Field Samples: Trying to Predict Ecosystem Changes Before They Occur

 Field Samples is a weekly Q&A asking researchers what they’ve been up to and what they’ve learned. Today, post-doctoral researcher, Eric Larson, from Chicago’s Shedd Aquarium, talks about better managing our resources by trying to predict ecosystem changes before they occur.
Who are you, where are you from, and how did you get here?
Eric in the field
Eric Larsen runs water samples as he hunts for eDNA of the invasive rusty crayfish in a Vilas County lake in Wisconsin. Image: Eric Larsen

I’m Eric Larson, a postdoc at the Daniel P. Haerther Center for Conservation and Research at Chicago’s John G. Shedd Aquarium. I’m also joint appointed with David Lodge’s lab at the University of Notre Dame Environmental Change Initiative. Before Chicago, I was a postdoc for two years at the University of Tennessee’s Department of Ecology and Evolutionary Biology working with Paul Armsworth on ecological economics and protected area design, largely around projects with The Nature Conservancy in Appalachia. My PhD was with Julian Olden at the University of Washington in Seattle, where I worked on the ecology and management of both native and invasive crayfishes in the Pacific Northwest. Going even farther back, I got my undergraduate degree in fisheries at the University of Idaho in Moscow, and also have a Masters in biology from the University of Arkansas in Fayetteville. So I’ve covered a lot of ground (and water) over the last decade!
Pretend we just boarded an elevator and you only have a one-minute ride to tell me about your research – can you capture it a few sentences?
I’m a conservation scientist focused primarily on protecting and managing freshwater species and ecosystems. My work is unified by an interest in improving conservation decision-making under data-limited circumstances. Ideally, we’d like to be able to anticipate species at risk of extinction before they begin experiencing population declines, or predict species likely to become invasive before they’re introduced to new environments. In both of those cases, we’re often limited by the data available to make predictions. I’m trying to get the most out of our statistical and modeling methods, so we can see around the corner and anticipate environmental challenges before they happen. By being proactive on these issues, we save money spent on management or mitigation, and hopefully prevent unwanted impacts to species and ecosystems.

What question did you ask and answer or do you hope to answer? What other questions might your work lead scientists to ask?
Although my work tries to push at the boundaries of what we can infer given our considerable data limitations, I also care about trying to reduce those data limitations themselves. For example, I work primarily on crayfish, a taxonomic group where perhaps a third to half of the over 300 species native to the United States are considered vulnerable to extinction. For the vast majority of those species, we know almost nothing about their basic biology or life history. That type of natural history research is increasingly difficult to fund and publish, but is the foundation for managing and conserving these species, or asking more complex questions about their ecology. So how do we make research into the basic biology of these organisms appealing (and fund-able) to researchers? How do we do it in a systematic way that stretches our limited resources to fill in the most important data gaps? I’ve been involved in launching a Southeastern Crayfish Biologists Working Group with a number of other researchers around the US to start tackling that question, and it’s my hope that we’ll succeed in both expanding our understanding of the basic natural history of crayfishes for conservation applications while also learning some new and exciting things about these organisms.
Pacifastacus leniusculus, or the “signal crayfish.” Photo: Jeff Benca
Not to sound harsh, but why should someone NOT in the field of freshwater sciences care about your work? What’s a bigger picture implication, in other words?
Freshwater is so central to human society and quality of life that I don’t think it’s difficult to motivate most people to care about it. Whether it’s drinking water quality or aesthetics and recreation, people are inclined to care about rivers and lakes, and the organisms that live in them. Incidentally, almost everyone I meet is curious about crayfish, or has a story about catching crayfish as a kid or attending crawfish boils. They’re great, charismatic organisms to engage people both inside and outside of science with how we both depend on and affect freshwaters. It probably irritates my family and friends how easily I can steer almost any conversation into crayfish, and from there into freshwater ecology and conservation more broadly.
What do you love about your work? What do you love, well, not-so-much?
Lake Shikotsu, Japan. One of the perks of field work. Photo: Eric Larsen
Lake Shikotsu, Japan. One of the perks of field work. Photo: Eric Larsen

