How Do You Science | Meet a Marine Biologist

Welcome back, young scientists. I’m Dr. Universe.  If you’re anything like me, you’ve got lots of big questions about our world.
 
Today we're talking about birds with Wes Dowd, a marine biologist and environmental physiologist at Washington State University. 

• Learn about tiny crustaceans called copepods, which are a type of plankton— and rock out to this song about zooplankton
• Check out ocean mussels and their freshwater cousins
• Discover how to explore tide pools gently

Resources You Can Use

• Spend some time on the American Museum of Natural History's marine biology page
• Learn more about ocean plankton with Black in Marine Science

As always, submit burning questions at askdruniverse.wsu.edu. Who knows where your questions will take us next.

Transcript

 Dr. Universe

Welcome back, young scientists. I'm Dr. Universe, and if you're anything like me, you've got lots of big questions about our world. 

When I was a kitten, I loved playing in the ocean. That's why I was excited to talk about marine biology with Wes Dowd of Washington State University. We talked about copepods, mussels, and even giant sea spiders he saw in Antarctica. Check the show notes to learn more about those animals. And let's get started.  

So, can we first talk about what marine biology is?  

Wes Dowd

Sure. At the most basic level, it's just studying life in the ocean.  And what makes it fun is life in the ocean is so different than what we're used to.

Dr. Universe

Can we talk about what kinds of animals you study? What kinds of things you do as your research? 

Wes Dowd

I study primarily small things that don't have backbones. So, they're invertebrates that live on rocky seashores. So, the two main animals that we study, at WSU are copepods, which are tiny crustaceans that swim around in tide pools on the seashore. And for them, we're really interested in how they respond to changes in their environment.

Well, that's kind of the running theme of all my research is how animals in the ocean or right on the shore respond to changes in the environment. And the shoreline is One of the most dynamic places, which means it's one of the places that changes the fastest and most frequently. Every day and every night is really different if you're an animal that lives in those habitats, and so we're trying to figure out how they work there. 

The other animal that we study are mussels that also live on rocky shores.

They're almost plant-like animals, because as adults they can't move around. So, they're stuck on the shore. The tide goes out twice a day, and they kind of have to hold their breath and wait for the tide to come back in. And that could be six hours or longer.  And they could do that twice a day every day throughout their adult life. 

Dr. Universe

I remember you telling me that, and it freaks me out. It makes me feel kind of claustrophobic to imagine holding my breath just waiting for it to come back, right? 

Wes Dowd 

Yeah, for us It's almost impossible to imagine. For them, it's just part of everyday life. So, evolution has favored ways that they can survive this and do it every day, and it's no big deal. I mean, actually some people, myself included, think that if you put these animals in an environment where they're always submerged, it might be harder for them.

Dr. Universe

About how big are they?

Wes Dowd

The mussels? So, they come into the shoreline as larvae, and they're, you know, difficult to see with the naked eye. You wouldn't know they were there.  And then they metamorphose and have a tiny little shell—less than a millimeter long probably when they first settle. And then the adults, which is mostly what we work on, are roughly 3 to 10 centimeters. A really big one would be 10 or 15 centimeters. On average, I'd say they're five or six centimeters.  

Dr. Universe

How big is five or six centimeters? What's a common object that's about the same size? 

Wes Dowd

Oh, so like your pinky finger? A little bit longer than that—roughly the length of a ring finger.   

Dr. Universe

I saw on your lab website some pictures of like some little sensors that might've been maybe glued on to their shells. Is that the kind of thing you might do?  

Wes Dowd

Yeah, so that's how we try to understand what the animals actually go through when they're out in nature. If we want to understand how they live there, we first need to know exactly what they experience So, we have to put sensors on them to try to figure out what they're going through.

And so that was a project that I did mostly before I got to WSU in a previous job. But we built a package of sensors that would measure body temperature. So, it had a little temperature sensor, and we would drill a tiny hole in the shell and put this little probe through the shell. So, we measured the internal temperature, and then it measured how open or closed the two parts of the shell are—we call that gaping. So, when the tide goes out, and they're not underwater anymore, they typically close their shell, and when tide comes back in, they open, and that's how they feed and get access to oxygen. So, we wanted to measure temperature and gape.

And then the third thing we did was put essentially like a gyroscope,on the outside of the shell so we could understand how they were positioning their body in sort of three dimensional space, right? So, were they lying flat on the rock? Were they standing straight up and down?

And were they moving, depending on sort of how hot it was? What I really selfishly hoped is that they would be sort of the opposite of sunflowers. You know, sunflowers—typically we think of as following the sun, and the big disc is always facing the sun.

