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Secrets of the green sea turtle revealed

03 February 2015

It’s turtle nesting season and the Nyul Nyul Rangers have been recording this unique event on the Kimberley coast to learn more about the genetics of the green sea turtle and help ensure its survival.

The rangers joined scientists from CSIRO and the Western Australian Marine Science Institution (WAMSI) to monitor and record turtle nesting sites across the Lacepede Islands and gather skin samples for genetic research. The field trip was held from December 5-11, 2014.

Nyul Nyul Ranger Ninjana Walsham said green turtles were listed as vulnerable to extinction which was why it was so important to find out more about their genetics. He said the research trip was a success with the group exceeding proposed targets and collecting 48 genetic samples and installing 12 remote sensors.

“We went out at night when they were nesting and there were just heaps of turtles everywhere on the beach. Before the female went to lay her eggs, we took just a little skin sample from the back right flipper,’’ Ninjana said.

“That information will be used to tell us how turtles are related and a bit about their family tree. It’s pretty amazing that from one little bit of tissue you can get all that information.

“We also tagged some of the turtles. They now have their own number so we can keep track of them and record information about them. We’ll use this information for future knowledge and to help us with management plans so we can continue to protect them.’’

Genetic sampling of sea turtles forms part of a two-year project by WAMSI to work out relationships between different turtle nesting groups, identify when and where turtles nest in the region and to assess possible climate change impacts to the species.

What is already known about green turtles is that adults can weigh up to 300kg and live for more than 80 years. Females can lay up to 100 eggs per clutch with nest temperatures determining the sex of the hatchlings. In the wild mostly females are born because incubation temperatures are above 29 degrees.

Ninjana said watching a group of hatchlings being born and make their way into the ocean for the first time was the highlight of the trip.

“There were lots of little hatchlings coming out. We had to help a couple, but it was just pretty amazing and pretty intense,’’ he said.

“It’s good to see that there are heaps of turtles out there nesting and knowing that your country is healthy. Every turtle goes back to the same nest where it was hatched to lay its eggs. We have a lot of turtles which is a really good sign.’’

Click here to listen to Dr Oliver Berry talking on ABC Kimberley