Les écosystèmes d’eaux continentales sont des milieux rares, ils ne couvrent que 2 % de la surface terrestre, mais présentent une valeur écologique exceptionnelle. Ils abritent une biodiversité très spécifique et fragile, avec une forte proportion d’espèces menacées. Bien que, dans les Pyrénées, ils soient souvent perçus comme des espaces naturels peu altérés, l’influence humaine y est présente depuis longtemps et a contribué à leur transformation.

Dans ce contexte, le projet LimnoPirineus a œuvré à améliorer l’état de conservation des espèces et des habitats aquatiques d’intérêt européen dans des espaces tels que le Parc national d’Aigüestortes i Estany de Sant Maurici, le Parc naturel de l’Alt Pirineu et l’Estanho de Vilac, dans le Val d’Aran.

L’exposition poursuit un double objectif : d’une part, sensibiliser le public à la valeur, à la diversité et aux menaces qui pèsent sur ces écosystèmes; d’autre part, faire connaître les résultats et les actions de conservation menées dans le cadre du projet.

Aujourd’hui, grâce à LIFE RESQUE ALPYR, cet outil de sensibilisation reste actif et accessible, renforçant l’engagement en faveur de la conservation des écosystèmes de haute montagne. L’exposition peut être mise à disposition pour des activités éducatives, dans des centres ou à l’occasion d’événements, afin de diffuser ces connaissances auprès du plus grand nombre.

Ils sont partout, mais ils sont petits. Bien que parfois, pas au point d’être invisibles : avec un peu de patience et une bonne lumière, certains peuvent être aperçus à l’œil nu comme de petits points mobiles dans l’eau. Cependant, pour apprécier pleinement leurs formes inhabituelles et leur diversité, il faut les observer de plus près. Sous le microscope, se révèle un monde plein de structures extravagantes et de créatures qui semblent parfois venir d’une autre planète.

Dans cet article, nous vous invitons à découvrir quelques-uns de ces petits et surprenants habitants des lacs alpins.

• Alona

Ce petit cladocère habite la zone littorale du lac, près des rives. L’exemplaire que nous voyons ici est une femelle portant un grand œuf dans une cavité dorsale. Elle le gardera protégé jusqu’à ce que le jeune soit entièrement formé, une stratégie efficace dans des environnements froids et imprévisibles.

• Cyclops abyssorum

Mesurant environ 2 mm de long, ce crustacé prédateur se distingue par son grand œil unique, situé sur le haut de la tête — d’où son nom. Il vit près du fond du lac. Bien que ses longues antennes puissent sembler intimidantes, elles ne servent pas à chasser : le mâle de Cyclops abyssorum les utilise comme pinces lors de l’accouplement.

• Keratella cochlearis

À première vue, il ressemble plus à une fleur qu’à un animal. Ce minuscule rotifère de 0,1 mm nage à la recherche de microalgues et de bactéries, propulsé par un organe cilié situé près de ses épines supérieures.

• Daphnia longispina

Elle peut atteindre 2,5 mm, et ses grands yeux composés lui donnent une expression presque attendrissante lorsqu’on l’observe au microscope. En plus d’être l’un des cladocères les plus communs, c’est une espèce clé des réseaux trophiques de nombreux lacs, grâce à son appétit vorace pour les algues.

• Chydorus sphaericus

Rond et sympathique, c’est le plus petit crustacé du groupe, mesurant entre 0,2 et 0,5 mm. C’est une espèce cosmopolite considérée comme le cladocère le plus répandu au monde, présente dans une grande variété d’habitats d’eau douce.

This year, we conducted our first pilot test with rotenone to eliminate invasive fish species from high-mountain lakes. This action is part of a broader strategy to restore high-altitude aquatic habitats, aiming to transform the restored lakes into biodiversity reservoirs and ecological corridors.

We have also focused on protecting mires, vital habitats for biodiversity and water regulation. Through strategic selective deforestation operations, we have reduced shading and created better conditions for their regeneration. In addition, we have continued the mire protection actions initiated in previous years, such as mowing wet hay meadows and livestock management through the installation of temporary and permanent fences.

Beyond our fieldwork, we remain committed to public engagement. Our participation in events like Science Week and European Researchers’ Night has allowed us to raise awareness about the importance of conserving high-mountain aquatic ecosystems and to connect with the community. Furthermore, our team has participated in numerous scientific and technical conferences and events this year, aiming to share the results and knowledge generated at both national and international levels.

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You can read the full newsletter at the following link.

The first video, titled “How to Eradicate Fish from High-Mountain Lakes,” presents the project’s main goals, focusing on the conservation and restoration of these lake ecosystems. High-mountain lakes are traditionally isolated from valley rivers by natural barriers that prevent the arrival of fish. However, many of these lakes now host fish species introduced through historical interventions, which have disrupted the natural ecological balance. These introduced species have become invasive, negatively affecting native fauna and the ecological quality of the habitat.

The video also highlights the collaboration with the FishME project, which uses a multidisciplinary approach to analyze the impact of fish and pollution, and to develop practical tools for managing and restoring mountain lakes.

