A look at Biodiversity in Long Island Seagrass Meadows with Stony Brook Professor Bradley Peterson


“The earth laughs in flowers.”

― Ralph Waldo Emerson


Eelgrass, Photo, Bradley Peterson

Brad Peterson will be joining me as a guest speaker at my “Earth Laughs in Flowers” exhibition at Sara Nightingale Gallery on June 30th, 5-7Pm. This interview highlights the important ecosystem services seagrass meadows provide, as well as the importance of community in restoration efforts for changing the fast disappearing meadows.

Earth Laughs In Flowers

Sara Nightingale Gallery

June 29- July 14

Artist & Scientist Talk: June 30th 5-7pm, 2022

26 Main Street

Sag Harbor, NY 11963


I just was wondering how you got started with seagrass ecosystem?

I took a very kind of torturous route in my career. So I, I grew up in the Midwest among the corn, and I longed for the sea because I was so far away from it. At the time, not many years ago, I thought that I had to get a bachelor’s degree in marine biology. And there were only seven programs in the country at that time. And so I went to Florida Institute of Technology. I started working with nudibranchs, which are the snails that don’t have shells. Well, there’s some cool


Nudibranchs are beautiful they look like little dancing jellyfish

 Yeah, yeah. So I worked with them. And then when I graduated, I expected that I was going to continue to work with them. So I went to the University of Rhode Island. And there I got into a lab that kind of touted itself as a Molluscan Ecology Lab. But it was really more of a systematics taxonomy lab. So I had kind of a bad experience there. And when I left, I was ready to go sell lamps or do something different. But I got invitation to go work at the Williams College Maritime Studies program in Mystic Connecticut.


And it was a fantastic program. You know, the program was limited to 22 kids, they’d come out there for a semester, and I ran their Marine Station. And what I remember distinctly was that they would rent out the sailing vessels from Woods Hole, and they take the kids out for 14 days.  In the in the summer & spring they would be in the Caribbean and in the fall, we would go out over Georges Bank. So I took the kids out in the fall one year over Georges Bank, it was just a magical, wonderful time. Probably one of the top 10 memories I have is when we caught the edge of a nor’easter which was the first time that the boat got up to about 12 knots. And it made enough of a bow wake that the dolphins would come and play. but you couldn’t see them at night all you could see laying in the net of the bow sprit were the tunnels of phosphorescence that were created as they swam.

How Cool!

Anyway my boss at the time was Jim Carlson who was a very large invasive species guy who did his work in San Francisco Bay. He sits on the congressional committees dealing with ballast water. He was my boss, and when I got back from this trip, we had one of those “What do you want to do when you grow up” conversations. The next day he showed up with 10 names, and he said contact these 10 people. And so I did. Of the 10 names, six responded and so I went and visited all six of them. And one of them was a guy named Ken Heck, at the Dauphin Island Sea lab down in Alabama. Ken was someone who had early on began looking at sea grasses. If you go and tow a trawl net in seagrasses versus unvegetated substrate, the stuff you get is just orders of magnitude more. Animals hide in the seagrasses.  I like to think of it as kind of like when you’re driving down Sunrise Highway, you see the deer on the side of the road. If you’re lucky. They don’t run out in front of you, but when they get scared they run into the trees. Sea grasses are the only three dimensional structure that most coastalbays and estuaries have. Estuaries may have mangroves on the edge or salt marshes and they have a similar kind of function right along the edge. They may have oyster reefs that also provide three dimension structure, but the most dominant kind of three dimensional hiding space there is in estuaries is seagrasses. So I got very interested in how animals use seagrass. And there’s a whole suite of ways that sea grasses are important. Okay, so we’ll go through the list, and we can talk about them, right. So when you stand in a forest on a windy day, you hear the wind, but you don’t feel the wind. The wind is buffeted. So as the water moves through a seagrass, it slows down. And as that water slows down, those things that are suspended in the water will fall out. Things like particulate dead stuff, or chlorophyll, or larvae, all of these things will settle out inside seagrass beds, usually around the edge, because they slow down the water exponentially as it moves through the blades.


Why is that important?

It means that they trap a lot of particles. So they’re known for increasing water quality by removing particles from the water. They’re known for binding the sediment with their roots. Think about waves moving across an area and that seagrass is pliable, so as the water really rushes over, those seagrass blades lay down flat, and they cap off that sediment, preventing it from being washed away. So they are really important for wave attenuation and erosion control. Unlike so many plants in the ocean, sea grasses actually started off on land, and then were reintroduced into the marine world. So they are true flowers, true seeds, true roots, the true rhizomes.


“The earth laughs in flowers.”

― Ralph Waldo Emerson

Does this quote resonate with your experience of eelgrass meadows?

Yeah, seagrass is very diverse. In fact, just like bees, remove pollen from the flowers, right? It’s been demonstrated that amphipods play that role in certain tropical sea grasses by moving pollen around from plant to plant. If you were to Google seagrass flowers, you’ll see a whole suite of different kinds

Have you have you physically seen the flowers?

