Stuart Carlton 0:00
Let's go with the theme song in the intro, um, now

"theme song" 0:03
teach me about the Great Lakes. Teach me about the Great Lakes.

Stuart Carlton 0:08
I forgot to ask if you could hear that. Could you hear that? Yes, perfect. Welcome back to teach me about the Great Lakes, a twice monthly ish with an emphasis on the ish podcast. Let me try that one again. What I even say, welcome back to teachers, twice monthly podcasts in which I ask people are smarter. Wow, this is where we are. The thing is, I started thinking, it'll be fun, okay, all right, so, so you're gonna do it, sure. All right,

"theme song" 0:38
teach me about the Great Lakes. Teach me about the Great Lakes.

Carolyn Foley 0:44
Welcome back to teach me about the Great Lakes, a twice ish monthly podcast in which I Stuart Carlton, get people who are smarter and harder working than me to teach me all about the Great Lakes. I am Stuart. No, I'm not Stuart Carlton, but Stuart Carlton is here.

Stuart Carlton 1:01
arMy name is Stuart Carlton, and I now remember the introduction to the podcast. And I know a lot about asking Carolyn, what is the introduction to the podcast that we have not had a regular schedule for for approximately I don't know one year, but I don't know a lot about the Great Lakes, and that's the purpose of this show. In fact, I'm joined today by the one, the only, the special. Carolyn. Foley, Carolyn, what's up?

Carolyn Foley 1:25
I'm channeling you today. Stuart, so I will talk into more emphatic noises. I'm doing well. I'm excited for today's show because it's one we've been hoping to get going for a while.

Stuart Carlton 1:37
It has been a while. Am I overly emphatic? I could be less emphatic,

Carolyn Foley 1:40
no, no, no, no, no, I'm just being silly.

Stuart Carlton 1:43
That makes sense. Why? Yeah, I'm excited too. We have been waiting for a while to talk to today's guest, and we're gonna talk about something that I knew a lot about when I lived in Florida, but I didn't even know it was a thing in the Great Lakes until recently, and that thing is bull sharks is largely what we're going to be talking about today. No, we are not talking about bull sharks. We are talking about sinkholes. Sinkholes. That's what it was also in Florida where I learned about that. Maybe we'll get into bull sharks potentially, because, who knows. But anyway, let's just go straight to it. First, of course, since we're speaking with a researcher, it's time for our researcher feature.

"theme song" 2:18
You a researcher feature, a feature in which your research are gonna teach us about the Great Lakes.

Stuart Carlton 2:38
Our guest today is Dr Bopi Biddanda Biddanda. He is a professor of Water Resources at Grand Valley State University in the Annas Water Resources Institute in Muskegon, Michigan, home of drowned river mouths, al the wazoo or the Kalamazoo anyway. Bopi, how are you today?

Bopi Biddanda 2:54
I'm very good and I'm very excited about this. I have a feeling this is going to be more, even more fun than the sinkhole research I do,

Carolyn Foley 3:02
that's probably not likely

Stuart Carlton 3:06
we'll do our best well, so let's talk about that, actually. So sinkholes, so I did know that they existed in Florida. I lived in the St Petersburg area, and every now and again, a sinkhole would open up and, like, swallow your yard, maybe a dog, often an alligator or whatever. So do they have my understanding is, you do research on sinkholes in the Great Lakes. Do they have sinkholes in the Great Lakes?

Bopi Biddanda 3:26
Yes, they do. It's not uncommon to find sinkholes on land like in Florida, in the Yucatan peninsula, which are basically slabs of limestone, karst, karst which are very porous and dissolvable sedimentary rocks, mostly made out of carbonate you find on lands in coals around Alpena, Michigan, which is, which is, you know, topped by limestone. You know, we have our largest quarries out there for, you know, for limestone. And you can see them. If you fly in an aircraft and you're Alpena, you'll really all online sinkholes that are perfectly round with with water in the bottom, rainwater and groundwater. But what was today is all submerged sinkholes, sinkholes that pop up in the bottom of the Great Lakes. Yes, yes, there are many of them. We have only studied a few. With that there are hundreds, if not 1000s of them in all four of the Great Lakes which are underlain by limestone karst.

Carolyn Foley 4:35
So is that that's a requirement that it for them to form? Is this karst layer?

Bopi Biddanda 4:41
Yes, a cost layer seems to be a requirement, because cost is the most porous of rocks in by by that nature, it makes it very precious for humankind, because they, in fact, roughly 50% of the wells in the world going. Cost aquifers, because they're very spongy. They hold a lot of water, in fact, and the dissolution creates caves and caverns and spaces where water can fill, but also water dissolves. That's why you have sudden giveaways, where you have a house swallowed up, or a road falls down, and things like that. But a similar thing can happen underwater, where, you know, groundwater percolates down, rainwater percolates down through karst conduits, and then it hits a different bedrock, like one of those, you know, non sedimentary rocks that are being cooked in the belly of the earth that don't yield anymore. And so, you know, there's no more down to go. So it climbs up, and it can pop up below the Great Lakes, which are still, you know, limestone, and over time, dissolve it, and then groundwater start pouring out.

Carolyn Foley 5:59
Okay, that's wild, okay?

Bopi Biddanda 6:01
And if, in my studies, and if so, those are just sinkholes being created by groundwater dissolving limestone at the bottom of the lake. But if, if these, this groundwater goes through Paleozoic marine evaporates, which, by which I mean 400 years ago, when Michigan was under the sea, and where the seas have left behind their salts Paleozoic evaporate, then along the way, they pick up the salts, especially sulfates and sulfur. And if the continuity is long enough, they lose all their oxygen because any any organic carbon that's in rainwater and in soil and in the ground, it's respired away into carbon dioxide, so there's no oxygen and high sulfate from the Marine evaporates, it picks up, and that creates a whole New stage, stage similar to what early Earth was. It's when its shallow seas were low in had almost no oxygen. In fact, no oxygen, and were high in sulfur. So low and behold, when, when water with the suburbs sink in the sinkholes, pops up, pops up, but carrying these marine evaporate salts, sulfur sulfate in particular, and has gone through a long conduit where all the oxygen is gone, increase those primordial conditions and and there you will see proliferation of microbial match, Just like maybe how it was in the early biosphere. There are there. Their reflections are provided view into how the early biosphere might have been and how that might have led to oxygenation of our planet over a long time, talking to 2.5 billion years,

Carolyn Foley 8:02
billion years.

Stuart Carlton 8:03
So there's a lot, a lot to unpack here. So essentially, as the water forms these sinkholes and picks up the salts, and if it sort of has this primordial gumbo down in the bottom of the sinkhole, essentially, you said that, at least, to the formation of a microbial mat. I don't even, first of all, what is a microbial mat? Is that? I mean, I mean, I think of a mat as something that's like stitched together or thickness. Is it that? Or is it just so many that are close together? It looks like a mat?

Bopi Biddanda 8:27
That's a good question. Mats, you can imagine them almost like a carpet in your hole, or the throw rug. And these first cyanobacteria that made you know, that came about and learned how to do photosynthesis or filamentous and by nature, they became mad farmers. They would weave in and out and and expand, seeking better habitats in the shallow seas of the of the of the ancient seas. You know, you know between 332, point 5, billion years ago. So they would crawl around and and view mats and cling to the surface. Probably they clung to the shallow seas where at that depth, where UV was not too strong, but not too deep, where there was no light at all. So they couldn't photosynthesize. And we find the same kind of system in Lake Huron sinkholes, where the mats are very motile. The filaments, in fact, they they can run 10s of micrometers in minutes, even though they are only, you know, point, about five to 10 micrometer thick. They can run in terms of body length. They can run faster than a cheetah. Very fascinating. So they're very, very they're speedy. Gonzalez they and they most rapidly move at the turn of the day and the night. The photosynthetic filaments move. Rapidly upward, seeking sunlight at dawn. And there are chemosynthetic ones that are probably even more ancient than the photosynthetic ones, because at first they were, you know, there was the very first life supposedly learned how to crack the chemicals, preferably around the thermal vents in the sea, okay, where the sulfate rich environment. There was no sunlight but the sulfur, they could crack h 2s, just like photosynthetic organisms now can crack H 2o, the water. So there's the sulfide water analogy. So those organisms will will climb up at night to the Mad surface. The they're white in color or pigmentless. So the Mad they're seeking hydrogen sulfide that's been generated in the in this in the sediment at the surface, and harvest so they can chemosynthetically grow. And at dawn, the photosynthetic ones migrate up and and harvest the sunlight to photosynthesize. So you have this day and night shift where it's purple during the day and white at night. So it's pretty dramatic, dramatic. We call it the one millimeter journey, after that movie, the 100 foot journey, one millimeter journey. But to think that for the longest time ever, you know, two to 3 billion years. This one millimeter journey might have been the largest mass moment of life on the planet. That is amazing. You know, right now, it is the zooplankton that migrate hundreds of meters all over the planet, including the Great Lakes. You know, during the day, they go down to hide from predators, and UV at night, they come up to heart, you know, feed on the phytoplankton and not be picked up by visual predators. So zooplankton are the biggest mass movement of life on the planet daily. But to think that these microbial mats might have been doing those one millimeter journeys for a long time, and to think that that might have been crucial for this success in this turbulent primordial ocean, you know, being able to take, stay on top with the way the biochemistry changed, they could be on the top and harvest sunlight at the same time. It's a, it's a, you think it's probably the was the very first tango in life, daily dance.

