Transcript: 10x10: Sand Beach
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[beach ambi rise]
Sam Evans-Brown: This is Outside/In. I’m Sam Evans-Brown.
Diane Cardwell: To me the thing I always notice first is the colors. On certain days, if it’s a cloudless sky, the ocean is this incredibly dark blue. Almost like a sapphire.
Sam Evans-Brown: And that’s Diane Cardwell, here standing on the beach at Rockaway in February, 2021. FYI - it was still coronavirus winter in New York at the time - so, double masks. The sound’s a little muffled.
Diane Cardwell: I don’t know what it is about a beach in winter. But there’s something that I find truly magical. I mean there's just something so incongruous about snow on the beach. But I think that’s only because that’s how we are used to using it. It’s like, it’s always here.
Sam Evans-Brown: It’s comforting, isn’t it? To think that the beach and the ocean are always there.
Diane is a writer, and she started spending a lot of time at Rockaway after what you might call a mid-life crisis. She had just gone through a divorce and dealing with fears that she would never be happy again.
But, long story short, she discovered surfing.
Diane Cardwell: And I was terrible. Just terrible. Still, I’m not very good. But I loved it. I managed to get to my feet for just a few seconds, and I just was so in love with that feeling, just gliding across the water as if you’re some kind of magical creature, right?
[mux: Clay Pawn Shop (Rhodes)]
It’s like the board sort of disappears and you become part of the ocean, and part of this kind of cosmic force that is energy in water making waves.
[beach ambi fade]
Sam Evans-Brown: Diane fell so in love with surfing that she ended up moving to Rockaway, and in 2020, published a memoir titled - Rockaway: Surfing Headlong into a New Life.
Rockaway, by the way, is in Queens, on a peninsula at the western edge of Long Island.
And it’s famously a surf town. People come in from Brooklyn or the city for the day, to surf, hang out, watch the waves. And there’s also a solid local, year-round community.
All that - on a spit of sand on the edge of the Atlantic Ocean.
A very tenuous spit of sand. Just how tenuous - came into sharp relief just a few months after Diane moved in, as she told our producer Justine Paradis.
Diane Cardwell: So I had moved here about six months before the storm hit and I had spent a lot of time and effort and energy and money renovating my little crazy bungalow to be this kind of single woman recovery house.
Justine Paradis: Hah, I've had some of those.
Diane Cardwell: Right?! It’s like, I was post divorce, I was making a new life, this was establishing my beachhead, so to speak. And so it was all sort of perfect and lovely, and I was learning to surf, and then the storm hit...
Sam Evans-Brown: October of 2012. Hurricane Sandy. Diane had decided to defy the evacuation order - a lot of her neighbors weren’t leaving either, and she thought it would be okay.
Diane Cardwell: I had some tuna fish and some whiskey and extra water. A complicated shortwave radio I couldn't really figure out how to use.
Justine Paradis: The tuna fish whiskey plan is just excellent.
Diane Cardwell: haha. Some peanut butter and crackers.
Sam Evans-Brown: But then. At some point in the night -
Diane Cardwell: Well, first I heard shouting outside my window, and I looked out and I saw that the water… the ocean was essentially flowing down my street.
I just panicked, and literally saw the water rising up. I suddenly understood what people were talking about, I’d seen on the news saying, "the water just came up so fast". So I just thought, I can’t be here alone. I got myself together hastily, and I actually went out into it.
[sound design]
And you know, kind of looked around at first to make sure there were no downed power lines and then, you know, closed my eyes, let my foot sink into the really cold water. Luckily, I didn't fry to death. And I kind of trudged out to the street. And what I was trying to do was get to a friend's house, and when I got out into the water, I was just like, I'm not going to make it. There's just no way.
And I thought, I could die out here.
It almost felt electric. I had never felt, you could feel the energy that was in the water because the ocean was coming onto the block, right?
