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Galician Atlantic Islands: Underwater, terrestrial and aerial fauna

The fauna and flora of the Parque Nacional das Illas Atlánticas de Galicia are a unique example of a maritime-terrestrial ecosystem in the world. The Galician Atlantic Islands, thanks to their privileged geographical position at the entrance of the Rías Baixas, are an obligatory stop for numerous colonies of migratory birds. In addition, thanks to the ocean currents that bathe their coasts, the waters of these islands are full of animal and plant species that inhabit the rich and delicate seabed.

If you want to know more about the amazing biodiversity found throughout the Cíes and the other islands that make up the National Park of the Atlantic Islands of Galicia, the fauna that takes refuge in its cliffs and settles on its land and in the interior of its marine environment, or if you want to know in more detail how they work for the conservation and protection of the natural environment of this special area, we invite you to read on and discover all the mysteries of this window to the Atlantic Ocean.


Galician Atlantic Islands: Animals in an unspoiled environment

Fauna in the Cies and Ons Islands (Atlantic Islands of Galicia)

Macaón Butterfly in the Atlantic Islands of GaliciaThanks to its recognition as a National Maritime Terrestrial Park, in the Atlantic Islands of Galicia, the fauna that inhabits both its waters and ocean floor, as well as the species that inhabit the surface, are currently extremely protected. and is actively working on everything related to environmental protection, the fight against invasive species and nature conservation, so that human influence causes the least possible impact, making their habitats protected areas.

The national park extends from north to south along the Rías Baixas, covers more than 84 km2 and includes both the different islands that compose it and the sea and ocean waters that surround it.The latter make up the majority of the park’s surface area, almost 85%. It is composed of the Cíes archipelago, in the Vigo estuary, Ons Island and Onza Island, located at the mouth of the Pontevedra estuary, Sálvora Island and Cortegada Island, at the entrance to Arousa Island.

The road to this status has not been easy. For Galicia, the Cíes Islands and, of course, the rest of the archipelagos that make up the park, have always been of the utmost environmental importance, and both the Xunta and the Vigo City Council have fought for decades for the importance and fragility of their ecosystems to be considered. In 1980, this site was declared a Natural Park, and throughout the 80s and 90s, measures were gradually taken for the conservation and improvement of an environment that had suffered great deterioration until then, such as the prohibition of spearfishing since 1992.

However, it was in 2002 when the Atlantic Islands of Galicia National Maritime Terrestrial Park was finally created. The islands that compose it and the waters that bathe them, drawing a strip of 100 meters from the coast, are within the network of national parks.The company’s environmental protection and preservation policy is the same as that of such emblematic places in our geography as the Picos de Europa in the Cantabrian Mountains, Ordesa and Monte Perdido in the Aragonese Pyrenees, the Tablas de Daimiel in Ciudad Real, the Archipelago of Cabrera in the Balearic Islands, the Caldera de Taburiente or the Teide and Timanfaya Parks in the Canary Islands.


Atlantic Islands of Galicia: Underwater Fauna

Galician Atlantic Islands: underwater animals

As a consequence of really special geographic and oceanographic conditions, the water surrounding the islands contains high levels of nutrients, which translates into high productivity that maintains an enormous biodiversity throughout its marine environment, forming stable populations or serving as a passage route.

crabs in Galician IslandsDifferent aquatic habitats are observed that vary with water depth and geographic position, and can change radically from island to island. In the eastern area we find sandy seabeds, which, despite the instability of the substratum and the scarcity of flora, They present a multitude of communities of polychaetes (segmented worms), flat fish such as rays and turbot, cuttlefish and small bivalves and crustaceans that live buried in the sand, as well as cockles and razor clams.

We also have what is known as gravel bottoms, formed by the remains of mollusk shells, a medium in which there is a varied fauna composed of various species of octopus, crabs and fish such as pout, mosaic rays and spotted stingrays. On this substrate, almost permanently in contact with it, inhabit most of the specimens that we will find in this habitat, labrids, serranos and sparids.

Other groups of fauna and flora of the islands prefer the safe haven of the rocky bottoms, where, thanks to the rich resources of its waters, reefs of mussels and barnacles are formed. The area of Cortegada Island and Sálvora Island, for example, is very rich in bivalves with commercial interest, deeply rooted in the culture and gastronomy of the land, finding large banks of clams and cockles. All this abundance is possible thanks, among other factors, to the great mass of laminaria that extends along the entire sublittoral, forming kelp forests, one could even say parks and gardens where octopuses and cuttlefish find food and shelter to lay their eggs. In addition, several scientific initiatives such as the Hippoparques Project are in charge of monitoring seahorse breeding.

