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CAPE FEAR MEMORIAL BRIDGE CLOSURE: UPDATES, RESOURCES, AND CONTEXT

In the Wild Coastal Plain with surprisingly wild suburban ponds, amid pervasive pollution (Rebroadcast from October 17, 2023)

A natural pond in New Hanover County
RLH
A natural pond in New Hanover County

Andy Wood: Bullfrog tadpoles have an alkaloid in their skin. It’s a chemical compound that tastes a little bit like rotten lemon and Ajax. It’s a horrible taste, so very few things eat them.

RLH: Have you tried this? It’s a very, um, specific description.

AW: I would never admit that.

In the wild coastal plain of southeastern NC, Andy Wood and I explore the wildness of suburban stormwater management ponds. What we find is, no surprise, quite a surprise.


We hear the sound of crickets buzzing and gentle traffic in the background. 

Andy Wood: There’s somebody big swirling right here, so we may be – if there’s a big alligator in here, there’s a really good chance I am intriguing it.

Rachel Lewis Hilburn: Okay! Well, wanna go up the bank a little bit?

AW: No.

RLH: You’re not afraid of this alligator at all.

AW: I’m not afraid of it. I respect it.

I know that it could do me great harm. But it also knows I could do it great harm in that to it, I’m a big thing. So it’s going to be wary. It hasn’t even popped up yet. But that swirl smacks of an alligator.

What I could do, but won’t, is squat down at the water’s edge, yeah I will, and pat my hands to see if it does come up.

This is a really stupid thing to do, but in the interest of science…

Splashing / patting the surface of the water

Siren

RLH: Well, that’s good timing!

MUSIC UP

RLH: Andy Wood aborts. The water isn’t clear enough to see whether a large alligator might be moving closer underwater. I don’t say anything, but I do heave an enormous, albeit silent, sigh of relief.

This is truly a don’t-try-this-at-home moment. Andy Wood knows what he’s doing and has worked around alligators for decades.

He is Director of the Coastal Plain Conservation Group. I’m Rachel Lewis Hilburn, and you are in the wild coastal plain of southeastern North Carolina.

AW: There’s a turtle, probably either a slider or river cooter, our common basking turtle. They’re the ones that you see hauled up on the shore, up on a log, basking in the sun.

So we have grass going right down to the water’s edge and at the water’s edge, there’s a mix of plants dominated by pennywort, dollar weed.

RLH: On this sweltering August day, we’re less wild, more suburban, in the Wilmington suburbs on the other side of the Cape Fear River in northern Brunswick County. The heat index is well over 100 degrees, and today we’re exploring local ponds, the ones created specifically for stormwater management, just to see how wild they still might be.

A suburban stormwater management pond in Brunswick County
RLH
A suburban stormwater management pond in Brunswick County

RLH: We see a wading bird: dark blue feathers, long legs, sharply pointed bill, at the water’s edge.

AW: That’s a little blue heron, which is a bird in decline, unfortunately, throughout its range. So it’s marvelous, seeing it here. They are a wading bird, a heron, that feeds in shallow waters. They’ve got long legs. Their feathers don’t get coated with oil like a duck or a goose. Their feathers have a talc-like material that coats them, providing a little bit of waterproofing, but not enough for the bird to feel comfortable getting its body in the water. So they have those long legs to keep their body out of the water. They’ve got a long neck, and that serves as a pole, so to speak, of a spear – well, it’s not a spear, it’s more a tweezer –

The little blue heron catches a fish.

Herons and egrets don’t usually spear their prey. They use their bill like tweezers and grab the fish.

RLH: A bright green, exotic-looking plant, unlike anything I’ve ever seen around SE NC, appears to float on the water.

WALKING DOWN THE BANKS

AW: Interesting!

RLH: What is it?

AW: Water hyacinth. It’s a tropical species from South America—noxious, invasive.

RLH: Andy Wood grasps the water hyacinth and hoists it above the water to reveal roots not attached to anything except the plant itself.

water hyacinth is a noxious, invasive species, but cleans water by absorbing pollutants into its root system
RLH
water hyacinth is a noxious, invasive species, but cleans water by absorbing pollutants into its root system

AW: So you can see the root network on this plant. It’s an incredible filter system. This is doing a great service for the pond.

Andy Wood shows the root system of the water hyacinth
RLH
Andy Wood shows the root system of the water hyacinth

RLH: And yet he just said it’s a noxious, invasive plant. If left to its own devices, and if it can survive a North Carolina winter, the plant would eventually cover the pond. Andy is conflicted about its presence here.

AW: Personally, I think it would be great to have this plant covering this pond.

RLH: Why?

