Let’s talk about fishery science! Join me in my conversation with Mandy Karnauskas, a fishery biologist with NOAA Fisheries and long-time resident of Miami, Florida. We cover Mandy’s love for fish from a young age, the many interconnected components of a fishery ecosystem, climate impacts and red tide in the Gulf of Mexico, and how exactly science gets translated and used in managing fisheries.
Welcome to Fish & Us: Climate Stories from the Waterfront. This is a podcast series of recorded interviews and stories about the impacts of climate change on marine fisheries, as told by the people who spend their days catching, managing and researching fish from the ocean. In today’s episode we talk to Mandy Karnauskas, a NOAA Fisheries scientist at the Southeast Fishery Science Center living in Miami, Florida. I'm Alliyah Lusuegro and this is a production of Ocean Conservancy.
If you ever wondered how exactly people determine what makes something sustainable, such as quotas and catch levels in sustainable fisheries, this is the episode for you. Research and scientific data are a huge part of this process and is our topic today. In fisheries, providing information - like stock assessments, which Mandy will talk more about - guides fishery managers to set policies with the goal of supporting fishing in the long-term.
Connecting with Mandy was so exciting to me because, like her, I’ve loved science since I was a child. In first grade, I remember nerding out about the metamorphosis unit with butterflies in our classroom. I was so curious about how in the world a caterpillar turned into a cocoon turned into this beautiful flying creature. From then I did scientific research in my home city of Chicago as my first ever job at 16 years old, and here I am now leaning into social sciences and science beyond the Western paradigm.
Keep on listening to hear Mandy and I talk about our love for science and the role it plays in fishery management. We also touch on the changes she’s seeing in her home, in the Southeast region of the U.S.
Let’s get right into it.
So I'm Mandy Karnauskas, and I'm the ecosystem science lead at the Southeast Fisheries Science Center. And we are part of NOAA Fisheries, and our center provides the scientific advice and data that are needed to effectively manage the living marine resources in our region. And we have a bunch of labs throughout the Southeast U.S. region.
But I'm in Miami, Florida, and I've been in my position for a little more than a decade, which could seem like a long time. But there's really such an incredible institutional knowledge at the center that oftentimes I still feel like I'm new.
So what's your relationship with the ocean since it's right there and or like the marine environment, have you lived close to the water for some time or has it been your whole life?
Yeah, so I've been in Miami for the last sixteen years, but I actually grew up in a landlocked area outside of Chicago near suburbs and farmland. So I actually didn't see the ocean until I was about seven years old. And I can really vividly remember my first interactions with the ocean, the first time I saw an estuary, the first time I saw a kelp forest.
It was until I was an undergraduate that I first saw coral reef for the first time and, you know, just being really fascinated by that. So yeah, I spent a long time away from the ocean and not seeing it very much, but I feel like now I'm making up for lost time. So definitely very close to the ocean now.
And I've lived very close to the ocean for the past 20 years. And I'm definitely out on the water every chance I can get.
So yeah, you talked about coral reefs and like kelp forests, and seeing the ocean for the first time, is that when you knew you were like, oh, maybe this could be like something that is like my future career? Or did it just maybe happen later on organically?
Yeah. So I think I have always been a budding fish biologist from a very early age. I've also, I've always had this strange obsession with fish. I was a pretty nerdy kid, and I grew up and had all these aquariums throughout my house. And I would actually when I was little, I would go to the pet store and I would search out all of the sick and near dying fish, and I would bring them home and try and nurse them back to health.
That was one of my biggest hobbies. And I remember by the time I was in middle school, I had like all these volumes on just fish diseases, and I would read them and carry around these books with me. And I would also keep all these detailed medical records of my specimens. My mom just sent these. She found them in a closet and she sent them to me a couple of years ago.
So I have all these notebooks of all these, you know, records of my sick fish. So looking back, I think I was a pretty weird kid, but I guess it's kind of telling in terms of how I got to where I am today as a fish biologist. I've just always loved fish. So nowadays I mostly enjoy fishing and eating fish, but I still do have one aquarium.
