The oyster is a huge part of coastal culture and economy in the U.S. But a historic sewage spill and climate change could put decades of restoration efforts at risk.

Guests

Amy Strzegowski, fifth generation seafood wholesaler based in Maryland.

Betsy Nicholas, president of the Potomac Riverkeeper Network.

Ben Ford, Chesapeake Bay conservation advocate and Miles-Wye Riverkeeper for ShoreRivers.

Also Featured

Sen. Chris Van Hollen, U.S. senator representing Maryland.

Michael Sieracki, director of the Horn Point Laboratory at the University of Maryland Center for Environmental Science.

Andrea Unzueta Martinez, postdoctoral research fellow in Organismic and Evolutionary Biology at the Girguis Lab.

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Transcript of Full Broadcast

The version of our broadcast available at the top of this page and via podcast apps is a condensed version of the full show. You can listen to the full, unedited broadcast here:

Part I 

MEGHNA CHAKRABARTI: On January 19th, 2026, a 60-year-old sewer line carrying wastewater from Maryland and Virginia to a Washington, D.C. treatment plant collapsed along the Potomac River.

NEWS ANCHOR: Hundreds of millions of gallons of raw sewage has been spilling into the Potomac River after a pipe collapsed. Now officials tell News 4 they won’t be able to stop that flow until sometime next week. That means 40 million gallons of sewage a day.

CHAKRABARTI: In the days that followed, roughly 240 million gallons of untreated sewage poured into the Potomac River before emergency teams could stop the flow. It became one of the largest sewage spills in American history.

Now, that spill happened along the Virginia-Maryland border, but the pipe is owned and operated by the District of Columbia Water and Sewer Authority, and it’s on a canal that is federal property. In February, President Donald Trump and Maryland Governor Wes Moore fought over who should clean it up.

DONALD TRUMP: No I don’t like the job that Wes Moore’s doing. I don’t like the job he’s doing on the bridge. I don’t like the fact that he did that horrible deal with the pipes in the Potomac, and he’s not doing the job. They gotta do it, and we’re gonna, I’m gonna have to get the federal government involved in getting it fixed because he can’t fix anything.

WES MOORE: What the president’s talking about is a break in a D.C. pipe that took place on federal land. How Maryland gets caught up in this, I have no idea. That is just some very creative facts from the president of the United States.

CHAKRABARTI: Washington, D.C. Mayor Muriel Bowser declared a public emergency on February 18th and requested federal assistance. President Trump did end up approving a federal government response for repairs along the canal where the spill originated.

Those repairs were completed in March. But 60 miles downstream, another question emerged. What would happen to the Chesapeake Bay? Maryland imposed a precautionary shellfish harvesting closure in part of the Potomac while scientists tested waters downstream. State officials later lifted the closure after weeks of monitoring found no detectable impact to shellfish waters and no evidence that harvesting areas further downriver had been contaminated.

But the damage to some bay communities had already been done. Oyster farmers and harvesters in those areas could not work during the closures, and customer demand dropped precipitously. Here’s Robert Brown, president of the Maryland Watermen’s Association, in an interview with WUSA-TV in February.

ROBERT BROWN: Nobody wants to buy oysters out of the Potomac River.

The men who were shucking oysters and selling oysters other places say, “Look, we don’t want no more oysters out the Potomac because we have questions when we go to sell the oysters.”

CHAKRABARTI: Today, we’re going to focus on those oysters. They’re critical, not only for the shellfish and aquaculture industry in and around the Chesapeake, but they’re also a critical tool in helping restore the health of the Chesapeake Bay itself.

And that restoration effort, along with the spill and sudden changes in federal policy, are a cautionary tale to everybody, no matter where you are, about how fragile ecosystems rely on the good faith and smooth cooperation of many highly complicated human systems around them. So let’s start with the men and women of the area’s oyster industry.

