COMMENTARY BY DAVE SAMUEL
For years, we’ve observed how DNA analysis affects our lives. We can track our genealogy, save falsely convicted prisoners on death row, and check parent genes to show the chances that their unborn child could have a genetic disorder. DNA has also cut a wide swath in the study of wildlife, and here are just a few examples of how this new science is saving wildlife, not just in West Virginia but around the world.
For the last 15 years, scientists have been using environmental DNA, commonly known as eDNA, to study wildlife, capture poachers and monitor wildlife diseases. In 2003, we learned large animals and plants drop enough DNA in their environment via defecation and shedding cells, to be detected. Then, in 2008, French researchers found DNA in pond water could detect bullfrogs, an invasive species from America. Think about what that means: Within certain limits, one can sample water and determine what is living there.
Researchers in Montana are able to sample snow tracks, and from that, they can determine what species made the track. Former methods to make a positive identification of a species in an area would take much more time and money. The bull trout lives in rivers in Montana. It is endangered and hard to monitor. The normal way to determine their presence is to electrofish rivers. Electrofishing involves a team of workers, boats and tedious hours in one river or stream. Obviously, to sample many rivers takes weeks. But getting a sample of water, and from that looking at DNA in that water, takes much less time. In fact, it’s estimated to be 10 times faster and as much as five times more cost-effective than electrofishing.
There is now a genetic database that holds DNA from thousands of African rhinoceroses. When a poacher is caught with a horn, they can link that to a fresh carcass. Two pounds of rhino horn sells for $60,000. One biologist calls rhino horn, “gold cocaine.” This new tool probably won’t save the rhinos, but it will convict some poachers. African countries are now eDNA sampling captured elephant tusks and can then determine what part of the country the poachers are focusing on.
eDNA is also being used in West Virginia. Caroline Harms, a WVU wildlife graduate student working out of the Wild Genomics Lab, is asking trappers to send a small piece of hide or other tissue from trapped fisher carcasses to learn more about scattered fisher populations in West Virginia. Lucas Price is studying Lyme disease and black-legged tick ecology at Fort Drum Military Installation. As part of this project, Lucas is working to determine past blood meal sources of ticks using genetic techniques.
That study is another brain tickler. Using eDNA technology, Lucas can catch a tick and determine what species it last fed on simply from the DNA in blood. One can go to a small pond, sample the water and determine if a fungus that kills frogs and salamanders is found there. That is being done with the hope that you find it soon enough and can treat that water to kill the fungus before it wipes out all frogs found there. And yes, there is such a fungus and we have it in West Virginia.
We’ve just scratched the surface on how eDNA can save wildlife.
Various aquatic species are being followed in West Virginia via eDNA. This led Janet Clayton, wildlife diversity biologist for the WVDNR, to say, “The development and validation of the eDNA methodology will profoundly change how aquatic populations are monitored and significantly improve the ability to conserve and recover rare aquatic species.”
No question, eDNA is a great new tool for wildlife, fisheries and environmental biologists.
Dr. Samuel is a retired wildlife professor from West Virginia University. His outdoor columns have appeared, and continue to appear, in Bowhunter magazine and the Whitetail Journal. If you have questions or comments on wildlife and conservation issues, email him at drdave4@comcast.net.
