Very Short Introductions: Brilliant, Sharp, InspiringCoral reefs are among the most beautiful, and most diverse, of ecosystems. Early seafarers were wary of them, naturalists were confused by them, yet many coastal people benefited greatly from these mysterious rocky structures that grew up to the surface of the sea. They have been rich in their supply of food, and they provided a breakwater from storms and high waves to countless coastal communities that developed from their protection. Their scale is enormous and their value high. Found incountless locations around the world, from the Indo-Pacific coral reef province to the Caribbean and Australia, they support both marine and human life.But today coral reefs are in trouble, with many dying or suffering from over-exploitation, pollution, and the warming and acidification of the oceans. Understanding reefs, their conservation and management, is vital, and so is conveying this to authority if we are to preserve these remarkable ecosyst