SPM sampling
This week our class discussed the paper by Diaz et al. (2020) regarding eDNA detection of fish from suspended particulate matter (SPM) in German rivers. I was pretty amazed by the fact that frozen, banked river samples (in the German Environmental Specimen Bank) were a thing, as I did not realize the prevalence of environmental sample banks. While their study proved they could detect fish eDNA through this sampling method, it is hard to know what other conclusions can be made. Considering the initial intention of banking samples was not for genetic analysis, the potential for contamination during sampling and storage could potentially be a bigger issue than the authors acknowledged. My favorite part of class was the discussion of how the methods for sampling SPM are really not standardized, and the potential to disturb the substrate in the process of sampling can vary significantly. I was impressed at the level of creativity and expertise displayed during what seemed like a typical paper discussion, and I loved hearing the class’s ideas for troubleshooting approaches to this type of sampling. I have no doubts that SPM sampling methods will be improved by the work of some of our class members!