Great Barrier Reef National Geographic

May 16, 2013 by  

Great Barrier Reef National Geographic, Largest structure on the planet built by living organisms, Australia’s coral rampart hosts a carnival of sea life.

Sometimes at its outer edge and sometimes closer, the beam from the flashlight kept reflecting off big cat eyes. They glimmered pale silver, with pupils darker than the darkness through which they glided. But cats don’t patrol 40 feet (12 meters) deep in the Coral Sea. These were sharks. It was hard to tell what kind they were, but some of the shadowy bodies looked a lot longer than mine.

I breathed up my scuba tank’s air sooner than planned and had to surface far from the boat. Then I was swimming through black swells toward the ship’s distant light as though mired in one of those dreams where you need to move faster but can’t. I promised myself that it would be a while before my next night dive on Australia’s Great Barrier Reef. Yet within days I was beneath a full moon and 50 feet (15 meters) of water looking at more cat eyes.

These belonged to an epaulette shark, small and lovely and speckled, lithe as an eel as it curled round a coral pillar. Two lionfish with fins like flared wing feathers cruised upside down beneath a coral table as though that were the seafloor. Above them a pinnacle of coral twisted nearly to the surface, lit from behind by the ship’s lamps and the moon.

Silhouetted, each shelf, frond, curlicue, and fan emphasized the eerie configurations that develop in the near absence of gravity. Drifting weightless beside them seemed like sightseeing on another planet. But the moment I thought that, I realized that I had it wrong. This scene was the very essence of our home planet, which is, after all, ocean blue. A single coral wall holds a broader representation of earthly life—species from more phyla, or major groups—than an entire continent does. It seems otherworldly only to those of us born above tide line.

Coral reefs form when colonies of tropical marine plants and animals with limestone skeletons rise atop earlier generations. They fashion the most visually diverse natural environments a human can experience, and the Great Barrier Reef is the world’s single largest coral domain. With the broad, shallow continental shelf of tropical northeastern Australia providing an ideal pedestal for growth, this coral complex reaches as far as 160 miles (260 kilometers) offshore and more than 1,250 miles (2,000 kilometers) from north to south. The Great Barrier Reef covers 135,000 square miles (350,000 square kilometers), an expanse greater than Poland.

To explore what amounts to an offshore nation, photographer David Doubilet and I roamed 4,000 miles (6,400 kilometers) on dive boats. We spent so many hours submerged that I began to think land looked weird. The day I found the same sort of remora fish that clings to sharks and manta rays hitching a ride on my leg, I wondered if it might not be time to dry out.

Although the name suggests a continuous strip, the Great Barrier Reef is actually a commonwealth of at least 2,800 reefs. Only some are true barrier reefs—breakwaters rising near the edge of the continental shelf. In the calmer seas behind that cordon, more reefs appear as irregular circles and crescents known as platform reefs. Smaller formations, called patch reefs, are scattered throughout shallow areas.

Report to Team

Please feel free to send if you have any questions regarding this post , you can contact on

Disclaimer: The views expressed on this site are that of the authors and not necessarily that of U.S.S.POST.


Comments are closed.