The sea snail Phorcus turbinatus (Von Born, 1778) as bioindicator of metals in hydrothermal vents: preliminary resultsls in hydrothermal vents: preliminary results

Phorcus turbinatus is a long-lived intertidal snail of the genus Phorcus which, due to its wide distribution in the Mediterranean and Atlantic oceans, its year-round presence, and its ease of sampling, is studied by numerous branches of science, from paleontology to ecology. Due to its ability to accumulate relatively high concentrations of metals from water and sediments, it is also considered a good bioindicator of metal pollution. Hydrothermal vents are a source of numerous trace metals in the sea, many of which are essential micronutrients for most marine organisms. The metal composition of fluids rising from sediments depends on the geographical area and depth of the vents. In addition, exceptional degassing events, such as that occurred in the area surrounding Panarea in November 2002, can determine a huge release of trace metals (Na, K, Mg, Ca, Cl and Br), and significant input of toxic metals (Hg, Cd, Pb and As) that can last for several months causing changes in the surrounding marine ecosystems. The aim of this study is to assess the potential role of P. turbinatus as bioindicator of metals of hydrothermal origin. Samples were collected from different locations around the Aeolian Archipelago and Gulf of Patti, including hydrothermal and control areas. After sampling, the snails were taken to ECCSEL- ERIC NatLab Italy in Panarea and immediately stored at -20 degrees. Prior to analysis, opercula were removed, digested overnight in H2O2 and then rinsed with ultrapure water. The opercula were then analysed using a scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDS). The metals that showed the highest weight percentages in opercula were Br, N, and Fe. Among all, Fe seems to be the most capable of distinguishing the hydrothermal areas from the others. Lower weight percentages were also recorded for Mg, K, Cl.