Delta Dispatches: Sediment – The Building Blocks of Land Building

On today’s show, Simone and Jacques are joined by journalist and author Jim Robbins to talk about his book “The Wonder of Birds: What They Tell Us About Ourselves, the World, and a Better Future ” and why sediment is an important part of Louisiana’s ecosystem. On the second half of the show, Alex Kolker speaks about his new paper and why the Cubit’s Gap subdelta provides the perfect study site for future river diversion projects.

Below is a transcript of this week’s Delta Dispatches Podcast. Subscribe to our feed in iTunes and Google Play.

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Show Transcript

Jacques: Hello. Welcome to Delta Dispatches. This is Jacques Hebert

Simone: And I’m Simone Maloz.

Simone: This is Delta Dispatches, and we’re discussing Louisiana’s coast, it’s people, wildlife and jobs and why restoring it matters.

Jacques: All right. It’s good to be back another week with you all. Of course, our thoughts are with our neighbors in Texas with Hurricane, well, eventually, Hurricane Harvey approaching.

Simone: It’s certainly, grown in intensity, and so we’re thinking about our neighbors in Texas, who might have 30 inches or so of rain.

Jacques: Yeah, it just strengthened really quickly. Of course, we’re not necessarily fully out of the clear, here in Louisiana, so it’s important to stay vigilant and stay prepared. We’ve covered this on a previous episode.

Simone: Yeah, we’ve had some great discussions about don’t panic, but be prepared. Get your plan in order, and at least monitor the situation and be aware of it.

Jacques: Right, and you can go, actually, if you don’t have your evacuation emergency plans, to There are a ton of resources there about, just a checklist, what do you need in the case of an evacuation or an emergency? Again, now is the time to prepare, not panic, and hopefully, you’ll be prepared for nothing.

Simone: Yeah. Yeah. We are no strangers to water, good or bad, but today we’re going to talk about sediment.

Jacques: Yeah, sediment. The sands, silts, muds, and clays that flow through our rivers and have built the land here in coastal Louisiana over time. We’ve talked about that in the past, but some quick facts about sediment.

Simone: Is there going to be a test?

Jacques: Well, there is a quiz. 348 million tons of sediment have flown past gauges on the Mississippi River in Belle Chasse, Louisiana since 2014. Unfortunately, a lot of that sediment is flowing right past the wetlands that need it and out into the outer continental shelf. We’re going to talk about that, but also more about, from a global scale, like what the importance of sediment … If you want to quantify or guess what kind of quantity of sediment is flowing past the river, we have a fun quiz set up. You can go to and guess how many sacks of crawfish, Mardi Gras floats, or riverboats that equals.

Simone: Fun stuff, stuff you’ve always wanted to know, right?

Jacques: Yeah, exactly.

Simone: We had some congressional staffers come down in April and we had them on a trip. The CPRA was with us, and they were trying to tell the staffers how much sediment that was, and they were trying to relate it to them. They threw it over to Brent Haas, who is a previous guest of our show. They were like, “Brent, how many Superdomes would that fill?” Brent just deadpans. He goes, “A million.”

Jacques: Wow.

Simone: It was just kind of funny. That does make it visual, and it makes it relatable to people.

Jacques: It’s hard to quantify millions of tons. Yeah.

Simone: Yeah, as silly as it sounds. Alisha Renfro did some tight math behind there.

Jacques: Yeah, she did. She did, so go check it out. Very excited to have our first guest on the show. With us is Jim Robbins. Jim has written for the New York Times for more than 35 years. He’s also written for numerous magazines including Audubon, Condé Nast Traveler, the Smithsonian, Scientific American, Vanity Fair, the Sunday Times, and Conservation. He has covered environmental and science stories across the United States and around the globe, and he is the author of many books, including the Man Who Planted Trees: A Story of Lost Groves, The Science of Trees, and A Plan to Save the Planet, as well as Last Refuge: the Environmental Showdown and the American West, as well as a Symphony in the Brain: the Evolution of the New Brain Wave Biofeedback.

His most recent book we’re going to talk about today, which I’m especially excited about as an Audubon employee, is the Wonder of Birds: What They Tell Us About Ourselves, the World, and a Better Future. Before we get to that, we want to talk about an article he wrote for Yale Environment 360 about sediment. Welcome to the show, Jim. Thank you so much for being on.

