Piranhas in the Chicago River

Our Faith

Ecologist Reuben Keller knows that caring for the planet requires thinking beyond the environmental sciences.

Trek up to Reuben Keller’s Chicago office, and you’ll likely catch a glimpse of Lake Michigan on your way. Actually, you can nearly see it from his desk. It’s a fitting location for Keller, a freshwater ecologist and assistant professor at Loyola University Chicago’s Institute of Environmental Sustainability.

But this institute isn’t just for scientists, and Keller—who talks just as passionately about statistics and economics as he does about the rapid evolution of a snake species—prefers it this way. Keller studies the relationship between living things and the environments in which they live, and most of his career has focused on the environmental impact of invasive species. In order to make effective environmental policy changes, however, Keller realized he also needs to focus on the economics and politics of globalized ecosystems.

“The broadening of what I was interested in came from my experience of being an ecologist, coming up with ecological models, and thinking I’d answered everything, that everyone would change their policy because I told them so,” he says. “Of course, barely anyone reads my papers, let alone does what I tell them to.”


So, he changed his approach. In 2011, he organized a conference of experts in a wide range of fields—economists, engineers, and legal scholars among them—to discuss invasive species. Keller and two collaborators even published Invasive Species in a Globalized World (University of Chicago Press), a collection of papers and essays based on the conference.

“As an ecologist, I have an important role in reaching the solution, but it’s a very small role,” he says. “We’re all part of the solution.”

What are invasive species?

An invasive species is a nonnative species that is established and breeding and causing harm. Different people have slightly different definitions, but that’s the most common one. Basically, it’s a nonnative species that we wish would go away because it’s causing some sort of measurable harm.

Nonnative species can be quite benign, though. Most of the species that become established, we don’t really know what they do. That’s probably partly because there aren’t enough ecologists to study them all. It’s also partly because they fit into their community and exist in small numbers. They don’t cause really big problems. The really bad ones are the ones we are most concerned about. Things like the zebra mussel, Asian carp, kudzu—things like that. These are the ones ecologists get most energized about.

How do species become invasive?

So, we see a lot of alligators and piranhas get caught from the Chicago River. It’s not that infrequent. The only explanation for this is that people buy these organisms for their personal use. And when they get too big, the owner has to get rid of them.

Many believe the most humane thing to do is release them. So that’s what they do. With alligators and piranhas, you don’t need to worry about them. They’ll never survive out there through the winter, but they’re good examples of species that couldn’t have come from anywhere else. There’s no way an alligator just accidentally came up the Mississippi River.

We’ve created this invasive species problem because we’ve basically globalized the world. We’ve done it economically: We can buy whatever we want from China or Malaysia or Western Europe, and it can be delivered in three days.

What that has also done is globalize our ecosystems. Our ecosystems are now connected to other ecosystems around the world that they could never have conceivably been connected to in the absence of humans establishing this trade and travel.

How have we contributed to the problem?

We’ve sort of connected all of these ecosystems that have been evolutionarily distinct. It’s just inconceivable that they would have been connected otherwise. And we have so many different ways of doing this. There’s shipping on the Great Lakes. There’s the aquarium trade, the pet trade, and the bait trade, where lots and lots of little fish are bred in the southern United States. We’ve connected the Great Lakes to the Mississippi River and the Atlantic Ocean via the Chicago Sanitary and Ship Canal and similar seaways.

Once they are connected—once we are moving these organisms around—it is not surprising that we get a lot of invaders. This past summer, I did some work with students around the Chicago region looking at crayfish.

We’re finding this one species of crayfish—red swamp crayfish—all over the place. It’s the species that restaurants serve if you order crayfish—or crawfish, whatever they call them at that restaurant. They get imported in huge crates from southern states. Sometimes they get released, and we’ve started finding them all over Chicago.

There’s this vast web connecting the globe. It’s generally pretty good in a lot of ways, but there’s also this reality that we’ve connected all these ecosystems, which, in a lot of ways, is very, very bad.

Why is it a bad thing to have connected ecosystems?

Well, there are ecological impacts, which are the ones that ecologists are doing really well at studying. We can look at how the species affects native populations of animals and plants. But there are also economic impacts, which essentially means that someone has to pay more money because the invasive species has arrived.

These species can impact human health, too, which occurs mostly in the form of disease, usually communicable disease. Various strands of bird flu and swine flu emerge in one place, but then they get moved around. That’s why they’re so harmful.

When we hear invasive species, our minds tend to jump to wildlife conservation. Are humans affected too?

One thing ecologists haven’t done a very good job at is looking at how invasive species affect humans and human welfare. They can have really, really large impacts, particularly through agriculture. If an invader destroys or reduces a crop, that’s bad—especially if you’re a subsistence farmer. Invaders can also have a load of impact by reducing access to freshwater.

There are these floating aquatic plants that can grow across an entire lake, and you just can’t access the water. You can’t put your fishing boat onto the water. I was contacted by someone in Kashmir, India who had just finished his Ph.D. He was working on a lake there called Wular Lake, which is incredibly important for the people who live around it because there are reasonably large villages nearby that are dependent on harvesting plants, agriculture, and fishing.

The villagers are very poor, marginalized people. And there’s this huge lake, which is fascinating from an ecological point of view. It was recently invaded by some floating aquatic plants—alligator weed and Azolla—which are slowly spreading out across the whole lake and threatening the surrounding communities.

If they are not controlled quickly, they will cover the whole lake. When they do that—if they get to that point—fisheries will disappear because you can’t throw a net in if the lake is covered in these aquatic plants. The plants don’t let enough oxygen into the water for the fish to survive. Even if you could throw a net, there’s nothing to catch.

Who pays for damage like this?

