Andrew S.: Hi. You're tuned into 90.7 FM, KALX Berkeley. I'm Andrew Saintsing, and this is The Graduates, the interview talk show where we speak to UC Berkeley graduate students about their work here on campus and around the world. Today I'm joined by Emily King of the Department of Integrative Biology. Welcome to the show, Emily.
Emily K.: Hi. Thanks for having me.
Andrew S.: It's great to have you here. So Emily, you study invasive species, is that correct?
Emily K.: Yeah.
Andrew S.: Why don't we just start by defining an invasive species?
Emily K.: That is a good place to start, and kind of a complicated place to start. So most folks define an invasive species as something that did not evolve in the place where it currently resides, and it could have been brought there accidentally by humans or accidentally by extreme weather events, but most folks now put another kind of caveat on top of that. It's not just something that didn't evolve in the place where it currently is; it also is causing damage in that place or has the potential to cause damage.
So we can think of a lot of invasive species as being like weedy plants, things that grow over their neighbors or out-compete their neighbors, and some animals species especially, they eat other animals that we care about. So yeah, usually invasive species are associated with bad things, but that's part of where some of the complexity comes from. Some scientists don't like that. They think we're kind of assigning value judgments to just what's happening in nature and they think that's a bad idea because so many folks want to remove invasive species. The scientists who think that we are misplacing our values think we're trying to play God a little bit in whatever we think of as restoration.
Andrew S.: Right. That's really interesting. So, I just had in my mind that an invasive species is something that human beings introduced, but you're saying that that's not even necessarily true.
Emily K.: Yeah. Sometimes there are accidents. So in the case of like the tsunami that hit Japan in 2011, we've found animals that have made it to the west coast of North America that we only used to find in Japan, but they were attached to tsunami debris that also made it across the ocean. So some of those things have established here on the west coast, and another, in a human adjacent case, a lot of marine organisms especially get transported around on the holes of ships. So, you know, those aren't people actively saying, "We want to bring this thing to a new place." You know, it was in the harbor where they docked their ship the first time and it goes into the next harbor on the other side. That's not on purpose, but it's definitely, it's an accident but something to think about.
Andrew S.: Right. So like you were saying with the value judgment, I guess in the case of the Japanese tsunami, you could argue that that's just a natural occurrence, and so how could we to decide whether or not to remove Japanese animals that have established from that event?
Emily K.: Exactly. So that's where the complexity really lies, and I think a lot of folks are just encouraging each other to think about what their values are. At least if you can acknowledge that you have values around what you're talking about, you might try to work to not include those and how you do your science, but if you do, you can say that that's part of your worldview.
Andrew S.: So how would you remove human assigning values, you know what I mean, to the study of invasive species?
Emily K.: Yes. A lot of it's a language thing. So we often use almost aggressive language when describing invasive species. They "take over" and they "out-compete" and they "push out." We sometimes also say that we're "combating" native species or you know, we're trying to "protect" our ecosystems, and those are all things that are really human human values.
Andrew S.: It's like we're going to war, yeah.
Emily K.: Yeah. Some people even say that there's a war on non-native species. So that's like a very clear example of when we let our human values or desires color the way we talk about science.
Andrew S.: Right.
Emily K.: So instead of just thinking about a cause and effect, you know, the effect of one species next to another, we're talking about, you know, detriments of having this species next to another. Sometimes that might be the effect, but if we talk about it like that from the outset, we're setting ourselves up to expect something "bad" to be happening when sometimes nothing is happening.
Andrew S.: So there's examples of like species that have "invaded," but they haven't disturbed the ecosystem they've invaded.
Emily K.: Yeah, I mean there a lot of evidence, and I can't come up with a good example off the top of my head, but sometimes when you think about weedy plants, you know, especially in like an urban environment. We already took out our native plant species. When we get weeds, they're not disrupting maybe what was already disrupted. It's just not going back to what it might have looked like before humans ended up in that place.
Andrew S.: Right. Okay. So that's an example where I guess the ecosystem that was there is completely gone now.
