(Reuters) The geology of the volcanic island of Trindade in Brazil has fascinated scientists for years, but the discovery of rocks made from plastic debris in this remote turtle refuge is causing concern.
The melted plastic became entwined with rocks on the island, located 1,140 km (708 miles) from the southeastern state of Espirito Santo, which researchers say is evidence of the increasing influence of man on the geological cycles of the Earth.
“It’s new and terrifying at the same time, because pollution has reached geology,” said Fernanda Avelar Santos, a geologist at the Federal University of Parana.
Santos and his team performed chemical tests to find out what kind of plastic is in the rocks called “plastiglomerates” because they are made up of a mixture of sedimentary granules and other debris held together by plastic.
“We have identified (the pollution) mainly comes from fishing nets, which are very common debris on beaches on the island of Trinidade,” Santos said. “The (nets) are carried by the sea currents and accumulate on the beach. When the temperature rises, this plastic melts and becomes embedded in the natural material of the beach.”
Trindade Island is one of the world’s most important conservation sites for green sea turtles, or Chelonia mydas, with thousands arriving each year to lay their eggs. The only human inhabitants of Trindade are members of the Brazilian Navy, which maintains a base on the island and protects nesting turtles.
“The place where we found these (plastic) samples is a permanently preserved area in Brazil, near where the green sea turtles lay their eggs,” Santos said.
The discovery raises questions about the legacy of humans on earth, Santos says.
“We talk so much about the Anthropocene, and that’s it,” Santos said, referring to a proposed geological epoch defined by humans’ impact on the planet’s geology and ecosystems.
“Pollution, garbage in the sea, and plastic dumped incorrectly in the oceans become geological materials…preserved in Earth’s geological record.”