Fishermen in Lake Clumet, Illinois—just six miles downstream from Lake Michigan—netted a fish on Tuesday. That generally being what fishermen do, the news wouldn’t have caused much of a stir, but this was no ordinary fish. They caught a 20 lb. bighead carp, one of a number of Asian carp species that were imported into the U.S. in the 1970s and subsequently escaped into the Mississippi River, invading aquatic ecosystems along the way. The fact that fishermen were able to catch an Asian carp in Lake Clumet—upstream from an electrical barrier on the Mississippi River system designed to keep the carp out—is the first concrete evidence that the fish may have established themselves in the Great Lakes. “This is a tremendous concern and creates a tremendous urgency to act in a number of ways,” said Senator Debbie Stabenow of Michigan in a conference call with reporters.
So why is the landing of a single fish so tremendous? That’s because the Asian carp aren’t your average kettle of fish. As I wrote back in February for Time.com, the carp are aggressive eating machines, and the Great Lakes ecosystem is like an all you can eat Big Boys buffet:
Asian carp are particularly dangerous. Native to China and parts of Southeast Asia, the freshwater fish have been cultivated for aquaculture for more than 1,000 years, often raised in submerged rice paddies. Catfish farmers in the U.S. imported Asian carp decades ago to eat up the algae in their ponds; the fish slowly escaped into the wild and have been making their way up the Mississippi River. They are eating machines; bighead carp can grow incredibly quickly and reproduce rapidly as well. “They just eat so much,” says David Ullrich, executive director of the Great Lakes and St. Lawrence Cities Initiative. “They’re like the locusts of the river.”
That’s what makes them so dangerous to the lakes. Asian carp aren’t direct predators, but they eat plankton, which knocks out the bottom layers of the food chain. If they were to successfully establish themselves in the Great Lakes and start breeding, they could utterly disrupt the existing ecosystem, potentially starving out the trout and other native fish that make the Great Lakes a tourism hot spot.
Not only that, but one species of Asian carp—the silver carp—can turn itself into a sea-to-air cruise missile, leaping out of the water when startled by engine noise. And full-grown, at up to 40-lb. (18 kg), they can break fishermen’s noses and collarbones. It turns a fishing trip into American Gladiator, as you can see at the great Redneck Fishing Tournament in Illinois, where silver carp are the target and the fish can actually fight back:
Officials hadn’t been certain that the Asian carp had yet made it into the Great Lakes system. (The Mississippi River and the Great Lakes are only connected through the man-made Chicago Sanitary and Ship Canal, which leads from Lake Michigan to the Illinois River.) To keep the carp out, the Army Corps of Engineers installed an electric barrier on the canal, but in January a team of scientists still discovered Asian carp DNA in Lake Michigan—though no live fish yet.
That changed Tuesday—vindicating scientists like Notre Dame biologist David Lodge who had been warning about the invasion—and now officials in the Great Lakes states are scrambling to come up with a response. Stabenow and Michigan Representative David Camp are working to pass the CARP Act, which stands for Close All Routes and Prevent Asian Carp Today. (It’s sort of an acronym.) The bill would order the Army Corps to immediately close the Chicago-area locks and canals, pending a permanent separation of the Great Lakes and the Mississippi River watersheds. “We must act quickly, or risk the destruction of the Great Lakes ecosystem, and the countless industries and communities that rely upon the resources provided by these great bodies of water,” said Michigan Representative Dale Kildee in a press release.
Chicago-area businesses, however, have always opposed closing the canal locks, claiming the move would damage the shipping industry. It might still be years until the fish have established themselves in the vast waters of the Great Lakes, and right now there’s no immediate action being taken. ” At this time, there is no intention to close the locks,” Mike White of the Army Corps told the Chicago Sun-Times.
But the carp incursion is a reminder that invasive species can do serious damage to ecosystems and economies. In the U.S., invasive species like the tree-consuming Rocky Mountain pine beetle, cause an estimated $120 billion worth of damage each year. And that as the world warms and human development disrupts existing wild territory, the problem will only get worse.
Of course, maybe we should feel some sympathy for the Asian carp—and not because we’re the ones who brought them from China to the Midwest. There’s another species that has grown to vast numbers—billions of individuals—and has spread to nearly every corner of the planet, often ravaging pristine ecosytems along the way and wiping out other species. They’re called human beings.