Green Watch

Invasion of the Species

Bureaucrats and activists look at the endangered species problem the wrong way

To be successful in a conflict, one must aim for the right targets. To be blinded to the facts by pre-conceived notions or by political ideology can be disastrous. We see that principle at work in the effort to preserve endangered species.

The Obama Administration is preoccupied with fighting a war on the threat supposedly posed by a distant and indeterminate degree of climate change.  Meanwhile, for almost eight years it has paid precious little attention to an obvious, immediate, and severe environmental threat, one with obvious and immediate ecological, economic, and public health consequences: invasive species.

Defining the problem

Increased global trade, the ability of businessmen and tourists to travel across oceans in hours instead of weeks, and a generally more mobile and well-traveled population in the developed world, are all generally viewed as positive aspects of life in the 21st Century.  There is, however, a serious detrimental, unintended consequence of globalization that presents significant economic, ecological, and public health challenges that affect our lives every day.

That unintended consequence is the spread of invasive species.  The problem’s manifestations vary in severity and nature from one region of the United States to another, but the problem is universal, whether it is being played out in suburban New York City, the open range of Montana, downtown Chicago, Florida’s Everglades, or San Francisco Bay.

An ecological collapse is in the offing in Florida’s Everglades.  Over the last 20 years the federal and state governments have spent about $3 billion in the name of ecosystem restoration to undo the negative consequences of the well-intended water management decisions of the 1960s and 1970s that were supposed to provide flood control and economic development in the Sunshine State.  Yet a more insidious ecological problem is threatening to negate any benefit from all that spending, and render futile the tough political and economic decisions that have been made to try to re-plumb South Florida.

Like the wave after wave of barbarian hordes that infiltrated and ultimately wrecked the Roman Empire, Florida has been subject to successive waves of ecological invasions.  Burmese pythons, tegu lizards, and most recently man-eating Nile crocodiles have all found their way into Florida.

Burmese pythons are currently the most dramatic case illustrating the point.   Whether deliberately released into the wild by pet owners who belatedly decided it might be inconvenient to continue to care for a pet snake that eventually grew into a twenty-foot behemoth, or accidentally released when one of Florida’s hurricanes trashed the facilities rearing the prospective pets, the state is now faced with the problem of dealing with the estimated hundreds of thousands of Burmese pythons that have established a very prolific and successful breeding population in South Florida.

First observed in the wild in the year 2000, like the proverbial serpent in the Garden of Eden, these reptiles are up to no good.  Indeed, they are eating everything they can get their jaws into and their coils around.  As a result, native animal populations are being decimated.  Rabbits and foxes can no longer be easily found in the Everglades, while populations of raccoons are down an estimated 99.3 percent, opossum by 98.9 percent, and bobcat, 87.5 percent.

Pythons have been caught with deer in their stomachs. Pythons eat endangered species that the federal government has spent millions trying to recover.  Those recovery efforts were also often made at the expense of private sector development opportunities and job growth. Pythons regularly do battle with American alligators, and often win those fights to the death.  In their Asian homeland, the pythons are known to kill leopards, so they may well occasionally be eating endangered Florida panthers, adding to the difficulty of efforts to recover those animals.  It is reasonable to assume that the pythons will eventually push some native Florida mammals or birds onto the endangered species list, with significant economic implications for Florida’s landowners, as well as for the ecosystem.

Economic impacts

According to Cornell University estimates, invasive species cost the American economy over $120 billion per year in revenue forgone and other costs. The California Academy of Sciences estimates the annual global impact from invasives to be roughly $1.2 trillion.

Agriculture suffers about half the damage, but no sector of society is immune.  Terrestrial and aquatic ecosystems are both at risk. Zebra mussels and the closely related quagga mussels evolved in the freshwater Caspian Sea and rivers in eastern Europe.  Around 1988 some immature zebra mussels were inadvertently sucked into the ballast water reservoirs of a Soviet freighter headed across the Atlantic and into the Great Lakes, where it probably docked at Detroit, or nearby Windsor, Ontario, to take on cargo. In order to accommodate the weight of the cargo, it had to release some of the ballast water.

The zebra mussels were carried along with that ballast water into the Detroit River.  They were soon found in Canada’s Lake St. Clair, where they multiplied and spread across the Great Lakes. From the Great Lakes they have hitchhiked on the hulls of commercial vessels and recreational boats and spread across most of eastern North America.  In the Great Lakes they number in the billions, covering beaches with their shells, and growing in dense masses across the Lakes.  They clog pipes, encrust a wide variety of infrastructure in contact with infected waters, and smother everything they come in contact with, including native mussels.

Electric utilities, water utilities, factories, marinas, navigation locks, dams, power plants, all are affected by zebra and quagga mussels.  The estimated annual increased maintenance cost of water facilities in the Great Lakes alone is $500 million.

The mussels were accidentally moved by Midwestern recreationists on the hulls or in the bilge water of their pleasure boats into the Colorado River Basin, where they now can be found in the chain of reservoirs from Lake Mead south to the Mexico border.  They pose a constant threat to the irrigation and water delivery systems of the Central Valley of California, and the Columbia River Basin’s navigation, hydroelectric, and irrigation facilities. If these invasive mussels become established in those systems, the economic impact would be in the billions, affecting electric ratepayers, the cost of exports to Asia, and the water supplied to the most valuable agricultural area in the country.

Because these mussels are incredibly effective filter feeders, they concentrate pollutants and toxicants in the water, and pass them on in concentrated form to any fish or waterfowl that dares to eat them. As a result, they have been associated with outbreaks of avian botulism, hurting the recreational opportunities and associated tourism industry in the Great Lakes, as well as causing significant ecological problems.

