[gentle music] - Hi there I'm Frank Graff.

A unique plan to save and restore coral reefs, waterproofing an historic town, and the science of sourdough.

Yes, you're getting hungry.

It's all coming up on Sci NC.

- [Announcer] This program was made possible by contributions to your PBS station by viewers like you.

[upbeat music] - [Announcer 2] Additional funding for the Sci NC series is provided by GSK.

[upbeat music] ♪ - This is the Tar river and the town of Princeville built right alongside it.

Princeville was founded by freed slaves after the Civil War.

It is historic, but because climate change is sending the Tar River over its banks more and more often, and flooding the town, Princeville is in trouble.

As we continue our series, state of change Sci NC producer Michelle Lotker explains how Princeville hopes to survive by making itself flood proof.

This series is part of the Pulitzer Center's, Nationwide Connected Coastlines Reporting Initiative.

♪ Oh, freedom, freedom hill ♪ ♪ We built thee round by round ♪ ♪ From the waters Princeville came ♪ ♪ Birthed from thy hollow ground ♪ - Princeville has flooded many times.

And we've been asked as a group collectively.

Well, why don't you all just leave?

Especially after the flood Matthew.

People would say, okay, enough already.

on it that quick.

- [Michelle] The historic town of Princeville sits on low lying land within the 100 year floodplain of the Tar River.

In 1885, it was the first town incorporated by African-Americans in the United States, even with a levy between the town and the river, big storms like Hurricane Floyd in 1999.

And Hurricane Matthew in 2016 have brought devastating floods to the town.

Hurricane Matthew flooded 80% of Princeville filling most buildings with over eight feet of water, including the elementary school.

- When I first arrived here in Edgecombe.

It was maybe two years after the flood.

And when I walked in the building, it was pretty much a shell, furniture destroyed.

It looked like an abandoned building and a lot of broken windows because it had been left vacant for a few years.

- We lost our school so therefore we lost everything, even personal belongings of the children and the teachers.

It played a very big impact on our students because they were displaced.

- We had to stay in another school for a long time.

- I was wondering what was gonna happen.

- I was kind of scared cause are we gonna go back to school?

- [Michelle] Despite the impacts of these floods and the potential for flooding in the future, residents of Princeville are working to rebuild.

- Princeville is not going anywhere.

If people read the history of Princeville, then that will lead them to the answers.

The reason why citizens are still in this community today, this is family, this is home.

Our ancestor's blood, sweat, and tears paved the way for us.

So the least that we can do and where we are today is continue to build upon that momentum.

- [Michelle] But with climate change increasing the likelihood of storms with even more rainfall in the future, they're rebuilding with flood resiliency in mind.

NC State and the Princeville community developed a flood print plan, converting vacant land into community garden plots and building green infrastructure like rain gardens around Princeville elementary.

- It's making the school site more storm friendly if you will, because it's dealing with the water that's coming off parking lots, roofs and other impervious surfaces.

And then at the same time, it provides a multitude of benefits through working with teachers on how it's incorporated into the curriculum.

And so think of the landscape as the largest classroom at Princeville Elementary School.

- [Michelle] The landscape around the school, isn't the only thing being redesigned with flooding and learning in mind.

- [Jerome] The whole building is still original, but the inside was good at 100%.

Some of the things we did such as raising all the light switches and receptacles above four feet high removed all the sheet rock.

So all of our walls now are masonry walls so that if we were to have water again, it's just a matter of coming in, wiping them down.

The interior doors are now what you call FRP doors.

You just wipe the doors off.

We actually put in flood vents that if the water ever came in, instead of it being trapped in here, the doors will open up automatically and they will allow the water to escape.

And we put the air conditioning air handlers on top of the mezzanine, and we moved all the electrical panels above the ceiling as well.

So now that if we were to experience water, we would not lose the major system.

- [Michelle] The mezzanine also serves as an elevated storage space for critical parts of the school if they hear that a flood is coming.

