For almost three decades, oceanographers have been puzzled by the ability of microscopic algae to grow in mid-ocean areas where there is very little nitrate, an essential algal nutrient. In this week's issue of Nature, MBARI chemical oceanographer Ken Johnson, along with coauthors at the University of Washington and the University of Hawaii, show that mid-ocean algae obtain nitrate from deep water, as much as 250 meters below the surface. This finding will help scientists predict how open-ocean ecosystems could respond to global warming. Read more.