My mother told me a story when I was very young, one with an image so vivid that I can’t remember a time I couldn’t visualize it. In the early 1980s, my father, an air force officer, was stationed at Andersen Air Force Base in Guam; walking to the grocery store on base one day, my mother saw dead snakes hanging drooped over power lines. Snakes, she explained to me, had been brought to the island to control mice populations. But with no natural predators of their own, their numbers had expanded in abundance.
To her, the lesson was clear, and she repeated it often. “You take care of one problem,” she told me, “and you create another problem.”
Growing up, I often pictured snakes draped over wires like discarded wet ropes, the silhouettes of their bodies dark, strange ribbons swaying against a bright sky. After moving to Chicago for graduate school, where I focused on creative nonfiction about the environment, I felt compelled to write about the snakes. I found the image as disturbing as a nightmare. Mystery lurked there. Though I believed my mother’s tale was in earnest, it felt incomplete.
The snakes in Guam, I discovered, were tremendous climbers. Scaling palm-like branches of paipai, they fed voraciously on birds. But contradicting my mom’s story about the military bringing the snakes to Guam deliberately, the reports I read said their arrival was unintended. Still, the military had had a role to play: following World War II, the US began shipping old war cargo that had been sitting in the jungles of Papua New Guinea to Guam. It’s likely that several snakes hid in cargo vessels, reaching Guam unnoticed. It would only have taken one pregnant female to disrupt the island’s ecosystem.
Forest birds fled tree branches and built homes on power lines, but the snakes sought them there too. Scaling a grounded pole, a serpent had only to stretch from the pole toward a bird’s nest. But with tail grounded and body lengthening to touch live wire, execution was quick. The corpses of the snakes hung in spirals from the power lines as people walked underneath them.
The snakes systematically eradicated nearly all of Guam’s native forest birds, in one of the earliest and most devastating cases of predation by an invasive species. Guam’s forests fell silent. Some birds, like the bridled white-eye, were last observed in Guam’s forests in 1983, the year before I was born at the naval hospital, months before we moved to Lubbock, Texas, where my father was stationed next. The consequences of snakes have been disastrous for Guam: spider populations have exploded, and with no birds to disperse seeds, tree canopies have thinned, leaving the forest’s limestone floor overexposed to the sun’s heat.
In my mom’s telling, talk around the base had designated the reptiles as Philippine rat snakes. But my research showed that they were a totally different species: brown tree snakes. Why had one species been mistaken for another? Snakes, like other organisms, are endemic to particular ecosystems, but the mistaken national designation of “Philippine” left me uneasy. Why had the snake been marked as a kind of other?
I later learned that the brown tree snakes began to appear at the same time that Filipino migrant workers were hired to repair Guam’s infrastructure after its decimation in World War II. As I learned more, I saw it was not uncommon for stories about invasive species to conceal humans’ hand in introducing them.
Picture rural Arkansas, one of the country’s largest sources of catfish. Bred commercially, the whiskered scavengers inhabit rectangular pools called earthen ponds. Water gleams like panes of green glass plated in neat rows across the land. Browsing images online, I’m surprised to find the farms strangely beautiful. Their symmetry is clean and minimalist. If I didn’t know better, I might mistake the shimmering surfaces for panels in an art installation by a Donald Judd wannabe. But beneath the surface, these waters can be murky. The warm temperatures and stagnation of the ponds, among other problems, lead to dense accumulation of algae. These algal or plankton blooms, as they’re called, harm fish by sucking up the water’s oxygen and blocking sunlight from reaching plants on the pond floor. In such cases, researchers advise, the water should be fertilized.
The publication of Rachel Carson’s Silent Spring in 1962 sent shock waves through state agencies. The following year, in 1963, the Arkansas branch of the Bureau of Sport Fisheries and Wildlife (which later became the US Fish and Wildlife Service) imported grass carp as an organic treatment for catfish ponds. Carp, with their voracious appetites for plankton, were a chemical-free filter. When the approach proved successful, additional species — black, silver, and bighead carp — were brought from Vietnam and Malaysia, and later from China and Russia as well. Without differentiating among the species, agencies like the US Department of Agriculture and environmental organizations like Alliance for the Great Lakes began referring to them as “Asian carp.”
