Deep-Sea Octopuses Are Making Shelters Out Of Human Trash

One man’s trash is an octopus’ treasure.

A group of researchers from Italy and Brazil wanted to take a closer at how deep-sea octopuses interact with trash that makes its way to the ocean after being discarded by humans.

While the eight-armed creatures have been photographed with litter for years ― doing things like hiding inside bottles or carrying around halves of discarded coconut shells ― there hasn’t been a lot of scientific research about the phenomenon, the scientists wrote in a paper published in the journal Marine Pollution Bulletin last month.

For their own study, the researchers crowdsourced 261 images taken by divers that show ocean floor-dwelling octopuses interacting with trash all over the world. They then used those images to help them determine exactly what octopuses do with human garbage.

“The deep-sea records were extremely interesting, because even at great depths these animals are interacting with the litter,” Maira Proietti at the Federal University of Rio Grande in Brazil, who supervised the research, told The Guardian.

The primary way octopuses appeared to use litter was for shelter, like hiding inside a bottle. Glass containers were what they most frequently used, followed by plastic and then metal ones.

They also used smaller pieces of trash in other ways, the researchers noted, repurposing objects like “metal and plastic caps/lids, glass and plastic
fragments, a metal spoon, and coconut shells as camouflage,” or making use of bigger items like cans, plastic bags and even part of a surfboard to help them hide between rocks.

While this ingenuity demonstrates the cephalopods’ intelligence and “extreme ability to adapt,” Proietti stressed that “it is not a good thing to think that the animals may be using litter as shelter because the seashells are gone.”

And some of the octopuses’ behavior could be dangerous for them, like using broken glass for shelter. Proietti told the CBC that one octopus was photographed sheltering inside a car battery, which could be giving off harmful chemicals.

The researchers acknowledged that their study had some limitations. For example, it appeared that the number of photos of octopuses with trash was increasing over time. But it’s not clear if this was because of more trash in the ocean, or due to digital and underwater photography becoming cheaper and more accessible, meaning that more divers would be taking photos.

But they see their analysis as a jumping-off point for more research to be done on the subject.

“It is possible that the negative impacts of litter on octopuses is underestimated due to the lack of available data, and we therefore emphasize that the problem must be more thoroughly assessed,” they wrote in the paper.