You're saying it's weird, but I think that's pretty cool. Like, I would have thought that you were awesome and just like to nurse those like fish back to health, I think that's a pretty cool hobby too. That takes commitment and dedication and I could see how like that, like love for fish started at a young age.
And then you fish now. Like who taught you or did anyone teach you? Like, did you teach yourself?
Yeah so I learned to fish a lot in doing work in the Caribbean. I lived in a few different countries in the Caribbean and did field work for my graduate dissertation so a lot of my fishing skills come from working with fishermen in those regions and having them teach me how to fish.
But I'm guessing it was beautiful to, like, learn how to fish there in the Caribbean?
Yeah, they actually fish with handlines, yo yos. And so I'm actually pretty good at fishing with a yo yo or there they even just use a Coke bottle and just grab the line around anything really. So I'm pretty good at that. And have hauled in some barracudas and things on handlines, so. But yeah I'm not much good with a rod.
And then at some point you studied or you chose to study fisheries science. Was there any doubt with that or was it like, oh, I'm going to go for this because it's been like a lifelong passion of mine.
Yeah. I'm not sure I got really interested in fisheries when I was in my undergrad, and that kind of got cemented when I went to the Peace Corps. So when I graduated with my undergraduate degrees, I had degrees in animal science and biology, and I made the decision to apply to Peace Corps. And I knew I was interested in fisheries.
So I requested that and I was specific in asking for that. And I ended up going into their environmental program and I ended up serving in a fishing community in Haiti, just a couple hours north of Port au Prince. And then following that experience I did some similar work with fisheries in the Dominican Republic and then later in Belize.
And so that really cemented my interest in fisheries. It's really fascinating to study the marine management issues that they have in all these diverse places and all the sticky challenges that surround those.
Which brings us to where you are right now at the Southeast Fisheries Science Center, where you said you’ve been for a decade! That’s awesome. How do you feel like it’s changed, or maybe stayed the same, since when you began there?
Yeah. How are things at the center have changed? There's definitely been an increasing focus on what we call ecosystem based fishery management, just trying to look at fisheries systems in a more holistic way. There's also been increasing focus on climate and what we can expect to see and climate resiliency and needing to build that. So we've definitely seen some increased focus on that in the past few years.
And since you're talking about you being the Ecosystem Science Lead at the Southeast Fisheries Science Center, what are fisheries science centers? Like, how do they work?
So, NOAA Fisheries Science Centers essentially provide the scientific advice to guide marine fisheries management in their respective regions. And so the principals, sort of the customers that we serve as science centers are the Regional Fishery Management Councils and these are government appointed bodies that decide on the regulations that are put in place for fisheries.
So in the southeast region, we actually have more councils than any other region. We provide scientific advice to the Gulf of Mexico Fishery Management Council, the South Atlantic that goes from Florida to North Carolina and the U.S. Caribbean. And we also provide advice to the Atlantic High Seas through ICCAT, which is the International Commission for the Conservation of Atlantic Tunas.
So we really have a ton of area to cover in the Southeast, essentially from Texas to North Carolina. And then all the way across the pond to Europe and Africa. And in addition to that, we do science that allows us to meet other legal mandates like the Endangered Species Act and the Marine Mammal Protection Act.
Wow, that's really cool. I didn't know, I thought the partnership there was only with the Gulf Council. I didn't know it's in the Southeast, or sorry, the South Atlantic and the Caribbean. And even more, it seems international?
Yeah, we have a lot of ground to cover. So we do science and provide stock assessments for all those management bodies and other types of scientific information as well.
And you just said stock assessments. So what are they and why are they important?
Yeah. So stock assessments are basically a mathematical representation of biological populations. And so we at NOAA Fisheries and other partners, state academic partners, collect data on these populations. So for example, we collect data on growth, on reproduction, what the age structure looks like. We do surveys to look at trends and abundance over time.
