Breakthrough as 12,000-mile loggerhead odyssey is mapped

A A A

Marine biologists believe they have solved a long-standing puzzle: what do endangered loggerhead turtles get up to in their early years, after hatching on an Australian beach?

The answer is, they hitch a lift on ocean currents that transport them all the way from Queensland across the Pacific to South America then back to Australia – a round trip of more than 12,000 miles.

The migratory behaviour of the juvenile turtles was confirmed by marine biologists at Queensland's James Cook University, who did genetic testing on loggerheads found stranded on the Australian coast and captured by long-line fishing vessels off Peru. Turtles at the two locations on opposite sides of the Pacific shared the same genetic background.

While loggerheads can be found around the world, in tropical and sub- tropical waters, scientists are particularly anxious to find out more about the Queensland nesting population, which has declined by up to 80 per cent over the past decade. The latest study has helped fill in the "lost years" of the juveniles, whose early movements were a mystery until recently.

The study, published in the scientific journal Proceedings of the Royal Society B, tracks the turtles from the time they emerge from their nests on Mon Repos beach near Bundaberg, in southern Queensland, during the southern hemisphere summer.

First, baby turtles head for the water and swim out to sea, according to the lead researcher, Michelle Boyle. Then, like the turtles in the animated film Finding Nemo, they hitch a ride south on the East Australian Current, taking them down the east coast towards Sydney.

From there, the loggerheads travel east, passing Lord Howe Island, north-east of Sydney, then the northern tip of New Zealand. They then pick up the Humboldt Current, traversing the South Pacific all the way to the coast of Peru and Chile. Later, they return to Queensland using another ocean system, the Southern Equatorial Current, researchers hypothesise.

In her paper, Dr Boyle, of the university's School of Marine and Tropical Ecology, says many questions remain to be answered. It is unclear how long the odyssey takes, for instance, and whether the loggerheads spend most of their time swimming or moving passively with the currents.

Scientists have no reliable means of calculating the age of turtles. But juveniles are just 2in long when they leave Australia and nearly 28in on their return. They remain in coastal waters off Queensland until they are ready to breed at the age of about 30.

Dr Boyle and her colleagues took tissue samples from the young loggerheads found off Australia and Peru and analysed their genetic make-up. She says the findings reinforce a need for international collaboration on conservation efforts.

The study had filled in some of the gaps about the turtles' early movements, she said. "No one knew where they went, or how long they went for."

While the population in eastern Australia has declined dramatically, its prospects look slightly better than a few years ago thanks to improved protection and the compulsory use of trawl nets in Queensland waters, designed to allow captured turtles to escape.

Australian turtles are not the only long-distance travellers; Californian loggerheads have been found to have a genetic affinity with those in Japan.

With their wide-ranging migrations, the species is vulnerable to accidental capture in nets and long-lines. But "turtle excluder devices" used in Queensland are still not mandatory everywhere. More than 100 species, including barnacles, crabs and algae, have been found living on turtles.

Arts & Entertainment
Madonna in her music video for 'Like A Virgin'
music... and other misheard song lyrics
News
Waitrose will be bringing in more manned tills
newsOverheard in Waitrose: documenting the chatter in 'Britain's poshest supermarket'
News
Russia's President Vladimir Putin gives his annual televised question-and-answer session
peopleBizarre TV claim
News
The energy drink MosKa was banned for containing a heavy dose of the popular erectile dysfunction Levitra
news
VIDEO
Have you tried new the Independent Digital Edition iPad app?
News
Much of the colleges’ land is off-limits to locals in Cambridge, with tight security
educationAnd has the Cambridge I knew turned its back on me?
Sport
Australia's Dylan Tombides competes for the ball with Adal Matar of Kuwait during the AFC U-22 Championship Group C match in January
sportDylan Tombides was diagnosed with testicular cancer in 2011
Arts & Entertainment
Martin Freeman as Lester Nygaard in the TV adaptation of 'Fargo'
tv
Extras
indybest10 best gardening gloves
Arts & Entertainment
tvIt might all be getting a bit much, but this is still the some of the finest TV ever made, says Grace Dent
Arts & Entertainment
Comedian Lenny Henry is calling for more regulation to support ethnic actors on TV
tvActor and comedian leads campaign against 'lack of diversity' in British television
News
Posted at the end of March, this tweeted photo was a week off the end of their Broadway shows
people
News
peopleStar to remain in hospital for up to 27 days to get over allergic reaction
Arts & Entertainment
The Honesty Policy is a group of anonymous Muslims who believe that the community needs a space to express itself without shame or judgement
music
News
Who makes you happy?
happy listSend your nominations now for the Independent on Sunday Happy List
Life & Style
life
Have you tried new the Independent Digital Edition iPad app?
iJobs Job Widget
iJobs General

Apprentice IT Technician

£150.00 per week: QA Apprenticeships: This company is a company that specializ...

