A Burmese python is submerged for eDNA analysis. Credit: Analise Fussell.
Scientists have developed a groundbreaking method for detecting the DNA of invasive snakes in Florida.
Scientists at the University of Florida have developed a pioneering tool to bolster Florida’s defences against invasive species: a DNA-based environmental monitoring test that can pinpoint where they’ve been, aiding eradication efforts.
Once a non-native species gets into an environment, it is often too late to get rid of it, and the focus shifts to containment or long-term management.
Both approaches come with heavy costs concerning native wildlife and funding, explained Melissa Miller, lead author of the study and an invasion ecologist at the UF/ IFAS Fort Lauderdale Research and Education Center (UF/ IFAS FLREC).
She said: “We hope this novel eDNA sampling tool we have designed will help increase efficiency in invasive species management, allowing for early detection and rapid removal of nonnative species.”
Known as a tetraplex digital PCR assay, this method of testing allows researchers to use water or soil samples for rapid and precise identification of Burmese pythons, northern African pythons, boa constrictors and rainbow boas from environmental DNA – which scientists refer to as eDNA – collected in the wild.
The test can identify four invasive snake species simultaneously.
That eDNA refers to genetic material shed by organisms into their surroundings. The scientists tout this as a significant advancement in detecting invasive snakes and a strategic tool for protecting Florida’s ecosystems.
Sergio Balaguera-Reina, co-author and research assistant scientist at the UF/ IFAS FLREC, said: “Cryptic species, like most snakes, are problematic when introduced outside of their range, as detectability is low, even in high densities.
“With this new method, we increase our ability to detect these cryptic species tremendously, no matter how many there are.”
Melissa Miller in the Florida Everglades taking measurements of an invasive species. Credit: UF/ IFAS Croc Docs.
Non-native species
Florida is home to over 500 non-native species, with reptiles leading the way.
More than 50 non-native reptile species are now established across the state, with many posing severe threats to agriculture, native ecosystems, public safety and the state’s economy.
Current monitoring methods depend on visual surveys by scientists, which often fail to detect invasive constrictors because they’re elusive and cryptic.
Traditional survey techniques are estimated to identify less than 5% of Burmese pythons.
In contrast, the newly developed tetraplex assay by UF/ IFAS scientists can identify DNA traces of these snakes even weeks after they have left an area.
This breakthrough offers wildlife managers a crucial tool to verify the presence of these hidden species and assess the success of removal efforts.
Miller said: “While eDNA sampling has been applied to detect non-native wildlife, the benefit of our methodology is that we can now sample for numerous target species within a single sample.
“This can aid natural resource managers by reducing costs required to survey for non-native species in multi-invaded ecosystems.
“With the high accuracy and specificity of this testing for detecting invasive constrictor snakes, resource managers can implement effective management strategies, such as removal efforts, quickly and with confidence.”
Frank Mazzotti, co-author and professor of wildlife ecology at UF/IFAS FLREC, said: “There are two important next steps for harnessing the power of this eDNA analysis.
“First, we plan on adding additional species that can be identified using the tetraplex digital PCR assay, especially fish such as Asian swamp eels and bullseye snakeheads.
“Second, to fully take advantage of this new methodology, we plan on implementing a regional multi-species sampling network with the purpose of early detection for rapid response to new invasions and evaluating success of removal efforts on existing invasions in the Comprehensive Everglades Restoration Plan footprint.”
The study is published in Ecology and Evolution.
