__NOTOC__ Lake Cadagno (Italian: ''Lago di Cadagno'') is a

meromictic lake A meromictic lake is a lake which has layers of water that do not intermix. In ordinary, holomictic lakes, at least once each year, there is a physical mixing of the surface and the deep waters. The term ''meromictic'' was coined by the Austr ...

in the Piora valley (canton of

Ticino Ticino (), sometimes Tessin (), officially the Republic and Canton of Ticino or less formally the Canton of Ticino,, informally ''Canton Ticino'' ; lmo, Canton Tesin ; german: Kanton Tessin ; french: Canton du Tessin ; rm, Chantun dal Tessin . ...

), Switzerland. As one of a few meromictic lakes in Europe, it is the object of numerous scientific studies. The Piora valley - located in the

Saint-Gotthard Massif The Gotthard Massif or Saint-Gotthard Massif (german: Gotthardmassiv or ; it, Massiccio del San Gottardo; rm, Massiv dal Gottard) is a mountain range in the Alps in Switzerland, located at the border of four cantons: Valais, Ticino, Uri and G ...

(central Swiss Alps) in the Southern part of Switzerland near Airolo at an altitude of 1921 m above sea level - is a landlocked alpine valley whose scientific value has been recognized for more than two centuries. In the past, the lake was used as a

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

. Lake Cadagno is a rare example of crenogenic meromixis. Its waters show a permanent stratification due to a natural geological phenomenon. The lower abounds with dissolved mineral salts (sulphate, magnesium, calcium, carbonate) originating from sublacustrine springs, whereas the separate upper layer is permanently oxygenated. Anaerobic phototrophic bacteria – among them ''

Chromatium okenii ''Chromatium okenii'' is a Gram-negative bacterium found in water. It belongs to the Purple sulfur bacteria.George M. Garrity: ''Bergey's Manual of Systematic Bacteriology''. 2. Auflage. Springer, New York, 2005, Volume 2: ''The Proteobacteria ...

''—thrive between the two layers where they find the ideal conditions for their development. Such an ecosystem provides a good opportunity to study the metabolisms connected with

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

on a stable model, as it is well known that one of the advanced stages of eutrophication is biogenic meromixis.

Research

For the last 25 years the area has been increasingly used for scientific purposes, both for teaching and researching various environmental subjects. In view of stimulating educational and scientific activities at a university level, the Alpine Biology Center (ABC) has been set up by the Canton of Ticino, in cooperation with the universities of Geneva and Zurich. For this purpose, two 16th century buildings of the Alpe Piora have been turned into a laboratory and lodgings. The Microbiology Institute of the canton of Ticino is responsible both for managing the center and coordinating its activities. Cyclobotryococcatriene, a

botryococcene ''Botryococcus braunii'' is a green, pyramid-shaped planktonic microalga that is of potentially great importance in the field of biotechnology. Colonies held together by a lipid biofilm matrix can be found in temperate or tropical oligotrophic ...

-related hydrocarbon, was isolated from and identified in organic-rich

sediments Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity In physics, gravity () is a fundame ...

in Lake Cadagno in 2000.

References

Tonolla M, Storelli N, Danza F, Ravasi D, Peduzzi S, Posth NR, et al. Ecology of Meromictic Lakes - Lake Cadagno: Microbial Life in Crenogenic Meromixis. chapter 7; Vol. 228. 2017. Available from: https://link.springer.com/10.1007/978-3-319-49143-1 Wagener S, Schulz S, Hamselman K., Abundance and distribution of anaerobic protozoa and their contribution to methane production in Lake Cadagno (Switzerland) FEMS Microbiology Letters, Volume 74, Issue 1, October 1990, Pages 39–48, https://doi.org/10.1111/j.1574-6968.1990.tb04050.x

External links

*http://www.cadagno.ch *http://www.supsi.ch/lma/ricerca-servizi/microbiologia-ambientale/aree-ricerca.html {{DEFAULTSORT:Cadagno Lakes of Ticino Meromictic lakes Reservoirs in Switzerland

Research

See also

References

External links