[Carolyn Foley]
Teach me about the Great Lakes. Teach me about the Great Lakes. Welcome back to Teach Me About the Great Lakes, a monthly-ish podcast in which Stuart Carlton of Illinois Indiana Sea Grant, who is originally from Louisiana, gets people who are smarter and harder working than him to teach him all about the Great Lakes.

My name is not Stuart Carlton, my name is Carolyn Foley. I am a researcher with Illinois Indiana Sea Grant, and I know a lot about not doing Stuart's bits for the podcast correctly and saying things completely wrong. And I know more about the Great Lakes than Stuart, but I don't think that anyone can say they know a lot about the Great Lakes, because even the people who know the most, there's just always more to learn.

My co-host today is Megan, the lake lover Gunn. Megan, how are you today?

[Megan Gunn]
I'm doing great, Carolyn. I'm also really excited because, I mean, I know things about the Great Lakes, but there's things that are always changing. Like, it's constantly changing, and we'll learn that a lot in our episode today with our researchers.

[Carolyn Foley]
Yes, so let's just go right into it with the Researcher Feature, because it's one of Megan's favorite songs. Okay. Okay, our guests today are a superstar panel of individuals who know a lot about invasive species that are in the Great Lakes, because we are going to do a discussion about a bunch of new invasive species that are, because we've talked about Dry Synids, we've talked about other things, but we're going to talk about some of the ones that are maybe not on your radar already.

We first have El Lower, who has been on the show before. El is the Glances Communication Specialist with Michigan Sea Grant. El, welcome back.

[El Lower]
Thank you so much for having me. Glad to be back.

[Carolyn Foley]
Exciting.

Then we have Dr. Katie O'Reilly, an Aquatic Invasive Species Specialist with Illinois Indiana Sea Grant. She's been on the show once or twice. How are you today, Katie?

[Katie O'Reilly]
I'm doing great, Carolyn. Really excited to be here and talk about, you know, I don't know if I want to say my favorite thing invasive species, but something that's definitely, you know, flows at mind.

[Carolyn Foley]
Thank you. Finally, we have Dr. Brian Roth, who was one of our very first guests way back at the beginning of Teach Me About the Great Lakes. Incidentally, we will drop all of their past episodes into the show notes.

Dr. Brian Roth, Professor, Associate Chair of Research in the Department of Fisheries and Wildlife at Michigan State University. Welcome back.

[Brian Roth]
Thank you so much. I'm really happy to be here. Thank you for inviting me.

[Carolyn Foley]
Thank you. Okay. So, I'm going to turn it over to the lake lover herself, Megan, because it's not quite a draft.

It's not quite a draft episode, but it's something. We're definitely doing something today.

[Megan Gunn]
Yeah. So, I guess one of the things, because some people are new to our episodes and listening in, could one of you share the difference between an invasive species and a native species and what makes a species invasive?

[Katie O'Reilly]
That is an excellent question, Megan, because I think we throw around a lot of different terms when it comes to invasive species, non-native. You may see even things like non-Indigenous. So, there's a lot of different terms.

What we really are talking about when we say invasive species is generally something that's not native to a certain location, meaning it was brought in by some variety of a pathway. It's generally also established, which to us as scientists just means that there's a population that's reproducing, so it's able to maintain itself and expand. And then the final kind of invasive sign or marker is something that causes harm.

And when we say harm, that can be environmental, competing with native species for things like food or a habitat. But it can also be economic or social harm, things like preventing you from taking your boat out on the lake because there's a big explosion of an invasive plant that blocks your way. So, it is kind of a general term and there's a lot of debate back and forth, but generally we're talking about something that's not originally from a location and that causes harm and has established itself.

It's not just a one-off.

[Megan Gunn]
Okay, thank you. And like we mentioned, things are constantly changing. And so, we were really struck by how many new invasive species are now threats to the Great Lakes region.

And so, what is a relatively... I'm sorry, Brian. What is a relatively new invasive species to the Great Lakes region that you think people should know about?

[Brian Roth]
There's a number. Certainly, I work on, say, red swamp crayfish, which we've talked about before. And that's certainly one we should know about, but one that I think flies under the radar of a lot of people.

It's not actually new, per se, but I think it's getting on people's radar more and more, which is the flathead catfish. So, the flathead catfish, even going back to the 30s or so, was not in the Great Lakes. And if it was, it was in such small numbers that no one really noticed.

But starting about in the 90s, going until today, the range has really expanded throughout the Great Lakes. And we're not necessarily sure if this is just you know, them finding new habitats just kind of randomly, or if it's kind of instigated by warming. Flathead catfish are normally kind of a warm water species, and they're found pretty far south.

But they seem to be doing just fine in our Great Lakes rivers. And clearly, they're using the open Great Lakes to get from river system to river system. Their ecology is, you know, somewhat well known in the Great Lakes.

But one of the concerns is that, you know, they may compete with our native predators for food sources, or may affect our native predators. I mean, Michigan, the state of Michigan, someone caught the state record in the past year or so, and it was 64 pounds. These are not small fish.