Emily K.: Mm-hmm.
Andrew S.: So can there ever be a species that invades an undisturbed ecosystem that doesn't disturb that ecosystem?
Emily K.: I mean, I imagine it could happen. I can't think of an example right now. There are a lot of, especially ecologists and like wildlife managers, asking these questions because we want to know, you know, are we spending money to get rid of something that either we can't get rid of or it's actually not doing the horrible things that we thought it might? So are we wasting resources? Are we wasting energy? Are we assigning values to things that really don't make a difference to us or the way that we see the ecosystem?
Andrew S.: Right. So I guess the main problem is there are some obvious examples where invasive species have come at, like rats on islands-
Emily K.: Rats on islands, zebra mussels in the Great Lakes. There's a lot of beavers where beavers shouldn't exist, which is kind of funny because lots of places in North America want their beavers back.
Andrew S.: Oh, interesting. I didn't know beavers were an invasive species or-
Emily K.: Yeah, beavers are invasive, or at least problematic, in parts of South America. They are eating forests that don't need beavers to regenerate. Whereas a lot of the southeastern part of the United States needs beavers and has no beavers.
Andrew S.: Interesting. Wow, so like there's the two issues there: you gotta get beavers out of the one place and then you've got to reestablish beavers and the other place.
Emily K.: Right.
Andrew S.: Do you look into that as well, and re-establishing?
Emily K.: No, but at least the species that I work on kind of flies under the radar in its native habitat and people are worried about it here, but yeah. In New Zealand, they don't really care about the mud snails.
Andrew S.: Oh yeah. So let's talk about the species you work on. So you work on a mud snail from New Zealand?
Emily K.: Right.
Andrew S.: Can you just describe it a little more?
Emily K.: Yeah, it's really, really tiny. You know, smaller than the eraser on the end of your pencil. They are freshwater snails. They are clones of each other, at least in places outside of New Zealand. Because they're clones, they can have incredibly large population sizes very, very quickly after being introduced to a new place. They have incredibly broad tolerance for types of environments that they might live in. Everything from the freshest of glacier melt water in rivers to salty estuary conditions, warm water, cold water. They just do their little snail thing.
Andrew S.: Is that kind of like an invasive species thing that you can survive in extreme regions?
Emily K.: Yeah. One hallmark of a lot of invasive species is that they, yeah, they're like weeds. They just hang out everywhere.
Andrew S.: Right, yeah. So they reproduce asexually-
Emily K.: Right.
Andrew S.: And so there's like no diversity in their population or ...?
Emily K.: Yeah, that's what we think about the western US. So a lot of other scientists that have worked on this in the last 30 or 40 years in the US have done a lot of work trying to understand if around the country we do have all the same strain or if they're different. They have pretty much decided that everything west of the Rockies is one clonal strain that started in Idaho. I was introduced originally to Idaho.
Andrew S.: So they can trace it back to a single snail in Idaho.
Emily K.: Yeah.
Andrew S.: Do they know like where in Idaho?
Emily K.: Yeah, there's like a pinpoint in the snake river, but that's because this snail has another kind of cool ability, that it is almost indigestible by fish. So the leading theory is that we were stocking imported fish from New Zealand in Idaho, and one of these snails was inside the gut of a fish. Because they pass through the fish mostly unharmed, it established in the river.
Andrew S.: Wow.
Emily K.: Yeah. There's-
Andrew S.: It can pass through the stomach unharmed.
Emily K.: Yes.
Andrew S.: Why, or how?
Emily K.: If you think about a snail shell, these guys have, or gals I suppose; they're all female, have like a really spiral shaped shell, and if you think of like a spiral-shaped seashell, but snails of lots of species have what's called an operculum. Basically it's a trap door that they use to cover the opening of the shell. So once they kind of close up and deploy this trap door, they are almost impenetrable.
Andrew S.: Dang.
Emily K.: Their biggest risk is, I mean chemical that might get into the shell, or drying out becomes the biggest risk at that point.
Andrew S.: So does anything eat these snails in New Zealand?
