|
|
IMPACT OF MUNICIPAL POLLUTION ON FISH LIVING IN A SMALL STREAM
HORA, Vojtěch
Main objective of this thesis is evaluation of the impact of extraneous substances that enter Živný stream through the WWTP Prachatice onto the stream's fish population. Brown trout (Salmo trutta m. fario) was selected as a sampling organism. Sampling was conducted in 2012 using an electrical aggregate at three locations. The sample counted a total of 36 fish. Subsequently there was conducted blood sample and tissue analysis using selected biomarkers (vitellogenin and EROD). Furthermore, an analysis of fish tissue and water samples was made to identify presence of selected extraneous substances.Concentration of vitellogenin in blood plasma of male fish in the controled location was zero, in polluted location the average concentration varied between 275 and 573 ng.ml-1. Concentration of vitellogenin in blood plasma of female fish was the lowest at a location directly downstream the WWTP (7 185 823 ng.ml-1). At other locations, the average concentration ranged between 9 250 302 - 11 614 177 ng.ml-1. The activity of liver detoxifying enzymes (EROD) was the highest at polluted locations, between 63,9 - 87,4 pmol.mg-1protein.min-1. In the controled location was the lowest activity EROD (5,4 pmol.mg-1protein.min-1). The result of identification of selected extraneous substances in fish tissues (liver) and in the water is a sum of all detected pharmaceuticals. In fish tissues was the sum of all detected pharmaceuticals in the range from 20,8 to 138,8 ng.g-1, while in water it varied between 0,07 - 3,00 ?g.l-1. The highest values were again measured in polluted areas. The results of the analyses conducted imply, that the present concentrations of extraneous substances in Živný stream downstream from Prachatice have a negative impact onto live organisms.
|
guest ::