 So when you look at eelgrass, and you see the reproductive shoots, what you’ll see on those where the seeds are, early on in the year, you’ll see these fibers that come out the stamens, so these are the pollen collectors. The flower is actually part of where the seeds are collected. And so they’re not as visually appealing as flowers, aside from Turtle Grass ones.

Well, I’ve seen I have Fred Shorts book, Fred short. So in his book, he has these ones. They’re so amazing. They look like lilies. Some of them look around. There’s so many different I was just wondering, curious if you’d actually seen real ones.

I have seen them, but on the eelgrass these flowers are actually part of their seed container, where they ripen and are stored until they drop.

What are turtle grass flowers like?

So their flowers are like a very narrow five star pattern that is easily recognizable as a white flower.


Turtle Grass Flower, Gov. of Bermuda, https://environment.bm/seagrass-beds

And where did you find these?

I was working in Florida, they are in warmer temperatures.

One thing to keep in mind is that the diversity of the seagrass is much more limited in the temperate than in the tropics. While we only have two species of seagrass here on Long Island. In Florida, you could actually get to places where there are five different species of seagrass all within the same area.

So they actually like the warm temperatures?

It is more of an issue of diversity. So evolutionary theory would tell you that stable environments, over long periods of time, allow for diversification or speciation to occur. The diversification breaks the niche up into multiple different types of specialized species. And so that would one  argument for why there’s more diversity of different species in general, but also that includes sea grasses. In the tropics.

Is the soil not stable?

No, it’s mostly temperature, but also in other environmental parameters as well. So think about our climate on Long Island how we oscillate from spring, summer to winter, cold, summer, winter cold.Our plankton blooms come in the spring and goes away. And but in the tropics, the temperature range is very small. And the phytoplankton is mostly consistent so the seasonality in the tropics is mostly driven by wet and dry, not by temperature.


Florida is  having terrible problems of algae blooms, that is over nitrification right?

Yeah, that’s primarily human driven. And that’s really in the confined water of areas like Indian River Lagoon.


Over 1100 manatees have died right because of seagrass loss?


That’s a little more complicated. So the death of the manatees are probably an issue of food availability.

Over the last decades, the number of manatees have increased dramatically due to their protected status. And so they also were consuming the seagrasses. So it’s quite likely that their population got to a size that was just unsustainable, with the resources that are available.


It’s like the big seals that we have on the cape. They just sit out there and eat fish then they get eaten by the sharks.

But it’s very sad. You know, it’s very sad to hear about these animals starving to death.

What is happening in the Peconic Estuary. What do you see for biodiversity?

There are many juvenile fish that live in the seagrasses. The three dimensional structure of seagrass lets them hide from predators. They are a critical nursery ground for numerous animals including black seabass and blackfish.  The seagrass canopy is a lifelong home for pipe fish and sea horses.


Source: Long Island Seagrass Conservation Website


You’ve seen see horses here?

Oh, yeah, all the time.

I’ve seen pipe fish and Maine, I thought it was too cold for seahorses in NY?

Yes. If you if you were to Google, the fish guy, his actual name is Chris Paparo and he is the Marine Station Manager here at Southampton. But as the Fish Guy, he sells photos and takes photos all the time. And he’s got some fantastic photos of animals in seagrasses and among the most popular ones are these seahorses.

Scallops, photo: Brad Peterson

Cool, what about scallops?

When scallops are small juveniles, they attach to the seagrass leaves to hold them up off the bottom. There are lots of little crabs on the bottom that want to eat them.. So they migrate up on the leaves and stay higher up until they are about the size of a quarter. And then they’re too heavy to be held up on the leaves.

So seagrasses play a really important role in enhancing the survival of our Bay scallops.


What is happening to Seagrass in Long Island?

So, seagrass has diminished in all bodies of New York water. Let me be very specific in the South Shore estuary reserve, which is all a Great South Bay, CenterMoriches and Shinnecock Bay. Seagrass has diminished in all of those bays over the last 20 years. In Peconic Bay, seagrass has been moving further and further towards the mouth estuary in that same time period. There was a 35% loss in sea grass in the Peconics from 2004 to 2017.

So we’re almost like at 50%. What happens when we hit 50%?

This is a complicated question, because, it depends on how you’re losing it. What I mean is that, if we loss some shoots over time but the meadow remains a continuous meadow that is very different than if the meadow starts to become a bunch of small patches.


Why are we losing so much seagrass?

So there’s several major issues.Remember, this is a plant? It needs light and a lot of it.  More than other marine plants.. So any kind of impact on water clarity, is going to cause a problem. As our septic systems age and leak more nitrogen into our bays this leads to phytoplankton blooms, they diminish the amount of light to the bottom. And that causes a problem for seagrass. We have no seagrass in New York existing below two meters. So that’s kind of unusual, but that’s telling about our water quality.

Does no grass grows below two meters depth?