AW: They’re actually used in wastewater treatment plants as the tertiary treatment process. Not here – Massachusetts and a few other places, because its dense network of submerged roots that serve as biological attachment area for bacteria and other things that are processing nutrients out of this water. These plants are growing very robustly because this is nutrient-rich water and they’re doing a superb job of cleaning this water.

RLH: Wow.

AW: They will actually remove heavy metals from the water.

So the problem with water hyacinth is it cleans the water, so those plants’ tissue are saturated with all of the stuff that’s in this water and when they die, they decompose and release all that stuff back into the water.

RLH: He suggests an experiment. Create an encircled area of the pond where you grow water hyacinth and harvest it before it dies and can release toxins back into the water.

The harvested plants, though, would be hazardous waste.

AW: If you do a bio-assay of what’s in that plant tissue, you‘ll find every compound that’s sprayed in this neighborhood: lead. Chromium. Arsenic. Mercury. All the stuff that’s on the street is in that plant.

bladderwort, an aquatic, carnivorous plant
NC State Extension / Sam Kieschnick
bladderwort, an aquatic, carnivorous plant

RLH: He picks up another aquatic plant. Tiny, feathery leaves, similar in appearance to dill or fennel, float on the water’s surface.

AW: This is bladderwort, a carnivorous plant.

RLH: Not what I expected to see in a suburban retention pond on the side of a moderately-busy road.

RLH: Okay, can we do some dip-netting and see what’s in here?

AW: Yes.

RLH: You’re putting your boots on. Your snake boots?

AW: Oh, these are just boots to keep me dry.

RLH: Okay.

RLH: To find out what actually lives in these ponds, Andy sweeps a fine-mesh net on the end of the long wooden stick through the water.

He lets the water drain out and then examines what’s left in the net.

This pond, oval-shaped, is bounded on one side by the main road through this subdivision. On the other side is a cluster of native trees, a little clump of forest, which buffers a row of single-family homes.

A nearby sign warns about alligators in the pond. Another sign informs potential interlopers that fishing is only for residents.

AW: First, we’ll go out in open water. No surprise. Nothing. Out in the open water.

But now when you come in to where the plants are–

RLH: gasp

Little fish!

AW: We have a bluegill, sunfish, right there, and ubiquitous mosquito fish.

RLH: We’re looking at a handful of tiny fish – most of them no more than an inch long.

AW: So that’s the mosquito fish. Looks like a guppy. It’s the North American counterpart to the South American guppy.

Mosquito fish akin to the guppy
RLH
Mosquito fish akin to the guppy

Dip-netting sounds

Another bluegill. This may have been stocked with bluegill at some point. It’s a common, very common fish.

Bluegill from a suburban stormwater management pond in Brunswick County
RLH
Bluegill from a suburban stormwater management pond in Brunswick County

RLH: Do people eat bluegill?

AW: Yes. They get large, up to a pound – pound and a half – they are so delicious, very sweet.

RLH: We could dip net most of the day, says Andy, catch mosquito fish galore, and that would be about it – perhaps the odd tadpole. Possibly a crayfish. But it’s time to move on.

Then we see more swirls on the surface of the pond. Those swirls are created by carp. Big fish.

AW: What’s happening here, this is again, kind of the silliness, some brilliant person said, oh yeah, just put grass carp in there that will take care of it – of the weeds. So they’ll eat plants but they poop out what they’ve digested as unadulterated nutrient and promotes more plant for the carp to eat and then when we have a major flood event, a rain event, and water is spilling directly out of that pipe, grass carp, evolutionarily, are predisposed to leaving a contained body of water. They don’t want to be in this pond. They want to be in a river. So when water is flowing out of that pipe, if they can get into that pipe, they will.

AW: Time and time again, carp are introduced into a pond like this and then the owner comes back to the guy who put them in there and says I gave you 10k for carp and they’re all gone. And they weren’t eaten by birds; they’re just all gone.

AW: Yeah, they probably swam out which is what happens in Greenfield Lake every time they put ‘em in there which is why we have them in Cape Fear River now.

RLH: What’s the problem with that?

AW: Grass carp eat plants, but they also eat dragonfly larvae, snails, clams, freshwater mussels, crayfish, small fish, whatever will fit in their mouth, they’ll eat.

RLH: This pond is connected to another slightly larger stormwater management pond on the same busy suburban street. The two ponds are separated by a naturally-occurring creek. Their purpose, of course, is to handle big rain events, directing water away from roads and structures, into water bodies that ultimately drain into the Brunswick River, which flows into the Cape Fear River which flows into the Atlantic Ocean.

Will the larger pond hold different kinds of aquatic life?

Splashing into the water

AW: There are things in here that bite.

RLH: Oh!

AW: Yeah. Fiercely. Painfully.

RLH: Did you get a crayfish?

RLH: Andy’s been bitten. And the perpetrator was not a crayfish.

