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Blue Nitrogen: The Nutrient Story Coastal Wetlands Have Been Hiding · How To Protect The Ocean

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Most of the time on this podcast when we're talking about coastal wetlands,
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we talk about carbon sequestration.
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The fact that carbon dioxide can actually be sequestered and put into
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the soil of coastal wetlands like marshes and mangroves and seagrasses
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and salt marshes, all these different types of coastal wetlands which
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are great for the environment.
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And of course, you know, the destruction of these environments
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because of development or because of sea level rise or things like that
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can really cause problems for the release of carbon and carbon dioxide.
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Today we're gonna be talking about a different type of sequestration.
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We're talking about nitrogen sequestration and how much more important it could
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be than carbon when we're talking about making the environment healthy.
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We're going to talk to Dr. Adam Langley, who's a global change
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ecologist in the biology department at Villanova University, located
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in Pennsylvania, where he is the director of the graduate program.
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His lab group studies carbon and nutrient cycling with a keen focus on
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sustainability of marshes and mangroves.
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He is also a research associate at the Smithsonian Environmental Research
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Center, where he conducts long-term global change experiments focused on
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predicting how future changes such as rising atmospheric CO2, rising sea levels,
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nutrient pollution, and exotic plant invasion will influence the ability of
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coastal wetlands to tolerate sea levels.
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We engage in a great conversation around why these coastal habitats are
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so important and how climate change is changing their distribution, sometimes
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for the good, sometimes for the bad, and how it's going to change places like
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Florida, the state of Florida, and what changes we're actually seeing already.
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Some of it's not so great, some of it's really optimistic, uh, so we're
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gonna see what you think about this on this episode of the How to Protect
1:44
the Ocean podcast, your place Monday to Friday to catch all the information
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on ocean news, ocean updates, science, ocean science, and ocean conservation,
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starting right here today with Dr.
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Adam Langley on global ecological change.
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Enjoy this interview, and we'll talk to you after.
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Hey, Adam.
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Welcome to the How to Protect the Ocean podcast.
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Are you ready to talk about blue nutrients and coastal wetlands?
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I'm very excited to do that.
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All right.
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I'm super excited because I know, like, a lot of times people would
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be like, "Why are you so excited about, you know, nutrients and
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wetlands? Why is that important?"
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And we're gonna find out today why it's so important.
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If you don't like your water green, this is why it's so important to
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learn about how wetlands can sequester nutrients, just like we talk about how
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wetlands, mangroves, and other coastal habitats will sequester carbon dioxide.
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It's just as important to get those nutrients in that soil and keep
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them contained, as have they've done for, you know, decades and centuries
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and so forth that we've seen.
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But then when they get wrecked and they're not able to do that ecosystem
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service for us anymore, it kinda goes to the wayside and we get
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blooms and potentially red tides down the road and all that nasty stuff.
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So we are gonna talk about an important study that Adam did, uh, and we're gonna
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get to know Adam a little bit more.
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So Adam, why don't you just let us know who you are and what you do?
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Okay.
3:08
I'm Adam Langley.
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I'm a global change ecologist here at Villanova University.
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I come from the mountains and I did my graduate work actually
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in the high desert of Arizona.
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So it's a strange place- Nice … for a, a coastal wetland ecologist to be trained.
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Uh, but, you know, I consider myself an ecosystem ecologist, so I study
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the flows of energy and matter through ecosystems, carbon and
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nitrogen and water, heat, whatever.
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And so if you're an ecosystem ecologist, the particular setting isn't as important
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as the processes that you're studying.
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So a lot of the processes- Mm-hmm … are, are universal to,
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uh, whether it's, uh, you know, the high plains or a coastal wetland.
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So in terms of looking at the different systems, what drives you as a scientist
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to really, like, what knowledge are you seeking when you seek this?
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Like I know, like, for certain people who look at sharks, they'll
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look at, you know, predator-prey relationships, and they wanna find out
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different predator-prey relationships.
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And sometimes they'll go outside of sharks and go to, like, tuna or
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salmon to look at different types of predator relationships- Mm-hmm
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within different animals, different types of species.
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For you, in terms of looking at, like, say, like a desert area or even a
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coastal wetland, is there something in the middle that really drives the
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question that you're looking for or has been driving the question that
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you've been looking for recently?
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Coastal wetlands are really unique among all ecosystems.
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Some people consider them marine, some people consider them terrestrial.
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They're kind of in between, so they kind of fall through
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the cracks there a little bit.
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Um, but what's really unique about them is the biogeochemistry that happens there.
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Um, because they're getting, um, water from the ocean, um, they're getting runoff
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from land, they're p- partially saturated, sometimes fully saturated, so they're-
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Mm-hmm … kind of oxygen deprived.
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Um, you have a lot of mixing that goes on of things that don't mix elsewhere,
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so you get a lot of unique processes.
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Um- They're very dynamic ecosystems, so from year to year
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things can really change there.
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To me, that alone makes them pretty fascinating.
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One of the big things that's very different is that in a forest
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you kind of hit an equilibrium.
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Mm-hmm.
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And this is one of the things that's important to this paper ultimately,
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where after so many centuries, the mass of that forest doesn't really
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change, and that forest is no longer, like, it has no net absorption of
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carbon from the atmosphere, say.
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So it's kind of maxed out.
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That doesn't really happen in coastal wetlands.
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They kind of adjust based on water level.
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So as long as- Oh, interesting … since sea level has been rising for roughly
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the last 5 to 10,000 years, depending on where you are, they continue to build.
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So they're constantly growing to keep up with sea level.
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So it's almost, you know, you can think of it like this super organism
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that's hit this different kind of equilibrium that you don't see Yeah
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just anywhere else.
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Yeah.
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It's interesting, like, so, uh, like to kind of picture… What I'm picturing is,
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like, mangrove forests, so the mangrove trees, depending on the species, 5 to
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10,000 years ago were, like, shorter in terms of height- Um … because they, the
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sea r- didn't r- rise to where it is now?
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Or is it just more- Yeah.
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So I'm, I'm really talking about the whole ecosystem.
6:39
Okay.
6:39
So the soil was shallower.
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Ah.
6:42
So you can… Yes.
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And so I should back up.
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When I say coastal wetlands, I'm talking in this paper specifically
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about marshes and mangroves.
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Gotcha.
6:50
So I'm glad you mentioned mangroves.
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Right.
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Um, because that's one that people are, you know, sometimes familiar with.
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Sometimes they think- Yeah … I'm talking about a mango fruit.
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Um, but we're talking about the mangroves.
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Those are the, really tropical coastal wetlands that have trees,
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trees that are incredibly durable.
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Yeah.
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Um, they can tolerate flooding, they can tolerate salinity, and they can grow
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in some places hundreds of feet tall.
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Um, if you've been to Florida, you might have seen some tangled rooty
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trees- Mm-hmm … along the coast, and those are probably mangroves.
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So I said the ecosystem can grow, and I mean there it's building soil.
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Gotcha.
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So you could take a core- Mm-hmm … and when you date that core we can see
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that the soils in some of these wetlands have been accumulating
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for, you know, 5,000 years- Yeah
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just building layer on layer on layer.
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Um, that's something you wouldn't see in a- No … in an upland forest.
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So as that layer continues to add on, you can put more nutrients, carbon
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dioxide in those layers because- Exactly … it continues to build up.
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And that's why these ecosystems can sequester or absorb much more carbon or
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nitrogen or soil, anything else- Yeah
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much more quickly than anywhere else on Earth.
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Really?
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That's interesting.
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Yes.
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I didn't know that.
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It's, uh, let's say roughly 10 times the rate of the most productive forest.
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Right … it's really staggering.
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Yeah.
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Amazing.
8:20
Amazing.
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You started to look at these coastal wetlands and you mentioned
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something earlier that a lot of times the understanding or even
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the study of these coastal areas kind of fall through the cracks.
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We know a lot more about land and a lot about the ocean.
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Mm-hmm.
