(pleasant acoustic music) - Well, we're just down from Willie the Walleye here in Baudette at the DNR area headquarters.

And behind us is the Rainy River.

Now this has become just a world-class lake sturgeon fishery, and that's due to a couple of things.

The cleanup that took place here, the recovery efforts, including the Clean Waters Act back in the 1970s, and then a lot of research that's being done by the Minnesota DNR.

(pleasant acoustic music) So while this is a popular area to target surgeon in the spring, we're here in August, we're gonna head out on the river with the DNR to go check these nets for sturgeon.

(pleasant music) - We went out yesterday, set different gill nets out on the river as part of our juvenile sturgeon and just general Rainy River survey.

Ideally, we're looking for kind of that juvenile stage sturgeon.

So we have two different sites to check today with three different nets at each site.

(pleasant music) - Now part of this process will involve some bycatch, catching walleyes, suckers, sauger and other fish in those nets.

But those fish are becoming a vital part of their research as well.

(pleasant music) So we're out here on the river at your nets that you set out yesterday.

- Yep.

- What's the next step here?

- So we're gonna lift these nets.

We're starting on the downstream side.

So we have three different nets in the water.

We're gonna start with our 2 1/2 inch mesh.

So it's about 100 feet long, and this one's set perpendicular to the shoreline.

Then the next one's what we call an experimental gill net.

So there's 250-feet long of net all strung together, and there's 5 different panels of mesh in that gill net that range from 3/4" all the way up to 2" mesh.

So it's gonna catch a variety of different fish.

We're doing kind of two surveys in one today.

So we're doing a population assessment on the Rainy River itself.

So we're looking at walleye and sauger numbers, sizes, ages, as well as juvenile sturgeon.

So these nets are really good at catching smaller sturgeon.

We'll tag 'em from here and take length and weights on 'em.

(serene music) As they get tangled in the net, sometimes the net rubs on 'em a little bit.

And they get kind of, like, a rug burn, but they have really hard skin, kind of, like, a leathery type of skin and some rough scales.

So they're typically not an issue for 'em.

(serene music) Yeah, so this is a juvenile sturgeon.

So you can see, a lot of times, they're kind of this lighter sandy color compared to the adults are more darker.

And you can see the scutes on its side here, on the top, are really sharp.

When they're younger, they're, I guess, fresher scales, so they still have that sharp feel to 'em.

So we like wearing gloves when we're handling 'em.

And then as they get older and kind of rub up against different stuff in the river and just live their life, they kind of start wearing those scutes down.

- All right, lake sturgeon 2 1/2 inch, 633.

- So each one of these sturgeon that we get, we wand 'em with a, it's called a PIT tag reader.

So we have PIT tags in a lot of these smaller fish.

It's basically like the same type of microchip you'd see like in a dog that you get from a vet.

It just has a unique number that identifies that fish.

And we use these on our smaller fish, 'cause they're really small.

They're kind of just slightly larger than a grain of rice, (serene music) that we inject into 'em with a little syringe.

So if we recapture 'em again, we can look at how much they've grown since the last time we've captured 'em.

And then once they get to be a certain size, then we put what's called a Carlin tag in 'em, which is the external tag that you can see when you're fishing.

It's a yellow kind of dangler tag off their dorsal fin.

(pleasant music) So if we did detect a PIT tag on this one, we'd write down the tag number and then we would add that we put a Carlin on it, 'cause it was over 600 millimeters.

So it's big enough.

The reason why we wait till they're 600 millimeters is just you don't want 'em when they're smaller to have this hindrance that would limit their ability to swim.

(pleasant music) - [Grant] We're gonna take this leading fin spine.

This is a way to age the sturgeon, slight clip.

And it pulls right off.

- So we use a low speed saw, like a diamond blade saw that spins fairly slow, and you can cut a little slice off the end of it.

And then you can age it like a tree.

There's rings on it.

(tranquil music) The sturgeon fishing on the Rainy River's pretty good.

I mean, we've met a lot of our recovery goals for sturgeon population in the river.

The last, like, goal of our recovery plan is to see an 80 incher.

And a lot of us, we kind of debated whether it's out there.

And if it's not out there, it probably will be soon.

- Yeah.

- But I would think that there's gotta be one.

(tranquil music) We do yearly monitoring, netting for taking fish and stuff, and we're seeing pretty diverse year classes.

That was one of the things in our recovery goals, is having several year classes.