Emily K.: Yeah, some birds do eat them, but mostly what keeps them in check in New Zealand is that they have 13 different types of parasites, or there's 13 parasitic worms that could essentially castrate them and keep them from reproducing.
Andrew S.: Interesting.
Emily K.: Right, and we don't have those here.
Andrew S.: I guess it would be a bad idea to introduce a parasitic worm into the population-
Emily K.: Yeah. Usually that's another sticky subject and a dangerous game to play, but some researchers have tried in the lab, and it did work for a little while, but they think that the co-evolution between the parasite and the host is so fast that after about five years, it didn't work anymore.
Andrew S.: Yeah, and I assume people would test how the parasite interacts with natural populations before they-
Emily K.: Right, yeah. I don't know if they got that far, if they tried their lab studies and decided it wasn't working well enough and to even go beyond that, but there are some other types of animals that can eat them. Some fish have like almost like, what's this, kind of like a gizzard in a chicken or something that would grind, but there aren't that many fish of that kind around here, and the best is critically endangered. It's called the tidewater goby. There's like, they're mostly up in Humboldt Bay and there's a couple out on the Golden Gate National Seashore, but they're not going to help us in the inland waters, and some crayfish, but because crayfish, again, can crush with their kind of chelipeds, but there's not enough of those things to kind of combat the problem we have now.
Andrew S.: Do you think if we had this problem just overrun our streams and lakes that then we would see increases in populations of these crawdads and fishes with like gizzards?
Emily K.: You know, I don't know. The snails are not particularly nutritious. They're mostly water. So, I imagine that it would probably be frustrating to be a crawfish trying to eat enough of these snails, or crushing up shells to get somewhere good enough nutrition.
Andrew S.: So the snail is bad news.
Emily K.: Yeah, in some places. In some of the older populations in Idaho and Wyoming, there have been lots of studies about how they eat most of the algae that is produced in the river, which doesn't allow anything else to eat that algae, you know, other invertebrates that become fish food, essentially. It can take up all this space that all these other little invertebrates might be crawling on because they essentially can form mats over rock surfaces, but here in California, we have some really large populations, but we haven't seen these declines in other types of organisms yet.
Andrew S.: So that's good.
Emily K.: Yeah.
Andrew S.: Is it just a matter of time or is it just that there's something in the California ecosystems that's-
Emily K.: Yeah, we're not really sure. So, part of my work has been trying to understand seasonal population size and trying to understand what else we see in creeks with these snails. So far, I haven't looked very comprehensively; it's been mostly observational, like, "What do I see when I'm in the creek?", and I see other things, and I sometimes see other native snails. So the worst case scenario, it doesn't seem to be happening here, and they're mostly in urban creeks, which as an example I gave before, are kind of already not the same ecosystem they might've been without human involvement.
Andrew S.: Right.
Emily K.: So lots of storm drains go into to our Bay Area, creeks. They've been kind of channelized, so many folks have probably driven over what looks like a creek or a river, but it's encased in concrete and sometimes they're very deep and there's not very much water at the bottom. Litter becomes a problem. All those things kind of changed the landscape already, so it's unclear if the same thing would happen in a really natural system where this snail had been introduced versus the urban systems where we see them most.
Andrew S.: Right. So are they in Strawberry Creek here on campus?
Emily K.: I have not found them on campus, but they are in Strawberry Creek, you know,, like about a mile or so away from campus at this [inaudible 00:14:58]. I think it's called Strawberry Creek Park actually, down off of Allston. So I have found them there. They are in the creek, but exactly how much of the creek is hard to tell because Strawberry Creek is mostly above ground here on campus and spends most of the rest of its journey out towards the Bay underground in tunnels. So the park is one of the other places where the stream is open to the air, and someone could get into observe what's in it, but there aren't very many places along the creek where you could do that south or west of campus.
Andrew S.: In creeks that are below ground, is there much life going on there?
