Tiny marine algae, known as phytoplankton, are the backbone of the marine food chain, yet a new study in Nature has found that this backbone is disintegrating. Researchers discovered that since 1950 phytoplankton has declined by approximately 40 percent across the Northern Hemisphere, a decline that corresponds to warming waters due to climate change. Given that these microscopic plants feed the oceans’ abundance all the way up the food chain—from zooplankton to fish to seabird to sharks to humans—the decline has likely impacted the very structure of the ocean.