Public health impacts

Each year invasive species of microbes from overseas make Americans sick, putting people in the hospital or killing them. For instance, West Nile virus came to the U.S. in 1999, presumably brought to the country from north Africa by an infected international traveler, who in turn was bitten by mosquitos that themselves became infected and passed on the disease to others.  The invasive Asian tiger mosquito is a particularly threatening vector for the disease. Although a real threat to human health, the disease was especially deadly to birds. By 2012, millions of North American birds had been killed by the virus, along with 1,500 people.  More than 37,000 Americans had been sickened by the disease, causing millions in medical costs.

In 2014, America had a handful of occurrences of the Ebola virus, whose roots are in West Africa. While the domestic public health scare was disproportional to the actual impact here, Ebola is a deadly disease.  The West African epidemic killed more than 11,000 people.  The U.S. government has so far spent nearly $3 billion to address Ebola.

The Zika virus originated in east Africa and first appeared in the Western hemisphere in 2015, when it was found in Brazil.  By 2016 international travelers had brought it to the United States, resulting in 755 domestic cases.  Although rarely life-threatening, the disease produces birth defects in unborn children, making it a serious public health threat.

The invasive Asian tiger mosquito is again a vector for spreading Zika, and the risk is compounded due to the mosquito’s interaction with yet another invasive species: bamboo.  The Asian tiger mosquito is particularly difficult to eradicate since it can breed in remarkably small quantities of water, such as the water that collects in the chambers of broken bamboo reeds.  Hence the invasive plant bamboo creates great habitat for invasive Asian tiger mosquitos, which in turn are a significant vector for the invasive Zika virus.


The concept of invasive species has been in the scientific vernacular for several decades.  The earlier and closely related concept of animal and plant “pests” probably goes back many thousands of years to the first Egyptian and Mesopotamian efforts involving intensive agriculture and construction of granaries.

While several federal laws address invasive species, U.S. law has no single comprehensive definition.  The generally accepted definition is found in Executive Order 13112, signed by President Bill Clinton on February 3, 1999.  The Order defines an invasive species as an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.

While there are certainly troublesome native species, such as coyotes in the West or white-tailed deer in Mid-Atlantic suburbia, these animals are technically not invasive species since they are not aliens; they have been in North America since pre-Columbian times, indeed perhaps for millions of years.

The term “alien,” in this context, is typically understood to mean not native to a given continent, in our case North America.  When such an alien species threatens our economy, environmental quality, or public health, it qualifies as invasive.  Of the three, the public health test is the most clearcut.  If an alien species is sending people to the doctor or hospital, or killing us, then it is demonstrably invasive.

The economic test is usually straightforward. If the alien species is killing crops, destroying forests, or increasing costs borne by utility ratepayers, then the economic impact is clear.  However, sometimes the situation is ambiguous.  The invasive species may create economic benefits for some people and economic or environmental costs for others.  An example is the deliberate stocking of the gamefish striped bass from the New Jersey coastal area into the San Francisco Bay-Delta estuary.  The striped bass is a prized sportfish and good eating, and so has been a boost to the tourism and recreational fishing industries in northern California. Unfortunately, it also likes to eat a small fish known as the Delta smelt, which is now listed under the federal Endangered Species Act.

To try to protect the smelt, the federal government has spent hundreds of millions of federal taxpayer dollars and imposed billions of dollars in costs on California farmers and other water users, who have been deprived of water they need to produce crops, or have had to make investments to protect the smelt at the cost of higher water rates for their customers.  To the Central Valley farmers, the striped bass is an invasive species that is costing them money, but to the fishing tackle vendors it’s a source of income.

Usually the environmental harm caused by invasive species is obvious and undeniable, such as the impact of Burmese pythons on South Florida populations of native birds, mammals, and reptiles.  In other cases there may be partially offsetting beneficial environmental impacts.  The same zebra and quagga mussels that are incredible pests in the Great Lakes are also filtering so much water in the Great Lakes that they are indirectly contributing to improved water visibility and higher fish populations for some species, even as the mussels depress populations of other fish species.

Not all immigrants cause problems. Not every alien or exotic species is invasive. It’s estimated that 50,000 exotic species live in the United States.  Of these, Harvard biologist E.O Wilson has estimated that perhaps 10 percent find their way into the wild, and of those, about 10 percent exhibit invasive characteristics.  So only about one percent of the exotic organisms found in the United States are actually problematic. Being called exotic means simply that an organism evolved somewhere else, whereas invasiveness describes behavior: whether and how that exotic species behaves in a problematic way in its new environment.

Many exotic species are incredibly valuable economically, and provide directly or indirectly much of the food Americans eat.  Watermelon is native to central Africa. From the eastern Mediterranean region we get asparagus, beets, broccoli, cabbage, cauliflower, celery, endive, kale, lettuce, parsley, parsnips and rhubarb.  Carrots and onions come from the Middle East. Brussel sprouts originated in Northern Europe. The artichoke came from Italy. Peas came from Eurasia, and spinach is native to Iran.  India has given the world four vegetables: cucumber, eggplant, mustard, and cowpeas.  Radishes and soybeans came from China and Japan. Also from China came peaches, oranges, and apricots.  Apples, pears, and cherries originated in Western Asia and the hill country around the Black Sea and Caspian Sea.

The date is a flowering plant originally from Arabia and Egypt. Olives originated in Syria, Egypt, and Greece.  Figs came from Syria.  Wheat, oats, and barley also originated in the Near East, and rice and millet come from Asia.

A challenge for centuries

Probably the most devastating example of public health impacts from invasive species was the spread of the Black Death from the steppes of Asia, where it was endemic, to Europe, where it was not normally found.  The Black Death was caused by a bacterium, Yersinia pestis, carried in the bloodstream of rats, and transmitted by fleas on the rats to humans.