And so we put all that data together in a mathematical model that recreates what the population looked like in the past and then how that population has responded to various levels of fishing pressure and then once we have that understanding of how the population responds to fishing pressure and get a sense for how productive it is, using those mathematical relationships we can figure out what level of fishing effort allows us to maximize the catch that can be extracted from the ocean sustainably over the long term. And we call that value that long term catch level, the maximum sustainable yield.
And by law, by the Magnuson Stevens Act, the Fishery Management Councils are required to try and keep the fish populations at that size where you have that spawning population that's going to produce that maximum sustainable yield.
And the councils are required to not allow fishing effort to exceed a level that's sustainable over the long term. So essentially the stock assessments provide the scientific guidance to help the Fishery Management Councils ensure that the regulations are in line with the laws.
That was great. Like that was such a great explanation. One of the best explanations I've heard about just maximum sustainable yield and how that works.
And then lastly on this topic, so “ecosystems” is in your role. And I just wanted to ask what are the parts that make up a fishery ecosystem?
Yeah. So the possibility is kind of endless there. There's so much that can be included. There's everything from the, you know, physical components, what the background environment is doing, the currents, the water properties, the temperature or the water chemistry. And then you have the biological components, which in the marine ecosystem includes everything from tiny plankton to fish to whales.
And then sometimes forgotten are the human components and not just the people and the fishermen themselves, but also the social and the economic forces, the communities that people live in and the governance structures. All of those things shape and are important parts of the fishery ecosystem. So, you know, probably sounds kind of cliche to say that fishery ecosystems are incredibly complex, but really they truly are.
I'm often surprised in doing analyses of ecosystems, how something seemingly external to the system can have a kind of profound impact on the ecosystem systems.
Speaking of ecosystems, I'm interested in hearing more about the one at the Gulf of Mexico. What are some of its characteristics and what distinguishes it from other marine bodies?
Yeah, so I've traveled around the region, Gulf and Caribbean, a bit, and each area has its unique traits. But the Gulf of Mexico is a pretty different place, especially compared to the other ecosystems that we manage in the United States and federal fisheries. So the Gulf of Mexico is pretty diverse, both in its biology and also in the people and the communities that depend on it.
We have a lot of different species of economic and recreational interest, and there's also a lot of different types of communities pursuing the resources so like on the commercial side, you know, we have communities that primarily fish to provide seafood to others and make a living off of marketing commercial fish. There's also communities that are dependent on the fish for subsistence or for traditional cultural activities.
And on the recreational side, it's also very large and diverse in the Gulf of Mexico. Actually, the Gulf alone accounts for about half of all the recreational fishing in the entire United States. So we really have a lot of recreational fishing here. And, you know, that includes everything from the tourists who visit occasionally out in the water and have fun to the really avid anglers who out there almost every day and there's just a lot of diversity in the kinds of experiences that recreational anglers seek on the water and kind of how they relate to the resource as well.
And then the Gulf is also really unique in that it's an industrialized environment. So there's a lot of energy production, there's shipping. Some of the major ports in the US are in the Gulf of Mexico.
There's tourism, there's a ton of people moving to this region now, and there's a lot of population centers in Gulf communities that are growing at a much faster rate than elsewhere in the country. And of course, you know, with all these people coming, human development brings a whole host of pressures in itself. And so the fisheries have to compete with a lot of user groups outside the fishing industry.
And I think that these competing uses, you know, exist in other ecosystems, but probably not to the extent that you see in the Gulf of Mexico.
Something that's sticking out to me is that it's a region where recreational anglers come and it's so popular. Do you know why that is? Like, is that the fish that's bringing them here? The climate? Like the culture? Can you talk more about that?
Yeah, that's a great question. I think all of the above that you mentioned, the diversity of fisheries that the Gulf of Mexico offers, you know, everything from onshore to offshore fisheries. The culture, there is a lot of fishing culture. It’s very important in a lot of the communities. And then the climate as well. I mean, it's warm most of the year.
You can be outdoors year round in a lot of the Gulf communities. So I think that that definitely helps draw tourism and recreational fishing to the region.
