♪ - Hi there.

I'm Frank Graff.

You know, you can learn a lot by listening to bats.

A dangerous chemical is leaving its mark on alligators and sea levels are rising.

Will beach nourishment programs preserve the beaches we all love?

It's all coming up on sci-nc.

- [Narrator 1] This program was made possible by contributions to your PBS station by viewers like you.

- [Narrator 2] Additional funding for the sci-nc series is provided by GSK.

♪ - Hi again, and welcome to sci-nc.

You know, you ask residents and visitors alike, what they love about North Carolina's coast the top answer you'll likely hear, the beach.

The sand, the surf, the sun generate almost $2 billion for coastal towns.

But warming climate means sea levels are rising, storms are getting stronger, that's not good for a beach.

So PBS North Carolina is launching a new project looking at resilience in the face of climate change.

It's called state of change.

In our first story PLANTS producer, Michelle walked, looks at how beach nourishment is buying time for the coast, but how much time?

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

- There's never two years that are the same about our beach.

It builds up, it drops down, it gets ledges.

We've actually had it to where the people are pushed all the way up against the sand dunes.

It's just an, it's an unpredictable thing.

- We really enjoy being waterfront and seeing how it changes, how we lose sand, how we gain sand.

The bad part is, you know, when the hurricanes come, we're going to be the ones that get the first hit - That's part of living on a beach.

- One thing people who live on the coast know is that the only constant is change.

[thunder] Waves and wind move sand around daily and when a storm comes through, dramatic changes to the shape of the coast can happen overnight.

- The power of mother nature and what she can do to months and years of investment and movement and the power of the sea, combined with the power of a storm is surely astonishing.

- And with a warming climate bringing rising seas and more severe storms, the dynamic beach becomes even more fragile and unpredictable.

- Sea level is rising at a rate that, you know, we can deal with.

We could say that pretty, pretty definitively.

We're dealing with it by nursing beaches on the marsh, we're adding plants.

We could do seawalls, we could do all sorts of things that we haven't been doing.

And they've been, you know, working to a certain degree.

- [Michelle] For a beach town like Emerald Isle the toughest challenge is holding onto the beach that residents and tourists love.

The solution, 'feeding the beach'.

[hard rock music] ♪ - [Man 1] It's basically taking sand from outside the beach system and putting it on the beach.

- [Michelle] During beach nourishment, giant pumps siphon sand from off shore and discharge it onto the beach.

But it turns out you can't just dump any sand on the beach.

- I mean, sand is everything, but if you ask anybody what is sand you'll get a thousand different answers.

Sand is a very scientific term.

It's any grain that's between 1/16 and two millimeters.

And that's our kind of bread and butter.

Now, if it's finer then, you know, sand and has a very scientific term, it's called mud.

If it's above sands, it's called gravel.

You wanna match the native beach sand.

If you think about it, you take a bucket of mud and throw it out it's gonna ooze all over the place.

Well, you don't want the oozy stuff on the beach and vice versa.

If you take a bucket of rocks or gravel, it's gonna be really steep.

- And once you find the right kind of sand, you can't just dump it and forget about it.

Beaches are sculpted.

- We don't just throw the sand on the beach, right?

You have to contour.

You don't want the next little storm to come and take away a bunch of fine grain sand or mud that you put on the beach.

Hurricane Florence took away the incipient dunes, or as I like to call them my baby dunes.

So our job was to put back those baby dunes and then also provide the flat part of the beach and underwater part of the beach.

So that point, right there, is right where the old vegetation meets the brand new vegetation.

It looks kind of angular, like, just like I have a photo now, but, like, in a year, the dune plants will start collecting the sand and you'll have this nice, hummocky almost wavy type of feel like you do in the native area And I'll tell you another thing too.

Mother nature also likes this outer bar here.

That's part of the beach system.

We know that we're going to lose part of the towel space.

We're going to lose that as it forms a new outer bar.

- Precise measurements before hurricane season allow town officials to know how much sand was lost in the storm and how much remains.

Beach nourishment begins when specific thresholds for sand loss are met.

- We went almost 30 years without having a major storm, if you will.

And then all of a sudden the nineties came birthing Fran, Bonnie in '98, then we had Dennis one and two, it hit us twice.

And then we had Floyd.

