Dissertation committee:
Εμμανουήλ Δασενάκης, Ομότιμος καθηγητής, τμήμα Χημείας, ΕΚΠΑ
Σεραφείμ Πούλος, Καθηγητής, τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Ευάγγελος Μπακέας, Καθηγητής, τμήμα Χημείας, ΕΚΠΑ
Σωτήρης Καραβόλτσος, Επίκουρος καθηγητής, τμήμα Χημείας, ΕΚΠΑ
Αικατερίνη Καρδιτσά, Επίκουρη καθηγήτρια, τμήμα Διαχείρισης Λιμένων και Ναυτιλίας, ΕΚΠΑ
Χριστίνα Ζέρη, Ερευνήτρια Α ΕΛΚΕΘΕ
Ελένη Καμπέρη, Ερευνήτρια Α ΕΛΚΕΘΕ
Summary:
The aim of the present PhD thesis was the study of metal pollution of West Saronikos Gulf, through the processing and analysis of sediments cores. In addition, metal concentrations were determined in the sea water, too. Ten stations had been studying, eight of which were located in the west part of Saronikos Gulf, the ninth in the east part and the last one on the boundary of the East and West Saronikos Gulf. Seven stations of West Saronikos Gulf, were located at the northwest part, near the industries and the settlements and the eighth one, which is the deepest of the gulf (407m), in the center of the Epidaurus basin. The chemical analyses were conducted in the Laboratory of Environmental Chemistry of the National and Kapodistrian University of Athens. According to the results in the sea water, the concentrations of dissolved oxygen showed that, except for some hypoxic points at high depths (>200m), the rest ones were oxygenated. The concentrations of metals (Ni, Fe, Mn, Co, Cu, Pb, Zn, Cd, V, Cr, As) in the sea water were lower than the criteria of the water quality. The research focuses on the results of processing and analysis for granulometry and geochemistry of core sediments. The total concentrations of nine metals (Al, Cr, Ni, Fe, Mn, Cu, Pb, Zn, Cd) and the percentages of organic carbon and carbonates were determined in the sediments. The metal concentrations were determined by Flame and Graphite Atomic Absorption Spectroscopy and Inductively Coupled Plasma Mass Spectroscopy. The Al, Mn, Cu, Cd and TOC contents of fine (<63μm) sediments were higher than those of sandy (>63μm) grains. The percentages of organic carbon in the sediments were lower than 3%. Moreover, they were characterized by high surficial values that decreased with depth. The percentages of carbonates were higher (18-79%). The cores were fairly homogeneous, in terms of carbonates. The spatial distribution of Al, Mn, Cu, Pb και Zn in surface sediments, presented increasing concentrations from the northeast to the southwest part of the study area, from the shallow to the deeper parts, in contrast to Cr and Ni which were increased in the northern nearshore stations. Based on the vertical distributions, the concentrations of Cu, Pb and Zn, showed a constant decrease over depth along most cores, indicating the anthropogenic effects to surface sediments. Enrichment factors (EF) indicate minimal (EF<2) or moderate (21,5) for Cr and Ni. The metal concentrations in the surface sediments of the northwestern Saronikos Gulf were similar to those of a decade earlier. The levels of Cu, Pb and Zn in the surface sediments of West Saronikos Gulf, were much lower than those of Elefsis Bay and other hot spots of the Mediterranean Sea. The management of the marine area of West Saronikos Gulf, is necessary, for the achievement and maintenance of its good environmental status.
