Lake Cadagno

The Lago di Cadagno ( Cadagno ) is a natural lake in the Piora region in the municipality of Quinto in the canton of Ticino in Switzerland.

The ecosystem of Lake Cadagno with named after the Val Piora Piora fluctuation is unique both in Switzerland and in Europe and is in the " Centro di biologia alpina di Piora " (Research Centre for Alpine Biology ), which is near the lake is investigated. To research each year more than 2000 researchers from all over Europe and from the United States to investigate the phenomenon of geogenic meromixis site.

In the geogenic meromixis seasonal mixing of surface water with the water from the deeper Seeschichten. The phenomenon is very relevant from a scientific point of view, because it allows the research of metabolisms, which are associated with eutrophication. The surface layer is separated by a bacterial filter from the rest water layers in the depth of the lake.

The Cadagno consists of three layers: the top is fresh mountain water from the granite sources in the middle - eleven meters below the surface - a 1.5 meter thick, inhabited by red sulfur bacteria layer, and at the bottom a layer with high salt and sulfur water from underground water sources of the dolomite layer. The sulfur bacteria allow the life in the upper fish-rich layer and separate the fresh mountain water from the toxic and stinking of rotten eggs underwater.

Originally the phenomenon in neighboring Ritomsee and Girottesee in France ( Haute Savoie) was to be found before these natural lakes have been altered by structural measures for energy production.

In the fall of 2005, the SBB, which operate the Ritom power plant in Piotta, fall into criticism because in too short a time too much water was left out of the Cadagno to feed the neighboring Ritom reservoir. Some representatives from the Leventina brought the matter up even before the cantonal parliament in Bellinzona. The critics argued that the amount of water that comes from the Cadagno, in relation to the total amount of the Lake Ritom is very low and also endangering the survival of the entire ecosystem of Cadagno. SBB could therefore dispense with the water of Cadagnosees without affecting the performance of the power plant. As a result of these criticisms, the SBB in spring 2006 renounced under the license renewals for the Ritomsee on the use of water from the Cadagno.