Here We Are: What Makes Us Human

60. Melissa White [Fish Virology]

• Joy Bork • Episode 60

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Today's episode is brought to you by....SCIENCE! Put on your imaginary lab coats, and let's learn all about fish virology!

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Joy Blue:

Welcome to Here We Are. The podcast where we celebrate the beauty of being a nerd by learning about nerdy things from fellow nerds. I'm your host, Joy Blue. Okay, we gotta talk about this. I didn't know that today's guest nerd existed until just a few weeks ago. And now that I know, I have a new fascination and respect for not only aquaculture, which was a word I learned from this podcast, but virology. Today we are going to take a virtual tour of science at work. Put on your imaginary lab coat and let's get to work. So without further ado, here's Melissa White to talk with us all about fish virology.

Melissa White:

Hello, I'm Melissa White. I live in Oregon and I'm a scientist and I work with fish viruses.

Joy Blue:

That is amazing. So Shannon, who was on the podcast two weeks ago, introduced Melissa and I and said, Oh, you need to talk to my friend Melissa. She does fish viruses. And I was like, Excuse me, what?

Melissa White:

Yep.

Joy Blue:

I need to know everything. We're talking about fish viruses. What's the technical? Is it like fish virology?

Melissa White:

So my position is a fish virologist slash fish health specialist.

Joy Blue:

Okay. How does one get started in fish virology?

Melissa White:

Yeah. I've found myself in a unique little corner of science. I started with a microbiology degree. And then I decided I wanted to go to grad school, got a cellular molecular biology degree in the Midwest, so Kansas City area. And then I worked with yeast about 4 years. Yeah,

Joy Blue:

You worked with yeast?

Melissa White:

And then I decided this is fine, but it's not that exciting to me anymore.

Joy Blue:

hold on, hold on, Hold on. You worked with yeast.

Melissa White:

Yes.

Joy Blue:

What does that mean?

Melissa White:

We were doing a lot of research on like the life cycle of yeast and what causes it to like sporulate, and what it really meant was I was spending a lot of hours in a dark room with a microscope and a little clicker counting yeast spores.

Joy Blue:

Wow.

Melissa White:

yeah,

Joy Blue:

Okay. And then moving on, you said this is cool, but

Melissa White:

yeah. Yeah, so then I decided I wanted to do something that could combine like outdoors and lab work. And I started looking online at jobs, and then I thought, Oh, here's a cool job I really don't know anything about fish, but I'm certain that all the lab work and lab experience, like I'm qualified for it. And it's out in Oregon and I had just visited Washington and I'm like, Love it out there. I love the Pacific Northwest. And so I applied and magically got it. I mean it all just really lined up.

Joy Blue:

Okay. How many years have you been a fish Virologist now?

Melissa White:

I've been a fish virologist for about seven years,

Joy Blue:

Okay.

Melissa White:

and then four years previous to that, I was still in the Fish Health lab as a microbiologist.

Joy Blue:

Okay. Wow. What have been some of your biggest learning curves? Like what has been surprising to you?

Melissa White:

Honestly it was just working with these huge salmon that are, 20, some of'em, 20, 30 pounds. That's a lot bigger than a tiny little

Joy Blue:

Little yeast And clickers

Melissa White:

Yeah.

Joy Blue:

So when you work with a fish, what does that mean?

Melissa White:

So I'm in a diagnostic lab. And so I really study the fish pathogens and not the fish, but we will go out to, if there's like a fish die off or something like that in nature or at a hatchery, we have a lot of hatcheries out here in the Pacific Northwest to make sure that the populations of Salmonas like don't go extinct. So we'll go out and try to diagnose, see what's going on. And if it's a parasite or bacteria, it's fairly easy to diagnose just with like a microscope, a regular light microscope. But viruses are so small you can't just see them with a regular microscope. There are microscopes with higher resolution and more power that you can, but it's not, it's very expensive and not reasonable to use that as a screening mechanism.

Joy Blue:

Interesting.

Melissa White:

So what we do if we suspect a virus or if we're just screening a population for virus, is use a technique called cell culture. And so that is taking healthy cells that you are culturing in controlled conditions, so you're growing them up in a flask or a plate and you know what the healthy cells do, and then you put the sample that you suspect has virus in it

Joy Blue:

Yep.

