The Whale X team will demonstrate the biological export of carbon from the surface ocean by mimicking the action of whales in delivering nutrients to support ocean primary production. At less than 1% of photosynthetic biomass on earth, phytoplankton contribute 50% of global primary production and are critical to the planet’s carbon cycling. This biological pump is weakened by the reduction in whale numbers. Whale X will replenish missing nutrients and restore Gt scale ocean carbon removal.