polar front is not, as previously thought, acting as an impenetrable barrier which would have prevented microplastics from entering the Antarctic region.
'Ocean currents and winds are the vectors for plastic pollution to travel across the globe and even to the remotest corners of the world', shared Nuria Rico Seijo, Nekton Research Scientist, the co-lead author of the research. 'The transboundary nature of microplastics pollution provides more evidence for the urgency and importance of a strong international plastic pollution treaty.'
The concentration of microplastics was also discovered by the team to be far higher in sea ice than in other sample types. Research indicates that microplastics are being trapped during the creation of the sea ice layer every year.
'Sea ice is mobile, can travel vast distances and reach the permanent ice shelves of the Antarctica continent where it can be trapped indefinitely with its gathered microplastic pollutants', shared Dr Mánus Cunningham, Nekton Research Scientist, the co-lead author of the research. 'We believe the acquisition of microplastics in the multi-year sea ice combined with its seasonal changes could also be considered a temporary sink and one of the main transporters of microplastics within the Antarctic region.'
Extensive research was also conducted on sediment samples retrieved at depths ranging from 323 to 530 metres below the sea's surface during the Weddell Sea Expedition. 'Our discovery of microplastics in seabed sediment samples has revealed evidence of a plastic sink in the depths of the Antarctic waters', said Professor Woodall. 'Yet again we have seen that plastic pollution is being transported great distances by wind, ice, and sea currents. The results of our research collectively demonstrate the vital importance of reducing plastic pollution globally.'
Scientists on the Weddell Sea Expedition taking ice core samples. Image credit: Nekton 2022.The scientific and forensic experts at Nekton's Oxford University and collaborating laboratories (Staffordshire University, University of Cape Town and Nelson Mandela University) used a range of investigative methods to analyse the samples in the study. These include optical (Polarised Light Microscopy), chemical (Raman Spectrometry) investigative technologies and even a specialist adhesive "crime scene" tape to identify the polymer type. The modelling analysis used a method called Air Mass Back Trajectory analysis.
According to the research team, the findings add urgency for a binding, globally agreed treaty to prevent microplastics from entering the environment, particularly oceans. Ahead of the Global Plastic Treaty discussions, they call on policy makers to:
⦁ Reduce plastic pollution and production globally, by creating a robust global plastics treaty that builds on national and regional initiatives;
⦁ Align plastic reduction actions with natural and societal targets to achieve multiple positive outcomes for society;
⦁ Empower local communities to co-develop and use programmes that support full life-cycle solutions to plastic waste management.
They add that concerned individuals can also play their part by adopting simple lifestyle habits to reduce synthetic microfibre pollution.
The study 'The transport and fate of microplastic fibres in the Antarctic: The role of multiple global processes' can be read in the journal Frontiers in Marine Science.
