Ascension Island – SATO South Atlantic Turtle Odyssey

Georgetown, Ascension Island, 2009-05-05

After 11 years of absence I am back at Ascension Island, for field work on green turtles (Chelonia mydas). It is an interesting experience coming back, since there are many things that seem to have changed over this period. First the island appears to me much greener than last time I was here, thanks to recent rains making the endemic grass and other plants grow and flower, but also because of the Mexican thorn that is spreading across the island -up the slopes of the mountains as well as across some of the barren lava fields.

We (Brendan Godley at Exeter and I) are here to attach GPS transmitters to egg-laying female green turtles entering the shore at night to study their migration. Last night Jacquie (responsible for the turtles on the Island), Brendan and I attached the first transmitter to a female that took more than 6 hours to decide where to place her clutch. The recent night there has been many more females entering the shore, but last night the sea was unusually rough thanks to a storm somewhere at sea. Enormous waves where splashing in against the shore, creating a massive sound source – which I imagine could be heard far away for an animal having the necessary sensory capability.

Although the adult females were not frequent at the beach, the hatchlings were present in much greater numbers. This is the peak hatching time of the year and I could see at least 10 different nests hatching, in which the 70-100 young hatchlings were crawling out from the sand and thereafter were heading towards the sea in a long scattered plume of turtles eager to reach the water. On Long Beach near Georgetown where we are working, the hatchlings seem to be of high quality, since they were big and full of strength. They quickly crawled to the sea and left their typical signs in the sand. The full moon is helping us at the shore, and it was easy to see the new nests opening first with sleepy hatchlings slowly crawling at the surface, but after some stimulation from other turtles' movement, the nest was boiling of active hatchlings ready to leave for some 30 years at sea before they return to the Island as sexually mature adults. Magic!

I am looking forward to tonight’s field work!
/Susanne