As Beth Faulkner bobbed up and down in the Maldives' Hanifaru Bay, she did some quick mental math. "There's probably about 100," she said in reference to the number of reef manta rays swimming just below her. "Usually it's about 50 to 60." Faulkner is a project manager at the Manta Trust, a conservation and research charity that studies these gentle giants. Close relatives of sharks, the largest mantas have wingspans that can reach over 20 feet.
Unlike their stingray cousins, which can deliver deadly injuries, mantas are harmless, according to Faulkner. "They have no sting, no teeth, nothing they can do to hurt humans. So they're absolutely wonderful to swim with in the water." Although manta rays pose no danger to us, people are doing terrible damage to them. According to the International Union for Conservation of Nature, the global population of reef manta rays is declining, mainly due to fishing, habitat degradation and global warming.