- Just ahead on "This American Land"... crabs, oysters, and climate change.

The folks on Maryland's Smith Island have depended on the bounty of the Chesapeake Bay for generations.

- The Bay is right in on us, and it is a very bad problem.

We really need help with the erosion.

- Will sea-level rise change their future or their culture?

- Now they're often one foot or one paw ahead of us.

- Nature's most clever builders get a boost from artificial intelligence.

- EEAGER stands for Earth Engine Automated Geospatial Elements Recognition Model.

- [laughs] This is AI.

- Yes, this is AI but for beavers.

- What beavers can teach us about fighting floods, droughts, and wildfires.

We've got plenty of stories you can sink your teeth into.

[dynamic music] ♪ ♪ - Welcome to "This American Land."

I'm your host, Ed Arnett.

And in every episode, we'll meet some of the scientists, artists, farmers, and storytellers who cherish our natural resources and inspire others to do the same.

There's only one way to get to Smith Island in Maryland, and that's by boat.

First settled in the 1600s, families have made their living here for generations, harvesting crabs and oysters from the Chesapeake Bay.

We visited this area back in 2011, when discussions of sea-level rise were just gaining people's attention.

What's happening now?

The waters are still rising, and many young people over the years have been lured away to jobs elsewhere.

But when our team returned, they found out this is a community that's resolved not just to stay but to grow.

[indistinct chatter] It's a 50-minute ferry ride to Smith Island across the Chesapeake Bay's Tangier Sound.

You have to squeeze in next to locals, tourists, and all the mail and packages headed to the island that day.

[light music] And when you step off the boat, it's a bit like stepping back into time.

- There it is.

- Thank you, Will.

- As anyone who's visited Smith Island will tell you, it's a special place.

♪ ♪ Its nautical vibe and slower-pace lifestyle hark back to a simpler era, as our reporter Natalie Pawelski found out when she visited here in our first season.

- First settled in the 1600s, there are 200-some people living here now, down from about 800 a century ago.

Everybody knows each other.

There's no jail and no police force.

- Back then, she introduced us to a community of people who were hopeful that they could stay on their island and preserve their way of life, even in the face of dire predictions regarding sea-level rise.

Scientists say the Chesapeake Bay will likely get 1 to 2 feet of sea level rise by 2050 and more than 4 feet by the end of the century.

So what did we find that changed in the 13 years since our first story?

Hope for the future is still very much the order of the day.

But in the last few years, Smith Islanders have also gotten organized and down to business.

♪ ♪ - My name is Mark Kitching.

I was born and raised on Smith Island.

My father and grandfathers were all watermen.

- For many generations, life on Smith Island has revolved around the work of the watermen, men like Mark who make their living harvesting oysters and crabs in the Bay.

- Currently, there are six people on the island doing the work that I'm doing right now-- crab scraping that is-- in the summertime.

Originally, when I started, back in the mid '80s, it was roughly 50 to 60 crab scrapers.

- Mark says the community got a big wake-up call in 2012, just after Hurricane Sandy caused wide destruction along the mid-Atlantic Coast.

At the time, Maryland state officials offered to buy out some homes on the island, with the condition that the property never be occupied again.

- As a community, as an island, as a group of people, we didn't want that to happen to our island.

You know, we have ancestors here.

And all these homes on Smith Island were built by watermen families.

- That was the genesis of Smith Island United-- a nonprofit they put together to preserve the island's culture and economy.

Mark is the group's vice president.

- We started talking with government agencies, working with government agencies on all levels--federal, state, and county levels.

You know, we started looking for projects.

- Erosion control was first on the list.

The U.S.

Fish and Wildlife Service came in and built a living-shoreline project to protect marshland in the wildlife refuge along the northernmost part of the island.

The Army Corps of Engineers put in jetties to stabilize the shoreline.

And with support of the U.S. Department of Agriculture, a new wastewater treatment plant is going in, along with new sewer systems.

They've razed roads that previously were prone to flooding, and telecom services got a big upgrade.

All in all, Smith Island has become a more comfortable, convenient place to live in the last decade or so... Perhaps, even a good place to move.

Here, price can be a selling point.

Some homes go for less than $100,000.

- A typical buyer just really wants to escape the chaos of the mainland.

- Laura Evans is the island's resident real estate agent.

Inventory is not a problem.

As people have moved off the island in recent years, homes were left empty.

- If I can just bring one or two really nice families in, just to make a change, to move in some of these neglected properties, take care of the grass, have some lights on, fix the house up, put a little love into it, I would be thrilled.

- One new resident is Cori Ertha-Fukuchi, a martial arts enthusiast and former teacher who bought here a couple of years ago.

- I needed an affordable house.

I needed a house that I could pay off all at once.

- With its open floor plan and high ceilings, the old schoolhouse in the community of Tylerton really fit the bill.

