What are coral reefs? What are threats to coral reefs? What is coral bleaching? Objective Students will be able to: 1. Define the vocabulary terms global warming and adaptations. 2. Identify several coral reef species in American Samoa and explain their role. 3. Describe coral reef adaptations and how global warming threatens the health of coral reefs. Background American Samoa has unusual coral reefs in some ways. First, many of the reefs are dominated by a marine plant that does not even look like it is alive: coralline algae. This is a plant that usually grows as a smooth pink coating (it l Duration: 60 Minutes.