William Strzegowski and his wife, Amy, have an oyster shucking and wholesale food seafood business in Maryland, and they’ve been going for five generations. And joining us now is Amy. Amy, welcome to On Point.

AMY STRZEGOWSKI: Hi, Meghna. How are you?

CHAKRABARTI: I’m doing well, and it’s P.N.B. Seafood, I should say. I should have given the company name out there, right there at the top.

Tell me a little bit about how the last six months have been for you, your husband, and the business.

STRZEGOWSKI: High anxiety. We are the middleman, so of course we have divers, we have oyster farms. We get our oysters. Being fifth generation, we have a lot of resources. However, the problem is a negative reporting is what devastates sales.

So it’s more of an economical public relations epidemic rather than a direct environmental toxicity problem, meaning that, once it’s in your head and you think that the oysters are from the Potomac and that they’re sewage, you’re not going to eat them, which means we can’t sell them, which means we have to go to further out, get them shipped in to us.

So it impacts all of us.

CHAKRABARTI: I see. So just to be clear, the oysters that you’re harvesting have been totally cleared of any kind of contamination, but it’s just the sort of public perception around them that’s really been damaging. Is that right?

STRZEGOWSKI: Yeah, correct. And most of the oyster beds are well south of the spill.

And our oysters we get from the Eastern Shore as well, so that’s not around there. But, the word of mouth is just, if someone thinks that they’re eating raw sewage, would you eat it? No.

CHAKRABARTI: Yeah, no, I take your point. So but just to be clear, the beds are clear, they’re clean where you’re harvesting them.

So tell me a little bit more then about where you get the oysters. Is there a particular sort of dive season when you’re getting all the shellfish out?

STRZEGOWSKI: Yeah the dive season starts, I know you’ve probably heard with eat oysters with the letter R in the month.

Yes. That’s no longer true. What happens is that the oysters the local oysters that we get, we have a diver that dives on the Eastern Shore. That’s where most of our oysters come from, not all. We do outsource and get our PEIs from Canada, some from Boston. But those oysters are freshest in the months with the letter R.

Now, we’re able to eat them outside of the month with the letter R because a lot now is farm-raised. So these oysters and we have a whole program with the oyster recovery where they collect our oyster shells, and they put them back in the Chesapeake Bay, and the spats turn into full-grown oysters over a course of actually the water getting colder and it helps the oysters grow.

The problem is if it’s too cold, the oysters can die. So that’s why those oysters sometimes are more expensive than the regular local ones.

CHAKRABARTI: Okay. So then tell me a little bit more about where the business is now in terms of your annual sales, and do you and other people in the industry are you seeking assistance?

What does the immediate future look like for you?

STRZEGOWSKI: So as a shucker we kind of get left out of that assistance realm. We’re not actually the watermen who, if they don’t go out or if they lose a whole day of work, we can get oysters other places. However, they’re more expensive, which then trickles down to the consumer.

So in that case, that’s where we lose our money. However, we’re not the actual ones dredging the oysters, so we don’t always get the financial aid. We have to prove a lot so we kind of just have to compensate by raising our prices and losing business, and then hopefully it regains once September and the local oysters are again plentiful.

The problem is that, sometimes, like I said, the water quality is not to blame, the fear is. When the Maryland Department of Environment closed the Potomac as a safety precaution, it wasn’t because the water quality testing was raising the alarms. It was just that, the water quality was fine.

CHAKRABARTI: Okay.

STRZEGOWSKI: But yeah.

CHAKRABARTI: No, I didn’t mean to interrupt you there.

STRZEGOWSKI: No, it’s okay.

CHAKRABARTI: Yeah. So I guess what I’m wondering is, I also, we’ll talk a little bit later in the show with other folks about the winter that you guys have had there. But is there, your husband told us earlier this week that his concern wasn’t necessarily for the immediate impacts because you can get through them even though it might be challenging.

But he was a little bit more worried about long-term impacts to your business. Do you wanna talk about that a little?

