A mermaid is a legendary aquatic creature with the upper body of a female human and the tail of a fish. Mermaids appear in the folklore of many cultures worldwide, including the Near East, Europe, Africa and Asia. The first stories appeared in ancient Assyria, in which the goddess Atargatis transformed herself into a mermaid out of shame for accidentally killing her human lover. Mermaids are sometimes associated with perilous events such as floods, storms, shipwrecks and drownings. In other folk traditions (or sometimes within the same tradition), they can be benevolent or beneficent, bestowing boons or falling in love with humans.
Mermaids are associated with the mythological Greek sirens as well as with sirenia, a biological order comprising dugongs and manatees. Some of the historical sightings by sailors may have been misunderstood encounters with these aquatic mammals. Christopher Columbus reported seeing mermaids while exploring the Caribbean, and sightings have been reported in the 20th and 21st centuries in Canada, Israel and Zimbabwe. The U.S. National Ocean Service stated in 2012 that no evidence of mermaids has ever been found.