This project is sponsored by the INOS-HICoE Research Grant (2013 -2015)
Through conservation efforts at nesting beaches, thousands of hatchlings are released annually into the sea. However, very little is known about what happens to them until many years later when they return as juveniles to the reefs and sea-grass beds established as their foraging grounds. Turtle scientists often refer to this early pelagic phase as their ‘lost years’ where it is presumed that they suffer high mortality. It is often said that only one in a thousand hatchlings will ever survive to maturity. However, this estimate lacks support from scientific data. The purpose of this study is to find answers to this mystery for our local turtle populations, to establish where these hatchlings go when they swim out to sea, and to assess the threats they face in the increasingly polluted oceans.
Previous studies had shown that hatchlings swim against nearshore waves and subsequently orient themselves according to geo-magnetic fields (Lohmann 1991). Hatchlings are believed to use Sargassum as developmental habitat throughout their first years of life (Carr, 1986). However, most research on hatchlings focused only on the North Atlantic and North Pacific loggerhead turtles (Bolten & Balazs, 1995). Up to now, it is still very limited data for the green and hawksbill turtles especially in our region. This study will attempt to investigate the hatchlings in the open ocean during their ‘lost years. This will be done by finding and surveying Sargasum floating in the sea. Once Sargasum is found, it will be checked for hatchlings. Hatchlings encountered will be collected for body measurements. Blood or tissue will also be collected for genetic analysis. Satellite transmitters will be attached to the Sargassum to track its movements.