In the second video, “Mountain Lake Rewilding Works!” Dr. Ventura explains how, after removing the introduced fish species, the original fauna of these lakes begins to recover. This rewilding has led to the return of native species, especially amphibians and macroinvertebrates, and has facilitated the recolonization of small mammals such as the Pyrenean desman, a rodent that relies on aquatic insects for food.

These videos emphasize the importance of conserving and restoring mountain ecosystems and demonstrate essential tools for effective, evidence-based management of these unique natural environments.

In addition to being introduced species, they are considered invasive species, as they have a negative impact on the ecosystem.

Salmonids introduced in the Pyrenees include brown trout (Salmo trutta), rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis). The European minnow (Phoxinus sp.), a small Cyprinid, has also been introduced in many of the lakes in the Pyrenees, but in this case, the arrival is related with its use as live bait for fishing trout.

The species introduced in Mont Avic Natural Park are Arctic char (Salvelinus alpinus), the European minnow (Phoxinus spp.), the Italian riffle dace (Telestes muticellus), brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss); and the species introduced in Gran Paradiso National Park are brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta).

The proliferation of fish in these lakes has had negative consequences on the native fauna, has affected the structure and balance of the entire ecosystem and altered its trophic food web. Furthermore, the impact of introductions can also have consequences on terrestrial fauna populations such as birds, bats and small mammals such as the Pyrenean desman, which depend on aquatic insects as a food source.

The brochure can be consulted in digital format on the project’s website, but it can also be found at the tourist offices of the Alt Pirineu Natural Park and the Aigüestortes and Sant Maurici National Park in Catalonia, and the Mont Avic Natural Park and Gran Paradiso National Park in Italy.

Starting today, you will find a new capsule every month.

The videos can be seen on the project’s Instagram profile, but also on the media section of the website and on the YouTube channel of the CEAB-CSIC, the project’s coordinating center.

Today, May 21, is the Natura 2000 Day

We are also taking advantage of this launch day to celebrate the European Natura 2000 Day, of which we are a part. The Natura 2000 Network is a collection of protected areas designated to conserve certain species and habitats that live there.

In total, there are more than 27,000 of these areas across Europe.

The protection of these spaces aims to ensure the long-term survival of Europe’s most valuable and threatened species and habitats. Natura 2000 sites reflect Europe’s rich variety of wildlife and habitats. They cover almost one fifth of land and one tenth of surrounding seas – which is about the size of Spain and Italy combined.

But what makes it special?

In addition to the numerous species of animals, plants, and habitats it protects, the Natura 2000 Network is the result of the cultural and historical interaction between humans and nature.

Bats are distributed throughout most of the planet, except for the poles. They are found on continents as well as on islands far from the mainland. They can live from mountain ranges to desert oases, from tropical regions to boreal ones. They can take refuge in caves, tree hollows, rock crevices, buildings, or amidst the lushness of vegetation. Some even hide among the pebbles along riverbanks.

Unlike birds, bats fly with their hands while birds fly with their arms. They are the only flying mammals. The forelimbs of bats have evolved by elongating fingers and forearms. The bony structures we see in their wings are the fingers of the hand and support a thin, naked membrane called the patagium, which has muscular fibers and many blood vessels. The aerial life of bats has led to various flight-related adaptations. Like birds, bats have a highly developed pectoral musculature that allows them to move their wings and perform flapping flight. However, this musculature requires a rigid bony anchoring structure. This is the sternum, which is also quite developed and in many species has a keel-like shape. The size of bats varies greatly depending on the species.

Bats have other flight adaptations that, while not as evident as wings, are also important for flight. Most species only have one offspring, a characteristic that allows greater maneuverability for gestating females, thereby increasing the probability of survival.

The seasonal movements of bats can vary greatly from one species to another or even among populations of the same species. Some can make long seasonal migrations that in some cases exceed thousands of kilometers. This is the case of the lesser noctule bat (Nyctalus leisleri), very abundant in the forests of the Pyrenees.

In Catalonia, the most well-known migrations are those of the Schreiber’s bat (Miniopterus schreibersii), a species that flies relatively quickly and can make seasonal movements exceeding 300 km.

Another interesting aspect of bat biology is their longevity. It is longer compared to what would be expected based on their body size.

Bats exploit a wide range of food resources, from those that eat fruit to the mythical vampires. There are bats that eat frogs, birds, fish, small reptiles, scorpions, or even carrion. Another type of diet is nectarivorous, which corresponds to feeding on the nectar and pollen of flowers. Bats with this dietary regime contribute to pollinating a large number of plants.

There are even plant species whose pollination is highly specialized and depend on certain bat species. However, the majority of species (70%) of bats eat insects.

They have the ability to emit ultrasound for orientation, communication among themselves, and also for locating and hunting prey

The calls emitted for communication among bats, also known as social calls, are used between mother and offspring in breeding colonies, for mating, for marking territory, or for defense when they feel threatened. The process by which animals locate objects they cannot see or touch through the emission of acoustic signals and the analysis of their echoes is called echolocation. Ultrasound calls are produced by the vocal cords. The ultrasound emitted undergoes reflection when it encounters obstacles, and the echoes are captured again by the emitting bats. Echolocation allows measuring the distance between the emitter and the obstacle, but it also enables calculating the relative speed of the prey, since normally neither the bat nor the prey are stationary. Bats also use echolocation to receive information about the shape, size, and texture of the surface of the object in front of them.