It's the perfect place to practice her aerial arts, and her new neighbors made her feel really welcome.

- Living here, from a community standpoint, it's been pretty amazing.

And the difference between living here and living on the mainland is that people have to live with the things they say and do, so they watch what they say and do.

- Shanon Abbott and her family are also newly minted Smith Island property owners.

- We're known as come-heres-- is how they affectionately refer to people who are not born, you know, on the island.

- The Abbotts are investing in new construction on their property, replacing a trailer with a new house and extensively renovating an old waterman shanty and dock.

She says she immediately fell in love with the people, and all the infrastructure upgrades really sealed the deal for them.

- That is what made us decide that we would live here.

I mean, we have invested our life savings.

This is going to be our life now for the next however long we're still on this Earth.

- So things seem to be looking up on Smith Island.

But what about the sea-level rise?

Mary Ada Marshall has lived on Smith Island all her life.

Mary Ada is something of a local celebrity, known as one of the premier bakers of the Smith Island cake.

It's the official dessert of the State of Maryland and one of the island's big tourist draws.

She whipped one up for us and talked more about the tides.

- The Bay is right in on us, and it is a very bad problem.

We really need help with the erosion.

I can see a change even this past year because we've had so, so many high tides this year.

- Still, she was like most people we talked to on the island.

By and large, they don't think the worst-case scenario will come to pass.

- I feel like as long as the Lord's got His hand on us, we ain't going nowhere.

That's how I feel.

- Hilary Harp Falk is the president and CEO of the Chesapeake Bay Foundation-- a group that is working for the restoration and protection of the Bay.

They run an environmental education center on the island.

Smith Island holds a special place in her heart, and she's been coming here since she was a child.

- There's a saying-- when people come visit that you get the mud between your toes.

And that means that you take part of Smith Island with you when you go.

And I certainly have gotten the mud between my toes, and many other people have as well.

- She and her group struggle with how to balance hope for the well-being of this special place with the harsh reality of the global climate problem.

- I think we can continue to support coastal communities and the people who live here to look at solutions.

Even if they're near-term or imperfect, I think there's more we can do to support places like Smith Island, who are really grappling with issues of sea-level rise.

- From headache to hero, beavers are gaining new respect in their role in creating healthy ecosystems.

And now one researcher is even using artificial intelligence to find where nature's engineers are working their magic.

Brad Hicks shows us how beavers have hit the big-time.

- The path Emily Fairfax has taken to get to this pond... - This is a beaver canal.

This is one of their water highways.

- Is as winding as the canals through these Colorado wetlands.

- I worked at the National Laboratory as a weapons-system engineer.

I wasn't really feeling that job.

And a documentary called "Leave It to Beavers" came on TV, on PBS... and I was absolutely hooked.

- She is now one of the leading beaver experts and advocates in America.

- I study beavers all the time.

Like, that's my jam.

- And she is leading us to a beaver pond that best illustrates why she has never looked back.

- We're coming up on the main beaver dam.

These are super, super-solid structures.

We've got moose that walk across these all the time.

Speaking of, keep your eye out for moose.

They like this site.

One of the ways we can tell that this is a very active site still is really fresh packed mud right on the dam.

And they pack it on with their little hands like cement, and they leave it there.

- Mm-hmm.

- We also know it's active because we've got a very freshly chewed log here.

I won't change their engineering plans, so I'll leave it there.

- The entire area is an engineering marvel.

The dam, 400 feet long and capable of holding back an enormous amount of water.

The pond, with its network of channels on the bottom and spots to stockpile fall foliage they weigh down with stones for when the water ices over in winter.

The lodge where they live, with distinct rooms for different activities and underwater entrances so they can come and go unseen.

[drone whirring] And the surrounding wetlands with that road map of beaver-made boulevards that take them to food sources and act as escape routes.

She has brought us here not just because it's a healthy beaver habitat, but because it holds a valuable lesson for humans.

It sits at the center of the 2020 Cameron Peak Fire, the biggest wildfire in Colorado history.

- Which you might not notice looking around because everything is green.

The beaver lodge looks fine.

There's pine trees with all their needles on them.

But if you look at the hill slopes, everything around them is burnt.

All of the ponding water, all of the canals moving water around, all of the tree chewing, which thins the foliage, that's what makes this so fire resistant.

So it's really important to know where the beaver ponds are so that we can build off of what they've already done.

And for a long time, to do this, we would manually find all the beaver ponds.

We need to be more nimble than that as scientists, because right now they're often one foot or one paw ahead of us.

- So now she is using artificial intelligence to pinpoint the beaver ponds.

We'll see how she does it in a moment.

But before we go high tech... - You can try it.

- A little low tech.

