(upbeat music) -[Carlee] Up next an ancient fish fighting to survive in the modern world.

Field notes with Kirk Steffensen.

And I'll take you behind the scenes at the Omaha Zoo's Amphibian Conservation Center.

I'm Carlee Moates.

Welcome to Conservation Works.

(gentle music) (water running) (gentle music) (nature sounds) -[Narrator] This ancient looking creature is the pallid sturgeon.

Sturgeon have thrived in North America's open waterways for over 70 million years.

But today, in the Great Plains along the Missouri River, infrastructure for flood control and shipping have compromised the survival of this species and climate change may be making the situation worse.

(water rippling) -[Gerald] The ecosystem is in trouble on the Missouri River.

It's not the pallid sturgeon is in trouble.

The Missouri River flooded very infrequently prior to us channelizing the river as we narrowed the channel of the river to deepen it for navigation, flood heights increase and flood frequencies increased to the point where we were at today, where in certain parts of the river it floods every year.

(gentle music) -[Narrator] In 1933, the US Army Corps of Engineers began building a series of dams in the Upper Missouri River basin for flood control.

Then the lower half of the river system was significantly altered.

(gentle music) The stream bed was narrowed to a deep, serpentine waterway that sped up the current to keep sediment from clogging the navigation channel for the shipping industry.

The dams have generated enough energy to power more than 1.2 million households for a year.

But the changes took a toll on the river ecosystem, including the pallid sturgeon population.

Over the years, it became rare to catch one.

-[Wayne] What they were capturing was older fish, all older fish, never the small, young juveniles, teenager type pallids.

And so there was a major concern about, are we going to have this population go extinct because we're not seeing natural reproduction.

-[Narrator] Biologists were worried about what it meant.

If this fish that survived millions of years was struggling.

Those concerns kick-started a hatchery that raises pallid sturgeons from eggs and releases them into the river to keep the population going.

Scientists track them to learn where they go and what they do, to understand more about what the fish need to thrive.

(water rushing) - There are a lot of pallid sturgeon in the river.

They're just largely hatchery fish.

So it's a stopgap measure.

-[Narrator] For the long-term success of the species.

Pallid sturgeons need to reproduce naturally and grow in the Missouri without any help.

(water running) And for that to happen, biologists think the fish need side streams of slow, shallow waters to grow up without getting swept up in a fast current or a catfish's mouth.

In other words, the fish need the very habitats that were eliminated by mega-engineering projects of the 20th century.

In order to help the pallids, in 1986, the Corps of Engineers began restoring historic aquatic habitats by purchasing land from willing sellers.

But changing stretches of the river for endangered species hasn't been popular.

It came to a head after the region saw devastating floods in 2011 and 2019.

Some landowners sued the corps and won arguing habitat restoration, changed the floodplain and contributed to erosion and increased flooding.

(gentle music) -[Wayne] I've been in meetings where busloads of people show up and say, my farm is not your laboratory.

-[Narrator] And there could be another problem with the way the river has been engineered.

Flooding could get worse as the frequency and intensity of storms increase.

Rezaul Mahmood studied how the Missouri River has changed over the last 70 years.

(gentle music) -[Rezaul] We particularly looked at very extreme yearly top 1% of the extreme precipitations.

So we found that there is a change in frequency of those events and also the magnitude, they're more frequent, and they are larger.

(gentle music) -[Narrator] Climate change may prove the current river design isn't working for anyone.

(gentle music) -[Wayne] Although we've put lots of things in place to protect infrastructure, protect homes along this river.

Ultimately, nature can override some of that.

So not only for pallids, but how do we adapt for the human needs along this river system?

(gentle music) -[Narrator] Gerald Mestl says in order to help pallids and mitigate flooding, another approach is needed.

Widen the river to allow more room for high water levels.

Such a massive undertaking begins with a hard look at today's Missouri River.

(gentle music) -[Gerald] Yes, it will cost a lot of money, perhaps less than one flood's worth of money to do it completely, but have a system that will meet our needs today and for a long way in the future.

