The marshes are shared between the municipalities of
Isla Cristina for and
Ayamonte for some . Marshes in general are humid areas, low-lying, swampy terrains that are flooded by sea water during high tide. They usually lay in estuaries areas, such as here. The tidal dependence of these ecosystems gives them an almost total absence of seasonality. From the landscape point of view one can differentiate between the marshes, those areas in which man's intervention has transformed the ecosystem for its own use and the other better preserved areas. Where the marshes have been transformed, among others for the development of marine aquaculture, bodies of water distributed as ponds and pools are the main elements of the landscape. Despite the uses developed in this area they maintain the original channels and estuaries of the marsh. The constancy that the marsh has acquired is very significant. In the areas where the marshes are better preserved, it maintains the characteristic bushes of these wetlands. The vegetation consists of communities of halophytes, typical of these types of habitats and adapted to the daily tidal flooding. The animal communities are also important. The birds are the most representative group in this ecosystem, contributing an important peculiarity to the landscape. The homogeneity of the color of the scrub is contrasted with the presence of water, an element which carries great attraction. In this reserve the panoramic landscape has a special importance; its very flatness allows a scenery with very broad views, opening to one's view the lands of neighboring units, emphasizing the views of the city of Isla Cristina or of the pine forest. A highlight throughout the day are the distinct tonalities of the marsh due to the changes in light as the day goes by. Follows a more detailed description of the different parts comprised within the Marshes of Cristina Island.
Carrera marsh The unit is 266.12 hectares. It is a protected natural place where
needlegrass (
esparto) is the most abundant species along with
halophyte (salt tolerant) species. In less flooded areas appear the
broom bush and the
reed. The geomorphology shows a large flat coastal fringe, a transition from land to sea with seasonal fluctuations. The bird life (see Fauna for more details) of the marsh includes many species of water fowl which bring great value to the unit. Along with the fauna of the highly valued ecological marsh, one should emphasize the values of the landscape, since the unit is of great interest both for its high quality and its fragility. In the southern part it is closely bound to the city of Isla Cristina, in the north the marsh is bordered by the Verde Litoral road.
The Meadow marsh (Marisma del Prado) Known as Prado Hondo, this arm of the marsh covers 30.29 hectares dried up for the cultivation of strawberries. The environmental characteristics of the area are very similar to the above Carrera marsh. This small part of the marsh borders the Redondela, from which starts a path.
Puntal Canal marsh It includes the west part of the marsh between the city of
Isla Cristina, the reed area (
cañas) and the limit of
Ayamonte, with an area of 371.24 hectares. It is a degraded marsh, transformed long ago for the exploitation of table salt and currently developing aquaculture. These uses degrade the marsh, bringing homogenisation and impoverishment that weigh on its ecological value. Here stands a well-preserved
tidal mill (
es: El Pintado tidal mill) restored in 1995, presently used as a small visitors' center.
Transformed marsh of Carreras An environmental unit with similar characteristics to the Puntal Canal marsh, occupying 76.62 hectares, this area includes three transformed places of the marsh, in the area of Carrera. The human uses that are developing are: aquaculture, with the building of pools which divide the marsh, and the cultivation of strawberries, all resulting in damage to the marshes.
The Moral The 311 hectares hydrophilic, halophytic grasslands with tidal influence have been transformed with the repopulation of
tamarisks (
Tamarix canariensis,
Tamarix africana) and the formation of well-preserved salt marshes of
salicornia (
Arthrocnemetea), and grasslands of eel grass (
Spartina densiflora). Within the Mediterranean mountain (presence of copses of Mediterranean deciduous species) some endemic taxa appear such as
Teucrium algarviense,
Thymus mastichina subs. that are not included in the ecosystem in study although they belong to the unit for the protection of the marsh.
The Slumps' Saltworks (Salinas de los Pérez) A tidal marsh with
Arthrocaulon macrostachyum (former
Arthrocnemum) as typical vegetation, it also shelters protected endemic
relic species
Picris wilkommi and other rare species such as
Armeria linkiana and
Spergularia fimbriata, spread over about 166 hectares. Its basin is transformed by saltworks. See Flora for the species specific to the marsh.
The Tamijar An important formation of halophytes (
sarcocornia), its characteristics are similar to that of the
caño del puntal (see flora for more details). It is one of the main units of the nature reserve with 589 hectares and various saltworks. Its northern part is crossed by the Via Verde Litoral road. Some continental marshes retain important halophyte prairies of
needlegrass (
esparto). Populations of waders,
laridae (gulls),
ardeidae (
herons) and others, are abundant. See flora and fauna for the species typical of the marsh.
Robalito Point Ii includes the Canela lagoon and Pinillo lagoon on its northern and southern fringes, leaving an area of saltworks near the heart of Ayamonte which degrades the marsh's landscape. This unit forms a 237 hectares island of
almajos and
Frankeniaceae prairies. In its southern area the degradation from urbanisation is quite high.
Salón de Santa Gadea Connects directly with Ayamonte and more than half of its 97 hectares are salty.
Almajos and
needlegrass are the most abundant vegetation. == Geography ==