although the effects have been alleviated over the past 15 years due to mitigation measures (Degobbis et al., 2000). Approximately rectangular in shape, the Gulf of Trieste (Fig. 1) is the northernmost gulf of the enclosed Adriatic Sea, with an average depth of ,20 m, a surface area of 600 km2 and a volume of 9.5 km3. Freshwater inputs are larger along the northern than the southern coast, approx. annual rate of flow of 90– 130 m3/s, and peaks of over 1000 m3/s, when compared with 5–10 m3/s and peaks up to 100 m3/s (Mozeticˇ et al., 1998), respectively. The structure of the water column and water movements vary greatly with dominant seasonal influences.