(Reuters) The geology of Brazil’s volcanic Trindade Island has fascinated scientists for years, but the discovery of rocks made from plastic waste in this remote turtle sanctuary has raised alarm.
Molten plastic has become intertwined with rocks on the island, located 1,140km (708 miles) from the southeastern state of Espirito Santo, which researchers say is evidence of human’s growing influence on Earth’s geological cycles.
“This is new and scary at the same time, because pollution has reached geology,” said Fernanda Avelar Santos, a geologist at the Federal University of Parana.
Santos and her team conducted chemical tests to find out what kind of plastic is in the rocks, called “plastiglomerates,” because they’re made from a mixture of sedimentary grains and other debris that plastic holds together.
“We found that (the pollution) comes mainly from fishing nets, which is common on the beaches of Trinidade Island,” Santos said. “The (nets) get carried away by the ocean currents and pile up on the beach. When the temperature rises, this plastic melts and becomes embedded with the natural material of the beach.”
Molten plastic has become intertwined with rocks on the island.
Trindade Island is one of the world’s most important protected sites for green turtles, or Chelonia mydas, with thousands arriving each year to lay their eggs. The only human inhabitants on Trindade are members of the Brazilian Navy, which has a base on the island and protects the nesting turtles.
“The place where we found these samples (made of plastic) is a permanent protected area in Brazil, near where green turtles lay their eggs,” Santos said.
The discovery raises questions about humans’ legacy on Earth, Santos says.
“We talk so much about the Anthropocene, and this is it,” Santos said, referring to a proposed geological era defined by the impact of humans on the planet’s geology and ecosystems.
“The pollution, marine litter and plastic that is inappropriately dumped in the oceans is geological material… preserved in Earth’s geological records.”