engleski

Biological responses of Prussian carp (Carassius gibelio, Bloch 1782) to the impact of industrial wastewaters in the Ilova River

Ilova River is a part of “Lonjsko polje” Nature Park, but it is threatened by industrial wastewaters polluted by metals. The existing anthropogenic impact was estimated upstream (reference site) and downstream (polluted site) of the pollution source in autumn (2017) and spring (2018) using a dominant fish species, the Prussian carp, as a bioindicator. Metal exposure assessment involved metals measurement in fish intestinal homogenates (total metal levels) and cytosolic fractions (metabolically available metal levels), in order to estimate the proportion of potentially toxic metal fractions from the dietary uptake route. Additionally, biomarkers of metal exposure (metallothioneins, MT), oxidative stress (malondialdehyde, MDA) and antioxidant capacity (total glutathione, GSH ; catalase activity, CAT) were used to assess pollution impact. Disturbed environmental conditions at polluted sites were confirmed in both seasons by significantly higher levels of most measured metals in water, of Cd and Cu in homogenates of fish, and of Ca, Cd, Cu and Fe in cell cytosols. Less than 50% of the total Cu and Fe concentrations were present in cytosols, while those of Cd, Co, Mo, and Zn were over 55% in cytosols, where metals can bind to sensitive biomolecules, therefore causing toxic effects. Significantly higher MDA concentrations in both seasons and CAT activity in spring in fish from the polluted site pointed to oxidative stress. Higher MT concentrations were evident at the same site, while GSH did not show clear trend. These results indicated potential risks for the protected area of nature park and emphasized the need of continuous monitoring.

bioindicators ; wastewaters ; Ilova River ; metals

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