Up to a million king crabs are discovered on the edge of Antarctica, probably carried by warm water, raising fears for the local ecosystem.
The researchers sent the Genesis, a submersible remotely operated vehicle (ROV) from the University of Ghent in Belgium, into the Palmer Deep in March last year.
The idea was to look at what life was down there, rather than specifically to look for crabs; and the team was somewhat surprised by how many they found.
Judging by the density of the crabs and their tracks, the scientists estimate there may be 1.5 million crabs in the basin.
A female crab retrieved from the area was found to be carrying mature eggs and larvae.
“Our best guess is there was an event, or maybe more than one, where warmer water flushed up across the shelf and carried some of the larvae into the basin,” said project leader Craig Smith from the University of Hawaii.