And so, I heard a friend across the street. I heard my name kind of drifting ghostly over the roar, i thought, am I making, is that my name -
[sound design]
I looked across the street, and my neighbor and friend Kevo, was saying out there saying, ‘Diane, Diane, hold on! Hold on!’
[sound design]
And she came back with a pole. And I sort of walked into the middle of the street, bracing myself.
[sound design]
And I suddenly noticed motion, you know, different motion, and there’s a garbage can hurtling toward my head. And she's like watch out!
And then, this is still the most insane thing to me: I had been working out with a trainer twice a week, to try get strong enough for surfing, and I heard his voice in my head saying "Use your core!” hahaha.
Justine Paradis: [laughing]
So I sort of like, tightened up my core - and I was like, okay, I only have two steps, and I'll make it over there, and then I went upstairs and spent the night there.
[mux and ocean fade]
But about, I don’t know, maybe an hour later we were sitting in her living room. She’d given me pants to put on, and the whole thing. And suddenly we hear, like, crash.
[mux: Dany PDI Volda Syn]
... metal scraping on asphalt, and car alarms going off, and then all of a sudden, a guy standing behind me goes, 'duuuude... that's the booooardwalk."
[ocean sound rise]
And it WAS. The boardwalk had basically been ripped up off of its concrete supports and came, like, javelined down our block.
Like, crushing cars. And that’s when I just felt like, oh my god. Anything could happen.
Sam Evans-Brown: But the real reason you’re hearing this story - is what Diane saw the next day.
Diane Cardwell: And the next morning, basically the beach was on our block. Right? We had piles and piles of sand, it was almost like hills and valleys and rivulets, and then these weird half block-long sections of the boardwalk, which were still entirely intact. Right, I mean, they were bent and twisted and weird, but there was a bench, and a street, and a lamppost. I mean, it was just CRAY CRAY
But really nothing could have prepared me for what I saw when I got to the beach itself. All the sand had been hollowed out. Sand everywhere where it shouldn't be, no sand where it should be… it was something else.
[theme rise]
Sam Evans-Brown: This is Outside/In, a show about the natural world and how we use it. I’m Sam Evans-Brown.
And today, we’ve got another in our occasional 10x10 series - the sand beach.
When Diane Cardwell walked out of her friend’s house after Hurricane Sandy at Rockaway Beach, she saw a display of how a sand beach can respond to a storm.
The beach… moved.
But even in the quietest of times, beaches, and specifically sand beaches, are defined by movement and change.
Bianca Charbonneau: I think it's fair to say the beach is one of the most flexible or dynamic, if you will, habitats in the world. It’s super geologically unstable.
Larry Ward: The beach essentially is constantly changing. It’s either accreting or building up or eroding. .
Sam Evans-Brown: So today - a look at how beaches move: the systems and feedback loops on and around the sand beach, the science taking place there, and how the way beaches are changing is itself changing... in a changing world.
… did I say “change” enough times?
Here’s producer Justine Paradis.
////
WHAT BEACHES ARE MADE OF: SAND
Justine Paradis: In the ice-free world, just over 30% of shorelines are sandy.
Donya Frank-Gilchrist: The sand is basically just soil of a particular size
This is Donya Frank-Gilchrist - she’s a research oceanographer and a coastal engineer. And she explained - sand is a type of soil particle.
Donya Frank-Gilchrist: That's how we categorize different soils or sediments, is by size or diameter. So sand can be as fine as flour that you cook with everyday or as coarse as a grain of salt, And then anything smaller than flour would be classified as silt - anything larger than that pinhead would be classified as gravel.
Sand, to cut to the chase, is very small rocks.
[curious mux begin]
Donya currently contracts with the US Geologic Survey St. Petersburg Coastal and Marine Science Center, in St. Petersburg, Florida. In her career, she’s studied how individual sand grains move, plus researched how oil and sand mix together and move after oil spills, and, for the Navy, the underwater movement of objects like, say, unexploded munitions.
