Ocean Alkalinity Enhancement (OAE) is a promising method for carbon dioxide removal (CDR). It aims to accelerate natural rock weathering by introducing ground rocks to the ocean's surface waters. This process increases the ocean's alkalinity, thereby increasing its carbon storage potential. We conducted deck board experiments to directly assess the impact of OAE materials (steel slag, olivine, NaOH) on Southern Ocean phytoplankton. These chosen materials are byproducts of mining and steel production and offer cost-effective CDR solutions. While the chemistry behind OAE is well understood, there remains uncertainties concerning the biological impacts, largely due to the presence of additional metals in these materials. Metals like nickel, phosphorus, iron, and manganese may affect phytoplankton growth and community dynamics.
Our deck board incubations mark the first direct investigation into Southern Ocean phytoplankton response to OAE. Our findings specifically looked into OAE's potential to stimulate growth and how the community composition of phytoplankton was altered. This research contributes insights into OAE's ecological implications as a CDR strategy in marine ecosystems.