[Coral reefs are delicate because the majority need many particular conditions to form. They tend to require tropical climates with water temperatures around 20-30 degrees Celsius. They also contain microscopic photosynthetic organisms called zooxanthellae. If too much sun is blocked, such as by dust in the water, the zooxanthellae will not be able to produce enough energy for the corals to build their exoskeletons. This can also happen if they are coated with pollutants. Finally, corals are saltwater animals, so a significant amount of runoff from land can dilute the water and impact their survival.]

Why are coral reefs considered delicate? | Study.com