Vítek T., P. Spurn˘, J. Mare‰, A. Ziková: Heavy Metal Contamination of the Louãka River Water Ecosystem. Acta Vet Brno 2007, 76:149-154. Heavy metal contamination of the Louãka River water ecosystem was assessed in July 2005. We analyzed concentrations of T-Hg (total mercury), Cd, Pb, Cr, Cu, Zn, and Ni in water, sediments, zoobenthos, and in the brown trout (Salmo trutta m. fario) muscle and liver tissues (a total of 28 individuals) at four sampling sites. The highest Pb and Ni concentrations (4.634 -12.050 and 0.689 -24.980 mg·kg -1 ) were found in sediments. The zoobenthos was most contaminated by Zn and Cu (0.556 -1.505 and 2.925 -74.300 mg·kg -1 ). The heavy metal contamination of river water was highest in Ni and Cr (0.1 -6.8 and 0.5 -10.0 mg·l -1 ). Concentrations of heavy metals in the brown trout muscle were following (in mg·kg -1 ): Pb 0.108 ± 0.073 -1.010 ± 0.506, Cd 0.003 ± 0.002 -0.026 ± 0.022, Zn 3.956 ± 0.371 -5.801 ± 1.718, Ni 0.058 ± 0.018 -0.102 ± 0.046, Cr 0.028 ± 0.005 -0.073 ± 0.039, Cu 0.329 ± 0.079 -0.437 ± 0.064 and Hg 0.065 ± 0.008 -0.106 ± 0.047. Statistical differences (P < 0.05) in the brown trout muscle were in Pb and Zn. Cd, Cu and Zn were markedly accumulated in the brown trout liver (concentrations 0.107 ± 0.066 -0.223 ± 0.078, 59.973 ± 38.951 -145.800 ± 48.286 and 30.671 ± 3.574 -34.274 ± 7.226 mg·kg -1 ). Humans of 60 kg body mass may consume 1.5 kg of brown trout muscle from the Louãka River weekly without any risk. Adverse influence of the Uniglas distillery on the Louãka River environment contamination by heavy metals was not confirmed.

During the years 2001 and 2002 we conducted hydrochemical monitoring of intensively managed pond to evaluate the impact of high pig slurry doses on eutrophication. Pig slurry application was carried out in colder period of the year (February–April) via tube system with sludge pump from nearby piggery. Our results showed that pig slurry application do not permanently affect the water quality of Jarohněvický pond. When the correct application is made slurry is effectively utilized by biomass for the growth, which prevents surface and underground waters to be polluted as in the case of incorrect application on agricultural land.Critical point of this technology in terms of water management is the way of pig slurry application and the exact dose. Even extremely high slurry doses (16.1 kg . m−2 in 2001 and 15.6 kg . m−2 in 2002) used in Jarohněvický pond did not negatively affected pond ecosystem. Only higher amount of organisms that increased natural fish production was recorded. It is necessary to implement this ameliorative intervention in colder period of the year considering higher hazard of variations in decisive hydrochemical parameters at higher water temperature.

Abstract:© Versita Sp. z o.o. Received 22 February 2011; Accepted 12 August 2011 Keywords: Mercury determination • Fish muscle • Scale • FinThe determination of mercury in fish typically involves analysis of muscles. For predicting the concentration of mercury in fish muscle on the basis of the analysis of fish scales or fins, the relationship between total mercury concentrations in fish muscles and in fish scales and fins was studied. Mercury content in fish muscles, scales and fins was determined by atomic absorption spectrometry with thermal decomposition of the sample in a flow of oxygen. A number of scale treatments were applied in order to remove impurities and to enhance the prediction quality. For scale treatment, 40 min of washing with DI water in an ultrasonic bath is recommended. A coefficient of determination r 2 = 0.93 for the relationship between Hg concentrations in muscles and scales was achieved for 40 fish among the different fish species tested (European bream, perch, roach) from the Hamry Reservoir, Czech Republic. With respect to fin sampling, the coefficient of determination r 2 for these fish was 0.86. The analysis of fish scales and caudal fins is a useful screening tool for assessing the relative mercury contamination of monitored fish. The method of sampling scales is not suitable for fish species with small scales such as brown trout.

