Eating More Oysters Helps Us—And The Chesapeake Bay

IRA FLATOW: This is Science Friday. I’m Ira Flatow, coming to you live from GWU in Washington DC.

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OK. You like to applaud. This is good, because I want a round of applause of how many of you have eaten striped bass fresh from the Chesapeake bay? Yeah?

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How about blue crab?

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And in fact, the bay– this is amazing– produces around 500 pounds million pounds of seafood every year. It is one of the most productive bodies of water in the world. Yeah, you can applause for your bay.

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But if you live here and you know this, that the bay is constantly in flux due to overfishing, pollution, climate change, the works that’s going on over there. And scientists have a plan that will conserve the bay’s biodiversity, support the people who rely on it, and keep us all well fed. And one piece of the solution is oyster farming. Let’s hear it if you love oysters and you want to see [INAUDIBLE].

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Great. My next guests are here to discuss the bay’s history and how food production and conservation go hand in hand. Let me introduce them. Imani Black, aquaculturist and grad student at University of Maryland’s Center for Environmental Science. She also founded the nonprofit Minorities in Aquaculture. Dr. Tara Scully, biologist and associate professor right here at the George Washington University in Washington DC. Welcome to Science Friday.

[CHEERING]

IMANI BLACK: Yeah. Thank you for having us.

TARA SCULLY: Thank you for having us.

IRA FLATOW: I hear that– Imani, that you and Chesapeake Bay go way back. Is that right? Tell me about that.

IMANI BLACK: Yeah, something like that. Well, I grew up on the eastern shore of Maryland, and so I just have been around the Chesapeake Bay for a while. But in my family’s genealogy, we can trace back watermen in our family to the early 1800s, so yeah. A long time. Skipped a few generations before it got back to me, but yeah. We still brought it back full circle.

IRA FLATOW: And Tara, what about you?

TARA SCULLY: So I haven’t lived here my whole life, but I grew up in Connecticut. I’m one of nine kids and I have 28 first cousins. And I think that growing up, the most important thing to our family was getting out into nature, especially my mom and dad– who are in the audience– they brought us across the street to go collect blueberries, and to go collect fiddlehead ferns, and we had a huge, urban garden back when urban gardens weren’t a thing.

I then moved to New Orleans and got hooked. I got hooked on looking at the natural environment and seeing how we’re impacting it. I had an amazing professor, Dr. White, who was so impactful that, when I moved here, I wanted to do something. And actually, I owe it to my brother, Sean, who actually said we should do something. And I was like, yeah. You’re right. We should do something. And so I started working with the Chesapeake Bay Foundation. And so that’s how I got involved.

IRA FLATOW: Did you actually move on to the bay?

TARA SCULLY: Well, we have a family house down there, and so we started to help the bay by growing oysters ourselves, but donating them back to the Chesapeake Bay Foundation for their programming.

IRA FLATOW: Now Imani, you’ve worked on an oyster farm before.

IMANI BLACK: Yeah.

IRA FLATOW: How do you take care of a bunch of oysters? What do they want?

IMANI BLACK: Well, really they’re just glorified rocks. Like, they just– [LAUGHS] they don’t really give you a fuss. They don’t really give you a fight, so they’re pretty easy, especially in their adult stage. So my experience I’ve experienced from all the way from the beginning when they’re babies until they’re on your dinner plate. But they’re really wanting to have good water quality, good salinity, good food access, right? So the oysters eat microalgae, so that’s always available in the water, but especially during the summertime.

IRA FLATOW: They’re filter feeders.

IMANI BLACK: Yeah.

IRA FLATOW: So they filter the water.

IMANI BLACK: They do.

IRA FLATOW: They clean it.

IMANI BLACK: Yeah.

IRA FLATOW: Wow. And then you eat the oyster that’s filtered out all that stuff–

IMANI BLACK: [LAUGHS]

IRA FLATOW: –out of the water.

