S01E01 - The Great Barrier reef, a series of coral reefs along Queensland's coast, is the largest structure created by organisms. Where geology and tides are favorable, coral reefs are created by innumerable minute organisms, animal and vegetable corals and the microorganisms they host. The islands are the richest maritime biotope for fish and other aquatic creatures. It all changes quickly with the tides, the season and shaping forces such as erosion.
IMDB.