Simone: From Montana to Louisiana, huh, Jim?

Jim: Yeah. Right? I’m in Helena, Montana. We have our own alert going on here. We have wildfires all over the state, including one that just blew up right outside of town here. People are keeping a watch on that.

Simone: Yeah. I was on a panel one time, and we were with some wildfire folks. It’s amazing how much damage that can cause as well. It’s just something so unfamiliar to us, because those fires, we could put out really quickly. Welcome to the show, Jim.

Jacques: Yeah.

Jim: It’s interesting, because fire is one of those things we’ve always thought, we didn’t want it. We put it out of mind. It’s just like sediment. We didn’t want it. It stayed behind the dams. Now, we’re realizing that both sediment and fire are important to the ecosystem.

Jacques: Right, yeah. There’s, I think, studies about what happens to the land after those fires. Of course, we’re hoping everyone is safe. I remember when I was in California, in the Bay Area, that was a huge problem. It seems to be getting worse. Jim, I want to talk to you a little bit about your story that you wrote, your article for Yale Environment 360, Why the World’s Rivers are Losing Sediment and Why It Matters. What made you want to take on the issue of sediment?

Jim: Well, it’s one of things you hear about, and it’s kind of an a-ha moment. I was talking to someone, a scientist, about dams. One of my areas that I’ve covered quite a bit is changes we’ve made, and how we’re finding out now, just now, we made the changes 50 or 100 years ago, we’re finding out now how much it’s really cost us in terms of changes to the ecosystems. When he told me that this sediment that we always thought clogged up rivers and streams and caused problems in marshes and swamps were critical minerals and nutrients to ecosystems. It’s one of things that you turn, and you think, “Wow, I’ve always thought it was a bad thing to have sediment. Now, I’m told it’s vital and important for climate change, to have sediment in these river systems.

Jacques: Well, let’s talk a little bit about that. Why? What is the importance of sediment? Obviously, we know, in Louisiana, we need it for land-building, and to help sustain wetlands that are rapidly disappearing. But in terms of elsewhere around the world, why is sediment so valuable?

Jim: It’s a building material for ecosystems, essentially. I think there were two dams, kind of the ultimate case for this, a test case for this, were the Elwha and Glines dams on the Elwha River, up near, in northwestern Washington State. They took the dams out, and they realized that there were probably about 24 million cubic yards of sediment behind these dams, enough, according to the scientists, to fill the Seattle Seahawks football stadium eight times. I’ve only been there once, and I don’t remember how big it was, but eight times any football stadium is a lot of sediment.

When they took these dams out, gradually, this sediment rushed downstream. What it did is it rebuilt a lot of the landforms on the coast. It created new beaches off shore. It created a brand new wetland complex, because this sediment is important for, as sea levels rise, building up these important ecosystems off the coast that buffer sea level rise. They buffer wave action. Without them, without this ability to build, then we’ve got nothing out there to keep the sea at bay, and it will only eat up more land as sea levels rise.

Jacques: Right. Obviously, we know the issue here in Louisiana, in terms of sediment loss, a lot of it has to do with the leveeing and channelization of the Mississippi River, and keeping it in place, so a lot of that sediment goes off shore, beyond where it can do any good. What are some of the challenges with sediment? You mention, in the world’s rivers, we’re losing it, so why are we losing sediment elsewhere?

Jim: Well, the big thing is dams. We have 57,000 large dams in the world, and countless small ones, so these dams all have this tons, billions, if not trillions, of tons of sediment stored behind them. That’s the main reason why this sediment is stuck, essentially, in these river systems. There’s a number of different efforts to try and free this imprisoned sediment, to pump it out, or to move it out with trucks, but the best way seems to be to take down dams. There’s a lot of places where small dams, and some places where large dams, are coming down, where this sediment is being restored to the riverine ecosystem, so the river can build up its natural attributes to help protect against these rising sea levels.

Jacques: Right. I’m sure, as you know, here in Louisiana, we’re working to construct, with our state coastal agency, and the US Army Corps of Engineers, some sediment diversions that would strategically place gates in the Mississippi River, levees to deliver that sediment out to our wetlands and capture a lot of that opportunity that’s missed.

Simone: Yeah. This has been a great discussion. We do have to go to a break, Jim. If you hold on with us just through the break, we’ll ask you a few more questions. We want to talk about your book as well.