While farmers continued to release these carp into their catfish farms, the state began an experiment that used silver and bighead carp to filter sewers. When the FDA, citing sanitation violations, promptly shut the project down, state officials found themselves with a surplus of carp and released them into local streams, where the carp took to the wealth of plankton and thrived.
My mom’s refrain — you fix one problem and create another — resonates with what happened next. Silver and bighead carp, with their voracious appetites for plankton, were a chemical-free filter that could help to reduce the rapid accumulation of phytoplankton that produces algal blooms. A bighead carp can grow to be over one hundred pounds; it eats 20 to 40 percent of its body weight daily. The carp quickly started to replace other fish because they could outeat them. Now, in many corridors of the Mississippi River, the carp occupy close to 90 percent of the biomass, or total mass of a given species in one area. Environmentalists fear that next, the carp will decimate fish populations in Lake Michigan.
The fish are a problem, but what kind of problem? Their impact on Lake Michigan could devastate a fishing and recreational industry with economic values estimated to fall between $4.5 and $16 billion. Carp could disrupt the lake’s ecology, which is closely tied to the region’s economy. But ecologists aren’t the ones calling the shots. Managing “invasive species” falls under the responsibilities of the US Army Corps of Engineers, according to their website. Framed as invaders, the carp become a military problem, as though the fish have mounted a national assault. For me, they are a language problem: the term obscures the larger context of human engineering.
The threat they pose is facilitated not by another nation but, closer to home, by a small rivet in Chicago’s water infrastructure: the Chicago Sanitary and Ship Canal, a thirty-mile stretch of concrete connecting the watersheds of the Great Lakes and the mighty Mississippi.
When I moved to Chicago from Texas in 2016, I was immediately struck by the water geography: the soft blue surface of Lake Michigan rippling to the horizon, the beryl-green Chicago River ensconced by skyscrapers. As vast as these waters are, I once considered them regional. But in 1900, the direction of the Chicago River was deliberately reversed by the opening of the Chicago Sanitary and Ship Canal. At the time, the river teemed with offal from Chicago’s historic meatpacking industry and waste from the growing populace; the canal redirected the river to carry disease away from the lake. For over a century now, the waters of the Chicago River have coursed into other Midwestern rivers to eventually merge with the Mississippi River. In this way, a thirty-mile canal connects the Great Lakes to the Gulf of Mexico, forming a pathway that many new reports and environmental organizations today refer to as a highway for Asian carp. To my ear, that makes it sound like a trench forged by a carp platoon, not a landmark of human engineering.
On a map, the Chicago Sanitary and Ship Canal extends in a clear, blue, uniform stretch that eventually connects to the Des Plaines River. A few miles south of my home, I-55 lifts into an overpass over the canal. I wanted to see it for myself, to move from conceptual to concrete. But as I drove, viewing the canal from my car on I-55 was challenging; trees and development obstructed it as townships undulated out from the Chicago city limit.
Twenty miles in and with no clear sighting of the canal, I pulled up to a forest preserve dotted with quarries and stepped out of the car. Above me, a blue heron flew toward the city, as though following the canal back to the point where it connects to the Chicago River. She began to fade from view, and I still couldn’t see the Asian Carp Highway. Below the heron, I pictured the canal waters coursing with microplastics, agricultural nutrients, and other pollution. Yet the call to prevent the bighead and silver carp from reaching the Great Lakes overshadows what are arguably more entrenched problems of pollution and shipping industry use. To Robert Hirschfeld, a water policy expert at the conservation organization Prairie Rivers Network, this approach is shortsighted. “We are dealing with an entire ecosystem,” he told me in a phone interview. The carp are only part of the story.
Since they were initially observed in the Mississippi, the carp have appeared in news headlines like “Invasion USA: Asian Carp Invaders Have Taken the Mississippi, Are the Great Lakes Next?” and “Asian Carp: How One Fish Could Ruin the Great Lakes.” One reporter for The New York Times described the carp as “bottom-sucking ogres.” Silver carp are often pictured arcing out of the water by the hundreds, thrashing dangerously at outnumbered fishermen. It’s the kind of image that, like snakes on a wire, ignites the imagination. Calling the carp “invaders” designates them as outsiders and endows them with purpose, as though they intend to wreak havoc in Lake Michigan. The USDA and ecological sciences often use the euphemism “non-native,” which has its own racist baggage.