Emily K.: That's something I don't know the answer to. I'm sure there are a lot of folks who do know, but because I've only gotten in where I can get in right now and I haven't thought about it, but I would imagine there's not a whole lot going on if it's not close to one of the ends of these tunnels, mostly because the aquatic food webs are based on algae which need light to grow. So, unless some of these almost cave-like sections of the creek are having bacterial-based food webs, I don't know if we would find much and out there.
Andrew S.: So that's like a thing, like a barrier maybe for these mud snails?
Emily K.: Yeah, they could be washed through though. So a lot of animals could move, you know, through some sort of tunnel or piping system to traverse the length of the creek and we would only see them in one place at where it's open.
Andrew S.: Right.
This is just a reminder that you tended to the graduates. I'm Andrew Saintsing and today I'm speaking with Emily King.
Have you always been interested in studying invasive species or this particular snail? I mean, how did you get on this topic?
Emily K.: I've always been interested in aquatic systems. My background and my undergraduate work is all in marine science, and I think the best way to describe myself as a scientist is a physiologist, an environmental physiologists. So that means that all of my interest is about how animals live where they are, how they deal with the challenges of living in that kind of an environment, whether it's places that change in temperature or the amounts of oxygen in the water. When I got to Berkeley I knew that just kind of some resource limitations were going to make it really hard for me to study ocean critters, and I was thinking about other types of aquatic systems, and I kind of happened on this snail by accident.
I was working with an undergraduate who was telling me about some aquatic snail that was invading rivers. So I got online and I was looking at invasive snails in California, and this one is newsworthy. I suppose. There's lots of writing, especially from fish and wildlife agencies, to talk about how it's spreading all over the state and we'd like to stop it. So once I was like, "What is this thing that's everywhere?", that was really interesting to me, and when I learned that fish can't eat it, it survives in salt water and in freshwater I was like, "Oh I have to study this." It seems like almost like a little super-powered animal that nobody knows how to get rid of.
I'm not necessarily interested in how to get rid of it, but why does it survive in all the places that it does is an interesting question. From a management perspective, how do we manage our lands and creeks, but also from like an evolutionary perspective, like how does something evolve in one place that potentially is very, very different from all the places that it ends up and it does just fine? So that's another question that kind of fits really well with what a lot of my colleagues in integrative biology look at.
Andrew S.: Right. So that's what you would say, like management is the answer for why other people should be interested in this-
Emily K.: Right.
Andrew S.: But you're more interested in this idea that animals can live in these extreme environments, but not all animals, and what's the difference between the animals that can live in the extreme environments.
Emily K.: Yeah, and especially without a lot of genetic diversity.
Andrew S.: Yeah.
Emily K.: So one strain of snail lives in geothermal fed streams in Yellowstone and also the Columbia River estuary and high mountain streams in the eastern Sierra, but also just right here in Berkeley. So those environments are very different in temperature and salinity, in other nutrients that are in the water, and that's just mind boggling to me.
Andrew S.: Yeah. People have sort of sequenced the genes of the snails collected from these different environments.
Emily K.: Mm-hmm, and they seem to be pretty similar. Yeah, no large scale patterns at all.
Andrew S.: That's crazy. Okay. So you were interested in aquatic systems to start with. So in undergrad, you studied marine science.
Emily K.: Mm-hmm.
Andrew S.: So did you think that you would be studying the ocean? You said that you were kind of thinking you would study the ocean. How do you feel about moving from the ocean to freshwater?
Emily K.: I think that it's been a real process of discovery for me. I grew up in this area, I'm working in creeks that I have seen my whole life, and I never considered really what was in them and should we be protecting them. I walked next to them and I drove over them and that was the end, and I think a lot of folks get really excited about marine science because of the diversity of animals. Those animals tend to be really exciting to the public, but there's also really exciting things happening in our backyards, and I think I'm really, really building an appreciation for freshwater systems, and I think it's really fun. Part of why I wanted to be a scientist is to keep discovering things, and even if this process of discovery is to kind of fuel my own enjoyment, I'll take it.
Andrew S.: Yeah. So the PhD is the first time you studied freshwater, though.
Emily K.: Yeah.
