ON SHAM WAN BEACH on Lamma Island, government conservation officers in drab uniforms take 80 critically endangered green turtles from a plastic bin and set them free. At three weeks old, each turtle is no longer than a finger.
Confronted by a life-or-death situation, the newborns freeze: where is the sea? They take in visual cues (the light is brighter towards the ocean) and, after detecting the beach's downward gradient, like wind-up toys they charge towards the water.
The babies have been hatched from eggs laid by the only turtle known to have nested in Hong Kong this year, which highlights the species' hastening spiral towards extinction. The mother does not remain with the eggs after she has laid them and only one in 1000 hatchlings survive to mate.
The Agriculture, Fisheries and Conservation Department (AFCD), chose to remove the 100-odd eggs, which resemble leathery ping-pong balls, from their natural nest on the beach and incubate them artificially. This virtually guaranteed that the highest possible number of the species - protected by local laws and listed on the Convention on International Trade in Endangered Species (CITES) - would hatch. But will they return?
Artificial incubation is a controversial issue among conservationists. The debate revolves around the phenomenon of adult sea turtles travelling thousands of kilometres to return to the beach on which they were born, to lay another generation of eggs. How do they perform such pinpoint navigation?
While theories range from the elusive turtles using the earth's magnetic field, their sense of smell, ocean currents and landmarks to return to their birthplace, it is indisputable that none of this can be achieved without what biologists call 'imprinting': the sensory clues the birth beach impresses upon the sea turtles which enable them to find their way back and continue the cycle of life.