As a pathological organism that was not native to Europe Y. pestis fits the definition of invasive species.  International trade facilitated rapid transcontinental movement of the disease across Europe from 1346 to 1353, much as international trade is the primary mechanism for movement of invasive species in our own time. Contaminated rats moved with trans-Asian caravans, then crawled into the holds of trading ships, from which they spread from European seaport to seaport, and ultimately into the interior of continental Europe.

Estimates vary—it’s hard to keep track of casualties when entire towns vanish—but, by one calculation, about 60 percent of Europe’s population of an estimated 80 million people died from the disease, making the loss of those 50 million lives the most traumatic and dramatic episode in the history of Western culture, rivaling the fall of the Roman Empire in its sociological significance, and no doubt as terrifying to live through as the scariest of today’s zombie apocalypse movies.

About two centuries after the Black Death ravaged Europe, European immigration to the Western Hemisphere resulted in even more devastating introduction of a variety of invasive disease organisms into native American populations.

Scholars estimate that perhaps 75 million native people lived in the Americas at the time of European exploration. The population shrank by perhaps 90 percent over the next three centuries, primarily due to diseases of European origin.

The first introduction of a European disease likely came along with Columbus on his second voyage in 1493, when influenza germs carried by Spanish livestock spread to natives on the island of Hispaniola.  It rapidly spread across the Caribbean and into Florida. Measles, bubonic plague, typhoid fever, small pox, diphtheria, and other invasive disease organisms followed.

Smallpox was likely the most virulent European disease to invade the Americas, where it killed between 50 and 95 percent of exposed populations. Around 1507, Spanish explorers first brought smallpox to the New World, where it spread from the Caribbean to the mainland of Central America.  Over the next three centuries, wave after wave of epidemics of smallpox and other European diseases devastated Native American populations.  The military and political impact of these accidental waves of disease was as significant as if the colonists had deliberately waged biological warfare on the Native Americans.

And not just human communities have been ravaged by invasive diseases. In 1904, some imported Asian chestnut saplings entering New York City from Japan were the unintended source of the introduction into the United States of an invasive fungus known as chestnut blight.  Previously, the American chestnut tree had been a dominant component of forests in the eastern United States.  It was a keystone species in the eastern forests, representing about 25 percent of the trees in our deciduous forests, and providing food for a wide variety of animals that took advantage of its nutritious nuts.  Carried by the wind, the chestnut blight spores soon resulted in a crash of the American chestnut population, killing an estimated 4 billion American trees by 1940, or close to 95 percent of the trees that existed before the invasion.  While American chestnut seedlings can sprout from dead trunks of older trees, the blight usually kills the new trees before they grow enough to reproduce.

Efforts are underway to try to hybridize the few remaining isolated American chestnuts with blight-resistant Asian varieties, and so reintroduce a form of chestnut into American eastern forests. Genetic engineering may also save the American chestnut, as scientists have learned to introduce a gene from wheat that fights the biochemistry of the fungus.

At about the time that chestnut blight had peaked in its damage to American forests, another Asian invader entered the United States indirectly from Europe: Dutch elm disease.  The disease is a fungus spread by an invasive bark beetle that made its way from China west to Europe in 1910.  During World War I, western European elms began dying inexplicably in large numbers.  Battle-weary societies initially thought the trees had been killed by the same chemical warfare agents that sickened or killed thousands of soldiers on the Western Front.  Dutch plant disease scientists eventually traced the cause to an Asian fungus, transmitted by insects.

In 1931, a Cleveland furniture company inadvertently imported infected European elm logs and European elm bark beetles from the Netherlands, and so the fungus was introduced to America.  Unlike the Chestnut blight, which primarily affected forested suburban and rural areas, the Dutch elm disease caused the most damage in American cities, where the American elm had been a preferred shade tree growing along the streets in countless northeastern and Midwestern neighborhoods, often growing to 100 feet in height with a wide canopy. American elm trees died by the hundreds of thousands, reducing property values, increasing air conditioning bills, placing higher demands on city budgets to remove the large dead trees before they became problems for public safety and property, requiring expensive efforts to reduce contaminated stormwater runoff, and depriving many communities of much of their aesthetic appeal.  Between 1930 and 1989, an estimated 75 percent of the 77 million elms in North America were killed by Dutch elm disease.

Control efforts initially focused on insecticides to kill the exotic and native elm bark beetles that transmitted the fungus, but a more effective strategy turned out to be focusing on the fungus.  Still, the damage to North American elms had already been done by the time effective controls had been developed.

Island extinctions

While the continent-wide impacts of invasive species have been both dramatic and ecologically severe, the most catastrophic impacts have no doubt been on island ecosystems.  Of the 724 species extinctions over the last 400 years, about half were of island species.  At least 90 percent of all bird species that have gone extinct have been island birds.  Island species are vulnerable to extinction because they have a small geographic range; they have no place to go.

They often have low population numbers in the first place because the islands are small.  They are especially vulnerable to new predators because they typically have few predators on their home island, and so they are not accustomed to dealing with the predators that mainland species have long learned to avoid. Particularly in the Pacific and Indian oceans, dozens of species that inhabit islands have literally been driven to extinction by invasive species.

A classic example is the island of Guam, where during World War II the brown tree snake was a stowaway on naval vessels and warplanes from the Asian mainland.  Since then, it has decimated Guam’s native species of birds, reptiles, and bats.  Over half of Guam’s native bird and lizard species as well as two out of three of Guam’s native bat species have been driven to extinction by the snake. Ten out of 12 species of Guam’s forest birds were driven to extinction. The brown tree snake also has an affinity for crawling into electrical distribution facilities, where it has caused thousands of blackouts over the last 40 years, when a snake’s body simultaneously touches live and grounded conductors.  As a result of the blackouts on this island with a major U.S. military installation, the snake actually impinges on U.S. military readiness, as well as causing economic disruptions.

