(upbeat music) - When unwanted aquatic species enter Wyoming waterways, it's a serious problem, and the Wyoming Game and Fish Department has to get involved.

We'll speak with Wyoming Game and Fish Fishery Supervisor, Bobby Compton.

I'm Steve Peck of Wyoming PBS, and this is, "Wyoming Chronicle."

(music continues) - [Narrator] Funding for this program is made possible in part by the Wyoming Humanities Council, helping Wyoming take a closer look at life through the humanities, thinkWY.org, and by the members of the WyomingPBS Foundation.

Thank you for your support.

- We're here in "Wyoming Chronicle" with Bobby Compton of Wyoming Game and Fish Department.

Bobby, tell us what your title is exactly.

- Sure, I'm the Laramie Region Fishery Supervisor.

- Fishery Supervisor, and that's gonna figure into what we're talking about primarily today.

We're here at Saratoga Lake, just outside the town of Saratoga.

The issue of invasive water species around Wyoming crops up from time to time, it cropped up here at Saratoga Lake recently.

You were telling me off camera, it's not the first time it's happened here, something particular about certain places makes it more likely to happen.

Tell us what went on here over the past year or two that became alarming to you and to the department.

- So in 2021, we had a graduate student at the University of Wyoming.

- [Steve] Really?

- He was doing some survey work, and he was collecting smaller fish, so he had some traps out, and he gave us a phone call and said, "I think I found some small perch," so he found some yellow perch.

They were born in 2021, they were two or three inches.

Once we got ahold of 'em and verified they were indeed yellow perch, that kind of raised the alarm, because we've never stocked yellow perch in Saratoga Lake, nor do we have them anywhere in the watershed within the Platte Valley.

The closest we have in the North Platte drainage with yellow perch is Glendo Reservoir, so pretty far downstream.

And so once we could verify they were yellow perch, that's when we had conversations on what to do with them.

Again yellow perch, not invasive, we have some species in Wyoming that are listed invasive, and those are the cogans, zebra mussels, and animals we're really trying to keep outside of Wyoming.

- [Steve] What's the word you'd use?

- What I would call it is just unwanted, and illegally brought in.

- The point you've made is that yellow perch is a fish that does exist harmoniously in other parts of Wyoming, but it's not supposed to be here.

Why is that such a big deal?

- Yeah, you're correct.

You know, we do manage yellow perch as a sport fish, appreciate their value.

Anglers love 'em, 'em probably why, you know, they were brought in here.

Somebody wanted to catch a yellow perch and not a trout.

Yellow perch have a role in the food chain, in the food web in many lakes.

We were afraid here in Saratoga Lake it would disrupt kind of the food chain, and that's one of the reasons that we acted.

I could explain that in a little bit, but so there was gonna be some direct impacts to the fishery here at Saratoga Lake with yellow perch, but kind of on the watershed scale, we knew they would likely escape from Saratoga Lake.

So Saratoga Lake is connected to the North Platte River.

- So the North Platte flows into it?

- [Bobby] Correct.

- Flows back out front.

- [Bobby] Yeah.

- And that's how the fish can get out, and that would be an even worse problem.

- [Bobby] Yes.

- [Steve] In the larger frame of things.

- Yeah, so the North Platte River starts in Colorado, travels north, water comes in and out near Saratoga, but you know, not too far downstream, you run into Seminoe Reservoir, the Medicine Bow River, and then down to Pathfinder, Alcova, Gray Reef, and so it almost posed as a headwater source for perch that could escape and end up in all these other waters, including the rivers, and we just thought that was too big of a threat to live with them, you know, moving on and expanding in those reservoirs.

- When you say it would impact the fishery, the fishery that you want in Saratoga Lake is trout, right?

- [Bobby] Correct.

- What would the perch do to the trout?

Would they just out-compete them, would they attack them?

What's the issue when they exist in the same body of water?

- Primarily, it would be competition for food.

You know, perch are not as predacious as say walleye or even a brown trout for example, but they can be prolific.

That's the other kind of life history strategy with perch is females lay a lot of eggs, they're very fecund, and so in a short amount of time, you know, three to five years, they can really expand to numbers that are amazing, really, and so- - They're more fruitful and multiply faster than the trout do?