-[Narrator] Getting there is a long shot without conversations among people who depend on the river.

-[Joe] One thing pallid sturgeon are teaching us is that there are solutions that takes a lot of effort.

It's good science and a lot of work with stakeholders.

We do that on the Missouri River because of pallid Sturgeon.

(gentle music) - Hi, I'm Carlee Moates.

Welcome to Conservation Works, a series exploring the creative and inspiring ways Nebraskans are helping people, wildlife and the land thrive together.

In the studio with me is Kirk Steffensen, Missouri River program manager for Nebraska Game and Parks.

Pallid sturgeon have been around since the age of the dinosaurs, nearly 200 million years.

But today, the species struggles to reproduce successfully in the wild.

Kirk joins me to talk about the remarkable natural history of this ancient fish and the latest conservation efforts to help it recover.

Kirk, thanks for being here today.

- Thank you.

Glad to be here.

- Yeah.

So today we're talking about pallid sturgeon.

They're pretty unique creatures.

What's what are some interesting things about these fish?

- Well, like you said in the intro is they're a dinosaur fish.

The sturgeon as a species have been around for 200 million years since literally the dinosaurs, the Jurassic Age.

Pallid sturgeon themselves, they evolved in the Missouri River.

They've lived and thrived for many years.

They have a really unique life history for a fish.

They are a big river species.

They learn to thrive in the Missouri River.

Migrating two, three, 400 miles to spawn.

They have amazing site fidelity as they can go back to this exact small little patch to spawn and live.

Um, after they spawn the, the eggs incubate for three or five to seven days depending on water temperature.

After that the little embryos hatch and they, they enter the drift.

So basically they're at the mercy of the river.

They drift down river again, two, three, 400 miles depending on temperature, the current, the river levels.

After that, they settle down into the river, find some nursery habitat, start feeding, and hopefully survive for many years and get to do it themselves.

10-12 years later and become a reproductive fish themselves.

- So 10 to 12 years, it takes that long for them to go back upstream to spawn?

-[Kirk] Correct.

It takes about it takes females a little bit longer.

Males in our reach of the river will generally become reproductively ready.

And, uh, 7 to 8 years females are more 8 to 10 years.

But it's a long term investment for those fish to mature and produce viable gametes.

- Mhm.

So we can't talk about the pallid sturgeon without having a conversation too, about the habitat, because they're pretty specific with what they're looking for at different stages of their life.

How is the world that they're underwater world that they're navigating today in these rivers, How is that looking different than it might have those 10,000 years ago?

- It's vastly different.

And that's one of the challenges with pallid sturgeon recovery is, like I said at the beginning, is they evolved and they lived in a river that was natural.

It had its natural channel morphology.

It had a natural hydrograph, turbidity, you know, everything about it was just untouched by man.

Over the last 120, 150 years, we've really put our fingerprint on the Missouri River.

It's been fragmented.

There are six main stem dams up the Missouri River that cut their migration routes.

Starting at Sioux City, It's been highly engineered and channelized.

So instead of having this dynamic river system that's braided with multitude of habitats, that's evolving, that has the natural hydrograph to cue the spawning efforts.

Now we got this river that's essentially a ditch.

It's a couple hundred meters wide.

It moves fast.

It's designed to move sediment downstream for the channelization, um, mainly for the navigation industry.

So the pallid sturgeon's habitats are really, really restricted to what it has been or was with the contemporary Missouri River.

-[Carlee] Mhm.

So the turbidity, when it's changing the sediment flow, that turbidity, is that essentially the measure of how dark the water is or how not clear or clear it is?

- Yep.

- What are some of the things that these fish, if they had it their way, what would they be seeking out at these different stages?

- Well, if you go back to the historic Missouri River, they called it the Muddy MO.

Um, it was flowing chocolate milk.

It was high, high levels of suspended sediments.

Now, because of the fragmentation and the dams is a lot of that sediment gets trapped behind the dams.

And when the water comes through the powerhouses, it's clean water.

