By now, many of us have heard about the Great Pacific Garbage Patch, a pair of massive, swirling islands of floating trash in the Pacific Ocean—one of which is roughly twice the size of Texas.
But in Australia's Sydney Harbor, the refuse isn't just floating: It's on the bottom.
Groups of volunteers divers are working to remove the "carpet" of trash covering the sea floor.
"The stuff on the bottom has been accumulating for 200 years," Dave Thomas, a local diver, told Yahoo News Australia. "And its only now we're really trying to pull it out in any sort of quantity."
Over 900 tons of garbage wash up on Sydney's beaches per year, city officials say. But that trash is easy to see.
"It's been out of sight and out of mind," Thomas said. "If it was on land you would be disgusted and you would do something about it."
It's not just plastic bags and Fosters cans, either.
According to the BBC, there are bikes, "lots of bikes," scattered at the bottom of the harbor.
The toxic trash—which flows into Sydney Harbor from the city's waste water—is often ingested by fish and other marine life, environmental experts say, threatening the underwater ecosystem. Tides then take debris from the undersea scrapheap and deposit it into the Pacific.
The cleanup effort isn't terribly elaborate: Divers have been filling bags with trash and bringing them to the surface.
"Unless someone cleans it up, it could be there for years, it could there for hundreds of years," Dean Cropp, a member of the environmental group Two Hands, said, "doing damage the whole time."