Jacques: Yep. You’re listening to Delta Dispatches, and we’ll be back right after this short break.


Jacques: Welcome back. We’re back. You’re listening to Delta Dispatches, and we’re here with Jim Robbins, who is an author and reporter. We were talking to you before the break about your article about the sediment and the importance of sediment, which is clearly a huge issue here in Louisiana, but it’s a big issue around the world as well. I want to talk about your book, but first, tell us a little bit about DredgeFest, the Dredge Research Collaborative. It seems to be there’s this growing mindset and effort to capture sediment and really …

Simone: Or release it, right?

Jacques: Release it, yeah, as the resource that it is.

Jim: Yeah. The DredgeFest is kind of a tongue-in-cheek name for a group of scientists and other people, managers, and government officials, and so on, who get together. What they’re trying to do with it is to shift the way we think about sediment. When I came into the story, I still thought sediment was a problem that clogged up rivers, and marshes, and swamps, and so on. What they’re trying to do is turn people around and say, “Well, sometimes, sediment is a problem, but most of the time, it’s a very important part of the ecosystem. It needs to be understood and used, and we need to raise awareness about that. DredgeFest is a way to raise awareness about the importance of these minerals and sediment that can be used to buffer the coastline against climate change. They want to think about something called a sediment shed, just like a watershed, and how important it is, and that we need to use it and think of it in the same way.

Simone: I like when smart people get together and do things like that.

Jacques: Yeah. It’s good to hear, yeah, the innovative side of things. We often hear the negative, so it’s good to see solutions being implemented. Well, I want to shift a little bit to your recent book. As an Audubon employee, I know a lot of my colleagues are probably really jealous that I get to talk to you about it. Your book is the Wonder of Birds: What They Tell Us About Ourselves, the World, and a Better Future.

I just want to read a little excerpt from a Wall Street Journal review that says, “It’s a must-read, conveying much-necessary information. An easily-accessible form in awakening one’s consciousness to what might otherwise be taken for granted, the Wonder of Birds reads like the story of a kid let loose in a candy store and given free rein to sample. That is one of the strengths. The convert’s view gives wide appeal to those who might never have known birds well.” I think that’s a really amazing review.

Simone: Yeah.

Jacques: Definitely get out and get a copy of the book. I want to ask you, Jim, so at Audubon, one of our founding beliefs is that where birds thrive, people prosper. Did you find a similar correlation in writing this book?

Jim: Yes. I couldn’t agree more. Birds are unique in that way, is that they’re everywhere. They’re on my front yard, and your front yard, and they’re on our roofs, and so on. There’s no other animal that has that kind of ubiquity in the world. The more birds we can create habitat for, it’s an indicator species for how well the natural world is doing. It’s unique that way, and it’s a symbol of how successful we are. There’s something we use birds for, it’s called a sentinel species.

I know a guy in Missoula, a researcher, who counts the number of black-backed woodpeckers. The more black-backed woodpeckers there are means that there’s been more forest fires, because they feed only in burned timber. Burned timber, burned forest, is a nursery for biodiversity. The more black-backed woodpeckers there are, the better biodiversity is doing. That’s all he needs to know, is how many black-backed woodpeckers there are. He goes all over the West counting them. Numbers are up, things are good. Numbers are down, “Oh, we need to start paying attention to our lack of biodiversity.”

Simone: I love that thought, that birds are everywhere, in almost every … Cities, there are birds, in the country there are birds, and apparently, in burned forests, that’s a good place for birds. That’s an interesting way to think of that.

Jacques: Yeah. That’s a huge motivator for the work that we do here at Audubon Louisiana for preserving and restoring critical bird habitat. 100 million birds, migratory birds, use coastal Louisiana and the Mississippi River Delta for nesting, migration, stopover habitat, so our efforts here are crucial there. In terms of, I know you talk a lot about the relationship between humans and birds, what are some of the most important things that we have and/or can learn from our feathered friends?

Jim: Well, there’s a whole range of things. For example, there’s a chapter on how we learn about dinosaurs from birds, because we can look at them and go back, and look at some of the fossils, and when dinosaurs first started to fly. Birds, which are the dinosaurs that made it, according to one scientist, really give us a window back into what the dinosaurs were like hundreds of millions of years ago.

