Vertical transport of mercury by settling particles in Kaštela Bay

Abstract

      The vertical flux of mercury to sediments in the vicinity of a PVC-factory was measured by sediment traps in spring and autumn 1986. The differences in mercury flux between spring and autumn were significant. Depending on the distance from the coast (10-500 m), the flux was 500-50 µgHgm^-2d^-1 and 1800-150 µgm^-2d^-1 in spring and autumn, respectively.

      Total mercury concentrations in sea water were, depending on the distance from the coast, 330-40 µgHgm^-3 for the spring measurement and 380-180 µgm^-3 for the autumn measurement. Assuming a homogeneous distribution of Hg in the water column overlaying the bottom and first order kinetics of mercury removal by settling particles, the average mercury residence time in water was calculated to be about 20 days.