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Background. Fish are often used as indicators of pollution levels in water environments. The omnivorous chub inhabiting rivers of Europe, including their more polluted parts, is a potentially suitable indicator. The information published, however, on the metal accumulation in the tissues of chub living in varyingly polluted waters (both polluted and unpolluted environments) is scarce. The presently reported study was conducted to examine the metal concentrations in selected tissues of chub living in a natural submontane river. Materials and Methods. Sediment samples (0–5 cm layer) and chub, Leuciscus cephalus (L.), were collected from the upper (stations 1–4) and lower (stations 5–8) sections of the Biała Tarnowska River in summer 2003. Fish age was determined from the otoliths. The AAS method was used to determine metal concentrations (Cd, Pb, Cu, and Zn) in sediment and chub tissues (spleen, liver, and muscle). Results. According to the values of the geochemical index (Igeo), the river sediments were not polluted by Pb, Cu, and Zn, while in various degrees polluted by Cd. Despite the low metal concentrations, the mean Cd and Cu concentrations were higher (c. 2× and 4×, respectively) in the upper part of the river compared to the lower section, while concentration of Pb and Zn were similar in the two areas. Chub accumulated the greatest amount of Cu in the liver, while the bulk of Cd, Pb, and Zn was found in the spleen. In the upper part of the river, elevated concentrations of trace elements in selected tissues of chub were found: Cu (spleen, muscle), Cd (spleen), Zn (muscle). The pollution status of the river, on the basis of trace element contents in the sediment, was also determined. Conclusion. The obtained results indicated tissue-specific metal accumulation in chub. Selected chub tissues are sensitive to Cd and Cu contents in the river sediment.
The effects of pollution on the biodiversity and genome response of Chironomidae larvae (Diptera, Insect) were evaluated in the trace metal contaminated water environments. No change on the Chironomid species diversity was found. The higher concentrations of trace metals (Cd, Pb, Cr, and Zn) affect the genome of 5 cytogenetically studied Chironomid species: Chironomus bernensis, C. plumosus, C. sp.1. Kiefferulus tendipediformis (cytotype 2), Glyptotendipes cauliginellus (syn. Glyptotendipes gripekoveni). Genome instability of Chironomid larvae was manifested by two ways: 1. Fixed chromosome rearrangements; homozygous inversions and tandem fusions created new gene linkage groups and show an intensive microevolutionary process of species. 2. Somatic structural (inversions, deficiencies, deletions, breaks); and functional alterations (decreasing the activity of the key structures: Balbiani rings (BRs) and Nucleolar Organizer (NOR)) in salivary gland chromosomes of cytogenetically studied Chironomidae species. Detecting somatic rearrangements in salivary gland chromosomes of these widely distributed aquatic insects is potentially one of the best validated bioassay and can be used as a cost effective early warning signals of environmental damage in freshwater basins.
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