🪸 Coral Identification Lab

Coral Reefs: The Rainforests of the Sea

Coral reefs are built by tiny animals called coral polyps, which secrete hard skeletons made of calcium carbonate. Living inside each polyp are microscopic photosynthetic algae called zooxanthellae, which provide the coral with up to 90% of its energy — a partnership called mutualistic symbiosis. When ocean temperatures rise even slightly above normal, corals expel their zooxanthellae and turn ghostly white in a process known as coral bleaching. Without zooxanthellae, corals can starve and die, threatening the thousands of marine species that depend on reef ecosystems for food and shelter. New York students can observe cold-water coral relatives right in Long Island Sound, where they form important habitats along the seafloor.