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But these coastal wetlands kind of take a backseat.
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Is it because it can be so complex?
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Because they're facing both environments a lot of the time, and people just
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weren't interested in knowing about them before 'cause they were more complex?
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I would almost think it's the opposite 'cause they're so
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special because they have that.
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Like, why do you think they fall through the cracks?
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Well, I think we're catching up now.
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Um, I- Yeah … you know, I think it's maybe kind of just a historical
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bias, um, that, you know, you get to your coast and the marsh smells bad.
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And people considered it a wasteland, right?
9:13
Yeah.
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Um, and would dump dredge spoils there, whatever else,
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bodies you want to get rid of.
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Um, I kind of think that might have more to do with it.
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Um- Okay … but, you know, now in the recent decades, we've really come to
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recognize the inordinate importance- Yeah
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um, that these ecosystems have in not just our estuaries,
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but really in the biosphere.
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Yeah.
9:40
Yeah.
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No, no doubt.
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Now, um, so with that said, like this whole study, like you have a
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lab, the Global Change Ecology Lab, I believe is what it's called, right?
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Did I get the name right?
9:49
You did.
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Okay.
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Perfect.
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Now this lab, it looks at all these different types of processes for…
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is it all coastal wetland systems or is it just mangroves and marshes or do
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you expand and depending on who's there and what type of project's coming up?
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Yeah, it kinda fluctuates a little bit, but we have had a strong
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coastal wetland focus for- Okay
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uh, 15 years or so.
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Okay.
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Yeah.
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Okay.
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Interesting.
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And then how many people are in this lab right now, like graduate students
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and maybe like research thesis undergrads that are currently in this?
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Um, we have probably four or five grad students and- Okay
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… probably that many undergrads.
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I work closely with some other, um, professors here at Villanova as well.
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Okay.
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I got a lot of young researchers and students who are in the audience right
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now listening to this, if they got interested, they want to know more about
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these types of coastal wetlands and these type of biogeochemical processes, what
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type of, I guess, background education do a lot of the graduate students in
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your lab have or who have come through?
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Like what do they need or what kinda knowledge do they
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need to succeed in your lab?
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That's probably something that, you know, if you asked me that 10 years
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ago, I think that's changed too.
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Different.
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Um, but it's, you know, definitely some ecological
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experience, uh, field experience.
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We, some of the places we work in are, are very adverse too.
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I
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can imagine.
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Yeah.
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Which is a, I think that's another reason that they were historically understudied.
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Right … They can be very difficult to access.
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I mean, we're slogging around waist-deep in mud a lot of the time.
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Um, and you know, I was just down in some of the more remote wetlands on
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the East Coast in the South Carolina on the coast and talking to some
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researchers down there, and they're like, " No one has studied these because
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they're really difficult to get to."
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Yeah.
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You can't quite get where you need by boat, and you can't get there by land.
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Um, so sometimes, you know, a lot of our work requires, like,
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you can't be afraid of mud.
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Uh, that's- … definitely part of it.
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Gotta be willing to get dirty.
11:56
Yeah.
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Um, you know, some technical expertise, like, we've done a
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little bit of, like, gas exchange.
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More and more, like I think more of my students have used some remote
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sensing as that data has gotten to be just an incredible resource.
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The coverage- Yeah … and the detail that you can see from space.
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That's had a big impact on our field 'cause these places you can't get
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to, well, now you can see them.
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Um- Right.
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Right … so my students all have much better, uh, GIS skills than I have.
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That's huge.
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As they learn through it.
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Yes.
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Um- Yes … which is a great synergy that we have.
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Oh, yeah.
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I always find, I, like, I did a GIS diploma, advanced diploma after my-
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Mm … uh, undergraduate degree.
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My master's supervisor told me to do it.
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He's like, " You're gonna need this," like, for- Yeah … I was doing MPA work.
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Um, but I've always used it.
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Like, I've used it in a number of different jobs, whether it's in and out
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of science, like, you can always use it.
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I know I've done a couple side contracts with business owners on looking
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at- Mm … how to divide up things.
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You can use GIS remote sensing in pretty much anything.
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But speaking of which, with a lot of the way people are moving, like,
13:08
whale sampling is moving to, like, drones and, you know, sampling,
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like, whale, uh, excrement from their blowholes and things like that.
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Can you use, like, uh, more specified types of drones in these wetlands?
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I guess it'd be hard to do a core with a drone, but to sample anything else?
13:28
Right.
13:28
Uh, definitely.
13:29
I spent some time this summer taking some imagery, some, um, drone imagery,
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and the algorithms for determining, you know, plant cover, which is, we
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spend a lot of time measuring this.
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Mm-hmm.
13:42
Um, you know, the old ecologist in me is like, "Well, it's just not quite as good."
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Um, and it's not.
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If you have, like- Right … the plots that we're going to.
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But if you want full coverage of on your marsh, you can do this pretty well now.
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You can use algorithms to not just tell you we're interested in, like, how
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green is it, how much biomass is there, but also what plant species are there.
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Yeah.
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Algorithms are getting really good at that, especially in coastal wetlands,
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where we tend to have few species.
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Mm-hmm.
14:10
So they're pretty easy to distinguish, uh- With, you know, AI technology or
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whatever other algorithm you're using.
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Yeah.
14:18
Um, so I think, and I have colleagues that, um, have used drones.
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I've probably used… And I've used some of the imagery myself.
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I don't fly them myself, but I think that's- Right … gonna be key.
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Um- Yeah … one of the key variables in our ecosystems is elevation.
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We need to know it to the centimeter because it just determines
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how flooded that site is, and everything else that happens there.
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And we can get really good elevation data, um, with drones.
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Yeah.
14:45
Um, it's a little tricky in tidal wetlands when you've got
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standing water, but it can be done.
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We're gonna see things that we haven't been able to see before.
14:53
Absolutely.
14:54
And we've seen, I guess, you know, drones as sophisticated, having
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LIDAR machines on them too, right?
14:59
Yeah.
14:59
And, and being able to get that, which is incredible, how fast the technology
15:03
has come, you know, in terms of- Mm-hmm … like when I started GIS 20 years ago,
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we were just getting into digital GIS and out of the mapping- Mm-hmm … like
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paper maps, and now we're getting into drones that can do LIDAR, like up
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close and personal, so it's kinda cool.
15:16
And it does make me a little nervous that people will do just that, um, uh, only
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re- you know- 100% … drone sensing.
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And I feel like- Yeah … we still need some on the ground
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measurements like you mentioned.
15:25
Absolutely.
15:26
And of course anything happening in the soil, there's no
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magical technology for that.
15:30
Nope.
15:30
It's a lot of old-fashioned taking cores and we do that- Oh, yeah.
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And, and, and I'm, I'm a- Yeah … proponent of that.
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As, as a marine biologist, you know, knowing, like a, that did remote sensing
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and GIS in, in college, like the first things one, you have to ground truth.
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So you have to get on that ground.
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You still have to get dirty, you still have to get through, and
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then, yeah, there's still other information that you need to get.
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It only provides you, you know, one or two pieces of information, but to get the
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full picture of sampling and getting in there, you really have to do the cores, do
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everything, really get that, that- Mm-hmm
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three-dimensional kind of, or even four-dimensional kind
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of learning, which I love.
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Like, 'cause that's the fun part of field work though too, is getting
16:06
dirty and going through the hardships.
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It brings the team closer, uh, if you do it all together, right?
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There's no way to bond like being, you know, waist deep in a hole
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in a marsh with your colleagues.
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I love it.
16:18
I love it.
16:19
Okay.
16:20
Um, so that's great.
16:21
So, and within the lab, like you guys are looking at all
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different types of questions.
16:26
We're gonna get into one of those specific questions with
16:28
this paper in just a moment.
16:29
Can you just talk about some of the different types of studies
16:31
that are going on in the lab?
16:33
Sure.
16:33
So I did a postdoc at the Smithsonian Environmental Research Center.
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It's just, uh, outside of DC.
16:40
It's on the- Yeah … Chesapeake Bay.
16:43
Um, and so a lot of what's going on out there, well, it's-- we
16:46
have this, uh, what we call the Global Change Research Wetland.
16:51
Um, it's probably the most experimented-on wetland in the world.
16:57
We have, uh, experiments that have been running for over 40 years in some cases,
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um, where we're poking and prodding this marsh in every way possible.
17:08
It looks like aliens have landed on this marsh.
17:11
Um, but it's just scientists, and we've been there for a while.
17:14
So we're adding, um, extra CO2 to the atmosphere.
17:18
We're adding, um, extra nitrogen to some of the plots
17:21
to simulate nutrient pollution.
17:23
There's a big warming experiment, active warming, where we're
17:26
trying to simulate climate change.
17:28
Mm. We've manipulated sea level.
17:31
We have a plant invasion, um, element.
17:35
Um, so that's one of the thrusts of my work is, is looking at
17:39
these long-term experiments.
17:41
And like I said, some of them have been running for decades, which allows us-
17:44
Yeah … to look at these treatment effects that we're interested in, but
17:48
also superimposed on the background change that's actually happening.
17:52
The rate of sea level rise has accelerated there, um, probably doubled
17:57
since we started the experiment.
17:59
Mm-hmm.
17:59
Um, so it makes this really fascinating interplay of these different factors.
18:04
Yeah.
18:05
, That's one element.
18:06
A lot of what the lab is doing now is happening in Florida because we have
18:10
several interesting things going on.
18:13
We do have coastal wetland loss.
18:16
Um, at the same time, we have mangrove, uh, encroachment.
18:22
I'll call it encroachment.
18:23
I don't really call it invasion, but mangroves are moving northward-
18:27
Hmm … in Florida, and this is kind of a general trend around the world.
18:32
They tend to be moving poleward.
18:35
And so while we're losing a lot of mangroves to development around the world,
18:39
they're also, um, colonizing new areas.
18:43
And in Florida, this seems like it's mostly driven by climate change, the
18:47
declining frequency of deep freeze events Um, that's historically
18:53
what's restricted, uh, mangrove range- Mm-hmm … on the north end.
18:57
Um, my colleagues though have recently found, um, mangroves
19:02
in Georgia for the first time.
19:03
That's been documented.
19:04
I was about to ask.
19:05
I was wondering, does it go as far as Georgia?
19:07
Interesting.
19:07
Okay.
19:07
They do.
19:08
Um- Yeah … And that's just in the last couple of years they found them.
19:11
We knew the climate there probably would suit them.
19:13
Mm-hmm.
19:13
They just hadn't quite gotten there yet.
19:16
Gotcha.
19:16
So we're, asking a lot of questions down there about, like, what happens to
19:19
these marshes when mangroves come in?
19:22
Yeah.
19:23
Um, so what happens to the carbon cycle?
19:25
What happens to the nutrient cycle?
19:27
Also, do these mangroves maybe, I mentioned, you know, we're losing
19:31
coastal wetlands pretty rapidly up there, but these mangroves seem
19:34
like they might give these wetlands a better chance at survival.
19:38
A little bit more stability?
19:40
A little bit more stability.
19:41
They can build soil, um, we think more rapidly- Mm-hmm … than
19:46
the herbaceous marsh plants can.
19:49
Yeah.
19:50
They resist erosion maybe a little bit better.
19:54
Um, we have a new paper out about that.
19:56
Nice.
19:56
Um, so that's, yeah, one of the other main topics that's happening there.
19:59
And then interestingly, on top of all that, we did have one of these big
20:03
freezes last winter, so it kind of caused some mortality in these mangroves
20:10
that had just recently colonized.
20:12
But it's looking like, we're just now learning, it's like it wasn't
20:15
as severe as it seemed like.
20:17
A lot of these mangroves that looked like they got- Yeah
20:20
frozen to death are starting to re-sprout and come back, so.
20:24
Just took a little bit.
20:26
Yeah.
20:26
Yeah.
20:27
It's just t- it took them longer.
20:28
If you looked at one of these, it looks just crispy, and you're like,
20:30
"Oh, that's definitely dead." But they start to, uh, re-sprout again.
20:34
Okay.
20:34
But working down there is like nowhere else because, I mean, I
20:37
know of no ecosystems that have changed as dramatically as these
20:42
in the last couple of decades.
20:43
We're talking about in some cases, near complete conversion
20:48
from a marsh to a mangrove.
20:50
Um, and in a matter of, you know, five, 10 years, you have kind of a
20:56
swampy, a forest colonize it with, you know, large mangrove trees.
21:02
Yeah.
21:02
It's just, which is pretty incredible to see them move up that much to look
21:06
at how that's gonna change the landscape in Georgia from what a, you know,
21:12
the marsh type to a mangrove type.
21:14
You said they're moving towards the pole, so I assume the same thing is
21:16
happening south of the equator, too?
21:19
They're starting to move down?
21:20
Yeah.
21:21
Yep.
21:21
Wow.
21:21
I think, you know, there's other forces that are driving mangrove expansion
21:27
and retraction all over the world.
21:30
Mm-hmm.
21:30
And it's not always as clear that it's- Right … climate driven.
21:34
Um, you can have sediment dynamics change- Mm-hmm … and that can
21:39
cause, um mangrove invasion.
21:41
There's sea level rise rates are different around the world.
21:44
Mm-hmm.
21:44
But yeah, in general, um, the range is expanding.
21:49
And I don't think that anytime soon, uh, Georgia is gonna
21:53
be dominated by mangroves.
21:55
Right.
21:55
Right now it's just, it's literally a few individual trees.
21:58
Yeah.
21:58
Um, but they could be a bigger player in the ecosystem in 20 years.
22:03
Yeah.
22:03
Well, and it, it's interesting too, just talking about mangroves, I recently
22:07
saw a story within the last month or two, um, where, you know, for a while
22:12
the entire, like, global mangrove populations and cover were decreasing.
22:17
I think they lost something around 12,000 square kilometers I think it was.
22:21
Mm-hmm.
22:22
And now recently there was a paper showing that it's actually increased, like,
22:25
globally by about 2,000 square kilometers.
22:28
So not nearly what they've lost, but we're starting to see that increase.
22:32
And they're saying even in the face of climate change, um, like as you mentioned,
22:36
there are other things at play here that will allow them to grow, but it could
22:40
also just be the expansion of a new maybe type of habitat, or a new habitat- Right
22:45
or growing habitat.
22:46
Right.
22:47
Um, you know, I think of that kind of thing as it's like if you give Mother
22:52
Nature a chance, um, that she can rebound, and that's- Right … that
22:57
kind of seems like what's happening.
22:58
Uh, mangroves, we've probably lost roughly half of mangroves,
23:02
um, in the last century.
23:05
Yeah, yeah.
23:06
Um, mostly to development.
23:08
Yeah.
23:08
Um, but yeah, I saw that paper too, that we've made some gains in area.
23:14
Yeah.
23:14
Uh.
23:14
Yeah.
23:15
And there's some, you know, large scale restoration projects that have
23:19
probably helped that as well, but there's a lot of natural, um, expansion
23:24
and recolonization that's going on.
23:26
Yeah.
23:27
Interesting.
23:27
Uh, you mentioned, you know, sea level rise is playing a role in
23:31
certain aspects of coastal ecology and how it's shaping coastal ecology.
23:36
I always find sea level rise very similar to, like, something like getting
23:40
people to care about biodiversity.
23:42
They don't really get it, you know, when you say, "Oh, well, you know, sea level is
23:46
rising by, like, a centimeter or a couple of inches," or, you know, depending on
23:51
where you are in the world, people are just like, "Well, what does that matter?
23:53
It's a very small amount.
23:54
It's not gonna make a difference." Can you just talk about how, uh, sea level
24:00
rise is affecting, uh, especially, like, because we're talking about mangroves
24:04
and, marshes, how it's affecting those types of habitats, uh, either
24:08
for the positive or for the negative?
24:10
Yeah.
24:10
So, you know, marshes and mangroves are extraordinarily sensitive to sea level.
24:18
They can keep up with some sea level rise, and in fact, they've been
24:22
doing so for the last 5,000 years.
24:25
Sea level has been rising over that timescale pretty steadily until
24:31
the last, you know, 75 years or so.
24:35
Mm-hmm.
24:35
We've got an acceleration coming in.
24:38
We know that these ecosystems have a limit of how much they can keep
24:45
up with, and we've started to learn pretty well about what that limit is.
24:51
Um, it seems like several different, very different approaches have converged on a
24:56
rate of about eight millimeters per year.
25:00
They keep up by accumulating soil, exogenous sediment
25:05
that passes through wetlands.
25:06
They trap some of that.
25:08
They build organic matter, so by photosynthesis, building plant
25:13
tissues, and a lot of those tissues get buried in the soil.
25:17
And because that soil's saturated, they just accumulate.
25:20
They don't rot.
25:21
Mm. There's no oxygen to support the decomposition, so it just
25:24
builds up on top of itself.
25:27
Um, but those mechanisms have a limit.
25:29
That limit definitely varies with, like, how much sediment is around.
25:33
Mm-hmm.
25:33
But we've learned from past, one way is they've learned from
25:38
past sea level rise events.
25:41
They can look at sediments and reconstruct when a wetland
25:46
was no longer able to keep up.
25:48
And- Hmm
25:50
my team has used some modeling.
25:52
You try to do this process model where you put all that stuff in a
25:55
model, how much sediment's gonna accumulate, how much organic-
25:58
Right … matter's gonna build, and we come up with roughly the same number.
26:02
It's about eight millimeters per year.
26:05
Now, that's important because, um, you know, if you ask an
26:09
oceanographer, "50 years ago, what's the rate of sea level rise?"
26:12
You know, they might say two and a half millimeters per year,
26:17
but now we're closer to five- Hmm … millimeters per year globally.
26:21
Double.
26:21
Yeah.
26:22
And no one knows, you know, how much more there's gonna be in the future.
26:27
You can g- you, you know, ask 100 different oceanologists- Yeah
26:30
… you'll get 100 different answers.
26:32
For sure.
26:32
Um- Yeah … but the estimates, you know, we very well could pass that
26:36
threshold in the next couple of decades, depending on what happens to,
26:41
you know, ice- Yeah … at the poles- Well, absolutely … or Greenland.
26:46
Yeah.
26:46
So it's, um, alarming and- Yeah … you know, as a scientist,
26:51
it's kind of an exciting time, right?
26:53
Well, we'll see.
26:54
We'll see how much- Yeah … we'll test our model- Yeah … um,
26:56
with r- this massive uncontrolled experiment that we're doing.
27:00
Yeah.
27:01
No, exactly.
27:02
It's interesting from a scientific perspective, but also you don't
27:04
wanna see the results of that getting you know, too much and so forth.
27:08
Um- Now, you know, we talk a lot about climate change, we talk
27:11
a lot about coastal wetlands.
27:13
One of the things that coastal wetlands is known for is sequestration.
27:17
I talk a lot about on the, on the podcast about how CO2 can
27:17
be sequestered by mangroves,
27:24
seagrasses, salt marshes, and so forth, at a much higher rate than a
27:28
lot of, uh, land, trees, and forests.
27:31
Um, and that's a, a really great thing, obviously, you know.
27:34
And obviously with the loss of those wetlands, uh, there's a much more need
27:39
for restoring those wetlands to bring some of that to help with that process.
27:43
Uh, but what a lot of times we don't talk about, especially on this podcast,
27:46
is the fact that it's, that we call it blue carbon sort of, uh, wetlands, but
27:50
there's also blue nutrients, uh, which is, is something you covered on, your
27:53
newest paper with your co-authors, looking at how nutrients really play a role in
28:00
coastal wetlands at a pretty high rate.
28:02
Your database was pretty big in this situation.
28:06
Um, so I wanna talk a little bit about that paper.
28:08
Can you give us sort of the synopsis of the paper and just to kinda give us a, a
28:12
little bit of a overview, and then we'll kinda get into the nuances of the paper?
28:15
Okay.
28:17
Yeah, I mean, I'll start with nitrogen itself.
28:19
Well, we thought we coined this term blue nitrogen, um, to kinda piggyback on what
28:24
people know about blue- Yeah … carbon.
28:26
Um, and so why are we interested in nitrogen?
28:29
You know, nitrogen is a nutrient that is essential to life.
28:35
Um, and that's exactly why we use so much of it, because
28:39
it tends to make things grow.
28:41
Mm-hmm.
28:41
We have a lot of nitrogen in our bodies.
28:43
Plants need a lot of nitrogen to grow Um, but you can have too much of a good thing.
28:49
Mm-hmm.
28:49
And this is what has happened.
28:51
You know, our ability to, um, obtain nitrogen from different sources,
28:58
including the atmosphere, is really what's fueled the green revolution in
29:02
agriculture over the last hundred years.
29:04
We're much more efficient.
29:05
We can grow a lot more food per acre partly because we can take
29:09
nitrogen out of thin air and add it- Yeah … to our crops.
29:14
Um, and so that, you know, you might consider that a good thing.
29:17
More nutrients, that's a good thing.
29:18
Until these nutrients, you know,
29:20
they can get to a level where they cause problems, and that tends to happen as
29:25
waters run off of agricultural fields.
29:28
Mm-hmm.
29:29
They wind up in our creeks, in our rivers, in our estuaries, and the
29:34
amount of nitrogen ending up there can really build up to a high level.
29:39
So for the exact same reason that we use it because this level is
29:44
damaging because it can fertilize the growth of algae- Mm-hmm
29:50
um, to a level that is deleterious to the ecosystem.
29:55
So it causes… It can kill off, uh, fish.
29:58
It can… We've had, you know, manatee deaths in, down in Florida where they're
30:03
just washing up in unnatural numbers.
30:06
Um- You know, then there it's because the nitrogen is causing
30:12
this algal bloom, which… Well, there's a couple things going on.
30:16
So, uh, the algae grow and bloom, but then they die.
30:20
And when they die, they decompose, and that sucks oxygen out of the water, so you
30:25
get these oxygen dead zones in estuaries.
30:29
Some of these algae also produce these other toxins that have these secondary
30:34
effects, and that can also directly kill, uh, fish and manatees and humans.
30:40
I mean, it can really cause respiratory problems.
30:43
Uh, we were talking earlier about, uh, a red tide, and if you've ever been
30:48
around one of those, I think it's a really freaky thing to experience.
30:52
I was sitting on the beach with some friends and family,
30:56
and suddenly everyone…
30:57
This is down on the Gulf of Mexico.
30:59
Everyone started coughing.
31:00
And you couldn't see anything.
31:03
You couldn't see the red tide.
31:04
You couldn't smell it.
31:06
Um, but it got difficult to breathe, and so people started
31:09
leaving the beach abruptly.
31:12
Um, so that- Did they know what it was?
31:14
Like, did they have an idea?
31:15
I don't, I don't think people- Or they were just, like, everyone coughing?
31:18
Um, I think someone I, I was there with looked it up and was like, "Oh yeah,
31:22
there's a red tide right there." Oh, okay.
31:24
Yeah.
31:25
And so they, you know, they monitor it, and they know.
31:27
Yeah.
31:28
So this nitrogen, we have an unnaturally high amount of nitrogen
31:32
that's entering our waterways.
31:34
This getting back to the paper, um, what we wanted to learn is how much
31:39
can coastal wetlands, marshes and mangroves in particular, uh, sequester?
31:44
Like you mentioned, blue carbon.
31:46
These coastal wetlands take up a lot of carbon.
31:50
They put it in organic matter.
31:51
It sticks to soil, and that soil's accumulating, and that
31:54
organic matter's accumulating.
31:57
Um, but to take up that carbon, they also have a lot of
32:00
nitrogen that goes with that.
