A set of plastic rocks found on Hawaii Island could become a new marker of human pollution.
Scientists from the University of Western Ontario found the rocks on Kamilo beach on the Big Island, which is famous for collecting ocean debris.
They are calling them plastiglomerates and they’re formed when plastic and beach sediment fuse together in high heat like a campfire or lava flow.
Objects like fishing gear and toothbrushes are still visible in the rocks, which vary in size from a small stone, to one the size of a pick-up truck. Scientists say that the rocks could survive as a matter of geographic record even if they are buried or sink in the ocean.
Charles Moore is captain of the Alguita research vessel which tracks plastic pollution in the pacific. He helped discover the plastic rock.
The research was published in the journal of the Geologic Society of America. You can read the full report here.