1st Line Technical Service Desk Analyst IT Apprentice

£153.75 per week: QA Apprenticeships: This company is an innovative outsourcin...

1st Line Helpdesk Engineer Apprentice

£150.00 per week: QA Apprenticeships: This company has been providing on site ...

Sales Associate Apprentice

£150.00 per week: QA Apprenticeships: We've been supplying best of breed peopl...

Day In a Page

How I brokered a peace deal with Robert Mugabe: Roy Agyemang reveals the delicate diplomacy needed to get Zimbabwe’s President to sit down with the BBC

How I brokered a peace deal with Robert Mugabe

Roy Agyemang reveals the delicate diplomacy needed to get Zimbabwe’s President to sit down with the BBC
Video of British Muslims dancing to Pharrell Williams's hit Happy attacked as 'sinful'

British Muslims's Happy video attacked as 'sinful'

The four-minute clip by Honesty Policy has had more than 300,000 hits on YouTube
Church of England-raised Michael Williams describes the unexpected joys in learning about his family's Jewish faith

Michael Williams: Do as I do, not as I pray

Church of England-raised Williams describes the unexpected joys in learning about his family's Jewish faith
A History of the First World War in 100 moments: A visit to the Front Line by the Prime Minister's wife

A History of the First World War in 100 moments

A visit to the Front Line by the Prime Minister's wife
Comedian Jenny Collier: 'Sexism I experienced on stand-up circuit should be extinct'

Jenny Collier: 'Sexism on stand-up circuit should be extinct'

The comedian's appearance at a show on the eve of International Women's Day was cancelled because they had "too many women" on the bill
Cannes Film Festival: Ken Loach and Mike Leigh to fight it out for the Palme d'Or

Cannes Film Festival

Ken Loach and Mike Leigh to fight it out for the Palme d'Or
The concept album makes surprise top ten return with neolithic opus from Jethro Tull's Ian Anderson

The concept album makes surprise top ten return

Neolithic opus from Jethro Tull's Ian Anderson is unexpected success
Lichen is the surprise new ingredient on fine-dining menus, thanks to our love of Scandinavian and Indian cuisines

Lichen is surprise new ingredient on fine-dining menus

Emily Jupp discovers how it can give a unique, smoky flavour to our cooking
10 best baking books

10 best baking books

Planning a spot of baking this bank holiday weekend? From old favourites to new releases, here’s ten cookbooks for you
Jury still out on Manchester City boss Manuel Pellegrini

Jury still out on Pellegrini

Draw with Sunderland raises questions over Manchester City manager's ability to motivate and unify his players
Ben Stokes: 'Punching lockers isn't way forward'

Ben Stokes: 'Punching lockers isn't way forward'

The all-rounder has been hailed as future star after Ashes debut but incident in Caribbean added to doubts about discipline. Jon Culley meets a man looking to control his emotions
Mark Johnston: First £1 million jackpot spurs him on

Mark Johnston: First £1 million jackpot spurs him on

The most prize money ever at an All-Weather race day is up for grabs at Lingfield on Friday, and the record-breaking trainer tells Jon Freeman how times have changed
Ricky Gervais: 'People are waiting for me to fail. If you think it's awful, then just don't watch it'

Ricky Gervais: 'People are waiting for me to fail'

As the second series of his divisive sitcom 'Derek' hits screens, the comedian tells James Rampton why he'll never bow to the critics who habitually circle his work
Mad Men series 7, TV review: The suits are still sharp, but Don Draper has lost his edge

Mad Men returns for a final fling

The suits are still sharp, but Don Draper has lost his edge
Google finds a lift into space will never get off the ground as there is no material strong enough for a cable from Earth into orbit

Google finds a lift into space will never get off the ground

Technology giant’s scientists say there is no material strong enough for a cable from Earth into orbit