Tissue distribution of Cd, Cu, Zn, Ni, Cr, Pb and Hg in Striated Heron Butorides striatus (Aves: Ardeidae) in a fluvial ecosystem

Abstract

In this study, the striated heron (Butorides striatus), a species that reproduces in the Middle Paraná River floodplain, was examined for lead, cadmium, chromium, zinc, nickel, mercury and copper concentrations, using liver, kidney, muscle, vertebra and feathers. The results showed low exposure to chromium because all tissue samples had concentrations below the limit of detection. Similar results were obtained for nickel and lead, with the exception of vertebra. This might be associated with either long-term exposure to these metals, or it may be that both nesting and wintering areas are non-polluted. Zinc and copper, both essential<br />metals, were found in all tissues and their concentrations were within the ranges reported in the literature. Mercurywas also found in all tissues, but at very lowconcentrations and even at concentrations belowthose that produce negative effects in several species of birds (e.g. reproductive success, food intake). Studies of this type are needed to interpret the role of organisms within environments impacted by different human activities.