Reefs in the Caribbean Sea have lost nearly half of their coral since 1980. That's according to a new study. Experts say the 48% decrease in coral is caused by climate change , which has altered marine heatwaves. Heatwaves impact the tiny algae that the coral relies on for food. The warmer water makes the algae toxic. That forces the coral to expel them. In turn, they go without food. Coral then “bleaches,” or fades into a whitish color. In 2023-24, the region’s coral experienced “the most destructive thermal stress ever recorded,” Dr. Jérémy Wicquart of the Global Coral Reef Monitoring Network told The Guardian. He is one of the study’s editors. It caused a 169% decrease in coral year-on-year. Coral reefs play a key role in our ecosystem. They provide shelter, spawning areas, and protection from predators for thousands of species. Some of those species are facing extinction. The economic value of the world’s coral reefs has been estimated at $27 trillion per year. Coral reefs in the Caribbean alone generate $62 billion per year through fisheries and tourism. And reef tourism accounts for 10% of the Caribbean region’s yearly income. More than 54% of coral reefs around the world have suffered heat-related bleaching. That's based on a calculation of temps of the world's oceans. The study of the Caribbean was compiled by more than 300 scientists from 44 countries. And it also revealed some success stories. For example, parts of the Gulf of Mexico have suffered severe heat stress since 2023. But experts found resilient coral colonies that had no disease. They contained critically endangered coral species. That’s due to conservation areas created by the Mexican government. Reflect: When you learn that an environment you care about is changing or disappearing, what responsibility do you think people have to protect it?