Beach takeover: Spider crabs swarm St Ives

Thousands of crabs have swarmed the beach of St Ives, Cornwall, an increasingly common site due to rising sea temperatures.

The sea of spider crabs were prominently seen at Porthgwidden Beach, in St Ives, where they were reported to be in the thousands.

However they were not actually the crabs themselves, but rather their shells, which are shed before the crabs return to depths of up to around 90 metres.

Whilst this is not necessarily an unusual site in summer, their mass gatherings are becoming more common because of rising sea temperatures.

The crabs like to gather in warm, shallow waters to moult together, protecting themselves from predators whilst their new exoskeleton toughens up.

Higher water temperatures can mean a faster shedding duration, though temperatures getting too high can impact their survival and growth.