They grow in shallow water so they get enough light. The problem in the southern bays is that as the water clarity has diminished, the seagrass has had to move into shallower and shallower waters. But as it’s moved, it’s getting into water that’s too warm for it. So it’s kind of pinched between shallow warm water and deep cooler water that doesn’t have enough light. So those are the two issues in the south shore estuaries, temperature and light. To complicate things even morethere’s a third issue that’s important for us. And that is organic matter or how muddy the sediment is. Have you ever been to salt marsh during low tide?

Yes, sometimes smells like rotten eggs?

Yeah, sulfide. Exactly. So this organic matter breaks down and releases sulfide.

It’s also nitrates right?

 Yes. nitrogen fuels the stuff that that grew in the water column and when it die off and sinks to the bottom is becomes organic matter. So this is organic matter accumulation. What happens when organic matter breaks down naturally, sulfide is produced. Sulfide is toxic to all living things. But it now adds a stress to the grass. So the grass is stressed by the sulfide. And that means it needs more light to survive. So it can’t grow as deep. If the sediment is high in organic matter, the plant has to be shallower because it requires more light, because it’s stressed out.It’s kind of like a bank account, you take a little here and  a little bit there and a little bit here and a little bit there. At some point, you account runs out.   For the plant, they’re no longer getting enough carbon to make it and they go into a carbon debt and die. And so those are the three big Trifecta issues that are going on for us on Long Island.

If we lose grass from an area, as grass moves closer and closer to an inlet. It’s kind of like, you lose all of it, and it’s migrating towards the inlet. But another way that you can lose grass is within that same area, your shoot count, which was 400 per square meter now becomes 200 per square meter, or becomes 100. At some point, it doesn’t have enough of itself to exist. And it just all breaks down because these are clonal plants. So that’s another thing to keep in mind. Just like coral are clonal and can grow by budding, which allows them to be very, very large, and to live for very, very long periods of time. Did you know seagrass the oldest organism on the planet?

Neptune Gass, Oil on Canvas, 48″x 60″, 2022, Nedret Andre

Neptune grass, yes I have, and have a painting I just completed called Neptune Grass! Did you hear about the Neptune balls? By the way? I just find that one.

( Brad goes to an area of his office and pulls out a coconut looking Neptune Ball)


Neptune Ball, Brad Peterson

No way, is that a Neptune ball, I’ve been reading about these Neptune grasses producing these balls and with plastic and sending them off on to land?

Well, they come in all sizes, right. These are just the kind of the rhizome root hairs rolling around. But anyway with plastic.

Is it true that seagrasses are collectors of micro-plastics.

Yes, it’s one of the great thing about seagrass. You know their plants, because they breathe into the sediments because they have roots that leak oxygen. And so what that means is that the plants injecting oxygen into the sediment, which allows a lot of things to live in the sediment that couldn’t live there otherwise, so clams and worms, stuff that wouldn’t be able to survive. But now, the grass breathes during the day, when it’s photosynthesizing, it just injects all this oxygen into the sediment. But at night, it respires like all plants and sucks that oxygen back up again. And so you have this input of oxygen and removal of oxygen within the seagrass beds, which makes them really, really important areas for microbial communities that perform lots of different transformations of nutrients, and chemical species are going on in the sediments of seagrass beds, which is also what makes them weird. Yeah, back to what you were talking about with Emerson’s quote “The Earth Laughs in Flowers” – there is so much diversity to talk about.

I read that  50 million invertebrates live in one acre of seagrass- does that sound right?

Costanza et al 1997 in Nature looked at the values of different habitats. They gave a value to marshes and oyster reefs and a value to coral reefs and seagrass. And of all of those different habitats that they looked at, because of these ecosystem services that they provide. Seagrasses were valued the most, more than twice what coral reefs are. Most people wouldn’t think that. If you were to ask someone on the street, what’s of more value a coral reef or seagrass? I think most people would say, well, coral reef.

Yes, I love corals too, but Corals get way more PR and they’ve been in the media consistently. Mangroves are heading into extinction and seagrass’s are getting barely any attention. We need more advocacy, awareness building- we need a whole community of advocates coming together to work on saving seagrass. I believe it can still be saved. We need a way forward.

Well, I was sitting on a committee for the Chesapeake Bay a month ago. And the result of that committee was that they expect to lose all of their eelgrass beds in the next two decades.

Is this were they have grown the largest meadows in Oyster Village where I went to visit?

Yes, Oyster Village. The idea is that, that that, that what they have in oyster village might be the only eelgrass that’s left. But the problem is that the temperature rise is called is causing a lot of that grass. That could that was the greatest restoration of eelgrass on the planet.

Isn’t that where they have the largest restoration site in the world?

But it’s also been diminishing Recently, because of the temperature.

They have all those tanks that I went to look at, they have oxidization tanks and seeds. When I  flew into Norfolk, I saw huge algae blooms in the Chesapeake Bay area. So the bays on one side were filthy, whereas the Outer Banks were pristine.

