May 25, 2021. The conductivity, temperature, depth (CTD) rosette pictured from below. The CTD is used to collect water samples that will be used for environmental DNA analysis. Environmental DNA, or eDNA, is a huge area of interest during the 2021 Technology Demonstration. Meredith Everett, Ph.D., is sailing on the expedition as a part of the eDNA team and describes how the technique can be used to better understand an environment: "eDNA sampling is like a net: just like you can have a little net that captures tiny things and is very specific, or a giant net that can cover a large area but might miss smaller things; you can do the same thing with eDNA. For example, we can use a single assay that only tests for one animal and that would be very sensitive, so that even if there are only a tiny number of those animals around we could still detect them -- you would use a technique like this for things like endangered species detection or looking to see whether or not an invasive species is present. On the other end of the spectrum is what we are doing on this expedition -- we are using a set of genetic markers that's pretty common across a wide variety of animals. This way, we'll be able to detect many more species, but it won't necessarily be as sensitive to rare species."