the island that cost Mexico an oil field by NOT existing — Bermeja

Slightly off the deep-sea beat but it's an ocean mystery so I'm posting it. There was an island called Bermeja in the Gulf of Mexico, off the north Yucatán coast, drawn as a small reddish lump ("bermejo" = reddish). It shows up in a Spanish atlas of all the world's islands in 1539, Alonso de Chaves ……