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The battle against invasive species rages on

Attack of the killer species.

April 5, 2012 | 12:00 a.m. CST

Deters puts a female carp in a pond where the species is kept for testing so scientists can learn more about their enemy.Joe Deters and Karl Anderson are experts when it comes to dealing with dangerous fish. Although not every trip means a catch, when something does come abroad they know what to release, keep or kill. The men stir up water in Auxvasse Creek to get fish moving in hopes they swim right into the nets Deters and Anderson have thrown into the water. Carp usually prefer water that is warm and calm.On this particular trip all the male bighead carp are killed after being caught. This is not always the case, but there is a law that forbids releasing invasive species back into the local habitats. On average, an adult bighead carp weighs around 50 pounds, so it's no surprise when Karl Anderson helps Joe Deters with a catch.


The Plant Problem

Tim Banek has been with the Department of Conservation for 25 years, and within the last four years, has held the demanding position of invasive species coordinator. Banek promotes public information, secures grant money to fund equipment, holds invasive plant workshops, represents Missouri at multi-state committee meetings and helps in eradicating and controlling invasive species. Although he oversees many facets of invasive species control, Banek has personally spearheaded the control effort against plant species.

“If we just let [invasive species] grow, we wouldn’t have any natural areas, they would be all invaded by invasive plants,” Banek says. But with so many different species being introduced continuously, many of these unwelcome guests are quickly becoming permanent residents.

“Invasive species science is not that old,” says Banek. “We’ve known that we’ve had invasive plants for some time, but it becomes more and more of a problem with the increase in global trade.”

Plant species travel in different ways. Many are introduced unintentionally, stowing away in grain shipments or on other packing materials. Once these plant species become established in an area, they become almost impossible to eradicate.

According to Banek, Missouri has more than 800 non-native plant species, but only 1-2 percent of those species are considered invasive.

For Banek, it’s essential that the public understand the crucial role they play in determining the future of the native ecosystem. “If we didn’t have people, we wouldn’t have invasive species.”


--Darren Orf

The plains are peaceful, the rivers calm and the forests tranquil, but for some biologists this picturesque moment of nature is a battleground. And at times, the battle seems eerily conventional. Biologists armed with guns track their quarry with strategically placed cameras and scout local rivers in hopes of scaring aquatic invaders from their watery hideouts. In Missouri, the front lines are everywhere, and the enemy conquers in silence. Each species has its own story. Some species were brought to the U.S. to decorate front lawns, some for more commercial interests and others by sheer accident. Experts are in agreement despite their storied backgrounds — they have got to go.

These few words represent a daunting task. The U.S. is host to more than 6,500 nonindigenous species according to the United States Geological Survey. Specialists consider any species, plant or animal invasive if it harms the surrounding native wildlife, though not all nonindigenous species are necessarily invasive. The estimated annual cost of invasive species ­— economic, environmental and health-related ­— exceeds the yearly cost of all natural disasters. Some species alone cost billions of dollars in damage. In Missouri, troublesome species such as Asian carp and feral hogs are significant problems for native wildlife. For every problem, there is a solution, but sometimes help comes too late.

The aquatic quandary

Although science is the guiding principle behind invasive biology, there is no science to catching a fish. No one knows this better than Joe Deters. Having spent almost nine years with the Geological Survey and an incalculable amount of hours trolling the muddy Missouri River for fish, Deters still has a few tools that help. He mans the helm of a 22-foot, gray metal boat equipped with four plastic bins filled with hundreds of feet of netting, an empty water tank and two empty coolers. He speaks with a fisherman’s jargon; words such as “plunge pool” and “box dike” dot his vocabulary. He knows his enemy well — the silver carp.

The silver carp is only one of four Asian carp in North America. The Asian carp, including black, grass and bighead carp, have established populations all the way from the Gulf of Mexico to the Great Lakes. These fish prefer calm waters, often seeking refuge in dikes, much like the ones that line the Missouri River.

The steel boat idles in one such dike. Fellow biologists Karl Anderson and Michael Lucey stand at the front of the boat. One foot each rests on the raised platform and sunglasses cover their eyes. The day is warm and sunny, but spray from the almost zero-degree water creates a shivering wetness that clings to your skin. Anderson and Lucey start to bring in the net, their hands gripping and pulling against the resistance of the river. The fishermen watch the thin, black line snake across the water. They are able to see if any fish are caught if the net dips below the water’s surface. This time, the net catches a few things: a leaf, a twig, a branch, but no fish. The hunt continues.

“I’m sorry guys,” Deters says. “I thought we’d get lucky.”

Luck is nowhere to be found, just like the silver carp. It’s noon, that was their fourth net, and no fish have been caught. The river’s been silent.

