DEAN E. FLETCHER,^*† WILLIAM A. HOPKINS,^‡ TERESA SALDAÑA,^§ JENNIFER A. BAIONNO,^†
CARMEN ARRIBAS,^§ MICHELLE M. STANDORA,^† and CARLOS FERNÁNDEZ-DELGADO^§

^†Savannah River Ecology Laboratory, University of Georgia, PO Drawer E, Aiken, South Carolina 29803, USA
^‡Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg Virginia 24061, USA
^§Departamento de Zoología, Edificio Charles Darwin, 3 Planta, Campus Universitario de Rabanales, Universidad de Córdoba, Córdoba 14071, España Spain

Abstract
Catastrophic collapse of a mine tailings dam released several million cubic meters of toxic mud and acidic water into the Guadiamar River valley, southern Spain, in 1998. Remediation efforts removed most of the sludge from the floodplain, but contamination persists. Clean-up activities also produced clouds of aerosolized materials that further contaminated the surrounding landscape. Whole-body concentrations of 21 elements in the Moorish wall gecko, Tarentola mauritanica, a common inhabitant of both rural and urban areas, were compared among seven locations. Locations spanned an expected contamination gradient and included a rural and an urban non–mine-affected location, two mine-affected towns, and three locations on the contaminated floodplain. Multivariate analyses of whole-body concentrations identified pollutants that increased across the expected contamination gradient, a trend particularly evident for As, Pb, and Cd. Additionally, higher contaminant concentrations occurred in prey items eaten by geckos from mine-affected areas. Comparison of element concentrations in tails and whole bodies suggests that tail clips are a viable nondestructive index of contaminant accumulation. Our results indicate that areas polluted by the mine continue to experience contamination of the terrestrial food chain. Where abundant, geckos represent useful taxa to study the bioavailability of some hazardous pollutants.

 

Keywords
Gecko; Bioindicator; Trace element; Mine pollution; Guadiamar River

 

*To whom correspondence may be addressed
Fletcher@srel.edu

SREL Reprint #2979