Fighting Ohio's Invasive Species: 'Everyone Can Be Part of the Battle'

Bighead carp closeup

Editor: National Invasive Species Awareness Week is March 3-8.

COLUMBUS, Ohio -- Kathy Smith says not every bush, beetle, fish or fungus that lives in Ohio belongs there. And she wants you to know it. And pitch in. And give them the boot.

As forestry program director for Ohio State University Extension, the statewide outreach arm of Ohio State’s College of Food, Agricultural, and Environmental Sciences (CFAES), she’s part of a statewide coalition recognizing National Invasive Species Awareness Week from March 3 to 8.

“We’re trying to open people’s eyes to what’s going on in the environment around them so hopefully they’ll take action, whether by removing invasive species on their own land, reporting a sighting, joining a volunteer group or just helping us spread the word,” said Smith, who leads OSU Extension’s Ohio Woodland Stewards Program. The program conducts outreach programs on forestry and wildlife, including spotting and controlling invasive species.

Video (0:46): Kathy Smith, forestry program director for Ohio State University Extension, discusses National Invasive Species Awareness Week. 

Invasive species are those that aren’t native to a place but arrive through people’s actions, either by accident or on purpose. They escape, usually spread fast, and can reduce or eliminate native species by eating, shading, crowding, damaging, infecting or outcompeting them, Smith said.

In the process, invasive species damage their new home’s environment and cost people, communities and businesses money, she said.

The exotic emerald ash borer, for instance, has killed tens of millions of Ohio’s native ash trees. If it continues unchecked, it could wipe out all of the state’s -- and North America’s -- native ashes. The Ohio Department of Natural Resources (ODNR) says the cost of the pest’s invasion to Ohio citizens could top $3 billion.

National Invasive Species Awareness Week is being observed this week through March 8 to focus attention on the harm done by invasive species in the U.S.

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Stinker: Garlic-mustard, a perennial plant originally from Europe, aggressively outcompetes native woodland wildlflowers. (Photo: U.S. Fish and Wildlife Service.)

The National Invasive Species Council, which is sponsoring the week nationally, said invasive species cause a multibillion-dollar annual drain on the nation’s economy. And the Convention on Biological Diversity calls invasive species the second biggest threat to the world’s biodiversity after habitat loss.

“We live in a global society. Invasive species should be on everyone’s radar,” said Amy Stone, who’s an educator in OSU Extension’s Lucas County office and a member of Extension’s Nursery, Landscape and Turf Team (ENLTT). The team conducts programs that improve Ohio’s multibillion-dollar lawn-, garden-and ornamental plant-related industries.

“(Invasive species) potentially can impact the food we grow, our landscapes, our communities and ultimately our pocket books,” she said. “The sooner we can identify them, the less the damage and the lower the cost to manage them.”

And sometimes, too, invasive species come by sea. Or in Ohio’s case, by lake and river.

To date, some 184 invasive species have been documented in the Great Lakes, including Lake Erie, said Eugene Braig, OSU Extension’s aquatic ecosystems program director.

Four species of Asian carps, meanwhile, are knocking at the lakes’ door. To the south, the silver carp, which is one of those species, is already in the Ohio River. The carps devour plankton that young native fish need to survive, breed quickly, grow large and come to dominate the waters they live in. In some parts of the Missouri River, Asian carps make up 90 percent of the fish now.

“Once an aquatic invasive species becomes established, eradication ranges from difficult and costly to impossible,” Braig said. “Prevention is key.”

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Ashes to ashes: The emerald ash borer, native to Asia, has killed tens of millions of Ohio’s native ash trees. If it continues unchecked, it could wipe out all the native ash trees in the state and in North America. (Photo: U.S. Department of Agriculture.)

Ohio’s Invaders

Examples of Ohio’s invasive species include tree pests such as emerald ash borer and Asian longhorned beetle; aggressive plants such as kudzu, garlic-mustard, callery pear, bush honeysuckles and hydrilla, an aquatic weed; West Nile virus; zebra mussel; and round goby, a fish.

Other Ohio invaders include plants such as common reed, tree-of-heaven and Canada thistle; tree pests and diseases such as gypsy moth, chestnut blight and Dutch elm disease; European corn borer, a major corn crop pest; aquatic species including the common carp and sea lamprey, the latter being a primitive fish that parasitizes game fish; and birds such as the house sparrow and European starling, both of which muscle out bluebirds and other native species for nest sites.

More recent arrivals include feral pigs, white-nose syndrome in bats, the hemlock tree killer called hemlock woolly adelgid, the aggressive ground-covering plant called lesser celandine, and the walnut twig beetle, which can spread deadly thousand cankers disease in walnut trees.

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Stranglehold: Lesser celandine is an escaped ornamental plant, originally from Europe. It forms large, dense, yellow-flowered patches in woodlands. The patches smother native plants, especially spring wildflowers. (Photo: Tom Forney, Oregon Department of Agriculture.)

