Now Britain gets its own monster from the deep

The big, amorphous blob which caused such a stir when it was washed up on a Tasmanian beach turned out to be whale blubber. Now a genuine, entire monster of the deep has come ashore on the Suffolk coastline. And there is no doubting what it is - a quarter of a tonne of very recently deceased leatherback turtle, measuring more than two metres from nose to tail.

It was found stranded in the surf on the beach at Sizewell nuclear power station by a woman walking her dog. It required a fork lift truck, borrowed from Nuclear Electric, to get the corpse out of the waves and safety ashore before the tide carried it back out to sea. Then, Froglife, the reptile and amphibian conservation organisation which supervised the recovery, had the turtle trucked down to London Zoo's Institute of Zoology for a post mortem examination.

That was performed by the zoo's veterinary pathologist, Andrew Cunningham, and Brendan Godley of Glasgow University's Marine Turtle Research Group. They found the turtle, weighing as much as three men, to be in good condition internally and externally apart from old and infected wounds on its shoulder and left eye. These would have left it half blind and with impaired mobility and probably contributed to its death. The scientists believe the shoulder wound was the result of being entangled in a fishing net or rope. Tissue samples will be analysed to find out what burden of pollutants and toxins the turtle was carrying.

Mr Godley said more than 50 leatherbacks had been washed up on the British shoreline during the 1990s, but the great majority had been on the west coast. They were almost always badly decomposed so finding a near pristine specimen on the North Sea coast was a great rarity.

The largest of seven marine turtle species, the black, white and crimson reptiles swim thousands of miles across oceans in a year, live for decades and do not even start to breed until they are 10 years old. They bury their eggs in the sand of tropical beaches but they swim into the cold waters of high latitudes for their jellyfish prey. They have no hard external shell, relying on sheer bulk and the toughness of bone and hide to deter predators.

"They're extremely endangered," said Mr Godley. Their fate is either to be caught accidentally in nets, then wounded or drowned, or to be killed for their meat when they come ashore to breed. Their eggs are also dug up and eaten.

Thousands of porpoises are also killed by fishing nets each year in the waters around Britain. Now a study is to take place into whether "pingers" - small, underwater acoustic devices - can reduce the death toll. These should deter the marine mammals, but not fish.

Irish and Cornish fishermen are taking part in a year-long evaluation of electronic pingers in the Western Approaches. They will be attached to gill nets, set in a long line on the sea bed and left for a day or two to trap fish swimming through.