We look at bird brains. We study them, because they’re similar in many ways to human brains. There are people who take apart bird brains to understand better the workings of human brains. There are a lot of people who study bird song, because how birds learn to sing is very similar to how humans learn to talk. I spoke with one scientist who believes, because he’s pulled apart this system in birds, he can teach birds, like a pigeon, that aren’t able to sing, he can inject them, and change the brain, in order to create a song pathway. They have the right pipes, which is called a syrinx, but they don’t have the right software in the brain. He thinks, using these injections, that he can teach a pigeon to sing.

Jacques: Wow.

Jim: That’s pretty far out, but it would someday lead to drugs or therapy for people who aren’t able to speak, or who have speech problems. There’s lots of things like that. On the other end of the scale, birds are transcendent. Many people who go birdwatching or who raise birds, who spend time with birds, see them as a way to kind of lift their spirits. We all know that, especially Audubon Society. I kind of tunneled into that quite a bit, and wrote about culture of falconers in inner city Washington DC, who use birds to come out of their difficulties that they were raised in. There’s a cadre of youthful offenders, youthful violent offenders, in Washington DC, who are learning how to work and to rehabilitate falcons and other birds as part of their ability to make something more out of their lives than they’ve been able to so far.

Jacques: Yeah. We actually had an example of that recently, where our executive director, Karen Profita, purchased some … Audubon sells these stuffed animals, stuffed birds, but they have the actual birdsong or bird call that you can squeeze them and it plays. We sent some to a hospital where there were some Alzheimer’s patients. Just them interacting with the stuffed animals and hearing the bird songs, the physicians there and the nurses said it really just lifted their spirits and inspired them. There’s so many great examples like that. I have two questions, and we’re almost out of time, but what was the most surprising thing you learned about birds in writing the book?

Jim: Well, one of the most. There’s lots of surprising things I learned about birds in writing this book, but I think of the most surprising is how they are conflated with angels throughout history. People saw birds as angelic beings in many cultures. Many indigenous cultures see birds as connections to the divine. It’s universal. I think that that’s very interesting. I’d like to know more about that.

Simone: Yeah, definitely. Right? That’s kind of a global symbol. I get to ask the last question. I’m going to jump in on Jacques, just because we do like to ask a fun question of all of our guests. Jim, what is your favorite bird?

Jim: Well, it’s hard to say [crosstalk 00:19:16]. Actually, the one I’ve seen, the bird that I would like to spend more time with and learn more about, because it’s so darn beautiful, is the Aplomado falcon, which is from South America. I met a fellow who uses them to keep birds from eating grapes in the wine country of Napa. They chase off the starlings. They are so beautiful. Google it. Check it out.

Simone: A protective bird? I like that, like a watchdog, right?

Jacques: Yeah. I have to say, I’m impressed that you actually answered that question. Our director of bird conservation, Eric Johnson, we’ve had him on and asked, and he says, “Whatever bird I’m looking at,” which I think is a little bit of a cop out.

Simone: Yeah.

Jim: Well, I equivocated, but I did pick one that leads the pack.

Simone: You gave us some information. One time, David Muth, also, too, we teased him, and we told him, “Not a bird that you could eat.” He was like, “I wouldn’t eat them. No, no.”

Jacques: Yeah. Well, Jim, again, thank you so much for being on the show.

Simone: Where can we find more information?

Jacques: Yeah. Well, so your book is the Wonder of Birds: What They Tell Us About Ourselves, the World, and a Better Future. Any favorite places where people can go to purchase the book?

Jim: Independent book stores.

Jacques: Okay.

Simone: Yeah.

Jacques: Yeah. We love our local book stores. Definitely go check out a copy, the Wonder of Birds: What They Tell Us About Ourselves, the World, and a Better Future, by Jim Robbins. Jim, we’ll continue to follow your reporting on these environmental issues. Clearly, what we’re dealing with here in Louisiana is happening, maybe not in the same form, but other challenges, other environmental challenges around the world, and I know you’ve been covering these issues for a long time. I highly recommend checking out your reporting, and thank you so much for being on the show. We really appreciate it.

Simone: Best wishes to you in Montana, too, Jim.

Jim: You’re welcome. All right. Thanks. You guys take care.

Simone: We’ll be back with Delta Dispatches after the break.