- Absolutely, yeah, and actually, trout don't even reproduce in a lake like this.

That's, we get, you know, a fishery by stocking.

But you know, we have examples in other parts of state.

Two come in mind in the Sheridan region where perch got in, one is Black Hills power and Light near Newcastle, another one, Healy Reservoir just east of Buffalo, and in both cases, the trout fisheries were abandoned, you know, in a short amount of time, just mainly because there were so many small perch.

So once you have a lot of perch, they pretty much eat all the food, so there's not food for trout, so we don't see any growth in the trout, but the perch also don't grow.

So then you end up with a lot of stunted two to five inch trout.

And I just say like in general, if you or I were gonna go out and, you know, harvest some fish for a meal- - You want a trout bigger than that.

- And you want a perch bigger than that too.

You know, you might want a seven eight inch perch, you know, that gives you enough food to eat.

So in those cases, those lakes are so full of small fish that really, there's not much of a fishery at all, and so, you know, we walk away from 'em.

- What is the story of Saratoga Lake?

It's a manmade lake that's been here for half a century or so, is that right?

- Yeah, yeah, I think it was built in the '40s.

It doesn't serve any true irrigation like many other reservoirs in the state - [Steve] Here for recreation?

- Primarily for recreation.

You know, it's a unique situation in that the Wyoming Game and Fish Department manages the public access, the fishing, waterfowl hunting, and some wetland habitat below, but it's owned, a portion of it's owned by the town of Saratoga, and they really, there's a campground, and it's a great place, you know, for tourists to come in and spend a weekend either going into Saratoga or passing through, so it brings a lot of money into the town, the campground does, and when the fishery is operating at a high capacity and it's drawing in anglers, we know that that also brings in a lot of income to the town of Saratoga.

- Again, just to reiterate, when the fishery is operating at high capacity the way you want it to, that means I could stand here on the shore, or maybe go out in my boat and cast a line, and reel in a decent sized trout.

That's the desirable outcome?

- Correct, and you know, Saratoga, is at 7,000 feet.

- [Steve] Yeah.

- You know, it's a cold environment.

It's ideal for trout, not only Saratoga Lake, but the North Platte River, it's one of the premier wild trout fisheries in Wyoming or the West between, and so that's another reason we're trying to protect what we have in the river with these perch.

But yeah, the Saratoga Lake, when it's doing well, we experience really high growth rates, and it's a phenomenal trout fishery too.

- What's the difference then between a lake where you'd see perch, but wouldn't care as much, and this one?

Is it because the lake is bigger or deeper or different temperature, why would you, and we're gonna talk about what you had to do, decided had to be done to restore the trout fishery here.

In a lake where you didn't take action, what would be some of the differences?

- I'll just use Boysen Reservoir as an example.

You know Boysen, close to your home.

It's a large reservoir, it's deep.

It also has a better food base for fish like walleye, you know, which is, you know, a lot of people travel to Boysen to fish for walleye.

So you know, it kind of has the tiers you want to support perch, so perch in Boysen you could fish for, you know, they'd grow to nice sizes.

They're typically not too prolific, because the walleye can keep them down, but outside of walleye eating perch, you know, there's a lot of minnows for forage, and there's just a better food base to support those kind of top level predators.

Here in Saratoga Lake, it's pretty simple.

It's driven by aquatic insects, so scuds and damsel flies, and those sort of things the trout really like.

There's also zooplankton the trout will eat, but as far as what can support perch and then even a next kind of level predator, we don't have that here.

It's shallow.

- How deep at its deepest, roughly?

- Max depth would be about 20, but on average, it's about six to eight feet.

- Yeah.

- And again, that kind of matches up to some of those waters shared in these shallow waters where it didn't really produce, you know, a perch fishery that people would want to go there to fish for.

- Yeah, so there are different lakes, different fish, different unwanted fish in a different place, and this is something that Game and Fish, in this case, in cooperation, as you said, with a municipality, is called upon to deal with in some different ways.

- We knew we had a problem, and there's many examples of this happening in other places, we talked earlier, whether it's, you know, lake trout in Yellowstone, or walleye in Buffalo Bill, burbot in Flaming Gorge.