- [Jerome] And people don't think about, simple as buying library books, it takes a while to get those books ordered and restored back into the building.

- [Sheila] I pray that we don't have another flood, but it won't take us a long time to get back in our building.

- [Michelle] Beyond the financial implications.

All of this matters because being displaced from a school they're familiar with can have a big impact on kids.

- I got scared cause there are some other new kids here are all of my friends moved away.

- I've been at this school for a long time.

And it felt kind of different, this change.

- A lot of times school is a place that kids feel safe.

You already know, okay, I'm coming to school.

I know I'm gonna have breakfast and I'm gonna have lunch.

And you have a place that you can just be a kid and learn.

You first walk through that door after three years, it was just like, I'm getting emotional just thinking about it.

It was just like, we're back home.

[upbeat music] - Each time Princeville flood.

It may take some time for it to become back to a livable condition.

But each time obviously we bounced back even before my time, somebody bounced back.

So I say well if they bounced back, the town of Princeville and the crew bounce back.

I can stay here and help it to bounce back.

♪ Standing tall through wind and rain ♪ ♪ From the waters rose the game ♪ ♪ Oh Princeville yet remain ♪ ♪ God's faithfulness abound ♪ [upbeat music] - Scallops grow in the shallow waters of North Carolina sounds and estuaries.

They used to provide an important industry in the state until its combination of problems wiped them out.

Well, now scientists are trying a unique plan to restore the scallop.

- Found a live adult wild scallop.

They get to be a bit larger than this.

I would say he's what we would call a teenager, juvenile scallop.

- [Frank] But sad to say, this is a pretty lonely teenage bay scallop.

To find out why dive down to the sandy sea grass beds at the bottom of North Carolina's bays and estuaries.

- They have a very neat life history where they're in the water as a larvae for a month or so.

And in that time they have a little shell just like an adult scallop.

They eventually find a fuse that means sea grass is probably in the area.

They float down towards the bottom or swim down towards the bottom.

And they use something called bristle threads, a little line that they can attach to individual sea grass blades.

So they hang on the sea grass blades until they grow to a size that's safer.

And then they drop to the bottom and just live laying on the bottom in the sea grass meadow.

- [Frank] Those sea grass beds were filled with bay scallops in the 1920s, North Carolina topped the nation with 1.4 million pounds harvested but a red tide in the 1980s decimated the population.

over fishing, natural predation, and a decline in sea grass caused by rising water temperatures and lower water quality, all combined to put the species at risk.

- [Amy] Since then bay scallops have not recovered.

And the fishery has been officially closed since 2006.

So they can flap their shells together in order to propel themselves through the water.

And that's how they swim.

1367 is 8.81, 1289 is 8.6.

- [Frank] But now the bay scallop is getting some love.

- 1453 was 8.32.

All species are important to the biodiversity of our ecosystem.

These guys, I would say the most important function that they serve as a prey item for other important species.

However, they also perform filtering functions similar to oysters.

Our estuaries are increasingly becoming more and more sedimented, filled with nutrients.

And these guys are one of the critters available to filter out some of those nutrients that are becoming harmful and detrimental to the ecosystem.

1303 is 5.85.

- [Frank] In a unique research project requiring a lot of patients and utilizing a drop of glue, fishing line, metal frame and living bay scallops scientists are tethering more than 1600 scallops to mark steel frames.

- So the aim of this research is to discern why bay scallops have not recovered.

We have a few hypotheses as to why that has occurred.

And we also want to look into what would be the best landscape of artificial sea grass, or in future natural sea grass to focus our efforts on for the restoration of bay scallops.

- [Frank] The living scallops are tethered because they can swim through the water.

The frames and tiny scalps are then placed in nine artificial sea grass beds on Oscar Shoal.

That's just off Beaufort, the beds vary in size and thickness.

Bay scallops were once abundant in the area.

- And if there's sun, you can see the outlines and really you navigate by breaks, kind of where there are spaces between the mats.

But as I said today, it's kind of, you have no choice, but to dive down and put your face right up against it and try to navigate that way.