STRZEGOWSKI: Yeah, sure. So this year because of the freezing of the Chesapeake and also the Potomac spill they did extend the oyster season by two weeks. However, again, they extended it, which was great, but, when you, like I said, already have the fear of eating raw oysters or anything raw, people tend to shy away from that.

So in Maryland, we have what’s popular is to have a bull and oyster roast. And that a lot of fundraising happens that way, and we supply oysters to these kind of events. Now in the future, if no one wants to eat raw seafood, they’re going to turn those oyster roasts into maybe shrimp roast.

Where that impacts us, and then we have less oyster sales. We have a lot of restaurants that do we call it buck-a-shucks. They sell oysters for a dollar. If people don’t want to eat this, they’re going to drop that special, and then we lose that account. Yeah. So in the long term, if the fear of eating raw seafood continues but we have to be certified.

If someone gets sick, we’re out of business, so we take that, it’s very important to us to make sure we take our classes, we get certified. We keep logs and dates of where our oysters are harvested, when we get them, when we deliver them, the temperature. We have tags on every bushel.

So we take pride in delivering the freshest seafood that we can.

CHAKRABARTI: Amy, you mentioned buck-a-shuck. A couple of years ago, I was down in Baltimore, I was in Baltimore, and I participated in that great tradition that you talked about, and I thought I had come very close to heaven with dollar oysters, for real.

I have about 30 seconds left with you, Amy. Can you tell me a little bit about what this business and industry has meant? I think it’s your husband’s family that’s been in it for five generations now. What has that meant for your family?

STRZEGOWSKI: Yeah, my husband’s family is from Hoopers Island on the Eastern Shore, and they dredged oysters.

He used to be on a boat when he was younger, and then they moved to Baltimore and opened a seafood restaurant. So he was always in the business, taught to shuck oysters. Ironically, my grandparents had a produce and seafood store two blocks away because it was the city. And so they sold to the tugboats fresh seafood.

So we both were raised in this business. So when we finally came together, we decided to continue the oyster side of it.

Part II

CHAKRABARTI: Let’s bring in Betsy Nicholas. She is the president of the Potomac Riverkeeper Network, and she joins us from Washington. Betsy, welcome to On Point.

BETSY NICHOLAS: Hi, Meghna. Glad to be here.

CHAKRABARTI: And I’d also like to bring Ben Ford into the conversation. He is a Chesapeake Bay conservation advocate and Miles-Wye Riverkeeper for ShoreRivers.

Ben Ford, welcome to you.

BEN FORD: Thanks for having me, Meghna.

CHAKRABARTI: Okay, so let’s actually listen to a little bit about how the Trump administration responded to news of that big sewage spill that took place in January. Here’s White House Press Secretary Karoline Leavitt responding to a question about the odor caused by the spill.

This is from February 18th.

REPORTER: For America 250, the president wants people from all over to come to the nation’s capital. Is he worried that by the summer the Potomac River will still smell like poop?

KAROLINE LEAVITT: He is worried about that. Which is why the federal government wants to fix it, and we hope that the local authorities will cooperate with us in doing so.

CHAKRABARTI: Okay, Betsy Nicholas, let me start with you. Ha funny, but not funny. What exactly happened with that pipeline, do we know, that caused this, actually quite major disaster?

NICHOLAS: Yes. At this point we have a pretty good idea. Yeah. Basically, when you have big, great big pipes like this with sewage running through it, you get gases that go up in them.

So this pipe is in the area where it collapsed six feet wide, and it was installed 60 years ago. So as you get these gases going up, they corrode the pipe, wear through the concrete, and make weak spots. Unfortunately, when it was constructed, they put the boulders. Because they had to blast in order to put this pipeline underground, on top of it.

So when it weakened from these gases, it just collapsed inwards. Because one of the things we heard in the news that was a head-scratcher is that they found boulders inside the collapsed pipe. So there was a little investigation before we found out how the boulders got there.

