Hakai Magazine

Coastal science and societies

Dumbo octopus
This record-breaking octopus was filmed in the Java Trench in Indonesia. Photo by Atlantic Productions for Discovery Channel 2020

How Low Can an Octopus Go

In 1971, scientists photographed an octopus living 5,100 meters beneath the waves. It was the deepest-dwelling octopus ever seen—until now.

Authored by

by Chris Baraniuk

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For decades, deep-sea researchers have wondered whether octopuses can survive down in the murkiest recesses of the ocean. Occasionally, they’ve found hints that they can. Deep-sea trawler’s nets, plunging 5,000 meters down, have occasionally ensnared an octopus or an egg case. But these incidental finds are not proof. The specimens might simply have become tangled in the trawlers’ nets at shallower depths before being pulled to the surface.

Mike Vecchione, a zoologist at the Smithsonian Institution, dreamed of finding an octopus in the ocean’s most inhospitable depths. In his lab, Vecchione keeps a jar containing the preserved body of an octopus that he believes may have come from the hadal zone, from 6,000 to 11,000 meters deep. This octopus was pulled up by a trawler in the Southern Ocean about a decade ago.

“I’ve wondered for a long time what to do about it, because it didn’t quite meet the standard of proof that I wanted,” Vecchione says. Reports of similar specimens go back to the 1950s. And in 1971, scientists working in the seas off Barbados reported that they had taken a black-and-white photograph of an octopus at a depth of 5,100 meters, about a kilometer shy of the hadal zone.

But then, in October last year, Vecchione got an email. It was from Alan Jamieson, chief scientist on the Five Deeps Expedition and a marine ecologist at Newcastle University in England. Vecchione recalls Jamieson’s excitement—he had seen something no one else had seen before: a video recording of an octopus nonchalantly puttering about in the Java Trench in Indonesia, nearly 7,000 meters below the surface.

Jamieson sent Vecchione the footage, recorded with cameras mounted on autonomous submersibles. Filmed in April 2019, it showed two octopuses in marvelous clarity: one at a depth of 5,760 meters, the other at 6,957 meters—more than two kilometers deeper than the previous record holder, the octopus snapped in the early 1970s near Barbados.

At hadal depths, the water pressure is a crushing 69,000 kilopascals, roughly the same crushing power as a Tyrannosaurus rex’s jaws. It’s cold, not much above 1 °C, and very dark. But as Jamieson and Vecchione report in a recent scientific paper about the discovery, the octopuses in question appear unperturbed by the harshness of their habitat.

“It wasn’t sick from being sucked down by a current at depths that were too great for it,” says Vecchione. In one clip, one of the octopuses seemed to be foraging for food. “It was acting like it belonged there.”

The discovery greatly extends the range of possible octopus habitat, from 75 percent to 99 percent of the world’s seafloors, Jamieson and Vecchione write in their paper.

“It’s really nice to see natural history observations from the deep sea. This is an important one because it’s such a big depth extension,” says Daniel Jones, a deep-sea ecologist at the National Oceanography Centre in England who wasn’t involved in the research.

Vecchione says it’s likely the octopuses are a new species. But with large flappy protrusions coming out of their heads, it’s all but certain they are a type of Dumbo octopus—a genus, Grimpoteuthis, named after the cute Disney elephant. Vecchione would have to examine the octopus physically to be certain it is indeed a new species. He says that even if the differences aren’t obvious, it’s possible these deep-sea dwellers may be physiologically distinct from shallow-water species in subtle ways—the proteins in their bodies, for example, may be unique.

The footage raises other questions about the biology and ecology of these ultradeep octopuses, Jones says, such as whether they have specialized diets. It also reminds us that the deepest parts of the oceans are far from fully explored.

“There’s plenty more discoveries out there to be made,” says Jones.