AW: Predaceous diving bug.

RLH: It’s swimming around in his jar of pond water.

AW: They have a jointed, piercing, sucking mouth part. They are a true bug. All bugs are insects but technically not all insects are bugs.

RLH: He’s about to explain that the bug is feeding on something in the jar – when someone driving by the pond sees us and yells out a warning –

AW: It’s grabbed something-

Passerby: Watch out for that gator!!

RLH: Watch out for that gator.

RLH: We’ve been warned now by two different people about the gator.

RLH: We go back to the predaceous diving bug with the fiercely painful bite. He’s eating a Physella snail.

AW: What I’m going to do is pin it down so you can see its mouth underneath, but I’m not going to pick it up, because every time I do I get nailed. It’s like a bee sting.

Andy Wood presses the underside of a predaceous diving beetle against his jar for a view of the piercing mouth part (that just bit him).
RLH
Andy Wood presses the underside of a predaceous diving beetle against his jar for a view of the piercing mouth part (that just bit him).

Can you see it?

RLH: Hmm mm.

RLH: With his finger, Andy is pressing the predaceous diving beetle against the side of the jar so that I can see the underside and that piercing mouth part that he just used on Andy.

AW: A very common aquatic insect, but an indicator of biodiversity.

RLH: This native species is doing just fine, says Andy, taking refuge in some noxious invasive alligator weed, which is actually providing habitat for other kinds of pond life, as well.

Andy surprises me with a spider, probably at least two inches long, maybe three, sitting on his hand.

AW: Here’s the long-jawed orb weaver.

long-jawed orb weaver spider
RLH
long-jawed orb weaver spider

RLH: Oh. Oh. Wow.

AW: Nice, huh?

Ow!!

RLH: Oh - did he bite you?

No. Yes.

RLH: Oh!

AW: Not to hurt me. It is – what is this? It only touched my finger. It wasn’t defense or anything like that. But I always react. That’s the orb weaver it really was not trying to hurt me – that wasn’t defense. They just think I’m a weird tree. I’m not a tree. Why would they bite a tree? I’m not food for them.

RLH: This long-jawed orb weaver has a long, narrow body with longer segmented, hairy front legs.

AW: So we don’t need to be all anxious about spiders.

RLH: Sure.

AW: Wow, it is warm out here.

RLH: Yeah, it is.

RLH: The heat is getting to us. We catch another small bluegill. More people are warning us about the alligators in this pond.

Andy says he appreciates the neighborliness.

AW: We all need to be aware of our surroundings. You see that log moving? That's an alligator.

I’m casting my eyes across the pond constantly. I want to see that log swimming – that way I know where it is. Once I know where the alligator is, I’m not going to worry about it.

When it is oriented toward me and then submerges, that’s when I step away from the water because it’s sneaking on the bottom. They’re not stupid. They’ve been around for 150-plus-million years.

RLH: But it is time to move on.

MUSIC UP

We’re going to head out to a genuinely wild pond, protected by acres of wilderness in northern New Hanover County. But before we go there, there’s one more suburban pond we want to explore – with water birds, frogs, snakes, and of course, a resident alligator.

END OF SEGMENT 1

IN THE WILD COASTAL PLAIN OF THE SUBURBS WITH POND LIFE

SEGMENT 2

Rachel Lewis Hilburn: I’m RLH and you’re in the Wild Coastal Plain of Southeastern North Carolina. Andy Wood, Director of Coastal Plain Conservation Group, is our guide today as we explore the wildlife in suburbanized stormwater management ponds in Leland. That’s in northern Brunswick County.

Andy Wood: This looks like herbicide damage on the shoreline.

RLH: The pond management company sprays herbicides on the vegetation around the pond and the vegetation, the water lilies, in the pond.

AW: It’s easier to spray an herbicide than it is to come in with loppers and clip this down. But that’s really what should be done. We should be paying people a respectable salary to come in with hand tools and cut these and take them away rather than spray them with an herbicide, because the herbicide spraying is going to be repeated time and time again.

Herbicide damage around the perimeter of a suburban stormwater management pond in Brunswick County
RLH
Herbicide damage around the perimeter of a suburban stormwater management pond in Brunswick County

And what the company will say is, well, if we just cut them it’s going to grow back. Well, yeah. So cut it instead of spray it. You’re going to be back anyway.

This looks like a pretty standard stormwater control measure, out of compliance, which is typical of this region. These stormwater systems are built on the minimum design criteria guiding principle: do the least and hope for the best.

RLH: Single-family homes line both sides of this long, narrow, almost rectangular pond. Large, cement inflow pipes are visible on all four sides.

Andy’s noticing the erosion on the banks of the pond.

RLH: What does out of compliance mean?

