Thursday, September 11, 2008

A turtle called Carol

Carol is the name given to the surviving hawksbill turtle that MCSS had equipped with a hi-tec satellite-relayed GPS tag at the end of last year… and Carol seems set to cause quite a stir in scientific circles!

The impetus for this project came from Barclays Bank Seychelles who wanted to assist MCSS with turtle conservation in Seychelles. Carol was named by Jessica Marengo, the winner of a ‘name-the-turtle, competition organised by MCSS in association with the Ministry of Environment and the Wildlife Clubs of Seychelles as a part of the turtle awareness campaign funded by Barclays Bank Seychelles. This programme was aimed at increasing public awareness of Seychelles turtles through a programme that integrated research into the activities of the schools and Wildlife Clubs as well as re-invigorating public awareness by several competitions including an art contest and a science-project contest. The science project was based on the position information transmitted from Carol’s tag as she moved away from her nesting beaches on the south of Mahe.

Until this project there was no information on the movement patterns of the nesting turtle populations on the developed islands of Mahe and Praslin, nor where they go to forage between nesting seasons. With the support of Barclays Bank, two turtles nesting on the beaches on the South of Mahe were fitted with satellite tracking tags that recorded their movement patterns and diving habits during the following months.

The fast-loc satellite tag used for Carol, photo Elke Talma.

Unfortunately, one of these was killed by a poacher off south Mahe on December 26th 2007 but luckily Carol escaped his rampage and left the area safely. Carol’s location was tracked on-line through the facilities of and were shared with teachers at local schools via the Wildlife Clubs through the internet with Barclays Bank providing two computers to the Wildlife Clubs at the Centre for Environment and Education (Nature Seychelles), Roche Caiman.

Carol fitted with her satellite tag heads back to the sea, photo Gilberte Gendron.

So what is Carol up to that is so surprising? The map in the sidebar on the right tells the story… Carol appears to be living off the Mitsio islands off north-west Madagascar!

In an earlier study five hawksbill turtles were satellite tracked from Cousin Island, a protected nature reserve with almost no human habitation; after nesting, all five moved away from Cousin but stayed on the shallow Seychelles plateau, well inside Seychelles territorial waters. After that study it had been generally accepted that hawksbill turtles in Seychelles were a distinct population that did not migrate to distant or foreign foraging grounds….. until Carol!

On the 23rd of January Carol left south Mahe heading in a southerly direction across the plateau until she reached deep water and then she continued on southwards, past Isle Platte and heading towards Coetivy. In mid-February, she seemed to change her mind and turned due east towards the Mascarene ridge before turning north and then west until she met her original path which she then back-tracked along north towards Mahe. By mid-March she seemed to have regained her navigational bearings and turned south-west and during the next four weeks she passed the Amirantes, Providence and Farquar islands heading straight for north-west Madagascar. On April 27th, it appears that Carol had arrived at her destination off the Mitsio islands just north of Nosy Be, north-west Madagascar, where she seems to be quite happy having been tracked around that area until the present date, the beginning of August!

This long distance migration of over 2350 km was unexpected as was her destination, her foraging grounds off Madagascar. Since her arrival there, her tag has been providing information about her daily diving activities and her exact GPS location and she seems to have settled in to a fairly consistent daily pattern. What is also surprising is the length of time that her tag has stayed active. The original expectations were that the tag’s battery life would be around three months but the tag is still transmitting daily after more than seven months of deployment.

So the question has to be raised is Carol Seychellois or Malagasy? As she was born in Seychelles we think that makes her a Seychellois turtle, even if she seems to prefer to feed around our neighbour’s reefs to the south!

No comments: