Silicic acid controls the production of diatoms, a predominant phytoplankton in the Southern Ocean. Diatoms are major contributors to the biological carbon pump, which is particularly active in the Southern Ocean as well as in areas naturally enriched in iron, such as around the Kerguelen Plateau. This study evaluates the factors controlling the biogeochemical cycle of Si and its dynamics in this area and how it is impacted by...

Contrasting concentrations of macronutrients and micronutrients induce different nutrient limitations of the oceanic productivity and shape the composition of the phytoplankton communities of the South Indian Ocean and Indian sector of the Southern Ocean. o assess the phytoplankton response to nutrient release by desert dust and volcanic ash aerosols in these distinct biogeochemical regions, we conducted microcosm incubation e...

We report 2 yr of monthly data from the Congo River (the second largest river in the world) on dissolved silicon concentrations, biogenic silica particle concentrations, isotopic signatures of dissolved silicon, and biogenic siliceous particle counts. Diatoms predominated in the biogenic silica fraction, especially during low flow; phytoliths and sponge spicules were more abundant than diatoms only during the rainy season, whe...