A new study, led by Woods Hole Oceanographic Institution (WHOI) and Columbia University, identifies a diverse set of molecules released by marine phytoplankton that fuel microbial life and help drive Earth's carbon cycle. While scientists know that carbon is moved through an invisible network of phytoplankton and other microbes in the surface ocean, the specific compounds have long been a mystery. These compounds are small, chemically difficult to detect in salty seawater, and are rapidly consumed by other organisms almost as soon as they are produced.