- We are tethering bay scallops in order to come back day after day and follow the fate of that same scallop through time.

Each time we revisit this scallop, we will record whether it is present or absent, meaning whether it has survived its night, or it has been eaten by a predator potentially.

And after a few days to a week, we can come back and we can measure that same individual and calculate a growth rate.

Survival and growth are both important factors that we need to consider for scallop restoration.

- [Frank] Researchers expect to find survival and growth rates will differ between sea grass landscapes.

Once researchers determine which bed has the best survival rate, more than 10,000 scallops will be scattered throughout the natural and artificial sea grass beds to see where they prefer to locate themselves without human intervention.

- And it's a species that we would love to understand what makes it tick and to be able to tweak the system if possible, in a way that helps scallops or to understand where to try to restore scallops.

Could we pick the meadows if we were going to put out a hatchery raised little baby scallops, where's their best chance of surviving to become spawners themselves?

[upbeat music] - Watch this.

That is spawning baby coral.

Coral reefs, of course an important ocean habitat, but warming seas are killing coral reefs.

I have producer Michelle Lotker shows us how North Carolina researchers are trying to save the coral reef.

- [Michelle] You're watching history in the making, this species of coral is called Orbicella faveolata or mountainous star coral.

And it had never spawned in the lab before this moment.

Not many people get to see this phenomenon.

Let's watch that again.

- [Nicole] These corals are so amazing when they spawn because they're pulse spawners.

So they synchronously release their gametes in one pulse.

- [Michelle] Spawning is one way that corals reproduce.

They release gamete bundles of eggs and sperm into the ocean where they float to the surface and mix.

- You can imagine if you're looking at an entire reef and all of these individual star corals are releasing at the same time, and then you're just swimming through what looks like a pink snowstorm of these gamete bundles.

It's really something to put on your bucket list.

I just remember being underwater for many nights in a row.

It's dark waiting for these corals to spawn.

And finally this huge star coral that we were monitoring just erupted in coral gamete bundle.

And at that moment, I think is when like, yep, this is it.

This is what I'm going to dedicate my career to.

And 20 years later here I am, and I'm watching the same species of star corals spawn but this time in my lab here in captivity.

And it's just, it's very overwhelming and humbling that we now have the technology to do this in captivity.

- [Michelle] The ability to have corals reproduce in the lab could have huge implications as corals around the world are being stressed by the effects of climate change and threatened by diseases like the mysterious stony coral tissue loss disease, which is currently working its way through the Caribbean.

- It just quickly kills some of these corals and we don't really know what causes it yet.

We don't know what the pathogen is.

And I have a feeling that this is gonna be the straw that broke the camel's back as it circulates around the Caribbean, because unlike some of the other disease, this affects over 20 corals.

And so it can devastate an entire reef not just one or two species.

And if we lose coral reefs, obviously it's gonna affect the global economy and it's gonna affect all of us.

- [Michelle] Coral reefs play important roles in the seafood industry, shoreline protection, ecotourism, and maintaining biodiversity in the ocean, not to mention their potential to contain medical compounds that we haven't discovered yet.

- [Nicole] Corals are in trouble and that's worldwide, particularly in the Caribbean, but even the great barrier reef has seen devastating decline.

- That's actually what caused all these corals to come into captivity.

And it was so bad that they're like, we need to start taking these almost seed banking them because they might all die out in the water.

And so we need to keep the population in captivity.

Phase two now is how can we start reproducing them?

How can we get them back out into the water?

And that's where we're starting to really jump in.

- [Michelle] Spawning corals in the lab will allow scientists to increase the genetic diversity of coral reefs.

- For the past, probably 20 years.

Most of the restoration has been focused on asexual fragmentation and taking a little piece of coral and then growing it out into a nursery setting, then they can out plant them to the reef and this is effective and it's a good way to restore, but there's no new genetic information that you're putting out in the reef.

The problem with that is that then all the different stressors that have led to choral decline are still gonna be there.

