Analýza vlivu environmentální zátěže modelových lokalit na společenstva vícebuněčných cizopasníků jelce tlouště
| Title in English | The effect of environmental stress on parasite communities of chub (Leuciscus cephalus) in model localities |
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| Authors | |
| Year of publication | 2007 |
| Type | Appeared in Conference without Proceedings |
| MU Faculty or unit | |
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| Description | The main aim of this study was to monitor effects of aquatic pollution on parasites and their hosts and to find reliable indicators of environmental stress. In total, 61 chub (Leuciscus cephalus (L.)) were collected at two model sites with different level of pollution in the Vlára and the Bílina Rivers (Czech Republic) during September 2005. Polycyclic aromatic hydrocarbons (PAH) appeared to be predominant organic pollutants at both sites, and their levels were elevated particularly in the Bilina River. In addition, the concentrations of heavy metals were several fold higher at the locality Bílina. By contrast, the concentrations of polychlorinated biphenyls (PCB) were very low at both sites. EROD activity was used as a specific biomarker of dioxin like compounds (PAH, PCB, dioxins). Concentrations of PAH metabolite 1-hydroxynapthol (1-OH-Nap) in fish bile, PCB congeners and heavy metals in fish muscle were measured. The induction of EROD activity was significantly elevated at the Bílina River and a positive correlation between EROD activity and concentration of 1-OH-Nap in fish bile was found at both sites. The parasite communities of chub from the Bílina and the Vlára Rivers were fractionated according to host specificity into generalists and specialists. There was no relationship between the presence of either specialist or generalist parasites and the exposure to dioxin like compound (measured as EROD activity) at either one of the sites. We confirmed the resistance of Paradiplozoon megan and a higher sensitivity of the genus Dactylogyrus to pollution. Developmental instability measured as fluctuating asymmetry (FA) was assessed for both chub and their parasite Dactylogyrus folkmanovae. There were no significant differences in FA among fish from different localities. A higher level of FA (the index of hook basis traits) was found for D. folkmanovae from the locality Bilina, however, this effect could be caused by variation in measurement error. There were no correlations between FA in the parasites and their hosts or other data on chemical contamination. From all the measured variables, EROD activity is a quality parameter for estimating the contamination of environment by PAH pollutants. Other variables, such as FA or the presence of either specialist or generalist parasites seem to be insignificant for assessing environmental stress. |
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