Assessment of the Heavy Metal Contamination in the Danube Delta from the Bioaccumulation Perspective
The objective of this work is to assess the heavy metal contamination of water and sediment in the Danube Delta, approaching also the bioaccumulation and trophic transfer issue. It was conducted in15 sampling sites in Sf. Gheorghe Branch, were collected water, sediment and biological samples from two species of fish with different habitat and trophic level (Crucian carp – Carassius auratus gibelio and Zander – Sander lucioperca). All samples, were analyzed for Pb, Cd, As and Hg by atomic absorption spectrophotometry. The bioaccumulation and trophic transfer assessment was done calculating the bioaccumulation (BAF) and biomagnification factor (BMF). Our pilot study showed that the heavy metal concentration varies from sediment to water where a significant correlation between water-sediment metals concentration was only in case of As. The distribution of the metals in fish organs shows differences between the two investigated species: in Crucian carp the concentrations of metals were Pb>As>Cd>Hg, Pb and As being predominant in external organs and in Zander the concentrations of metals were Pb> Cd>As> Hg, Cd,As and Hg being predominant in internal organs. BAFs showed a fairly high rate for mercury and lead and low arsenic rate in both species.