I pulled back onto the road and drove south to Romeoville, where the Army Corps of Engineers operates a lock and dam and a series of three submerged fences. I imagined that in Romeoville I would be able to observe the lock, if not the fences, but when I arrived I discovered I could see neither. I needed official documentation to drive up to the lock, and it wasn’t visible from the kiosk where a voice buzzed through, telling me to turn around.
Schematics I accessed online suggest that the barriers are impossible to see from the water’s surface. Rows of steel electrodes, which look like steel cable rope on steroids, reach 160 feet across the canal and are fixed to its floor, twenty-five feet deep. A control building on the canal’s concrete bank generates a pulse through the electrodes, creating a field of electrified water. Graphics and photos show the electrode wires stretching across the bottom of the canal, flagged with symbols of lightning bolts that remind me of the warning label attached to the cord of my hair dryer. The Army Corps of Engineers describes invasive species as biological terrorists; a report on the website for the Chicago District of the Army Corps of Engineers claims that “the Electric Barriers are operated to deter the inter-basin establishment of Asian carp.” The water between the barriers is designated an “electroshock hazard area.” The canal fuses the American Midwest to the South, the waters in it not only channeled but electrified. When I spoke with Robert Hirschfeld, he called it “militarized water.”
Though the electronic barriers at Romeoville were greeted with praise and wonder, there are questions about their adequacy: traces of carp DNA have been detected above the barriers. As part of the Biden administration’s Infrastructure Investment and Jobs Act, the Corps will receive more than $225 million in funding for plans to develop additional deterrents south of Romeoville at the Brandon Road Lock and Dam near Joliet. Illinois Congressman Bill Foster celebrated the announcement, saying in January 2022 that “the Brandon Road Lock and Dam is the last line of defense for preventing invasive Asian Carp from reaching Lake Michigan and all of the tributaries and lakes in the Great Lakes basin.”
Feminist biologist Banu Subramaniam suggests that what we consider to be biological variation is largely premised on a specific, localized, and bounded idea of “place.” Organisms may migrate, interact, overlap. A bird carries a seed; a bur bothers a fox from the meadow to the wood; sandhill cranes slow-wing their way across the North American continent. Nevertheless, we have come to associate specific organisms with particular places. Doing so naturalizes the idea that life forms belong not only to particular ecosystems but also to specific geographies. Our social categories are embedded in ecological ones.
A painting by artist Alexis Rockman entitled Pioneers tells a different, more transparent story about invasive species. At six by twelve feet, the canvas is large enough to seem like a mural. Standing in front of it, you are submerged, looking onto a lake floor. Brought together in one image, the details of the piece unfold chronologically, and you take in the piece as one would read an English sentence, from left to right, beginning with images from the Ice Age. Deep, stark blue water purls at the foot of a glacier; the fossil of a mammoth gleams up at a few sparse schools of fish swimming in the enormous space of a prehistoric ocean; a sturgeon twists toward a sun-bleached sky. The writer Louise Erdrich describes wild sturgeon as a “living relic of life before the age of the dinosaurs, and to see one is to obtain a glimpse of life 200 million years ago.” Such an expanse of time is condensed and sped up in Rockman’s piece. Absorbing the work requires not only your eyes but also, because of its breadth, your body too. With one step, you cross epochs.
When I saw the painting on display at the Chicago Cultural Center, I stepped from the Pleistocene to the Holocene, the moment of introduced species. There, the waters change to a lighter blue and swallow a sunken steamboat. The final inches of the painting represent the present day: the shadow of a cargo ship hovers at the surface of the lake. Below it, a cloud of ballast water explodes in jaundice and brown — the colors of illness and industrialization — as the vessel spills its toxic weight. An anchor and its chain drop from the freighter and twist into the lake floor. The piece ends with invasive species. They coil amid the ballast water in a parallel column with the anchor chain; the introduced species are now a permanent fixture of the lake’s ecosystem. I recognized many of these creatures: eel-like lampreys, shimmering alewives, the dark shells of quagga and zebra mussels, toxic algae. Rockman’s painting placed these species in the larger contexts of commodity exchange and consumerism. Imports and exports of goods carry new creatures with them; in this way, Rockman’s painting invites us to see how the paths of capital disrupt ecosystems. Invasive species signify devastation, but they are not the cause.