So, you know, we saw with our eyeballs, I sort of saw what was happening, but we wanted to put neo numbers on it, and quantify how are we going to quote unquote, fix it?

So at that time we started what we call a monitoring program.

So we survey the beach from the top of the dune underwater.

- The rolling tripod is what they were using to measure the amount of sand, because the amount of sand that's at 10 feet deep, that matters too, how much sand is just right here off shore.

That's called the engineered beach.

Now we've got the numbers right here.

And as soon as the hurricane strikes, put that machine back, go again and say, we lost this much.

- The federal government will reimburse a community for sand lost during a specific storm.

- Yeah they do it just, you know, for that event.

Hence why we survey just before the hurricane season, because you know, we got that perfect snapshot.

- But who pays for beach nourishment when it's needed any other time of year.

- Carteret County, we have, when you stay at a hotel condo, you pay a 6% Oxy tax or bed tax.

That's a very common rate.

And half that goes to the sole purpose of ocean front beach nourishment, besides the Oxy tax, which is our kind of bread and butter for funding.

Each town has a little bit of a portion of their ad valorem property tax going towards nourishment as well.

- Why put so much money into something that could wash away with the next storm?

The beach fuels the economic engine with ripple effects across the state.

- Well, the beach is our lifeblood.

I mean, this is what this place is all about is, the beach.

- Tourism is one of the biggest industries in the state of North Carolina and beaches are one of the biggest attractions.

- If you think about it, we don't have a convention center.

We don't have massive hotels.

We don't got the Carolina Panthers or the Hurricanes.

We have the beach and we're, and we're up there with the big boys if you will.

- For now, beach nourishment and the plan to pay for it is staying ahead of the changes brought by a warming climate.

- I mean, people spend their whole year thinking about that one week they're here at the beach.

- We love going on the beach with the grandchildren.

We love walking on the pier.

We love walking all around the neighborhood.

- The fishing and the restaurants and the hikes that we take around, it's just a great place to be, you know, in the summertime.

- So from an economic feasibility perspective, unless there's an outlier in the future that we can't predict, an engineered beach for us at this point in time is strong in the future.

It looks even more prosperous.

- The question is how long will beach nourishment be able to keep up with a more dynamic coast?

And how long will we be able to afford it?

- We have to nurse every year, the same place.

Well then that's going to be sustainable.

Nourish the same place every three to five to seven years, we can do that.

- Moths come in all shapes and sizes.

Most people think of moths simply as insects that are attracted to lights.

Researcher Adrian Smith from the North Carolina Museum of Natural Sciences uses high-speed photography to show us moths in a new light.

- I think science is all about trying to see and appreciate the world in a new way.

So as a scientist, sometimes I think the most useful thing I can do is point the fancy science cameras at some moths and capture them flying in slow motion.

This one is a rosy maple moth.

One of the most colorful moths we have here in North Carolina.

And for me getting to see it like this up close and in super slow-mo is a special thing.

It's one of seven local laws.

I recently filmed and after spending time capturing each one of these, I think the way I see and appreciate moths is going to be different from now on, This is a polyphemus moth, a gigantic species of silk moth.

What you're seeing like all the rest of the clips here was filmed at 6,000 frames per second.

And the playback you're watching is around 200 times slower than real life.

Both of its wings have transparent windows.

And if you can catch a glimpse of the top side, you'll see how they're circled in yellow, blue and black form Eyespots.

This is my finger, and on it is what's called a Dark Marathyssa.

At rest, these moths are unmistakable.

Their wings appear rolled up and held down at their sides while their abdomens are flipped up and held above their bodies.

In flight, their abdomens still arch upwards and their unrolled wings, glisten and shimmer with a metallic like reflection.

Here's a Virginian tiger moth.

These shockingly white moths are distinguished from a closely related species by the splashes of yellow on their abdomen, which you can see when this one raises its wings in preparation for a flight.

♪ At rest, this moth tries its best to look like bird droppings.

It's common name is the beautiful wood nymph.

At take off, especially with the one on the left look for the cloud of dusty scales that it kicks up off its wings and body.

♪ While some moms might be pink and yellow, others have Mohawks and fluffy leg warmers, like this white dotted, prominent.

♪ And finally another big species with big eyespots.

A blinded sphinx.

For how big of a body this moth has, It's surprisingly agile once it gets into the air, going from vertically up, to head down and out of frame in an instant.

