Evaluating environmental impact of STPs situated on streams in the Czech Republic: an integrated approach to biomonitoring the aquatic environment.

Sewage water treatment plants (STPs) are frequently associated with the release of xenobiotics and, consequently, with biological responses of fish to these substances. The impact of three STPs situated on small streams was assessed in 2009. Brown trout (Salmo trutta fario L.), captured upstream and downstream of these STPs, were used as biomonitors. The concentrations of 39 organic pollutants (PCBs, OCPs, PBDEs, HBCDs, and MCs), and the biological responses related to oxidative stress (lipid peroxidation and carbonyl protein), and antioxidant responses (superoxide dismutase, glutathione peroxidase and glutathione reductase) were measured. Through chemometrics of these parameters, three groups with 97.62% of the total accumulated variance were distinguished. Integration of the assessed biomarkers using the IBR index, ranked environment impact on sites as: DS Pacov > DS Prachatice > DS Brloh > US Pacov > US Prachatice > US Brloh (most to least affected). STPs are a major source of xenobiotic pollution in streams of the Czech Republic. The combined use of chemical analysis and biological responses is necessary to validate the efficacy of a battery of biomarkers chosen to detect environmental stress due to pollution.

Evaluation of continuous 4-day exposure to peracetic acid as a treatment for Ichthyophthirius multifiliis.

The parasitic ciliate Ichthyophthirius multifiliis infests all species of freshwater fish and can cause severe economic losses in fish breeding. The most effective treatment, malachite green, has been banned in Europe and North America for use in food fish production. Peracetic acid (PAA) was found to be toxic to I. multifiliis theronts at low concentrations. I. multifiliis-infested carp were exposed to 1 mg/l PAA in a dynamic exposure by means of peristaltic pumps. Five days after infestation, gills, tail fins, and skin below the dorsal fin were observed microscopically for I. multifiliis abundance. After PAA exposure, PAA-treated fish showed lower infestation of I. multifiliis in all investigated tissues than the unexposed control fish. The infestation increased in the control group whereas the infestation in the PAA-exposed groups significantly decreased (p = 0.0083, Bonferroni correction). The fish in the two exposure groups showed a slight reinfestation with I. multifiliis. This might be caused by a peroxide degradation (hydrolysis) and/or reduction of the delivered PAA concentration. Thus, PAA concentrations were possibly too low to be effective on the released trophonts and/or the infective theronts. This hypothesis is corroborated by the fact that the I. multifiliis in the gills, skin, and fins of the PAA-exposed carp were in an early developmental stage.

Effects of subchronic simazine exposure on some biometric, biochemical, hematological and histopathological parameters of common carp (Cyprinus carpio L.).

OBJECTIVES: This study assessed the subchronic effects of a triazine compound, simazine, on common carp (Cyprinus carpio L.) though, via by means of biometric, biochemical, hematological, and histological examination. DESIGN: One-year-old fish were exposed to simazine at four concentrations, 0.06, (reported concentration in Czech rivers), 4, 20, and 50 microg L-1 for 28 days and compared to carp in a non-treated control group. RESULTS: Exposure of fish to simazine at 0.06 microg L-1 had no effect on measured parameters. However, exposure to simazine at the concentrations of 4, 20, 50 microg L-1 showed significant differences in biochemical, hematological, and histopathological profiles of fish compared to controls. CONCLUSION: Our data suggest that simazine in the recorded environmental concentration 0.06 microg L-1 had no effect on common carp. Subchronic exposure to 4, 20, and 50 microg L-1 of simazine was associated with alterations in biochemical and hematological indices and in fish organ tissues.

The effect of praziquantel applied per os on selected haematological and biochemical indices in common carp (Cyprinus carpio L.).

The aim of the study was to assess the effects of the anthelminthic, praziquantel, on the haematological and biochemical indices of the blood of common carp (Cyprinus carpio L.). Fish were divided into six groups: two groups received 30 mg kg(-1) body weight (bw) of praziquantel, and two groups were given 50 mg kg(-1) bw of praziquantel mixed into the heat-treated amyloid vehicle. Fish in the remaining two groups were given only the amyloid vehicle and were used as controls. Fish were examined either 24 or 96 h after administration. Praziquantel treatment was characterised by a significantly lower erythrocyte count, haemoglobin level, packed cell volume and total protein at both dose levels after 24 h compared with the controls, but these parameters were similar to the control values at 96 h. The activity of alanine aminotransferase (ALT) was significantly higher after 96 h in the treated groups, which could be attributed to slight hepatocyte damage caused by praziquantel. However, the differences between the treated and the control groups were not great, and we presumed that they were reversible.