Translations:AY Honors/Coral Reefs/Answer Key/72/en

When conditions change (temperature, pH, light levels salinity, etc.) the corals dump out their colorful zooxanthella and become white (the color of their calcium carbonate shells); then they take in new zooxanthella with different characteristics that might thrive better than the previous zooxanthella. It’s just a "gamble" to try to survive better with a different genetic combination. For some corals, the gamble is lost and they die. For other’s the new Zooxanthella do make a difference and the remaining coral takes over the reef building on top of the old coral. Climate change is resulting in increased temperature in the coral reef areas and is causing a lot of bleaching. Too much bleaching can cause the reef to die because it simply can’t keep up.