There are 7 species of marine turtle and we find 3 of those here on the Ningaloo Reef. The loggerhead, green and hawksbill turtles are the varieties that we see in this region. Turtles are air-breathing reptiles that are thought to have evolved around 100 million years ago. They are long lived animals but we don’t know how old they live to be as we only really started studying them in the 1970’s. We will often see turtles feeding, swimming and sleeping in the waters around Coral Bay and have even got a special sanctuary zone for them.
We have a resident population of turtles that live around Coral Bay all year round and during October we start to see mature turtles that have migrated here to breed. The mature breeding turtles mate (the females will mate with several males and store up the sperm) and over the next couple of months the female will lay her eggs. The girls will leave her comfort zone and struggle up the beach at the night time high tide. She will dig a depression in the sand with her front and back flippers and then dig an egg chamber with just her back flippers. After laying those eggs she will cover up and try to disguise where she has made her nest before returning to the sea. Two weeks later the next batch of eggs will be ready to go and she will make the journey up the beach again.
The different species of turtles will differ in the number of eggs in each clutch and the number of clutches that are laid. But after all the clutches have been laid the turtles will then return to their feeding ground and might not return for a couple of years.
Between 5-10 weeks after the eggs have been laid the little baby turtles will emerge from their shells and spend a few days crawling up through the sand. They will wait about 10cm below the surface and wait for it to cool down – this will mean that it is night time and they will have the cover of darkness to run down the beach. It is thought that as the babies run down the beach they imprint the magnetic fields of the earth into their brain so that when they mature they will be able to find their way back to the very same beach.