Carolyn Foley 12:28
Yeah, that's fantastic. So do you have images of like a daytime mat and a nighttime

Bopi Biddanda 12:35
Yes, we have, and we they are available in that EOS or American Geophysical Union article we published. And the last time we were out there a year ago, we put a time lapse camera down there. I had them go, go, you know, take half an hour snapshots through day and night. Oh, it is dramatic to watch this turn, you know, go purple during the day, I switched to white during the night, and then back in the lab, divers collected intact cores, you know, intact cores, but carbon rich sediment in the bottom and a thin layer of intact mats on the top. And we we have this, what is called a micro profiler. You all know about this, like oxygen probes and temperature probes, like thermometers and so on that we can use to measure a water column, but these microprobes are so thin, they're only as thick as your hair, you know, just 100 micrometer thick. And with an automated, programmed motor. You can tell them to go only 50 meters, 50 micrometers at that at a time. So they can go like they can have 20 intervals in a one millimeter mat. So they can probe from the water to the mat, through the mat, down to the sediment. We have classic Day Night profiles of how, you know, oxygen increases during the day towards the top of the mat, and hydrogen sulfide decreases then and at night. At night, things reverse. Hydrogen Sulfide increases, oxygen declines. So that's what these organisms are making and optimizing their position for.

Carolyn Foley 14:28
Yeah, so cool.

Bopi Biddanda 14:29
So that's very nice synchrony, and we published that in the Journal of Great Lakes research last year.

Carolyn Foley 14:35
So we'll, we'll have those links. I think this will wind up being episode 99 or it might be 98 but it'll be in the show notes. And at teachmeabouttheGreatlakes.com. I have one question. So you mentioned divers. How deep are they diving that they're collecting the cores that you then bring back to the lab and do additional. Uh, studies on how deep is the location that they dive to collect those cores.