But I kind of had a basic question for her -- which I think she thought was a little amusing.
Justine Paradis: Why is all the sand on the beach? How does it get there? Like, why is it sand?
Donya Frank-Gilchrist: Okay... um… [laughing] why is it sand... okay..
So, there’s a couple reasons - 1 - rivers are a big source of sand: the currents pick up and carry rocks to the coast, and as they go, wear them down until they are sand sized.
But also, sand actually forms at the coast.
Donya Frank-Gilchrist: In addition to the wave action and wind and other weather forces breaking down the rocks and eroding them into smaller pieces…
The second reason that sand is at the beach is what it’s made of. The composition of sand can vary a lot depending on the location. So, in Hawaii, black sand beaches formed from broken down lava - in many places, the sand contains a lot of coral -
Donya Frank-Gilchrist: For instance, in the Carribean. I think in Barbuda, they actually have pink sand!
on Okinawa off Japan, the beaches have “star shaped sand”, which are actually the tiny shells of a single-celled organism called Foraminifera -
Donya Frank-Gilchrist: In some regions, sand also comes from poop of parrotfish that eat algae from ocean rocks and coral reef.
But overwhelming, the world over, sand is mostly made of quartz, the second most abundant mineral in Earth’s crust, made of Silica and Oxygen. Quartz is relatively stable and pretty hard - so, quartz sand is basically what remains after most everything else is blown or washed away.
These days, Donya is applying her research of how sand moves at a small scale - literally down to the grain - to a larger scale, like how sand moves on beaches and barrier islands.
And to talk more about that - about how sand moves on the beach level -- let me also introduce Larry Ward - he’s a research associate professor with the University of New Hampshire Center for Coastal and Ocean Mapping. He specializes in geologic oceanography and beach processes and morphology - which basically means. ...
Larry Ward: Features. Berms, sand bars, tidal inlets. It’s about the landscape and the forms that it takes.
And measuring how a beach changes is hard because, and here’s one of my very favorite things about beaches, and therefore, one of my favorite things about the world: is that, basically by definition, a beach is always changing.
Larry Ward: The beach essentially is constantly changing. It’s either accreting, building up, or eroding
So, a beach doesn’t actually stop at the waterline.
In fact, if you were to try to pinpoint the boundary of the beach… well… I would say that the shape of the boundary is less a line and more of a kind of pixelated cloud, ripples and spools of sand swirling in the water and the wind.
And the location of that swirling pixelated edge -- it’s constantly moving.
The beach has two classic profiles - I’m calling it the winter and summer beach, but Larry told me that technically, you’d call them erosional versus accretional.
So, as for an accretional beach - well, basically, think about a classically ideal sunny day in August on the beach in New England.
[Nantucket August beach audio rise]
The beach is nice and wide - and you pick a nice, sunny spot a little way back from the waves to pitch your umbrella - here, you’re on the upper beach -
Larry Ward: The upper beach, the backshore, the place where you tend to put your blankets, would have a higher elevation..
And once you’re ready for a swim, you can head down to the water -
Larry Ward: And then some sort of slope down to what we call the low tide terrace *
and indeed, you’re heading down a slope, to the water. There’s a big berm - just before you reach the swash zone, where waves are breaking against the shore.
This berm is like a sand savings account. In my terminology, this is the classic summer beach. Lots of sand, up on shore.
But then — as happens often in winter — a storm rolls in.
[wave crash]
Larry Ward: So, if you have a storm come by, a northeast storm or something creating large waves - something that generates the energy of the waves - the waves get bigger and they’re resuspending the sediment. They’re throwing sand up in the air.
The waves eat into this sand savings account- that summer berm. And the wind picks up the sand too - and all this resculpts the beach - to the erosional profile. The winter beach.
Larry Ward: Flatter, narrower. The upper beach isn't built as high.
