NASA reports that warming ocean waters are increasing nutrient-related stress on phytoplankton—the microscopic organisms that sit at the base of ocean food webs—by limiting vital nutrients across much of the globe. The study, published June 5 in Science Advances, used satellite observations plus lab and field data to infer stress from subtle shifts in the ratio of carbon to chlorophyll—a clever workaround when you can’t (ethically) mail nutrients home for...