And they can become quite abundant. And it seems like their range is expanding not only across the Great Lakes, but within individual rivers within the Great Lakes. And so here you have this apex predator that isn't harvested to the extent like a lot of our native predators like walleye or northern pike, but they could potentially compete or even eat pretty much all of our native predators besides perhaps like, you know, a full-grown Chinook salmon.

[Megan Gunn]
That is incredible. What's something that people can do to help minimize the the spread and movement of the flathead catfish?

[Brian Roth]
That's the tough one. Really, the only thing that we can do, I think, at this point is catch them and keep them. They are a legal fish, and you'll find a number of anglers that are pretty excited about them because they bite all year round.

You can catch them through the ice. And, you know, you might have to get out a chainsaw and drill a bigger hole through the ice. But other than that, I mean, you can catch them all year round.

And so there's a number of anglers that are pretty excited about them. And apparently, I haven't had this and I wouldn't mind trying, but apparently they taste really good. So, you know, you can catch them and keep them.

But, you know, there's not like a commercial fishery or anything like that for them. And because they're integrated within our food webs, you can't really just say, you know, treat the St. Joseph River in southwestern Michigan or the entire Grand River. That's just not really feasible.

[Megan Gunn]
I mean, that seems like something that can just be sold in grocery stores alongside other catfish if they can find them quick enough.

[Brian Roth]
Maybe. Yeah. I mean, I think that, you know, if history is any teacher to us, I think that it's important that we make sure that, you know, our Great Lakes fish are safe to eat.

[Megan Gunn]
Yes. Yes.

[Carolyn Foley]
That is accurate. Yeah. And it's making me think of another frequent guest on our show, Titus Seilheimer, maybe the best Great Lakes Titus, who like instantly when you said it, like, oh, can I eat it?

Because Titus talks about eating everything. But I don't know that I'm going to ask that question of everyone with every species that they share today. But for the catfish, I can say, can I eat it?

And the answer seems to be, maybe. Yes.

[El Lower]
Yeah. As your resident forager, I've probably tried eating it if it's come across my path. But I'm not quite standard that way.

[Brian Roth]
I don't know if you're really doing your job correctly if you haven't tasted your study.

[Megan Gunn]
Thank you, Brian. We will go to El next then. El, what's a relatively new invasive species to the Great Lakes that you think people should know about?

[El Lower]
Well, this is a great question because this is actually a species that's not only new to the Great Lakes, but is actually fairly new to science. So I want to talk about the marbled crayfish, a.k.a. Procambarus virginalis. This is a very, very strange creature that was discovered in 1995.

So, you know, this animal, this entire species, is just a few years younger than I am. This species has been all over the news and for good reason. This is the notorious self-cloning crayfish that you may have heard about.

It is a huge problem in Europe, in Africa, in Madagascar, where it is spread. It was discovered in the pet trade, actually. This is not a naturally occurring species.

Some sort of weird mutation happened in somebody's fish tank. And all of a sudden, there was a population of all-female crayfish related to the slew crayfish, which is native to North America. But no one has quite been able to get a straight answer out of how exactly this happened.

Literally, the original pet trade where it originated, the story has been reported as totally confusing and unreliable as to how this happened in the first place, according to Wikipedia here. Long story short, it's really a problem when an invasive species can clone itself. One female can set up a whole new population of these crayfish, and they are aggressive, as in we're worried about their ability to out-compete some of our native crayfish.

They also carry crayfish plague, which is a disease that is really unfortunate because a lot of European and Eurasian and African freshwater species do not have resistance to it in the same way that our North American species do. They get everywhere. It's a little bit worrisome, the thought that somebody might dump their aquarium pet, and all of a sudden, you have an attack of the clones on your hands.

[Carolyn Foley]
Oh, my gosh. Also, boo, attack of the clones. Boo. All of the attack of the clones.

This is just wild to me. Where do they live mostly? Do they live in shallower areas?

I know when we talked about red swamp crayfish before, we talked about them running across golf courses and things like that. Are they potentially going to have battles and things? I don't know.

This is just crazy to me.

[El Lower]
Yeah, it's a possibility. The trouble with crayfish, of course, is they're perfectly comfortable on land for short periods of time. Yeah, you will sometimes see them on your golf courses.

You will see them outside on your patio and go, what the heck is that doing there? They can also move pretty fast over land. If you've ever chased a crayfish, which I spent a lot of my childhood in North Carolina doing, they scoot backwards with great vigor when you're trying to catch them in creeks.

They can really move at a decent clip. You don't want to have to be doing a cloned crayfish roundup if possible. As I always say, please don't dump your aquariums.

Do you have any idea how much paperwork that creates for me? I'm begging you.

[Katie O'Reilly]
Do the right thing and help El out here. Don't dump your aquariums.

[Megan Gunn]
Oh, my gosh. I'm guessing they don't have any natural predators because they're able to spread unchecked.

[El Lower]
Right. Literally, they've only been around for a couple of decades as a species. They have no native habitat.