Jacques: Hello. We’re back, and you’re listening to Delta Dispatches. We’re discussing Louisiana’s coast, its people, wildlife, and jobs. We are excited to have a repeat guest on the show.

Simone: Repeat.

Alex: It’s good to be back. It’s good to be back.

Simone: Dupree is unavailable.

Alex: My dog Dupree is unavailable. As I said before, he is running for mayor.

Simone: He’s qualified.

Alex: He’s highly-qualified, and he is running on a pro-cat and pro-flood control …

Simone: A bi-pet ticket?

Alex: Bi-pet. Yes, exactly. A bi-pet. His running mate is an orange tabby.

Jacques: What is his position on potholes?

Simone: His dad’s position, too?

Jacques: Yeah. Well, let’s ask who his dad is. Let’s introduce his dad.

Simone: Go ahead.

Alex: Hi. My name is Alex Kolker. I’m an associate professor at the Louisiana Universities Marine Consortium, down in Cocodrie.

Simone: And a repeat guest.

Alex: Yes. Yes. Yes.

Simone: Yes. We’re glad to have you back. Last week, I had the exciting week. Jacques held down the fort. This week, Jacques had the exciting week, and you were part of it.

Alex: We were down in the field. We were down in the Cubit’s Gap subdelta, which is one of, I have to say, it’s one of the most beautiful parts of the system that we work in. It’s about 25 miles southeast of Venice, and it’s an area where the river has, almost on its own, cut. Basically, it functions like a diversion. It’s kind of an interesting area. There was a crevasse, basically a hole in the river levee that developed in the early, mid-19th century. That crevasse basically functioned like a diversion and created this huge fan-shaped delta that … Over the course of almost a century.

Jacques: Yeah. It was a wonderful day. It was Tuesday. We went out of Venice. I’d just say, being on a boat, and then being on the Mississippi River, and you’re seeing these tankers go by, and then all of a sudden, you’re almost at Pilottown, and then before that, you’re in Cubit’s Gap, and seeing the land that was built was just incredible. Really interesting history that we were talking about right before the break.

Simone: Yeah. We just talked about that.

Alex: My understanding is that the crevasse was cut by the daughters of Mr. Cubit.

Simone: I told Jacques, I was like, “I have two sisters. I’m so glad my dad never made us cut a crevasse.” He made us cut the grass every now and then.

Alex: My grandfather made us fix fences just so we would know how to work. That’s the story. Someone else was saying maybe it was the Navy, but as far as I understand …

Simone: Yeah, like associated with the war.

Alex: Maybe, yeah, but I don’t know.

Simone: I think the daughter story is way better.

Alex: It’s a better story, and at the end of the day, I’m a scientist, and I am not a historian. The interesting thing is this small crevasse functions like a diversion. It widened, and it carries, I don’t know, between 50 and 100,000 cubic feet per second of fresh water, which is considerable.

Simone: Oh, wow. Yeah. Absolutely.

Alex: It’s about the size of the large diversion. It’s about the size of the Mid-Breton or the Mid-Barataria diversion. The Mid-Barataria diversion is 75,000 CFS. This is between 50 and 100,000 CFS, so pretty close. As a study site, it makes a better study site than Caernarvon or Davis Pond.

Simone: Yeah. Just for comparison, a Caernarvon and Davis Pond are 10, 12,000 CFS or less.

Alex: They’re 10,000 or so max, but often, they’re running a whole lot less. Davis Pond is like, on average, the base flow is about 1,000, maybe gets up to four or five every now and then.

Simone: So 100 times that, yeah.

Alex: Yeah, 50 to 100 times that, so much, much, much bigger.

Jacques: Well, and one of the cool things about it is what it’s done. We were there in the Delta National Wildlife Refuge, which is this huge expanse of land in the Bird’s Foot Delta area, that was built by opening the river and the crevasse and depositing sediment. Tell us a little bit about the land that has been built by the crevasse.

Alex: Yeah. Okay. The land that’s built, it’s fresh, and somewhat-intermediate marshes, so it’s mostly fresh marshes close to the river. Then, as you move away, the system gets saltier. There is a lot of Roseau cane out there, and then there’s also a lot of crevasses in there, a lot of small cuts that are basically like mini-diversions in there. Those areas have American water lotus. They’ve got arrowheads. There’s beautiful birds. There’s some of my favorite birds …

Alex: Some of my favorite birds, which are the magnificent frigate birds, which are one of my favorites.

