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I'm Frank Graff.

Could a minnow help cure eye disease?

Using drones to protect North Carolina's sounds from climate change and why scientists hope returning fresh-water mussels to streams will help restore waterways.

They do a lot more than just filter the water.

It's all coming up on Sci NC.

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Think for a second about your eyes and how important they are.

Now think about these numbers.

The US Centers for Disease Control reports 12 million people over age 40 has some kind of vision impairment, and that number is expected to double.

But what if our bodies could learn the magic secrets of the zebrafish and repair those eye issues on their own.

- For humans, eyesight I would argue, is one of the most important senses that we have, right?

It's the way that we interact with our world.

It's the way that we understand what's going on around us.

It's a way that we communicate visually.

- But what happens if the eye issues that allow us to see are damaged?

Zebrafish could hold the key to slowing or even reversing eye diseases that affect millions of people.

That's because zebrafish are masters at regenerative medicine.

That's an organism's ability to repair damaged tissue.

- So regenerative medicine right now is a field of medicine where essentially we are trying to figure out how if a organ is damaged, so either cell death that's going on, tissue damage, how can we repair that?

- Humans obviously can't, we can't regenerate our eye cells, but these zebrafish can.

So I think by coming up with a method of regeneration and using zebrafish as a model, we could potentially translate that into the human eye.

We could potentially be looking at potential treatments for human eye diseases like glaucoma and macular degeneration.

- It turns out zebrafish can regrow a variety of body parts.

Researchers at High Point University want to learn how zebrafish can repair a damaged retina and restore sight in about a month.

- So in our laboratory, that's really the broad focus that we look at.

Can we take a tissue that has been damaged, take the healthy cells that are still in that tissue and instruct them then to make the new cells that we're going to need to repair that tissue.

- It's important for our research because we're using a model system right now that can completely regenerate.

So understanding that pathway, that's going to drive that process so that we can then move that up through higher animal models.

And hopefully then to the context of human health, that's what's going to be important.

- First though, a quick refresher of how the eye sees what it sees.

Light reflects off whatever you're looking at and passes through the outer part of the eye called the cornea.

It then goes through the pupil.

That's the dark circle in the eye.

The colored area is the Iris, which opens and closes the pupil depending on how bright it is.

Behind the pupil is the lens.

It adjusts So you can see things up close and far away.

Light is then focused on the back of the eye, which is the retina.

There are 130 million tiny cells that are sensitive to light lining the retina.

Those cells detect light.

They turn it into electrical signals and those signals go through the optic nerve to the brain.

It's those damaged cells lining the retina that the zebrafish can repair.

- We actually have a fish in this tank.

His name is Frank.

- A fish called Frank.

- Yes, a fish called Frank.

- We have an idea of how they do it.

There, there are steps.

So now we're trying to think of different ways we can trigger it and start that regeneration and then kind of work backwards and say, okay, well, how did they get to that point with what we're doing.

- So you can see the heart developing just.

- Oh right there.

- Yep, yep, yep.

So just, just below the eye, that is a developing heart and that's what's pumping, obviously the rest of the blood.

- The zebrafish is a minnow, but in the lab, it's a whale of a model system for studying tissue regeneration.

- So they have an external fertilization.

They have a transparent developmental cycle.

So you can see every single stage.

- Unlike mice models, zebrafish can develop rapidly.

And so the activity that you just saw there, is an activity called a spontaneous coiling.

And that is actually the first signs of motor development within a zebrafish and it's where the muscles and the nervous system are beginning to attach for the first time.

- Besides being easy to study, zebrafish express about 70% of the same genes as humans.

Zebrafish retinas are also similar to humans.

- We are looking at the developing [indistinct] so you can see it almost complete.

Oh, you just zoomed out.

- Scientists now believe glial cells are key to the zebrafish's ability to repair its damaged retina.

Glial cells usually provide support to other cells in the nervous system.

The glial cells make sure the system is healthy, but after the retina is damaged, glial cells appear to be reprogrammed and become replacement retinal neurons.

- So what that means is that it can revert from its matured, normal glial state, back into a cell that we consider to be developmentally a little bit unstructured and early.

So we call it a stem cell.

And then now what can happen is we can coax that cell to become any cell within the retina that we need it to become.

- This is a damaged retina.

Yes.

- And these images show those glial cells moving into position on a damaged retina.

