[1] Univ Palermo, Dipartimento Sci Terra & Mare DiSTeM, Viale Sci Ed 16, I-90128 Palermo, Italy
[2] CNR Messina, IAMC, Spianata S Raineri 86, I-98122 Messina, Italy
[3] Univ Catania, Dept Ind Engn, Catania, Italy
[4] Bangor Univ, Sch Ocean Sci, Fisheries & Conservat Sci Grp, Menai Bridge LL59 5AB, AB, Wales