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2C (2) - Biomarkers (WE7/4) Relationship between biomarker responses and metal bioaccumulation in feathers of passerine birds, Gauteng, South Africa. Wepener, Victor1, Meyer, Izak1, 1 Rand Afrikaans University, Johannesburg, Gauteng, South Africa ABSTRACT- The use of passerine bird feathers as biomonitors of terrestrial metal contamination is receiving increasing attention. However, very few studies attempt to link metal bioaccumulation (measure of exposure) to biological responses (measure of effect) in these birds. In this study Al, Cr, Cu, Fe, Mn, Ni and Zn concentrations in the feathers of two passerine birds species Southern Masked Weaver (Ploceus velatus) and Red Bishop (Euplectes orix) were determined from a number of sites in the industrial heartland of Gauteng, South Africa. Breast feathers, water samples from the wetlands and air samples were collected for metal analyses using standard ICP techniques, while blood samples were collected for biomarker and haematological analyses. The biomarkers studied were indicators of genotoxicity (DNA damage expressed as average base-pair lengths) and oxidative stress (catalase activity). In addition the following haematological variables were assessed: total red and white blood cell count, haemoglobin content, mean corpuscular volume and haematocrit. Results indicated significant spatial metal concentration differences (particularly Cr, Cu, Mn, Ni and Zn) in the bird feathers. Similar spatial differences were recorded for biomarker responses. Multivariate statistical analyses revealed that there were significant correlations between metal concentrations in feathers and genotoxic, immunotoxic, and oxidative stress responses. It can be concluded that metal concentrations in feathers of passerines can be used as a representative measure of metal contamination in wildlife in the industrial regions of Gauteng, South Africa. Key words: bioaccumulation, biomarker, metals, birds |