Heck, we've had small mouth bass in Sloan's, and it happens a lot, but here, we just thought we could catch it in time so we could maybe eradicate the perch before they proliferated, but it was a small enough system where you could have a project with some chance of success.

- And so the thing that was decided in this case, and it's not possible to do in other cases, and wouldn't be desirable to try, but when you say eradicate, the thing you did was essentially, let's use the word, you killed all the fish in the lake, essentially, and restocked only with the ones that were desirable, including some others.

Am I halfway right there?

- No, you're right.

You're right, and likely the hardest thing I'll ever do in my career, I don't wanna do that a ton.

- [Steve] You're a fisheries guy.

- I'm a fisheries guy, I love fish, and it's hard to make those decisions, but you know, from our chief of fisheries, our director, we decided that we wanted to act, and act immediately, and not wait any longer, 'cause we have examples of when we didn't, of what the results are.

So what typically would take three to five years to plan, and there's a lot that went into it, whether it's finding the money, reaching out to the local community, the homeowners, it was very complicated, but we were able to do it in a year.

The fisheries biologist Chance Kirkeeng that spearheaded the project went above and beyond, and again nothing that we like to do, but something we felt like we needed to do.

- You found, as it turned out, or you knew and realized maybe even to a bigger extent, there are other fish besides the perch that were causing a problem here, and they needed to be dealt with also.

- Another reason why we decided to do it is that because Saratoga Lake is connected to the North Platte River, again water in water out, the fish in the North Platte River can come in here too.

So it was actually treated in 1998, so a similar project using rotenone in 1998, that time we did it just to suppress the white suckers.

- [Steve] White suckers?

- Yeah, so white suckers are native to the North Platte River, and we actually conserve them, protect them in other places in their natural habitats, but when they get in impoundments, they can, much like perch, just artificially expand to levels that you would never see in natural habitat, and so what that happened here, they were very prolific.

We watched that expansion through the years, and so we knew once, you know, we treated the lake with rotenone, those white suckers would go away, that that would again free up food that you know, trout compete with.

The other thing too is that there's brook stickleback in the valley.

They also got in, they're actually an invasive species, so a listed species.

They were in the lake at high numbers, and another reason why we treated.

In fact, the BLM Bureau of Land Management out of Rollins, their aquatic folks, they helped out a lot on this project, because they wanted to try to eliminate a source of that AIS that is spreading through the valley too.

- So here, you have a municipality involved, a state agency involved, a federal agency involved.

You come together as needed to help each other solve a problem as you find it, and here's an example of it, and this happens in different ways around Wyoming.

You used, you mentioned the product rotenone, and it's a poison, correct?

- I don't call it a poison as in it's toxic.

So rotenone is actually derived from a root from a plant in the bean family in South America, and so when we get it as product, you know, in a barrel, it's ground, it's just pure ground rotenone root, you know, it's a pretty high concentrate.

What we get it at and what we apply it at is two different things.

So we apply it at a really low level and a very precise level, but why I wouldn't say it's a poison is it doesn't kill fish, or harm, you know, birds, others by ingesting.

What it does is it doesn't allow the fish to take up oxygen.

Okay, so any gilled animal, fish being one of 'em, they can't take up oxygen, and that's how they end up dying.

But once that leaves the system, usually takes a week or two for it to kind of precipitate out, you know, it's gone.

- [Steve] It's gone from the water.

- It's gone, it's gone from the water.

- Especially in the flow through that you have here, enhances that, or maybe accelerates a little bit too, I would guess.

- Yeah.

- So the fish die, and this included the trout that still were here.

I presume the procedure then is the dead fish need to be removed from the water?

- [Bobby] Yes.

- How many fish were we talking about in this case?

- Yeah, so here, like you said, we didn't really know what we were gonna see.

You always think you know what you have until you end up, you know, being able to see every fish you've got.

Again we didn't count 'em, but we estimated to pick up about 10,000 dead fish, again an effort that I don't ever wanna do again.

That was really hard, hard on all of our crew.

We worked really hard with it, but we got about 70% white suckers, about 10% perch, and about 20% trout.

So we did kill a lot of trout, really beautiful trout, and that was no good.

It was no good killing any of those fish.

