And that is the same reef that's the same reef 15 years ago that's the same reef today.

And there's a beautiful reef, very complex reef, with lots of animals, including a lot of octopus.

We're crocheting a coral reef.

Coral reef in New Caledonia.

I'd never seen the reef here before.

Coral reef ecosystems are invaluable human treasures.

Very unlikely, Joe would jump on a pristine coral reef, a virgin coral reef with lots of coral, sharks, crocodiles, manatees, groupers, turtles, etc.

Why on earth are you crocheting a reef?

I'm an ecologist, mostly a coral reef ecologist.

The coral reef is the region's prime attraction.

They clean the reef everything that grows enough to be seen, they eat, and they keep the reef clean and allow the corals to replenish.

The Australian Great Barrier Reef is another success story.

Why not chisel a coral reef out of marble?

Now, see this strange, underwater, coral reef looking thing?

Under the realization from tourist operators, fishermen, the Australian Great Barrier Reef Authority and scientists that the Great Barrier Reef is doomed under the current governance regime.

Do we have evidence of this? Yes, coral reef systems.

This is our invocation in crochet of a bleached reef.

How does the reef work? Well, it's very, very simple.

Another example Nassau groupers in Belize in the Mesoamerican Reef.

And the people in Chicago made a reef of their own.

The water had started coming back. It was foaming over the reef.

Anyway, one tree is situated right next to a beautiful coral reef.

The reef is 1,600 kilometres long and covers about 8,000 square kilometres.

And so now you can walk through a coral reef without getting wet.

I want to be able to go back to this reef. Thank you.

So in 2007 we had an exhibition, a small exhibition of this crochet reef.

So we had our own miniature rainforest, a private beach with a coral reef.

We thought we had a handle on all the reef fish diversity evidently not.

It's the only threat, the only influence that the reef had to deal with.

If Joe jumped in a coral reef, there are many things the alien could see.

It's like scuba diving into a coral reef, except you're going upward instead of downward.

Finally, oysters can attenuate and agglomerate onto each other and form these amazing natural reef structures.

Well, the good news is it's recovered and recovering fast, faster than any reef we've seen.

Fiji notes the need for the mainstreaming of sustainable coral reef management into national development strategies.

In respect of the claimed loss of coral reefs, Iran has provided remote sensing evaluation of changes in the coral reef cover sedimentation rate analysis chemical analysis of heavy metals, TPH and polycyclic aromatic hydrocarbons and a study on coral reef growth bands.

In each of these cities, the local citizens, hundreds and hundreds of them, have made a reef.

According to the comprehensive foreign reports of the Central News Agency, the U.S. official who requested anonymity revealed that the United States Navy destroyer, USS Decatur, cruised into the 12 nautical mile territorial limit of Gaven Reef and Johnson Reef of the Nansha Islands.

So if the United States removes a million dollars' worth of lobsters from a reef, Kiribati gets 50,000 dollars.

But gradually, as the buildings are repaired, we will see the accretion of a limestone reef beneath the city.

They've borrowed the recipe from the coral reef, and they're using CO2 as a building block in cement, in concrete.

Here's an octopus moving across the reef, finds a spot to settle down, curls up and then disappears into the background.

A great deal of this has been happening in the Great Barrier Reef, particularly in coral reefs all over the world.

If we get all of the fish of a coral reef together and weigh them, this is what we would expect.

104. Welcomes the publication of the Status of Coral Reefs in Tsunami Affected Countries 2005 by the Global Coral Reef Monitoring Network

So, albeit a very small creature and very modest, this creature is incredible, because it can agglomerate into these mega reef structures.