Unique marine life in Antarctica will be at risk from an invasion of sharks, crabs and other predators if climate change continues, scientists warn.

Crabs are poised to return to the Antarctic shallows, threatening creatures such as giant sea spiders and floppy ribbon worms, says a UK-US team. Bony fish and sharks would move in if waters warm further, threatening species with extinction, they say. In the last 50 years, sea surface temperatures around Antarctica have risen by 1 to 2C, which is more than twice the global average.

Speaking in Boston at the annual meeting of the American Association for the Advancement of Science (AAAS), the researchers said global warming could fundamentally change the ecosystem, leading to the loss of some species. “Sharks are going to arrive in Antarctica as long as the warming trend continues, a bit more slowly than crabs – crabs are going to get there first,” said Professor Cheryl Wilga of the University of Rhode Island (URI), US. “But once they do get there they are capable of eating the organisms that live there.”