So Mandy, you mentioned the word climate and that’s something I want to talk about except with climate change. And I wanted to ask you how does climate change show up in your life, in your day to day or how does it show up in your work?
Yeah, I can first talk about how it kind of shows up in my day to day. And so, climate change is a pretty gradual process. And I think it's tough to say that you see day to day changes, but certainly over the span of decades, you know, I've been biking to work or grad school on the same island for the past sixteen years.
And I bike along Biscayne Bay and I've had the same route every year. So I have noticed some changes over the past sixteen years that I've been here in Miami. We definitely see more sunny day flooding and erosion and shifting coastlines in recent years. You can see the impacts, the infrastructure. You know, there's some businesses that go by that are no longer in existence because they've been knocked out by some of the major hurricanes that we've had.
You can see them in the biology, the manatees and the eagle rays that we spot under the bridges and sort of the seasonality of their appearances and some changes in their behavior that are probably related to changes in the environment.
You can even notice the changing composition of the wrack lines along the beach. For example we have a lot more Sargassum now than in the past. It’s brown algae, and it piles up on the beaches and it even has a really distinct smell. I feel like the smell of the beaches has changed over the years because you get these pile-ups that you didn't used to see. And even like the color of the water.
I remember some years ago we had a seagrass die off and then it was a really windy day and the water changed this color like the color of toothpaste and it was just really distinctive. I remember biking and looking at it. So, you know, in terms of climate change, it's really tough to tease out whether climate change is the principal cause of all these things or exactly what role it plays.
But you do see changes and certainly the gradual sea level rise and the increasing water temperatures that we have here. And, you know, the severe flooding events impact our water quality. And so these things probably play some role in the day to day things that we see here.
Could you talk more about a prominent example of a climate related event or issue that's taking place in the Gulf? And also, could you go into how it's impacting the fisheries there?
Yeah, I can maybe talk more generally about how climate impacts our day to day at work. So, you know, again, we see some very gradual changes. For example, I hear a lot of talk about perceptions that migratory patterns of fish has changed. And this is probably in response to changing temperature patterns. And we definitely have some fishing communities that are being heavily impacted by things like sea level rise and land loss.
This is particularly true in Louisiana where you have the compounded effects of, you know, not just sea level rise but land subsidence, reductions in sediment load from the construction of dams. Oil spill damage to the marsh habitats that then leads to erosion. So we do see those gradual changes.
But from a day to day perspective at work, you know, one of the things that I find particularly overwhelming is the number of extreme events and disasters that NOAA Fisheries has had to deal with lately.
So if you look, for example, at the number of federal fishery disasters in the southeastern U.S. alone, in the past decade, there's been 14 fishery disasters declared as opposed to only five in the 2000s and six in the 1990s. And what these disasters are, they're defined by when there is a large unexpected decrease in the fish populations or some other change that results in loss of access to the resource by fishermen.
And so these are things like major hurricanes, severe flooding that caused a lot of freshwater input into the marine environment, causes damage to fisheries or harmful algal blooms. And then by law, under the Magnuson Stevens Act, NOAA fisheries is required to conduct impact assessments to determine the economic losses to the industry. So these kinds of extreme events, you know, impact the day to day at NOAA Fisheries because we have to respond to these disasters that increases our workload.
You know, we have to be responsive, not just from a legal standpoint but also from a scientific standpoint. And these severe events also complicate how we give our management advice because when you have a sudden change that’s impacted a fish population or the fishing industry, you have to account for those changes in model predictions that are used to inform future management advice and if it's something that's unprecedented and we haven't seen it before, it's really difficult to predict what the impacts of that event are going to be.
And then something I'm seeing in the media these days a whole bunch is Red Tide. Could you tell me more about Red Tide? When did this start becoming, I guess like more noticeable and yeah, just becoming an issue of note?
Yeah. So Red Tide is an issue that we've had to deal with that is, you know, potentially linked to climate change. And with a lot of these severe events we don't know to what extent climate change is causing these events to occur. But certainly the increasing frequency of extreme weather events is consistent with what you would expect with the observed increases in temperature. So the linkages with climate change aren't quite so clear.
