The two planes jettisoned four unarmed bombs in more than 50m (165 ft) of water, away from coral, to minimize damage to the World Heritage Site, the US navy said. The planes were low on fuel and couldn't be unloaded at the base, so they dumped them.
It stretches for more than 2,600km (1,680 miles) along Australia's eastern coast.
Australia's Great Barrier Reef is already in trouble according to the country's government. The conditions are poor and extreme events in recent years, such as cyclones, flooding, and the effects of climate change are to blame. Also, chemicals used in farming, which find their way into the water, have had a big impact. Poor water quality is bad news for the fish and sea creatures.
One of Australia's most remarkable natural gifts, the Great Barrier Reef is blessed with the breathtaking beauty of the immense coral reef. The reef contains an abundance of marine life and comprises of over 3000 individual reef systems and coral cays and literally hundreds of picturesque tropical islands with some of the worlds most beautiful sun-soaked, golden beaches.
The Great Barrier Reef is one of the seven wonders of the natural world, and pulling away from it, and viewing it from a greater distance, you can understand why. It is larger than the Great Wall of China and the only living thing on earth visible from space.
v Thirty species of whales, dolphins, and porpoises have been recorded in the Great Barrier Reef
v Six species of sea turtles come to the reef to breed
v 215 species of birds (including 22 species of seabirds and 32 species of shorebirds) visit the reef or nest or roost on the islands
v Seventeen species of sea snake live on the Great Barrier Reef
v More than 1,500 fish species live on the reef
v There are at least 330 species of ascidians (sack-like invertebrates - sea squirts) on the reef system
I'm aghast about the jettisoned bombs. If they'd been armed, would the fighter jet personnel have bombed the reef? This is what I think: Mankind's toys of war are getting out of hand.