CHAKRABARTI: Okay. So Betsy, the engineer in me is actually quite interested in this.

So let me stick with this for one second. So yeah, so when sewage flows through pipes and it’s untreated, it off-gases a lot of gas. And you say that was corroding, the interior of the pipe. And so when the pipe got significantly weakened, as you said, and because there were boulders, presumably heavy ones, on top of them that they used to refill the channel that they had sunk the pipe into, is it the weight of those boulders that ended up collapsing the pipe?

NICHOLAS: Yes. The two things together.

CHAKRABARTI: The two things together. Okay.

NICHOLAS: And we’ve seen that kind of wear from the gas’s infrastructure in many different places.

CHAKRABARTI: Ah, okay. So this happened 40 million gallons a day, the newscaster said, that was from the clip we pulled at the top of the show here.

That’s just, even if it was just one day, that would be an enormous amount. Can you give us a sense as to how the overall volume of sewage that came out before the spill could be stopped, how that compares to other similar wastewater disasters that you’ve observed?

NICHOLAS: Yeah, it really dwarfs them.

Okay. So in, for example, some in the area in Baltimore, there was a leaky, very leaky sewage system that over the course of a year leaked about that much sewage, but this was all in about seven days. So it was just such a high volume in such a short period of time. It looked, actually Stephen Colbert’s word for it was a poop geyser, but it looked like a volcano of sewage coming up from under the ground.

CHAKRABARTI: Oh, wow. Okay. Since this was such a large spill, and as you said, other wastewater pipes have similar construction elsewhere, was there an issue now retrospectively of, I don’t know, like, how one or how a management company working to maintain these kinds of facilities, do they, should there be more, I don’t know, pipeline inspection?

And if so, like, how do they do that? Is that part of the conversation now?

NICHOLAS: Yes. I can say that there absolutely should be more inspection and maintenance. Just think about anything that you have for 60 years. My house is almost 100 years old. Imagine if we never checked for leaks and holes or rodents getting in, right?

I think they’d take over. So there needs to be much more emphasis on protecting this infrastructure. We bury these things, so you don’t see them. They’re not top of mind every day, but it is right next to our drinking water source for the region.

CHAKRABARTI: Yeah. Okay. So Betsy, hang on here. Let me just turn to Ben.

Ben, so let’s talk about the immediate ecological impacts of pumping 240 million gallons of untreated sewage into the Potomac River. How would you describe how that changed the sort of the immediate environment right around the spill area?

FORD: I want to just have a quick caveat that this, as you said, Meghna, this is an issue that is happening all around us, all the time. And this is the probably the largest sewer spill in history that we know, or U.S. history that we know about, but this sort of thing happens around the Chesapeake regularly, it’s just not at the same volume. So it’s really important that we invest in this infrastructure. And it happens on the Eastern Shore, too.

Though we weren’t over here directly impacted by the spill, the impacts to the Upper Potomac I think still remain to be seen. The amount of nutrients and chemicals that came out into the environment maybe still have not played out. And that’s to say nothing of the bacterial contamination in that part of the Potomac.

And luckily if there’s a silver lining, it’s that it happened when most of the river was iced up and people weren’t interacting with the waterway.

CHAKRABARTI: I see. Okay, so can we talk about that for a second? Because we had mentioned a little earlier the sort of tough winter this year, and the spill happened in January.

So did that, if most of the river being iced up, did that actually concentrate the area in which the pollutants were flowing and perhaps, as you said, maybe made it or saved the Chesapeake Bay itself from more contamination than it otherwise might have had?

NICHOLAS: It probably saved people from being, coming into direct contact with that bacterial contamination in those months because people were staying out of the water given the time of year.

But having all that sewage now is locked up in ice it went from being, as Betsy and Stephen Colbert called it, a poo geyser to a massive poo cube. So it didn’t go anywhere. It just got locked up.

