Hermit crabs in danger

More than half a million hermit crabs have died after being trapped in plastic bottles and other rubbish on two remote islands.

The number killed is equivalent to one to two crabs per square metre of beach – a significant percentage of the population, according to researchers.

They conducted surveys that found 508,000 trapped crabs on the Cocos (Keeling) Islands in the Indian Ocean and 61,000 on Henderson Island in the Pacific. The problem is likely to be widespread on islands across the world, they said.

Their research, published in the Journal of Hazardous Materials, found piles of plastic pollution on island beaches create both a physical barrier for the crabs to navigate and a series of traps.

Hermit crabs live in scavenged sea snail shells and when they die they release a chemical signal to others of their species that a home is available.

This attracts more crabs into the rubbish that trapped them, creating a 'gruesome chain reaction', the scientists said.

The study was led by the Institute for Marine and Antarctic Studies at the University of Tasmania and included researchers from London's Natural History Museum and the Two Hands Project, a community science organisation.

The researchers have previously revealed that the Cocos and Henderson islands are littered with millions of pieces of plastic.  (Daily Mail)