(Gerlache Strait) In the fragile and isolated ecosystem of Antarctica, Colombian researcher Paulo Tigreros plunges his net into the icy waters to collect tiny particles. He knows that the presence of microplastics in one of the best preserved corners of the world is a thermometer of the planet’s pollution.
Like a sieve, the net lets water pass through and retains the small solid particles that float in these icy waters of the Gerlache Strait, a natural corridor approximately 160 kilometers long separating the Palmer Archipelago and the end of the Antarctic Peninsula.
At the end of the world, far from the hustle and bustle of the planet, this pristine place is supposed to be safe from the environmental degradation that affects the rest of the Earth.
The samples collected will, after microscopic examinations and other analyses, determine the level of microplastics they contain. The size of these particles – most often invisible to the naked eye – made of polymers and other toxic compounds varies between 5 mm to a thousandth of a millimeter.
Deadly threat
For the 51-year-old marine biologist and his fellow scientists aboard the ARC Simon Bolivar, a Colombian navy ship, there is no doubt that these particles have already reached Antarctica, where the waters of the Pacific Oceans, Atlantic and Indian come together.
As a result of the large-scale pollution of the world’s waters by our millions of tons of waste, the presence of these particles has already been proven many times in these oceans.
These microplastics are the result of the physical and chemical degradation of objects that take hundreds of years to degrade. Their impacts have only been studied since the beginning of the 2000s, but are still little known.
For Mr. Tigreros, they are already “omnipresent” in the oceans, their effects can be fatal for animals and ecosystems.
“We consider Antarctica as a continent totally isolated” from human activity, but “it reflects the environmental problems” of the planet, explains to AFP Jorge Tadeo Lozano, researcher at the University of Bogota, who accompanied this 10e Colombian Navy scientific expedition.
Research carried out in 2019 by New Zealand’s University of Canterbury revealed the existence of microplastics in Antarctic snow, while more than 430 million tonnes of plastic are produced each year worldwide, according to the UN.
Despite its remoteness, the “white continent” is very exposed to external threats, Mr. Tigreros is alarmed.
The particles may have arrived there naturally, carried by ocean currents heading south. They can also travel in the atmosphere or in the excrement of marine mammals and fish which, at certain times of the year, migrate to the tropics only to return a few months later.
With pliers in hand, the researcher grabs a krill and some algae recovered from a sample. The crustacean feeds on these microscopic algae called phytoplankton, but which it often confuses with microplastics floating in its environment due to their small size.
Thus contaminated, krill is itself the basis for the consumption of many other larger animals. And the rest of the food chain is affected.
“When a whale feeds on this krill, the microplastic most likely enters its intestines,” affecting its lung system, reproductive system and even its ability to swim.
The Antarctic ice sheet, with its penguins and seals, has been suffering for years from rising global temperatures.
According to the United Nations International Atomic Energy Agency (IAEA), which has just launched an expedition with Argentina on this theme, microplastics could further damage the great white continent “by reducing the reflection of the ice , by modifying the roughness of the surface, by stimulating microbial activity” and “by acting as a thermal insulator”.
According to the World Meteorological Organization, the melting of glaciers, which contain 90% of the planet’s fresh water, could cause sea levels to rise by up to 60 meters.