Simone: You all know your all birds around here. Super impressed.

Alex: Yeah. It’s a beautiful area. There was this interesting scientific mystery, because some areas, what we looked at, and some areas are building land some areas are losing land. We thought this actually was a really cool spot to look at, to test some of the hypotheses about why and how diversions build land. Because I’m a scientist, and as scientists, we like to put ideas to the test. That’s one of the things that science is great at doing. There were some controversies, particularly post-Katrina, about whether or not diversions could build land. Some people looked at the area around Caernarvon and said … There was a lot of land loss around Caernarvon around Katrina, and some people looked at that and said, “Well, it was the fresh water marshes that were built by Caernarvon that made them really structurally-unstable,” and that salt marshes were more stable.

We took a different … We thought, “Well, Caernarvon,” like I said, “It’s not the best example, because it’s relatively small. We thought, “Maybe Cubit’s Gap is a better place to test these hypotheses, these ideas.” It was myself and another guy from Tulane, [inaudible 00:27:02], who’s a great geospatial, does geospatial analyses, which is kind of like Google Earth on steroids, think of it like that.

Simone: Good analogy.

Alex: Yeah. He looked at that area, and then also his student, who’s over there, who’s a grad student at Tulane. We looked at that area, and we mapped out the areas that were building land and the areas that were losing land. Then we tried to relate that, looking at the properties of the sediments, and what were the properties of the sediments in the areas that were gaining land, and the areas that were building land? It turned out that …

Simone: I’m on the edge of my seat. I want to hear what he has to say.

Alex: Yeah. It turned out that the areas that were building land were the areas that were closest to the river. Those were the areas that had the most mineral sediments. Those sediments were the strongest structurally, and they were the freshest sediments. The areas furthest away from the river, the ones out close to the ocean, close to Breton Sound and that side over there, those were the marshes that were losing land, that were most prone to erosion. Those were the marshes that were the most organic. They were furthest from the river, so they didn’t have much of a sediment source. Actually, those were kind of salty, too.

We think that the issue is not a fresh water versus salt water, or at least, not much of one. The real, the big point is whether or not the marshes have a lot of sediment. The sediment provides the structural stability.

Simone: So the base …

Alex: The mineral … Yeah, the base of it, which is, the sediment that we’re talking about is, it’s basically ground up rock. The marshes that are comprised of sediment are really tough pieces of ground-up rock. We actually tried to take a core out there, and in some places, it was really tough.

Jacques: Yeah. I was going to say that. That was one of the coolest parts of the trip. We pulled our boats up to some of the new land that had been built over the last decade. People got out and were walking. It was really solid. Then Alex tried to shove the sediment core in there. You really had to power … I think we had to get more people to get it in there, because it’s not just about the acreage or how much land was built, but how deep it is.

Simone: The foundation …

Alex: Yeah. It’s all of the properties of the … Exactly, it’s the properties of the foundation. These marshes have a solid foundation, because they were made out of mineral sediment. That means that they were tough and they were relatively resistant to erosion, and during a period that had a bunch of storms. During a period that had Katrina, and Rita, and Isaac, these areas basically maintained their place. Actually, in some cases, these marshes were actually developing during a period that had intense storms.

Jacques: Right. Going back to what we were discussing earlier with Caernarvon, obviously, there has been a lot of discussion around that, and why the areas in Breton Sound, south of Caernarvon, lost so much land after Katrina. One, it was Katrina was a massive storm. Then two, there was not a lot of sediment in that system, because Caernarvon is small and it was …

Simone: It’s not intended …

Jacques: No, not intended. It’s actually operated pretty infrequently. When we’re looking at diversions like the Mid-Barataria sediment diversion, that can carry a lot of sediment into that basin, that’s what you need as the building blocks for a strong foundation.

Alex: Right. It’s those tough mineral sediments that are the key to building strong land down here in the delta. Yeah, the organic-y, fresh marshes that are not nearly as stable.

Simone: We have a lot more to talk about with the candidate for mayor’s campaign manager.

Alex: I’m his campaign manager and his bodyguard.

Simone: And his bodyguard, right. We want to come back with Alex, and we have a lot more to talk about, some media that followed your trip, and some really great supporting pieces, so we’ll be back with Delta Dispatches, WGSO 990, after the break.


