Invasive round goby fish have impacted fisheries in the Great Lakes and the Finger Lakes by competing with native species and eating the eggs of some species of game fish.

But the camouflaged bottom dwellers can be difficult to find and collect – especially when they first enter a new body of water and their numbers are low and they might be easier to remove.

In a proof-of-principle study, Cornell researchers describe a new technique in which they analyzed environmental DNA – or eDNA – from water samples in Cayuga Lake to gather nuanced information about the presence of these invasive fish.

The study, “Nuclear eDNA Estimates Population Allele Frequencies and Abundance in Experimental Mesocosms and Field Samples,” was published Jan. 12 in the journal Molecular Ecology.

While eDNA techniques have been increasingly studied for the last decade, previous methods typically focused on whether a species was present in an ecosystem.

“With these new advancements to eDNA methods, we can learn not only which invasive species are present in the environment, but because we identify the genetic diversity in the samples, we can also predict how many individuals there are and possibly where they came from,” said Kara Andres, the paper’s first author and a graduate student in the lab of co-author David Lodge, professor of ecology and evolutionary biology in the College of Agriculture and Life Sciences (CALS) and the Francis J. DiSalvo Director of the Cornell Atkinson Center for Sustainability.

“For the first time, we demonstrate that there is sufficient genetic information in environmental samples to study the origins, connectivity, and status of invasive, elusive, threatened or otherwise difficult to monitor species without the need for direct contact,” added Jose Andrés, senior research associate in the Department of Ecology and Evolutionary Biology in CALS and a senior author of the study.

Invasive round goby fish have impacted fisheries in the Great Lakes and the Finger Lakes by competing with native species and eating the eggs of some species of game fish.

But the camouflaged bottom dwellers can be difficult to find and collect – especially when they first enter a new body of water and their numbers are low and they might be easier to remove.

In a proof-of-principle study, Cornell researchers describe a new technique in which they analyzed environmental DNA – or eDNA – from water samples in Cayuga Lake to gather nuanced information about the presence of these invasive fish.

The study, “Nuclear eDNA Estimates Population Allele Frequencies and Abundance in Experimental Mesocosms and Field Samples,” was published Jan. 12 in the journal Molecular Ecology.

While eDNA techniques have been increasingly studied for the last decade, previous methods typically focused on whether a species was present in an ecosystem.

“With these new advancements to eDNA methods, we can learn not only which invasive species are present in the environment, but because we identify the genetic diversity in the samples, we can also predict how many individuals there are and possibly where they came from,” said Kara Andres, the paper’s first author and a graduate student in the lab of co-author David Lodge, professor of ecology and evolutionary biology in the College of Agriculture and Life Sciences (CALS) and the Francis J. DiSalvo Director of the Cornell Atkinson Center for Sustainability.

“For the first time, we demonstrate that there is sufficient genetic information in environmental samples to study the origins, connectivity, and status of invasive, elusive, threatened or otherwise difficult to monitor species without the need for direct contact,” added Jose Andrés, senior research associate in the Department of Ecology and Evolutionary Biology in CALS and a senior author of the study.