Great Barrier Reef, Australia

The Great Barrier Reef stretches over 1,200 miles off the coast of Queensland, Australia. It is also the only living organism that can be seen from space. Since 1985 the reef has lost more than half of its corals due to climate change, pollution, and overfishing. Even worse, in December 2013 the Australian government authorized the construction of a new port next to the reef. The construction will involve dredging 3 million cubic meters of seabed.