A baseline assessment of potentially toxic elements in smooth-coated otter (Lutrogale perspicillata) spraints from the estuarine landscape of Goa, India

Apex predators are effective indicators of bioaccumulation and biomagnification of xenobiotics. In this study, we determined the concentrations of eight potentially toxic elements (PTEs) (Pb, Cd, As, Cu, Zn, Mn, Fe, Cr) in the faeces (spraints) of smooth-coated otters (Lutrogale perspicillata) from the Mandovi-Zuari estuarine complex, Goa, India. Sampling was conducted at two locations: Study site-1 in the Mandovi estuary and Study site-2 in the Zuari estuary. Both rivers originate in the Western Ghats and are characterised by similar anthropogenic influences, including agriculture, urban expansion, and industrial activity. Three spraint samples were collected from each site and analysed for PTEs using Atomic Absorption Spectroscopy (AAS). The mean concentrations of PTEs (mg/kg d.w.) at study site-1 were as follows: Fe (365.4) > Zn (174.3) > Cu (38.5) > Mn (26.8) > Cr (21.4) > Pb (8) > Cd (2.3) > As (0.1). The mean concentrations of PTEs (mg/kg d.w.) at Study site-2 were as follows: Zn (167) > Fe (60.6) > Mn (45) > Cu (28) > Cr (20.2) > Pb (7.7) > Cd (2) > As (0.2). This study provides valuable preliminary insights into the exposure of L. perspicillata to PTEs in the estuarine landscape of Goa, India.