The whale shark is the largest fish in the world, and yet it remains a scientific mystery. For the majority of the year, they make their way slowly through the oceans relatively unnoticed. However, on the eve of a spectacular coral spawning event on Australia’s Ningaloo Reef, hundreds arrive. Six weeks later, they disappear. Where do they go? New findings suggest that whale sharks from Australia, Africa and India could all come from the same migratory population – meaning that this would be the largest migration on earth. But how can we find out for sure? In this programme, Australian marine biologist, Mark Meekan tags eight sharks in Ningaloo. Thanks to specially designed on-shark cameras, DNA fingerprinting and satellite tracking devices, we can follow their dramatic journey. Pituus: 50 min. Ohjelma sopii kaikenikäisille.