32:02
So we wanted to add that up for the first time.
32:05
People have done this many, many times for carbon.
32:08
I think there just tends to be more economic interest in carbon.
32:13
Um, but why not nitrogen?
32:16
So we did it for nitrogen, You know, we came up with a number, a big number,
32:20
is 3.2 teragrams of nitrogen per year that marshes and mangroves- Jeez … are
32:27
taking up and sequestering in the soil.
32:32
So you know, that's a hard number to wrap your head around because a teragram- Yeah.
32:37
Well, that's one gram with 12 zeros behind it.
32:41
Yeah.
32:42
Um, so I, I was trying to think of, like, what's that equivalent to?
32:45
Well, it's roughly equivalent to the amount of fertilizer that
32:50
we add to corn fields in the US.
32:53
So that- Geez … I don't know if that's helpful.
32:55
You could also say it's, um- That's kinda scary, though.
32:58
Like, when you think about how much fertilizer is put down.
32:59
Yeah.
33:00
Yeah.
33:00
You know, all that- And how much pollution that causes.
33:02
Yeah … you know, right.
33:03
Right.
33:04
And I was just trying to visualize, like, what is a teragram?
33:07
Um, so if you took 3.2 teragrams, that would be equivalent to the
33:11
mass of 700,000 African elephants.
33:15
And that's if they were made of pure nitrogen, which they're not.
33:18
Right.
33:19
Yeah.
33:19
Um, so that's how much these wetlands are taking up and
33:23
holding- Mm-hmm … in their soil.
33:24
When they have it in the soil, as long as it stays there, it's pretty much inert.
33:28
So it's not gonna contribute to algal blooms at that point- Right
33:32
if the wetlands are stable.
33:35
Right.
33:36
That's amazing.
33:39
Now, so for this study that you did, Like, what did you wanna get out of this study?
33:45
You wanted people to understand what role these wetlands play, and what's affecting
33:53
them in their ability to continue to keep this nitrogen sequestered and
33:58
continue to sequester more nitrogen?
34:00
Right.
34:01
We wanted to- Or nutrient, sorry … to get… Yeah, exactly.
34:04
We've called these wetlands like nature's kidneys because of kind of
34:07
this property before, that they tend to… I think people associate that
34:12
with, like, other pollutants, but we're talking about a nutrient pollutant.
34:16
So we wanted to add that up globally for the first time.
34:20
Yeah, we wanted to project, like, how might this change in the future?
34:24
So this 3.2 teragrams of nitrogen per year that they're sequestering.
34:28
That's happening in the background without us really knowing it or
34:32
even thinking about it until now.
34:34
Um, but as these coastal wetlands, I mentioned they're really dynamic.
34:38
As they change in the future, how might that number change, and
34:41
what consequences would that have?
34:43
There's not actually, not much agreement on exactly what's gonna happen to
34:47
coastal wetlands in the future.
34:49
We could gain coastal wetland area, we could lose it.
34:53
Um, and so we took some different scenarios.
34:57
If we gain coastal wetland, if we lose it, how much more nitrogen could
35:02
they take up if we're gaining area?
35:04
Or how much might they release if we lose it?
35:08
So if these coastal wetlands erode and- that soil that was kind of sequestered
35:16
and all the nutrients in there got recirculated in the ecosystem, you
35:20
know, how much more could come back out?
35:22
So we wanted to kind of pose that question.
35:26
Um, you know, hopefully, yeah, we're you know, targeting policymakers ultimately.
35:32
Mm-hmm.
35:34
Mm-hmm.
35:34
'Cause we- For them to listen and be like, "Hey, this is what we need
35:36
to do." Now, looking at the size itself, you got a lot of measurements.
35:40
I think it's over 8,000-plus measurements, 255 sites.
35:45
How long did it take to bring in that amount of information?
35:48
I want people to understand the scale of this study.
35:52
That was a struggle.
35:53
Um- It's a lot of mud But it's a lot of mud.
35:56
Um, you know, so some of these cores I took myself.
35:59
Most of them we were getting, uh, data that were available from other colleagues.
36:05
A lot of the co-authors have taken these themselves, and I was like, "Okay, let's
36:09
bring all this-" Yeah … "data together." A lot of it's already published.
36:13
Some of it wasn't.
36:14
Um, but yeah, You notice there's a very long author line on here.
36:18
I wanted to acknowledge the blood, sweat, and tears that went into- Right
36:22
to getting all those data.
36:23
'Cause it's- Yeah … not easy.
36:25
You know, that's a lot of soil cores, yeah, taken in, uh, as
36:28
many places as we could find.
36:31
Um, so yeah, it took a while to bring all that together
36:35
and- Yeah … comb through it.
36:36
And so looking at studies, that probably ranged over quite a long timescale too,
36:40
in terms of getting, like, bringing in all those different papers and
36:43
samples and things like that, right?
36:45
Yeah.
36:45
And, luckily, I think what made this possible is how much
36:49
interest there has been in carbon.
36:51
Mm. Um, because a lot of these studies were targeting carbon.
36:55
Ah, okay.
36:56
It just… It's, it's a nice coincidence, or it really, um, worked out well for
37:01
us that when you… The way we analyze carbon, or the way most people do it,
37:05
you happen to get nitrogen at the same time if you use an elemental analyzer.
37:10
Mm. So I could go in and see, find some data, and I'd find the carbon
37:15
data that they published, and there's, if I go to the raw data, sometimes
37:18
there was another column of nitrogen data that they never published.
37:22
Right.
37:22
But they were- Um … just getting it because they could,
37:24
because that's, that's the idea.
37:24
They were getting it because they could.
37:25
Yeah.
37:26
Okay.
37:27
And, and so we took advantage of that, and that really helped.
37:30
This whole project really was, like I said before, piggybacking
37:34
Mm-hmm … on blue carbon.
37:36
You know, that was also kind of the motivation.
37:38
Like, um, policymakers, you know, internationally are
37:42
very aware of blue carbon.
37:44
Mm-hmm.
37:45
For sure.
37:45
Um, and they're putting very hard dollar values on what it's worth.
37:50
Um, but they're not doing that for nitrogen, so we wanted to raise that.
37:54
You know, that goes back to your previous question.
37:56
That was really- Yeah … one of the motivations.
37:58
Yep.
37:59
Yeah.
37:59
No, I love that.
38:00
Can you talk a little bit about, you know, looking at blue nitrogen, like burial?
38:05
Like, how does it actually work in soil, and does it differ
38:07
between mangroves and marshes?
38:10
And you don't have to go into, like, extreme detail, but just in-
38:13
Yeah … terms of, like, how that works.
38:15
Does it work the same… You k- kind of mentioned earlier with
38:17
carbon and things, like as the soil grows you can have more space.
38:20
But how does it actually get buried in there?
38:23
Right.
38:24
Yeah, that's a great question.
38:26
It's largely two processes.
38:29
I would say there's, uh, the biological side where plants absorb this nitrogen.
38:35
So the water infiltrates into the soil, and it's carrying some nitrogen with it.
38:40
Um, some of this nitrogen is coming from nitrogen-fixing bacteria in the soil.
38:45
Mm-hmm.
38:45
But so then the plants take up that nitrogen, they grow, they die, they
38:53
fall over into the soil, or the below ground structures just die in place.
38:58
Mm-hmm.
38:58
And it's key that these are saturated soils, so oxygen is consumed more
39:07
rapidly than it can diffuse in.
39:09
And that keeps this soil really anoxic and tends to preserve organic matter- Mm-hmm
39:15
for long time.
39:16
You might have seen like the bog mummy from- Right.
39:20
… Scotland.
39:21
So in a wetland there was a- Yeah … a really old, I don't know how old, tens
39:25
of thousands of years old human that fell in, and they're- Yeah … really
39:28
well preserved because there's no oxygen in that bog- Right … um,
39:33
to stimulate decomposition.
39:35
Same thing happens here.
39:37
So organic matter builds up.
