Utilizing Artificial Upwelling to Enhance Carbon Removal by Stimulating Seaweed Cultivation

The application of artificial upwelling (AU) has garnered increasing scientific interest for its potential to enhance the transport of nutrient-rich bottom waters to the surface, thereby stimulating seaweed growth and increasing organic carbon removal from coastal environments. However, field experiments validating this hypothesis remain scarce. To address this issue, we developed a robust, solar-powered, air-lifted AU system to withstand harsh weather conditions while effectively fertilizing the surface ocean. This study was conducted in the oligotrophic Aoshan Bay, Shandong Province, China, to assess the impact of the AU system on regional carbon removal. Comparative analysis of temperature and nutrient profiles between AU-affected sites and reference locations indicated successful lifting of nutrient-rich waters to the surface. Our findings demonstrate that AU significantly stimulated seaweed growth, with the average weight of individual plants increasing by 8.98 grams. This approach could potentially lead to an additional carbon removal capacity of approximately 14.8 thousand tons in coastal waters, if implemented along the Chinese coastline.