- 1. Marine Protected Areas
- 2. What is the Coastal Zone?
- 3. The Formation and Biology of Coral Reefs
- 4. Coastal Zone Interactions and Threats
- 5. Human Impacts on Coral Reefs—Litter
- 6. Human Impacts on Coral Reefs—More
- 7. Animals on the Reef
- 8. Animal Interactions and Food Webs
- 9. Endangered Species
- 10. Glossary
3. The Formation and Biology of Coral Reefs
Where do corals grow?
Refer to the map to see where coral reefs are found around the world. What do coral reefs need to grow?
- Warm Water
- Sunlight
- Clear Water
- Salty Water
- Stable Rocky Beds
- No Pollution
What do corals eat?
Coral polyps (animals that build corals) have zooxanthellae (small plants) living in their tentacles arm like forms). Zooxanthellae use sunlight to make sugars for the coral to use as energy providing 98% of their food. The zooxanthellae have a nice safe home to live in without being in danger and use the waste from the coral polyp. This is a special relationship where both the coral polyp and the zooxanthellae benefit. This relationship is called symbiosis.
Common Types of Reefs
A Fringing reef is usually the most common type of reef in an area. It is the reef that surrounds an island. If you walk off the beach and onto a reef that is called a fringing reef.
A Barrier reef is formed after many years. It is when the island slowly starts to sink into the ocean and at the same time pushing out the surrounding fringing reef.
An atoll is a low coral island enclosing a lagoon and is found in tropical oceans where it is mostly covered by corals and algae.
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