Heavy Metal Concentrations In Fruticose Lichen, Usnea Aurantiacoatra of King George Island, South Shetland Islands, West Antarctica

Abstract

The accumulation of various heavy metals in the fruticose lichen, Usnea aurantiacoatra is reported in the vicinity of the Korean research station located in the Barton Peninsula, King George Island. During the 2006/2007 Korea Antarctic Research Program (KARP) expedition, lichen samples were collected from 25 sites. At each site, collected samples were classified into three groups according to their size and weight: young (ca. 0.1 g), middle (ca. 0.7 g) and old (ca. 5 g) groups. Heavy metal concentrations (Cr, Cu, Zn, As, Cd, Pb, Hg, Co, Ni, Ag, V, Se, Rb, Sr, Ba, U) in lichen thalli were analyzed by induced coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrophotometry (AAS). As expected, lead concentrations showed a dramatic decrease with distance from the research station, suggesting that the bioaccumulation of Pb in lichen has been influenced by the anthropogenic sources. Similar but weak patterns are also found in distribution patterns of Cr and V. However, no geographical patterns were observed in most of the heavy metals analyzed. Our analytical data for the age groups show that mean values of Cr, Al, V and Rb were statistically higher in old group, while those of Cu, Zn, Se and Pb were higher in young group. This result indicates that lichen samples of similar size should be collected for the comparison of heavy metal concentrations.