Extending over more than 2.000 kilometers off the East Coast of Australia, the marvellous rainbow-colored sea garden reveals itself. In 1768, the French sailor Louis-Antoine de Bougainville described for the first time "dangerous reefs". He then decides to change directions, missing those treasures! With its 3.000 reefs and 1.500 islands, the marine park of the Great Barrier Reef is part of the UNESCO World Heritage, and regroups numerous varieties of corals. Gobies, clownfish and triggerfish copy their color to remain invisible. Overlooking the coral reefs, about 1.400 sharks live in this park! Scientists study the reef to look after its health; they explore solutions to protect it from climate change and its effects.