Bopi Biddanda 15:05
Very good point. This is something I should have stated the beginning. Sinkholes occur at all depths. Okay, so we have a natural gradient. They're once in El Cajon Bay, six miles from Alpena, Michigan, in the Turner Bay National Marine Sanctuary, where you can wade into gurgling springs. You know, in alcohol and Bay, you can see them on the surface. They're a me in a meter below or so the groundwater comes and it it is popping out because, due to hydrostatic pressure, and creates rings on the surface. So you can see something is bubbling out there, and it smells hydrogen sulfide there, just like how the early Earth probably was, was a stinky place. And and then down at the very bottom, you see purple and white filaments bafting in the in the in the groundwater flow, and patches of mats that are clinging to the lake flow everywhere else. The lake is different. It's got this, you know, green algae, large macrophytes growing and then phytoplankton in the water. But here it's very different. No oxygen, high sulfur, and only microbial, you know, like how it might have been in the early part. There was no room for larger organisms and complex organisms because it was oxygen less. Yeah. So we have a gradient from these shallow variable springs to the one we have studied a lot, which is divable at 23 meters. It's, it's at middle island. It said island about six miles offshore of Rockport, Michigan, north of Alpena. There we can dive down. You see, if there's a just next to middle Island, and the north face, like like horseshoe shape in the shoreline has been carved out. That's where the sinkhole formed, and groundwater gushes out in a pot and forced out and spreads out. It's a, you know, amongst it's created amongst huge boulders of cars, of limestone that are size of a bus. And you can see the camera and where groundwater is pouring out, and then down below it's this colorful mats, which are purple during the day and white at night. So divers have a ball with this and underwater waterfall, because groundwater flows over a sill and goes down about 10 meters into the into the up to from about 10 meters up to 23 meters to the lake floor, you can kind of surf the underwater waterfall all around you is suddenly it's like a is like a painting tapestry of colors, okay, just until you get maybe it's the size of a football field, until you get to the edges, where it again, bigger gets to be boring. Grail, Great Lakes floor. And there you can see fishes and invertebrates and all trying to grab a piece of the pie, you know, because it's reasonably oxygenated, because now the groundwater is mixed, yeah, and groundwater is salty and also low temperature. So together they it helps them cling to the bottom. So it's a constant, you know, almost like a chromatograph, you know, you know, condition that helps the mats thrive. You know, from the source, groundwater comes out. It pours out and spreads from its center outwards, so it can be as thick as five meters at the origin, and then down to almost nothing in a distance. So metazoans and higher organisms, fishes, like bar boats and other fishes, will try to enable at the periphery, but they cannot really come in to the to the microbial world. So then we have offshore sinkholes where it's here in the 23 meters, but five to 10% of light gets down. You know, five to 10% of what hits the surface gets down. So they can be photosynthesis, and efficient photosynthesis, because of cyanobacteria are masters at harvesting low levels of light with their, you know, phycocyanin pigment and accessory pigment, in addition to chlorophyll. But there are offshore sinkholes, a fortic at over, over the 100 meter isobat there. There's no sunlight, so you kind of have the photosynthetic cyanobacteria. You only have the chemosynthetic, wide or pigmentless, filamentous archaea and bacteria that make that make chemosynthetic carbon, just like numb. What happens around the thermal vents and cold seeps in the in the sea. And so they are white in color. There's no other pigmentation, no green or purple there. So that is also fascinating to think that we have analogs of the deep sea vents and seeps right here in the in the Great Lakes at just 100 meters. We're not talking about 1000 or 10,000 meters. We're talking about 100 meters. And in fact, we have genetic information from genomics that show big geotoma, which is one of the dominant sulfur oxidizing groups, is those filaments are here too, the same genus, but we don't know if it's the same species, but the same genus. So there's a lot of these parallels to deep sea. You know, everywhere you go, even on land or fresh water, we see marine connections. Because I think we're still a ocean planet, you so, you know, in this case, it's the memory of the old seas. You know, the salts that are fueling, fueling these mats, Mats under the water. So there's a gradient of them. And I should mention before I forget that you know, for a long time we were only been studying the Lake Huron sinkholes. We always suspected from anecdotal stories from divers from Ontario, from Lake Erie and Lake Michigan. Oh, my family went diving here and there and from purple mats, and they were even sent some pictures and so on so. But recently, we've done some scientific studies that show that there's definitely sinkholes with purple and white mats in the Lake Erie Basin.

Carolyn Foley 21:40
Which Which part of Lake Erie, which?

Bopi Biddanda 21:43
It's the like Monroe County. It's this South East, most corner of Michigan.

Carolyn Foley 21:50
Okay, okay,

Bopi Biddanda 21:53
yeah, it's called The Great sulfur springs. It's a it's been engineered now because there's farming and other things around it, but the sinkhole still, still is there and seems, the mat seems, still seems to process again. It's high sulfur, no oxygen, water, high conductivity because of the salt. At the very bottom, there's this purple mats that are, you know, and it's fascinating, because they some in the during the late growing season, the mats, the carpets, they kind of pull up into little hills because their sedimentary gasses, methane, builds up and it burns so it pulls up the mats. And in places you can see them even torn off. We think that's how the mats actually disperse, torn off, and then they float to the surface, and then they could land in the beach, dry up and get air carried, or become part of the water current in in the Great Lakes and go places. Yeah,

Carolyn Foley 22:52
so, so do they rehydrate later and kind of reestablish

Bopi Biddanda 22:56
the lab we have seen. My students are actually running an experiment, a torture experiment to speak of torturing them in different ways and seeing if they revive, them for different different times at different temperatures, and then see if they revive. And the initial implication indications are that they rapidly revive. They they hydrate, and the pigment colors come back. My students tell me that they won't start moving me moving towards, you know, like if you put them in a petri dish, hydrate them. You give them only a pinpoint of light, you know, or, you know, cover them in aluminum foil, but only give them a pinpoint of light in one corner, and you see them moving towards that, you know, over hours and days. So they say there is there's indications they are already moving towards that. So these are all encouraging signs that they are tough. Probably they made it through all this deep time and are able to disperse. Yeah, in case you didn't know the closest analogies to these purple mats and hills they make. You know there are little we call them purple Ridge Mountains, like the Blue Ridge Mountains, although these are only a food high or so have been found in in the dry Valley lakes, dry Valley permanently ice covered lakes of Antarctica. Oh, wow. National Science Foundation as a program studying them as analogs for possible you know, extraterrestrial life we may find. You know, under the icy Ice, ice and oceans of icy, oceans of Europa, for example. Yeah, that is so cool.