AW: Looking across the water here, that shoreline with all of that erosion – they put down a grass mat that is incorporated with a monofilament netting. You can see it on this bank, as well. That’s just plastic debris and a potential entangling mechanism for everything from mice to frogs, snakes, turtles, you name it. Anything can get tangled up in that.

The shoreline itself, the slope is too steep, so erosion is rampant, as you can see, in places. The herbicide that they’re using is wildly toxic to all plants. That should be a concern to everybody.

RLH: But the purpose of this pond is not to support wildlife. The purpose is to serve as a stormwater management tool.

AW: That’s correct. That’s what these are designed to do. They’re not meant to be ecologically beneficial even though that’s what we’re told – is that stormwater systems collect stormwater – retain it for a period of time so that silt and sediment can be removed from the water before this water flows into receiving public trust waters: streams, creeks, that eventually drain into a river which eventually goes out to the ocean.

The folly in all of this is the fact that these are designed to receive roughly an inch-and-a-half of rain in a rain event and that’s all. Anything beyond that is more than the structure is designed to handle and so if we get a two-inch rain, it just flows straight out to the receiving water totally untreated.

And to say that this is treated is a misnomer. This water is not treated in any way.

You’re looking at a witches’ brew of chemical compounds in this pond right here. I wouldn’t swim in this. I’ll dip my hands in it and then be sure to wash them thoroughly. But this is not wholesome water, by any means.

It contains fertilizers, herbicides, insecticides, fungicides, miticides, every pesticide that’s used by licensed pesticide applicators in every yard that drains into this pond – every one of those chemicals is in this water.

RLH: It also happens to be garbage collection day in the neighborhood, and along comes a truck.

AW: Even the pot licker from that trash truck, when you see those trucks turning on a street and you see that water flow out from the bottom, the pot licker, wow, you don’t want to know what’s in that. Well, you do. We all need to know what’s in that liquid, because it’s spilling onto the road, going into the stormwater infrastructure and then flowing into here. That pot licker, if you will, I don’t like to think about what’s in there. It’s every chemical that comes out of our homes.

RLH: A medium-sized alligator, mostly submerged, watches us from the water. We also see a little blue heron – our second one of the day. Neighbors report seeing great blue herons, cormorants, non-venomous plain-bellied water snakes, harmless black racers and rat snakes, a host of different kinds of frogs. Toads.

RLH: There’s lots of wildlife here and you’re saying this is a witch’s brew – how can that be?

AW: Because they don’t know they shouldn’t be in here and the chemicals in this pond are in their tissue. You may have heard that the state has just issued another fish-eating advisory for the Cape Fear River, primarily focused on PFAS, but PFAS as I have always said is just the tip of the chemical iceberg in Cape Fear River.

The animals that live in this system are incorporating the chemicals into their body tissue.

You definitely don’t want to eat anything out of this water.

RLH: So what’s the long-term impact on these animals?

AW: There may be some genetic disruptions in it. I don’t know that for a fact. That’s a study worth doing. The fishes that are in here, the turtles and snakes, those are resilient animals. They’ve been around for many millions of years and are fairly resilient but they’re not immune to these new things that are coming into their environment. And these are all very new compounds.

AW: This is what we’re forcing nature to contend with.

BREATHE DEEP THE GATHERING GLOOM

AW: Sorry, breathe deep the gathering gloom. Andy Wood is in the room.

Sorry – I didn’t coin that. My wife did.

Laughter

RLH: Oh, that’s so sad.

If you were king of the world and had to meet both of those goals: maybe not poisoning the earth quite as much and making this a really effective stormwater management pond, what would you do?

AW: The first thing is for us to acknowledge the soils need to be included in the calculation for the stormwater pond dimension. What happens in stormwater management development is we look at impervious surface area: roads, driveways, rooftops. What we’re not including is the ground itself, which by and large throughout this neighborhood, is irrigated.

So the ground is already wet.

When we receive a 2-inch rain or a 1 1⁄2 inch rain, the water sheet flows off of the roofs and off of the streets, but it also sheet-flows off of the ground because it’s already wet from irrigation.

The houses and the roads are compacted before -- the ground under them is compacted before development goes on. So this is all compacted ground. And it’s soil that is naturally poorly-draining. Let’s say--

LEOPARD FROG DEATH CROAK

Southern leopard frog in Brunswick County
RLH
Southern leopard frog in Brunswick County

AW: That may have been – yeah, that’s a leopard frog getting eaten.

RLH: Who’s eating him?

AW: Probably a water snake.

RLH: Oh! There’s a water bird right there. Can you tell what that is?

AW: Oh yeah, great blue heron. But the activity is right here – about a hundred feet from us.

So I think it’s getting taken down by a snake.

How cool is that?