Catching fish is only a small part of the Geological Survey’s efforts to eradicate Asian carp. While Deters spends the day exploring the Missouri River, Duane Chapman, described by his peers as the Jimi Hendrix of Asian carp, is hard at work conducting research and learning everything he can about his aquatic assailants. In the past 25 years, his knowledge has become encyclopedic.

Chapman, an invasive biologist for the Geological Survey, has spent countless hours behind microscopes, in fisheries and on rivers studying these fish, specifically silver and bighead carp. He continues to learn how they were introduced, what habitats they prefer and most importantly, how to kill them.

The Asian carp came to the U.S. in the late 1960s and early ’70s as biological control in reaction to Rachel Carson’s book Silent Spring, which facilitated the ban of such agricultural chemicals as DDT. With chemicals becoming a highly politicized issue, many aquacultural ponds and sewage treatment plants opted for biological control with voracious bottom feeders, such as Asian carp. It was only a few months later that these carp were found in the wild. “If you have any organism that you’re farming, it’s very difficult to keep it in one place, even fish,” Chapman says. “There are floods, poor practices, drains break and eventually something happens. There was an incident recently (when) someone lost a lot of black and grass carp due to a tornado.”

Despite the fish’s enormous population, Deters, Lucey and Anderson continue to come up empty-handed. Because of the cold water and strong current, the carp are not very active. Deters reflects as Lucey and Anderson pack up the net.

“I was sitting right up there,” Deters says as he points to the front of the boat. “And this fish jumped right through a hole in the net and started hitting me in the leg. They can hurt.”

With some silver carp reaching more than 60 pounds, it’s easy for a fish to cause serious physical damage. If someone was sent overboard by the blow, the chilly river water could be enough to cause hypothermia.

Chapman also has gotten a few scrapes from silver carp over the years. Through evolution, silver carp have developed a fright reaction in which they jump 10 feet in the air, in hopes of distracting a predator. The resulting effect is the equivalent of a bowling ball soaring in the air at 17 miles per hour. “Lots of people have had broken bones and serious injuries to their necks, jaws and noses,” Chapman says. “I had one fish hit me in the cheek. My neck was hurting for weeks, but had it been an inch lower, I would have lost a tooth.”

Despite the dangers, Deters looks for a new place to fish. He peers across the river. He knows what he’s looking for. Any slight discoloration in the water, changing from a muddy brown to a dark green, shows evidence of phytoplankton, which is considered a buffet for bottom feeders such as the silver carp. After a few more failed attempts, Deters gets an idea.

“Let’s try the Lamine,” he says. “If we don’t find anything there, we might have to call it a day.”

The Lamine River is a tributary that empties into the Missouri River. The stream’s waters are slower and warmer, which might be enough to lure silver carp. The boat arrives at the small tributary, only about 100 feet across, with the motor revving.
Several silver-scaled fish leap out of the water. The three-man crew scurries to set up the net. They watch the thin black line bobbing in the water, hoping for their first catch of the day.

Asian carp are a diverse threat because they’re difficult to eradicate, they compete with native species for food, and they slowly diminish the number of indigenous fish. Currently, a lot of resources are directed at preserving the Great Lakes fishery. One of the most valuable fisheries in the U.S., the Great Lakes could be devastated by invading Asian carp — and they’ve been spotted close but have not yet moved in. The first symptom of an Asian carp infestation is the disappearance of larger zooplankton. Because so many fish in North America rely on this food source, the fear is that the Asian carp could drive some native aquatic species to extinction. That’s why Deters and Chapman work tirelessly to track, capture and study Asian carp so that they can help apply improved eradication techniques to vulnerable areas such as the Great Lakes, where time is running out.

After four hours searching, Deters’ aquatic sixth sense pays dividends. The net stretches across the narrow Lamine and quickly begins dipping in several spots. The once lethargic boat becomes alive as Anderson and Lucey cut away the net to free the silver carp. Some are stored in the large water container for live research. Other fish, either extremely bloodied or another invasive fish such as the bighead carp, are hit with a billy club between the eyes, a mercy compared to the excruciating pain of gasping for air. Deters explains that it’s illegal to release any invasive species back into the wild, so they must be dealt with. The occasional native fish, which have been declining due to the increased Asian carp population, are released back into the river.

After a half-hour long net haul, the three biologists are in high spirits with a dozen live specimens. Deters transfers the fish from the boat to a specially outfitted tank that will help transport the live fish back to the lab in Columbia.

It’s a strange paradox, biologists who must kill to preserve, but there is also a sense of awe. Chapman can’t help respect his forsworn foe. “It is kind of a love-hate relationship because I’m super impressed with these fish,” Chapman says. “And who doesn’t like a big fish?” The enemy typically commands respect, which is also true in the form of fierce hogs.