Their native habitat is a German aquarium, apparently. Where they've spread through Europe and through Africa, plenty of people eat them, apparently. One of the reasons that they've spread throughout Madagascar is that people use them as a food source.

If they happen to escape from a bucket, remember, it only takes one. Yes, they are edible. I have not yet sampled one, but if one happens to come across my plate, I'm sure it will be quite delicious.

[Katie O'Reilly]
It doesn't actually take two to tango, in this case. It's a single dance. Just the one. Very interpretive. I think the interesting thing, especially with marbled, is that there's been a few instances around Lake Ontario, mostly by Toronto. It's not something that is established in the Great Lakes yet. I'm knocking on the imaginary wood here.

There have been some incidents. It's really been important to catch those early on. I know there's been a lot of efforts where they found them in Ontario to hit it hard.

These are small ponds near Lake Ontario, at least a couple of them. Really trying to hit it early in this invasion process. As Elle said, when you just need one individual to reproduce, you don't have a lot of wiggle room in terms of trying to hit things early.

[Brian Roth]
I'm going to add one more thing to the creepy aspect about marbled crayfish. They're really common in the aquarium trade. They're not legal in multiple states, including here in Michigan.

In places where they are, they're oftentimes one of the least expensive varieties of crayfish you can find. You can imagine why, right? It doesn't take a lot to sustain a culture of marbled crayfish.

In fact, it almost takes nothing at all. As you guys know, or may not know, crayfish are perfectly happy eating each other. When one dies, they'll eat each other.

You can almost have a self-sustaining population or brood of marbled crayfish without feeding them at all.

[Katie O'Reilly]
I was just thinking perpetual crayfish machine.

[Brian Roth]
Perpetual crayfish machine, more or less. All the ones that the tank can't support get eaten by the other crayfish. They may not have all the minerals, whether or not they eat the old carapaces or not.

You may need tank water and algae wafers every now and then. That's about it. They'll sustain themselves for long periods of time.

[El Lower]
Cloning cannibalism. This is shaping up to be a great Halloween episode. It's going to be released in October.

[Carolyn Foley]
That's so many weird potential applications. I do want to of our guests, if we were doing a draft like we've done in the past, all three of our guests would have drafted. Like I said, I don't know that you want them on your team, but maybe you do in this particular case because you've got a team that's huge and forever.

But for the marbled crayfish.

[Katie O'Reilly]
Yeah. First round pick. You could have your whole team made up of marbled crayfish just by getting one.

[Megan Gunn]
Katie, I'll move to you next. What's a relatively new invasive species in the Great Lakes region that you think people should know about?

[Katie O'Reilly]
Yeah, so a relatively new or I would say probably under noticed species in the Great Lakes that I think people should know about is the black carp. So people are, I would say people are pretty familiar with the showy invasive carp. The ones that are jumping out of the water, hitting people in the face.

Things like silver and bighead carp. The black carp is part of this family of carp that we're calling invasives or previously Asian carp. And it is a little bit more, a little bit more out, it stays out of the limelight a bit.

This species, similar to the silver and bighead carp, came to the United States in about like the mid-60s, 1970s, generally for use in fish ponds in the southeastern U.S. Whereas the silver and bighead carp eat plankton, the black carp eats mussels and snails. And so these guys were really good at keeping the ponds free of snails that would have diseases that would transfer to the fish. Unfortunately, as with all the invasive carp species, these ponds most of the time are disconnected from other water bodies, but we know that the Mississippi River can flood pretty frequently.

And so it was during those flood times that the various carp species made it into the Mississippi River and then that's kind of a super highway to get many other places in the country. So we really started seeing the black carp show up in some rivers here in Illinois where I'm based, kind of early 2000s, but it's been something that we've noticed more and more and they've made their way kind of marching towards the Great Lakes at a similar kind of, similar path to the silver and bighead carp that we're so concerned about getting to the Great Lakes. As I mentioned, the concern with these guys is not the dramatic jumping out of the water and hitting you in the face.

Their main impact is because they are so good at eating mussels and clams, the fear is that they will be another stressor on top of an already pretty stressed out native freshwater mussel population. The native freshwater mussels we have in North America, not doing so hot. A lot of them are endangered or threatened due to a whole host of factors and this would just be kind of another stressor that they don't need on top of things.

I will say in terms of controlling them, one of the issues has been that it's because they feed on mussels, they tend to hang out on the bottom of rivers and streams, which makes the black carp kind of difficult to sample. And so there's been actually a program through the Illinois Department of Natural Resources to try, it's a bounty basically, you know, you catch a black carp and turn it into them, you get like a hundred dollars. So it's been something like we may not know the full extent of how black carp are, you know, to where they are in the state of Illinois, but I think it's tough because like they're hard to catch, they don't jump out of the water and hit you in the face literally.

And it's, yes, the mussels are an important thing, but I think that, you know, people are also worried about some of the impacts of like silver and bighead carp being, taking plankton out of the water, which is a really important food source for a lot of native fish species. So the black carp, I think it's a little overshadowed, but it is still something I think should really be on people's radar.