AW: This is a conundrum for me. I want you to feel like this is a really cool aquatic ecosystem and in many ways it is, but in many ways, it’s endangered. And if it is endangered, that should be cause for concern for us. Humans think we’re separate from this world, and we’re not. We’re part of this ecosystem, as well.

What happens in this pond and what happens in the surface waters – that this pond drains into – has impacts on us.

RLH: But how? If I’m not eating anything that comes out of this pond and if I’m not swimming in this pond, does it really matter how contaminated it might be?

AW: Yikes.

Well, uh, for one thing, this is inadequate to meet the needs of a hurricane. And we are wildly vulnerable to hurricane events. So when we do get a hurricane and if it dumps ten inches of rain on this area, this pond is going to flood wildly. Will it reach these houses? Quite unlikely. But it’s still going to flood tremendously into surface waters. So it’s everybody downstream.

People around this pond, in particular, may never see the ultimate consequences of what this pond is doing. It’s just taking in water but spewing it out almost as quickly as it brings it in.

And that’s because we aren’t incorporating the other -- what I’ll call – impervious surface. These poorly draining, compacted soils that aren’t put into the calculus.

This is never going to be able to hold the water for a period of time required for settling. In addition, when we get those rains, every chemical that’s been put down on the yard flows straight into this pond and is now in the sediment of this pond. And because everything in this pond is what it eats, from microbes in the soil to daphnia and worms on up to the fishes, snakes and birds, they’re incorporating all of these chemicals as well.

BREATHE DEEP THE GATHERING GLOOM

AW: Not good news.

RLH: No. No.

AW: Sorry.

But to try to answer your question, and it is a difficult question, how do we get people to care about something that looks rather unsightly – this does. I love the water lilies and the water lilies are actually a huge benefit to the pond.

AW: Is that the alligator right there?

AW: Yes it is.

RLH: We’ve seen this alligator now several times while standing at the water’s edge. About five or six feet long, he’s popped his head up in a couple of different spots, watching us. What we haven’t really noticed is his movement in between those spots.

But as long as we’re upright, we look too large to be a food source.

AW: So the water lilies are benefitting this pond in a number of ways. Number one, their leaves are broad and round and sitting right on the water’s surface so they’re providing shade and that cools the water. In addition, that cooling provides safe haven for small animals that live in here.

If you were to get in the water and dive around in that cluster of water lilies, you’d see lots of little fishes, probably some turtles. There are all kinds of things living in that cluster, just like you’d find in a forest. So that’s an aquatic forest, so to speak.

These plants are taking up nutrients – including the nitrogen we put down on our yards for fertilizer, so, they’re growing robustly in response to the compounds we’re putting in the water.

RLH: There’s an oily film on the water’s surface.

AW: When I run the net handle through it, see how it just kind of swirls and doesn’t break up? It just kind of swirls.

RLH: It’s runoff from the road – automobile oil and other greasy chemicals from the street.

Then Andy points to some much smaller films on the surface close to the shoreline.

AW: Watch what happens when we swirl it. See how it breaks up? It shatters as though it were a thin piece of glass. That metallic-looking oil, that’s plant fats. Fatty lipids from plants.

RLH: Tiny fish swarm the area Andy disturbed. They’re mosquito fish, which means the pond won’t have any mosquito larvae in it – since, according to Andy, that’s ice cream to these fish.

AW: This is a vibrant pond–

RLH: with a film of automobile oil on top.

There are bullfrogs in this pond. Andy identified the death croak of a leopard frog. There are probably other types of frogs in the pond.

If frogs are a sign of ecosystem health, how long will it take for them to disappear?

AW: A young bullfrog right there–about a foot off of the shoreline.

BULLFROG SOUNDS

AW: Frogs are an indicator of environmental health but primarily frog diversity. In the case of the bullfrog, we know from recent studies that bullfrogs happen to be incredibly chemical-resilient.

We find them in the pot licker that comes out of our landfills. They’ll be in those ponds, as well, which are just blazing chemical pools. And the bullfrogs do okay. So bullfrogs are very resilient.

You mentioned a great diversity of frogs – and there probably is a pretty good diversity in here but in southeastern North Carolina where we have roughly 23 diff kinds of frogs – unrivaled on the Atlantic coastal plain – except by a few places in Florida and a few places in Georgia. We have more frogs than you can almost shake a stick at.

In this pond, there will be, I would predict, southern toad, bullfrog, southern leopard frog, probably squirrel tree frog and that might be about it because there’s fish in here and most frog tadpoles are edible. One notable exception is the bullfrog.

Bullfrog tadpoles have an alkaloid in their skin. It’s a chemical compound that tastes a little bit like rotten lemon and Ajax. It’s a horrible taste, so very few things eat them.

