Invading Crabs Could Threaten Life in the Antarctic

The brachyuran crab Halicarcinus planatus from the Beagle Channel, south of Tierra del Fuego. This adult female has recently moulted. Oocytes and other internal structures arevisible through the carapace, which is 15 mm wide. Inset shows a preserved, adult-sized female of the same species discovered at Deception Island, Antarctica in 2010. That crab’s carapace is 12 mm wide, and its fifth-left walking leg (pereiopod) separated after it was collected. Images taken by S.T.

Life on the Antarctic sea floor is under threat from crabs that could invade the area thanks to favorable conditions as a result of global warming, researchers warn.

In a Journal of Biogeography editorial, experts say invasive species degrade marine ecosystems by preying on or outcompeting local species. Early signs of biological invasion are already apparent.

“Biological invasion is a major worry in the Arctic,” said lead author Dr. Richard Aronson, “but we should be just as concerned about the Antarctic.” Assessing the extent of the problem requires long-term monitoring programs.