39:39
The other side, so there's the inorganic side where these wetlands,
39:45
because they have vegetation that's sticking up into the water that
39:49
floods through them, they tend to trap little particles of- Okay … silt.
39:53
Right.
39:54
And, you know, some amount of nitrogen will stick to those
39:58
little particles as well.
40:00
Okay.
40:00
Um, you know, there's a lot of work right now and a lot of
40:03
interest on this very question.
40:05
What is it that, um, helps stabilize especially carbon, but also
40:10
nitrogen in these wetland soils?
40:12
What are the mechanisms?
40:13
And I think we still don't really know- Mm-hmm … you know, some…
40:16
They can last for millennia down there.
40:18
What is it that keeps any bacterium from trying to, uh,
40:23
consume these for that long?
40:25
It's, uh, it's, you know, anoxia is part of it.
40:28
Sometimes you get some acidity in these soils and that might help a little bit.
40:34
Yeah.
40:34
Um, We're really trying to explore.
40:37
I have some colleagues working on this, uh, Lisa Chambers down in Florida.
40:42
Um, there's some abiotic mechanisms where y- you just have carbon and
40:49
nitrogen kinda stick in these little crevices to tiny little soil particles,
40:54
and it's- Yeah … gets locked away.
40:56
Yeah.
40:58
That's so cool … inaccessible to microbes.
41:00
Yeah.
41:01
Yeah.
41:01
No, that's so cool.
41:03
Let's get into some of the results of the study.
41:05
Um, 'cause you had this large database.
41:08
Uh, one of the things that you guys saw, it was like, there's like a,
41:12
a, like a th- I think this was one of the results, like a 13% to 15%
41:16
marine nitrogen burial figure, right?
41:19
How significant is that number in the context of, like,
41:21
the global nitrogen cycle?
41:23
I keep saying nutrients.
41:24
Nitrogen cycle.
41:25
And what was it estimated before the study?
41:29
, We dug and dug and it couldn't find any good-- any estimates for a global
41:36
nitrogen burial rate in coastal wetlands.
41:38
And I think it goes back to what we said before, like, kinda
41:41
slipped through the cracks.
41:43
Mm-hmm.
41:43
You had people that were estimating, looking at the nitrogen cycle
41:47
on land and that and the ocean.
41:49
Um, and we could not find any good global estimate.
41:54
So we can't say we increased or decreased it.
41:57
There really wasn't one.
41:59
Um, so marine burial, I have seen numbers for that.
42:04
Um, and so it turned out to be a pretty significant portion of that.
42:09
Um, as far as the global nitrogen cycle, you know, there are some
42:14
big fluxes in the global nitrogen cycle- Of course … and humans have
42:18
tended to make them much larger.
42:21
This is really staggering with nitrogen.
42:24
You know, we've affected the carbon cycle, but we've really
42:27
affected the nitrogen cycle.
42:29
Um- More than the carbon cycle?
42:30
Yeah, I would- Oh, wow.
42:31
Yeah, that's, that's- Okay … that's a fact, because if you look at the
42:35
natural fluxes of nitrogen into ecosystems, um, through deposition from
42:45
the atmosphere and fixation, um, we've more than doubled the rate of nitrogen
42:51
inputs through- Wow … fertilizer production, fossil fuel combustion.
42:57
So yeah, It is extreme.
43:00
Um- Yeah … this rate of burial, y- you know, and it's probably, like,
43:08
on the order of a couple of percent of some of these other large fluxes,
43:13
like total input into ecosystems.
43:16
So in that, in that sense, it's not huge.
43:19
It's on par with, um, blue carbon.
43:23
If you look at the rate of blue carbon burial, that is about 60
43:29
teragrams of carbon per year globally.
43:33
That's a lot.
43:35
Um, but global emissions are 10,000 teragrams.
43:38
In fact, it's so big we measure it in petagrams.
43:40
It's about 10 petagrams.
43:44
So what's that make?
43:46
That's about, uh, a half a percent of emissions that is
43:50
being buried in coastal wetlands.
43:52
That's something.
43:52
That's big.
43:53
Um, but, you know, in the big scheme of things, it's a little smaller.
43:57
And this is where nitrogen is fundamentally different from carbon.
44:01
So it makes sense to talk about carbon on a global scale And it makes sense
44:06
for nitrogen as well, but the effects of nitrogen are really magnified locally.
44:13
So whereas, you know, we talk about carbon because one molecule
44:16
of CO2 when it's emitted, it goes up and it warms in the atmosphere,
44:20
but that warming isn't localized.
44:22
Right.
44:22
That's really well mixed up there, so it can cause warming all around the globe.
44:28
That's not the case with nitrogen the way we're talking about it, 'cause
44:31
when it's taken up from an estuary or released into an estuary, its
44:36
effects are manifested right there.
44:39
Mm-hmm.
44:40
So in a way, I'd say, the role of coastal wetlands is probably
44:45
greater in terms of nitrogen than it is in terms of carbon- Mm-hmm
44:50
because of these acute local effects that nitrogen has.
44:52
Yeah.
44:54
Wow.
44:55
That's incredible.
44:57
That's incredible.
44:57
Now, we talked about sea level rise earlier, uh, but you found
45:00
that sea level rise could increase nitrogen sequestration in wetlands,
45:05
but only if the wetlands survive.
45:07
What is meant by that?
45:08
Like, what determines whether a wetland survives in sea level rise?
45:12
And if it does, then it's a big benefit.
45:14
Right.
45:15
Yeah, and this is what I said is really not very well resolved in my field.
45:20
I've got colleagues on both sides that think, some think, sea level
45:26
rise is going to drown wetlands.
45:29
Uh, once- Right … we pass these thresholds, there's not one
45:32
threshold, let's not kid ourselves.
45:33
There's a range of thresholds.
45:35
Right.
45:35
But in some cases, the thresholds are being passed if the rate of sea level
45:39
doubles, we're gonna lose more wetlands.
45:42
Now wetlands are dynamic though.
45:44
They can build vertically, and that has a limit, but they
45:46
can also transgress laterally.
45:49
Mm-hmm.
45:49
And so there have been papers that suggest, um, that as sea level rises, we
45:56
could even gain wetland area because they just has to do with the topography of the
46:01
inland area where they're transgressing.
46:03
So when I say transgress, I mean- Yeah … move.
46:06
Like move to the right or to the left- Landward
46:08
or… Yeah, landward.
46:09
Yeah.
46:10
My hunch is that's not going to happen.
46:12
We're gonna lose coastal wetland area with higher rates of sea level.
46:16
But, for the purpose of this paper, we didn't wanna tackle that- Right.
46:20
Of course … can of worms.
46:21
Yeah.
46:21
So we just took all these different scenarios.
46:24
So we said in the rosiest scenario, say wet- sea level rise increases,
46:30
and the area of wetlands expands.
46:34
The rate of sea level rise, so if wetlands keep up with that rate of
46:37
sea level rise, well, that means they're burying soil more rapidly.
46:41
Mm-hmm.
46:41
Um, they have to, to keep up.
46:43
Yeah, to keep up.
46:44
Yeah.
46:48
But, you know, it, I think more realistically, that scenario to me,
46:52
a high rate of sea level rise and wetland area gain is not very realistic.
46:56
I think if we have higher rates of sea level, we're gonna see more loss of-
47:02
Makes sense … of coastal wetlands.
47:04
Yeah.
47:05
Yeah.
47:05
It's like- 'Cause it would be, it would be hard to keep up
47:07
with that soil rising- Mm-hmm
47:10
with that, if sea level gets over, rates too high and it
47:13
gets over the wetland, right?
47:14
I think of it like a conveyor belt and, like, if you're in a chocolate
47:18
factory and you turn up the speed of the conveyor belt, well, that
47:21
might help increase production for a while, but if you go too far- Mm-hmm
47:25
you're gonna end up with a Lucy and Ethel situation and the-
47:28
Mm-hmm … whole system breaks down.
47:29
I like the reference.
47:33
Awesome.
