IberiaNature

Lake Banyoles

Lake Banyoles (Lago Banyoles / Estany de Banyoles) in Girona is the second largest lake in Spain. It covers 107 ha and is 46.4m deep. It is karst in origin, and is bordered by the town of Banyoles (15,000 inhabitants) and its forested water catchment basin. Together with the lake, there are small marshes Lagunas del Vilar y de las Guixeres, and the inflowing rivers Castellana y de la Puda, covering a total of 132 ha. This is one of the best examples of a karst catchment on the Iberian peninsula. The lake supports a rich and diverse aquatic vegetation of permanent and temporary pools. The turtles Emys orbicularis and Mauremys leprosa and the fish Barbus meridionalis are of interest at an EC level. Tourism and recreation are present in most of the wetland area

Information below adapted from Ramsar Directory of Wetlands of International Importance (2002)

Importance: The site is a representative example of karst catchment on the Iberian peninsula, in the Mediterranean region. The local sulphur, iron and carbon cycles support characteristic bacterial communities. A rich and diverse aquatic vegetation of permanent and temporary pools and the associated fauna contribute to the environmental importance of the site. The wetland harbours EC-listed habitats of importance, such as “Mediterranean temporary ponds”, “Calcareous fens” and “Alluvial forests with Alnus glutinosa and Fraxinus excelsior. The Catalan-protected plant species Thelypteris thelypteroides, Riccia fluitans, Ranunculus lingua, Mentha cervina, Baldellia ranunculoides and Teucrium scordium are also found on the site. The wetland supports EC-listed reptiles (e.g. Emys orbicularis, Mauremys leprosa, Lacerta viridis, Elaphe longissima ), amphibians (e.g. Triturus marmoratus, Alytes obstetricans, Hyla meridionalis ), fish (e.g. Barbus meridionalis ), invertebrates (e.g. Coenagrion mercuriale, Oxygastra curtisii, Euphydryas aurinia, Lucanus cervus, Aeshna viridis, Proserpinus proserpina ) and mammals (e.g. Rhinolophus hipposideros, R. ferrumequinum ). The wetland is a nesting site for the EC-listed birds Ixobrychus minutus, Dendrocopus minor, Alcedo atthis, Milvus migrans, Circaetus gallicus, Burhinus oedicnemus , and a wintering/stop-over site for the EC-listed species Phalacrocorax carbo, Nycticorax nycticorax, Ardeola ralloides, Egretta garzetta, Ardea purpurea, Ciconia ciconia, Himantopus himantopus .

Wetland Types: The wetland comprises a complex of karstic lakes and temporary ponds, grasslands, and gallery- and oak forests. The main part (999 ha) consists of the upstream freshwater lake adjacent to Banyoles town (15,000 inhabitants) and its forested water catchment basin. Within the site, the lake itself, the small marshes Lagunas del Vilar y de las Guixeres, and the inflowing rivers Castellana y de la Puda cover together 132 ha. The site includes also a separate part (34 ha) of the catchment of the Laguna de Espolla pool.

Biological/Ecological notes: The site harbours EC-listed habitats such as “Hard oligo-mesotrophic waters with benthic vegetation” (code 3140), “Natural eutrophic lakes” (code 3150), “Mediterranean tall humid grasslands” (code 6420), ” Quercus ilex and Quercus rotundifolia forests” (code 9340) and ” Salix alba and Populus alba galleries” (code 92A0). The aquatic habitats harbour photosensitive bacterial communities, participating in the cycles of sulfur, iron and carbon. The aquatic fauna includes invertebrates (e.g. genera Unio, Anodonta, Atyaephyra, Lymnaea, Triops cancriformis ) and fish (e.g. Barbus meridionalis, Leuciscus cephalus, Blennius fluviatilis ). The terrestrial habitats, with shore vegetation such as genera Phragmites, Typha, Scirpus, Carex and Juncus , is of particular importance for nesting and wintering birds (e.g. Acrocephalus schoenobaenus, A. scirpaceus, Sylvia borin, Phoenicurus phoenicurus, Emberiza schoeniclus ). The diversity of habitats offers refuge to a variety of associated fauna, including birds, mammals (e.g. Arvicola sapidus, Mustela putorius, Sus scrofa ) and subterranean invertebrates (e.g. genera Niphargus, Stenasellus ).

Hydrological/Physical notes: Lago de Banyoles is a lake of tectonic origin. It contains a unique succession of aerobic and anaerobic sedimentation layers (e.g. travertine layer). In the surroundings, “tufas” indicate the presence of an ancient, more extensive, lake area. Lake Espolla has also a travertine layer, formed of loams, gypsum and limestones originating from the ancient lago de Banyoles. The dissolution of gypsum layers gives the area its characteristic “dolines” shape. The soils belong to “dry floodplain” types. Lake Espolla, situated 42 m above the system’s water level, is only filled when the underground water pressure is sufficient. The origin of the complex’ aquifer lays in the calcareous mountains of the Alta Garrotxa region. In the site, three aquifers are interconnected by subterranean circulation. The catchment of the Lago de Banyoles unit spreads over 12 sq. km and contributes to 20% of the total water volume. The remaining volume originates from the underground. These waters have their outlet, through a number of channels, in the Río Terri. Lake Espolla has a catchment of 95 ha. Its overflow pours into Río Fluvià. The two units have the same aquifer origin (Banyoles-Besalú), but they belong to two separate river basins (Ter and Fluvià). Lago de Banyoles’ water is oligo-mesotrophic, with high concentrations of calcium carbonates and sulphates. Some of the adjacent lakes are eutrophic. Lake Espolla has been modified by humans and its depth at maximum flood reaches 5 m. The climate is of humid Mediterranean type, with 940 mm of yearly precipitations, falling mainly during spring and autumn. The temperatures are at maximum 32°C, at minimum -10°C and average 15°C.

Human Uses: The lands are privately owned, the waters are in municipal and communal property. Human activities include tourism and recreation in most of the wetland area, except a few inaccessible parts. Small-scale farming and livestock rearing takes place in the surroundings. Conservation education and scientific research is also carried out. Lago de Banyoles provides water to the surrounding town and industries, and for irrigation purposes.

Conservation Measures: Lake Banyoles and its outskirts were declared as an Outstanding Landscape in 1952, followed in 1963, by the creation of the “Patronato del Lago de Bañolas” for maintaining the landscape. In 1967, the proposed management plan was approved by the Provincial Commission of Urban Planning and Architecture. In 1978, the site was chosen by the Institute for the Conservation of the Nature (ICONA) for proceeding an Open Inventory on Natural Areas of Special Protection. In 1981, additional protection norms for Natureal Areas of Special Interest were approved by the Catalonian Government. In 1990, the municipality of Banyoles edited a Special Plan of Protection, Ordering and Restoration for the eastern part of the lake. In 1993, the Regulation Activities of the Lake (RAE) were approved. The area has been proposed to the European Life-Natura project, for funding. In 2001, the site was included in the Inventory on Catalonian wetlands. Lago Banyoles has been proposed as an EC Site of Community Interest (Natura 2000 network).

Adverse Factors: Adverse factors within the site include recreational and tourist activities, illegal hunting and fishing, introduction of exotic species (fish, crustacean, reptile), and habitat fragmentation (roads)

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