Right, So it’s beautiful, clear water which is why it was so successful. It was recruitment limited, because there wasn’t any grass there. That’s one thing to keep in mind. Some seagrass seeds can last very long periods of time. Eelgrass seeds only lasts two years. So if you have two bad years back to back, you’ve lost all the seeds that would have been there to bring it back. Which is why when you went out to someplace like the Outer Banks, there wasn’t any seagrass. They threw seeds out in very good water quality, lots of clear water. They responded really well and came back well.

What about that? I wonder if the thing has something to do with it to the sediment quality? The Earth?

Okay, you need to Google this Shinnecock Bay Restoration Project (ShiRP). So Chris Gobler, and I, back in 2006, we had a project that was looking at what would happen if there was a barrier breach in our island.. We were using distance from the inlet as our proxy for water quality. We noticed that the further and further away we got from the inlet, the more and more chlorophyll there was. The chlorophyll cells got smaller and smaller, which means that it would reflect the light, more and more, and our eelgrass productivity went down, our eelgrass survival diminished.


So more chlorophyll in the water – the less light. Seagrass gets ?

Yes. We thought this is bad, whats causing all these problems at that point, we realized that the problem was the nitrogen coming out of the septic systemsAnd so the ultimate answer is to reduce the nitrogen at the source. Okay, but that’s a billion dollar answer. That’s a political answer. And so Chris, and I were like, what can we do right now? Well, we started looking at hard clams and oysters as filters. So these biotic filters, we know that if you were to take an area and turn the water over in that area, every four days that water is under biotic control. So then we started figuring out well, how many clams how many oysters would we need to be able to do that in western Shinnecock Bay? And that started this Shinnecock Bay Restoration Project.

Western Shinnecock Bay used to be known for brown tides and red tides every year. It would be closed to shellfishing ever year.. As the hard clam numbers increased in the sanctuaries and the oyster reefs grew, we haven’t had a brown or red tide and the western bay hasn’t been closed in four years.

That’s amazing!

We started this in 2012.  This was a huge project. 7 million adult clams were put into 64 spawner sanctuaries and  four oyster reefs were created. This improved water clarity and the plant, eelgrass, has has an incredible ability to take space when the conditions are right.

So the clams and oysters helped clean the water?

Yes, as the water quality improved in this area, we had 100 acres of seagrass grow. We don’t believe in in adult shoot movement that doesn’t mean it doesn’t work. It’s very labor intensive. It’s very expensive. Where as seeds are not. So since 2012. We’ve been putting out about 6 million seeds over in Western Shinnecock to jumpstart the restoration..


Where do you get your seeds from? Where do you get your seeds from? Eastern Shinnecock? Do you dive down and get them or do you have a machine?

All of our seeds are collected by hand. So it’s either divers or snorkelers, we collect 25,000 reproductive shoots from eastern Shinnecock. We have the advantage of having very high reproductive shoot counts. We have somewhere between 20 to 40 reproductive shoots every square meter.

Brad Peterson at work

So you’re just collecting seagrass shoots, so people that dive need to know how to find reproductive shoots?

 Yes we take those reproductive shoots, just like Bob Orth does in Virginia and we put them in big tubs.

Oh, you have oxidization tanks and wasn’t allowed. Okay. So when they when you put them there? How long do you keep them because they keep them in Virginia they have them through the hot months.

The very first year we used something called the BUDS system, which is where you take the reproductive shoots, and you put them into mesh bags, and you tie them onto a cinder block with a buoy. And the seeds mature and will just rain down. They’ve been fertilized. And so they’ll just float around. And as they mature within the mesh bags they rain down around that cinderblock. We started with this approach for many reasons. One, we didn’t have to hold the seeds, we didn’t have to take care of them. And there was no expense for holding them.  We could get the community involved. So they would come and they would help put the seeds in the seed bags, we’d all go out on the boat and throw them off in a restoration area.

Hah- They’re like seed bombs, but you’re actually putting the whole shoot not necessarily getting all the one by one seeds labor intensive, right. So and you having a bag just float around with a shoot?

So we would usually have multiple mesh bags tied to a lobster buoy that was tied to a cinderblock.  We would put 50 of these units out in five rows of 10. When we would return next year, , you would see kind of a doughnut shape around where the cinderblock was.  We changed our seed release strategy because our  biggest mortality of our seeds was due to the little hermit crabs. The  little crabs would eat the seeds as they fall down. Now these crabs will pass by one seed, but the seeds are dense, and so they’ll kind of migrate into any depression. And so if this crab comes across 10 seeds, they’ll stop and eat them.

All 10 of them!

So we moved away from this method since we got a much higher return if we held on to the seeds and put them out in October in colder water when the crab metabolism diminishes.

Oh, okay.

So we collect them in June and then we hold them until they all fall out of the reproductive shoots and we keep the seeds until October at our Southampton Marine Station and then we broadcast them by hand in our restoration areas. 

