Polar Biol (1996) 16:513 520 9 Springer-Verlag 1996 R. Bargagli 9 L. Nelli 9 S. Ancora 9 S. Focardi Elevated cadmium accumulation in marine organisms from Terra Nova Bay (Antarctica) Received: 6 June 1995/Accepted: 23 November 1995 Abstract As a contribution towards identification of the principal environmental factors involved in cad- mium accumulation in Antarctic marine organisms and tile establishment of a baseline near the Italian Antarctic Station "Baia Terra Nova", surface sedi- ments, plankton and benthic organisms were studied in coastal waters of Terra Nova Bay (Ross Sea). The cadmi~lm content of sediments was similar to that re- garded as background in most marine coastal areas, whereas in surface water, phyto- and zooplankton it was similar to values measured in areas of enhanced upwell[ng. Algal and animal taxa dominating benthic associations had a higher cadmium content than re- lated species from other seas. Very high concentrations of the metal were found in sponges (10-80 ~tg/g dw) and in the digestive gland of molluscs (up to 345 ~tg/g in Neobuccinum eatoni). The rapid regeneration of cad- mium and its natural occurrence and bioavaitability in highly productive coastal waters seem to be responsible for cadmium accumulation in the tissues of marine organisms near the "Baia Terra Nova" station. Introdut:tion Cadmiam is regarded as one of the most biotoxic elements and as a top pollutant. Most of the cadmium ever produced was refined in the last few decades and there is evidence of a body burden increase in the human population of Europe and Japan (Hutton et al. 1987). To understand the local- and global-scale impact of human activities on the biogeochemical cycle of cadmium, much effort is being made to determine its concentrations in remote and largely uncontaminated areas. The Antarctic is often seen as a symbol of the pristine environment, and the biotic and abiotic com- ponents of its terrestrial and marine ecosystems are used as indicators of background levels. Alth'ough information on heavy metals in the Ant- arctic Ocean is very scarce, there are indications that cadmium concentrations in surface waters, especially before the algal blooms, are higher than those in the central gyres of the Atlantic and Pacific Oceans (Orren and Monteiro 1985). Likewise, high concentrations of the metal have been reported in Antarctic caridean decapods, certain amphipods and isopods (Petri and Zauke 1993), and the hyperiid amphipod Themisto 9audichaudii (Rainbow 1989). Crustaceans constitute a potential source of dietary cadmium uptake in pen- guins, other birds, seals and whales. Indeed, high cad- mium concentrations in the liver and kidney of these vertebrates have been widely reported (Schneider et al. 1985; Honda et al. 1987; Yamamoto et al. 1987). There is also evidence of cadmium accumulation in the digestive and excretory organs of some benthic organisms. Concentrations of 100-200 gg/g dw have been shown in the kidney and digestive gland of Ant- arctic molluscs (Nigro et al. 1992) and extraordinarily high levels (up to 2,000 gg/g dw) have been measured in the sponge Tedania charcoti (Capon et al. 1993). This paper presents the results of cadmium distri- bution in surface sediments and in an assemblage of organisms representing different habitats and different levels of the Antarctic marine food webs in a coastal environment (Terra Nova Bay). The aim was to identify the main environmental parameters involved in cad- mium bioaccumulation and to contribute to a base- line for cadmium near the Italian station "Baia Terra Nova". R. Bargagli ( ~ ) . L. Nelli 9 S. Ancora. S. Focardi Department of Environmental Biology, University of Siena, Via delle Cerchia 3, 53100 Siena, Italy Materials and methods Surface sediments and benthic and pelagic organisms were collected during the 5th and 6th Italian Antarctic Expeditions (austral