[Megan Gunn]
Could they be used to eat quagga and zebra mussels?

[Katie O'Reilly]
That is the, you know, million dollar question. I think it's possible. I also, I'm not sure like what kind of selectivity they have and that being like, you know, do they prefer to eat mussels that are easier to crack open with their crazy throat?

I wish we had visuals here, but like they basically got these crazy teeth in the back of their throat, but you know, they, they crush the shells. And I mean, I would think, you know, zebra and quagga mussel shells wouldn't be too different, but I guess I'm not sure what, in terms of their preferences. We have seen other species of native Great Lakes fish, like freshwater drum eat quagga and zebra mussels.

It just hasn't been enough to like battle the numbers. So it's like, maybe, but is it really going to make an impact?

[Brian Roth]
One of the things that's kind of difficult about the scope of the quagga mussel issue in the Great Lakes is the depth at which they occur, right? So at this point, almost all of Lake Michigan is covered in quagga mussels, all the way out to just about the deepest parts of the lake. And, and thermally, right?

So most fish have an optimal thermal temperature that they prefer to be in. It is cold down there and most fishes won't go there unless they absolutely need to or are well adapted to it, right? Like I think our native lake trout, some of our sculpin species, et cetera, they, they may go there.

But oftentimes these invasive carps, they, they prefer warmer water. And so it's unlikely that they would be able to control quagga mussels out in those areas where they're actually most abundant, where there's the most real estate that is covered by quagga, simply because it's, it's too cold. You know, I don't, I don't like to swim in cold water.

And I'm guessing that these fish don't either.

[Megan Gunn]
There's part of me that finds there's, where's that problematic line of fighting an invasive with an invasive? And then you have, then what do you do bring in another one? And then, yeah.

[Katie O'Reilly]
Like the little old lady who, you know, swallowed a fly. It feels like kind of that situation, like, you know, are we potentially bringing in something that could be more harmful?

[Megan Gunn]
Exactly. Well, we won't know until we know, right? So we'll take it back to Brian.

Do you have another fish species or another, not, not just fish species, but another invasive species that you think people should know about?

[Brian Roth]
One that I think that, and I'm going to stick to the crayfish theme simply because it is my area of, you know, focal area of study, is the signal crayfish. So the signal crayfish was found in a lake in Minnesota, kind of outside the Twin Cities somewhere. And there was multiple adults.

They're actually native to the Pacific Northwest, and they are one of North America's largest crayfish species. And they have these really, really big, robust claws with this little white patch on it, which is the reason how they got their name, a signal, because if they raise their claws, you see a signal, right? And there is real concern because they are a North American crayfish species.

They're not susceptible to the plague, right? And so they could, in fact, establish. They're actually a northern species.

They're found way up into the mountains in the Pacific Northwest. And so there is some concern about signal crayfish that they could become a problem. Now, luckily, it appears as though that population in Minnesota may have declined.

They haven't really found them recently. But it is a fairly common species that's captured commercially, particularly in the Pacific Northwest, and as a result, could become established elsewhere. Like this is, you know, this taxa, at least, yeah, I think it's a signal.

It's what led to severe declines in the European crayfish once it was introduced. And so because of that, there is a real concern, and they are a problem elsewhere in the world, that it could also happen in the Great Lakes. That's yet to be determined.

Our native fish populations like crayfish. And what we're finding with red swamp is that it doesn't matter whether it's red swamp or it's rusty or it's one of our native taxa, they will eat it, right? But the difference is to what degree will they eat it, right?

And so oftentimes what happens with these different crayfish species when one invades is that our native fish species will prefer to consume the native crayfish over the invasive. So while they will eat it, it won't be as much as they'll eat the native, and that kind of accelerates or accentuates the invasion as a whole. So, you know, that's one of the concerns about signal.

We don't know, right? This is something, this is a totally untested hypothesis, whether or not our native predator species would consume signals over our native species or vice versa. So, you know, hopefully we don't actually find out the answer to that.

If signals don't make it here, then I think that that's a happy ending.

[Megan Gunn]
So what is one thing we could do to minimize their movement here? Is there anything that we can do?

[Brian Roth]
Yeah, so certainly I think our state governments for the most part around the Great Lakes have done a pretty good job restricting the possession of many crayfish species more generally. And in particular, states such as Minnesota and Wisconsin have very restrictive crayfish regulations as well as Pennsylvania. So Pennsylvania, you can't possess crayfish, period.

So that's just, you know, but that's pretty restrictive. And some of our other states, you know, this is something that I'm actually working on a project with Katie about regarding regulations on crayfish. And so some of our other states are a little more lax.

And so, you know, put some pressure on your state legislatures to ensure that, you know, some of these invasives that we don't want in the Great Lakes don't make it here.

[Katie O'Reilly]
Yeah, and Brian brings up a really good point, too. You know, in the Great Lakes, it's sort of a patchwork of regulations, and we're only as strong as kind of the weakest regulation because crayfish don't necessarily follow boundaries. Like, you know, if you import it in one state close to a border, they have, you know, pretty, I would say pretty minimal geographic understanding.

