Nancy Knowlton holds the Sant Chair for Marine Science at the Smithsonian's National Museum of Natural History. A specialist on coral reefs, she was the founding director of the Center for Marine Biodiversity and Conservation at the Scripps Institution of Oceanography.
News about ocean ecosystems is almost without exception grim. Collapsing fisheries, expanding dead zones, and the prospect of ever warmer and more acidic seas makes optimism a tough sell. When sounding the alarm bells, marine conservation scientists have focused primarily on the loss of "ecosystem services" -- things like food, shoreline protection, and tourist-attracting seascapes -- that translate into direct economic benefits for humankind. The fate of the basic building blocks of marine ecosystems, namely the many species that together make up the assemblages that provide those services, is far less often discussed.