The crabs and other crushing predators are thought to have been absent from antarctic shelf waters for millions of years because the water was too cold, allowing the evolution of a unique antarctic seafloor fauna with little resistance to predatory crabs.
Researchers, including scientists from the University of Hawaii, say rapid warming of antarctic waters has allowed the crabs to move into an area of the antarctic shelf called the Palmer Deep, digging in soft sediments, preying on seafloor animals and altering the basic ecosystem of the ocean bottom, a university release said Thursday.
Echinoderms such as sea lilies, brittle stars, asteroids and sea urchin, which normally are common and numerous in antarctic waters, were wholly absent in the crab zone in Palmer Deep, the researchers said.
Scientists estimate more than 1 million crabs live in a 56-square-mile area of the Palmer Deep in water deeper than 3,000 feet.
If the warming trend goes on, they said, the king crabs may be able to colonize the vast west Antarctic Peninsula within one to two decades.