It looks for mermaids near you and does not find any, because there are none. What it shows instead is everything within reach that has been mistaken for one, or that somebody hopeful named after them, ranked by how often it has actually been recorded there. Each card explains precisely how it fails to be a mermaid.
Manatees and dugongs, whose entire order is named Sirenia after the sirens. Seals and sea lions, which account for most sightings and all of the selkies. Belugas, which are white, sociable and able to turn their heads. Skates, whose egg cases are mermaid's purses. Mermaid's wineglass, a single cell that grows a stem and a parasol. Mermaid's hair, which is algae. Sirens, which are salamanders. Mermaidweed, which is a marsh plant. Oarfish and giant squid, which belong to entirely different legends but are too good to leave out.
Because several of those live in fresh water or on land, this works inland as well as on the coast. Not well, but honestly.
The natural history is. Columbus really did log three mermaids off Hispaniola in January 1493, and really did record that they were not as beautiful as they are painted; he was looking at manatees. Sirenia really is named for the sirens. A mermaid's purse really is a skate. Only the conclusion is a joke, and only because the alternative would be lying to you.
Photographs come from iNaturalist and are shown only where the photographer has applied a Creative Commons licence. Each one is credited, and tapping any photo opens it large.
Finding a usable one takes three goes. A species' headline photo is often all rights reserved, so the app then checks the taxon's photo gallery, and if that is also restricted — or holds a single image, as happens more than you would think — it searches the observations themselves filtered by licence. A blank tile means all three came up empty, which is now rare.
Your position never leaves your device un-rounded — it is snapped to roughly 100 m before any search is sent, which makes no difference at these search radii. It is not stored, and it never appears in the address bar, so nothing can pick it up from there either.
Tap anywhere — somewhere coastal works best.
Starts at 200 km, because oysters are sparse: most coasts have only one to three species, and a wider sweep simply finds more of the few there are. Narrow it if you want to know what is on your own stretch of shore.
