fundamentals of eDNA

Reflection week 3 blog post

This week’s lecture and discussion focused around experimental design. It was interested to learn about experimental design in a classroom setting because I’ve had it touched on in statistics before, but in my experience it’s not commonly taught as specifically as it has been this week for eDNA. The DeSouza et al., 2016 paper was an excellent choice for discussion because the experimental design had many factors that we could consider. My group pointed out issues with river bottom substrate, complexities of eDNA studies in quickly moving water, using probe based assays versus general qPCR among other topics, all of which may be relevant to our work in the Gulf of Maine (GOM). Near the end of discussion, someone also brought up how pollutants might affect eDNA detection as well as the organisms living in the stream, something that isn’t as important or applicable anymore in the GOM, but still important to note. My favorite aspect of this paper though was the seasonality examined and the various wrenches that throws into eDNA research. As discussed in my group, previous work has shown that physiological stress such as temperature can increase eDNA shedding rates from some organisms. There seem to be a lot of confounding variables in this study which are important to consider in our own research; not all of them are avoidable but may help explain noise in the data further down the line. Lastly, I appreciated the discussion with Andy and Erin about publishing; not everything you publish is going to be groundbreaking, but especially in such a competitive environment, your work should be shared and any discovery is valuable.