A. Apo Reef, Philippines
B. Great Barrier Reef, Australia
C. Florida Keys, United States
D. Red Sea Coral Reef, Red SeaCoral reef is an underwater ecosystem characterized by reef-building corals. The Great Barrier Reef is the world’s biggest coral reef, located off the coast of Queensland, Australia.
how long is the great barrier reef?
The reef is the only living thing visible from space and is made up of 3000 reef systems. The Great Barrier Reef covers over 1,800 miles and can reach a width of 40 miles in some spots.