47:34
Awesome.
47:35
Um, yeah, that definitely, uh, makes sense.
47:38
Um, like, are there real world examples showing, like, already
47:42
showing, like, this source versus sink?
47:44
Like where we see a, maybe a flip, or we see, um, you know,
47:48
where wetlands actually survive?
47:50
Have we seen that, again, with higher rates of sea level rise?
47:54
Or has it been the opposite?
47:56
So I'm thinking on the other side, I feel like we've definitely
47:59
seen cases where we feel like the wetlands have sunk and started to
48:04
erode because of sea level rise.
48:08
Um, there are some, probably some cases maybe in the Gulf, um, where I think
48:14
that's where you see your highest rates of relative sea level rise,
48:17
which can exceed a centimeter per year.
48:20
We've been talking about millimeters, so- Mm-hmm … because you- Which is like,
48:25
yeah, order of magnitude more, yeah.
48:26
Yeah.
48:27
Because you have a lot of, uh, subsidence of deep sediments,
48:31
and so the whole area is sinking.
48:35
Plus you have, you know, whatever sea level rise rates.
48:38
So if you add those two, that's how much relative sea level rise is.
48:42
So you can get some really high rates.
48:43
And there are are certainly cases of wetlands that are keeping up with that.
48:47
I'd say it's- Mm-hmm … most likely where you have a lot of sediment available to
48:51
be deposited and help build that soil.
48:54
Um, but I think that the net effect that I see at my sites when I'm,
48:59
especially in Florida, is just that we're losing, um, in this recent paper,
49:05
it's about a linear meter per year off every coastline of every wetland,
49:11
um, which is, yeah, it's extreme.
49:13
That's significant.
49:14
It's very significant.
49:16
And you can go yourself on Google Earth and look at the past, the
49:19
older imagery compared to the current, and you'll see- Yeah
49:22
this, this retraction that's happening.
49:25
And there it is.
49:26
It's definitely partly sea level rise and accelerating- Yeah … sea level rise.
49:30
Um- Right … Our paper recently points to some other human influences
49:35
like boats, boat- Mm-hmm … traffic along the coasts of these wetlands.
49:40
So this study was centered on the Intracoastal Waterway- Mm-hmm
49:44
in northeastern Florida.
49:46
And there are more boats, they're moving faster, they're bigger,
49:52
they're more frequent, and you get a lot of wave energy that's generated
49:56
that just wasn't there in the past.
49:58
Mm-hmm.
49:59
These all coastal wetlands they tend to form in lower energy environments.
50:04
Yeah.
50:05
Um, so when you add energy to the system, you're gonna tend to erode those edges.
50:10
One twist on that was we did find that areas that had mangroves in
50:14
Florida tended to have lower rates of erosion, so they seemed more, more
50:21
resistant- Right the shoreline erosion.
50:25
Yeah.
50:26
Now, looking at all of this, you know, all the worry and, obviously
50:29
this paper adds to the demonstration that people like policy makers and
50:34
regulators should be looking at managing nutrients just as much as they're
50:39
managing carbon in very similar ways.
50:42
From a regulation and policy standpoint, I assume that hasn't happened at
50:46
this point, where it's not equal, or I assume carbon's taking the bigger
50:51
attention span because of climate change and everything working on that.
50:54
How can policymakers or regulators gain on this policy and make it equal if not more?
51:00
Because, you know, obviously we've demonstrated here that it's got a huge
51:03
effect on a lot of different things.
51:06
You know, water quality, it's especially we're looking at
51:09
erosion and security of coastlines.
51:11
I mean, you're making me think that this prediction, the, this IPCC prediction of
51:15
sea level rise with Florida losing, you know, half of its area at some point in
51:19
time is gonna happen sooner than later, just with the way things are moving.
51:23
Um, how can regulators and policymakers really start to ramp up the work
51:28
on looking at at nitrogen and blue nitrogen as a focal point?
51:32
I think, um, what we point to is the potential monetary value
51:36
and, you know, follow the money.
51:39
For better or worse, um, when you can readily quantify the monetary value of
51:46
an ecosystem service, it's more likely that you'll see action, and that's
51:51
what's happened with blue carbon.
51:54
We're not economists on this paper, but we did throw out some numbers just using
51:59
some other people's values for how much is it worth to sequester a gram of nitrogen
52:06
and to keep that out of your waterway.
52:08
So we took some numbers and then extrapolated using the 3.2 teragrams
52:14
that we came up with, and the value could exceed the value of blue
52:21
carbon, and so that's pretty big.
52:23
So blue carbon is calculated by saying like how much damage can climate change
52:28
cause if that carbon is in the air?
52:31
Um, so if we store it in a wetland, you know, how much are we offsetting?
52:36
So the global value of that blue carbon in coastal wetlands was
52:41
estimated to be $191 billion.
52:44
Um, we think blue nitrogen could be more.
52:47
Wow.
52:47
It's a little, it's a little more difficult to calculate because like I
52:52
said, it's not as global in its effects.
52:54
Mm-hmm.
52:55
Um, so storing, sequestering a gram of nitrogen in a really polluted estuary
53:01
might be worth more than somewhere else.
53:05
Um- Right.
53:05
Right … whereas for carbon, it's just more fungible.
53:09
You can probably come up with one number maybe that works for the globe.
53:12
I don't know how these economists do this, but, um.
53:14
Right.
53:15
Yeah.
53:15
So I do think it's a little more complicated with nitrogen, but I think
53:18
those are complications that can readily be worked out, and once you have a value
53:23
that we're getting by, um, protecting wetlands or restoring wetlands, I
53:28
think it becomes much more clear to policymakers, to private interests,
53:33
like, you know, this is why we should save these places or restore them.
53:38
Saving a wetland isn't as easy as it might sound.
53:44
You can't just, like, put a fence around it and hope it survives.
53:48
Um, you know, when you're talking about conserving an upland
53:53
forest, maybe that's what you do.
53:54
Just- Right … don't let- Yeah … someone bulldoze it.
53:58
Um, or if you think about, like, marine protected areas, which I'm
54:01
sure you've talked about a lot.
54:04
Yeah.
54:05
it's more about, like, surveying the area and, um, having some eyes on
54:11
it and maybe regulating fishermen.
54:14
Yeah.
54:15
Yeah.
54:15
In a wetland, you know, the, there are those threats.
54:18
There are some… You know, your bulldozers are a threat.
54:21
That's a very acute one, but you've got this sea level rise, and,
54:23
like, a fence won't keep that out.
54:25
No.
54:26
Um, so it's like, you know, ultimately, if you want to preserve the wetland,
54:32
and not just the carbon and nitrogen, but everything else they do, like you
54:36
mentioned, coastal protection, uh, habitat, um, sustaining our fisheries,
54:44
we've kinda gotta deal with the sea level issue, that's a big one.
54:48
A bigger … That's a bigger, that's a, a bigger solution, a bigger ask.
54:52
Yeah.
54:53
Right.
54:53
Yeah.
54:54
If your endpoint is trying to reduce, you know, nitrogen loads, you're like,
54:58
I think wetlands are a big part of that.
55:01
If we can sustain healthy wetlands, I think they will
55:04
really help us with our problems.
55:05
But we've also got to just, um, manage our nitrogen better.
55:09
Yeah.
55:10
One thing we're seeing in Florida is that a lot of the nitrogen that's
55:17
polluting the waterways is organic- Mm-hmm … which is different from elsewhere.
55:22
It tends to be, um, you know, nitrate.
55:24
Right.
55:25
But here it's, a lot of it's organic.
55:27
And we think that- the wetland erosion that we're seeing might very well be
55:31
contributing to those higher loads of organic nitrogen in the estuary.
55:37
That's one of the thrusts of what we're trying to work on is linking those two.
55:40
Are we actually seeing already what we're predicting might happen in the
55:45
future where we lose wetlands and they re-release all these nutrients- That
55:50
they've been- … into the waterway
55:51
sequestering for centuries?
55:52
Yeah.
