1 Aug 2024

Detection and Decay of Different Classes of Environmental RNA (eRNA) from Zebrafish (Danio rerio)

Purpose: This technical note contributes to the growing body of knowledge about macroscopic eukaryotic environmental RNA (eRNA) by exploring detection and decay for several different zebrafish (Danio rerio) eRNAs in a mesocosm setting. The study addressed four basic hypotheses: (1) D. rerio would deposit detectable levels of eRNA into water, (2) different classes of eRNA would be detected, (3) different eRNA sequences (for example, loci) would degrade at different rates, and (4) abiotic and biotic factors would influence rates of degradation. For the last hypothesis, we tracked eRNA concentration decay under treatments with different water temperatures and levels of microbiological activity, two factors known to significantly influence environmental DNA (eDNA) decay (Barnes et al. 2014; Lance et al. 2017; Nielsen et al. 2007; Strickler et al. 2015).

11 Jul 2024

Environmental DNA (eDNA) Assays for the Detection of Ridgway’s Rail (Rallus obsoletus) in the United States

Abstract: We designed two novel environmental DNA (eDNA) assays for the detection of Ridgway’s Rail (Rallus obsoletus), and successfully validated each assay using eDNA samples collected from the species’ known distribution within the United States. These assays add to the suite of tools available for the monitoring of this rare and secretive marsh bird, and may help to further elucidate its movement patterns as well as identify important migration corridors. Observed sensitivity of the assays indicates exceptional performance, with limits of detection at ≤ 8 copies of the target eDNA fragment per reaction. Our publication adds to the growing body of literature supporting eDNA surveys as viable tools for bird monitoring endeavors.