So it's one of those things like, we are only as strong as kind of the weakest link.

[Carolyn Foley]
Goodbye.

[Megan Gunn]
This is so troubling.

[Carolyn Foley]
But then, yeah, but like you were saying, like, and it's like, okay, so, but then what's going to happen? But then what's going to happen? And then I was like, yeah, anyway, yep.

[Katie O'Reilly]
But I think what's interesting, too, you know, is things sometimes happen not as we expect. As Brian said, it's sometimes we can hypothesize based on what has happened with a species somewhere else. Sometimes there's whole new novel interactions that we aren't necessarily, we don't always anticipate when a new species arrives somewhere.

[Carolyn Foley]
You guys are making me go back to, like, entomology and Emerald Ash Borer. I remember when, like, everybody was just like, we know nothing about this. And there was all this stuff.

Cool research that happened, but also not good that the research had to happen. So I like your comment, Brian, about we don't necessarily want to know the answer to that question.

[Megan Gunn]
Thank you all. I mean, this is fantastic. Fantastic information.

Not that the species and all the trouble that they're causing is fantastic. But, yeah, thank you for the information. The next El, you're next.

What's a relatively new species?

[El Lower]
Okay. So, taking us away a little bit from our animal bias, let's move to the world of invasive plants. I am our team's sort of de facto plant guy.

I have a little bit of a botany background, and one of the species that is haunting and vexing me most here at the doorstep of the Great Lakes is a very beautiful floating aquatic plant called water hyacinth, or Icornia crassipes. Now, this plant is, I mean, it's very, very pretty. So you can see why people really like to have it in their aquariums and water gardens.

It's called water hyacinth because it does look, in fact, like the spring flowers that you'll see, you know, in April, usually here in Michigan. It's got these beautiful purple flower spikes, and then it's got a really interesting shape. It's got these sort of air-filled sacks or bulbs at the base of its leaves, its petioles here, that help it float on top of the water.

It's just very pretty, very cool to look at. Of course you'd want that in your water garden. As a bonus, it's really hard to kill.

Yeah. Here's the trouble with that, of course. Water hyacinths are, they reproduce like crazy.

These plants can basically clone themselves, and their population can double in just two weeks. That means that, like, if you have 10 initial plants, in three months you're gonna have over 600, and they get packed in really close. They create enormous amount of plant biomass and whatever water body or your little pond that you have.

And, you know, if they're out in the wild, they could actually clog water intakes for power plants and factories. They can get caught in boat propellers. And then there's the usual issues with aquatic plants, as they basically can block out sunlight to all the submerged plants, which is a huge issue.

And then if they die off, they cause that whole reaction that can basically choke oxygen out of the water as they decay and sink to the bottom. It's a big issue. Now, these plants are not currently considered established within the Great Lakes Basin, but here's the problem.

Little populations keep popping up here and there, and so it's like playing whack-a-mole. We have some reported sightings along the Detroit River and in Lake St. Clair, and so the real scientific question has been, okay, are these plants that keep showing up in the same spot, are they actually able to, like, reproduce and overwinter? And we didn't think they'd survive our Great Lakes winters because they really don't like being frozen.

This is a tropical plant. But then why do they keep showing up in kind of the same area again and again? And so, you know, I actually just edited the species profile on this for Glancis, which is the Great Lakes Aquatic Non-Indigenous Species Information System, where we keep track of all of the species we've talked about here.

And so right now the scientific consensus is no, the growing season here in Michigan isn't long enough to actually let them set viable seed. So it's not like a seed bank is set up in the bottom of the lake here and recurring. People keep dumping them.

Remember how I said they reproduce super quickly? Well, it's a great way if you've got, like, a little pond in your backyard. That's not going to be so big.

If your population is doubling every two weeks, then you're going to have to get rid of those plants somehow. And some people think they're doing a kind thing by saying, oh, well, I really don't feel like throwing this in my compost pile or setting it out in the sun to solarize. I'm just going to put it in the water.

Surely this is fine. Spoiler alert, it is not fine. Please do not do this.

So that is water hyacinth for you. And that, along with a number of other aquatic plants that are quite popular in aquariums, are definitely on my own personal watch list. But the thing is, they're not restricted in Michigan currently.

In fact, I can go to the aquarium store a mile up the road for me, and they have some of this stuff sitting in their outdoor tank, floating their whole tank home with them. And I'm like, oh, boy. So I'm hopeful that we will have new regulations on the species before too long, because it's kind of a glaring omission for a plant that can cause so many problems.

[Megan Gunn]
So speaking of causing problems, well, I was trying to see how pretty they were. And they are gorgeous. And you may not have the answer to this.

But one of the things that popped up was an article that shows that they have been effective at removing microplastics. Do you know anything about that?

[El Lower]
A fair number of aquatic plants can actually be used for that kind of phytoremediation, actually. It's not specific to water hyacinth. In fact, a great number of the plant species that we use in Glancis are used for all kinds of remediation purposes around the world.