Among invasive species’ harmful impacts in Ohio:

  • The zebra mussel and its cousin, the quagga mussel, cost U.S. and Canadian water users in the Great Lakes region an estimated $5 billion from 2000 to 2010, according to the U.S. Fish and Wildlife Service. How: By clogging municipal water-intake pipes and requiring costly cleanup and prevention.
  • Bush honeysuckle plants are causing Ohio’s state bird, the cardinal, to be less genetically fit, an Ohio State study reported. The non-native shrubs produce less-nutritious berries than those of displaced native dogwoods and highbush cranberries. Male cardinals that eat the inferior berries end up less healthy but still keep their trademark bright red color, which normally tells a female that they’ll make a quality mate. But in this case, due to their diet, they won’t. When females choose these vivid but secretly weaker males, the “survival of the fittest” reproductive strategy gets disrupted.
  • Cardinals nesting in bush honeysuckles also fledged 20 percent fewer young, another Ohio State study found, leading the study’s authors to call the plants “ecological traps.”
  • At risk from the potential arrival of Asian carps -- not just the silver but the grass, black and bighead, too -- is a Great Lakes commercial fishery worth $7 billion, according to the Congressional Research Service. Lake Erie produces more of that harvest than the other Great Lakes combined, says a study by Michigan Sea Grant Extension.

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Not-so-little piggy: Feral pigs, a cross between Eurasian wild boars and escaped domestic swine, can weigh up to several hundred pounds. They live in southern Ohio now. (Photo: Makro Freak via Wikimedia Commons.)  

  • Japanese barberry creates a denser, more humid environment in forests. The change leads to big increases in the number of ticks and the mice that spread them, a Connecticut study found. Smith said bush honeysuckles may do the same thing.
  • In places, white-nose syndrome has killed 90 to 100 percent of the bats hibernating in caves in winter. Bats provide an average of $740 million a year worth of pest-eating services to Ohio farmers, according to a study in the journal Science.
  • Thousand cankers disease, if it comes to Ohio, threatens all of the state’s walnut trees, which produce lumber worth $1.2 billion and tons of edible nuts. The disease is spread by the walnut twig beetle, which was found in Ohio for the first time in late 2012, but the disease itself hasn’t appeared.
  • Feral pigs, which are now in southern Ohio, root up crops in farms and gardens, erode soil, and muddy streams with their wallowing. An ODNR Web page calls them “living rototillers.” They eat the eggs and young of ground-nesting songbirds, the young of deer and livestock, and the acorns that deer, squirrels and wild turkeys require. They can also carry pseudorabies and swine brucellosis, which can be spread to pets, livestock and wildlife.

‘They Disrupt Our Natural Areas’

Invasive species cause negative effects in a number of ecosystems, said Marne Titchenell, an OSU Extension wildlife specialist who’s also a member of the Woodland Stewards Program.

“They disrupt our natural areas in a lot of ways, but one of the biggest is by reducing biodiversity, which is key to keeping our ecosystems functioning in a self-sustaining way,” she said. “Healthy ecosystems provide us with many of the things we enjoy about the outdoors -- wildlife, hunting, fishing, birdwatching, walks through the woods, wildflower hikes, timber production, forest products, and clean air and water, to name just a few.”


The fast-growing kudzu vine -- originally from Japan, infamous in the South, shown here in Missouri -- has made it to Ohio. (Photo: Gsmith via Wikimedia Commons.)

For their part, Titchenell, Smith, Stone, Braig and others hold workshops and classes on invasive species, speak at events such as the annual Farm Science Review trade show, and give talks around Ohio to groups focused on farming, fishing, gardening and other fields. They team up to present many of these programs with experts from other state and local agencies, such as ODNR and county soil and water conservation districts.

They also work with scientists studying invasive species at Ohio State’s Ohio Agricultural Research and Development Center, which is the research arm of CFAES.

And they’ve co-developed a new smartphone app that lets citizens join the fight. The Great Lakes Early Detection Network app equips users to take pictures of suspected invasive species, then upload the pictures and locations for verification. It can be downloaded free at

Data submitted by the app’s users goes into the Web-based Early Detection and Distribution Mapping System, which tracks the location and spread of invasive species throughout the U.S. and Canada, Smith said.

Based on this information, she said, scientists can send out alerts, map a species’ movements and form a battle plan.

“Everyone can be part of the battle against invasive species,” Stone said. “We need everyone’s help for monitoring and early detection.”

Indeed, since 97 percent of Ohio’s land is privately owned, Ohio residents can make a big difference in the fight against invasives, Titchenell said.

“It seems no matter the area -- forest, wetland, pond, prairie, city park, backyard -- invasive species are everywhere,” she said. “Odds are that no matter where you are in Ohio, you can make a difference when it comes to detecting, managing and eradicating invasive species.”

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Editor: Parts of this press release appeared in “Ohio Groups Recognizing National Invasive Species Awareness Week March 3-8,” March 4, 2013,

Also related to this story:

  • “Ohio Invasive Species Profile: Asian Longhorned Beetle,” March 5, 2013,
  • “New App Lets You Report Invasive Species,” Oct. 18, 2012,
  • “Ohio State Experts Available to Speak on Thousand Cankers Disease in Walnut Trees,” Dec. 11, 2012,
CFAES News Team
For more information, contact: 

Kathy Smith

Marne Titchenell

Amy Stone

Eugene Braig