If you look at a pallid sturgeon itself is they evolved in that high turbidity system.

They have really small eyes.

They do not sight feed like, you know, like a like a walleye or a bass or something like that.

They rely on their other sensory organs to, to feed.

And it's just what they evolved in this river system.

- Mhm.

And a big part of this life cycle of the pallid sturgeon is that time when they're larvae moving through the water, are the adults seeking something different than what these really tiny baby fish are looking for?

- Um, in terms of habitat?

Uh, yes.

The bigger the fish get, the more tolerant they are of velocity and, and, um, high those higher current levels of... -[Carlee] They're stronger.

- Yep.

-[Carlee] Okay.

- The little fish.

So as they passively drift downstream and once they start to settle and be able to position themselves in the water.

They're very selective of the water velocities they're seeking.

They can't tolerate much faster current than that or they just keep continuing to wash downstream.

And then as they start growing bigger and bigger, they become a little bit more tolerant of that high water velocities.

So if you look at the Missouri River, it's kind of amazing that these fish seek a really narrow band where the depth and velocity is, is suitable for them to survive.

- So when you're doing restoration on the river to accommodate more of the larvae, that's to ensure that they can get big enough to eventually go and spawn their own eggs.

And these, the pallid sturgeon, are federally endangered.

Do you know about where the population numbers are today?

- Um, in the lower Missouri River we kind of separate them into two groups.

In general, there's the wild-origin fish.

Those are the ones that were naturally produced, lived in the river for their whole life.

We estimate that population around 2000 fish.

It's hard to quantify really.

But then there's also that hatchery origin, pallid sturgeon, that they were reared in the hatchery.

We've stocked them in the river intentionally to bolster the population.

Those are doing a lot better just because of the supplementation program.

I think the last estimates put about 8 to 9000 fish in the Lower Missouri River.

Basically, it's about a one wild to 8 to 10 hatchery fish out there.

-[Carlee] The intention then with these hatchery fish is that to have them over time, be more sustainable with the wild fish, so that they can just go and all be wild someday?

-[Kirk] Yeah.

The ultimate goal is to have these hatchery fish grow up to that adult size, so they're able to naturally reproduce in the system to spawn in the wild and then have their young.

You know, naturally recruit to the population and eventually become a self-sustaining population.

So we don't have to interact and be part of the recovery.

- The efforts that you're making for now to contribute to that population in the hatchery.

What does that look like?

How do you raise pallid sturgeon?

-[Kirk] It's an interesting and it takes a lot of partners to get it to work.

First of all, you need the adult fish.

So that's where the Game and Parks and my crews come into play is, is we're out there actively fishing and we capture these adult sized fish.

Um, roughly three feet long is about what it takes for them to become reproductively ready.

We run genetics to make sure that they are indeed a wild fish.

So if we capture a fish that hasn't been used before, we actually contact Gavins Point National Fish Hatchery up in Yankton, South Dakota.

They come down, they get the fish and haul it up to their facility.

And then, yeah, just the hatchery process where they roll the eggs takes five, seven days to hatch.

They go out little guys, and then they just keep them in the hatchery tanks for about a year to 15 months.

And at that point, they're about 12 to 15in long.

And then they'll return them back to the river at several locations all the way from Yankton to Saint Louis.

- And keeping them in the hatchery that long ensures that they can be strong enough for those faster currents.

- Correct.

Because the big recovery bottleneck happens in that smallest life stage is, um, (no audio) there's a lot of mortality associated with a fish that's six, eight millimeters long to get them to that biggest size.

Um, so growing them through that first winter and getting them to that advanced age one fish.

That greatly, greatly improves their chance of survival in the wild.

- What is the success for this hatchery reintroduction looking like?

And how do you even monitor how it's going?

- Um, there's each hatchery fish that goes in the goes into the river has a unique tag in it.

Um, there's a little tag about the size of a grain of rice that we can scan it that gives us a unique alphanumeric code.

So every fish that goes in, we can track it as an individual.

