Trace metal contamination in a mediterranean coastal pond (Acquatina, Puglia)

As the interface between land and sea, transitional areas are often negatively impacted by anthropic activities. This impact is the result of many processes, including direct input of pollutants which accumulate in both sediments and aquatic organisms. The aim of this paper is to identify trace metal (As, Cd, total Hg and Pb) contamination in the Acquatina pond (Apulia, Italy), using sediment and fish (A. boyeri, C. labrosus, D. annularis, D. dentex, D. sargus, D. vulgaris, E. encrasicholus, G. paganellus, L. ramada, M. surmuletus, S. salpa, S. solea) as descriptors. Sampling was carried out in three stations (South, Central and North) and four seasons (summer and autumn 2007, winter and spring 2008). Fish metal concentrations were correlated with δ15N values, which is an indicator of their trophic position. Both sediment and fish trace metal concentrations were compared with regulatory limits. Results showed that trace metal concentrations in sediment were comparable to levels found in moderately contaminated areas. The North station was more contaminated, probably because of freshwater discharges through the Giammatteo channel. Within ichthyofauna, higher metal levels were found in demersal fish. A significant relationship between trace metal and δ15N was found only in total Hg in demersal fish.