(Sometimes I ask people to guess how many bird and mammal species have gone extinct in the last couple of hundred years, other than on islands. When I tell them the number is eight to 15 species, birds and mammals combined, they look at me funny. They say, that’s can’t be right! But it is. And it’s evidence that we need to re-think our approach to the endangered species problem.)

Invasive species in American law

The oldest federal law dealing with invasive species actually pre-dates the popular use of the term. The Lacey Act was enacted in 1900 and has been amended several times since then. The law has a number of provisions, but the one that addresses what we now know as invasive species is a section that authorizes the U.S. Fish and Wildlife Service of the Department of the Interior to publish regulations listing species as injurious. If a species is listed under the Lacey Act, the importation and transport of that species, including offspring and eggs, is restricted. Wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, and reptiles are the only organisms that can be added to the injurious wildlife list.  Currently about 240 species are listed as injurious.

Species listed as injurious may not be imported or transported between U.S. states, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the U.S. by any means without a permit issued by the Fish and Wildlife Service. Permits may be only granted for the importation or transportation of live specimens of injurious wildlife and their offspring or eggs for bona fide scientific, medical, educational, or zoological purposes.

A recent U.S. District Court decision has called into question the Lacey Act’s applicability to interstate commerce, although the United States is appealing the District Court’s decision as inconsistent with 116 years of statutory interpretation.

In 1955, the U.S. and Canada responded to the impact of the invasive sea lamprey on the fisheries of the Great Lakes by launching an international effort that also involved both state and provincial governments. With the opening of the St. Lawrence Seaway to oceangoing vessels, the route was also opened for the invasive sea lamprey to enter the Great Lakes, where that eel-like parasite did enormous damage to that valuable fishery.  The Fish and Wildlife Service was the lead federal agency in the resulting Great Lakes Fishery Commission, and FWS has since then been the primary federal agency with responsibility for managing aquatic invasive species.

In 1990, Congress passed the Nonindigenous Aquatic Nuisance Prevention and Control Act (NANPCA) in hopes of dealing more systematically and comprehensively with aquatic invasive species. These were species that, for decades, had plagued the Great Lakes in ever-increasing numbers and variety, but also were becoming increasingly problematic in other watersheds around the country. Aquatic ecosystems in the United States were being transformed wholesale by aquatic invasive species of invertebrates, fish, and plants, many of them carried to North America in ships’ ballast water.

Besides the profound ecological effects, the impact was significant on commercial and recreational fisheries, the tourist economy, and other water users. NANPCA required EPA and Coast Guard to write regulations on ballast water to reduce the risk of invasive species being transported into the United States through that pathway. It also authorized research funding on aquatic invasives in a number of watersheds around the country and set up a network of intergovernmental regional aquatic nuisance-species task forces to facilitate interagency coordination on aquatic invasives on a regional basis. The Act also authorized a program to more effectively control the brown tree snake in Guam.

Agriculture authorities & others

The U.S. Department of Agriculture (USDA) has the longest history of dealing with invasive species in the United States, and has a variety of authorities provided by Congress.  Perhaps one of its very first challenges was to deal with the boll weevil in the 1890s, when this insect first crossed the Rio Grande and invaded the United States. Native to Mexico and Central America, the weevil soon became a major and expensive threat to American cotton agriculture, estimated to cost cotton growers tens of millions of dollars in lost revenue annually.

The first federal regulation of plant imports began with the Plant Quarantine Act of 1912.  In 2000, a variety of USDA statutory authorities to deal with plant pests were rolled into the Plant Protection Act. The USDA Animal and Plant Health Inspection Service (APHIS) has most USDA responsibilities for combatting invasive species, although USDA’s extensive research and extension agencies also play an important role, as does the U.S. Forest Service in forest ecosystems.  The Animal and Plant Health Inspection Service focuses on protection of agriculture, both by teaming with the Department of Homeland Security to exclude pests from entering the country in the first place, and by working with states to coordinate eradication programs of invasive species that successfully penetrate our borders.

USDA also deals with invasive and native pest animals through its authorities under the Animal Damage Control Act of 1931, which recognized that a variety of birds and mammals, such as European starlings and native coyotes, posed threats to crops and livestock.

The U.S. Forest Service’s role with invasive species primarily deals with efforts to protect forests from native and invasive insect pests that kill trees.  This tree mortality damages forest ecosystems, reduces the value of timber, and also dramatically increases the risk of catastrophic forest fires. Fighting wildland fire annually costs the U.S. hundreds of millions of dollars in direct costs, destroys homes and other manmade facilities to the tune of tens of millions of dollars, and all too often results in the death of firefighters and homeowners.

President Bill Clinton signed Executive Order 13112 on Invasive Species in February 1999.  It established an interagency National Invasive Species Council co-chaired by the Secretaries of the Departments of Agriculture, the Interior, and Commerce.  Interior was given administrative responsibility for the Council.  The Order required the Council to produce and periodically update a National Invasive Species Management Plan, establish an external advisory committee under the Federal Advisory Committee Act, and more generally to improve the efficiency and effectiveness of invasive species management efforts.  But its effectiveness has been limited by its budget, competition for the attention of the political leadership of the co-chair agencies, and the energy of the career civil servants on the Council staff.  A December 2015 Congressional oversight hearing by the Interior Subcommittee of the House Government Oversight and Government Reform Committee underscored the fact that the Council per se has no management control over the actions, policy decisions, and budget priorities of its now 13 member agencies.

We have met the enemy…

Many of the historical and current invasive species problems facing the United States are the direct or indirect result of the federal government’s actions or inactions.  All too often it is fair to say—in the phrase popularized by cartoonist Walt Kelly—“We have met the enemy and he is us.”