And even the composition of the beach itself changes. The finer sand grains get carried away - some by wind, some by sea.
Larry Ward: And you get pebbles and coarser material lagging behind.
This sand, churned up and suspended in the water column drifts down the beach and offshore ...but it doesn’t disappear! Eventually it does sink -- often, forming a sandbar.
As powerful winter waves continue to move into shore, they break against the sandbar, offshore, before they get to the beach, so some of that powerful energy gets dissipated -- mitigating the force of those eroding waves .
So it’s like, by being in motion, by being flexible, the beach has a self-protective mechanism built-into its basic structure.
And then eventually, the season of storms ends.
Larry Ward: And the beach starts to rebuild
The gentler waves push the sand landward -
Larry Ward: If you’ve laid in the surfzone and felt a wave go over, you kind of rock forward with the wave direction. It kind of pushes sand and eventually it creates sand bars, grain by grain, it pushes the sand back up on the beach. And then another one comes in, and then another, and the beach builds up. Given long enough, it recovers.
But that’s key - given long enough.
Larry Ward: If it doesn’t have time, then it doesn’t recover.
Alyson Eberhardt: This ability, this storm-buffering capacity, is really one of our first defenses against storms and increasing storms and severity of storms with climate change and rising seas.
This is Alyson Eberhardt, coastal ecosystems specialist with NH Sea Grant + the University of New Hampshire Cooperative extension.
Together, she and Larry help run a community science project with NH Sea Grant in which about 35 volunteers are trained to measure the beach profiles we just heard about, on 13 different beaches on New Hampshire’s Seacoast.
[beach ambi rise]
Alyson Eberhardt: Hey guys! How are you all?
Volunteers: It’s been a long time!
And this winter, I met Alyson at one of them - Seabrook beach - to see this community science in action.
That day, it was a group of three volunteers, plus me and Alyson and her colleague, Wells Costello.
The volunteers go out every month at the lunar low tide, and also sometimes , before and after significant storms. And they’ve been doing this for the past five years, to try to understand both how beaches are responding to storms and to get a broader sense of the trendline.
Alyson Eberhardt: And they’re moving very fast. They're very experienced.
Justine Paradis: They’re efficient.
Alyson Eberhardt: yes I know! Haha.
They’re using a technique called the Emery Method - which Alyson said is also known as “two sticks and a string” - measuring the elevation of the beach from the dunes to the low tide terrace.
Alyson Eberhardt: She’s looking vertically and finding where it lines up with the horizon, establishing a straight line, and getting a reading off of the poles, an elevation reading.
Justine Paradis: Would they be out there even if it was like sleeting?
Alyson Eberhardt: They've been out here literally with gale force winds, in ten degree weather. Weather-wise, they come out in anything. It’s only the horizon that is the dealbreaker.
Justine Paradis: Wow.
[mux rise]
THE SHAPE OF THE BEACH.
Let’s take this opportunity to look more carefully at the shape of the beach, starting at the waterline.
Again, that day, it was the lunar low tide - the one of the two monthly moments when the moon and the sun are aligned, plus the moon is at the closest to the earth in its orbit - so there’s more of a gravitational pull dragging the tides in and out -- So basically it’s the highest high tides and the lowest low tides of the month.
So that day, the intertidal zone was very visible - a long, low, flat, wet stretch of sand, solid enough to walk on but wet enough that you might find puddles and you want to move quickly so your shoes don’t get too soaked.
Justine Paradis: Alyson, do you know what these little bubbles are here?
[digging]
Right at the edge of the water, there’s a little lip, also known as the “beach step” - where, at high tide, waves would be washing against the beach. And here, we came across little holes in the sand -
Alyson Eberhardt: I mean there’s burrowing clams and crustaceans
Justine Paradis: Look, there's one! With the little bubbles coming up, there.
Sand fleas or moles crabs also live right here at the water’s edge. You’ll often see piping plovers or other shorebirds foraging here, darting in and out of the waves edge.
