2012 Summer — June 12, 2012
The scope of invasive impacts demands response

Hoping to prevent the spread of Asian long-horned beetles, Canadian authorities posted a sign in Toronto warning about the risks of transporting firewood. (Credit: GTD Aquitaine/Wikimedia)

When crude oil is washing up on our beaches, or a hurricane bears down on our community, or a wildfire is raging toward our homes, we act quickly and decisively to prevent or mitigate damage. So why do individuals, communities, and governments often stand idle against the onslaught of invasive species? Nonnative animals, plants, and pathogens that become harmful (invasive) in ecosystems are threatening to wipe out a century of conservation gains in North America, irreparably transforming our landscapes and costing our economies billions of dollars.

The threat is at least as massive, fast-moving, and tangible as the global climate change crisis, with impacts mounting daily at every level. This is the age of the “homogocene,” a term coined by ecologist Gordon Orians to describe the current period of global history in which widespread and rapid mixing of species is occurring at rates never before known on the planet (Rosenzweig 2001).

Research shows that about 42 percent of threatened or endangered species are at risk primarily because of invasive species (Wilcove et al. 1998), and we humans have made their rapid spread possible through high-speed transportation and trade, deliberately or inadvertently moving species to new areas of the world literally overnight. The influx, combined with shifting climates and inaction, creates potential for the perfect storm of invasive species impacts across the planet. Scientists and conservationists are aware of the issues. Now, awareness must yield to action.

Laying the Foundation

Warnings and calls to action against the spread of invasive species are not new. For decades, wildlife and fisheries professionals, ranchers, farmers, foresters, and others have recognized that invasive species pose a major environmental and economic threat demanding management and policy action. Concerns about invasive species accelerated in the latter part of the 20th century, resulting in several broad-based efforts to help lay the foundation for a coordinated response.

In the early 1990s, for example, the Aquatic Nuisance Species Task Force (ANSTF) and the Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW) were established in the U.S. to help provide a coordinated structure to identify problems, recommend policy and management practices, foster partnerships with state and local governments and the private sector, and identify needs for research, technology, and public education about harmful exotic species.

In 1992, Canada was the first industrialized country to ratify the United Nations Convention on Biological Diversity, developed at the multinational Rio Earth Summit earlier that year. The convention called on all parties to prevent the introduction of invasive species and to “control or eradicate those alien species which threaten ecosystems, habitats, or species.” Soon after, the U.S. Office of Technology Assessment (OTA) published a landmark report titled “Harmful Non-Indigenous Species in the United States” (OTA 1993) — at that time the most comprehensive review of the invasive species issue ever undertaken by the U.S. government. The OTA report left no doubt regarding the magnitude of the threat and the need for enlightened policies, reliable information, and adequate resources to effectively safeguard “our national interests.” A few years later, in 1996, 80 nations met in Norway for the UN Conference on Alien Species, the first major international conference on the invasive species issue, highlighting the implications to conservation, sustainable development, and world trade.

After FICMNEW released “Pulling Together — A National Strategy for Invasive Plant Management” in 1997 — supported by more than 100 conservation organizations — roughly 500 scientists and conservationists (including such notables as E.O. Wilson, Don Schmitz, and Peter Vitousek) sent a letter to Vice President Al Gore with a compelling request to increase the nation’s response to the global invasive species problem. Gore directed the departments of Agriculture, Commerce, and the Interior to plan a coordinated attack on the problem. In 1999, that effort was formalized when President Clinton signed Executive Order 13112, establishing the National Invasive Species Council (NISC) and outlining U.S. federal agency responsibilities to address the invasive species problem.

Recent years have seen additional infrastructure advancements against invasives. States have been actively creating invasive species councils and passing relevant legislation and, in 2003, the U.S. established the National Environmental Coalition on Invasive Species (NECIS), a coalition of environmental groups — now including The Wildlife Society — that provides scientific expertise to influence invasive species policy. Likewise, in 2004 Canada released “An Invasive Alien Species Strategy for Canada” calling for a coordinated national response. Today,Canada has a National Invasive Species Council in place and almost every province has a non-profit council involved in the effort.

