Yearslong war on Asian carp showing some progress, but end is uncertain

Wade White was bow fishing on the Cumberland River in a Jon boat below Barkley Dam in Western Kentucky one night about eight or 10 years ago when he was startled to see a sizable fish go airborne and land in his boat.

“I had no idea what it was,” White recalled. “I thought, how did this fish fly through the air like it did?”

“Everything was dark,” he said. “It scared us all to death. We didn’t know what had happened.”

That was the first, but certainly not the last time, that an invasive Asian carp, specifically a silver carp — spooked by the sound of a boat motor — had leapt out of the water and landed in a boat with him.

White is a lifelong fisherman who lives near and regularly fishes on Lake Barkley. He had been aware that Asian carp — one of several invasive species of fish in U.S. waters — had made their way into rivers and lakes stretching from Mississippi to Minnesota, including Kentucky, Indiana, Illinois.

It wasn’t long before videos, news stories and anecdotes emerged about Asian carp — carp flying in the air as boats approached, carp smashing into people’s heads, waters seemingly boiling with carp, carp possibly crowding out native species like bass that draw sport and professional fishermen.

White was also the county judge/executive of Lyon County, Kentucky, a community on the shores of Lake Barkley that, along with the adjoining Kentucky Lake, are the crown jewels of Western Kentucky tourism and sportfishing.

As such, White felt compelled to seek measures to protect the huge reservoirs from these invasive species for the sake of tourists — boaters, skiers, fishermen — and the untold numbers of folks who own lakeside homes for weekend relaxation or their retirement years.

But he could hardly have imagined how he would become engaged with what became known as the War on Carp in the years that followed.

And there was no certainty that, as the 2023 tourism season approaches, that there would be cause for cautious optimism.

The origin story

What Americans call Asian carp — species such as silver, bighead, grass and black carp — have long been coveted, even mythologized, in Asia as a food source; there is evidence of carp aquaculture (fish farms) in China dating back thousands of years.

It’s widely reported that Asian carp species were introduced to the United States during the 1970s and 1980s at private fish farms and wastewater treatment facilities to reduce algae growth and improve water quality in those ponds.

By the 1990s, the U.S. Fish & Wildlife Service says, they had begun escaping into the Mississippi River. Worse, they began successfully reproducing in U.S. waters.

Asian carp have been documented throughout the Mississippi River Basin and its tributaries, including the Ohio River, the Wabash and Green rivers and, in far-Western Kentucky, the lower Cumberland and Tennessee rivers.

For a time, White and others hoped that the unwanted guests wouldn’t make their way upstream from the Cumberland and Tennessee rivers into Lake Barkley and Kentucky Lake.

But get into the lakes they did, traveling alongside barges and other craft that navigated upstream from the rivers through the locks at Barkley Dam and Kentucky Dam into the two immense reservoirs.

“From 2013 to 2017, Barkley and Kentucky were really saturated with adult silver carp,” according to Joshua Tompkins, fisheries program coordinator for the Kentucky Department of Fish and Wildlife Resources’s critical species investigations.

Jumping Jehoshaphat

The growing numbers of silver and bighead carp in particular were worrying for multiple reasons.

First and most visible is that silver carp can come flying out of the water when spooked by the sound of or vibrations from an outboard motor or personal watercraft, particularly in shallower waters. And not just one or two carp, but sometimes dozens at a time.

Silver carp can grow to 20 pounds or larger and can leap several feet above the water line, which can make boating and skiing hazardous on some waters. (Bighead carp can grow to more than 100 pounds but are far less likely to leap from the water.)

As early as 2007, “Several boaters have suffered injuries from leaping silver carp, including broken jaws, noses, ribs, arms and legs after being hit by flying carp,” according to the National Wildlife Federation.

In 2015, a 19-year-old Illinois man was struck in the face by a leaping carp while he was being pulled on an inner tube by a boat driven by his father along the Mississippi River. The collision fractured his nose and broke bones above his eye brow; surgery to repair his face took 3½ hours, according to a news report.

“With a boat speed of over 20 mph and fish that can weigh over 20 pounds, this can be disastrous,” according to the U.S. Geological Survey, which is the scientific arm of the Department of the Interior. “Jumping fish have seriously injured many boaters and damaged boats. Water skiing on the Missouri River is now exceedingly dangerous because most of the fish jump behind the boat.”

One Henderson father said he stopped taking his family for weekend trips to the lakes after a spooked silvery carp landed in his daughter’s lap while she was inner-tubing.

“It got to the point it was driving tourists away (because of silver carp) leaping in air, landing in boats,” White said (though biologists say jumping carp are a much greater threat in shallower and narrower waterways such as the Illinois River than Barkley and Kentucky lakes, which are vastly wider and deeper).

Growing numbers

Second, Asian carp are prolific reproducers.

“Three species of carps (bighead, silver, and grass) are reproducing at alarming rates and threaten Kentucky’s aquatic ecology,” Kentucky Fish and Wildlife’s website declares. Females can produce over 1 million eggs a year, it said.

That’s true, but that would be for a “very large” female said Duane Chapman, a research fish biologist with the U.S. Geological Survey and one of the nation’s foremost authorities on Asian carp.

“We estimated that one very large bighead carp, over 100 pounds, had roughly 3.5 million eggs,” Chapman said in one of a series of email responses to a reporter’s questions. “A first spawn by a youngish female silver carp might have 60 (thousand) to 150K eggs.”

A pressing concern for Lake Barkley and Kentucky Lake was whether the carp could successfully reproduce in those reservoirs.

In 2015, a “really big” number of Asian carp eggs hatched in the Cumberland and Tennessee rivers just below Barkley Dam and Kentucky Dam, respectively, “just enormous numbers of juvenile invasive carp in the tailwaters below both dams,” probably totaling “millions and millions” of young fish, according to Adam Martin, the fisheries program coordinator for Kentucky Fish and Wildlife’s Western Fishery District.

Young carp were found that year in the lakes themselves. “That indicates it was possible they spawned in the lakes themselves,” Martin said, which was alarming. If Asian carp could successfully spawn in the lakes, they could take over those ecosystems.

“It was never confirmed by Kentucky or Tennessee wildlife agencies,” Tompkins said. “It’s likely there was some spawning, but it was never validated.”

But there is promising news. “Since then, there has been no sign of successful reproduction, even in the tailwaters,” Martin said.

“It’s difficult to say” why the carp don’t seem to be reproducing in the lakes, he said, “but the most logical theory” is that successful spawning requires turbulent water that keeps females’ eggs suspended long enough to come in contact with male sperm. “If there is slack water with no current, the eggs will sink to the bottom and die.”

Still, successful reproduction is documented in other U.S. waters, and adults have been able to migrate through the locks to the twin lakes.

Food fight

Third, silver and bighead carp feed on plankton, which is a crucial food source for young fish called fry as well as small bait (or forage) fish such as minnows that gamefish feed on. Fish biologists say the Asian carp feed almost continuously, their large, toothless mouths open, taking in plankton that they filter from the water.

“In Kentucky, invasive carp … are outcompeting native fishes for forage,” according to the Kentucky Fish and Wildlife website.

“Asian carp not only out-compete native sport fish like crappie and largemouth bass, but some species feed on the freshwater mussels that help keep our aquatic systems healthy by providing good fishing and good water quality for people, waterfowl and other wildlife species,” Allan Brown, assistant regional director for the U.S. Fish and Wildlife Service, testified before a U.S. House of Representatives subcommittee in 2018.

“Fishermen stopped coming (to the lakes) because carp overwhelmed all other populations,” White said. “They’d go into a bay and filter out all the good stuff the little fry eat. There was hardly any live bait in the water.”

The idea that invasive carp could outcompete native species by consuming the plankton that fry and bait fish rely on to become the dominant species was alarming.

But biologist Martin has some doubts.

“There is very little chance of dietary overlap between adult silver carp and juvenile bass and crappie,” he said. “The adults are only feeding on offshore plankton” while young sportfish such as bass “are hiding out near shore.”

Further, Martin declared, “There are zero studies that evaluated dietary overlap between juvenile sportfish and juvenile silver carp.”

The issue “has been inadequately researched, in regard to young sportfish,” the USGS’ Chapman agreed. “It is a hard question to research effectively.”

