Manta rays are intelligent, recognise people, embark on extensive migrations and demonstrate complex social behaviour. Australian marine biologist Kathy Townsend knows that with the largest brain to body size of sharks and rays, there’s more to manta rays than just an enormous fish. From Project Manta’s base on the Great Barrier Reef to manta hotspots around the globe, dive into the secret world of these exceptionally graceful creatures. But mantas are under threat at a time when they could be key indicators of our rapidly changing world.