Northern Adriatic is characterized by high levels of Hg originating from the Isonzo/Soča river inflow. Hypoxic and anoxic conditions at the sediment-water interface are frequently observed mainly due to strong late summer water column density stratification. Higher benthic Hg and MeHg fluxes in anoxic conditions are linked to sulphate reduction, dissolution of Fe and Mn oxyhydroxides and formation of sulphides but not to dissolved organic matter. The reoxygenation lowers both fluxes due to their adsorption onto Fe and Mn oxyhydroxides and enhanced demethylation.
COBISS.SI-ID: 2307919
The hydrolysis of the macroaggregate matrix using alfa-amilase, beta-glucosidase, protease, proteinase and lipase revealed the simultanous degradation of polysaccharides and proteins while lipids seem largely preserved. A pronounced hydrolysis of alfa-glycosidic bond occured in the "fresh" samples. The degradation of high MW polysaccharides in colloids was fast. Our results indicate that different fractions are subjected to compositional selective reactivity wit important implications for their persistence in the seawater column and deposition and on the Hg - organic matter interaction.
COBISS.SI-ID: 2258511