Plastic rocks discovered on a remote island are a ‘horrifying’ marker of the anthropocene

Trindade island, a volcanic outcrop off the coast of Brazil, is one of the most isolated places on Earth. But there, geologist Fernanda Avelar Santos found rocks formed from the glut of plastic pollution floating in the ocean.

Santos is a professor at the Federal University of Parana, in southern Brazil. She first found the plastic rocks in 2019 after travelling to Trinidade to research her doctoral thesis, which was on a different topic: landslides, erosion, and other “geological risks”. However, while working near a protected nature reserve known as Turtle Beach, she came across a large outcrop of blue-green rocks. Intrigued, she took some back to her lab after her two-month expedition.

She and her team identified the specimens as a new kind of geological formation. The rocks were formed by merging the materials and processes the Earth has used to form rocks for billions of years with a new ingredient: plastic rubbish.

Santos told Agence France-Presse (AFP):

We concluded that human beings are now acting as a geological agent, influencing processes that were previously completely natural, like rock formation…

It fits in with the idea of the Anthropocene, which scientists are talking about a lot these days: the geological era of human beings influencing the planet’s natural processes. This type of rock-like plastic will be preserved in the geological record and mark the Anthropocene.

Horrifying discovery

Santos said the finding left her “disturbed” and “upset”. She described Trindade as “like paradise”. Its remoteness makes the island a refuge for all sorts of species including sea birds, unique species of fish, nearly extinct crabs, and green turtles.

The only human presence on the South Atlantic island is a small Brazilian military base and a scientific research centre. As a result, Santos described the island as “marvellous”. However, she went on to say that:

it was all the more horrifying to find something like this – and on one of the most ecologically important beaches.

Continuing her research, she found similar rock-like plastic formations had previously been reported elsewhere since 2014. They included Hawaii, Britain, Italy, and Japan. However, Santos said Trindade island is the most remote place on the planet that people have discovered these rocks. And she fears that, as the rocks erode, they will create more microplastic pollution in the environment, further contaminating the island’s food chain.

The ubiquity of plastic

She and her team’s study, published in the journal Marine Pollution Bulletin, classified the new “rocks” into several types. They are: plastiglomerates, similar to sedimentary rocks; pyroplastics, similar to clastic rocks; and plastistones, similar to igneous rocks formed by lava flow. Researchers hadn’t previously identified plastitones.

The team wrote:

Marine pollution is provoking a paradigm shift for concepts of rock and sedimentary deposit formations

Human interventions are now so pervasive that one has to question what is truly natural.

The main ingredient in the rocks Santos discovered was remnants of fishing nets, they found. But ocean currents have also swept an abundance of bottles, household waste and other plastic rubbish from around the world to the island. Santos said she plans to make the topic her main research focus, adding that Trinidade:

is the most pristine place I’ve ever seen…

Seeing how vulnerable it is to the trash contaminating our oceans shows how pervasive the problem is worldwide.

Featured image via Reuters/YouTube

Additional reporting by Agence France-Presse