RLH: Have you tried this? It’s a very, um, specific description.

AW: I would never admit that.

It’s the same with toads.

If you know what a toad tastes like, that's very much what a bullfrog tadpole tastes like.

RLH: I don’t know what a toad tastes like.

AW: I don’t recommend it.

RLH: Cooked or raw?

AW: I’m the youngest of five boys, and we all come from a very long line of biologists and so at a young age I was told this is part of the scientific process. You need to understand why very few things eat toads or other bad-tasting animals.

I’m not the only one that’s done that. It’s inquiry. Maybe not the most intelligent inquiry.

RLH: Uh, yeah. In case you lost the thread with that image of Andy Wood eating bullfrogs and toads, there is limited frog diversity in this pond because the fish eat the yummier tadpoles.

AW: You won’t find barking tree frog, pine woods tree frog, oak toad, little grass frog… probably southern cricket frog. They’d be in---mmm—they might be in here.

RLH: Don’t worry, I’m not asking Andy what barking tree frogs taste like. This is the end of the frog-eating portion.

AW: This water is kind of skank because it’s exposed to sunlight which promotes algae. Now that it’s been sprayed with herbicide, all of that dead plant matter that you see in the water – that’s all sugars, starches, and carbohydrates being released as they decompose back into the water.

The business model for stormwater maintenance is brilliant: come in, let plants grow to a point, kill them with herbicides, they’ll release nutrients back into the water, promoting more plants, you come back and spray again.

I get it.

But that’s not necessarily in our human, long-term interest.

How long are we going to be spraying these really wildly toxic chemicals into our environment?

RLH: At this point, we have a pretty clear idea of what’s in this pond. But we’re going to dip-net just to see what we get.

AW: I’m just going to do a quick dip through the water lilies and these are fragrant water lily, which is a common native water lily here and you can see the bulk of what we got are mosquito fish, in fact… ooop and a frog –

RLH: What kind of a frog was that?

AW: Probably a leopard frog.

DIP NETTING SOUND

AW: Lots and lots of mosquito fish. This is chock full of mosquito fish in here. Notice with those two dip-nettings, we didn’t get any sunfish.

RLH: So what did we learn about these three suburban ponds? No two ponds are alike. They have their unique ecosystems even when they’re connected. The slightly more isolated backyard pond shows off more diversity above the water – in the form of birds, frogs, snakes, toads – but less diversity in the water. We only found one kind of fish -- mosquito fish -- when we dip-netted.

The larger ponds on the main road offered a wider variety of fish – maybe from deliberate stocking.

It’s time to head into the wild for a comparison.

After this short break, we’ll meet you in one of the last large swaths of natural area in northern New Hanover County.

I’m RLH in the wild coastal plain.

END OF SEGMENT 2. 

SEGMENT 3

Rachel Lewis Hilburn: You’re In the Wild Coastal Plain. I’m RLH, and our guide today is Andy Wood, Director of the Coastal Plain Conservation Group.

We just examined three not-so-wild stormwater management ponds in the suburbs.

But now…

Andy Wood: We are in southeastern North Carolina, New Hanover County. I can say we’re in northeast New Hanover County, to be fairly specific, in an undeveloped tract of land, privately owned, that is being worked on with several different habitat management strategies to restore what was a languishing natural habitat back to what it should be as a vibrant natural habitat.

SOUND OF FLY BUZZING

RLH: Are you hurting her?

AW: No, if I were to release it now, she’d fly off without knowing anything has happened.

RLH: Okay, tell me again what this is.

AW: It is called a Carolina horsefly.

RLH: Andy is holding this creature. Yes, holding it. In his hand.

Andy Wood holds a Carolina horsefly to show off its scalpel-like mouth part.
RLH
Andy Wood holds a Carolina horsefly to show off its scalpel-like mouth part.

AW: It’s our largest horsefly. This one is probably almost ¾ of an inch long, maybe even a little longer than that, maybe 3/8 inch wide. It’s a large fly and in the timing of their bite, if they haven’t injected enough of the desensitizing agent, you will feel the bite, and you’ll swat them. Oftentimes, even with that huge mouth, this thing will gorge on you and you not know that you were ever bitten.

RLH: How did we get here? In the preceding moments, which I failed to capture on tape, one of us screams a little bit when this very large horsefly lands inside the pickup truck.

AW: You can see they’ve got gorgeous eyes – well, not this one. It’s just kinda brown.

RLH: Okay, is that necessary? Just fyi, songs have been written about brown eyes.

Brown-eyed girl 

AW: Some horseflies have iridescent green, blue, and gold-banded eyes. They’re just gorgeous.

RLH: A swarm of these biting insects are following the vehicle we’re in, and Andy is explaining what the not-so-impressive brown eyes might see.