- They're proliferating, they're growing.

And then they're going to differentiate and turn into the cells that are needed in order to repair the injury or whatever damage was caused.

All these little green dots, these are the new cells.

These are the [indistinct], the new proliferating cells.

- One of the interesting things about the stem cell right now is that we don't understand how it knows what to become.

We just know that it becomes what it needs to.

It's fascinating and it's fun and it never ends.

Right?

The question that you attempt to answer once you get there, just probes the next question.

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- You may have heard about the kind of mussels you can order at a seafood restaurant.

Mussels, salad, rice, little wine.

I'm getting hungry.

Well, it turns out there's a freshwater version of those mussels and you probably shouldn't eat those.

Freshwater mussels are endangered.

They are a crucial part of the ecosystem.

Science producer at Rossie Izlar has the story.

- If you want to know how clean a North Carolina river is, put on a snorkel and look for mussels.

No, not these kind of muscles, the mussels I'm talking about live at the bottom of rivers, burrowed in the substrate.

These humble bivalves filter water and anchor the river bed.

And that's why I'm wearing a wet suit and sticking my head in the freezing Cheoah River.

Because after years of nurturing, we're setting these babies free.

- The question we always get is, you know, can you eat them.

And for most of these, you probably can, but I wouldn't recommend it.

- Yeah, you don't want to eat mussels because they're endangered.

30% of mussels went extinct over the last century.

And 65% of the remaining species are threatened or endangered.

We have a long history of harvesting freshwater mussels.

We made buttons with their shells and removed them for pearls.

But today it's impaired rivers and streams that are threatening mussels.

- If you've been lucky enough to actually come in contact with a freshwater mussel in your life, it's an indication that that river is in pretty good shape.

- Unfortunately many rivers in North Carolina aren't in great shape.

Mussels don't like fast-moving, dirty water and rivers end up on the receiving end of polluted stormwater runoff.

Healthy rivers also have fish and mussels need fish.

That's because mussels spend a part of their lifecycle attached to fish gills, and how they get there is a stroke of evolutionary genius.

Mature breeding mussels release a part of their flesh called a conglutinate to learn fish and to taking a bite.

The conglutinate forms a lure, which looks incredibly like a small fish or an insect.

Every mussel has their own unique lure.

Some look like crayfish, some look like insects, anything to tempt a predator fish into taking a bite.

For example, this mussel releases a lure that looks almost exactly like a shiner fish hovering on the river bottom.

So a predator fish like a bass will pounce on the lure, triggering the mussel to release its larvae, which attach to the fish's gills.

The baby mussels poach the fishes nutrients for a few weeks before dropping off in another part of the river.

- They don't harm the fish.

They just kinda hitch a ride like a parasite, like a tick.

- But because mussels need fish to complete their life cycle, it makes them even more vulnerable When rivers are dirty or unstable.

- Many of you've seen this, your rivers running like chocolate milk.

And it's really dirty looking.

Most of the interactions with the mussel and the fish are visual.

And so if the fish can't see the mussel to interact with it, it becomes really challenging for that interaction and them to complete their life cycle.

- But if we can't eat mussels and we don't need them anymore for buttons, why should we care?

Because mussels are kind of like the oysters of the river.

They can clean water better than a wastewater treatment plant.

They also stabilize the river beds by anchoring into the substrate, preventing critical habitat from being washed out after a big rain.

They're kind of the core of an ecosystem.

And they act as a really good indicator of a healthy functioning ecosystem.

- To have a functioning ecosystem, you need mussels, and they're not as common as they used to be.

Rachel is trying to change that by raising baby mussels in the thousands at a hatchery in Marion, North Carolina.

- So we're collecting the larvae, the glochidia, and then we're going to take them down to the other part of our hatchery to propagate them.

So you know, this species is really imperiled.

It's very rare and it kind of needs assistance.

- The hatchery basically bypasses the luring stage and puts mussels in direct contact with fish so they can feed on the fish's nutrients.

They drop off the fish gills after a few weeks and the team moves them into a larger tank.

And at every step of the process, Rachel and her team count living baby mussels to see how they're doing.

- There's probably 10,000, two-month-old mussels in here right now.

And it really makes me think when you see the bottom of a river, that there could be thousands of mussels in there that you just don't see.