- Yeah, it's too bad.

I hear what you're saying about that, 'cause your job is protecting fish, but in the larger sense, people that know what they're doing have experienced this before, people of game, fish, and science understood that this was the best chance to control the issue here in this relatively closed small body of water.

There was an opportunity to do it.

What happens to all those dead fish?

- In this case, we just, we buried them.

- [Steve] Just buried them.

- Yeah, we buried them.

- There's some cases I think I've read about where if there's a fish die-off for whatever reason, sometimes they can be put to some other purpose, but that's not what this was about.

- Correct.

- So then this lake's essentially sitting here without any fish in it.

How do you put 'em back in?

- First off, we want to make sure the rotenone's out of the system, and it's actually a pretty simple way in that we use what we call canary fish.

So we will immediately start putting fish in cages in the water.

It's kind of like a bioassay, and you know, if a fish gets sick or dies, there's still, you know, a toxic level of rotenone.

But after about two or three weeks here, fish were surviving.

We were using trout, they were surviving, so we knew the rotenone was out, and we also did a ton of netting.

So we had a lot of gill nets all through fall, just to confirm that we, you know, didn't have any fish left.

So that happened, actually the lake stayed fishless all winter, and then starting in spring, after we got a fish screen in to stop white suckers and brook stickleback from coming back, we wanted to start bringing water back in and fish back in, so we turned on the water, and then we started stocking trout in the spring.

- When you say stocking trout, there's a fish hatchery near Saratoga.

- Yes.

- Is that where you went for these?

- Yeah, you know, it's a unique situation in that we typically don't use a lot of fish from the Saratoga National Fish Hatchery.

You know, they have different obligations.

Whether they're raising fish for the Wind River Indian Reservation or fisheries around the US for that matter, we typically stock fish from Wyoming Game and Fish department hatcheries, but in this case, they did have some really, really nice rainbow trout.

The community felt strongly about using, you know, or receiving fish from, you know, their local hatchery, so it worked out in that we stocked about 12,000 near catchable rainbow trout from Saratoga Fish Hatchery.

- How big is near catchable?

- Yeah, they were eight to nine inches.

When this lake does not have suckers, and you know, the bugs are back, we could expect fish to grow, you know, four to eight inches in a year.

It's really, really phenomenal growth.

- So they come over in a, how are they transported from the hatchery to here?

Tank of some sort?

- [Bobby] A hatchery truck that has a, you know, an aerated tank.

- [Steve] I think I've seen this.

There's a big hose sort of, and you just- - [Bobby] Yep, actually here, you know, they just back up to the boat ramp.

- [Steve] Because there's strong flow through inflow from the river?

- Yeah, it's just that you get enough depth, and you can just stock the fish right into the lake.

- They want to swim.

- Yeah, they swim away.

- Once they get in there.

Now, that must be fun to do.

- It's fun.

It was wonderful to see these fish back.

In addition to the rainbow trout, we stocked some tiger trout.

That's a sterile cross between a brook and a brown trout.

- [Steve] Why put them there?

- So we did them and brown trout.

The reason we put those two fish in, a couple reasons, one of the reasons, and we've been surveying and talking to the anglers here for years, one of the complaints, if there was one, was there was not enough variety of fish, you know?

And it appears that, you know, yellow perch were one they wanted, but we heard that loud and clear.

We just knew we couldn't stock other non-trout, but so to get a little more variety, we now are stocking tiger trout, brown trout, rainbow trout.

The other reason we did the tigers and the browns was they're more predacious, so more willing to, you know, eat fish, and the thought is, is if those white suckers, or brook stickleback end up in the lake again, we want to have those predators, the brown trout and the tiger trout big enough to, you know, to feed on the few, you know, white suckers or stickleback if they get in again, and provide variety.

- Yeah, these predatory trout don't eat other trout.

Is that what you've found?

- They will eat other trout.

It's just that we stock the trout just like those Saratoga National Fish Hatcheries.

If they're stocked at, you know, five to eight inches, they're too big to be consumed, so you can still have both.

- How do we think this happened to Saratoga Lake?

How specific is the knowledge of why the perch got here?

