[Botulism in birds living in an aquatic environment in Nové Mlýny in the Breclav District].

Epizootic of wild water birds caused by the toxin Clostridium botulinum of C type occurred in extensive shallow artificial lakes of the Nové Mlýny dam system from May to October 1988 and later on from February to early April 1989. In total more than 3,000 dead or dying birds of 44 species were found, the following orders were prevailing: Anseriformes (56%), Lariformes (33%), Charadriiformes (6%) and Ralliformes (4%). Botulotoxin was detected at high concentrations in sarcophagic fly larvae of Calliphora vomitoria and Lucilia sericata which were collected in bird cadavers, but it was not found in different components of the aquatic environment (water, submersed vegetation, phytoplankton, zooplankton, Gastropoda, Crustacea, Oligochaeta, larvae of Odonata, Chironomidae and Ceratopogonidae). Future development of the epizootic situation in the Nové Mlýny artificial lakes will depend on the water level and meterological conditions in the critical period (May to September).