[Egtved virus in three fish farms: report on mortality and economic consequences of outbreak of Egtved disease in the winter 2000]

danemark denmark dinamarca enfermedades de los peces exploitation piscicole fish culture fish diseases fish farms haemorrhagic septicaemia virus maladie des poissons mortalidad mortalite mortality oncorhynchus mykiss piscicultura pisciculture production economics temperatura del agua trout trucha truite water temperature