Graduation Date
Spring 2026
Document Type
Thesis
Program
Master of Science degree with a major in Natural Resources, option Fisheries
Committee Chair Name
Andrew Kinziger
Committee Chair Affiliation
Cal Poly Humboldt Faculty or Staff
Second Committee Member Name
Andre Buchheister
Second Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Third Committee Member Name
Darren Ward
Third Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Keywords
Environmental DNA, Desiccation, Smith-Root, Hatchery, Estuary, Rainbow trout, Tidewater goby
Abstract
This study investigates the effectiveness of self-preserving filter packs (filters designed to passively dry and stabilize captured eDNA without liquid preservatives or cold-chain) in maintaining the integrity of environmental DNA (eDNA) under varying temperature and environmental conditions. eDNA degradation was assessed at three temperatures (23, 33, and 43 °C) using water collected from two distinct study sites that differ in species composition and salinity, a freshwater hatchery and a brackish lagoon. To capture early degradation dynamics, eDNA concentrations were quantified using quantitative PCR assays immediately after filtration (t = 0) and after 2, 4, 8, 16, 32, and 64 days of storage. Decay dynamics in eDNA concentration were evaluated using candidate survival/decay models. Model selection supported nonlinear decay, with biphasic dynamics frequently top-ranked and consistently competitive, indicating a rapid early loss fraction (f = 0.82–0.97) followed by slower decay fraction, with most loss occurring within the first 4 days of storage. Formal within-site model comparisons indicated minimal temperature influence on concentration-based decay dynamics in hatchery samples, whereas temperature effects were supported in the low-concentration Big Lagoon dataset. Detection results showed a clear and operationally important temperature dependence in the low-concentration Big Lagoon setting: per-sample detection remained 100% through day 32 at 23 °C and through day 16 at 33° C, but declined rapidly at 43 °C (≤70% by days 4–8 and 20% by day 16). These results emphasize that the largest loss of eDNA occurs rapidly after filtration in self-preserving filters, and that warm storage can substantially reduce detection success in low-abundance field samples. Self-preserving filters nonetheless retained high detectability for weeks under moderate heat exposure (e.g., 100% detection at 33 °C through day 16), supporting their use for eDNA monitoring while highlighting the importance of minimizing sustained high-temperature exposure.
Citation Style
AFS
Recommended Citation
Boche, Megan, "The effects of temperature on the persistence of environmental DNA in self-preserving filters" (2026). Cal Poly Humboldt theses and projects. 2554.
https://digitalcommons.humboldt.edu/etd/2554