This reserve is managed through an agreement with the Camargo City Council, the Santander City Council and a concession from the Cantabria Coastal Authority.

The Alday Marsh is the vestige of what was once a great marsh. It is currently located in a very anthropized area, surrounded by infrastructure such as highways, railway lines and the Valle Real de Maliaño shopping centre, in whose parking lot is located the interpretation centre of the Fundación Naturaleza y Hombre. The railway line crosses the marshes, dividing it into two: the salt-water area and the fresh-water area.

In spite of the humanization of the area, the Alday Marsh is of great ornithological and environmental interest, being the habitat of numerous aquatic birds and a place of temporary stay and refuge of many others during the migrations that take place every year.

It is an intertidal plain where the waters of the Raos estuary and the Alday channel once met those of the Cantabrian Sea. Currently, only the salty area is influenced by the tides. The most common plant species are reeds, rushes and bulrushes. On the edges of the paths, there are plant species also associated with wetlands, or riverside forests such as hazelnut trees, willows, birches or ash trees. The areas damaged by invasive species such as the Pampa grass (Cortaderia selloana) and the sea myrtle (Baccharis halimifolia) should be highlighted, and work is frequently carried out to eliminate them. In recent years, the area colonized by these species has been considerably reduced.

To eliminate these species we work in two ways. One consists of the manual or mechanical elimination of these invasive species, by clearing the aerial part and pulling out the root systems. The other way is through the use of Spanish horses and donkeys which eat the young sprouts and avoid the proliferation of these species; this method is very effective as they keep the marsh in a perfect state of conservation. The Losino horse is an endangered equine species from the Losa Valley, north of the province of Burgos.

During the last decade, work has been carried out to recover a large part of the marshes which, due to their location in a highly urbanised environment, were very deteriorated. Thanks to good management and the application of corrective measures, the Marismas currently play an important role for birdlife, complementing the marshy areas of the Cantabrian coast. Alday is an important stopover on the migratory route of many species of waterfowl, herons and egrets, waders and birds of prey.

The greatest richness appears during the winter, when it is easy to observe a great number of migratory species. During the summer, nesting birds and some resident birds can be observed. Examples of these are herons, cormorants, sandpipers, plovers, ducks, etc.

This reserve has three observatories and a viewpoint that facilitate the observation of the birds of the marsh; in addition there is a wide network of paths that connect the different points of observation.

The visit to the Marshland allows access to the Salt- water Zone through the interpretative centre located in the parking lot of the Valle Real Shopping Centre. While the entrance to the Freshwater Zone is located in the vicinity of Makro. In spite of this, a footbridge has recently been installed in the train stop of the Shopping Centre, which makes it possible to connect the two areas of the marshes in a simple, pedestrian way.

In addition, the Alday Marsh can be visited using public transport. The train line Santander-Liérganes, has a stop in Valle Real, just a few hundred meters from the entrance to the Marsh.

Collaborators:

• Camargo City Council.
• Santander City Council.
• Ministry of the Environment, Rural and Marine Affairs Cantabria’s Coastal Region.
• Directorate General for the Sustainability of the Coast and the Sea.
• Caja Madrid Obra Social y Cultural.
• Citroen Auto Gomas Official Citroën Dealer.
• Department of the Environment of the Government of Cantabria.