Wachenfeld: “When the algae photosynthesize, they take energy from sunlight and carbon dioxide, then make sugars which help to supply energy to the coral.”

 

It's one of nature's perfect partnerships. By capturing the energy from sunlight, the algae supercharges the coral, providing it with up to 20 times more energy, fueling the rapid growth of the reef. When the first coral arrived on Australia's east coast, they found the best place on Earth to make a home--one huge, shallow sun trap.

 

Trillions followed in the biggest construction project the world has ever seen, exploiting every piece of real estate, right up to the very edge of the continent ,where the seabed plunges into the abyss.

 

Today, it may look like paradise. But hidden deep beneath the waves lies one of its most brutal and violent secrets.

 

The Great Barrier Reef seems idyllic--life in perfect harmony, bathing in warm water all year round. But in the past, this paradise has gone through hell.

 

Scientists now believe that it has endured massive catastrophes that wiped out the reef, almost stripping it of life, catastrophes that traumatized the entire planet. Scientists are only just beginning to uncover the whole truth.

 

On the outer edge of the reef, there is evidence of an anomaly. It looks like another reef. But it's 190 feet below the surface, where no reef can survive. No one has ever sampled it. Geologist Jody Webster is about to be the first.