The salt marshes of O Ulló and Larache are located in a protected area due to their natural characteristics. They are protected by European regulations, the Habitats Directive, which is applicable at both national and Galician level, because in and around the salt marshes there are two habitats that are considered a priority for conservation. Scientific studies have already detected more than 300 species of living beings that live there, both marine and terrestrial.
Sixty-nine of these species are considered protected species by European, state and regional regulations. The main habitats are the intertidal mudflats, the mudflats and the riverside forests. These three occupy a different area but no one is more important than each other. In the intertidal zone, conditions change with each tide. Twice every 24 hours the water and salt water appear and the animals and plants endure these changes, adapted to living there. Also the lack of sudden water movements at the bottom of the estuary causes mud to appear, which mixes with thicker gravel.
Gradually the bottom changes and grows until it is exposed out of the water, even at high tides. There, plants begin to grow and new animals begin to visit, turning it into a marsh. These plants and animals are still adapted to the salinity and are the intermediate step for the arrival of more typically terrestrial plants. Thus we come to the vegetation and riparian woodland on the edges of the marshes, of the channels of the streams and brooks that flow into them. These forests are filters and drains for the water, but their roots also help to maintain the soil and prevent erosion. Forests are therefore key in the conservation of terrestrial but also intertidal and marine territory.
However, there are also invasive and exotic species that need to be controlled and regulated. Although we can consider the environment of the Salt marshes de O Ulló and Larache to be in a good state of conservation, we must not neglect invasive plants and animals that can cause a serious imbalance in the area. These living beings, such as the Australian blackwood (Acacia melanoxylon), the Blue gum (Eucalyptus globulus), the Asian Hornet (Vespa velutina) or the yellow-eared slider (Trachemys scriptason) are in direct competition with the native and common plants and animals of the area, but also endemic species or species that are only present in this territory, and of course, those that are in danger of extinction. These exotic and invasive species have an easier time developing, growing and reproducing. They spread much more successfully and quickly occupy other people's spaces, even preventing others from surviving or transmitting diseases.