Between 1981 and 2010, almost three out of four new drugs originated from, or were inspired by, naturally occurring compounds. Just a tiny fraction, however, came from the sea, and that puzzles William Fenical. “Most of the world’s biodiversity exists in the ocean,” says Fenical, distinguished professor of oceanography and pharmaceutical science at Scripps Institution of Oceanography at UC San Diego. “A milliliter of seawater holds more than a million microorganisms. And there are a billion microorganisms we know very little about in a cubic centimeter of bottom sediment. And we’re not developing those?” Fenical is widely regarded as the dean of marine pharmacology in the United States. He arrived at the Scripps Institution as a researcher in 1973 with the idea of searching the sea for compounds with medicinal properties—a neglected field of research at the time, even though the FDA had approved cytarabine a few years earlier.