The  Great Barrier Reef  is the world's largest coral reef system, with more than 2900 individual reefs and including 900 islands stretching more than 1400 miles.   Is said to be the largest single structure made by living organisms, and is known as one of the Seven Natural Wonders of the World. There are 400 species of coral growing. Is 12 times larger than the state of Hawaii, just smaller than Montana and the size of 70 million football fields. Located in the Coral Sea off the coast of Queensland. But, ah, the reef has lost more than half its coral cover since 1985.  And the 2020 bleaching even will even more reduce this wonder.  Why?  Global warming. But recovery is possible. Reefs can increase in diameter by up to 2 inches per year, and vertically almost 10 inches/year. But only down to a depth of 500 feet (needs sunlight), and not above sea level. A bleached reef is not dead, and can recover. Corals only spawn once/year, in the October/November period...