Dolphins off the coast of Cíes Islands

Next to the famous Rodas Beach, undoubtedly one of the best beaches in Vigo, Lago dos Nenos, a lagoon with a high salinity but which does not prevent the development of a wide biodiversity. Diverse fish genera benefit from abundant food supply and the variety of shelters they find under its waters. Among the most important, we can observe mullets, mojarras and maragotas. In addition, this habitat serves as a food source for numerous species of seabirds and waders.

With such a profusion of life, it is logical to think that large predators and marine mammals also have a place in its waters. This is the case in the pelagic zone, i.e., the water column that does not lie on the continental crust. As it happens all around the Ría de Vigo and its islands, large schools of mackerel, sea bass and sandeels can be seen. Also congregate colorful groups of mammals such as the common dolphin (Delphinus delphis) or the bottlenose dolphin (Tursiops truncatus). Have you ever expected to see dolphins in Galicia?


Animals on the surface of Galicia’s Atlantic Islands


In the Atlantic Islands of Galicia, wildlife greets visitors before they even touch land. The colonies of seabirds that inhabit the islands, which we will talk about later, welcome us to paradise. that opens in front of our eyes.

Hedgehogs in the Atlantic Islands of Galicia, wild animals

Most of the field studies in the National Park are carried out on the Cíes Islands, where some species endemic to the archipelago have been found among the invertebrates, such as certain beetles or earwigs, which can be seen on any island among the scrub on the cliffs. Also noteworthy is the beautiful macaon butterfly, which is in decline throughout Europe.

Amphibians and reptiles are not very well represented among the island’s biodiversity, although their biological value is very important, as they have inhabited an isolated environment for 10,000 years and with hardly any fresh water or subway humidity. Populations, due to the limiting factor of water, vary greatly from one island to another. For example, the Iberian spadefoot toad, an endangered species of toad, has not been observed in the Cíes Islands for years, while in Sálvora it is much more abundant, perhaps due to the humidity conferred to the terrain by its large laurel forest. Other invertebrate species worth seeing include the common salamander, the Iberian newt or reptiles such as the ocellated lizard, the largest in Europe, with a length of up to 18 centimeters not counting the tail.

Reptiles in the maritime terrestrial ecosystem of the Atlantic Islands of Galicia.

As for mammals, due to the small land area, the biodiversity found in the Atlantic Islands is much lower than that of the surrounding continental coasts. Among its native forests, characterized by melojo oak, carballo oak, holly, butcher’s broom and broom, there is an important population of rabbits, hedgehogs and other small mammals such as mice, rats and moles. Its caves are inhabited by, at least, three species of bats, the most vulnerable being the greater horseshoe bat. There is a record of the presence of otters in the past – there is a cave known as “Cueva de las Nutrias” (Otter Cave) – but no otters have been counted in recent years.

Invasive species appear and must be controlled because of the danger they pose to the balance of the ecosystem. These are the feral cat, introduced by man, as well as the American mink, perhaps originating from continental surface farms. While the former are a threat to smaller mammals, minks are predators of eggs and chicks of seabirds nesting on Ons Island. Thus, we end our review by returning again to the birds, the most characteristic and important group of fauna of our islands. Want to know why?


Wildlife flying over the ocean in the Atlantic Islands of Galicia


One of the special features of a National Maritime Terrestrial Park is the special protection of its aquatic environments, coasts and maritime basin. In the case of the Atlantic Islands of Galicia, the marine fauna constitutes one of the greatest biological treasures to be found in Spain.

If anything characterizes the Atlantic Islands of Galicia and its fauna is, without a doubt, the great presence of seabirds. Due to the scarce human presence, the orography of the terrain, which allows the establishment of ideal breeding sites and, above all, thanks to the wealth of resources in the surrounding waters, numerous families of different species nest and develop on the islands, populating the sky with their presence. Both the Cíes and Ons archipelagoes are considered to bes Special Protection Areas for Birds at the European level. The presence of these colonies was decisive in providing the park with maximum environmental protection measures.

