Limiting immigration has been a focus for Donald Trump and Joe Biden is pledging to reverse many of Trump’s policies.
San Bernardino National Wildlife Refuge, Arizona, United States – Biologist Myles Traphagen flips through images captured by his wildlife cameras and shakes his head in disbelief: a javelina, a bird watcher, a couple of US Border Patrol agents – that’s it.
Here, in one of the most remote corners along the US-Mexico border, the desert teems with life as a vast range of species wander across mountains and river basins that stretch between the two countries.
But Traphagen says things changed a few months ago when government contractors rolled in with heavy machinery, floodlights and dynamite, blasting through nearby mountains and delicate desert ecosystems to build a nine-metre-high border wall.
“That’s all we have since the last time I was out here – just some javelina,” Traphagen says, sitting at the base of a river basin in the San Bernardino National Wildlife Refuge in southeastern Arizona.
“It’s unprecedented, to not have a couple mountain lions, bobcats, deer, turkey, tons of stuff, I would come out here and there would be five or six hundred photos… Now, there’s hardly anything.”
As US President Donald Trump’s final days in office tick away, construction crews are working day and night in a final push to follow through on the Republican president’s chief campaign promise of building a wall along the US’s 3,220km (2,000-mile) southern border.
But even with President-elect Joe Biden promising to stop construction on day one of his incoming administration, scientists and environmentalists worry that a permanent environmental scar has already been created.
They say the border wall could have long-term, evolutionary consequences in one of the most biodiverse regions in North America, home to 93 endangered and threatened species. In rugged areas like the one surrounding San Bernardino, once largely untouched by people, those effects are being felt perhaps more acutely than anywhere.
“This is all one big experiment,” says Traphagen, the borderlands programme coordinator for the Wildlands Network. “It’s an engineering experiment and it’s also an ecological experiment because we’ve collected no baseline data to determine what many effects might be across many aspects of the border wall.”
So far, the Trump administration has completed 727km (452 miles) of its $15bn border wall, according to US Customs and Border Protection (CBP), and much of that has gone up on once federally protected land, as well as in refuges and on Indigenous land.
In order to do construction quickly – and bypass red tape and potential lawsuits from building on private land – the administration has used a provision in a 2005 law that allows federal authorities to waive laws to “ensure expeditious construction of certain barriers and roads at the US border”.
CBP said rapid construction is important to border security, but it also means builders are going in virtually blind, without any environmental impact studies.
Trump lauded the administration’s success in building the barrier ahead of a final visit as president to the US-Mexico border on Tuesday. “As you know, we’ve completed the wall. They may want to expand it. We have the expansion underway. It’s been tremendously successful, far beyond what anyone thought,” Trump told reporters before he left for Texas.
He credited the wall with stopping the flow of illegal drugs, as well as preventing people from entering the country without necessary immigration permits. “The wall has made a tremendous difference on the southern border,” Trump said.
Traphagen says the wildlife captured around the area by the cameras has dropped by 90 percent since the wall has been built here, however.
But wildlife migration is not the only concern. San Bernardino was created in 1982 to protect four endangered and threatened fish species living there, primarily the endemic Yaqui chub and Yaqui topminnow.
But the natural artesian wells that have fed their wetland habitat for thousands of years have been largely drained by groundwater pumping. Contractors use the water to mix concrete for the barriers.
Their natural habitats have been left as little more than puddles, and man-made wells have had to be installed in the refuge to ensure the fish do not die off. Such pumping has occurred in other border areas such as Organ Pipe Cactus National Monument, where last year crews uprooted saguaro cacti so old that some stood taller than the barrier itself.
Officials at the US Fish and Wildlife Service repeatedly warned the Trump administration of the dangers of pumping groundwater to build the wall, even calling the extraction along the border “the current greatest threat to endangered species in the south-west region”.
Yet their warnings went unheeded.
Meanwhile, 16km (10 miles) away, the sound of dynamite blasts and the roar of excavators and bulldozers echoes across Guadalupe Canyon as workers plow through the mountain. Large piles of rubble and six-metre (20-foot) boulders sit discarded in a nearby wash. Floodlights illuminate the mountains by night as crews work around the clock.
The surrounding mountain ranges provide a critical habitat to species like the ocelot and the last remaining North American jaguars, which move across the border to mate.
Laiken Jordahl, who works in the borderlands for the Center for Biological Diversity (CBD), said watching the blasts is like “a punch to the gut”.
“The construction we’re seeing now, blasting into these rugged mountainous corridors, it is so damaging,” Jordahl told Al Jazeera. “I mean, we’re talking about thousands of pounds of dynamite being detonated in critical habitats for endangered species. We’re talking about erosion stemming from this project for decades.”
The full scope of the damage remains largely unknown, however.
CBD is among a number of environmental, civil rights and Indigenous groups that have launched lawsuits against the Trump administration and urged Biden to halt border construction on day one of his administration.
Jordahl and other environmentalists say dismantling sections of the wall will be crucial to preventing what could be decades of ecological damage. But when asked in August if he would tear the wall down, Biden didn’t directly answer, instead saying, “there will not be another foot of wall constructed under my administration”.
Even that promise may be difficult to fulfil, as it could require the new administration to pay to break contracts with private companies – while also potentially riling up Trump’s fierce political base.
Meanwhile, as Traphagen walks along the border wall, which in the low afternoon sun casts long shadows over the desert he has worked to preserve for decades, he says he hopes they can soon assess the damage.
“The ecological effects are going to continue to cascade over time the longer this border wall is left up,” he says. “We need to be able to stop and see, ‘What have we done?’ – and move towards a better solution.”