Dust storms transport continental material to the sea, where its deposition can modify seawater chemical composition and influence biological productivity. The aim of this study was to determine the effect of dust on seawater by analysing changes in macronutrient concentration, salinity, pH, and particulate silica. For this purpose, dust samples were collected using passive collectors at four sites in eastern Patagonia. Samples differed in grain size and mineralogical composition depending on their source. Two separate experiments were conducted under controlled conditions and using filtered seawater: the first assessed changes in physicochemical parameters (pH, salinity, and temperature) and macronutrients (dissolved silica, and nitrate) over 72 h; the second measured particulate silica (biogenic and lithogenic) at a single time point after dust addition. The short‐term effects of dust deposition on seawater chemistry were greatest during the first 48 h, after which new conditions stabilised. Furthermore, all samples contributed abundant lithogenic silica, whereas biogenic silica concentrations varied according to the dust sample. The results confirm that dust is an important regulator of seawater chemistry, with its impact dependent on composition and grain size. Understanding the effects of dust on marine ecosystems is essential for evaluating ocean fertilisation and its implications for biogeochemical cycles.
Pierattini‐Martinez et al. (Sun,) studied this question.