CHAKRABARTI: I appreciate the attempt to bring a little bit of lightheartedness to a serious issue, but also the visuals will not leave my mind, Ben.

So thank you for that. Betsy, back in my environmental engineering days, there was a very trite little saying that we had about that, dilution is the solution to pollution. Is that sort of part of the cleanup MO here, or does a lot more work have to be done to get the Potomac at least, let alone the Chesapeake, back to where it was before January?

NICHOLAS: I think it’s a both/and there because a river system naturally processes waste. It has all kinds of critters living in it, first of all, but you get runoff from, you know, dog poop to deer to geese, every time it rains going into the river, and a river can assimilate those and make it safe downstream.

The Potomac is very wide, shallow mostly, but it is a huge river, 14,000 square mile watershed, and covers most of the states, all except for one of the same states that the Chesapeake Bay does. And the Potomac provides nearly 40% of the fresh water that goes into the Chesapeake Bay. So we’re talking about a huge river here.

But there are, as Ben was talking about, some localized impacts because of the weather conditions, but also just because of river flow. There are some little, tiny islands in the Potomac where people recreate a lot. There’s a lot of kayaking, rowing in Georgetown, but all through the Potomac area, and Georgetown’s just a few miles south or downriver from where this happened.

So we’re now concerned with some contamination in the sediments, and they settled there during that giant freeze phase here where the Potomac was completely iced over. But there were, for example, first responders doing exercises in the river and calling us to find out where they could do that safely.

Because people might walk on the river and fall in. So they needed to do those exercises, and we wanted to make sure they didn’t get contaminated with the waste.

CHAKRABARTI: Wow. Okay. So Ben and Betsy, thank you so much for giving us more of the background of the spill itself. Because infrastructure, of course, is one of the quote-unquote human systems, as I’m calling them, that has to really work in concert with other aspects to keep very cherished waterways like the Potomac and the Chesapeake clean, and not just for the natural world, but for, Betsy, as you said, the humans that use it as well.

Now, Ben, give me a little bit of history here because and do correct me if I’m wrong, but as far as I understand, several decades ago the Chesapeake itself wasn’t in the greatest condition, and in fact, in the long-term restoration efforts for the bay, oysters have actually played an important role.

Is that right?

FORD: Absolutely. So oysters are filter feeders, and they are combing the water column for algae, which is their food source. We want generally less algae in the water column because when algae dies, it decomposes and sucks all the oxygen out of the water, which fish and crabs need to survive.

It’s also filtering out sediment and other particulate matter even though it’s not consuming those. It excretes those in pelletized form and drops it to the bay floor. And anecdotally it’s been said that oysters can filter 50 gallons of water per day per oyster, and we’re planting millions of oysters per year in the bay.

And that 50 gallons is probably a little high. That’s probably in a perfect world. But the fact remains that oysters are an important tool a very important arrow in the quiver of bay restoration efforts that have been ongoing since, yeah, 1983.

CHAKRABARTI: 1983. Okay, a little bit later in the show we’re gonna hear from the director of the Horn Point Laboratory and Hatchery.

But you said that you’re planting millions of oysters a year. So these are oysters that are being, what, strategically planted in different parts of the bay in order for their filtration system to help clean the waters of the Chesapeake?

FORD: That’s right. So historically, oysters were, you go way back, oysters were a threat to navigation. I use threat loosely, right? So in colonial times you could run aground on a massive oyster reef. Post-Civil War there was a period of time called the Oyster Wars, where the first kind of natural resource police force called the Oyster Navy, did literal battle with kind of commercial interests harvesting the oysters in an effort to protect that resource.

And oysters have always been contentious, but they’ve always been an important cultural and ecological keystone in the Chesapeake.

CHAKRABARTI: I understand that actually during colonial times oysters were, they weren’t considered a luxury food at all. Is that right?

FORD: That’s true. They were an incredibly important food source for everybody in the Chesapeake region.

