"Nitrite poisoning of fish in aquaculture facilities with water-recirculating systems"@en . "methemoglobinemie; hmotnostn\u00ED pom\u011Br Cl-/N-NO2-; Silurus glanis L.; Tinca tinca L.; Oreochromis niloticus; biologick\u00FD filtr; nitrifikace"@en . "Kroupov\u00E1, Hana" . "Three cases of severely compromised fish health and death in newly commissioned aquaculture facilities with water-recirculating systems are described. The cause of the damage and death was increased concentrations of water-borne nitrites and the subsequent methaemoglobinemia. The aim of the study was to better understand the aetiology of these cases of poisoning to help prevent them, and to examine effects of some water quality parameters on nitrite toxicity. The increased NO2 - concentrations in water were caused by impaired functionality of biological filters in the second stage of nitrification, i.e. the conversion of NO2- to NO3-. Chloride concentrations in water were considered the main factor influencing NO2- toxicity in all of the cases described. In the case of death of catfish and tench, the Cl- to N-NO2- weight ratios were in the range of 13 - 28 and 11 - 19, respectively. In the case of tilapia health impairment without symptoms of toxicity, the ratios were between 50 and 150. In the water" . "Nitrite poisoning of fish in aquaculture facilities with water-recirculating systems" . "Acta Veterinaria Brno" . "M\u00E1chov\u00E1, Jana" . "Otrava ryb dusitany v recirkula\u010Dn\u00EDch syst\u00E9mech"@cs . "12610" . "Ham\u00E1\u010Dkov\u00E1, Jitka" . "Byly zpracov\u00E1ny 3 p\u0159\u00EDpadov\u00E9 studie po\u0161kozen\u00ED a \u00FAhynu ryb (l\u00EDn obecn\u00FD, sumec velk\u00FD a til\u00E1pie nilsk\u00E1) p\u0159i zah\u00E1jen\u00ED provozu rybochovn\u00FDch objekt\u016F s recirkulac\u00ED vody. P\u0159\u00ED\u010Dinou po\u0161kozen\u00ED a \u00FAhynu ryb byla ve v\u0161ech p\u0159\u00EDpadech zv\u00FD\u0161en\u00E1 koncentrace dusitan\u016F ve vod\u011B a n\u00E1sledn\u00E1 methemoglobinemie. Ke zv\u00FD\u0161en\u00ED koncentrace NO2- do\u0161lo v d\u016Fsledku nedostate\u010Dn\u00E9 funkce biologick\u00FDch filtr\u016F ve druh\u00E9 f\u00E1zi nitrifikace, tj. p\u0159em\u011Bny NO2- na NO3- . Jako hlavn\u00ED faktor ovliv\u0148uj\u00EDc\u00ED toxicitu NO2- byla ve v\u0161ech p\u0159\u00EDpadech vzata do \u00FAvahy koncentrace chlorid\u016F ve vod\u011B. Hmotnostn\u00ED pom\u011Br Cl- : N-NO2 byl v p\u0159\u00EDpad\u011B \u00FAhynu sumc\u016F v rozmez\u00ED 13-28, l\u00EDn\u016F 11-19. V p\u0159\u00EDpad\u011B po\u0161kozen\u00ED zdravotn\u00EDho stavu tilapi\u00ED bez p\u0159\u00EDznak\u016F otravy byl tento pom\u011Br v rozmez\u00ED 50-150. V p\u0159\u00EDtokov\u00E9 vod\u011B se hmotnostn\u00ED pom\u011Br Cl- : N-NO2 pohyboval v rozmez\u00ED 2 000 a\u017E 10 000. Zastoupen\u00ED methemoglobinu v krvi bylo v p\u0159\u00EDpad\u011B sumc\u016F a l\u00EDn\u016F se siln\u00FDmi p\u0159\u00EDznaky otravy nad 80%, v p\u0159\u00EDpad\u011B tilapi\u00ED 21% (bez klinick\u00FDch p\u0159\u00EDznak\u016F po\u0161kozen\u00ED, pouze nahn\u011Bdl\u00E1 barva \u017Eaber). Na z\u00E1klad\u011B anal\u00FDzy \u00FAdaj\u016F"@cs . . . . "CZ - \u010Cesk\u00E1 republika" . . "RIV/60076658:12610/05:00006294" . . "532889" . "74" . . "Z(MSM6007665809)" . "H\u016Fda, Jan" . . . . "1" . . . . "Otrava ryb dusitany v recirkula\u010Dn\u00EDch syst\u00E9mech"@cs . "129-137" . "Svobodov\u00E1, Zde\u0148ka" . . . "Nitrite poisoning of fish in aquaculture facilities with water-recirculating systems"@en . "Poleszczuk, Gorzyslaw" . "RIV/60076658:12610/05:00006294!RIV06-MSM-12610___" . "6"^^ . "[C9BF2E01F0D1]" . . "9"^^ . "0001-7213" . . . . . . "Nitrite poisoning of fish in aquaculture facilities with water-recirculating systems" . . . "Three cases of severely compromised fish health and death in newly commissioned aquaculture facilities with water-recirculating systems are described. The cause of the damage and death was increased concentrations of water-borne nitrites and the subsequent methaemoglobinemia. The aim of the study was to better understand the aetiology of these cases of poisoning to help prevent them, and to examine effects of some water quality parameters on nitrite toxicity. The increased NO2 - concentrations in water were caused by impaired functionality of biological filters in the second stage of nitrification, i.e. the conversion of NO2- to NO3-. Chloride concentrations in water were considered the main factor influencing NO2- toxicity in all of the cases described. In the case of death of catfish and tench, the Cl- to N-NO2- weight ratios were in the range of 13 - 28 and 11 - 19, respectively. In the case of tilapia health impairment without symptoms of toxicity, the ratios were between 50 and 150. In the water"@en . "4"^^ .