The trick is just keeping that in check and not introducing them to new environments. So while they can be used, a lot of the plants that we work with are used for wetland remediation to kind of catch stormwater overflow, too much phosphorus on the farm fields and absorb it, stuff like that. Microplastics, willow species can be used to remediate legacy industrial contaminants and stuff like that.

It's actually a very amazing technology. But that's not to say you want to introduce these highly invasive, highly prolific species to an area because you'd like to suck microplastics out of the water. Let's try to find some local solutions for that instead, or at least keep things under very careful control.

[Carolyn Foley]
Because then you wind up with the grass carp situation we were discussing earlier, how things just keep going. And it's like, oh, gosh.

[El Lower]
Yeah. So make good choices, folks.

[Megan Gunn]
That makes complete sense to me. Katie, what is a, what's something else we should know about?

[Katie O'Reilly]
So I am going to take us into a slightly similar direction as El. It is not a plant, but it's actually a macroalgae. And it is called starry stonewort.

First showed up in the Great Lakes area in New York around like late 1970s, early 1980s. It's been on my radar specifically because in the last couple of years, it's shown up for the first time in the Chicago area, specifically in some of the marinas and harbors on, you know, in Lake Michigan. And the challenge here is it as a macroalgae, it grows into these really dense, dense mats.

It actually gets its name. It forms these little star shaped white bulb structures, which are super cute, but that is besides the point. But in growing so rapidly, forming these dense mats, it, you know, reduces the diversity of native plant species, can kind of choke out the water as it dies, removing oxygen, especially in the harbors.

I know there's some concern about like, is this going to affect boat traffic? And it, we believe it made it to the Great Lakes through one of the most notorious pathways, which is ballast water. So for the ships in the Great Lakes coming from the ocean, or really from anywhere, a lot of these big cargo ships have to basically balance the weight of the cargo they're carrying and doing, and they do that balance by taking in and letting out water at different ports.

And so if you have a ship coming from, for example, Europe, that is, you know, taking in water into its ballast there, and then dumping that water when it's unloading or loading in the Great Lakes, you can potentially get something unexpected, an unexpected hitchhiker. That's how our friends, the drysented, the zebra and quagga mussels made it to the Great Lakes, and starry stonewort's kind of in that, you know, most unwanted class as well. I think what's interesting about starry stonewort, besides the kind of cute, cute name, is that it, at least in North America, there's only been male plants found, which is suggesting it's reproducing asexually through fragments and the bulbs.

So, you know, it's kind of in contrast to the marbled crayfish, where we have all-female marbled crayfish, we have all-male starry stonewort. But the biggest thing with that is, because it is this really successful species through fragmentation, there's a lot of concern about boats spreading it unintentionally. Like, you know, if your prop chops up some starry stonewort, it sticks to your boat, it's easy to take it somewhere else unexpectedly.

Exactly. And then, like, you know, all you need is, you know, some fragments to get another population going. So that is really just a good reminder that if you're going out, you know, with your boat or with your fishing gear, making sure that you're cleaning off your equipment before you go to another water body.

You know, we say if you can use something like a pressure washer, that's, like, awesome. But even leaving it out in the sun for, you know, five, like, basically a week, you know, if you are unable to, you know, actually take the time, you know, to clean. But it's just always really tough, because there's all those nooks and crannies in your boat that can keep water.

And we really want to make sure everything's just dried out and clean. So can't stress the importance of that enough, especially, you know, when it comes to things like algae or plants that always seem to just stick where you can't get them off.

[Brian Roth]
Yeah, starry stonewort is, it looks like a number of native macroalgae species. But those stars definitely are indicative. And you can see them.

It's not like, you know, you have to bust out a microscope while you're fishing to see what you got. But I think Katie hits on a really important point, which is the precautionary principle. Like, even if you're not sure what it is, take it off your boat.

I know that, you know, many people now, and I've seen them, you know, when they're inspecting their trailer to make sure the boat's on right, or to, you know, get ready to haul their boat away. Most people do, you know, take a look down. But there are many places, like Katie said, that this can hide.

And so one of those places is in between the bunks of the trailer. So that's the flat part that the boat sits on, and the boat itself, you just can't see it. And because those bunks are oftentimes covered in carpet, they retain water.

And as a result, you know, it does take upwards of a week or so until those dry out, if not even longer sometimes. So, you know, being really careful is a really good start. But, you know, trying to be diligent about plants on your trailer is really important.

[Megan Gunn]
I hadn't thought about them getting stuck between the boat and the boards. That is such a good tip to be looking out for.

[Carolyn Foley]
So the themes I'm seeing emerging from the species that you've picked are, you know, weird cloning, asexual reproduction, and warming trends, or other, like warming in particular, making habitat where maybe there wasn't habitat before, or, you know, shorter winters, meaning things don't necessarily die off. So that is all the more reason, I feel like, for people to pay more attention, because those are not necessarily things that we can control just yet, right? Like, we're not necessarily going to be able to change the genetics of a plant or something like that.

