March 24, 2011

Finally the day had come for our expedition out to the Great Barrier Reef, our reason for choosing Hamilton Island as a destination in the first place. The island is about 70 km (45 miles) from the reef. We covered the distance in a little under two hours in a catamaran:

Our destination was a giant pontoon called Reefworld:

The pontoon was more like a floating hotel without hotel rooms, including massage rooms, shops, sundeck and an underwater observatory:

There was even a helicopter stationed next to it, where you could pay a small fortune to see the reef from the air:

A giant fish, an almost 3 meter long Queensland Groper, lives permanently under the pontoon. They’ve even named it. Meet George:

We dumped activities like massage and helicopter rides, We were here to see the reef and all the underwater life around it. Once again we dressed up in “stinger suits” to avoid those nasty lethal jellyfish:

To get into the water we walked down a staircase to a metal grid that was a few centimeters under water. Neat.

Last time you met the Incredibles, or as Hal called us, the Incrediblues. This time, say hello to the Teletubbies:

The reef was just as fantastic as its reputation. Even after the corals and marine life we saw in Aitutaki, we were impressed. We snorkeled for a couple of hours and it felt like 10 minutes.

Coral reefs are fascinating things. They are created by very small creatures called polyps. These create a protective exoskeleton surrounding them. Each individual polyp is only a few millimeters (teeny fraction of an inch) in diameter. Most of them live off tiny unicellular algae called zooxanthellae. This is why they can only grow in shallow waters, the algae need sunlight.

The polyps reproduce in two different ways. They create genetically identical clones of themselves, this is how individual corals grow, creating all sorts of spectacular patterns and structurues which seem to be a single organism. In fact they are the skeltons of many polyps attached to each other.

In addition polyps spawn and reproduce sexually, thus forming new corals. Spawning is always done a couple of nights around the full moon. Isn’t it sweet? Polyps get romantic when the moon is full.

Corals are dependent on water to survive, so they tend to grow upwards until they reach the surface.

The history of the Great Barrier Reef starts about 600 000 years ago, when the first reef structure was formed. Interestingly enough the reef died out and the current reef has grown on top of the old one, but is otherwise not related to it. The current reef started growing as recently as 20 000 years ago, in the middle of the last ice age, when sea water levels were 120 meters under what it is today. As sea levels rose, the corals followed, until the sea reached roughly the level it is at today, about 6000 years ago.

The Great Barrier Reef is not really one large reef, but a complex collection of over 2900 individual reefs, It stretches over 2600 kilometers (1600 miles) and covers an area of 344 000 square kilometers (133 000 square miles). That’s actually larger than mainland Norway.

The reef is very fragile and a large part of it is protected in the Great Barrier Reef Marine Park.

We could only snorkel in a very limited clearly marked area and we were given clear instructions never to step on the reef. The limited area did not feel like a limitation at all, we were amazed by the number of beautiful corals, and the many fish and clams:

Nemo!

With flippers you can get down pretty deep, especially now that I have mastered the art of pressure equalization by holding my nose and blowing.

The boys also did some dives. Here’s Viktor:

We had been told on the way out that if we were really lucky we might see a turtle, but that they were relatively rare. I drifted off alone for a while and suddenly it was there, flying by me. It was a green sea turtle which was about 1 meter (3 feet) long. What a majestic creature!

After snorkeling and an excellent buffet lunch we took a ride in this semi-sub.

It’s basically a boat with seats and glass windows under water. It gave us some more great views of the reef outside the snorkeling area:

The kids ended the day on the pontoon with rides on the slide

Iseline, the smallest Teletubby, thoroughly enjoyed it:

Just before we left another turtle showed up to take a deep breath. These amazing creatures only need to breathe for 1-3 seconds every 5 minutes,:

We were back on Hamilton Island in the late afternoon. It had been a fantastic day and we were again extremely lucky with the weather. There has been more or less continuous rain in this area for several months and when we showed up we got sun on both our excursion days.

Eirik

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