Jacques: Welcome back to Delta Dispatches. I’m Jacques Herbert with Audubon Louisiana.

Simone: I’m Simone Maloz with Restore or Retreat. Alex, let’s talk about your paper, Remote Sensing of Environment: A Propensity for Erosion and Deposition in a Deltaic Wetland Complex, Implications for River Management and Coastal Restoration.

Alex: Right. It’s an academic paper, and academics like lots of words and big words.

Simone: Let’s break it down. Let’s talk about … That’s why we wanted to take the media out there.

Alex: Yeah. We brought people out, because actually, I think that as a scientist, I really think it’s important that people in the public understand the work that we’re doing.

Simone: I agree.

Alex: I’m really, really glad that folks from the media were out there with us on Tuesday. What we did when we were out there, we tried to show them areas where land was being built and where land was eroding.

Simone: Right next to each other almost, right?

Alex: Well, no, about 10 miles apart from each other.

Simone: Okay.

Alex: Not exactly right next to each other, but about 10 miles apart from each other. We wanted to show them the properties of the sediment, so we went out, and we went into an area where land was building, and we took a core. That’s the area that had the really tough mineral sediments that I was talking to you about. Then we went out to the very far edge of the delta, where the delta is eroding. The sediment out there was almost like a coffee grounds.

Jacques: Coffee grounds, that was one of the coolest things, too, seeing that, and you’re like, “Wow, that really looks like a whole bunch of coffee grounds that are …”

Alex: Yeah.

Jacques: Why is it like that?

Alex: Yeah. That’s basically the ground-up, eroding marsh, and that’s the ground-up organic …

Simone: It’s unhealthy, right?

Alex: Yeah. It’s all the ground-up, eroding marsh that’s actually gotten reworked, and almost was forming a little bit like a beach, but like a beach of decaying march.

Simone: It sounds like a drink. All kidding aside, that’s interesting, because we heard that, coffee ground, we’ve heard that analogy before and what that means but from a scientific side.

Alex: Yeah. It’s almost like a kind of sediment type. I don’t know if we formally call it coffee grounds, but it’s almost … We do think of sediment as having certain types and certain properties, and that’s a common word for one common type of sediment, and it’s often a type of sediment that’s associated with degrading and dying marshes.

Simone: We did an exercise at LUMCON, we do it often through Louisiana Sea Grant, they have a training program where they train young scientists on how to deal with the media. One of the things, they asked me a couple times to participate, Jacques has done it as well, but what they try to do is how can you make your work relatable to the media? I think what you all did this week is an excellent way and an excellent example of your work is great, but you have to be able to relate that, and have people understand how that fits into everyday life.

Alex: Yeah. For me, down at LUMCON, I feel like part of our job at LUMCON is to help people understand the coast, and help people understand how our complex but fascinating and beautiful coast works. A lot of my colleagues do it, and we all do it, and we all do it in different ways that relate to our specialty. Myself being so interested in sediments and coastal restoration, I try to do it in this way. I really want people to understand what our coast looks like where, and you might think that mud is boring, but it’s actually fascinating.

Simone: It’s fascinating for a lot of people.

Alex: Yeah. It’s fascinating for a lot of people, and it’s what so much of the system is built on. If we want to understand how the system works, we have to understand the basics, the foundation, the building blocks of it. I want people to understand there is some mud that’s really actually really tough, and very structurally solid, and you can stand on it. There’s some things that you might look at and think of as mud, and they are so soft you’re going to sink right through.

Simone: Yeah. I remember that as a talking point from your trip. We had a couple of tweets, and it was you said that, “This is solid.” That’s what people maybe see, but they can’t match the science behind it, so you help to do that.

Alex: Right. We wanted to say, “The science behind the solid mud is that it has a river sediment and it’s close to the river, and so areas that receive lots of river sediments. One of those pathways for sediments is a river diversion. You want to have a river diversion that is big enough, and carries enough water, and often, that’s deep enough, that’s the right size and right shape to carry a whole lot of sediment. That is sort of the implication of the work.

Jacques: Right. I think that was one of the things that was really fascinating on Tuesday, is just with diversions, you’re not just influencing the area that’s directly in the outfall area of the diversion, but you’re introducing sediment into the system that can be distributed throughout, right?

Alex: Right.