In some cases, the road to environmental hell is paved with the federal government’s good intentions. Indeed, several of our most problematic invasive species were promoted by the federal government to address some unrelated policy objective. For instance, kudzu, “the vine that ate the south,” was introduced from Japan in 1876 at the Centennial Exposition in Philadelphia, and soon thereafter was marketed as an ornamental plant to shade porches.  The USDA Soil Erosion Service, the predecessor to today’s Natural Resources Conservation Service, subsequently encouraged farmers to plant kudzu as a soil erosion control method during the 1930s.  Over time, with USDA’s help, the plant extended its invasion of the southeastern United States from approximately 3 million acres in 1946 to more than 7 million acres currently.  Kudzu smothers trees and entire forests in its path, laying out an impenetrable green carpet. It greatly diminishes the productivity of southeastern timber lands and crowds out native plants and the animals that depend on them.  USDA ultimately listed kudzu as a weed in 1970, but by then the proverbial genie was long since out of the bottle.

In 2013, the Congressional Research Service pointed out that in the past decade some listings of injurious species under the Lacey Act had taken five to six years to make it through the regulatory process.  The requirement to apply the National Environmental Policy Act (NEPA) process to Lacey Act listings is apparently responsible for at least some of these delays, since Lacey Act listings usually happened much faster prior to NEPA’s enactment in 1970.  These totally unacceptable delays can easily result in the injurious organism spreading widely through commerce before it is effectively regulated.  In a number of instances, members of Congress have actually introduced legislation to list species as injurious, because the “normal” regulatory process is perceived to take too long.  The fact that in at least some cases these bills have been introduced by Congressmen who would normally characterize themselves as not desiring more federal regulatory intrusion on American society only underscores how frustrated Congress is with the Lacey Act’s glacial implementation.

Five swings before a strike

While USDA and its Animal and Plant Health Inspection Service set the regulations designed to control the introduction of invasive plant pests into the United States, the Department of Homeland Security’s Customs and Border Protection (CBP) agency enforces those regulations.

CBP’s primary focus is on preventing terrorism, naturally, so the plant protection mission, which it took over from USDA when DHS was created in 2002, tends to receive less attention.  CBP only inspects for pests about 5 percent of the actual shipments entering the United States.  The primary vector for pests entering the country is as a stowaway on solid wood packaging.  Pallets, wooden dunnage, crates, and wooden reels have all been implicated in the introduction of highly damaging insects into the country.

International standards adopted in 2002 to reduce the invasive species risks posed by wood packaging were heavily influenced by the United States.  In 2007, CBP adopted policy to be consistent with USDA regulations relating to the international standard.  When CBP finds an infected shipment, it can refuse entry into the country, require that the shipment be treated with a pesticide, and potentially impose a fine on the importer.

Amazingly, CBP’s 2007 policy allows each importer five violations per year of the international standard before the importer can be fined.  This policy, first adopted ten years ago to smooth transition to the new regulatory requirements, was misguided then and is an absolute travesty now.  Where else in our legal framework can you violate the law five times per year before being penalized?  Does a traffic cop give you five free speeding violations each year before you get a ticket?  Can you rob five banks each year before a court issues a warrant for your arrest?  It is never a good idea to foster contempt for the law. In my opinion, CBP needs to start fining all violators for every offense, with no more free rides.

Because a lot is at stake.


Invasive species pose a biosecurity risk to the United States, threatening public health, the economy, and the environment.  The threat may not be as obvious as other national security threats, but it is no less real.

The United States is a highly technological society with the world’s best medical care.  As a result, we are unlikely to experience an epidemic like the medieval Black Death or colonial era smallpox that kills a large fraction of the population.   But even an epidemic that sickens a minority of the population and only kills a fraction of those sickened could produce medical costs in the billions of dollars and be a drag on the economy, in addition to the terrible human toll. Swine flu, avian flu, Zika virus, West Nile virus, Ebola have all threatened Americans to varying degrees over the last decade.   In some ways, the fear and anxiety associated with a prospective epidemic may exceed the actual impact of the disease, but the psychological impact on the population is real, with political, budgetary, and social consequences.

Risk to domestic food supply

One tactic in ancient warfare was to burn the crops of your enemy in order to starve them into submission.  If you succeeded, it became unnecessary to defeat them on the battlefield.  With invasive species, the American food supply is at real risk, although in our case the risk is facing higher prices at the grocery store or being more reliant on imports, rather than starvation.  Still, inflation and an increasing balance of trade deficit are real long-term threats to our economy.  Four examples will illustrate the point.

The term “Florida orange juice” has been a beloved marketing phrase in American consumer culture for at least half a century, but the Florida citrus industry now faces an existential threat from an invasive insect from Asia.  The Asian citrus psyllid is a tiny insect with a big impact.  It spreads an Asian disease called Huanglongbing, or citrus greening, a bacterium that attacks orange and grapefruit trees, eventually killing them within five years.  As a result, orange production in Florida is now down about 75 percent in the last decade, related employment is down nearly 20 percent, acreage in oranges is down by about a third, and economic loss to the state economy is about $1 billion annually.  For those farmers fighting back against the insect with pesticides, their costs have gone up substantially.  A citrus grower now spends $2,250 an acre to grow trees. (Prior to citrus greening, he would spend $850 an acre, according to Florida Citrus Mutual, an industry association.)

Not everyone is willing to fight.  By 2014, about 125,000 acres of citrus groves had simply been abandoned, according to the Atlantic Monthly. The impact is national. When you buy a carton of orange juice from your local grocery store, look at the label. Odds are it will say at least some of the oranges that went into the carton came from Central or South America.  Florida is not the only state at risk from this Asian invader.  California and Texas citrus growers are warily watching developments in Florida—and hoping USDA finds a silver bullet to fight the psyllid or the bacteria it spreads.

