Mercury and Methylmercury Concentrations in Muscle Tissue of Fish Caught in Major Rivers of the Czech Republic

The aim of the study was to evaluate mercury contamination at twelve outlet sites of rivers in the Czech Republic (Labe, Ohře, Vltava, Berounka, Sázava, Otava, Lužnice, Svratka, Dyje, Morava and Odra). As an indicator, we used muscle tissue of the chub (Leuciscus cephalus) caught at selected sites in 2007. A total of 96 fish were examined. Total mercury was determined by atomic absorption spectrophotometry using the AMA 254 analyzer and methylmercury was determined by gas chromatography with electron-capture detection. Total mercury (THg) and methylmercury (MeHg) concentrations ranged 0.039–0.384 mg kg-1 fresh weight and 0.033–0.362 mg kg-1 fresh weight, respectively. Mercury bound in methylmercury (HgMe) made up on average about 82.2% of total mercury. The highest mercury concentrations were found in fish from Obříství, a site on Labe (THg 0.263 ± 0.086 mg kg-1; MeHg 0.256 ± 0.084 mg kg-1). Mercury concentrations in fish from rivers that cross the borders of the Czech Republic (Labe, Odra and Morava) were low. The Czech Republic therefore does not contribute significantly to river pollution outside its national borders. Hazard indices of the sites monitored were well below 1, and reached 1.365 only in Obříství on Labe for fisherman’s family members (i.e. in the case of annual consumption of 10 kg fish). This indicates possible hazards involved in eating meat of fish caught in that location. Based on PTWI for methylmercury, the maximum amount of fish meat allowed for consumption per week was calculated. The site with the lowest value was Obříství on Labe (0.44 kg). The results of this study present a partial contribution to health risk assessment on the major rivers in Czech Republic

Valuation of Public Goods: The Case of Emissions from Livestock Holdings in the Czech Republic

Designed paper is focused on the analysis of public goods in the form of greenhouse gas emissions in livestock production in Czechia. The main aim of the paper is to quantify the amount and valuation of greenhouse gas emissions produced in beef cattle breed (dairy and meat), pig breed, and poultry breed (meat and eggs). The partial aim of this paper is to compare greenhouse gas emissions production across sectors of livestock production and to evaluate a development of volume, value and share of emissions as a form of public goods. The methodology is based on the conceptual model MITERRA-Europe (The model was developed to assess the effects and interactions of policies and measures in agriculture on N losses and P balances at a regional level in EU-27), which is partly based on the CAPRI (Common Agricultural Policy Regionalised Impact) and the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) models using the tools for quantification of the emission factors indicators defined by the IPCC (Intergovernmental Panel for Climate Change) organizations. Part of the solution is to determine the value of public goods quantified through a European platform for carbon emissions trading with its futures contract based on the EU Allowances. The result of this paper is quantified emission value of public goods in livestock production in Czechia and their appreciation in the period 2000-2014. In the final consequence is quantified the proportion of the value of public goods in the total production of the analyzed livestock sector

Comparison of Technology and Technical Efficiency in Cereal Production among EU Countries

The paper presents the analysis of cereal production in the EU. The analysis provides the comparison of production technologies and technical efficiency among EU countries using the country specific multiple output distance function models in the first step and metafrontier approach in the second step to determine the level and development of technical efficiency. The results show the high technical efficiency of cereal producers in the analyzed countries. On average, the differences in technical efficiency among the analyzed countries are not pronounced; however, the technologies used as well as the determinants of technical efficiency differ significantly

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 tank inflow, the Cl- to N-NO2- weight ratios were between 2000 and 10000. Blood methaemoglobin levels of catfish and tench (severe symptoms of poisoning) and of tilapia (no signs of impairment, only brownish discolouration of gills) were over 80 % and 21%, respectively). In order to minimize risks in culture of fish in water-recirculating systems, it is necessary to choose a proper stock of fish and a proper feeding ratio, not to treat th

Nitrite Intoxication of Common Carp (Cyprinus carpio L.) at Different Water Temperatures

Common carp (Cyprinus carpio L.) were exposed to nitrite (1.45 mmol l-1 NO2-) for 48 hours at 14 °C and 20 °C, in order to investigate the mechanism of nitrite poisoning at these water temperatures. The effect of nitrite exposure on fish was assessed on selected haematological and biochemical indicators of the blood. Moreover, nitrite accumulation in the blood, liver and muscle was measured. Nitrite exposure produced high levels of methaemoglobin (88.2 ± 3.3% and 92.9 ± 6.1%) at both water temperatures compared with controls (0.3 ± 0.6% and 2.6 ± 3.0%). High fish mortality occurred in experimental groups (30% and 51%) compared with controls (0%). Nitrite exposure also resulted in an accumulation of nitrite in the fish body. The highest nitrite levels developed in the blood plasma, followed by the liver and muscle, respectively. Carp concentrated nitrite in the blood plasma and tissues to markedly higher levels at higher temperature (20 °C). The plasma nitrite concentrations (10.5 ± 1.9 mmol l-1) were in this case more than 7 times higher than the environmental one. At lower temperature (14 °C), plasma nitrite concentration reached 5.0 ± 1.5 mmol l-1. In either event, plasma K+ levels increased and Cl- levels and osmolality remained unchanged. Plasma Na+ levels slightly decreased at the higher temperature. Nitriteexposed fish showed lower haematocrit values (PCV) at both experimental temperatures compared with controls. At 20 °C, the blood haematocrit decrease (0.20 ± 0.02 l l-1) was accompanied by a low erythrocyte count (1.05 ± 0.12 1012 l-1) and by a low haemoglobin level (51 ± 11 g l-1). At the lower temperature (14 °C), the haematocrit decrease (0.25 ± 0.02 l l-1) was caused by a low mean corpuscular volume (167 ± 27 fl). No significant changes were observed in the mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), or selected erythrocyte dimensions (major axis, minor axis and aspect ratio)

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