It was December, and as we moved away from the water, we were walking up a flat gradual profile -- aka what I call a winter beach -- no berm. And eventually --
Alyson Eberhardt: You can see the extent of the last high tide here...
We came to the wrack line - basically, the stuff that gathers at the high tide mark. That day, we saw grasses and algae -
Alyson Eberhardt: ...algae. This is probably Spartina alterniflora, which is our salt marsh cordgrass, one of the main plants in our New England salt marshes. And then certainly some beach grass in here too
So, you might find seaweed, jellyfish, dead birds, crab shells… while we were walking, Alyson also found a long, narrow clam shell.
Alyson Eberhardt: This is a razor clam. My daughter calls these sea hot dogs.
Justine Paradis: Ha!
That she calls SEA HOT DOGS.
Plus, you might find human trash - helium balloons, fishing gear, plastic -- plus flotsam and jetsam, which are actually specific terms referring to trash thrown off of ships - flotsam being NOT deliberate, jetsam being on purpose - like jettison.
The wrack line is pretty important for a few reasons. In a lot of ways, the beach is rather desert-like - very little shade, lots of exposure to wind and salt and UV rays, big temperature swings, very little fresh water - but the wrack line provides shelter, and habitat to invertebrates like sand fleas, predators like spiders...
Alyson Eberhardt: But this is exactly the stuff… so piping plovers nest on this beach, which are a protected species.
Another thing about objects in the wrack line is that they can catch sand -- grains that are caught in the wind, skipping along the surface of the beach - hit the wrack line and gather. Basically any obstruction is important because it could start to help form… dunes.
[mux]
DUNES.
Dunes are one of the most important parts of a beach -- and in fact, it’s high time we got here. Because, talking about a beach without talking about a dune is maybe like talking about a tree without talking about its roots.
Bianca Charbonneau: The dunes are exceptionally pretty different times of the year. In the fall, that’s when you get the goldenrod budding. Bright yellow, and you’ll see lots of butterflies. In early summer is when you’ll see the beach pea. And end of the summer is when you’ll see those beach plums.
And if we’re talking about dunes, who better to call than -
Bianca Charbonneau: Bianca Charbonneau, or I guess, Dr. Bianca Charbonneau. I’m also known as the Dune Goon.
The DUNE GOON -
Bianca’s roommate gave her that nickname when she was getting her masters. But more specifically, Bianca is a coastal ecologist -
Bianca Charbonneau: And I specialize in how plants respond to and recover from storms.
So, what’s a dune, beyond “a pile of sand”?
A developed dune system has a classic topography.
Bianca Charbonneau: So, there’s ridges in the system.
The ridge closest to the ocean is called the foredune - the most exposed and stressful environment. Behind it, there’s a little valley called the “interdune” -- and then behind that, another ridge - aka the secondary dune, or backdune.
There are a few different plants that can live in the dune, but in the Mid-Atlantic region, dunes are characterized by one in particular.
Bianca Charbonneau: American Beachgrass is Ammophila breviligulata.
Justine Paradis: Breviligulata
Bianca Charbonneau: Breviligulata. It’s a mouthful.
American beachgrass.
Bianca told me that globally there are only a handful of plants that can withstand the extreme environment of the dune - and not only can it withstand the extreme environment, but beachgrass also helps CREATE dunes.
Bianca Charbonneau: These foredunes are built up over time by the plants, but the habitat itself selects what plants can actually survive there.
[mux begin]
And so there’s this unique feedback between the plants or the ecology of the system and the geological processes.
Here’s that feedback loop:
Bianca Charbonneau: This wind blown sand is approaching a plant - it hits the plant - it falls to its base - and it accumulates over time
Grain by grain.
Bianca Charbonneau: And then the plants themselves, their roots are producing different materials that help bind individual grains into clumps or aggregates of sand, and that’s going to give the system more stability as well. And these individual mounds are a fun word called a nebkah.
