| one publication added to basket [247496] | Influence de la qualité chimique de l'eau ardennaise sur la survie de l'alevin de truite en élevage intensif Salmo trutta (L.)- Salmo gairdneri (Richardson)
Dupont, E. (1981). Influence de la qualité chimique de l'eau ardennaise sur la survie de l'alevin de truite en élevage intensif Salmo trutta (L.)- Salmo gairdneri (Richardson) . Ann. Soc. R. Zool. Bel. 110(1): 22-44
In: Annales de la Société Royale Zoologique de Belgique = Annalen van de Koninklijke Belgische Vereniging voor Dierkunde. Société Royale Zoologique de Belgique: Bruxelles. ISSN 0771-5528, more
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| Keywords |
Salmo gairdneri Richardson, 1836 [WoRMS]; Salmo trutta Linnaeus, 1758 [WoRMS]
Marine/Coastal |
| Abstract |
There is no doubt that acid water, with low rate of dissolved Ca induces poor biological production and can even be harmfull for the fishes. (Schäperclaus 1933, Arrignon 1976). The spring and surface waters of the Ardennes (France-Belgium-Germany) present these characteristics : pH 5 - 6,5 and calcium content of less than 6 ppm. Frequent difficulties in rearing fry in several places of this area seem to be related to the chemical quality of the water.Four experiments in 1977, 1978, 1979 showed every time that the acidity’s neutralization together with the increase of the calcium content determined an important reduction (50 to 90%) of the mortality rate during the first seven weeks of feeding the fry. This chemical improvement of the water is easily obtained by a continuous neutralization of the dissolved C02 by CaC03 with formation of Ca (HC03)2 which dissolves into the water and increases the calcium rate.There are some indications that the difficulties would come from the acidity rather than from the low calcium content. This acidity would determine a greater sensibility of the fry to some bacterial or parasitic illness. |
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