The mouth of Eo River in the Cantabrian Sea forms the “Ría de Ribadeo” Estuary. It is the easternmost estuary of Galicia, or the westernmost one of Asturias, as it forms the border between the two autonomous regions. Both autonomous communities have administrative competences over the estuary. As in all estuaries, in the “Ría de Ribadeo” there is an exchange of freshwater from the river and saltwater from the sea. This peculiarity gives rise to an ecosystem with very special characteristics, in which the different varieties of flora and fauna have to adapt to these conditions. The sediments carried by the river with those brought by the own tides create a biotope very rich in nutrients, from which a large number of animal and plant species take advantage. Many of them are distributed in different areas of the estuary depending on various factors such as the degree of salinity, water level or type of sediments that form the bottom, which in turn affects predator species to feed in one area or another.

And if “Ría de Ribadeo” stands out for something, it is for being an especially important place for birds. During the winter, it becomes a haven for a wide variety of species that come from Northern Europe in search of more benign climates to spend the cold season. Many of them use the estuary as a stopping place to rest and get their strength back, before continuing their journey to their winter quarters (South of the Peninsula or Africa).

By contrast, many other species choose our estuary as their final destination which becomes their wintering place. At this time, it is notable the large number of groups of waders, sea gulls, herons, and very especially the anatids, with large concentrations of Northern Pintail (Anas acuta), Mallard (Anas platyrhynchos), Wigeon (Anas Penelope) or Common Teal (Anas crecca). Anyway, even though it is the season with more abundance of birds due to the arrival of the over-wintering birds, birdwatchers can enjoy the observation throughout the year, because in the different periods of migrating, or even in summer, new species from other latitudes can be seen, in addition to those that live here during the whole year.

Due to this great richness, the “Ría de Ribadeo” has been receiving various forms of protection to showcase its great environmental value. In this sense, it is designated as “SCI-SPA of the Ría de Ribadeo” (Site of Community Importance – Special Protection Area for Birds) pursuant to the EU Habitats Directive and included into the Natura 2000 Network; “Wetland of International Importance” under the Ramsar Convention; “ZEPVN” (Special Protection Area for Natural Values) and “Protected Wetland ” by the Galician Network of Protected Natural Areas and “Partial Nature Reserve” under the Asturias Management Plan for Natural Resources.

In addition, the estuary belongs to the UNESCO Biosphere Reserve of the Río Eo, Oscos and Terras de Burón which includes seven municipalities in Galicia and other seven in Asturias.

However, despite all these splendid declarations and international recognitions, “Ría de Ribadeo” continues to be a very delicate ecosystem, and its natural values are constantly threatened by incessant human pressure. Thus, some of its most notable winter bird populations have drastically declined and formerly abundant species have even disappeared at a local level. However, at the same time, other species have increased their presence in the estuary. All this shows that this is a living ecosystem, extremely sensitive, that can be easily affected by a wide variety of factors, particularly those related to human activities.

On the other hand, As Catedrais SIC (Site of Community Importance) is a narrow section of coastal land stretching across 15 km to the neighboring municipality of Barreiros. Its main value comes from its geological, vegetable and marine features, and its prime example is the famous beach of As Catedrais which has been declared as Natural Monument and whose greatness will not be discovered here. When it comes to birds, there are numerous sites for bird watching in this area. Almost every point and cape is a good place for seabird watching. It also has a modest artificial wetland named Charca del Rinlo that can bring us pleasant surprises.