mermaids
I was over in Lansdale or Towamencin where I overheard a story about an island where mermaids used to live in peace until the humans arrived. Not that the humans themselves brought unrest. The young mermaids and humans grew quite fond of each other in fact. But by various accounts, all stories for different posts, some combination of fate and grandpa and grandma's intervening hands drove a wedge between the two. So in their discerning wisdom The Elders Who Knew What They Were Doing sank the island and all its merhabitants, who continued to rule their underwater kingdom all the same but for the addition of the sad songs they sang with the whales. The Humans drowned for the most part, but several washed up on the coast of Florida where their babies were born top half mermaid and bottom half human.