Contrary to popular belief, bats are not blind. They have eyes that allow them, when there is sufficient light, to perceive the world in black and white.

Tracking 7 species of bats

One of the novelties of this new LIFE compared to the previous one is the study of some bat species. The studied bats are insectivores that feed on large quantities of insects and usually hunt around ponds.

The project includes tracking 7 species of bats: the Barbastelle bat (Barbastella barbastellus), the Greater mouse-eared bat (Myotis myotis), the Alpine long-eared bat (Plecotus macrobullaris) present in the Pyrenees and the Alps, and the Lesser horseshoe bat (Rhinolophus hipposideros), the Greater horseshoe bat (Myotis blythii), Bechstein’s bat (Myotis bachsteinii), and the Greater noctule bat (Nyctalus lasiopterus).

Technologies and tools for studying bats

The study of bats is complex and for this reason, it is the most unknown group of mammals that exists. They are difficult animals to observe because they hide in places that are inaccessible or not easily accessible and they fly at night, which makes their observation difficult. Some of the methodologies used to study them are:

• Bat captures
• Shelter boxes
• Shelter monitoring
• Listening stations with ultrasonic detectors
• Radio tracking

In the case of the LIFE project, the study of bats is carried out through the installation of ultrasonic recording devices emitted by bats and the installation of networks that allow specific identification of individuals, provide data on the biological cycle, and allow the collection of feces for analysis of their feeding and health status.

Thanks to ultrasonic recording devices, the activity of bats and the species that frequent ponds can be known. Their excrement allows us to know what they eat.

They have an important ecological role

Bats provide significant ecosystem services: they pollinate plants, act as seed dispersers, and help control insect populations – a bat can consume up to 3000 insects per night – making them natural pest controllers in agricultural and forest environments. They are major consumers of mosquitoes and therefore help us keep these insects, which are major disease vectors such as malaria or dengue, in check.

One of the interesting tasks of the project is to compare the presence of bats in ponds with fish and ponds without fish. When there are fish in a pond, the entire biodiversity of the pond is affected and modified. The study aims to determine if this mentioned impact on biodiversity also affects the structure of the bat community, that is, the abundance and diversity of bats.

Fonts:

• Serra-Cobo J, López-Roig M, Bayer X, Amengual-Pieras B i Guasch F. 2008. Els ratpenats: ciència i mite. Publicacions i Edicions de la Universitat de Barcelona.
• Serra-Cobo J, López-Roig i Bayer X. 2015. El tresor ecològic de les mines de Can Palomeres: els ratpenats. Publicacions de l’Ajuntament de Malgrat de Mar.
• Serra-Cobo J, Sanz V i Martínez-Rica JP. 1998. Migratory movements of Miniopterus schreibersii in the north-east of Spain. Acta Theriologica, 43(3): 271-283.
• https://secemu.org
• Guia de camp. Els ratpenats de Catalunya
• https://www.batmonitoring.org/v0/CAT/coneguem/coneguem.php

In flat areas, water flows through tortuous streams or forms small ponds, saturating the soil along the riverbanks. This creates a high mountain wetland environment known as a mire.

In this second publication, we elaborate the characteristics of these ecosystems and their significance. Furthermore, we delve into the primary threats they encounter and outline the key conservation efforts undertaken by the project.

The brochure is available on the project’s website and also at the tourist offices of the Alt Pirineu Natural Park and the Aigüestortes and Sant Maurici National Park, in Catalonia, and of the Mont Avic Natural Park and the Gran Paradiso National Park, in Italy.

Our summer field campaign has been pivotal, involving meticulous monitoring of high mountain lakes and the study of valuable mires ecosystems. We have made significant strides in eradicating invasive fish and successfully carried out the initial restoration initiatives in mires. This hands-on work is providing us with invaluable data, empowering us to make wellinformed decisions to restore and conserve these fragile environments.

The LIFE RESQUE ALPYR project aims to restore and improve the conservation of high mountain aquatic habitats, focusing mainly on ponds, alpine and subalpine meadows, peat bogs and carbonated springs. The project is a continuation of two previous LIFE projects, the LIFE LIMNOPIRINEUS in the Pyrenees and the LIFE BIOAQUAE in the Alps.

If you are interested in receiving more information about the project you can subscribe to the newsletter here,

Here you can download the newsletter in pdf.

This initial publication, edited in 6 languages, contains general information about the project. It details the target species and habitats, the conservation actions being undertaken, and explaining the main threats faced by high-mountain aquatic ecosystems and the species inhabiting them.

The brochure will be available on the project’s website and also at the tourist offices of the Alt Pirineu Natural Park and the Aigüestortes and Sant Maurici National Park, in Catalonia, and of the Mont Avic Natural Park and the Gran Paradiso National Park, in Italy.