The very term “invasive species” frames these organisms as international foreigners poised to attack and suggests that they threaten a stabilized ecosystem balanced by an even distribution of native species. The term officially entered the sciences in 1958, with the publication of ecologist Charles Elton’s The Ecology of Invasions by Animals and Plants. In the context of World War II, Elton writes that ecological invasions are akin to nuclear attack and war. He describes invasive species in terms of “explosions…bursting out from control of forces that were previously held in restraint by other forces.”
There’s more to “invasion” than the place where an introduced species is heading. The term also evokes where the species are from. Establishing the term “invasive species,” Elton describes invaders as “those that occur because a foreign species successfully invades another country.” His book includes cartography of the United States speckled with an infestation of rats. There’s also a map of Brazil, darkened in regions inhabited by the African malaria mosquito. To occupy a new ecosystem, early invasive ecology suggests, is to assault the country.
Echoing what Hirschfeld told me, Rockman’s work suggests that our approach to changing ecologies, and to climate change, must take the whole picture of an ecosystem into account. Looking at it, we understand how, as the Army Corps builds submerged fences, trade continues to move on the water’s surface.
The Greater Chicago Chapter of the fishing club Salmon Unlimited meets monthly at Elk Grove’s Veterans of Foreign Wars hall, a white shoebox of a building in the western suburbs that is, I was warned, easy to miss. The president of the chapter was a guy named Cole whose email address was “reelguilty.” He had contacted the University of Illinois at Chicago’s Freshwater Lab, where I conducted research on the social contexts of invasive species, to ask if someone would speak to the chapter about carp. He explained that Salmon Unlimited was interested in all aspects of fishing on the Great Lakes, including ecology and conservation. I responded eagerly; I wondered how these fishermen would react to my skepticism about using military responses and walls to deter fish.
Salmon Unlimited was composed largely of retired Korean War veterans who, as far as I could tell, were splitting the remainder of their days between the surface of Lake Michigan and sports bars like the one where I met them for dinner before the meeting. The men sped through their phones’ photo libraries and showed off pictures of their catches. One of the members had also taken innumerable photos of prairie life; he often interrupted the annals of his fishing history with: “Oh, there’s that deer again.”
Reelguilty Cole was more ponderous with his trophies. He showed me a picture of a sturgeon that stretched the full length of his not inconsiderable torso. “Caught that one in the fall,” he said. I’ve never been fishing, a fact I keep to myself among Midwesterners who embody its masculine associations. I am not a man, but my status as an interloper among white men who fish is less about my gender and more about my lifetime avoidance of the moment, right after the catch, of killing the fish. The process has been described to me in gruesome detail and involves whacking the fish’s body on the boat deck or a rock, or else letting it writhe until it asphyxiates. It’s a full-on internalization of the false binary that suggests I exist in a domain separated from systems — ecological and economic — that produce my food.
Nothing about Salmon Unlimited members suggested that their obsession with fish was about deconstructing dualisms. The men’s preoccupation with the weight of fish was about conquest and competition, the age-old archetype of man versus nature. The bigger the fish, the greater the man, the story seems to go, and it’s a story that extends to invasive carp too.
In my talk at Salmon Unlimited, attended by about forty men and two women — the wife of one fisherman, and his mother, who slept soundly through the entire evening — I began by saying that I wanted to focus on the stories we tell about carp. “I figure,” I continued, speaking into a microphone hooked up to the portable PA system, “you fishermen know a thing or two about telling stories.” Among experts on rivers and catch, I had to remind myself why I was there. For the fishermen, the question of how to address the growing presence of the carp was a live one; they were worried about the carp reaching the ecosystem that supported their sport and, for some, their livelihood.