Stuart Carlton 24:49
So these are really sounds like dynamic systems, right? And I think a lot of your work probably is just using this as an. Analog, like you're saying for early conditions on Earth, because it's a way to sort of look back into prehistory or primordial times. But, but what is the relationship between the sinkholes and like the lakes more broadly? If that makes sense, like is, is it a source of nutrients or something for other organisms within the lake? Or how? How do they affect the broader lakes in general?

Bopi Biddanda 25:24
Yeah, this is a very important line of inquiry. We just started. We don't even know the age of groundwater. That's popping out. Not only, not only, we know something about the composition, because we measure the nutrients and conductivity, sulfate content and nitrate and phosphorus content and those things, but yes, what is the contribution of sinkholes? Groundwaters are big contributors to the lakes, often ignored because we only measure measurable surface water flows. There are USGS studies that show that groundwater contribution to the Great Lakes dynamics is almost as important as the surface run runoff into and out of them. So these are big, what portion of that is, think coal derived? We don't know, but I think it's, it's definitely, you know, at an around, or maybe more than one person, okay, you know, depending on how numerous and numerous they are. There's very little reason to think they're not. They're not, you know, 1000s, if not hundreds of 1000s in the in all over the Great Lakes which are limestone based. Yeah. So we, we're also worried about contaminants that could go rapidly from from anthropogenic sources on land to distancing calls, you know, or even in terms of conservation, we are worried also about what happens if we pave over a potential, you know, rainwater source for distancing, coal? Do we just choke it. You know, there's all these considerations. So we're trying to quantify the age. Preliminary information is they're not, they're a mix of old, ancient water and new but tending tours more recent, because they have signals of sulfur hexafluoride SF six, which is a anthropogenic production, you know, made for, you know, or as a refrigerant, and so on in the last 60 years or so, so dominance, the major indication seems to be there a mix of old and new water. But the new water is showing a dominant signal in the, at least in the about three sinkholes we measured so that there they might even reflect rainfall on land with a lag of few weeks or days.

Stuart Carlton 27:48
So here's the here's the depressing questions, and I got two of them. One is, have you figured out whether or not sinkholes are loaded with microplastics? And then the related question is, what percent of sinkholes are PFAs? Do you think at this point?

Bopi Biddanda 28:03
Yeah, there's if, the if the if our initial signals are that these are, these are not receiving predominantly ancient water, meaning, you know, Melanie or more they would have, they would be actually very good sentinels for looking at some of these modern anthropogenic contaminants, because, as it's very possible, they have not yet got them, or are just beginning to be contaminated with both the ones you mentioned, you know, plastics and PFAs, The Forever chemicals. So those would be good sentinels to start looking at now, and there would be great observatories. That's what I think as as an indicator of change up and above in the terrestrial biosphere, because they're kind of distant, distant and removed as of now, but probably not for too long, yeah, because they are intimately connected with the surface of all

Carolyn Foley 29:07
it's almost like you can do time travel, where you're going back and forth. That's really, really cool.

Stuart Carlton 29:15
Well, Bopi, this is really interesting. And I could sit here and listen to you talk about sinkholes all day, genuinely, genuinely Yes, and your knowledge is amazing, and your poetic way of speaking about them is inspiring. But that's actually not why we invited you here on teach me about the Great Lakes this week. The reason that we invited you on teach me about the Great Lakes is to ask two questions, and the first one is this, if you could choose to have a great donut for breakfast or a great sandwich for lunch. Which would you choose?

Bopi Biddanda 29:45
I'm not a big donut person, so I'll go for the sandwich. I go. Muskegon here, where I live, has a lot of good places, good eating places. I'd go for fatty Lumpkin sandwich shack. Which is a walking distance from here, and me and my lab mates often go over there for for a bite to eat.

Stuart Carlton 30:08
There we go. All right, so when I when I'm in Muskegon, looking at the Drowned river mouths or what have you, and I go to fatty Lumpkin sandwich shack. What sandwich should I get from fatty Lumpkin?

