From Boston, at a meeting of the American Association for the Advancement of Science
Antarctica may be the battleground for the next world war. Crabs, sharks, and other predators vanquished from the frigid continent millions of years ago are ready to strike back, researchers say.
Propelled by the fast-warming Southern Ocean, the invaders' return will hit hardest animals such as brittle stars, which evolved within a food chain of little predation, says Richard Aronson, an ecologist at the Dauphin Island Sea Lab in Alabama.
Beginning about 40 million years ago, temperatures in Antarctic waters plummeted by 10°C, Aronson says. While crabs, sharks, and other bony fish fled to warmer waters, benthic marine animals flourished. Without shell-crushing predators, Antarctic animals developed few defenses, such as thick, ridged shells. "They are ecological throwbacks to an earlier time," Aronson says.