Effect of Metals on Metallothionein Content in Fish from Skalka and Želivka Reservoirs

The aim of this study was to determine the metal content (Hg, Cd, Cu, Ni, Pb, Zn, and As) of muscle and liver in fish from the Skalka and Želivka (control) reservoirs and to assess the capacity of metals to induce synthesis of metallothioneins in muscle, liver, and gill under natural conditions. The content of total mercury was significantly higher (p < 0.05) in muscle and liver from Skalka Reservoir than in samples from Želivka Reservoir. Methylmercury represented the main form of total mercury in all muscle samples. Significant differences (p < 0.05) between tested sites were observed for copper, zinc, and arsenic. No significant differences were found in metallothionein content when comparing the localities. Metallothionein liver content was negatively correlated (p < 0.05) with total mercury at both reservoirs. The results indicated that metallothionein did not seem to be induced by high metal contamination, therefore the suitability of metallothioneins as a marker of chronic metal exposure in fish is uncertain under field conditions.