Nebkah - that’s actually an Arabic word, for “small sandy hillock.” They’re basically - a sand dune that forms around vegetation.
Bianca Charbonneau: And they range in size anywhere from a couple cm in size to meters in size.
Nebkah can encroach on other nebkah, start catching more grains of sand, changing the flow pattern, catching more sand -
Bianca Charbonneau: And over time, we think about seven years, you will get a dune that forms. And what I’m talking about there is a continuous ridge.
[mux fade]
So: a dune is a kind of habitat that’s called bio- or eco-geomorphic: as in places where organisms contribute to shaping the landscape.
And so, by virtue of its growing conditions (that it helped create), beachgrass has to be able to handle getting buried -
Bianca Charbonneau: And so, not only do they tolerate being buried, but increase vigor/growth, as a function of being buried *** instead of folding under pressure, rise to occasion, grow taller and faster to get out of that burial.
And one reason American beachgrass is able to survive sand burial - is that it spreads clonally.
Bianca Charbonneau: If you look at one plant, it's gonna look like there's a ton of stems, but if you were to dig, and you shouldn't dig, they actually come together underground to one central point.
So what might appear to be individual graasses might actually be connected.
Bianca Charbonneau: Yeah they can pass water back and forth as well as nutrients.
But the thing that beachgrass REALLY can’t handle is being walked on.
Bianca Charbonneau: You might not feel it - but there’s a good chance if you're walking on the dune, you're breaking them.The actual roots of plants itself are also sand-colored and very fine, sometimes they’re thicker but they have a lot of fine roots and these can break without you knowing at all.
Meanwhile the dune is also a habitat and wildlife corridor. You might see hawks and snowy owls...
Alyson Eberhardt: ...voles, moles, even skunks, raccoons, fox... we definitely see a lot of rabbit pellets just generally and right where we're standing… I’m seeing it everywhere... hah *
The farther you get back from the ocean, the more that can survive there, because the environment gets less extreme.
By the time you get to the backdune, you might start to see shrubs like northern bayberry, wax myrtle, beach plum. And eventually, the dunes transition into maritime forest, like at Seabrook, the beach Alyson, Wells, and the community science volunteers were profiling that winter day
Alyson Eberhardt: RIght here on the other side of 1a where you see trees and shrubs - that’s all maritime forest. And that’s our only example.
=
But the thing about this particular maritime forest ? They’re disappearing all the world over -- this one, in fact , is the only one left in New Hampshire. Because of course, humans are involved too.
That’s coming up after the break.
// BREAK //
[vacation mux rise]
A few years ago, Donya Frank-Gilchrist went on vacation with her family.
Donya Frank-Gilchrist: Okay, I’ll try not to name the hotel. But it was a very nice fancy hotel in Florida and my family and I were really looking forward to relaxing by the beach and enjoying that vacation. A
It was somewhere between late winter and early spring - pre-tourist season.
Donya Frank-Gilchrist: And when we got there, we saw the sign up and there were bulldozers and tractors and all this huge construction equipment that you don't typically expect to see at a beach.
What Donya was witnessing - was a beach nourishment project. In which sand is trucked in - to build up a beach, or replace sand that might have been lost. Remember, Donya is a research oceanographer and coastal engineer…
Donya Frank-Gilchrist: It was interesting though to see it in action because as a scientist I study it all the time.
….so she was kinda into it.
Kind of.
Donya Frank-Gilchrist: But unfortunately I don’t get to go to the beaches as often as I’d like.
Sand replenishment, generally speaking, is the kind of intervention that becomes necessary to maintain the existence of a beach when the overlapping systems that once supported - and in fact, created - the beach - are no longer intact.
Let me back up. Many of the scientists I spoke to referred to the idea that a resilient beach needs a “sediment source” -- sand supply.
Sand takes millions of years to form - it’s not unlimited -- and you can’t really control it.