IMANI BLACK: Yeah. We get that question a lot, but they only– they kind of break down the particles. And so by the time that they get into their digestive tract, they’re not harmful anymore.

IRA FLATOW: Let me ask you– because I think a lot of people may be wondering. What’s the difference between an oyster and a clam? Because they’re both shellfish.

TARA SCULLY: They are bivalves, so we don’t have a prop, but– so it’s a certain group of organisms that they form a shell that have a hinge to them. And so they have a soft body inside. Yes, it’s a glorified rock [LAUGHS] to a certain extent, but inside all of them are filter feeders as bivalves. And so they’re the ones doing the job. Oysters, mostly because their population is so huge in the bay and historically they’re the ones who have been the dominant species, that is the filter feeder.

IRA FLATOW: How does the oyster market for oysters compare to other seafood like striped bass, things like that, Imani?

IMANI BLACK: Yeah. We were just talking about this off stage, and it’s actually one of the highest, right?

TARA SCULLY: Yeah, so in comparison pound for pound, the oysters actually go for about the same amount of money, but most of the oystermen are now farming, so they’re doing aquaculture instead of taking the oysters from the natural environment. And so that means that the natural populations are still there to filter. Whereas for the striped bass, we’re taking the natural population out of the bay, and so that affects the other organisms in the bay, because it’s a food web and they’re part of that food web.

IRA FLATOW: You mentioned how good that the oysters are at filtering, Tara. How much water do they filter a day?

TARA SCULLY: An adult oyster filters 50 gallons of water a day.

IRA FLATOW: 50 gallons?

TARA SCULLY: 5-0, yes.

IMANI BLACK: And that’s a two inch oyster, two to three inch oyster.

TARA SCULLY: Yeah.

IMANI BLACK: It’s not that big.

TARA SCULLY: Yeah.

IMANI BLACK: Not big at all.

IRA FLATOW: Any way to come up with a wild guess of how many oysters there are in Chesapeake Bay?

TARA SCULLY: Well, I know that it’s– right now it’s at 1 to 2% of the highest ever counted, so it’s a very low population in comparison to historically, but the good news is, in the past two years, we’ve seen the counts of juveniles go way up. They’re at four times the amount that they have been in the average of the past– I think it’s 38 years.

IRA FLATOW: And why is that?

TARA SCULLY: Because of restoration. [LAUGHS]

IMANI BLACK: Yeah. Restoration, oyster farming, so yeah. Let’s give a round of applause for the oyster. Yeah.

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[LAUGHS] There’s a lot of efforts that are happening right now, and there’s a lot of misconceptions about aquaculture and oyster farming in general, but it actually, just like Tara said–

IRA FLATOW: Not yet. No, you can’t say that without telling us what the misconceptions are.

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IMANI BLACK: Well, OK. So I think that for oysters specifically– because there’s multiple different sections of aquaculture, but for oysters specifically I’ve heard that there are genetically modified, that we put harmful chemicals in them and different things like that. And so I’m here to set the record straight by just saying that it’s natural selection. We just pick the best ones that survive in the saltier environments, or the less salinity environments, or the more brackish environments, and then we just keep breeding them. So they’re really like families that we get really good, viable oysters that are actually susceptible to the common oyster diseases.

IRA FLATOW: Years ago, I would never have thought you could have conspiracy theories about oysters, but these days, anything.

IMANI BLACK: Yeah.

IRA FLATOW: What else, Tara, do they do for the bay besides clean it up?

TARA SCULLY: Well, they’re also a foundation species. And what that means is that they establish a habitat for all the other organisms in the bay. Just like a coral reef, I think the oyster reefs are more amazing than coral reefs. I know that they get– they’re prettier or whatever, but they do support an entire habitat for different organisms to come and breed, to come and live. There’s even like the most amazing crab ever called the ghost crab that lives inside the shell with the oyster, but doesn’t harm it and actually helps to protect it. And it’s really neat, and so there’s a lot of different organisms that rely on the oysters in order to survive.

