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The Formation of Coral Reefs

Coral reefs are often called the "rainforests of the sea" due to their incredible biodiversity. These underwater structures are built by colonies of tiny animals called coral polyps. A single polyp is a soft-bodied organism that attaches itself to rock on the sea floor and then secretes a hard, calcium carbonate skeleton. Over many generations, the skeletons of these polyps build upon one another, forming the massive structures we know as coral reefs. This process can only occur in specific marine conditions: warm, clear, shallow, and sunlit waters.

The vibrant colors of a healthy coral reef are not from the corals themselves but from microscopic algae called zooxanthellae that live within the coral's tissues. This is a symbiotic relationship; the algae perform photosynthesis, providing the coral with essential nutrients, and in return, the coral provides the algae with a protected environment. This relationship is fragile. If ocean temperatures rise even slightly, corals will expel the algae, a process known as coral bleaching. This leaves the coral colorless and vulnerable to starvation and disease.

Coral reefs are vital to ocean health. They protect coastlines from storms and erosion, provide habitats for approximately 25% of all marine species, and support fishing industries that feed millions of people. The delicate balance required for their survival means they are highly sensitive to environmental changes. Protecting these ecosystems is a critical challenge for marine conservationists worldwide, as their loss would have catastrophic consequences for both marine life and human communities.