♪ If you want to see moths like these for yourself, one method you can use right at home like I did is attracting them with a black light.

Everything you just saw came to a set up just like this, just hang up an old bedsheet, string up a black light, and wait for the sun to go down, and the moths will start flying.

- Still in the air, but while moths are seen around lights, bats are not.

They are nocturnal.

And that makes it difficult to study them, unless you listen.

- When you're asleep, the skies are filled with multiple species of bats.

So we don't see them.

We don't hear them.

So those 17 species of bats are just sort of something that we don't really know about.

And what we do in my lab is we work to really understand what are all those different species doing?

- So to find out what the bats are doing, researchers at the University of North Carolina at Greensboro, listen.

- They are a very acoustic species and group of animals.

So what we do for all of our studies is we put out microphones all across the landscape so that we eavesdrop on them and we can study them by eavesdropping on those sounds.

- Well, they don't listen to bats in a traditional way.

Bats produce ultrasonic sounds.

That means the sounds are at a higher frequency than humans can hear.

- We typically set these up to record from sunset to sunrise because that's the time when bats are active.

So we can see that the box is there and the microphone is several meters above.

And that's because some of bats are really high flyers, some are low flyers, but this gives us an opportunity to catch more of the vocalizations of the bats that are passing through.

And what's amazing about these bats is that you can assign specific species to the calls that they make.

So each species produces a different type of call.

And so that is one way that we can understand the types of bats that we have in the area, and how often they come through here, we can understand when they are actually present.

- And they use those sounds to communicate with each other, as well as find their way by echo location.

The sound waves bounce off obstacles bats need to avoid and prey they're going to eat.

- Bats produce calls in the ultrasonic range, which humans are unable to hear.

However, using computer software, we're able to slow down that recordings and change the frequency so that way they're in the audible range.

So this is the echolocation calls and terminal buzz of a big brown bat played back at 1/8th of original speed.

[bird-like sounds] - So as you look at it, you could almost think the bat is looking, looking, looking oh, found something, found something, gotta find.

- Yeah.

Yes.

The regular echolocation calls are when the bats navigating and searching for food items, it's producing these calls and then it waits until it hears the echo of the previous call before it emits the next call.

And then when the bats getting a lot closer to an insect, the echos are going to be returning at a lot more rapid pace.

- Bats can be identified by their calls.

Each species is unique.

Researchers are also learning there are different calls for different situations, including avoiding danger and looking for a mate.

- So this is another call from a big brown bat.

[bird-like tweeting] So we have a search phase echolocation call, and then we have this social call, which is made of a rapid succession of down sweeps and then followed by a terminal buzz.

This call is actually used when two bats are competing over the same insect.

So another example of an evening bat social call.

[successive single tweets] - This is connected, and we're going to have a microphone go outside of this box.

That's good there.

I want to make sure the tripod is level.

- The research team with help from citizen scientists is collecting bat calls from almost 200 sites across North Carolina.

[static sounds] - This is how we passed the microphone.

Sometimes we use keys and to shake behind the microphone [keys jingling] to make sure to sound can travel around it and be recorded.

[keys jingling] - It's part of the Carolinas regional acoustic bat survey.

- We would put microphones across the landscape in urban, suburban, ex-urban agricultural areas, as well as very pristine areas.

Then we'd see which species are active when and how they are being active.

- So we can, we can learn if they're doing well, the range is expanding your state, or they're not doing well where their range is shrinking our state.

We actually found certain species are expanding.

They go to new places over years and some species unfortunately the range actually is shrinking.

- That bats are on the coast in bottom line hardwood swamps are different than the species that are in the mountains.

In the Piedmont, there's a mix of both of those species.

And in North Carolina, what all of those bat species are doing is just eating insects.

What they're doing really in terms of a service is they're controlling insects.

- Hey, parents, teachers, and home schoolers looking for lesson plans, you'll find free interactive ones about all types of sites covered by sci-nc online.

- Not far from the coast, alligators are found in swamps and marshes, and they might look healthy, but scientists are finding sores and infections on their skin.

It's a legacy from a dangerous chemical dumped in the state's waterways.

Science producer Rossie Islar explains.

- [Narrator] This is Greenfield Lake.

It's in the heart of Wilmington, surrounded by neighborhoods and busy city streets.

So it might be surprising to know that Greenfield Lake is home to lots of alligators.