[Brian Roth]
One kind of key point is that even though we think that Michigan is cold, and you see ice on our lakes, right, or, you know, less and less often, of course, but even still in places where there is ice on lakes or ponds, it's still wet underneath. It's still warmer than freezing underneath, right? And as a result, and even as you get closer to the sediment, because of all the decomposition that's occurring in the sediment, it's actually even warmer in the sediment, right?

And so because of that, you know, these species have a tendency to kind of buck our expectations regarding whether or not they can survive a winter here. You throw into that, like cooling ponds from our power plants, or sewage outflows, and things like that, where we have kind of artificially elevated the temperature of the water, those may support species that you don't expect or wouldn't think could survive, say, a Michigan winter, or a Wisconsin winter, or a Minnesota winter. Those hot ponds that come out of power plants, those are hot, right?

They're, in fact, so hot that, you know, most fish will leave them during the summer, right? But during the winter, oh, nice and toasty. Let's get in the sauna.

You know, that's what they're telling their buddies.

[El Lower]
And I mean, that also helps invasive aquatic plants survive as well. If there's an area that doesn't have ice cover, or feels nice and tropical to some of these plants, that is where they're going to set up shop. So if you're looking for invasive species, you can do a lot worse than checking the outflow of some of these power plants and factories with that warm water, because you'll get a very interesting array of species there sometimes, taking advantage of that toastiness.

[Carolyn Foley]
That's wild. Okay, well, this has all been really, really eye-opening. And it is, we've talked a lot about drysonids on this show.

I think, you know, they're major ecosystem engineers and stuff like that. But there's so much out there that we need to pay more attention to, I think. Thank you for sharing some tips that we can do, and a couple of new species to explore.

But of course, as you all know, this is not why we brought you on to teach me about the Great Lakes. We brought you on to teach me about the Great Lakes to ask if you could choose to have a great donut for breakfast, or a great sandwich for lunch, which would you choose? And since there's three of us, and we're running a bit short on time, and I want to make sure you can get to your next, I guess they're not necessarily a Zoom meeting now, but maybe go real quick, you know, like, donut or sandwich?

And where's one, like, your favorite place to get one near where you're sitting right now?

[El Lower]
I don't really have much of a sweet tooth. So, you know, I'm always going to pick sandwich. And I got to plug my favorite restaurant, which is Bellflower here in Ypsilanti.

If you are a fan of fried fish, they have a fabulous fried fish sandwich. And in fact, they even have smelt, fried smelt in the spring when they're running. So come enjoy some delicious invasive species at Bellflower Ypsilanti.

[Carolyn Foley]
Thank you, Elle.

[Katie O'Reilly]
I'll jump in next. I'm also all for the sandwiches.

I think you have a lot of variety there. And my favorite sandwich, if you're ever in at the University of Illinois in Urbana-Champaign, there's a place on campus called The Bread Company, appropriately enough, and they have some awesome sandwiches.

[Carolyn Foley]
What's the one to get?

[Katie O'Reilly]
There's a portobello mushroom one that they have, a vegetarian option that is, it just is perfection.

[Carolyn Foley]
Awesome.

[Brian Roth]
I am also not a sweet tooth person. So I'm also going to choose a sandwich.

[Carolyn Foley]
Ah Sandwich.

[Brian Roth]
All sandwich. I'm not a sweet person. I mean, I'm sweet, but my tooth is not sweet.

And my vote for the world's greatest sandwich period is a banh mi. And so there's a local place here near campus called Fusso One, and it's right near campus and it makes the most delicious hot banh mis that I have ever had. And so get the beef or pork and you'll be set.

In fact, you can get two for like the price of a burger because that's one of the great things about banh mi.

[Carolyn Foley]
Awesome. Awesome.

Awesome.

[Megan Gunn]
Thank you. We have linked those to, we will link them in the show notes. I'm excited to go and try all the new places.

We will, like one of the things Stuart and I talk about is like, okay, well, I guess I talk about, he doesn't talk about, let's go on a field trip to all these restaurants that everybody has mentioned and visit them while we're there. Visit the guests while we're there. My question for you all is, what is a special place in the Great Lakes that you'd like to share with our audience and what makes it special?

[El Lower]
Sure. So I have shared a couple places before since I've been on this podcast a few times, but today's choice is Belle Isle on the Detroit River. So it's really cool.

It is between the US and Canada. You can get to it over a little bridge and they have so much cool stuff to see and do there. It is, I believe it is, you can get in what the state parks pass, but they have an aquarium that was built in the 1910s.

They have this beautiful conservatory full of tropical plants that just underwent renovations. They have a nature center so you can learn about Great Lakes native species, as well as some of the habitat threats that are facing the Detroit River, as well as the Museum of the Great Lakes, where you can learn more about the Edmund Fitzgerald, you can learn more about shipping in the Great Lakes, and you can even drive a boat simulator and try not to crash into the buoys. On top of that, there's beaches, there's walking paths.

