May 2006
Writers on the Range

Fencing Off Mexico is an Ecological Blunder
Gary Wockner

Gary Wockner Medical doctors have their Hippocratic Oath in which they pledge to heal the sick to the best of their ability and do no harm. We ecologists have our own guiding principle: Call it the Leopold Oath.

The late Aldo Leopold, who worked for the U.S. Forest Service and is considered to be one of the fathers of ecology, wrote several fine books about what he called the “land ethic.” But one quote stands out as symbolizing the ecological mindset: “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.”

It is with such guidance that we ecologists interpret the world, interpret history and interpret current events. The great immigration debate is the current event of the year, and the border fence its latest incarnation. And thus, by any measure of a Leopold Oath, I have to call the border fence an ecological nightmare.

It is fitting that this fence is all about immigration. Immigration, of course, is not just a human activity, but something that every critter on this planet does to one extent or another. The fence will stop human immigration, but it will stop most wildlife migration, too.

The border fence that already exists in parts of Southern California has wreaked ecological havoc; the new 15-foot-tall, triple-decker fence will make matters worse. The U.S. government may have to suspend or completely ignore most of its environmental laws -- the National Environmental Policy Act, the Clean Air Act, the Clean Water Act, and the Endangered Species Act -- to build and accommodate the border fence that will separate San Diego and Tijuana. This is the place where, over the last few decades, the city of San Diego, the state and federal governments and the Mexican government have spent nearly $600 million to protect the sensitive ecology of the Tijuana River Estuary. When the last portions of the fence are built in this area, the estuary will be ecologically blocked.

The conflict in Tijuana is only one example of what could happen along a fenced U.S.-Mexican border that contains a biologically rich swath of parks, forests, wilderness area, and bi-national wildlife habitat. Thousands of species, and millions of individual animals, travel back and forth across the border along daily or seasonal migration paths. Endangered species such as the Sonoran desert pronghorn, the Mexican wolf and the American jaguar all move back and forth across the border in parts of Southern California, Arizona and New Mexico.

The American jaguar offers a specific example. Hunters, ranchers, and trappers killed every jaguar in America by the mid-1900s, while rural Mexicans to the south did not. Over the last few decades, a few jaguars have migrated back from Mexico into America, most around Tucson, Ariz., where there’s also a heavy human immigration path. The border fence will stop this jaguar passage, and thereby stop the animal from ever naturally re-inhabiting its native American range.

The U.S. Senate endorsed its version of a border fence a few weeks ago, calling for 370 miles of triple-wide fencing that will cost at least $1 billion. A more elaborate $2.2 billion version is being discussed in the House of Representatives, which would cover nearly 700 miles through each of the four states bordering Mexico. The fence even has its own citizen’s support group and website,, that, under the guise of national security, calls for a fence stretching the entire length of the border.

It is usually during times of political crisis when the greatest ecological harm is done. The legacy of Cold War nuclear facilities and bomb-testing, plus the Superfund sites that followed, stands out as one prominent example. And now we have the border fence.

An ecological way of seeing the world takes a long view, one untainted by the political vagaries of the day. No matter the issue -- global warming, nuclear fallout, ozone depletion, air and water quality -- nature offers the ultimate verdict. This longer and more formidable border fence does not preserve the integrity, stability, and beauty of the biotic community. It tends otherwise, and it is wrong.

Gary Wockner is a contributor to Writers on the Range, a service of High Country News ( He lives in Fort Collins, Colorado.