The monitoring of the contents of heavy metal pollutants: total Hg, Pb, Cd, Cr, Ni, Cu and Zn in fish muscle, water, bottom sediments and zoobenthos was realised in May and July of 2007 on two localities: Vladislav, upstream the Dalešice and Mohelno dam reservoirs (Czech Republic), and Hrubšice downstream them. Samples of fish muscle were taken from chub (Leuciscus cephalus), barbel (Barbus barbus) and brown trout (Salmo trutta m. fario). Water, bottom sediments and zoobenthos samples were taken as representative ones from both localities. The samples were analysed with the apparatus AMA 254, AA-300 and SPECTR AA-30. In water of both sites there was found above-limit (0.1 µg / l) content of mercury (0.99 µg / l Hrubšice, 2 µg / l Vladislav). The bottom sediments in Vladislav were most contaminated by Pb (120.21 mg / kg) and Cr (164.90 mg / kg) and in Hrubšice locality by Ni (90.66 mg / kg). High concentration of Pb (25.84 mg / kg) in Vladislav and of Ni (240.90 mg / kg) and Cr (140.5 mg / kg) in Hrubšice was found in zoobenthos. In the point of view contents of heavy metals in fish muscle tissue, statistically significant (p < 0.05) higher content of Hg was found in barbel and chub from Vladislav (0.155 ± 0.012 mg / kg and 0.163 ± 0.064 mg / kg) in comparison with Hrubšice (0.073 ± 0.035 mg / kg and 0.095 ± 0.082 mg / kg) as similarly as the concentration of Cd in chub (0.062 ± 0.140 mg / kg at Vladislav and 0.006 ± 0.002 mg / kg at Hrubšice), whereas the content of Ni in barbel was statistically significantly higher at Hrubšice (0.175 ± 0.042 mg / kg) compared to Vladislav (0.050 ± 0.017 mg / kg). The last significant difference was found in Pb concentrations, when fish from Hrubšice were more contaminated (concentrations 0.155 ± 0.048 mg / kg in barbel and 0.182 ± 0.110 mg / kg in chub) than the same species from Vladislav (contents 0.050 ± 0.017 mg / kg and 0.064 ± 0.005 mg / kg). In theme of consumption risk of the muscle tissue of fish by FAO/WHO, the Hg was limiting factor at both sites. In the locality Vladislav provisional tolerated weekly intake (PTWI) was 1.94 kg in barbel and 1.84 kg in chub. In the Hrubšice it reached 4.12 kg in barbel, 3.15 kg in chub and 5.51 kg in brown trout.

No abstract

The influence of the fishpond on the chemical composition of the stream was mainly demonstrated by a higher concentration of organic matter and total phosphorus. Altogether, 128 species of algae and cyanobacteria were recorded in the stream. The species richness of phytobenthos per site was very similar. We observed the presence of typical phytoplankton species among the phytobenthos assemblages. Cyanobacteria species (Woronichinia naegeliana) were particularly dominant in the phytoplankton of the fishpond in autumn. Altogether, we identified 164 taxa of benthic macroinvertebrates in running waters of the stream. The structure of macrozoobenthos communities from all localities of the stream indicated good water quality and a low influence of environmental stressors with no negative effects of the fishpond. In total, six fish species were registered in all profiles. The condition of the fish population was mainly influenced by the fishery management of the stream (stocking, angling). Generally, the influence of the discharge water from the fishpond was recognizable in small changes in both chemical and biological variables of the stream.

VÍTEK, T., KOPP, R., MAREŠ, J., BRABEC, T., SPURNÝ, P.: The infl uence of changes to abiotic parameters on the fi sh assemblage structure of a lowland stream. Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 3, pp. 207-216 Ichthyological monitoring and the assessment of 16 physical and chemical parameters of the water environment were conducted at two localities on the Dyje River, Czech Republic, at diff erent distances downstream from the Znojmo Reservoir (at 12 and 31 km) to reveal habitat alterations. Canonical correspondence analysis confi rmed that diff erences in fi sh abundance between localities were infl uenced by diff erent hydrological regimes characterized by discharge and fl ow velocities and also by water conductivity, which increased with the distance from the reservoir. The infl uence of chemical parameters of water related to water quality on fi sh assemblage structure was insignifi cant. The second locality (further from the reservoir) was characterised by substantial water shortage during the vegetation season. Changes in hydrological regime and the loss of connectivity in the Dyje River both connected with dam building and water shortage for irrigation have led to dramatic changes in the fi sh assemblage structure since the 1950s and the complete loss of common nase.

CILEČEK, M., BARÁNEK, V., VÍTEK, T., KOPP, R., MAREŠ, J.: Production eff ect of diff erent commercial feeds on juvenile tench (Tinca tinca L.) under the intensive rearing conditions. Acta univ. agric. et silvic. Mendel. Brun., 2011, LIX, No. 6, pp. 93-98 Feeding experiment with juvenile tench was focused on evaluation of production eff ect of three diff erent commercial feeds with diff erentiated level energy and protein (Karpico Crumble Excellent Ex, Dan Ex 1352, Pro Aqua Brutfutter). In the 42-day experiment at 26 °C, commercial starters were fed intensively to tench of initially 18.92 mm mean total length and 69.41 mg individual mean body weight. Main monitored indices were -survival rate (%), individual body weight (mg) and specifi c weight growth rate (%.d −1 ). The best result was achieved with commercial starter Pro Aqua Brutfutter -mean individual body weight 483.38 mg, specifi c weight growth 4.44 %.d −1 and survival 99.1 %. Increasing level energy and protein increased production parameters of juvenile fi sh. starter's feed, feeding, juvenile tench, fi sh breeding, Artemia salina nauplii The tench (Tinca tinca L.) is species of great interest in Europe aquaculture. In the Czech Republic tench is traditionally reared in the fi shponds since the 11 th