Donya Frank-Gilchrist: The sand will - may get eroded eventually, so every few years they'll have to go back and spend those millions again to renourish that beach if it’s really worth it to them when they look at their cost-benefit analysis. Which I guess it is, because they keep doing it. And the tourists bring in a whole lot more money than the cost of the nourishment.
Alyson Eberhardt: That sand material is an incredibly value and frankly rare resource.
That’s Alyson Eberhardt again, with NH Sea Grant + UNH Cooperative Extension.
Alyson Eberhardt: From our data, we know that many of our beaches are sand starved - so when you have this valuable resource, you want to put it to beneficial use.
So, we’ve just walked with Alyson on a mostly-intact-beach system, from the ocean to the dune, stopping at the wrack line - and that beach landscape means different things to different people.
For instance, the wrack line is an important forage site and a feature of the beach that helps prevent erosion. It is also a pile of seaweed and decomposing animal carcasses - it can smell. So sometimes, people remove it.
And as far as the dune: in a lot of towns right on the coast, it doesn’t exist at all.
After visiting Seabrook, that beach with the wide intertidal zone and dune system and maritime forest, Alyson and I darted 10 minutes up the road to another beach in the project - North Beach, which is in an area with a classic boardwalk vibe: pizza joints, ice cream stands, arcades, beachy cottages facing the waves… and a seawall.
Alyson Eberhardt: At these beaches, there's not much space at high tide. There’s not much beach available for putting your blanket down or your chair. So these are mostly used at low tide and that’s because they’re just much narrower beaches and have a lot less sand.
There’s a few reasons that the beach is narrower - like, the shape of the coastline, for instance. But you can hear one of those reasons - the road is right there, running north-south, parallel to the ocean, right where the dune used to be one of the systems that helps sustain the beach.
So what happens on a beach without a dune?
Alyson Eberhardt: But what we do know is that sand dunes are an important source of sand storage and so they can serve to help replenish beaches and just keep a high supply of sand in the system. And we don’t have that here, where there are seawalls.
And when there’s no dune, the way that a beach erodes and responds to storms - is very different.
Here’s Bianca Charbonneau again, aka the Dune Goon. She told me that, first of all, the wider the dune - the more waves it can potentially withstand.
Bianca Charbonneau: Because you think of the dune kind of like an onion, where a wave is hitting and it’s absorbing the destructive power of that wave by sloughing off a layer of sand. And again that sand is aggregated or clumped and stabilized by the roots. The roots are acting, you can think of, like, a spider net. It’s not just a free-for-all, loose sand in there. It’s held together in some way.
And so individual layers of sand are being pulled away with each wave, and so the dune is in theory getting thinner and thinner and thinner, as that onion, or that dune, erodes.
Compare that to when a wave hits a hard seawall -
Bianca Charbonneau: It’s hitting that hard wall and it has nowhere to go. And so it’s turning underneath itself, and kind of creating, creating turbulent eddy, or basically a washing machine effect, right at the base of that seawall, so you’re getting accelerated erosion right at base of that sea wall as well as water is pulled out back to ocean
Not all seawalls are created equal, so some work differently - some make things worse in different ways, like sometimes creating conditions in which waves breach more easily.
Poorly designed seawalls tend to be very hard, and vertical. Better designs are more inclined and porous.
But the bottom line is - seawalls are intended to protect what’s behind them - not just hotels, but also houses, roads, utilities.
They are not intended to protect the beach.
In December 2020, ProPublica and the Honolulu Star-Advertiser published an article on seawalls in Hawaii. It was headlined “Hawaii’s Beaches Are Disappearing.”
And it laid out how even though Hawaii has a “no tolerance” policy for new seawalls - local officials granted exemptions to this policy to 230 homeowners and hotels, allowing them to keep or install seawalls and sandbags in front of their structures. Others were even built without any approval at all.
And many of those beaches in front of those seawalls are gone.
