• Steve Brown

Thousands of scientists find planned border wall a threat to biodiversity

The Trump border wall prototypes east of Otay Mesa, as viewed from the Mexican side of the border. Photo by Steve Brown.

A group of approximately 2,700 scientists from around the globe have signed a letter in support of a scientific paper from Defenders of Wildlife that concludes the Trump administration's planned border wall constitutes a threat to biodiversity. Defenders submitted the paper for peer review to the Geoscience Journal, and the reaction from the scientific community has been highly supportive.

The paper, Nature Divided, Scientists United: US-Mexico Border Wall Threatens Biodiversity and Binational Conservation, notes, "Fences and walls erected along international boundaries in the name of national security have unintended but significant consequences for biodiversity. In North America, along the 3,200-kilometer US–Mexico border, fence and wall construction over the past decade and efforts by the Trump administration to complete a continuous border “wall” threaten some of the continent's most biologically diverse regions. Already-built sections of the wall are reducing the area, quality, and connectivity of plant and animal habitats and are compromising more than a century of binational investment in conservation."

The paper notes three major areas in which border wall infrastructure and security operations threaten biodiversity: The border wall bypasses environmental laws; the border wall harms wildlife populations by eliminating, degrading, and fragmenting habitats; and, the wall devalues conservation investment and scientific research.

The five Borderlands Conservation Hotspots identified by Defenders of Wildlife, which highlight areas of high biological diversity and significant investment in conservation land and projects. See Peters and Clark (2018) for more information.

The border wall bypasses environmental laws

In 2005, Congress gave the Department of Homeland Security (DHS) the authority to waive any laws that slow construction of a border wall. This includes the Endangered Species Act, and NEPA, the National Environmental Policy Act. This means no meaningful environmental impact analysis may be conducted, no consideration of less destructive alternatives, no public input, no mitigation, and no ability to seek legal remedies. DHS has issued eight waivers in the four border states, including three in 2017 by the Trump administration for construction in California and New Mexico.

The border wall harms wildlife populations by eliminating, degrading, and fragmenting habitatsAccording to the paper by Defenders of Wildlife, the border region traverses six ecoregions (see map above). The ecoregions include desert scrub, temperate forests and woodlands, semi-desert and plains grasslands, subtropical scrublands, freshwater wetlands, and salt marshes. The paper notes that these environments span portions of a broader Nearctic - Neotropical transition zone and supports an incredible range of biodiversity. Their analysis shows the border bisects the geographic ranges of 1,506 native terrestrial and freshwater animal and plant species, including 62 species listed as Critically Endangered, Endangered, or Vulnerable by the International Union for Conservation of Nature Red List. Defenders of Wildlife has identified five Borderlands Conservation Hotspots that represent high priority areas of biological diversity and binational investment in conservation threatened by border wall construction.As of 2017, DHS has constructed 1,050 kilometers (more than 652 miles) of "primary" pedestrian and vehicle barriers serviced by 8,000 kilometers (4,971 miles) of roads, in addition to undesignated routes created by off-road patrol vehicles, human activity, light, and noise, which all combine to displace and deny habitat and migratory corridors to wildlife.Border walls threaten some populations by degrading landscape connectivity, preventing or discouraging access to food, water, mates, and other resources, disrupting annual or seasonal migration. The paper notes as climate change and increasingly warm and dry conditions occur, the wall may prevent some populations from responding appropriately to changes, adding that, "Fragmented populations may suffer from reduced genetic diversity and face greater extinction risk."The paper notes a continuous border wall could disconnect more than 34 percent of US non-flying native terrestrial and freshwater animal species from the 50 percent or more of their range that lies south of the border, and that 17 percent of the 346 species analyzed would have residual US populations covering 20,000 square kilometers or less, elevating their risk of extirpation within the United States.

Border walls, such as the Trump border wall prototypes located near Otay Mesa in California, are up to 30 feet in height, and are created as one solid surface. Walls of this height and construction could hinder low-flying bird species and insects. This could have impacts on migrations and genetic diversity.

The border wall devalues conservation investment and scientific research

The US government, tribal governments, the Mexican government, organizations, and private landowners have set aside millions of acres of protected land and have invested millions of dollars in conservation, often coordinated binationally. Within 80 kilometers (50 miles) of the border, 4.5 million hectares of protected areas are managed for biodiversity conservation. Numerous binational collaborations have also targeted specific species of concern. The border wall places these significant investments at risk by undermining their objectives and diverting funds away from conservation projects toward wall construction.

The wall also obstructs scientific research. US and Mexican scientists have reported stories of intimidation, harassment, and delay by border security officials.

Some scientists are already labeling the construction of the border wall and the wall itself as an ecological disaster.

Read more HERE.

Read Arizona Public Media's story on this paper HERE.

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