So when our crews are out there doing doing our sampling, we can detect and we can follow these fish across many, many years.

Overall, once we get them to that age one size, their survival is pretty high.

We're seeing about a 75 to 90% survival rate.

- That's awesome.

So it seems like it's working.

-[Kirk] It is.

The numbers have greatly improved with the hatchery supplementation program.

- While you are helping bolster the population and your role is more so helping the fish themselves.

Um, what does that look like for successful habitat engineering or, um, some restoration that can happen so that these fish are able to have those, the little guys when they first hatch survive.

Are there any successful examples of restoration.

- In the Lower Missouri River, that's one of the big obstacles.

Um, the Missouri River is managed for eight authorized purposes.

So Fish and wildlife, uh, is one of them.

But the Corps of Engineers is mandated by the federal government to meet other guidelines.

Um, habitat construction and improving their chances of survival in the lower river has been an uphill battle.

One of the interesting, um, projects has come from that upper basin area below Fort Peck Dam.

That population highly utilizes both the Missouri and then the Yellowstone River.

Um, that feeds into there just below Lake Sakakawea, about 70 miles up the Yellowstone River, is this structure called the Intake Diversion Dam.

Basically it's a concrete wall, low head dam that funnels a bunch of water for irrigation for, for eastern Montana farmers.

Um, that was blocking upstream pallid movement and other native fish.

So they came in and built a bypass channel, just a simple off channel chute that goes around this.

And fish have really taken advantage of this new bypass channel.

And it's opened, I think, 160, 70 river miles on the Yellowstone until the next dam.

But then it also opened parts of the Tongue and the Powder River.

And they, the Montana folks up there have actually documented successful passage of that intake dam using that bypass and spawning above that area.

- So I want to make sure that I'm understanding it right.

Essentially, this bypass is allowing the fish to go further upstream so they can spawn further ahead to give those little guys, those new fish longer time to get stronger before it's their turn to be back in this flow.

- Correct.

Because the big obstacle of that sturgeon population is those embryos don't have enough drift distance to drift.

So they hit the headwaters of Lake Sakakawea, and the flow reduces as it turns into a lake, and the little embryos fall to the bottom of the bottom of the lake, where it's an anoxic zone.

And they basically suffocate.

- Because fish need oxygen, just like we do.

They just get it out of the water through their gills.

- Correct.

- Why does it matter to put that much effort into one fish?

Why the pallid sturgeon?

-[Kirk] The pallid sturgeon is the keystone species for the Missouri River.

The Missouri River itself is an ecosystem that's been highly degraded, but the pallid carries hopefully ecosystem restoration, um, with the management actions that have been done, you know, that bypass channel, the thought is what helps the pallid will hopefully help other native river species, you know, survive because, because the majority of the native river fish species are becoming, the numbers are decreasing and multiple ones are imperiled or near threatened.

-[Carlee] So I'm hearing it's the theme that applies to a lot of ecology efforts is even if you focus on one species, the trickle down and everything that that covers also benefits from those efforts as well.

- Yep.

Correct.

- And so having more healthy fish is good for the fish, good for the water, and also good for the anglers and people and everything.

- Yep.

- That makes sense.

Interesting.

Well, Kirk, thank you for all your help.

Um, helping out the pallid sturgeon the other fisheries and waterways and your efforts are noticed and seen and they're making a difference, I think.

Thanks for joining us.

- Thank you for having me.

-[Carlee] Yeah.

Up next, a behind the scenes look at the Henry Doorly Zoo and Aquarium's efforts to save endangered amphibians.

(no audio) (upbeat music) -[Carlee] We are here at Omaha's Henry Doorly Zoo and Aquarium.

I'm joined today by Derek Benson, the supervisor of Amphibian Conservation area here at the zoo.

And today we're going to get a behind the scenes tour.

- We are.

Yeah.

Thank you for visiting Carlee.

And we're excited to showcase amphibian conservation to you in a hallway in the orangutan building.

- Awesome.

Let's check it out.