So you're out planting these corals into the same environment that killed the parents essentially.

With sexual reproduction what we're able to do is we're able to increase the genetic diversity with the hope that certain combinations of individuals will produce babies that might be more resistant to disease or thermal stress or certain pollutants.

And then those will be the future of the reef.

And that's where labs such as mine come in.

We can test these various factors on the earliest life history stages and see which of these environmental factors lead to coral death.

- [Michelle] Labs like Dr. Foggarty's need access to a lot of developing corals and getting them from the wild has its own set of challenges.

Corals only spawn once or twice a year.

And something as simple as bad weather can keep researchers from getting out on the reef at the right time.

On land researchers use aquarium technology to control temperature, salinity, wave action, and even the sun and the moon.

- These LEDs have really been super important and revolutionary because they can allow it to seem like the sun is actually rising.

So that's what I'm adjusting throughout the year for intensity.

And then on top of that, they also have their sun up and sun down cycles that they ran through.

Then we have these lunar lights.

So they're just these little tiny LEDs that run across it.

And they're super bright, but over the month, it'll go higher and lower in intensity to really show like a full moon versus a new moon.

And everything in between.

- [Michelle] Data from the wild is used to program these systems to make the corals feel like they never left the ocean.

- The computer just has inputs that you can set for everything.

Using data from South Florida, we made the seasonal variability.

That's when it starts to really think it's out in the wild still.

Usually we get to the point, we do our experiments when they're larvae, and then we put them back out in the water and they're done, but now we're like, okay, we have them, we have these aquariums, let's keep them going.

Let's grow them out.

We have an infinite amount of time with them.

And so we can keep cultivating and seeing how they work.

- Coral embryos are awesome.

No one has been able to look at coral embryos in this level of detail.

And so that's why this is super exciting.

And I got this text in the middle of the night.

She said, hey, I have these coral spawning.

And I came into lab and I was like, embryos, let's do it.

- [Michelle] Molecular biologists use specialized chemicals and equipment that can't easily be brought into the field.

- In this case, I've stained this with different stains, fluorescent stains, which label parts of the cell.

And so what we see here in blue, we see the nuclei, in red we can see the cell outlines and in green, these are the cilia that the embryo uses to swim throughout the water column.

This opens up the avenue to doing further experimental approaches that would be completely infeasible in the field.

Like genetically modifying these organisms or testing the function of different genes.

- [Michelle] And the more we can learn about corals, the more likely it is we'll be able to give them a chance to survive in the wild.

- In the end, we just need to really maintain genetic diversity.

So if a new emerging disease comes up or there's some other stressor that we have no idea, invasive species, some new pollutant that will have some corals are able to withstand it.

So what I like to remind people of is that we're not just spawning corals, but we're spawning hope that we can help corals recover naturally.

[upbeat music] - And just in case you're getting hungry.

How about some sourdough?

Sci NC producer Rossie Izlar cooks up all the Sci NC in that bread.

- In the beginning, there was sourdough bread.

It's chewy, airy, wholesome, humans have been baking it for thousands of years and sourdough bread wouldn't be possible without a mother dough also called a sourdough starter.

If you leave out water and flour for awhile, eventually wild yeast and bacteria will move in, we can thank these tiny organisms for making dough rise.

Without them sourdough bread would look something like this, but we really don't know much about the bacteria and yeast living in a starter.

And they have a huge influence on how bread tastes.

So scientists at NC State and Tufts University are trying to understand the secret lives of microbes, using little bits of sourdough starters from all over the world.

[upbeat music] First, let's go back to baking school.

Most breads you get from the store don't use a starter.

They rely on commercial yeasts to rise.

The kind you see in packets like these.

These microbes are good at one thing, making dough rise fast.

And sometimes that's what you want because baking is hard.

There's no dash of this and sprinkle of that in baking.

Here's what happened when I tried that method.

Mm.

But I'm going to make some sourdough bread because it's for Sci NC.

Here's how you do it.