That would be counterproductive for a mussel because, if you had the maximum surface exposed to the sun, you would heat up really fast. And so, I thought that they would actually track the sun by pointing the tip of their shell directly at the sun to reduce how hot they were. But it turns out they don't do that at all.

Unfortunately, they're not as capable of adjusting that as we had hoped. And so, their movements are mostly random from one point to the next as far as we could tell. So, they're not sunflowers, and they actually will heat up so much that they'll die before they'll change their posture.

 Which is pretty interesting. You know, we think if it gets too hot, we just go to a different room or go to a different state. But in their case, they really don't have that option. 

Dr. Universe

I wonder—when you have a hypothesis or a guess about how something might turn out, and then it doesn't turn out that way, is that disappointing? Is that still really fun? Is that just more information?

Wes Dowd

Yeah. And that's just how science works. Most of the time we're wrong. But figuring out sort of how you're wrong and why you're wrong is as important—or more important, I think—than proving that you're right.

Because it gets you closer to understanding nature.  So, yeah, I think it's not a failure, and that's probably one of the things that is hardest for students to learn. And I think people think about science—they think about, you know, having to get everything just right, but, in fact, that's not the way it works most of the time for real scientists.

Dr. Universe

How do you come up with the questions? Like, there are so many questions out there. How do you figure out what to study? 

Wes Dowd

When you first start out as a student, a lot of it is driven by the people that you are working with—your research mentors and the types of questions that they're interested in.

You read what other scientists have done previously. And then, an important step is to figure out, “Okay, we know X and Y, but we still don't know Z. So that's the gap that we need to fill.”

And so that's one way, and the other is to just go out in nature and start looking around and saying, “Well, that's weird.”  And, to be honest, I think a lot of the most interesting stuff comes from that sort of just observation, of just paying attention and seeing something that looks strange or unexpected and then trying to figure out why it's happening.

Dr. Universe

So, it seems like some of your work is going to the ocean or to the tide pools. 

Wes Dowd

That's right. Yeah. 

Dr. Universe

How often do you do that? 

Wes Dowd

I don't do it as much anymore as I would like. My students go a lot more than I do. So, I probably go on average once a year I would say to intertidal habitats. But my students get to go more frequently. And a lot of our work now we're getting animals and bringing them back into the laboratory. So, with those devices like I told you about,and other ways of monitoring the environment, we now know the types of changes that these animals do experience.

But in nature—out in the field—we don't have control over that. So, we actually do a lot of work in the laboratory where we can manipulate temperature, oxygen, salt levels or pH levels of the water, or temperature when the tide goes out, things like that, in a very controlled way, and then we can really understand the effects. 

So, we know what the range of values is from studying things out in nature, and then we can really accurately fine tune, manipulate, and control them. So, that's what a lot of our work now is doing.  

Dr. Universe

Basically building an artificial tide pool.

Wes Dowd

Yeah. So, we spent a couple of years—almost two years—building a system that can basically take the equivalent of one of these puddles of water—a tide pool on the shoreline—and through a complicated set of microcomputers and gas cylinders and wires and tubes kind of going in all directions, we can change things like temperature, oxygen levels or pH in those artificial pools in the laboratory. And then our animals are in there, and we can measure their responses. So, yeah, it looks like mad science. 

Dr. Universe

Do you have a lot of animals in the lab?  

Wes Dowd

It depends on the time. With the copepods, yes. We usually have thousands if not tens of thousands of those because each one of those is about one to two millimeters long. So, you know, the part of your fingernail that you cut off when it gets too long. That's about how long an adult copepod is.

So, they're tiny, and we keep them in glass mason jars. If your parents or grandparents can tomatoes, and they put them in those mason jars, that's what we use to keep hundreds of copepods alive in saltwater—it’s just rows and rows of mason jars. 

But mussels are bigger and more finicky, and typically we get them for, you know, a period of time, and then we'll do experiments, and then we'll sample them. So, we'll actually take tissue samples or protein or DNA samples to analyze later. So, we don't rear the mussels from babies up to adults.

We typically go out and collect adults and bring them back to the lab. It's a lot harder to keep the larvae happy for the mussels, whereas the copepods are super easy.  

Dr. Universe

Do you have a favorite project that you're working on right now?

Wes Dowd

I'm really interested in the copepods. We've found this unusual, unexpected result that—so basically in these pools, they heat up in the middle of the day, and so the sun beats down on them, and the water in this little puddle where the copepods live will get really warm.