[motor whirring] In Southern Wyoming, just west of the Continental Divide, where beavers once crowded a place called Muddy Creek, they want to bring the beavers back.

♪ ♪ - We're trying to correct historic damages that have occurred within this watershed, many of them man-made.

- So Trout Unlimited is building, as best they can, beaver dams.

[tools pounding, whirring] - As you build it, we can actually watch that water level go up.

- They're called Beaver Dam Analogs, or BDAs, replicas that can help rebuild riparian habitats.

- We want to create kind of the beaver starter kit so they have some deep-water habitat and add to the dams that we built.

And then, essentially, they're going to be the caretakers of these projects.

[saw buzzing] - Some people watching may say, Trout Unlimited?

You're trout people.

What are you doing with beaver stuff?

- We're clean-, cold-water people, too.

So if we're doing good things for clean, cold water, then we're going to be doing good things for trout.

[water rushing] - As the benefits of beavers become better understood, BDAs are being built all across the West.

In addition to forming a natural firebreak, the ponds and wetlands are a refuge for other wildlife during fires.

They create climate resilience by storing water in the landscape, mitigating both floods and drought.

The slower flows filter water as it moves downstream.

And scientists are beginning to appreciate the key role they can play in carbon capture.

But it's not as simple as just putting BDAs on any old stream.

♪ ♪ Near Telluride, Colorado, ecologist Alli Vitello is searching for the perfect places to put BDAs.

[cattle mooing] - Site selection for these restoration projects is pretty critical to their long-term success.

So that might be a relic structure over there.

- The San Miguel Watershed Coalition wants to embrace beavers and use BDAs to help bring things back to how they used to be.

- Just finding the right site to do this type of work has been definitely a challenge.

- Having the relic dam is super useful because you can mimic the beaver even more when you kno where they've been.

It's only appropriate to do beaver-based restoration in locations where we believe beaver historically occupied.

- But finding beaver dams, whether old or in use, isn't always so easy.

At the University of Minnesota, Emily Fairfax has pioneered a better way to plot them.

- And you might think, okay, mapping one dam is easy.

But in some of these places, it's not one.

It's not two.

It can be thousands and thousands of beaver dams in a single watershed.

And we would do this all by hand.

- So this is what made you say, there's got to be a better way.

- Yeah, we realized that we were spending all of our time mapping out these beaver dams, and we should be spending that time understanding how the beavers are actually changing the landscape.

And so that's why we built the EEAGER model.

- EEAGER, like, eager beaver.

- Mm-hmm.

- And what does EEAGER stand for?

- EEAGER stands for Earth Engine Automated Geospatial Elements Recognition model.

- [laughs] This is AI.

- Yes, this is AI but for beavers.

- They wrote code so the computer recognizes features unique to beaver habitats.

When it makes mistakes, it learns from those mistakes.

EEAGER can now do a month of work in minutes with high-confidence predictions.

- It's surprising how fast the machine can learn sometimes.

And the model is getting smarter and smarter and better at finding the beavers.

- What do you hope will come from it?

- What I really want to do is find more and more examples of patches like this.

It's only very recently that we've really seriously thought about the fact that beavers are preserving thousands of kilometers squared of area during wildfire.

And I really hope that by showing over and over and over again how powerful beavers are, that people appreciate them more and really think about what it means to manage beavers.

You're not just managing an animal.

You're managing an entire ecosystem.

[guitar music] - The largest wetland ecosystem in the United States is getting some help restoring its forests and stream habitats.

Since 2017, the Lower Mississippi Alluvial Valley Restoration Fund has helped provide more than $25 million in conservation support.

These projects are enhancing forest habitat in an area that covers millions of acres across seven states.

It's reducing flooding, sequestering carbon, and creating more hunting and fishing opportunities with help from private landowners.

Here's a look at some other efforts to restore these wetlands.

[light music] ♪ ♪ - The Lower Mississippi River Valley was traditionally a large, forested wetland complex.

The whole entire valley is low, and it floods frequently because of the Mississippi River and its tributaries.

My name is Ron Cease.

I work the Lower Mississippi River Valley for the Nature Conservancy.

So bottomland hardwoods are the long-term vegetation that's adapted to there.

- Bottomland hardwoods are different species of oaks and cypress that are very hard in nature compared to a softwood like a pine.

My name is James L. Cummins.

I'm executive director of Wildlife Mississippi.

But these species provide many nutritional benefits in the form of acorns and mast that a diversity of wildlife feed upon.

- There's over 25 million acres in that valley, and the vast majority of it has been cleared for agriculture.

And so not only did they take away the forested wetlands, but then they altered the hydrology.

So we don't have those natural wetland functions like we used to anymore.

♪ ♪ - Part of the problem was land that was not good farmland was cleared to be farmland, and it was not profitable.

