The estuary of the river Miñor, known as "A Foz", is situated in the bay of Baiona, in the south of  the Ria of Vigo, Galicia (NW coast of Spain).  The area is an important place for shellfish activities (Venerupis sp, Cardium sp, Donax sp.) and at the same time it is used as a resting place for some migrating birds (Numenius sp., Haematopus ostralegus, Ardea cinerea, Egretta garzetta, Phalacrocorax aristotelis, Limosa sp, ...). The main vegetation are halophyte species distributed in relation with the environmental conditions.  The salted marshes are protected from the direct action of the sea by a sandy beach  (Praia Ladeira) where a camping site has been established. The main river that leads to the marshes is the river Miñor which flows into the bay, and there are also two other smaller rivers (Belesar and Grova river) that flow into A Foz. The estuary is situated over metamorphic rocks (mainly schists)  belonging to the Ordovicic age, that are surronded by granitic materials. The climate is coastal-mediterranean, maximum rainfall during the colder months, and dry season in June/July. The average temperature is about 15ºC. The most important problems that affect the estuary are: 1 Artificial filling. 2 The building in the surroundings: houses, roads, promenades. 3 The camping site on Ladeira Beach makes it difficult for marine sediments to enter the estuary in periods of waves and storms, and it breaks the natural balance between the "input" and "output" of sand in the estuary. 4 Contamination: organic and solid waste that has produced the  growth of green weeds in the salted marshes.