More recently, in early 2011, NECIS sent Congress and President Obama An Action Plan on Invasive Species requesting adequate funding for specific actions to combat invasives, such as tougher regulations and screening of non-native plant and animal imports.

Aptly named for its green gleam, the emerald ash borer is projected to kill most of the nearly eight billion ash trees (Fraxinus spp.) throughout North America, causing damage at a scale greater than that from chestnut blight or Dutch elm disease. (Credit: Daniel Herms/The Ohio State University)

All the coalitions, agencies, conferences, and action plans in the world can’t solve the invasive species problem if we don’t take meaningful action. Ultimately, effective action against invasives will require changing human behavior across the broad spectrum of our society, a major challenge in itself. Intentional human actions — such as importing exotic pets and plants, moving bug-infested firewood from one forest to another, or dumping bilge water filled with invasive mussels — must be curbed. Such human-accelerated biological invasions are a widespread and significant component of anthropogenic global environmental change, and represent a breakdown of the regional distinctiveness of Earth’s flora and fauna, thereby degrading human health and threatening native biodiversity (Vitousek et al. 1997). By adapting programs that have successfully changed human behaviors in the past — such as those regarding seat-belt safety, smoking, littering, and recycling — we can encourage the public to adopt “social norms” that decry the introduction of invasives and support their removal.

A few such efforts are already underway. For example, a U.S.-based group called Protect Your Waters offers the “Stop Aquatic Hitchhikers” program to teach recreational boaters how to prevent the spread of non-native plants, animals, and organisms that may be transported on boating equipment. Canada’s Clean, Drain, Dry program offers similar education and outreach. The Don’t Move Firewood campaign teaches campers about tree-destroying pests and how to avoid transporting them in bundles of firewood. Wildlife Forever’s Threat Campaign teaches hunters, anglers, boaters, and others about the need to combat the spread of invasives. And Australia and Canada offer the Grow Me Instead campaign to teach gardeners about which plant species are non-native for their particular regions.

Success against the grasp of an invader is usually achieved at relatively small scales, at a community or watershed level. But persistence is necessary, and those small victories are vital: Once established, an infestation creates exponentially increasing losses and management costs. Being proactive is therefore critical, but the concept of “pay now, or pay a lot more later” seems to be hard for some to accept. When we procrastinate, the rates of invasive species establishment and spread almost always outpace control and containment efforts.

Those efforts, however, may be stymied by debates over the methods of control (such as applying pesticides or using biological controls), particularly regarding short-term risks of collateral damage to native species. Repelling an entrenched invasive ‘enemy’ may result in the killing of some ‘civilian’ natives. Conservation professionals need to understand that the invasive species battle will be hard, bloody, and unpleasant, and they should be willing to use whatever integrated tools are necessary to achieve the desired conditions on the landscape.

Sometimes, a few of the innocent will be harmed for the sake of the long-term protection of the broader ecosystem. Those in our society who want a guarantee that there will be no casualties to individual non-target native species probably don’t fully understand that invasive species pose a much greater danger to the long-term survival of those native species.

The Cost-Benefit Equation

Deciding what action to take may be easier than deciding how much to take — or to spend. “Every delay adds costs and lowers our chances of success,” says the National Wildlife Federation’s Corry Westbrook as quoted in the NECIS action plan. Calculating what is cost effective is itself a massive challenge, however, because although the price for any management action can be high, the cost for inaction may be far worse. Consider:

  • The Nature Conservancy estimates that damage from invasive species worldwide in 2010 totaled more than $1.4 trillion — 5 percent of the global economy (TNC 2011).
  • Researchers from Cornell Universityhave estimated that the economic impact from invasive species in theU.S.exceeds $120 billion annually (Pimentel et al. 2005). Such damages include environmental impacts (loss of ecosystem services) as well as economic losses in property values, tourism, and infrastructure.
  • Preliminary research on the Great Lakes region suggests that the annual cost from invasive species introduced by shipping may exceed $200 million a year, in part because invasions limit the ability of the natural ecosystem to support fisheries, raw-water uses, and wildlife watching (Lodge and Finnoff 2008).
  • A study of invasive weeds on public lands in Nevada estimated lost wildlife-related recreation values from $5 million to $17 million per year, with as much as $34 million lost over a five-year period (Eiswerth et al. 2010).

