Essex coast pilot whale died from starvation Published duration 22 November 2014

image copyright ZSL image caption The whale was found on a beach with "partial rigor mortis", said cetacean experts

The first long-finned pilot whale to beach in the southern North Sea for 22 years died from starvation, post-mortem tests have found.

The whale, among a 40-strong pod seen along the East Anglian coast, washed up near Goldhanger, Essex, on Thursday afternoon.

Marine experts successfully encouraged most of the whales from the shallow Blackwater Estuary into deeper waters.

But one - a 2.18m female - was found dead.

image copyright Stacey Belbin image caption The pilot whales became distressed after an ebb tide resulted in shallower waters off Brightlingsea

Rob Deaville, cetacean strandings programme manager at ZSL, said the whale was found on a beach with "partial rigor mortis".

"[This] indicates that the whale is likely to have died that morning, possibly around the time that the pod of whales was observed up the Blackwater River near Osea Island," he said.

"The whale had stranded alive before dying on the beach."

Tests showed the whale was in "very poor nutritional condition" with "no significant evidence of recent feeding".

He said: "The most likely cause of stranding and death at this stage is starvation, although we are waiting for the results from follow-up tests, including several to determine whether the animal had an underlying infection."

media caption The British Divers Marine Life Rescue and Essex Police's marine unit are trying to herd the whales back out to deeper water

Some 12,000 cetacean strandings have been recorded in the UK since 1990.

Mr Deaville said: "In that time, only one long-finned pilot whale has been recorded stranded on the UK coast in the southern North Sea - a single individual in Norfolk in 1992 - indicating how unusual this event is."

The pod of whales has been off the Norfolk, Suffolk and Essex coastlines in recent weeks.