Estimation of mercury mass balance in the Gulf of Trieste

Abstract

        The annual mercury mass balance of the Gulf of Trieste, which includes inflows from the river Soča and from the open sea of the Northern Adriatic, (wet) atmospheric deposition and bottom sedi­ment resuspension is presented. The sinks are the outflow to the open sea and burial. The river Soča inflow (1500 kg Hg year^-1, approx.) and bottom burial (1300 kg Hg year^-1, approx.) are the two major items of the mass balance. In spite of some strong resuspension, 82 % of mercury is removed from the water column by burial. On the other hand, the bottom sediment is a major source of monomethyl mercury (MMHg) for the Gulf, with a net upward flux of 90 kg of MMHg year^-1 at the sediment-water interface.