IN MCMURDO STATION, ANTARCTICA Sven Thatje has been predicting an invasion of deep-water crabs into shallow Antarctic waters for the past several years. But the biologist and his colleagues got their first look at the march of the seafloor predators while riding on an icebreaker across frozen Antarctic seas this winter.
The ship towed a robot sub carrying a small digital camera that filmed the seafloor below. It caught images of bright red king crabs up to 10 inches long, moving into an undersea habitat of creatures that haven't seen sharp teeth or claws for the past 40 million years.
"There were hundreds," Thatje said in an interview on board the Swedish icebreaker Oden, which docked at the main U.S. base in Antarctica, McMurdo Station, after a two-month research cruise. "Along the western Antarctica peninsula, we have found large populations over 30 miles. It was quite impressive."
Thatje, an evolutionary biologist at the University of Southampton in England and chief scientist on the cruise, is part of a U.S.-Swedish team of marine researchers who are trying to figure out where, when and how fast this invasion is occurring. King crabs, of which there are 13 species, live in the deep waters off Alaska and Russia and across the Southern Ocean in the waters off New Zealand, Chile and Argentina. But here in Antarctica, crabs haven't been able to survive because, until now, it's been too cold. As a result, many bottom-dwelling creatures such as mussels, brittle stars and sea urchins have not developed any defenses against the crabs.
What's happened is that the waters around the Antarctic peninsula have begun to get warmer. (read more)
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