On reasons of fish mass-killings in pond farms. Part 1. [freshwater fishes, ponds, water pollutants, wastewater, pesticides, oxygen, light, temperature, fish diseases, mortality, Hungary]

agentes nocivos agricultural chemicals aguas servidas alimentos animal animal aquatique animales animals aquatic animals aquatic organisms desechos diseases eastern europe elements enfermedades de los peces estanques europa europa oriental europe europe orientale facteur nuisible fish diseases fishes foods freshwater fishes gases gaz health hongrie hungary hungria injurious factors light liquid wastes luz maladie des poissons mortalidad mortalite mortality no metales nonmetals organisme aquatique oxygen peces peces de agua dulce pesticide pesticides physical states physiographic features plaguicidas poisson d'eau douce pollution pollution de l'eau ponds produit agrochimique produit alimentaire radiation salud temperatura temperature vertebrados vertebrates vertebre vital statistics wastes wastewater water pollution