Dead leatherback turtle a long way from home

DoC officer Kari McLeod examines the leatherback turtle. The species is high on the worldwide endangered list. Picture / Glenn Jeffrey

A giant turtle usually found swimming in the warmer waters of the northern Pacific has been discovered dead on a South Auckland beach.

The leatherback, the largest species of turtle and famous for its hatchlings' race to the sea to escape predatory seabirds and its return to breed at the same spot each year, is an unusual visitor to New Zealand.

"It's pretty amazing to find one in the upper reaches of the Manukau Harbour where it's just mud and oyster shells - not a very pleasant habitat," said Department of Conservation spokesman Karl McLeod.

DNA samples would be taken by University of Auckland researchers and sent to the United States to be added to an international database, he said. The head would be kept for "educational" purposes.

But the rest of the carcass would be buried because, unlike other turtles, the leatherback's carapace, or shell, disintegrated after death.

Mr McLeod said the turtle had died shortly before being found on Saturday but it was impossible to know the cause.

"There was no sign of fishing gear injury from set-netting ... It may just have succumbed to age."

The 2m-long turtle had a 2.4m "wingspan" and weighed about 650kg.

"We had to dissect it before we could deal with it," he said.

Leatherbacks, while rare this far south, can restrict the flow of blood to their extremities, allowing a tolerance of colder water. They are high on the worldwide endangered list.

The turtles were once plentiful throughout the Pacific Rim, nesting on beaches in Mexico, Costa Rica, Malaysia and Thailand.

But commercial fishing, particularly for swordfish, and development on coasts where leatherbacks breed have caused numbers to plummet.

Scientists estimate that nesting females have declined 95 per cent over the past 22 years and they fear that the species, which has survived for more than 100 million years, could be extinct within two decades.