Bopi Biddanda 30:19
I don't remember. chicken sandwiches or beef sandwiches are just very, very good. I sound like a promotion.

Stuart Carlton 30:29
Oh, yeah. Well, that's what we're here for. All right, I'm going to their website now. No, I don't want you to lose my location. All right. Well, I'll let you know.

Bopi Biddanda 30:39
Okay, okay, and

Carolyn Foley 30:42
that's great, and that's just a great name for us,

Stuart Carlton 30:46
fatty Lumpkin.

Bopi Biddanda 30:47
It's probably little hole in the wall place.

Carolyn Foley 30:52
Okay? So the second question we wanted to ask is, what is a special place in the Great Lakes that you'd like to share with our audience, and what makes it special?

Bopi Biddanda 31:03
I mean, from my if it's related to the sinkholes, I would definitely say the Thunder Bay and the Thunder Bay National Marine Sanctuary. It's incredible place because you have, you know, wealth of shipwrecks there maritime history, and the centuries, it's one of the first, and I think the one of the second in the freshwater system. You know, there are marine centuries. You know, there's Wisconsin has one now, but this has been there for quarter century, and it's full fledged great maritime museum for visitors, and boats can take you out to see shallow shipwrecks, and I guess you can go diving with sports divers to visit some of these shallow sinkholes as well. So I would call that my favorite. But I definitely have to put in a pitch for where I am the Drowned river mode systems. There is, there's something over 24 of them along West Michigan, and they are all in, you know, I'm a carbon carbon cycle person, a microbial ecologist. They're all hot spots of carbon cycling. They are, they are these estuaries are at the end points of major watershed, small and big. You know, Muskegon, it drains the second largest watershed in Michigan. They make their great balance between the less productive rivers, which are, you know, which are nutrient rich, but are turbid so light doesn't get in, but when the water comes into this drowned river mode estuaries there, they find a great balance the the opaque particles settle down, and the phytoplankton see the nutrients, and they go to town. They make organic matter. They can make food and fishes and other thing. Food web thrives in them, and the residence time of a week to couple of months in these in these systems is just right. So things don't get just flushed out, but they can complete life cycle. So we have some of the best fishing grounds in all along these two dozen drowned river wild estuaries. And it's wonderful that they also make good places for harbors. And they are great, you know, places for people to live by the water, you know, major estuaries, okay? They also are problem sites because of anthropogenic impact. Okay, so we have this gradient of north to south. You know, you know, less anthropogenic impacted to more anthropogenic impacted systems. We're trying to make these, this wealth of naturally and anthropogenically impacted systems. As, you know, argued that it be one of the national national assuring research reserves. They're hoping we have a petition to the Michigan, you know, at Michigan, and to forward it to at national level. Hopefully it'll be successful. So we can invest in studying these, you know, very biodiverse, and they are basically carbon cycling hotspots and fisheries rich and people rich places, hopefully we can study them better and invest in long term conservation of these, these water bodies, yeah, ground river mount systems, and our institute is right at the Bank of one Muskegon Lake. So, you know, we can see Lake Michigan from here. It's a Yeah, it's one of my favorite places.

Stuart Carlton 34:42
Fantastic. Well, Dr Bopi Biddanda the professor of Water Resources at Grand Valley State University, at the Ennis Water Resources Institute in Muskegon, Michigan, home of drowned river mouth and, of course, fatty Lumpkins sandwich. Thank you so much for coming on and teaching us all about the Great Lakes.

Bopi Biddanda 35:00
Thank you,

Unknown Speaker 35:20
well, that

Stuart Carlton 35:27
was excellent. So cool to hear somebody talk so passionately about sinkholes, which, a, I barely know a thing and B, I had no idea that they were so fascinating and so prevalent in the Great Lakes.

Carolyn Foley 35:38
Yeah, it's the like, this is the primordial soup. Is just like, just made the head exploding thing, because this is a recording.

Stuart Carlton 35:47
It was a little, oh yeah, for those you write not watching, which is everybody except me and Carolyn, yes, yeah.

Carolyn Foley 35:56
But it's also, it just makes me think of that, that quote that it's bacteria's world, and we're all just living in it, or, like, it's my microbial world, and we're all just living in it, like, yep, they will survive. They will survive.