But I can talk about red tide which is a big issue for us as the red tide is a type of harmful algal bloom in the Gulf of Mexico, and it's caused by a microscopic organism. Karenia brevis is the scientific name, and that organism produces a toxin that attacks the nervous systems of marine organisms and humans too.
And it's common in the Gulf of Mexico, it's always floating around. But there are certain conditions where it will reproduce and accumulate in large quantities and then it forms these toxic blooms that that's what we know is red tide. And then those toxins are released in the water and they can also become airborne and impact human health when people breathe in the toxins and red tide blooms have been occurring for hundreds of years.
I mean, there's historical records of severe red tide events, you know, hundreds of years ago. But some of the science that NOAA Fisheries has done recently suggests that Red Tide really started becoming an issue, at least for the marine ecosystems offshore and the fisheries that we manage, when these blooms are unusually long or severe and when they're associated with low oxygen zones at the bottom of the ocean. We see these along the west Florida shelf now.
We call this condition hypoxia when the bottom of the ocean is devoid of oxygen. And so what we found is that we see a lot of fish mortality in these years where you have hypoxia present and so what we think is that it might not just be the red tide blooms, but also the hypoxia that's impacting our fish populations.
And which fish populations are being impacted? Do you know of any specific ones?
Yeah. For the offshore federally managed fish populations that NOAA Fisheries studies, it mostly seems to be an issue for grouper populations, so red grouper, gag grouper. And it could be that they're either more sensitive to the toxins or they're just less adept at getting out of the way when the blooms come along. So our analyses that NOAA Fisheries has done has estimated that in really severe red tide years we can lose as much as 30% of the grouper populations in one year.
So it's really impactful. And when Red Tide is near shore, it also kills off a lot of forage, bait species. And so there's probably some impacts to the entire ecosystem although we haven't really measured these yet. And some of the work that we've done with our collaborators also shows that red tide impacts human economies. You know, through losses in tourism, there's missed opportunities for aquaculture, reduced real estate prices.
So it's not just an issue for the fish but also for the humans.
And so how are we addressing this issue right now? By “we”: the agency, the government, like anyone who has a role in this, what are the actions and policies taking place?
Yeah. So, you know, obviously getting rid of red tide would be the optimal solution. Everyone doesn't want to see red tide. But we know that the blooms are to some extent naturally occurring. And it's not clear how much we control them through human actions. And at minimum, that control is not under the jurisdiction of NOAA Fisheries or fisheries managers.
We provide advice for fisheries management, just, you know, fish populations, but we don't have jurisdiction over things like water quality or nutrient input. So, in terms of how to address red tide, that would be a much bigger question and it would require collaboration across agencies, which does occur. But what NOAA fisheries can do and under our control is to work with industry members to help them adapt to red tide.
And the same could be said for any of these other external stressors, you know, hurricanes, freshwater inputs, we don't control them but we can help industry members adapt. So for example, red tide is really patchy and there's areas just outside the blooms that are perfectly suitable for fishing. So with better monitoring and prediction of where the blooms are occurring, NOAA Fisheries can help the industry respond so that they're not wasting a lot of time searching for suitable areas.
We've also done some research looking into resilience, trying to understand how people keep their businesses afloat when these severe events come along. So for example, they might respond by moving their boats to different areas, shifting target species, shifting gears, or even temporarily leaving fishing and just coming back when the conditions resolve. So the more that we can understand about these events and the things that help people become resilient to them, the more NOAA fisheries can help the policymakers set regulations that allow people to adapt.
Awesome, yeah. And I like that you're connecting the work that you're doing in the science to like working with industry members and working with the people who are affected. And also working with management and the councils on that? Like, could you speak more to that?
Yeah. So, you know, there's a process for how our science enters the management cycle. And again, our primary management body that we deal with are the Fishery Management Councils. But most management bodies, like the Fishery Management Councils, have an advisory panel that helps them distill the science into suitable policy actions because the management bodies aren't necessarily composed of people of scientific background.
