Bioaccessible Trace Elements From South America's Primary Dust Source Region to Patagonian Coastal Environments

Atmospheric CO 2 fluctuations are crucial to Earth's climate regulation, with the southern oceans housing the largest CO 2 reservoir. During glacial periods, dust inputs to these oceans modulated atmospheric temperature and CO 2 concentrations. Today, Colhué Huapi Lake in central Patagonia (46°S) serves as South America's primary dust emission hotspot. This shallow lake has experienced declining water levels over 15 years, exposing sediments that form dust clouds reaching Comodoro Rivadavia city (≈90 km east) and the South Atlantic Ocean. These dust events deliver trace elements to high‐nutrient, low‐chlorophyl waters offshore Patagonia, potentially enhancing ocean productivity and promoting CO 2 drawdown. Beginning August 2023, we monitored dust sources and atmospheric transport affecting Comodoro Rivadavia's urban center, examining how trace elements from dust—including iron, manganese, copper, cobalt, zinc, and cadmium—potentially impact ocean biogeochemistry. Results suggest coastal dust samples exhibit modified grain‐size distribution after short‐range transport (<100 km) with significant enrichment in total trace elements (Co, Cu, Zn) and labile metals (Fe, Mn, Co) compared to lake basin source sediments. However, increased coastal anthropogenic activity may contribute to elevated metal concentrations. Future research should address coastal sediment contamination and identify key phases controlling metal delivery to ocean waters and effects on coastal populations.