A pod of 40 pilot whales has been spotted in the Blackwater Estuary this week, leading to concerns that they may become stranded in shallow waters.

The pod was first spotted off the Norfolk coast near Cley last week, and travelled south as far as Kent before making their way along the Essex coast, where they were initially seen off the coast of Jaywick on Tuesday.

"They should be in the deep ocean waters around the north-west of Scotland, but here we have shallows and sandbank channels - it's like a maze where they can find themselves trapped," said Charlie Oliver, of Essex Wildlife Trust.

The pod is being monitored by the Essex Police Marine Unit, Essex Wildlife Trust and British Divers Marine Life Rescue. For more information please click here