Andrew S.: As an undergrad, you did research on marine systems?
Emily K.: Yeah, yeah. I did mostly fish and crab research as an undergrad and those systems are also, you know, really cool, and I worked on a lot of fish species that people eat, so those were exciting species to study-
Andrew S.: Because you got to eat the-
Emily K.: You know, I never did. I didn't, but you know, other folks. You know, I was eating, I was not eating, I was studying fish species that other folks might buy in a grocery store, so thinking about how we could protect fish species for their own intrinsic value to the environment, but also first for human consumption was really interesting and exciting.
Andrew S.: Did you go straight from undergrad into grad school into your PhD program here or ...?
Emily K.: Yeah, I did. So I mentioned really briefly working on crabs, and I did that with one of my PhD advisors, Dr Jonathon Stillman, when I was in undergrad, and I was really just interested in how their lab thought about physiology and environmental change and how that affects organisms. So their lab is very focused on climate change and how shifts in temperature especially will change the distribution of these crabs and potentially make it very hard for them to survive, in the places that they're already living, but thinking about, again, why animals are distributed where they are. How do they do it now, and can they do it in the future, I think is a problem that's really pressing in science.
Andrew S.: So what did you actually do with the crabs?
Emily K.: My project was about trying to understand if stress experienced by competition between species of crabs or different individuals can be seen at the cellular level. So in this system, if you imagine kind of a rocky beach that are common in northern California, in a lot of places, under these big boulders are these tiny crabs called porcelain crabs, and we have lots of different species in California, but they live in these kind of stripes along the beach from where it's wettest the longest to where it stays dry or when the tide goes out. So there is two or sometimes three species depending on where you are, and they don't really interact with each other much but at the edges of these boundaries. With climate change, with rising ocean temperatures and rising air temperatures, we think that the ones that are normally driest the longest at high tide were going to get too hot and they're going to have to migrate down the shore towards the water, but as they do that, they're likely to run into the species that borders them.
So my work was trying to understand, "Okay, when you put these two species together, what happens? Do they coexist? Do they fight? Do they push each other out? Are they just going to keep pushing down the shore until they're underwater all the time? And, is that process going to be stressful? So I had some behavioral components. I essentially had little crab boxing rings to see=
Andrew S.: Nice. That sounds fun.
Emily K.: It was cold, it was cold, and lots of watching crabs do nothing, but when they did, they do get very territorial. This particular species of crab is a filter feeder, so they have almost fan-like mouth parts that they sweep through the water in front of their face to gather up particles that they then put into their mouth. So with too many crabs densely packed, they don't have room for these mouth parts to do that.
So they have kind of buff little crab arm claws that are really good for pushing each other out of the way. I was essentially tallying how many times did different groupings of crabs just push each other out of the way, trying to maintain this space. Then we wanted to know, "Do we see differences in the expression of genes associated with stress after these kind of battles?", I suppose. Unfortunately we didn't see a direct correlation, but that's still something that's really highly, [inaudible] under a lot of investigation right now. Lots of scientists in lots of different kind of species groups are trying to understand, you know, "Can we see markers of this type of stress because pushing away your neighbor all the time has got to be stressful, but do we see it on the cellular level?" We're not sure yet. We might see effects in other levels. So that's how I met one of my PhD advisors, and he got me here at Berkeley.
Andrew S.: Nice. So you said that your research there was mostly watching crabs.
Emily K.: It was a lot of watching crabs and a lot of DNA sequencing.
Andrew S.: Would you say that on a day-to-day basis, the actual things that you do to gather data are not the most interesting?
Emily K.: You know, when the grabs were moving, it was really fun to watch. I do a lot of behavioral- adjacent experiments; right now, I watch snails climbing tubes, so there's a lot of folks, I imagine, would think that that is the most boring thing I could spend my time doing, but I don't. I like to think about why animals might be doing what they're doing and under what conditions will they change those behaviors. So yeah, so I think it's fun. I imagine some folks don't.
Andrew S.: So it's fun because you know why you're looking at it today.
