Why are so many whales getting washed up?

The shores of Lincolnshire and Norfolk, as well as Germany and Holland, have become the last resting place of 17 sperm whales recently. But are these deaths natural or the fault of humans?

The five dead whales washed up on the beaches of Lincolnshire and Norfolk represent the biggest mass sperm-whale stranding in British waters for 20 years. Twelve sperm whales also washed up dead off Germany and Holland earlier this month and others could follow: at least one more of these colossal cetaceans has been spotted off the Norfolk coast.

Are these deaths natural or the result of human interference in the last great wilderness - the ocean?