No matter how we measure the impacts, dealing effectively with invasive species is economically vital. Management treatments need to surpass an invader’s ability to spread, but with limited budgets, resource managers must evaluate the economic and environmental costs of doing a little (and perhaps wasting money) versus doing enough to make a difference. That calculation often leads to sticker shock. For example, a report by the Maine Department of Environmental Protection (MDEP) notes that all New England states as well as 41 other states and six Canadian provinces are battling Eurasian watermilfoil, water chestnut, zebra mussels, and other waterborne invasives at a cost ranging from $200 to $2,000 per lake acre per year — with no end in sight. Vermont alone spends more than $200,000 annually just on the staff who manage invasives at 46 of the state’s 285 larger lakes.

In their book Fading Forests II: Trading Away North America’s Natural Heritage, authors Faith Campbell and Scott Schlarbaum note that “public agencies have already spent tens of millions of dollars attempting to eradicate just one of several recently introduced pests — the Asian long-horned beetle.” But if that beetle thwarts containment efforts, they write, “it will cost an estimated $600 billion to replace city trees killed” by the bug, along with additional losses from declines in tourism, maple syrup sales, and timber production (Campbell and Schlarbaum 2002).

Clearly invasive species are draining our economy on many levels. The solution, then, may lie in simultaneously addressing both the economic and environmental problem by using the fight against invasives to stimulate new jobs, not just in eradication and control but in research, technology, education, marketing, and other fields. President Obama recently took a step in that direction when, in February 2012, he announced a new Veterans Job Corps program that would include $1 billion in conservation funds, some of which would go toward employing veterans to eradicate invasive species.

Getting off the Dime

Such programs may help plug the holes in our economic buckets, but they aren’t enough, and the broader conservation community — particularly the fish and wildlife management profession — appears to be significantly overwhelmed by the scale and complexity of the invasive species problem. Declining government capacity to fund conservation programs also limits our ability for proactive action. Like many other conservation issues, there are too few resources and too many priorities to address, particularly on public lands. Private landowners (who control the majority of the landscape) are in even worse shape, having little capacity to protect themselves or their neighbors against harmful aquatic or terrestrial invasions.

In addition to the significant lack of investments, our conservation profession seems to be devolving into bureaucracy, with our traditional “get-er-done” genes transitioning to a recessive trait. With relatively porous borders and the global expansion of trade and transportation, thousands of invasive species are storming the gates while we fumble about with more bureaucracy and search for silverbullet solutions that are politically neutral and often hamper the immediate response needed to repel the onslaught.

When environmental contaminants poison our children, society is usually quick to call for stronger regulatory protections for the environment and human health. When our economic stability is under assault, we respond with massive amounts of money and policy revisions to patch the holes. Likewise, success against invasive species may be found by showing that this is as much a human-health and economic issue as an environmental one, thereby broadening the set of supportive stakeholders.

The agriculture, fisheries, forestry, ecology, and wildlife management professions need to reinvigorate their collective energies against aquatic and terrestrial invasive species and take a leadership position on this issue — or risk losing the ground we have gained for conservation. We must join with the public and private sectors to address the clear and present danger of invasive species. The call to action is now! The solution is working together to stop the spread.

Author Bios

Michael Ielmini, CWB, is the National Invasive Species Program Manager for the U.S. Forest Service.

Gail Wallin is Executive Director of the Invasive Species Council of British Columbia.

George Beck, Ph.D., is Professor of Weed Science at Colorado State University.

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