So then then the seeds have already fallen down and you just collect the seeds and then disperse at a better time.  What is the sediment like in Shinnecock Bay?

Okay, the sediment is mostly sandy with some mud in it.

Karen McGlathery in Virginia, a wonderful marine biologist has been studying sand, the sand size in eelgrass beds.  Is sand is really important? I didn’t quite understand that because I thought you need good soil, but it turns out you need sand as well. How does that work?

Okay, so again, we tend to think with our terrestrial mindset of what sediment looks like, in the marine world, the sediment is the soil.If you were to go into your garden, where your plant are, it’d be a very different soil than if you were to go to a playground.


High in organic matter, rich in nutrients and ready for your flowers and plants. The sediments under the water act differently because the water fills up all the gaps between the soil particles.  The particle size of the soil is going to determine how much the water moves through it. So if you had two five gallon buckets, one full of mud and one full of sand, both with a hole at the bottom, and you had two pitchers of water, and you poured them into each bucket. The water in the sand is going to go right through, but the water in the mud bucket is going to take a much longer time to go through it because the particles are much, much smaller. They are very cohesive to each other and the water has a much more difficult time moving through it. The water carries oxygen in it as so as that water has a hard time moving the sediment, oxygen has a hard time moving through that muddy sediment. So particle size has an impact on how well substances are going to be able to move through that marine sediment.

So we want to find a location with sand?

Sand usually is good. But if you get too sandy, with no organic matter, now it can be kind of nutrient poor. So you need to have some organic matter for the plant to have enough nutrients to actually take up and use to grow.

It’s like the $50 million question, right? What? Has anyone done studies on this?

There’s been a number of people who’ve actually looked at this question.  I think that if you are going to look into this, you probably should fixate on sulphide because most people are going to be looking at sulfide. But sulfide is directly correlated to how much organic matter and how small the particle sizes are.

Okay, so we actually want bigger sand particles, so the water can move right through.

We go from all sand to what we would call sandy muds to muddy sand to mud That’s the sediment continuum So muddy sand is what we want. We don’t want sand. We don’t want mud.

Fascinating, in the mud flats up in Maine, I found seagrass up there in Milbridge, which is

 weird, but that you’re talking about weird stuff there because those are those are grasses that are out of the water. Right?

Those seagrass beds are exposed at low tide. So they’re getting lots of oxygen when they’re exposed.

Back to this question of diversity? What is on the leaves themselves become a surface for plants to grow on? So the word that we use is epiphytes, animals on a plant, right?

Yes. And those epiphytes are really important food resources. So lots of small invertebrates come and eat those food resources. And then other things come to eat those inverts that are eating those epiphytes. That’s another reason for why diversity is so high in seagrass beds. It’s a great place to hide but also it’s a food resource. And then there’s lots of things that don’t live in seagrass that go to seagrasses to eat and forage.

Shinnecock Bay is definitely a success story, how much did the meadow expand?

The seagrass meadows expanded over 100 acres, so there was grass there, but it’s expanded by about 100 acres.

Wow, when did this all begin and how?

The project started in 2012, we didn’t really see any change in the water clarity for the first three years, two or three years to get any momentum. So, since 2017, is where we’ve seen the biggest change.

The biggest increase, and you attributed that to putting these bivalves in so they can take some increased water clarity which in turn created a perfect space for eelgrass to flourish. Did you get help from other organizations like the Nature Conservancy? Or how did you get community engagement?

 So, this project, got off the ground by a philanthropic, private investment. We inspired a funder and after the first three years, we got some money from the state from a water quality improvement program. And then the governor came and saw what was happening in Shinnecock Bay and  used it as a model for the shellfish driven water quality improvement for Long Island. So he put $10 million into five other locations around Long Island using the same principle.

Wow that is amazing. I love that a true example of community involvement that leads to major change!!!!

Yes it’s a great success story of eelgrass restoration in Long Island

Wonderful!  I only knew about Virginia, I think they have grown 100 acres of seagrass.

Oh, they have 10 hectares

Do You actually live in Southampton?

I live in Hampton bays Hampton Bays.

So that would be Peconic. Right, so Sag Harbor opens up into the Peconic Bay and has no seagrass?

I mean, yes, Sag Harbor is the area where there’s seagrasses in Peconic Bay from Sag Harbor to the mouth of Peconic Bay.So it’s the seagrass is limited to the area of Peconic Bay with the most ocean exchange.

Have they’d been seen declined that too?

Well, I can’t speak for Sag Harbor I wouldn’t know. Joyce Novak from the Peconic Estuary Partnership would have more details for you if you reach out to her.

I was on your Stony Brook website and it kept saying nutrient availability, What is what is nutrient availability?