55:52
Right.
55:53
And you're looking at Everglades, which covers a significant portion
55:56
of Florida, and you lose that, that's a lot of nitrogen going
56:00
back into the system, right?
56:02
Oh, gosh.
56:03
I haven't done- … that math on the Everglades, but that
56:05
would be- Don't do that math.
56:06
We don't wanna see that.
56:07
We don- don't do that math.
56:08
But I, I guess the, I guess the, the, the quote-unquote quicker fix would
56:12
be restoration to ensure that we don't have this loss, but that doesn't
56:17
necessarily replace the nitrogen that's been sequestered because
56:20
those are gonna be very new systems.
56:23
And if we lose the other systems, it becomes- Mm-hmm
56:26
it becomes a little bit more difficult.
56:28
The longer process is reduce climate change, and let's hope for the… Like,
56:33
cross your fingers and hope for the best at this point, 'cause we're already
56:36
past- Yeah … a lot of thresholds, uh, that we weren't supposed to pass.
56:40
Um- Right … and of course, you know, from a, from an action standpoint,
56:43
I always say vote for, uh, better politicians who actually care about
56:48
the environment, and this is worldwide, not just the US, but worldwide.
56:53
And realizing that coastal ecosystems, although they might be difficult to
56:56
tread on, they might be difficult to, you know, smell, like the smell's not
57:01
the best when you're in those areas or, you know, things like that, but
57:03
they're actually quite beautiful.
57:04
Whole lot of biodiversity, whole lot of nutrients, uh, and nitrogen and
57:09
carbon, and we literally need them.
57:11
We need everything we can get right now, and, and it's, they've been
57:13
saving our butts for a long time, and right now it may not be enough.
57:18
Because of all that, I've learned to love the smell.
57:21
Yeah.
57:21
Yeah.
57:22
I like that.
57:24
Who's had to deal with it?
57:26
That's it.
57:27
I love it.
57:29
Yeah, it's great.
57:29
I love that.
57:30
I love that.
57:30
Adam, I wanna thank you so much.
57:31
You've given us so much, uh, to think about and to work.
57:34
I guess, like, uh, for people who are listening to this podcast, I
57:36
know there's a lot of like, uh, high-level stuff, like a lot of policy
57:40
needs to be done and like tackling climate change is a difficult thing.
57:43
But what could, what, like, action would you say, uh, people could take, or what
57:49
would you suggest for them to do, uh, in regards to helping with this problem?
57:55
Um, well, I mean, you know, I really think this comes down to this question
58:01
with the same thing with carbon.
58:04
You know, you can calculate your carbon footprint.
58:07
You can calculate your nitrogen footprint.
58:09
You can Google that, and you can go look up and see.
58:11
You know, everything we do, because nitrogen is so important
58:15
to life, everything we do- Yeah
58:17
generates some nitrogen waste.
58:20
Regarding both those questions, it's like, can your personal actions matter-
58:26
Mm-hmm … compared to policy actions?
58:30
And, you know, it's like, yeah, I don't know.
58:34
I don't know if- Yeah … if they can- It's true … directly, but I do
58:37
know that they are at least symbolic.
58:40
Mm-hmm.
58:41
And when you take the action, you know, maybe reduce your nitrogen
58:46
footprint, that's like eating lower on the food chain, um,
58:50
reducing fossil fuel combustion- Mm-hmm … whatever you can do, I
58:53
think that symbolically matters a lot.
58:56
For sure.
58:57
Um, as far as saving, you know, coastal wetlands, uh, I'd say,
59:02
like, one, don't buy a super yacht.
59:04
Those are bad for wetlands in multiple ways.
59:07
Right.
59:08
Right.
59:08
But like what you said, you know, voting is obviously- Yeah … a lot
59:11
of it starts there because I really do believe, like, it takes collective action
59:17
to make a difference on these issues.
59:18
These are- Yeah … these are necessarily collective issues.
59:22
These, you know, nitrogen, just like carbon, doesn't
59:25
really know borders like we do.
59:26
It's everybody's problem.
59:28
Yep.
59:28
And so it takes everybody to solve it.
59:30
Absolutely.
59:31
Absolutely.
59:32
And one day we'll get it right, but there is a big election coming up
59:34
in November in the United States.
59:36
Uh, a lot of elections going on in the United States that I think will
59:39
hopefully, if, uh, certain people win, hopefully they'll make some decisions
59:44
that'll be better for the environment and sort of bring back the funding, uh,
59:47
for a lot of these situations that we're in right now that, uh, not necessarily
59:51
in the last three years or in the last year or two, but, uh, hopefully help
59:55
us get out of it, uh, in the future.
59:56
So, uh, Adam, thank you so much for the work.
59:59
Uh, appreciate everything you and your colleagues have done.
1:00:01
I'll put the link to the paper so that people can take a look, uh, and your lab
1:00:05
so people can take a look at what other stuff that you guys have been up to.
1:00:07
And we really appreciate you coming here, and we'd love to have you
1:00:10
back to talk more about wetlands and, and all the latest research
1:00:13
that you guys have been doing.
1:00:14
Thanks, Andrew.
1:00:15
It's been a pleasure.
1:00:17
You bet.
1:00:17
Thank you.
1:00:18
Thank you, Adam, for joining us on today's episode of the How
1:00:20
to Protect the Ocean podcast.
1:00:21
It was great to have you on.
1:00:22
To be able to have a discussion on coastal wetlands that we really haven't had before
1:00:27
on this podcast is really special to me.
1:00:29
I've always admired mangroves, salt marshes, mud flats, seagrasses,
1:00:34
even coral reefs, all these different types of habitats.
1:00:37
Not only are they great to dive on and dive in and just they're beautiful in
1:00:40
nature and the way they actually, uh, just are, like, just the way they look, the
1:00:44
way they act, and what they can do for the ecosystem, but it's also, it's really
1:00:48
important to have these conversations to look at how climate change, how sea
1:00:51
level rise, how development has changed the landscape, and to how sometimes that
1:00:56
could be a good thing, and sometimes that can be a really bad thing.
1:00:59
And we talked a lot about looking at what happens when mangroves and salt marshes
1:01:03
kind of release nitrogen into the water if they get flooded or if they die.
1:01:08
Uh, it's just as like we see with wildfires and carbon.
1:01:11
You know, if wildfires release as much carbon as they've been sequestering
1:01:14
for years, it's really difficult.
1:01:16
You can do restoration on, you know, forests as well as mangrove forests
1:01:20
along the coast and marshes, but it's not the same because they haven't
1:01:23
been spent decades and centuries just sequestering that carbon and that
1:01:29
nitrogen, which is very important to our environment, very important to
1:01:32
the changes in our environment that we could see in the future, which are a
1:01:35
lot worse and can really accelerate the changes that we see with climate change.
1:01:40
So I wanna thank Adam for joining us, coming in and telling
1:01:43
us all about his research.
1:01:44
Looking forward to having him come back, talk more about wetlands, more about
1:01:48
mangroves, more about marshes, and more about how sea level rise, as well as
1:01:52
other things like invasive species, uh, like looking at, uh, whether they're, um,
1:01:57
nutrient pollution, rising sea levels, at- rising atmospheric CO2 change the
1:02:02
way everything happens with the coastal environments that we talked about today.
1:02:06
So if you have any questions or comments for Adam or for
1:02:09
myself, please let me know.
1:02:11
If you're on Spotify, just hit me up in the comments.
1:02:13
If you, uh, wanna go the social route, my social media links are in the show
1:02:17
notes, and I'll put the links to Adam's website as well as lab site so that
1:02:22
you can get to know more about him, and we'll get to know more about him
1:02:25
when we ask him back on the podcast.
1:02:27
That'll be a lot of fun.
1:02:28
But thank you again for joining us on today's episode of the How
1:02:31
to Protect the Ocean podcast.
1:02:32
I'm your host, Andrew Lewin.
1:02:33
Have a great day.
1:02:34
We'll talk to you next time, and happy conservation.