- And you can see they've got really dark, healthy guts.

So they're starting to eat the algae that we feed them and they're cruising around.

- And when they get big enough, Rachel and Luke put on wet suits and release them in the wild.

the Cheoah River is downstream from a dam built in 1926.

And for close to 80 years, it cut off the natural flow of the river, decimating mussels and other river creatures.

But today the dam now releases enough water to mimic a natural river and mussels are thriving here.

- It's great that we have a place that we can put them they're actually happy.

- The team, plants mussels in areas where they think we'll do well.

Clear waters, not too deep, not too shallow.

- What does it feel like to come out here and be like, whoa, that's one of our hatchery mussels?

- It's really amazing.

I'm just like laughing.

I like seeing them all in the lake, we did it.

There's my babies.

They're all here and they're growing up and they're having babies of their own.

And I'm a grandma.

- When you're putting a species back that hasn't been there for at least 100 years, probably 200 years, you know, it's you feel like, I mean, you really feel like you've, you're actually doing something.

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- It is pretty impressive when a scientist names a new species.

Adrian Smith at the North Carolina Museum of Natural Sciences, introduces us to a researcher who has named a new species of crayfish every year.

- This person with their head in a muddy hole is a crayfish biologist.

She's digging for a burrowing species, something that's right now known as a sickle crayfish.

- Whew.

I've lost the hole big time.

- They're not the easiest thing to catch.

- All right.

This burrow is.

Try the water trick on this one.

If this doesn't work, then.

There we go.

There are 48 named species in North Carolina.

Given what we have discovered over the last couple of years, we probably have doubled that number.

- Bronwyn Williams is on a mission to discover and preserve North Carolina's invertebrate biodiversity.

I caught up with her to learn about her research and collections work on these animals.

- Specimens that I collect when I'm in the field, ultimately end up back here in the North Carolina Museum of Natural Sciences, non-molluscan invertebrate collection.

They're fixed, they're housed in, in, in ethanol basically for, you know, long-term, I hopefully forever storage.

Okay.

So we're now in one of the three major collections ranges or rooms.

Out at the research lab, the museum, this area is sort of dedicated to the non-molluscan invertebrates, which include all of the crayfishes.

The idea of being stewards of this collection is to make sure that we sort of care for and maintain these for permanent use.

If we cycle back around kind of, these are more foothills and Piedmont crayfishes.

And some of our many, we are currently working on crayfishes over on, on sort of this side.

When a species is described, so let's say we were to take one of these sort of known undescribed species back there and describe it.

You designate what's called a type series, which are specific individuals that you use that are sort of designated as the examples of what that species is.

And we have several hundred of these, these type specimens of crayfishes that we keep in fireproof cabinets under lock and key.

They're that valuable.

So this is one of two type cabinets as fireproof cabinets that we have here in the non-molluscan invertebrate collection.

[doors open squeakily] This one houses most of our crayfish-type specimens, which are kind of in these four shelves.

And one of the specimens that I'm particularly proud of is this one, it's the South Mountain's crayfish.

This is the [indistinct] type which I helped describe in 2019.

It's only found in a state of North Carolina and primarily kind of in, and just outside of South Mountain State Park.

I'm interested in crayfish for the sake of crayfish, but also all of the other organisms that basically live on the crayfish.

I study a group of worms that are closely related to leeches and a group of ostracods or seed shrimp that are obligate inhabitants of, of crayfishes.

Different species are actually sort of found on different parts of the crayfish.

Sometimes you'll find them in the gill chamber.

Sometimes they'll be between the bases of the walking legs or on the claws.

And sometimes there'll be very, very visible.

You'll have one that's right on the rostrum or that nose-like projection.

My goal with my research with this work is to ensure that the entirety of the biodiversity of crayfishes in this state is adequately conserved.

I think a subsidiary goal is to have people get really excited that we have such a diverse, you know, group of organisms that literally are in our backyards.

So right now this is considered the sickle crayfish, but let's say in another two or three years down the road, once our work is completed, this will become probably the newest species to be described from North Carolina, which is pretty neat for having something like this sort of in the outskirts of Charlotte.

So there's a lot left to discover.

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♪ - Drones aren't just a novelty anymore.

sure you see the images in movies and videos, but drones are used for bridge and power line inspections, farm surveys, disaster response.