Melissa White:

in with the cells and see what the effect is. If it doesn't do anything, there is no evidence of virus. And if it kills the cells or changes them in some way, then that's called a cytopathic effect. And you might have a virus there,

Joy Blue:

It feels like you're a mad scientist. Do you sometimes step back and laugh evilly when things work or don't work?

Melissa White:

Uh, no, But when I tell stories to friends, they do so

Joy Blue:

appropriate. You're just over here casually like, Yeah, whatever. It's fine. Yeah. But

Melissa White:

The other day I said to my therapist that I had to go to a spawn and she couldn't stop laughing. She didn't know what to think of that.

Joy Blue:

what does that mean?

Melissa White:

That's exactly what she said.

Joy Blue:

I don't understand I have so many things popping into my head of what it could be, and it looks like fish dancing around a bonfire for some reason.

Melissa White:

Then, In her mind they had like little devil horns.

Joy Blue:

Oh, okay, cool. Like spawn of the devil. Yeah. Okay.

Melissa White:

really just collecting some ovarian fluid. And I'm making it worse, aren't I?

Joy Blue:

Don't stop. Keep going.

Melissa White:

You know, you collect ovarian fluid, you collect some tissues, that virus are mostly present if it's gonna be there, and then we take'em back to the lab and it's a two week process to get the results most of the time.

Joy Blue:

Wow.

Melissa White:

But yeah. In that case of spawning, we're just monitoring where virus is in the state and. It goes into management decisions on like if we do detect a virus in a small fit, like we don't wanna transport that to a place that has never seen virus before or that particular strain of

Joy Blue:

Yeah, that makes total sense.

Melissa White:

So yeah, I have a weird job,

Joy Blue:

I love this for you. I just have so many questions and still the fish are dancing around the bonfire in my head.

Melissa White:

Yeah that's a good image.

Joy Blue:

dancing on your tail. That's just, I don't know. Does that hurt? It's better than flopping on your side. I don't know. I don't know. Is there awe connected to your job? What keeps you in it? What keeps your attention?

Melissa White:

Yeah I would say yes, definitely. So many times when I'm scanning through these samples, we don't see a ton of virus, thank goodness. But then when you do, there is that moment of like, ah, like this is new, this is exciting. What does this mean? And most of the time I have an idea based on what that cytopathic effect looks like, what the temperature was like, the history of the stuff of what the virus is. But there's definitely times where it could be a new virus and then we have to figure it out. And it's a mystery. And I think that's what always drew me to science in the first place. I think, you know, in, in high school, I mean I still like science, but I, you're presented of like, here's this complete picture of everything. And then when I moved into College, then it's like, oh wait, we really know very little. We know a lot more than we used to, but there's still just huge areas where it's unknown.

Joy Blue:

So much room for wonder.

Melissa White:

Yeah.

Joy Blue:

So what is the process from identifying a virus to figuring it out? That sounds like you're Nancy Drew in some ways of like trying to find the connections, trying to find what's familiar. Do you have software that says, Oh, this looks like this. Or how do you start down the path of figuring that out?

Melissa White:

Yeah, I think a lot of times, and when I'm training someone on this, it's like you kind of just have to look through tons and tons of cells to see what normal is because there's a whole range of what normally happens in these cell lines. And at a certain point, you'll know when something looks off. One of the viruses that I deal with the most, it is a rhabdovirus. Which everyone's probably heard of rabies. That's a rhabdovirus. So this is a fish rhabdovirus, and it causes the healthy cells to swell up and almost look like grapes. And then at a certain point, the virus will multiply inside the cells so much that it will then splice and then the virion, the little virus particles can go into all the neighboring cells. And so it's a pretty drastic effect. And with that particular virus, it's our most common, if I've seen it in an area, in a river, you know, every year for the last 10 years, when it pops up, I'm not that surprised. We still have to confirm that though. And so at that point I would take some of that sample and do a PCR which probably in the days of covid, a lot of people have heard of PCR testing. It's basically a molecular test that targets a certain portion of the gene. And if you can amplify that in PCR that confirms that, yes, what you thought was this virus is this virus, because those, the target is so specific that it amplify any other virus out there,

Joy Blue:

Interesting.

