When the general public thinks of the problems of plastic leaking into the environment, they may use the image of a turtle with a plastic straw caught in its nose or birds caught up in a plastic ring originally used for a multipack of drinks.
Now there are the plastic rocks on a remote volcanic island off Brazil that is home to a turtle sanctuary.
Fernanda Avelar Santos, a geologist at the Federal University of Parana, documented the "plastiglomerates" — made up of natural sediment and bound by plastic — on Trinidade.
"We identified [the pollution] mainly comes from fishing nets, which is very common debris on Trinidade Island's beaches," Santos told Reuters. "The [nets] are dragged by the marine currents and accumulate on the beach. When the temperature rises, this plastic melts and becomes embedded with the beach's natural material."
This isn't the first time plastiglomerates have been found, according to the Coordination for the Improvement of Higher Education Personnel (CAPES), part of the Brazilian Ministry of Education.
They were first reported in Hawaii and have since shown up in England, Japan, Italy, Portugal and Peru. Those sites, however, had individual rocks. On Trinidade they combined to create an outcrop of several "plastic rocks."