AW: They see light and dark, shadow, they find their prey by silhouette – they can’t necessarily see your face and distinguish it from mine, but they see our shape, and as with all flies, they have one pair of flight wings and then they’ve got this little stub of a second pair of wings. That’s its balancing mechanism.

THE FLY BUZZES AGAIN.

RLH: Gasp.

RLH: Okay, do you want to release her, maybe, outside the truck?

AW: No, I’m going to feed her to something, because—

SCREAM

AW: –if that’s okay. You don’t have to put that on the air. Because this is food.

RLH: He was planning to feed her to a carnivorous plant, but he decides to let her go. Not before showing me, though, up close, her piercing mouth part which looks a lot like a scalpel.

AW: It’s not like metal or shiny or anything like that. But it’s a mouth part that has slight serrations in it and the fly lands and secretes a little bit of anticoagulant and a little bit of a desensitizing chemical and slices – not like a chainsaw, but the mouth moves in such a way with those serrations that it slices the skin, injecting those two compounds at the same time so you don’t feel it but the anticoagulant makes your blood flow more easily –

RLH: So she’s after your blood, like a mosquito, not your flesh.

AW: Correct. Yes, the blood is the goal and that is to provide nourishment for her eggs.

Otherwise, most horseflies, all male horse flies, feed on nectar. They’re pollinators.

RLH: Comparable to mosquitoes, says Andy, which are, first and foremost, also plant pollinators.

If we got rid of the horse flies,

AW: Deer, first, would thank us. They’re a real nuisance to deer and horses. There would be some problems. The horse fly’s larvae is a predator in water and so they’re eating organisms in the water, helping with that food chain flow of energy thing.

The horsefly is one of those rivets.

RLH: This is a reference to his comparison of the earth’s biodiversity to rivets that hold the International Space Station together. For more on that, catch episodes one and two of In The Wild Coastal Plain.

But before we compare aquatic wildlife from the suburban stormwater management ponds to what we find here in a natural pond, Andy decides it’s time for a lesson in environmental economics.

AW: When we think about the environment, it’s helpful to think about it as a food pyramid and the food pyramid – simplistic in a pond or even the Cape Fear River.

At the base of the pyramid, you have algae and vascular plants that you see all around here that are eaten by snails, turtles, and they poop out nutrient-rich waste that’s eaten by zooplankton and insects, that in turn are eaten by mosquito fish, and then sunfish and ultimately bass.

In the pyramid of this pond, if you look at it closely, you’ll see there’s lots of tee-intzies in the water.

RLH: Tee-intzies?

AW: The mosquito fish you saw, that animal weighed less than a gram. But let’s say it weighs a gram. In order to get to be a gram, it has to eat at least 10 grams of zooplankton – not quite microscopic, think about an exclamation point on a typewritten page – or even a period. They’re small, but visible. That’s food for mosquito fish.

If I have a pound of mosquito fish in my cupped hands, it takes 10 pounds of zooplankton for that pound to be formed.

RLH: Moving up the pyramid, what eats a mosquito fish?

AW: Remember the bluegill sunfish we saw. A one pound bluegill had to eat at least 10 lbs of mosquito fish, which in turn had to eat least 100 pounds of these little teeincies.

What eats a sunfish?

A large mouth bass.

RLH: Uh…Andy is holding a bendy plastic fish. In fact, it’s the old Big Mouth Billy Bass popular in the late 90s and early aughts…

Yup, that's Big Mouth Billy Bass held by Andy Wood.
RLH
Yup, that's Big Mouth Billy Bass held by Andy Wood.

[SOUND - TAKE ME TO THE RIVER]

RLH: Not exactly an operatic bass, like, oh, Paul Plishka… but musical, nonetheless.

Paul Plishka as Falstaff in the Verdi opera
Metropolitan Opera
Paul Plishka as Falstaff in the Verdi opera

AW: A one-pound bass had to eat at least 10 pounds of sunfish, which had to eat 100 pounds of mosquito fish, which had to eat 1000 pounds of zooplankton.

What about a ten-pound bass?

It had to eat 100 pounds of sunfish, which had to eat 1000 pounds of mosquito fish, the equivalent – not just mosquito fish, which had to eat 10,000 pounds of zooplankton.

Five tons.

The equivalent of a school bus in little teeincies is required to produce one ten-pound bass.

The reason I make this point is that most people say or many people, politicians, especially say we want to save the environment. We care about the environment, but we have to take care of the economy first. Well, I will argue that because largemouth bass in North Carolina is a $150-million industry each year, that’s part of our economy.

RLH: All the expenditures that make up that kind of tourism: the fishing boat, the motor, the boat trailer, the gear, maybe even a hotel stay; certainly restaurants would be part of it – since largemouth bass are contaminated with methylmercury and typically get thrown back.