“Carp are sometimes called bioterrorists,” I said. “I want to think together about how calling the carp terrorists leads to certain kinds of actions, like militarizing water.” I hoped for a discussion about the role that narrative plays in the way we address ecological problems like carp. What could happen if we began to acknowledge the human drivers and infrastructure — like the canal — that facilitate the presence of new species? Perhaps we could engage with the shipping industry, which insists that the pathway between the Great Lakes and Mississippi remain open. I paused and looked across the room. Many of the men sat calmly with their arms crossed. A few nodded. One adjusted his hearing aid, though whether to turn it off or on, I’ll never know. I took a deep breath and continued, talking about the electric barriers at Romeoville.
One of the men raised his hand. “I got a question,” he said. “How did the carp get here?”
“Yeah,” I said. “I guess I should have started with that.”
Backtracking, I outlined one of the common myths about the carp: the story usually goes that the fish “escaped” from the catfish ponds in flooding events. “But in truth,” I said, “the Arkansas Game and Fish Commission released the carp into freshwater tributaries after a failed sewage experiment. By the 1980s, all four carp species sprung up in the lower Mississippi basin. By the time Asian carp were making headlines in 2001, they occupied many corridors in the Mississippi watershed, and they were populating Illinois waterways relatively quickly.”
A guy in a Packers hoodie unfolded his arms and raised his hand.
“That didn’t happen, miss,” he said. “The carp weren’t released.” He fluttered his fingers in the air. “They jumped from the catfish ponds to the streams and got in that way.”
The fishermen eyed me. My stomach tightened. I don’t seek out confrontation, but I anticipated this might be a tough crowd. Later I would consider the worn nerves so many veterans bear; perhaps the men felt like I was telling them that the country they fought for — and now fished for — had betrayed them. But I rallied: I brought up Dan Egan’s book, The Death and Life of the Great Lakes, which goes into detail about how the state contributed to the presence of carp in the Mississippi watershed. I also planned to point out that only silver carp jump, not grass or black or bighead. But I didn’t get a chance to talk about the nuances of jumping fish because another fisherman stood and raised his hand like a preacher.
“Twenty years ago, I was in New Orleans,” he said. “The story of flooding? Of carp escaping? I met a fisherman there who told me it was a cover-up by the state, which had released the carp into the Mississippi. They didn’t want to be held responsible.” He pointed at me. “Tonight, for the first time in twenty years, that story has been verified.”
I lifted the microphone. “Can I get an amen?”
Bighead carp are dull-eyed, open-mouthed; any parallels with humans are not ones we care for. Even amid the largesse of consumerist culture, the plenteousness of carp insults our sensibilities. They overproduce, overeat, and overstay their welcome. When I Google “the meaning of carp in dreams,” my first hit tells me that “to see a live fish in dreams is very much a good sign, unless that fish is a carp.”
We don’t even want to eat them. “People tell me, ‘Don’t call it carp — call it something else,’” Dirk Fucik, the owner of a small fish market in north Chicago, told me. His shop had wood floors and shelves stacked with housemade rubs, marinades, and panko bread crumbs. A wraparound counter displayed shrimp, salmon, trout, and fresh fillets of walleye from Lake Erie. Fucik told me he’d just received sixty pounds of Asian silver carp that morning. “And I’ll be shipping about half of it up to a shop in Wisconsin,” he said. “I have cookouts on Saturdays trying to get people used to eating carp. Folks don’t even want to try it at first.”
There are a number of reasons why so many Americans don’t want to eat carp. While the fish inhabit higher parts in a river’s water column, they are colloquially often referred to as bottom-feeders. Their reputation for being voracious eaters seems to have extended from the fact that carp eat a lot to the myth that they eat everything. Black carp eat mussels, while bighead and silver carp consume plankton and plankton only. Standing in Dirk’s Fish & Gourmet Shop, I found myself wondering if, in the same way we’ve conflated all three species into one, we’ve created an amalgam of their eating behaviors that results in identifying the carp as a scavenger species.
