|Using Road Killed Mammals to Assess Hg Contamination
|Gabriel Oliveira de Carvalho
|Federal University of Rio de Janeiro
|Special Session - Mercury in the Southern Hemisphere
|Gabriel Oliveira de Carvalho,Rodrigo Ornellas Meire,Adan Santos Lino,Dbora Regina Yogui,Arnaud Lonard Jean Desbiez,Jo?o Paulo Machado Torres,Olaf Malm
Abstract Information :
An effective approach in wildlife contamination studies are non-invasive sampling methods, such as the use of fur, as it enables the use of carcasses, which has lower costs and can be more time-effective compared to sampling living organisms. Due to its slow growth and continuous incorporation of elements, the fur provides information on long-term contamination of months and years. The giant anteater (Myrmecophaga tridactyla), a Latin America native species, is found throughout several biomes of Brazil and can live both in preserved habitats and anthropogenic environments. The Cerrado biome, where the samples were collected, is considered one of the world?s biodiversity hotspots, but a large part of it has been converted to pasture and agricultural land. This study aimed to investigate the occurrence of Hg in giant anteater fur, as well as to establish the influence of biotic and abiotic variables in its concentration. Total Hg (THg) concentrations in fur were determined in 141 roadkilled individuals, using cold vapor atomic absorption spectrometry. The range of concentrations found herein (0.27 to 4.80 æg ú g-1) were in accordance with studies of other Brazilian terrestrial mammals and within safe threshold levels. The decomposition stage of the carcasses was not correlated with Hg concentrations, suggesting element stability in the matrix (F(4, 136) = 1.15, p = 0.34). Juveniles had lower concentrations when compared to adults (t(132) = 3.02, p = 0.003). Spatial patterns were also observed and this could be related with environmental or anthropogenic activities. In this regard, samples in the eastern-southeastern region of the state presented higher concentrations. This was the first study investigating the occurrence of Hg in giant anteaters. The potential of utilizing roadkilled fauna to monitor large-scale contamination in wildlife was demonstrated by this study.