🪸 Coral Reefs

What you’ll learn

1. What Is a Coral Reef?Understand what coral is, what a reef is, and why reefs are biological powerhouses.You've learned that coral reefs are vast cities built by tiny animals. Each reef is a living limestone structure laid down over millennia, home to a quarter of all marine species.
2. The Secret PartnershipUnderstand the symbiosis between coral and zooxanthellae and why it's the engine of the reef.You've uncovered the deal at the heart of every reef. Algae living inside coral tissue feed the polyps through photosynthesis, fueling reef growth but creating a dangerous dependence.
3. A City Beneath the WavesExplore the staggering biodiversity of reefs and the roles different organisms play.You've toured a thriving underwater metropolis. Fish, invertebrates, and cleaner organisms each fill a niche, weaving the dense food web that makes reefs so productive.
4. How Corals Build and ReproduceUnderstand how corals grow their skeletons and the dramatic ways they reproduce.You've seen how reefs renew themselves. Corals grow by adding skeleton, clone themselves to expand, and once a year spawn in mass synchrony to seed new reefs.
5. When Reefs Turn WhiteUnderstand what coral bleaching is, what causes it, and why warming oceans are so dangerous.You now understand the reef's most visible crisis. Bleaching is the breakdown of the coral-algae partnership under heat stress, and repeated events are killing reefs worldwide.
6. Threats Beyond HeatExamine the range of human and natural threats facing reefs beyond warming.You've mapped the gauntlet reefs run. Overfishing, pollution, destructive practices, disease, and outbreaks of predators compound the damage from a warming sea.
7. Why Reefs Matter to UsUnderstand the ecological, economic, and human value reefs provide worldwide.You've seen that reefs are not a luxury but a lifeline. They feed millions, shield coastlines, drive economies, and hold untapped medical promise, making their loss a human crisis.
8. Saving the ReefsExplore the science and policy of reef conservation and restoration, and reasons for hope.You've ended on hope grounded in action. From breeding heat-tough corals to protecting reefs and cutting emissions, real tools exist, but the biggest fix is climate itself.

Questions this course answers

Grounded in trusted sources

• NOAA
• Smithsonian National Museum of Natural History
• Australian Institute of Marine Science

Every Wunder lesson is built from real, reputable sources — never invented.

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