So not only does this mean that sometimes public beaches and space is lost - but it also means that the mechanism - the movement of sand, which can protect the beach - no longer exists.
[mux swell]
It might be possible, though, to protect seaside communities in a way that doesn't wash away our beaches. A hybrid, between the rigidity of the seawall, and the responsiveness of the dune. In fact, everyone I spoke to told me that within coastal management, in recent decades, there’s been a general movement toward "living shorelines." -- which can still include beach nourishment as an element.
Alyson Eberhardt: Living shorelines, which are these hybrid approaches, where you may have a structural element - sometimes its rocks, or trees, or geotubes, combined with elements from nature, so plantings, or nooks and crannies that can serve as habitat rather than a poured concrete wall.
But, as Bianca said earlier, it takes about 7 years to see a really established dune. And one thing that this might point to is that living shorelines - can take time and space.
Bianca Charbonneau: I’m all for plants. You just gotta be patient cuz they take a lot longer. That’s part of the problem is I think that a wall, a seawall, offers immediate comfort and it’s rigid, versus a plant which will support the habitat over time, and is more of a long term investment, but it also takes time to build up habitat and you don't know what's coming at you.
[mux: Clay Pawn Rhodes]
We don’t really know what’s coming at us. even in places where it’s possible to build a restored dune, we still have the challenge of sea level rise and bigger, more frequent, and more intense storms, storms like that of Hurricane Sandy - where the surges pushed the groundwater level up from below while powerful waves tear at the shore from above -
During Hurricane Sandy, The Army Corps of Engineers estimated that, “more than 1.5 million tons of sand was torn from Rockaway beach.”
Diane Cardwell: See there’s a shadow forming on the horizon? That’s the wave… he’s actually in a halfway decent spot.
Rockaway, where, here, Diane Cardwell is standing, looking at the ocean as a surfer paddles out.
Diane Cardwell: Ayup! He's going! Paddle paddle… go go go! there… double paddle…. In it…
After Sandy, it took a little while for Diane to get back in the water - surfing didn’t feel right while people’s basements were filled with mud -- plus, a couple local sewage treatment plants had flooded and it wasn’t even safe to go surfing.
And by the time she did get back in the water - it wasn’t just the beach that had shifted. The waves had changed too.
Diane Cardwell: you know, it's a beach break, so most of the waves, not all of them, but most of the waves are made by sandbars. And those just shift with the way the water moves things around. And so most waves in Rockaway are lefts, meaning that you ride them to the left. But I remember people being very excited that this "right" seemed to have emerged, somewhere in the middle. Because depending on which way you like to surf with either your left or your right foot forward - one direction is just easier and more comfortable. So that’s really the only big difference that I remember, was, “oh, dude, did you see that right?!”
And in the years after, Rockaway has been fortified with a combination of hard structures like groins and seawalls - and living shoreline approaches. They reconstructed the dune, and planted grass - and dumped huge quantities of sand onto the beach and even into the ocean.
Diane Cardwell: And that just killed the wave.
Diane Cardwell: So for, like, an entire season, there was no wave to be had. And so I ended up going to a much farther break which was kind of the old school, where all the old timers used to go and hang out.-
Justine Paradis: I notice you're not sharing the location - you don’t want it to be crowded?
Diane Cardwell: Yeah, you know, I think i won't say. You know, no one has run me out of town yet for having written a book but I didn't actually say where that break is in the book. So I’m going to keep that (laughing).
[water, mux]
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CREDITS
This episode of Outside/In was produced by Justine Paradis, with help from Taylor Quimby and me, Sam Evans-Brown.
Erika Janik is our executive producer.
Special thanks to Dr. Meagan Wengrove, Daniel Helber, and Jen Poyant [POI aunt].
Music in this episode came from Blue Dot Sessions.
Our theme music is by Breakmaster Cylinder.
Outside/In is a production of New Hampshire Public Radio.