Jonah Ventures is currently working with Cameron Thrash at Louisiana State University to quantify the organisms of the Mississippi River using eDNA. The project is an amazing effort on the part of volunteers that have rowed the entire length of the Mississippi, collecting water samples as they go. Our contribution is to analyze the DNA in the samples for higher organisms such as phytoplankton, insects, and fish.
Something like this has never been done before. Our preliminary results have been encouraging. Analyzing the DNA in the samples, we’ve been able to reconstruct the phytoplankton community along 3000 km of river. Below is the abundance of just one taxa, Skeletonema marinoi (and/or related species), which is a diatom that apparently is more abundant in the larger portions of the river, especially below the confluence with the Missouri.
Skeletonema looks something like this:
Normally, if one wanted to determine its abundance, one would have to take a water sample, filter it, and then examine the contents under a light microscope, counting each shape that resembled something like the SEM above.
Using eDNA, we can do the same counting likely better (because we’re also counting all the green algae and cyanobacteria as we go) and a lot faster.
We’re working on publishing the phytoplankton data and should be acquiring data on insects and fish soon.