It’s back-to-school time and anti-bullying campaigns have been getting a lot of media attention these days (deservedly so). But there’s another kind of bully threatening to take over a Great Lakes school system: the Asian carp.
True, it’s just a fish, so it’s not consciously being malicious—it doesn’t even look all that intimidating. Still, this non-native character has the potential to devastate the ecosystems and economy of the entire Great Lakes region.
Sound overblown to you? Some people think there’s much ado about nothing when it comes to the threat of Asian carp entering the Great Lakes. After all, they’ve seen invasive species enter local waterways before that did not appear to trigger any widespread calamity. The bad news is, there’s nothing overblown about this.
We won’t mince words: Experts from across the Great Lakes and Mississippi River basins predict ecological catastrophe and economic woe should Asian carp successfully enter the Great Lakes. Why? We took the proverbial bait and asked Kim Rice, resident Asian carp policy planner at Friends of the Chicago River, and Jared Teutsch, water policy advocate at the Alliance for the Great Lakes to give us the lowdown.
The Basics: Meet the Bullies
Malicious or not, Asian carp pose a huge risk to our aquatic ecosystem because a.) they devour everything at the base of the food chain, b.) they’re likely to succeed in reproducing and developing quickly, even with limited populations, and c.) there’s no one else around to eat them—except us (but that’s another story).
So just who are these scaly bullies, threatening to topple local ecosystems and economies, albeit unwittingly?
“Asian carp” is a catch-all name for four species of carp: silver, bighead, grass, and black. They entered the U.S. in the ’70s, back when fish farmers along the Mississippi River imported them for aquaculture. In the ’80s, massive river flooding carried the carp into the Mighty Mississippi itself—and they’ve been slowly making their way north ever since. This year alone, 28 water samples taken from within 10 miles of Lake Michigan have tested positive for silver carp DNA. Once they make it into the lake, they’re expected to easily spread to the other Great Lakes within 20 years.
All four species are considered risks, but Teutsch and Rice explain that silver and bighead are the most worrisome, in part because they’re related closely enough that they can interbreed.
One of the big problems with both bighead and silver carp is that they’re filter feeders, which means they eat plankton, a frothy mix of algae and tiny animals that native aquatic species depend on, too. Problem is, these carp have a truly voracious appetite: Young bighead and silver carp can consume up to 120 percent of their body weight every day. “Eating the bottom of the food chain means they starve everyone else out,” explains Teutsch. “Think of it like a big Jenga game–if you pull the bottom out, the whole thing collapses.”
They’re also hard to keep up with—their fast speeds, quick rates of reproduction, and, in the case of bighead carp, impressive size, make Asian carp a unique challenge for potential aquatic predators and humans alike. Bighead carp can grow to more than 3 feet long, and weigh in at upwards of 80 to 100 pounds. Silver carp aren’t quite so big (weighing an average of 15-20 pounds), but they make up for lack of size with their well-documented reputation as jumping dangerously high when alarmed.
Neither Teutsch nor Rice have personally been knocked over by silver carp, but both know people who have. Since they travel as a school, and can leap 10 feet out of the water when alarmed by a sound—say, that of a passing motor boat—their mere presence endangers anyone recreating on the water. How big a danger can a few jumpy fish be? Teutsch knows several southern Illinoisans who have gotten concussions from silver carp. He compares the force of a silver carp strike with getting clubbed with a 10-15 pound bat, or—depending on how fast you’re going and how many fish there are—getting hit by a bunch of little flying missiles.
So okay, they’re hungry, big and/or jumpy, and can decimate an entire habitat just by moving in. But the worst part? The fact that their potential for destruction isn’t limited to just one area. As it stands, the entire Great Lakes basin is at risk—including the 1.5 million jobs, $62 billion wages, and $7 billion commercial and sport fishing industry that depend on vital aquatic populations to succeed. Ouch.
Connecting the Aquatic Dots
To understand why these fish pose such a threat to so many areas, we need to take a quick look at the connection between the Great Lakes, Chicago’s waterways, and the Mississippi River.
Contrary to the EcoMyth, what happens in Chicago waterways doesn’t stay in Chicago water, what happens in our water also happens across the Great Lakes and Mississippi River watershed, thanks to the artificial connection we have engineered between them all in the form of the Chicago River System (CRS). This system links the Great Lakes to the Illinois River, which in turn connects to the Mississippi River—making the CRS the single most likely entry point for Asian carp into the Great Lakes basin.