California wine now ranks with the best in the world, regularly competing well against the best that French vineyards have to offer.  Yet that world-ranked wine industry, and the billions of dollars in economic value it represents, face numerous foreign threats.  Three of the more serious constant threats are the glassy-winged sharpshooter that transmits bacterial Pierce’s disease, the vine mealybug that transmits the viral leafroll disease, and the European grapevine moth.

The California Department of Food and Agriculture and USDA are fighting what amounts to a constant guerilla war against these pests. After being in decline for most of the 2000s, the sharpshooter has staged a resurgence in the 2010s in southern California, according to the University of California. So far, it has successfully been excluded from the heart of the wine industry in northern California, because cold winters kill the bacteria.  The vine mealybug reduces vineyard productivity and was introduced accidentally on contaminated nursery stock.  Hot water immersion is effective at removing the bug from nursery stock.  The grapevine moth is the biggest threat to Europe’s wine industry.  While it was found in large numbers in the Napa Valley in 2010, it has now largely been exterminated from California, due to an effective quarantine program that bans movement of farm equipment and vines from still-infected areas.  Constant vigilance against invasive species is the price of a robust California wine industry.

Vermont maple syrup is another iconic agricultural product at risk from invasive species.  Currently, most maple syrup sold in the U.S. actually comes from Canada, with Vermont in second place.  Maple trees are a favorite target of the Asian long-horned beetle, which first entered the U.S. in New York City from contaminated wood packaging from China in 1996.  The beetle has had several outbreaks in the mid-Atlantic states, New England, and the Midwest.  The environs of Worcester, Massachusetts, has been the hardest hit area, with 34,000 infected trees removed in order to stop the spread of this (luckily for us) poor-flying insect.  To date, infestations have been localized and contained in urban areas in trees along city streets, or in city parks. But if the insect ever breaks into the northern hardwood forests of New England, the impact on the maple sugar industry would be serious.  A secondary impact would be on tourism, as the fall foliage in New England would be not nearly as bright without scarlet maple leaves.

In Asia, Africa, and South America, viral hoof and mouth disease is a constant threat to livestock herds.  Vaccination has successfully kept this invasive animal disease at bay in Europe and North America.  The last outbreak in the U.S. was almost a century ago, in 1929.  Infected animals are killed, buried, or burned in order to avoid the spread of the contagious virus, and the quarantine imposed essentially cuts off beef, pork, and lamb exports from the infected region. While vaccinated animals show no symptoms, they can still carry and transmit the disease to uninfected animals.  If a terrorist group wanted to do damage to the American food supply and economy, a well-designed biological attack against our Midwestern livestock herds would be an effective strategy.

The increase in regulatory burdens

Invasive species have done so much damage to native species that they have contributed to more than 40 percent of the listings under the Endangered Species Act (ESA).  This means that invasive species contribute significantly to the regulatory burden society bears under the ESA.  Anyone who would prefer to avoid having their activities subject to ESA regulation ought therefore to be interested in reducing the risks posed by invasive species.

The most famous recent near-miss involving invasive species and the ESA is the case of the greater sage grouse.  This bird, once numerous and widespread across the West, has been experiencing population declines for a number of years.  Its sagebrush habitat has been degraded by increasingly severe and frequent wildfire, caused by the invasive plant cheat grass.  Cheat grass is native to Europe, North Africa, and the Middle East.  It arrived in North America in contaminated shipments of grain in the early 1860s, and soon spread across the West.  Cheat grass grows in dense mats and turns brown early in the growing season, making it the perfect fuel for wildfire.

The Western states, USDA, and the Department of the Interior took heroic measures at rangeland restoration over several years in order to reassure the U.S. Fish and Wildlife Service that listing the greater sage grouse under the Endangered Species Act is not warranted.  An ESA listing would have resulted in severe restrictions on virtually all economic activity on rangeland across 11 Western states. While the states dodged this particular ESA bullet, the price was additional restrictions on economic activity on federal land in the West, which many still find onerous.

The next west-wide endangered species listing caused by an invasive species may prove to be the whitebark pine tree, common at higher elevations across the West.  The invasive whitebark pine blister rust disease, which came into North America in the early 1900s in contaminated nursery stock, has placed this pine on the candidate list for listing under the ESA.

A better way

How can we improve our approach to the invasive species problem?

Secure the border

One of the most basic roles of the national government is to secure the borders.  Illegal immigration into the United States stirs continual public controversy; we have a parallel problem with illegal non-human immigrants into the country.

The federal government has failed to protect the country from illegal immigration by invasive species.  While building a wall along the Mexican border would not solve the problem of illegal invasive species immigration, the federal government can take a number of concrete steps to reduce the risks of illegal biological immigrants. In particular, the U.S. government should negotiate more aggressively with foreign governments to ensure they do a better job at home of enforcing international standards designed to prevent the introduction of invasive species into our nation.  We need more emphasis on keeping invasive species from leaving their host country in the first place, rather than putting the burden on CBP to intercept contaminated shipments once they approach our borders.

We also need to recognize that a handful of other countries have been more effective at some aspects of invasive species management than has the United States.  New Zealand, Australia, and South Africa each have some globally leading practices and policies.  The State Department should proactively facilitate the efforts of USDA, CBP, and FWS to identify and characterize international best practices, so those agencies can share those as case studies with our own state and other federal agencies dealing with invasive species, so we can take advantage domestically of the best practices employed by other nations.

The federal government should assist interstate coordination to combat invasive species, fostering regional approaches to early detection and rapid response to new invasive species occurrences, and helping states take a coordinated strategic approach to established pests.  The federal government should not dictate how the governors set invasive species priorities or how they decide to approach this issue on a regional basis, but instead should support their efforts by directing the appropriate federal agencies in each region to implement their own programs consistent with the approach chosen collectively by the governors.  In some cases, this may mean providing budget increases to federal land management agencies so they can be more effective partners and good neighbors in working with the states.