Melissa White:

and then you have to take it a step further and sequence it, which we send that off. I don't do that myself. You can have many different variations of the same virus, and they affect different fish differently. So it can become a little complicated if you have an outbreak, you know what you do with those results. And as a fish health specialist and fish virologist, we give recommendations. But then really above that it's, managers of the program that make the final decision on if those fish can be transported to this other area or what happens to them.

Joy Blue:

Sure. So you find these viruses in the fish, but what is the life cycle of that virus? Where is it introduced? What are its effects down the line? What's that look like?

Melissa White:

Yeah, that's a good question. Some of that is not known. So I'll talk about the specific virus again. It's called IHNV, Infectious Hematopoietic Necrosis Virus. I mostly deal with salmoneds and chinook salmon. There's, as adults, they swim up river back to where they were hatched and somehow they can sense, like whether it's the amino acid composition in the water, somehow they can get back to where they know that they're supposed to start the next generation. And then those fish die after they have laid their eggs or they age out. And some of those fish can bring back virus to the rivers and then they're constantly shedding it into the water. And so then small juvenile fish can pick that up. And so it's horizontal transfer. And then it's just, you know, those fish can swim out. Every fish, everything that they're passing on the way, there's a chance that they're gonna pass it. And so that's really how it keeps going. This particular virus can stay viable for quite a while, like a month in the water as well. I think at 15 degrees Celsius, then it can just hang out. But there. studies that show that a leech can be a host for it as well. And so if you have other organisms that are potentially this host, then yeah, you're just never really going to get completely rid of it.

Joy Blue:

So in the face of something that is gray and hairy and gnarly, and you don't really know where it comes from or where does it go, your job is just monitoring?

Melissa White:

It's monitoring and making sure that as an organization we don't add to what nature's doing already.

Joy Blue:

So there's a part of me that's like, it's a virus, it should go away. But that's not what I'm hearing you say. Like, We're not introducing more things into the environment to mitigate the virus or countermeasures. You're purely just seeking to understand.

Melissa White:

Well, We're seeking to understand and control in the ways that we can control it. Cuz we're never going to get rid of it. I mean, That would be great if we could, because especially for a fish virus, there's no treatment that we can give a group a fish after they come down with it. And even in a hatchery setting where we could, you know, give them a treatment for a bacterial infection or parasitic infection, there's just nothing you can do for a virus. So it's in wild fish. A lot of our situations that we've had are, because fish get above a hatchery intake, and then they're shedding the virus into the water. And unfortunately, hatcheries are, I mean, you have a lot of fish you know, high density they're gonna just, yeah. So they're just gonna spread whatever they have around. And the best thing you can do is to avoid it to begin with, but we're realistic and know that that's not always what's going to happen. It's being passed around in nature. And one of our goals is like not to put it out there in higher number than we should. Yeah.

Joy Blue:

From a layman's perspective, I'm sitting here listening to you being like, essentially it is what it is. We're seeking to understand and do the best we can with what we have, which is a surprisingly balanced approach to so many things that I don't necessarily hear everywhere. Like it doesn't sound like you're scrambling for control. It doesn't sound like, you know, you're taking action, which then has ripple effects down the line that, Oh, we didn't know about that later. It's just so interesting to me to hear, like for some reason, my mind is blown of like, y'all are literally seeking to understand, letting what happens, happens, but you're observing, doing the best you can with what you have. Trying to keep the information out there. It sounds like you're doing an amazing public service.

Melissa White:

Thank you.

Joy Blue:

Is that accurate?

Melissa White:

I would say that's accurate with viruses that are known to us and that have been around for a while. I will say that like if new ones pop up in aquaculture sometimes things can get a little chaotic then. Trying to figure out what this is to begin with. Trying to figure out is it our responsibility to euthanize a stock so it doesn't spread if it's bad enough. there have been situations where people have had to make bad calls and hard calls. So It's not always as calm and collected as you made it seem. Most of the time it is though.

Joy Blue:

That's so interesting.

Melissa White:

But I, yeah, I just wanted to throw that out there, that there are unique cases where everyone's like, Okay, like this is a new virus. We don't know what it's going to do. And again, it's like getting more data monitoring, There are different research groups. I'm not really in research anymore. Most of my job is purely diagnostic.

Joy Blue:

Fascinating.