And, at some point, it can get warm enough that they can't survive anymore. And that's a concern with things like climate change, but we've found that if the amount of salt in the water is also higher—we call that the salinity of the water—that their ability to tolerate high temperatures goes up.

And so this is surprising because normally you think two bad things would kind of compound each other and be worse overall. But, in this case, the second quote/unquote bad thing actually increases the ability to deal with the first bad thing. And so, we're trying to figure out how that works. As a physiologist, I want to understand not just what happens but how it happens inside the body of the animal.

And the other project that I'm working on right now, which is completely different, is about Antarctic fish. So, I had a phase of my postdoc years ago where I went to Antarctica as part of a research training group and collected some samples from fish in Antarctica that live at temperatures that are so cold that they should theoretically be frozen. So, it's cold enough that their bodies should freeze solid, but they don't.

And they have some proteins in their bodies that prevent ice from growing, but they also seem to have lost the ability to deal with heat stress or high temperatures because they've lived in minus one degree. So, they've been, you know, really, really cold for millions of years. So, they never see heat.

And so, I'm trying to figure out what things have changed in this group of fish that have forced them to lose the ability to respond to high temperature.

It's a really interesting and completely different group of organisms. Rather than experiencing, you know, lots of different things every day, their environment is pretty flat. It's very stable.  especially in terms of temperature.  

Dr. Universe

If you're looking at something that they've lost the ability to do, do you have something to compare it to?    

Wes Dowd

You've probably heard the expression “the tree of life.” So, by comparing the genes that are in the different species—or proteins that those genes code for—we can look at changes between a species that lives, for example, in South America or New Zealand, where it's still above freezing, versus the ones that live around Antarctica, where it's below freezing.

So, I'm actually having to learn a whole bunch of things—new techniques and new areas of biology—to do this project, which is fun. You know, one of the nice things about this job is that you always are learning something new. 

Dr. Universe

I have to ask: when you went to Antarctica during your postdoc, what was that like?

Wes Dowd

Oh, it was amazing. I mean, it's a phenomenal place. It's just so different from anything any of us are really used to. So, you fly in over giant swaths of sea ice—mile after mile—and everything's white. And the plane lands on a floating glacier. It's this big U.S. military transport plane that you travel down there on, and when the plane lands, the engineers there can actually measure how much the glacier sinks into the ocean. 

So, just the logistics of working there are pretty incredible, and then the life there—both in terms of life as a researcher but also just the biology—is so different because it is so isolated and so cold, and it has been cold and isolated for a long time. So, you get really unique animals and microbes and other things, too. So, the fish there are really unlike anything you find anywhere else.  

Dr. Universe

Wow. That is so cool I can hardly stand it. 

Wes Dowd

Yeah.  

 Dr. Universe

What is the coolest animal that you saw there?

Wes Dowd

Oh, gosh. There are so many. One of the things that's really interesting down there is this phenomenon called polar gigantism. And so. this is an observation that, if you go to polar regions, you find things that are related to species that you find in the temperate or tropical areas, they’re just like 8 to 20 times as big. 

So, things like sea spiders, which are called pycnogonids. They're maybe a few centimeters long in temperate regions, and some of the species around Antarctica—I don't know exactly—but, you know, they're probably 20 centimeters long.

Dr. Universe

 Giant sea spiders. 

Wes Dowd

Yeah, and that's true of other groups as well. There's enormous sponges and things like that.  I mean, I was there to mostly study fish, and the fish there—the species of fish are really found nowhere else. 

There's this idea in biology called endemism, which is that something is found in one place but nowhere else on the planet. And something like 80 to 90 percent of the fish around Antarctica—the different species—are only found there.

They're endemic to Antarctica, and we think of places like Hawaii or Easter Island as having high rates of endemism, but there it's like 20 or 25%. So, Antarctica is off the charts in terms of how unique the fish are. 

Dr. Universe

Do you have any advice for aspiring scientists who are like 8 or 13? 

Wes Dowd

Just be curious. And don't be shy about asking questions. There's so much information out there and so much still to be learned. From a practical side, learn as much as you can about as many different things as you can because no matter how unrelated it might seem, it actually is probably something you can relate to what you're doing. So, that's just basic curiosity, I think, too. 

 Dr. Universe

That's all for this episode, friends. Big thanks to Wes Dowd of Washington State University. Don't forget to check the show notes to learn more about some cool marine critters. 

As always, if you've got a question for me, you can submit it at askdruniverse.wsu.edu. That's A-S-K-D-R-U-N-I-V-E-R-S-E dot W-S-U dot E-D-U. 

Who knows where your questions will take us next.