(Reuters) — The geology of Brazil’s volcanic island of Trindade has fascinated scientists for years, but the discovery of rocks made of plastic debris in this remote turtle haven is raising alarm.
Molten plastic mixed with rocks on the island, located 1,140 kilometers from the southeastern state of Espirito Santo, is evidence of increasing human influence on Earth’s geological cycles, researchers say.
“This is new and terrifying at the same time, because pollution has reached geography,” said Fernanda Avelar Santos, a geologist at the Federal University of Paraná.
Santos and his team conducted chemical tests to find out what types of plastics the rocks contained, which are called “plastyglomerates” because they are made up of a mixture of sediment particles and other debris held together by plastic.
“We found that (the pollution) comes from fishing nets, which is the most common type of garbage on the beaches of Trinidad,” Santos said. “The nets are pulled by ocean currents and pile up on the beach. As temperatures rise, this plastic dissolves and becomes embedded with natural material on the beach.”
Trindade Island is one of the world’s most important green turtle conservation sites. Chelonia midas, where thousands of specimens come to spawn every year. Trindade’s only residents 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 protected area in Brazil, close to where green turtles lay their eggs,” explains Santos.
The discovery raises questions about the legacy of humans on Earth, Santos says.
“We talk a lot about anthropology, and this is the moment,” Santos said, referring to the geological era defined by human impact on the planet’s geography and ecosystems.
“Pollution, marine litter and improperly dumped plastics in the ocean are becoming geological material … preserved in the Earth’s geological record.”