Summary: Coral reef ecosystems support a quarter of all marine life on Earth, but they are slowly dying under the relentless stresses of overfishing, pollution, disease and climate change. As part of our ongoing series "Saving Species," William Brangham dives into the steps that scientists are taking to try to preserve the corals that remain. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders
