How Asian carp could soon take over the Great Lakes — and how they could be stopped

click to enlarge Silver carp jumping in the Fox River in Illinois. - Ryan Hagerty/U.S. Fish and Wildlife Service
Ryan Hagerty/U.S. Fish and Wildlife Service
Silver carp jumping in the Fox River in Illinois.
Reprinted from The Death and Life of the Great Lakes by Dan Egan. Copyright 2017 by Dan Egan. With permission of the publisher, W. W. Norton & Co., Inc. All rights reserved. This selection may not be reproduced, stored in a retrieval system, or transmitted in any form by any means without the prior written permission of the publisher.

On a brisk November day in 1963, a station wagon pulled up to the brown brick federal research lab in eastern Arkansas loaded with a radical new weed killer. In the wake of the publication of Rachel Carson's Silent Spring the previous fall, there was an increasing awareness of the potential perils of all the herbicides and pesticides flowing in our rivers, across our croplands and orchards, down our grocery aisles, onto our dinner tables, into our bloodstreams. Poisoning rivers to get rid of nuisance fish was particularly in vogue at the time, including the Russian River in northern California and Utah's Green River, and a clamor was growing for a smarter, gentler approach to combating unwanted creatures and vegetation. So researchers at the U.S. Department of Interior's Fish Farming Experimental Laboratory, located in the heart of Arkansas catfish farming country, were taking delivery of what they hoped would be a new generation of nontoxic aquatic weed-control agents.

The station wagon's tailgate was dropped and three cardboard boxes, each with two white arrows pointing up, were hauled through the lab doors. The label on the boxes from Malaysia told the handlers that this was not just another toxic chemical compound whipped up in a lab. It read: "Live Fish." The boxes contained dozens of juvenile grass carp, a species native to Asia and famous for taking to forests of seaweed like locusts to crops. The idea at the research lab was to deploy these fish instead of chemicals across the South to clean fish farm ponds as well as weed-choked rivers and irrigation ditches.

"When they did this, this was right. This was the thing to do," said Andrew Mitchell, a recently retired biologist from the federal research lab. "It was one fish to do one job — keep chemicals out of the environment."

That station wagon's payload was the first documented shipment to the United States of a group of fish collectively known as Asian carp. Within a decade of the grass carp's arrival, an Arkansas fish farmer seeking his own batch of the exotic weed-eating fish accidentally imported the three other Asian carp species: black, bighead and silver carp. He didn't know what to do with these other types of Asian carp because they weren't weed-eating machines. Silver and bighead carp are filter feeders that strip plankton and other floating nutrients from the waters in which they swim. Black carp live off mollusks.

The fish farmer did what he thought was the right thing. He turned his exotic fish over to the government. State fishery workers could have destroyed these Adams and Eves. Instead they decided to try to get the novel brood to reproduce — just for kicks, apparently.

"We had this little agreement that if we learned how to spawn them, that he got some of the stock back," former Arkansas Game and Fish Director Scott Henderson told me. "It was all cordial. We were interested in doing some research to see what they were, and I guess at the time, getting them out of the public."

The fish farmer gave Henderson's department 22 adult silver carp, 20 adult black carp, and 18 adult bighead carp and, like cavemen trying to spark a fire, the state hatchery workers tried feverishly to get their brood of exotic fish to breed. They had little luck because, it turns out, raising Asian carp in hatcheries is an absurdly intricate procedure that requires precise timing and water conditions, as well as injections of crushed fish pituitary glands and human hormones harvested from the urine of pregnant women.

The hatchery workers killed all the black carp before they could reproduce a single fish, but they had better luck with the bighead and silver carp when they turned to S.Y. Lin, a professor at National Taiwan University who had moved to Washington, D.C., as an employee of the United Nations Food and Agriculture Organization. In his three weeks in Arkansas back in the early 1970s, Lin took two 12-pound silver carp and produced nearly 1 million eyelash-sized silver carp fry. The one 15-pound bighead carp Lin worked with produced 20,000 little bigheads.

And the Arkansas fish biologists had their fire.

Not long after they had cracked the breeding problem, the Arkansas Game and Fish Commission agreed to send some of their fish to other aquaculture research facilities, including Auburn University. They also entered into a contract with the U.S. Environmental Protection Agency to employ the curious carp in sewage treatment experiments. Former Arkansas Game and Fish chairman-turned-fish-farmer Mike Freeze explained to me the rationale behind the bizarre experiments while bouncing around in his pickup along the levees containing his crops of catfish. Arkansas waterways in the 1970s, Freeze explained, were like waterways everywhere else in the country — ridiculously filthy, in part because small communities didn't have adequate sewage treatment systems.

So Arkansas turned to the filter-feeding carp in an elegant, if a bit repugnant, plan to clean up its waters. Phase One was to plant bigheads and silvers in experimental sewage lagoons and let them convert the decaying human waste into fish flesh. Phase Two would be to sell those fish as food to fund small cities' sewage treatment costs. The fish, particularly bighead carp, are favored in Asia for their flaky, mild flesh. "I remember we sent sample after sample [of fish] from the sewage ponds to Baylor University to make sure they didn't have any viruses or things like that," said Freeze, who was an hourly worker at the state hatchery during the time of the carp experiments. It didn't take long for word of Arkansas' feces-to-flesh business plan to spread, and the federal Food and Drug Administration soon stepped in. "They had a standing policy," said Freeze, "that it was not legal to take these fish out of sewage ponds and sell them for human consumption."

The experiments stopped when federal funding dried up. Some fish were destroyed. Others were simply set free. Freeze remembers containment screens swinging open and gates being lifted to drain hatchery ponds — and their inhabitants — into Arkansas ditches and streams. It all seemed innocuous at the time — the fish were so difficult to breed under even precise hatchery conditions that nobody thought there was any chance that the carp would be able to breed on their own in the wild. This was a blunder of the highest order. Soon baby bighead and silver carp started turning up in rivers and streams across the South, and the swarming fish have been migrating north ever since.

The problem is bighead and silver carp don't just invade ecosystems. They conquer them. They don't gobble up their competition. They starve it out by stripping away the plankton upon which every other fish species directly or indirectly depends. Bighead carp can grow larger than 100 pounds and each day consume up to 20 pounds of plankton. Bighead and silver carp have so squeezed aside native species that the Asian carp biomass in some stretches of rivers in the Mississippi basin is thought to be more than 90 percent — the same dire situation that an alewife-plagued Lake Michigan suffered in the 1960s.

It's not just native fish species that suffer where these fish succeed. Silver carp, which are slightly smaller than bighead carp, have become YouTube sensations because of their penchant for rocketing out of the water like piscine missiles when agitated by the whir of a boat motor. One such video starts with a Star Wars-style opening. Text scrolls in front of a globe spinning in space, and an arcing red line shows the invasive fish's journey from Asia, across the Pacific Ocean to the Illinois River town of Peoria. What follows is some four minutes of young men water skiing while wielding swords and wearing football helmets bristling with giant nails. Fish-impaling spikes poke similarly from shin guards. One water skier protects his torso by wearing a bum-in-a-barrel-style metal garbage can. The water skiers swat, smack, and hack at the hundreds of fish bursting from the water like popcorn.

All joking and ridiculously dangerous stunting aside, water skiing and jet boating have become impossible in some places, particularly on the Illinois River where things are so bad that the town of Bath hosts an annual "Redneck Fishing Tournament." It is the one time of year in this southern Illinois hamlet you will find the river packed with motorboats. They are piloted by beer-swigging, helmet-wearing anglers who try to catch as many silver carp as possible in three hours — not with hooks and lines, but by waving fishing nets in the air.

click to enlarge The “Redneck Fishing Tournament” on the Illinois River. - Judd McCullum
Judd McCullum
The “Redneck Fishing Tournament” on the Illinois River.

The year I attended the tournament I saw several people leave the water after being battered and bloodied by the jumping fish that hit hard as a fist. I saw one man, not smart enough to wear a helmet, spit out a tooth. The tourney's 78 registered boats that day landed 1,840 fish, all of which were buried with a backhoe on the riverbank. The bar owner who hosted the tournament assured me the mass grave didn't even dent the population swarming in the river, but insisted that was not the point of the event. She hosts it to provide locals a bit of zany, late summer fun and, more importantly, she said it serves as a warning to people across the country of what could be coming to their own lakes and rivers. She had a particular set of lakes in mind.

"If these things get into the Great Lakes," she told me, "you are in trouble."

The word "trouble" doesn't really capture what is at stake, both environmentally and economically, if the oversized fish succeed in what has so far seemed like their inevitable push to colonize the Great Lakes, the biggest home they could ever hope to find, and one that still sustains a multibillion-dollar commercial and recreational fishery.

While silver carp make the headlines for their leaping ability, bighead carp lurk largely out of the public's consciousness. Not so for commercial fisherman Orion Briney, who more than a decade ago figured out how to eke out a living by catching bigheads on the Illinois River and selling them to a wholesaler who guts, ices, and ships them by the refrigerated container-full back to China.

Briney can catch 15,000 pounds of bigheads in his nets. Not in one day. In 25 minutes. Here is a little perspective on that number: Wisconsin's quota for commercial perch fishing on all the state waters of Lake Michigan in some past years has been about 20,000 pounds. That's not a per-day limit. That's the limit for an entire year.

I went out one steamy summer day with Briney and was left gobsmacked (and silver carp-smacked) by what had become of the river since the invaders had swarmed in just a few years earlier. Briney fishes cowboy-style, using his boat to herd his quarry. "See that big wave?" he asked me as we roared downstream at dawn. I could see only a patch of choppy black water. "I'll bet there is 400,000 to 500,000 pounds in there!" He arced his boat toward the fish and then swooped down behind them, chasing the thrashing mass into his nets. Briney had no interest in the silver carp flying about the boat — and his head, which he deftly shielded with his Popeye-sized forearms. He was angling only for bigheads, a tastier and less bony fish that has a small market in the United States and, because bigheads are typically sold live in Asia, has only limited appeal abroad.

It took him less than a half hour to round up more than 13,000 pounds of fish — and another 3½ hours to pluck out the bigheads, one by one, from 800 yards of net. The biggest weighed nearly 40 pounds, monsters that lurked so low in the murky water they're rarely seen by the pontoon boaters and recreational anglers who still dare to venture out on the river. Seeing one up close is unnerving. The fish have mouths big enough to gobble softballs whole and their eyes are so low on their head that they appear to swim upside down.

"Most people don't even know them's here," Briney said as he piled the writhing bigheads on the boat floor. "They just see the silvers jumping." Does he see the carp finding a future in the Great Lakes basin next door? "They'll thrive. There's plenty of food," he said. "They'll love it." Then he asked me: "The lakes are, what, 20, 30 feet deep?" No. The Great Lakes are hundreds of feet deep.

"Good Lord!" he groaned. "By the time [anyone] knew they had a problem, it'd be too late."

Biologists remain dubious about whether bigheads and silvers could thrive similarly in the Great Lakes' open waters, which are relatively sterile compared to the soupy rivers lacing the Mississippi basin. But it may be another matter altogether for the lakes' algae-rich bays and harbors, and the rivers that feed them — which also happen to be the places where most people boat, jet ski, and fish. Inland waters connected to the lakes are similarly threatened. The financial impact of an infestation of these areas alone could be staggering. The eight Great Lakes states alone are home to some 4 million recreational boats, about a third of the United States' total.

Arkansas' Freeze knows these numbers and he has lamented from afar the bighead and silver carp's inexorable march north. He told me he believes that after his crew let their fish go free there were subsequent escapes of bighead and silver carp from research facilities and fish farms (captive-raised bighead carp eventually became a common cash crop for fish farmers, though it is now illegal to transport them live across state lines.) He also provided me documentation showing that the federal government later helped fish farmers reimport black carp to control pesky snails in aquaculture ponds. Not surprisingly, black carp are now also swimming free in rivers down South.

But he acknowledges that the bighead and silver carp that got loose on his watch almost surely were among the first to get into the wild. He's not proud about his role in what is shaping up as a billion-dollar blunder. But he doesn't hide from it, either. "I'm old enough and big enough," he said, "to say that there are a lot of things in my life that I'd go back and change."

About The Author

Dan Egan

Dan Egan is a reporter at the Milwaukee Journal Sentinel and a two-time Pulitzer Prize finalist.
Scroll to read more Metro Detroit News articles


Join Detroit Metro Times Newsletters

Subscribe now to get the latest news delivered right to your inbox.