I grew up in Wyoming, and a close family friend was a biologist with the state fish and wildlife agency. From hanging out with him at his job, I figured out pretty early on that it was possible to have a career outdoors working with nature, and that just seemed like the most appealing way to possibly spend my professional life. And that’s what I still love most about my job: field work, the incredible places I’ve visited to do research, and the new things I’ve had the opportunity to discover about the world. Over the course of my graduate career, I transitioned from just being excited that someone would actually pay me to spend time outdoors, to being excited that I could build a career out of discovering new things and sharing that knowledge with the world. There’s nothing I’d rather be doing with my life, and I don’t find a lot of drawbacks to my career. 
But I did arrive here from being a high school and undergraduate student who was not particularly enthusiastic about math and statistics; that was what I didn’t love early in my professional life. If I could send a message back to myself in the year 2000, it would be to pay more attention in math and statistics classes, and probably take more of them.
If you’re anticipating a career in the sciences, you’re eventually going to have to engage with the reality that math, statistics, modeling, or coding will be part of your work. The more you choose to embrace that, then the more successful you’ll likely be.
Obviously, like any profession, ecologists face trade-offs with respect to how we choose to spend our time during our education. How do you balance learning the classic literature in the field, staying current on what’s new, training to be a naturalist and field biologist, becoming a strong writer and communicator, and figuring out statistics and modeling? You can’t necessarily do it all, or can’t do it all at once. But everyone needs a little math or statistics in the recipe to be successful, and that’s something I didn’t believe (or want to believe) early on.
Tell me about one funny, memorable, exciting or awesome moment from the lab or the field.
I’m heading into my fifteenth year of doing field biology, and there have been too many great experiences to easily recount. For example, I always loved the camaraderie of field research crews when I was an undergraduate technician; the best summers of my life were spent conducting stream surveys for trout and salmon out west with the Forest Service and Idaho Fish and Game.
But I would say that my most interesting and challenging field season was the summer of 2008, when I visited Japan as a National Science Foundation East Asia and Pacific Islands Summer Institute (EAPSI) fellow, hosted by Nisikawa Usio, who is now at Kanazawa University. I did a summer’s field work in national parks on the northern island of Hokkaido, getting lost in my rental car and spending nights in small, rural inns all over the countryside. Conducting field research always has its challenges, and those challenges are compounded by language and cultural barriers. But I had a great experience and was able to do some really good work for my PhD, and I’m so grateful to everyone who helped me and showed me kindness when I was bumbling my way through that project. And it probably doesn’t hurt my memories of that summer that I was working in some of the most beautiful lakes in the world.
Where do you hope to go from here? New research questions? Continuing with this work?
Two things really excite me about my current position. One is the incredible opportunity to contribute to outreach and education about freshwaters through Shedd Aquarium. Shedd is an exceptional platform to reach a broad and diverse audience about the role of freshwater in our lives, and how we can meaningfully affect the management and conservation of freshwater resources like the Great Lakes. I really enjoy the opportunities that Shedd affords to meet and talk with the public and school groups about my research, crayfish, and freshwater ecology and conservation in general.
And I’m also excited about the opportunity to work and collaborate with the laboratory of David Lodge at Notre Dame. That includes inheriting access to a wealth of data and natural history knowledge about organisms like the invasive rusty crayfish Orconectes rusticus in lakes of northern Wisconsin and Michigan, as well as learning new field and laboratory skills around the emerging methodology of environmental DNA (eDNA). The Lodge Lab has pioneered the use of eDNA (environmental DNA) to monitor and detect species invasions in the Great Lakes region and elsewhere, and I’ve enjoyed the opportunity to add experience with eDNA to my ecologist’s toolbox. Using eDNA to detect new invasions at population sizes where control or eradication is most feasible and cost effective really meshes with my research interests, and it’s been interesting to begin applying this tool to study crayfish populations.