The Cayman Islands, a UK Overseas Territory, once supported one of the world's largest sea turtle rookeries, which comprised some 6.5 million adult green and loggerhead turtles. These populations were driven into decline from the mid-1600s onwards, when massive harvesting of nesting turtles began. Only a few dozen individuals survive today.

New research, led by the University of Exeter's School of Biosciences and the Cayman Islands Department of Environment, reveals the astonishing distances these animals travel and the extent to which they are now threatened. The study was published open access today in the international conservation journal Endangered Species Research.

Marine turtles spend most of their lives at sea, but where these Cayman Islands survivors live when they are not nesting has been a mystery until now. Experts from the University of Exeter, the Cayman Islands Department of Environment and Duke University, USA, followed the journeys of ten endangered adult females over three years.

Using satellite transmitters, the team tracked the turtles travelling as far as Belize, Guatemala, Honduras, Mexico, Nicaragua and the USA. On these long journeys, turtles face the risk of being caught for meat, as well as accidentally captured by shrimp trawls, longlines, and gillnets. As turtles travel across boundaries between countries, conservation legislation is inconsistently applied and enforced, leaving them vulnerable.

Dr Brendan Godley of the School of Biosciences at the University of Exeter said: 'Having followed these turtles thousands of miles through the ocean, we now know where they go, so can identify which countries need to be involved in their conservation. We are running out of time and what is now needed is a team effort from all of the governments to save these fragile populations.'

Facts about sea turtles

• Turtles evolved hundreds of millions of years ago. These ancient reptiles have lived on earth since the time of the dinosaurs.
• Female turtles typically lay up to six 'clutches' of over 100 eggs.
• The temperature of the sand around a nest determines whether baby turtles, known as 'hatchlings', will be male or female. Colder temperatures produce males, whereas warmer temperatures produce females.
• Hatchling turtles always return to the beaches where they were born to nest.
• Baby turtles hatch from their nests at night and race to the sea by moonlight. Lights near the beach should be turned off during the summer so turtles do not go in the wrong direction.
• It may take decades for green and loggerhead turtles to mature in the wild.
• In some parts of the world, loggerhead and green turtles are hunted for meat, and their eggs are taken from nesting beaches. Today, both species are considered endangered.
• Sea turtles may be able to live for up to 100 years.
• Turtles drink saltwater and get rid of extra salt through special glands in their eyes.
• Loggerhead and green turtles are found in tropical and sub-tropical waters around the world.

Note: If no author is given, the source is cited instead.

• Endangered Animals
• Frogs and Reptiles
• Sea Life

• Environmental Policy
• Ecology
• Oceanography

• Sea turtle
• Marine conservation
• Snapping turtle
• Turtle
• Conservation status
• Endangered species