IRA FLATOW: Are there oyster reefs that–

TARA SCULLY: Yeah.

IMANI BLACK: Yeah? They protect the shorelines like coral?

TARA SCULLY: Yes. So Manhattan used to be surrounded by oyster reefs. The whole island was surrounded, but, of course, that’s not really good for shipping and development. So over the years– just like down here in the bay– they destroyed all the reefs, because they needed to get access to the land.

IRA FLATOW: And the population now, as you say, is healthy. It’s on the increase.

TARA SCULLY: It is. It’s not– we’re about to get from the Chesapeake Bay Foundation our– I think they do it every two years, the state of the bay report. And I’m hoping that it’s going to show that we’re definitely coming back and recovering from a lot of the issues that we have caused. But the Chesapeake Bay Foundation, the Oyster Restoration Program, all of these different organizations have gotten together in a coalition to help to place reefs in different tributaries that they think are important to restore, and I think now they’re up to nine out of 11 targeted for 2025. And so they’re hoping to get all 11 by the end of 2025.

IRA FLATOW: Wow. Wow, that’s great. Now Imani, I know that you’re wrapping up your master’s thesis. Congratulations.

IMANI BLACK: Yeah. Thank you. [LAUGHS]

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IRA FLATOW: Everybody’s rooting for you. What are you studying?

IMANI BLACK: So I am studying ecological anthropology of the Chesapeake Bay, so specifically I’m interested in how socially and culturally we’ve changed on the Chesapeake Bay and how that relates to what’s happening ecologically. So specifically, my title– or not the title, but just the overall topic is the historic African-American contribution in Chesapeake Bay commercial fisheries, because our Indigenous tribes were a huge part of creating the commercial fishing industry and so were African-Americans.

And so for a very long time, it wasn’t a high commodity to live on the water. It was actually a poor man’s thing to live on the water and eat seafood. And because of the enslavement era, African-Americans were pushed to the water’s edge. And so historical folks that we know– Harriet Tubman, Frederick Douglass– actually used their maritime skills of being on the water to escape slavery. So it’s been a huge, significant piece of our cultural heritage as African-Americans, and so there’s a lot of documents, people, accomplishments that have not been told before, and so I’m hoping to do that with my thesis.

IRA FLATOW: Has there been a decline in African-American oyster?

IMANI BLACK: Yeah, so there’s actually only 12–

IRA FLATOW: Only 12?

IMANI BLACK: Living Black captains on the Chesapeake Bay today, and they’re all over the age of 60 with no real push for the next generation to come behind them right now. So right now, it’s said that I am the only African-American female to be working in oyster farming from Maryland to Texas, which is insane. Insane.

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TARA SCULLY: Wow.

IRA FLATOW: When did we see that exodus from the business?

IMANI BLACK: Well, you got to wait for my thesis, because that’s like the chunk of it.

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Yeah, that’s the whole thing.

IRA FLATOW: I need a copy.

IMANI BLACK: Yeah, yeah.

IRA FLATOW: Send us a copy Tara, is there a new wave, Tara, in aquaculture happening now? Is things on the increase?

TARA SCULLY: Well, I think there’s not only a new wave, it’s a new thinking around the ownership of the land. I think a lot of oystermen originally thought they owned the space where the oysters were growing. Nowadays, like the Rappahannock Oyster Company, which were two cousins who had parents who were both oystermen, they went to their parents and they’re like, listen, we need to do things differently. We can’t keep on doing things the same way.

So they really focused on doing aquaculture instead of harvesting even though they could, they had the rights to do it. And now, they’re a huge company and they’re very successful. And I think that that’s the wave that we’re seeing is more young people want to get into this type of either vertical or horizontal type of aquaculture. It’s much easier and it’s not having that negative impact on the environment. And even it’s helping because you have those filter feeders in the water that are helping to filter. [LAUGHS]

IMANI BLACK: Yeah, I was just about to say. One oyster farmer annually puts out two million individual oysters a year, so– and imagine we have thousands of oyster farms in the Chesapeake Bay. And so even if those oysters are in the water for a week, or a day, or whatever, they’re still filtering 50 gallons of water a day. So oyster farming is actually kind of really helping in that really getting them back into filter feeding.

