Copper, Zinc, Cadmium, and Mercury in Southern Sea Lions (Otaria flavescens) from Argentina

Abstract

Copper, zinc, mercury and cadmium were studied in muscle, liver and kidney of three adults and one juvenile Southern sea lions, Otaria flavescens, found dead on beaches of Argentina. Heavy metals were determined by Atomic Absorption Spectrophotometry; cold vapor and air/acetylene flame techniques were applied for mercury and for the rest of metals, respectively. Previous acid digestion was made with nitric/sulphuric (Hg) and perchloric/nitric (Cd, Zn, Cu) mixtures. Quality was checked with a Certified Reference Material. Mercury concentrations were highest in liver, whereas cadmium levels were highest in kidney. Juvenile and adults presented the same tissue distribution pattern for all studied metals. Hepatic mercury concentrations ranged from 23.3 m g/g (juvenile female) to 47.6 m g/g (adult male), with renal cadmium concentrations between 0.8 m g/g and 5.7 m g/g, respectively.