Yellow-legged Gull in Cíes Islands

The main nesting communities in the Galician Atlantic Islands are composed of families of Yellow-legged Gulls, Shag and Lesser Black-backed Gull. The yellow-legged gull is the largest colony in Europe, with about 18,000 specimens, although the population has been gradually decreasing in recent years, due to the gradual closure of landfills on nearby coasts, where these birds used to obtain a large part of their food.

The shag, so called because of its characteristic crest during the breeding season, has a population of approximately 2,000 breeding pairs, in one of the places in the world with the highest representation of this species; It is common to see them flying along the water looking for sandeels and other fish to hunt, as well as concentrating on isolated rocky areas to dry their dark plumage in the sun. The black-legged kittiwake, very similar to the yellow-legged kittiwake, is concentrated entirely on the island of Sálvora, with just over one hundred breeding pairs.


There are also communities of land birds: peregrine falcon, kestrel, king swift, goshawk, buzzard, etc., as well as families of medium and small birds: robins, goldfinches, turtledoves, blackbirds… On the other hand, wading birds can be found in its lagoons and ponds, with the frequent presence of herons and curlews.

In addition, thanks to their mild climate and their location on the map, the Atlantic Islands provide shelter to numerous species of migratory birds, including the Balearic shearwater, which is the only endemic seabird species in Spain.

Peregrine falcon flies over Cíes Islands

Many of these colonies can be admired by anyone visiting the islands by walking any of the hiking trails offered by the park. A perfect leisure and nature plan that invites you to explore the Cíes Islands and get to know all its corners, its surprising virgin environments, beaches, forests and small monuments and natural sculptures that the sea breeze has carved into the rock over the centuries. Also the buildings that rise there, forming the footprint of our own species, its various lighthouses and chapels. The most famous of these routes is the Monte do Faro Route.

Different projects seek to reintroduce native birds whose populations have been decimated or have even disappeared due to human activity. This is, for example, the case of the common guillemot, a species that formed a colony of some 500 breeding pairs in the 1960s, but which has not been nesting for two decades.


Galician Atlantic Islands: the fauna is cared for by all of us.


The conservation and preservation of the Atlantic Islands is a task for all of us. Its recognition as a Maritime Terrestrial Natural Park (one of two in the country) largely shielded the action that humans could exert on their lands or waters. However, there is always work to be done to achieve a fully sustainable and ecosystem-friendly interaction with the environment.

  Atlantic Islands Galicia: Special Protection Zone for Birds (SPA)Since 2008, the management and protection of the waters and islands, their geological environment, flora and fauna, is the exclusive responsibility of the Xunta de Galicia. The national park also has numerous international recognitions in order to guarantee the best environmental protection, including:


  • Special Protection Area for Birds (SPA), as part of the Natura 2000 network. Declared for the purpose of conserving the avian fauna in the Atlantic Islands of Galicia, both migratory bird colonies and those that permanently inhabit each island. The Cíes Islands achieved this status in 1998 and it was not until 2002 that the islands of Ons, Sálvora and Cortegada were also recognized.


  • Sites of Community Importance (SCIs). At present, the Cíes, Sálvora and Ons are included in three Sites of Community Importance: Illas Cíes, Corrubedo Wetland Complex and Ons-O Grove Complex, respectively.Bird colonies in the Atlantic Islands of Galicia


  • In 2008, it became part of the OSPAR convention for the conservation of marine systems, including, naturally, the beaches and dunes that are so representative of these Galician islands.


  • Since 2016, the Starlight Foundation has awarded the park the title of Starlight Destination, for its outstanding qualities to contemplate and observe the starry night skies protected from light pollution that unfortunately we can find in other well-known tourist destinations in Galicia, such as A Coruña, Santiago, Vigo and its historic center or Sanxenxo.


Currently, the city of Vigo and its council have applied to both the Ministry of Culture and the Ministry of Ecological Transition for the whole park to be recognized by UNESCO. In addition, the Sisargas and Lobeiras Islands, also of great ornithological importance, are being considered for declaration as part of the park.


Galician Atlantic Islands: Unique fauna in an unparalleled location

Animals in the Atlantic Islands of Galicia

If you needed any more excuse to visit or return to the Parque Nacional das Illas Atlánticas, now that you know much more about its birds, its underwater richness and the biological importance of its terrestrial species, maybe it is the perfect time to visit one of the most charming spots. If you are looking for nature in its purest state, a paradise in the middle of the ocean but only thirty minutes away by boat, the Atlantic Islands of Galicia and its fauna are waiting for you.

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