N in the states of Sinaloa and Nayarit, Mexico. It is fed by the R o Acaponeta and tributary streams, including the delta of the R o San Pedro. There is only one direct opening to the sea that is found to the north in the small area located in the state of Sinaloa. The largest part of the area is located in the state of Nayarit. The area is extremely important to both breeding and wintering waterfowl of a wide variety of species.
Ospreys are also a common winter visitor.
Leo onca and Crocodylus acutus still occur, but are now rare. Shrimp farming, tourist recreation on weekends, small scale fishing in rivers, duck hunting in some areas and some agricultural and grazing use of sandbars. The Universidad de Nayar t is conducting studies of Marisma's fisheries. The Universidad Nacional Aut nomo de M xico in Nayar t is studying mangrove ecology and conducting a community profile in the area. Coordinated by the Priest of Mexcaltitan, Mexcaltitan Church, Mexcaltitan, Nayarit, Mexico.