There are massive what we call middens or trash piles that native people left on the shorelines. And some of them are absolutely huge. So people have been eating oysters on the shores of the Chesapeake Bay since thousands and thousands of years ago. But from enslaved workers going out to harvest oysters to George Washington was famous for having a pickled oyster recipe which sounds frankly kind of gross. But I feel like I’d give it a shot. To today, where it’s a multimillion-dollar industry supporting both a culture, as we heard about earlier in the program, and an ecological need of our local waterways.

CHAKRABARTI: Betsy, do you want to talk a little bit about the niche, or niche is probably not the right word, but the role of oysters in the Chesapeake, but also since you’re with the Potomac Riverkeeper Network in the Potomac itself?

NICHOLAS: Yes. So most of the Potomac is above the area or upstream of the area where there’s enough salt.

Because it has to be in the tidal areas, but they’re in those tidal areas are some of the biggest oyster farms in the region, and they supply oysters all around the country. It’s just good water quality for it. And it just hurts my heart to hear the struggles that the people whose livelihoods depend on this are facing. Because the area where it is, enough salt in the water for oysters to grow is at least 60 miles downstream of where the spill occurred.

And I strongly agree with what Maryland did in terms of in an abundance of caution is issue an advisory until they were able to get testing done and ensure it was safe. Because people get really sick from the raw sewage if they consume it. But it was determined to be safe some time ago, but in addition to the cultural and the food and the business part of oysters, as Ben was talking about, they clean the water.

We also use, in the areas where the water is too fresh, not enough salt, freshwater mussels for the same purpose. And these are not the type that people eat at all, so we don’t have to worry about that one complicating factor, but having something actually in the river, cleaning the river in a natural system is pretty much the most ideal response to pollution issues like this.

So it’s not safe generally to treat the water within the flowing stream itself. You’re going to mess up the ecology and chemistry of it more often than not.

CHAKRABARTI: But the filter feeders can be effective in those same locations, right?

NICHOLAS: They’re extremely effective and some might even call them charismatic.

Part III

CHAKRABARTI: In the previous segment, you heard Ben talk about how oyster reefs in the Chesapeake, in the nation’s largest estuary, were once so large and so vast and significant that early explorers described them as hazards to navigation.

That’s what Ben said. But obviously, in the subsequent decades and centuries, harvesting, disease, pollution reduced the Chesapeake Bay’s oyster population to a fraction of what it used to be. But they are making a comeback. Ben had talked about how there’s seeding going on in the Chesapeake Bay, and at the center of that effort is a hatchery on Maryland’s Eastern Shore.

Now, this year, though, now here’s where another human system comes in, and this one is the politics and policy system, because this year, that hatchery lost $400,000 in funding. It was a tiny dot in President Donald Trump’s extreme budget slashing, but that $400,000 was a catastrophic blow to the hatchery’s operations.

Michael Sieracki is the director of the Horn Point Laboratory and its hatchery.

MICHAEL SIERACKI: Our laboratory is 50 years old, and now we have one of the largest oyster hatcheries on the East Coast and maybe in the world. And so we’re really known for large-scale production of oyster larvae. It’s always been oriented towards the idea of restoring oysters into Chesapeake Bay.

CHAKRABARTI: Horn Point’s hatchery produces hundreds of millions of baby oysters destined for restoration reefs throughout the bay, and restoring them has become one of the Chesapeake Bay’s biggest environmental success stories.

SIERACKI: Of the goals for the Chesapeake Bay restoration, the oysters are like a shining light for progress that we’ve made in restoring the bay.

CHAKRABARTI: But of course, that progress depends on continuing investment, and last year, administrators at Horn Point learned that a major National Oceanic and Atmospheric Administration, or NOAA grant supporting hatchery operations would be cut in half.

SIERACKI: So the first thing we did was say we’ll have to cut our staff by about half, and that means our production would go way down.

We couldn’t promise 50% of production with half the staff. It would go way down to 30% of production, which would really impact the goals for the state in terms of their restoration project.