People often mistake one nonhuman species for another, or group several species into one; both of these have happened with carp, and with the brown tree snakes in Guam. When I asked a professor of ecology who studied the snake outbreak if the two species looked alike, he quipped, “Well, they are both snakes.” He went on to say that to a herpetologist, the brown tree snake and the Philippine rat snake couldn’t be more different.
“These are the kinds of instances where you get racialized and racist explanations for the appearance of a new species,” he said. “A new group of people, a new animal, must all come from the same place.”
Such conflation of species has other purposes and can even occur between species. Consider the relationship between humans and dogs. Donna Haraway writes that imagining canines as fluffy, fun-loving fantasy animals who love humans unconditionally establishes an affection economy premised on our own narcissistic projections. Affiliation, in this model, is based on similarity. When a dog bites, gnaws the couch, urinates on the rug, or enacts any other behavior falling outside the norms of humans’ conditional love, termination of the relationship, such as euthanasia or rehoming, is sometimes seen as justified. In other words, parallels with human behavior, in an affection economy, ethically obligate humans to their dogs only when their pets act like humans. The language of invasive species, though, is premised on difference: they came from somewhere else. Our response to this tends toward some combination of horror, fear, terror, panic, and myth. But to flourish in a multispecies world, Haraway writes, we can’t rely on similarity, as with dogs, and we shouldn’t react violently toward difference. Instead, we must appreciate the reality of difference — from labradoodles to carp — even when it is challenging. The language of invasion does not help us understand how to coexist in a rapidly changing world.
When I last visited my mother, I joined her for an excursion to a butterfly exhibition at the local science museum in Lubbock. I stood still to tempt butterflies of indigo and black, silky yellow and purple, to land on my shoulders and fingers and ears. They were very social insects. I thought about the butterfly tattoos on the ankles of so many women. I thought about the chrysalis metaphors dominating stories of rebirth and renewal.
To leave the exhibit, we walked through a series of corridors blocked off by doors. At each point, we were checked for stowaway butterflies hidden in creases of clothing or tresses of hair.
“Many of these butterflies are considered invasive species out here,” the staff told us. “If they got out, they would devastate West Texas.”
My mother nodded. “I know all about that.” She looked at me. “Take care of one problem,” she said, “and you create another problem.”
Even though the premise of her snake story is unfounded, what I like about my mom’s point is the word “create.” Invasive species are, in many ways, created by humans. “In truth,” Hirschfeld told me, “we are the invasive species.”
Over and over, I find myself returning to the brown tree snakes in Guam. Last year for Prism, journalist Frances Nguyen wrote about Guam’s struggle against US military buildup on the island, which threatens its environment and its residents: “More than 1,000 acres of native limestone forests, which have been part of the island landscape for millennia, will soon be cleared to construct a massive firing range complex as part of a planned US military buildup.” In the end, framing the brown tree snakes as invaders did little to protect the island’s ecology. But it had other effects. “When the invader is a nonhuman species, colonialists need not account for their presence on lands that once belonged to indigenous communities,” one of my professors, Dr. Rachel Havrelock, told me when we discussed my research on the carp. In my mom’s telling, the natives are — improbably and inaccurately — the US military men and women who find snakes in the cages of their pets, in cribs next to their babies. Looking up to find snakes on power lines, they see themselves as the ones being invaded. But the rhetoric of invasive species lets imperialist forces off the hook. My parents were no more native to Guam than the snakes.
Like all ecological stories, the story of those snakes, and of Asian carp, is ongoing. Invasive species are a problem not only of trade and climate change but also of language. I feel ensnared by the term. Thinking about what else might we call them, I find myself looking back to Rockman’s painting. It concentrates epochs to speed up deep time; it shows environmental collapse from the perspective of rock. Environmental disruption occurs through an accretion of economic and ecological events. The invasive species vortex turns underneath a freighter. In Rockman’s rendering, these species are not invaders but, as the title of the painting suggests, colonizers — linked by the biochemistry of the lake, by the paths of commodity that connect the Great Lakes to the Atlantic and the Gulf. At the edge of the painting, a shopping cart sinks to the lake floor. A white sun blazes above the water, too large in a shrinking expanse of sky. The circle of light reminds me of a camera’s blinding flash, concealing the human behind the lens.