And today scientists from NC State are reeling them in to see how they're doing.

[upbeat music] - [Scott] This one we can handle pretty easily.

So Andrew, why don't you c'mere a second?

We know where the hooks are cause those are what's gonna hurt us now at this point.

He is... he's got a lot of these open wounds here, - [Andrew] Mm hmm, a lot of little ones.

- [Scott] And he's skinny.

- [Andrew] He is pretty skinny.

- [Scott] He's not very healthy.

So if you wanted to come in here, these are some of the phenotypes that we've noticed here with a higher pressure is these infections.

Alligators usually don't have infections.

- [Narrator] The animals and people living in the Cape Fear River Watershed are still haunted by Gen-X, a pollutant that a chemical manufacturing company released in the water for decades.

Gen X is part of the PFAS family.

A group of chemicals that scientists are sounding the alarm on.

They're called forever chemicals because they don't break down in the environment, and they are in tons of consumer products from Teflon pans to waterproof boots to makeup.

The alligators at Greenfield Lake are downriver from the plant that manufactured and released those chemicals for years.

And that's why Scott and his team are checking on them.

- We're looking at levels of PFAS and looking to see if there's any health effects on the alligators.

Alligators are a really great model for us.

They have an immune system that's very similar to humans, they've been in the water now since the beginning of the PFAS manufacturing discharge in North Carolina.

And we think that's a really good historical model to look at for potential health effects.

- [Narrator] But before you can examine a gator, you need to catch one.

[baby alligator whooping] - [Scott] Essentially we take a big fish hook and we cast across the animal.

Usually bring it into shore with the hook kind of catching, it not too much further than just its skin.

- [Man] I have both.

[water splashing] - [Scott] Quickly secure their jaws.

[tape rips] - [Man] Good.

- [Scott] We can take a blood sample and then have them released usually within 10 or 15 minutes.

One of the key things that we do is actually minimize the stress.

So we work very quickly.

Could imagine that if an animal is caught in a trap that could really increase the stress of being restrained and all of this.

So we try to avoid that.

[alligator growls] - [Man] Shh, shh.

You're so big, I know.

[woman laughing] - [Man in Background] Help me cut this line.

[soft instrumental music] - [Narrator] Side note, that's me in the blue shirt, trying to figure out if I should be worried that the alligator seems to be coming towards me.

It all worked out.

Alligator blood can tell scientists how much PFAS chemicals are in the water and how gators are responding to them.

And so far things don't look great.

- I think one of the scariest things for me was seeing the really young juvenile alligator, where he had wounds that hadn't healed and knowing that alligator's wounds normally heal very, very quickly, you know that there's something wrong, especially for a young alligator.

- [Narrator] Erin and PhD student MaKayla Foster want to compare the levels of PFAS in alligators at Greenfield Lake to the gators at Lake Waccamaw, a more rural lake that isn't directly downstream from the chemical company.

- And so we're seeing much higher levels in the alligators that are near the point source as we would expect.

- [Scott] The animals at our exposed sites are in poorer condition than those that are, have the actually much lower exposure, to the ones at Lake Waccamaw.

- [Narrator] Of course it's not just alligators that are reacting to PFAS exposure.

These chemicals are ubiquitous in the U.S.

Most of us have it in our bloodstream.

Researchers found that exposure to PFAS can put people at risk for an array of health problems, including cancer, thyroid diseases, and immune disorders.

- Some people I think are still pretty unaware of the presence of PFAS around, so our goal is just to keep showing what we're finding and make people more aware of what's out there because the more aware they are, the more chances there are for change.

- Ultimately, we're trying to weed out the bad actors, if you will, there may be some in here that are perfectly safe and useful.

However, this idea of bioaccumulation and persistence is a hard one to get over.

We really don't want chemicals accumulating in the environment upon cumulating in the environment, upon cumulating in the environment, and then there forever.

- [Narrator] And in the meantime, Scott will continue checking on the alligators at Greenfield Lake.

- [Scott] It's certainly a thrill to be close to these extremely powerful and amazing animals.

- Here we go.

- [Woman] Bye, bud!

Miss you!

[water splashes] - And that's it for sci-nc for this week.

I'm Frank Graff.

Thanks for watching.

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Visit us online.

- Additional funding for the sci-nc series is provided by GSK.