Sure. The dead coral is most often due to bleaching, which has a primary cause increasing ocean temperatures, often exacerbated by nutrients. Bleaching means the algae living symbiotically in the coral tissue (zoozanthelle) are expelled by the coral as not doing their job. Their job, as plants, is to take up the sunlight and produce O2 for the coral animal, which in turn outputs nutrient for the algae. Symbiosis; they need each other. Increasing temperatures harms this delicate balance, and the coral animal's
survival strategy is to expel its zoozanthelle and hope some better, hardier stuff comes floating through the water that it can pick up and live with. It only has days or a week or two to live this way, then it dies. See for more info:
coral bleaching | Definition, Causes, Consequences, & Facts.
Ocean acidification has to do with the changing pH balance of the seawater, dwhich is normal slightly basic, but shifts toward more acidic as more an more CO2 gets dissolved in the ocean. The consequence is an inability of the little crustaceans, for example, to form calcium carbonate shells. See for more info:
ocean acidification | Definition, Causes, Effects, Chemistry, & Facts.