Stony Brook University

Okay, so remember, I told you that I was interested in how animals are in the seagrasses. So I’m always very intrigued in is how plants and animals interact with one another. So one thing that we found is that if you the tissue of the plant, you can look at how much carbon, nitrogen and phosphorus is in that plant.   The ratio of nitrogen to phosphorus tells you a great deal about the environment the plant is growing in.  If that ratio is less than 30 it tells you that the plant is nitrogen limited.  So many places where you think of seagrass you think of areas that are eutrophied and has  lots of nitrogen. But there are lots of places where that’s not true. And so if you were to add, a hard clams into the seagrass, the hard clams going to take all that particulate organic nitrogen and phosphorus in the phytoplankton that’s just moving in the water column, they’re going to eat it, and then they’re going to poop it out right next to them. So they take this moving resource and place it in a fixed point  in the sediment. And the plants use that. Many times when you dig up seagrass you can see how the roots have grown into the shells of dead animals in the sediment. Those roots are looking for nutrients.


Are you saying that the clams are the bivalves give them nutrients, they fertilize Seagrass, they fertilize them with nitrogen?

Yes and phosphorus, but yes, mostly it’s a nitrogen issue for us.  In tropical locations where the sediments are primarily calcium carbonate which phosphorus can bind to then it becomes much more phosphorus limitation and a phosphorus issue, but not here with our sandy sediments.

So, and at the same time, that word nitrogen also is also in all the algae blooms.

That’s correct. Think about how your nitrogen is getting to the water If the nitrogen is coming from runoff into the water, the advantage goe to the phytoplankton there are single cell organisms, they’re going to absorb that nutrient way before something else is going to be able to. If that nitrogen is coming from the groundwater, it’s going to go through the roots and rhizomes of eelgrass first before it gets out into the water column. And so seagrass has the advantage in that situation, if it’s living in the area where the groundwater is coming out, so it depends on where your nitrogen is coming from. Is it coming directing into the water or is it coming through the sediments. Clams are adding nitrogen into the sediment and they’re actually taking nitrogen out of the water column. And putting it into the sediments. Just like any kind of bivalve it doesn’t have to be hard clam. Blue Mussels do this. So one of the things that we looked at was how other animals can be a resource provider for seagrass. And one of the things that came out that was so intriguing to me, is that if you shaded the plant, we did experiments where we had plants that were unshaded, and plants that were shade, and we put either a tree spike or a hard clam,  in the sediment with the eelgrass we found that the shaded plants, those plants that were stressed, the addition of the nutrient had a much bigger effect on them than it did on those that weren’t stressed.


But I think it goes back to that idea of kind of the bank account, when you’re giving the plant something when your bank accounts is already low, it’s going to make a bigger impact on you than when your bank accounts is high.

So if it’s not getting enough nutrients, because of muddy water?

Our currency here is carbon. The ability of the plant to store carbon for its use to grow. So if it’s not able to make enough carbon for itself through photosynthesis and goes into carbon debt meaning it’s using up more carbon to survive an it is able to create then if I can do something at that low point, it’s going to have a bigger impact on that plant than if the plant is fat and happy. Now having an addition carbon that is simply a surplus it’s not really that big of a deal because the plant is already okay.

So once these like Shinnecock area they’ve developed and you have a healthy meadow that you’ve you’re happy with Are you just gonna monitor that that 100 acres that you have?


We continue to monitor our restoration areas.  One of the things that is really important for all restoration projects is the ability to quantify what the changes and the increase in targeted habitat.  To accomplish this we are using aerial photography and drone imagery. Aerial photography is really expensive. We are using imagery acquired by  the Agricultural department. They fly over once every two years. The Agriculture Department flies over Long Island to look at crops. Well, they don’t turn off the camera when they fly over Shinnecock Bay. So we’ve been able to get their imagery. It’s great for us.. But the problem is they only do it every other year. We’d like to do more than that.

Have you spoken to Jill Carr? She is one of the tech people who uses drones sonar and arial  mapping. She is a  Coastal Data Scientist at the Massachusetts Bays National Estuary Partnership (MassBays)


So we do our drone imagery with a DJI Phantom 4 which isa small drone, it would be very difficult and time consuming to get imagery of the whole area. The drones that can cover the whole area are $50,000 drones, which are outside our price range. We are looking at satellite imagery, though, because sometimes although the footprint is much larger, they’re getting smaller and smaller pixels, which improves their usefulness for us. But again, we’re currently limited to the satellite images what we can get access to for free. So the really fancy stuff cost money.


What about Sonar?

Sonar would work too. But the problem is you get a small swath of the bottom in shallow depth so you have to drive the boat back and forth a great dealIt would take you a very long time to cover a large area. Since the footprint of your sonar is really small in shallow waters, it would probably take a month to drive a boat over all of the area where the seagrass is.. It doesn’t sound like that makes a lot of sense.


You mentioned you have four more projects coming up in the Peconic Estuary, what does this look like?

So the first thing that we’re going to do in the Peconic right now is because we are so concerned with temperature, that’s our big concern.