Well now Elizabeth City State University's drone program is using the aerial platform to protect one of North Carolina's sounds from climate change.

- That one, just hold it, just go up on it.

[explosive noise] It'll speed up.

So it goes up.

[drone buzzes] - The payload on the drone is what gathers an imagery.

Like a drone can fly, but if you don't have the right camera, then that data is of no use.

- Drones capture beautiful images, but the work that Elizabeth City State University's drone technology program is doing in Currituck Sound is about more than just pretty pictures.

- Now, we got a chance, an opportunity to actually work on a conservation project.

- Kuldeep Rawat is flying the drone program into new territory.

- Well, I got interested personally into drones because my background is in engineering.

- Rawat builds drones, pilots drones, designs the software and hardware payloads that drones carry.

This is what we call it an experimental quad-copter.

- That cage allows an experimental quad-copter to be safely tested and flown in the lab before taking it out in the field.

- You can see it has these four propellors here and then the heart of this quad-copter is this high processing computer that can process the data coming out of the sensors that you put in here.

And it can also send a signal out to these speed controllers to actually control the speed of these motors.

- Different models of drones and different payloads are adapted to fit the needs of each project.

- There are 400 different applications that you could actually use a drone.

- Now the drone team is partnering with the Audubon Society to survey Pine Island in Currituck Sound.

The society has a refuge there.

- Pine Island sanctuary is a 2,600-acre sanctuary that we manage and protect, and it's located in the wildest corner of the Northern Outer banks.

And it also happens to be a globally important bird area.

Like I said, the sound is one of the most important places in the entire hemisphere for birds.

And that includes 96 species that Audubon has identified as being climate threatened.

- So one of the projects that we are doing in the Pine Island is to look at the changes in the shorelines.

And then we can compare that data with satellite imagery maybe 20 years back.

And we can make that comparison.

- Drones will also be used to map the marsh vegetation around the sound.

- What kind of vegetation is there.

And so we will be using some multispectral and hyperspectral sensing technology put on the drone to actually figure out what kind of vegetation is on Pine Island.

Every vegetation is going to absorb and reflect light differently and based on what, what is absorb and how does it reflect it?

I can measure that, that sensor would measure that and tell me why this vegetation is different from the other vegetation.

And so once we get all that imagery, we will have to then bring that imagery to the lab here and then use, you know, sophisticated software and actually look, stitch that all that imagery together, and then basically be able to analyze it and tell, okay, what kind of vegetation is up there in Pine Island.

- They're doing this in a big, huge area with the bigger drone so they can see a big map.

And then when they go down and use smaller drones, they can really see up close and what's going on.

- And based on the size of the area, we want to cover, I'll program that parameter in.

It will automatically calculate how far to space my tracking so it could cover that amount of area plus get the correct overlap on the photo images so we can stitch all these, these pictures together and give me the data that I need.

It's back and forth repeatedly, where I'll have a front and back overlap for each image.

And on the next track or leg, there has to be a side-to-side overlap for each image.

What the processing software does is, it'll look at identical pixels from multiple pictures.

From that it can tie them together in what we call a stitching, an orthomosaic.

- Currituck Sound is about three miles wide and roughly 42 miles long.

It stretches from Kitty Hawk at the sound end to Back Bay and the Virginia border at the north end.

It's large, but also very shallow.

Most of the sound is only one to three feet deep.

In addition, Currituck Sound is not a tidal estuary.

There are no lunar tides like the high tides and low tides found at the coast.

Wind tides rule in Currituck Sound.

I would think that would ease the erosion concerns.

It doesn't sound like that's the case.

- Those tide events, I guess we really would refer to them more as water level events.

So when you have a wind coming from the north, what happens is the water gets all blown out of the sound.

And then you have winds blowing from the south, obviously water is blown up into the sound.

So you have this higher water level and that change in water level, which happens actually fairly rapidly often in the sound, actually has led to increased erosion of the marshes.

And so part of what this project will allow us to do is take a closer look at what the current state of those marshes is.

And then compare that to past imagery that we have and get an understanding, okay, what is the actual change that we're experiencing and how can we address some of that?

- So when this opportunity with other one came, in a little while, this will be really great to use drones in conservation projects.

This gives me opportunity to actually go out and actually apply it to a application that you know is for benefit of the society.

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

I'm Frank Graff.

Thanks for watching.

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