Leeches as Sensor-bioindicators of River Contamination by PCBs.

The aim of the study was to evaluate the use of leeches of the genus Erpobdella as a means of assessing polychlorinated biphenyl contamination of watercourses. The River Skalice, heavily contaminated with PCBs, was selected as a model. The source of contamination was a road gravel processing factory in Rožmitál pod Třemšínem from which an estimated 1 metric ton of PCBs leaked in 1986.

Bioaccumulation of mercury in muscle tissue of fish in the Elbe River (Czech Republic): multispecies monitoring study 1991-1996.

The study monitored mercury (Hg) contamination of fish muscle tissue at 13 geographical sites that can be regarded as crucial points for an ecotoxicological assessment of the Czech Republic section of the Elbe River. The descriptive part of the study was primarily aimed at comparative evaluation of the Hg load during the period 1991-1996. The conclusions were supported by multivariate statistical analyses of the content of Hg in the muscle tissue of 1251 fish belonging to 23 species with four dominant indicator species: Perca fluviatilis (n=163), Abramis brama (n=173), Rutilus rutilus (n=148), and Leuciscus cephalus (n=166).

Bioaccumulation of mercury in various fish species from Orlík and Kamýk water reservoirs in the Czech Republic.

The study evaluated contamination of fish by mercury in two important Czech water reservoirs, Orlík and Kamýk, which receive water from the whole watershed of Otava and Vltava rivers. Contamination of these reservoirs reflects the situation in southern and western Bohemia. Six environmentally representative sites were sampled in the area of interest and the evaluation was based on regression models relating Hg concentrations in fish tissues to the age of fish.