Coral reef

What is coral bleaching? Coral bleaching happens when corals lose their vibrant colors and turn white. But there’s a lot more to it than that. Coral are bright and colorful because of microscopic algae called zooxanthellae. The zooxanthellae live within the coral in a mutually beneficial relationship, each helping the other survive. But when the ocean environment changes—if it gets too hot, for instance—the coral stresses out and expels the algae. As the algae leaves, the coral fades until it looks like it’s been bleached. If the temperature stays high, the coral won’t let the algae back, and the coral will die. What triggers coral bleaching? The leading cause of coral bleaching is climate change. A warming planet means a warming ocean, and a change in water temperature—as little as 2 degrees Fahrenheit—can cause coral to drive out algae. Coral may bleach for other reasons, like extremely low tides, pollution, or too much sunlight. Why does coral bleaching matter? Coral bleaching matters because once these corals die, reefs rarely come back. With few corals surviving, they struggle to reproduce, and entire reef ecosystems, on which people and wildlife depend, deteriorate. Bleaching also matters because it’s not an isolated phenomenon. According to the How does coral bleaching impact wildlife? Coral reefs support some of the most biodiverse ecosystems on the planet. Thousands of marine animals depend on coral reefs for survival, including some species of sea turtles, fish, ...

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Although seas are important waterways, fishing grounds, and so much more, they also host some of the most diverse ecosystems, including As the name suggests, coral reefs are formed when the coral skeletons cluster in groups to form colonies. These coral colonies are held together by calcium carbonate deposits present in the seawater. Most reefs form best in clear, shallow, warm, and agitated waters. Although the first coral reefs appeared over 400 million years ago, most of the existing ones are less than 10,000 years old. The world's Distribution And Location Source: Spalding MD, Ravilious C, Green EP (2001) World Atlas of Coral Reefs. University of California Press, Berkeley, USA. According to the UNEP World Conservation Monitoring Center, coral reefs cover about 109,800 284,300 km 2 or less than 0.1% of the World Ocean's total surface area. The area covered by the reefs is almost the size of Cuba or half the size of France. The largest coral reef area (about 92% of the total area) is within the Indo-Pacific region, a region comprising the Pacific, Indian Ocean, Southeast Asia, and the Red Sea. Of the reefs in the Indo-Pacific, 32.3% are in Southeast Asia, while 40.8% are in the Pacific. The Caribbean and the Atlantic area accounts for about 7.6% of the world’s coral reefs. The Indian Ocean accounts for up to 60% of the global coastal reefs, the Pacific Ocean 25%, and the West Atlantic 15%. The Hawaiian Island, Madagascar, and the Philippines also have coral reefs. In So...

Did you know that more wildlife lives around coral reefs than in any other part of the ocean? Find out more about these important ecosystems in our coral reef facts… What are coral reefs? When you look at a coral reef, you might think that you are seeing a group of colourful rocks. But don’t be mistaken! Reefs are actually made out of living creatures called coral. • Where are coral reefs found? Coral reefs can be found all over the world! However, most coral reefs grow in shallow, clean ocean waters on either side of the Equator, because they need sunlight and warm temperatures all year to survive. Some famous coral reefs include the Great Barrier Reef in Australia, the Amazon Reef in Brazil and French Guiana, the Tubbataha Reef in the Philippines and the Miami Terrace Reef in the United States. The “Heart Reef”, which forms part of the Great Barrier Reef in Australia • Quick facts about coral reefs… • – Coral have growth rings, just like trees! • – The first coral reefs formed on Earth 240 million years ago. That’s before the dinosaurs were alive! • – Most coral reefs today are between 5,000 and 10,000 years old. • – There are more than 800 different types of hard coral around the world. • – The Great Barrier Reef is the largest reef system on Earth. You can even see it from space! Life in coral reefs Lots of different types of sea creatures call coral reefs their home – giant clams, starfish, eels, cuttlefish and many, many more. The reefs provide this diverse range of ...