Jacques: We went to that little crevasse or ditch and you just saw beautiful vegetation. It was just incredible to see that.

Alex: These developing deltas have almost this lacework of channels. They’re really quite beautiful. If someone could just go to Google Earth and look at the area, go to Venice, Louisiana, and then look southeast about 20 miles, and they’ll see this big, fan-shaped deposit. There’s almost this lacework of … It’s almost a maze of channels that are, they come out in a fan, but they split, and then they coalesce, and then they split and they coalesce. It’s a beautiful, intricate pattern, but that intricate pattern is the pathway for sediments to get deep into a system.

One of my colleagues from UNO, has shown that those channels are really highly efficient. They’re really good at carrying water and sediment. Those channels have an ability to carry sediment further than you might think, and that, having that network of channels is crucial to having an operating and functioning diversion.

Simone: That water has a mind of its own, right?

Alex: Yeah. It has a mind of its own, but we can also work with that mind of its own to help us restore the coast.

Jacques: Yeah. That’s something that I’ve learned during flyovers, and with Alisha Renfro, who is one of our staff scientists. Anytime there is a straight line, that’s not natural. The natural stuff is a fan or irregular patterns, and that’s their sort of thing. That’s how it works, and that’s how it functions and sustains itself.

Simone: Yeah. We are so happy to have you with us today tell us another interesting story. You’re going to have to be a regular with us.

Alex: It’s a pleasure. I will come back anytime.

Jacques: Well, Alex, thank you so … I know you’ve written blog posts, and you’ve been on our show …

Simone: You have the Twitter, yes?

Alex: I do have Twitter, so you can follow me on Twitter. I post up there.

Simone: Yay.

Jacques: What’s your handle?

Alex: AlexSKolker.

Jacques: Great.

Alex: Very simple. Very simple.

Jacques: Follow AlexSKolker. Thank you again for all of the support that you’ve given in really trying to make the science relatable and engaging, and get people to care about these issues.

Alex: Thank you. Thanks to the folks at the LRD campaign for all the hard work that they’re doing.

Simone: Yeah. You’re an easy one to deal with. Jacques, we were just mentioning, but we do have an action alert related to sediment diversion.

Jacques: We do. Speaking of sediment diversions, the Army Corps of Engineers is still taking comments, scoping comments, for their draft, or for their scoping report that will inform the Draft Environmental Impact Statement.

Simone: Just a couple more weeks, right? September 5th?

Jacques: Yeah. September 5th is the last day. You can go online,, and give your comments on … Let the Corps know how important this project is to Louisiana.

Simone: You can find previous episodes of Delta Dispatches, which Alex was on with us, and other previous guests like Dr. Renfro, at

Jacques: That’s correct.

Simone: Anything going on next week?

Jacques: I think we have to figure out what we’re doing next week. We had a good schedule for August, and now, we’re nearing the end of August, so it’s time to plan for September.

Simone: Well, we want to make sure, again, that everybody stays safe. Again, don’t panic, but be prepared.

Jacques: Go to

Simone: Go to, and so hopefully, everybody will be safe and will be tuning in next week with us.

Jacques: Yeah. You can definitely, obviously, follow your local media, but National Weather Service, Alex Krautmann, remember, we had him on to talk about …

Simone: Yes. Yes. Wait, we didn’t even talk. How did your audition go? Before we go, we have to …

Jacques: Simone, it’s a long process. She’s referencing, if you’re just tuning in, to my 610 Stompers audition.

Simone: Yes. It’s still not done?

Jacques: I had another event last night, so I’m hoping maybe next episode I’ll have some news, but we’ll see.

Simone: Yes, breaking news. Breaking news.

Jacques: Either way …

Alex: Good luck.

Jacques: Thank you Alex. Either way, it’s been a lot of fun. It’s a great process. They’re a great organization. They donate a ton of money to charity. They’ll go to children’s hospitals and all kind of things like that, so they’re a fun group.

Simone: Yeah. Like we were talking about last week, just very iconic New Orleans. They have a good time for a good cause, and that’s certainly great to note.

Simone: Well, thank you everybody for being with us again on Delta Dispatches this week. Hopefully, you’ll listen to us again next week.

Jacques: Thanks so much. Thanks, Alex.

Alex: Thank you.

Jacques: All right. Have a good week, everyone.