AW: All of those elements add up to a significant economic engine. Fueled not by the bass, but by these little tee-incies and these aquatic plants.

RLH: The tourism numbers come from a U.S. Fish and Wildlife study.

But what about that technical term?

Teeincie?

AW: T-E-E-I-N-C-I-E?

Laughter

AW: I have no idea. Little teeincies. That’s all I know. Somehow, somewhere I either invented it or heard it from somebody.

RLH: Let’s head over to the natural pond.

A natural pond developed from an old borrow pit in New Hanover County
RLH
A natural pond developed from an old borrow pit in New Hanover County

AW: This was dug years ago, decades ago. As you know, looking around here, we have lots of sand mines and borrow pits. And this is a borrow pit that was created to get material for some project.

RLH: This pond is ringed by thick vegetation – tall grasses, bushes, and a mix of pine trees and other hardwood trees.

AW: What I’m hoping we find are species of sunfish along with this really sweet little fish called Swamp darter, which is a tiny little fish, kind of cigar shaped. It’s only two inches long, an inch long.

RLH: We get out of the truck and walk down to the pond.

getting out of the truck

Walking down to the pond

DIP-NETTING SOUND

AW: I can also tell this water is in the upper 80s in temperature. Most of them are going to be out in the deeper water to keep from overheating.

RLH: It’s another hot August day with heat indices well over 100. We’ve had so many very hot days in a row, Andy figures the heat wave is affecting pond life.

[dip-netting sound]

Then he catches a young banded sunfish. A very good sign.

AW: Tadpoles!

And a catfish – ooh ooh— c’mere, you! A bullhead catfish.

Andy Wood holds a baby bullhead catfish caught in his dip net in a natural pond.
RLH
Andy Wood holds a baby bullhead catfish caught in his dip net in a natural pond.

RLH: He pulls out the tiniest catfish I’ve ever seen. This baby with tiny little whiskers can’t be more than an inch long.

AW: Here’s a blue spot sunfish. Isn’t that gorgeous?

splashing sounds water sounds

AW: Wow, this is warm water, hot water.

RLH: We see the green heron, catch another blue spot sunfish, but the one that Andy really wants to catch – the swamp darter – that’s nowhere in sight. He’s losing hope.

AW: The reason I’m excited about darters - they are an indicator of high water quality even if they’re in a swamp. We often think of darters as a mountain species – cold water – but, no, we have them here on the coast as well. But even though they’re in coastal waters, they require high water quality.

Andy Wood with his dip net on the edge of a natural pond in New Hanover County
RLH
Andy Wood with his dip net on the edge of a natural pond in New Hanover County

RLH: He’s about to give up. And then…

AW: Yeah, team.

RLH: You got a darter?

AW: Got a darter.

SPLASH

AW: Let me get it in the jar.

RLH: Success. Andy proudly displays the tiny swamp darter, a narrow, brown-spotted fish with gossamer-like fins.

In this wild pond that started as a borrow pit in northern New Hanover County, we’ve found banded sunfish, blue-spotted sunfish, a bullhead catfish, plenty of tadpoles, and the swamp darter – an affirmation of this pond’s health.

Compare that to the suburban stormwater ponds that boasted only sunfish, stocked bluegill, and mosquito fish. But is it a fair comparison when the suburban ponds’ only stated purpose is stormwater management?

AW: What we do to the environment, we do to ourselves. When we’re spraying pesticides, we’re spraying ourselves. In the 60-plus years of chemical warfare waged against insects, we have yet to bring about the extinction of a single pest insect.

We have controlled the cotton boll weevil. We’ve only controlled it. We have not brought about its extinction.

AW: If you believe you’re disconnected from that environment then don’t worry about it. But if you think that you’re breathing the air that smells of smoke from fires created by developers clearing the land or you smell the insecticide being sprayed by your neighbor, that’s a direct impact on you just as it is an impact on the dragonflies, the way it is on the birds, the turtles, the frogs.

Am I equating humans to birds and turtles and frogs?

Without a doubt. We are all part of the same ecosystem, the same environment. What goes around most definitely comes around. And it comes around to us in a very big way because we’re at the top of the food pyramid. We have the most to lose.

RLH: We are at the top of the food pyramid with the most to lose.

Thanks to Andy Wood of Coastal Plain Conservation Group for being our guide. I’M RLH, and thank you for joining us in the wild coastal plain.

Rachel hosts and produces CoastLine, an award-winning hourlong conversation featuring artists, humanitarians, scholars, and innovators in North Carolina. The show airs Wednesdays at noon and Sundays at 2 pm on 91.3 FM WHQR Public Media. It's also available as a podcast; just search CoastLine WHQR. You can reach her at rachellh@whqr.org.