It's just a really fun day trip.

[Katie O'Reilly]
I can jump in next. Similar to Elle, I've mentioned a few places over the years. And this time I have to give a shout out to Bradford Beach in Milwaukee, Wisconsin, which is just a really nice, it's right there in the downtown area, but you wouldn't think you are in a super urban environment.

It just is a really cool beach. And part of that is a selfish reason I'm plugging at this time. My brother is getting married in downtown Milwaukee and he and his fiancee go to Bradford Beach all the time.

So I'm just excited. They're going to have their ceremony with Lake Michigan as the backdrop. So you can't ask for a better Great Lakes family experience.

[Brian Roth]
I'm going to support one of our Michigan towns, Bel-Air. So that is probably best known as the place where Shorts Brewing is. However, it is up north and it's a little isolated.

It takes a little bit to get there. However, it is surrounded by some of the prettiest lakes you will see in the entire state. So Torch Lake, Lake Bel-Air, Intermediate Lake, Antrim Lake, et cetera.

Plus places like Traverse City and Sleeping Bear Dunes are not that far away. So you really have access to a lot of the northern Michigan tourist sites in a short distance, but it's still a very small town. So if that is something that you enjoy, I really encourage you to check out Bel-Air in Michigan.

[Megan Gunn]
Excited for travels.

[Carolyn Foley]
Absolutely. Well, thank you all so much for joining us yet again and sharing knowledge with us. About invasive species and the locations and the food.

And it's always really, really fun to hear what you all have to say. You're all so good at what you do. So thank you for joining us and coming on again.

This is one of those Stewart's gimmicks that bits that I mess up. Thanks for coming on and teaching us all about the Great Lakes.

[Megan Gunn]
I'm only mildly terrified about all the new movement and just things sound scary.

[Carolyn Foley]
It's wild. So the whole lake, they're cloning and it's like, meh, okay. From a science side, that is fascinating. That is just straight.

Because I was thinking about how, before we did this episode, I was thinking about what invasive species haven't we talked about a bunch? And I was thinking about the fish lice and the water fleas. And I'm like, they look like they're from another planet and they're from here.

And I thought, oh, well, and then they start talking about this. I should probably be, I probably shouldn't admit this, but I hadn't heard of marbled crayfish before because I live in a hole sometimes. And I was just like, what?

This is crazy.

[Megan Gunn]
Even that. Flathead catfish are native to the southern Wabash River area. And so to know that they're invasive elsewhere that's not that far is crazy. But even just like being able to reproduce from the fragments, I think that's probably one of the most terrifying because things rip all the time.

All the time. And just like, maybe it got caught up in like a prop or something.

[Carolyn Foley]
Yeah. Yeah. And it was interesting to hear about the water hyacinth because back, like it was a while ago when I was at the University of Windsor, like 20 plus years ago, when there was a master's student who was working on water hyacinth. And every single year, because there you had to give a presentation as a grad student every single year on your update, on your research to the department. Every single year, there was one person who said, what are you doing?

Because the student was doing a bunch of different lab experiments and like looking at, I don't know if it was genetics or chemistry or different things like that. Every single year they asked, what are you doing with your leftovers? Like, what are you doing?

And what they wanted to hear, and this was all in a lab, right? But what they wanted to hear was, you know, because I was an undergrad, I was like, why do they keep asking that? And somebody said, it's because they want to hear like we're incinerating them or things like that so they can't.

Yeah, crazy, crazy. Oh, okay. So before we forget, we did have, this is for Stuart, we did have a short discussion.

So like Katie was talking about, you know, starry stonewort being cute. And we're talking about how the plants are beautiful and things like that. I actually think that round gobies are kind of cute, like with their cheeks and stuff like that.

We did talk briefly about goby dogs. Apparently the goby dog idea came up after Brian Roth at one point, because he said, what do you say? Do I want to know what a goby dog is?

And everybody else on the line said, no, no, you do not. No, you do not. But then Megan very kindly explained Stuart's business plan.

So. Teach Me About the Great Lakes is brought to you by the fine people at Illinois Indiana Sea Grant. They are fine people.

They are wonderful people. We encourage you to check out all the cool stuff we do, which is pretty broad and very interesting. And that's not a humble brag.

That's like the truth. At iiseagrant.org and at ilinseagrant on Facebook, Blue Sky, Instagram and other social media.

[Megan Gunn]
Our senior producer is Carolyn Foley and Teach Me About the Great Lakes is produced by Megan the Lake Lover Gunn and William Miles. Ethan Chitty is our associate producer and fixer and our coordinating producer is Moti Gumbiade. Our super fun podcast artwork is by Joel Davenport and the show is edited by Sandra Sabota.

[Carolyn Foley]
If you have a question or comment about the show, please email it to teachmeaboutthegreatlakes at gmail.com or leave a message on our hotline at 765-496-4474. Or if you want, send Stuart a postcard because he really loves postcards.

[Megan Gunn]
And for our audience, thank you for listening and keep creating those lakes.