Trophic Transfer of Trace Elements in an Isotopically Constructed Food Chain From a Semi-enclosed Marine Coastal Area (Stagnone di Marsala, Sicily, Mediterranean) Salvatrice Vizzini • Valentina Costa • Cecilia Tramati • Paola Gianguzza • Antonio Mazzola Received: 13 December 2012 / Accepted: 10 June 2013 / Published online: 12 July 2013 Ó Springer Science+Business Media New York 2013 Abstract Trace element accumulation is particularly important in coastal and transitional environments, which act as contaminant buffers between the continental and marine systems. We compared trace element transfer to the biota in two locations with different open-sea exposures in a semi-enclosed marine coastal area (Stagnone di Marsala, Sicily, Italy) using isotopically reconstructed food chains. Samples of sediment, macroalgae, seagrasses, inverte- brates, fish, and bird feathers were sampled in July 2006 and analysed for stable carbon and nitrogen isotopes (d 13 C, d 15 N) and trace elements (arsenic [As], cadmium [Cd], total mercury [THg], and lead [Pb]). Trophic magnification factors were calculated through the relationships between trace elements and d 15 N in consumers. As and Pb were greater in organic matter sources (sediments and primary producers), whereas Cd and THg were greater in bird feathers. At the food chain level, an insignificant trophic transfer was found for all elements, suggesting biodilution rather than biomagnification. Sediments were more con- taminated in the location with lower open-sea exposure. Macroalgae and seagrasses overall mirrored the spatial pattern highlighted in sediments, whereas differences between the two locations became further decreased moving toward higher trophic levels, indicating that trophic transfer of sediment and macrophyte-bound trace elements to the coastal lagoon food chain may be of relatively minor importance. Marine coastal areas are ecosystems of great ecological value due to their high productivity and their roles as nurseries for fish and in staging during bird migration. They are characterized by complex interactions among multiple factors, including abiotic, biotic, and anthropic. Naturally unstable environmental features due to shallow- ness and confinement from the open-sea produce stressful conditions (Reizopoulou and Nicolaidou 2004). In addi- tion, the geographical continuity with terrestrial ecosys- tems determines continual exchange and transfer of organic and inorganic materials, thus often resulting in accumula- tion of organic matter (OM) and pollutants as well as alteration to the natural equilibrium (De Lacerda 1994). In particular, coastal basins act as buffers between the conti- nental and open-sea systems retaining contaminants from different sources (industrial, domestic, and agricultural). As a consequence, these systems are often heavily impacted by human activities. Among the anthropogenic contaminants, trace elements are of the greatest environmental concern (De Lacerda 1994). A number of metals are naturally present in sea- water and marine sediments, and, although several ele- ments are known to be essential to marine organisms (e.g., copper [Cu] and zinc [Zn]), they are all toxic above certain threshold bioavailable levels. Human activities have dra- matically increased levels of trace elements, and consid- erable attention has been focused on their adverse effects on aquatic ecosystems. Trace elements from both natural and contaminated sources tend to concentrate in aquatic organisms, and some can be transferred up through the food chain by way of biomagnification. Consequent risk to the health of humans, as top-level predators, means the study of biomagnification is increasingly important (Wang 2002). S. Vizzini (&) Á V. Costa Á C. Tramati Á P. Gianguzza Á A. Mazzola Dipartimento di Scienze della Terra e del Mare, CoNISMa, Universita ` degli Studi di Palermo, via Archirafi 18, 90123 Palermo, Italy e-mail: salvatrice.vizzini@unipa.it 123 Arch Environ Contam Toxicol (2013) 65:642–653 DOI 10.1007/s00244-013-9933-1