When an invasive snail slides along, it leaves traces of DNA behind, enabling researchers to track its presence, the Verge reports.
The New Zealand mud snail, Potamopyrgus antipodarum, is small and hard to spot until there are too many of them present to do much about, it adds. But researchers from the University of Iowa and Pennsylvania State University-Altoona collected water samples from eight sites in Pennsylvania not known to house the invasive snails but that were in the same watershed as sites with snails. As they report in Biological Invasions, the trio used environmental DNA testing techniques including PCR analysis to find snail DNA at five of the eight sites. They further confirmed their finding at one site by finding a live snail there.
"From the conservation perspective, that's enough to say, 'Hey, we should really be more careful with these sites," co-author Maurine Neiman, an associate professor of biology at Iowa, tells the Verge.
Penn State-Altoona's Edward Levri adds there that the New Zealand mud snail can crowd out native snails and, in some spots, make up some 90 percent of the biomass, underscoring the need for early detection and prevention of its spread.