And that's one of the things we get from taking our age structures, those fin raises, we can determine the years that the fish were born and then we can kind of backlog it.

So we've seen several year classes, and that's kind of what we've done with our survey this year, with these juveniles is just kind of continuing that, making sure we're still seeing spawning occurring, recruitment happening in the population.

(tranquil music) - Sauger.

234, 40.

So we're gonna be pulling the otoliths out of this sauger, which is a structure similar to like an ear bone if you compare it to humans.

And that's a way that you can get the age from these fish.

- So this would be part of that Rainy River evaluation I was talking about earlier.

We wouldn't normally do this if we were just looking at sturgeon, but since we're already setting nets, makes sense for us to... - Utilize some of the bycatch that we're getting.

- Yep.

(tranquil music) - Walleye.

(gentle music) 282, male, immature.

So the testes or the ovaries are kind of what you look for.

And it's gonna be really small, but this is a undeveloped testi basically.

Super skinny, small red.

And then the females will be a little more fleshy, a little bit larger at this size.

And then clearly, when they're mature, the ovaries will be full of eggs.

(serene music) - Now that we went out and collected all the different aging structures and stuff, so we'll go back and we can look at each site, how many fish we caught at each site.

We can compare that to historical catches in that river section.

We can get ages off those fish that we took a fin ray from so we can go back and look when those fish were born.

We can look at river conditions when they were born to see.

You know, are there thresholds that sturgeon need as far as flow or river level to have a successful spawning year?

For the walleye and sauger, we can look at ages on those as well with the otoliths that we took.

And we can look at the amount of growth that they've had in the river.

We can look at length and age.

So a two-year-old fish, how long are they in the river compared to the lake, are there differences there?

Is it the same population?

Along with the sturgeons who we can look at when now that we have an age and a length for them when we capture them, if they get recaptured again down the line with, we can look at how much it's grown.

(pleasant music) So another way we research these fish is we have what's called acoustic transmitters in these adult fish.

And basically, what those do is they send out a coded ping, and we have receivers intermittently throughout the river.

As the fish swims by one of these receivers, the receivers are listening for those pings, and when it sends it out, it can recognize that sequence of pings.

It'll have an ID number associated with that fish.

So we can tell when a fish swims past a certain receiver.

And then we have this box here too that allows us to basically put in a, what's called a hydrophone into the water, which can also listen for those signals.

We can kind of track fish individually as they move throughout the river system.

And we have receivers out on Lake of the Woods as well right now too.

So we can kind of track 'em all the way from International Falls Dam, all the way down the Rainy River into the lake.

(pleasant music) We don't have a whole lot of data on juvenile fish.

So kind of understanding where they're hanging out throughout the year and what kind of, like, habitat they prefer throughout the year.

And then for the adults, we know some spawning areas.

We're kind of looking to see are there other spawning areas that they're using?

And then looking at, like, when they're spawning, are they going from site to site?

The timing of when they move up for spawning in the springtime and when they leave, if they leave right after spawning, where do they go?

Do they go, you know, all the way to the lake?

Do they just kind of coast down?

Just kind of understanding overall, what are they doing on a year-to-year basis, kind of at different stages of their life.

(pleasant music) (fish chirping) - That's a fish.

- That's a code for sure.

- 39542 - [Announcer] Fish 39542 was 19.1 inches when it was originally tagged on August 14th, 2024 near the Vitus boat ramp.

And including today, it was detected three more times near Baudette in August of 2025.

- We had one fish that, you know, went from the Big Falls area all the way down out into Lake of the Woods in just a couple days.

And we've had some fish that prefer to stay in the river.

They haven't really left the river, or they hang out kind of by four-mile bay down by the lake.

Some fish move a lot and some fish don't move a lot.

And we're looking at, do they come up the same river every year?

Are the Rainy River fish only coming up the Rainy or are they straying?

We don't have a whole lot of data on juvenile sturgeons, so that's why us being able to take some of these younger fish and seeing where they hang out before they, do they go to the lake right away?

Are they hanging out in the river for a couple of years until they get big enough?

Just getting an idea of where those are hanging out.

It seems like just from our preliminary data, a lot of them hang out in the river, and for the first couple years before they start moving out into the lake environment.

But there's obviously fish that move more than others.

- It's research like this that builds a world-class fishery.

And we have one right here for sturgeon on the Rainy River.

(tranquil music)