The federal government should also provide a national information technology infrastructure for the states to customize and use to organize and support regional invasive species efforts.  This shared platform would be more cost-effective than expecting the states to create multiple independent information technology infrastructures to support regional efforts.  On a regional basis, states have mechanisms for coordinating and sharing information on a wide variety of topics.  The Southern Governors Association, Western Governors Association, and Council of Great Lakes and St. Lawrence Governors and Premiers are all examples of such coordinating mechanisms.  Yet there is relatively little interaction between these organizations, and the federal government can help share invasive species best management practices across regions of the country.

Provide defense in depth

Any regulatory regime that is 100 percent effective at excluding invasive species from entering the United States would likely also be incredibly expensive for business and government, and very burdensome to administer.  The law of diminishing returns applies.  As a result, the U.S. needs a defense-in-depth strategy with a federally funded and regionally administered network of state-managed early detection and rapid response capabilities.  Such a system would detect, identify, and dispose of new invasive species infestations at their early stages, before they become widespread and expensive, if not impossible, to eradicate.

Fund biological and technological research and risk assessment

Research and development is one area where the federal government has often excelled. This is true of the field of invasive species science as well.  Research on biocontrol efforts, where predators, diseases, sterile males, pheromones, or parasites of the invasive species can be used to control them, is often promising.  One promising biocontrol is the USDA Agricultural Research Survey’s work on a native North American bacterium, Pseudomonas fluorescens (ACK55), that appears to have the capability to destroy cheatgrass without harming native rangeland grasses. There have also been great successes with development of highly selective pesticides, like TFM, and Bayluscide. These are two compounds that have successfully killed more than 90 percent of exposed sea lamprey larvae in streams flowing into the Great Lakes, without doing significant harm to other species inhabiting the streams where the sea lamprey spawn.  As a result, they have been instrumental in restoring the Great Lakes fishery valued at an estimated $7 billion annually, representing an estimated 75,000 jobs, according to the Great Lakes Fishery Commission.

Remove bureaucratic obstacles / Streamline NEPA compliance

Ironically, the National Environmental Policy Act (NEPA) is a barrier to environmental quality improvement, at least when it comes to invasive species. Federal agencies have to comply with NEPA before applying pesticides to kill invasive species, or performing other activity to physically control invasive species on federal lands, such as conducting prescribed burns.  Even in the best of circumstances the NEPA process can easily take months.  Worse, any extremist environmental organization can file suit, arguing that the agency’s NEPA analysis is inadequate thereby delaying the invasive species project for years.

Meanwhile, the invasive species problem in a particular locality spins out of control, causing more economic and environmental damage.  The solution is for Congress to legislatively provide a categorical exclusion from NEPA for invasive species control projects, or for the Council on Environmental Quality to do the same by regulation and provide the same procedural protections for all federal agencies.

Less efficient but still workable approaches would be for each agency involved with invasive species control projects to do either its own categorical exclusion regulation, or undertake a programmatic Environmental Impact Statement that would cover all of the agency’s invasive species control projects nationwide for a number of years.

Remove bureaucratic obstacles / Streamline ESA compliance

Section 7 of the Endangered Species Act requires that federal agencies consult with the U.S. Fish and Wildlife Service before conducting activities that may affect endangered species or their critical habitat.  Situations occasionally arise where invasive species and endangered species occupy the same habitat.  This is not surprising, since the invasive species is often a reason that the endangered species became endangered in the first place.  In these situations, the delays and bureaucracy associated with Section 7 consultation can lead to abandoning invasive species control efforts, or delaying them so long that the chances of eradicating the invasive species are diminished, and the invasive species is given more time to expand its range and cause greater economic and ecological damage.

A case in point involves the State of Colorado’s highly successful campaign to rear bugs that like to eat the tamarisk/saltcedar tree.

Tamarisk originated in Asia and was imported as an ornamental shrub to the U.S. early in the 20th Century.  It spread across Western riparian areas (areas adjacent to rivers and streams), and has displaced native willows and cottonwoods across the West. Tamarisk depletes groundwater in riparian areas more extensively than native trees.  As a result, thousands of acre-feet of precious water is being diverted and consumed by tamarisk—water that could otherwise support native fish and wildlife, irrigated agriculture, and municipal and industrial water supply across the drought-stricken West.  Tamarisk also has an oily sap that burns readily, causing even more habitat destruction.  Furthermore, in riparian areas that flow through cities, the smoke from the burning tamarisk causes air pollution and associated public health problems for city residents with vulnerable respiratory systems.

Heavy mechanical equipment and herbicides are the traditional tools for fighting tamarisk, but Colorado developed a more elegant solution.  In 2005, the Colorado Department of Agriculture brought tamarisk leaf beetles into Colorado, under a USDA permit.  The beetles feed on tamarisk in their shared native Asian habitats.  This seemed to be a golden opportunity for Colorado to help other Western states deal with their own tamarisk infestations. However, by 2009, USDA revoked all permits for interstate transportation of the leaf beetle because FWS was concerned that the beetle might spread to tamarisk trees being used for nesting by an endangered bird known as the Southwestern willow flycatcher.

Ironically, the spread of tamarisk—and the resulting loss of native willows—is one reason the flycatcher is endangered. While the flycatcher will nest in tamarisk if willows are unavailable, it does not prosper in tamarisk thickets. The solution is not to ban shipments of the bugs that kill tamarisk.  Instead, it is to restore riparian areas cleared of tamarisk by replanting native willows and cottonwood trees, thereby saving water and creating better flycatcher habitat at the same time.  Luckily, the beetles are doing what beetles do best: making more beetles. They are spreading naturally from Colorado to adjacent states, without approval from FWS regulators, killing water-sucking tamarisk as they go.  Ironically, the ESA is getting in the way of recovering endangered species.

