Contaminant concentrations, biochemical and hematological biomarkers in blood of West Indian manatees Trichechus manatus from Brazil

► Blood Al, Pb, Cd and Sn are higher than values reported for manatees and for other mammals. ► Blood Pb, Cd and Sn in manatees kept in Paraiba indicate possible toxicological effects. ► Inhibition of blood butyrylcholinesterase in manatees indicate exposure to insecticides.