CHAKRABARTI: Horn Point also supplies young oysters to Maryland’s growing aquaculture industry and to watermen who seed harvest areas.

The hatchery produces roughly half a billion oysters annually. Strong years, they do even more. But there was public outcry around the cuts, those funding cuts, and Maryland state lawmakers stepped in with emergency funding. And after a push from Democratic lawmakers at the federal level, NOAA ultimately restored the full grant for the final year of its funding cycle.

Here’s Maryland’s Democratic senator, Chris Van Hollen.

CHRIS VAN HOLLEN: I was pleased to join with scientists and NOAA employees outside their Maryland headquarters over a year ago to push back and protest those cuts, and we’ve been successful here in the Senate because the Trump administration proposed very deep cuts to NOAA, and I was able to reverse those cuts. And in fact, the bill that we ultimately provided from the Congress was $1.7 billion higher for NOAA than the bill that had been proposed by the Trump administration. And as a result of that, we were able to protect many vital programs, including those that benefit the Chesapeake Bay and the bay’s oyster population.

CHAKRABARTI: So for now, the hatchery is operating at full capacity, but its director Michael Sieracki, says that the episode exposes this larger question about how secure is that funding for future restoration efforts.

SIERACKI: Oysters fill the role of filtering the water, improving the water quality, restoring the bay.

They also are called ecosystem engineers. Their growth and lifestyle creates reefs, and reefs are habitats for other species. And so it really provides good living conditions for small fish and small crabs and other things that we like to have in the bay.

CHAKRABARTI: Meaning the broader health of the Chesapeake Bay. Okay. So Ben, tell me a little bit more about the hatchery and the fragility now that they feel on funding to keep these restoration efforts going with the oysters.

FORD: Absolutely. I think it, as Michael said, it exposes something that we’ve always considered one of the flaws here in oyster restoration is that you have to have both funding and political will to do it.

Most people agree that we want to restore our oyster reefs. And, prior to this undertaking of what is likely the largest oyster restoration in human history which is pretty cool to say a lot of people considered that oyster abundance in the Chesapeake was roughly a percent of the historic level.

And now, in some of these restored sanctuaries, and we call them in Maryland the Big Five, there’s five in Maryland, five in Virginia, that are what we call large-scale oyster restoration sites. The oyster populations are now 300 to 500% higher than that historic low or than they were before restoration.

And that’s really, that sounds impressive, but if you’re increasing by 500% something that was at 1%, that’s only 4 to 12% of the oysters that once were there. So oysters are definitely a success story, but we can’t let off the gas. This is something that we’ve got to keep doing if we want to restore the Bay, create all those ecosystem services and interstitial space, all the little nooks and crannies in an oyster reef that the polychaete worms and tunicates and mud crabs.

Those are the things that we like to eat, like to eat. So we want more rockfish, for striped bass for folks up in Boston. We want more perch and crabs. If we want those things, we need more oysters, and we need three-dimensional oyster reefs. And funding and political will are critical components to keeping our hatcheries producing, and the oysters has to have to get from the hatchery to the reef location.

There are these gigantic barges that bring what we call spat on shell. So tiny baby oysters dotting all over an oyster shell, and they get hosed off the deck onto a restored reef site. All that takes time and all that takes money.

CHAKRABARTI: Betsy, I’m going to come back to you in just a second to also talk about the funding and policy portion of this question, but the general coolness, if I can put it that way, of oysters is something that we want to celebrate a little bit more.

Because we actually haven’t talked about climate change all that much yet, but it turns out that scientists are also looking at oysters as a model for understanding how to build resilience in rapidly changing environments.

ANDREA UNZUETA MARTINEZ: In here, I have a setup of my experimental tanks. It’s super intricate and complicated, so it takes a lot of note-taking and keeping track of what goes where.

