Aquatic Invasive Wildlife
Ohio is a beautiful place, with lands and waters boasting exceptional geographic and biological diversity. Its countless array of habitats, which support native plants and animals, also offer a variety of recreational opportunities. But the state’s environment is under threat as never before from damaging non-native plants, animals, and pathogens. Ohio is a major player in interstate and global trade. With a thousand miles of navigable waterways, the tenth largest highway network in the nation, and international seaports, the state is a major hub for commerce. These assets fuel Ohio’s economy, but they also provide the circumstances for entry and establishment of damaging nonnative species, which arrive through canals, shipping containers, ships’ ballast water, the intentional import of live commercial plants and animals, and many other mechanisms.
These so-called invasive species have affected all of the state’s economic sectors, including agriculture, fisheries, forestry, energy production, and recreation. Invaders cost at least tens of millions of dollars each year, and damage could reach into the billions. Current state and federal policies are far from adequate. This report reviews the costs of invasive species in Ohio and suggests a range of state and federal policies that could better protect the state’s native habitats and bolster its economy. Most of these policy changes are currently being considered in Columbus and Washington, DC. But it is clear that the sooner they are made, the better. Once invasive species become established, it is increasingly difficult and expensive to keep them from spreading and none of them respect state boundaries.
How Do Invasive Species Hurt Ohio?
Not all non-native species are harmful. Of those that arrive, a majority will die off or maintain small and contained populations. But some will find habitats in which they can thrive; in so doing, they may outcompete native species, change the biophysical environment, damage property, or adversely affect human, wildlife, and economic health.
Economic Costs:
No one has documented the total amount of money that Ohio loses or spends because of all the invasive species it harbors. However, we can get indicators from the figures that exist for a few of the most damaging species:
• The Animal and Plant Health Inspection Service of the U.S. Department of Agriculture (USDA) has already spent nearly $27 million in Ohio on controlling the emerald ash borer.
• Removing the one to four million infected ash trees currently growing in Ohio’s parks, along streets, and on private property would cost an estimated $700 million to $2.9 billion. Replacing each of these trees with another small shade tree would cost an additional $300 million to $1.3 billion.
• Eliminating invasive species is a central means of restoring rare oak savannas in northwestern Ohio. Such an effort is being supported by a 10-year, $23-million tax levy plus partial matching grants from the state.
• Annual expenditures throughout the Great Lakes region for controlling the sea lamprey exceed $15.9 million.
• By the late 1990s, just a few years after its initial invasion, the Eurasian ruffe (a non-native fish) was estimated to have caused losses of $600 million to Great Lakes sport fisheries.
Environmental Costs:
The state’s environmental costs are also high. At least 20 percent of Ohio’s threatened and endangered wildlife species, such as lake sturgeon, are affected by invasive species. Their various impacts include:
• Bush honeysuckles, three species of aggressive invaders, have displaced numerous native plant species in parks and wilderness; at least one has also reduced the growth of hardwood trees.
• Non-native mussels, fish, and insects have spread diseases to wildlife in the region, resulting in sizeable die-offs.
• Zebra and quagga mussels are thought to facilitate the oxygen-depleted conditions in the Lake Erie “dead zone.”
Costs To Human Health:
Invasive species also have direct impacts on human health. For example:
• The recently arrived Asian tiger mosquito is host to a number of viral diseases, including dengue fever, yellow fever, encephalitis, and West Nile virus.
• Organisms in ballast water, the ubiquitous Norway rat, pet amphibians and reptiles, and other carriers can transmit diseases to humans.
|Invasive Species in Ohio: Pathways, Policies, and Costs Executive Summary Union of Concerned Scientists|
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