So for example, for the Fishery Management Councils, they have what are called scientific and statistical committees. And so most of the science that we produce at the science center will initially go to that group for review and then that committee makes recommendations to the council as to whether or not the science is robust and how it should be used.
And then the Fishery Management Councils take that information and use it to guide policy. So those policies you know, can include things like setting a catch quota, how many fish can be taken out of the ocean in any given year, what sizes of fish are allowed to be caught, designation of protected areas and closed seasons and other management measures with permitting. And so once those regulations get codified into law, they go to NOAA's regional office to be implemented.
So we have a partner regional office that's located in Saint Petersburg, Florida.
Awesome. Thank you. And then to connect it a little bit. You talked about quotas and like catch levels. And then going back to when you were talking about maximum sustainable yield. So you would give them that information and then they would produce policies out of the scientific information that you give them or the stock assessments?
Yes, exactly. In the stock assessment we basically forecast the stock dynamics, the fish population dynamics into the future, and then we're able to calculate what levels of catch the population can sustain without it being overfished and keeping it at that optimal level where it's producing the maximum sustainable yield. So yeah, that's how the stock assessment information would translate into management, although there's different considerations that have to be taken, there's some buffers to account for scientific uncertainty.
So obviously, you know, we don't know the exact information or the exact answer for how many fish can be taken out. So there's some uncertainty around that and that has to be taken into account. And then there's also management uncertainty. So how precisely the managers can actually control what's being taken out, how it can be monitored throughout the year to make sure that there's no overages.
And so the stock assessment will give the catch quota advice. And then in the advisory panel and council process, they would decide on, you know, appropriate buffers to reduce uncertainty or reduce the catch in light of that uncertainty.
Talking about science and management, and you also like kind of hinted at this earlier where you work with industry members in the context of red tide, I wanted to ask how do we effectively apply research and science to make our fishing and coastal communities resilient to climate change?
Yeah, I don't know if I have an easy answer for that one. I think that a lot of the work still needs to be done to figure that out. And obviously this is an area of research that has really come into focus in the recent years.
But I think that, you know, probably a key element of figuring out how we make fisheries and coastal communities resilient to climate change is recognizing all the linkages that occur, especially between the biological communities and the human communities. So what fish populations are doing in space and time greatly impacts how people, the fleets target them and then changes in fishers’ behavior and how people prosecute the resources then also create changes in the fish population.
So there's a lot of interrelationships between the humans and the biology and the fish that need to be recognized. And I think the more that we can recognize how all those pieces are interlinked, you know, the better we can assist management with more precise science and better predictions. And in finding ways to create resilience for both the fish and the fishermen.
Yeah, I really like that, like recognizing those relationships and like that is what the ecosystem is all about.
Do you have any final words?
When it comes to trying to solve these really complex and sticky issues, I think it's good to remember that there's something to learn from everyone. And I'm a big believer in that philosophy. So, you know, I think often in the sciences and elsewhere, we look to collaborate with people who look like us and think like us.
And we tend to shy away from working with people who we think might strongly disagree with us and I think that's really a disadvantage to the science because, it's only by talking to people who don't think just like you that you get the opportunity to revisit your basic assumptions and question those assumptions and think about new ways to do things and potentially learn something new so, you know, my final words would be whether you're a scientist or in some other profession, I think it's really important to seek out meaningful conversations with people who are different from you.
Because you’ll probably learn something that makes you better at your work or just makes you a better citizen of the world. And at least that's been my experience.
Thanks Mandy! I’m also a big believer in the philosophy that we can learn something from everyone. From you I learned how fisheries science centers work, about red tide and the importance of linking people, and fish, and the environment into science which gets reflected into policy and management.
You can learn more about the Southeast Fishery Science Center by heading over to the NOAA Fisheries website at fisheries.noaa.gov.
Lastly, I want to give a shoutout to Nicole Dornsife of thornwolf.com for our logo design featuring photography by Rafeed Hussain. And we thank 4Site Interactive Studios for all of our editing magic.
This is Alliyah signing off, till next time.