Prospects of fish scale and fin samples usage for nonlethal monitoring of metal contamination: a study on five fish species from the Danube River

Abstract

The development of nonlethal methods for the monitoring of environmental contamination is essential to minimize the negative effects on studied species and communities. Fish scales and fin clips can be used as nonlethal indicators of water quality given that they are in direct contact with the environment and can accumulate high concentrations of metals and trace elements. Fin clipping causes minimal harm to fish and it does not affect fish growth or survival. In this study, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn concentrations were measured by inductively-coupled plasma mass spectrometry (ICP-MS) in scales, fins, and muscle of common bream (Abramis brama), white bream (Blicca bjoerkna), wels catfish (Silurus glanis), northern pike (Esox lucius), and pikeperch (Sander lucioperca) from the Danube River. The analysis showed a positive correlation for Hg between scales and muscle in pikeperch. Anal fin and muscle were positively correlated in white bream for Hg, in wels catfish for Cu, and in northern pike and pikeperch for As. The results suggest that scales and fins have a potential to be used as indicators of muscle tissue contamination with As, Cu, and Hg, depending on species' ecological traits.