Emily K.: Right, right. Yeah, so it's not always the most fun story to tell at a party. Like, "Hey, I just spent three hours watching snails climb in a tube," but you have to put it in context for folks to understand why that might be interesting.
Andrew S.: For sure. Did you know before you got to undergrad that you wanted to be a scientist?
Emily K.: Yeah. I was interested in science from a very young age, especially marine science. I think if you had told my 10 year old self that I was studying things in creeks and rivers, my 10 year old self would be almost appalled, but I was an avid fan of the film Free Willy, and I thought I was going to study orcas from a very, very young age. I watched the VHS tape so many times that I think I burnt it out or I broke it, and my parents desperately needed to find another one, so they've known for a long time that animals really excited me. So I spent a lot of time at the beach as a kid trying to understand what the different types of animals are, why they do what they do.
So that kind of sustained me through my childhood into adulthood. Science has always been important to me.
Andrew S.: And you're thinking that it's going to be like your career as you move forward. Are you thinking about being an academic scientist afterwards?
Emily K.: I've thought about it. I can't say that I know my path is after finishing my program here, but I know that it'll involve science, but it'll probably also be heavily involving mentorship. I've learned a lot about being a mentor and being mentored here, and I work with a lot of students, so I found a lot of enjoyment in doing that and helping other folks navigate academia, navigate science and research, and that has been really fulfilling too. So, being in a space where there are scientists and lots of scientific ideas is important to me, but also helping other folks flourish in science is really important to me.
Andrew S.: What sort of programs are there to help people flourish in science here?
Emily K.: Yeah, I am the research coordinator for the Biology Scholars program, and we're a program that supports students in stem. Generally, most of the students that we work with come from underrepresented backgrounds, and that includes both ethnic or gender, like gender expression and socioeconomic groups. We spend our time helping them, yeah, navigate Cal, navigate their route towards their chosen career path in STEM. I'm just kind of being supportive, right? We want to take students that have these aspirations and give them just the support to continue doing the great things that they were already planning to do.
Andrew S.: Great, and you do a BASIS as well, right?
Emily K.: Yeah, yeah. So BASIS is Bay Area Scientists in Schools, and it's mostly graduate students and some post-docs, and some actually professional scientists from other groups around the Bay area, but we do science lessons in elementary schools. So yeah, there's lots of different lessons and lots of topic areas, and for K through five. We spend an hour at a time in a classroom doing science with young kids because most kids have never met a scientist. They might think science is not for them cause if they have seen scientists, maybe that person doesn't look like them, they don't talk like them. We want to show students that science could be for them and that it's fun, and that you can answer all kinds of cool questions but it also helps teachers.
Many primary school teachers are not formally trained to a very high level in science. They're all trained in science because they do teach it, but they sometimes aren't very comfortable teaching science as they spend a lot of time focusing on some other subjects. So in addition to helping students feel more comfortable with science, we want to help teachers feel more comfortable teaching science. So some of us write our own lessons to grade level. That's something I've done. In my lesson plans, I can help teachers do the same activity that I did with his or her students, or their students. They could do it again the next year if another volunteer isn't available to come. So yeah, we do it the first time and they can see how it went, and then they can kind of replicate it and feeling more comfortable about doing so.
Andrew S.: This is just a reminder that I've been speaking with Emily King. We've talked about her work on invasive snails and how she got here to Berkeley, but is there anything else you'd like to say?
Emily K.: Yeah. I would just encourage folks to check out their local streams. Lots of streams are accessible at public parks. Go appreciate them and then help other folks appreciate them by reminding everyone that they're important. They're often where some of our drinking water comes from and they are full of lots of cool animals, but when you do that and make sure you clean off your shoes, because the snails that I mentioned get tracked around mostly by people's footwear. So if you go between streams, you want to make sure that you've cleaned off the bottom of your shoes and you don't have any hitchhikers.
Andrew S.: Good advice for everyone. Keep a clean shoe.
I'm Andrew Saintsing. This has been The Graduates. Tune in in two weeks for the next episode.