But the fact that there are a lot of Asian carp in the region’s rivers and lake remains worrisome.

And they can grow quickly “if the resources (such as food) are there,” Chapman said.

What to do?

There has been plenty of handwringing, sure, but there have also been plenty of strategies to try to control Asian carp.

Since 2005, volunteers have gone out on Jon boats, pontoon boats and other craft with haul nets to snag flying silver carp out of the air during the annual Redneck Fishing Tournament on the Illinois River near little Bath, Illinois. Last year, the teams (some of whose members wore helmets to protect them from possible head strikes from a flying silver carp) removed 3,000 carp totaling some 20,000 pounds, according to one news report.

Plenty of people hunt and kill them with bow and arrows, often for sport but also for the satisfaction of relieving the U.S. of some of the invasive carp.

Asian carp bowfishing tournaments have even been organized. In August 2022, for example, Aquatic Protein LLC, which operates a fish-processing plant in Beardstown, Illinois, sponsored its third annual bowfishing tournament at Barkley Dam for harvesting Asian carp. The winning team brought in 1,934 pounds of fish and was awarded top prize of $3,000. Three other teams of brought in more than a half-ton of fish. Aquatic Protein, which produces fish oils, fertilizer and dog and cat food from the carp, paid 9 cents per pound for the fish brought to its receiving station at Eddyville.

“We have a pretty strong bowfishing community in Western Kentucky” that particularly target the Cumberland and Tennessee rivers, just below the dams, Tompkins said.

“In 2021, bowfishing harvested around 300,000 pounds” out of those waters, he said.

On the menu

Meanwhile, because Asian carp are, in fact, a tasty white fish, there have been multiple attempts to encourage Americans to eat them.

It hasn’t been simple. When most Americans think of “carp,” they think of the common carp that was imported from Europe in the 19^th century and is regarded as the proverbial bottom-feeding scum sucker — a muddy-tasting trash fish.

Asian carp, however, aren’t bottom feeders; they are filter feeders who consume plankton and algae. The U.S. Geological Survey declares “Asian carp of all types have white, firm, mild flesh, which is excellent table fare.”

More than a decade ago, there were efforts to rebrand Asian carp as “white fin,” “Kentucky white fish” or “Kentucky tuna.”

French Chef Philippe Parola included the four species of invasive carp in his recipe book “Can’t Beat’ Em, Eat’ Em.”

In June 2022, the state of Illinois unveiled a rebranding of Asian carp as Copi, which it described as “mild, clean-tasting fish with heart-healthy omega-3s and very low levels of mercury.”

A second issue is that the flesh of Asian carp is quite boney. The USGS’s Chapman has gone so far as to create a series of videos demonstrating how best to filet the fish.

“I eat every grass carp I can get my hands on,” he reported. “Next to walleye, (it’s) my second favorite fish to eat in Missouri.” (For Super Bowl weekend, he reported, “I have a bowl of grass carp ceviche waiting for me”).

Yet another approach is to harvest and sell Asian carp to those who already love them: Asians. At Wickliffe, Kentucky, where the Ohio River meets the Mississippi, Chinese-American entrepreneur Angie Yu’s Two Rivers Fisheries declares itself to being “America’s largest Asian carp processor and exporter,” buying carp from commercial fishermen (or “fishers”) who harvest them in the two big rivers as well as Barkley and Kentucky lakes. It markets them as “wild caught in the USA” (as opposed to fish-farmed) and sells them as fish steaks, ground fish meat, meatballs, patties, salted fish and more.

Two Rivers is one of about a half-dozen buyers of Asian carp in Western Kentucky, paying varying amounts depending on the end use — less for grinding them to fish meal, more for processing them for human consumption.

Bubbles and sound

Other approaches are more specialized.

In 2019, an experimental barrier called a bio-acoustic fish fence (or BAFF) was installed on the downstream side of the lock at Barkley Dam as part of a three-year, $7 million state-federal evaluation to deter Asian carp from migrating from the Cumberland River to Lake Barkley.

The BAFF sends a curtain of bubbles, sound and strobe lights from the riverbed to the water surface, meant to deter Asian carp from entering the lock chamber.