Lençóis Maranhenses National Park is a national park located in Maranhão state in northeastern Brazil, just east of the Baía de São José. Protected on June 2, 1981, the park includes of coastline, and an interior composed of rolling sand dunes. During the rainy season, the valleys among the dunes fill with freshwater lagoons, prevented from draining due to the impermeable rock beneath. The park is home to a range of species, including four listed as endangered, and has become a popular destination for ecotourists.
Physical geography
The park is located on the northeastern coast of Brazil in the state of Maranhão along the eastern coast, bordered by of beaches along Atlantic Ocean. Inland, it is bordered by the Parnaíba River, the São José Basin, and the rivers of Itapecuru, Munim, and Periá. The park encompasses an area of, composed mainly of expansive coastal dune fields, which formed during the late Quaternary period. While much of the park has the appearance of a desert, the area receives about of rain per year, while deserts, by definition, receive less than annually. About 70% of this rainfall occurs between the months of January and May. The sand is carried to the park from the interior of the continent by the Parnaíba and Preguiças rivers, where it is then driven back inland up to by winds, creating a series of sand dunes rising as much as tall. During the rainy season, between the months of January and June, the rainstorms fill the spaces among the dunes with fresh water lagoons of up to in length and in depth, and together comprising as much as 41% of the area of the park. The water in the lagoons is prevented from draining by a layer of impermeable rock located beneath the sandy surface. The lagoons typically have a temperature between and, pH of between 4.9 and 6.2, and low levels of dissolved nutrients. When the dry season returns, the pools quickly evaporate, losing as much as of depth per month. In the interior of the park are located two oases or restingas, Queimada do Britos, covering an area of, and Baixa Grande, covering an area of. The area of the park has an average annual temperature of between and and an annual temperature variation of about 1.1 °C.
Ecology
The lagoons in the park are often interconnected with one another, as well as with the rivers that run through the area. They are home to a number of fish and insect species, including the wolf fish, which burrows down into wet layers of mud and remains dormant during the dry season. Besides the dunes that form the centerpiece of the park, the ecosystem also includes area of restinga and mangrove ecosystems. The park is home to four species listed on the Brazilian List of Endangered Species, the scarlet ibis, the neotropical otter, the oncilla and the West Indian manatee. The park also includes 133 species of plants, 112 species of birds, and at least 42 species of reptiles.
Tourism
Lençóis Maranhenses National Park receives as many as 60,000 visitors a year, and is a popular destination for ecotourism, given its unique physical features. Common activities within the park include "night sky observation, surfing, bicycle touring, canoeing, ecotourism, adventure tourism, rustic camping, horseback riding, and all-terrain vehicle...and water tours." The best route of entry is flight to the regional capital of São Luís, and then travel by jeep to the interior of the park from Barreirinhas.
