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

Lugar: washington; Año: 2018 vol. 31 p. 33 - 39

1042-8275

The role of Patagonian wind-borne dust as a source of macronutrientsto the surface waters of the Southwest Atlantic Ocean was evaluated for the first time.During spring 2016, a series of experiments with dust was conducted to evaluatethe dynamics of macronutrient dissolution in seawater. The results showed a differentialcontribution of macronutrients to seawater depending on the dust source andthe amount added. Addition of a conservative amount of Patagonian dust to the seawatercontributed nitrate (NO3 − ) 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 field did not contribute any macronutrientsto the seawater. Thus, each dust event may affect biological productivity differently,depending on the source of the particles. Dissolution experiments suggest that macronutrientsfrom dust are available immediately after particle deposition on the sea surface.The study includes field measurements of macronutrient concentrations beforeand after a dust storm at three nearshore marine stations. The data are consistent withmacronutrient increase after the storms. Dust storms could become a very importantsource of nutrients to the ocean in future global warming scenarios.