ELEVATED CADMIUM ACCUMULATION IN MARINE ORGANISMS FROM TERRA-NOVA BAY(ANTARCTICA)

As a contribution towards identification of the principal environmenta l factors involved in cadmium accumulation in Antarctic marine organis ms and the establishment of a baseline near the Italian Antarctic Stat ion ''Baia Terra Nova'', surface sediments, plankton and benthic organ isms were studied in coastal waters of Terra Nova Bay (Ross Sea). The cadmium content of sediments was similar to that regarded as backgroun d in most marine coastal areas, whereas in surface water, phyto- and z ooplankton it was similar to values measured in areas of enhanced upwe lling. Algal and animal taxa dominating benthic associations had a hig her cadmium content than related species from other seas. Very high co ncentrations of the metal were found in sponges (10-80 mu g/g dw) and in the digestive gland of molluscs (up to 345 mu g/g in Neobuccinum ea toni). The rapid regeneration of cadmium and its natural occurrence an d bioavailability in highly productive coastal waters seem to be respo nsible for cadmium accumulation in the tissues of marine organisms nea r the ''Baia Terra Nova'' station.