A white rhino is being monitored while it is sedated and awaiting the insertion of a dosage of radioisotopes into its horn by members of the Rhisotope Project.
What if radiation, feared for its destructive power, could instead become a tool for wildlife protection? That provocative question sparked a pioneering international collaboration to halt one of Africa’s devastating wildlife crises: rhino poaching.
Led by James Larkin, the University of the Witwatersrand (Wits) Rhisotope Project has spent the past six years transforming this novel idea into reality. Nuclear technology is being used to combat rhino poaching by embedding low-level radioactive isotopes into rhino horns. This makes the trafficked horns detectable at borders, effectively disrupting the illegal trade.
The conservation initiative is the brainchild of researchers from Wits in collaboration with the International Atomic Energy Agency (IAEA) and other international partners. Now, after rigorous modelling, safety testing and border detection simulations, the project has reached operational status.
“We have demonstrated, beyond scientific doubt, that the process is completely safe for the animal and effective in making the horn detectable through international customs nuclear security systems,” said Larkin, the project’s chief scientific officer and the director of the radiation and health physics unit at Wits.
Six months ago, radioisotopes were embedded into the horns of 20 rhinos in the Unesco-listed Waterberg Biosphere in the pilot phase. Blood tests and veterinary monitoring showed no adverse effects on the animals from the isotopes levels used.
Using a technique known as biological dosimetry, researchers cultured blood samples and examined the formation of micronuclei in white blood cells — a proven indicator of cellular damage. No such damage was found.
“This is just one example of how Wits University’s researchers work and think innovatively, stepping out of the clinical environments of their laboratories to bring bold, creative solutions to some of the world’s toughest challenges — often going above and beyond in their commitment to make a real difference,” Wits vice-chancellor and principal Zeblon Vilakazi said in a statement.
Detection tests using 3D-printed rhino horns — designed to mimic real keratin — were run through carry-on luggage, air cargo and even inside full shipping containers. In each case, even a single horn with significantly lower levels of radioactivity than what would be used in practice, successfully triggered alarms in radiation detectors, Larkin said.
The Rhisotope Project was launched to counter the high levels of the poaching of South Africa’s rhinos, with more than 10 000 of the animals lost to the crime in the past decade.
Although the focus is on rhinos, especially the critically endangered black rhino and near-threatened white rhino, Larkin sees broader potential.
There will be a number of different ways in which the poacher will learn not to come onto a property to poach rhinos, the project team said.
“There will be strategic signage posted at regular intervals on the perimeter fencing, there will be an extensive local education effort to inform residents in the area that these animals have been treated, and more generally a social media campaign.
“The marking of those animals that have been treated on a reserve will be in a manner agreed upon by the rhino owner or the reserve management team. The research team will be looking into the pros and cons of an obvious mark placed on the animal, post treatment.”
Larkin said the methodology could be adapted to protect other endangered species such as pangolins and elephants. “We’re already in discussions about applying this to elephant ivory … I hope this significantly curtails wildlife smuggling of these megaherbivores.”
These radioisotopes will provide an “affordable, safe and easily applicable method” to create long-lasting and detectable horn markers that cause zero harm to the animals and environment.
Collaboration with customs agencies and international security bodies is under way, while the researchers are also in discussions with airlines, because much of the illicit trade travels as commercial luggage and freight.
“We’ll keep watching what fantastic organisations like Traffic [the wildlife trade monitoring network] are doing in terms of their research on where horn is seized and that sort of thing as we develop,” Larkin said.
“We recognise that we’re in an arms race, so the research stuff has not stopped. Me and my colleagues at Necsa [Nuclear Energy Corporation of South Africa] are having regular meetings … to look at other ways we can use nuclear science to devalue rhino horn.”
On whether the end user will be harmed by ingesting some of the radiation, the project team notes that a person would have to consume a whole rhino horn to cause any harm to themselves.
“The intention is not actually to harm the end user but to use their natural fear of radioactive materials to dissuade them from wishing to purchase or otherwise acquire radioactive horn. They might get sick if they consume enough of the horn.”
With the Rhisotope Project now a registered nonprofit and fully operational from this month, the team is urging private rhino owners, conservation NGOs and national authorities to come forward.
“We’ve got to work with forward-thinking, early-adopter rhino owners in South Africa and in Southern Africa and wherever else there are rhinos in significant numbers,” Larkin said.
“Once they show it works, the others will come along by necessity, dare I say. Eventually, I hope we can bring big players like SANParks on board and then we can really give these poachers a proper kicking in some ways.”
Rafael Mariano Grossi, the director general of the IAEA, said this project exemplifies how nuclear science can be applied in novel ways to address global problems. “By leveraging existing nuclear security infrastructure, we can help protect one of the world’s most iconic and endangered species.”
The IAEA said tagging rhino horns with radioactive material makes the horns detectable by radiation portal monitors (RPMs), which are already deployed at borders, ports and airports worldwide.
“These RPMs, commonly used to detect nuclear and other radioactive material, can now be harnessed against wildlife crime.
“With millions of vehicles and people crossing borders every day, the use of an estimated 10 000 RPMs worldwide has become a critical tool for detecting unauthorised transboundary movements of nuclear and other radioactive material.”
Rhisotope Project chief executive Jessica Babich put it simply: “Our goal is to deploy the Rhisotope technology at scale to help protect one of Africa’s most iconic and threatened species. By doing so, we safeguard not just rhinos but a vital part of our natural heritage.”
The project team said the final testing phase had been made possible through the collaboration of the IAEA, Wits, Necsa, the Limpopo Rhino Orphanage and the Unesco Waterberg Biosphere.