They call it the Greatest Shoal on Earth, the ocean counterpart of the annual wildebeest migration across the Mara and Grumeti Rivers on Tanzania's Serengeti plains.
Billions of fish take part in thousand-mile journey From Fred Bridgland in Johannesberg
They call it the Greatest Shoal on Earth, the ocean counterpart of the annual wildebeest migration across the Mara and Grumeti Rivers on Tanzania's Serengeti plains.