A new area that we are currently exploring is sampling water for environmental DNA in order to reconstruct biotic assemblages. In general, the organisms present in a stream or lake provide an index of the quality of the water. Since different species have different tolerances and competitive abilities for waters that differ in nutrient availability or temperature or salinity, quantifying the abundance of species in the waters provides an integrated index of those environmental conditions. Right now, that work is pretty intensive. If you want to sample fish communities or insect communities, technicians have to go out and collect the organisms. The organisms then need to be identified and counted. That’s a slow and expensive operation. It costs about $3000 to sample one site for one group. If you want insects and fish, that’s $6000.
eDNA has the potential to revolutionize all of this. Organisms in water shed DNA. This DNA can be sequenced in order to reconstruct the biotic assemblage. Instead of intensive sampling and expert identification, a technician merely needs to take a water sample, filters it, and the DNA is then sequenced. What makes this approach so potentially amazing is not only can it provide information on one taxonomic group, it can provide information on multiple taxonomic groups simultaneously. Fish, plants, insects, diatoms…they all shed DNA and can be sequenced. Using this technique reduces costs by ~90% and provides a broader suite of data than can be done with physical sampling alone.
Now, by no means is eDNA a complete replacement for physical sampling. eDNA cannot provide information on the age and size structure of a fish community, for example. But, it is a complementary piece that can revolutionize our ability to monitor biotic communities and water quality.
We are currently exploring new techniques for aquatic eDNA right now. We’ll be running preliminary tests this year and hope to have this product offered soon. Stay tuned.