An Australian man who has circumnavigated the world 11 times in a yacht has used his most recent voyage to collect seawater samples, which scientists now say are proof that microplastics have polluted even the world's most remote oceans.
Researchers from Curtin University used samples collected by lone sailor Jon Sanders to develop what they described as the first accurate measure of the presence of microplastics in far-flung ocean environments.
"The aim of the study was to target areas of the world's oceans not previously sampled for microplastics and to produce a complete global snapshot of microplastic distribution," Professor Kliti Grice, the lead researcher on the study, said.
Mr Sanders collected hundreds of samples during his expedition, which he completed in January last year, spanning 46,100 kilometres of ocean, including areas that have never been tested for microplastics before.
Project initiated by sailor
The water-sampling project was initiated by Mr Sanders, who had witnessed the extent of visible plastic pollution during his previous voyages around the world.
He wanted to investigate the presence of less-visible microplastics in oceans that had never been tested before.
Co-researcher Curtin University's Alan Scarlett told Nadia Mitsopoulos on ABC Radio Perth that previous tests had focused on other parts of the world.
"Most of the scientific voyages have been in the northern hemisphere, off like the UK coast and that sort of thing, so there was hardly any data on the Southern Ocean," Dr Scarlett said.
"So it was actually Jon that came up with this idea. He came to us."
Microplastics come from products such as vehicle tyres, textiles, building debris, cosmetics and packing materials.
Some of the particles are as small in width as a human hair.
Samples couriered to WA
During his 455-day journey on board the Perie Banou II, samples were couriered back to the lab in Western Australia as Mr Sanders stopped at various ports along the way.
Mr Scarlett said the average sample taken around the Australian coast detected about 33 particles of microplastics per cubic metre of seawater — which he said was in line with the global average.
But the scientists believe their findings may be just the tip of the iceberg, with many fibres that were detected being too small to analyse.
Mr Scarlett said other studies also suggested there were far greater numbers of microplastics at a greater depth than was sampled during this study.
Curtin University's analysis of the samples was released on Friday in a report entitled "Around the Plastic World in 455 Days."