You take water, you take flour, you add equal parts, water and flour to a bowl, put a blankie on it, name it something cute like goose.

And then you feed it flour and water every day.

Time to feed the beast again.

If all goes well, after a few days, the microbes are flourishing and your starter is ready to bake with.

They're basically like a very useful Tamagotchi.

And it's weird.

You sort of develop a fondness for these jars of fermented slop.

Some starters are hundreds of years old passed from generation to generation.

San Francisco miners supposedly cuddled their starters at night to keep them from freezing.

There's even a business in Stockholm that will babysit your starter when you go on vacation.

Josh Bellamy gives his starter credit for the success of his bakery.

- [Josh] There is something that's distinctly romantic for me about having used the same starter for almost every loaf of bread that we baked here.

It's a thread that runs through our entire history as a bakery.

- But if it died tomorrow, you could make another one.

- If it died tomorrow, I think it'd be pretty bummed.

I don't know.

I haven't even, I won't let that into my brain.

- It's clear we humans have a pretty intimate relationship with our starters, but how do they actually work?

A quick lesson on fermentation.

- Growing a sourdough starter from scratch.

It's like growing your own microbial garden.

The flower is your soil.

- [Rossie] This is Dr. Erin McKenney.

- We bow to the little ones.

- [Rossie] When you leave out flour and water, bacteria and yeast invade.

At first, the bacteria do most of the work feeding on the starches in the flour and creating a more acidic ecosystem.

- And then that clears the way for those yeast to move in.

They're producing carbon dioxide, which makes those lovely bubbles that make our bread rise.

- [Rossie] So we know the basic functions of these microbes, but not the more detailed information, like why does some sourdough taste different from others even when they come from the same ingredients?

Why can't I replicate Josh's sourdough exactly?

Is there something special about the microbes in his starter or on his hands?

So that's where the research comes in.

Erin and her team collected more than 500 sourdough starters from people all over the world and asked their owners some basic questions.

- What type of flower do you feed your starter?

How often do you feed it per day or per week?

Is your body male or female?

And if you are handling your starter and your bread dough, then you are imparting your own microbial signature into your starter and your bread.

- These types of factors could influence microbes in a starter.

And as a result, how your bread tastes, the team also sequence the DNA of the microbes in each starter to pinpoint what kind of yeast and bacteria are living in them.

I'm too late for the study, but I'm still curious about what's in my starter.

So Gibbs and I took a trip to the big city to get tested at NC State with Erin.

- This pipette, it really sucks just like a champ.

- [Rossie] Erin took a sample of my sourdough and then swabbed my hand to see if the microbes on my hand look anything like the microbes in my starter.

- [Erin] We'll go up in these crevices a little bit to see what you're hiding from the world.

- [Rossie] We checked back the following week to see what grew.

- [Erin] There's a really bright raised one in the very center of that plate.

That looks the same at one of the colonies that we saw in the starter.

Did Rossie pick up that bacteria from her starter, or did she give that bacteria to her starter?

- Get ready for the big takeaway.

And so it might seem like my starter and I have a deep relationship.

Erin and her team found that what we do to our starters, where we keep them, what we feed them.

All those factors only explain 13% of the data.

So basically, although we've been baking bread for thousands of years, our influence on microbes might only be a small part of why they behave the way they do.

Pretty humbling.

- So the next question was, if it's not about humans, is it about the microbes themselves?

So we're trying to get a handle on those different interactions at the microbial level, because maybe that explains the other 80% of the variation that we just have no idea about right now.

- If scientists can understand how microbes behave in a sourdough starter.

They might be able to unlock the secrets of microbe behavior in more complicated environments like stomachs, which have a huge influence on our health.

- Sourdough is like a stomach in a jar.

It's a wonderful model for a lot of more complex microbial communities.

- Okay and I did end up baking some sourdough bread.

This is how it turned out, but it's not my fault.

I'm blaming the microbes.

- And that's it for Sci NC for this week.

I'm Frank Graff, thanks for watching.

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Visit us online.

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