Chris Clapp and I are kind of birds of a feather. We gave the eelgrass restoration community a call to arms last year had lots of virtual fruit thrown at us. Because resource managers want to be able to have some kind of actionable item that they can do, we’re going to reduce nitrogen by x, and that’s going to help us with eelgrass.

How do you address rising water temperature., Resource managers are not going to be able to regulate water temperature and make it cool, unless you’re going to do something like make a breach, bringing cool water, which people are talking about. But I think that’s probably not a very wise move on an island where the sand moves so much. Now, we had a natural breach in Great South Bay as a result of Superstorm Sandy, and it had a big impact on eelgrass because it brought in cooler, clear water. So we’re looking right now at using natural groundwater sites which are leaking cooler water into the sediment as potential restoration areas, that’s one of the projects that we’re  working on this summer

That’s because the natural the brackish water has, it’s cooler and it’s also more nutrients maybe?

Usually groundwater also is enhanced in carbon, they’re more acidic, which means they have higher CO2 in them. And the plants are usually carbon limited. Most studies where they have increased the CO2 in the water, the plants have responded positively. So groundwater not only is cooler which is less stressful but also has more of what the plant needs to grow, carbon.

I heard that that seagrasses are doing fine in some warming waters since they are not affected by PH levels like Corals- is this the case?

 It depends on where you are.  So eelgrass is only found in the northern hemisphere. And it’s only a temperate seagrass, but it’s found throughout the northern hemisphere.So you find eelgrass all around the planet. In the Northern Hemisphere, there are only a few species of seagrass.  Primarily it’s Zostera marina which is what we have on Long Island, Zostera japonica and Zostera noltii.

Wait where does the cut off start for Seagrass?

 Seagrass exist along the coasts of every continent except Anatartica.

 Does Brazil have seagrass?

Yes.  It has three genera of seagrass.  Halodule, Halophila and Ruppia.  The Ruppia is the same species we find here in Long Island. 

What about Ruppia?

Ruppia maritima is really a brackish plant. It can survive in places that eelgrass grows. But when you compare the two, so I’m thinking of their functional roles, eelgrass, which can grow from 15 centimeters to over two meters, it’s a very plastic.  Ruppia is 10 cmtall ( not very tall). Now, there are reproductive shoots that are very tall, but they’re not there all the time. So the kinds of animals that can hide in Ruppia is very different. So the functional role of Ruppia which most people think is going to become the seagrass of the future for Long Island is very different. Ruppia is not going to have the same ability to bind the sediments, it’s not going to have the same ability as a nursery, or the ability to oxygenate the sediments. So it will be a very different world if we lose our eelgrass and Ruppia is the only grass present.

So Ruppia is less ecosystem service oriented. Now, we saw these parchment worms, what’s the, what’s the scoop with these parchment worms? Because they almost looked like they were hugging the sediment and holding it down. There was like a colony. Are they good or bad?

I mean, it just depends on what you’re defining is good or bad. They are what we call sediment stabilizers. So they’re going to help stabilize the sediment. In many ways that would be good, particularly for water clarity. However, if I’m a deposit feeder who moves to the sediment to survive the sediment stabilizers are bad news to me. It makes it more difficult for me to move through the sediment.

I didn’t understand the last bit that you made. Sound dollars?

Think that you’re sitting on a beach? Yout then take 100 straws and push the straws into the beach sand.

Now you’re trying to take your finger through the straws underneath the sand and as you move your hand your finger keeps running into those straws.  That would be the same think for those animals trying to move through a seagrass patch.

Okay I get it

So things that want to move through the sediment because that’s how they eat or acquire their energy. Like, we’re not going to like these guys.


Is it invasive?

Seagrass can be invasive.  Zostera japonica on the west coast of the US would be considered an invasive. All of the seagrasses on Long are native.

I like the worms while we were out on the Cape with Holly(Previous interview). They wrap all the shells and they make tubes. Kind of like a  bower bird. Back to nutrient availability, is what you’re studying to find like most suitable location for eelgrass seeds.

So, what I’m doing is looking at the ratio of nitrogen to phosphors to find out if there is too much nitrogen in an area and the plant will tell me. The plant is like a piece of litmus paper and absorbs the nutrients in the water over a long period of time. So I can use the plant tissue tofind areas where the plant is nutrient limited.

And if it’s limited, then I can enhance its growth by enhancing its nutrient availability with the bivalves, but that would all depend on the context. Adding shellfish may be of no value.If you know the ratio of elements in the tissue of an organism, you can learn a lot.  This is called ecological stoichiometry. Stoichiometry means the nutrient ratio inside the organism. So you might have heard of the Redfield ratio, which is 106:16: 1 . And that’s what phytoplankton elemental ratio of carbon to nitrogen to phosphorus It is named the scientist that determined thisAnd now they use that as the standard to compare other organisms to.

They test phytoplankton to test how much nitrogen they have?


They use the Redfield data to define the area- to say is this area is limited in productivity or not. They use it in lakes and streams, coastal bays and the ocean..