(upbeat music) -[Derek] This is for Wyoming Toad specifically.

We have a bio secure area, so we try not to let any pathogen in or out.

So we're going to get you set up in a lab coat, some booties and gloves so that we're protecting the toes, but also protecting Nebraska wildlife.

-[Carlee] Wow.

How many toads are in this room?

- So we've got just over 100 toads in here right now.

(upbeat music) This is really just a big breeding operation for an endangered species.

This entire species population started from ten toads that were collected in the wild as they were dying off.

So this was kind of a last ditch effort to get these animals, get them into somewhere safe, and then see if we can continue their survival.

These are found in the Laramie Basin area of Wyoming.

That is the only place in the world where this toad occurs.

-[Carlee] Why does this one little toad matter?

-[Derek] So we look at it from a biodiversity protection standpoint.

So amphibians are predator and prey.

So in order to maintain that relationship within the ecosystem, we know that they eat insects but they also feed birds of prey and snakes.

So if any one piece of that ecosystem is missing, it starts to fall apart.

So you can see, (upbeat music) -[Carlee] Oh wow.

(upbeat music) -[Derek] So here is a little Wyoming toad.

So every other day these get crickets and roly polies and beetles to diversify their diets.

And they get fresh water every day.

(upbeat music) You look so on his front limbs, if he sticks them out, he's got what are called nuptial pads.

So they're kind of pink areas.

He's using that in the breeding season to grab onto females.

So it's super competitive in the world of the Wyoming toad.

So when a male finds a female he's got to hang on because otherwise a male will kick him off and take his place.

So those little pads are the sticky projection.

-[Carlee] So there's guests coming to the zoo every day to see the wonderful creatures that are in here, but there's a lot of behind the scenes science and conservation work that's happening.

-[Derek] Yeah.

So we have a lot of conservation projects that we cannot put on exhibit because the species is highly endangered and protected.

So our job is to save species from extinction.

So we harbor them behind the scenes, and then we have them in our educational and outreach programs.

-[Carlee] So even if somebody is visiting the zoo just for a nice day to visit, they're also supporting this conservation work behind the scenes.

-[Derek] 100%.

(upbeat music) (no audio) I'm going to show you two examples of successful amphibian conservation, one and one that we are struggling with.

So we have Panamanian golden frogs here.

These are extinct in the wild and we do not reintroduce them currently.

But realistically they only exist in zoos right now.

And then on the other side, we have Puerto Rican crested toads that we release three times a year in every life stage.

So it's a much more successful program.

- I see and hear that you're doing more than just breeding.

It seems like there's some sort of agility exercise happening with the frogs.

What is going on in here?

-[Derek] So we have artificial rock walls that these toads get to climb to increase their fitness, to increase their survival rate.

-[Carlee] Kind of like training for a marathon.

It's just training to be back in the wild.

-[Derek] It's literally a rock climbing wall that they get to exercise on every day.

-[Carlee] Do they like it, though?

-[Derek] They seem to love it.

And it makes sense, right?

That's the environment that they come from.

(upbeat music) So this is a Blomberg's toad.

This is one of the world's largest toad species.

So if you'd like to hold her, it definitely takes two hands.

(upbeat music) - Oh my goodness.

This is incredible.

Hello.

(upbeat music) -[Derek] They're from basically Colombia and Ecuador right on the border.

So lowland forest.

But they are not super common.

- Yeah.

- The two are kind of on the same wavelength here, so.

- We're kind of friends, I think.

She's kind of checking everything out.

(upbeat music) -[Carlee] Thank you for joining us on this edition of Conservation Works.

As we close, enjoy the beauty of the Missouri River near Brownville.

(upbeat music) The Mighty MO, a waterway that continues to connect Nebraska's past, present and future.

(upbeat music) (no audio) (upbeat music) -[Announcer] Support for Conservation Works provided by the Clare M. Hubbard Foundation, Ken and Pat Cheloha, the Carol Gendler Estate and Larry and Pat Ruth.

(gentle music)