Melissa White:

I mean, Those groups are important to, to try to figure out like, we have this new virus we also have this, you know, historical important group of fish. how do we protect them?

Joy Blue:

Yeah. That's so interesting. Okay, so when you're gathering these cell cultures and you're mining your data, are you spending a lot of time outside? Are you catching fish? Are you a master angler? Are you a fly fisher? Are you, No. Okay. That was very glamorized in my head.

Melissa White:

am not I would say during different times of the year, I have field days. And field days to me are like going to a facility. It's not like actually out in the field. Sometimes we do get rare opportunities where we're doing more wild fish work, but yeah, maybe three to four times a month. We have other positions that during spawning season, they're out four days a week, 10 to 12 hour days. I mean, it, there's a lot of collecting samples

Joy Blue:

Yeah.

Melissa White:

and yeah, in a hatchery setting the samples are basically like there for us to collect. We're not out catching fish or anything. The adults come back, they're held in ponds until they're ready to spawn. And then as they're taking the eggs, then, you know, we just have a little Dixie cup, collect some eggs.

Joy Blue:

Who knew a Dixie Cup could be a scientific tool?

Melissa White:

I know and then we use a syringe, get some of the liquid out, and then put the eggs back in with the others, and then that only, that little syringe comes back to the lab with us,

Joy Blue:

So interesting. Time period wise, from gathering the sample to your conclusions on that sample, typically, how long is that?

Melissa White:

It's a two week minimum.

Joy Blue:

Okay.

Melissa White:

Because once the sample gets onto cells, you know, some viruses are really quick and you can see the cytopathic effect in 24 hours and some could take two weeks. Because we're dealing with the types of samples we are, sometimes there's contamination or toxicity to the cells. And so at that point you kinda, you have to filter out your sample or dilute it out and start the process over again on new healthy, fresh cells. And so I would say two weeks minimum. Um, Sometimes it's three to four weeks depending on what we see. Now once I see what I think is IHNV that will happen at about day five or six, I can go ahead and do the molecular PCR testing right away. And so that takes a day.

Joy Blue:

Sure.

Melissa White:

And then I can have a confirmation pretty quick. But if something does not have evidence of virus, we let it go the full two weeks. And, you know, if something is a new novel virus, it might take a month to get to the bottom of it because, We've never seen it before. And so you're talking to your colleagues in different areas, different agencies, like, Hey, here's what I saw. Here's the temperature. Here's how long, here's when Cytopathic effects started. Do you have any ideas on what this could be? And yeah,

Joy Blue:

What a cool job. What's one thing you want people to walk away from this podcast with?

Melissa White:

Viruses are cool and we should respect them.

Joy Blue:

What does respect of a virus look like?

Melissa White:

we could make it about the pandemic, but like they have. I was gonna say a mind of their own, but like that's not true. They're not doing one thing or another. Like based on

Joy Blue:

Yeah, they don't have free will.

Melissa White:

Yeah, they don't have free will. But I think the respect is like they're gonna do what they're gonna do and just because we want to believe it or not, doesn't change anything. All organisms have a virus, right? Like some virus that's going to either harm or hurt them. And we also have tons of viruses that do nothing to us and it's beneficial. So in some ways, but

Joy Blue:

Respect the virus,

Melissa White:

respect the virus.

Joy Blue:

All right. This has been amazing. Thank you for sharing your nerd with us.

Melissa White:

Thank you.

Joy Blue:

My mind is I still just have so many questions and there's still fish dancing around a bonfire, but it's fine. Thank you so much.

Melissa White:

Yeah. Thank you.

Joy Blue:

So here we are. Never did I ever think that I would have the opportunity to know about or even interview a fish virologist, and now you all have met one too! Melissa, thank you for jumping on the call with me, for sharing the passion of your work and for the timely reminder to respect viruses. I love how your nerd shows and comes to life. If you've got a flavor of nerd that you want me to celebrate, I would love to hear all about it. So go ahead and email me at herewearethepodcast@gmail.com, and tell me everything. I love taking time to sit and make space for nerd to be celebrated. If you really like this podcast and wanna financially support what I'm doing, head on over to patreon.com, search for Here We Are The Podcast, and sign up for one of the many beautifully written support tiers that I'm very proud of. So until next week, don't forget that curiosity wins and the world needs more nerds. Bye.