Interesting. Your  next phase is to analyze data on locations and pick the best possible spots for eelgrass restoration.


I noticed online that your student is working with some sort of bio optical model for site location?

 Her project got us thinking about how are we going to deal with the rapidly changing water temperature? For example at the last annual Zosterapalooza meeting we talked about these topic.


Oh does this relate to the assisted migration discussion at the last meeting ?

Yes. When we talk about assisted migration or genetic enhancement of eelgrass stocks along the eastern US


When you say genetic enhancement are you talking about cross breading two or three different types of seagrass? Or changing the DNA?

The question right now is what options do we have on the table?


The coral guys are genetically modifying the DNA of corals so it can live in warmer temperatures.

I don’t even know if that is even an option for eelgrass. Right now what’s on the table is looking for these – functional genotypes for heat tolerance within the state. So you are looking at warm water populations and seeing if there are warm water genotypes which we can use in other places within the New York. I would like to begin looking at genotypes outside of states. Right now we can’t do that because of regulations.

Today we live in a place where the grass is segregated by artificial boundaries. Where as 100 years ago this wasn’t the case.


The Brant birds that you talked about at the last meeting was a good analogy- of how they eat seagrass seeds in one state and naturally deposit them in other states (laugh)

We are trying to look and see “Can we use some of these southern populations of eelgrass, the ones that have survived in warmer waters. Can we borrow some of their genes and bring them up here?”

I did try to bring seeds from Virginia in 2018, but they didn’t want to let them go.

They are concerned about other things. Like there is a fungus that grows on the eelgrass plant called Labyrinthula. Labyrinthula was the fungus that caused of the big die off of eelgrass in 1930s

Is that called Wasting Disease?

Yep, same thing

So they are concerned, that we could bring that back up to the east coast.

Didn’t we also have Wasting Disease in eelgrass in 1930s in MA?

Yes, so Wasting Disease was an Atlantic wide die off – all over.

Interestingly they took the eelgrass coming from Washington State and used it to try and restore grass in New York in the 1930s.

You probably need to get clearance and try to experiment.

Yes, we are getting together this summer – various scientists across states coming together to look at:

What can we do?

What should we do?

How can we do it?

There needs to be state and federal regulators in this conversation too.

The concern that I have is that here on Long Island we may not have that long to wait !


How can local Long Islanders do help ?

For East End Islanders like us, the number one thing that can be do is upgrade our septic

systems to a denitrifying system.

The single best thing to do is to reduce the current level of nitrogen entering our watersheds., if the state continues to subsidize the conversion of our septic systems, it’s not really that expensive.

That’s great to hear the state is helping out, septic tanks are a huge problem for nitrate pollution

Yes, it’s a huge problem. Our septic systems on the east end are old and leaky. So replacing them would be great. But the idea of denitrifying them. Taking the nitrogen out of our watershed is huge. I would point you to the CLEAN WATER TECHNOLOGY CENTER for Long Island. They have been working with the county on a variety of solutions for denitrifying septic tanks.


Chris Clapp is the director of Ocean Sewage Alliance and he has worked diligently in getting these denitrifying septic systems here in the Eastern part of Long Island.

OK, I will reach out!

He would be bring a really good perspective for you.

On top of everything this is the best thing that homeowners can do right?

It can help make change.

People eating clams and oysters. If nitrate levels are too high they become toxic right and give you brain damage?

There are certain phytoplankton that can cause problems for human consumption.  New York State has a division of shellfish that monitors sites around Long Island to make sure that they are safe for harvest.  If not, they then close areas to shellfishing.

I remember signs up in Maine, where there were warning people not to dig for clams because of toxicity levels were high. It’s a real problem

 One of the reasons we have been so successful at Shinnecock is that the clammers are so excited about the project. If they don’t get closed out of areas, they can clam anywhere all year round. So since the start of the project having a series of years with no shellfish closures, they are happy about that.

It’s so important to highlight these cost- benefit scenarios with our communities.  When you promote the number of clams dug in healthy clean water. Creating x % increase in clammers livelihoods. Or fisherman’s ability to find fish..it makes more of a human impact.

The connection to fish is important. The anglers who are in the room, want to know how do we enhance our fish populations. Well it has been demonstrated multiple times that fish abundance and seagrass abundance are correlated.

As your seagrass declines, so does your fish abundance.

Thank you for sharing all your knowledge – I’m very happy to learn about Shinnecock Bay Success Story and all the work behind it. Amazing- I learnt so much!

Looking forward to meeting you personally at Sarah Nightingale gallery for a seagrass talk on June 30th at 5-7pm!


Please join both Brad Peterson and me at Sara Nightingale Gallery for our “The Earth Laughs In Flowers” Exhibition and Talk. More info can be found here.


Earth Laughs In Flowers

Sara Nightingale Gallery

June 29- July 14

Artists Talk: June 30th 5-7pm, 2022

26 Main Street

Sag Harbor, NY 11963


For more info on Bradley Peterson please check out: