THE USE OF EPILITHIC ANTARCTIC LICHENS (USNEA-AURANTIACOATRA AND USNEA-ANTARTICA) TO DETERMINE DEPOSITION PATTERNS OF HEAVY-METALS IN THE SHETLAND ISLANDS, ANTARCTICA

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heav y-metal levels have been measured through atomic absorption spectropho tometry, following internationally accepted analytical methods. The re sults obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities develo ped at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. Th e geographical distribution of trace metals atmospherically transporte d in the area close to 'Jubany Station' was studied through the corres ponding metal contents of the assessed lichens. Finally, the suitabili ty of both analyzed lichen species, Usnea aurantiacoatra and U. antart ica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. (C) 1997 Elsevie r Science B.V.