Does all this mean that Asian carp are the most terrible invasive species the region has ever seen? Yes and no. “They’re the canary in the coal mine,” says Teutsch. In its federally funded Great Lakes Mississippi River Interbasin Study, the U.S. Army Corps of Engineers has identified 39 invasive aquatic species of concern. According to Teutsch, an expert in invasive aquatic species, each species on the list has been identified as high risk because of their “capacity to overwhelm native species and cause eco devastation.”
An Ecosystem Tipping Point
And what about the 185 other invasive species that have already come in the last 50-60 years? It’s easy enough to imagine that those other species didn’t have a long-term effect because it’s not immediately visible. But what’s happened beneath the water’s surface tells another story. Teutsch tells us that those previous invaders already have decreased plankton levels so much that our aquatic ecosystems are now especially vulnerable to new invaders.
When those hungry Asian carp get to an already stressed ecosystem, the effect would be, as Teutsch puts, “like you’re tipping over the last domino and the whole crash occurs.”
Is your hair standing on end now or what? Same here. Fortunately, a whole lot of people are trying to solve the problem.
Working Together to Stop the Madness
“It’s not a question of if they get here but when they get here—and what do we do between now and then,” says Rice of the prospect of Asian carp making it to the gates of the Chicago River. Regional and national organizations like the NRDC and Sierra Club are all working to develop both long-term solutions and short-term fixes for the interim period.
Here are some quick-fix-type tactics that are under consideration or already underway:
- Electric barriers: Built by the Corps in the Chicago Sanitary and Shipping Canal to prevent “nuisance species” from entering the Great Lakes, by emitting an electric current in the water that discourages fish from crossing it. A couple of problems include the fact that power must be shut down periodically for maintenance, and there’s always the potential for unplanned power outages. (More on that in this Corps PDF.)
- Fishing them out: Netting and bow fishing (which is permitted in Wisconsin) have been slightly more effective than hook and line fishing. Still, Teutsch explains that none of the fishing efforts to control the population in the Illinois River have even made a dent on the population base.
- Introducing other species as predators: There are multiple problems with this idea, but one of the most glaring is that Asian carp are just too fast for other species to catch. So instead of going after the carp, the new species would be coming into an already-stressed environment, and causing yet more damage to the native fish population.
There are a host of complicated long-term solution ideas on the table, but the general consensus across all lines seems to be that ecological separation—literally disconnecting the watersheds—is the only effective solution we’ve got.
Unfortunately, as George Harrison says, “It’s gonna take a whole lot of precious ti-i-me…and it’s gonna take money, plenty of money, to do it right.” Yes, as our experts explain it, effective ecological separation requires undoing one of the great engineering feats of the 19th century—re-reversing the Chicago River, so that the river flows into the Great Lakes, not away from it as it currently does. This would cut off what the Corps calls “the only known continuous connection between the Great Lakes basin from the Mississippi River,” thus sealing in existing native populations and keeping new aquatic invasive species out.
This mammoth undertaking would take as-of-yet unspecified years, boatloads of money, and highly coordinated interstate cooperation. Not only would the river have to be re-engineered, it also would have to meet higher water quality standards so it can legally discharge into Lake Michigan. That means disinfection has to be fully online, and TARP has to be in place to deal with CSOs—which isn’t set to happen until 2029.
What now? Well, the next step in the process is in the Corps’ court. In June, Congress passed the Stop Invasive Species Act, which calls for the Corps to submit a progress report within 90 days of the bill’s passage, and to complete the full plan sometime in 2013.
Until then, Rice, for one, remains hopeful. “It’s been 100-plus years since we’ve overhauled the infrastructure. This is really an opportunity to look at the system and ask ourselves, ‘How can we meet today’s recreational, transportation, and economic needs with a greater environmental vision for the region?’”
Good questions, right? Now, only time (and engineers) will tell.
EcoMyth Outcome: Myth Busted
The threat of Asian carp entering the Great Lakes is serious indeed. Allowing this and other new invasive aquatic species to enter the Great Lakes basin would devastate the ecosystem, wipe out native populations, and weaken the Great Lakes economy. Talk about clear and present danger!
One Green Thing You Can Do
Make your voice heard: Contact your representatives to say you support working together to develop smart solutions to the threat of Asian carp entering the Great Lakes.
Other ways to help:
- Support organizations working on the issue, such as Alliance for the Great Lakes and Friends of the Chicago River
- Learn more about the issue by following news about #AsianCarp on Twitter.
- Talk it up. Part of the problem is that many people still don’t realize the true danger posed by Asian carp and other aquatic invasive species. Share the scoop on Facebook, and chat with your friends and family about it.