Reward good behavior

Companies that take actions that can demonstrate full compliance with invasive species regulations or best management practices ought to be rewarded with government incentives in the form of reduced regulatory burdens and cost-sharing opportunities.  For instance, importers who have a strong track record of meeting or exceeding regulatory standards to exclude invasive species ought to be allowed to have their product go to the head of the CBP inspection line at ports of entry to the United States, and so receive expedited treatment for their shipments.  Farmers who take steps to voluntarily control invasive species on their land ought to receive priority for financial benefits under the Farm Bill.


Invasive species are a clear and present danger to the public health, economy, and environment of the United States.  The issue deserves far more attention from the federal government than what it is giving to far less pressing environmental problems.  And the federal government needs to take action focusing on invasive species, including clearing out the bureaucratic underbrush that is impeding the ability of the public and private sectors to successfully address this issue.

The “Species Problem”: How bureaucrats use undefined and ill-defined terms to expand their power

By Dr. Steven J. Allen

The Endangered Species Act (ESA) is an example of legislation twisted by bureaucrats into a form its sponsors and original supporters could not recognize. Often, as with the ESA, such twisting is made possible by vague and undefined terms that, in a manner the Founders never intended, give power to unelected, anonymous bureaucrats.

Take the act’s title term “species.” No one knows what a species is. The common definition says a species is a group of living things that can produce fertile offspring with each other but not with members of other species. But lions and tigers and many other pairings of members of apparently different species can produce fertile offspring, and many plants and most microorganisms reproduce without breeding. Scientists have a number of definitions of species, but each has its own ambiguities and, as scientists say, fuzziness. This problem is so well recognized it even has a name: “the species problem.”

Because no accepted scientific definition of species exists, bureaucrats can classify any group of animals, plants, or other living things as a species. Should vertebrates—animals with backbones—be given priority over invertebrates? Yes, according to some Congressional directives, and no, according to other Congressional directives. Can a subspecies, or just a “segment” or “population” of plants or animals that clearly doesn’t meet the qualifications for a species, be a species anyway if the government calls it a species? Yes, nonsensically.

Often, the legal status of a species or other recognized grouping of living things is based on “sue-and-settle.” That’s when an interest group, such as an environmental organization, sues a government agency to take a certain action—for example, designating something as an endangered species—and the bureaucrats roll over and decline to defend themselves. The plaintiffs win, and the court orders the bureaucrats to do the thing they wanted to do all along.

Thus, the lack of clarity on the term “species” is a godsend to bureaucrats and interest groups.

In a 2007 article in the UCLA Journal of Environmental Law & Policy, Ezequiel Lugo wrote, “The term ‘species’ is central to all of biology, yet it is ambiguous and has no universally accepted definition. A major difficulty with any definition of species is the tacit assumption that a species is a clearly delineated group because species are really ‘fuzzy sets’ with unclear demarcations.” In other words, it’s not really possible to say with certainty where one species ends and another begins.

Among the different methods for classifying species, Lugo noted, are “the morphological species concept, which defines a species based on a set of shared physical characteristics,” “the phylogenetic species concept, which defines a species as a group of organisms sharing at least one unique characteristic and having a common pattern of ancestry and descent,” and “the biological species concept, which defines a species as a naturally interbreeding group of organisms.” There are other methods, too.

“Species,” like many scientific classifications, is among many categories created for the convenience of human beings. Nature does not put things into neat boxes. Is Pluto a planet, as we were told for most of the 20th Century, or not a planet, as we are told now? The answer boils down to: Pluto is a planet if we call it a planet.

Compounding the problem is that such characterizations as “endangered” and “threatened” also have definitions that are vague, that use weasel-words like “significantly” and “likely,” and that are, therefore, subject to bureaucratic whim.

Taxonomy is the science (or the art) of putting things into categories. Much of the force of government is rooted in taxonomy—the power to put things in categories and treat some categories differently from others. Very often, Congress delegates this awesome power to regulatory agencies and those agencies’ bureaucrats.

Categories of “race” and “ethnicity” often determine whether people get jobs, government contracts, and college admissions and student aid. These categories determine how political power is distributed through the redistricting process. Yet such categories do not exist in science and nature. They are the province of the bureaucrats, who can merge and create categories, as when the Census Bureau arbitrarily merged the defunct category of “Mexican” with Cuban-Americans, Puerto Ricans, and others to create the “Hispanic” category. How different the discussion of the 2016 election would have been if categories had been different—if, say, German-Americans, the country’s largest ethnic group, had been treated as a separate category, or if Appalachians had been so treated, or Italians, or if African-Americans with Caribbean ancestors had been separated from other African-Americans, or if Indian-Americans had remained classified as “white” rather than Asian.

Similarly, bureaucrats decide arbitrarily where the poverty line is, thereby directing the flow of trillions of dollars of taxpayers’ money. (Poor people exist, of course, as do beautiful people and ugly people. But bureaucrats can no more determine the number of poor people objectively than they can determine objectively the numbers of people who are “beautiful” and “ugly.”)

“Carcinogen,” “renewable” sources of energy, “inflation” and “unemployment” rates, “assault weapons”—these are just a few of the ill-defined or undefined terms that, in the hands of the Washington bureaucracy, become things of wax to shape as they please. Therein lies much of the power of the bureaucracy, a branch of government the authors of the Constitution never envisioned and upon which they would look in horror.

Scott J. Cameron

Scott J. Cameron is a former Deputy Assistant Secretary at the Department of the Interior.
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Dr. Steven J. Allen

A journalist with 45 years’ experience, Dr. Allen served as press secretary to U.S. Senator Jeremiah Denton and as senior researcher for Newt Gingrich’s presidential campaign. He earned a master’s…
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