Patagonian Dust as a Source of Macronutrients in the Southwest Atlantic Ocean

PAPARAZZO, FLAVIO; CRESPI-ABRIL, AUGUSTO; GONÇALVES, RODRIGO; BARBIERI, ELENA; GRACIA VILLALOBOS, LEILÉN; SOLÍS, MIRIAM; SORIA, GASPAR

OCEANOGRAPHY

OCEANOGRAPHY SOC

Año: 2018 vol. 31 p. 33 - 39

1042-8275

Te role of Patagonian wind-borne dust as a source of macronutrients to the surface waters of the Southwest Atlantic Ocean was evaluated for the frst time. During spring 2016, a series of experiments with dust was conducted to evaluate the  dynamics of macronutrient dissolution in seawater. Te results showed a differential contribution of macronutrients to  seawater depending on the dust source and the amount added. Addition of a conservative amount of Patagonian dust to the seawater contributed nitrate (NO-3) and silicic acid (Si(OH)4), but not phosphate (PO43?). Additional dust input to the  system resulted in higher macronutrient concentrations. Particles collected from a nearby burned feld did not contribute  any macronutrients to the seawater. Tus, each dust event may affect biological productivity differently, depending on the source of the particles.  Dissolution experiments suggest that macronutrients from dust are available immediately afer particle deposition on the sea  surface. Te study includes feld measurements of macronutrient concentrations before and afer a dust storm at three nearshore  marine stations. Te data are consistent with macronutrient increase afer the storms. Dust storms could become a very important source of nutrients to the ocean in future global warming scenarios.