Corals

Fascinating facts about the Corals

• Corals are animals, not plants — and they're older than dinosaurs. A single coral polyp is a predator that stings and eats plankton with tentacles fringed in venom-loaded harpoons called nematocysts. But the real genius is the partnership: each polyp hosts millions of symbiotic algae inside its cells that photosynthesise and feed the coral sugar. Break that bond — raise ocean temperature by just 1–2°C — and the algae abandon ship. The coral starves within weeks, turning white and skeletal. This isn't disease. It's eviction.
• A single reef produces more biomass than a rainforest of the same size, yet grows on some of Earth's poorest soil. The Great Barrier Reef spans 2,300 kilometres — visible from space — and is built by animals smaller than a rice grain, stacked across centuries. Each polyp secretes a limestone skeleton. Trillions of them, layer upon layer, create structures that shelter 25% of all marine fish species despite covering less than 0.1% of the ocean floor. It's a city built from sunlight and patience.
• Corals were thriving 240 million years ago, surviving the asteroid that killed the dinosaurs 66 million years ago. They've weathered ice ages and sea level swings of hundreds of metres. Yet in the last 40 years, half the world's coral reefs have vanished — not from evolution's slow blade, but from heat spikes that last a few seasons. A coral's entire lifespan of reproduction, growth, and survival was fine-tuned for stability. Chaos kills it faster than change.
• When a coral bleaches, it's not dead yet — just starving and desperate. Some reefs recover if cooler water returns within weeks. Others don't. Scientists in Australia have engineered heat-resistant corals by selectively breeding the toughest survivors and even editing their genes in the lab. It's controversial: we're asking whether we should redesign nature's survivors to fit our damaged world, or whether that's a band-aid on a bullet wound we're still firing.
• A healthy coral reef is a pharmacy. Compounds from reef organisms have yielded cancer drugs, sunscreen, antibiotics, and painkilling compounds now in human trials. One molecule from a reef sea whip is being tested against leukaemia. We've only screened a fraction of reef biodiversity. Destroy the reef, and we incinerate a library of evolutionary solutions we haven't even read yet — medical breakthroughs our grandchildren will never discover.

At a glance

About the Corals

In the warm, crystal waters of the tropics, coral reefs come alive as vibrant, living cities, their delicate, branching forms swaying gently in the ocean currents like an ethereal ballet. As the tide rises and falls, these underwater metropolises pulse with a kaleidoscope of colors, their intricate, symbiotic relationships with the creatures that call them home a testament to the remarkable resilience and beauty of these vulnerable, yet vital, ecosystems. With each delicate polyp working in harmony to create a thriving, interconnected whole, corals embody the very essence of life's boundless diversity and intricate complexity.

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