Stuart Carlton 36:10
They will. Yes, they will. It's interesting to talk to a Yeah, because he's a, he's a water guy, right? And, and what? And so I'm like, Oh, what is, What influence does this have on the broader Great Lakes? And I'm waiting to hear about salmon. And you know, if everything goes wrong, maybe you'll hear about, like Lake Sturgeon or whatever, but, but instead, it's, it's all varied water. So that's, it's good to get that diversity in terms of how people think through science as well.

Carolyn Foley 36:33
Yeah. And it was also, so we were talking about the Drowned river mouths, like along there, and that was one of the first places I ever did field work, you know, a number of years ago when I worked with Jan szubarowski. And they're, they're just stunningly beautiful, like there's, they're gorgeous drum over mountain, well, like the the surrounding area I was there in, you know, if you go there in, like fall or late summer, you start to get these beautiful colors. And it's just like, they can be really, really pretty. Muskegon is a really big one. It's also, like, really interesting. But some of the smaller ones along the way, or, like, there's a wetland that is just barely connected, and things like that, they're really, really pretty. And so in my head, I'm like, Yeah, they're pretty. And he's like, they're so interesting from like, a carbon cycling and I was like, that's awesome. That's just awesome that there's so many ways to appreciate them.

Stuart Carlton 37:27
Yep. So we got a little confession time. I have no idea what a drowned river mouth is like. I go to every one of Thomas's students presentation and they start talking about drowned river mouths, and I just am like, oh, a drowned river mouths. That sounds nice. So for today's Great Lakes factoid, Carolyn, why don't you go ahead and help me understand what a drowned river mouth is. It's a great lakes factoid, a Great Lakes factoid. It's a great factoid about the Great Lakes.

Carolyn Foley 37:57
You're like, I'm in Billington or something. We're talking about time travel. You've got crazy anyway. Okay, so a drowned river mouth in the in the Great Lakes, it's like, when I was first introduced to them, it was as like a drowned river mouth wetland. But that's not necessarily the case. They can be a lot bigger. It's, they function kind of like estuaries, but it's all fresh water, so it's, you know, along the edge of the lake, conditions in the landscape and stuff like that are such that you have this kind of area that gets flooded. So if you look at, like, a GIS map of it, you've got all these little kind of like, like, there's a river that comes in, and then there's a spot where there's a whole bunch of other water, and then it goes out into the lake. And you actually can see signals that they do cut, like the way estuary on the coast, like of the ocean, you can look at like the salt water. So like, there's a fresh water river coming in, and then there might be a mix. And then when you go out to the ocean proper, it's salty. In the Great Lakes, you don't have, you know, salt water, but you can see, like, pretty distinct signals in other in a whole bunch of other things that kind of, they are fairly different habitats. So it's basically like an estuary.

Stuart Carlton 39:20
There we go, and that's why they're interesting to study, excellent and like they're,

Carolyn Foley 39:25
I mean, any race, any place that's like an area of transition and change. I feel like scientists are like, or ecologists are like, yes, that is where I would like to study.

Stuart Carlton 39:34
So I did my senior project on one of my English classes was transitional areas in jazz fest audiences in New Orleans, and I tried, in a very half assed way, probably can't say that I tried, in a very half hearted way to make connections between the ecology I was learning in Edge communities and like edge communities at the different stages at a music festival. So transition is. Interesting,

speaking of,

Carolyn Foley 40:10
teach me about the Great Lakes is brought to you by the fine people at Illinois, Indiana Sea Grant, we encourage you to check out the cool stuff we do at IIS grant.org, and at i L, I n, C, Grant on Facebook, Twitter, Instagram and other social media. I think they're really up to their Instagram. So we gotta add that in.

Stuart Carlton 40:31
Our senior producer is Carolyn Foley, who teach me about the Great Lakes. Is produced by Megan the lake lover, gun Renee miles. Ethan Chitty is our associate producer and our fixer, our super fun podcast artwork is by Joel Davenport, and the show is edited by Sandra Svoboda. If you have a question or comment about the show, please email it to teach me about the Great lakes@gmail.com or leave a message on our super hot Hotline at 765-496-4474, and then we wonder, like, do people actually read this? But that's part of why I didn't use things here. Okay, listen to it, not read it. You can also follow the show on Twitter at Teach daily, either way. Thank you so much for listening and keep grading those late you

Unknown Speaker 41:20
did it?

Unknown Speaker 41:31
Ciao.

Transcribed by https://otter.ai