- This is Louis Fertizzi of Fertizzi Nursery, and Louis has been planting seedlings approximately 30 years and planted over 100,000 acres.

- Cypress trees here, you're looking at-- farmers were going out of business.

So they'd come and spend two or three years here farming, and then they'd be out of business because water would get over it.

These are all hand-planted.

That all is a lowland species.

This is over cup.

- Something besides an oak tree.

- Ducks feed on these acorns.

We're trying to put forest back where forest ought to be and not cropland.

♪ ♪ - In the early '90s, the Wetland Reserve Program was created by the United States Congress.

The program actually pays an easement payment to the landowner to help offset agricultural production costs.

It also helps pay for restoration of wetland and bottomland hardwood habitat.

♪ ♪ [indistinct shouting] - The federal government will restore those properties.

So it's basically planting back those bottomland hardwoods and developing those wetlands again.

So, in our three states that we concentrate our work in, in Arkansas, Louisiana, and Mississippi, there's been over 700,000 acres that have been enrolled into the Wetland Reserve Program.

- By really looking at using some of the best agricultural land to produce commodities and some of the worst land for producing wetlands, we're actually helping the farmer and their overall profitability, improving the health of the overall agricultural economy in the region.

Ducks Unlimited has a great statement.

It's, "farming the best and conserving the rest."

And that sums up what we're really trying to do here out on the landscape here in the Lower Mississippi Valley.

- Land that's not as productive that I'm seeing losses on, I can turn it in to wildlife habitat conservation, and I'm seeing it productive.

This tree right here, I think, is 38 years old-- that I planted right here.

I'm still planting cypress trees in this break today.

My name is Bo Prestidge.

I'm a farmer.

I'm a wildlife conservationist, and I live in Itta Bena, Mississippi.

So I got cypress trees from knee-high up to 40 feet high.

I was taking land that some people called wasteland.

Well, there's no such thing as wasteland.

You just got to find out what it's needed for and what to do with it.

So I took land that was not developed that you just could not produce on and you couldn't do those things, but it was great for wildlife.

So what I saw was an opportunity with Wildlife Inc to let people use my property.

I started a commercial duck-hunting daily-rate business.

This deer right here came from my own property.

And I had no idea it would grow to what it did.

So what it does by developing my wildlife habitat, it lets me maximize my land.

- Our thought process is, let's restore those lands, get those ecological functions back.

And a lot of times, this allows that farmer to, you know, stay in business, because he was losing money on the lower land.

He can take and put that land into the program.

He can get some additional economic benefits if he, you know, leases that land for hunting or sells hunting rights on that.

[dramatic rock music] ♪ ♪ - There's some deer right there running.

When I started here, there was significant more income from farming than it was from recreation.

But in our 12th year of business, now our recreation money is more than our agriculture money.

My name is Drew Keith.

I'm the CEO of Honey Brake Lodge LTD here in Jonesville, Louisiana.

The total acres of the property we own is right at 20,000 acres.

And it's 9,800 acres of Wetland Reserve Program.

Because of the habitat, the wildlife is thriving now.

The highlight of it is the 2,766 acres that we're looking at putting in WRP.

The biggest incentive for landowners is the government will pay you a marketable price for your land to put the perpetual easement on it to restore it back to its original habitat.

- We'll work with you.

We'll develop a restoration management plan.

- Y'all ready?

- For us at Honey Brake, the incentive, you know, was to put it in the WRP program and then be able to enhance it and use it to introduce people to the outdoors in a positive way.

[duck call sounding] So the programs that we run, from alligator hunting to deer hunting to waterfowl hunting, you know, the program helps us focus just on wildlife.

- When we as a nation think of the Farm Bill, most people think about something that provides help to the farmer in terms of crop assistance.

But it's also the single-largest private-lands conservation program in the United States.

[soft music] Wetland Restoration provides benefits for citizens throughout the United States.

These bottomland hardwood trees are sequestering carbon.

The improved water quality that we're seeing as a result is benefiting the Gulf of Mexico, which is, in turn, improving seafood for many, many Americans and drinking water as well.

[engine turning over] - It's great to see, you know, the landowners voluntarily making the decision to do this because we're getting conservation on private lands.

They still own that land.

And it's a great win for our society in total because of the water-quality impacts and the wildlife habitat and the migratory birds that use those lands.

It's affecting, you know, this whole region and this nation.

[guitar music] - Now here's a look at some stories coming up on our next show.

- What we're doing here at the Science Center is educating a mile a minute.

We believe once you can connect, you can care.

And once you care, you can make change.

- Protecting the North Atlantic right whale-- some urgent changes are in the works to keep these gentle creatures from extinction.

- That's our show for today.

We'll see you next time with more stories about the dedicated people working to conserve and defend all of our public lands and natural resources.

- And you can watch us anytime on PBS Passport.