Mermaids appear in the folklore of many cultures worldwide, including the Near East, Europe, Africa and Asia. The first stories appear in northern Syria (8th–7th century BC), where the chief goddess was Atargatis. She was a primarily known as a fertility goddess whose cult eventually spread to Greece and Rome. She was also responsible for the protection of the city and the people's well-being. Often depicted in mermaid form, Atargatis is perhaps the “original” mermaid. Legend has it that after accidentally killing her human lover, she dove into a lake out of shame to become a fish, but only her bottom half was transformed.

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 blessings or falling in love with humans. It has also been told that they possessed the power to change the mighty course of nature, but were forbidden to do so by Neptune, the stern and watchful god of the sea.

One dark and storm-ravaged night, with sails ripping and masts cracking, a schooner fought to find safety in Friendly Cove off Nootka Island in the San Juans. The ship was familiar to the mermaid who swam along its side as she had weathered many crossings with this ship and its captain. As the ship heeled in the violent wind, the captain lost his hold on the wheel, tumbling perilously close to the raging sea. In an instant, the mermaid calmed the wind and tamed the waves, changing the course of nature and saving the life of a man she had grown to love from afar. For her impetuous act, Neptune banished the sobbing mermaid to the oceans depths, condemning her for eternity never to surface or swim with the ships again. To this day, her gleaming tears wash up on the beaches as sea glass... crystalline treasures in magic sea colors, an eternal reminder of true love. Another legend states that each time a sailor drowned at sea, the mermaids would cry and the sea glass that washed ashore was actually their tears. Some believe that the color of the tears a mermaid would shed match the color of her fin.