Marismas Nacionales–San Blas mangroves

Marismas Nacionales–San Blas mangroves is a mangrove ecoregion of the Pacific coast of Mexico. The marismas nacionales ("national marshes") stretches from Mazatlán, Sinaloa southwards to San Blas, Nayarit.

Geography
The Marismas Nacionales–San Blas mangroves occupy an area of 2000 km2 in coastal Nayarit and Sinaloa states.

The Marismas Nacionales is an interconnected complex of lagoons and wetlands on the alluvial plain formed by the Acaponeta, San Pedro Mezquital, and Grande de Santiago rivers. Beach ridges separate the wetlands from the sea. The central Agua Brava Lagoon and northern Teacapán Lagoon are the principal lagoons. The San Blas mangroves are the southernmost in the complex, located south of the Grande de Santiago river mouth.

Other mangrove areas north of the Marismas Nacionales complex include the Presidio River delta, the Baluarte River delta, and the Urías estuary south of Mazatlan.

Flora
Red mangrove (Rhizophora mangle), black mangrove (Avicennia germinans), white mangrove (Laguncularia racemosa), and button mangrove (Conocarpus erectus) are found in the ecoregion. Black mangrove is predominant near Teacapán in the northern part of the ecoregion, and white mangrove is predominant near Agua Brava in the southern part of the ecoregion. Trees that grow in association with the mangroves include ciruelillo (Phyllanthus elsiae), zapotón (Pachira aquatica), and anona (Annona glabra).

Fauna
The mangroves are home to over 250 species of birds, and serve as an important winter habitat for migratory birds. The Marismas Nacionales Biosphere Reserve also support an important number of mammal species, like deer, jaguar, ocelot and lynx.

Conservation and threats
Since 2009, Fonatur (Fondo Nacional de Fomento al Turismo), the Mexican tourism investment office, is planning a large tourism development adjacent to Marismas Nacionales that will include over 43,000 hotel and vacation home rooms, at least three golf courses, two marinas, commercial centers, and general urbanization. The direct and indirect impacts of this development, including the city that will be created nearby to house the workers servicing the tourism lodging and attractions, pose a substantial threat to the conservation of the Marismas Nacionales-San Blas Mangroves.