The Usumacinta mangroves ecoregion (WWF ID:NT1437) covers the mangrove forests ont the Gulf Coast of Mexico, around the margins of the Laguna de Términos ("Lagoon of Ends"). The "Ends" in the name refer to the mouths of the rivers that empty into the lagoon, including the Usumacinta River. This region, which is due south of the mouth of the Mississippi River across the Gulf of Mexico, receives an estimated one-third of the wintering birds migrating on the Mississippi Flyway. It is estimated that the lagoon supports 90 endangered species.