The terrestrial terror

About 100 miles southeast of the Missouri River, Tom Meister drives along winding gravel roads. Meister is a wildlife damage biologist for the Missouri Department of Conservation. Southeast Missouri, from Cape Girardeau to St. Louis, is his territory. He spends most of his days helping with domestic problems: territorial geese, troublesome beavers and misinformed residents who confuse house cats with mountain lions. Meister is also in charge of tracking, surveying and exterminating feral hogs, an invasive species that causes millions of dollars in damage statewide.

Meister drives through a densely wooded conservation area. He talks about local land owners who are helping to combat the terrestrial menace.

He slowly applies the brakes and pulls up to a locked gate. He hops the gate and heads down a green pasture with patches of yellowing grass. The cultivated ground begins to get rocky and is filled with small foxholes — whole swaths of land completely uprooted.

“That’s hog damage right there,” Meister says, pointing at one of the holes. He glances at the rest of the pasture. “And it doesn’t take many to do a boatload of damage.”

The sprawling meadow is plagued with similar holes stretching hundreds of yards. What would take someone days to achieve with a shovel, a small group of feral hogs accomplishes in one night.

This scene is becoming increasingly familiar throughout Missouri with the feral hog population on the rise. Meister oversees hundreds of miles of land, so he doesn’t work alone.

Rex Martensen, a specialist on feral hogs for the Department of Conservation, coordinates feral hog control throughout Missouri, and he knows it’s an uphill battle. “Our goal is eradication,” Martensen says. “We started learning from other states who have been dealing with hogs for a long time, like Texas and Florida, that these things are bad news.”

Missouri’s history with feral hogs started decades ago. But by the early ’80s, the hog market took a big decline, and a lot of pigs were let loose. After a few years, hog hunting became popular, and soon hogs were transported throughout the state for hunting purposes. “Some of these hogs they were bringing in were Russian- and Eurasian-type boar,” Martensen says. “When you cross that with some of the domestic pigs, you get a real adaptive, prolific breeder that can survive and reproduce well.”

With feral hogs typically producing two litters a year, Meister’s job is endless. Although with his work, he has developed a keen tracking sense. He looks down at the upturned earth and sighs.

“I’m trying to find some fresher stuff, but this looks pretty old,” Meister says, his toe pushing around the dirt. Meister can tell by the color of the grass and dirt surrounding the hole approximately when the hog was in the area. “The hogs just put their nose to the ground,” Meister says. “If they smell worms, bugs or roots … they eat whatever is on the ground.”

Destroying private and public land is only a small portion of the damage that feral hogs can cause. Feral hogs harm fish and wildlife by ruining habitats and competing for food; they annihilate private property and agriculture costing millions of dollars and pose a danger to residents. Feral hogs are vectors for disease, especially swine brucellosis. Although hogs try to avoid humans, some reach up to 300 pounds and are extremely dangerous when provoked. “They destroy good habitat,” Martensen says. “They wallow in our pristine streams and our springs. They don’t care; they’re just pigs.”

The Department of Conservation’s best way of controlling feral hogs is using router gates, a trap designed so that hogs can enter but can’t leave. Martensen and Meister also deploy helicopters and simple bait-and-shoot traps to control populations. “We are one of the few states in the nation that has this kind of approach and this aggressive of an approach,” Martensen says. “You can only shoot one or two, then they’re gone. They’re really smart, and they learn.”

Meister must discern the best places to set traps across thousands of acres. To help narrow the search, he affixes motion-sensor trail cameras to tree trunks pointed at bait piles. The camera snaps a picture any time movement occurs around the bait pile.

Meister unhooks the camera and snakes a USB cord from the camera to his laptop to upload pictures. More than 1,000 pictures are on the camera, and Meister quickly taps through them. After a few minutes pass, only clicks of a trackpad and silence, he pauses on a picture.

“That’s one right there,” Meister says. “You see it?”

The photo has a chiaroscuro effect, a bright center that tapers off into blackness. In the center of the photo is the bait pile, which is covered by brush to discourage larger animals like deer from trying to eat the bait. To the right, a black boar around two feet tall, inches close to the food. Meister continues clicking through the photos. The feral hog is the star of his own video. His head bobs up and down as he continues to feed for an hour. The pictures were time stamped four days earlier, and he has returned every night since, sometimes staying five hours at a time.

“The hope is that you’ll get them hooked on that corn, so that they’ll come back to feed every night,” Meister says. He plans on returning later to set up a single trap in hopes that the hog will return one last time.

Much like any other invasive specialists, eradication is the goal, but the road is a long one. In Texas, the feral hog population is estimated in excess of 1.5 million, but for Missouri, with a feral hog population close to 10,000, pig-free is a possibility. The biggest beneficiaries of a hog-free show-me state are its citizens. “They are going to see less damage, it’s going to cost less, and they’re going to have more wildlife opportunities,” Martensen says. “If we could ever eradicate pigs from the state of Missouri, that would be a big deal.” For Martensen, those last words hold importance, so he repeats them, “That would be a big deal.”

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