DNA tracking could combat pest turtles

A study commissioned by the Victorian government has confirmed that the eradication of an established pest species can be extremely resource-intensive and costly, and recommends investment in novel tools such as innovative monitoring techniques and improved prevention strategies.

The research analysed a series of programs to eradicate or control the invasive red-eared slider turtle from southern Europe. The turtles are a growing local and national threat, periodically appearing in many capital cities in Australia. To address this issue, the Victorian government commissioned work to understand how Australia can improve the management of this reptile pest.

The study was led by Pablo Garcia-Diaz, who recently completed his PhD with the University of Adelaide, and published in the journal Biological Invasions. Together with colleagues from Australia, Spain and Portugal, Garcia-Diaz found that we need better tools to confirm eradication of pest species.

“Our paper recommends that, given the low capture rates of some pest species (like the slider turtle), alternative methods need to be considered such as environmental DNA and visual surveys,” he said.

Environmental DNA is a new technology which detects small DNA traces that an animal releases into their environment, such as skin cells or faeces, avoiding the need for physical capture. Just last year, researchers from the University of Canberra revealed that the technique was particularly effective at tracking multiple species of pest fish.

“Successful management (and potentially eradication) of pest species requires approaches from multiple disciplines, and a serious commitment for science to inform policy development,” Garcia-Diaz said.

The study recognised that the management and eradication of slider turtles will be extremely costly, with one of the control projects evaluated in the paper having a budget equivalent to $1.5 million over a two-year period. With this in mind, Garcia-Diaz concluded that the government should also be investing in prevention programs.

Image caption: The red-eared slider turtle is a major pest threat within Australian waterways. Image credit: Pablo Garcia-Diaz.