IRA FLATOW: And we talked about conspiracy theories about what’s going on with oysters, but can, Tara, genetically engineering make the oysters grow more efficiently?

TARA SCULLY: Well, we have– actually, Dr. Allen, who just– he retired I think three years ago, yeah, from the Virginia Institute of Marine Science. He actually created the original triploid oyster.

IRA FLATOW: Triploid oyster.

TARA SCULLY: And what that means is you have three sets of DNA. You and I and Imani all have two sets from your mom and dad, but the way he did– he did several different techniques, but ultimately what he did was he figured out a way to have a tetraploid, which has four, and then a diploid have a baby. And it’s because the tetraploid can give two sets of their chromosomes, and that’s a male, and then the female gives one set, and then you have a baby that has three sets.

And so the reason why that’s important is because they’re infertile, which sounds weird, but this means that it grows faster, it’s not susceptible to disease like the normal oyster is, and it grows to market size much quicker because it doesn’t have to reproduce. So the reason why you can’t eat oysters during the months without an R is because they’re putting all their energy into making sperm and eggs. And so they shrink up, and they’re making their sperm and eggs, and they don’t taste as good. These you can eat all year round. And so that’s another benefit of aquaculture.

IRA FLATOW: Are they actually growing them out in the oceans?

TARA SCULLY: Yeah.

IRA FLATOW: Yeah. Wow, and hopefully they’ll take over more of the population?

TARA SCULLY: Well, these are the aquaculture oysters. These are the ones that we’re growing in aquaculture.

IRA FLATOW: I see. And Imani, what inspired you to get into writing your thesis and founding Minorities in Aquaculture?

IMANI BLACK: Yeah. Well, I didn’t expect to do either, but 2020 had different plans, and so I just kind of took the opportunity. I wasn’t expecting to do it at the same time, but they sort of kind of cascaded, and I really kind of– after being an oyster farmer for six years before starting both, I had to be really intentional about, well, I’ve got this beast of a train that’s moving on with Minorities in Aquaculture. I need to think of a thesis project that is really going to tie into that so I can be efficient on reading. There’s a lot of reading in master’s programs, so I was just trying to cut that down in half really.

[LAUGHTER]

IRA FLATOW: I was going to ask you how fast you can shuck an oyster, but I’m going to–

IMANI BLACK: Oh, I got a video in the back. You want to see? It’s like five seconds probably.

IRA FLATOW: Five seconds?

IMANI BLACK: Yeah. I can’t do that consistently. I’m not doing any shucking contest, but I was just saying to Tara I should have had like a little basket of shells. I should have just like been, anybody want a shucked oyster? Shucked them and thrown them out there, because–

IRA FLATOW: Wow. Wow.

IMANI BLACK: I can be efficient when I need to be.

[LAUGHTER]

IRA FLATOW: I’m afraid to ask this next question now, but what do you want our audience to take home tonight, to know about their seafood? What should they take home in the message?

IMANI BLACK: Yeah. I think for me, just know where your seafood is coming from, right? Local seafood is how you become more sustainable. That’s the buzzword with people in our food security is sustainability. The way to be more sustainable with your seafood, one, eat more oysters. Oysters are the most sustainable protein on the planet compared to beef, chicken, all the things. So eat more oysters.

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Second, just know where your seafood is coming from. Get it from a local source. Really shake hands with that person so that you can say for yourself that you understand how it’s being produced, how it’s being harvested, and you can be OK with that, and you can support that in any way that you want to.

IRA FLATOW: Great final message. I want to thank both of you for taking time to be with us today. Imani Black, aquaculturist, grad student University of Maryland Center for Environmental Science, and Tara Scully, biologist, associate professor at GWU here in DC. Thank you, again, both for coming in.

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