Join marine biologist Kathy Townsend as she reveals the secret world of the manta ray. Journey to manta hotspots in Mexico, Micronesia, the Maldives and Project Manta's base on Australia's Great Barrier Reef where Kathy and her team are finding there's more to manta rays than just an enormous fish. But, mantas are under threat, and this at a time when they could be key indicators of our rapidly changing world.