River Eo

Approximately 287 km of its catchment area run through the Principality and two of the westernmost Asturian towns, Castropol and Figueras, overlook it.

In estuaries such as that of the Eo, the river waters mix with the marine waters, bringing with them a multiplicity of environments. The confluence of both fluvial and tidal flows means an important contribution of sediments and organic matter, thus creating rich nutrients for living beings.

Plant life

The most original plant communities are the underwater meadows formed by the two species of Zostera.

In the Eo estuary, and specifically in the Linera inlet, there is a formation of Zostera marina, the size of which probably makes it the largest in the Cantabrian Sea. Also of great interest are the Zostera noltii formations found in this and other coves.

Halophilous scrubland is a type of vegetation that is frankly scarce in this estuary, the best-preserved fragments of which are located in the Tarrón inlet. The reed beds and reed beds are located in the areas where the influence of the high tides is less pronounced. The reed beds dominated by Juncus maritimus form very appreciable extensions at the tail of the estuary, next to the villages of Miou and Louteiro. Reed beds of various types accompany the reed beds in this area.

Wildlife

Focusing the analysis of the fauna on vertebrates, it is necessary to highlight the special interest of this enclave for birdlife.

The Eo estuary is considered to be the main wintering and migratory resting area for European waterfowl populations in Asturias. Forty-nine species have been identified, of which 16 are waders, 13 anatidae and 9 lizards, the rest being distributed among other groups.

Most of these are wintering birds, although there is a small group of spring and autumn migrants and another that can be observed throughout the year.

This wetland area is classified as internationally important for three duck species: wigeon, pintail and tufted duck.

The presence of important populations of oystercatchers, grey plovers, sandpipers, sandpipers, whimbrels and black-winged godwits give it the status of regional importance for these species.