So I have numbers in all of the tanks and all of the cables that go to the tanks to make sure everything stays organized and I can keep track of what’s what. Here is a station where I measure pH and also oxygen. So I have a pH meter and an oxygen meter that are attached to a computer.

CHAKRABARTI: So this is Harvard University post-doctoral researcher Andrea Unzueta Martinez, and she studies the microscopic organisms that live inside of oysters.

UNZUETA MARTINEZ: I think it’s really important to learn about all aspects and foundational aspects of oyster life because that will better inform us about how they may be resilient. Understanding the foundations of how oysters work and how they go about doing their life and making their shells will become more relevant as there are changes in seawater chemistry.

CHAKRABARTI: The resilience is important in the face of, like I mentioned, climate change and other disasters, like the Potomac spill. Because ocean acidification means that for shell-building animals, conditions can become so acidic that the shell weakens or dissolves. But oysters actually have a really interesting strategy around this.

They create a protected space between their body and the shell, a kind of internal construction site. And inside that chamber, they regulate chemistry to create conditions that are better for building shell than the ocean itself, and that’s where Unzueta Martinez found something unexpected.

UNZUETA MARTINEZ: So we found that there are microbes that live in the spaces where shell formation happens, and they have the genetic tools to change the chemistry of these spaces.

We can think of it the way we think about building a home, how we build a house. And oysters are really good at maintaining these conditions in their shell construction sites. But our findings suggest that microbes have the capacity to change the chemistry in this construction site as well. And even more interesting than that, we’re also finding that there appears to be a dialogue between the oyster host and the microbiome.

So we can think of these microbes as tiny little chemical engineers that are mediating chemical processes and changing the chemistry of their environment.

CHAKRABARTI: And she says the more scientists understand how oysters build and maintain those shells, the better they can understand how oysters and potentially other animals persist in environments that are becoming increasingly inhospitable.

UNZUETA MARTINEZ: This work is very foundational, and foundational research can have applications in all sorts of different fields. So for instance, there’s a whole field of biomaterials and understanding how materials are built in the sense of calcium carbonate, which is the material that shells are made out of. We can understand how microbes could contribute to making this as partners with animals.

CHAKRABARTI: So that’s Andrea Unzueta Martinez, a fellow at Harvard’s Girguis Lab. So Betsy, I just, if you wanna talk about a little bit about climate change actually also, and general environmental or ecosystem resilience along the Potomac, I’d love to hear about that. But also just save me a second to ask you about politics and funding as well.

NICHOLAS: Absolutely. One thing that a lot of people might not know about the Potomac is we have dolphins, and I got to go out in a boat and see them. They come up through the Chesapeake Bay and go upstream into the Potomac and eat fish. So we have to think about, as Ben was saying, the connectivity with all of these ecosystem issues and concerns.

If we don’t have the little, tiny microscopic critters in there and the oysters and mussels and little creatures, we’re not going to get the fish, we’re not going to get the dolphins or anything else. Because it throws off the ecology of the entire system, and climate change impacts have just accelerated all of this change pretty dramatically, particularly in our waterways.

CHAKRABARTI: Okay. So then what’s really also, I think, critical here is that in the vast scheme of federal funding, we’re not talking about, even state funding. We’re not talking about huge amounts of money, but we’re talking about smaller amounts of money when they get, those funding sources get disturbed, it can actually cause quite a large and negative impact.

Is that a kind of a real weakness in the long-term restoration efforts of both Potomac and the Chesapeake, Betsy?

NICHOLAS: Absolutely. In fact I was pretty shocked to see the proposed cuts to EPA’s budget focused on infrastructure, exactly the kind of thing that would have prevented the Potomac disaster here of sewage, was cut by 60%.

So what they’re going into is we’re having these big maintenance and infrastructure failures and less money going towards it, while at the same time, EPA nationally has recognized a $1.3 trillion deficit in terms of underspending for maintenance of key infrastructure like our sewage treatment systems across the country.

This article was originally published on WBUR.org.