Growing Coral

According to a 2017 study by the UN, coral reefs may cease to exist by the end of the century. In an effort to save these vital ecosystems, biologists at the Georgia Aquarium in Atlanta are growing coral in labs. Our partner Science Friday has the story.


According to a 2017 study by the UN, coral reefs may cease to exist by the end of the century.

In an effort to save these vital ecosystems, biologists at the Georgia Aquarium in Atlanta are growing coral in labs.

Our partner 'Science Friday' has the story.


I love working with corals because of the diversity of them, the brilliant colors that they have, the different textures that they can create.

Coral is a colony, and each polyp is actually an individual animal itself.

And when you start to see those animals do what they naturally do, when it comes to reproduction, you feel pretty privileged to witness such a beautiful process and just hope you can help.

♪♪ We do a lot of work here at the Georgia Aquarium with corals.

Part of my role here is to help create habitats.

So, behind me, you see one of our creations, which is the Indo-Pacific Reef tank.

It's about 16 feet deep.

It's 164,000 gallons.

It's pretty cool.

I work with a team of biologists to take what we've learned with caring for corals in this setting and be able to bring it out into the field and be able to help the wild population.

We are working with propagating and restoration, with the ultimate goal of helping corals in the wild to be self-sustaining.

First of all, corals are actually animals.

They're in a group called cnidarians, but within their tissue, they have algae cells called zooxanthellae that are photosynthetic, but it's a symbiotic relationship.

The coral itself provides a home for those cells to live in, and the by-product of those cells give nutrients to the coral itself, too, so it's kind of a win-win for both sides.

You hear that term 'bleaching,' corals are bleaching.

Bleaching is the process of the zooxanthellae leaving the tissue of the coral, and if it doesn't reabsorb zooxanthellae quickly, then, unfortunately, the coral will actually die because it does need the nutrients and the by-product of the zooxanthellae to continue to be healthy and to survive.

♪♪ We work with the Coral Restoration Foundation in the Florida Keys, and what they have out there is an underwater nursery.

Corals have a very unique reproduction style.

The two species that we specifically work with, which is the staghorn coral and the elkhorn coral, reproduce only one week a year.

It's crazy.

So, they're basically cued on the tide, the lunar cycle, and the temperature of the ocean.

They wait for the high tide at night because that's when the current is the strongest, so when they release their eggs and sperm, they have just the right conditions for them to mix and find each other.

But, unfortunately, right now, there's a lot of distance between the corals, so they're having a hard time finding each other when they are ready to reproduce.

So that's where we come into play.

We work as a team in the collection of the gametes.

We basically separate out the sperm and the egg so we know we're getting a different genetic makeup, and then we combine the eggs and sperm to produce a free-swimming planula -- or larvae, so to speak -- and then we bring the planula back out onto the reef, and we disperse it out into the reef for them to just survive and thrive and grow.

So, the main goal out there is to get a large, diverse genetic population so over time they can do it all on their own and we don't have to be out there to help them find each other.

We basically take a small subset of what we were able to fertilize in the wild and bring that back to do our own research so we can know what it needs in the wild in order to survive.

What you see right here along these shelves are plugs and tiles that are in the process of being seeded.

So, we utilize subadults to help provide the zooxanthellae to the baby corals when they're placed in here after spawning.

And it takes a while for that coral and algae to grow on that material, so we try to give it as many months as possible.

So, what we're looking at right now is one of our settled corals from coral spawning down in Key Largo.

We have named him Baby Groot.

And some of the things that we look for when we check on him -- the coloration of the tissue, number of polyps that have developed.

We also look for the base of the coral to be encrusting along the settlement material, which he's doing right now, which is good.

This is probably about nine years' worth of work trying to get to this point, but he looks really, really good right now.

He looks beautiful today, actually.

I think it certainly is an uphill battle, but it's a battle that I think we have to fight for them.

They need our help.

As a biologist, you have to be very comfortable with failure, but with failure comes success.

We might not know what's going to happen to the reefs, but I want to make sure that, in the future, I can look at my daughter and say, 'I tried.'