Mobility and bioavailability of mercury in sediments of the southern Baltic sea in relation to the chemical fractions of iron: Spatial and temporal patterns.

Marine sediments play a significant role as reservoirs for mercury (Hg), a bioaccumulative toxic pollutant that poses risks to human and ecosystem health. Iron (Fe) has been recognized as an influential factor in the complexation and bioavailability of Hg in sediments. However, limited studies have investigated the interactions between the chemical fractions of these elements in natural settings.

Biogeochemical and mineralogical effects of Fe-P-S dynamics in sediments of continental shelf sea: Impact of salinity, oxygen conditions, and catchment area characteristics.

In this study, we investigate how salinity, oxygen concentration and catchment area characteristics impact the dynamics of Fe-P-S cycling in the continental shelf sea sediments. Samples were collected from three sites representing different environmental conditions: Gdańsk Deep (southern Baltic Sea), Gotland Deep (central Baltic Sea) and Bothnian Sea (northern Baltic Sea). Sediments were analysed for their mineral composition and speciation of iron and phosphorus.

Impact of methane occurrence on iron speciation in the sediments of the Gdansk Basin (Southern Baltic Sea).

Due to changing climate conditions, such inland seas as the Baltic are expected to become more eutrophicated and less saline (causing lower availability of sulphates). This may promote methanogenesis as the main process of organic matter (OM) degradation in marine sediments. Presence of methane, in turn, may affect biogeochemical cycling of many elements, including iron.