- You know, we can't say for certain how, but it's highly likely that, you know, somebody took it upon themselves to, you know, catch them in another spot, transport 'em, and then release 'em, and that's what- - So they go, so people would go to the trouble of catching a fish and keeping it live in a cooler or something, and bringing it here just to establish them here so that they could fish for those?

- Yes.

Now, we spent the whole summer trying to figure out if that happened, so you know, we started by just talking to our neighbors, you know, our colleagues in Colorado with Parks and Wildlife.

We wanted to know, have they ever, do they have fish in the upper headwaters of the Platte?

Have they stocked 'em?

Have they ever permitted private fish stocking?

Have they ever seen any, you know?

And the answer was no, we don't believe there's any perch above, you know, upstream of Wyoming.

Then we spent a lot of the summer sampling the river, seeing like maybe they're already established in the river, and they came in, or if they've already escaped, and there was a population established from here.

So after we did all that, we also reached out to Saratoga National Fish, have you ever had 'em?

No, they haven't, and then finally, you know, then it's like, well maybe, you know, people would say that we stocked them, and maybe they were in a load of trout, but we've never had perch, you know, on any station, any hatchery in Wyoming.

- [Steve] Pretty careful about that?

- Yeah, we don't stock yellow perch.

We (indistinct) fish that we get, Steve, we get from other states, so we trade trout.

I think we stocked maybe 4 million walleye and other species last year.

Those all came from outta state, so they don't mix at all, you know, with our trout in our hatcheries.

- What if you had been able to determine down to an individual or a few who had done this thing that we talked about, deliberately caught the perch elsewhere, come here to release them, that's a crime, isn't it?

- Yeah, it's a serious crime.

In fact, I think within the last 10 years or so, we've changed, you know, some statute to increase the penalties for illegal introductions.

Our legislators have been very supportive of that.

In fact, I think we have some of the toughest laws in the West, and so I mean, we spent $140,000 last year doing this.

That's an expensive act, or you know- - Which was sort of off budget, right?

I mean, wasn't- - Very off budget.

- You weren't counting on having to do that.

We are here in the first day of August, as it happens.

What's the status of the lake now?

What fish are there today?

- Yeah, so right now, we have the rainbow trout, tiger trout, and brown trout, so they're all here.

- There's no closed fishing season in Wyoming, except this clearly was closed for fishing for a while.

Is it open now?

- It's open to fishing now, yeah, and you know, another thing that goes on here in Saratoga is a very popular and renowned ice fishing derby.

- [Steve] Oh yes.

- It would've been the 40th year last year, and they actually had to cancel, another, you know, unfortunate problem, but it will be back this year.

I think the fish will be of size, and I think it'll be really fun, you know?

Again thank the town for being patient with us, and I know they lost a lot of money last year with that, but we're getting there.

- You talked about the cooperation, and we mentioned (indistinct), and Saratoga's a small town of about less than 2,000 people, and you have the state agency, and then you have the federal agency.

What I've found is, I think, and see if you agree with this, that wildlife and fisheries is something where people of all kinds of different ideologies, we might say, can come together and find common ground, and that must've, that pretty much had to happen here.

- It did happen here, and we were pleasantly surprised, but after working with our partners, and the community realized just a lot of good people that understood and trusted us in what we were trying to do and supported, and that was just one part of the project that was unexpected and was just really rewarding, is to work with everyone, including, you know, the private landowners that surround the lake.

- And you had people who normally would be very, very protective of something that humans would do to cause a mass die off of fish if it were a chemical spill or something like that.

- [Bobby] Absolutely.

- But in this case, you found that Game and Fish was trusted, the situation was explained, and made a harder problem a little bit easier at least.

- Yeah, and even the people that maybe didn't agree with why we were doing it, they were at least open to the reason for doing it, and you know, just- - [Steve] They could understand.

- They understood, yes.

- They were heard.

- They were, yep.

- And they at least could.

- And this isn't one of those situations where we actually knew we were going to do it.

We had directive from our director and our chiefs of fisheries, so we weren't actually able to ask if people wanted us to do it or not.

We knew we had to do it, but I feel like we did a pretty good job of explaining why, how it was gonna go, and then what the result was gonna be at the end, and I think that's where everybody came together and really worked towards that goal.

- [Steve] Good.