US EPA

5940741 

Journal Article 

Elimination of bryozoans in intensive fish farming 

Mares, L; Reznickova, P; Brumovska, V 

2016 

23 

331-336 

English 

WOS:000392968500060 

The aim of this study was to establish a methodology for efficient elimination of bryozoans in fish farms and their water sources. Another point was to evaluate the economic effectiveness of the suggested measures. The presence of bryozoans in aquaculture may be unfavourable because they are hosts of myxozoa that cause proliferative kidney disease (PKD), accompanied by high mortality of fish and thus high economic damages. The second problem is that bryozoans’ colonies may cover surfaces as pipes and biofilters. To test the elimination of bryozoans, agents commonly used in aquaculture, such as Savo, Persteril, and formaldehyde were used. Two species of bryozoans were selected as model species (Plumatella emarginata and Cristatella mucedo) and were tested using different concentrations of metioned substances. Colonies of species C. mucedo were more resistant against the chemicals than colonies of species P. emarginata. All individuals of species P. emarginata were killed in concentrations 0.025% for Savo, 0.0031% for Persteril, and 0.0063% for formaldehyde. All individuals of bryozoan C. mucedo were killed in concentrations 0.1% for Savo, 0.0063% for Persteril, and 0.0125% for formaldehyde. The concentrations of formaldehyde, as the only product used, killed bryozoan colonies at lower concentrations than quoted lethal concentrations for fish and selected aquatic invertebrates. Therefore, in devices with fish, the recommend concentration is 0.0125% (1.38 mg/l). Formaldehyde is the most expensive of all the tested agents at CZK 37.4/m3, while Savo is the cheapest at CZK 30/m3. 

myxozoans; bryozoans; Tetracapsuloides bryosalmone; PKD 

INTERNATIONAL PHD STUDENTS CONFERENCE 

Brno CZECH REPUBLIC 

November 6–7, 2019