Part of the reason that we don’t have better management of invasive species is the distribution of benefits and costs when nonnative species are introduced. These very large industries, like the aquarium trade and the pet trade and the nursery plants trade, who intentionally introduce species—many of which become very harmful invaders—are just divorced from those effects. They don’t pay a dime for it.

From their point of view, introducing these species is a really big net benefit in their limited world. Their economic incentive is to introduce as many new species as possible because they may be profitable in the market. But once those species become invasive, the costs are born much more broadly.

Here, the Illinois Department of Natural Resources, along with other government and federal agencies, spends a lot of money trying to control invasive species. That’s all coming out of our tax dollars, but it’s not something that we really think about because it’s a pretty small amount. No one is going to vote for a president based on invasive species.

There’s this real distribution problem, which is that the benefits from this pollution—we can call invasive species biological pollution—accrue to a very small part of society that is very motivated to maintain the status quo.

On the other hand, the costs are spread broadly across society. That’s really one of the big hurdles that regulations and better legislation has to overcome. By and large, it hasn’t happened yet. I’ve been up to Washington, D.C. a couple of times to present to congressional staffers on why we should be pushing better legislation to keep these invaders out. When these things do get addressed, the bills generally don’t make it to the floor of the House.

Is there any legislation that is talking about invasive species as a whole?

The way that we hear about invasive species in Chicago is almost always, “Asian carp is terrible. We’ve got to deal with this.” We hear about it for a couple of months. Then it goes away.

The way invasive species get presented to us is on this species-by-species basis. What I try to emphasize in my research is that there is something much more systematic going on here with these thousands of species coming to the U.S. Legislatively, there are tools that exist to address this. They are just not used. And when they do get used, they tend to be used reactively.

The Burmese python, which is this enormous constrictor snake that grows to be 12 feet long, was established in the Florida Everglades. It breeds fairly easily in captivity. It used to be sold. You could buy it for just a couple of dollars—a six-inch-long Burmese python on your way out of the pet store. It was like candy at a grocery store.

So people bought them and, lo and behold, they get big—bigger than someone can deal with. So they were often released. Pythons are now banned from import to the United States. But they are already well-established in the Everglades.

By and large, this is the way species are banned from import. They get imported. They get released. We realize how terrible they are. We ban their import. There’s a problem there.

What is ecology and how could it alone be an answer to the problem of invasive species?

Ecology has a part of the answer, but certainly not the whole answer. The average person doesn’t spend time thinking about ecology or the impacts of invasive species. That shouldn’t be their number one priority. They’ve got to balance that against many, many other priorities.

We live in a world where there’s no longer anything pristine. We live in a world where we actually manage every single ecosystem on Earth to different degrees. We manage Antarctica, in a way, by releasing millions of tons of carbon dioxide, which is leading to ice shelves collapsing and things like that.

It’s complicated. And from a policymaker’s point of view, it’s really complicated. They’ve got economic concerns and they’re trying to weigh up what sort of response they’re going to get from these different stakeholders and how they’re going to justify that. You’ve got to put together a pretty nuanced picture to make a convincing argument.

Is it difficult to get people in other fields to understand the importance of this problem?

It’s hard. To work with economists, I’ve had to learn how to talk to economists. They have a different language. They have their own jargon. They have this whole community and they all have their ways of interacting. Learning how to talk to them is difficult.

I’m not by any means an economist, but I’ve learned exactly as much as I need in order to converse with them and understand what they’re doing. I’m now able to explain my problem—the invasive species problem—in economic terms. I frequently felt unintelligent because I was sitting there talking to someone talking back at me in words I don’t understand.

I don’t know this for a fact, but I think my interdisciplinary work hurt me on the job market because there’s no such thing as a bioeconomics department. I sent applications off to ecology programs and biology programs. They’d look at my CV and wonder what they’d do with me. What would you do with someone who uses dollar signs in their ecology work? There’s no easy, natural place for that to fit anywhere in the way universities are organized, except here, in Loyola’s Institute of Environmental Sustainability.

And there are more and more departments like this popping up. I was very lucky to be on the job market as this was being developed.

How is the environmental program at Loyola different from something you might find at another university?

Loyola has an environmental program, which is not traditional. The traditional way a university offers an environmental science degree is where one academic is in charge of the major, and they farm the students out to the different departments. They take a little chemistry. They take a little biology, a little physics. They take math. At the end of it, you give them an environmental science degree. That’s even what the model was at Loyola for quite a while.

Loyola’s environmental-specific program is not unique, but it is different from most programs in that the environmental program has its own faculty. We have people who are hired to be part of this environmental program. It’s my job to support this type of interdisciplinary learning and scholarship.

Why is it important to approach environmentalism from multiple disciplines?

The environmental problems that we have can’t just be solved by ecologists. For instance, if we think about climate change, it probably falls into a physics department, where they do climatology. But we can’t understand what climate change will do without also understanding demographics and agricultural science and ecology.

Part of the increase in interdisciplinary collaboration is that over the last several decades, we’ve created environmental problems that are bigger than we’ve ever had. They’re not confined to geographic boundaries. Climate change and invasive species are real global phenomena now. We can’t ignore what happens in China or Saudi Arabia or Europe, because it matters for our environment here. It makes a big difference.

I also think academia has a much longer history of talking about interdisciplinary work than actually supporting it. It’s hard to support these projects within a department structure, where departments are divided by specialties and everyone’s trying to impress the chair of their department. If you’re working within a context where everyone around you is a biologist and you start doing something different, then that’s not always looked upon favorably.

But Loyola is very supportive of it. There are internal grants that you can get to support working across disciplines. Loyola is very supportive of that sort of thing.

This article appeared in the December 2015 issue of U.S. Catholic (Vol. 80, No. 12, page 32–37). 

Image: Flickr cc via Philippe Gillotte