Caratterizzazione ambientale di siti costieri mediterranei attraverso associazioni a foraminiferi bentonici e ostracodi Environmental assessment through benthic foraminifera and ostracod assemblages in Mediterranean coastal sites

A multidisciplinary approach is here used in order to evaluate the quality of three Mediterranean coastal sites with a different level of environmental contamination: Pozzuoli Bay, Torregaveta-Cuma coastal area (Campania, Italy) and Silivri Bay (Turkey). The comparative study of benthic foraminifer and ostracod assemblages, chemical and ecotoxicological analyses of the sediment contributes to an integrated assessment of pollution-induced degradation. Taxonomic and ecologic analyses of both systematic groups provide data necessary to complete the water resources cognitive framework. Benthic foraminifers (Protista) and ostracods (Crustacea) secrete a calcareous shell (respectively test and carapace), commonly preserved in bottom sediments and allowing the post-mortem examination of subrecent assemblages (Schafer et al., 1975; Samir, 2000; Pascual et al., 2002; Triantaphyllou et al., 2003; Vilela et al., 2003; Bergin et al., 2006; Ruiz et al., 2008). Assemblage analysis is a reliable tool determining the effects of pollutant exposure on decadal scale. The eco-toxicological analysis have been performed using organisms pertaining to different taxa, in order to allow a wide-ranging and more accurate evaluation of pollution levels. The 3 selected biomarkers are: Vibrio fischeri (bioluminescent Bacteria), Dunaliella tertiolecta (Clorophyta, unicellular green algae) and Artemia salina (Crustacea). Chemical analysis measured the concentration of PAHs (Polycyclic Aromatic Hydrocarbons) by SPE extraction and subsequent HPLC analysis. The results allow to state that the evaluation of a marine ecosystem health has to consider the study on coastal sediments, and the different approaches here described provide more complete data on effects of human activities on natural systems. In addition the present investigation provides the first distribution data on foraminifer and ostracod assemblages in the three study areas. The three study areas showed variations in the marine benthic communities structure due to natural factors or human activities. Protist and crustacean assemblages features respond in different ways to environmental changes. The comparison with assemblages recorded in areas barely affected by environmental stress (e.g. La Strea Bay, Porto Cesareo, Apulia, Ionian Sea) evidenced the loss of biotic diversity in polluted areas.