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

Reef them down. Men!

Coral reef in New Caledonia.

We're crocheting a coral reef.

Self Parking, Events Center, Shark Reef.

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

like Kingman Reef, which is now protected.

I'd never seen the reef here before.

The ship was wrecked on a sunken reef.

Nassau groupers in Belize in the Mesoamerican Reef.

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

Why on earth are you crocheting a reef?

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

The Australian Great Barrier Reef is another success story.

Why not chisel a coral reef out of marble?

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

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

This is our invocation in crochet of a bleached reef.

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

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.

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

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.

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

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

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.

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.

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

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

So if the United States removes a million dollars' worth of lobsters from a reef,

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.

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

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

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

And we've got this 3,000 square foot gallery and we want you to fill it with your reef.

When you think of a coral reef, this is what most people think of these big, hard, elaborate corals,

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.

If you look at this diagram of a coral reef, we know a lot about that part up near the top.

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

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

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

And actually most of the fish, they are a little spot on the debris, the piles of debris, were coral reef fish.